Aspects of the interaction of Vibrio cholerae toxin with the pigeon red cell membrane.
The ganglioside galactosy-N-acetylgalactosaminyl [sialosyl] lactosyl ceramide (GM1) is readily accumulated in pigeon red cell membranes soaked with [3H]GM1 (1-100 mug/ml) at 37 C for 30 min. This treatment enhances the activation of adenyl cyclase by the toxin of Vibrio cholerae. An attempt was made at correlation of the amount of incorporated GM1 with the increased binding of toxin and activation of adenyl cyclase. Cells with less than 2 mug of incorporated GM1 per 4 X 10(9) cells bind 5-10 mug more toxin than do untreated cells, which bind 0.25 mug per 4 X 10(9) cells. Cells with more than 2 mug of GM1 bound (per 4 X 10(9) CELls) which has been incorporated from micellar solutions of GM1 (greater than 20 mug/ml), do not bind any more extra toxin. In untreated cells, 0.1 mug of toxin is involved in the activation of adenyl cyclase. In GM1-treated cells 0.25-0.5 mug of toxin is involved, although at least 5 mug of toxin is bound. It is concluded that 90% of the extra toxin-binding sites on the GM1-treated cell are nonproductive.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D010856:Columbidae; D004768:Enterotoxins / Q000378:metabolism* / Q000494:pharmacology; D004789:Enzyme Activation; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism*; D005732:Gangliosides / Q000378:metabolism / Q000494:pharmacology; D014734:Vibrio cholerae
D004768:Enterotoxins; D005732:Gangliosides; D000262:Adenylyl Cyclases