IMMUNOFLUORESCENCE LOCALIZATION AT THE MAMMALIAN NEUROMUSCULAR-JUNCTION OF THE MR43,000 PROTEIN OF TORPEDO POSTSYNAPTIC MEMBRANES
IMMUNOFLUORESCENCE LOCALIZATION AT THE MAMMALIAN NEUROMUSCULAR-JUNCTION OF THE MR43,000 PROTEIN OF TORPEDO POSTSYNAPTIC MEMBRANES
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DOI：
10.1073/pnas.78.8.5230
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发表时间：
1981-01-01
期刊：
影响因子：
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通讯作者：
COHEN, JB
中科院分区：
文献类型：
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作者：
FROEHNER, SC;GULBRANDSEN, V;COHEN, JB
来自电鳐电组织的高度纯化的胆碱能突触后膜除了含有乙酰胆碱受体（AcChoR）外，还含有MW为43，000和90，000，以及可以通过碱处理从膜中去除的少量蛋白质。制备了这些碱可提取蛋白质的抗血清，该抗血清与MW 43，000蛋白质反应，但不与任何其他主要膜蛋白（包括AcChoR亚基）反应。电鳐电组织切片的免疫荧光染色显示，该抗血清结合到受神经支配的电细胞表面，但不结合到未受神经支配的电细胞表面。在大鼠膈肌中，这种抗血清识别的抗原高度集中在突触处。通过预先将抗血清与MW 43，000蛋白孵育而不是与亲和纯化的AcChoR孵育，可以消除肌肉的突触染色。这种抗血清染色终板的肌肉去神经7天。AcChoR的抗血清与电解质和肌肉的突触下膜结合，但不与MW 43，000蛋白反应。纯化的AcChoR阻断抗AcChoR对突触的染色，但MW 43，000蛋白质不能。分子量为43，000的蛋白质明显定位于电鳐电细胞的神经支配膜上。一种免疫学上类似的成分可能高度集中在哺乳动物肌肉的突触后膜上。
Highly purified cholinergic postsynaptic membranes from Torpedo electric tissue contain, in addition to the acetylcholine receptor (AcChoR), major proteins of MW 43,000 and .apprxeq. 90,000, and minor proteins that can be removed from the membranes by alkaline treatment. An antiserum to these alkaline-extractable proteins that reacts with the MW 43,000 protein but not with any of the other major membrane proteins, including the AcChoR subunits, was prepared. Immunofluorescent staining of sections of Torpedo electric tissue shows that this antiserum binds to the innervated but not the uninnervated surface of the electrocytes. In rat diaphragm muscle the antigens recognized by this antiserum are highly concentrated at the synapse. Synaptic staining of muscle is eliminated by prior incubation of the antiserum with the MW 43,000 protein but not by incubation with affinity-purified AcChoR. This antiserum stains end plates of muscles denervated for 7 days. Antiserum to AcChoR binds to the subsynaptic membranes of electrolytes and muscle but does not react with the MW 43,000 protein. Purified AcChoR blocks staining of synapses by anti-AcChoR but the MW 43,000 protein does not. MW 43,000 protein is apparently located in the innervated membrane of Torpedo electrocytes. An immunologically similar component is probably highly concentrated in the postsynaptic membrane of mammalian muscle.