醋酸镉对成年大鼠大脑皮层突触体ATP二磷酸水解酶（EC 3.6.1.5；腺苷三磷酸双磷酸酶）的抑制作用。

Inhibitory effect of cadmium acetate on synaptosomal ATP diphosphohydrolase (EC 3.6.1.5; apyrase) from adult rat cerebral cortex.

作者信息

Barcellos C K, Schetinger M R, Battastini A M, Silva L B, Dias R D, Sarkis J J

机构信息

Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.

出版信息

Braz J Med Biol Res. 1994 May;27(5):1111-5.

PMID:8000330

Abstract

ATP diphosphohydrolase (EC 3.6.1.5; apyrase) is an enzyme that can promote ATP and ADP hydrolysis to AMP plus inorganic phosphate and depends on divalent cations such as Ca2+ or Mg2+. In previous papers we described this enzyme in the synaptosomal fraction from the central and peripheral nervous system. The present report examines whether cadmium acetate could affect the in vitro activity of the enzyme in the synaptosomal fraction from the cerebral cortex of adult male Wistar rats. Cadmium (Cd2+), a heavy metal with neurotoxic effects, inhibited the enzyme in a concentration-dependent manner. All concentrations tested (0.05-1.0 mM) significantly inhibited the hydrolysis of both substrates (ATP and ADP), with the exception of 0.05 mM on ATP hydrolysis. The kinetic data indicate a noncompetitive inhibition between the cations Cd2+ and Ca2+.

摘要

ATP二磷酸水解酶（EC 3.6.1.5；腺苷三磷酸双磷酸酶）是一种能够促进ATP和ADP水解为AMP加无机磷酸盐的酶，并且依赖于二价阳离子，如Ca2+或Mg2+。在之前的论文中，我们在中枢和外周神经系统的突触体组分中描述了这种酶。本报告研究了醋酸镉是否会影响成年雄性Wistar大鼠大脑皮质突触体组分中该酶的体外活性。镉（Cd2+）是一种具有神经毒性作用的重金属，它以浓度依赖的方式抑制该酶。所有测试浓度（0.05 - 1.0 mM）均显著抑制两种底物（ATP和ADP）的水解，但0.05 mM对ATP水解除外。动力学数据表明阳离子Cd2+和Ca2+之间存在非竞争性抑制。