Partial purification and characterization of human erythrocyte phosphoglycollate phosphatase.
Human erythrocytes contain a phosphatase that is highly specific for phosphoglycollate. It shows optimum pH of 6.7 and has Km 1 mM for phosphoglycollate. The molecular weight appears to be about 72000. The enzyme is a dimeric molecule having subunits of mol. wt. about 35000. It could be purified approx. 4000-fold up to a specific activity of 5.98 units/mg of protein. The activity of the enzyme is Mg2+-dependent. Co2+, and to a smaller extent Mn2+, may substitute for Mg2+. Half-maximum inhibition of the phosphatase by 5,5'-dithiobis-(2-nitrobenzoate), EDTA and NaF is obtained at 0.5 microM, 1 mM and 4 mM respectively. Moreover, it needs a univalent cation for optimum activity. Phosphoglycollate phosphatase is a cytoplasmic enzyme. Approx. 5% of its total activity is membrane-associated. This part of activity can be approx. 70% solubilized by freezing, thawing and treatment with 0.25% Triton X-100.
D000838:Anions / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000097:blood* / Q000302:isolation & purification; D012995:Solubility; D013379:Substrate Specificity
D000838:Anions; D002413:Cations, Divalent; C022408:phosphoglycolate phosphatase; D010744:Phosphoric Monoester Hydrolases