SUBUNIT STRUCTURE OF DIHYDROPYRIDINE-SENSITIVE CALCIUM CHANNELS FROM SKELETAL-MUSCLE
SUBUNIT STRUCTURE OF DIHYDROPYRIDINE-SENSITIVE CALCIUM CHANNELS FROM SKELETAL-MUSCLE
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DOI：
10.1073/pnas.84.15.5478
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发表时间：
1987-08-01
影响因子：
11.1
通讯作者：
CATTERALL, WA
中科院分区：
文献类型：
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作者：
TAKAHASHI, M;SEAGAR, MJ;CATTERALL, WA
从兔横小管膜中纯化的二氢吡啶敏感钙通道由三种非共价相关的亚基组成：α。（167 kDa）， .beta。（54 kDa）和。(30 kDa)。二硫键的断裂显示出两个不同的α。多肽和一个额外的成分，δ….alpha。1亚基是一个175 kda的多肽，没有n -糖基化，包含二氢吡啶结合位点、camp依赖性蛋白激酶磷酸化位点和大量的疏水结构域。2，一个143 kda的糖蛋白，没有。α的特性。1，但结合凝集素和含有约25%的n -连接碳水化合物。2是二硫连接到。δ，一个24- 27kda的糖肽。β。（54 kDa）含有camp依赖性磷酸化位点，但没有n -糖基化，也没有疏水结构域。（30kda）的碳水化合物含量约为30%，具有广泛的疏水结构域(s)。亲和纯化anti- α沉淀。1个抗体或。2特异性扁豆凝集素琼脂糖证明了。α。1. α。2. β…在洋地黄苷或3-[（3-胆酰胺丙基）二甲酰胺]-1-丙磺酸盐存在时表现为络合物，而。复合体能从。α。1。β。在Triton X-100存在的情况下在这些观察的基础上，提出了亚基相互作用和膜插入的模型。
Purified dihydropyridine-sensitive calcium channels from rabbit transverse-tubule membranes consist of three noncovalently associated classes of subunits: .alpha. (167 kDa), .beta. (54 kDa) and .gamma. (30 kDa). Cleavage of disulfide bonds reveals two distinct .alpha. polypeptides and an additional component, .delta.. The .alpha.1 subunit, a 175-kDa polypeptide that is not N-glycosylated, contains the dihydropyridine binding site, cAMP-dependent protein kinase phosphorylation site(s), and substantial hydrophobic domain(s). .alpha.2, a 143-kDa glycoprotein, has none of the properties characteric of .alpha.1 but binds lectins and contains about 25% N-linked carbohydrate. .alpha.2 is disulfide-linked to .delta., a 24- to 27-kDa glycopeptide. .beta. (54 kDa) contains a cAMP-dependent phosphorylation site but is not N-glycosylated and does not have a hydrophobic domain. .gamma. (30 kDa) has a carbohydrate content of about 30% and extensive hydrophobic domain(s). Precipitation with affinity-purified anti-.alpha.1 antibodies or .alpha.2-specific lentil lectin-agarose demonstrated that .alpha.1.alpha.2.beta..gamma..delta. behaves as a complex in the presence of digitonin or 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, whereas the .alpha.2.delta. complex dissociates from .alpha.1.beta..gamma. in the presence of Triton X-100. A model for subunit interaction and membrane insertion is proposed on the basis of these obesrvations.