Shapiro D L, Marchesi V T
J Biol Chem. 1977 Jan 25;252(2):508-17.
Studies of phosphorylation in membranes of intact human erythrocytes were performed by incubating erythrocytes in inorganic [32P]phosphate. Analysis of membrane proteins by polyacrylamide gel electrophoresis showed a pattern of phosphorylation similar to that observed when ghost membranes were incubated with [gamma-32P]ATP. Membrane lipid phosphorylation was also similar in intact cells and ghosts. The most heavily phosphorylated lipid, polyphosphoinositide, was closely associated with glycophorin A, the major erythrocyte membrane sialoglycoprotein obtained when the sialoglycoprotein fraction was isolated by the lithium diiodosalicylate-phenol partition procedure. Only 1 molecule of glycophorin A out of every 100 was found to be phosphorylated, and the phosphate exchange occurred specifically in the COOH-terminal intracellular portion of glycophorin A. These studies show that the human erythrocyte can be used as a model for membrane phosphorylation in an intact cell system.
通过将红细胞置于无机[32P]磷酸盐中孵育，对完整人红细胞膜中的磷酸化进行了研究。用聚丙烯酰胺凝胶电泳分析膜蛋白，结果显示出的磷酸化模式与用[γ-32P]ATP孵育血影膜时观察到的模式相似。完整细胞和血影中的膜脂磷酸化情况也相似。磷酸化程度最高的脂质——多磷酸肌醇，与血型糖蛋白A密切相关，血型糖蛋白A是通过二碘水杨酸锂-苯酚分配法分离唾液糖蛋白组分时得到的主要红细胞膜唾液糖蛋白。每100个血型糖蛋白A分子中只有1个被发现发生了磷酸化，且磷酸交换特异性地发生在血型糖蛋白A的COOH末端细胞内部分。这些研究表明，人红细胞可作为完整细胞系统中膜磷酸化的模型。
