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：1980
卷号：77
期号：8
页码：4823-4827
DOI：10.1073/pnas.77.8.4823
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A biotinylated derivative of alpha-bungarotoxin and tetramethylrhodamine-labeled avidin were employed to fluorescence label the acetylcholine receptors (AcChoR) on the surface of rat myotubes in primary culture. Because of the multivalency of both the biotinylated bungarotoxin and the avidin, this treatment extensivey crosslinks the AcChoR. AcChoR crosslinking immobilizes more than 90% of the normally laterally mobile AcChoR as verified by the fluorescence photobleaching recovery technique; it also redistributes the AcChoR into visible micropatches. Biotinylated alpha-bungarotoxin/avidin-induced AcChoR crosslinking greatly accelerates the rate of internalization of surface AcChoR; this rapid internalization affects both the normally immobile AcChoR in areas of diffuse distribution and the normally immobile AcChoR in preexisting patches. The peculiar pattern of fluorescent avidin binding to AcChoR patches previously bound with biotinylated bungarotoxin suggests that almost all AcChoR patches are in very close contact (< 70 A) with the glass substrate. AcChoR immobilization leads to a partial immobilization of concanavalin A receptors in the myotube membrane.
