高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (9): 1840-1846.doi: 10.7503/cjcu20190252

• 分析化学 • 上一篇    下一篇

多光谱法和分子对接模拟法研究黄腐酸与胃蛋白酶的相互作用

王晓霞1,*(),马力通1,聂智华2,王正德1,崔金龙1,赵文渊1,赛华征1   

  1. 1. 内蒙古科技大学化学与化工学院, 包头 014010
    2. 清华大学生命科学学院, 北京 100084
  • 收稿日期:2019-04-30 出版日期:2019-09-10 发布日期:2019-09-09
  • 通讯作者: 王晓霞 E-mail:wxx572369@163.com
  • 基金资助:
    国家自然科学基金(21766025);内蒙古自治区科技计划项目(201702027);内蒙古自治区高等学校科学研究项目(No.NJZY17166)

Interaction Between Fulvic Acid and Pepsin Investigated by Multispectral and Molecular Docking Simulation

WANG Xiaoxia1,*(),MA Litong1,NIE Zhihua2,WANG Zhengde1,CUI Jinlong1,ZHAO Wenyuan1,SAI Huazheng1   

  1. 1. School of Chemistry and Chemical Engineering, Inner Mongolia University of Science and Technology,Baotou 014010, China
    2. School of Life Sciences, Tsinghua University, Beijing 100084, China
  • Received:2019-04-30 Online:2019-09-10 Published:2019-09-09
  • Contact: WANG Xiaoxia E-mail:wxx572369@163.com
  • Supported by:
    ? Supported by the National Natural Science Foundation of China(21766025);the Inner Mongolia Autonomous Region Science and Technology Plan Funding Project, China(201702027);the Inner Mongolia Autonomous Region Higher Education Research Project, China(No.NJZY17166)

摘要:

利用荧光光谱、 同步荧光光谱、 三维荧光光谱、 紫外-可见吸收光谱、 傅里叶变换红外光谱和圆二色光谱以及分子对接模拟方法研究了黄腐酸(FA)与胃蛋白酶(PEP)之间的相互作用. 荧光光谱分析表明, FA-PEP荧光猝灭的类型为静态猝灭. 根据Stern-Volmer方程和静态猝灭双对数公式计算得到猝灭常数Ksv和结合位点数n. 根据Vant’t Hoff方程计算得到热力学常数ΔH=-59.86 kJ/mol, ΔS=-98.13 J·mol -1·K -1, ΔG=-30.62 kJ/mol(298 K). 热力学分析表明, 氢键和范德华力是PEP与FA之间的主要结合力, 其反应为自发过程. 根据F?rster非辐射能量转移理论, 计算得到PEP和FA之间的结合距离为2.436 nm, 表明在FA与PEP之间发生了非辐射能量转移. 三维荧光光谱分析表明, 在FA存在下PEP的肽链骨架结构发生了改变. 此外, 紫外-可见吸收光谱、 同步荧光光谱和红外光谱结果表明, FA使PEP的二级构象发生变化. 分子对接模拟结果表明, FA引起PEP荧光猝灭的结合作用力不仅有氢键和范德华力, 还有疏水作用力.

关键词: 黄腐酸, 胃蛋白酶, 多光谱法, 分子对接模拟法

Abstract:

The interaction of fulvic acid(FA) with pepsin(PEP) was investigated using fluorescence spectra, UV-Vis absorption spectra, three-dimensional fluorescence spectra, synchronous fluorescence spectra, Fourier transform infrared spectroscopy, circular dichroism and molecular docking simulation method. Fluorescence spectrum analyses shows that the type of fluorescence quenching by FA-PEP is static quenching. According to the Stern-Volmer equation and the static quenching double logarithmic formula, the quenching constants(Ksv) and the number of binding sites(n) were calculated. According to the Vant’t Hoff equation, the thermodynamic parameters were calculated to be ΔH=-59.86 kJ/mol, ΔS=-98.13 J·mol -1·K -1 and ΔG=-30.62 kJ/mol(298 K). Thermodynamic analysis suggests that hydrogen bonds and van der Waal’s forces are the main forces between PEP and FA, and the interaction is spontaneous process. According to the theory of F?rster’s non-radiative energy transfer, the binding distance between PEP and FA was calculated to be 2.436 nm, implying that non-radiative energy transfer occurs between FA. The molecular docking simulation technique displays that the binding force of FA-PEP includes not only hydrogen bonds and van der Waals forces but also hydrophobic interaction forces.

Key words: Fulvic acid, Pepsin, Multispectroscopy, Molecular docking simulation method

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