Question

Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed,

1) polypeptide A would bind to target cells.
2) polypeptide A would enter the cells.
3) polypeptide B would not be able to enter the cells.
4) Vibrio would not produce cholera toxin.
5) Vibrio would bind to target cells.

Answer 1

If the gangliosides were removed, polypeptide A and polypeptide B of the cholera toxin would not be able to bind or enter the target cells, but this would not affect the production of cholera toxin by Vibrio cholerae.

Step-by-step explanation:

Effects of Removing Gangliosides on Cholera Toxin Interaction

Cholera toxin, which is produced by Vibrio cholerae, is an A-B toxin with the B subunit binding to gangliosides on target cells for attachment and entry. If gangliosides were removed, several things would occur:

Polypeptide A would not bind to target cells since its attachment depends on the presence of gangliosides.

• Without binding, polypeptide A would not enter the cells as the entry is mediated by the earlier binding process.
• Similarly, polypeptide B requires binding to the gangliosides to enable entry, so it would not be able to enter the cells.
• The removal of gangliosides does not influence the production of cholera toxin by Vibrio, so the bacteria would still produce cholera toxin.
• Lastly, whether Vibrio would bind to target cells is unrelated to the cholera toxin's action. Instead, it is determined by other adhesion factors on the bacteria.

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