[Reaction between rabbit skeletal muscle creatine kinase and ATP gamma-amides]

The interaction of creatine kinase from skeletal muscles of rabbit with ADP, ATP and gamma-amides of ATP: gamma-anilide ATP (1), gamma-benzylamide ATP (2), N-2-hydroxyethyl-N-methyl-gamma-amide ATP (3) and 4-(N-2-hydroxyethyl-N-methylamino)-benzyl-gamma-amide ATP (4) was investigated. The values of dissociation constants of nucleotides were determined by fluorescence quenching method. All analogs preserve their affinity to the enzyme, analogs 1 and 2 being the strongest in affinity. The values of dissociation constants of these analogs are equal to those for ATP and ADP. The influence of Mg2+ and creatine on gamma-amides ATP enzyme binding was investigated. The affinity of gamma-amides of ATP in the presence of Mg2+ and creatine was shown to decrease. It is concluded that gamma-amides of ATP (1,2) have the suitable structure for the preparation of affinity reagents for creatine kinase.