PURIFICATION AND PROPERTIES OF ASPARTATE AMINO TRANSFERASE (E.C2.6.1.1) FROM SKELETEL MUSCLE OF DIRRHINA MRIGALA

Abstract

Aspartate aminotransferase (E. C. 2.6.1.1.) from the skeletal muscle of fresh water fish Cirrhina mrigala has been purified 40 fold by ammonium sulphate fractionation, adsorption on alumina Cs gel and chromatography using DEAE-cellulose column and the properties of the purified enzyme studied. The pH optimum of the enzyme is 7.8. The Km value of aspartic acid and 2-oxoglutaric acid are found to be 2.8 x 10- 3 M and 1.0 x 10-4 M respectively. The activity of enzyme is inhibited by p-chloromercurybenzoate, hydroxylamine hydrochloride and sodium cyanide. The inhibition by pchloromercurybenzoate is reversed by reduced glutathione, B     mercaptoethanol and cysteine. Dicarboxylic acids such as maleic acid, malic acid and succinic acid inhibit the enzyme activity. The enzyme is not activated by any of the metalions tested and heavy metal ions such as mercury and silver strongly inhibit the enzyme activity.