Co-reporter:Shuangshou Wang, Yanrong Wen, Yijia Wang, Yanyan Ma, and Zhen Liu
Analytical Chemistry May 16, 2017 Volume 89(Issue 10) pp:5646-5646
Publication Date(Web):April 25, 2017
DOI:10.1021/acs.analchem.7b00965
Recognition of cancer cells is essential for many important areas such as targeted cancer therapy. Multimonosaccharide-based recognition could be a useful strategy to improve the recognition specificity, but such a possibility has not been explored yet. Herein we report pattern recognition of cells via multiplexed imaging with monosaccharide-imprinted quantum dots (QDs). Imprinted with sialic acid, fucose, and mannose as the template, respectively, the QDs exhibited good specificity toward the template monosaccharides. Multiplexed imaging of cells simultaneously stained with these monosaccharide-imprinted QDs revealed the relative expression levels of the monosaccharides on the cells. Pattern recognition constructed using the intensities of multiplexed imaging unveiled the similarities and differences of different cell lines, allowing for the recognition of not only cancer cells from normal cells but also cancer cells of different cell lines. Thus, this study paved a solid ground for the design and preparation of novel cancer-cell targeting reagents and nanoprobes.
Co-reporter:Xueying Tu, Pir Muhammad, Jia Liu, Yanyan Ma, Shuangshou Wang, Danyang Yin, and Zhen Liu
Analytical Chemistry December 20, 2016 Volume 88(Issue 24) pp:
Publication Date(Web):November 24, 2016
DOI:10.1021/acs.analchem.6b03597
Glycoproteins play significant roles in many biological processes. Assays of glycoproteins have significant biological importance and clinical values, for which immunoassay has been the workhorse tool. However, immunoassay suffers from some disadvantages, such as poor availability of high-specificity antibodies and limited stability of biological reagents. Herein, we present an antibody-free and enzyme-free approach, called molecularly imprinted polymer (MIP)-based plasmonic immunosandwich assay (PISA), for fast and ultrasensitive detection of trace glycoproteins in complex samples. A gold-based boronate affinity MIP array was used to specifically extract the target glycoprotein from complex samples. After washing away unwanted species, the captured glycoprotein was labeled with boronate affinity silver-based Raman nanotags. Thus, sandwich-like complexes were formed on the array. Upon being shined with a laser beam, the gold-based array generated a surface plasmon wave, which significantly enhanced the surface-enhanced Raman scattering (SERS) signal of the silver-based Raman nanotags. The MIP ensured the specificity of the assay, while the plasmonic detection provided ultrahigh sensitivity. Erythropoietin (EPO), a glycoprotein hormone that controls erythropoiesis or red blood cell production, was employed as a test glycoprotein in this study. Specific detection of EPO in solution down to 2.9 × 10–14 M was achieved. Using a novel strategy to accommodate the method of standard addition to a logarithmic dose–response relationship, EPO in human urine was quantitatively determined by this approach. The analysis time required only 30 min in total. This approach holds promising application prospects in many areas, such as biochemical research, clinical diagnosis, and antidoping analysis.
Co-reporter:Daojin Li, Danyang Yin, Yang Chen, Zhen Liu
Journal of Chromatography A 2017 Volume 1498(Volume 1498) pp:
Publication Date(Web):19 May 2017
DOI:10.1016/j.chroma.2016.10.054
•A MOFs-based monolith was prepared for selective enrichment of phosphopeptides.•An off-line platform of the selective extraction with MALDI-TOF MS was developed.•Efficient phosphorylation analysis by this platform was demonstrated.Protein phosphorylation is a major post-translational modification, which plays a vital role in cellular signaling of numerous biological processes. Mass spectrometry (MS) has been an essential tool for the analysis of protein phosphorylation, for which it is a key step to selectively enrich phosphopeptides from complex biological samples. In this study, metal-organic frameworks (MOFs)-based monolithic capillary has been successfully prepared as an effective sorbent for the selective enrichment of phosphopeptides and has been off-line coupled with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for efficient analysis of phosphopeptides. Using š-casein as a representative phosphoprotein, efficient phosphorylation analysis by this off-line platform was verified. Phosphorylation analysis of a nonfat milk sample was also demonstrated. Through introducing large surface areas and highly ordered pores of MOFs into monolithic column, the MOFs-based monolithic capillary exhibited several significant advantages, such as excellent selectivity toward phosphopeptides, superb tolerance to interference and simple operation procedure. Because of these highly desirable properties, the MOFs-based monolithic capillary could be a useful tool for protein phosphorylation analysis.
Co-reporter:Pir Muhammad, Jia Liu, Rongrong Xing, Yanrong Wen, Yijia Wang, Zhen Liu
Analytica Chimica Acta 2017 Volume 995(Volume 995) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.aca.2017.09.044
•A new approach called plasmonic affinity sandwich assay was developed for fast probing glucose and fructose in plant tissues.•Molecularly-imprinted needles were prepared as microprobes to specifically extract glucose and fructose in plant tissues.•Plasmon enhanced Raman scattering was used to provide high-sensitivity detection.•Spatial distributions of glucose and fructose in apple fruit were investigated by the approach.Determination of specific target compounds in agriculture food and natural plant products is essential for many purposes; however, it is often challenging due to the complexity of the sample matrices. Herein we present a new approach called plasmonic affinity sandwich assay for the facile and rapid probing of glucose and fructose in plant tissues. The approach mainly relies on molecularly imprinted plasmonic extraction microprobes, which were prepared on gold-coated acupuncture needles via boronate affinity controllable oriented surface imprinting with the target monosaccharide as the template molecules. An extraction microprobe was inserted into plant tissues under investigation, which allowed for the specific extraction of glucose or fructose from the tissues. The glucose or fructose molecules extracted on the microprobe were labeled with boronic acid-functionalized Raman-active silver nanoparticles, and thus affinity sandwich complexes were formed on the microprobes. After excess Raman nanotags were washed away, the microprobe was subjected to Raman detection. Upon being irradiated with a laser beam, surface plasmon on the gold-coated microprobes was generated, which further produced plasmon-enhanced Raman scattering of the silver-based nanotags and thereby provided sensitive detection. Apple fruits, which contain abundant glucose and fructose, were used as a model of plant tissues. The approach exhibited high specificity, good sensitivity (limit of detection, 1 μg mL−1), and fast speed (the whole procedure required only 20 min). The spatial distribution profiles of glucose and fructose within an apple were investigated by the developed approach.Download high-res image (146KB)Download full-size image
Co-reporter:Danyang Yin;Xinglin Li;Yanyan Ma
Chemical Communications 2017 vol. 53(Issue 50) pp:6716-6719
Publication Date(Web):2017/06/20
DOI:10.1039/C7CC02247F
Plasmonic nanomaterials have been widely used for photothermal therapy (PTT) of cancer, but their recognition specificity remains challenging. We prepared monosaccharide-imprinted gold nanorods (AuNRs) for targeted cancer PTT, using sialic acid (SA) as a representative monosaccharide. The SA-imprinted AuNRs exhibited good specificity, enabling the killing of cancer cells without damaging healthy cells.
Co-reporter:Yang Chen, Daojin Li, Zijun Bie, Xinpei He, and Zhen Liu
Analytical Chemistry 2016 Volume 88(Issue 2) pp:1447
Publication Date(Web):December 18, 2015
DOI:10.1021/acs.analchem.5b04343
Protein phosphorylation is a major post-translational modification and represents a ubiquitous mechanism for the cellular signaling of many different biological processes. Selective enrichment of phosphopeptides from the complex biological samples is a key step for the mass spectrometric (MS) analysis of protein phosphorylation. Herein, we present phosphate-imprinted mesoporous silica nanoparticles (MSNs) as an ideal sorbent for selective enrichment of phosphopeptides and an off-line combination with matrix-asisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for highly efficient analysis of protein phosphorylation. The phosphate-imprinted MSNs were prepared according to a newly reported strategy called dual-template docking oriented molecular imprinting (DTD-OMI). The prepared molecularly imprinted mesoporous material exhibited several significant merits, such as excellent selectivity toward phosphopeptides, tolerance to interference, fast binding equilibrium, and large binding capacity, which made the molecularly imprinted mesoporous material an ideal sorbent for selective enrichment of phosphopeptides. Using β-casein as a representative phosphoprotein, highly efficient phosphorylation analysis by the off-line platform was verified. Phosphorylation analysis of a nonfat milk sample was also well demonstrated. Because of their highly desirable properties, the phosphate-imprinted MSNs could find more applications in the analysis of protein phosphorylation.
Co-reporter:Shuangshou Wang, Jin Ye, Xinglin Li, and Zhen Liu
Analytical Chemistry 2016 Volume 88(Issue 10) pp:5088
Publication Date(Web):April 18, 2016
DOI:10.1021/acs.analchem.5b04507
Förster resonance energy transfer (FRET) has been essential for many applications, in which an appropriate donor–acceptor pair is the key. Traditional dye-to-dye combinations remain the working horses but are rather nonspecifically susceptive to environmental factors (such as ionic strength, pH, oxygen, etc.). Besides, to obtain desired selectivity, functionalization of the donor or acceptor is essential but usually tedious. Herein, we present fluorescent poly(m-aminophenylboronic acid) nanoparticles (poly(mAPBA) NPs) synthesized via a simple procedure and demonstrate a FRET scheme with suppressed environmental effects for the selective sensing of cis-diol biomolecules. The NPs exhibited stable fluorescence properties, resistance to environmental factors, and a Förster distance comparable size, making them ideal donor for FRET applications. By using poly(mAPBA) NPs and adenosine 5′-monophosphate modified graphene oxide (AMP-GO) as a donor and an acceptor, respectively, an environmental effects-suppressed boronate affinity-mediated FRET system was established. The fluorescence of poly(mAPBA) NPs was quenched by AMP-GO while it was restored when a competing cis-diol compounds was present. The FRET system exhibited excellent selectivity and improved sensitivity toward cis-diol compounds. Quantitative inhibition assay of glucose in human serum was demonstrated. As many cis-diol compounds such as sugars and glycoproteins are biologically and clinically significant, the FRET scheme presented herein could find more promising applications.
