Iota-conotoxins bind to voltage-gated sodium channels and act as agonists by shifting the voltage-dependence of activation to more hyperpolarized levels. This toxin acts on Nav1.6/SCN8A > Nav1.2/SCN2A > Nav1.7/SCN9A sodium channels. Produces general excitatory symptoms upon intracorporeal injection and repetitive action potentials in the frog cutaneous pectoris muscle. Natural peptide (with D-Phe) is active on nerve, but not on muscle. Synthetic peptide (with L-Phe) is not active on both nerve and muscle. Expressed by the venom duct. The cysteine framework is XI (C-C-CC-CC-C-C). The natural D-Phe-44 form of the peptide is more potent than the L-Phe-44 form. Does not have effect on sodium channels Nav1.1/SCN1A, Nav1.3/SCN3A, Nav1.4/SCN4A, Nav1.5/SCN5A and on potassium channels Kv7.2/KCNQ2, Kv7.3/KCNQ3, Kv1.2/KCNA2, Kv1.3/KCNA3, Kv1.4/KCNA4, Kv1.5/KCNA5 and Kv1.6/KCNA6 (PubMed:18486102, PubMed:17696362). Belongs to the conotoxin I1 superfamily.