the non-covalent binding of the ouabain derivatives ( npt-ouabain , designated i , ii , and iii ) was followed ( i ) by their ability to inhibit the activity of sodium- and potassium-activated atpase ( ( na+ , k+ ) -atpase ) purified from the electric organ of electrophorus electricus , ( ii ) by the binding of [ 3h ] npt-ouabain i to the enzyme , and ( iii ) by the inhibition of [ 3h ] ouabain binding with unlabeled npt-ouabain i .
C0001473
atpase
C0001479
na