Co-reporter:Yang Chen, Danyang Yin, Yanyan Ma, Zijun Bie, and Zhen Liu
Analytical Chemistry 2016 Volume 88(Issue 16) pp:8123
Publication Date(Web):July 26, 2016
DOI:10.1021/acs.analchem.6b01853
Molecular nanoparticles (MNPs) have gained increased attention recently due to their unique structures and properties. However, their applications remain largely unexplored. Herein, we present an Ag MNPs-based multimodal plasmonic assay. This assay relied on changes in optical properties due to stimuli-responsive state trans-formation from MNPs to plasmonic nanoparticles (PNPs). As a proof-of-concept, naked-eye colorimetric assay, spectrophotometric assay and “turn-on” Raman assay of Cu2+ were developed. The feasibility of this approach for real-world applications was demonstrated with the determination of Cu2+ in human serum. This multimodal plasmonic assay exhibited several significant advantages, including selectivity, sensitivity, label-free nature, and multimodal capability. Because of these merits, Ag MNPs could be promising nanosensors for wide important applications such as diagnostics and environmental analysis.
Co-reporter:Xinglin Li, Yunjie He, Yanyan Ma, Zijun Bie, Baorui Liu, and Zhen Liu
Analytical Chemistry 2016 Volume 88(Issue 19) pp:9805
Publication Date(Web):August 31, 2016
DOI:10.1021/acs.analchem.6b02907
Capillary electrophoresis (CE) and magnetic beads have been widely used for the selection of aptamers owing to their efficient separation ability. However, these methods alone are associated with some apparent drawbacks. CE suffers from small injection volumes and thereby only a limited amount of aptamer can be collected at each round. While the magnetic beads approach is often associated with tedious procedure and nonspecific binding. Herein we present a hybrid approach that combines the above two classical aptamer selection methods to overcome the drawbacks associated with these methods alone. In this hybrid method, one single round selection by boronate affinity magnetic nanoparticles (BA-MNPs) was first performed and then followed by a CE selection of a few rounds. The BA-MNPs-based selection eliminated nonbinding sequences, enriching effective sequences in the nucleic acid library. While the CE selection, which was carried out in free solutions, eliminated steric hindrance effects in subsequent selection. Two typical glycoproteins, Ribonuclease B (RNase B) and alkaline phosphatase (ALP), were used as targets. This hybrid method allowed for efficient selection of glycoprotein-binding aptamers within 4 rounds (1 round of BA-MNPs-based selection and 3 rounds of CE selection) and the dissociation constants reached 10–8 M level. The hybrid selection approach exhibited several significant advantages, including speed, affinity, specificity, and avoiding negative selection. Using one of the selected ALP-binding aptamers as an affinity ligand, feasibility for real application of the selected aptamers was demonstrated through constructing an improved enzyme activity assay.
Co-reporter:Daojin Li, Yang Chen and Zhen Liu
Chemical Society Reviews 2015 vol. 44(Issue 22) pp:8097-8123
Publication Date(Web):17 Sep 2015
DOI:10.1039/C5CS00013K
Boronate affinity materials, as unique sorbents, have emerged as important media for the selective separation and molecular recognition of cis-diol-containing compounds. With the introduction of boronic acid functionality, boronate affinity materials exhibit several significant advantages, including broad-spectrum selectivity, reversible covalent binding, pH-controlled capture/release, fast association/desorption kinetics, and good compatibility with mass spectrometry. Because cis-diol-containing biomolecules, including nucleosides, saccharides, glycans, glycoproteins and so on, are the important targets in current research frontiers such as metabolomics, glycomics and proteomics, boronate affinity materials have gained rapid development and found increasing applications in the last decade. In this review, we critically survey recent advances in boronate affinity materials. We focus on fundamental considerations as well as important progress and new boronate affinity materials reported in the last decade. We particularly discuss on the effects of the structure of boronate ligands and supporting materials on the properties of boronate affinity materials, such as binding pH, affinity, selectivity, binding capacity, tolerance for interference and so on. A variety of promising applications, including affinity separation, proteomics, metabolomics, disease diagnostics and aptamer selection, are introduced with main emphasis on how boronate affinity materials can solve the issues in the applications and what merits boronate affinity materials can provide.
Co-reporter:Danyang Yin, Shuangshou Wang, Yunjie He, Jia Liu, Min Zhou, Jian Ouyang, Baorui Liu, Hong-Yuan Chen and Zhen Liu
Chemical Communications 2015 vol. 51(Issue 100) pp:17696-17699
Publication Date(Web):22 Oct 2015
DOI:10.1039/C5CC05174F
Molecularly imprinted nanoparticles were prepared as surface-enhanced Raman scattering tags for the selective imaging of cancer cells and tissues against normal cells and tissues relying on the use of sialic acid-templated imprinting to recognize cancer cells, which are over-expressed with sialic acid at the surface.
Co-reporter:Yang Chen, Xinglin Li, Danyang Yin, Daojin Li, Zijun Bie and Zhen Liu
Chemical Communications 2015 vol. 51(Issue 54) pp:10929-10932
Publication Date(Web):11 Jun 2015
DOI:10.1039/C5CC03207E
We present a new strategy, called dual-template docking oriented molecular imprinting (DTD-OMI), for facile and highly efficient imprinting within mesoporous materials. As compared with bulk imprinting, which is a widely used strategy, DTD-OMI did not require additional steps, but provided significantly improved imprinting efficiency and binding properties.
Co-reporter:Xiaodong Bi, Daojin Li, and Zhen Liu
Analytical Chemistry 2015 Volume 87(Issue 8) pp:4442
Publication Date(Web):March 27, 2015
DOI:10.1021/acs.analchem.5b01034
Lectin array is an important tool in the fields of carbohydrate chemistry, glycobiology, and glycomics. Because natural lectins are associated with some apparent disadvantages such as tedious purification and easy loss of activity, artificial materials are applied to overcome such shortages by mimicking and replacing lectins in an artificial lectin array, among which boronate affinity-based materials are very outstanding and widely used. However, complicated synthetic works are often involved to design and create boronate affinity-based lectin-mimics. In this work, a facile and novel method was proposed to establish a virtual lectin array based on boronate affinity-based pH-featured encoding for discrimination of monosaccharides by pattern recognition. The dependence of boronate affinity on environmental pH was selected to encode each monosaccharide for feature generation, and the pH-featured encoding was used to construct the virtual lectin array. On the basis of the virtual array, pattern recognition algorithms were applied for data analysis. Monosaccharides were discriminated by principal component analysis, and the relations in the virtual lectin array were unraveled by cluster analysis. In this proof-of-concept work, without complicated synthesis or preparation, the proposed method was successful in mimicking lectin array and discriminating nine elementary monosaccharides found in nature, and it was also a new way of encoding in expanding the applications of boronate affinity-based materials and methods in the field of biomimetics.
Co-reporter:Daojin Li, Yang Li, Xinglin Li, Zijun Bie, Xianghua Pan, Qian Zhang, Zhen Liu
Journal of Chromatography A 2015 Volume 1384() pp:88-96
Publication Date(Web):6 March 2015
DOI:10.1016/j.chroma.2015.01.050
•A high boronate avidity monolithic capillary was prepared.•The monolithic column exhibited enhanced binding strength toward glycoproteins.•The monolithic column could bind glycoproteins under neutral and weak acidic conditions.•The monolithic column was applicable to real samples such as human saliva without pH adjustment.Boronate affinity materials, as effective sample enrichment sorbents for glycoproteomic analysis, have attracted increasing attention in recent years. However, most of boronate affinity materials suffer from an apparent limitation, limited binding strength. As a result, extraction of glycoproteins of trace concentration is rather difficult or impossible. In this study, we present a high boronate avidity monolithic capillary. Branched polyethyleneimine (PEI) was used as a scaffold to amplify the number of boronic acid moieties. While 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA), which exhibited ultrahigh affinity toward cis-diol-containing compounds, was employed as an affinity ligand. Due to the PEI-assisted synergistic multivalent binding, the monolithic column exhibited high boronate avidity toward glycoproteins, with binding constants of 10−6–10−7 M. Such binding strength was the highest among already reported boronic acid-functionalized materials that can be used for glycoproteomic analysis. Besides, the boronate avidity monolithic column exhibited one additional beneficial feature, lowered binding pH (≥6.5). These features greatly favored the selective enrichment of trace glycoproteins from real samples. The feasibility for practical applications was demonstrated with the selective enrichment of trace glycoproteins in human saliva. As compared with other boronate avidity/affinity materials, the boronate avidity monolithic capillary exhibited the best performance.
Co-reporter:Xianghua Pan;Yang Chen;Peixuan Zhao;Daojin Li;Dr. Zhen Liu
Angewandte Chemie International Edition 2015 Volume 54( Issue 21) pp:6173-6176
Publication Date(Web):
DOI:10.1002/anie.201500331
Abstract
Labeling is critical for the detection, quantitation, and structural identification of saccharides. However, conventional liquid-phase labeling suffers from apparent disadvantages, such as time-consuming, the presence of excessive labeling reagent, and high applicable saccharide concentration. A solid-phase approach is presented for highly efficient labeling of saccharides, using boronic acid functionalized mesoporous silica nanoparticles (MSNs) as a selective extraction sorbent and nanoscale reactor. The solid-phase labeling approach exhibited several significant advantages, including: much faster reaction speed (taking only 2 min), high product purity, and much lower applicable saccharide concentration (four orders of magnitude lower than that of liquid-phase labeling). Thus, this labeling approach opens up new avenues to the facile and efficient labeling of saccharides.
Co-reporter:Xianghua Pan;Yang Chen;Peixuan Zhao;Daojin Li;Dr. Zhen Liu
Angewandte Chemie 2015 Volume 127( Issue 21) pp:6271-6274
Publication Date(Web):
DOI:10.1002/ange.201500331
Abstract
Labeling is critical for the detection, quantitation, and structural identification of saccharides. However, conventional liquid-phase labeling suffers from apparent disadvantages, such as time-consuming, the presence of excessive labeling reagent, and high applicable saccharide concentration. A solid-phase approach is presented for highly efficient labeling of saccharides, using boronic acid functionalized mesoporous silica nanoparticles (MSNs) as a selective extraction sorbent and nanoscale reactor. The solid-phase labeling approach exhibited several significant advantages, including: much faster reaction speed (taking only 2 min), high product purity, and much lower applicable saccharide concentration (four orders of magnitude lower than that of liquid-phase labeling). Thus, this labeling approach opens up new avenues to the facile and efficient labeling of saccharides.
