TaoLei Sun

Developing an Inositol-Phosphate-Actuated Nanochannel System by Mimicking Biological Calcium Ion Channels

Co-reporter:Qi Lu, Qiuhan Tang, Zhonghui Chen, Shilong Zhao, Guangyan Qing, and Taolei Sun

ACS Applied Materials & Interfaces September 27, 2017 Volume 9(Issue 38) pp:32554-32554

Publication Date(Web):September 5, 2017

DOI:10.1021/acsami.7b09992

In eukaryotic cells, ion channels, which ubiquitously present as polypeptides or proteins, usually regulate the ion transport across biological membranes by conformational switching of the channel proteins in response to the binding of diverse signaling molecules (e.g., inositol phosphate, abbreviated to InsP). To mimic the gating behaviors of natural Ca2+ channels manipulated by InsPs, a smart poly[(N-isopropylacrylamide-co-4-(3-acryloylthioureido) benzoic acid)0.2] (denoted as PNI-co-ATBA0.2) was integrated onto a porous anodic alumina (PAA) membrane, building an InsP-actuated nanochannel system. Driven by the intensive hydrogen bonding complexation of ATBA monomer with InsP, the copolymer chains displayed a remarkable and reversible conformational transition from a contracted state to a swollen one, accompanied with significant changes in surface morphology, wettability, and viscoelasticity. Benefiting from these features, dynamic gating behaviors of the nanochannels located on the copolymer-modified PAA membrane could be precisely manipulated by InsPs, reflected as a satisfactory linear relationship between real-time variation in transmembrane ionic current and the InsP concentration over a wide range from 1 nmol L–1 to 10 μmol L–1, as well as a clear discrimination among InsP2, InsP3, and InsP6. This study indicates the great potential of biomolecule-responsive polymers in the fabrication of biomimetic ion nanochannels and other nanoscale biodevices.Keywords: biointerfaces; calcium ion channel; gating behavior; inositol phosphate; porous alumina membrane; smart polymer;

A novel aggregation-induced emission enhancement triggered by the assembly of a chiral gelator: from non-emissive nanofibers to emissive micro-loops

Co-reporter:Wenrui Chen;Guangyan Qing

Chemical Communications 2017 vol. 53(Issue 2) pp:447-450

Publication Date(Web):2016/12/22

DOI:10.1039/C6CC08808B

In this study, a novel aggregation-induced emission (AIE) enhancement triggered by the self-assembly of chiral gelator is described. Tuning of molecular chirality in situ triggers different assemblies of superstructures exhibiting fluorescence. This novel AIE material can constitute an emerging library of chiral supramolecules for turn-on fluorescent sensors. It will also help in better understanding the effects of chiral factors on the photophysical process.

Stereoselective One-Pot Sequential Dehydrochlorination/trans-Hydrofluorination Reaction of β-Chloro-α,β-unsaturated Aldehydes or Ketones: Facile Access to (Z)-β-Fluoro-β-arylenals/β-Fluoro-β-arylenones

Co-reporter:Jingli Zhang;Liran Liu;Junxin Duan;Lianghu Gu;Bifeng Chen;Yuefa Gong

Advanced Synthesis & Catalysis 2017 Volume 359(Issue 24) pp:4348-4358

Publication Date(Web):2017/12/19

DOI:10.1002/adsc.201700981

AbstractThe monofluoroalkene substructure shows a high potential as a fluorinated synthon in organic synthesis. However, control of the Z/E stereoselectivity of multi-substituted monofluoroalkene products in one-pot reactions still remains a challenge. An unprecedented one-pot approach for the highly regio- and stereoselective preparation of functionalized (Z)-β-monofluoro tri-substituted alkenes from readily available β-chloro-α,β-unsaturated aldehydes or ketones has been explored. Mechanistic studies demonstrated that the reaction is initiated by dehydrochlorination of the substrates to give alkynyl aldehydes/ketones, followed by their trans-hydrofluorination. It is worth mentioning that a fluorinating reagent with suitable basicity and nucleophilicity plays a key role in promoting the formation of (Z)-β-fluoro-β-aryl tri-substituted monofluoroalkenes.

