Dihydropyridine-sensitive calcium channels in cardiac and skeletal muscle membranes: studies with antibodies against the alpha subunits.
Dihydropyridine-sensitive calcium channels in cardiac and skeletal muscle membranes: studies with antibodies against the alpha subunits.
复制标题
心脏和骨骼肌膜中二氢吡啶敏感的钙通道：针对α亚基的抗体的研究。
DOI：
10.1021/bi00391a046
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发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Catterall,WA
中科院分区：
文献类型：
--
作者：
Takahashi,M;Catterall,WA
华盛顿大学药理学系，西雅图，华盛顿 98195 收稿日期：1987 年 2 月 9 日；修订稿于 1987 年 3 月 31 日收到摘要：制备了针对纯化的骨骼肌钙通道的多克隆抗体 (PAC-2)，并通过免疫印迹和免疫沉淀显示其针对该蛋白质的亚基。这些多肽的表观分子量为162000，没有二硫键的还原。在保留纯化的骨骼肌钙通道的功能特性的条件下，{3个亚基（Mr 50000）和7个亚基（Mr 33000）共沉淀，证明这三种多肽在纯化的骨骼肌通道中的特异性非共价缔合。 PAC-2 免疫沉淀心脏钙通道，用 [3H] 异丙酯 4-(2, L, 3-苯并恶二唑-4-基)-1, 4-二氢-2, 6-二甲基-5-(甲氧基羰基) 吡啶-3-甲酸 ([3H] PN200-110) 标记，浓度比骨骼肌通道高 3 倍。与心脏钙通道预孵育仅阻断 PAC-2 对骨骼肌通道的 49% 免疫反应性，表明这两种蛋白具有同源和不同的表位。通过免疫沉淀和聚丙烯酰胺凝胶电泳鉴定心脏钙通道的免疫反应成分为多肽，二硫键还原前表观分子量为170000，还原后表观分子量为141000，与骨骼肌通道a2亚基的性质非常相似。结论是，这两个钙通道具有同源但不同的亚基作为主要多肽成分。Totage敏感性钙通道在调节钙相关细胞功能中发挥重要作用，包括肌肉收缩、神经递质和激素释放，以及通过控制细胞外环境中的钙流入来实现细胞内蛋白质的钙依赖性磷酸化（Hagiwara＆Byerly，1981；Tsien，1983）。二氢-
Department of Pharmacology, University of Washington, Seattle, Washington 98195 Received February 9, 1987; Revised Manuscript Received March 31, 1987 abstract: Polyclonal antibodies (PAC-2) against the purified skeletal muscle calcium channel were prepared and shown to be directed against a subunits of this protein by immunoblotting and immunoprecipitation. These polypeptides have an apparent molecular weight of 162000 without reduction of disulfide bonds. Under conditions where the functional properties of the purified skeletal muscle calcium channel are retained,{3 subunits (Mr 50000) and 7 subunits (Mr 33000) are coprecipitated, demonstrating specific noncovalent association of these three polypeptides in the purified skeletal muscle channel. PAC-2 immunoprecipitated cardiac calcium channels labeled with [3H] isopropyl 4-(2, l, 3-benzoxadiazol-4-yl)-l, 4-dihydro-2, 6-dimethyl-5-(methoxycarbonyl) pyridine-3-carboxylate ([3H] PN200-110) at a 3-fold higher concentration than skeletal muscle channels. Preincubationwith cardiac calcium channels blocked only 49% of the immunoreactivity of PAC-2 toward skeletalmuscle channels, indicating that these two proteins have both ho-mologous and distinct epitopes. The immunoreactive component of the cardiac calcium channel was identified by immunoprecipitation and polyacrylamide gel electrophoresis as a polypeptide with an apparent molecular weight of 170000 before reduction of disulfide bonds and 141 000 after reduction, in close analogy with the properties of the a2 subunits of the skeletal muscle channel. It is concluded that these two calcium channels have a homologous, butdistinct, a subunit as a major polypeptide component.Toltage-sensitive calcium channels play important roles in the regulation of the calcium-linked cellular functions including muscle contraction, neurotransmitter and hormone release, and calcium-dependent phosphorylation of intracellular proteins by controlling calcium influx from the extracellular environ-ment (Hagiwara & Byerly, 1981; Tsien, 1983). Dihydro-