Isoelectric point heterogeneity of the two oligomeric forms of heart mitochondrial creatine kinase.
Rabbit heart mitochondrial creatine kinase has been recently shown to exist in two oligomeric forms: a dimer and an octamer, the latter being the form associated with the inner mitochondrial membrane [(1988) Biochem.Biophys. Res. Commun. 153,1310.]. We report here on the determination of the isoelectric points (pI) of the two purified forms by thin layer isoelectric focusing. The pI of the dimer is 8.2 and that of the octamer is 8.8; the former is higher by more than one pH unit than that of the cytoplasmic form MM-CK. It is proposed that the higher pI of the octamer is responsible for its binding to the inner membrane.
LBTM-CNRS-ICBMC-Université Claude Bernard, Villeurbanne.
E
E
Quemeneur
O
O
Marcillat
D
D
Eichenberger
C
C
Vial
D000818:Animals; D003402:Creatine Kinase / Q000302:isolation & purification*; D004588:Electrophoresis, Cellulose Acetate; D007525:Isoelectric Focusing / Q000379:methods; D007526:Isoelectric Point; D007527:Isoenzymes; D008929:Mitochondria, Heart / Q000201:enzymology*; D011817:Rabbits; D013552:Swine
D007527:Isoenzymes; D003402:Creatine Kinase