Two peptides (Ct1a/Ct1b) lethal to sheep blowflies were isolated from venom of the Australian tarantula Coremiocnemis tropix.
Ct1a/1b are initially produced as prepropeptide precursors that are post-translationally processed to the mature toxins.
Ct1a/1b may have a novel fold as the cysteine pattern does not conform to the knottin motif commonly found in spider toxins.
Ct1a does not target insect voltage-gated sodium channels.