Bungarus neurotoxin (BTX)

Bungarus neurotoxins are a group of highly potent proteinaceous toxins found in the venom of kraits, specifically Bungarus multicinctus and Bungarus candidus. These toxins are primarily classified into alpha-bungarotoxins, which are post-synaptic three-finger toxins, and beta-bungarotoxins, which are pre-synaptic phospholipase A2 enzymes [1, 2]. Alpha-bungarotoxins bind with high affinity and near-irreversibility to nicotinic acetylcholine receptors at the neuromuscular junction, leading to a blockade of neuromuscular transmission [1, 3]. Beta-bungarotoxins act by depleting synaptic vesicles and damaging motor nerve terminals, further contributing to paralysis [2, 4]. Clinically, these toxins cause severe envenomation characterized by progressive muscle weakness and respiratory failure, which is the leading cause of death in krait bite victims [3, 5]. Therapeutic intervention relies on the administration of specific antivenoms that target and neutralize these toxins in the bloodstream [3]. Beyond their role in pathology, these neurotoxins, particularly alpha-bungarotoxin, are essential pharmacological tools used to study the structure and function of acetylcholine receptors [1].

Other names

BungarotoxinKrait neurotoxinAlpha-bungarotoxinBeta-bungarotoxinGamma-bungarotoxinKappa-bungarotoxinMany-banded krait neurotoxinMalayan krait neurotoxin

Antivenoms contain specific antibodies or antibody fragments that bind to the neurotoxins, neutralizing their ability to interact with physiological targets such as nicotinic acetylcholine receptors or presynaptic membranes, thereby preventing or reversing paralysis [3, 5].