Crystallization and properties of rat liver malate dehydrogenase (decarboxylating) (NADP).

Rat liver malate dehydrogenase (decarboxylating) (NADP) ((L-malate: NADP) oxidoreductase (oxaloacetate-decarboxylating), EC 1.1.1.40) was purified and crystallized from medium containing 30 mM Tris-HCl buffer (pH 7.7), 5 mM MgCl2 and 2 mM 2-mercaptoethanol. The enzyme formed rhomboid crystals free from coenzyme, and appeared homogeneous on isoelectric focusing. The crystalline enzyme had an isoelectric point of pH 6.3. Amino acid analysis showed that it contained more acidic amino acids than basic ones.