Interaction of Cu2+ ion with milk xanthine oxidase

被引：14

作者：

Sau, AK ^{[1
]}

Mondal, MS ^{[1
]}

Mitra, S ^{[1
]}

机构：

[1] Tata Inst Fundamental Res, Dept Chem Sci, Bombay 400005, Maharashtra, India

来源：

BIOCHIMICA ET BIOPHYSICA ACTA-PROTEIN STRUCTURE AND MOLECULAR ENZYMOLOGY | 2001年 / 1544卷 / 1-2期

关键词：

xanthine oxidase; copper ion; circular dichroism; stopped flow kinetics;

D O I：

10.1016/S0167-4838(00)00207-7

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The interaction of Cu2+ ion with milk xanthine oxidase (XO) has been studied by optical spectroscopy, circular dichroism, ESR and transient kinetic techniques. It is observed that XO forms optically observable complexes with Cu2+ ion. The pH dependence studies of the formation of Cu2+-XO complex by optical spectroscopy and circular dichroism show that at least one ionizable group may be responsible for the formation of the complex. The EPR studies show that Cu2+ ion binds to XO with sulfur and nitrogenous ligands. The transient kinetic study of the interaction of Cu2+ with XO shows the existence of two Cu2+ bound XO complexes formed at two different time scales of the interaction, one at less than or equal to 5 ms and the other one at around 20 s. The complex formed at longer time scale may be responsible for the inhibition of the enzyme activity. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：89 / 95

页数：7

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