Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper reports on the discovery of a protein kinase activity associated with the inner membrane of mammalian mitochondria. The enzyme does not respond to addition of cyclic AMP or cyclic GMP and has a preference for whole histone as phosphate acceptor. Some standard assay systems for the cyclic nucleotide-dependent cytosol protein kinases would be unable to pick up this activity of the orthophosphate concentration is higher than 25 mM and the pH or the assay lower than pH 6.5. The enzyme described here has an apparent pH optimum of 8.5. Activity in liver mitochondria is not evident unless the mitochondria are disrupted by either sonication or freezing and thawing. Distribution of kinase activity in centrifugal fractions of both liver and heart mitochondrial sonicates was parallel to that of the two inner membrane marker enzymes succinic dehydrogenase and cytochrome oxidase and quite different from that of the matrix enzyme malic dehydrogenase. Experiments with preparations enriched in outer or inner membranes confirmed the contention that this enzyme is located on the inner membrane. Since disruption of the inner membrane by a freeze-thaw treatment (after the outer membrane had been disrupted by swelling in phosphate) was necessary for full expression of activity by this enzyme, the tentative conclusion was reached that substrate is accepted only from the matrix side of the inner membrane.
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PMID:Protein kinase activity at the inner membrane of mammalian mitochondria. 1 32

Escherichia coli O127:B8 lipopolysaccharide (LPS), prepared by the Westphal procedure, caused a marked decrease in the activities of mitochondrial malate dehydrogenase, succinate dehydrogenase, and adenylate kinase in African green monkey kidney (Vero) cells and primary cultures of mouse liver cells within 2 h after exposure to 10 micrograms of LPS/ml of culture medium. These three enzyme activities leaked into the supernatant fraction, and cytochrome oxidase activity was lost from the mouse liver mitochondrial particulate fraction within 45 min after exposure to 10 micrograms of LPS/mg of protein. Loss malate dehydrogenase activity from isolated mitochondria was also accelerated by LPS from E. coli O26:B6 (Boivin preparation) or Salmonella typhosa O901 (Westphal preparation), and by lipid A from Salmonella minnesota or Shigella sonnei. In addition, LPS and lipid A inhibited state 3 respiration by isolated mitochondria with attendant loss of respiratory control, but adenosine 5'-diphosphate/O ratios were relatively unchanged. Impaired mitochondrial function is an early event after exposure to biologically relevant amounts of LPS or lipid A.
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PMID:Action of bacterial endotoxin and lipid A on mitochondrial enzyme activities of cells in culture and subcellular fractions. 11 91

The histochemistry of the neural cells was studied in the submandibular ganglia of 5 Callithrix jacchus (3 males and 2 females) and 4 Callithrix penicillata (2 males and 2 females). These cells contain neutral mucopolysaccharides, nucleoproteins and lipidic materia, but are apparently devoid of glycogen. It is impossible to demonstrate in them any reactivity for UDPG-GT, phosphorylases, ATPase at pH 6.3, leucine aminopeptidase and alanyl aminopeptidas. The reaction for the other searched enzymes was as follows: weak (F-1,6-P Ald and cytochrome oxidase), weak to moderate (ADH, 6-P-GDH, ICDH, SDH, MDH, alpha-GPDH and beta-OHBDH), moderate (G-6-PDH, F-1,6-PA, LDH and GDH), moderate to strong (ATPase at pH 7.4, nonspecific esterase and acid phosphatase) and strong (G-6-PA, NADH2,-TR, NADPH2-TR, ATPase at pH 8.5 and 9.4 and alkaline phosphatase).
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PMID:Histochemical studies on the submandibular ganglia of marmosets (Callithrix jacchus and Callithrix penecillata). 14 13

The epithelial cells in the taste buds of C. jacchus and C. penicillata show a moderate amount of ribonucleic acid an a concentration of a PAS-positive diastase-resistant material at their apical part. These cells are devoid of UDPG-GT, phosphorylases, G-6-PA, alanyl aminopeptidase, leucine aminopeptidase, cholinesterase and MAO; they present a weak reaction of F-1, 6-P Ald, LDH, SDH, MDH, cytochrome oxidase, beta-OHBDH, nonspecific esterase and acid phosphatase and a stronger reaction to ADH, NADPH2-TR, ATPases, alpha-GPDH, alkaline phosphatase, 5-nucleotidase and GDH. Although some enzymes (alkaline phosphatase, 5-nucleotidase and ATPases) have an almost uniform reactivity by the several taste buds, the other ones react with a lesser intensity in the smaller uniform reactivity by the several taste buds, the other ones react with a lesser intensity in the smaller taste buds of the fungiform papillae. As a rule the apical part of the cells shows a stronger enzymatic reactivity. The taste buds of the marmosets are penetrated by acetylcholinesterase positive nerve fibers whereas the autonomic ganglia in the connective tissue contain both-acetyl and butyrylcholinesterase.
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PMID:Histochemical observations on the taste buds of the marmosets (Callithrix jacchus and Callithrix penicillata). 15 39

