Malate dehydrogenase (MDH; EC 1.1.1.37) from Dictyostelium discoideum was purified and characterized. MDH activity from whole cells was purified 275-fold. The mitochondrial cytoplasmic MDH present co-purified through three ion exchange and affinity chromatography steps. The isoenzymes were barely separable by either disc gel electrophoresis or isoelectric focusing. The purified preparation containing both isoenzymes had a single pH optimum (9·3–9·5) and an apparent molecular weight of 70000. It exhibited linear kinetics and responded to known inhibitors of MDH, i.e. thyroxine and hydroxymalonate. Michaelis and dissociation constants obtained with this preparation were similar to those obtained with a 10-fold purified mitochondrial MDH.
FluryV.,
HeerB.,
FiechterA.1974; Regulatory and physiochemical properties of two isozymes of malate dehydrogenase from Schizo-saccharomyces pombe.
. Biochimica et biophysica acta 341:465–483
HohorstH. J.1965; Determination of malate with malic dehydrogenase and DPN. In Methods of Enzymatic Analysis, 1st. pp. 328–332BergmeyerH. U.
Edited by New York:: Academic Press.;
KellyP. J.,
KelleherJ. K.,
WrightB. E.1979b; Tricarboxylic acid cycle in Dictyostelium discoideum. A model of the cycle at preculmination and aggregation. Biochemical Journal 184:589–597
KomunieckiP. R.,
DeTomaF. J.,
LawrenceM. H.,
didomenicoL.1980; ADP phosphorylation and glutamate oxidation in mitochondria isolated from Dictyostelium discoideum amoebae. Biochemical and Biophysical Research Communications 96:1017–1023
MurphyW. H.,
KittoG. B.,
EverseJ.,
KaplanN. O.1967; Malate dehydrogenase. I. A survey of molecular size measured by gel filtration. Biochemistry 6:603–610
TeagueW. M.,
HenneyH. R.Jr1973; Purification and properties of cytoplasmic and mitochondrial malate dehydrogenases of Physarum polycephalum.
. Journal of Bacteriology 116:673–684
ThompsonS. T.,
CassK. H.,
StellwagenE.1975; Blue dextran sepharose: an affinity column for the dinucleotide folds in proteins. Proceedings of the National Academy of Sciences of the United States of America 72:669–672
WrightB. E.1964; Biochemistry of Acrasiales. In Biochemistry and Physiology of the Protozoa3 pp. 341–381HutnerS. H.
Edited by New York:: Academic Press.;
WrightB. E.1981; A transition model of the citric acid cycle in Dictyostelium.
. Abstracts of the Annual Meeting, American Society for Microbiology abstract 1144 p. 111