[乙二醇双四乙酸（EGTA）对钙转运及钙结合细胞系统钙亲和力的作用机制]

[Mechanism of the effect of EGTA on the affinity to calcium of Ca-transporting and Ca-binding cell systems].

作者信息

Orlov S N, Sitozhevskiĭ A V, Pokudin N I, Agnaev V M

出版信息

Biokhimiia. 1985 Nov;50(11):1920-5.

Abstract

The activity of Ca-ATPases of erythrocyte ghosts and sarcoplasmic reticulum and the rate of ATP-dependent uptake of 45Ca by erythrocyte membrane inside-out oriented vesicles, sarcoplasmic reticulum vesicles and mitochondria were investigated. It was found that in all cases studied the addition of EGTA to the incubation mixture caused an increase in the affinity of Ca-pumps for Ca2+; their maximal activity remained thereby unaffected. A similar effect of EGTA was observed when the affinity for Ca2+ of calmodulin, troponin C and the fluorescent dye quin 2 were determined. It was assumed that the effect of EGTA on the affinity for Ca2+ of Ca-transporting and Ca-binding systems of a cell is due to a removal of admixtures of bi- and trivalent cations.

摘要

研究了红细胞血影和肌浆网中钙 - ATP酶的活性，以及红细胞内翻膜泡、肌浆网泡和线粒体对45Ca的ATP依赖性摄取速率。结果发现，在所研究的所有情况下，向孵育混合物中添加乙二醇双四乙酸（EGTA）会导致钙泵对Ca2+的亲和力增加；其最大活性因此不受影响。在测定钙调蛋白、肌钙蛋白C和荧光染料喹啉2对Ca2+的亲和力时，也观察到了EGTA的类似作用。据推测，EGTA对细胞钙转运和钙结合系统对Ca2+亲和力的影响是由于去除了二价和三价阳离子的混合物。