Co-reporter:Chang Liu;Yajing Guo;Fang Luo;Pingfan Rao;Caili Fu
Food Analytical Methods 2017 Volume 10( Issue 6) pp:1982-1990
Publication Date(Web):26 December 2016
DOI:10.1007/s12161-016-0771-4
A simple, fast, sensitive, and homogeneous electrochemical method has been developed for ochratoxin A (OTA) determination, which combines the advantage of the high selectivity of aptamer to OTA and high efficiency of exonuclease (Exo) III-assisted recycling amplification mechanism. The metastable hairpin probe (HP) was designed into three parts: regions I is the aptamer of OTA as the target recognition; regions II is poly[dA] sequence as extended DNA (E-DNA); regions III as the target DNA (T-DNA) is complementary to a part of the aptamer to stabilize the hairpin-sharp form of the HP in the absence of OTA. The DNA probe with a methylene blue tag at its 3′ terminus (MB-DNA) was designed to be complementary with T-DNA. Introduction of OTA into the assay leads to the formation change of HP from hairpin shape to open form, thus facilitating the hybridization between T-DNA and MB-DNA. The electrochemical signal is amplified through continuous Exo III cleavage. Under the optimal conditions, the differential pulse voltammetric (DPV) response had a linear relationship with the logarithm of OTA concentration in the range of 0.001~0.5 ng mL−1. In addition, the developed method has been successfully applied to detect OTA in wheat standard quality control sample. This homogeneous electrochemical sensor may have a potential prospect in detecting other molecules or proteins, which possesses the corresponding aptamer, through easily designing the hairpin probe.
Co-reporter:Ying Li;Yajing Guo;Chang Liu;Wu Wang;Pingfan Rao;Caili Fu
Food Analytical Methods 2017 Volume 10( Issue 6) pp:1965-1971
Publication Date(Web):26 December 2016
DOI:10.1007/s12161-016-0772-3
The application of wavelength variable selection before partial least squares (PLS) regression to rapidly discriminate the adulteration of apple juice by Fourier transform near-infrared (FT-NIR) was investigated in this study. Successive projections algorithm (SPA) combined with four swarm intelligence optimization algorithms, including genetic algorithm (GA), particle swarm optimization (PSO), group search optimizer (GSO), and firefly algorithm (FA), was applied to extract effective wavelength variables. The results demonstrated that the variable number of SPA-PSO-PLS models was validly improved with a wavelength variable of four. The accuracy of model was satisfactory with the coefficients of determination of prediction (R2p = 0.9986) and good root mean square errors of prediction (RMSEP = 0.0628). The results suggested that SPA combined with swarm intelligence optimization algorithms for wavelength variable selection could rapidly and efficiently discriminate the adulteration of apple juice.
Co-reporter:Xu Chen;Jin-hong Wu;Ling Li;Shao-yun Wang
European Food Research and Technology 2017 Volume 243( Issue 7) pp:1149-1156
Publication Date(Web):20 December 2016
DOI:10.1007/s00217-016-2830-x
This study was to evaluate the effect of antifreeze peptides from pigskin collagen hydrolysates (CoAPPs) on the fermentation properties, texture properties, water distribution and water mobility of dough during freezing and freeze–thaw cycles. The fermentation properties of the frozen dough were more stable in the CoAPPs groups than those of control groups. The texture profile analysis showed that the hardness, gumminess and chewiness of the CoAPPs breads were significantly smaller (P < 0.05) than controls. The NMR showed that addition of CoAPPs weakened the influence of the freeze–thaw treatment on water mobility and influenced the water distribution in frozen dough. The results suggest that CoAPPs could potentially serve as a food-origin cryoprotectant in the conventional dough products.
Co-reporter:Qingyan He;Yan Huang;Binbin Lin
Journal of Applied Phycology 2017 Volume 29( Issue 3) pp:1541-1552
Publication Date(Web):27 December 2016
DOI:10.1007/s10811-016-1030-1
This paper describes an edible nanocomposite packaging film fabricated with simultaneously extracted protein-polysaccharide (biopolymers) from the marine red alga Gracilaria lemaneiformis and TiO2 nanoparticles. Both proteins and polysaccharides were synchronously extracted using the alkali extraction method. Different amounts of TiO2 nanoparticles (TiO2 to biopolymer content ratio of 3.33, 5.00 and 10.0% w/w) were added to prepare the TiO2-protein/polysaccharide nanocomposite film. The addition of TiO2 nanoparticles increased the tensile strength and decreased the water vapor permeability of the film. This was because the uniformly embedded TiO2 nanoparticles interacted strongly with the biopolymers which enhanced the mechanical properties of the film, whereas the particles increased the diffusion pathway distance and lead to lower water permeability. These hypotheses were confirmed by UV spectra, FTIR, and X-ray diffraction studies. Antibacterial measurements against food-borne pathogenic bacteria revealed that the growth of Escherichia coli and Staphylococcus aureus was effectively inhibited by the TiO2-biopolymer nanocomposite film. Additionally, nutrition retention and quality improvement were observed in cherry tomatoes when coated with the TiO2-biopolymer nanocomposite film. These findings suggested that this alga-sourced nanocomposite film could serve as a promising coating material in the food industry.
