Effect of the A and B protomers of choleragen on release of trapped glucose from liposomes containing or lacking ganglioside GM1.
Liposomes containing trapped glucose were used to examine the interaction of the A and B protomers of choleragen with ganglioside GM1 and lipid model membranes. The B protomer (choleragenoid) was as effective as choleragen in causing release of trapped glucose from liposomes containing GM1; the A protomer did not release glucose from GM1 liposomes. Neither choleragen nor the A or B protomers caused release of trapped glucose from glycolipid-free liposomes. Anti-choleragen and complement, however, caused release of trapped glucose from ganlioside-free liposomes previously incubated with the A protomer but not from those incubated with the B protomer or choleragen. These results suggest that the A protomer, but not intact choleragen or B protomer, bound to ganglioside-free liposomes. Presumably, the A protomer must be freed of the constraints present in the intact choleragen in order to interact with the liposomal model membrane system.
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005677:G(M1) Ganglioside; D005947:Glucose; D007700:Kinetics; D008081:Liposomes; D046911:Macromolecular Substances; D008954:Models, Biological; D014734:Vibrio cholerae
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D008081:Liposomes; D046911:Macromolecular Substances; D005677:G(M1) Ganglioside; D005947:Glucose