it is concluded 1 ) that the ca-atpase enzyme possesses two classes of atp binding sites , 2 ) that the affinity of these two sites and the nature of their interaction is modulated by the h+ and mg2+ concentrations , and 3 ) that the hydrolytic activity of the high affinity atp binding site is activated by atp or tnp-amp-pnp ( or tnp-atp ) binding in a low affinity atp binding site .
C0001473
atpase
C0020291
hydrolytic