Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.9.3.1 (cytochrome oxidase)
8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Physical exercise produces several adaptive changes in skeletal muscle. However, the molecular mechanisms of these effects are poorly understood. We performed serial analysis of gene expression (SAGE) to quantify the global gene expression profile in sedentary and endurance-trained muscle. A total of 10869 SAGE tags was sequenced and represented 4727 genes. The genes most expressed in muscle are mainly involved in contraction and energy metabolism. Thirty-three genes were differentially expressed between endurance athletes and sedentary individuals. Four genes such as myosin binding protein C fast-type, glycogen phosphorylase, and pyruvate kinase were expressed less in endurance athletes, whereas eight genes coding for expressed sequence tag similar to (EST) crystallin alpha B, EST myosin light chain 2, EST surfactant pulmonary-associated protein A1, EST thrombospondin, EST fructose-bisphosphate aldolase A, EST cytochrome oxidase 1, NADH dehydrogenase 3, and G8 protein were up-regulated. Most of the up-regulated tags corresponded to novel genes. On the other hand, different isoforms of fructose-bisphosphate aldolase A were also differentially expressed. The current study underlying the most highly expressed genes allows a better understanding of global muscle characteristics in normal and endurance-trained individuals. Moreover, the current data suggest novel candidate genes that may be responsible for enhanced endurance performance.
...
PMID:Serial analysis of gene expression in the skeletal muscle of endurance athletes compared to sedentary men. 1522 64

The decrease of neurological performance in normal aging is directly related to brain oxidative stress and inversely related to lifespan. Male mice lifespan was increased by 8-10% (median and maximal lifespan, respectively) in mice with high spontaneous neurological activity, by 21-15% after moderate exercise; and by 25-20% after supplementation with vitamin E. Oxidative stress markers, TBARS and protein carbonyl content, were found increased on aging; a higher content of oxidation products is considered an effective aging factor, specially in the brain, with a majority of postmitotic cells. Mitochondrial enzyme activities, mitochondrial nitric oxide synthase (mtNOS), NADH dehydrogenase and cytochrome oxidase, behaved as markers of brain aging. The decrease in enzyme activities was directly related to the content of oxidation products and to the loss of neurological function in aged mice, this latter was determined in the tighrope and the T-maze tests. The above mentioned conditions that increased mice lifespan were effective to decrease the level of oxidative stress markers, and to retard the decreases in mitochondrial enzyme activities and neurological function associated to aging. The activities of mtNOS, NADH dehydrogenase and cytochrome oxidase may be used as indicators of the effectiveness of antiaging treatments.
...
PMID:Mitochondrial enzyme activities as biochemical markers of aging. 1505 15

Plant mitochondria were previously shown to comprise respiratory supercomplexes containing cytochrome c reductase (complex III) and NADH dehydrogenase (complex I) of I(1)III(2) and I(2)III(4) composition. Here we report the discovery of additional supercomplexes in potato (Solanum tuberosum) mitochondria, which are of lower abundance and include cytochrome c oxidase (complex IV). Highly active mitochondria were isolated from potato tubers and stems, solubilized by digitonin, and subsequently analyzed by Blue-native (BN) polyacrylamide gel electrophoresis (PAGE). Visualization of supercomplexes by in-gel activity stains for complex IV revealed five novel supercomplexes of 850, 1,200, 1,850, 2,200, and 3,000 kD in potato tuber mitochondria. These supercomplexes have III(2)IV(1), III(2)IV(2), I(1)III(2)IV(1), I(1)III(2)IV(2), and I(1)III(2)IV(4) compositions as shown by two-dimensional BN/sodium dodecyl sulfate (SDS)-PAGE and BN/BN-PAGE in combination with activity stains for cytochrome c oxidase. Potato stem mitochondria include similar supercomplexes, but complex IV is partially present in a smaller version that lacks the Cox6b protein and possibly other subunits. However, in mitochondria from potato tubers and stems, about 90% of complex IV was present in monomeric form. It was suggested that the I(1)III(2)IV(4) supercomplex represents a basic unit for respiration in mammalian mitochondria termed respirasome. Respirasomes also occur in potato mitochondria but were of low concentrations under all conditions applied. We speculate that respirasomes are more abundant under in vivo conditions.
...
PMID:Identification and characterization of respirasomes in potato mitochondria. 1506 71

