PURIFICATION OF AMP DEAMINASE FROM MUSCLE OF SNAPPER PAGRUS-AURATUS

AMP deaminase (EC 3.5.4.6) which catalyzes the deamination of AMP to IMP was solubilized from the skeletal muscle of the snapper Pagrus auratus with potassium phosphate buffer (pH 7.0) containing 0.1 m KCl and 1 mm 2-mercaptoethanol, and purified by ammonium sulfate fractionation and three steps of column chromatography on cellulose phosphate P11, 5'AMP Sepharose 4B, and Butyl-Toyopearl 650S. The purified enzyme was shown to be homogeneous by SDS-polyacrylamide gel electrophoresis and the specific activity of the enzyme was 40.7 units/mg protein, showing 254-fold purification. The molecular weight of the native enzyme was estimated to be 3.12 x 10(5) by gel filtration and 8.2 x 10(4) by SDS-polyacrylamide slab gel electrophoresis. These results suggest that the native enzyme has a tetrameric structure and that it has somewhat larger molecular weight than that of AMP deaminases from the muscle of other species.