Publications

• Diverse allosteric and catalytic functions of tetrameric d-lactate dehydrogenases from three Gram-negative bacteria.

  Furukawa N., Miyanaga A., Togawa M., Nakajima M., Taguchi H.

  NAD-dependent d-lactate dehydrogenases (d-LDHs) reduce pyruvate into d-lactate with oxidation of NADH into NAD(+). Although non-allosteric d-LDHs from Lactobacilli have been extensively studied, the catalytic properties of allosteric d-LDHs from Gram-negative bacteria except for Escherichia coli r ... >> More

  NAD-dependent d-lactate dehydrogenases (d-LDHs) reduce pyruvate into d-lactate with oxidation of NADH into NAD(+). Although non-allosteric d-LDHs from Lactobacilli have been extensively studied, the catalytic properties of allosteric d-LDHs from Gram-negative bacteria except for Escherichia coli remain unknown. We characterized the catalytic properties of d-LDHs from three Gram-negative bacteria, Fusobacterium nucleatum (FNLDH), Pseudomonas aeruginosa (PALDH), and E. coli (ECLDH) to gain an insight into allosteric mechanism of d-LDHs. While PALDH and ECLDH exhibited narrow substrate specificities toward pyruvate like usual d-LDHs, FNLDH exhibited a broad substrate specificity toward hydrophobic 2-ketoacids such as 2-ketobutyrate and 2-ketovalerate, the former of which gave a 2-fold higher k cat/S0.5 value than pyruvate. Whereas the three enzymes consistently showed hyperbolic shaped pyruvate saturation curves below pH 6.5, FNLDH and ECLDH, and PALDH showed marked positive and negative cooperativity, respectively, in the pyruvate saturation curves above pH 7.5. Oxamate inhibited the catalytic reactions of FNLDH competitively with pyruvate, and the PALDH reaction in a mixed manner at pH 7.0, but markedly enhanced the reactions of the two enzymes at low concentration through canceling of the apparent homotropic cooperativity at pH 8.0, although it constantly inhibited the ECLDH reaction. Fructose 1,6-bisphosphate and certain divalent metal ions such as Mg(2+) also markedly enhanced the reactions of FNLDH and PALDH, but none of them enhanced the reaction of ECLDH. Thus, our study demonstrates that bacterial d-LDHs have highly divergent allosteric and catalytic properties. << Less

  AMB Express 4:76-76(2014) [PubMed] [EuropePMC]

• D- and L-lactic acid dehydrogenases in Lactobacillus plantarum.

  DENNIS D., KAPLAN N.O.

  J Biol Chem 235:810-818(1960) [PubMed] [EuropePMC]

• Chemical characterization of D-lactate dehydrogenase from Escherichia coli B.

  Tarmy E.M., Kaplan N.O.

  J Biol Chem 243:2579-2586(1968) [PubMed] [EuropePMC]

• An aldo-keto reductase with 2-keto-l-gulonate reductase activity functions in l-tartaric acid biosynthesis from vitamin C in Vitis vinifera.

  Jia Y., Burbidge C.A., Sweetman C., Schutz E., Soole K., Jenkins C., Hancock R.D., Bruning J.B., Ford C.M.

  Tartaric acid has high economic value as an antioxidant and flavorant in food and wine industries. l-Tartaric acid biosynthesis in wine grape (<i>Vitis vinifera</i>) uses ascorbic acid (vitamin C) as precursor, representing an unusual metabolic fate for ascorbic acid degradation. Reduction of the ... >> More

  Tartaric acid has high economic value as an antioxidant and flavorant in food and wine industries. l-Tartaric acid biosynthesis in wine grape (<i>Vitis vinifera</i>) uses ascorbic acid (vitamin C) as precursor, representing an unusual metabolic fate for ascorbic acid degradation. Reduction of the ascorbate breakdown product 2-keto-l-gulonic acid to l-idonic acid constitutes a critical step in this l-tartaric acid biosynthetic pathway. However, the underlying enzymatic mechanisms remain obscure. Here, we identified a <i>V. vinifera</i> aldo-keto reductase, Vv2KGR, with 2-keto-l-gulonic acid reductase activity. Vv2KGR belongs to the d-isomer-specific 2-hydroxyacid dehydrogenase superfamily and displayed the highest similarity to the hydroxyl pyruvate reductase isoform 2 in <i>Arabidopsis thaliana</i> Enzymatic analyses revealed that Vv2KGR efficiently reduces 2-keto-l-gulonic acid to l-idonic acid and uses NADPH as preferred coenzyme. Moreover, Vv2KGR exhibited broad substrate specificity toward glyoxylate, pyruvate, and hydroxypyruvate, having the highest catalytic efficiency for glyoxylate. We further determined the X-ray crystal structure of Vv2KGR at 1.58 Å resolution. Comparison of the Vv2KGR structure with those of d-isomer-specific 2-hydroxyacid dehydrogenases from animals and microorganisms revealed several unique structural features of this plant hydroxyl pyruvate reductase. Substrate structural analysis indicated that Vv2KGR uses two modes (A and B) to bind different substrates. 2-Keto-l-gulonic acid displayed the lowest predicted free-energy binding to Vv2KGR among all docked substrates. Hence, we propose that Vv2KGR functions in l-tartaric acid biosynthesis. To the best of our knowledge, this is the first report of a d-isomer-specific 2-hydroxyacid dehydrogenase that reduces 2-keto-l-gulonic acid to l-idonic acid in plants. << Less

  J. Biol. Chem. 294:15932-15946(2019) [PubMed] [EuropePMC]

  This publication is cited by 6 other entries.