摘要
以DMPO(5.5-dimethyl-1-pyrroline-N-oxide)为自旋捕捉剂,通过ESR技术测定了兔肝金属硫蛋白(ZnMT_1、ZnMT_2、CdMT_1和CdmT_2)与·OH反应的速率常数.并利用金属硫蛋白与高铁细胞色素C(ferricytochrome C)竞争O_2^-的反应,测定了这四种MT与O_2^-的反应速率常数.结果表明,k_(OHMT)与MT亚型及结合金属有关,对上述四种MT其顺序为ZnMT_2>ZnMT_1>CdMT_2>CdMT_1.而四种MT的k_(O_2^-MT)无明显差异.
The bimolecular rate constants (kOHMT) f皉 tne reaction of hydroxyl radical with metallothionein (MTs) were determined by studying the kinetic competition between MT and a spin trap, DMPO. It was found that kOHMT varies with its iso-form and metallo-form: ZnMT2 (5.6 ×1013) >ZnMT1 (5.4×1012) >CdMT2 (4.8 × 1012) >CdMT1 (2.9× 1012) (mol/L) -1s-1. Similar competition studies between MT and ferricytochrome C, gave ko2-MT of the order of 3.4-4.4× 105(mol/L)-1s-1 for the mentioned MTs.
出处
《生物物理学报》
CAS
CSCD
北大核心
1993年第3期472-477,共6页
Acta Biophysica Sinica
基金
863-103-21-09金属硫蛋白资助项目
关键词
金属硫蛋白
动力学
氧
自由基
Metallothionein Hydroxyl superoxide radicals Kinetics