Co-reporter:Zijun Bie;Yang Chen;Jin Ye;Shuangshou Wang ;Dr. Zhen Liu
Angewandte Chemie International Edition 2015 Volume 54( Issue 35) pp:10211-10215
Publication Date(Web):
DOI:10.1002/anie.201503066
Abstract
Lectins possess unique binding properties and are of particular value in molecular recognition. However, lectins suffer from several disadvantages, such as being hard to prepare and showing poor storage stability. Boronate-affinity glycan-oriented surface imprinting was developed as a new strategy for the preparation of lectin-like molecularly imprinted polymers (MIPs). The prepared MIPs could specifically recognize an intact glycoprotein and its characteristic fragments, even within a complex sample matrix. Glycan-imprinted MIPs could thus prove to be powerful tools for important applications such as proteomics, glycomics, and diagnostics.
Co-reporter:Zijun Bie;Yang Chen;Jin Ye;Shuangshou Wang ;Dr. Zhen Liu
Angewandte Chemie 2015 Volume 127( Issue 35) pp:10349-10353
Publication Date(Web):
DOI:10.1002/ange.201503066
Abstract
Lectins possess unique binding properties and are of particular value in molecular recognition. However, lectins suffer from several disadvantages, such as being hard to prepare and showing poor storage stability. Boronate-affinity glycan-oriented surface imprinting was developed as a new strategy for the preparation of lectin-like molecularly imprinted polymers (MIPs). The prepared MIPs could specifically recognize an intact glycoprotein and its characteristic fragments, even within a complex sample matrix. Glycan-imprinted MIPs could thus prove to be powerful tools for important applications such as proteomics, glycomics, and diagnostics.
Co-reporter:Shuangshou Wang, Jin Ye, Zijun Bie and Zhen Liu
Chemical Science 2014 vol. 5(Issue 3) pp:1135-1140
Publication Date(Web):03 Dec 2013
DOI:10.1039/C3SC52986J
The molecular imprinting of proteins is of great importance but remains a challenge. Particularly, efficient, universal and facile approaches for protein imprinting are limited. Here we report a new general approach, boronate affinity-based controllable oriented surface imprinting, for the efficient and facile imprinting of glycoproteins. A glycoprotein template was first covalently anchored onto the surface of a boronic acid-functionalized substrate by boronate affinity binding. The substrate surface was then deposited with a thickness-controllable imprinting coating generated by in-water self-copolymerization of dopamine and m-aminophenylboronic acid (APBA). After removal of the template with an acidic solution, 3D cavities complementary to the molecular shape of the template were formed in the imprinting layer. The imprinting layer was hydrophilic and showed limited residual boronic acid, thus non-specific binding was avoided. The approach has significant advantages, including high specificity, high imprinting efficiency, and widely applicable substrates (from 2D to 3D, from regular size to nanoscale). Uniquely, the prepared molecularly imprinted polymers can rebind the templates in dual modes: a high affinity mode (boronate affinity interaction is on) and a low affinity mode (boronate affinity interaction is off), and the overall binding strength can be tuned by adjusting the surrounding pH. Such an affinity-tunable dual-mode binding mechanism enables the binding strength to be adjusted while keeping the specificity, which allows for wider applications, and also sheds new light on the role of affinity-determining factors in molecular imprinting.
Co-reporter:Qianjin Li, Xueying Tu, Jin Ye, Zijun Bie, Xiaodong Bi and Zhen Liu
Chemical Science 2014 vol. 5(Issue 10) pp:4065-4069
Publication Date(Web):13 Jun 2014
DOI:10.1039/C4SC01269K
The nanoconfinement effect may dramatically influence the physicochemical properties of substances. Porous materials have been widely used as separation media in liquid chromatography. However, the confinement effect of pores was usually considered as a detrimental factor. Here, we report novel types of functional materials, nanoconfining affinity materials (NCAMs), which rely on the nanoconfinement effect of porous materials with pore sizes comparable to the molecular sizes of proteins to provide dominant affinity. Two NCAMs, which have a pH-responsive capture–release ability for proteins, were developed. The NCAMs are able to bind proteins with a molecular mass larger than 18 kDa, when the surrounding pH is ≥6.0, and the captured proteins can be reversibly released upon switching the environmental pH <3.0. The dissociation constants for three test proteins ranged from 10−5 to 10−7 M. The NCAMs retained the conformation and activities of the captured proteins. Promising applications of the NCAMs for enantiomer resolution, immobilized enzyme reactors and the depletion of serum proteins were demonstrated. The nanoconfining strategy opens up new avenues for the rational design of unique functional materials.
Co-reporter:Xiaodong Bi and Zhen Liu
Analytical Chemistry 2014 Volume 86(Issue 24) pp:12382
Publication Date(Web):November 18, 2014
DOI:10.1021/ac503778w
Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10–10 M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.
Co-reporter:Xiaodong Bi and Zhen Liu
Analytical Chemistry 2014 Volume 86(Issue 1) pp:959
Publication Date(Web):December 17, 2013
DOI:10.1021/ac403736y
Molecularly imprinted polymers (MIPs), as inexpensive and stable substitutes of antibodies, have shown great promise in immunoassays. Glycoproteins are of significant diagnostic value. To facilitate the application of MIPs in clinical diagnostics, a general and facile imprinting method toward glycoproteins oriented for an enzyme-linked immunosorbent assay (ELISA) in the form of a 96-well microplate is essential but has not been fully explored yet. In this study, a new method called boronate affinity-based oriented surface imprinting was proposed for facile preparation of glycoprotein-imprinted microplates. A template glycoprotein was first immobilized by a boronic acid-modified microplate through boronate affinity binding, and then, a thin layer of polyaniline was formed to cover the microplate surface via in-water self-copolymerization. After the template was removed by an acidic solution, 3D cavities that can rebind the template were fabricated on the microplate surface. Using horseradish peroxidase (HRP) as a model target, the effects of imprinting conditions as well as the properties and performance of the prepared MIPs were investigated. α-Fetoprotein (AFP)-imprinted microplate was then prepared, and thereby, a MIP-based ELISA method was established. The prepared MIPs exhibited several highly favorable features, including excellent specificity, widely applicable binding pH, superb tolerance for interference, high binding strength, fast equilibrium kinetics, and reusability. The MIP-based ELISA method was finally applied to the analysis of AFP in human serum. The result was in good agreement with that by radioimmunoassay, showing a promising prospect of the proposed method in clinical diagnostics.
Co-reporter:Zijun Bie, Yang Chen, Hengye Li, Ronghu Wu, Zhen Liu
Analytica Chimica Acta 2014 Volume 834() pp:1-8
Publication Date(Web):27 June 2014
DOI:10.1016/j.aca.2014.04.035
•An off-line hyphenation of boronate affinity extraction with MALDI-TOF MS was established.•It allowed for direct extraction of glycoproteins/glycopeptides from biosamples without pH adjustment.•It showed the best performance for the analysis of glycopeptides from tryptic digest.•Trace intact glycoproteins from human saliva were successfully identified.Boronate affinity materials have attracted increasing attentions as sample enrichment platforms for glycoproteomic analysis in recent years. However, most of the boronate affinity materials that have already employed for proteomic analysis are suffering from apparent disadvantages, such as alkaline pH for binding, weak affinity, and relatively poor selectivity. Benzoboroxoles are a unique class of boronic acids which have showed excellent binding properties for the recognition of cis-diol-containing compounds. Recently, a 3-carboxy-benzoboroxole-functionalized monolithic column had been reported and it had exhibited the best selectivity and affinity as well as the lowest binding pH among all reported boronate affinity monolithic columns. In this study, an off-line hyphenation of this boronate affinity monolithic column-based extraction with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was developed and the powerfulness of this hyphenated approach in the analysis of glycoproteins and glycopeptides in complex samples was investigated. The approach was first applied to the analysis of glycopeptides in the tryptic digest of horseradish peroxidase (HRP). Totally 22 glycopeptides were identified. To the best of our knowledge, this is the best performance among all the boronic acid-functionalized materials. We further employed this approach to the analysis of intact proteins in human saliva. Totally 6 intact glycoproteins were successfully identified. As comparison, when the samples were analyzed without extraction, only a few glycopeptides were identified from the tryptic digest of HRP while no glycoproteins were found from the saliva samples.
Co-reporter:Daojin Li, Qianjin Li, Shuangshou Wang, Jin Ye, Hongyuan Nie, Zhen Liu
Journal of Chromatography A 2014 Volume 1339() pp:103-109
Publication Date(Web):25 April 2014
DOI:10.1016/j.chroma.2014.02.084
•A 3-pyridinylboronic acid-functionalized hybrid monolithic column was prepared.•The monolith exhibited the lowest binding pH (4.5) to date.•The monolith showed improved affinity toward negatively charged cis-diol compounds.•The monolith exhibited anion exchange-driven secondary separation capability.Boronate affinity chromatography (BAC) is a unique means for the selective separation and enrichment of 1,2 and 1,3 cis-diol-containing compounds. However, conventional boronate affinity materials require a basic binding pH (usually ≥ 8.5), which gives rise to not only inconvenience in operation but also the risk of degradation of labile compounds. Although the applicable pH has been expanded to 5.0 in recent years, the current boronate affinity materials still fail to meet the acidic pH end of frequently used biosamples, particularly urine (pH 4.5). In this study, we report a 3-pyridylboronic acid-functionalized organic–silica hybrid monolithic capillary that exhibited a binding pH of 4.5, the lowest so far in BAC. Such a binding pH enabled direct extraction of cis-diol-containing biomolecules such as nucleosides from urine samples without pH adjustment. The boronate affinity monolithic capillary showed enhanced affinity toward negatively charged cis-diol-containing analytes such as ribonucleotides. Moreover, it could function as an anion exchanger at acidic pH (∼2). The column was found to retain multiple compounds from urine, which can be assumed to be at least mostly if not entirely cis-diol-containing compounds.
