Omega-agatoxins are antagonists of voltage-sensitive calcium channels (Cav) (By similarity). Toxic to mice by intracerebroventricular injection. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the neurotoxin 04 (omega-agtx) family. 03 (type II/III omega-agtx) subfamily.