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)

Nucleoside reverse-transcriptase inhibitor (NRTI) therapy for human immunodeficiency virus (HIV) infection has been associated with mitochondrial DNA (mtDNA) polymerase-gamma inhibition and subsequent mtDNA depletion. Effects on mtDNA mutation, although suggested by critical involvement of polymerase-gamma in DNA-repair reactions, are unknown. In the present study, we assessed the nature and frequency of mitochondrial genome sequence differences in peripheral-blood samples taken prior to NRTI therapy and after 6-77 mo of treatment in 16 NRTI-treated patients. Samples from 10 HIV-infected, treatment-naive control individuals were taken at similar time intervals. Single-stranded conformation polymorphism (SSCP) and DNA-sequencing analysis techniques were used to detect mitochondrial genome sequence variants between paired longitudinal samples, and heteroplasmic populations were quantified after cloning and repeat SSCP/sequencing. Of 16 individuals treated with NRTIs, 5 exhibited altered SSCP profiles associated with the development of novel heteroplasmic DNA sequence changes, whereas no SSCP pattern change within these regions was observed in the control individuals. Heteroplasmic sequence changes were distributed across four regions of the genome: the noncoding region to 12S ribosomal RNA, reduced-nicotinamide-adenine-dinucleotide dehydrogenase 1, and cytochrome oxidase subunits I and III. Of the total of 26 patients who were examined in the present study, 4 of 5 patients with detectable mtDNA sequence changes since commencement of therapy developed evidence of peripheral fat wasting (lipoatrophy) between sample intervals (P=.031). One patient, without detectable sequence changes on NRTI therapy, also developed lipoatrophy. Levels of mtDNA copies/cell in blood samples were determined by quantitative PCR for 11 of the 16 NRTI-exposed patients; 7 of these 11 patients showed reduced levels of mtDNA in blood after therapy, including all 3 patients tested with evidence of mtDNA sequence changes on therapy. These data indicate that NRTI therapy provides conditions permissive for the development of peripheral-blood mtDNA mutations in vivo.
...
PMID:Accumulation of mitochondrial DNA mutations in human immunodeficiency virus-infected patients treated with nucleoside-analogue reverse-transcriptase inhibitors. 1258 93

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

A 9-month-old male German Shepherd dog was referred for evaluation of progressive exercise intolerance. Clinical examination revealed a stiff, stilted gait and marked atrophy and hypotonia of skeletal muscle. The dog had raised creatine kinase (181 U/liter), lactate dehydrogenase (510 U/liter), and aspartate aminotransferase (123.6 U/liter) levels, suggesting a muscle disease. Histochemical evaluation of muscle biopsies revealed the presence of subsarcolemmal oxidative activity, reduced nicotinamide adenine dinucleotide, and succinate dehydrogenase, and the absence of cytochrome oxidase activity. Ragged red fibers were demonstrated with Gomori trichrome stain. Ultrastructural examination of the muscle confirmed the presence of subsarcolemmal accumulations of mitochondria and morphologically atypical mitochondria.
...
PMID:Mitochondrial myopathy in a german shepherd dog. 1294 7

Dowler, William M. (University of Illinois, Urbana), Paul D. Shaw, and David Gottlieb. Terminal oxidation in cell-free extracts of fungi. J. Bacteriol. 86:9-17. 1963.-The terminal respiration in cell-free extracts of ten representative fungi is mediated by an electron transport system similar to that observed in animal tissue. Reduced nicotinamide adenine dinucleotide (NADH) and succinic cytochrome c reductases and NADH oxidase activity are contained in the extracts. An antimycin-sensitive site and cytochrome oxidase are present. Dehydrogenases including glucose-6-phosphate, triose phosphate, isocitric, glutamic, succinic, and malic dehydrogenase were found, but pyruvic and alpha-ketoglutaric dehydrogenases were absent. The soluble nature of the dehydrogenases indicates probable disruption of the mitochondria, since normally these enzymes are found within the mitochondria. Particles containing most of the terminal respiratory activity could be sedimented by centrifugation at 40,000 x g for 30 min. Oxygen was utilized by cell-free extracts with NADH, succinate, and isocitrate as substrates, but not with glucose.
...
PMID:TERMINAL OXIDATION IN CELL-FREE EXTRACTS OF FUNGII. 1405 29

