Catalyzes an oxidative deamination of predominantly hydrophobic and aromatic L-amino acids, thus producing hydrogen peroxide that may contribute to the diverse toxic effects of this enzyme (PubMed:26273287, PubMed:31078582). Is highly active on L-Met, L-Leu, L-Trp, and L-Phe, moderately active on L-Ile, L-His, and L-Arg, and weakly or not active on L-Gln, L-Val, L-Asn, L-Ala, L-Lys, L-Ser, L-Thr, L-Pro, L-Asp, L-Gly, L-Tyr, L-Cys and L-Glu (PubMed:31078582). This enzyme exhibits diverse biological activities, such as hemorrhage, hemolysis, edema, apoptosis of vascular endothelial cells or tumor cell lines, antibacterial and antiparasitic activities, as well as regulation of platelet aggregation (PubMed:26273287). Its effect on platelets is controversial, since it either induces aggregation or inhibits agonist-induced aggregation (PubMed:26273287). These different effects are probably due to different experimental conditions (PubMed:26273287). In vitro, the enzyme exhibits cytotoxicity against fibroblast cell line and kills Leishmania amazonensis promastigotes, intensified by substrate addition (PubMed:31078582). an L-alpha-amino acid + H2O + O2 = a 2-oxocarboxylate + H2O2 + NH4(+) H2O + L-leucine + O2 = 4-methyl-2-oxopentanoate + H2O2 + NH4(+) H2O + L-phenylalanine + O2 = 3-phenylpyruvate + H2O2 + NH4(+) H2O + L-tryptophan + O2 = H2O2 + indole-3-pyruvate + NH4(+) H2O + L-methionine + O2 = 4-methylsulfanyl-2-oxobutanoate + H2O2 + NH4(+) H2O + L-isoleucine + O2 = (S)-3-methyl-2-oxopentanoate + H2O2 + NH4(+) H2O + L-arginine + O2 = 5-guanidino-2-oxopentanoate + H2O2 + NH4(+) H2O + L-histidine + O2 = 3-(imidazol-5-yl)pyruvate + H2O2 + NH4(+) Optimum pH is 7.0. Activity is reduced to about 70% and 60% after incubation at pH 5.0 and pH 9.0, respectively, for 1 hour. Homodimer; non-covalently linked. Expressed by the venom gland. N-glycosylated (PubMed:26273287, PubMed:31078582). N-glycan probably consists of the disaccharide N-acetylglucosamine-fucose (HexNAc-Fuc) (PubMed:31078582). Belongs to the flavin monoamine oxidase family. FIG1 subfamily.