title: Properties of alpha-hydroxyacid dehydrogenase isozymes from Trypanosoma cruzi.
abstract: Whole cell extracts of culture epimastigotes of Trypanosoma cruzi (Tulahuén strain) have alpha-hydroxyacid dehydrogenase activity which catalyzes the NAD-linked reaction alpha-ketoacid in equilibrium with alpha-hydroxyacid, with a variety of substrates. Two molecular forms of the enzyme have been separated by means of gel electrophoresis. These isozymes were partially purified by DEAE-cellulose chromatography and ammonium sulfate precipitation. Molecular weights were estimated and some catalytic properties were determined with purified isozymes. The faster migrating fraction (isozyme I) has a molecular weight of 85 500 and showed significant activity against linear 3-5 carbon chain substrates. The lowest Km value was obtained for pyruvate. Isozyme II (MW 60 500) utilizes linear and branched chain substrates with 4-6 carbon atoms. Its highest activity and lowest Km value were recorded with alpha-keto-isocarproate as substrate.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002087:Butyrates / Q000378:metabolism; D006880:Hydroxy Acids / Q000302:isolation & purification / Q000378:metabolism; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007651:Keto Acids / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase; D045022:Lactate Dehydrogenases; D008970:Molecular Weight; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid; D013379:Substrate Specificity; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D002087:Butyrates; D006880:Hydroxy Acids; D007527:Isoenzymes; D007651:Keto Acids; D011773:Pyruvates; C015963:2-ketopentanoic acid; C005087:alpha-ketobutyric acid; D019289:Pyruvic Acid; D000429:Alcohol Oxidoreductases; D045022:Lactate Dehydrogenases; D007770:L-Lactate Dehydrogenase; C071195:D-lactate dehydrogenase; C021379:D-2-hydroxyacid dehydrogenase