Pecina 2003 Biochim Biophys Acta
| Pecina P, Capkova M, Chowdhury SK, Drahota Z, Dubot A, Vojtiskova A, Hansikova H, Houstekova H, Zeman J, Godinot C, Houstek J (2003) Functional alteration of cytochrome c oxidase by SURF1 mutations in Leigh syndrome. Biochim Biophys Acta 1639: 53-63. |
Pecina P, Capkova M, Chowdhury SK, Drahota Z, Dubot A, Vojtiskova A, Hansikova H, Houstekova H, Zeman J, Godinot C, Houstek J (2003) Biochim. Biophys. Acta
Abstract: Subacute necrotising encephalomyopathy (Leigh syndrome) due to cytochrome c oxidase (COX) deficiency is often caused by mutations in the SURF1 gene, encoding the Surf1 protein essential for COX assembly. We have investigated five patients with different SURF1 mutations resulting in the absence of Surf1 protein. All of them presented with severe and generalised COX defect. Immunoelectrophoretic analysis of cultured fibroblasts revealed 85% decrease of the normal-size COX complexes and significant accumulation of incomplete COX assemblies of 90β120 kDa. Spectrophotometric assay of COX activity showed a 70β90% decrease in lauryl maltoside (LM)-solubilised fibroblasts. In contrast, oxygen consumption analysis in whole cells revealed only a 13β31% decrease of COX activity, which was completely inhibited by detergent in patient cells but not in controls. In patient fibroblasts ADP-stimulated respiration was 50% decreased and cytofluorometry showed a significant decrease of mitochondrial membrane potential ΞΞ¨m in state 4, as well as a 2.4-fold higher sensitivity of ΞΞ¨m to uncoupler. We conclude that the absence of the Surf1 protein leads to the formation of incomplete COX complexes, which in situ maintain rather high electron-transport activity, while their H+ -pumping is impaired. Enzyme inactivation by the detergent in patient cells indicates instability of incomplete COX assemblies. β’ Keywords: Cytochrome c oxidase, SURF1, Leigh syndrome, Mitochondrial disorder
β’ O2k-Network Lab: CZ_Prague_Zeman J, CZ_Prague_Houstek J
Labels:
Stress:Mitochondrial Disease; Degenerative Disease and Defect"Mitochondrial Disease; Degenerative Disease and Defect" is not in the list (Cell death, Cryopreservation, Ischemia-reperfusion, Permeability transition, Oxidative stress;RONS, Temperature, Hypoxia, Mitochondrial disease) of allowed values for the "Stress" property., Genetic Defect; Knockdown; Overexpression"Genetic Defect; Knockdown; Overexpression" is not in the list (Cell death, Cryopreservation, Ischemia-reperfusion, Permeability transition, Oxidative stress;RONS, Temperature, Hypoxia, Mitochondrial disease) of allowed values for the "Stress" property. Organism: Human Tissue;cell: Fibroblast Preparation: Intact Cell; Cultured; Primary"Intact Cell; Cultured; Primary" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property. 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.
HRR: Oxygraph-2k
