Size of acetylcholine receptors in the membrane. An improved version of the radiation inactivation method.
Size of acetylcholine receptors in the membrane. An improved version of the radiation inactivation method.
复制标题
膜上乙酰胆碱受体的大小。
作者：
M. Lo;E. Barnard;J. Dolly
采用辐射失活法研究完整膜结合状态下乙酰胆碱受体的大小。这项技术被重新研究，并进行了修改，消除了影响其先前应用于此类蛋白质的实质性困难。参考一组蛋白质标准品，推导出分子大小，并根据给定的内酶分子量标准品定义失活比，构建并应用蛋白质标准品失活比的线性校准图。用这种方法发现，鱼雷电器官、猫去神经肌肉和鸡胚肌中的乙酰胆碱受体在膜中以大小相同的同质群体存在。这种受体，当通过α -神经毒素结合靶结构识别时，表观分子量为300000，分子体积约为350 nm3。相比之下，经广泛交联后凝胶电泳分析，猫肌受体溶解后的分子量为270000 +/- 20000。根据细胞膜中受体蛋白的情况和结构，这两个值被认为是相等的。如果膜中存在二硫桥二聚体受体（如鱼雷的其他证据所示），则每个单体在结合α -神经毒素时独立起作用，因为单体可以通过鱼雷膜中的辐照独立灭活。在肌膜中，没有发现任何形式的受体二聚体存在的证据。
The radiation inactivation method was used to study the size of acetylcholine receptors in the intact membrane-bound state. This technique was reinvestigated, and modifications were made which remove substantial difficulties affecting previous applications of it to such proteins. The molecular size was deduced here by reference to a set of protein standards: an inactivation ratio was defined relative to a given internal enzyme molecular weight standard, and a linear calibration plot for the inactivation ratios of the protein standards was constructed and applied. The acetylcholine receptor in Torpedo electric organ, cat denervated muscle, and chick embryonic muscle was found by this method to exist in the membrane as a homogeneous population of the same size in each case. This receptor, when identified thus by the alpha-neurotoxin-binding target structure, has an apparent molecular weight of 300000 or a molecular volume of about 350 nm3. In comparison, the molecular weight of the cat muscle receptor when solubilized, as analyzed by gel electrophoresis after extensive cross-linking, was found to be 270000 +/- 20000. These two values are thought to be equivalent by virtue of the situation and structure of the receptor protein in the cell membrane. If a disulfide-bridge dimeric receptor exists in the membrane (as other evidence has indicated for Torpedo), each monomer acts independently there in binding alpha-neurotoxin, since the monomers can be inactivated independently by irradiation in the Torpedo membrane. In the muscle membrane no evidence for the existence of receptor dimers, of any kind, has been found.
重构膜中乙酰胆碱受体单体和二聚体形式的功能特性。
DOI：
10.1016/0006-291x(81)91764-2
发表时间：
1981
影响因子：
3.1
作者：
Wu,WC;Raftery,MA
通讯作者：
Raftery,MA