Cross-linking of beta-bungarotoxin to chick brain membranes. Identification of subunits of a putative voltage-gated K+ channel.
beta-Bungarotoxin (beta-Butx), a presynaptically active neurotoxin from snake venom, is thought to bind to a subtype of voltage-gated K+ channels. 125I-beta-Butx was cross-linked to its high-affinity binding site in membrane fractions from chick brain by using the bivalent reagents 1-ethyl-3-[3-(dimethyl-amino)propyl]carbodiimide and sulfosuccinimidyl 6-[(4-azido-2-nitrophenyl)amino]hexanoate. Two major adducts of apparent Mr 90,000-95,000 and 46,000-49,000 were obtained with both cross-linkers. Formation of both adducts was inhibited by the K+ channel ligands dendrotoxin I and mast cell degranulating peptide. Our data indicate that the putative beta-Butx-sensitive neuronal K+ channel contains at least two different types of subunits of about 75 and 28 kDa.
Schmidt
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ZMBH, Universität Heidelberg, FRG.
Betz
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D000818:Animals; D001386:Azides / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002038:Bungarotoxins / Q000378:metabolism* / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002645:Chickens; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004546:Elapid Venoms / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000494:pharmacology; D015640:Ion Channel Gating; D008970:Molecular Weight; D010455:Peptides / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism*; D013388:Succinimides / Q000494:pharmacology
D001386:Azides; D002038:Bungarotoxins; D003432:Cross-Linking Reagents; D004546:Elapid Venoms; D010455:Peptides; D015221:Potassium Channels; D013388:Succinimides; C062325:sulfosuccinimidyl 6-((4-azido-2-nitrophenyl)amino)hexanoate; C008331:mast cell degranulating peptide; C020273:dendrotoxin; D005022:Ethyldimethylaminopropyl Carbodiimide