Pecina 2004 Am J Physiol Cell Physiol

Pecina P, Gnaiger E, Zeman J, Pronicka E, Houstek J (2004) Decreased affinity to oxygen of cytochrome c oxidase in Leigh syndrome caused by SURF1 mutations. Am J Physiol Cell Physiol 287: C1384-C1388.

» PMID: 15269007

Pecina P, Gnaiger E, Zeman J, Pronicka E, Houstek J (2004) Am J Physiol Cell Physiol

Abstract: Mutations in the gene SURF1 prevent synthesis of cytochrome-c oxidase (COX)-specific assembly protein and result in a fatal neurological disorder, Leigh syndrome. Because this severe COX deficiency presents with barely detectable changes of cellular respiratory rates under normoxic conditions, we analyzed the respiratory response to low oxygen in cultured fibroblasts harboring SURF1 mutations with high-resolution respirometry. The oxygen kinetics was quantified by the partial pressure of oxygen (P_O2) at half-maximal respiration rate (P₅₀) in intact coupled cells and in digitonin-permeabilized uncoupled cells. In both cases, the P₅₀ in patients was elevated 2.1- and 3.3-fold, respectively, indicating decreased affinity of COX for oxygen. These results suggest that at physiologically low intracellular P_O2, the depressed oxygen affinity may lead in vivo to limitations of respiration, resulting in impaired energy provision in Leigh syndrome patients. • Keywords: Oxygen kinetics, Mitochondrial disease

• O2k-Network Lab: AT_Innsbruck_Gnaiger E, CZ_Prague_Zeman J, CZ_Prague_Houstek J, AT Innsbruck MitoCom, CZ Prague Bioenergetics

Labels: MiParea: Respiration, nDNA;cell genetics, mt-Medicine, Patients Pathology: Inherited

Organism: Human

Preparation: Intact cells Enzyme: Complex IV; Cytochrome c Oxidase"Complex IV; Cytochrome c Oxidase" is not in the list (Adenine nucleotide translocase, Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase, Inner mt-membrane transporter, Marker enzyme, Supercomplex, TCA cycle and matrix dehydrogenases, ...) of allowed values for the "Enzyme" property. Regulation: O2"O2" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property. Coupling state: ROUTINE

HRR: Oxygraph-2k