赖氨酰氧化酶的活性位点化学

Active site chemistry of lysyl oxidase.

作者信息

Govindaraju K, Nair B U, Ramasami T, Ramaswamy D

出版信息

J Inorg Biochem. 1987 Feb;29(2):111-8. doi: 10.1016/0162-0134(87)80018-1.

PMID:2881978

Abstract

The bimolecular reduction of the Cu(II)-based enzyme lysyl oxidase with two inorganic reductants, tris bipyridylchromium(II) and (1,3,6,8,10,13,16,19)-octaazabicyclo (6,6,6)eicosanecobalt(II) has been examined at various ionic strength and [H+] conditions. The electrochemical properties of the enzyme have also been examined. The results show that Cu(II) is the redox site in the enzyme and has E 1/2 = 0.05 +/- 0.005 V against SCE. The observed rate constants, kobs, for the reduction of the enzyme by either Cr(bpy)32+ or Co(sep)2+ at any concentration of the reductant increased with the ionic strength of the medium. The ionic strength dependence of kobs has been analyzed in terms of the charge of the active site being 1 +.

摘要

研究了在不同离子强度和[H⁺]条件下，基于铜（II）的赖氨酰氧化酶与两种无机还原剂三（联吡啶）铬（II）和（1,3,6,8,10,13,16,19）-八氮杂双环（6,6,6）二十烷钴（II）的双分子还原反应。还研究了该酶的电化学性质。结果表明，铜（II）是酶中的氧化还原位点，相对于饱和甘汞电极，其E₁/₂ = 0.05 ± 0.005 V。在任何还原剂浓度下，由Cr（bpy）₃²⁺或Co（sep）²⁺还原酶的观测速率常数kobs随介质的离子强度增加而增大。已根据活性位点电荷为1⁺对kobs的离子强度依赖性进行了分析。