Co-reporter:Ling Li, Jin-Hong Wu, Li Zhang, Xu Chen, Yan Wu, Jian-hua Liu, Xue-qing Geng, Zheng-Wu Wang, Shao-Yun Wang
LWT - Food Science and Technology 2017 Volume 77(Volume 77) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.lwt.2016.12.004
•Sericin peptides (3K-SP) were rich in some amino acids associated with the cryoprotective activity.•3K-SP induced ice to melt at lower temperatures and in a shorter time compared to control solution.•3K-SP inhibited ice recrystallization by maintaining irregular ice crystals as smaller sizes.•3K-SP provided high cryogenic optimal protection of L. Bulgaricus cells at 1.0 mg/mL and pH 7.0.•3K-SP exerted cryoprotection by making cells in a glassy matrix and keeping the membrane integrity.In order to exploit their industrial applications, sericin peptides (3K-SP) were obtained by membrane separation and their physiochemical properties and cryoprotective function were investigated. Results showed that 3K-SP were mostly distributed less than 3000 Da, and rich in the amino acids Ser, Asp, Gly, Thr and Glu, which have been associated with the cryoprotective activity of ice-structuring proteins. Addition of 3K-SP to a frozen solution led to the reductions in melting temperature and melting time compared to control solution. In addition, 3K-SP inhibited ice recrystallization, since it could maintain small ice crystal sizes within a frozen solution. Furthermore, 3K-SP demonstrated high cryogenic protection activity of Lactobacillus delbrueckii Subsp. Bulgaricus during freezing, and provided optimal protection of cells at conditions in which its concentration was 1.0 mg/mL and the pH of the solution was 7.0. In these conditions, the percentage of surviving cells was as high as 84.78 ± 3.07%. Flow cytometric and scanning electron microscopy analyses showed that treatment with 3K-SP increased the percentage of viable cells from 52.9% to 80.1%, and suggest that 3K-SP may mediate its protective effects through interaction with cell membranes, whereby it surrounds cells in a glassy matrix that helps maintain their membrane integrity.
Co-reporter:Xu Chen, Miaohong Wu, Qian Yang, Shaoyun Wang
LWT - Food Science and Technology 2017 Volume 77(Volume 77) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.lwt.2016.12.005
•PBPs showed nutritional value for the highly essential amino acids content of 43%.•The hydrophobic amino acids related to antioxidant activity took up 50.47%.•PBPs exhibited lipid peroxidation inhibition activities both in linoleic acid and liposome-meat system.•The functional properties of PBPs suggest their potential application in food system.Phycobiliproteins (PBPs), the family of hydrophilic pigment proteins with fluorescence, have great potential in food industry as functional ingredients. The objective of this research was to prepare and characterize food grade phycobiliproteins from Porphyra haitanensis, and to investigate its application in liposome-meat system.The existence of both phycoerythrin and phycocyanin in food grade PBPs was confirmed using UV–visible spectrum, with 3 absorbance peaks at wavelength of 498 nm, 560 nm and 615 nm, respectively. The purity ratio of food grade PBPs was 1.39, which was enhanced to 3.14 by DEAE chromatography. The optimum pH for emulsifying and gelation properties was 10, and the optimum temperature for emulsifying property was 40 °C. The IC50 values of food grade PBPs and purified PBPs were as follows: DPPH radical scavenging activities were 166 μg/mL and 84 μg/mL, ABTS radical scavenging activities were 29 μg/mL and 32 μg/mL, Fe2+ chelating activities were 200 μg/mL and 32 μg/mL, respectively. Moreover, both linoleic acid peroxidation and the growth of TBARS value in liposome-meat system could be inhibited significantly by phycobiliproteins. The findings indicated that food grade PBPs from Porphyra haitanensis are applicable as a potential additive to be utilized in liposome-meat system.
