从小肠结肠炎耶尔森菌138A14中分离出的汞还原酶中的必需精氨酸。

Essential arginines in mercuric reductase isolated from Yersinia enterocolitica 138A14.

作者信息

Blaghen M, el Kebbaj M S, Vidon D J, Tritsch D

机构信息

Laboratoire de Biochimie, Faculté des Sciences I Université Hassan II, Casablanca, Morocco.

出版信息

Biochimie. 1992 Jun;74(6):557-60. doi: 10.1016/0300-9084(92)90154-7.

DOI:10.1016/0300-9084(92)90154-7

PMID:1520735

Abstract

The mercuric reductase from Yersinia enterocolitica 138A14 was inactivated by the arginine modifying reagents 2,3-butanedione and phenylglyoxal. The inactivation by 2,3-butanedione exhibited second order kinetics with rate constant of 32 min-1 M-1. In the case of phenylglyoxal, biphasic kinetics were observed. The oxidized coenzyme (NADP+) prevented inactivation of the enzyme by the alpha-dicarbonyl reagents, whereas the reduced coenzyme (NADPH) enhanced the inactivation rate. The loss of enzyme activity was related to the incorporation of [2-14C] phenylglyoxal; when two arginines per subunit were modified the enzyme was completely inactivated.

摘要

小肠结肠炎耶尔森菌138A14的汞还原酶被精氨酸修饰试剂2,3 -丁二酮和苯乙二醛灭活。2,3 -丁二酮导致的灭活呈现二级动力学，速率常数为32 min⁻¹ M⁻¹。对于苯乙二醛，观察到双相动力学。氧化型辅酶（NADP⁺）可防止α -二羰基试剂对该酶的灭活，而还原型辅酶（NADPH）则提高了灭活速率。酶活性的丧失与[2 - ¹⁴C]苯乙二醛的掺入有关；当每个亚基的两个精氨酸被修饰时，酶完全失活。