This family consists of toxic peptides (Magi 5) found in the venom of the Hexathelidae spider. Magi 5 is the first spider toxin with binding affinity to site 4 of a mammalian sodium channel and the toxin has an insecticidal effect on larvae, causing paralysis when injected into the larvae [1].

1: Distinct primary structures of the major peptide toxins from the venom of the spider Macrothele gigas that bind to sites 3 and 4 in the sodium channel. Corzo G, Gilles N, Satake H, Villegas E, Dai L, Nakajima T, Haupt J; FEBS Lett 2003;547:43-50. PMID:12860384