咖啡酸与牛血清白蛋白相互作用的荧光光谱法研究

Insight into Interaction of Caffeic Acid with Bovine Serum Albumin

采用荧光光谱法研究咖啡酸与牛血清白蛋白(BSA)结合反应。实验表明,咖啡酸对BSA的荧光猝灭为静态猝灭。二者之间的作用力为静电引力和疏水作用力。在离子强度符合生理条件的情况下,以疏水作用力为主。在溶液中二者以物质的量浓度比1:1结合,并求出二者的结合常数。以华法林(Warfarin)和布洛芬(Ibuprofen)为标记物,利用荧光光谱法确定了咖啡酸在BSA的结合位置为siteI。根据Forster非辐射能量转移理论,求出了给体(BSA)与受体(咖啡酸)间距离(r0)为3.64nm。另外,利用同步荧光法考察了咖啡酸对牛血清白蛋白构象的影响。..

The binding reaction of caffeic acid with bovine serum albumin（BSA） was studied using fluorescence spectroscopy.Caffeic acid quenched the fluorescence of BSA through a static process.The primary binding pattern between caffeic acid and BSA included electrostatic and hydrophobic interaction,and the latter was identified to be the main force under physiological condition.It was found that caffeic acid was located near the Tyr residue region of site I in BSA by competing binding experiment using warfarin and ibuprofen as site markers by fluorescence spectra.The distance between the donor（BSA） and receptor（caffeic acid）,r0,was obtained to be 3.64 nm according to Forster＇s non-radiative energy transfer theory.In addition,the effect of caffeic acid on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.