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

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

The natural developmental gradient of light-grown primary leaves of barley (Hordeum vulgare L.) was used to analyze the biogenesis of mitochondrial proteins in relation to the age and physiological changes within the leaf. The data indicate that the protein composition of mitochondria changes markedly during leaf development. Three distinct patterns of protein development were noted: group A proteins, consisting of the E1 beta-subunit of the pyruvate dehydrogenase complex, ORF156, ORF577, alternative oxidase, RPS12, cytochrome oxidase subunits II and III, malic enzyme, and the alpha- and beta-subunits of F1-ATPase; group B proteins, consisting of the E1 alpha-subunit of the pyruvate dehydrogenase complex, isocitrate dehydrogenase, HSP70A, cpn60C, and cpn60B; and group C proteins, consisting of the four subunits of the glycine decarboxylase complex (P, H, T, and L proteins), fumarase, and formate dehydrogenase. All of the proteins increased in concentration from the basal meristem to the end of the elongation zone (20.0 mm from the leaf base), whereupon group A proteins decreased, group B proteins increased to a maximum at 50 mm from the leaf base, and group C proteins increased to a maximum at the leaf tip. This study provides evidence of a marked heterogeneity of mitochondrial protein composition, reflecting a changing function as leaf cells develop photosynthetic and photorespiratory capacity.
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PMID:Heterogeneity of mitochondrial protein biogenesis during primary leaf development in barley 980 54

Cytochrome-c oxidase is the copper-dependent terminal respiratory complex (complex IV) of the mitochondrial electron transport chain whose activity in a variety of tissues is lowered by copper deficiency. Because inhibition of respiratory complexes increases the production of reactive oxygen species by mitochondria, it is possible that copper deficiency increases oxidative stress in mitochondria as a consequence of suppressed cytochrome-c oxidase activity. In this study, the activities of respiratory complex I + III, assayed as NADH:cytochrome-c reductase, complex II + III, assayed as succinate:cytochrome-c reductase, complex IV, assayed as cytochrome-c oxidase, and fumarase were measured in mitochondria from HL-60 cells that were grown for seven passages in serum-free medium that was either unsupplemented or supplemented with 50 n M CuSO4. Fumarase activity was not affected by copper supplementation, but the complex I + III:fumarase and complex IV:fumarase ratios were reduced 30% and 50%, respectively, in mitochondria from cells grown in the absence of supplemental copper. This indicates that copper deprivation suppressed the electron transfer activity of copper-independent complex I + III as well as copper-dependent complex IV. Manganese superoxide dismutase (MnSOD) content was also increased 49% overall in the cells grown in the absence of supplemental copper. Furthermore, protein carbonyl groups, indicative of oxidative modification, were present in 100-kDa and 90-kDa proteins of mitochondria from copper-deprived cells. These findings indicate that in cells grown under conditions of copper deprivation that suppress cytochrome-c oxidase activity, oxidative stress in mitochondria is increased sufficiently to induce MnSOD, potentiate protein oxidation, and possibly cause the oxidative inactivation of complex I.
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PMID:Copper deprivation potentiates oxidative stress in HL-60 cell mitochondria. 1035 26

Maruyama, Yoshiharu (Cornell University, Ithaca, N.Y.) and Martin Alexander. Localization of enzymes in the mycelium and microconidia of Fusarium oxysporum. J. Bacteriol. 84:307-312. 1962-Extracts prepared from mycelium and microconidia of Fusarium oxysporum f. cubense were fractionated into a soluble and four particulate fractions by differential centrifugation, and the distribution of several enzymes in the isolated cell constituents was examined. Succinic dehydrogenase, cytochrome oxidase, and a large amount of the reduced diphosphopyridine nucleotide (DPNH) cytochrome c reductase and reduced triphosphopyridine nucleotide cytochrome c reductase were associated with one of the particulate fractions prepared from the hyphae; fumarase and DPNH oxidase activities were largely found in the soluble and in a second particulate fraction. The highest recovery and concentration of diphosphopyridine nucleotidase was observed to be bound to a third type of hyphal granule. Aldolase, aconitase, glucose-6-phosphatase, and uricase were recovered entirely with the soluble mycelium constituents. Similar enzyme-distribution patterns were observed in microconidia. Several enzymatic activities of the mycelial extracts were compared with those in the extracts of microconidia.
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PMID:Localization of enzymes in the mycelium and microconidia of Fusarium oxysporum. 1447 Jun 62

