Subunit structures of AMP deaminase isozymes in rat

AMP deaminases A and B have been purified to apparent homogeneity from rat muscle and liver, respectively. The molecular weights of 286,000 and 351,000 were obtained for the native muscle and liver enzymes, respectively, by sedimentation equilibrium studies. On polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, the muscle preparation exhibited a single polypeptide band with a molecular weight of 72,000; the liver preparation, a molecular weight of 85,000. The data indicate that each enzyme has a tetrameric structure.