Froehner S C, Rafto S
Biochemistry. 1979 Jan 23;18(2):301-7. doi: 10.1021/bi00569a011.
The acetylcholine receptor from Torpedo californica electroplax was purified approximately 100-fold by affinity chromatography on alpha-neurotoxin-Sepharose 6B. Four putative subunits (alpha, beta, gamma, delta) of apparent molecular weights of 43,000, 52,000, 58,000, and 63,000 were found when the purified material was analyzed by sodium dodecyl sulfate (NaDodSO4) gel electrophoresis. In some preparations, however, the amount of the gamma polypeptide was small. The presence of N-ethylmaleimide throughout the purification procedure greatly enhanced the amount of the gamma chain. To investigate the possibility that the putative subunits may be structurally related, they were isolated by preparative NaDodSO4 gel electrophoresis and subjected to peptide mapping analyses. The patterns of fragments generated by Staphylococcus aureus V8 protease, papain, or chymotrypsin were different for each of the polypeptides. Thus, it is unlikely that they are derivatives of each other.
通过在α-神经毒素-琼脂糖6B上进行亲和层析，加州电鳐电器官的乙酰胆碱受体被纯化了约100倍。当用十二烷基硫酸钠（NaDodSO4）凝胶电泳分析纯化后的物质时，发现了四个推定的亚基（α、β、γ、δ），其表观分子量分别为43,000、52,000、58,000和63,000。然而，在一些制备物中，γ多肽的量很少。在整个纯化过程中存在N-乙基马来酰亚胺极大地增加了γ链的量。为了研究推定的亚基在结构上可能相关的可能性，通过制备性NaDodSO4凝胶电泳将它们分离，并进行肽图谱分析。金黄色葡萄球菌V8蛋白酶、木瓜蛋白酶或胰凝乳蛋白酶产生的片段模式对于每种多肽都是不同的。因此，它们不太可能是彼此的衍生物。
