The reaction of phosphages with ATP: Creatine phosphotransferase

Abstract

• 1.

  1. A kinetic investigation has been made of the effect of various phosphagens on the reverse reaction catalysed by creatine kinase (ATP: creatine phosphotransferase, EC 2.7.3.2.).

• 2.

  2. The results indicate that phosphoglycocyamine functions as a substrate of the enzyme with a maximum velocity only 0.18% of that obtained with phospho-creatine. Phosphotautocyamine and phosphoarginine were found not to act as substrates although they could combine with the enzyme as inhibitors.

• 3.

  3. Values have been obtained for the tru kinetic constants associated with the reaction of each phosphagen with both the free enzyme and the enzyme-MgADP complex.