The ultrastructure of perfused livers and of mitochondrial fractions from 6 months and 30 month-old C57/BL mice were studied. In old mice the liver cell mitochondria were enlarged and rounded with a light "foamy", vacuolated matrix, short cristae and a loss of dense granules. Quantitative studies showed a 60% increase in the mean size and an increased proportion of larger mitochondria in intact 30 month-old perfused livers. Endothelial and Kupffer cell mitochondria were smaller than those of the parenchymal cells. Mitochondria in pellets prepared from 6 and 30 month-old livers were rounded and condensed although there were a few larger and "foamy" mitochondria in the preparations from old mice. Up to 47% of large mitochondria in the old livers were lost during cell fractionation. The levels of cytochrome oxidase and malate dehydrogenase were slightly decreased with age but their cytochemical localization was unchanged.
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PMID:The effect of age on mitochondrial ultrastructure and enzymes. 16 2

There was no significant difference between the levels of cytochrome oxidase and malate dehydrogenase in whole liver homogenates or in mitochondria isolated from the livers of 6-month-old and 30-month-old C57/BL mice. Little change with age was found in the cytochemical localisation of either enzyme. There were no significant changes in endogenous, state III or state IV respiration of mitochondria isolated from the livers of young and old mice.
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PMID:The effect of age on mitochondrial enzymes and respiration. 16 82

The changes in the activities of some mitochondrial and soluble enzymes in the lungs of guinea pig, caused by three varieties of asbestos dust 120 days after intratracheal injection, were studied. Marked increase was observed in mitochondrial cytochrome oxidase, diaphorase and malic dehydrogenase. Among the soluble enzymes, lactic dehydrogenase showed the maximum variation.
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PMID:Enzymatic changes in lung tissue of asbestotic guinea pigs. 17 80

Studies were performed in the activities of certain enzymes from oxidoreductase group: cytochrome c-oxidoreductase (EC 1.6.99.3), succinate dehydrogenase succinates: cytochrome c-oxidoreductase (EC 1.3.99.1), cytochrome oxidase (EC 1.9.3.1) and malate dehydrogenase (EC 1.1.1.37) in mitochondria from neuronal and glial-enriched fractions. The mitochondrial fraction purity was observed by the electron microscope. The enzyme activity of the glial mitochondrial fraction was much higher than that in the neuronal mitochondria. Malate dehydrogenase from glial enriched fraction consists of three isoenzymes, while neuronal mitochondria had two isoenzymes of malate dehydrogenase. The neuronal mitochondria were found to be more stable to lubrol and digitonin.
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PMID:[Differences in the enzymatic activity of mitochondria from enriched neuronal and glial fractions]. 18 84

Eschscholtzia californica stigmas with germinating pollen at different stages of development were the subject of histochemical studies which aimed the localization of several enzymes like phosphorylase, leucine amino peptidase, nonspecific esterase, cytochrome oxidase, aldolase, alpha-glycerophosphate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, monoamine oxidase, alpha-galactosidase, beta-glucosidase and beta-galactosidase. Pollen and pollen tubes were shown to contain starch, lipid, proteins and soluble sugars as the storage products. These storage products were utilized during germination and tube growth. The role of different enzymes in the process of germination and tube growth is discussed. From the distribution of oxidoreductases it is inferred that respiration plays an essential role in the tube growth. During pollen germination probably the reserve proteins were transported to pollen tube tip. The increase of activity of alpha-and beta-galactosidase in pollen tubes indicates on their involvement in carbohydrate metabolism. The role of alpha-galactosidase in the metabolism of galactolipids is also inferred. Similarly, the reaction catalysed by beta-glucosidase resulted in the production of aglycon and glucose; of these the former possibly act as a substrate of peroxidase. Some of the glycosidases diffused out of pollen wall on the stigma and participated in the release of free sugars of the female tissue.
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PMID:Studies on the physiology of pollen and pollen tube growth. IV Eschscholtzia californica Cham. 22 Jan 58

An increase in activity of several dehydrogenases of tricarboxylic acid cycle (NADP-dependent malate dehydrogenase, alpha-ketoglutarate dehydrogenase) was observed in rat liver tissue under conditions of acute hemorrhage. The enzymatic activity was slightly higher in the group of animals with relatively prolonged life-time as compared with those, which lived less than 4 hrs. Activity of cytochrome oxidase was inhilited in the both groups of animals (by 27% and 29%, respectively). The less distinct decrease in both temperature in the group of animals with prolonged life-time might maintain the rate of Krebs cycle substrates oxidation. Activation of respiration in liver tissue under conditions of the hemorrhage is considered as a compensatory reaction tending to improve oxygen utilization in hypoxia. At the same time, inhibition oy cytochrome oxidase demonstrates the impairment of electron transport and decreased rate of energy production in liver mitochondria.
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PMID:[Tissue respiratory enzymes in the rat liver in acute blood loss]. 22 69


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