【摘要】 应用红外光谱和荧光光谱方法研究了人血清白蛋白 (HSA)与 β 1,2 ,3 ,4,6 五 O 倍酰 D 葡萄糖 (PGG)的相互作用 .荧光光谱结果显示 ,PGG在CPGG/CHSA<0 5和 0 5 <CPGG/CHSA<3两个浓度范围内在HSA分子上分别有一个和两个结合位点 ,结合常数分别为 1 66× 10 4和 8 98× 10 8L·mol-1.运用蛋白质红外光谱酰氨Ⅲ带和酰氨Ⅰ带结合的方法对HSA与PGG作用后二级结构的变化进行了定量分析 .随着药物浓度的增加 ,PGG和HSA之间的相互作用主要使HSA的二级结构发生了由α 螺旋向 β 转角和无规结构的转化 .结合荧光光谱和红外光谱结果 ,探讨了HSA与不同浓度PGG作用引起的荧光猝灭与二级结构变化之间的关系 ,并讨论了HSA和PGG相互作用的模式更多还原

【Abstract】 Interaction of β-1,2,3,4,6-penta-O-galloyl-D-glucopyranose (PGG) with human serum albumin (HSA) has been studied by Fourier transform infrared (FT-IR) and fluorescence spectroscopic methods. Fluorescence data revealed the presence of one binding site on HSA when C PGG/C HSA<0 5, and two sites when 0 5<C PGG/C HSA<3. The binding constants (K A) are 1 66×10 4 and 8 98×10 8 L·mol -1 in the two concentration ranges respectively. The changes of the secondary structure of HSA after interacting with PGG were estimated by combining the curve-fitting results of amide Ⅰ and amide Ⅲ bands of the protein infrared spectra. It was found that with the increase of PGG concentration, the interaction of PGG with HSA has mainly caused the change from the α-helix structure to β-turn and random coil structure. Combining the results of fluorescence and FT-IR, the relationship of fluorescence quenching and the changes of HSA secondary structure induced by PGG binding was investigated, and the PGG-HSA interaction mode was discussed.更多还原