OTOLARYNGOLOGY-HEAD AND NECK SURGERY
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2023
·
IF 3.4
Zhe Chen,Jia-Yu Zhang,Qian Jiang,Yang-Yang Bao,Zhi-Mei Li,Shui-Hong Zhou,Jiang-Tao Zhong,Zi-Ming Fu,Zai-Zai Cao,Jun Fan,Hong-Tian Yao
Objective To investigate the role of H + /K + ATPase in the proliferation of pepsin-induced vocal cord leukoplakia (VCL) cells. Study Design Translation research. Setting Affiliated Hospital of University. Methods Immunohistochemistry was used to detect pepsin, H + /K + ATPase (ATP4A and ATP4B subunits) in VCL cells with varying degrees of dysplasia. After primary cultures of VCL cells had been established, the effects of acidified pepsin on the proliferation, autophagy, and H + /K + -ATPase distribution of VCL cells were investigated. Results The levels of pepsin, ATP4A, and ATP4B were significantly higher in VCL tissue with moderate-to-severe dysplasia than in normal tissue ( p < .05); these levels gradually increased according to dysplasia severity. The expression levels of ATP4A and ATP4B were significantly correlated with the amount of pepsin in VCL cells ( p < .01). Acidified pepsin enhanced the levels of proliferation and autophagy in human VCL epithelial cells. The cloning- and autophagy-promoting effects of acidified pepsin on VCL cells were partially reversed by pantoprazole; these effects were completely blocked by the autophagy inhibitor chloroquine. Finally, acidified pepsin promoted the colocalization of H + /K + -ATPase and lysosomes in VCL cells; it also mediated lysosome acidification. Conclusion Pepsin and H + /K + -ATPase may contribute to the progression of VCL. Specifically, acidified pepsin may regulate lysosome acidification by promoting lysosomal localization of H + /K + -ATPase.
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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
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高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2020
·
IF 4.006
Yujing Sun,Tianyuan Zhen,Yang Li,Yihui Wang,Mengwei Wang,Xiaojing Li,Qingjie Sun
With the wide applications of food-grade nanoparticles (NPs) in foods, increasing attention has been focused on the fate of NPs in the gastrointestinal tract. In this study, titanium dioxide nanoparticles (TiO 2 -NPs) were used as model NPs with the aim to investigate the interaction between NPs and pepsin in simulated gastric fluid. Transmission electron microscopy revealed the possible formation of protein corona, mainly soft corona, between TiO 2 -NPs and pepsin. With the increase in the TiO 2 -NP concentration from 0.01 to 0.05, 0.1, and 0.2 mg/mL, the fluorescence of pepsin was quenched, and its ultraviolet–visible intensity was weakened. Results indicated that TiO 2 -NPs can react with pepsin, leading to changes in the microenvironment of aromatic amino acids and a decrease in the hydrophobicity around tyrosine residues. Circular dichroism spectrum revealed that TiO 2 -NPs do not exert clear changes to the secondary structure of pepsin. However, the pepsin activity decreased within the measured concentration range.
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高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Yuanyuan Yue,Zhiyue Wang,Yanyan Zhang,Zhixian Wang,Qingzhang Lv,Jianming Liu
The use of antibacterial agents, triclosan (TCS) and triclocarban (TCC), in personal care products can result in direct human exposure. Density Functional Theory (DFT) was utilized to evaluate the electronic properties of TCS and TCC, and the determined energetically accessible transitions across the HOMO-LUMO gap. Choosing pepsin as a model protein, we explored the binding effects of TCS or TCC on pepsin by molecular docking and dynamic simulations. Titration of pepsin with TCS or TCC at pH 2.2 led to quenching of the pepsin intrinsic fluorescence via formation of a ground-state complex. The binding constants of the TCS/TCC-pepsin complexes, determined at 296 K, were (7.053 ± 0.030) × 10 4 M −1 and (6.233 ± 0.060) × 10 4 M −1 , respectively. Analysis of the thermodynamic properties of each system at various temperatures demonstrated that the binding reaction is a spontaneous process driven by hydrophobic interactions. The spectroscopic results revealed that changes in the secondary structure of pepsin are induced by TCS or TCC. The thermal stability of pepsin was evaluated, and no change in thermal stability was observed upon substrate binding. However, the binding of either TCS or TCC to pepsin effectively reduced the activity.
