摘要
为探究pH值对咖啡酸β-苯乙醇酯(caffeic acid phenethyl ester,CAPE)与人血清蛋白(human serum albumin,HSA)相互作用的影响,采用荧光发射光谱和同步荧光光谱研究在不同pH值(3.0、5.0、7.4)条件下CAPE对HSA的荧光猝灭作用,并计算猝灭常数、结合常数和热力学参数,分析荧光猝灭机理,最后通过位点Marker实验确定结合位点。荧光发射光谱表明,不同pH值条件下CAPE对HSA内源荧光均产生了猝灭作用,生理pH 7.4时猝灭率最高,结合常数最大;热力学参数表明CAPE与HSA主要通过范德华力和氢键作用结合;同步荧光表明CAPE和pH值的共同影响改变了HSA的构象;位点Marker实验表明,CAPE与HSA的结合位点位于Sudlow’s site I附近。结果表明,pH值的增加促进了CAPE与HSA的结合,这将为CAPE活性稳态化保持、靶向递送提供理论依据。
In order to explore the effect of pH on the interaction of caffeic acidβ-phenethyl ester(CAPE)with human serum albumin(HSA),the quenching effect of CAPE on the fluorescence of HSA under different pH(3.0,5.0 and 7.4)conditions was investigated using fluorescence emission spectroscopy(FES)and synchronous fluorescence spectroscopy(SFS),and the quenching constants,binding constants and thermodynamic parameters were calculated.Meanwhile,the fluorescence quenching mechanism was analyzed,and the binding site was determined by site marker experiment.The fluorescence emission spectra showed that CAPE could quench the intrinsic fluorescence of HSA under all pH conditions tested.The quenching rate was the highest and the binding constant was the largest at physiological pH 7.4.The thermodynamic results suggested that the binding of CAPE to HSA was mainly driven by van der Waals force and hydrogen bonds.SFS indicated that binding to CAPE and the change of pH jointly induced the conformational changes of HSA.The results of site marker experiment showed that the binding site of CAPE to HSA was located near Sudlow’s site I.Altogether,the results revealed that the combination of CAPE with HSA could be promoted by the increase of pH,which can provide a theoretical basis for activity homeostasis maintenance and targeted delivery of CAPE.
作者
范金波
邢莉
李孟雨
麻奥
吕长鑫
励建荣
FAN Jinbo;XING Li;LI Mengyu;MA Ao;Lü Changxin;LI Jianrong(Food Safety Key Laboratory of Liaoning Province,National&Local Joint Engineering Research Center of Storage,Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products,College of Food Science and Engineering,Bohai University,Jinzhou 121013,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2021年第22期31-37,共7页
Food Science
基金
国家自然科学基金面上项目(31972107)
辽宁省教育厅项目(LJ2020004)。