Co-reporter:Jin Ye;Yang Chen ;Dr. Zhen Liu
Angewandte Chemie International Edition 2014 Volume 53( Issue 39) pp:10386-10389
Publication Date(Web):
DOI:10.1002/anie.201405525
Abstract
Immunoassay has been an essential tool in many areas, including clinical diagnostics. However, it suffers from drawbacks, such as poor availability of high specificity antibodies, limited stability of biological reagents, as well as damage to health and susceptibility of chemical labels to the sample environment. Here we present a new approach, a boronate-affinity sandwich assay (BASA), for the specific and sensitive determination of trace glycoproteins in complex samples. BASA relies on the formation of sandwiches between boronate-affinity molecularly imprinted polymers (MIPs), target glycoproteins, and boronate-affinity surface-enhanced Raman scattering (SERS) probes. The MIP ensures the specificity, while the SERS detection provides the sensitivity. BASA overcomes the drawbacks of traditional immunoassays and offers a great prospect for application.
Co-reporter:Jin Ye;Yang Chen ;Dr. Zhen Liu
Angewandte Chemie 2014 Volume 126( Issue 39) pp:10554-10557
Publication Date(Web):
DOI:10.1002/ange.201405525
Abstract
Immunoassay has been an essential tool in many areas, including clinical diagnostics. However, it suffers from drawbacks, such as poor availability of high specificity antibodies, limited stability of biological reagents, as well as damage to health and susceptibility of chemical labels to the sample environment. Here we present a new approach, a boronate-affinity sandwich assay (BASA), for the specific and sensitive determination of trace glycoproteins in complex samples. BASA relies on the formation of sandwiches between boronate-affinity molecularly imprinted polymers (MIPs), target glycoproteins, and boronate-affinity surface-enhanced Raman scattering (SERS) probes. The MIP ensures the specificity, while the SERS detection provides the sensitivity. BASA overcomes the drawbacks of traditional immunoassays and offers a great prospect for application.
Co-reporter:Heye Wang, Zijun Bie, Chenchen Lü and Zhen Liu
Chemical Science 2013 vol. 4(Issue 11) pp:4298-4303
Publication Date(Web):16 Aug 2013
DOI:10.1039/C3SC51623G
Boronic acid-functionalized materials have been the subject of increasing attention in recent years due to their capability in the facile selective extraction of glycoproteins. However, boronic acids are associated with weak binding affinity, and it is thereby difficult for boronate affinity materials to extract glycoproteins of low concentration. Here we present for the first time a boronate avidity material, dendrimeric boronic acid-functionalized magnetic nanoparticles, with significantly enhanced binding strength towards glycoproteins. Due to the dendrimer-assisted multivalent synergistic binding, the boronate avidity material exhibited dissociation constants of 10−5 to 10−6 M towards glycoproteins, which are 3–4 orders of magnitude higher than the affinities of single boronic acid binding. Such an avidity enabled the selective extraction of trace glycoproteins; an extractable concentration as low as 2 × 10−14 M was demonstrated. Meanwhile, the boronate avidity material was tolerant of the interference of abundant competing sugars. Moreover, the dendrimeric boronic acid-functionalized magnetic nanoparticles exhibited two additional advantages: high binding capacity and fast binding/desorption speed. Due to these favourable features, the selective enrichment of trace glycoproteins by the boronate avidity material became not only possible but also efficient. Efficient enrichment of trace glycoproteins from human saliva was demonstrated. The dendrimer-assisted synergistic binding strategy is also applicable to other types of boronic acid-functionalized materials and other types of functionalized materials.
Co-reporter:Chenchen Lü, Hengye Li, Heye Wang, and Zhen Liu
Analytical Chemistry 2013 Volume 85(Issue 4) pp:2361
Publication Date(Web):January 28, 2013
DOI:10.1021/ac3033917
The affinity of boronic acids to cis-diol-containing biomolecules has found wide applications in many fields, such as sensing, separation, drug delivery, and functional materials. A sound understanding of the binding interactions will greatly facilitate exquisite applications of this chemistry. Although a few analytical tools have been available for the characterization of the interactions, these techniques are associated with some apparent drawbacks, so they are only applicable to a limited range of boronic acids and cis-diol-containing biomolecules. Therefore, a widely applicable method is still greatly needed. In this work, an affinity capillary electrophoresis (ACE) method was established and validated to probe the interactions between boronic acids and cis-diol-containing biomolecules. The method was proven to be applicable to almost all types of cis-diol-containing biomolecules and boronic acids. Based on this method, a quantitative, comparative study on the interactions between 14 boronic acids that have important potentials for application with 5 typical monosaccharides of biological importance was carried out. The findings provided new insights into boronate affinity interactions, particularly the relationship between the binding strength with the molecular structures of the binding species. Besides, effects of pH and temperature on the binding strength were also investigated. This method exhibited several significant advantages, including (1) possibility of simultaneous study of multiple interactions, (2) low requirement on the purity of the binding species, (3) wide applicability, and (4) high accuracy and precision.
Co-reporter:Hongyuan Nie, Yang Chen, Chenchen Lü, and Zhen Liu
Analytical Chemistry 2013 Volume 85(Issue 17) pp:8277
Publication Date(Web):July 29, 2013
DOI:10.1021/ac4015353
Systematic evolution of ligands by exponential enrichment (SELEX) is the workhorse method for selecting aptamers that are capable of binding target molecules from a random oligonucleic acid library. However, conventional SELEX methods are associated with apparent drawbacks including labor-intensive, time-consuming, large reagent consumption and strong nonspecific binding with separation media. Herein, we report a boronate affinity monolithic capillary-based SELEX approach for rapid selection of high-specificity glycoprotein-binding DNA aptamers. Boronate affinity monolithic capillary is an advanced functional material appeared in recent years, which allows for facile capture/release of glycoproteins in a pH-switchable fashion. By using boronate affinity monolithic capillary as a platform for target immobilization and aptamer isolation, the proposed SELEX method allowed for efficient selection of glycoprotein-binding aptamers by 6 rounds and the dissociation constants were at 10–8 M level. Because of the employment of boronate affinity monolithic capillary, the new SELEX approach overcame the above-mentioned drawbacks and provided several significant advantages, including rapid selection speed (only 2 days were needed), high specificity toward the target molecules, and minute reagent consumption.
Co-reporter:Yue Lu, Zijun Bie, Yunchun Liu and Zhen Liu
Analyst 2013 vol. 138(Issue 1) pp:290-298
Publication Date(Web):02 Oct 2012
DOI:10.1039/C2AN36048A
Boronate affinity functionalized materials have recently drawn increasing attention due to their capability to selectively isolate and enrich glycoproteins and glycopeptides. As cheaper and more stable competitors to lectins, boronic acids are generally believed to yield a relatively wider spectrum specificity to glycoproteins. For better understanding and effective utilization of boronate affinity, it is necessary to establish if boronic acids exhibit lectin-like narrow specificity towards individual or a sub-class of glycoproteins. Here we report a pH manipulation strategy for fine-tuning the specificity of boronate affinity monoliths towards two sub-classes of glycoproteins, sialylated and nonsialylated glycoproteins. When the binding pH > the pKa of the boronic acid by one pH unit or more, the boronate affinity monolith preferentially binds to glycoproteins containing neutral sugars and excludes sialic acid containing glycoproteins due to electrostatic repulsion. When the binding pH < the pKa by one pH unit or more, the boronate affinity monolith binds to sialylated glycoproteins due to the exceptional binding affinity of the boronic acid towards sialic acid residues. The alternative specificity towards sialic acid and neutral sugar was first verified using an off-line combination of boronate affinity extraction with nano-ESI-Orbitrap MS/MS detection. The alternative specificity towards sialylated and nonsialylated glycoproteins was then demonstrated by means of off-line combination of boronate affinity extraction with MALDI-TOF MS. Finally, the developed approach was applied to the alternative extraction of intact sialylated and nonsialylated glycoproteins spiked in human serum.
Co-reporter:Qianjin Li, Chenchen Lü, Zhen Liu
Journal of Chromatography A 2013 Volume 1305() pp:123-130
Publication Date(Web):30 August 2013
DOI:10.1016/j.chroma.2013.07.007
•Three fluorophenylboronic acid-functionalized monoliths were prepared.•The monoliths exhibited untrahigh boronate affinity toward cis-diol compounds.•The boronate affinity was strongly influenced by spacer arm length.•The monolith with appropriate spacer arm length can bind with cis-diols at pH 6.0.Boronic acids are important ligands for the selective recognition and capture of cis-diol containing compounds, such as nucleosides and glycoproteins. In a recent study, it was found that 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA) exhibited an ultrahigh boronate affinity for binding with monosaccharides. Herein three DFFPBA-functionalized monolithic columns with varying spacer arms were synthesized and characterized. Different cis-diol containing compounds were used for the evaluation of the boronate affinity of the DFFPBA-functionalized monoliths. The DFFPBA-functionalized monoliths exhibited advantageous characteristics. These monoliths exhibited an ultrahigh boronate affinity toward cis-diol containing compounds. Moreover, the monolith with appropriate spacer arm exhibited a low binding pH (6.0) for cis-diols of small molecular weight. These advantages made DFFPBA-functionalized monoliths suitable for the enrichment of trace cis-diol containing compounds in neutral and weak acidic real samples. In addition, it was interesting that the length of spacer arms strongly influenced the boronate affinity: increasing the spacer arm resulted in apparently reduced boronate affinity, and inappropriate spacer arm length even eliminated the boronate affinity toward glycoprotein. To explain such a phenomenon, a possible mechanism was proposed. Finally, the potential of DFFPBA-functionalized monoliths for real applications was demonstrated with the selective enrichment of modified nucleosides from human urine.