Co-reporter:Jinhong Wu, Yuzhi Rong, Zhengwu Wang, Yanfu Zhou, Shaoyun Wang, Bo Zhao
Food Chemistry 2015 Volume 174() pp:621-629
Publication Date(Web):1 May 2015
DOI:10.1016/j.foodchem.2014.11.100
•The thermal hysteresis activity of ice-binding sericin peptides reached as high as 0.94 °C.•SM-AFP is a novel antifreeze sericin peptide with a molecular weight of 1009.50 Da.•The amino acid sequence of SM-AFP is TTSPTNVSTT.•Synthetic SM-AFP exerts hypothermia protective effects on L. bulgaricus LB340.•Molecular dynamics modelling of the binding interface of SM-AFP and ice was performed.This study aimed to isolate and characterise a novel sericin antifreeze peptide and investigate its ice-binding molecular mechanism. The thermal hysteresis activity of ice-binding sericin peptides (I-SP) was measured and their activity reached as high as 0.94 °C. A P4 fraction, with high hypothermia protective activity and inhibition activity of ice recrystallisation, was obtained from I-SP, and a purified sericin peptide, named SM-AFP, with the sequence of TTSPTNVSTT and a molecular weight of 1009.50 Da was then isolated from the P4 fraction. Treatment of Lactobacillus delbrueckii Subsp. bulgaricus LB340 LYO with 100 μg/ml synthetic SM-AFP led to 1.4-fold increased survival (p < 0.05). Finally, an SM-AFP/ice binding model was constructed and results of molecular dynamics simulation suggested that the binding of SM-AFP with ice and prevention of ice crystal growth could be attributed to hydrogen bond formation, hydrophobic interaction and non-bond interactions. Sericin peptides could be developed into beneficial cryoprotectants and used in frozen food processing.
Co-reporter:Cai Xixi, Zhao Lina, Wang Shaoyun and Rao Pingfan
Food & Function 2015 vol. 6(Issue 3) pp:816-823
Publication Date(Web):05 Jan 2015
DOI:10.1039/C4FO00811A
The nano-composites of whey protein hydrolysate (WPH) chelated with calcium were fabricated in aqueous solution at 30 °C for 20 min, with the ratio of hydrolysate to calcium 15:1 (w/w). UV scanning spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering and atomic force microscopy were applied to characterize the structure of the WPH-calcium chelate. The nano-composites showed the successful incorporation of calcium into the WPH, indicating the interaction between calcium and WPH. The chelation of calcium ions to WPH caused molecular folding and aggregation which led to the formation of a WPH-calcium chelate of nanoparticle size, and the principal sites of calcium-binding corresponded to the carboxyl groups and carbonyl groups of WPH. The WPH-calcium chelate demonstrated excellent stability and absorbability under both acidic and basic conditions, which was beneficial for calcium absorption in the gastrointestinal tract of the human body. Moreover, the calcium absorption of the WPH-calcium chelate on Caco-2 cells was significantly higher than those of calcium gluconate and CaCl2in vitro, suggesting the possible increase in calcium bioavailability. The findings suggest that the WPH-calcium chelate has the potential in making dietary supplements for improving bone health of the human body.
Co-reporter:Xixi Cai, Qian Yang and Shaoyun Wang
RSC Advances 2015 vol. 5(Issue 116) pp:96097-96104
Publication Date(Web):22 Oct 2015
DOI:10.1039/C5RA17544E
The antioxidant and hepatoprotective activities of pigments in the natural form of a pigment–protein complex were investigated. Pigment–protein complex (PPC) was isolated from Chlorella vulgaris through thylakoid protein solubilization, anion exchange chromatography and gel filtration chromatography. PPC possessed a chlorophyll:lutein:protein ratio of 94:153:100 (w/w/w) according to HPLC and spectrophotometric analysis. Various antioxidant evaluation systems were used to evaluate the antioxidant activity of PPC in vitro. Results showed that PPC exhibited significant DPPH radical scavenging activity with an IC50 of 313 μg mL−1. Distinct Fe2+ ion chelating activity, reducing capacity and lipid peroxidation inhibition activity were observed at a concentration of 1 mg mL−1. For the hepatoprotective effects, administration of PPC at different concentrations (50 and 100 mg kg−1 BW) could significantly decrease the carbon tetrachloride-induced elevation of the hepatosomatic index. Increased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were attenuated with PPC pretreatment. In addition, PPC effectively restored suppressed hepatic superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities. Moreover, PPC significantly reduced the formation of malondialdehyde (MDA). The results obtained from this study clearly verified the hepatoprotective effect of PPC in CCl4-induced hepatotoxicity in vivo, suggesting that PPC has the potential to be exploited as a dietary supplement against free radical oxidation which could enhance resistivity against oxidative stress in the human body.
