几种金属离子对胭脂红与牛血清白蛋白相互作用的影响--荧光光谱研究

摘要

利用荧光光谱法研究了不同温度（15、27、39℃）下食用合成色素胭脂红对牛血清白蛋白（BSA）的内源荧光猝灭特性，考察了Cu2＋、Ni2＋、Pb2＋等金属离子对二者相互作用的影响，并测定了不同温度下的猝灭常数K SV 、结合常数 K A和结合位点数 n 。结果表明，3种金属离子基本不影响胭脂红对BSA荧光猝灭机理，但Cu2＋、Ni2＋、Pb2＋离子都与BSA有一定的结合能力，可在不同程度上增强胭脂红与BSA的结合作用及其对BSA内源荧光的猝灭。%Fluorescence spectroscopic method was adopted to study the quenching characteris-tics of endogenous fluorescence of bovine serum albumin (BSA ) by synthetic food pigment Ponceau 4R at different temperatures (15 ,27 and 39 ℃) ,and the effects of metal ions Cu2+ , Ni2+ and Pb2+ on the interactions between BSA and Ponceau 4R were investigated .Moreover , the quenching constant KSV ,binding constant KA ,and binding site n under different tempera-tures were measured .Results indicate that the three kinds of metal ion almost have no effect on the fluorescence quenching mechanism of BSA by Ponceau 4R .However ,Cu2+ ,Ni2+ and Pb2+are in some way able to combine with BSA ,thereby enhancing the interactions between BSA and Ponceau 4R as well as the quenching of the endogenous fluorescence of BSA .