Slowly and reversibly inhibits human nicotinic acetylcholine receptors (nAChR) alpha-7/CHRNA7 (IC(50)=45.7 uM). It is unknown whether it inhibits nAChRs by a competitive or a non-competitive mechanism. Expressed by the venom duct. The cysteine framework is III (CC-C-C-CC). Classified in the M-2 branch, since 2 residues stand between the fourth and the fifth cysteine residues. Has a free C-terminus. Monoisotopic mass. Has low or no effect on human alpha-3-beta-2/CHRNA3-CHRNB2 and alpha-7-beta-2/CHRNA7-CHRNB2 nAChR. Belongs to the conotoxin M superfamily.