L-amino-acid oxidase (Daboia siamensis) (LAAO)

L-amino acid oxidase (LAAO) from Daboia siamensis (formerly Daboia russelii siamensis) is a homodimeric flavoprotein and a major component of Russell's viper venom (UniProt P84387). This enzyme catalyzes the oxidative deamination of L-amino acids to their corresponding alpha-keto acids, producing ammonia and hydrogen peroxide (H2O2) as byproducts (Ali et al., 2013). The localized production of H2O2 is the primary driver of its biological effects, including the induction of oxidative stress, DNA damage, and apoptosis in target cells (Tan et al., 2015). In the context of envenomation, LAAO contributes to tissue necrosis, edema, and interference with the coagulation cascade. Conversely, its potent cytotoxic effects have made it a subject of interest in oncology research as a potential anti-tumor agent due to its ability to trigger the intrinsic apoptotic pathway in cancer cells. Therapeutic intervention typically involves the use of polyvalent or monovalent antivenoms that neutralize the enzyme's activity to mitigate systemic and local toxicity.

Other names

L-amino-acid oxidaseDr-LAAODs-LAAORussell's viper L-amino acid oxidaseL-amino-acid:oxygen oxidoreductase (deaminating)

Neutralization of enzymatic activity by specific antibodies in antivenom; induction of apoptosis via hydrogen peroxide production in therapeutic contexts.