Dworkin, Martin (University of Minnesota, Minneapolis), and Donald J. Niederpruem. Electron transport system in vegetative cells and microcysts of Myxococcus xanthus. J. Bacteriol. 87:316-322. 1964.-Respiration by intact cells of the fruiting myxobacterium Myxococcus xanthus is cyanide-sensitive and can be demonstrated in the vegetative cells but not in the microcysts. Cell-free particles from both vegetative cells and microcysts have cyanide-sensitive reduced nicotinamide adenine dinucleotide (NADH) oxidase, diaphorase, NADH cytochrome c reductase, and cytochrome oxidase activities. While the vegetative cell specific activities for NADH oxidase and diaphorase are slightly higher than those for the microcysts, the microcysts have ten times the cytochrome c reductase and cytochrome oxidase activities of the vegetative cells. Furthermore, the respiration of the microcyst particles is considerably less cyanide-sensitive than is that of the vegetative-cell particles. Difference spectra of the cell-free particles of vegetative cells and microcysts are qualitatively identical, showing the presence of b- and c-type cytochrome and flavoprotein. The a-type pigments are clearly present in the extracts of the vegetative cells and are suggested by the spectrum of the microcyst particles. The cytochrome oxidase activity of both extracts is consistent with the presence of a-type pigments in both. The spectra of the carbon monoxide-binding pigments were determined and, by this parameter, qualitative differences appear between the vegetative cells and the microcysts.
...
PMID:ELECTRON TRANSPORT SYSTEM IN VEGETATIVE CELLS AND MICROCYSTS OF MYXOCOCCUS XANTHUS. 1415 Oct 50

VanDemark, P. J. (University of South Dakota, Vermillion), and P. F. Smith. Respiratory pathways in the Mycoplasma. II. Pathway of electron transport during oxidation of reduced nicotinamide adenine dinucleotide by Mycoplasma hominis. J. Bacteriol. 88:122-129. 1964.-Unlike the flavin-terminated respiratory pathway of the fermentative Mycoplasma, the respiratory chain of the nonfermentative M. hominis strain 07 appears to be more complex, involving quinones and cytochromes in addition to flavins. In addition to reduction by reduced nicotine adenine dinucleotide (NADH) and reduced nicotine adenine dinucleotide phosphate, nonpyridine nucleotide-linked reduction of the respiratory chain of this organism occurred with succinate, lactate, and short-chained acyl coenzyme A derivatives as electron donors. Enzymes catalyzing the oxidation of NADH included an NADH oxidase, a diaphorase, a quinone reductase, and a cytochrome c reductase. The oxidation of NADH was sensitive to a variety of inhibitors, including 10(-4)m Atabrine, 10(-3)m sodium amytal, 10(-5)mp-chloromercuribenzoate, 10(-4)m antimycin A, and 10(-4)m potassium cyanide. The oxidase was resolved by the addition of 5% trichloroacetic acid and reactivated by the addition of flavin adenine dinucleotide but not flavin mononucleotide. The M. hominis sonic extract contained an NADH-coenzyme Q reductase. The oxidation of NADH was stimulated by the addition of either menadione or vitamin K(2) (C(35)). The oxidase was inactivated by extraction with ether or irradiation at 360 mmu. The ether-inactivated enzyme was partially reactivated by the addition of "lipid" extract of the enzyme and coenzyme Q(6). Difference spectra of the cell extracts revealed the presence of "b" and "a" type cytochromes. These cell extracts were found to contain a cyanide-and azide-sensitive cytochrome oxidase and catalase.
...
PMID:RESPIRATORY PATHWAYS IN THE MYCOPLASMA. II. PATHWAY OF ELECTRON TRANSPORT DURING OXIDATION OF REDUCED NICOTINAMIDE ADENINE DINUCLEOTIDE BY MYCOPLASMA HOMINIS. 1419 76

Pepper, Rollin E. (Michigan State University, East Lansing), and Ralph N. Costilow. Electron transport in Bacillus popilliae. J. Bacteriol. 89:271-276. 1965.-Bacillus popilliae was found to be unique among aerobic microorganisms in that it was deficient in a hydrogen peroxide-scavenging system. Neither catalase nor peroxidase was found. At the same time, a system for producing hydrogen peroxide during oxidation of reduced nicotinamide adenine dinucleotide (NADH(2)) was consistently present in the soluble fraction of extracts of cells from older cultures. Cells harvested from 9-hr cultures did not produce a significant amount of peroxide. The soluble NADH(2) oxidase was apparently a flavoprotein, since it was stimulated by flavin nucleotides, insensitive to cyanide and azide, and inhibited by Atabrine. Also, difference spectra demonstrated the presence of a reducible flavin in the soluble fraction of cell extracts. The particulate fraction of cell extracts was shown by difference spectra to contain cytochrome b(1); the strong inhibition of NADH(2) oxidation by cyanide, azide, and carbon monoxide indicated that a terminal cytochrome oxidase was also present. This system was also flavin-dependent, since it was strongly inhibited by Atabrine. The specific activity of the NADH(2) oxidase in the particulate fraction was lower in extracts of cells from older cultures than in those from exponentially growing cultures. Cytochrome c was not found in extracts of these cells. It is believed that the increased participation of the hydrogen peroxide-generating NADH(2) oxidase in cells of older cultures may be responsible for the rapid loss in cell viability noted in stationary-phase cultures.
...
PMID:ELECTRON TRANSPORT IN BACILLUS POPILLIAE. 1425 89

