JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2013
·
IF 2.906
Dong-Fang Li,Hao-Chen Ding,Tao Zhou
A commercially available trypsin–chymotrypsin mixture was covalently immobilized onto modified polyvinyl chloride (PVC) microspheres, which were activated by the subsequent treatment of PVC microspheres with ethylenediamine and glutaraldehyde. The immobilized mixed protease was characterized by FT-IR and SEM analyses. Immobilization conditions were optimized by Box–Behnken design and the response surface method. The activity of the immobilized mixed protease prepared under optimal conditions (pH 6.6, 23 °C, 2 h) reached 1341 U/g. Compared with the free form, the immobilized enzyme possesses a slightly higher optimal pH value and a wider pH-activity profile, superior thermal stability, and a higher Km value. Reusability of the immobilized mixed protease indicated that >70% of the original activity was retained after having been recycled six times.
研究领域:
生物化学
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Yanqing Wang,Qianqian Han,Gencheng Zhang,Hongmei Zhang
In this work, the effects of I 2 on the activities and conformational structures of digestive enzymes, trypsin and pepsin were studied. The results indicated that the enzyme activities were decreased to some extent in the presence of I 2 , especially trypsin. Upon gradual addition of I 2 , the intrinsic fluorescence quenching of trypsin and pepsin were observed by mainly static collision and hydrophobic forces . I 2 is more likely to cause the fluorescence quenching of trypsin than that of pepsin. Compared with pepsin, trypsin has a greater ability to bind with I 2 . The synchronous fluorescence spectral results indicated that I 2 induced the quaternary structure changes of trypsin/pepsin and changed the hydrophobicity of Tyr and Trp residues . In addition, molecular docking was used to obtain the binding mode and the various amino acid residues of trypsin and pepsin with I 2 . These investigations may constitute a solid work to further explain the process of migration and transformation of I 2 in digestive system.
研究领域:
生物化学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2014
·
IF 3.107
Yan-Qing Wang,Hong-Mei Zhang
The effects of bisphenol S on the structures and activities of trypsin and pepsin were investigated by various methods like UV–visible absorbance, fluorescence, circular dichroism, and molecular docking. The secondary and tertiary structures of trypsin and pepsin were altered by bisphenol S binding, which resulted in the loosening of the skeletons of trypsin and pepsin. In addition, bisphenol S induced microenvironmental changes around tyrosine and tryptophan residues of trypsin and pepsin. The activity experimental results showed that the activity of pepsin decreases obviously with the increasing concentration of BPS, while the activity of trypsin does not change remarkably. The binding and thermodynamic parameters obtained by molecular docking and fluorescence spectroscopy showed that the bindings of bisphenol S to trypsin and pepsin were spontaneous processes and hydrogen bonding and hydrophobic interactions played a vital role in stabilizing the bisphenol S–trypsin and bisphenol S–pepsin complexes. The binding constants (KA) of bisphenol S with trypsin were 7.42 × 104 (298 K) and 5.91 × 104 L/mol (310 K), and those of pepsin were 5.78 × 104 (298 K) and 4.44 × 104 L/mol (310 K). Moreover, there was one main kind of binding site for bisphenol S on trypsin or pepsin.
研究领域:
生物化学
·
环境毒理学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2018
·
IF 2.831
Mengxia Cheng,Rong Wang,Baofang Zhang,Zhenkun Mao,Zilin Chen
Proteolytic digestion and peptide separation are key steps in proteomic study, which has attracted much attention. A novel immobilized trypsin microreactor based on monolithic capillary column was developed for rapid proteolytic digestion in this work. The monolithic support was prepared using itaconic acid as functional monomer within a silanized fused-silica capillary. By taking advantage of itaconic acid with two carboxylic functional groups, trypsin was covalently immobilized onto the monolithic support by condensation reaction. The performance of proteolytic digestion by the microreactor was evaluated with cytochrome C and bovine serum albumin, and the digests were further analyzed by CE and HPLC. Compared to those obtained by conventional in-solution digestion, the digestion time was shortened from 12 h to 40 s, demonstrating the high digestion efficiency of the prepared microreactor. Difference of protein separation results obtained by CE and HPLC highlighted the potential of CE in fast and highly efficient peptide separation in proteomic study. All the results demonstrated that the microreactor combined with CE could be a promising tool in workflow of proteomic analysis.