Rapid and high-efficiency discrimination of different sialic acid species using dipeptide-based fluorescent sensors

Co-reporter:Qi Lu;Mimi Zhan;Lijing Deng;Guangyan Qing

Analyst (1876-Present) 2017 vol. 142(Issue 19) pp:3564-3568

Publication Date(Web):2017/09/25

DOI:10.1039/C7AN00762K

A series of dipeptide-based fluorescent sensors were developed that exhibit sensitive and distinct responses to six typical sialic acid (SA) species despite the interference of 300-fold D-glucose or other saccharides, thus contributing to a novel fluorescence sensing matrix allowing the rapid and high-efficiency discrimination of different SA species.

New Opportunities and Challenges of Smart Polymers in Post-Translational Modification Proteomics

Co-reporter:Guangyan Qing;Qi Lu;Yuting Xiong;Lei Zhang;Hongxi Wang;Xiuling Li;Xinmiao Liang

Advanced Materials 2017 Volume 29(Issue 20) pp:

Publication Date(Web):2017/05/01

DOI:10.1002/adma.201604670

Protein post-translational modifications (PTMs), which denote covalent additions of various functional groups (e.g., phosphate, glycan, methyl, or ubiquitin) to proteins, significantly increase protein complexity and diversity. PTMs play crucial roles in the regulation of protein functions and numerous cellular processes. However, in a living organism, native PTM proteins are typically present at substoichiometric levels, considerably impeding mass-spectrometry-based analyses and identification. Over the past decade, the demand for in-depth PTM proteomics studies has spawned a variety of selective affinity materials capable of capturing trace amounts of PTM peptides from highly complex biosamples. However, novel design ideas or strategies are urgently required for fulfilling the increasingly complex and accurate requirements of PTM proteomics analysis, which can hardly be met by using conventional enrichment materials. Considering two typical types of protein PTMs, phosphorylation and glycosylation, an overview of polymeric enrichment materials is provided here, with an emphasis on the superiority of smart-polymer-based materials that can function in intelligent modes. Moreover, some smart separation materials are introduced to demonstrate the enticing prospects and the challenges of smart polymers applied in PTM proteomics.

The size-effect of gold nanoparticles and nanoclusters in the inhibition of amyloid-β fibrillation

Co-reporter:Guanbin Gao;Mingxi Zhang;Dejun Gong;Rui Chen;Xuejiao Hu

Nanoscale (2009-Present) 2017 vol. 9(Issue 12) pp:4107-4113

Publication Date(Web):2017/03/23

DOI:10.1039/C7NR00699C

A significant pathological signature of Alzheimer's disease (AD) is the deposition of amyloid-β (Aβ) plaques in the brain and the synaptic dysfunction and neurodegeneration associated with it. Compounds or drugs that inhibit Aβ fibrillation are thus desirable to develop novel therapeutic strategies against AD. Conventional strategies usually require an elaborate design of their molecular structures. Here we report the size-effect of gold nanoparticles (AuNPs) and nanoclusters (AuNCs) in the inhibition of protein amyloidosis. Using L-glutathione stabilized AuNPs with different sizes and AuNCs as examples, we show that large AuNPs accelerate Aβ fibrillation, whereas small AuNPs significantly suppress this process. More interestingly, AuNCs with smaller sizes can completely inhibit amyloidosis. Dynamic light scattering (DLS) experiments show that AuNCs can efficiently prevent Aβ peptides from aggregation to larger oligomers (e.g. micelles) and thus avoid nucleation to form fibrils. This is crucially important for developing novel AD therapies because oligomers are the main source of Aβ toxicity. This work presents a novel strategy to design anti-amyloidosis drugs, which also provides interesting insights to understand how biological nanostructures participate in vivo in Aβ fibrillation from a new perspective.

