This family includes three peptides secreted by the spider Hadronyche versuta (Swiss:P82226, Swiss:P82227, Swiss:P82228). These are insect-selective, excitatory neurotoxins that may function by antagonising muscle acetylcholine receptors, or acetylcholine receptor subtypes present in other invertebrate neurons [1]. Janus atracotoxin-Hv1c (J-ACTX-Hv1c, Swiss:P82228) is organised into a disulphide-rich globular core (residues 3-19) and a beta-hairpin (residues 20-34). There are 4 disulphide bridges, one of which is a vicinal disulphide bridge; this is known to be unimportant in the maintenance of structure but critical for insecticidal activity [1].

1: Discovery and characterization of a family of insecticidal neurotoxins with a rare vicinal disulfide bridge. Wang X, Connor M, Smith R, Maciejewski MW, Howden ME, Nicholson GM, Christie MJ, King GF; Nat Struct Biol 2000;7:505-513. PMID:10881200