Co-reporter:Xin Wang, Yunchun Liu, Lianbing Ren, Hengye Li and Zhen Liu
Analytical Methods 2013 vol. 5(Issue 20) pp:5444-5449
Publication Date(Web):19 Aug 2013
DOI:10.1039/C3AY41045E
A new hydrophilic boronate affinity monolithic capillary was synthesized for the selective capture of cis-diol biomolecules including glycoproteins and nucleosides, using (3-acrylamidophenyl)boronic acid (APBA) and N,N-methylenebisacrylamide (MBAA) as the functional monomer and cross-linker, respectively. A comparison with other compositionally similar monolithic capillaries was carried out in terms of reversed-phase retention, selectivity, binding capacity and binding pH. The poly(APBA-co-MBAA) monolithic capillary exhibited notably different properties. As both the functional monomer and the cross-linker are hydrophilic, the monolith capillary showed suppressed reversed-phase retention and as a result excellent selectivity toward both nucleosides and glycoproteins was observed. It exhibited the highest binding capacity as compared with other compositionally similar monolithic capillaries. Besides, because of the lower pKa value of APBA, the monolithic capillary was able to selectively capture nucleosides at near-physiological pH.
Co-reporter:Li Li;Yue Lu;Zijun Bie; Hong-Yuan Chen ;Dr. Zhen Liu
Angewandte Chemie International Edition 2013 Volume 52( Issue 29) pp:7451-7454
Publication Date(Web):
DOI:10.1002/anie.201207950
Co-reporter:Li Li;Yue Lu;Zijun Bie; Hong-Yuan Chen ;Dr. Zhen Liu
Angewandte Chemie 2013 Volume 125( Issue 29) pp:7599-7602
Publication Date(Web):
DOI:10.1002/ange.201207950
Co-reporter:Yunchun Liu, Yue Lu and Zhen Liu
Chemical Science 2012 vol. 3(Issue 5) pp:1467-1471
Publication Date(Web):22 Feb 2012
DOI:10.1039/C2SC20125A
Antibodies are molecular workhorses in biological research, disease treatment and diagnostics. Purity is a critical prerequisite for antibody applications. Although protein A-based affinity chromatography has developed into the gold standard for antibody purification, protein A is associated with several apparent disadvantages, including high cost, poor stability and harsh product release conditions. Many attempts have been made towards molecular level biomimetics of protein A. However, practical substitutes have not yet been achieved. Here we present a novel functionalized material, called restricted access boronate affinity porous monolith, as a mimic of protein A for the specific capture of antibodies. This biomimetic relies on a novel strategy that combines the steric hindrance of the porous monolith with the chemical selectivity of boronic acid. This protein A biomimetic material demonstrated high specificity for antibodies. Meanwhile, original immunoaffinity and specificity of the captured antibodies were maintained. Compared with protein A, the monolithic biomimetic exhibited several significant advantages, including low cost, high stability and fast elution kinetics.
Co-reporter:Hengye Li, Heye Wang, Yunchun Liu and Zhen Liu
Chemical Communications 2012 vol. 48(Issue 34) pp:4115-4117
Publication Date(Web):05 Mar 2012
DOI:10.1039/C2CC30230F
A benzoboroxole-functionalized monolithic column was synthesized, which exhibited the best specificity and affinity towards cis-diol containing biomolecules as compared with the boronate affinity monolithic columns reported as well as significant secondary separation capability under acidic conditions.
Co-reporter:Xiaodong Bi, Jianzhao Yu, Li Li, Hancheng Jiang, Fengliang Huang and Zhen Liu
Analyst 2012 vol. 137(Issue 17) pp:4016-4022
Publication Date(Web):13 Jun 2012
DOI:10.1039/C2AN35650C
Detection is an essential aspect in analytical approaches. In liquid phase separations, many attempts have been focused on the capability to detect a partial or an entire column. However, detection in both spatial and temporal resolutions has not gained much attention yet. Here we present the concept of spatio-temporally resolved detection (STRD) and a proof-of-the-concept microchip electrophoresis (MCE)-STRD system. The MCE-STRD system was mainly composed of a microchip and an STRD unit, which were designed completely based on the requirements for spatial and temporal resolutions. In the STRD unit, a linear light beam expanded from a UV LED light source was employed to illuminate the whole separation channel of the microchip while a linear CCD sensor that has an identical effective length as the separation channel and more pixels per unit length was used to detect the absorbance signals through the separation channel. As each pixel of the CCD sensor can detect a corresponding channel space in real time, the CCD provides both spatial and temporal resolutions. A significant advantage of STRD over conventional detection schemes is its capability for monitoring the dynamic processes of molecular events occurring in the separation channel. This was demonstrated through the monitoring of the dynamic processes of protein–DNA and protein–drug interactions in chip isoelectric focusing (chip IEF). The MCE-STRD system provided not only whole pictures of the entire dynamic processes at-a-glance but also quantitative kinetic information (dissociation rate constants) of the dynamic processes. With further development, we anticipate that STRD could be a promising tool for the characterization of biomolecular interactions and the observation of migration behaviours of analytes.
Co-reporter:Qianjin Li, Chenchen Lü, Hengye Li, Yunchun Liu, Heye Wang, Xin Wang, Zhen Liu
Journal of Chromatography A 2012 Volume 1256() pp:114-120
Publication Date(Web):21 September 2012
DOI:10.1016/j.chroma.2012.07.063
A new boronate-silica hybrid monolithic column was prepared using a one-pot approach with 3-acrylamidophenylboronic acid (AAPBA) as the boronate affinity ligand. The AAPBA-silica monolith exhibited several attractive advantages. First, it is highly hydrophilic, providing excellent specificity and avoiding the presence of organic solvent in the mobile phase. Second, due to its large surface area, it exhibited a high binding capacity, 49.5 μmol/mL, the highest among the boronate affinity monolithic columns appeared in the literature. Third, the monolith can bind with cis-diol containing compounds at pH as low as 6.5, which not only avoids the use of basic pH conditions at which the silica monolith may hydrolysis but also facilitates the applications to wider sample range. Finally, the hybrid monolithic column exhibited apparent secondary separation capability, which allows for two-dimensional (2D) separation of cis-diol compounds in a single column. Due to these merits, the AAPBA-silica hybrid monolithic column can be a promising separation medium for the analysis of cis-diol containing compounds.Highlights► A high permeable boronate-silica hybrid affinity monolithic column was prepared. ► The monolith exhibited excellent specificity and high binding capacity. ► The monolith can bind with cis-diol containing compounds at pH as low as 6.5. ► The monolith exhibited secondary separation capability. ► An off-line 2D-BAC-CE platform was established.
Co-reporter:Heye Wang, Peng Dou, Chenchen Lü, Zhen Liu
Journal of Chromatography A 2012 Volume 1246() pp:48-54
Publication Date(Web):13 July 2012
DOI:10.1016/j.chroma.2012.02.017
Erythropoietin (EPO) is an important glycoprotein hormone. Recombinant human EPO (rhEPO) is an important therapeutic drug and can be also used as doping reagent in sports. The analysis of EPO glycoforms in pharmaceutical and sports areas greatly challenges analytical scientists from several aspects, among which sensitive detection and effective and facile sample preparation are two essential issues. Herein, we investigated new possibilities for these two aspects. Deep UV laser-induced fluorescence detection (deep UV-LIF) was established to detect the intrinsic fluorescence of EPO while an immuno-magnetic beads-based extraction (IMBE) was developed to specifically extract EPO glycoforms. Combined with capillary zone electrophoresis (CZE), CZE-deep UV-LIF allows high resolution glycoform profiling with improved sensitivity. The detection sensitivity was improved by one order of magnitude as compared with UV absorbance detection. An additional advantage is that the original glycoform distribution can be completely preserved because no fluorescent labeling is needed. By combining IMBE with CZE-deep UV-LIF, the overall detection sensitivity was 1.5 × 10−8 mol/L, which was enhanced by two orders of magnitude relative to conventional CZE with UV absorbance detection. It is applicable to the analysis of pharmaceutical preparations of EPO, but the sensitivity is insufficient for the anti-doping analysis of EPO in blood and urine. IMBE can be straightforward and effective approach for sample preparation. However, antibodies with high specificity were the key for application to urine samples because some urinary proteins can severely interfere the immuno-extraction.Highlights► A deep UV-LIF approach was established for sensitive detection of EPO glycoforms. ► An extraction approach was developed for specific extraction of EPO glycoforms. ► Combined with these approaches, a CZE method was developed for analysis of EPO glycoforms.
Co-reporter:Jing Liu, Lianbing Ren, Yunchun Liu, Hengye Li, Zhen Liu
Journal of Chromatography A 2012 Volume 1228() pp:276-282
Publication Date(Web):9 March 2012
DOI:10.1016/j.chroma.2011.08.079
High resolution separation of intact glycoproteins, which is essential for many aspects such as finger-print profiling, represents a great challenge because one glycoprotein can exhibit many isoforms with close physicochemical properties. Monolithic columns are important separation media for the separation of intact proteins due to its significant advantages such as easy preparation, high column efficiency and high permeability. However, there are few reports on high resolution profiling of intact glycoproteins. Herein, we presented a polymeric weak anion exchange (WAX) monolithic capillary for high resolution separation of glycoprotein isoforms. A base monolith was first prepared through ring-opening polymerization between tris(2,3-epoxypropyl)isocyanurate and tri(2-aminoethyl), and then modified through reacting with ammonia aqueous solution to convert the unreacted epoxide moieties into primary amino groups. The prepared monolithic capillary was characterized in terms of morphology, pore size, hydrophilicity and reproducibility. The obtained WAX monolithic capillary exhibited desired through-pores and mesopore size, stable skeleton and hydrophilic nature. The performance of the capillary was evaluated using several typical glycoproteins such as α1-acid glycoprotein (AGP) as mode analytes. Effects of the experimental parameters on the glycoform resolution were investigated. Under the optimized separation conditions, the tested glycoproteins were all resolved into distinct glycoforms. A comparative investigation with capillary zone electrophoresis (CZE) revealed that this WAX column provided better selectivity as more isoforms were observed, although the resolution of some glycoprotein isoforms decreased.