Co-reporter:Xixi Cai, Qimin Huang and Shaoyun Wang
Food & Function 2015 vol. 6(Issue 6) pp:1893-1899
Publication Date(Web):20 Apr 2015
DOI:10.1039/C4FO01096E
A novel kind of lutein–protein complex (LPC) was extracted from heterotrophic Chlorella vulgaris through aqueous extraction. The purification procedure contained solubilization of thylakoid proteins by a zwitterionic detergent CHAPS, anion exchange chromatography and gel filtration chromatography. Both wavelength scanning and HPLC analysis confirmed that lutein was the major pigment of the protein-based complex, and the mass ratio of lutein and protein was determined to be 9.72:100. Besides showing lipid peroxidation inhibition activity in vitro, LPC exerted significant antioxidant effects against ABTS and DPPH radicals with IC50 of 2.90 and 97. 23 μg mL−1, respectively. Meanwhile, in vivo antioxidant activity of the complex was evaluated using the mice hepatotoxicity model; LPC significantly suppressed the carbon tetrachloride-induced elevation of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and decreased hepatic malondialdehyde (MDA) levels and the hepatosomatic index. Moreover, LPC could effectively restore the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the treated mice livers. Our findings further the progress in the research of natural protein-based lutein complexes, suggesting that LPC has the potential in hepatoprotection against chemical induced toxicity and in increasing the antioxidant capacity of the defense system in the human body.
Co-reporter:Jiaping Lin, Xixi Cai, Mengru Tang, and Shaoyun Wang
Journal of Agricultural and Food Chemistry 2015 Volume 63(Issue 44) pp:9704-9714
Publication Date(Web):October 25, 2015
DOI:10.1021/acs.jafc.5b04001
Marine algae have been becoming a popular research topic because of their biological implication. The algae peptide-based metal-chelating complex was investigated in this study. Schizochytrium sp. protein hydrolysate (SPH) possessing high Ca-binding capacity was prepared through stepwise enzymatic hydrolysis to a degree of hydrolysis of 22.46%. The nanocomposites of SPH chelated with calcium ions were fabricated in aqueous solution at pH 6 and 30 °C for 20 min, with the ratio of SPH to calcium 3:1 (w/w). The size distribution showed that the nanocomposite had compact structure with a radius of 68.16 ± 0.50 nm. SPH was rich in acidic amino acids, accounting for 33.55%, which are liable to bind with calcium ions. The molecular mass distribution demonstrated that the molecular mass of SPH was principally concentrated at 180–2000 Da. UV scanning spectroscopy and Fourier transform infrared spectroscopy suggested that the primary sites of calcium-binding corresponded to the carboxyl groups, carbonyl groups, and amino groups of SPH. The results of fluorescent spectroscopy, size distribution, atomic force microscope, and 1H nuclear magnetic resonance spectroscopy suggested that calcium ions chelated with SPH would cause intramolecular and intermolecular folding and aggregating. The SPH-calcium chelate exerted remarkable stability and absorbability under either acidic or basic conditions, which was in favor of calcium absorption in the gastrointestinal tracts of humans. The investigation suggests that SPH-calcium chelate has the potential prospect to be utilized as a nutraceutical supplement to improve bone health in the human body.
Co-reporter:Jing Hong, Tao-tao Chen, Lei Hu, Jie Yang, Pei Hu, and Shao-yun Wang
Journal of Agricultural and Food Chemistry 2015 Volume 63(Issue 5) pp:1488-1495
Publication Date(Web):January 8, 2015
DOI:10.1021/jf5046014
A novel lectin, CLSL, was purified from Chinese leek seeds by ion exchange chromatography on SP Sephadex C-25 and gel filtration chromatography on Sephadex G50. The lectin had a molecular weight of 23.6 kDa and was composed of two identical subunits linked by disulfide bonds, a conclusion based on SDS-PAGE under reducing and nonreducing conditions. CLSL was a glycoprotein with a carbohydrate content of 3.6%. It exerted potent agglutinating activity against rat red blood cells at a concentration of 8.9 μg/mL. Hemagglutination of rat erythrocytes was inhibited by d-fructose, mannitol, and sorbose at the concentration of 20 mM. The hemagglutinating activity of CLSL was maintained at 100 °C for 60 min and under acidic pH conditions but was lost at neutral and alkaline pH conditions. The hemagglutinating activity was stimulated by Ca2+, Fe2+, and Cu2+ but inactivated by Ba2+ at a concentration of 10 mM. Ba2+-mediated inactivation of CLSL was caused by CLSL conformational change induced by barium ions, according to the results of circular dichroism and fluorescence spectroscopy. Deconvolution of the CLSL circular dichroism indicated that it was an α-helical lectin with α-helix and β-fold contents of 35.8% and 8.6%, respectively. CLSL could also selectively inhibit cell proliferation.
Co-reporter:Jing Hong;Tao-Tao Chen;Pei Hu;Shao-Yun Wang
European Food Research and Technology 2015 Volume 240( Issue 2) pp:327-333
Publication Date(Web):2015 February
DOI:10.1007/s00217-014-2332-7
Antibacterial peptides have been one of the most prospects as a new member of antibiotics in food and/or medicine industry. In this thesis, a novel antibacterial peptide, designated as CLP-1, was purified from Chinese leek seeds by a gel filtration chromatography and reversed-phase high-performance liquid chromatography. CLP-1 was composed of three amino acids, and the sequence was identified as Ser-Asn-Ala (SNA) using LC–MS/MS, which was a novel short antibacterial peptide from Chinese leek seeds. SNA showed moderate antibacterial activity against the growth of Gram-positive and Gram-negative bacteria, and the minimal inhibition concentration values of SNA against Escherichia coli, Staphylococcus aureus, Salmonella, and Bacillus subtilis were 4.31, 2.24, 4.31, and 2.24 mM, respectively. Moreover, SNA exerted slighter hemolytic activity at concentration of 3.44 mM.
