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：147-151
DOI：10.1073/pnas.69.1.147
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Experiments were performed to determine the specificity of [125I][α]-bungarotoxin binding to skeletal muscle. In adult rat diaphragm, [125I][α]-bungarotoxin was found to bind almost exclusively to those regions of the muscle that contain endplates and are known to be sensitive to acetylcholine. In contrast, chronically denervated adult muscle and muscle from neonatal rats, both of which are sensitive along their entire lengths, bound substantial amounts of toxin in all regions. Toxin binding to all muscles was inhibited by d-tubocurarine and by carbamylcholine, but not by atropine. The bound [125I]toxin was solubilized by homogenization of the tissue in 1% Triton X-100 and was recovered as a single band, distinct from free toxin, after zone sedimentation. Treatment of the solubilized, toxin-bound complex with 2-mercaptoethanol and sodium dodecyl sulfate resulted in the recovery of free toxin. A toxin-bound complex was also obtained when toxin was incubated directly with extracts of muscle endplate regions prepared by homogenization in Triton X-100. No such complex was observed with extracts prepared from muscle lacking endplates. These results are consistent with the interpretation that [α]-bungarotoxin binds specifically to the acetylcholine receptor of mammalian skeletal muscle.
关键词：snake venom ; denervated muscle ; neonatal muscle ; rat diaphragm ; SDS-polyacrylamide gel electrophoresis
