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)

Phenotypes of eight red cell enzymes at nine genetic loci were determined in the semi-free-ranging population of rhesus macaques; Macaca mulatta, that inhabit Cayo Santiago. The following enzymes were examined electrophoretically: adenosine deaminase, glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, indophenol oxidase, lactate dehydrogenase, malate dehydrogenase, phosphoglucomutase-1, phosphoglumutase-2, and purine nucleoside phosphorylase. Hemolysates from at least 372 animals were analyzed, and no variants of the enzymes were observed with the exception of malate dehydrogenase. Three animals displaying a variant form of malate dehydrogenase were found.
...
PMID:Genetic studies of free-ranging macaques of Cayo Santiago. I. Description of the population and some nonpolymorphic red cell enzymes. 41 22

The purpose of the study was to verify the influence of several weeks of chronic low-frequency electrical stimulation (LFES) on the metabolic profile and functional capacity of human skeletal muscle. Knee extensor muscles (KEM) of eight subjects were electrically stimulated at 8 Hz for 8 h/day and 6 days/wk. Vastus lateralis muscle samples were taken before, after 4 wk, and after 8 wk of LFES, and activities of anaerobic (creatine kinase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase) and aerobic-oxidative (citrate synthase, 3-hydroxyacyl-CoA dehydrogenase, cytochrome-c oxidase) enzyme markers were determined. KEM dynamic performance was also assessed before, after 4 wk, and after 8 wk of LFES. Activity levels of anaerobic enzymes were not altered, whereas the activity levels of citrate synthase (29%),3-hydroxyacyl-CoA dehydrogenase (22%), and cytochrome-c oxidase (25%) were significantly increased after 4 wk of LFES but were not further increased after 4 additional wk of LFES. KEM performance was also improved (P < 0.05) but leveled off after 4 wk of LFES. Although significant changes were observed, the results of the present study suggest that the muscle characteristics investigated in the current study have a limited capacity of adaptation in response to this form of chronic LFES.
...
PMID:Human skeletal muscle adaptation in response to chronic low-frequency electrical stimulation. 783 13

Inhibition of DNA polymerase gamma-function mediated by 3'-azido-3'-deoxythymidine (AZT) has been proposed to cause a myopathy by reducing mitochondrial DNA (mtDNA) replication. Repeated bouts of exercise stimulate an increase in mtDNA replication, mitochondrial content, and mitochondrial volume fraction. Therefore, adaptation of rat skeletal muscle [tibialis anterior (TA)] mitochondria exposed to AZT (1 mg/ml for 35 days) and then to electrical stimulation for 8 h/day (7, 14, 21 days) with continued AZT treatment was examined. Fourteen and 21 days of stimulation increased TA cytochrome oxidase (CO) activity, mtDNA, and CO subunit III and VIc mRNA levels in both groups. The TA CO activity and CO III mRNA increases after 14 and 21 days of stimulation were diminished in AZT-treated rats. TA glyceraldehyde-3-phosphate dehydrogenase was reduced in normal rats after chronic stimulation but was unchanged in AZT-treated rats. Chronic stimulation increased the mitochondrial volume fraction by 80 and 40% in normal and AZT-treated rats, respectively. These results indicate diminution, but not complete inhibition, of mitochondrial adaptation by AZT-treated skeletal muscle in response to stimulation.
...
PMID:Skeletal muscle mitochondria from AZT-treated rats have a diminished response to chronic electrical stimulation. 882 81

The etiology of the selective neuronal death that occurs in Huntington's disease (HD) is unknown. Several lines of evidence implicate the involvement of energetic defects and oxidative damage in the disease process, including a recent study that demonstrated an interaction between huntingtin protein and the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Using spectrophotometric assays in postmortem brain tissue, we found evidence of impaired oxidative phosphorylation enzyme activities restricted to the basal ganglia in HD brain, while enzyme activities were unaltered in three regions relatively spared by HD pathology (frontal cortex, parietal cortex, and cerebellum). Citrate synthase-corrected complex II-III activity was markedly reduced in both HD caudate (-29%) and putamen (-67%), and complex IV activity was reduced in HD putamen (-62%). Complex I and GAPDH activities were unaltered in all regions examined. We also measured levels of the oxidative damage product 8-hydroxydeoxyguanosine (OH8dG) in nuclear DNA, and superoxide dismutase (SOD) activity. OH8dG levels were significantly increased in HD caudate. Cytosolic SOD activity was slightly reduced in HD parietal cortex and cerebellum, whereas particulate SOD activity was unaltered in these regions. These results further support a role for metabolic dysfunction and oxidative damage in the pathogenesis of HD.
...
PMID:Oxidative damage and metabolic dysfunction in Huntington's disease: selective vulnerability of the basal ganglia. 915 27