Exploring the role of molecular chirality in the photo-responsiveness of dipeptide-based gels

Co-reporter:Zhonghui Chen;Ziyu Lv;Guangyan Qing

Journal of Materials Chemistry B 2017 vol. 5(Issue 17) pp:3163-3171

Publication Date(Web):2017/05/03

DOI:10.1039/C7TB00402H

Photo-responsive materials, particularly those based on peptides, hold much promise for numerous potential applications in biomedicine and bionanotechnology. For these switchable materials, one of the key issues is how their photo-response rate can be regulated precisely and reversibly. In this study, we used molecular chirality as a useful tool for modulating the gel–sol response rate of dipeptide-based gels consisting of azobenzene and two dipeptide arms. UV light irradiation triggered the trans-to-cis (E/Z)-isomerization of azobenzene that destroyed the planar structures of gelators and induced gel collapse. During this process, a distinct gel–sol transition speed was identified for the L-gel and D-gel, and remarkable differences were observed in the self-assembly behavior between the L-gelator and the D-gelator. Mechanistic studies revealed that molecular chirality dominated the rearrangement of the flexible dipeptide linkers, which further affected the competitive balance between E/Z-isomerization and gelation forces driven by π–π stacking among adjacent benzenes, thus resulting in the distinct disassembly behaviors of the L-gel and the D-gel. The remarkable difference in the gel–sol transition speed, good reversibility and the underlying competition mechanism suggest that molecular chirality may be an efficient parameter for regulating the performance of photo-responsive gels and devices.

Dipeptide-Based Carbohydrate Receptors and Polymers for Glycopeptide Enrichment and Glycan Discrimination

Co-reporter:Guangyan Qing, Xiuling Li, Peng Xiong, Cheng Chen, Mimi Zhan, Xinmiao Liang, and Taolei Sun

ACS Applied Materials & Interfaces 2016 Volume 8(Issue 34) pp:22084

Publication Date(Web):August 8, 2016

DOI:10.1021/acsami.6b07863

Glycoproteomics identifies and catalogs protein glycosylation and explores its impact on protein conformations and biofunctions. However, these studies are restricted by the bottleneck to enrich low-abundance glycopeptides from complex biosamples and the difficulties in analyzing glycan structures by mass spectrometry. Here, we report dipeptide as a simple but promising carbohydrate binding platform to tackle these problems. We build a hydropathy-index-based strategy for sequence optimization and screen out three optimal dipeptide sequences from 54 types of dipeptides. The optimized dipeptide-based homopolymers display excellent performance (e.g., selectivity up to ∼70% for real biosamples and strong anti-interference capacity capable of resisting 1000-fold bovine serum albumin interference) in glycopeptide enrichment. Meanwhile, our polymers exhibit high-efficiency chromatographic separation toward oligosaccharides with different compositions, polymerization degrees and even their linkage isomers. This brings another attractive feature that our materials can discriminate subtly variable glycan structures of glycopeptides, especially, isomeric glycosidic linkages. These features provide a solid foundation to analyze the complex glycan structures and glycosites simultaneously, which will benefit future development of glycoproteomics and glycobiology.Keywords: carbohydrate; enrichment; glycoproteomics; interface; polymer

Bioinspired Saccharide–Saccharide Interaction and Smart Polymer for Specific Enrichment of Sialylated Glycopeptides

Co-reporter:Xiuling Li, Yuting Xiong, Guangyan Qing, Ge Jiang, Xianqin Li, Taolei Sun, and Xinmiao Liang

ACS Applied Materials & Interfaces 2016 Volume 8(Issue 21) pp:13294-13302

Publication Date(Web):May 13, 2016

DOI:10.1021/acsami.6b03104

Abnormal sialylation of proteins is highly associated with many major diseases, such as cancers and neurodegenerative diseases. However, this study is challenging owing to the difficulty in enriching trace sialylated glycopeptides (SGs) from highly complex biosamples. The key to solving this problem relies strongly on the design of novel SG receptors to capture the sialic acid (SA) moieties in a specific and tunable manner. Inspired by the saccharide–saccharide interactions in life systems, here we introduce saccharide-based SG receptors into this study. Allose (a monosaccharide) displays specific and pH-sensitive binding toward SAs. Integrating allose units into a polyacrylamide chain generates a saccharide-responsive smart copolymer (SRSC). Such design significantly improves the selectivity of SA binding; meanwhile, this binding can be intelligently triggered in a large extent by solution polarity and pH. As a result, SRSC exhibits high-performance enrichment capacity toward SGs, even under 500-fold interference of bovine serum albumins digests, which is notably higher than conventional materials. In real biosamples of HeLa cell lysates, 180 sialylated glycosylation sites (SGSs) have been identified using SRSC. This is apparently superior to those obtained by SA-binding lectins including WGA (18 SGSs) and SNA (22 SGSs). Furthermore, lactose displays good chemoselectivity toward diverse disaccharides, which indicated the good potential of lactose-based material in glycan discrimination. Subsequently, the lactose-based SRSC facilitates the stepwise isolation of O-linked or N-linked SGs with the same peptide sequence but varied glycans by CH3CN/H2O gradients. This study opens a new avenue for next generation of glycopeptide enrichment materials.

