Abstract
An alkaline phosphodiesterase has been purified 2200-fold from the fruit body of Flammulina velutipes. The molecular weight is about 53, 000. The optimum pH for hydrolysis of bis-pnitrophenyl phosphate is 8.0. This phosphodiesterase is stable for 30 min below 40°C and in a pH range from 5.5 to 6.5. The Km values for bis-p-nitrophenyl phosphate and p-nitrophenyl deoxythymidine 5'-phosphate are 0.25mM and 0.09mM, respectively. The enzyme does not hydrolyze RNA and DNA, whereas adenosyl uridine 5'-phosphate is hydrolyzed at a considerable rate. The phosphodiesterase also hydrolyzes NAD, UDP-glucose, and ADP-ribose but does not act on ATP and cyclic AMP.
