Purification and characterization of arginine:mono-ADP-ribosylhydrolase from Euglena gracilis Z

Arginine:mono-ADP-ribosylhydrolase was purified from a protozoan, Euglena gracilis Z, using [32P]mono-ADP-ribosylated actin as a substrate. The enzyme showed molecular mass of 33 kDa both in SDS PAGE and gel filtration, indicating it to be a monomeric protein. It was strongly inhibited by ADP and ADP-ribose and activated by Mg2+, DTT, and 2-mercaptoethanol. These results suggest that it recognizes the ADP-ribose moiety of the modified protein. Since the enzyme activity increased in S phase and late G0 phase in a synchronous dividing culture, the enzyme may function in the regulation of the cell cycle.