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Singer 1956 J Biol Chem

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Publications in the MiPMap
Singer TP, Kearney, EB and Bernath P (1956) Studies on succinic dehydrogenase. Isolation and properties of the dehydrogenase from beef heart. J Biol Chem 223:599-613.

» PMID: 13385208 Open Access

Singer TP, Kearney, EB and Bernath P (1956) J Biol Chem

Abstract:

  1. Succinic dehydrogenase has been isolated from beef heart mitochondria as a soluble protein in a state approaching homogeneity by physico-chemical criteria. The overall purification is about 100-fold compared with a mitochondrial acetone powder.
  2. The enzyme is a ferroflavoprotein cont,aining 4 atoms of ferrous (non-hemin) iron and a mole of flavin per mole of protein (200,000 gm.). The dehydrogenase may be isolated from aged starting material with 2 atoms of iron per mole and half the specific activity.
  3. Among the common electron acceptors, only the following function with the dehydrogenase, at the relative rates indicated in parentheses: phenazine methosulfate (100), ferricyanide (39), O2 (0.02). The first two of these acceptors react via the iron moieties, whereas O2 seems to react directly with the flavin.
  4. The QO2, has been measured as 20,000 and the turnover number as 3000 under the standard assay conditions.
  5. The properties of the isolated dehydrogenase agree with those previously described for mitochondrial and other particulate preparations of the enzyme, except for properties related to the absence of contaminating hemoproteins. At 38 °C the pH optimum is 7.7; the K, for succinate is 1.3 X 10-3 M at 38 °C and 5.2 X 10-4 M at 21 °C. Oxalacetate, malonate, and fumarate are competitive inhibitors. Antimycin A and BAL do not inhibit the dehydrogenase. The dehydrogenase is highly sensitive to sulfhydryl reagents, p-chloromercuribenzoate inhibiting it in a reversible manner and the substrate protecting the enzyme from this type of inhibition.

Keywords: Succinic dehydrogenase, Beef heart mitochondria

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Organism: Bovines  Tissue;cell: Heart  Preparation: Isolated mitochondria, SMP  Enzyme: Complex II;succinate dehydrogenase  Regulation: Inhibitor, Temperature 



Made history