The activity of this natural homodimer has not been tested due to low abundance (PubMed:28598389). The synthetic linear peptide has been refolded, giving 4 different monomeric isomers (m1 to m4) with 2 disulfide bonds each (PubMed:28598389). All isomers potently inhibit rat alpha-1-beta-1-delta-epsilon/CHRNA1-CHRNB1-CHRND-CHRNE and human alpha-9-alpha-10/CHRNA9-CHRNA10 nicotinic acetylcholine receptors (nAChR) (PubMed:28598389). In addition, they show a modest inhibition at human alpha-3-beta-2/CHRNA3-CHRNB2, alpha-3-beta-4/CHRNA3-CHRNB4, alpha-7/CHRNA7, and alpha-4-beta-4/CHRNA4-CHRNB4 (PubMed:28598389). The synthetic monomer peptide without disulfide bonds shows a potent activity on alpha-9-alpha-10/CHRNA9 AND CHRNA10 (IC(50)=16.2 nM) (PubMed:28598389). This linear peptide does not act as a competitive antagonist, or as a channel pore blocker of nAChR (PubMed:28598389). Homodimer; disulfide-linked. Expressed by the venom duct. The cysteine framework is C-C-C-C-C. May contain 2 intrachain disulfide bonds and probably one interchain disulfide bond forming the homodimer. The disulfide pairing is not important for activity towards the different nAChR subtypes, since this peptide without disulfide bond or with different disulfide bonds shows the same activity. Belongs to the conotoxin O1 superfamily. Authors numbered this protein framework XXVII. Since this number is already attributed to another Cys arrangment (C-C-C-CCC-C-C), it is not indicated here to define the cysteine framework of this toxin.