Co-reporter:Hengye Li, Zhen Liu
TrAC Trends in Analytical Chemistry 2012 Volume 37() pp:148-161
Publication Date(Web):July–August 2012
DOI:10.1016/j.trac.2012.03.010
Cis-diol-containing biomolecules are an important class of compounds, including carbohydrates, glycoproteins, RNA, and nucleosides. Many are the main analytes at the frontiers of life science studies (e.g., proteomics, metabolomics and glycomics). As many cis-diol molecules of biological importance are present in very low abundance in samples while interfering substances are usually present in high abundance, specific capture and effective enrichment of target cis-diol biomolecules become key, challenging steps in the -omics analyses.Boronate-affinity chromatography (BAC) is a tool for specific isolation and enrichment of cis-diol compounds. In recent years, monolithic column-based BAC has attracted increasing attention. A variety of BAC monolithic columns have been developed and impressive applications in selective enrichment of glycopeptides and nucleosides have been demonstrated.We review recent advances in monolithic column-based BAC. We mainly focus on the common issues encountered during the development and application of monolithic columns for BAC. We suggest a set of strategies to guide how to select appropriate binding-buffer composition and how to design new BAC columns with the desired properties. We highlight progress and discuss trends in lowering the binding pH.Highlights► Development of monolithic column-based boronate-affinity chromatography. ► The mechanism of separation of boronate-affinity chromatography. ► Strategies for selectivity manipulation in boronate-affinity chromatography. ► Recent progress in lowering binding pH. ► Prospects for monolithic column-based boronate-affinity chromatography.
Co-reporter:Hengye Li, Yunchun Liu, Jing Liu and Zhen Liu
Chemical Communications 2011 vol. 47(Issue 28) pp:8169-8171
Publication Date(Web):20 Jun 2011
DOI:10.1039/C1CC11096A
A new Wulff-type boronate was designed and synthesized. Upon immobilization on a polymeric monolith and acidified as boronic acid, the ligand exhibited specific boronate affinity to cis-diol compounds at medium acidic pH condition.
Co-reporter:Yunchun Liu, Lianbing Ren and Zhen Liu
Chemical Communications 2011 vol. 47(Issue 17) pp:5067-5069
Publication Date(Web):23 Mar 2011
DOI:10.1039/C0CC05675H
We report a sulfonyl substituted phenylboronic acid containing monolith capillary that exhibited not only a strong boronate affinity at neutral pH but also secondary separation capability to cis-diol biomolecules.
Co-reporter:Liang Liang and Zhen Liu
Chemical Communications 2011 vol. 47(Issue 8) pp:2255-2257
Publication Date(Web):24 Jan 2011
DOI:10.1039/C0CC02540B
We report a single-step strategy called self-assembled molecular team to generate boronate affinity ligands that can specifically capture cis-diol biomolecules at neutral pH, which provides three significant advantages: a simple procedure, high affinity and high specificity.
Co-reporter:Peng Dou
Analytical and Bioanalytical Chemistry 2011 Volume 399( Issue 10) pp:3423-3429
Publication Date(Web):2011 April
DOI:10.1007/s00216-010-4447-4
Sample preparation is a crucial step for protein analysis. Functionalized magnetic nanoparticle (MNP)-based extraction has been developed to be a useful sample preparation technique for proteomic analysis. In this paper, we present a strategy for at-line coupling of MNP-based extraction (MNE) with gel isoelectric focusing (IEF). The key to the at-line combination is to use an anolyte or a catholyte as the desorbing agent. Thus, functionalized MNPs can be facilely at-line coupled with gel IEF, provided that the extraction/desorption process is pH-controlled. MNPs extracted with target proteins are added to the sample well, which can function as a natural adapter. Once a focusing electric field has been applied across the gel, proton ions migrating from the anolyte or hydroxide ions migrating from the catholyte can act as a desorbing agent, releasing the proteins from the MNE probes. The released proteins are consequently focused into distinct bands where the local pH equals their pI values. The at-line combination was well demonstrated with three types of functionalized nanoparticles: (1) phenylboronic acid functionalized MNPs for extracting glycoproteins through boronate affinity; (2) carboxyl-functionalized MNPs for extracting positively charged proteins through a weak cation exchange mechanism; and (3) amino-functionalized MNPs for extracting negatively charged proteins through a weak anion exchange mechanism. The at-line combination exhibited several significant advantages, including selectivity, sensitivity, and speed.
Co-reporter:Mingming Dong, Minghuo Wu, Fangjun Wang, Hongqiang Qin, Guanghui Han, Jing Dong, Ren’an Wu, Mingliang Ye, Zhen Liu and Hanfa Zou
Analytical Chemistry 2010 Volume 82(Issue 7) pp:2907
Publication Date(Web):March 3, 2010
DOI:10.1021/ac902907w
Protein phosphorylation is one of the most biologically relevant and ubiquitous post-translational modifications. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a powerful tool for the analysis of protein phosphorylation by detection of phosphopeptides in phosphoprotein digest. Enrichment of phosphopeptides by immobilized metal ion affinity chromatography (IMAC) or metal oxide affinity chromatography (MOAC) followed with MALDI analysis is the common approach. However, the pH for loading and elution of phosphopeptides is incompatible with protein digestion as well as the preparation of the MALDI matrix solution. Therefore, some pretreatment steps, such as pH adjustment and desalting, are required, which make the approach tedious and insensitive. In this study, a strong anion-exchange (SAX) capillary monolith was prepared to enrich phosphopeptides from protein digest for MALDI-TOF MS analysis. It was found that phosphopeptides could be specifically retained on the SAX column at high pH around 8 and could be eluted by 5% formic acid. Thus, the protein digests without any pretreatment could be loaded onto the SAX column under basic pH condition; after removing nonphosphopeptides by washing, the bound phosphopeptides could be eluted directly onto a MALDI target and analyzed by MALDI-TOF MS. This approach significantly simplified the analytical procedures and reduced the sample loss. Because of the excellent MALDI MS compatible procedure and the microscale SAX column, a detection limit as low as 50 amol for the analysis of phosphopeptides from β-casein digest was achieved. To circumvent the inconvenience of the sample loading, a new simple sample introducing method based on capillary action was proposed, which further reduced the detection limit to 10 amol.
Co-reporter:Jiangang He, Zhen Liu, Lianbing Ren, Yunchun Liu, Peng Dou, Kai Qian, Hong-Yuan Chen
Talanta 2010 Volume 82(Issue 1) pp:270-276
Publication Date(Web):30 June 2010
DOI:10.1016/j.talanta.2010.04.033
Boronate affinity solid phase microextraction (BA-SPME) is a new format appeared recently with great potential for specific extraction of cis-diol-containing compounds. Unlike conventional SPME, BA-SPME relies on covalent interactions and thereby features with specific selectivity, eliminated matrix effect and manipulable capture/release. However, only on-fiber BA-SPME and its off-line combination with high performance liquid chromatography (HPLC) have been reported so far. In this study, we report on-line coupling of in-tube BA-SPME with HPLC–electrospray ionization tandem mass spectroscopy (in-tube BA-SPME-HPLC–ESI-MS/MS) for the specific and sensitive determination of cis-diol-containing biomolecules. A boronate affinity extraction phase was prepared onto the inner surface of the capillary by copolymerization of vinylphenylboronic acid (VPBA) and ethylene glycol dimethacrylate (EDMA). The extraction conditions were optimized by choosing appropriate extraction/desorption solutions and extraction time. The extraction capacity, linear range, reproducibility and life-time were investigated. The developed method was successfully applied for the determination of dopamine in urine samples. Since many cis-diol-containing compounds are of great biological importance, the in-tube BA-SPME-HPLC method can be a promising tool.
Co-reporter:Liang Liang, Peng Dou, Mingming Dong, Xiaokang Ke, Ningsheng Bian, Zhen Liu
Analytica Chimica Acta 2009 Volume 650(Issue 1) pp:106-110
Publication Date(Web):14 September 2009
DOI:10.1016/j.aca.2009.01.026
Nuclease P1 is an important enzyme that hydrolyzes RNA or single-stranded DNA into nucleotides, and complete digestion is an essential basis for assays based on this enzyme. To digest a doubled-stranded DNA, the enzyme is usually combined with heat denaturing, which breaks doubled-stranded DNA into single strands. This paper presents an un-expected phenomenon that nuclease P1, in combination with heat denaturing, fails to completely digest a DNA sample extracted from salmon sperm. Under the experimental conditions used, at which nuclease P1 can completely digest calf thymus DNA, the digestion yield of salmon sperm DNA was only 89.5%. Spectrometric measurement indicated that a total protein of 4.7% is present in the DNA sample. To explain the reason for this phenomenon, the dynamic kinetic capillary isoelectric focusing (DK-CIEF) approach proposed previously, which allows for the discrimination of different types of protein-DNA interactions and the measurement of the individual dissociation rate constants, was modified and applied to examine possible protein-DNA interactions involved. It was found that a non-specific DNA-protein binding occurs in the sample, the dissociation rate constant for which was measured to be 7.05 ± 0.83 × 10−3 s−1. The formation of DNA-protein complex was suggested to be the main reason for the incomplete digestion of the DNA sample. The modified DK-CIEF approach can be applied as general DNA samples, with the advantages of fast speed and low sample consumption.
Co-reporter:Peng Dou, Liang Liang, Jiangang He, Zhen Liu, Hong-Yuan Chen
Journal of Chromatography A 2009 Volume 1216(Issue 44) pp:7558-7563
Publication Date(Web):30 October 2009
DOI:10.1016/j.chroma.2009.04.040
In recent years, functionalized magnetic nanoparticles (MNPs) have drawn continuously increasing attention due to their great potential for capturing biological molecules or species. However, functionalized MNPs as nanoextraction probes and the coupling with a separation platform for chemical analysis have not extensively investigated yet. In this study, boronate functionalized MNPs were synthesized and employed as extracting probes to capture and enrich cis-diol-containing biomolecules, and an off-line coupling method of the MNPs-based extraction with capillary electrophoresis (CE) was established by using pH junction, an on-line preconcentration technique in CE, as a bridge for the coupling. The prepared MNPs exhibited specific selectivity and sufficient capacity. The pH junction compressed a large injected sample volume into a much narrower sample zone and therefore significantly improved the detection sensitivity, solving the sensitivity mismatch between the MNPs-based extraction and CE. Experimental conditions for the pH junction and the desorption were optimized. Under the optimized conditions, the sensitivity was enhanced by 42-fold as compared with regular CE. N,N-dimethylformamide was found to be an effective desorption promoter, which reduced the desorption time to a few minutes. With the established method, riboflavin in a human urine sample was determined.