We showed that the human respiratory chain is organized in supramolecular assemblies of respiratory chain complexes, the respirasomes. The mitochondrial complexes I (NADH dehydrogenase) and III (cytochrome c reductase) form a stable core respirasome to which complex IV (cytochrome c oxidase) can also bind. An analysis of the state of respirasomes in patients with an isolated deficiency of single complexes provided evidence that the formation of respirasomes is essential for the assembly/stability of complex I, the major entry point of respiratory chain substrates. Genetic alterations leading to a loss of complex III prevented respirasome formation and led to the secondary loss of complex I. Therefore, primary complex III assembly deficiencies presented as combined complex III/I defects. This dependence of complex I assembly/stability on respirasome formation has important implications for the diagnosis of mitochondrial respiratory chain disorders.
...
PMID:Significance of respirasomes for the assembly/stability of human respiratory chain complex I. 1520 29

Blue native polyacrylamide electrophoresis (BN-PAGE) is a technique developed for the analysis of membrane complexes. Combined with histochemical staining, it permits the analysis and quantification of the activities of mitochondrial oxidative phosphorylation enzymes using whole muscle homogenates, without the need to isolate muscle mitochondria. Mitochondrial complex activities were measured by emerging gels in a solution containing all specific substrates for NADH dehydrogenase and cytochrome c oxidase enzymes (complexes I and IV, respectively) and the colored bands obtained were measured by optique densitometry. The objective of the present study was the application of BN-PAGE colorimetric staining for enzymatic characterization of mitochondrial complexes I and IV in rat muscles with different morphological and biochemical properties. We also investigated these activities at different times after acute exercise of rat soleus muscle. Although having fewer mitochondria than oxidative muscles, white gastrocnemius muscle presented a significantly higher activity (26.7 +/- 9.5) in terms of complex I/V ratio compared to the red gastrocnemius (3.8 +/- 0.65, P < 0.05) and soleus (9.8 +/- 0.9, P < 0.001) muscles. Furthermore, the complex IV/V ratio of white gastrocnemius muscle was always significantly higher when compared to the other muscles. Ninety-five minutes of exhaustive physical exercise induced a decrease in complex I/V and complex IV/V ratios after all resting times (0, 3 and 6 h) compared to control (P < 0.05), probably reflecting the oxidative damage due to increasing free radical production in mitochondria. These results demonstrate the possible and useful application of BN-PAGE-histochemical staining to physical exercise studies.
...
PMID:Evaluation by blue native polyacrylamide electrophoresis colorimetric staining of the effects of physical exercise on the activities of mitochondrial complexes in rat muscle. 1526 99

We have raised monoclonal antibodies capable of immunocapturing all five complexes involved in oxidative phosphorylation for evaluating their post-translational modifications. Complex I (NADH dehydrogenase), complex II (succinate dehydrogenase), complex III (cytochrome c reductase), complex IV (cytochrome c oxidase), and complex V (F1F0 ATP synthase) from bovine heart mitochondria were obtained in good yield from small amounts of tissue in more than 90% purity in one step. The composition and purity of the complexes was evaluated by Western blotting using monoclonal antibodies against individual subunits of the five complexes. In this first study, the phosphorylation state of the proteins without inducing phosphorylation or dephosphorylation was identified by using the novel Pro-Q Diamond phosphoprotein gel stain. The major phosphorylated components were the same as described before in sucrose gradient enriched complexes. In addition a few additional potential phosphoproteins were observed. Since the described monoclonal antibodies show cross reactivity to human proteins, this procedure will be a fast and efficient way of studying post-translational modifications in control and patient samples using only small amounts of tissue.
...
PMID:Focused proteomics: monoclonal antibody-based isolation of the oxidative phosphorylation machinery and detection of phosphoproteins using a fluorescent phosphoprotein gel stain. 1530 Jul 71

Chemical, i.e. cuticular hydrocarbons, and molecular data were used to probe the phylogeography of Reticulitermes termites collected from various parts of France, Spain and Portugal. Phylogenetic relationships were inferred from sequences of the internal transcribed spacer (ITS2) of nuclear ribosomal RNA genes as well as from two partial mitochondrial DNA segments, the cytochrome oxidase II gene and a sequence combining the tRNA-Leu gene and fragments of the NADH dehydrogenase I and ribosomal 16S genes. Two species, namely, R. grassei and R. banyulensis, were identified based on an analysis of cuticular hydrocarbons and the identification was confirmed by ITS2 haplotyping. However, phylogeny based on the analysis of mitochondrial DNA was not completely in agreement with the conclusions drawn from the chemical and nuclear data. An analysis of 56 R. grassei colonies revealed intraspecific differentiation into two major lineages with distinct geographical ranges. Whereas analysis of cuticular hydrocarbons showed that R. banyulensis was chemically distinct from R. grassei, analysis of mitochondrial DNA showed its close kinship with the R. grassei lineage occurring in southern Spain. This kinship could be explained by their evolution from a common polymorphic ancestor species in this ice age refugium.
...
PMID:Phylogeography of two European Reticulitermes (Isoptera) species: the Iberian refugium. 1536 23

