从牛神经垂体分离出的微囊泡的ATP依赖性Ca2+积累。

ATP-dependent Ca2+ accumulation by microvesicles isolated from bovine neurohypophyses.

作者信息

Torp-Pedersen C, Saermark T, Bundgaard M, Thorn N A

出版信息

J Neurochem. 1980 Sep;35(3):552-7. doi: 10.1111/j.1471-4159.1980.tb03690.x.

DOI:10.1111/j.1471-4159.1980.tb03690.x

Abstract

Microvesicles with and without coats were isolated from bovine neurohypophyses by a series of ultracentrifugation steps. They were similar to microvesicles previously isolated from brain. In the presence of ATP and Mg2+, the microvesicles accumulated calcium. Oxalate stimulated and the Ca2+ ionophore A23187 inhibited calcium accumulation. In the presence of Ca2+ and Mg2+ the microvesicles also demonstrated ATPase activity. As judged by SDS electrophoresis in polyacrylamide gels microvesicle protein composition was very different from that of neurosecretory granules, suggesting that they are not granule membranes "retrieved" after exocytosis. They may have an important function in regulation of Ca2+ ion concentration.

摘要

通过一系列超速离心步骤，从牛神经垂体中分离出有被和无被微囊泡。它们与先前从大脑中分离出的微囊泡相似。在ATP和Mg2+存在的情况下，微囊泡积累钙。草酸盐起刺激作用，而Ca2+离子载体A23187抑制钙的积累。在Ca2+和Mg2+存在的情况下，微囊泡也表现出ATP酶活性。通过聚丙烯酰胺凝胶中的SDS电泳判断，微囊泡的蛋白质组成与神经分泌颗粒的蛋白质组成非常不同，这表明它们不是胞吐作用后“回收”的颗粒膜。它们可能在调节Ca2+离子浓度方面具有重要功能。