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高影响因子
JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY
·
2026
·Vol. 40
·期 4
·e70788
·
IF 3.6
Ran Yu,Rong Shen,Liang Chen,Peng Li
The hydrolysis of proteins by pepsin is of great significance for the biological utilization of proteins and the discovery of functional peptide molecules. Bovine serum albumin (BSA) and bovine collagen I (BCI) are both commonly used natural source proteins for studying the hydrolysis characteristics of pepsin. UHPLC − MS/MS, peptidomics, and molecular docking technologies were employed to investigate the underlying mechanism responsible for the inhibitory effect of ofloxacin on pepsin. The molecular weight distribution of peptides produced by pepsin in this study was mostly in the range of 600 Da to 1800 Da, and peptide segments were mostly composed of 9−11 amino acids. The predominant terminal amino acids were proline, glycine, leucine, valine, serine, and threonine. Ofloxacin led to conformational changes of the hydrolysis active sites of pepsin by forming hydrogen bonds with aspartic acids. When the key aspartic acid residues in the active center of pepsin were inhibited, the numbers of peptides TPAQD, VSVDAA, TVLFD, and TVIFD were upregulated. The hydrolysis characteristics of pepsin were changed, shown as an increase in the proportion of low molecular weight peptides and a decrease in the hydrophobicity of peptide segments in the hydrolysates. The study contributed to the evaluation of the activity of peptides from homologous protein hydrolysis by pepsin and the elucidation of the inhibitory mechanism of ofloxacin on pepsin.
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高影响因子
JOURNAL OF FLUORESCENCE
·
2015
·Vol. 25
·期 2
·451-463
·
IF 1.927
Li Zhen,Li Zhigang,Yang Lingling,Xie Yuanzhe,Shi Jie,Wang Ruiyong,Chang Junbiao
In this paper, the interactions of pepsin with CYD (cytidine) or nucleoside analogs, including FNC (2′-deoxy-2′-β-fluoro-4′-azidocytidine) and CMP (cytidine monophosphate), were investigated by fluorescence, UV–visible absorption and synchronous fluorescence spectroscopy under mimic physiological conditions. The results indicated that FNC (CYD/CMP) caused the fluorescence quenching by the formation of complex. The binding constants and thermo-dynamic parameters at three different temperatures were obtained. The hydrophobic and electrostatic interactions were the predominant intermolecular forces to stabilize the complex. The F atom in FNC might weaken the binding of nucleoside analog to pepsin. Results showed that CYD was the strongest quencher and bound to pepsin with higher affinity.
研究领域:
生物化学
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结构生物学
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药物设计
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分子诊断
·
酶学
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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
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DOI
高影响因子
Food Science and Human Wellness
·
2023
·
IF 7
Jing Zhang,Di Wu,Lan Tang,Xia Hu,Zhen Zeng,Wen Wu,Fang Geng,Hui Li
Phlorizin (PHL) is a natural compound with strong antioxidant properties mainly found in apples. In this paper, the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation, fluorescence spectra, circular dichroism (CD), and fourier transform infrared (FT-IR) spectra at a molecular level. Fluorescence spectra showed that PHL quenches the pepsin/trypsin by static quenching. Thermodynamic parameters indicated that PHL binds to pepsin mainly through hydrogen bonds and van der Waals forces, and that of trypsin was electrostatic forces. The ground state complexes PHL and protease have a moderate affinity of 10 5 L/mol PHL binds more strongly to trypsin than to pepsin. CD and FT-IR spectra results showed that pepsin/trypsin decreased the β -sheet content and slightly changed its secondary structure upon PHL. These experimental results are mutually verified with the predicted computer-aid simulation results. Upon PHL and trypsin binding, the antioxidant capacity of PHL was elevated. Nevertheless, the antioxidant capacity of PHL was decreased after binding to pepsin. This work elucidates the binding of PHL binding mechanisms to pepsin/trypsin and provides useful information for the digestion of PHL to improve the application of PHL in food processing.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2022
·
IF 3.318
Pandeng Miao,Liu Zhang,Jian Zhang,Mingxuan Ma,Yingxiang Du,Jie Gan,Jiangxia Yang
Metal-organic frameworks (MOFs), defined as a class of microporous hybrid materials, are established by coordination of metal cations with functional organic ligands. In addition to outstanding porosity and large surface area, the structures and functions of MOFs can be designed and adjusted based on different destinations, which would be employed as stationary phases in various chromatographic modes. Pepsin, a class of protein, has been investigated as chiral selector owing to their unique interactions with analytes based on chiral or affinity selectivity. In this work, MOF-5 was exploited to grow on the support of poly (glycidyl methacrylate)–co-(ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths by layer-by-layer self-assembly method. Pepsin was subsequently bonded with the carboxyl group of MOF-5 through amidation reaction. The ultimate pepsin@MOF-5@poly(GMA-co-EDMA) column was applied for enantioseparation of six basic chiral drugs by capillary electrochromatography with good resolution and repeatability. Compared with the pepsin modified monolithic column, the newly prepared column with MOF-5 shows significantly enhanced enantiomeric resolution, which reveals that MOFs-modified capillary monolithic columns lead a promising road to separation of racemates by chromatography.
