This family consists of conotoxins isolated from the venom of cone snail Conus tulipa and Conus geographus. Conotoxin TVIIA, isolated from Conus tulipa displays little sequence homology with other well-characterised pharmacological classes of peptides, but displays similarity with conotoxin GS, a peptide from Conus geographus. Both these peptides block skeletal muscle sodium channels and also share several biochemical features and represent a distinct subgroup of the four-loop conotoxins [1].

1: Conotoxin TVIIA, a novel peptide from the venom of Conus tulipa 1. Isolation, characterization and chemical synthesis. Hill JM, Atkins AR, Loughnan ML, Jones A, Adams DA, Martin RC, Lewis RJ, Craik DJ, Alewood PF; Eur J Biochem 2000;267:4642-4648. PMID:10903496