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 myofibrillar fraction after repeated washing cycles; both the fraction and the absolute amount of CK bound are about threefold lower than in skeletal muscle. Almost all of the bound enzyme is located within the Z-line region of each sarcomere, as revealed by indirect fluorescent-antibody staining with antiserum against purified chicken BB-CK. After incubation with exogenous purified MM-CK, positive immunofluorescent staining for M-type CK at the H-region of heart myofibrils was observed, along with weaker fluorescence in the Z-line region. Chicken heart myofibrils may thus possess binding sites for both M and B forms of CK.
D000818:Animals; D002645:Chickens; D003402:Creatine Kinase / Q000378:metabolism*; D006651:Histocytochemistry; D007527:Isoenzymes; D008854:Microscopy, Electron; D009206:Myocardium / Q000201:enzymology* / Q000648:ultrastructure; D009210:Myofibrils / Q000201:enzymology* / Q000648:ultrastructure
D007527:Isoenzymes; D003402:Creatine Kinase
J Cell Biol. 1962 May;13:323-35
14457201
J Histochem Cytochem. 1969 May;17(5):314-20
4185309
Eur J Biochem. 1970 Aug;15(2):360-6
5502667
J Biol Chem. 1973 Jul 10;248(13):4803-10
4718746
J Cell Biol. 1973 May;57(2):261-77
4696547
Z Zellforsch Mikrosk Anat. 1969;98(3):437-68
4900458
J Biol Chem. 1975 Jun 10;250(11):4278-84
805138
J Histochem Cytochem. 1975 Jul;23(7):543-62
1095653
J Cell Biol. 1976 Jan;68(1):123-41
1245543
J Anat. 1971 Nov;110(Pt 2):259-73
5143831
J Cell Biol. 1967 Sep;34(3):827-40
6050948