An enzymatic process to α-ketoglutarate from l-glutamate: the coupled system l-glutamate dehydrogenase/NADH oxidase

Ödman, Peter; Wellborn, William B.; Bommarius, Andreas S.

doi:10.1016/j.tetasy.2004.07.055

Cited by 67 publications

(28 citation statements)

References 14 publications

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“…For nox-2 from L. sanfranciscensis, TTN is increased dramatically from 3500 to above 112,000 upon the addition of 5 mM DTT in the reaction buffer. [5] …”

Section: Discussionmentioning

confidence: 99%

“…[4] Regeneration of NADH Cofactor to NAD þ Many oxidative biological redox reactions require nicotinamide cofactors, such as the dehydrogenase-catalyzed transformation of monosodium l-glutamate (MSG) to a-ketoglutarate. [5] The regeneration of the co-produced cofactor NADH to NAD þ is essential for efficient transformation, especially on large-scale -not only for cofactor economics but also to drive the production reaction towards completion. Both kinds of NADH oxidase, nox-1 and nox-2, can catalyze the irreversible reduction of oxygen.…”

Section: Introduction Nadh Oxidases As Part Of the Oxygen Defense Systemmentioning

confidence: 99%

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Comparison of Alkyl Hydroperoxide Reductase (AhpR) and Water‐Forming NADH Oxidase from Lactococcus lactis ATCC 19435

2005

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Abstract:We have successfully applied the sequence comparison-based approach to develop a peroxidase (gene AhpC) and a water-forming NADH oxidase from Lactococcus lactis (L. lactis). We found a considerably lower maximum specific activity of nox-1 (AhpF) (15 U/mg) from L. lactis compared to its nox-2 counterpart (95 U/mg). Both nox-1 and nox-2 are turnover-limited, as expected for enzymes with labile, redox-active thiols in the active site. In the absence of exogenously added thiols, both nox-1 and nox-1/peroxidase are considerably more stable against overoxidation than nox-2: the total turnover number TTN is 82,000 for nox-1 and nox-1/peroxidase vs. 39,000 for nox-2. Addition of exogenous thiols, however, increases nox-2 stability by a factor of two, up to the level of nox-1. Kinetic and stability analysis does not reveal any clear advantage for oxygen scavenging via the nox-1 or the nox-2 routes in lactic acid bacteria. Expression levels in lactic acid bacteria upon exposure to oxidative stress rather than kinetic performance more likely account for the previously observed superiority of nox-2 effectiveness over nox-1.

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“…For nox-2 from L. sanfranciscensis, TTN is increased dramatically from 3500 to above 112,000 upon the addition of 5 mM DTT in the reaction buffer. [5] …”

Section: Discussionmentioning

confidence: 99%

Section: Introduction Nadh Oxidases As Part Of the Oxygen Defense Systemmentioning

confidence: 99%

Comparison of Alkyl Hydroperoxide Reductase (AhpR) and Water‐Forming NADH Oxidase from Lactococcus lactis ATCC 19435

2005

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“…[4][5][6] The use of chemoenzymatic methods to obtain these molecules is a suitable alternative to conventional synthetic routes. Aminoacylases, hydantoinases, aminotransferases and amino acid desidrogenases have been used to obtain enantiomerically pure non-proteinogenic aminoacids, [7][8][9] however the use of isolated enzymes increases process costs. To overcome this problem a wide number of microorganisms have been used reducing costs significantly.…”

Section: Introductionmentioning

confidence: 99%

Enantiomerically pure D-phenylglycine production using immobilized Pseudomonas aeruginosa 10145 in calcium alginate beads

