Mu-conotoxins block voltage-gated sodium channels (Nav). This synthetic toxin potently blocks rNav1.2/SCN2A, and rNav1.4/SCN4A. It also moderately blocks rNav1.1/SCN1A, rNav1.3/SCN3A, rNav1.5/SCN5A, and mNav1.6/SCN8A. The inhibition is reversible. Expressed by the venom duct. 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 block rNav1.7/SCN9A, and rNav1.8/SCN10A. Belongs to the conotoxin M superfamily.