腐胺与牛血清白蛋白的相互作用

Interaction Between Putrescine and Bovine Serum Albumin

采用荧光光谱法研究了腐胺与牛血清白蛋白(Bovine serum albumin,BSA)之间的相互作用,测定了它们之间的结合常数和结合位点数,探讨了其荧光猝灭机制,并根据热力学参数确定了它们之间的作用力类型。实验结果表明腐胺能够使BSA的荧光猝灭,根据Stern-Volmer和Scatchard方程得到的结果可知腐胺对BSA内源荧光的猝灭机理为静态猝灭,结合常数分别为1.67×104、1.41×104和1.12×104L·mol-1,结合位点数分别为0.83、0.86和0.76。根据Van’t Hoff方程,腐胺和BSA之间的热力学常数:焓变和熵变的值分别是-15.22K J·mol-1和31.97J·mol-1·K-1,这说明它们之间的相互作用力主要是静电作用力和疏水作用力。

The interaction between putrescine and Bovine serum albumin （BSA） has been investigated by fluorescence spectroscopy method. The binding constants, binding sites, fluorescence quenching mechanism and the main interaction between BSA and putrescine have been evaluated. Experimental results showed that the fluorescence intensity of BSA was quenched by putrescine,and according to the Stern-Volmer and Scatchard equations,the quenching mechanism was suggested as static quenching. The binding constants of putrescine with BSA at 293,303 and 313K were calculated as 1. 67× 104, 1. 41 ×104 and 1. 12 × 10^4L ; mol-1, respectively. According to the Van＇ t Hoff equation, the thermodynamic parameters of the reaction, standard enthalpy AH0 and entropy △S0,have been calculated to be --5.22kJ ; mol-; and 31.97J ; mo1-1 ; K-1, respectively,which suggests the electrostatic and hydrophobic interaction are the predominant intermolecular forces in stabilizing the putrescine-BSA complex.