JOURNAL OF MOLECULAR STRUCTURE
·
2019
·
IF 2.12
Xiaopei Wang,Yuanyuan Yue,Yanyan Zhang,Zhiyue Wang,Jianming Liu,Qinghu Tang
The use of the pesticide imidacloprid can be hazardous to human health. In this work, the impacts of imidacloprid on the secondary structure of pepsin were investigated through spectroscopic techniques and simulation studies. One binding site for pepsin with strong affinity was evident from changes in the fluorescence emission spectra of pepsin in the presence of imidacloprid. Calculated thermodynamic parameters based on the van't Hoff relationship indicate the predominance of hydrophobic and hydrogen bonding interactions contributing to the imidacloprid-pepsin complex. Structural changes in pepsin were also evident from changes in the UV, FTIR , CD , three-dimensional fluorescence (3D), and synchronous fluorescence spectroscopy (SFS) of pepsin upon titration with imidacloprid. Furthermore, density functional theory (DFT) calculations and molecular docking studies revealed predominant binding of imidacloprid in the hydrophobic pocket of pepsin.
研究领域:
生物化学
·
毒理学
·
计算生物学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Qian Zhang,Mingyuan Li,Cui Liu,Yutong Li,Yu Guo,Hanlu Jiang,Jie Liu,Min Hong
The antimicrobial, anticancer, and anti-SARS-CoV-2 activities of cepharanthine (CEP) combined with luteolin (Lut) were compared and analyzed by in vitro bioactivity experiment and molecular docking. CEP shows stronger biological activity than Lut, and their combination shows synergism without antagonism, especially in the fungal inhibition and anticancer activity experiments. It is believed that the antiviral activity is still effective confirmed by the simulation between two drugs and anti-SARS-CoV-2. Further, pepsin (Pep) was chosen for imitative gastroenteric environments to study its protease activity and structure effected by two drugs. The results show that the inhibitory mechanism of Lut/CEP is non-competitive inhibition, the binding mechanism is static quenching driven by enthalpy, the order of drug addition can affect the strength of binding ability, and the strength of binding ability is positively correlated with the inhibitory effect on enzyme activity. The ingestion of CEP before ingestion of Lut is more conducive to the efficient utilization of them. Their combination can not only decrease the dosage and toxicity, but also enhance the anti-inflammatory and anti-virus effects. These results can provide theoretical support for the development and utilization of Lut and CEP, and may supply one of the treatment for deal with the newly appeared viruses.
研究领域:
药理学
·
分子生物学
·
病毒学
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产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2014
·Vol. 37
·期 22
·3377-3383
·
IF 2.594
Tingting Hong,Cuijie Chi,Yibing Ji
Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday <0.53, n = 10; interday <0.53, n = 10; column-to-column <0.70, n = 20; and batch-to-batch <0.80, n = 20) indicated satisfactory stability of these columns. No appreciable change was observed in retention and resolution for chiral recognition of (±)-nefopam in 50 days with 100 injections. The proteolytic activity of this stationary phase was further characterized with bovine serum albumin as substrate for online protein digestion. As for monolithic immobilized enzyme reactor, successive protein injections confirmed both the operational stability and ability to reuse the bioreactor for at least 20 digestions. It implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation.
研究领域:
分析化学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2011
·Vol. 3
·期 2
·498-503
·
IF 0
Haoxiang Lu,Wei Wang,Zhen Zheng,Peiyu Sun,Xinling Wang,Feng-Chih Chang
Two kinds of novel peptide mimetic pepsin-inspired degradable polyurethanes were synthesized and characterized. A synthetic pseudo tripeptide acted as chain extender and provided active sites for pepsin biodegradation. In vitrodegradation behavior was investigated in simulated gastric fluid containing pepsin, and assessed by 1H NMR, mass loss and SEM. The results indicated that the pseudo peptide bonds in polyurethanes were effectively digested by the action of pepsin. Furthermore, the rate and degree of pepsin-inspired polyurethanes in simulated gastric fluid containing pepsin could be controlled by alteration of the soft segments and activity of pepsin. The influence of the polymers on human umbilical vein endothelial cells was evaluated by WST-1 assay. The results indicated that the polymers sustained much higher cell viability than the controls.