A developmental block is induced by phosphate in rat embryos at the late two-cell stage. The present study was designed to examine the energy metabolism of rat two-cell blocked and non-blocked embryos. Enzyme activity was measured in individual embryos by histochemical techniques. The activities of malate dehydrogenase, isocitrate dehydrogenase, lactate dehydrogenase, pyruvate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, and phosphorylase did not differ among non-blocked and blocked embryos. However, the activity of succinate dehydrogenase was significantly decreased in blocked embryos compared with non-blocked embryos. In blocked embryos, cytochrome oxidase activity was distributed homogeneously, but was located at the perinuclear region in non-blocked embryos. Active mitochondrial organization was visualized using the fluorescent probe rhodamine 123 and laser scanning confocal microscopy. In both non-blocked and blocked embryos, mitochondria were distributed homogeneously. The concentration of H2O2 measured fluorometrically in embryos cultured without phosphate did not change significantly during the culture period, but decreased in embryos cultured with phosphate. The timing corresponded to the occurrence of the two-cell block. In summary, these results suggest that the developmental block in rat two-cell embryos is induced by disturbance of mitochondrial energy metabolism.
...
PMID:Microscopic analysis of enzyme activity, mitochondrial distribution and hydrogen peroxide in two-cell rat embryos. 986 Nov 63

Manganism is a disorder characterized by hyperintensities in basal ganglia structures on magnetic resonance imaging which may be the consequence of manganese deposition in these areas. Since manganese is taken up avidly into astrocytes and is known to interfere with cerebral energy metabolism, we studied the effect of this metal on the expression and activity of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in primary cultures of astrocytes. Treatment with 100 microM manganese for 7 days increased both the Vmax and Km values for GAPDH which was not reproducible with other divalent metals. Using RT-PCR, increased GAPDH expression was detected in cells exposed to manganese compared with controls. No changes in cytochrome oxidase activity or ATP levels were observed, and lactate production was unaffected, in manganese-treated cells. These findings provide evidence of a possible role for GAPDH in the mediation of the effects of manganese on central nervous system function.
...
PMID:Increased expression of glyceraldehyde-3-phosphate dehydrogenase in cultured astrocytes following exposure to manganese. 1040 26

The effect of prolonged exposure to nitric oxide on enzymes involved in cell metabolism was investigated in T lymphocyte-derived Jurkat and L929 fibroblast human cell lines using a constant concentration of nitric oxide (1.5 microM) released by the nitric oxide donor DETA-NO (0.5 mM). Nitric oxide inhibited immediately the respiration of the cells acting reversibly at complex IV. With time, the inhibition became progressively persistent, i.e. not reversed by trapping of nitric oxide with oxyhaemoglobin, and was preceded by a decrease in the concentration of the intracellular reduced glutathione. This persistent effect of nitric oxide on respiration was due to inhibition of complex I activity which could be reversed by addition of reduced glutathione or by cold light, suggesting that it was due to S-nitrosylation of thiols necessary for the activity of the enzyme. The activity of other enzymes also known to be susceptible to inhibition by S-nitrosylation, i.e. glyceraldehyde-3-phosphate dehydrogenase and glutathione reductase, was progressively decreased by exposure to nitric oxide with a similar time course to that observed for the inhibition of complex I. Furthermore, inhibition of these enzymes only occurred when the concentrations of reduced glutathione had previously fallen and could be prevented by increasing the intracellular concentrations of reduced glutathione. Our results suggest that S-nitrosylation of different enzymes by nitric oxide may occur only if the reducing potential of the cells is impaired.
...
PMID:Oxidative stress and S-nitrosylation of proteins in cells. 1069 95

Mitochondrial adenosine triphosphate (ATP) generation plays a major role in insulin secretion in pancreatic islet beta cells. The relationship between age and nutritional status of the islet and mitochondrial gene messenger RNA (mRNA) expression was investigated. Three animal groups were studied: infant (12-day-old) rats fed either mother's milk or a high carbohydrate (HC) diet; young (2 to 4-month-old) rats; and old (12 to 14-month-old) rats. The expression of mitochondrial cytochrome oxidase (CYO) (subunits I, II, and III), beta-nicotinamide adenine dinucleotide, reduced form dehydrogenase subunit 4 (NADH-DH4), and ATP synthase (subunit 6) (ATP-SYN6) mRNAs was characterized by semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The mitochondrial gene mRNAs were identified in each of the groups of rat islets and in RINm5F cells. CYO-II mRNA expression in young and old rat pancreatic islets was 12.7- and 8.2-fold higher, respectively, compared with the level in infant rat islets. The expression of NADH-DH4 and ATP-SYN6 mRNAs was 47% and 40% lower, respectively, in young rat islets compared with the level in infant rat islets. CYO-I, CYO-III, and cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GPDH) mRNA expression did not differ between experimental groups. Artificial rearing of infant rat pups on a HC diet for 8 days lead to a 3.3-fold increase in islet CYO-II mRNA expression compared with mother-fed pups. However, glucose (11 mmol/L) stimulation of cultured isolated islets from young and old rats for 4 days failed to affect the expression level of mitochondrial gene mRNAs. Thus, aging affected the differential expression of CYO-II, NADH-DH4, and ATP-SYN6 mRNAs in rat islets. CYO-II mRNA expression was modulated only in infant rat islets after in vivo administration of carbohydrate.
...
PMID:Mitochondrial-encoded gene regulation in rat pancreatic islets. 1122 30

