Two forms of AMP deaminase from the lizard (Lacerta agilis) liver

Two molecular forms of AMP deaminase have been revealed by phosphocellulose column chromatography in the liver of uricotelic lizard. The calculated S0.5 value of the purified lizard liver AMP deaminase was 2.5 +/- 0.1 for the form I and 3.6 +/- 0.4 for the form II. Both forms of the enzyme were activated by ATP and ADP but the form II to a much higher extent. GTP activated only the form II and inorganic phosphate inhibited both forms. The occurrence of multiple forms of liver AMP deaminase in uricotelic species, as well as its difference from the mammalian enzyme regulation by GTP is suggested to be connected with the uricotelism in these animals.