[Differences in properties of creatine kinase BB from chicken tissues].

BB-creatine phosphokinases (CPK-BB, EC 2.7.3.2) were isolated and purified from the chicken brain, heart and gizzard with specific activities 250-300 IU/mg and equal electrophoretic mobilities. Certain differences in thermal stability, activation energy, Km and optimal temperature of the CPK reaction are shown. The amino acid analysis has also revealed different content of certain amino acids in CPK-BB molecules. The obtained results confirm the existence of tissue-specific heterogeneity in CPK-BB which may be significant for functioning of the phosphocreatine-creatine phosphokinase system in different types of tissues.