Co-reporter:Lina Zhao, Qimin Huang, Shunli Huang, Jiaping Lin, Shaoyun Wang, Yifan Huang, Jing Hong, and Pingfan Rao
Journal of Agricultural and Food Chemistry 2014 Volume 62(Issue 42) pp:10274-10282
Publication Date(Web):September 29, 2014
DOI:10.1021/jf502412f
A novel peptide with a specific calcium-binding capacity was isolated from whey protein hydrolysates. The isolation procedures included diethylaminoethyl (DEAE) anion-exchange chromatography, Sephadex G-25 gel filtration, and reversed-phase high-performance liquid chromatography (HPLC). A peptide with a molecular mass of 237.99 Da was identified by liquid chromatography–electrospray ionization/mass spectrometry (LC–ESI/MS), and its amino acid sequence was confirmed to be Gly-Tyr. The calcium-binding capacity of Gly-Tyr reached 75.38 μg/mg, increasing by 122% when compared to the hydrolysate complex. The chelating interaction mode between the Gly-Tyr and calcium ion was investigated, indicating that the major binding sites included the oxygen atom of the carbonyl group and nitrogen of the amino or imino group. The folding and structural modification of the peptide arose along with the addition of the calcium ion. The profile of 1H nuclear magnetic resonance (NMR) spectroscopy demonstrated that the electron cloud density around the hydrogen nucleus in the peptide changed was caused by the calcium ion. The results of ζ potential showed that the Gly-Tyr–Ca chelate was a neutral molecule in which the calcium ion was surrounded by the specific binding sites of the peptide. Moreover, thermogravimetry–differential scanning calorimetry (TG–DSC) and calcium-releasing assay revealed that the Gly-Tyr–Ca chelate exerted excellent thermal stability and solubility in both acidic and basic conditions, which were beneficial to calcium absorption in the gastrointestinal tract of the human body and, therefore, improved its bioavailability. These findings further the progress in the research of whey protein, suggesting the potential in making peptide–calcium chelate as a dietary supplement.
Co-reporter:Jing Hong, Tao-Tao Chen, Pei Hu, Jie Yang, Shao-Yun Wang
Journal of Functional Foods 2014 10() pp: 144-153
Publication Date(Web):
DOI:10.1016/j.jff.2014.05.014
Co-reporter:Lina Zhao, Shunli Huang, Xixi Cai, Jing Hong, Shaoyun Wang
Journal of Functional Foods 2014 10() pp: 46-53
Publication Date(Web):
DOI:10.1016/j.jff.2014.05.013
Co-reporter:Jinhong Wu;Yanfu Zhou;Zhengwu Wang
European Food Research and Technology 2013 Volume 236( Issue 4) pp:637-646
Publication Date(Web):2013 April
DOI:10.1007/s00217-013-1919-8
Sericin peptides (SPs) are a new cryoprotectant with protecting abilities for organisms or biomacromolecule in food stuff from freezing injury in subzero environments. The extraction of ice-binding sericin peptides (I-SPs) by ice affinity extraction adsorption and their cryoprotective effect on Lactobacillus Delbrueckii Subsp. bulgaricus LB340 LYO during frozen storage was studied in this paper. The optimal extraction conditions by application of a new and assembled ice absorption apparatus were identified as temperature of −3 °C, SPs concentration of 5 mg/mL, and extraction time of 3 h. Compared with SPs, I-SPs were found to be increased in the contents of some special amino acid residues, including Ser, Thr, Gly, and Ala, which might be relative with the ice affinity as well as the cryoprotective activity of ice-structuring proteins. Meanwhile, the molecular mass distribution data implied that the free amino acids in the SPs could be excluded from the ice affinity adsorption, and peptides containing 3–6 amino acid residues might be more liable to adsorb to ice surface. Furthermore, with addition of I-SPs at concentrations of more than 0.01 mg/mL, LB340 strain had a higher survival rate after frozen storage compared to the water control as well as SPs (p < 0.05).
