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. |
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 (mt) 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 (mt-CK–/–) and double knock-out (mtM-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 mtIM-CK–/– gastrocnemius mitochondria were twofold higher than those of WT, but were unchanged for mt-CK–/–. For mutant cardiac mitochondria, only the inline image of mitochondria isolated from the mtM-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 mtM-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