Chirality-Assisted Ring-Like Aggregation of A(140) at LiquidSolid Interfaces: A Stereoselective Two-Step Assembly Process

Co-reporter:Guanbin Gao; Mingxi Zhang;Dr. Pei Lu;Dr. Guanlun Guo; Dong Wang; Taolei Sun

Angewandte Chemie International Edition 2015 Volume 54( Issue 7) pp:2245-2250

Publication Date(Web):

DOI:10.1002/anie.201410768

Abstract

Molecular chirality is introduced at liquid–solid interfaces. A ring-like aggregation of amyloid Aβ(1–40) on N-isobutyryl-L-cysteine (L-NIBC)-modified gold substrate occurs at low Aβ(1–40) concentration, while D-NIBC modification only results in rod-like aggregation. Utilizing atomic force microscope controlled tip-enhanced Raman scattering, we directly observe the secondary structure information for Aβ(1–40) assembly in situ at the nanoscale. D- or L-NIBC on the surface can guide parallel or nonparallel alignment of β-hairpins through a two-step process based on electrostatic-interaction-enhanced adsorption and subsequent stereoselective recognition. Possible electrostatic interaction sites (R5 and K16) and a chiral recognition site (H14) of Aβ(1–40) are proposed, which may provide insight into the understanding of this effect.

Chirality-Assisted Ring-Like Aggregation of A(140) at LiquidSolid Interfaces: A Stereoselective Two-Step Assembly Process

Co-reporter:Guanbin Gao; Mingxi Zhang;Dr. Pei Lu;Dr. Guanlun Guo; Dong Wang; Taolei Sun

Angewandte Chemie 2015 Volume 127( Issue 7) pp:2273-2278

Publication Date(Web):

DOI:10.1002/ange.201410768

Abstract

Molecular chirality is introduced at liquid–solid interfaces. A ring-like aggregation of amyloid Aβ(1–40) on N-isobutyryl-L-cysteine (L-NIBC)-modified gold substrate occurs at low Aβ(1–40) concentration, while D-NIBC modification only results in rod-like aggregation. Utilizing atomic force microscope controlled tip-enhanced Raman scattering, we directly observe the secondary structure information for Aβ(1–40) assembly in situ at the nanoscale. D- or L-NIBC on the surface can guide parallel or nonparallel alignment of β-hairpins through a two-step process based on electrostatic-interaction-enhanced adsorption and subsequent stereoselective recognition. Possible electrostatic interaction sites (R5 and K16) and a chiral recognition site (H14) of Aβ(1–40) are proposed, which may provide insight into the understanding of this effect.

Chiral Effect at Protein/Graphene Interface: A Bioinspired Perspective To Understand Amyloid Formation

Co-reporter:Guangyan Qing ; Shilong Zhao ; Yüting Xiong ; Ziyu Lv ; Fenglei Jiang ; Yi Liu ; Hui Chen ; Mingxi Zhang

Journal of the American Chemical Society 2014 Volume 136(Issue 30) pp:10736-10742

Publication Date(Web):July 10, 2014

DOI:10.1021/ja5049626

Protein misfolding to form amyloid aggregates is the main cause of neurodegenerative diseases. While it has been widely acknowledged that amyloid formation in vivo is highly associated with molecular surfaces, particularly biological membranes, how their intrinsic features, for example, chirality, influence this process still remains unclear. Here we use cysteine enantiomer modified graphene oxide (GO) as a model to show that surface chirality strongly influences this process. We report that R-cysteine modification suppresses the adsorption, nucleation, and fiber elongation processes of Aβ(1–40) and thus largely inhibits amyloid fibril formation on the surface, while S-modification promotes these processes. And surface chirality also greatly influences the conformational transition of Aβ(1–40) from α-helix to β-sheet. More interestingly, we find that this effect is highly related to the distance between chiral moieties and GO surface, and inserting a spacer group of about 1–2 nm between them prevents the adsorption of Aβ(1–40) oligomers, which eliminates the chiral effect. Detailed study stresses the crucial roles of GO surface. It brings novel insights for better understanding the amyloidosis process on surface from a biomimetic perspective.

