title: [Spectrophotometric micromethod to determine L-lysine-alpha-oxidase activity].
abstract: A spectrophotometric micromethod is developed for estimation of L-lysine-alpha-oxidase. The method is based on measurement of hydrogen peroxide formed in enzymatic oxidation of L-lysine. Optimal conditions were developed for estimation of the enzymatic activity in the extracts of Trichoderma sp. The saturating concentration of L-lysine was 10 mM. Km values for L- and DL-lysines constituted 3.0 . 10(-3) M and 6.4 . 10(-4) M, respectively. The reaction proceeded without a latent phase and H2O2 formation versus time plot had a linear shape within 20 min. The enzyme optimal activity was found at pH 5.8-6.0. The best buffer, required for lysine oxidation in the reaction, proved to be phosphate, but not succinate, borate or glycine buffers. The method described was highly sensitive and reproducible.
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D006861:Hydrogen Peroxide; D003904:Mitosporic Fungi / Q000201:enzymology*; D010084:Oxidation-Reduction; D013053:Spectrophotometry / Q000379:methods*; D014242:Trichoderma / Q000201:enzymology*
chemical_list: D006861:Hydrogen Peroxide; D000594:Amino Acid Oxidoreductases; C041123:L-lysine oxidase
vernacular_title: Spektrofotometricheskiĭ mikrometod opredeleniia aktivnosti L-lizin-al'fa-oksidazy.