Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed,
A) polypeptide A would bind to target cells.
B) polypeptide B would not be able to enter the cells.
C) polypeptide A would enter the cells.
D) Vibrio would bind to target cells.
E) Vibrio would not produce cholera toxin.

Question

Quizplus · Accepted Answer

Cholera toxin polypeptide B is responsible for entering the cells and delivering the toxic A subunit. Without gangliosides on the surface of the target cells, polypeptide B would not be able to enter the cells and deliver the toxic A subunit, making option B correct. Since polypeptide A is responsible for binding to gangliosides, its ability to bind to target cells would be reduced, but it would still be present in the surrounding environment. Removal of gangliosides would not directly affect the binding of Vibrio to target cells or the production of cholera toxin.

Cholera Toxin Polypeptide a Binds to Surface Gangliosides on Target