FOOD CHEMISTRY
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2026
·
IF 10.4
Yin Yang,Kaize Ju,Junqiao Zhou,Qun Sun,Shiwei Jin,Shenghua Zhang,Laiyan Wu
BHT and its metabolites (BHT-OH, BHT-COOH) form stable complexes with pepsin via static quenching. • Hydrogen bonding and van der Waals forces are the primary driving forces for BHT derivatives-pepsin binding. • BHT derivatives induce conformational changes in pepsin and inhibit its activity in a dose-dependent manner. • Functional groups differentially regulate binding affinity and inhibitory potency: hydrophilic groups (-OH, -COOH) enhance binding affinity but reduce inhibitory potency, whereas hydrophobic groups (-CH₃, tert-butyl) weaken binding affinity but strengthen inhibitory potency. Butylated hydroxytoluene (BHT) is a synthetic phenolic antioxidant extensively used in food. Given the increasing biosafety concerns regarding BHT and its metabolites (BHT-OH and BHT-COOH), their interactions with pepsin were systematically investigated using multispectral techniques, molecular docking, and simulation methods. Fluorescence analysis indicated static quenching and stable complex formation, with binding affinities following the order BHT-OH > BHT-COOH > BHT. Hydrogen bonding and van der Waals forces dominated the interactions, and the carboxyl group of BHT-COOH contributed additional hydrogen bonds. Binding induced conformational changes in pepsin, altered the microenvironment of tryptophan residues, and resulted in dose-dependent inhibition of enzymatic activity. Meanwhile, the binding also significantly reduced the radical scavenging and reducing capacity of BHT and its metabolites. These findings highlight the critical role of functional group substitution in modulating gastrointestinal interactions and potential health risks of these compounds.
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高影响因子
Journal of Food Measurement and Characterization
·
2025
·
IF 3.3
Lv Junli,Ren Zhilong,Niu Jianjiao,Lian Guohua
Pepsin is a crucial digestive enzyme in the human body. However, its hyperactivity can readily contribute to the development of gastrointestinal disorders. Research has indicated that certain phenolic acids can bind to pepsin, thereby attenuating its activity, which may be affected by the molecular weight and conformation of phenolic acids. Nonetheless, there are few reports in the literature regarding comparative studies on the inhibition of pepsin by various phenolic acids. Hence, three phenolic acids—ferulic acid, chlorogenic acid, and gallic acid—were selected for investigation in this study. A combination of spectroscopic experiments, molecular docking simulations, and antioxidant tests were employed to elucidate the interactions and mechanisms between these phenolic acids and pepsin. The findings demonstrated that the interaction between the three phenolic acids and pepsin occurred via a static quenching mechanism. Notably, chlorogenic acid exhibited the most pronounced impact on the fluorescence of pepsin. At temperatures of 298 K and 310 K, the fluorescence intensity of pepsin was reduced by 75.23% and 76.17% at a concentration of 0.6 × 10 −3 mol/L, respectively. Furthermore, thermodynamic parameter analysis indicated that the interaction between the polyphenols and pepsin was a spontaneous process, primarily driven by van der Waals forces and hydrogen bonding interactions. Molecular docking results corroborated the thermodynamic analysis, highlighting hydrogen bonding as the predominant force. Through an analysis of binding free energy, it was determined that the binding affinity of phenolic acids to pepsin follows the order: chlorogenic acid > gallic acid > ferulic acid. Furthermore, upon interaction with pepsin, the DPPH radical scavenging activity of these phenolic acids was diminished. The findings of this study may enhance the understanding of the health implications of phenolic acids in future research.
研究领域:
生物化学
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分子生物学
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食品科学
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药物研究
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计算化学
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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
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药学
·
分析化学
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2022
·
IF 6.633
Yuanyuan Yue,Qimin Tu,Yiying Guo,Yunting Wang,Yue Xu,Yilin Zhang,Jianming Liu
In this work, the binding affinity of fanetizole with proteases pepsin and trypsin were investigated by spectroscopy and molecular docking. As a thiazole derivative, the interactions of fanetizole with either pepsin or trypsin resulted in a fluorescence quenching. As such, the calculated values of K manifested that the fanetizole-pepsin system has a stronger binding affinity than fanetizole-trypsin at 296 K. Moreover, steady-state, time-resolved fluorescence and thermodynamic studies of the interaction of fanetizole with pepsin or trypsin suggested that a static fluorescence quenching mechanism and the interactions were primarily attributed to hydrogen-bonding interaction. The observed changes in synchronous fluorescence, circular dichroism spectroscopy, and FTIR results were related to the secondary construction alternations of both proteases. In line with fluorescence spectroscopy, molecular docking demonstrated similar binding characteristics and domains. The range of r values showed energy transfer from pepsin/trypsin to fanetizole.
