6-氨基-5-氰基-3-甲基-4-(3-硝基苯)-1-苯基吡唑[3,4-b]并吡啶与人血清白蛋白结合作用的光谱特征

采用紫外光谱法和荧光光谱法研究了6-氨基-5-氰基-3-甲基-4-(3-硝基苯)-1-苯基吡唑[3,4-b]并吡啶(6A)与人血清白蛋白(HSA)的结合作用,利用同步荧光法和三维荧光法研究了6A与HSA作用前后人血清白蛋白的构象变化。观测到生理pH7.4条件下6A使HSA的紫外吸收峰增强,特征荧光峰猝灭。Stern-Volmer曲线显示,6A对HSA的荧光猝灭可能是一个单一的静态猝灭过程,并且得出18℃和37℃时的结合位点数和结合常数。根据F rster非辐射转移理论可求出6A与HSA作用距离r=3.73 nm;根据基本热力学参数ΔH、ΔS和ΔG判断6A和HSA主要通过氢键和范德华力发生相互作用。

Spectral characteristics of the interaction between 6-amino-5-cyano-3-methyl-4-(3-nitrophenyl)-1-phenylpyrazolo[3,4-b] pyridine(6A) and human serum albumin

The binding interaction between 6-amino-5-cyano-3-methyl-4-(3-nitrophenyl)-1-phenylpyrazolo[3,4-b] pyridine(6A) and human serum albumin(HSA) was investigated by ultraviolet absorption and fluorescence spectra.Synchronous fluorescence and three-dimensional fluorescence spectra were used to study the structure change of HSA with the addition of 6A.In physiological condition(pH 7.4),6A led to the increasing of UV absorption and the quenching of intrinsic fluorescence of HSA.The Stern-Volmer curve shows that th...