Co-reporter:Yongxiang Hong;Xixi Cai;Biao Shao;Jing Hong
European Food Research and Technology 2013 Volume 237( Issue 3) pp:457-465
Publication Date(Web):2013 September
DOI:10.1007/s00217-013-2013-y
A novel trypsin inhibitor with considerable thermal and pH stability, designated Glytine, was isolated from seeds of the Chinese black soybean Glycine max (L.) Merr. The purification procedure involved ammonium sulfate precipitation, ion-exchange chromatography on CM-Sephadex C-50, gel filtration chromatography on Sephacryl S-200HR, and gel filtration chromatography on POROS HS-20. The 20 N-terminal amino acid sequences were determined to be DEYSKPCCDLCMCTRRCPPQ, demonstrating close homology with the sequences of leguminous trypsin inhibitors. The molecular mass and isoelectric point of the inhibitor were estimated by SDS-PAGE and isoelectric focusing to be 19.9 kDa and 6.2, respectively. Trypsin could be completely inhibited by Glytine when the weight ratio was 1.5. The inhibitory activity of Glytine was unaffected by exposure to temperatures up to 100 °C, or within the pH range 2–12. Besides trypsin–chymotrypsin inhibition activity, Glytine demonstrated other biological activities including antiproliferative activity against tumor cells including human liver hepatoma cells Bel-7402 and neuroblastoma cells SHSY5Y. In addition, the inhibitor showed antifungal activity against Pythium aphanidermatum, Fusarium oxysporum, Alternaria alternata (Fr.) Keiss, Fusarium solani, and Botrytis cinerea. This study extended research on leguminous trypsin–chymotrypsin inhibitor and suggested exploitable potential.
Co-reporter:Shao-Yun Wang, Bei-Bei Zhu, Dan-Zhen Li, Xian-Zhi Fu, Liang Shi
Materials Letters 2012 Volume 83() pp:42-45
Publication Date(Web):15 September 2012
DOI:10.1016/j.matlet.2012.05.104
Nanocrystalline titanium dioxide (TiO2) particles coated with soy protein isolate (SPI) were fabricated in aqueous solution at near room temperature. The X-ray diffraction, UV scanning spectrum, photoluminescence and FT-IR measurements were applied to characterize the nanoscaled composite structure of SPI/TiO2. Laser scattering particle analyzer and zeta potential were used to determine the average particle size and stability of the system in basic solutions by adding various amounts of titanium dioxide. When exposed to two hour irradiation of UV light at 365 nm, the bactericidal activity of SPI films containing TiO2 nanoparticles (2.00 g/150 mL) against Escherichia coli and Staphylococcus aureus can reach 71.01% and 88.49%, respectively.Highlights► TIO2/SPI composite film was fabricated by Nano-TiO2 solution and SPI. ► X-ray, UV–vis, FT-IR and XRD were applied to characterize the structure. ► TIO2/SPI composite film showed the bactericidal activity. ► We report here its preparation and characterization for the first time.
Co-reporter:SHAOYUN WANG;BIAO SHAO;PINGFAN RAO;ZEYUAN DENG;MINGYONG XIE
Journal of Food Biochemistry 2011 Volume 35( Issue 4) pp:1206-1222
Publication Date(Web):
DOI:10.1111/j.1745-4514.2010.00445.x
ABSTRACT
Plants have been one of the hot research topics in the search for potent antifungals. The objective of this study was to isolate a novel antifungal protein from Phaseolus limensis. A protein designated Limlin, with both antifungal and antibacterial activity was isolated and characterized. The isolation procedure entailed extraction, precipitation, affinity chromatography on Affi – gel blue gel, ion chromatography on SP-Toyopearl and gel filtration on Sephadex G-75. The protein exhibited a molecular mass of 34 kDa in SDS-polyacrylamide gel electrophoresis both under reducing and non-reducing conditions. Its N-terminal sequence was determined as QNNPAGFKGDKANAMLKMGNLSFQT, showing some homology to peroxidases and peroxidase precursors from plants. It potently suppressed mycelial growth of Fusarium solani, Mycosphaerella arachidicola and Pythium aphanidermatum. Moreover, this novel protein showed antiproliferative activity towards human liver hepatoma cells Bel-7402 and neuroblastoma cells SHSY5Y. This investigation first demonstrates an antifungal peroxidase with antiproliferative activity in large lima legume.
PRACTICAL APPLICATIONS
Plants are an important and indispensable part of life. Plants have evolved a variety of potent defense mechanisms because they are exposed to a large number of pathogenic organisms. They synthesize proteins and peptides that have antifungal activity. As their names imply, antifungal proteins and peptides serve a protective function against fungal invasion and play an important role in the defense of crops against fungal attack, thus diminishing serious economic losses.
In this study, it is the first that demonstrates an antifungal peroxidase in large lima beans. The newly purified antifungal protein Limlin manifests antifungal, antibacterial activity and antiproliferative activity toward tumor cells. The aforementioned activities shown by peroxidase, provide further evidence for the potential significance in both medicine and agriculture.
