Botulinum toxin belongs to a group of toxins called A-B toxins.What does the term "A-B" refer to?

Question

Quizplus · Accepted Answer

The term "A-B" refers to the two subunits of these toxins. The A subunit is the enzymatically active subunit that causes toxicity, while the B subunit is responsible for binding to specific receptors on the surface of target cells. A-B toxins are characterized by their ability to enter the host cell by receptor-mediated endocytosis. Once inside the cell, the toxin's A subunit separates from the B subunit and brings about its toxic effects. Botulinum toxin, for example, cleaves proteins involved in neurotransmitter release, resulting in muscle paralysis.

Botulinum Toxin Belongs to a Group of Toxins Called A-B