研究领域:
生物化学
·
分析化学
·
蛋白质组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2025
·
IF 4.6
Xiangrong Li,Wanqing Xu,Xianfei Liu,Zhizhi Song,Zheng Li,Zihan Jia
In this study, the interaction mechanism of papain and bromelain with apigenin and luteolin in binary and ternary systems was compared and analyzed by spectroscopic methods, molecular docking, and molecular dynamics simulation. Additionally, the effects of apigenin and/or luteolin on the conformational changes and enzymatic activity of papain and bromelain were investigated. The results show that apigenin and/or luteolin exhibit a moderate binding affinity with papain/bromelain, with the binding constants K a in the range of 10 4 –10 5 L mol −1 . The order of addition of apigenin and luteolin significantly influenced their binding affinities to the enzymes. The main non-covalent forces of the papain-luteolin (first)-apigenin ternary system are hydrogen bonds and Van der Waals forces. Hydrophobic interactions, electrostatic forces and hydrogen bonds are the main non-covalent forces of other binary and ternary systems. These systems differentially alter the microenvironment of Trp and Tyr residues, secondary and tertiary structures, and enzymatic activity. Molecular docking and dynamics simulations identified specific binding sites of apigenin and/or luteolin on papain/bromelain, corroborating experimental findings. Notably, the ternary system exhibits a stronger inhibitory effect on papain activity compared to binary systems.
研究领域:
生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2020
·
IF 4.192
Yihui Wang,Yujing Sun,Jie Yang,Lei Dai,Na Ji,Liu Xiong,Qingjie Sun
Nanoparticles (NPs) can form a protein corona (PC) with proteins in biological fluids. We examined whether starch nanoparticles (SNPs) form a PC and interact with digestive enzymes in simulated gastric and intestinal fluids. We investigated the adsorption of pepsin and trypsin on unmodified, carboxyl-, and amino-modified SNPs (SNPs, COOH-SNPs, and NH2-SNPs, respectively). Quartz crystal microbalance data showed that a tight and irreversible pepsin corona formed on the NH2-SNPs, pepsin had little or no binding to the SNPs and COOH-SNPs, and trypsin had weak binding to all three kinds of NPs. Dynamic light scattering data showed that pepsin significantly increased the size of the NH2-SNPs from 120 ± 2.6 to 203 ± 12.2 nm and decreased their surface potential from 23.2 ± 1.0 to 12.7 ± 0.2 mV. NH2-SNPs could induce the fluorescence quenching of pepsin and change its secondary structures without affecting its activity.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xiaoyun Lin,Zhenmao Zhu,Chengfei Zhao,Shaoguang Li,Qicai Liu,Ailin Liu,Liqing Lin,Xinhua Lin
In this study, we developed a simple, sensitive and label-free colorimetric sensor for trypsin and its inhibitor using oxidase mimicking activity of protamine-stabilized platinum nanoparticles units (Pro-PtNPs units). Protamine is designed to stabilize PtNPs and served as the substrate of trypsin hydrolysis. The results show that protamine combines several PtNPs together to form active units, which have stronger oxidase mimicking activity than other PtNPs. In addition, the Michaelis constant of the Pro-PtNPs units is smaller than negatively charged citrate capped PtNPs, suggesting that the positively charged Pro-PtNPs units have better affinity with 3,3′,5,5′-tetramethylbenzidine (TMB), which is inconsistent with previous reports. The protamine stabilizer could be hydrolyzed in the presence of trypsin, and the Pro-PtNPs units would be decomposed and aggregated, resulting in a decrease of catalytic activity of Pro-PtNPs units. The color of the solution would be reduced according to the decrease of catalytic activity, so the catalytic activity is linearly related to UV absorbance. The linear range of trypsin detected by this new method is 0.06 μg/mL˜0.6 μg/mL, and the detection limit down to 0.03 μg/mL. Pro-PtNPs units have been successfully applied to the determination of serum trypsin and screening of inhibitors.
研究领域:
生物化学
·
纳米医学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL SCIENCES
·
2019
·
IF 1.618
Ruru Chen,Lian Zhou,Hui Yang,Hailing Zheng,Yang Zhou,Zhiwen Hu,Bing Wang
The degradation behavior of silk fibroin (SF) is a significant and intriguing subject in the area of archaeological ancient silk research. In the present study, the immunological detection techniques combined with traditional characterization methods, jointly studied the degradation process of SF from Bombyx mori (B. mori) and Antheraea pernyi (A. pernyi) through exposure to alkaline proteinase, α-chymotrypsin, pepsin, and trypsin. Spectroscopic analysis revealed that different enzymes showed similar hydrolysis effects on the secondary structure, but the changes of B. mori SF and A. pernyi SF were mainly reflected in the decrease of β-sheet and the reduction of α-helical structure, respectively. In further research of immunology, two diagnostic antibodies were prepared corresponding to SF of B. mori and A. pernyi, respectively. The enzyme-linked immunosorbent assay (ELISA) and western blot indicated the enzyme-treated SF proteins still exhibited higher immunoreactivity because the epitopes on the surface of SF molecules are retained. Although α-chymotrypsin possesses the most cleavage sites among these enzymes, the α-chymotrypsin-treated SF did not exhibit significant changes in secondary structures and high antibody binding capacity. The results deepen our understanding of the SF degradation process during enzymatic hydrolysis, and show far-reaching guiding significance in trace detection of SF.
