过氧化氢对烟曲霉氯过氧化物酶的不可逆失活作用。在氯离子和溴离子体系中的动力学研究。

Irreversible inactivation of Caldariomyces fumago chloroperoxidase by hydrogen peroxide. A kinetic study in chloride and bromide system.

作者信息

Shevelkova A N, Ryabov A D

机构信息

Department of Chemistry, M.V. Lomonosov Moscow State University, Russia.

出版信息

Biochem Mol Biol Int. 1996 Jul;39(4):665-70. doi: 10.1080/15216549600201731.

DOI:10.1080/15216549600201731

PMID:8843333

Abstract

The rate constants for the H2O2-induced irreversible inactivation (kinact) of chloroperoxidase from Caldariomyces fumago evaluated from the analysis of complete kinetic curves of chlorination or bromination of monochlorodimedon were found to follow the rate law kinact = k[H2O2]/(K + [H2O2]) with k = 0.009 > or = 0.002 and 0.0095 > or = 0.010 s-1 and K = (13 > or = 4) x 10(-3) and (9 > or = 2) x 10(-3) M in the presence of 0.01 M chloride and bromide, respectively, at pH 2.75 and 25 degrees C. The data show that chloroperoxidase investigated is more than by a factor of 10 less resistant toward hydrogen peroxide compared to horseradish peroxidase. The possible reason for it and the biotechnological implications are briefly discussed.

摘要

通过对一氯二甲基酮氯化或溴化的完整动力学曲线分析评估，发现来自烟曲霉的氯过氧化物酶被过氧化氢诱导的不可逆失活速率常数（kinact）遵循速率定律kinact = k[H2O2]/(K + [H2O2])，其中k = 0.009≥0.002且0.0095≥0.010 s-1，在pH 2.75和25℃下，分别在0.01 M氯化物和溴化物存在时，K = (13≥4)×10(-3)和(9≥2)×10(-3) M。数据表明，与辣根过氧化物酶相比，所研究的氯过氧化物酶对过氧化氢的抗性要低10倍以上。简要讨论了其可能的原因和生物技术意义。