Identification of antibacterial mechanism of l‐amino acid oxidase derived from Trichoderma harzianum ETS 323

摘要: Although L-amino oxidase (LAAO; EC 1.4.3.2) has been reported to be a potent antibacterial agent, the mechanism responsible for its activity not identified. The present study aimed identify of Th-LAAO, an LAAO recently isolated from extracellular proteins Trichoderma harzianum ETS 323, at same time as elucidating nature this enzyme. results obtained indicate that enzyme and structure Th-LAAO are stable pH 6-8 less both 4-5.5 9. At 7.0, optimum temperature was found 40 °C, comprising which enzymatic is greatest, with deceasing further increases in result thermal denaturation enzyme, leading partial 50 °C. by confocal microscopy flow cytometry interacts bacteria cause membrane permeabilization, interaction may promoted amphipathic sequence other cytotoxic LAAOs located N-terminus. findings increased exogenous H(2) O(2) production reactive oxidative species accumulation Th-LAAO-treated trigger forms cell damage, including lipid peroxidation DNA strand breakage bacterial growth inhibition. Taken together, processes interaction, permeabilization H(2)O(2) involved Th-LAAO.