Potent antagonist (IC(50)=1-10 nM) of M4 (CHRM4) muscarinic receptors (PubMed:8154745, PubMed:24793485,PubMed:21557730), and CHRM1, ADRA1A (PubMed:8154745), ADRA2A and ADRA2C adrenergic receptors. Also antagonises ADRA1B and ADRA1D adrenergic receptors with a 10-times lower affinity (PubMed:24793485). Expressed by the venom gland. Does not show interaction with adrenergic receptors (ADRA2B, ADRB1, ADRB2), dopaminergic receptors (DRD1, DRD2, DRD3, DRD4, DRD5), histaminic receptors (HRH1, HRH3, HRH4), muscarinic receptors (CHRM1, CHRM2, CHRM3, CHRM5), and serotoninergic receptors (HTR1A, HTR2A, HTR2B, HTR2C, HTR5A, HTR6, HTR7). Is classified as a P-type cytotoxin, since a proline residue stands at position 33 (Pro-31 in standard classification). Belongs to the snake three-finger toxin family. Short-chain subfamily. Aminergic toxin sub-subfamily.