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.
Amino Acid Oxidoreductases Hydrogen Peroxide