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:21539897). Is highly active against L-Met, L-Leu, L-norleucine (L-2-aminohexanoate), L-Trp, L-Phe, moderately active against L-Tyr, and no active on L-Gly, L-Ala, L-Val, L-Pro, L-His, L-Lys, L-Arg, L-Asp, L-Asn, L-Gln, L-Glu, L-Ser, and L-Thr (PubMed:21539897). Exhibits diverse biological activities, such as hemorrhage, hemolysis, edema, antibacterial and antiparasitic activities (By similarity). In addition, this protein induces apoptosis. It also interacts with endothelial cells, and inhibits collagen- and ADP-induced platelet aggregation. L-LAAO family effects on platelets are controversial, since it either induces aggregation or inhibits agonist-induced aggregation. These different effects are probably due to different experimental conditions. 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-2-aminohexanoate + O2 = 2-oxohexanoate + H2O2 + NH4(+) H2O + L-tyrosine + O2 = 3-(4-hydroxyphenyl)pyruvate + H2O2 + NH4(+) Optimum pH is 7.5-8.8 for L-Leu. Monomer. This is in contrast with most of its orthologs, that are non-covalently linked homodimers. Expressed by the venom gland. N-glycosylated. Has parasiticidal activities against both trypanosomes and leishmania, as a result of enzyme-catalyzed hydrogen peroxide production. Belongs to the flavin monoamine oxidase family. FIG1 subfamily. The existence of several isoforms has been reported that may be due to either different composition or different glycosylation or by the synthesis from different genes.