Alonso¹,

Antunes²,

Oestreicher³

2007

J. Braz. Chem. Soc.

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Em trabalhos anteriores em nosso laboratório, uma cepa de Pseudomonas aeruginosa demonstrou ter atividade enzimática na conversão de arilaminonitrilas em D-amino ácidos. Essa atividade enzimática aumentou por indução de modo a produzir D-fenilglicina enantiomericamente pura a partir de 2-fenil-2-aminoacetonitrila. No presente trabalho, as melhores condições para essa transformação são descritas. Para aumentar o uso potencial desse biocatalisador, células de Pseudomonas aeruginosa 10145 foram envolvidas em alginato em forma de pequenas esferas. Duas concentrações diferentes de alginato foram usadas nesse processo. A morfologia das pérolas foi analisada via microscopia eletrônica de varredura (MEV). As pérolas com altas porosidades, formadas com 1,5% de alginato de sódio conduziram às melhores conversões de 2-fenil-2-aminoacetonitrila em D-fenilglicina (20%, 3,0 horas de reação e excesso enantiomérico superior a 98%). Repetições em quatro bateladas consecutivas demonstraram a manutenção da atividade desse sistema catalítico.In a preliminary work in our laboratory, a Pseudomonas aeruginosa strain was found to have enzymatic activity to convert arylaminonitriles into D-amino acids. This enzymatic activity was increased by induction to produce enantiomerically pure D-phenylglycine using 2-phenyl-2-aminoacetonitrile as starting material. In this work, the best conditions leading to this transformation are described. In order to increase the biocatalyst potential use, cells of Pseudomonas aeruginosa 10145 were entrapped in calcium alginate gel beads. Two different concentration of sodium alginate were used to immobilize these cells. Beads morphology was demonstrated by scanning electron microscopy (SEM). The beads with higher porosity, formed with 1.5% (m/v) of sodium alginate led to the best conversion of 2-phenyl-2-aminoacetonitrile into D-phenylglycine (20% of conversion, 3.0 h of reaction enantiomeric excess higher than 98%). Recycling was performed in four repeated batch reactions, which proved the biocatalyst activity maintenance.

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“…Further increase in the concentration of α-ketoglutaric acid results the decrease in the biosensor response which, may attribute to an inhibitory effect of α-ketoglutaric on the enzyme activity [17]. Figure 2 illustrates the response of the biosensor towards various concentrations of ammonium (0, 0.1 and 0.25 mM).…”

Section: Figure 1(c)mentioning

confidence: 99%

An Optical Based Biosensor for the Determination of Ammonium in Aqueous Environment

Azmi¹,

Abdullah²,

Ahmad³

et al. 2012

AJAC

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A simple and rapid optical biosensor for the determination of ammonium was developed by immobilization of glutamate dehydrogenase (GLDH) and diaphorase (Dph) in chitosan film coated on a glass slide employing thiazolyl blue tetrazolium bromide (MTT) as a color indicator. The developed biosensor displays a purple color formation of formazan attributed to the unreacted NADH in the reaction system in the presence of ammonium. The color intensity was found to decrease proportionally with the increase of ammonium concentrations after 10 min exposure. The linearity of the biosensor towards ammonium was in the range of 16.8 -70 µM (R 2 = 0.9955) with detection limit of 11 µM. A good agreement (R 2 = 0.9984) with indothymol method was obtained in the measurement of fish pond water samples. The effect of potential interferences such as metals ion has also been evaluated.

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An enzymatic process to α-ketoglutarate from l-glutamate: the coupled system l-glutamate dehydrogenase/NADH oxidase

Cited by 67 publications

References 14 publications

Comparison of Alkyl Hydroperoxide Reductase (AhpR) and Water‐Forming NADH Oxidase from Lactococcus lactis ATCC 19435

Comparison of Alkyl Hydroperoxide Reductase (AhpR) and Water‐Forming NADH Oxidase from Lactococcus lactis ATCC 19435

Enantiomerically pure D-phenylglycine production using immobilized Pseudomonas aeruginosa 10145 in calcium alginate beads

An Optical Based Biosensor for the Determination of Ammonium in Aqueous Environment

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