Naslov
Coenzyme regeneration in the oxidation of amino acids

Autori
Findrik, Zvjezdana ; Vasić-Rački, Đurđa

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

Izvornik
8th International symposium on biocatalysis and biotransformations 8-13 July 2007, Biotrans 2007, Oviedo (Spain) / - , 2007, P-106

Skup
Biotrans 2007

Mjesto i datum
Oviedo, Španjolska, 08.07.2007. - 13.07.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
amino acids; coenzyme regeneration

Sažetak
There are various methods available for the stereoselective synthesis of optically pure amino acids [1]. One of these methods includes the use of L-amino acid dehydrogenases. Using these enzymes the synthesis of L-amino acid can be carried out from an  -keto acid as a starting material, while D-amino acid can be synthesized from the corresponding racemate, by complete oxidation of L-amino acid followed by separation of an  -keto acid [2]. Besides enantiomerically pure amino acids as valuable products, L-amino acid dehydrogenases can be used for an α -keto acid synthesis. In all cases coenzyme regeneration [3] system is necessary to ensure the equilibrium shift towards the wanted products. In this paper three different coenzyme (NAD+) regeneration systems were compared in their action in the reaction of L-methionine oxidation. L-methionine oxidation catalyzed by L-phenylalanine dehydrogenase (L-PheDH) from Rhodococcus sp. M4 is an equilibrium reaction. Without coenzyme (NAD+) regeneration only 5 % of L-methionine conversion can be achieved. This is the reason why three different regeneration methods were tested. The first one was NAD+ regeneration catalyzed by NADH oxidase from Lactobacillus brevis – relatively new and unstudied enzyme (Figure 1A). Using this regeneration method 100 % L-methionine conversion was achieved in the batch system. The second method was NAD+ regeneration in the pyruvate reduction catalyzed by L-lactate dehydrogenase from rabbit muscle (Figure 1B). 81 % L-methionine conversion was achieved using this regeneration system. The third regeneration method used was NAD+ regeneration in the phenylpyruvate reduction (Figure 1C) catalyzed by the same enzyme which catalyzes the main reaction (L-PheDH). Only 20 % of L-methionine was converted using this regeneration method.

Izvorni jezik
Engleski

Znanstvena područja
Drvna tehnologija

POVEZANOST RADA