期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1972
卷号:69
期号:1
页码:177-181
DOI:10.1073/pnas.69.1.177
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The technique of reversible equilibrium dialysis has been applied to the study of macromolecules that are essential for axonal conduction. A binding component from a preparation of an axon-plasma membrane has been characterized and shown to bind nicotine with a KD = 0.42 {+/-} 0.04 {micro}M and to the extent of 0.7 nmol/g of wet nerve. This binding was competitively blocked by acetylcholine (Ki = 43 {+/-} 7 {micro}M) and procaine (Ki = 2.9 {+/-} 0.2 {micro}M). This axonal macromolecule exhibits several of the properties of cholinergic postsynaptic receptors including its concentration in the tissue, blockade of its binding of nicotine by cholinergic drugs and [α]-bungarotoxin, and its phospholipoprotein nature. Some important differences are a lower affinity for acetylcholine and its binding of procaine. It is suggested that this nicotine receptor is on the internal surface of the axon plasma membrane and is a component common to both the Na+ and K+ gates.