Ter Veld 2005 FEBS J

ter Veld F, Jeneson JA, Nicolay K (2005) Mitochondrial affinity for ADP is twofold lower in creatine kinase knock-out muscles. Possible role in rescuing cellular energy homeostasis. FEBS J 272:956-65.

» PMID: 15691329

ter Veld F, Jeneson JA, Nicolay K (2005) FEBS J

Abstract: Adaptations of the kinetic properties of mitochondria in striated muscle lacking cytosolic (M) and/or mitochondrial (Mi) creatine kinase (CK) isoforms in comparison to wild-type (WT) were investigated in vitro. Intact mitochondria were isolated from heart and gastrocnemius muscle of WT and single- and double CK-knock-out mice strains (cytosolic (M-CK^–/–), mitochondrial (Mi-CK^–/–) and double knock-out (MiM-CK^–/–), respectively). Maximal ADP-stimulated oxygen consumption flux (State3 Vmax; nmol O2·mg mitochondrial protein^–1·min^–1) and ADP affinity (inline image; µm) were determined by respirometry. State 3 Vmax and inline image of M-CK^–/– and MiM-CK^–/– gastrocnemius mitochondria were twofold higher than those of WT, but were unchanged for Mi-CK^–/–. For mutant cardiac mitochondria, only the inline image of mitochondria isolated from the MiM-CK^–/– phenotype was different (i.e. twofold higher) than that of WT. The implications of these adaptations for striated muscle function were explored by constructing force-flow relations of skeletal muscle respiration. It was found that the identified shift in affinity towards higher ADP concentrations in MiM-CK^–/– muscle genotypes may contribute to linear mitochondrial control of the reduced cytosolic ATP free energy potentials in these phenotypes. • Keywords: Heart, Metabolic control, Mitochondrial respiration, Skeletal muscle, Transgenic mice

• O2k-Network Lab: NL Eindhoven Nicolay K

Labels:

Organism: Rat  Tissue;cell: Heart  Preparation: Isolated mitochondria 

Coupling state: OXPHOS 

HRR: Oxygraph-2k