蛋白质与刚果红结合反应的研究

A Study on the Reaction Mechanism between Congo-Red and Bovine Seum Albumin

研究了酸性溶液中蛋白质(BSA)与刚果红(CGR)的结合反应。BSA与CGR相互作用形成复合物,溶液颜色由蓝色变为红色,最大吸收波长紫移,表明在蛋白质正电荷作用下,CGR由游离态酸色型变为结合态碱色型。测得CGR与BSA的结合最大结合数约为43,符合Scatchard模型。荧光光谱表明,CGR与BSA作用导致BSA荧光猝灭,结合位点为BSA第212位色氨酸残基,相互作用为非辐射能量转移。

The combination reaction between protein (BSA) and congo red (CGR) in acidic solution was studied by both absorption specfroscopy and fluorescence specfroscopy. BSA interact with CGR fo form a compound which results in the color of solution changing from blue to red and the maximam absorption wavelegth moving to purple. The reason for this color change is that CGR was changed from the free acidic type to the combined basic type under the action of positive charge of protein. Both molar method and double wavelength method were employed to determine the maximum combinative mumber and a maximum combinative number of 43 was obtained. The combination of CGR and BSA is obeyed with the Scatchard model. The fluorescence spectrum shows that the interaction between CGR and BSA cause the BSA fluorescence quenching, and the combination point is found to be of the 212 tryptohan residue of BSA. The interaction is twon-radiation energy transfer.