Co-reporter:Shaoyun Wang;Biao Shao;Jingli Chang;Pingfan Rao
European Food Research and Technology 2011 Volume 232( Issue 4) pp:613-619
Publication Date(Web):2011 April
DOI:10.1007/s00217-011-1424-x
A plant lysozyme exhibiting antifungal activity and with a molecular mass of 20.1 kDa in SDS–polyacrylamide gel electrophoresis was isolated from Momordica charantia L using a procedure that involved aqueous extraction, vacuum freeze-drying of extraction, and ion exchange chromatography on high-performance liquid chromatography on Source Q and POROS 50 HS. Its N-terminal sequence was determined to be Q-L-C-E-L-A-A-C-M-K-R-H-G-L-D, showing relatively high homology (about 80%) with that of hen egg white lysozyme. Its pI was estimated to be 9.9. The lysozyme exhibited a pH optimum at pH 5.5 and a temperature optimum at 50 °C. Moreover, the lysozyme exerted an antifungal action toward Mucorracemosus and Rhizoctonia solani, in addition to an antibacterial action against Escherichia coli and Staphylococcus aureus.
Co-reporter:Shaoyun Wang;Pingfan Rao
European Food Research and Technology 2010 Volume 231( Issue 2) pp:331-338
Publication Date(Web):2010 June
DOI:10.1007/s00217-010-1285-8
A trypsin-chymotrypsin inhibitor, designated Limenin, with both antifungal and antibacterial activity, and exhibiting a molecular mass of 18.0 kDa in SDS–polyacrylamide gel electrophoresis, was isolated from the large lima bean (Phaseolus limensis) legumes by a combination of extraction, ammonium sulfate precipitation, ion exchange chromatography on SP-Toyopearl and high performance liquid chromatography (HPLC) on Mono S. The isoelectric point was estimated to be 7.6 by isoelectric focusing. The 15 N-terminal amino acid sequences were determined to be DFVIDNEGNPLENGG, demonstrating some resemblance to those other protease inhibitors and inhibitor precursors from leguminous plants. It exerted potent antifungal action toward Botrytis cinerea, Alternaria alternata(Fr.) Keissl, and Pythium aphanidermatum. It showed antiproliferative activity toward tumor cells including human liver hepatoma cells Bel-7402 and neuroblastoma cells SHSY5Y. However, it had no effect on bacteria Staphylococcus aureus and Salmonella.
Co-reporter:Shaoyun Wang;Biao Shao;Hong Fu;Pingfan Rao
Applied Microbiology and Biotechnology 2009 Volume 85( Issue 2) pp:313-321
Publication Date(Web):2009 November
DOI:10.1007/s00253-009-2074-9
Chitinases are listed as one class of pathogenesis-related proteins, and they have become a popular research topic because of their resistance to plant-pathogenic diseases. A chitinase with antifungal activity was isolated from the Canadian cranberry beans (Phaseolus vulgaris). The procedure included extraction, ammonium sulfate precipitation, affinity chromatography on Affi-gel blue gel, CM-Sephadex C-50, and Sephadex G-75. There was an almost 108-fold increase in specific activity of the purified chitinase compared with that of the crude extract. The enzyme exhibited a molecular mass of 30.6 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis both under reducing and non-reducing conditions, indicating that it was a monomeric protein. The pI was determined to be 7.6 by isoelectric-focusing electrophoresis. The optimum pH and the optimum temperature for activity towards N-acetyl-glucosamine was 5.4 and 40–55°C, respectively. It exerted a potent inhibitory action toward fungal species including Botrytis cinerea, Physalospora piricola, Fusarium oxysporum, and Pythium aphanidermatum. The chitinase was thermostable up to 58°C in both enzymatic reaction and antifungal activity. The present findings demonstrated a thermostable chitinase from cranberry beans with potentially exploitable significance.
Co-reporter:SHAOYUN WANG;ZHIBIN XU;PINGFAN RAO;XIUYUN YE;ZHIBIN XU;XIUYUN YE;PINGFAN RAO
Journal of Food Biochemistry 2005 Volume 29(Issue 2) pp:117-131
Publication Date(Web):7 JUN 2005
DOI:10.1111/j.1745-4514.2005.00017.x
A malate dehydrogenase (MDH) was identified and isolated from the seeds of the mung bean (Phaseolus mungo). The procedure entailed extraction, ammonium sulfate precipitation, ion exchange chromatography on CM-Sephadex and high performance liquid chromatography on POROS HS-20. The purified protein exhibited a molecular mass of 38 kDa in SDS-polyacrylamide gel electrophoresis under both nonreduced and reduced conditions. The pI was 9.7 by isoelectric focusing. The specific activity of the MDH was estimated to be 199 U/mg. The enzyme expressed its optimum activity at pH 7.2, 35C, and showed stable activity below 40C. The Km for oxaloacetate was 112 µM. The partial N-terminal amino acid sequence data analysis of the first 20 amino acids of the mung bean MDH revealed 95 and 80% homology with two reported MDH from soya bean (Glycine max) and potato (Solanum tuberosum), respectively.