Nitric oxide (NO), in excess, behaves as a cytotoxic substance mediating the pathological processes that cause neurodegeneration. The NO-induced dopaminergic cell loss causing Parkinson's disease (PD) has been postulated to include the following: an inhibition of cytochrome oxidase, ribonucleotide reductase, mitochondrial complexes I, II, and IV in the respiratory chain, superoxide dismutase, glyceraldehyde-3-phosphate dehydrogenase; activation or initiation of DNA strand breakage, poly(ADP-ribose) synthase, lipid peroxidation, and protein oxidation; release of iron; and increased generation of toxic radicals such as hydroxyl radicals and peroxynitrite. NO is formed by the conversion of L-arginine to L-citrulline by NO synthase (NOS). At least three NOS isoforms have been identified by molecular cloning and biochemical studies: a neuronal NOS or type 1 NOS (nNOS), an immunologic NOS or type 2 NOS (iNOS), and an endothelial NOS or type 3 NOS (eNOS). The enzymatic activities of eNOS or nNOS are induced by phosphorylation triggered by Ca(2+) entering cells and binding to calmodulin. In contrast, the regulation of iNOS seems to depend on de novo synthesis of the enzyme in response to a variety of cytokines, such as interferon-gamma and lipopolysaccharide. The evidence that NO is associated with neurotoxic processes underlying PD comes from studies using experimental models of this disease NOS inhibitors can prevent 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurotoxicity. Furthermore, NO fosters dopamine depletion, and the said neurotoxicity is averted by nNOS inhibitors such as 7-nitroindazole working on tyrosine hydroxylase-immunoreactive neurons in substantia nigra pars compacta. Moreover, mutant mice lacking the nNOS gene are more resistant to MPTP neurotoxicity when compared with wild-type littermates. Selegiline, an irreversible inhibitor of monoamine oxidase B, is used in PD as a dopaminergic function-enhancing substance. Selegiline and its metabolite, desmethylselegiline, reduce apoptosis by altering the expression of a number of genes, for instance, superoxide dismutase, Bcl-2, Bcl-xl, NOS, c-Jun, and nicotinamide adenine nucleotide dehydrogenase. The selegiline-induced antiapoptotic activity is associated with prevention of a progressive reduction of mitochondrial membrane potential in preapoptotic neurons. As apoptosis is critical to the progression of neurodegenerative disease, including PD, selegiline or selegiline-like compounds to be discovered in the future may be efficacious in treating PD.
...
PMID:Peroxynitrite and mitochondrial dysfunction in the pathogenesis of Parkinson's disease. 1288 Apr 86

Experimental traumatic brain injury (TBI) results in a significant loss of cortical tissue at the site of injury, and in the ensuing hours and days a secondary injury exacerbates this primary injury, resulting in significant neurological dysfunction. The mechanism of the secondary injury is not well understood, but evidence implicates a critical role for mitochondria in this cascade. This mitochondrial dysfunction is believed to involve excitotoxicity, disruption of Ca(2+) homeostasis, production of reactive oxygen species (ROS), ATP depletion, oxidative damage of mitochondrial proteins, and an overall breakdown of mitochondrial bioenergetics. Although oxidative damage occurs following TBI, the identities of proteins undergoing oxidative modification after TBI have not been investigated. In the present study, we utilized the 3-h post-injury controlled cortical impact model of experimental TBI in 20 young adult male Sprague-Dawley rats, coupled with proteomics to identify specific mitochondrial fraction proteins from the cortex and hippocampus that were oxidatively modified after TBI. We identified, from the cortex, pyruvate dehydrogenase, voltage-dependent anion channel, fumarate hydratase 1, ATP synthase, and prohibitin. From the hippocampus, we identified cytochrome C oxidase Va, isovaleryl coenzyme A dehydrogenase, enolase-1, and glyceraldehyde-3-phosphate dehydrogenase as proteins that had undergone oxidative modification following TBI. In addition, we have also shown that, following TBI, there is a reduction in the activities of pyruvate dehydrogenase (PDH), complex I, and complex IV. These findings demonstrate that, following TBI, several proteins involved in mitochondrial bioenergetics are highly oxidatively modified, which may possibly underlie the massive breakdown of mitochondrial energetics and eventual cell death known to occur in this model. The identification of these proteins provides new insights into the mechanisms that take place following TBI and may provide avenues for possible therapeutic interventions after TBI.
...
PMID:Proteomic identification of oxidized mitochondrial proteins following experimental traumatic brain injury. 1751 33


1 2 Next >>

---