Evidence for the Complex Nature of the Ganglioside Receptor for Cholera Toxin

• Published in: The Journal of infectious diseases Vol. 131; no. 6; pp. 643 - 648
• Main Authors: King, Carolyn A., van Heyningen, William E.
• Format: Journal Article
• Language: English
• Published: United States The University of Chicago Press 01-06-1975; University of Chicago Press
• Subjects: Active components; Adenosine Triphosphate - metabolism; Adenylyl Cyclases - metabolism; Animals; Binding Sites; Carbon Radioisotopes; Cell Membrane - metabolism; Cell membranes; Cerebrosides; Cholera; Columbidae; Cyclic AMP - metabolism; Erythrocytes; Formaldehyde; Gangliosides; Gangliosides - metabolism; Guinea Pigs; Hemolysin Proteins; Intestinal Mucosa - metabolism; Major Articles; Molecules; Receptors; Receptors, Drug; Skin - drug effects; Toxicity; Toxins; Toxins, Biological - metabolism; Toxins, Biological - toxicity
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/131.6.643

Choleragenoid binds more slowly and less strongly than cholera toxin to intestinal mucosal cells, and even less strongly to free ganglioside in solution. However, binding to ganglioside is greatly enhanced when the ganglioside is in the form of an insoluble complex with cerebroside. These findings suggest that both the binding and the active components of the toxin molecule may be necessary for optimal binding of the toxin to the intact cell, and that the ganglioside in the cell receptor is in a complex form. Choleragenoid only partially blocks the action of the toxin on ruptured cells. This observation indicates that, while binding to a membrane receptor is necessary for the action of the toxin on the whole cell, it is possible to activate adenyl cyclase in a perforated cell by a process apparently independent of membrane binding; however, this activation may be possible only if the toxin preparation contains the active component dissociated from choleragenoid.