Sun I, Morré D J, Crane F L, Safranski K, Croze E M
Biochim Biophys Acta. 1984 Feb 14;797(2):266-75. doi: 10.1016/0304-4165(84)90130-2.
Coated vesicles were isolated from rat liver in about 80% fraction purity as determined from electron microscopy and analyses of marker enzymes and compared with Golgi apparatus and other membrane fractions isolated in parallel. The fractions were enriched in NADH-monodehydroascorbate reductase, ascorbate oxidase and ascorbic acid. The NADH-monodehydroascorbate reductase and ascorbate oxidase of the Golgi apparatus and coated vesicles differed from that of the endoplasmic reticulum in being inhibited by the sodium selective ionophore, monensin, at physiological concentrations while these activities were stimulated by ethylenediaminetetraacetic acid in coated vesicles but not in Golgi apparatus. Activities of both coated vesicles and Golgi apparatus fractions depleted in the coat protein, clathrin, were activated by the addition of clathrin-rich supernatant fractions. The results are discussed in the context of monodehydroascorbate as an acceptor for electron transport-mediated transfer of electrons from NADH by coated vesicles as part of a possible mechanism to drive membrane translocations or to acidify the interiors of vesicles.
通过电子显微镜以及标记酶分析确定，从大鼠肝脏中分离出的包被小泡纯度约为80%，并与平行分离出的高尔基体和其他膜组分进行比较。这些组分富含NADH-单脱氢抗坏血酸还原酶、抗坏血酸氧化酶和抗坏血酸。高尔基体和包被小泡的NADH-单脱氢抗坏血酸还原酶及抗坏血酸氧化酶与内质网的不同，在生理浓度下，它们会被钠选择性离子载体莫能菌素抑制，而在包被小泡中，这些活性会被乙二胺四乙酸刺激，在高尔基体中则不然。包被蛋白网格蛋白缺失的包被小泡和高尔基体组分的活性，会因添加富含网格蛋白的上清组分而被激活。本文在单脱氢抗坏血酸作为电子受体的背景下讨论了这些结果，包被小泡通过电子传递介导将电子从NADH转移，这可能是驱动膜转运或使小泡内部酸化的一种机制。