研究领域:
生物化学
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药理学
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分子生物学
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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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
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分子生物学
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2026
·
IF 8.7
Bingqian Zhou,Yin Yang,Renshun Zeng,Kaize Ju,Jiayin Li,Jingjing Hu,Ke Chen,Shiwei Jin,Laiyan Wu
PPDs caused static fluorescence quenching of PEP. • PPDs alter the microenvironment and hydrophobicity of amino acid residues in PEP. • PPDs bind to PEP via hydrophobic interactions and hydrogen bonds. • N-substituent structural variations may affect PEP binding and subsequent functional effects. Herein, the interaction mechanisms between pepsin (PEP) and two p -phenylenediamine derivatives, DPPD and CPPD, were investigated via multi-spectroscopic, computational, and enzymatic methods. UV–vis absorption spectroscopy, fluorescence spectroscopy, and time-resolved fluorescence confirmed the formation of ground-state complexes with a static quenching mechanism. Binding constant analysis revealed a stronger, more endothermic, and entropy-driven binding of CPPD compared to DPPD, primarily driven by hydrophobic forces. Both compounds induced secondary structural changes in PEP, evidenced by an increase in β-sheet and a decrease in α-helix. Crucially, DPPD and CPPD exerted distinct effects on PEP conformation. Molecular dynamics simulations showed DPPD binding stabilized PEP's structure while CPPD increased its flexibility. Molecular surface electrostatic potential (MESP) analysis rationalized these differences: CPPD's more polarized and extensive electrostatic field, stemming from its asymmetric cyclohexyl substituent, fostered stronger interactions but greater structural perturbation. These structural changes provided a direct rationale for the observed inhibition of PEP's enzymatic activity, where DPPD, despite weaker overall binding, induced specific active-site changes causing more pronounced inhibition. The antioxidant activities of both ligands decreased upon complexation. This study elucidates how subtle ligand structural differences dictate binding modes and functional outcomes in protein-ligand systems.
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高影响因子
MEDICINAL CHEMISTRY RESEARCH
·
2016
·Vol. 26
·期 2
·405-413
·
IF 1.436
Wang Jie,Chan Calvin,Huang Feng-wen,Xie Jiang-feng,Xu Hong,Ho Ka-wai,Zheng Sheng-gang,Hu Zhang-li,Lu Jun,He Zhen-dan
The interaction of gastrodin with pepsin has been investigated by enzyme activity assay, fluorescence, UV–Visible, circular dichroism spectra, and molecular docking. The pepsin activity results suggest that gastrodin is an inhibitor of pepsin. The fluorescence experiments show that gastrodin can quench the fluorescence of pepsin via a static quenching process. The thermodynamic analysis suggests that hydrophobic interaction is the main force between pepsin and gastrodin. UV–Visible and circular dichroism spectra studies suggest that the binding of gastrodin leads to a loosening and unfolding of pepsin backbone with partial α-helix being transformed into β-sheet. All these experimental results have been validated by docking studies, which further show that besides hydrophobic interaction, hydrogen bond also help stabilize the gastrodin–pepsin complex. The results reveal the potential to develop the natural compound gastrodin for the treatment of diseases related to the excessive activity of pepsin.
研究领域:
生物化学
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药物化学
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2018
·
IF 4.513
Rui Li,Yunkang Chang,Yuran Zhang,Xiang'e Chen,Youshuang Zhu
The foam-induced enzyme denaturation , which often results in a large activity loss, is a common phenomenon in foam fractionation of enzymes. To reduce it effectively, we used a Tween 20-containing antifoaming agent to assist the renaturation of the enzyme molecules adsorbed at the gas-liquid interface during defoaming with pepsin as a model enzyme. We studied the roles of the antifoaming agent and its ingredients in renaturation of the adsorbed pepsin molecules. The results show that during defoaming, Tween 20 in the antifoaming agent was able to assist the adsorbed pepsin molecules to restore their native structures as soon as they were desorbed from the gas-liquid interface. The other ingredients, including polydimethylsiloxane, polyether L61 and aluminum silicate, did not affect the pepsin structure during defoaming. However, they enhanced the Tween 20-assisted renaturation of the adsorbed pepsin molecules by increasing the defoaming efficiency. Furthermore, the separation of the antifoaming agent from pepsin in the foamate had no significant effect on its specific activity. When the addition amount of the antifoaming agent in the foamate was 15.0‰ ( v / v ), almost all the adsorbed pepsin molecules were reactivated. Therefore, the foam-induced pepsin denaturation was reduced effectively without any changes of the foam fractionation process itself. The results are important to improve the performances of foam fractionation of enzymes.
研究领域:
生物化学
·
酶工程
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高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2017
·
IF 3.255
Shujuan Xu,Rongzhen Mo,Can Jin,Xiaoqin Cui,Ruihan Bai,Yibing Ji
In this study, a novel mesoporous silica nanoparticles incorporated chiral hybrid monolithic stationary phase was developed. The stationary phase was firstly prepared by an in situ copolymerization of amino-modified mesoporous silica nanoparticles (NH 2 -MSN), glycidyl methacrylate (GMA), and ethylene dimethacrylate (EDMA) and then functionalized with pepsin as chiral selector. The incorporated mesoporous silica nanoparticles provided additional interactions sites, and in turn yielded different enantioselectivity thus enhancing the overall separation. The column was successfully employed for enantioseparation of fifteen basic chiral drugs in capillary electrochromatography. Effects of nanoparticles percentage, pepsin concentration, the pH of running buffer and the applied voltage were investigated. All the analytes could be eluted in less than ten minutes and nine of them could achieve baseline separation. Satisfactory repeatabilities with relative standard deviations less than 4.2% were achieved through intraday, interday, column-to-column and batch-to-batch investigations. These results indicated that the simultaneous utilization of the unique properties of mesoporous silica nanoparticles and versatile features of monoliths could be a promising strategy for enantioseparation.
