Naslov
Amino acid oxidases as environmentally friendly enzymes for the production of enantiomerically pure amino acids

Autori
Findrik, Zvjezdana ; Vasić-Rački, Đurđa

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Environmental Biocatalysis: From remediation with enzymes to novel green processes / Lopez-Cortes, N ; Alcalde, M. ; Ferrer, M. ; Rojas-Cervantes, M.L. ; Plou, F.J. ; Ballesteros, A. - Cordoba, 2006, P-3

Skup
International Symposium on Environmental Bioc atalysis

Mjesto i datum
Córdoba, Španjolska, 23.04.2006. - 26.04.2006

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
amino acid oxidase; modelling; enzyme kinetics

Sažetak
Enantiomerically pure amino acids can be synthesized by the action of amino acid oxidases from the racemic mixtures of amino acids. Amino acid oxidases can also be used for the purification of amino acid preparations, since it is known that they contain certain amounts of other isomer. The use of amino acids in pharmaceutical industry is widely spread [1]. Amino acids are important as intermediates in the production of pharmaceuticals. They are used as food additives and in the production of agrochemicals [2]. Since production of these compounds requires optical purity, it is necessary to obtain pure amino acids as starting compound. In this work, synthesis of enantiomerically pure D-amino acid by the action of three different L- amino acid oxidases (from snake venom Crotalus adamanteus and Crotalus atrox and from bacteria Rhodococcus opacus) is presented. Methionine was used as a substrate. Reaction kinetics were measured by the initial reaction rate method. L-amino acid oxidases [3] were used to oxidize L-methionine and the influence of D-isomer on the initial reaction rate was followed. Both enzymes from the snake venom have the same activity on L-methionine as a substrate, while the activity of the bacterial enzyme was lower. The enzyme from bacteria was found to be the most specific to the substrate (the lowest Michaelis-Menten constant), and the enzyme from C. atrox is inhibited by substrate. Product inhibition by 2-oxo-4-methylthiobutyric acid was the strongest in the case of C. adamanteus enzyme, and in the case of bacterial enzyme no inhibition was detected. D-methionine inhibits the enzyme from C. adamanteus while no negative effect was found on the other two enzymes. All the kinetic parameters were estimated using the programme package SCIENTIST. Mathematical model for the system of methionine oxidation in the batch system was developed. The model was verified by the reactor experiments. In the reaction of amino acid oxidation catalyzed by amino acid oxidase, besides an α -keto acid, hydrogen peroxide originates as a product. Its influence on the mentioned reaction system was observed in the reaction of methionine oxidation where no catalase was added. In other experiments catalase was added to remove hydrogen peroxide from the system.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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