reported that mtDNA mutations resulted in complex I deficiency in the mitochondrial
respiratory chain in benign renal oncocytoma cells (19).
in 2000 described a patient harboring a novel heteroplasmic m.5874A-G somatic mutation presenting with exercise intolerance, mild bilateral ptosis, limb weakness, and
respiratory chain complex III deficiency, hypnotizing that the phenotype associated with this mutation is similar to cytochrome b deficiency because of a high content of tyrosine in cytochrome b and COX III subunits [10].
These data which resulted in increased expression of NDUFB8 and MTCO1 support the suggestion that increased activity of mitochondrial
respiratory chain could result from a proteome alteration leading to modulation of expression/activity of a range of mitochondrial components.
reported a correlation between CoQ10 concentration and respiratory rate which led to the assumption that physiological CoQ10 concentrations do not saturate the
respiratory chain [33, 34].
Human mtDNA is a small, circular 16,569 bp DNA encoding 13 subunits of mitochondrial
respiratory chain proteins including seven complex I, one complex III, three complex IV, and two complex V subunits that are essential to the assembly and function of the mitochondrial
respiratory chain [49, 50].
Besides the [DELTA][PSI] role in ATP synthesis, it is also involved in the production of ROS because an increased [DELTA][PSI] is known to slow electron transfer among the enzymes in the
respiratory chain; intermediates react allowing a single electron reduction of oxygen, this produces an electron scape and superoxide anion formation, which is then converted to other ROS (Murphy 2009).
Studies of individual mitochondrial enzymes or
respiratory chain complexes are widely used for assessing mitochondrial function.
ROS is produced by mitochondrial
respiratory chain and may alter the mtDNA copy number (19).
The defects of mitochondria, such as the reduced activity of the mitochondrial
respiratory chain and the overproduced ROS, are detected in the brains of subjects with aging-related neurodegenerative disorders [16-21].
Measurement of Mitochondrial
Respiratory Chain Complex Activity.
We should also be informed about the results of biochemical investigations to know about the activity of
respiratory chain complexes.
In this project, we are interested in modeling mitochondria and more particularly, the
respiratory chain, a metabolic pathway (enzymatic reaction chain) which takes place inside the inner mitochondrial membrane.
