Kinetics of Cu2+ inhibition of Na+/K+-ATPase

被引：64

作者：

Li, J

Lock, RAC

Klaren, PHM

Swarts, HGP

Stekhoven, FMAHS

Bonga, SEW

Flik, G

机构：

[1] CATHOLIC UNIV NIJMEGEN, FAC SCI, DEPT ANIM PHYSIOL, NL-6525 ED NIJMEGEN, NETHERLANDS

[2] CATHOLIC UNIV NIJMEGEN, FAC MED, DEPT BIOCHEM, NL-6525 ED NIJMEGEN, NETHERLANDS

来源：

TOXICOLOGY LETTERS | 1996年 / 87卷 / 01期

关键词：

copper; Na+/K+-ATPase (EC 3.6.1.3); K+-pNPPase; kinetics;

D O I：

10.1016/0378-4274(96)03696-X

中图分类号：

R99 [毒物学（毒理学）];

学科分类号：

100405 ;

摘要：

The interaction of Cu2+ With enzymatic activity of rabbit kidney Na+/K+-ATPase was studied in media with buffered, defined free Cu2+ levels. The IC50-values are 0.1 mu mol/l for Na+/K-ATPase and 1 mu mol/l for K+-pNPPase. Dithiothreitol (DTT) reverses the inhibitory effect of Cu2+ in vitro. Cu2+ exerts non-competitive effects on the enzyme with respect to Na+, K+, ATP or pNPP, but has a mixed-type inhibitory effect with respect to Mg2+. It is concluded that the appreciation of the inhibitory effect of CU2+ on this enzyme requires carefully composed assay media that include a buffer for Cu2+, and that the IC50-values calculated according to this model indicate that CU2+ may be more toxic than previously anticipated.

引用

页码：31 / 38

页数：8

共 30 条

[1] PROTECTION AGAINST CADMIUM TOXICITY AND ENZYME-INHIBITION BY DITHIOTHREITOL [J].