α-Neurotoxin

[5] All α-neurotoxins share the three-finger toxin tertiary structure, consisting of a small globular core containing four disulfide bonds, three loops or "fingers", and a C-terminal tail.

[4][6] These classes have significant sequence homology and share the same three-dimensional structure, but have differing specificities and kinetics of association/dissociation with the receptor.

[6] For specifics, see α-Bungarotoxin and nicotinic acetylcholine receptor α-Neurotoxins antagonistically bind tightly and noncovalently to nAChRs of skeletal muscles, thereby blocking the action of ACh at the postsynaptic membrane, inhibiting ion flow and leading to paralysis.

[13] There is evidence that alpha-neurotoxins have evolved rapidly and are subject to positive selection,[14] possibly due to an evolutionary arms race with prey species.

[18] The introduction of glycosylation sites on the receptor, resulting in steric hindrance at the neurotoxin binding site, is a well-characterized resistance mechanism found in mongooses, while the honey badger, domestic pig, and hedgehog lineages replace aromatic amino acids with charged residues; at least in some lineages, these molecular adaptations likely reflect predation on venomous snakes.