Question

You are an exotic animal vet. Your favorite patient, the banded sea krait, is back! You decide to collect venom from the krait and isolate alpha-bungarotoxin (a nicotinic ACh receptor antagonist). What is the primary function of alpha-bungarotoxin?

a) Increase acetylcholine release
b) Inhibit acetylcholine binding to receptors
c) Enhance acetylcholine degradation
d) Stimulate acetylcholine synthesis

Answer 1

Alpha-bungarotoxin is a potent toxin that irreversibly binds to nicotinic acetylcholine receptors, preventing acetylcholine from binding and disrupting normal neural communication, which is crucial for muscle contraction.

Step-by-step explanation:

The primary function of alpha-bungarotoxin, which is a component of the venom from a banded sea krait, is to act as an antagonist to acetylcholine (ACh) receptors, specifically the nicotinic ACh receptors. Alpha-bungarotoxin binds irreversibly to these receptors, preventing acetylcholine from binding at the synapse.

As a result, the normal function of the nicotinic receptor, which is to allow positive ions to cross the cell membrane leading to depolarization, is inhibited. This interference with the cholinergic system can disrupt neural communication and can be lethal, as these receptors play a critical role in muscle contraction.