|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 16, 473-479, Copyright © 1974 by Company of Biologists
Submitted on March 29, 1974
-Bungarotoxin Conjugates
1 Laboratory of Experimental Pathology, National Institute of Arthritis, Metabolism, and Digestive Diseases, and Behavioural Biology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20014, U.S.A.; University Hospital, San Diego, California, U.S.A.
2 Laboratory of Experimental Pathology, National Institute of Arthritis, Metabolism, and Digestive Diseases, and Behavioural Biology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20014, U.S.A.
3 Laboratory of Experimental Pathology, National Institute of Arthritis, Metabolism, and Digestive Diseases, and Behavioural Biology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20014, U.S.A.; Yale University School of Medicine, New Haven, Connecticut, U.S.A.
4 Laboratory of Experimental Pathology, National Institute of Arthritis, Metabolism, and Digestive Diseases, and Behavioural Biology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20014, U.S.A.; Harvard Medical School, Boston, Massachusetts, U.S.A.
-Bungarotoxin-ferritin conjugates were used to visualize by freeze-fracture and thin-section electron microscopy toxin-binding sites, presumably acetylcholine (ACh) receptors, in membranes of muscle cells grown in tissue culture. Toxin conjugated to ferritin by a glutaraldehyde reaction and purified by column chromatography in a buffer of high ionic strength remains active in blocking the effect of iontophoretically applied ACh. The potency of the conjugates was decreased 5-10 times compared to native
-bungarotoxin. Toxin-ferritin conjugates were identified in small clusters which were not uniformly distributed over the surface membrane. Binding was inhibited by preincubation in D-tubocurare or unconjugated toxin. The relation of the clusters to the non-uniform distribution of ACh sensitivity and
-bungarotoxin binding on cultured muscle fibres is discussed.