title: A novel dinitrophenylglutathione-stimulated ATPase is present in human erythrocyte membranes.
abstract: Vesicles prepared from human erythrocyte membranes were found to catalyze ATP hydrolysis that was stimulated by dinitrophenylglutathione (Dnp-SG). This activity was dependent on temperature and Mg2+ and independent of ion pump ATPases present in erythrocyte membranes. The activity was a linear function of protein and time up to 60 min. The Km values of ATPase for Dnp-SG and ATP were found to be 49 microM and 1.67 mM, respectively. This suggests that in erythrocytes, the transport of Dnp-SG requires direct enzymatic hydrolysis of ATP and both Dnp-SG-stimulated ATPase activity and the ATP-dependent efflux of Dnp-SG from erythrocytes represent different activities of the same protein.
mesh_terms: D000251:Adenosine Triphosphatases / Q000097:blood*; D001693:Biological Transport, Active; D004789:Enzyme Activation; D004910:Erythrocyte Membrane / Q000201:enzymology*; D005978:Glutathione / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D013696:Temperature
chemical_list: C030190:S-(2,4-dinitrophenyl)glutathione; D000251:Adenosine Triphosphatases; D005978:Glutathione; D008274:Magnesium