肽链对微过氧化物酶动力学及稳定性的影响。

The influence of the peptide chain on the kinetics and stability of microperoxidases.

作者信息

Spee J H, Boersma M G, Veeger C, Samyn B, Van Beeumen J, Warmerdam G, Canters G W, Van Dongen W M, Rietjens I M

机构信息

Department of Biochemistry, Agricultural University, Wageningen, The Netherlands.

出版信息

Eur J Biochem. 1996 Oct 1;241(1):215-20. doi: 10.1111/j.1432-1033.1996.0215t.x.

DOI:10.1111/j.1432-1033.1996.0215t.x

PMID:8898909

Abstract

Microperoxidases with increasing lengths of the peptide attached to the heme moiety have been isolated after proteolytic digestion of horse-heart cytochrome c (microperoxidases 6, 8, and 11) and of cytochrome c550 from Thiobacillus versutus (microperoxidase 17). The different microperoxidases catalyze the H2O2-dependent para-hydroxylation of aniline relatively efficiently but are rapidly inactivated under turnover conditions. The horse-heart cytochrome-c-derived microperoxidases have identical values for Vmax but show a decrease of the K(m) for aniline and a higher stability when the attached peptide is longer. The kinetic constants obtained for microperoxidase 17, differ markedly from the microperoxidases derived from horse-heart cytochrome c. Possible factors underlying the observed differences are discussed.

摘要

通过对马心脏细胞色素c（微过氧化物酶6、8和11）以及来自氧化亚铁硫杆菌的细胞色素c550（微过氧化物酶17）进行蛋白水解消化，已分离出与血红素部分相连的肽长度不断增加的微过氧化物酶。不同的微过氧化物酶相对高效地催化H2O2依赖性苯胺的对羟基化反应，但在周转条件下会迅速失活。源自马心脏细胞色素c的微过氧化物酶的Vmax值相同，但当连接的肽更长时，苯胺的K(m)值会降低且稳定性更高。微过氧化物酶17获得的动力学常数与源自马心脏细胞色素c的微过氧化物酶明显不同。讨论了观察到的差异背后的可能因素。