Peripheral proteins of postsynaptic membranes from Torpedo electric organ identified with monoclonal antibodies.
Peripheral proteins of postsynaptic membranes from Torpedo electric organ identified with monoclonal antibodies.
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DOI：
10.1083/jcb.99.1.88
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发表时间：
1984-07
期刊：
影响因子：
--
通讯作者：
Froehner SC
中科院分区：
文献类型：
--
作者：
Froehner SC
来自鱼雷电器官的高纯度突触后膜含有乙酰胆碱受体和其他蛋白质。为了识别突触特异性成分，我们制备了针对用二碘水杨酸锂或碱性处理从膜中提取的蛋白质的单抗。获得了10株能与3种不同蛋白特异的单抗。7株单抗与一个主要的43,000摩尔重量蛋白(43K蛋白)反应。该蛋白由等电变异体(pl=7.2-7.8)组成，每个单抗与所有变异体反应。通过竞争结合43K蛋白和免疫印迹中43K蛋白的蛋白水解性片段对这些单抗进行分析，结果表明它们至少识别5个不同的表位。两株单抗分别与90000molwt蛋白(90K蛋白)和58000molwt等电变异体蛋白(pl=6.4~6.7)(58K蛋白)反应。43K和58K蛋白似乎与含有受体的膜协同纯化，而90K蛋白则没有。免疫荧光实验表明，抗43K单抗与鱼雷细胞的神经面结合，并在大鼠神经肌肉接头处发现与43K蛋白相关的成分。抗58K单抗对神经支配的面部染色较弱，而抗90K单抗与非神经支配的膜反应强烈。因此，43K蛋白和58K蛋白可能是突触成分，而90K蛋白主要是非突触成分。
Highly purified postsynaptic membranes from Torpedo electric organ contain the acetylcholine receptor as well as other proteins. To identify synapse-specific components, we prepared monoclonal antibodies (mabs) to proteins extracted from the membranes with either lithium diiodosalicylate or alkaline treatment. 10 mabs specific for three different proteins were obtained. Seven mabs reacted with a major 43,000-mol-wt protein (43K protein). This protein is composed of isoelectric variants (pl = 7.2-7.8) and each of the mabs reacted with all of the variants. Analysis of these mabs by competition for binding to 43K protein and by reaction with proteolytic fragments of 43K protein in immunoblots showed that they recognize at least five different epitopes. Two mabs reacted with a protein of 90,000 mol wt (90K protein) and one with a protein of 58,000 mol wt composed of isoelectric variants (pl = 6.4-6.7) (58K protein). The 43K and 58K proteins appeared to co-purify with the receptor-containing membranes while the 90K protein did not. Immunofluorescence experiments indicated that the anti-43K mabs bind to the innervated face of Torpedo electrocytes and that a component related to the 43K protein is found at the rat neuromuscular junction. The anti-58K mab stained the innervated face, although rather weakly, while the anti-90K mabs reacted intensely with the non-innervated membrane. Thus, the 43K protein and possibly also the 58K protein are synaptic components while the 90K protein is predominantly nonsynaptic.