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)

Homogenates of HTC cells have been fractionated by differential centrifugation (in four particulate fractions: N, M, L, P, and a supernatant S) or isopycnic banding in linear sucrose gradients. On this basis, the following subcellular organelles may be characterized: (i) Mitochondria, detected by cytochrome oxidase and succinodehydrogenase, are collected in the M and L fractions, and equilibrate, as a narrow band, at a median buoyant density of 1.18 g/cm3. (ii) Lysosomes, detected by the latent hydrolases beta-glycerophosphatase and N-acetyl-beta-glucosaminidase, are largely sedimented in the M and L fractions, and display a broad density distribution pattern with a median value of 1.17 g/cm3. This density is decreased or increased after cultivation of the cells in presence of Triton WR-1339 or Dextran 500, respectively. The behavior of cathepsin D is somewhat at variance with that of the two other hydrolases. (iii) Plasma membrane is tentatively detected by alkaline phosphodiesterase I. Largely recovered in the P fraction, this enzyme equilibrates at a median density close to that of the lysosomal hydrolases; the bulk of cholesterol and about half of the leucyl-2-naphthylamidase are closely associated with alkaline phosphodiesterase I; HTC cells do not contain typical 5'-nucleotidase. (iv) Catalase-bearing particles, of high buoyant density (1.22 g/cm3) are present, but 30-40% of the catalase is also found readily soluble. NADPH- and NADH: cytochrome c reductase, and RNA show more complex distributions. It is suggested that the former enzyme is associated with the endoplasmic reticulum; as in liver, NADH reductase activity is shared between the endoplasmic reticulum and the mitochondria; half of the RNA is associated with free ribosomes of polysomes. True glucose-6-phosphatase could not be detected.
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PMID:Analytical fractionation of cultured hepatoma cells (HTC cells). 56 43

Improved, largely automated methods are described for the purification and analysis o peroxisomes, lysosomes, and mitochondria from the livers of rats injected with Triton WR-1339. With these new methods, it has become possible to obtain, in less than 6 hr and with reliable reproducibility, mitochondria practically free of contaminants, as well as the rarer cytoplasmic particles in amounts (about 100 mg of protein) and in a state of purity (95%) that make them suitable for detailed biochemical studies. The results obtained so far on these preparations have made more conclusive and precise previous estimates of the biochemical and morphological properties of the three groups of cytoplasmic particles. In addition, peroxisomes were found to contain essentially all the L-alpha-hydroxy acid oxidase of the liver, as well as a small, but significant fraction of its NADP-linked isocitrate dehydrogenase activity. Another small fraction of the latter enzyme is present in the mitochondria, the remainder being associated with the cell sap. The mitochondrial localization of the metabolically active cytoplasmic DNA could be verified. The relative content of the fractions in mitochondria, whole peroxisomes, peroxisome cores, lysosomes, and endoplasmic reticulum was estimated independently by direct measurements on electron micrographs, and by linear programming (based on the assumption that the particles are biochemically homogeneous) of the results of enzyme assays. The two types of estimates agreed very well, except for one fraction in which low cytochrome oxidase activity was associated with mitochondrial damage.
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PMID:The large-scale separation of peroxisomes, mitochondria, and lysosomes from the livers of rats injected with triton WR-1339. Improved isolation procedures, automated analysis, biochemical and morphological properties of fractions. 429 86

Postnuclear supernates from homogenates of skeletal muscle from rats subjected to starvation, injections of Triton WR-1339, dextran-500, and dextran + corticosterone were fractionated by means of rate and isopycnic zonal centrifugation in sucrose-0.02 M KCl gradients. Zonal fractions were analyzed for protein, RNA, cytochrome oxidase, and up to six acid hydrolases. The results indicate the presence of two groups of lysosome-like particles. One group contributes approximately 95% of the cathepsin D and acid phosphatase activity and 75% of the acid ribonuclease, beta-glucuronidase, and arylsulfatase activity in muscle. It is characterized by a modal equilibrium density of 1.18 that is decreased by starvation, but is not shifted by dextran-500 or Triton WR-1339. The second group has a higher proportion of acid ribonuclease, beta-glucuronidase, and arylsulftase; the equilibrium density can be shifted by dextran-500 and Triton WR-1339. It is suggested that this group of lysosomes is derived from macrophages and other connective tissue cells, whereas the former group represents lysosome-like particles from muscle cells.
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PMID:Lysosomes in skeletal muscle tissue. Zonal centrifugation evidence for multiple cellular sources. 432 73