We have studied the organization of the hypothalamus in an Australian diprotodontid metatherian mammal, the wallaby ( Macropus eugenii), using cytoarchitectural, histochemical and immunohistochemical techniques. Coronal sections of adult brains were processed for Nissl staining, histochemical reactivity (cytochrome oxidase, nicotinamide adenine dinucleotide phosphate diaphorase and acetylcholinesterase) and immunohistochemistry (antibodies to tyrosine hydroxylase, calbindin, calretinin, non-phosphorylated neurofilament protein, oxytocin and vasopressin). The distribution of immunoreactive neurons for these substances was mapped with the aid of a computer-linked microscope. In general, the wallaby hypothalamus showed a similar nuclear organization to that seen in rodents. The paraventricular nucleus could be divided into several subdivisions based on the different cellular parcellation, similar to that described in rodents. The ventromedial hypothalamic nucleus had cell-sparse dorsomedial and cell-dense ventrolateral subdivisions as seen in eutheria, suggesting a similar functional compartmentalization in all theria. The positions of tyrosine hydroxylase-positive neurons in the wallaby hypothalamus were also similar to those in eutheria. Oxytocin and vasopressinergic neurons were found in all the same major nuclear groups as seen in eutheria, although a nucleus circularis could not be identified. The general similarities between wallaby and eutherian hypothalamus indicate that the basic chemo- and cytoarchitectural features of the hypothalamus are common to eutheria and metatheria and validate the use of the wallaby as a mammalian model of wide applicability in investigations of hypothalamic functional development.
...
PMID:Cyto- and chemoarchitecture of the hypothalamus of a wallaby ( Macropus eugenii) with special emphasis on oxytocin and vasopressinergic neurons. 1451 76

To understand functional roles of striatal interneurons in primate basal ganglia circuitry, we ablated interneurons expressing substance P (SP) receptors (SPR) in the putamen with SP-saporin, a SPR selective neurotoxin. The effect of SP-saporin injection into the putamen was evaluated by examining the loss of cholinergic interneurons and NADPHd-positive (nicotinamide adenine dinucleotide phosphate diaphorase positive) interneurons. We then analyzed regional metabolic changes using cytochrome oxidase (CO) histochemistry. CO activity in some regions of the internal and external segments of the globus pallidus (GP) in the lesioned hemisphere was lower than that in the contralateral or surrounding GP regions. CO activity in the subthalamic nucleus, however, showed no significant change. The present findings suggest that striatopallidal projection neurons exert enhanced inhibitory influence on the GP without modulatory control by the striatal SPR-expressing interneurons.
...
PMID:Cytochrome oxidase activity in the monkey globus pallidus and subthalamic nucleus after ablation of striatal interneurons expressing substance P receptors. 1466 11

We report the complete sequence of the mitochondrial genome of Penicillium marneffei, the first complete mitochondrial DNA sequence of a thermal dimorphic fungus. This 35 kb mitochondrial genome contains the genes encoding ATP synthase subunits 6, 8, and 9 (atp6, atp8, and atp9), cytochrome oxidase subunits I, II, and III (cox1, cox2, and cox3), apocytochrome b (cob), reduced nicotinamide adenine dinucleotide ubiquinone oxireductase subunits (nad1, nad2, nad3, nad4, nad4L, nad5, and nad6), ribosomal protein of the small ribosomal subunit (rps), 28 tRNAs, and small and large ribosomal RNAs. Analysis of gene contents, gene orders, and gene sequences revealed that the mitochondrial genome of P. marneffei is more closely related to those of molds than yeasts.
...
PMID:The mitochondrial genome of the thermal dimorphic fungus Penicillium marneffei is more closely related to those of molds than yeasts. 1467 58


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

---