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 9
·2549-2557
·
IF 2.482
Wang Yun,Chen Xin-Yi,Liang Xin-Yi,Liang Zhi-Hui,Cheng Hong,Li Xiang,Li Li-Ling
Abstract Pepsin was found to catalyze asymmetric cross aldol reactions of aromatic and polycyclicaromatic aldehydes with cyclic ketones in ionic liquids and deep eutectic solvents for the first time. Pepsin exhibited high catalytic activity and excellent stereoselectivity in ionic liquids and deep eutectic solvents in the presence of moderate water. High yields of up to 93.1%, excellent enantioselectivities of up to 96% ee, and good diastereoselectivities of up to 5:95 dr were achieved. Graphic Abstract
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高影响因子
MEDICINAL CHEMISTRY RESEARCH
·
2018
·Vol. 27
·期 5
·1549-1557
·
IF 1.607
Liu Ting,Chen Xiaopeng,Xing Jinfeng,Ge Zhiqiang
The changes in activities and conformations of pepsin and trypsin induced by acetazolamide (ACZ) were studied with spectroscopic methods under their respective physiological pH conditions in vitro. The results showed that both the enzymes activities were obviously inhibited as increasing in acetazolamide concentration, while the inhibitory ratio of trypsin was higher than pepsin. The intrinsic fluorescence of the two enzymes was quenched by acetazolamide through static process. Acetazolamide bound trypsin in a more firmly way than pepsin. Thermodynamic analysis revealed that driving force of acetazolamide-pepsin was different from acetazolamide-trypsin. The electrostatic interaction had a significant effect on the binding process of acetazolamide-trypsin, whereas interaction of the acetazolamide-pepsin was driven by hydrogen bonding and van der Waals force. Circular dichroism spectroscopy and synchronous fluorescence showed acetazolamide induced conformational and microenvironmental changes of both the enzymes. These investigations suggested that acetazolamide at different physiological pH may have different effects on the conformations and functions of proteins through variant mechanisms. This study is helpful for understanding the changes in the function and structure of digestive enzymes influenced by acetazolamide in gastrointestinal tract in vivo.
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Analytical Methods
·
2019
·Vol. 11
·期 18
·2465-2472
·
IF 2.378
Yuefen Zhang,Yuying Wang,Yixia Tang,Ruijun Li,Yibing Ji
As pepsin is one of the most important enzymes in the digestive system and is closely related to several diseases, an online system was developed to study the kinetics of pepsin and screen inhibitors from natural products. In the present study, pepsin was immobilized onto an organic polymer monolith with glutaraldehyde as the linker. Both the immobilization and electrophoresis conditions were optimized to improve the performance of the immobilized enzyme reactor (IMER). The as-prepared IMER showed good reusability as it retained 95.9% of the relative activity after 40 repeated runs. As for the storage stability, it only lost 15.1% of its initial activity after 36 days of storage at 4 °C without other use. Moreover, the Michaelis–Menten constant (Km) of the immobilized pepsin was determined to be 0.51 mmol L−1. Eventually, the developed system was applied to screen pepsin inhibitors from 9 natural products.
研究领域:
生物化学
·
药学
·
分析化学
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高影响因子
危险品化学品经营许可证（带存储）