研究领域:
考古学
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材料科学
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生物化学
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免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2021
·
IF 5.645
Huan Wang,Chao Lei,Yunhang Zeng,Ying Song,Qixian Zhang,Bi Shi
Trypsin is used to remove non-collagenous proteins from cattle hide in leather processing but prone to damage hide surface and reduce leather quality due to its rapid protein hydrolysis action on the hide surface and slow penetration through the whole hide. A novel trypsin bating method was developed using a reversible inhibition of trypsin with high-yield, low-cost and environment-friendly soybean flour (SF). When the mass ratio of trypsin to SF was 1:20, the trypsin activity was decreased by 77 % at a reaction time of 5 min and completely returned in 100 min because of the competitive Kunitz trypsin inhibitor in SF. Bating with trypsin-SF mixture avoided the damage to hide surface caused by trypsin, improved the dispersion uniformity of hide collagen fibers and increased the softness and the mechanical strength of leather. This work exhibits huge potential for improving the leather quality and provides new insights into the soybean application.
研究领域:
生物化学
·
皮革加工
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Yumeng Guo,Liangbo Xu,Weifeng Lin,Shengfu Chen
Nonspecific protein adsorption-resistant materials, the so-called nonfouling materials, are crucial biomaterials in biomedical applications. Up-to-date, little attention was paid to the biodegradability of these materials. In this work, nonfouling zwitterionic copolymerized peptides composed of the N-l-glumatyl-l-lysine dimer (EK) and δ-l-lysinyl-l-glutamic acid dimer (E-K, glutamic acid with the lysine side chain) at various ratios were synthesized to investigate the enzymatic degradation rate. Two types of proteases (trypsin and alkaline protease), which represent a site-specific and less site-specific cleavage protease, respectively, were used to demonstrate the adjustable degradability by tracking the molecular weight (Mw) at different digestion times. Results showed that higher compositions of the E-K dimer lead to slower degradation rates by both proteases and larger fragments after 120 min digestion. With the composition of the E-K dimer over 50%, the degradation of copolymerized peptides by both proteases becomes very slow. This indicated that the bulky lysinyl side chain on E-K can alter the enzymolysis process for adjusting the enzymatic degradability of the newly synthesized zwitterionic copolymerized peptides, which could be promising candidates for biomedical applications in vivo.
研究领域:
生物材料
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生物医学工程
·
高分子化学
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 21
·3472
·
IF 4.7
Jia Li,Yuxin Liu,Huanhuan Yang,Luyun Cai,Wenqian Nong,Weiliang Guan
Water-free transportation (WFT) causes shrimp (Penaeus vannamei) flesh quality deterioration. However, the roles of endogenous protease-induced protein hydrolysis have been neglected in the research. In the present study, calpain zymography, gelatinase zymography, the hematoxylin–eosin staining method, and other methods were applied to investigate the response of various endogenous proteases (cathepsin, calpain, and gelatinase), the myofibril fragmentation index (MFI), and the microscopic morphology of shrimp muscle during WFT in comparison with the shrimp under the conventional water transportation strategy (WT). The results showed that the total activity of proteases in shrimp muscle increased significantly (p≤ 0.05) after simulated transportation. Cathepsins and gelatinases were activated during WFT. No significant (p> 0.05) changes of the activity of caspase-3 and the muscle cell apoptosis rate were detected in shrimp muscle cells after WFT. In addition, the MFI increased and the gap among muscle fiber bundles enlarged after WFT. Compared with WFT, no significant (p> 0.05) effect on the activities of calpain, gelatinase, and caspase-3 in the muscle of shrimp was found after WT, and only the activity of cathepsin L significantly increased (p≤ 0.05). Based on the findings, we concluded that the activation of various endogenous proteases was induced during WFT.
研究领域:
水产养殖
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蛋白质组学
·
食品科学
·
动物生理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Ge Ge,Jie Zhao,Jiabao Zheng,Mouming Zhao,Weizheng Sun
This study aimed to investigate the effect of tea polyphenol extract (TPE) on the in vitro gastric digestion of soymilk. Fluorescence recovery after photobleaching was applied to measure pepsin diffusivity in soymilk. The characteristics of soymilk digesta were evaluated by gel electrophoresis, degree of hydrolysis (DH), molecular weight distribution, free amino acid analysis, particle size, antioxidant capacity, and trypsin/chymotrypsin inhibitor activity (TIA/CIA). The binding between soy proteins and tea polyphenols could significantly impair in vitro gastric digestion of soymilk by decreasing pepsin diffusivity from 91.3 to 70.3 μm2/s and DH from 17.13 to 13.93% with 1.2 mg/g TPE addition. Soymilk with 0.6 mg/g TPE addition exhibited low TIA/CIA and a strong antioxidant capacity in gastric digesta, which might be good for the following intestinal digestion. A better understanding of the effect of polyphenol on the digestion of protein-based food may be beneficial to innovation in food manufacturing.
研究领域:
食品科学
·
营养学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）