研究领域:
生物材料学
·
高分子化学
·
生物医学工程
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产品关联
DOI
Analytical Methods
·
2014
·Vol. 6
·期 17
·6789-6795
·
IF 1.938
Wei Li,Zhao Gao,Rongxin Su,Wei Qi,Libing Wang,Zhimin He
Pepsin is an active digestive enzyme present in the acidic environment of animal stomachs, and has been widely used to prepare bioactive peptides in the food industry. In this work, a simple fluorescence sensor for scissor-based detection of pepsin activity was developed by using lysozyme-stabilized gold nanoclusters (AuNCs@Lyz) in aqueous media. Under acidic conditions (pH 3.0), enzymatic digestion of AuNCs@Lyz with pepsin results in a significant decrease of fluorescence intensity. Notably, its acidic environment not only helps maintain the maximum fluorescence of gold nanoclusters, but also ensures the highest enzymatic activity of pepsin. In addition to offering high selectivity because of the unique proteolytic action of pepsin under acidic conditions, this facile method provides high sensitivity. With the sensing system, the linear range for pepsin detection is found to be 1 μg mL−1 to 100 μg mL−1, with a detection limit of 0.256 μg mL−1 at a signal-to-noise ratio of 3. Furthermore, the AuNCs@Lyz based fluorescent sensing system could find applications in highly sensitive and selective detection of pepsin in food and biological samples.
研究领域:
生物化学
·
食品科学
·
分析化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Zhe Chen,Zheng Sun,Shanxiu Ming,Shuyi Li,Zhenzhou Zhu,Wenxiang Zhang
Peptides derived from food proteins exhibit a great application potential as natural health product. Conventional enzymatic membrane reactor for peptides production bears some disadvantages, such as high membrane fouling, clear enzyme leaching, and low operational stability. Herein, the bioinspired proteolytic membrane (BPM) with bilayer pepsin structure was fabricated to produce the peptides via reverse filtration and layered immobilization (polydopamine coating and polyethyleneimine grafting). The results of Fourier transform infrared spectroscopy and Emission scanning electron microscopy found that BPM could stably form 3 different structures by various fabrication methods: monolayer reverse proteolytic membrane (MR-PM), monolayer reverse bioinspired proteolytic membrane (MR-BPM) and bilayer reverse bioinspired proteolytic membrane (BR-BPM). Besides, with the increase of enzyme layers, the enzyme loading, enzyme activity and degree of hydrolysis BPM considerably improved. Then, BR-BPM filtration tests were conducted under various operation conditions (transmembrane pressure (TMP) (1–4 bar) and pepsin concentration (0.1–0.9 mg/mL)). BR-BPM acquired the higher enzyme loading, degree of hydrolysis (DH) and permeate flux than MR-PM and MR-BPM by bilayer pepsin structure. In addition, BR-BPM demonstrated the great filtration performance (permeate flux = 6.5 L m −2 h −1 bar −1 and DH = 45.7%) for the long-term tests (four continuous filtration cycles) at the optimized condition (TMP = 3 bar and pepsin concentration = 0.5 mg/mL). This work offers a promising guideline of the fabrication of functional membrane for peptides production.
研究领域:
生物技术
·
膜科学
·
酶工程
·
食品科学
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DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 53
·34548-34556
·
IF 4.036
Youdan Duan,Haiming Cheng
In the extraction of collagens from mammalian tissues, the free pepsin used in the acid–pepsin extraction system is hard to recycle, and there is a risk of enzyme protein contamination in the extracted collagen products, which limits their applications. To solve this problem, an immobilized pepsin was successfully prepared via the covalent crosslinking of glutaraldehyde using a 3-aminopropyltriethoxysilane (APTES) surface modified silica clay as the support. The immobilized pepsin was applied for the extraction of collagen from bovine hide. The optimal immobilization process involves incubating pepsin with an initial concentration of 35 mg mL−1 and glutaraldehyde with 5% activated APTES modified silica clay at 25 °C for 60 min, by which the loading amount of pepsin was 220 mg g−1 and the activity of the immobilized pepsin was 4.2 U mg−1. The collagen extracted using acetic acid and the immobilized pepsin method retained its complete triple helix structure. This research thus details an effective separation method using pepsin for extraction of collagen via an acetic acid–enzyme method, where the extracted collagen may be a candidate for use in biomaterial applications.