Catalase, glycolate oxidase, and hydroxypyruvate reductase, enzymes which are located in the microbodies of leaves, show different developmental patterns in the shoots of wheat seedlings. Catalase and hydroxypyruvate reductase are already present in the shoots of ungerminated seeds. Glycolate oxidase appears later. All three enzymes develop in the dark, but glycolate oxidase and hydroxypyruvate reductase have only low activities. On exposure of the seedlings to continuous white light (14.8 x 10(3) ergs cm(-2) sec(-1)), the activity of catalase is doubled, and glycolate oxidase and hydroxypyruvate reductase activities increase by 4- to 7-fold. Under a higher light intensity, the activities of all three enzymes are considerably further increased. The activities of other enzymes (cytochrome oxidase, fumarase, glucose-6-phosphate dehydrogenase) are unchanged or only slightly influenced by light. After transfer of etiolated seedlings to white light, the induced increase of total catalase activity shows a much longer lag-phase than that of glycolate oxidase and hydroxypyruvate reductase. It is concluded that the light-induced increases of the microbody enzymes are due to enzyme synthesis. The light effect on the microbody enzymes is independent of chlorophyll formation or the concomitant development of functional chloroplasts. Short repeated light exposures which do not lead to greening are very effective. High activities of glycolate oxidase and hydroxypyruvate reductase develop in the presence of 3-amino-1,2,4-triazole which blocks chloroplast development. The effect of light is not exerted through induced glycolate formation and appears instead to be photomorphogenetic in character.In senescing leaves excised from the plants decreases in activity of glycolate oxidase, and hydroxypyruvate reductase follow with some delay the decrease in chlorophyll content. The activity of catalase, however, is maintained at high levels, especially when the detached shoots are kept in light.
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PMID:Developmental studies on microbodies in wheat leaves : I. Conditions influencing enzyme development. 1665 92

Whole homogenates from cells of Glycine max grown in suspension culture were centrifuged on linear sucrose gradients. Assays for marker enzymes showed that distinct peaks enriched in particular organelles were separated as follows: endoplasmic reticulum (density 1.10 g/cm(3), NADH-cytochrome-c reductase), Golgi membranes (density 1.12 g/cm(3), inosine diphosphatase), mitochondria (density 1.18-1.19 g/cm(3), fumarase, cytochrome oxidase) and microbodies (density 1.21-1.23 g/cm(3), catalase). In cells which had ceased to grow (stationary phase) only a single symmetrical catalase peak at density 1.23 g/cm(3) was observed on the sucrose gradient. During the phase of cell division and expansion a minor particulate catalase component of lighter density was present; its possible significance is discussed.
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PMID:Isolation and characterization of organelles from soybean suspension cultures. 1665 87

Benzyladenine (BA) increases the rate of expansion of dark-grown sunflower (Helianthus annuus L.) cotyledons. The hormone slightly enhances the development of the two glyoxysomal enzymes, isocitrate lyase and malate synthetase, during the first 3 days of germination and greatly accelerates their decay in the 2 following days. The levels of the peroxisomal enzymes, glycolate oxidase and glyoxylate reductase, are enhanced by BA more than those of the two glyoxysomal enzymes. These effects of BA on microbody enzymes are very similar to those of white light. Mitochondrial enzyme activities are increased to a varying extent by BA: the increase is minimal for fumarase, and maximal for cytochrome oxidase. The level of cytochrome oxidase is enhanced 346% at the 5th day of germination. Also, the rate of O(2) consumption is increased by BA, but the time course of this increased O(2) consumption does not match with that of cytochrome oxidase. Fusicoccin, a fungal toxin, mimics the effect of BA on cotyledon expansion, but fails to duplicate its action on microbody enzymes. This suggests that the effect of BA on microbody enzymes is not closely linked with the mechanism of growth promotion.
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PMID:Effect of benzyladenine on some enzymes of mitochondria and microbodies in excised sunflower cotyledons. 1665 19

The expression of genes encoding various enzymes participating in photosynthetic and respiratory metabolism is regulated by light via the phytochrome system. While many photosynthetic, photorespiratory and some respiratory enzymes, such as the rotenone-insensitive NADH and NADPH dehydrogenases and the alternative oxidase, are stimulated by light, succinate dehydrogenase, subunits of the pyruvate dehydrogenase complex, cytochrome oxidase and fumarase are inhibited via the phytochrome mechanism. The effect of light, therefore, imposes limitations on the tricarboxylic acid cycle and on the mitochondrial electron transport coupled to ATP synthesis, while the non-coupled pathways become activated. Phytochrome-mediated regulation of gene expression also creates characteristic distribution patterns of photosynthetic, photorespiratory and respiratory enzymes across the leaf generating different populations of mitochondria, either enriched by glycine decarboxylase (in the upper part) or by succinate dehydrogenase (in the bottom part of the leaf).
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PMID:Phytochrome-mediated regulation of plant respiration and photorespiration. 2377 90