Solvent-Driven Chiral-Interaction Reversion for Organogel Formation

Co-reporter:Dr. Guangyan Qing;Xingxing Shan;Wenrui Chen;Ziyu Lv;Peng Xiong ;Dr. Taolei Sun

Angewandte Chemie 2014 Volume 126( Issue 8) pp:2156-2161

Publication Date(Web):

DOI:10.1002/ange.201308554

Abstract

For chiral gels and related applications, one of the critical issues is how to modulate the stereoselective interaction between the gel and the chiral guest precisely, as well as how to translate this information into the macroscopic properties of materials. Herein, we report that this process can also be modulated by nonchiral solvents, which can induce a chiral-interaction reversion for organogel formation. This process could be observed through the clear difference in gelation speed and the morphology of the resulting self-assembly. This chiral effect was successfully applied in the selective separation of quinine enantiomers and imparts “smart” merits to the gel materials.

Solvent-Driven Chiral-Interaction Reversion for Organogel Formation

Co-reporter:Dr. Guangyan Qing;Xingxing Shan;Wenrui Chen;Ziyu Lv;Peng Xiong ;Dr. Taolei Sun

Angewandte Chemie International Edition 2014 Volume 53( Issue 8) pp:2124-2129

Publication Date(Web):

DOI:10.1002/anie.201308554

Abstract

For chiral gels and related applications, one of the critical issues is how to modulate the stereoselective interaction between the gel and the chiral guest precisely, as well as how to translate this information into the macroscopic properties of materials. Herein, we report that this process can also be modulated by nonchiral solvents, which can induce a chiral-interaction reversion for organogel formation. This process could be observed through the clear difference in gelation speed and the morphology of the resulting self-assembly. This chiral effect was successfully applied in the selective separation of quinine enantiomers and imparts “smart” merits to the gel materials.

New approach for chiral separation: from polysaccharide-based materials to chirality-responsive polymers

Co-reporter:Peng Ding;BaiSong Chang;GuangYan Qing

Science China Chemistry 2014 Volume 57( Issue 11) pp:1492-1506

Publication Date(Web):2014 November

DOI:10.1007/s11426-014-5206-8

Chiral separation that is closely related to daily life is a meaningful research. Polysaccharide-(e.g., cellulose, amylose derivatives) based chiral packing materials afford powerful chiral stationary phases (CSPs) toward a broad range of racemic compounds. However, considering the explosive growth of specific chiral drugs, the separation efficiencies of these CSPs need further improvement, which calls for new approaches and strategies. Smart polymers can change their physical or chemical properties dynamically and reversibly according to the external stimuli (e.g., thermo-, pH, solvent, ion, light, critical parameters for chromatographic separation) exerted on them, subsequently resulting in tunable changes in the macroscopic properties of materials. In addition to their excellent controllability, the introduction of chiral characteristics into the backbones or side-chains of smart polymers provides a promising route to realize reversibly conformational transition in response to the chiral analytes. This dramatic transition may significantly improve the performance of materials in chiral separation through modulating the enantioselective interactions between materials and analytes. With the help of chirality-responsive polymers, intelligent and switchable CSPs could be developed and applied in column-liquid chromatography. In these systems, the elution order or enantioselectivity of chiral drugs can be precisely modulated, which will help to solve many challenging problems that involve complicated enantiomers. In this paper we introduce some typical examples of smart polymers that serve as the basis for a discussion of emerging developments of CPSs, and then briefly outline the recent CSPs based on natural and certain synthetic polymers.

Chiral polymer-based biointerface materials

Co-reporter:MinMin Li;GuangYan Qing;MingXi Zhang

Science China Chemistry 2014 Volume 57( Issue 4) pp:540-551

Publication Date(Web):2014 April

DOI:10.1007/s11426-013-5059-6

Chirality is a unique phenomenon in nature. Chiral interactions play an important role in biological and physiological processes, which provides much inspiration for scientists to develop chiral materials. As a breakthrough from traditional materials, biointerface materials based on chiral polymers have attracted increasing interest over the past few years. Such materials elegantly combine the advantages of chiral surfaces and traditional polymers, and provide a novel solution not only for the investigation of chiral interaction mechanisms but also for the design of biomaterials with diverse applications, such as in tissue engineering and biocompatible materials, bioregulation, chiral separation and chiral sensors. Herein, we summarize recent advances in the study of chiral effects and applications of chiral polymer-based biointerface materials, and also present some challenges and perspectives.

