在模拟人体生理条件下,用荧光光谱和紫外可见吸收光谱法研究了不同温度下4-(2-羧基苯偶氮)-连苯三酚(CBAP)与人血清白蛋白(HSA)的相互作用.结果表明,CBAP对HSA的荧光猝灭属静态猝灭.通过288、293、298 K时的荧光猝灭,得出CBAP与HSA的结合常数K分别为1.62×106,3.97×105和3.56×105,结合位点数n=0.92(平均值).据F(o)rster非辐射能量转移理论计算出CBAP与HSA的结合距离r=1.44 nm,由热力学参数焓变和熵变,推断两者反应时氢键和范德华力可能起主要作用.运用同步荧光和三维荧光技术分析了CBAP对HSA构象的影响,表明CBAP的加入改变了HSA中酪氨酸残基和色氨酸残基的构象.%The interaction between 4-(2-carboxy phenylazo) - pyrogallol (CBAP) and human serum albumin (HAS) in physiological solution has been studied using fluorescence and UV-visible spectroscopy. The results show that the quenching mechanism of the reaction between CBAP and HAS is static quenching; the binding sites number n = 0. 92 (average) and binding constant K = 1. 62 × 106,3. 97 × 105and 3. 56 × 105 at 288, 293 and 298 K were respectively measured by using fluorescence quenching method. The thermodynamic parameters indicate that hydrogen bonds and van der Waals interactions might play a major role in the reaction of CBAP with HAS; the distance r = 1. 44 nm between the donor ( HAS) and the acceptor ( CBAP) has been obtained according to the Forster non-radioactive energy transfer theory; the effect of CBAP on the conformation of HAS has been analyzed by means of synchronous fluorescence and 3D fluorescence spectra. This paper may provide references for the research on the toxicity and biological effect of azo dyes.
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