Kinetic studies on the dissociation of adenosine cyclic 3',5'-monophosphate from the regulatory subunit of protein kinase from rabbit skeletal muscle.

摘要: The exchange rate of unlabeled adenosine 3',5'-monophosphate (cAMP) with labeled [3H]cAMP in the dimeric regulatory subunit-cAMP complex cAMP-dependent protein kinase, type I, purified from rabbit skeletal muscle is described by using equilibrium isotope technique. Results indicate that carried out absence catalytic subunit (C) rather slow a half-life approximately 870 s. This not affected presence MgATP (50 microM). However, when both microM) and C (1-13 NM) are present, observed to increase markedly. Furthermore, less than stoichiometric amounts required for cAMP exchange, indicating effect on enhancement process. These results MgATP, ternary between must be formed, dynamic eternary its dissociable species reached within seconds. On basis our kinetic data, it proposed formation this intermediate allows rapid activation or inactivation kinase following changes cellular levels.