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 intracellular distribution of N-methyl-transferase requiring 5-methyl-tetrahydrofolic acid (5 MT-NMT) was studied in brain, kidney and liver of rats. Among these different tissues, the kidney displayed the highest enzyme activity, more than 20 times the activity detected in the brain. As the striatum and, to a lesser extent the hypothalamus, were found to contain slightly higher 5 MT-NMT than other cerebral regions, they were also selected for the study of the subcellular localization. Tissue fractionation was performed by differential centrifugation yielding five different fractions which were analyzed for their enzymatic content not only of 5 MT-NMT but also of marker enzymes, such as cytochrome oxidase, acid phosphatase and inosine diphosphatase. In all the tissues studied, 5 MT-NMT was recovered in the supernatant fraction. Therefore one may consider this enzyme to belong to the cytosol. Although a neuronal localization cannot be excluded, it is beyond doubt that the enzyme is contained in other cellular types. In the brain fractionation, the five fraction procedure seems to be very useful especially when the subcellular distribution of a given enzyme is compared to that obtained in other tissues like liver or kidney. Finally 5 MT-NMT may be considered a good marker enzyme for the supernatant fraction.
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PMID:Tissue fractionation in rat brain, kidney and liver. I. Intracellular localization of a 5-methyltetrahydrofolic acid requiring enzyme. 16 5

The enzymic activities of hepatocytes, especially the bile canaliculi, of rats with experimental obstructive jaundice were studied by using electron microscopic cytochemistry. Common hepatic duct was ligated in rats, and liver tissue was taken from these animals 4 days after the operation for comparison with that of normal rats. The main results of this experiment were as follows: (1) Lumens of bile canaliculi were obviously enlarged. The microvilli became shortened and thickened, or even disappeared. The exoplasm was thickened as well. (2) The activity of Na(+)-K(+)-ATPase, G-6-Pase, Ca(++)-ATPase and NDPase in the wall of bile canaliculi was obviously reduced. (3) The activity of cytochrome oxidase in hepatocytes was also obviously reduced. The significance of the changes in these enzymic activity is discussed.
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PMID:[Cytochemistry of bile canaliculi in rats with experimental obstructive jaundice]. 217 87

We describe the ultrastructure of various types of gastric carcinoma cells as well as their histochemical properties as visualized at the electron-microscope level. The histochemical properties of tumour cells were compared with those of homologous normal epithelial cells. The localization and activity of ATPase, IDPase, acidic phosphatase and alkaline phosphatase as well as of the oxidoreductases (cytochrome oxidase, succinate dehydrogenase and NADH-dehydrogenase) were studied. Our findings demonstrated that, in tumour cells, a complicated process of structural-functional restructuring takes place. It seems that a number of ultracytochemical properties may be preserved or may disappear altogether; also, such properties may become enhanced or weaker. This heterogeneity of the histochemical properties of tumour cells is discussed with regard to the role of the stem (polypotent) cell in the process of the histogenesis (cytogenesis) of human gastric carcinomas.
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PMID:Ultrastructural ultracytochemical investigation of human gastric carcinomas. 301 11

Homogenates of cultured rat embryo fibroblasts have been assayed for acid phosphatase, N-acetyl-beta-glucosaminidase, cathepsin D, acid deoxyribonuclease, cytochrome oxidase, NADH cytochrome c reductase, 5'-nucleotidase, inosine diphosphatase, acid pyrophosphatase, neutral pyrophosphatase, esterase, catalase, cholesterol, and RNA. The validity of the assay conditions was checked. Neutral pyrophosphatase is a readily soluble enzyme. Acid hydrolases, except acid pyrophosphatase, are particle-bound enzymes, which exhibit a high degree of structural latency. They are activated and solubilized in a parallel fashion by mechanical treatments and tensio-active agents. Catalase is also particle-bound and latent; activating conditions stronger than those for hydrolases are required to activate the enzyme. Acid pyrophosphatase, 5'-nucleotidase and inosine diphosphatase are firmly particle-bound, but not latent; they are not easily solubilized. In differential and isopycnic centrifugation, the latent hydrolases, cytochrome oxidase and catalase dissociate largely from each other; this suggests the occurrence of lysosomes and peroxisome-like structures besides mitochondria. The distribution patterns of 5'-nucleotidase and cholesterol are largely similar; digitonin influences their equilibrium density to the same extent; these two constituents are thought to be related to the plasma membrane. Inosine diphosphatase and acid pyrophosphatase are also partially associated with the plasma membrane, although some part of these enzymic activities probably belongs to other structures. NADH cytochrome c reductase is associated partly with the endoplasmic reticulum, partly with mitochondria.
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PMID:Analytical fractionation of homogenates from cultured rat embryo fibroblasts. 437 90

Tissue fractionation was used as an analytical tool to study the subcellular distribution of an adenosine triphosphatase activated by Mg2+ in adrenal medullae of the pig and ox and in whole adrenals of the rat. By measuring adenosine triphosphatase and various enzymes in the fractions obtained by differential centrifugation, the distribution pattern of adenosine triphosphatase was found to differ markedly from that of markers like catecholamines, dopamine beta-hydroxylase or cytochrome oxidase. In the pig and ox the distribution of inosine diphosphatase paralleled that of adenosine triphosphatase. After equilibration through sucrose density gradients, no adenosine triphosphatase activity was detected in the chromaffin granules in the rat. However, in bovine adrenal medullae, a large part of the adenosine triphosphatase activity equilibrated in that area of the gradient in which the chromaffin granules were found. This adenosine triphosphatase distribution pattern was an artefact produced by applying a too concentrated sample to the gradient. When a more diluted sample of bovine tissue was used no adenosine triphosphatase activity was found to be associated with the chromaffin granules. The present results lead to a reconsideration of the role of the adenosine triphosphatase in some processes in which the chromaffin granules are involved. Moreover, the degree of purity of many chromaffin granule preparations is again questioned.
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PMID:Tissue fractionation and catecholamines--IV. Adenosine triphosphatase in chromaffin granules: a distribution artefact. 1137 Feb 33

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