Role of Alcohol Dehydrogenase, Malate Dehydrogenase and Malic Enzyme in Flooding Tolerance in Brachiaria Species

2000 ◽  
Vol 9 (1) ◽  
pp. 45-47 ◽  
Author(s):  
Sewa Ram
Keyword(s):  
Alcohol Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Flooding Tolerance

Isozymes of amylase, alcohol dehydrogenase, malic enzyme, malate dehydrogenase, and superoxide dismutase in Chloealtis conspersa (Orthoptera)

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 596-600 ◽  
Author(s):  
Peter B. Moens ◽  
Steven Kolodziejczyk
Keyword(s):  
Superoxide Dismutase ◽  
Alcohol Dehydrogenase ◽  
Malate Dehydrogenase ◽  
X Chromosome ◽  
Gel Electrophoresis ◽  
Malic Enzyme ◽  
Duplicate Genes ◽  
Gene Linkage ◽  
Slow Band

Five enzymes of the grasshopper Chloealtis conspersa were studied for possible gene linkage. Because of the extreme localization of chiasmata throughout most of the genome of C. conspersa, it was expected that genes would appear either to be completely linked or to assort independently. Our results indicate that malic enzyme and alcohol dehydrogenase are probably on the X chromosome. Superoxide dismutase is produced from the product of duplicate genes where Sod 1-1 is monomorphic and Sod 1-2 has two alleles, one producing a fast-migrating band on gel electrophoresis and one a slow band. While amylase, malate dehydrogenase, and superoxide dismutase appeared to be autosomal, there was no evidence of linkage between them.Key words: Chloealtis conspersa, amylase, alcohol dehydrogenase, malic enzyme, malate dehydrogenase, superoxide dismutase.

Renal enzymes during experimental diabetes mellitus in the rat. Role of insulin, carbohydrate metabolism, and ketoacidosis

1984 ◽  
Vol 62 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Guy Lemieux ◽  
Manuel Rengel Aranda ◽  
Pierrette Fournel ◽  
Christiane Lemieux
Keyword(s):  
Lactate Dehydrogenase ◽  
Glutamine Synthetase ◽  
Glutamate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Ammonium Chloride ◽  
Malic Enzyme ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Diabetic Rats ◽  
Additional Role

The activities of various ammoniagcnic, gluconeogenic, and glycolytic enzymes were measured in the renal cortex and also in the liver of rats made diabetic with streptozotocin. Five groups of animals were studied: normal, normoglycemic diabetic (insulin therapy), hyperglycemic, ketoacidotic, and ammonium chloride treated rats. Glutaminase I, glutamate dehydrogenase, glutamine synthetase, phosphoenolpyruvate carboxykinase (PEPCK), hexokinase, phosphofructokinase, fructose-1,6-diphos-phatase, malate dehydrogenase, malic enzyme, and lactate dehydrogenase were measured. Renal glutaminase I activity rose during ketoacidosis and ammonium chloride acidosis. Glutamate dehydrogenase in the kidney rose only in ammonium chloride treated animals. Glutamine synthetase showed no particular variation. PEPCK rose in diabetic hyperglycemic animals and more so during ketoacidosis and ammonium chloride acidosis. It also rose in the liver of the diabetic animals. Hexokinase activity in the kidney rose in diabetic insulin-treated normoglycemic rats and also during ketoacidosis. The same pattern was observed in the liver of these diabetic rats. Renal and hepatic phosphofructokinase activities were elevated in all groups of experimental animals. Fructose-1,6-diphosphatase and malate dehydrogenase did not vary significantly in the kidney and the liver. Malic enzyme was lower in the kidney and liver of the hyperglycemic diabetic animals and also in the liver of the ketoacidotic rats. Lactate dehydrogenase fell slightly in the liver of diabetic hyperglycemic and NH4Cl acidotic animals. The present study indicates that glutaminase I is associated with the first step of increased renal ammoniagenesis during ketoacidosis. PEPCK activity is influenced both by hyperglycemia and ketoacidosis, acidosis playing an additional role. Insulin appears to prevent renal gluconeogenesis and to favour glycolysis. The latter would seem to remain operative in hyperglycemic and ketoacidotic diabetic animals.

