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

研究了不同温度下牛血清白蛋白(BSA)与头孢匹胺钠(CPMS)的相互作用及常见金属离子(Mg²⁺、Zn²⁺、Cu²⁺、Fe³⁺、Co²⁺、Ni²⁺)对BSA-CPMS体系的影响。结果表明:CPMS能使BSA的荧光发生猝灭,其过程为静态猝灭并伴有非辐射能量转移;CPMS通过静电引力与BSA结合,结合常数为10⁴数量级,结合位点数约为1;结合主要作用于BSA的亚结构ⅡA中,结合距离r≈2.60 nm。同步荧光光谱和圆二色谱(CD)均表明CPMS使BSA构象发生了变化。

Interaction of Cefpiramide Sodium with Bovine Serum Albumin and The Effect of Coexistent Metal Ion on The Reaction

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.