Ultrastructural and biochemical approaches were used to investigate the mode of action of tagetitoxin, a nonhost-specific phytotoxin produced by Pseudomonas syringae pv. tagetis (Hellmers) Young, Dye and Wilkie, which causes chlorosis in developing - but not mature - leaves. Tagetitoxin has no effect on the growth rate or morphology of developing leaves of wheat (Triticum aestivum L.) seedlings. Its cytological effects are limited to plastid aberrations; in both light-and dark-grown leaves treated with toxin, internal plastid membranes fail to develop normally and plastid ribosomes are absent, whereas mitochondrial and cytoplasmic ribosomes are unaffected. The activity of a plastid stromal enzyme, ribulose-1,5-bisphosphate carboxylase (RuBPCase, EC 4.1.1.39), which is co-coded by nuclear and chloroplast genes, is markedly lower in extracts of both light-and dark-grown toxin-treated leaves, whereas the activity of another stromal enzyme, NADP-glyceraldehyde-3-phosphate dehydrogenase (NADP-G-3P-DH, EC 1.2.1.13), which is coded only by the nuclear genome, is significantly lower in extracts of light-grown, but not of dark-grown, treated leaves. The mitochondrial enzymes fumarase (EC 4.2.1.2) and cytochrome-c oxidase (EC 1.9.3.1) are unaffected by toxin in dark-grown leaves, but fumarase activity is reduced in light-grown ones. Four peroxisomal enzyme activities are lowered by toxin treatment in both light- and dark-grown leaves. Light- and dark-grown, toxintreated leaves contain about 50% and 75%, respectively, of the total protein of untreated leaves. There are threefold and twofold increases in free amino acids in light-grown and dark-grown treated leaves, respectively. In general, the effects of tagetitoxin are more extensive and exaggerated in light-grown than in dark-grown leaves. We conclude that tagetitoxin interferes primarily with a light-independent aspect of chloroplast-specific metabolism which is important in plastid biogenesis.
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PMID:Tagetitoxin affects plastid development in seedling leaves of wheat. 2424 Nov 35

The development of mitochondria from promitochondria is regulated by phytochrome. This conclusion is based on four lines of evidence: 1. The activity of representative mitochondrial marker enzymes (fumarase, EC 4.2.1.2; succinate dehydrogenase, EC 1.3.99.1; cytochrome oxidase, EC 1.9.3.1) is increased by continuous far-red light and (in 2 of the 3 enzymes) by brief red pulses, the effect of which is reversible by brief far-red pulses. These effects do not merely represent a general growth or proliferation of mitochondria already present but specific responses of individual enzymes. Inhibitors of protein synthesis but not of RNA synthesis suppress the increase of these enzyme activities. 2. Continuous far-red light changes some structural properties of the mitochondrial membranes, detectable by an increased requirement of detergent (Triton X-100) for the solubilization of cytochrome oxidase and a more efficient retainment of the matrix enzyme fumarase during isolation of mitochondria. Continuous far-red light increases the apparent buoyant density of mitochondria on a sucrose density gradient. 3. Continuous far-red light has a strong effect on the morphology of the inner mitochondrial membrane system. Electron micrographs from dark-grown cotyledons show arrays of parallel, plate-like cristae while typical plant mitochondria with irregularly oriented sacculi are formed in the light. These responses indicate the involvement of mitochondria in cytophotomorphogenesis during the transition of the cotyledons from dissimilatory to assimilatory metabolism.
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PMID:Phytochrome-mediated development of mitochondria in the cotyledons of mustard (Sinapis alba L.) seedlings. 2442 27

The distribution of nitrate and nitrite reductase, glutamic dehydrogenase, cytochrome oxidase, fumarase, peroxidase and catalase in particular fractions of barley roots, separated by differential and density gradient centrifugation, has been determined. Evidence obtained suggests that there are three separate groups of particles, one, the mitochondria, containing cytochrome oxidase, fumarase and glutamic dehydrogenase, one containing catalase, and one containing nitrate and nitrite reductase. The results show that, under certain conditions, the high osmotic pressures obtained in sucrose density gradients may cause artefacts due to the release of enzymes, especially nitrite reductase, from the particles.
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PMID:Studies on the sub-cellular location of particulate nitrate and nitrite reductase, glutamic dehydrogenase and other enzymes in barley roots. 2449 11


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