Strongly inhibits the human alpha-3-beta-4/CHRNA3-CHRNB4 (IC(50)=15.7 uM) and alpha-7/CHRNA7 (IC(50)=77.2 uM) nicotinic acetylcholine receptor (nAChR). Incomplete inhibition of responses is observed for both subtypes, indicating a potential non-competitive mode of action. Expressed by the venom duct. The cysteine framework is C-C. Does not modulate oxytocin (OXTR), vasopressin (AVPR1A and AVPR1B), NMDA (GRIN1 and GRIN2A), and muscarinic (CHRM1 and CHRM3) receptors, and voltage-gated calcium (Cav) and sodium channels (Nav). Exists in two forms, due to cis-trans isomerization at 4-Ser-Pro-5. The conformer with the trans conformation is the most abundant (~65:30). 6-Cys-Pro-7 and the 7-Pro-Pro-8 peptide bonds are in the cis conformation.