Transient kinetics and thermodynamics of anthroylouabain binding to Na/K-ATPase.

The Na/K-ATPase is an integral membrane protein enzyme which uses energy derived from hydrolysis of ATP to pump Na+ out of and K+ into the cell. Ouabain belongs to a class of drugs known as cardiac glycosides, which are useful for treating congestive heart failure. Therapeutic value is achieved when these drugs bind to and inhibit the Na/K-ATPase of cardiac muscle.