Co-reporter:Lianbing Ren, Zhen Liu, Mingming Dong, Mingliang Ye, Hanfa Zou
Journal of Chromatography A 2009 Volume 1216(Issue 23) pp:4768-4774
Publication Date(Web):5 June 2009
DOI:10.1016/j.chroma.2009.04.036
Boronate affinity chromatography (BAC) is an important tool for specific capture and separation of cis-diol-containing compounds such as glycoproteins, RNA and carbohydrates. Only a few reports on monolithic column-based BAC have appeared. In this paper, boronate functionalized monolithic capillary column was synthesized by in situ free radical polymerization for the first time. The prepared column was first characterized in terms of morphology, pore properties, capacity and retention mechanisms. The column exhibited uniform open channel network and high capture capacity. Systematical investigation on the retention mechanism revealed that multiple intermolecular interactions occur between the analytes and the boronate affinity monolith, including boronate affinity, reversed-phase, cation-exchange and hydrogen bonding interactions, depending on the conditions used. In addition, the presence of Lewis base such as fluoride ion in the mobile phase was found to be favorable to the complexation between cis-diol-containing compounds with the boronic acid ligand under less basic conditions. On the basis of these fundamental investigations, the prepared monolithic column was then applied to the capture of adenosine and flavin adenine dinucleotide. The investigations in this study provide sound understanding not only on how to manipulate the separation selectivity through selection of appropriate mobile phase composition on the currently prepared columns but also on how to design next-generation columns with desired properties and functions.
Co-reporter:Ruijun Tian, Lianbing Ren, Huaijun Ma, Xin Li, Lianghai Hu, Mingliang Ye, Ren’an Wu, Zhijian Tian, Zhen Liu, Hanfa Zou
Journal of Chromatography A 2009 Volume 1216(Issue 8) pp:1270-1278
Publication Date(Web):20 February 2009
DOI:10.1016/j.chroma.2008.10.002
We report the development of a combined strategy for high capacity, comprehensive enrichment of endogenous peptide from complex biological samples at natural pH condition. MCM-41 nanoparticles with highly ordered nanoscale pores (i.e. 4.8 nm) and high-surface area (i.e. 751 m2/g) were synthesized and modified with strong cation-exchange (SCX-MCM-41) and strong anion-exchange (SAX-MCM-41) groups. The modified nanoparticles demonstrated good size-exclusion effect for the adsorption of standard protein lysozyme with molecular weight (MW) of ca. 15 kDa; and the peptides with MW lower than this value can be well adsorbed. Step elution of the enriched peptides with five salt concentrations presented that both modified nanoparticles have high capacity and complementarity for peptides enrichment, and the SAX-MCM-41 nanoparticles has obviously high selectivity for acidic peptides with pI (isoelectric point) lower than 4. Large-scale enrichment of endogenous peptides in 2 mg mouse liver extract was achieved by further combination of SCX-MCM-41 and SAX-MCM-41 with unmodified MCM-41 nanoparticles. On-line 2D nano-LC/MS/MS was applied to analyze the enriched samples, and 2721 unique peptides were identified in total. Two-dimensional analysis of MW versus pI distribution combined with abundance of the identified peptides demonstrated that the three types of nanoparticles have comprehensive complementarity for peptidome enrichment.
Co-reporter:Jing Liu, ;Mingchao Kang;Sichang Liu ;Hong-Yuan Chen
Journal of Separation Science 2009 Volume 32( Issue 3) pp:422-429
Publication Date(Web):
DOI:10.1002/jssc.200800387
Abstract
Resolution of glycoforms of a glycoprotein is usually a challenge for an analytical chemist, which is often associated with the difficulty of detecting a large number of glycoforms with sufficient sensitivity. CE is the main workhorse for the analysis of glycoproteins; however, the current methods are only applicable to high concentration samples. Therefore, the development of online preconcentration approaches is important for the CE analysis of glycoproteins. In this study, we present a combined strategy for online preconcentrating glycoforms of glycoproteins, which couples two individual online preconcentration techniques, i.e., large volume sample stacking (LVSS) and reversed pH junction (RPHJ). LVSS allows for compressing a large injected sample volume into a narrow sample zone, contributing to the main sensitivity improvement, while RPHJ coordinates the preconcentration process to improve the resolution. This strategy was verified with recombinant human erythropoietin (rhEPO), a typical glycoprotein, as the test analyte, and the effects of experimental conditions were investigated. It was found that there is a compromise between sensitivity enhancement and resolution for online preconcentration of glycoprotein glycoforms. By using this strategy, the detection sensitivity can be improved by 50–100 times for rhEPO.
Co-reporter:Lianbing Ren, Yunchun Liu, Mingming Dong, Zhen Liu
Journal of Chromatography A 2009 1216(47) pp: 8421-8425
Publication Date(Web):
DOI:10.1016/j.chroma.2009.10.014
Co-reporter:Jing Liu, Feifei Zhu, Zhen Liu
Talanta 2009 Volume 80(Issue 2) pp:544-550
Publication Date(Web):15 December 2009
DOI:10.1016/j.talanta.2009.07.023
A new on-line preconcentration technique called borate complexation-assisted field-enhanced sample injection (BCA-FESI) was proposed for preconcentrating cis-diol-containing compounds (CDCCs) in capillary electrophoresis (CE). The principle relies on amplification of the difference in the electrophoretic mobilities of CDCC in sample matrix and background electrolyte (BGE) through complexation of CDCC with borate in a sample matrix of basic pH and dissociation of the complex in a BGE of acidic pH. Meanwhile, CDCC and borate ions electro-injected into the capillary are finally in neutral state, which maintains the pre-filled low conductivity zone and thus allows for longer injection time. With catechol as a test compound, the principle and effectiveness of BCA-FESI was verified. As compared to conventional sample injection, BCA-FESI allowed for sensitivity enhancement of 1850-fold. The established method was further evaluated with three catechins, including (−)-epicatechin gallate (ECG), (−)-gallocatechin gallate (GCG), and (−)-epigallocatechin (EGC), in a standard mixture of trace content. The limit of detection (LOD) was found to be 1.4, 3.8, 17.5 nM (S/N = 3) for ECG, GCG, EGC, respectively. Finally, the BCA-FESI method was applied to a real sample of diluted tea beverage, in which the three catechins were detected.
Co-reporter:Lianbing Ren, Dr.;Yunchun Liu;Peng Dou ;Hong-Yuan Chen
Angewandte Chemie 2009 Volume 121( Issue 36) pp:6832-6835
Publication Date(Web):
DOI:10.1002/ange.200902469
Co-reporter:Lianbing Ren, Dr.;Yunchun Liu;Peng Dou ;Hong-Yuan Chen
Angewandte Chemie International Edition 2009 Volume 48( Issue 36) pp:6704-6707
Publication Date(Web):
DOI:10.1002/anie.200902469
Co-reporter:Jiangang He, Zhen Liu, Peng Dou, Jing Liu, Lianbing Ren, Hong-Yuan Chen
Talanta 2009 Volume 79(Issue 3) pp:746-751
Publication Date(Web):15 August 2009
DOI:10.1016/j.talanta.2009.04.061
A new format of solid phase microextraction (SPME), boronate affinity SPME, was proposed for the first time for covalent extraction of cis-diol containing biomolecules. This new SPME format is based on the reversible complex formation between boronic acids and 1,2- and 1,3-cis-diols. The complex formation and dissociation can be facilely controlled by changing pH. An extracting phase of poly-3-aminophenylboronate (polyAPBA) electrochemically deposited on a metal wire was employed to demonstrate the concept of this new methodology. Catechol and riboflavin were used as the test analytes, and the SPME extraction was combined off-line with high-performance liquid chromatographic (HPLC) separation followed by UV absorbance or fluorescence detection. Fundamental aspects, such as selectivity, extraction/desorption equilibrium, linearity, effect of competing compounds, reproducibility and life-time, were first investigated. Then the developed method was applied to beer samples since the content of riboflavin plays an important role in the flavor stability of beverages. Excellent performance of the SPME fibers was observed for both standard and real samples. Particularly, the expected excellent features of the polyAPBA extracting phase were experimentally verified, which include specific selectivity, eliminated matrix effect and manipulable capture/release. The new methodology of SPME can be a promising tool since a lot of 1,2- and 1,3-cis-diol-containing compounds are of great biological importance.
Co-reporter:Danyang Yin, Xinglin Li, Yanyan Ma and Zhen Liu
Chemical Communications 2017 - vol. 53(Issue 50) pp:NaN6719-6719
Publication Date(Web):2017/05/26
DOI:10.1039/C7CC02247F
Plasmonic nanomaterials have been widely used for photothermal therapy (PTT) of cancer, but their recognition specificity remains challenging. We prepared monosaccharide-imprinted gold nanorods (AuNRs) for targeted cancer PTT, using sialic acid (SA) as a representative monosaccharide. The SA-imprinted AuNRs exhibited good specificity, enabling the killing of cancer cells without damaging healthy cells.
Co-reporter:Danyang Yin, Shuangshou Wang, Yunjie He, Jia Liu, Min Zhou, Jian Ouyang, Baorui Liu, Hong-Yuan Chen and Zhen Liu
Chemical Communications 2015 - vol. 51(Issue 100) pp:NaN17699-17699
Publication Date(Web):2015/10/22
DOI:10.1039/C5CC05174F
Molecularly imprinted nanoparticles were prepared as surface-enhanced Raman scattering tags for the selective imaging of cancer cells and tissues against normal cells and tissues relying on the use of sialic acid-templated imprinting to recognize cancer cells, which are over-expressed with sialic acid at the surface.
Co-reporter:Liang Liang and Zhen Liu
Chemical Communications 2011 - vol. 47(Issue 8) pp:NaN2257-2257
Publication Date(Web):2011/01/24
DOI:10.1039/C0CC02540B
We report a single-step strategy called self-assembled molecular team to generate boronate affinity ligands that can specifically capture cis-diol biomolecules at neutral pH, which provides three significant advantages: a simple procedure, high affinity and high specificity.
