title: Immunological and binding studies on chloroform--methanol extracts from electroplax of Torpedo marmorata and from rat brain cortex. Comparison of the material solubilized by organic solvents with the receptor proteins solubilized by detergents.
abstract: We have investigated a chloroform--methanol extracted material from electric organ of Torpedo marmorata with respect to binding of [3H]-acetyl-alpha-neurotoxin and [3H]-acetylcholine. No binding was observed which is in contrast to observations with detergent extracted receptor. Further, no crossreactivity could be demonstrated between the chloroform--methanol extracted proteolipid and antibodies against the detergent extracted receptor. Labelling in the membrane with [3H]-acetyl-alpha-neurotoxin before extraction with chloroform--methanol gave a very low yield of extracted labelled compound. The protein yield is about 0.3% of the total in the homogenate and only 0.04% of the specifically bound neurotoxin. Using the alkylating affinity label [3H]-N-propylbenzilylcholine mustard (1) and also [3H]-atropine, which both bind, at low concentrations, specifically to the muscarinic acetylcholine receptor, binding was studied to the chloroform--methanol extracted proteolipid from rat brain cortex. No specific binding could, however, be demonstrated. Prelabelling in the membrane with 1 and subsequent extraction with chloroform--methanol gave a protein yield of about 1% and an extraction of 26% of the specifically bound label.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002540:Cerebral Cortex / Q000032:analysis; D002725:Chloroform / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D003429:Cross Reactions; D003902:Detergents; D004557:Electric Organ / Q000032:analysis; D005399:Fishes; D000432:Methanol / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D009498:Neurotoxins / Q000378:metabolism; D011485:Protein Binding; D051381:Rats
chemical_list: D003902:Detergents; D009498:Neurotoxins; D002725:Chloroform; D000109:Acetylcholine; D000432:Methanol