研究领域:
分析化学
·
生物医学工程
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BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2026
·
IF 2.5
Zhongguang Lu,Xuan Wang,Yanran He,Hua Zeng,Chengwei Zhou,Yexun Liu,Ziyi Huang,Qimeng Fan
Betulinic acid (BA) is a naturally occurring pentacyclic triterpenoid with diverse pharmacological activities. This study systematically investigated the binding mechanisms of BA with pepsin (PEP), trypsin (TRY), and α-chymotrypsin (CHY). Steady-state and synchronous fluorescence, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, molecular docking, and molecular dynamics (MD) simulations were employed to characterize the interactions, fluorescence quenching, and conformational changes. BA quenched the intrinsic fluorescence of all three enzymes in a concentration- and temperature-dependent manner; PEP underwent dynamic quenching, whereas TRY and CHY exhibited static or mixed-mode quenching. Binding analyses revealed a single dominant site on each enzyme, with the highest affinity observed for CHY. Thermodynamic analysis indicated that hydrophobic interactions predominantly drove BA–PEP binding, whereas electrostatic interactions and hydrogen bonding were critical for BA–TRY and BA–CHY complexation. FTIR confirmed that BA bound to all three enzymes via synergistic hydrogen bonding and hydrophobic interactions, inducing secondary structural alterations. Molecular docking revealed that BA stably occupied the active sites of each enzyme, forming enzyme-specific binding modes. MD simulations (RMSD, Rg, SASA, hydrogen bond analysis, and MMPBSA) validated the dynamic stability of the complexes, with binding free energies of −13.90, −20.14, and −23.08 kcal/mol for BA–PEP, BA–TRY, and BA–CHY, respectively, consistent with the experimental affinity trend. These findings elucidate the molecular mechanisms by which BA modulates digestive proteases, providing insights into its gastrointestinal behavior and bioactivity.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Junqiao Zhou,Jiayin Li,Lan Ma,Cong Cheng,Hao Liu,Laiyan Wu
In this study, the interactions between butylated hydroxytoluene (BHT) and its metabolite 2,6-Di-tert-butyl-p-benzoquinone (BHT-Q) with pepsin (PEP) were explored using multispectral measurements and computer prediction techniques. UV–vis absorption spectra, fluorescence lifetime, and Stern-Volmer quenching analysis showed static fluorescence quenching of PEP by BHT/BHT-Q. Negative thermodynamic parameters indicated that the spontaneous formation of complexes was primarily driven by van der Waals (vdW) forces and hydrogen bonds (HB). Synchronous fluorescence and circular dichroism spectroscopy revealed conformational changes induced by BHT/BHT-Q on PEP. Furthermore, BHT and BHT-Q inhibited PEP's enzymatic activity, while PEP suppressed their antioxidant activity. Interestingly, BHT-Q weakened BHT's binding strength to PEP, affecting the enzyme inhibition rate. Computer predictions highlighted the integral role of hydrophobic interactions. Moreover, BHT and BHT-Q exhibited different effects on the stability and compactness of PEP, the residue environment of PEP became more flexible or rigid in the presence of BHT and BHT-Q. Changes in the hydrophobic solvent accessible surface area (SASA) elucidated that the microenvironment of hydrophobic residues of PEP was changed after binding with BHT and BHT-Q. Ultimately, BHT's stronger binding affinity to PEP than BHT-Q was attributed mainly to its larger negative surface area, facilitating interactions with more amino acid residues.
研究领域:
生物化学
·
分子生物学
·
光谱学
·
计算化学
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DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2015
·
IF 2.353
Yan-Qing Wang,Hong-Mei Zhang
A comprehensive study of the effects of C.I. Food Red 9 on the conformation and activity of pepsin was performed using multi-spectral methods and molecular docking technique. Fluorescence and circular dichroism spectral analyzes showed that C.I. Food Red 9 binding induced the changes of secondary and tertiary structure of pepsin. The activity experimental results indicated that the activity of pepsin decreased remarkably with the increasing concentration of C.I. Food Red 9. Multi non-covalent interactions including hydrogen bonds, hydrophobic, and electrostatic forces played important roles in the complex formation between C.I. Food Red 9 and pepsin. The binding constants of pepsin with C.I. Food Red 9 were (1.21 ± 0.036) × 10 4 L mol −1 (298 K) and (1.05 ± 0.043) × 10 4 L mol −1 (310 K). Moreover, the putative binding site of C.I. Food Red 9 on pepsin was near to activity pocket. This study demonstrates that C.I. Food Red 9 could cause some negative effects on pepsin.
研究领域:
食品化学
·
生物化学
·
光谱分析
·
分子模拟
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DOI
高影响因子
危险品化学品经营许可证（带存储）