Publications

• Purification and properties of two glyoxylate reductases from a species of Pseudomonas.

  Cartwright L.N., Hullin R.P.

  1. Two enzymes that catalyse the reduction of glyoxylate to glycollate have been separated and purified from a species of Pseudomonas. Their molecular weights were estimated as 180000. 2. Reduced nicotinamide nucleotides act as the hydrogen donators for the enzymes. The NADH-linked enzyme is entir ... >> More

  1. Two enzymes that catalyse the reduction of glyoxylate to glycollate have been separated and purified from a species of Pseudomonas. Their molecular weights were estimated as 180000. 2. Reduced nicotinamide nucleotides act as the hydrogen donators for the enzymes. The NADH-linked enzyme is entirely specific for its coenzyme but the NADPH-linked reductase shows some affinity towards NADH. 3. Both enzymes convert hydroxypyruvate into glycerate. 4. The glyoxylate reductases show maximal activity at pH6.0-6.8, are inhibited by keto acids and are strongly dependent on free thiol groups for activity. 5. The Michaelis constants for glyoxylate and hydroxypyruvate were found to be of a high order. 6. The reversibility of the reaction has been demonstrated for both glyoxylate reductases and the equilibrium constants were determined. 7. The reduction of glyoxylate and hydroxypyruvate is not stimulated by anions. << Less

  Biochem J 101:781-791(1966) [PubMed] [EuropePMC]

• Purification and characterization of a novel NADPH(NADH)-dependent glyoxylate reductase from spinach leaves. Comparison of immunological properties of leaf glyoxylate reductase and hydroxypyruvate reductase.

  Kleczkowski L.A., Randall D.D., Blevins D.G.

  A novel reductase displaying high specificity for glyoxylate and NADPH was purified 3343-fold from spinach leaves. The enzyme was found to be an oligomer of about 125 kDa, composed of four equal subunits of 33 kDa each. A Km for glyoxylate was about 14-fold lower with NADPH than with NADH (0.085 a ... >> More

  A novel reductase displaying high specificity for glyoxylate and NADPH was purified 3343-fold from spinach leaves. The enzyme was found to be an oligomer of about 125 kDa, composed of four equal subunits of 33 kDa each. A Km for glyoxylate was about 14-fold lower with NADPH than with NADH (0.085 and 1.10 mM respectively), but the maximal activity, 210 mumol/min per mg of protein, was similar with either cofactor. Km values for NADPH and NADH were 3 and 150 microM respectively. Optimal rates with either NADPH or NADH were found in the pH range 6.5-7.4. The enzyme also showed some reactivity towards hydroxypyruvate with rates less than 2% of those observed for glyoxylate. Results of immunological studies, using antibodies prepared against either glyoxylate reductase or spinach peroxisomal hydroxypyruvate reductase, suggested substantial differences in molecular structure of the two proteins. The high rates of NADPH(NADH)-glyoxylate reductase in crude leaf extracts of spinach, wheat and soya bean (30-45 mumol/h per mg of chlorophyll) and its strong affinity for glyoxylate suggest that the enzyme may be an important side component of photorespiration in vivo. In leaves of nitrogen-fixing legumes, this reductase may also be involved in ureide breakdown, utilizing the glyoxylate produced during allantoate metabolism. << Less

  Biochem J 239:653-659(1986) [PubMed] [EuropePMC]

• Biochemical characterization of the 2-ketoacid reductases encoded by ycdW and yiaE genes in Escherichia coli.

  Nunez M.F., Pellicer M.T., Badia J., Aguilar J., Baldoma L.

  Glyoxylate is an important intermediate of the central microbial metabolism formed from acetate, allantoin or glycolate. Depending on the physiological conditions, glyoxylate is incorporated into the central metabolism by the combined actions of the activity of malate synthase and the D-glycerate ... >> More

  Glyoxylate is an important intermediate of the central microbial metabolism formed from acetate, allantoin or glycolate. Depending on the physiological conditions, glyoxylate is incorporated into the central metabolism by the combined actions of the activity of malate synthase and the D-glycerate pathway, or alternatively it can be reduced to glycolate by constitutive glyoxylate reductase activity. At present no information is available on this latter enzyme in Escherichia coli, although similar enzymes, classified as 2-hydroxyacid dehydrogenases, have been characterized in other organisms. A BLAST search using as the query sequence the hydroxypyruvate/glyoxylate reductase from Cucumis sativus identified as an orthologue the yiaE gene of E. coli encoding a ketoaldonate reductase. Use of this sequence in a subsequent BLAST search yielded the ycdW gene as a good candidate to encode glyoxylate reductase in this bacterium. Cloning and overexpression of the ycdW gene showed that its product displayed a high NADPH-linked glyoxylate reductase activity, and also catalysed the reduction of hydroxypyruvate with a lower efficiency. Disruption of the ycdW gene by a chloramphenicol acetyltransferase ('CAT') cassette did not totally abolish the glyoxylate reductase activity, indicating that another enzyme accomplished this function. The similarity with YiaE led us to test whether this protein was responsible for the remaining glyoxylate reductase activity. Purification of YcdW and YiaE proteins permitted their kinetic characterization and comparison. Analysis of the catalytic power (k(cat)/K(m)) disclosed a higher ratio of YcdW for glyoxylate and of YiaE for hydroxypyruvate. << Less

  Biochem. J. 354:707-715(2001) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• 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.