Yousef I M
Can J Biochem Cell Biol. 1983 May;61(5):293-300. doi: 10.1139/o83-040.
Plasma membrane fractions, microsomes, and mitochondrial membrane were prepared from rat liver. The effects of incubation of these membranes in various ionic strengths (1-12 mM) of NaHCO3 (pH 7.4) on the polypeptide patterns were studied in the absence or the presence of various concentrations of CaCl2 (1-12 mM). Many polypeptides were extracted from each of the membranes in the low ionic strength buffers (1 mM); these polypeptides were essentially similar to those remaining in the membrane after incubation. The extraction of these polypeptides continued when concentration of NaHCO3 increased. However, the presence of CaCl2 at a concentration of 4 mM or higher stabilized the membrane proteins and reduced the continuous loss of the polypeptides, and only low molecular weight polypeptides were affected. These data suggest that the organization of proteins in liver cell membranes may depend on the nature of their interaction with other membrane components (i.e., phospholipids), which could be affected by Ca2+ ions.
从大鼠肝脏中制备了质膜组分、微粒体和线粒体膜。在不存在或存在不同浓度氯化钙（1 - 12 mM）的情况下，研究了这些膜在不同离子强度（1 - 12 mM）的碳酸氢钠（pH 7.4）中孵育对多肽图谱的影响。在低离子强度缓冲液（1 mM）中，从每种膜中提取出许多多肽；这些多肽与孵育后留在膜中的多肽基本相似。当碳酸氢钠浓度增加时，这些多肽的提取仍在继续。然而，4 mM或更高浓度的氯化钙的存在使膜蛋白稳定，并减少了多肽的持续损失，只有低分子量多肽受到影响。这些数据表明，肝细胞膜中蛋白质的组织可能取决于它们与其他膜成分（即磷脂）相互作用的性质，而这种相互作用可能会受到钙离子的影响。
