Question

How does pertussis toxin inhibit phospholipase C?

Short answer

Pertussis toxin protects against G text protein and prevents GDT from being exchanged for GTP, inhibiting phospholipase C.

Step-by-step solution

Explanation of Concept

The bacterium Bordetella pertussis produces pertussis toxin, a protein-based AB5-type exotoxin that causes whooping cough.The colonization of the respiratory tract and the formation of infection are both aided by PT

Preventing it from Inhibiting

Pertussis toxin inhibits phospholipase$\text{C}$through a particular Cys residue of${\text{G}}_{\text{iα}}\text{,}$preventing it from exchanging GDP for GTP and hence preventing it from inhibiting adenylate cyclase.

Pertussis toxin prevents diffusion of GTP from G proteins, which activates phospholipase$\text{C}$.

Therefore, Pertussis toxin protects against G text protein and prevents GDT from being exchanged for GTP, inhibiting phospholipase $\text{C}$.