研究领域:
生物化学
·
材料科学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2013
·
IF 1.977
Ruiyong Wang,Yuanzhe Xie,Yuhai Zhang,Xiaohui Kang,Xiaogai Wang,Baoyu Ge,Junbiao Chang
The interactions between pepsin and four alkaloids, including caffeine (Caf), aminophylline (Ami), acefylline (Ace), diprophylline (Dip), were investigated by fluorescence, UV–visible absorption, resonance light scattering, synchronous fluorescence spectroscopy and 3D spectroscopy under mimic physiological conditions. The results revealed that Caf (Ami/Ace/Dip) caused the fluorescence quenching of pepsin by the formation of Caf (Ami/Ace/Dip)-pepsin complex. The binding constants and thermodynamic parameters at three different temperatures, the binding locality and the binding power were obtained. The hydrophobic and electrostatic interactions were the predominant intermolecular forces to stabilize the complex. Results showed that aminophylline was the stronger quencher and bound to pepsin with higher affinity than other three alkaloids.
研究领域:
生物化学
·
药物化学
·
分子光谱学
·
生物物理化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2015
·
IF 2.858
Ming Ying,Fengwen Huang,Haidong Ye,Hong Xu,Liangliang Shen,Tianwen Huan,Shitong Huang,Jiangfeng Xie,Shengli Tian,Zhangli Hu,Zhendan He,Jun Lu,Kai Zhou
The interaction between curcumin and pepsin was investigated by fluorescence, synchronous fluorescence, UV–vis absorption, circular dichroism (CD), and molecular docking. Under physiological pH value in stomach, the fluorescence of pepsin can be quenched effectively by curcumin via a combined quenching process. Binding constant ( K a ) and binding site number ( n ) of curcumin to pepsin were obtained. According to the theory of Förster's non-radiation energy transfer, the distance r between pepsin and curcumin was found to be 2.45 nm within the curcumin–pepsin complex, which implies that the energy transfer occurs between curcumin and pepsin, leading to the quenching of pepsin fluorescence. Fluorescence experiments also suggest that curcumin is located more closely to tryptophan residues than tyrosine residues. CD spectra together with UV–vis absorbance studies show that binding of curcumin to pepsin results in the extension of peptide strands of pepsin with loss of some β-sheet structures. Thermodynamic parameters calculated from the binding constants at different temperatures reveal that hydrophobic force plays a major role in stabilizing the curcumin–pepsin complex. In addition, docking results support the above experimental findings and suggest the possible hydrogen bonds of curcumin with Thr-77, Thr-218, and Glu-287 of pepsin, which help further stabilize the curcumin–pepsin complex.
