Antimicrobial properties of L-amino acid oxidase: biochemical features and biomedical applications

Abstract

Mucus layer that covers the body surface of various animal functions as a defense barrier against microbes, environmental xenobiotics, and predators. Previous studies have reported that L-amino acid oxidase (LAAO), present in several animal fluids, has potent properties against pathogenic bacteria, viruses, and parasites. LAAO catalyzes the oxidative deamination of specific L-amino acids with the generation of hydrogen peroxide and L-amino acid metabolites. Further, the generated hydrogen peroxide is involved in oxidation (direct effect) while the metabolites activate immune responses (indirect effect). Therefore, LAAO exhibits two different mechanisms of bioactivation. Previously, we described the selective, specific, and local oxidative and potent antibacterial actions of various LAAOs as potential therapeutic strategies. In this review, we focus on their biochemical features, enzymatic regulations, and biomedical applications with a view of describing their probable role as biochemical agents and biomarkers for microbial infections, cancer, and autoimmune-mediated diseases. We consider that LAAOs hold implications in biomedicine owing to their antimicrobial activity wherein they can be used in treatment of infectious diseases and as diagnostic biomarkers in the above-mentioned diseased conditions. Key points •Focus on biochemical features, enzymatic regulation, and biomedical applications of LAAOs. •Mechanisms of antimicrobial activity, inflammatory regulation, and immune responses of LAAOs. •Potential biomedical application as an antimicrobial and anti-infection agent, and disease biomarker.

Hydrogen peroxide from l-amino acid oxidase of king cobra (Ophiophagus hannah) venom attenuates Pseudomonas biofilms

“…Indeed, l -amino acid oxidase (LAAOs), an enzyme produced by many living organisms 36 , was identified as a potentially effective compound of OH venom with antimicrobial and anti-biofilm properties, partly through hydrogen peroxide (H 2 O 2 ) production. Although LAAOs have various l -amino acid substrates, especially l -leucine 37 , 38 , LAAO from the king cobra (OH-LAAO) seems to be very specific to l -lysine and l -arginine 39 , 40 . Indeed, snake LAAOs rapidly and strongly produce more H 2 O 2 than human LAAOs (encoded by interleukin-4-induced gene 1, IL4I1 ), but the human LAAOs induced higher indole-3-pyruvate (I3P) that promotes cancer survival 41 .…”

Fatores Causadores De Ruídos Na Unidade De Terapia Intensiva De Um Hospital De Referência De Pernambuco

“…As LAAOs são consideradas uma classe de multifuncionais enzimas em vista de sua capacidade de produzir peróxido de hidrogênio e amônia, sua participação no metabolismo celular, e seus possíveis efeitos protetores, incluindo seu efeito anti-séptico e atividade antimicrobiana em diferentes organismos. Além disso, a correlação entre a produção de LAAOs e sua utilização em vias metabólicas envolvendo nitrogênio, bem como como a produção de peróxido de hidrogênio, abre perspectivas para novas aplicações dessas enzimas como bactericida, agentes antivirais e antitumorais, tornando-os um agente biotecnológico (KASAI et al, 2021). Desta forma, as LAAOs isoladas de venenos de serpentes apresentam grande potencial como agentes antimicrobianos.…”

Fenton/Fenton-like metal-based nanomaterials combine with oxidase for synergistic tumor therapy

“…AAO is divided into l -amino acid oxidase (LAAO) and d -amino acid oxidase (DAAO). Both of them are able to oxidize the corresponding amino acids and generate strong oxidizing H 2 O 2 , further inducing synergy between tumor starvation therapy and oxidative therapy [ 10 , 80 , 81 ]. However, natural AAO is extremely unstable in vivo, which impairs its clinical effects.…”