丁氏双鳍电鳐(Narcine timlei)电器官烟碱型乙酰胆碱受体(AChR)某些生化性质的研究  

SOME BIOCHEMICAL PROPERTIES OF THE PURIFIED ACETYLCHOLINE RECEPTOR PROTEIN FROM THE ELECTRIC ORGAN OF NARCINE TIMLEI

作　　者：孙欣 龚潮樑 潘淑英 樊剑英[1] 何其伟[1] Sun Xin;Gong Chaoliang;Pan Shuying;Fan Jianying;He Qiwei(Kunming Institute of Zoology,Academia Sinica,Kunming)

机构地区：[1]中国科学院昆明动物研究所,昆明

出　　处：《Zoological Research》1985年第1期45-56,I0003,I0004,共14页动物学研究（英文）

摘　　要：本文报道了丁氏双鳍电鳐(Narcine timlei)电器官烟碱型乙酰胆碱受体蛋白(AChR)的某些生化性质。纯化的AChR经聚丙烯酰胺梯度(4%—30%)凝胶电泳,呈现一个主要蛋白带,经测定,表观分子量为440,000,与^(125)I-α-Bgt-AChR复合物的分子量相一致。等电聚焦电泳测得纯化AChR和^(125)I-α-BgtAChR的等电点(pI)分别为4.9和5.2;经SDS—聚丙烯酰胺梯度(4%—30%)凝胶电泳,纯化的AChR解离成三个主要亚基蛋白带,它们的表观分子量分别为38,000,42,000和66,000,其中前两个亚基的含量很高,约占总数75%。氨基酸组成分析表明,丁氏双鳍电鳐电器官AChR由18种氨基酸组成,(色氨酸未测定),其中酸性氨基酸含量很高,占总数的20%以上,说明纯化的AChR是一个复杂结构的酸性蛋白大分子。The present paper reports some biochemical properties of the purified ace-tylcholine receptor protein(AChR)from the electric organ of N.timlei.The dctcrgent-solublized purified nicotinic acetylcholine receptor protein exists in a major band,the apparent molecular weight is 440,000 on polyacrylamide gradient gel slab electrophoresis(4%-30%).It is in agreement with the molecular weight of 125Ⅰ-labellcd-α-bungarotoxin binding the purified AChR.The purified AChR of N.timlei is composed of 18 kinds of amino acid,it is rich in acidic amino acids,aspartic acid,glutamic acid(20%).The isoelectric points of the receptor and of the 125Ⅰ-α-bungarotoxin-AChR complex are pH 4.9 and pH 5.2 respectively on isoelectric focusing gel disc electrophoresis.Polyacrylarnide gradient gel slab electrophoresis of the purified receptor in the presence of rodium dodecyl sulfate reveals three bands of apparent molecular weights 38,000,42,000 and 66,000,the two heaviest ones being present in significantly lower amounts than both the subunits of 38,000 and 42,000.

关 键 词：乙酰胆碱受体 电器官 ’α—银环蛇毒素 

分 类 号：R74[医药卫生—神经病学与精神病学]