Takahashi M, Catterall W A
Science. 1987 Apr 3;236(4797):88-91. doi: 10.1126/science.2436296.
Voltage-sensitive calcium channels in different tissues have diverse functional properties. Polyclonal antibodies (PAC-2) against the alpha subunits of purified rabbit skeletal muscle calcium channels immunoprecipitated calcium channels labeled with the dihydropyridine PN200-110 from both skeletal muscle and brain. The immunoreactivity of PAC-2 with the skeletal muscle channel was greater than that with the brain calcium channel and was absorbed only partially by prior treatment with the brain channel. PAC-2 specifically recognized a large peptide in synaptic plasma membranes of rabbit brain with an apparent molecular size of 169,000 daltons. This protein resembles an alpha subunit of the skeletal muscle calcium channel in apparent molecular weight, antigenic properties, and electrophoretic behavior after reduction of disulfide bonds. Thus, the dihydropyridine-sensitive calcium channel of rabbit brain has an alpha subunit that is homologous, but not identical, to those of the skeletal muscle calcium channel. The different functional properties of these two calcium channels may result from minor variations in structurally similar components.
不同组织中的电压敏感钙通道具有多样的功能特性。针对纯化的兔骨骼肌钙通道α亚基的多克隆抗体（PAC - 2），能免疫沉淀来自骨骼肌和大脑的、用二氢吡啶PN200 - 110标记的钙通道。PAC - 2与骨骼肌通道的免疫反应性强于其与脑钙通道的免疫反应性，并且仅被预先用脑通道处理部分吸收。PAC - 2能特异性识别兔脑突触质膜中一条表观分子大小为169,000道尔顿的大肽段。该蛋白质在表观分子量、抗原特性以及二硫键还原后的电泳行为方面，类似于骨骼肌钙通道的α亚基。因此，兔脑的二氢吡啶敏感钙通道具有一个与骨骼肌钙通道α亚基同源但不相同的α亚基。这两种钙通道不同的功能特性可能源于结构相似成分的微小差异。
