ATP 耗竭诱导的鸟类和两栖类红细胞膜中磷脂对磷脂酶敏感性的变化。

Changes in phosoholipid susceptibility toward phospholipases induced by ATP depletion in avian and amphibian erythrocyte membranes.

作者信息

Gazitt Y, Ohad I, Loyter A

出版信息

Biochim Biophys Acta. 1975 Feb 28;382(1):65-72. doi: 10.1016/0005-2736(75)90373-9.

Abstract

About half of the sphingomyelin content of fresh and ATP-depleted chicken erythrocytes is hydrolysed by sphingomyelinase. Removal of spingomyelin exposes the rest of the membrane phospholipids to hydrolysis by phospholipase C only in ATP-depleted but not in fresh cells. Addition of both sphinogomyelinase and phospholipase C to ATP-depleted cells causes about 60-70 percent hydrolysis of the total phospholipids accompanied by extensive (90 percent) hemolysis. The phospholipids of toad erythrocytes are partially available to phospholipase C activity in fresh cells (17-25 percent hydrolysis) without prior sphingomyelinase treatment. However, in ATP-depleted toad cells phospholipase C hydrolyses 66 percent of phospholipids and causes extensive lysis. Treatment of either fresh or ATP-depleted toad erythrocytes by sphingomyelinase together with phospholipase C induces hydrolysis of most of the phospholipds with complete lysis. Restoration of ATP to ATP-depleted cells endows them with resistance to the attack of phospholipase C. The correlation between changes in ATP level and membrane organization as revealed by increased susceptibility toward phospholipases is discussed.

摘要

新鲜的和ATP耗尽的鸡红细胞中约一半的鞘磷脂含量可被鞘磷脂酶水解。鞘磷脂的去除仅使ATP耗尽的细胞而非新鲜细胞中的其余膜磷脂暴露于磷脂酶C的水解作用之下。向ATP耗尽的细胞中同时添加鞘磷脂酶和磷脂酶C会导致总磷脂约60%-70%的水解，并伴有大量（90%）的溶血现象。未经鞘磷脂酶处理时，蟾蜍红细胞的磷脂在新鲜细胞中可部分被磷脂酶C作用（17%-25%水解）。然而，在ATP耗尽的蟾蜍细胞中，磷脂酶C可水解66%的磷脂并导致大量细胞裂解。用鞘磷脂酶和磷脂酶C共同处理新鲜的或ATP耗尽的蟾蜍红细胞会诱导大多数磷脂的水解并导致完全裂解。向ATP耗尽的细胞中恢复ATP可使其对磷脂酶C的攻击产生抗性。文中讨论了ATP水平变化与膜组织之间的相关性，这种相关性通过对磷脂酶敏感性增加得以揭示。