Structural changes in alkaline-treated postsynaptic membranes from Torpedo marmorata are not due to lipid hydrolysis

The removal of the 43 kDa peptide from postsynaptic membranes from the electric organ of Torpedo by alkaline treatment (pH 11) or by lithium diiodosalicylate at pH 8 results in similar ultrastructural changes that cannot be produced by the action of porcine pancreatic phospholipase A2 or lysophosphatidylcholine. Thin-layer chromatography fails to reveal significant alkaline hydrolysis of membrane lipids from postsynaptic membranes and erythrocyte ghosts under the conditions used for peptide extraction.