Agatoxin

The ω-agatoxins are approximately 100 amino acids in length and are antagonists of voltage-sensitive calcium channels and also block the release of neurotransmitters.

[3][4] Agatoxins may be divided into three major structural subclasses:[1] Alpha-agatoxins are composed of polyamines which are attached to an aromatic moiety (see for example AG 489).

Mu-agatoxins are C-terminally amidated peptides, consisting of 35-37 amino acids and are constrained by four intramolecular disulfide bonds.

Omega-agatoxins in turn are subdivided in four classes based on their primary structures, biochemical properties and calcium channels specificity.

Because insects have a much smaller repertoire of voltage-gated calcium channels and have a different pharmacology than vertebrates the effects can vary between species.

NMR structure ( PDB : 1OAV ​) of Omega-agatoxin IVA. The peptide backbone is depicted by a curved cartoon diagram while the amino acid side chains are represented by capped sticks. Carbon atoms are colored grey, nitrogen blue, oxygen red, and sulfur atoms yellow.