The partial purification and characterization of soluble and mitochondrial malate dehydrogenase from the white shrimp (Penaeus setiferus)

Malate dehydrogenase was extracted from the muscle tissue of the White shrimp, Penaeus setiferus, and partially purified by successive ammonium sulfate fractionation and negative adsorption on carboxymethyl cellulose. The enzyme was separated into the soluble and mitochondrial form by diethylaminoethyl cellulose chromatography. Soluble and mitochondrial malate dehydrogenase were then characterized by a variety of physical-chemical and catalytic tests. Some of these tests included: polyacrylamide gel electrophoresis, Michaelis constants, NAD analogue ratios, substrate inhibition, thermostability, and molecular weight determinations. The results of these tests indicate that White shrimp malate dehydrogenase is in many ways similar to the malate dehydrogenases isolated from other organisms but differs markedly in respect to molecular weight and inhibition by oxalacetate and malate.