Binding of five cholinergic ligands to housefly brain and Torpedo electroplax. Relationship to acetylcholine receptors.
Binding of five cholinergic ligands to housefly brain and Torpedo electroplax. Relationship to acetylcholine receptors.
复制标题
五种胆碱能配体与家蝇大脑和鱼雷电板的结合。
作者：
M. Eldefrawi;A. Eldefrawi;R. O'brien
已研究了浓度接近 1 µM 的放射性麝香酮、尼古丁、十甲铵、二甲基 d-筒箭毒碱和阿托品与 Torpedo electroplax 和家蝇大脑制剂的结合。检查的因素包括结合常数和量、胆碱能和非胆碱能药物的竞争、可逆性以及对水解酶的敏感性。在 Torpedo electroplax 中，麝香酮、尼古丁和十甲铵似乎与相同的大分子结合，结合常数在 0.4 至 2.5 µM 之间。这些磷脂蛋白的含量为 1.0-2.1 纳摩尔/克（鲜重）；它们的特性与烟碱受体的特性相似。在家蝇的大脑中，相同的三个配体以及阿托品似乎以 0.2 至 3.2 µM 之间的结合常数结合到相同的大分子上，这些大分子的蛋白质含量为 2.2-3.2 nmole/g（鲜重）。后者表现出与烟碱受体和毒蕈碱受体相似的特性。
致谢 我们感谢 S. Rhine 先生的计算机分析。
The binding of radioactive muscarone, nicotine, decamethonium, dimethyl d -tubocurarine, and atropine to preparations of Torpedo electroplax and housefly brain has been studied at concentrations near 1 µM. Factors examined include binding constants and amounts, competition by cholinergic and noncholinergic drugs, reversibility, and sensitivity to hydrolytic enzymes. In Torpedo electroplax, muscarone, nicotine, and decamethonium appeared to bind, with binding constants between 0.4 and 2.5 µM, to the same macromolecules. These were phospholipoproteins present in the amount of 1.0-2.1 nmoles/g, fresh weight; their properties were similar to those of a nicotinic receptor. In the brain of the housefly, the same three ligands and also atropine appeared to bind, with binding constants between 0.2 and 3.2 µM, to the same macromolecules, which were proteins present in the amount of 2.2-3.2 nmoles/g, fresh weight. The latter exhibited properties similar to those of both nicotinic and muscarinic receptors.
ACKNOWLEDGMENT We are grateful to Mr. S. Rhine for computer analysis.