Ustilago maydis mitochondria contain the four classical components of the electron transport chain (complexes I, II, III, and IV), a glycerol phosphate dehydrogenase, and two alternative elements: an external rotenone-insensitive flavone-sensitive NADH dehydrogenase (NDH-2) and an alternative oxidase (AOX). The external NDH-2 contributes as much as complex I to the NADH-dependent respiratory activity, and is not modulated by Ca2+, a regulatory mechanism described for plant NDH-2, and presumed to be a unique characteristic of the external isozyme. The AOX accounts for the 20% residual respiratory activity after inhibition of complex IV by cyanide. This residual activity depends on growth conditions, since cells grown in the presence of cyanide or antimycin A increase its proportion to about 75% of the uninhibited rate. The effect of AMP, pyruvate and DTT on AOX was studied. The activity of AOX in U. maydis cells was sensitive to AMP but not to pyruvate, which agrees with the regulatory characteristics of a fungal AOX. Interestingly, the presence of DTT during cell permeabilisation protected the enzyme against inactivation. The pathways of quinone reduction and quinol oxidation lack an additive behavior. This is consistent with the competition of the respiratory components of each pathway for the quinol/quinone pool.
...
PMID:The mitochondrial respiratory chain of Ustilago maydis. 1545 Sep 62

Mitochondria of the malaria parasite Plasmodium falciparum are morphologically different between the asexual and sexual blood stages (gametocytes). In this paper recent findings of mitochondrial heterogeneity are reviewed based on their ultrastructural characteristics, metabolic activities and the differential expression of their genes in these 2 blood stages of the parasite. The existence of NADH dehydrogenase (complex I), succinate dehydrogenase (complex II), cytochrome c reductase (complex III) and cytochrome c oxidase (complex IV) suggests that the biochemically active electron transport system operates in this parasite. There is also an alternative electron transport branch pathway, including an anaerobic function of complex II. One of the functional roles of the mitochondrion in the parasite is the coordination of pyrimidine biosynthesis, the electron transport system and oxygen utilization via dihydroorotate dehydrogenase and coenzyme Q. Complete sets of genes encoding enzymes of the tricarboxylic acid cycle and the ATP synthase complex are predicted from P. falciparum genomics information. Other metabolic roles of this organelle include membrane potential maintenance, haem and coenzyme Q biosynthesis, and oxidative phosphorylation. Furthermore, the mitochondrion may be a chemotherapeutic target for antimalarial drug development. The antimalarial drug atovaquone targets the mitochondrion.
...
PMID:The multiple roles of the mitochondrion of the malarial parasite. 1555 97

Mitochondria are an active source of the free radical superoxide (O2-) and nitric oxide (NO), whose production accounts for about 2% and 0.5% respectively, of mitochondrial O2 uptake under physiological conditions. Superoxide is produced by the auto-oxidation of the semiquinones of ubiquinol and the NADH dehydrogenase flavin and NO by the enzymatic action of the nitric oxide synthase of the inner mitochondrial membrane (mtNOS). Nitric oxide reversibly inhibits cytochrome oxidase activity in competition with O2. The balance between NO production and its utilization results in a NO intramitochondrial steady-state concentration of 20-50 nM, which regulates mitochondrial O2 uptake and energy supply. The regulation of cellular respiration and energy production by NO and its ability to switch the pathway of cell death from apoptosis to necrosis in physiological and pathological conditions could take place primarily through the inhibition of mitochondrial ATP production. Nitric oxide reacts with O2- in a termination reaction in the mitochondrial matrix, yielding peroxynitrite (ONOO-), which is a strong oxidizing and nitrating species. This reaction accounts for approximately 85% of the rate of mitochondrial NO utilization in aerobic conditions. Mitochondrial aging by oxyradical- and peroxynitrite-induced damage would occur through selective mtDNA damage and protein inactivation, leading to dysfunctional mitochondria unable to keep membrane potential and ATP synthesis.
...
PMID:Free radical chemistry in biological systems. 1569 72


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---