In vitro, reversibly blocks human muscle-type nicotinic acetylcholine receptors (nAChR) alpha-1-beta-1-epsilon-delta/CHRNA1-CHRNB1-CHRNE-CHRND (EC(50)=0.44 uM) and alpha-1-beta-1-gamma-delta/CHRNA1-CHRNB1-CHRNG-CHRND (EC(50)=1.56 uM). Binds to nAChR from T.californica (IC(50)=0.03-0.18 uM), human neuronal nAChR alpha-7/CHRNA7 (IC(50)=22 uM) and acetylcholine-binding proteins (AChBP) from L.stagnalis (IC(50)=63 uM) and A.californica (IC(50)=230 uM). Monomer. Expressed by the venom gland. LD(50) is 2.6 mg/kg by intraperitoneal injection in mice. Has no effect on GABA(A) receptors alpha-1-beta-3-gamma-2/GABRA1-GABRB3-GABRG2 and alpha-2-beta-3-gamma-2/GABRA2-GABRB3-GABRG2 or on receptors HTR3A and HTR3A-HTR3B.