Oxaloacetate decarboxylases of rat liver.

1. Two oxaloacetate decarboxylases of rat liver are described; one is mitochondrial with no metal ion requirement and activity in the alkaline pH region; the other is cytoplasmic with Mn(2+) or Mg(2+) requirement and activity around pH5. 2. A method for the partial purification of the mitochondrial enzyme is described. 3. The apparent K(m) of the mitochondrial enzyme is 0.23mm. 4. Inhibition of the mitochondrial enzyme by substrate, CoA, acetyl-CoA, citrate and phosphoenolpyruvate is described.