研究领域:
生物化学
·
药物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
Pharmaceutics
·
2022
·Vol. 14
·期 10
·2025
·
IF 6.525
Dejuan Wang,Jingru Shi,Chen Chen,Zhiqiang Wang,Yuan Liu
The global prevalence of antimicrobial resistance calls for the development of novel antimicrobial agents, particularly for these orally available drugs. Structural modifications of the natural antimicrobial peptides (AMPs) provide a straightforward approach to develop potent antimicrobial agents with high specificity and low toxicity. In this study, we truncated 11-amino-acids at the C-terminus of Pleurocidin, an AMP produced byPleuronectes americanus, and obtained four peptide analogues termed GK-1, GK-2, GK-3 and GK-4. Minimum inhibitory concentration (MIC) tests showed that GK-1 obtained by direct truncation of Pleurocidin has no antibacterial activity, while GK-2, GK-3 and GK-4 show considerable antibacterial activity with Pleurocidin. Notably, GK-4 displays rapid bacteriostatic activity, great stability and low hemolysis, as well as enhanced hydrolytic resistance to pepsin treatment. Mechanistic studies showed that GK-4 induces membrane damage by interacting with bacterial membrane-specific components, dissipates bacterial membrane potential and promotes the generation of ROS. SEM and CD analysis further confirmed the ability of GK-4 to resist pepsin hydrolysis, which may be attributed to its stable helicity structure. Collectively, our findings reveal that GK-4 is a potential orally available candidate to treat infections caused by multidrug-resistant pathogens.Keywords:antimicrobial resistance;AMPs;bacteria;Pleurocidin
研究领域:
微生物学
·
药学
·
分子生物学
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DOI
PubMed
高影响因子
APPLIED SPECTROSCOPY
·
2013
·
IF 1.942
Yunchang Fan,Sheli Zhang,Qiang Wang,Junhai Li,Haotian Fan,Dongkai Shan
The molecular mechanism of the interaction between pepsin and two typical ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) and 1-octyl-3-methylimidazolium chloride ([C8mim]Cl), was investigated with fluorescence spectroscopy, ultraviolet absorption, and circular dichroism spectroscopy at a pH value of 1.6. The results suggest that ILs could quench the intrinsic fluorescence of pepsin, probably via a dynamic quenching mechanism. The fluorescence quenching constants were determined by employing the classic Stern-Volmer equation. The constant values are very small, indicating that only a very weak interaction between ILs and pepsin exists. The Gibbs free-energy change, enthalpy change (ΔH), and entropy change (ΔS) during the interaction of pepsin and ILs were estimated. Positive values of ΔH and ΔS indicate that the interaction between ILs and pepsin is mainly driven by hydrophobic interaction. Synchronous and three-dimensional fluorescence spectra demonstrate that the addition of ILs (0–0.20 mol L−1 for each IL) does not bring apparent changes to the microenvironments of tyrosine and tryptophan residues. Activity experiments show that the activity of pepsin is concentration dependent; higher concentrations of ILs (>0.22 mol L−1 for [C8mim]Cl and >0.30 mol L−1 for [C4mim]Cl) cause the remarkable reduction of enzyme activity. The presence of ILs also does not improve the thermal stability of pepsin.
研究领域:
生物化学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2014
·
IF 2.129
Liangliang Shen,Hong Xu,Fengwen Huang,Yi Li,Huafeng Xiao,Zhen Yang,Zhangli Hu,Zhendan He,Zheling Zeng,Yinong Li
Ligupurpuroside A is one of the major glycoside in Ku-Din-Cha, a type of Chinese functional tea. In order to better understand its digestion and metabolism in humans, the interaction between Ligupurpuroside A and pepsin has been investigated by fluorescence spectra, UV–vis absorption spectra and synchronous fluorescence spectra along with molecular docking method. The fluorescence experiments indicate that Ligupurpuroside A can effectively quench the intrinsic fluorescence of pepsin through a combined quenching way at the low concentration of Ligupurpuroside A, and a static quenching procedure at the high concentration. The binding constant, binding sites of Ligupurpuroside A with pepsin have been calculated. The thermodynamic analysis suggests that non-covalent reactions, including electrostatic force, hydrophobic interaction and hydrogen bond are the main forces stabilizing the complex. According to the Förster’s non-radiation energy transfer theory, the binding distance between pepsin and Ligupurpuroside A was calculated to be 3.15 nm, which implies that energy transfer occurs between pepsin and Ligupurpuroside A. Conformation change of pepsin was observed from UV–vis absorption spectra and synchronous fluorescence spectra under experimental conditions. In addition, all these experimental results have been validated by the protein-ligand docking studies which show that Ligupurpuroside A is located in the cleft between the domains of pepsin.
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DOI
高影响因子
危险品化学品经营许可证（带存储）