碱性介质中茜素黄R与牛血清白蛋白作用的荧光法研究

在碱性条件下，采用荧光光谱法研究了茜素黄R(alizarin yellow R, AYR)与牛血清白蛋白(BSA)结合反应的光谱特征。研究表明，pH 11.00，激发波长为393 nm时，BSA的发射峰位于641 nm，且AYR对BSA有较强的荧光猝灭作用，AYR在BSA分子上荧光敏感部位有五个结合位点;由温度对AYR-BSA体系荧光猝灭速率的影响和动态猝灭常数K_SV以及静态猝灭结合常数K_LB的计算得出，AYR对BSA内源荧光的猝灭机制属于形成BSA-AYR复合物的静态猝灭，荧光猝灭常数为1.6×104 L·mol-1;由反应前后热力学函数ΔHθ＜0，ΔSθ＜0以及AYR对BSA-CBBG(CBBG-考马斯亮蓝G)体系具有荧光猝灭作用推出，茜素黄R与牛血清白蛋白之间的作用力主要是氢键和范德华力。

Fluorescence Study on the Interaction of Alizarin Yellow R and Bovine Serum Albumin in Alkali Solution

The interaction of alizarin yellow R(AYR) and bovine serum albumin (BSA) was investigated by fluorescence method in alkali buffer solution. It was shown that AYR had a powerful ability to quench the BSA fluorescence at excitation and emission wavelengths of lambda(ex) = 393 nm and lambda(em) = 641 nm in the medium solution of pH 11.00, and there were five binding sites of AYR to BSA; The combination reaction of AYR with BSA was a static quenching process, and from the effects of temperature on the fluorescence quenching rate of AYR-BSA and the Stern-Volmer quenching constant (K(SV)) and the Lineweaver-Burk quenching constant (K(LB)), the binding constant was calculated to be K = 1.6 x 10(4) L x mol(-1); as the enthalpy change deltaH(theta) < 0 and entropy change deltaS(theta) < 0, and AYR has an ability to quench the BSA-CBBG fluorescence, it can be deduced that the Van der Walls force and hydrogen bond are the main binding forces between AYR and BSA.