Co-reporter:Shuangshou Wang, Jin Ye, Zijun Bie and Zhen Liu
Chemical Science (2010-Present) 2014 - vol. 5(Issue 3) pp:NaN1140-1140
Publication Date(Web):2013/12/03
DOI:10.1039/C3SC52986J
The molecular imprinting of proteins is of great importance but remains a challenge. Particularly, efficient, universal and facile approaches for protein imprinting are limited. Here we report a new general approach, boronate affinity-based controllable oriented surface imprinting, for the efficient and facile imprinting of glycoproteins. A glycoprotein template was first covalently anchored onto the surface of a boronic acid-functionalized substrate by boronate affinity binding. The substrate surface was then deposited with a thickness-controllable imprinting coating generated by in-water self-copolymerization of dopamine and m-aminophenylboronic acid (APBA). After removal of the template with an acidic solution, 3D cavities complementary to the molecular shape of the template were formed in the imprinting layer. The imprinting layer was hydrophilic and showed limited residual boronic acid, thus non-specific binding was avoided. The approach has significant advantages, including high specificity, high imprinting efficiency, and widely applicable substrates (from 2D to 3D, from regular size to nanoscale). Uniquely, the prepared molecularly imprinted polymers can rebind the templates in dual modes: a high affinity mode (boronate affinity interaction is on) and a low affinity mode (boronate affinity interaction is off), and the overall binding strength can be tuned by adjusting the surrounding pH. Such an affinity-tunable dual-mode binding mechanism enables the binding strength to be adjusted while keeping the specificity, which allows for wider applications, and also sheds new light on the role of affinity-determining factors in molecular imprinting.
Co-reporter:Heye Wang, Zijun Bie, Chenchen Lü and Zhen Liu
Chemical Science (2010-Present) 2013 - vol. 4(Issue 11) pp:NaN4303-4303
Publication Date(Web):2013/08/16
DOI:10.1039/C3SC51623G
Boronic acid-functionalized materials have been the subject of increasing attention in recent years due to their capability in the facile selective extraction of glycoproteins. However, boronic acids are associated with weak binding affinity, and it is thereby difficult for boronate affinity materials to extract glycoproteins of low concentration. Here we present for the first time a boronate avidity material, dendrimeric boronic acid-functionalized magnetic nanoparticles, with significantly enhanced binding strength towards glycoproteins. Due to the dendrimer-assisted multivalent synergistic binding, the boronate avidity material exhibited dissociation constants of 10−5 to 10−6 M towards glycoproteins, which are 3–4 orders of magnitude higher than the affinities of single boronic acid binding. Such an avidity enabled the selective extraction of trace glycoproteins; an extractable concentration as low as 2 × 10−14 M was demonstrated. Meanwhile, the boronate avidity material was tolerant of the interference of abundant competing sugars. Moreover, the dendrimeric boronic acid-functionalized magnetic nanoparticles exhibited two additional advantages: high binding capacity and fast binding/desorption speed. Due to these favourable features, the selective enrichment of trace glycoproteins by the boronate avidity material became not only possible but also efficient. Efficient enrichment of trace glycoproteins from human saliva was demonstrated. The dendrimer-assisted synergistic binding strategy is also applicable to other types of boronic acid-functionalized materials and other types of functionalized materials.
Co-reporter:Qianjin Li, Xueying Tu, Jin Ye, Zijun Bie, Xiaodong Bi and Zhen Liu
Chemical Science (2010-Present) 2014 - vol. 5(Issue 10) pp:NaN4069-4069
Publication Date(Web):2014/06/13
DOI:10.1039/C4SC01269K
The nanoconfinement effect may dramatically influence the physicochemical properties of substances. Porous materials have been widely used as separation media in liquid chromatography. However, the confinement effect of pores was usually considered as a detrimental factor. Here, we report novel types of functional materials, nanoconfining affinity materials (NCAMs), which rely on the nanoconfinement effect of porous materials with pore sizes comparable to the molecular sizes of proteins to provide dominant affinity. Two NCAMs, which have a pH-responsive capture–release ability for proteins, were developed. The NCAMs are able to bind proteins with a molecular mass larger than 18 kDa, when the surrounding pH is ≥6.0, and the captured proteins can be reversibly released upon switching the environmental pH <3.0. The dissociation constants for three test proteins ranged from 10−5 to 10−7 M. The NCAMs retained the conformation and activities of the captured proteins. Promising applications of the NCAMs for enantiomer resolution, immobilized enzyme reactors and the depletion of serum proteins were demonstrated. The nanoconfining strategy opens up new avenues for the rational design of unique functional materials.
Co-reporter:Daojin Li, Yang Chen and Zhen Liu
Chemical Society Reviews 2015 - vol. 44(Issue 22) pp:NaN8123-8123
Publication Date(Web):2015/09/17
DOI:10.1039/C5CS00013K
Boronate affinity materials, as unique sorbents, have emerged as important media for the selective separation and molecular recognition of cis-diol-containing compounds. With the introduction of boronic acid functionality, boronate affinity materials exhibit several significant advantages, including broad-spectrum selectivity, reversible covalent binding, pH-controlled capture/release, fast association/desorption kinetics, and good compatibility with mass spectrometry. Because cis-diol-containing biomolecules, including nucleosides, saccharides, glycans, glycoproteins and so on, are the important targets in current research frontiers such as metabolomics, glycomics and proteomics, boronate affinity materials have gained rapid development and found increasing applications in the last decade. In this review, we critically survey recent advances in boronate affinity materials. We focus on fundamental considerations as well as important progress and new boronate affinity materials reported in the last decade. We particularly discuss on the effects of the structure of boronate ligands and supporting materials on the properties of boronate affinity materials, such as binding pH, affinity, selectivity, binding capacity, tolerance for interference and so on. A variety of promising applications, including affinity separation, proteomics, metabolomics, disease diagnostics and aptamer selection, are introduced with main emphasis on how boronate affinity materials can solve the issues in the applications and what merits boronate affinity materials can provide.
Co-reporter:Yunchun Liu, Yue Lu and Zhen Liu
Chemical Science (2010-Present) 2012 - vol. 3(Issue 5) pp:NaN1471-1471
Publication Date(Web):2012/02/22
DOI:10.1039/C2SC20125A
Antibodies are molecular workhorses in biological research, disease treatment and diagnostics. Purity is a critical prerequisite for antibody applications. Although protein A-based affinity chromatography has developed into the gold standard for antibody purification, protein A is associated with several apparent disadvantages, including high cost, poor stability and harsh product release conditions. Many attempts have been made towards molecular level biomimetics of protein A. However, practical substitutes have not yet been achieved. Here we present a novel functionalized material, called restricted access boronate affinity porous monolith, as a mimic of protein A for the specific capture of antibodies. This biomimetic relies on a novel strategy that combines the steric hindrance of the porous monolith with the chemical selectivity of boronic acid. This protein A biomimetic material demonstrated high specificity for antibodies. Meanwhile, original immunoaffinity and specificity of the captured antibodies were maintained. Compared with protein A, the monolithic biomimetic exhibited several significant advantages, including low cost, high stability and fast elution kinetics.
Co-reporter:Yunchun Liu, Lianbing Ren and Zhen Liu
Chemical Communications 2011 - vol. 47(Issue 17) pp:NaN5069-5069
Publication Date(Web):2011/03/23
DOI:10.1039/C0CC05675H
We report a sulfonyl substituted phenylboronic acid containing monolith capillary that exhibited not only a strong boronate affinity at neutral pH but also secondary separation capability to cis-diol biomolecules.
Co-reporter:Hengye Li, Heye Wang, Yunchun Liu and Zhen Liu
Chemical Communications 2012 - vol. 48(Issue 34) pp:NaN4117-4117
Publication Date(Web):2012/03/05
DOI:10.1039/C2CC30230F
A benzoboroxole-functionalized monolithic column was synthesized, which exhibited the best specificity and affinity towards cis-diol containing biomolecules as compared with the boronate affinity monolithic columns reported as well as significant secondary separation capability under acidic conditions.
Co-reporter:Hengye Li, Yunchun Liu, Jing Liu and Zhen Liu
Chemical Communications 2011 - vol. 47(Issue 28) pp:NaN8171-8171
Publication Date(Web):2011/06/20
DOI:10.1039/C1CC11096A
A new Wulff-type boronate was designed and synthesized. Upon immobilization on a polymeric monolith and acidified as boronic acid, the ligand exhibited specific boronate affinity to cis-diol compounds at medium acidic pH condition.
Co-reporter:Yang Chen, Xinglin Li, Danyang Yin, Daojin Li, Zijun Bie and Zhen Liu
Chemical Communications 2015 - vol. 51(Issue 54) pp:NaN10932-10932
Publication Date(Web):2015/06/11
DOI:10.1039/C5CC03207E
We present a new strategy, called dual-template docking oriented molecular imprinting (DTD-OMI), for facile and highly efficient imprinting within mesoporous materials. As compared with bulk imprinting, which is a widely used strategy, DTD-OMI did not require additional steps, but provided significantly improved imprinting efficiency and binding properties.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 20) pp:
Publication Date(Web):
DOI:10.1039/C3AY41045E
A new hydrophilic boronate affinity monolithic capillary was synthesized for the selective capture of cis-diol biomolecules including glycoproteins and nucleosides, using (3-acrylamidophenyl)boronic acid (APBA) and N,N-methylenebisacrylamide (MBAA) as the functional monomer and cross-linker, respectively. A comparison with other compositionally similar monolithic capillaries was carried out in terms of reversed-phase retention, selectivity, binding capacity and binding pH. The poly(APBA-co-MBAA) monolithic capillary exhibited notably different properties. As both the functional monomer and the cross-linker are hydrophilic, the monolith capillary showed suppressed reversed-phase retention and as a result excellent selectivity toward both nucleosides and glycoproteins was observed. It exhibited the highest binding capacity as compared with other compositionally similar monolithic capillaries. Besides, because of the lower pKa value of APBA, the monolithic capillary was able to selectively capture nucleosides at near-physiological pH.
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