Meyer D I, Dobberstein B
J Cell Biol. 1980 Nov;87(2 Pt 1):498-502. doi: 10.1083/jcb.87.2.498.
Previous reports have shown that rough microsomes treated with high salt (Warren and Dobberstein, 1978, Nature, 273:569-571) or proteases (Walter et al., 1979, Proc. Natl. Acad. Sci, U. S. A., 76:1,795) are unable to vectorially translocate nascent proteins. Readdition of the high salt or protease extracts restored activity to such inactive rough microsomes. A detailed study was carried out to determine how this factor interacts with the rough microsomal membrane. Proteolytic cleavage was found to be necessary but not sufficient to remove this factor from the membrane. A subsequent treatment with high salt had to be carried out. Endogenous (pancreatic) protease could effect the required cleavage, but low levels of trypsin, clostripain, or elastase were far more efficient. Several proteases were not effective. The minimum level of salt (after proteolysis) required to solubilize the active factor was approximately 200 mM KCl. Salt extracts prepared by treatment with one of the effective proteases were capable of restoring activity to inactive microsomes produced by treatment with one of the others.
先前的报道表明，经高盐处理的糙面微粒体（沃伦和多伯斯坦，1978年，《自然》，273:569 - 571）或蛋白酶处理的糙面微粒体（沃尔特等人，1979年，《美国国家科学院院刊》，76:1795）无法将新生蛋白质进行定向转运。向这种无活性的糙面微粒体中重新添加高盐提取物或蛋白酶提取物可恢复其活性。开展了一项详细研究以确定该因子如何与糙面微粒体膜相互作用。发现蛋白水解切割对于从膜上去除该因子是必要的，但并不充分。随后必须进行高盐处理。内源性（胰腺）蛋白酶能够实现所需的切割，但低水平的胰蛋白酶、梭菌蛋白酶或弹性蛋白酶效率更高。几种蛋白酶无效。溶解活性因子所需的最低盐浓度（蛋白水解后）约为200 mM KCl。用其中一种有效蛋白酶处理制备的盐提取物能够恢复用另一种蛋白酶处理产生的无活性微粒体的活性。
