运用荧光光谱和同步荧光光谱法,研究在pH 7.40的Tris-HCI缓冲体系下,蒜氨酸与牛血清白蛋白(BSA)和人血清白蛋白(HSA)的相互作用.采用荧光分光光度计,以280 nm为激发波长,扫描300～500nm范围的荧光发射光谱;分别设置波长差△λ=15 nm和△λ=60 nm扫描同步荧光光谱图;用Stem-Volmer和Lineweaver-Burk方程及热力学方程处理数据.荧光光谱法结果表明蒜氨酸能猝灭BSA及HAS的荧光;得到蒜氨酸与BSA反应的结合常数在298和310 K时分别9.81×102和6.15×102 L·mol-1;与HSA反应的结合常数在298和310K时分别2.21×102和6.84×102 L·mol-1;蒜氨酸与两种蛋白的反应均为自发进行;与BSA的作用力为静电作用而与HSA的作用为疏水作用力;同步荧光光谱表明,蒜氨酸与BSA作用过程中主要影响酪氨酸残基,对HSA中的两种氨基酸残基均有影响.实验结果为研究蒜氨酸与生物小分子物质相互作用的机制提供了一定的理论依据.%The interaction between alliin and bovine serum albumin(BSA) and human serum albumin(HSA) was studied under a pH7.4 Tris-HCl buffer system with multiple spectroscopic techniques.The study took 280 nm as the excitation wavelength to scan the range of 300～500 nm of fluorescence emission spectrum by using fluorescence spectrophotometer while setting wavelength differential as △λ =15 nm and △λ=60 nm to scan synchronous fluorescence spectra.The fluorescence quenching data were analyzed by applying Stern-Volmer equation and Line weaver-Burk equation.It is shown that Alliin was effective in quenching BSA and HSA fluorescence.The binding constant obtained of alliin and BSA was 9.81 × 102 L · mol-1 at 298 K and 6.15× 102 L · mol-1 at 310 K.The binding constant obtained of alliin and HSA was 2.21 × 102 L · mol-1 at 298 K and 6.84 × 102 L · mol 1 at 310 K.The thermodynamic parameters,△H calculated by using Gibbs-Helmholtz Equation of the reaction of alliin and BSA is-29.9 kJ · mol-1 and △S is 43.0 J · mol-1 · K-1 and △G is-17.1 kJ · mol-1 at 298 K.△H of the reaction of alliin and HSA is 72.3 kJ · mol-1 and △S is 288 J · mol-1 · K-1 and △G is-13.4 kJ · mol-1 at 298 K.The main types of binding force of Alliin-BSA were hydrophobic interaction and the sorts of binding force of Alliin-HSA were electrostatic action.The results of synchronous fluorescence spectra showed that alliin has main effects on Tyr of BSA and both Tyr and Trp of HSA.The experimental results have provided the certain theory basis of the mechanism of interaction between alliin and biological small molecules.
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