RESUMO
The enzymes responsible for the conversion of N(alpha)-[(benzyloxy)carbonyl]-D-lysine (N(alpha)-Z-D-lysine) to N(alpha)-Z-D-aminoadipic acid (N(alpha)-Z-D-AAA) by Rhodococcus sp. AIU Z-35-1 were identified. N(alpha)-Z-D-Lysine was first converted to N(alpha)-Z-D-aminoadipic delta-semialdehyde (N(alpha)-Z-D-AASA) by D-specific amino acid deaminase, whereas N(alpha)-Z-L-lysine was converted to N(alpha)-Z-L-AASA by L-specific amino acid oxidase. The resulting N(alpha)-Z-D-AASA was then converted to N(alpha)-Z-D-AAA by the same aldehyde dehydrogenase that is responsible for N(alpha)-Z-L-AASA oxidation. The product amount of the D-specific amino acid deaminase reached the maximum at one day of cultivation in the L-lysine medium. The aldehyde dehydrogenase reached the maximum at three days of cultivation.
Assuntos
Ácido 2-Aminoadípico/análogos & derivados , Proteínas de Bactérias/metabolismo , Lisina/análogos & derivados , Rhodococcus/enzimologia , Ácido 2-Aminoadípico/metabolismo , Aldeído Desidrogenase/metabolismo , L-Aminoácido Oxidase/metabolismo , Lisina/metabolismo , Fatores de TempoRESUMO
The factors for selective production of N(alpha)-benzyloxycarbonyl-L-aminoadipate-delta-semialdehyde (N(alpha)-Z-L-AASA) and N(alpha)-benzyloxycarbonyl-L-aminoadipic acid (N(alpha)-Z-L-AAA) from N(alpha)-benzyloxycarbonyl-L-lysine (N(alpha)-Z-L-lysine) by Rhodococcus sp. AIU Z-35-1 were analyzed. The cultivation time was important for selective production of N(alpha)-Z-L-AASA, since N(alpha)-Z-L-lysine oxidizing enzyme reached maximum at the early stage of cell growth and then decreased. The differences of enzyme activities of N(alpha)-Z-L-lysine oxidizing enzyme and N(alpha)-Z-L-AASA dehydrogenase in pH and temperature also affected the selective production of N(alpha)-Z-L-AASA. For efficient production of N(alpha)-Z-L-AAA, it was important for cultivation time that N(alpha)-Z-L-AASA dehydrogenase activity be higher than N(alpha)-Z-L-lysine oxidizing enzyme activity, since a high concentration of N(alpha)-Z-L-AASA inhibited N(alpha)-Z-L-AASA dehydrogenase activity. The optimum pH of N(alpha)-Z-L-AAA production was affected by the instability of N(alpha)-Z-L-AASA dehydrogenase in the alkaline pH region.
Assuntos
Ácido 2-Aminoadípico/análogos & derivados , Proteínas de Bactérias/metabolismo , Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Rhodococcus/classificação , Rhodococcus/metabolismo , Ácido 2-Aminoadípico/metabolismo , Especificidade da EspécieRESUMO
The enzyme catalyzing conversion of N alpha-benzyloxycarbonyl-L-aminoadipic-delta-semialdehyde (N alpha-Z-L-AASA) to N alpha-benzyloxycarbonyl-L-aminoadipic acid (N alpha-Z-L-AAA) in Rhodococcus sp. AIU Z-35-1 was identified, and its characteristics were revealed. This reaction was catalyzed by a dehydrogenase with a molecular mass of 59 kDa. The dehydrogenase exhibited enzyme activity on not only N alpha-Z-L-AASA but also N alpha-Z-D-AASA and short chain aliphatic aldehydes, but not on aromatic aldehydes and alcohols. The apparent Km values for N alpha-Z-L-AASA, N alpha-Z-D-AASA and NAD+ were estimated to be 3.8 mM, 14.1 mM and 0.16 mM, respectively. The NH2 terminal amino acid sequence of this enzyme exhibited a similarity to those of a piperidein-6-carboxylate dehydrogenase from Streptomyces clavuligerus and a putative dehydrogenase from Rhodococcus sp. RHA 1, but not to those of other microbial aldehyde dehydrogenases.