Mu-conotoxins block voltage-gated sodium channels (Nav). This synthetic toxin moderately blocks rNav1.1/SCN1A, rNav1.2/SCN2A, rNav1.3/SCN3A, rNav1.4/SCN4A, rNav1.5/SCN5A, and mNav1.6/SCN8A (PubMed:21652775). This block is very slowly reversible (PubMed:16533055). Causes seizures when injected intracranially into mice. Expressed by the venom duct. Has not been isolated from the crude venom. The cysteine framework is III (CC-C-C-CC). Classified in the M-5 branch, since 5 residues stand between the fourth and the fifth cysteine residues. Does not inhibit Nav1.7/SCN9A and Nav1.8/SCN10A. Belongs to the conotoxin M superfamily.