Kinetic properties and the functional role of particulate MM-isoenzyme of creatine phosphokinase bound to heart muscle myofibrils.

Localization of creatine kinase isoenzymes in myofibrils. II. Chicken heart muscle

Chicken heart muscle contains almost exclusively the BB isoenzyme of creatine kinase (CK), its myofibrils, moreover, lack an M-line. This tissue thus provides an interesting contrast to skeletal muscle, in which some of the MM-CK present as predominant CK isoenzyme is bound at the myofibrillar M-line. Approx. 2% of the total CK activity in a chicken heart homogenate remains bound to the myofibr...

Release of enzymes from adult rat heart myocytes.

The release of lactic dehydrogenase, creatine phosphokinase, and aspartate aminotransferase from initially viable, metabolically competent adult rat heart myocytes has been examined. Freshly isolated cells contain levels of total lactic dehydrogenase, creatine phosphokinase, and aspartate aminotransferase, as well as lactic dehydrogenase and creatine phosphokinase isoenzyme profiles that are qu...

Intracellular targeting of isoproteins in muscle cytoarchitecture

Part of the muscle creatine kinase (MM-CK) in skeletal muscle of chicken is localized in the M-band of myofibrils, while chicken heart cells containing myofibrils and BB-CK, but not expressing MM-CK, do not show this association. The specificity of the MM-CK interaction was tested using cultured chicken heart cells as "living test tubes" by microinjection of in vitro generated MM-CK and hybrid ...

Assessment of The Diagnostic Capability of Serum Creatine Phosphokinase and Its Isoenzyme in Ectopic Pregnancy

Kinetic properties of the isoenzymes of human creatine phosphokinase.

Studies of the three human creatine phosphokinase (EC 2.7.3.2) isoenzymes, MM, MB, and BB, show that important differences exist in substrate dependency of the reaction rates. A method was developed to study these properties in which the ATP formed in the reverse reaction was measured by means of firefly luciferase. With substrate conditions at which the isoenzymes showed substantial difference...