Dual-Responsive Gold Nanoparticles for Colorimetric Recognition and Testing of Carbohydrates with a Dispersion-Dominated Chromogenic Process

Co-reporter:Mingxi Zhang;Guangyan Qing;Chenling Xiong;Ran Cui;Dai-Wen Pang

Advanced Materials 2013 Volume 25( Issue 5) pp:749-754

Publication Date(Web):

DOI:10.1002/adma.201203289

Synthesis and electrochemical performance of Li and Ni 1,4,5,8-naphthalenetetracarboxylates as anodes for Li-ion batteries

Co-reporter:Xiaoyan Han, Feng Yi, Taolei Sun, Jutang Sun

Electrochemistry Communications 2012 Volume 25() pp:136-139

Publication Date(Web):November 2012

DOI:10.1016/j.elecom.2012.09.014

Metal-1,4,5,8-naphthalenetetracarboxylates (Metal = Li and/or Ni) were synthesized and investigated as anode materials for lithium ion batteries. These complexes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetry. Electrochemical tests indicated that these materials exhibited superior electrochemical performance and good cycling stability.Highlights► Metal-naphthalenetetracarboxylates (M-NTC, M = Li and/or Ni) were synthesized via a rheological phase reaction. ► These complexes were investigated as anode material for lithium ion batteries. ► Li/Ni-NTC composite shows both high capacity and good cycling stability compared with Li-NTC and Ni-NTC.

A novel aggregation-induced emission enhancement triggered by the assembly of a chiral gelator: from non-emissive nanofibers to emissive micro-loops

Co-reporter:Wenrui Chen, Guangyan Qing and Taolei Sun

Chemical Communications 2017 - vol. 53(Issue 2) pp:NaN450-450

Publication Date(Web):2016/12/06

DOI:10.1039/C6CC08808B

In this study, a novel aggregation-induced emission (AIE) enhancement triggered by the self-assembly of chiral gelator is described. Tuning of molecular chirality in situ triggers different assemblies of superstructures exhibiting fluorescence. This novel AIE material can constitute an emerging library of chiral supramolecules for turn-on fluorescent sensors. It will also help in better understanding the effects of chiral factors on the photophysical process.

Exploring the role of molecular chirality in the photo-responsiveness of dipeptide-based gels

Co-reporter:Zhonghui Chen, Ziyu Lv, Guangyan Qing and Taolei Sun

Journal of Materials Chemistry A 2017 - vol. 5(Issue 17) pp:NaN3171-3171

Publication Date(Web):2017/03/21

DOI:10.1039/C7TB00402H

Photo-responsive materials, particularly those based on peptides, hold much promise for numerous potential applications in biomedicine and bionanotechnology. For these switchable materials, one of the key issues is how their photo-response rate can be regulated precisely and reversibly. In this study, we used molecular chirality as a useful tool for modulating the gel–sol response rate of dipeptide-based gels consisting of azobenzene and two dipeptide arms. UV light irradiation triggered the trans-to-cis (E/Z)-isomerization of azobenzene that destroyed the planar structures of gelators and induced gel collapse. During this process, a distinct gel–sol transition speed was identified for the L-gel and D-gel, and remarkable differences were observed in the self-assembly behavior between the L-gelator and the D-gelator. Mechanistic studies revealed that molecular chirality dominated the rearrangement of the flexible dipeptide linkers, which further affected the competitive balance between E/Z-isomerization and gelation forces driven by π–π stacking among adjacent benzenes, thus resulting in the distinct disassembly behaviors of the L-gel and the D-gel. The remarkable difference in the gel–sol transition speed, good reversibility and the underlying competition mechanism suggest that molecular chirality may be an efficient parameter for regulating the performance of photo-responsive gels and devices.

TOPICS

Abstract

Abstract

Abstract

Abstract