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:23287728). Shows activity on L-Leu (PubMed:23287728). Damages cell membranes of the Gram-positive bacteria S.aureus (MIC=8 ug/ml and MBC=16 ug/ml) and the Gram-negative bacteria A.baumannii (MIC=16 ug/ml and MBC=32 ug/ml). This antimicrobial activity is dependent on the production of hydrogen peroxyde, since it is inhibited by catalase, a hydrogen peroxyde scavenger. an L-alpha-amino acid + H2O + O2 = a 2-oxocarboxylate + H2O2 + NH4(+) H2O + L-leucine + O2 = 4-methyl-2-oxopentanoate + H2O2 + NH4(+) Monomer. This is in contrast with most of its orthologs, that are non-covalently linked homodimers. Expressed by the venom gland. Does not show antimicrobial activities against E.coli. Does not induce cytotoxicity toward C2C12 cells (at 40 ug/ml) and peripheral blood mononuclear cells (up to 200 ug/ml). Belongs to the flavin monoamine oxidase family. FIG1 subfamily.