Hydrolysis of a phosphonate ester catalyzed by an enzyme from Dictyostelium discoideum

• Published in: Archives of biochemistry and biophysics Vol. 197; no. 1; pp. 364 - 366
• Main Authors: Rossomando, Edward F., Jahngen, Jessica H.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.1979
• Subjects: 3',5'-Cyclic-AMP Phosphodiesterases - metabolism; 4-Nitrophenylphosphatase - metabolism; Alkaline Phosphatase - metabolism; Catalysis; Chemical Phenomena; Chemistry; Dictyostelium - enzymology; Hydrolysis; Nitrophenols - metabolism; Organophosphorus Compounds - metabolism; Phosphoric Monoester Hydrolases - metabolism
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/0003-9861(79)90257-1

An activity capable of hydrolyzing the phosphonate ester, 4-nitrophenyl phenylphosphonate has been detected in the eucaryotic microorganism Dictyostelium discoideum. This activity (4-nitrophenyl phenylphosphonate-esterase) was found in both membrane-enriched and soluble fractions. Two other activities present in this fraction, namely cyclic AMP-diesterase and an ATP-hydrolase, did not copurify with the 4-nitrophenyl phenylphosphonate-esterase. Also while ATP and cAMP inhibited the hydrolysis of 4-nitrophenyl phenlyphosphonate, they did so in a noncompetitive manner and, furthermore, saturating concentrations of 4-nitrophenyl phenylphosphonate had no effect on the hydrolysis of either cyclic AMP or ATP. The partially purified preparation was more active at pH 7 than at either pH 5 or 9, more active with acetate than chloride, and more active at 22 °C than at either 12 or 30 °C. The activity is inhibited by AMP in a competitive manner, but is not affected by levamisole, an inhibitor specific for alkaline phosphatase activity.