Co-reporter:Qingyan He, Yuchen Zhang, Xixi Cai, Shaoyun Wang
International Journal of Biological Macromolecules (March 2016) Volume 84() pp:153-160
Publication Date(Web):1 March 2016
DOI:10.1016/j.ijbiomac.2015.12.012
Biodegradable fish skin gelatin–titanium dioxide (TiO2) nanocomposite films were fabricated and characterized as a function of incorporating amount of TiO2 nanoparticles (gelatin/TiO2 ratio of 30:1, 20:1 and 10:1). A uniform distribution of TiO2 nanoparticles into gelatin matrix was observed using atomic force microscopy (AFM) micrographs. The data of intrinsic fluorescence spectra, Fourier transform infrared spectra (FTIR) and X-ray diffraction confirmed the interaction between protein and nanoparticles through hydrogen bonding. The TiO2-incorporated gelatin nanocomposite films exhibited more effective antibacterial activity for Escherichia coli after irradiating 120 min by UV light (365 nm), which were 54.38% for E. coli and 44.89% for Staphylococcus aureus, respectively. The analysis of physical properties revealed that addition of TiO2 nanoparticles to gelatin films significantly increased the tensile strength and elongation at break, while decreased its water vapor permeability. The light barrier measurements indicated that these films were highly transparent, and they had excellent barrier properties against UVC light at the same time. The results demonstrated the feasibility of incorporating nanoparticles to improve the properties of gelatin films, and it is of significance in utilizing the gelatin and titanium dioxide to produce biodegradable nanocomposite film as packaging material in food industry.
Co-reporter:Lina Zhao, Xixi Cai, Shunli Huang, Shaoyun Wang, Yifan Huang, Jing Hong, Pingfan Rao
International Dairy Journal (January 2015) Volume 40() pp:16-23
Publication Date(Web):1 January 2015
DOI:10.1016/j.idairyj.2014.08.013
A tripeptide peptide with strong calcium-binding capacity was isolated and purified from whey protein hydrolysates using diethylaminoethyl cellulose anion-exchange chromatography, Sephadex G-25 gel filtration, semi-preparative reversed-phase (RP) high-performance liquid chromatography (HPLC) and analytical HPLC. It was identified using liquid chromatography-electrospray ionisation mass spectrometry and shown to have a molecular mass of 396.98 Da with the confirmed amino acid sequence Tyr-Asp-Thr. The calcium-binding capacity of Tyr-Asp-Thr reached 79.5 μg mg−1, an increase of 134% compared with the unpurified hydrolysate complex. The characteristics of the Tyr-Asp-Thr-Ca chelate were investigated, indicating that the major binding sites included oxygen atom of the carbonyl group and nitrogen of amino group or imino group; structural modifications of the peptide arose with the addition of calcium ion. The findings suggest the potential of peptide-calcium chelates as dietary supplements.
Co-reporter:Shaoyun Wang
Trends in Food Science & Technology (January 2010) Volume 21(Issue 1) pp:52
Publication Date(Web):1 January 2010
DOI:10.1016/j.tifs.2009.08.004
Co-reporter:Jinhong Wu, Jun Wang, Shaoyun Wang, Pingfan Rao
International Journal of Biological Macromolecules (August 2016) Volume 89() pp:717-724
Publication Date(Web):1 August 2016
DOI:10.1016/j.ijbiomac.2016.04.092
A novel lectin with a molecular mass of 24.3 kDa, designated Lunatin, was isolated from edible seeds of Phaseolus lunatus billb. The purification scheme consisted of ammonium sulfate precipitation, affinity chromatography, ion exchange chromatography, and gel filtration chromatography. The lectin is a glycoprotein, as determined by staining with periodic acid-Schiff (PAS), and its N-terminal amino acid sequence was determined to be DAVIYRGPGDLHTGS. Lunatin exhibited hemagglutinating activity towards human blood group A erythrocytes, which was mostly preserved up to 50 °C and retained at ambient temperature at pH 2.0–11.0. d-fructose, d-galactose, d-glucose, and mannitol were capable of inhibiting its hemagglutinating activity. Lunatin was found to be a metal-dependent protein, as its activity was inhibited by the metallic compounds K2Cr2O7, SnCl2, and LiCl, though it was unaffected by MgCl2, ZnCl2, BaCl2, CuCl2, FeCl3, or CaCl2. In addition, Lunatin exerted potent antifungal activity toward a variety of fungal species, including Sclerotium rolfsii, Physalospora piricola, Fusarium oxysporum, and Botrytis cinerea. Finally, proliferation of K562 leukemia cells was strongly inhibited by Lunatin, with an IC50 of 13.7 μM, whereas HeLa and HepG2 cells were only weakly affected. These findings further the identification and understanding of functional factors in edible plant seeds.
