头孢匹胺钠与牛血清白蛋白的相互作用机理及共存金属离子的影响

Abstract

The interaction between bovine serum albumin(BSA) and cefpiramide sodium(CPMS) was investigated at different temperatures.The effect of common metal ions(Mg2+,Zn2+,Cu2+,Co2+,Fe3+,Ni2+) on the BSA-CPMS system was also researched.The results show that CPMS can quench the intrinsic fluorescence of BSA significantly,and the quenching mechanism is a static quenching process which follows the Frester spectroscopy energy transfer.The electrostatic force played an important role on the conjugation reaction between BSA and CPMS.The binding constants(Ka) was in the order of 104,and the number of binding site(n) in the binary system was approximately equal to 1.The binding distance(r) was about 2.60 nm and the primary binding for CPMS was located at sub-domainⅡA of BSA.Synchronous spectra and Circular dichroism(CD) spectra revealed that the microenvironment and the conformation of BSA were changed during the conjugation reaction.