title: [Characterization of changes in the activity of K+-n-nitrophenylphosphatase of erythrocyte ghosts under the influence of ouabain].
abstract: Variation of K+-p-NPP-ase of human ghosts under the action of ouabain (10(-11)-10(-3) M) has been studied. In human ghosts the activity of ouabain-sensitive K+-p-NPP-ase has been found to make up 65% of the total enzyme activity. The activity of ouabain-sensitive K+-p-NPP-ase reaches a maximum level at pH 7.6-8.0. A decrease in the activity of this enzyme caused by ouabain is of two-phase character. In the range of ouabain concentration from 10(-10) M to 10(-6) M and from 10(-5) M to 10(-3) M the enzyme activity lowers significantly; in the range of 10(-7) M to 10(-5) M it reaches the plato. Two types of the enzyme are assumed to exist differing by 4-5 orders of magnitude in their sensitivity to ouabain, inhibitor affinity constants and Michaelis constants.
authors.forename: G P
authors.initials: GP
authors.lastname: Gulidova
authors.forename: O N
authors.initials: ON
authors.lastname: Chekrygina
mesh_terms: D009597:4-Nitrophenylphosphatase / Q000097:blood*; D000328:Adult; D002301:Cardiac Glycosides / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000201:enzymology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010042:Ouabain / Q000494:pharmacology*; D010744:Phosphoric Monoester Hydrolases / Q000097:blood*
chemical_list: D002301:Cardiac Glycosides; D010042:Ouabain; D010744:Phosphoric Monoester Hydrolases; D009597:4-Nitrophenylphosphatase
vernacular_title: Osobennosti izmeneniia aktivnosti K+-n-nitrofenilfosfatazy teneĭ éritrotsitov pod vliianiem uabaina.