This family consists of several spasmodic peptide gm9a sequences. Conotoxin gm9a is a putative 27-residue polypeptide encoded by Conus gloriamaris and is known to be a homologue of the 'spasmodic peptide', tx9a, isolated from the venom of the mollusc-hunting cone shell Conus textile [1]. Upon injection of this venom component, normal mice are converted into behavioural phenocopies of a well-known mutant, the spasmodic mouse [2].

1: Structure of a novel P-superfamily spasmodic conotoxin reveals an inhibitory cystine knot motif. Miles LA, Dy CY, Nielsen J, Barnham KJ, Hinds MG, Olivera BM, Bulaj G, Norton RS; J Biol Chem 2002;277:43033-43040. PMID:12193600

2: The spasmodic peptide defines a new conotoxin superfamily. Lirazan MB, Hooper D, Corpuz GP, Ramilo CA, Bandyopadhyay P, Cruz LJ, Olivera BM; Biochemistry 2000;39:1583-1588. PMID:10677206