The p-nitrophenyl phosphatase activity of ubiquitin from bovine erythrocytes.
Ubiquitin, a unique protein with esterase and carbonic anhydrase activity, has been found to have also a p-nitrophenyl phosphatase activity. This phosphomonoesterase activity of ubiquitin has an acidic pH optimum; its true substrate appears to be the phosphomonoanion, with a Km of 1.8 X 10(-3) M. It is competitively inhibited by the typical acid phosphatase inhibitors, arsenate (Ki = 1.3 X 10(-3) M), molybdate (Ki = 1.2 X 10(-6) M), and phosphate (Ki = 1.4 X 10(-3) M). These inhibitors have no effect on the CO2 hydration and p-nitrophenyl acetate esterase activities of the ubiquitin. Acetazolamide slightly inhibited the p-nitrophenyl phosphatase activity.
Taniguchi
N
N
Matsumoto
H
H
D009597:4-Nitrophenylphosphatase / Q000097:blood*; D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000097:blood*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010744:Phosphoric Monoester Hydrolases / Q000097:blood*; D014452:Ubiquitins / Q000097:blood* / Q000302:isolation & purification
D006609:High Mobility Group Proteins; D014452:Ubiquitins; D010744:Phosphoric Monoester Hydrolases; D009597:4-Nitrophenylphosphatase