Kappa-conotoxins inhibits voltage-gated potassium channels. This toxin dose-dependently and reversibly inhibits the Kv1.2/KCNA2 channel in mammalia. Does not exert protective effect on cardiac tissue when administered after an ischemic event. Expressed by the venom duct. The cysteine framework is III (CC-C-C-CC). Classified in the M-4 branch, since 4 residues stand between the fourth and the fifth cysteine residues. monoisotopic. Has no or very low potency for Kv1.1/KCNA1, Kv1.3/KCNA3, Kv1.4/KCNA4, Kv1.5/KCNA5, Kv1.6/KCNA6, Kv7.2/KCNQ2-Kv7.3/KCNQ3, and KCa1.1/KCNMA1. Belongs to the conotoxin M superfamily.