scholarly journals Characterization of the functional role of allosteric site residue Asp102 in the regulatory mechanism of human mitochondrial NAD(P)+-dependent malate dehydrogenase (malic enzyme)

2005 ◽  
Vol 392 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Hui-Chih Hung ◽  
Meng-Wei Kuo ◽  
Gu-Gang Chang ◽  
Guang-Yaw Liu
Keyword(s):  
Malate Dehydrogenase ◽  
Conformational Changes ◽  
Malic Enzyme ◽  
Binding Pocket ◽  
Site Directed Mutagenesis ◽  
Activation Mechanism ◽  
Amino Acid Residues ◽  
Allosteric Site ◽  
Charged Amino Acids

Human mitochondrial NAD(P)+-dependent malate dehydrogenase (decarboxylating) (malic enzyme) can be specifically and allosterically activated by fumarate. X-ray crystal structures have revealed conformational changes in the enzyme in the absence and in the presence of fumarate. Previous studies have indicated that fumarate is bound to the allosteric pocket via Arg67 and Arg91. Mutation of these residues almost abolishes the activating effect of fumarate. However, these amino acid residues are conserved in some enzymes that are not activated by fumarate, suggesting that there may be additional factors controlling the activation mechanism. In the present study, we tried to delineate the detailed molecular mechanism of activation of the enzyme by fumarate. Site-directed mutagenesis was used to replace Asp102, which is one of the charged amino acids in the fumarate binding pocket and is not conserved in other decarboxylating malate dehydrogenases. In order to explore the charge effect of this residue, Asp102 was replaced by alanine, glutamate or lysine. Our experimental data clearly indicate the importance of Asp102 for activation by fumarate. Mutation of Asp102 to Ala or Lys significantly attenuated the activating effect of fumarate on the enzyme. Kinetic parameters indicate that the effect of fumarate was mainly to decrease the Km values for malate, Mg2+ and NAD+, but it did not notably elevate kcat. The apparent substrate Km values were reduced by increasing concentrations of fumarate. Furthermore, the greatest effect of fumarate activation was apparent at low malate, Mg2+ or NAD+ concentrations. The Kact values were reduced with increasing concentrations of malate, Mg2+ and NAD+. The Asp102 mutants, however, are much less sensitive to regulation by fumarate. Mutation of Asp102 leads to the desensitization of the co-operative effect between fumarate and substrates of the enzyme.

scholarly journals The role of malic enzyme in the regulation of lipid accumulation in filamentous fungi

Microbiology ◽  
1999 ◽  
Vol 145 (8) ◽  
pp. 1911-1917 ◽  
Author(s):  
James P. Wynn ◽  
Aidil bin Abdul Hamid ◽  
Colin Ratledge
Keyword(s):  
Filamentous Fungi ◽  
Lipid Accumulation ◽  
Malic Enzyme

scholarly journals The Role of Zinc in Alcohol Dehydrogenase

1959 ◽  
Vol 234 (10) ◽  
pp. 2621-2626 ◽  
Author(s):  
Bert L. Vallee ◽  
Robert J.P. Williams ◽  
Frederic L. Hoch
Keyword(s):  
Alcohol Dehydrogenase

scholarly journals The Role of Active Site Arginines of Sorghum NADP-Malate Dehydrogenase in Thioredoxin-dependent Activation and Activity

2000 ◽  
Vol 275 (46) ◽  
pp. 35792-35798 ◽  
Author(s):  
Isabelle Schepens ◽  
Eric Ruelland ◽  
Myroslawa Miginiac-Maslow ◽  
Pierre Le Maréchal ◽  
Paulette Decottignies
Keyword(s):  
Malate Dehydrogenase ◽  
Active Site

Changes in NAD(P)+-dependent malic enzyme and malate dehydrogenase activities during fibroblast proliferation

1982 ◽  
Vol 110 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Wallace L. McKeehan ◽  
Kerstin A. McKeehan
Keyword(s):  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Fibroblast Proliferation
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