scholarly journals Canine submandibular-gland hyaluronidase. Identification and subcellular distribution

1968 ◽  
Vol 110 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Y. H. Tan ◽  
J. M. Bowness
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Submandibular Gland ◽  
High Speed ◽  
Specific Activity ◽  
Mitochondrial Fraction ◽  
Product Formation ◽  
Triton X ◽  
Submandibular Saliva ◽  
Testicular Hyaluronidase

1. Submandibular glands from four species of mammal have been shown to contain a hyaluronidase active at acid pH; glands from dog and cat had a much higher content of this enzyme than has been found in other sources. 2. Product formation from hyaluronate after 24hr. incubation was almost the same as with testicular hyaluronidase, indicating that the enzyme is an endo-poly-β-hexosaminidase. 3. When submandibular-gland homogenates were fractionated by the scheme developed for liver by de Duve, Pressman, Gianetto, Wattiaux & Appelmans (1955), all the enzymes assayed, except cytochrome c oxidase, were found to occur partly in the soluble fraction and partly in the particulate fractions. Among the particular fractions, the highest specific activity was found in the heavy-mitochondrial fraction for cytochrome c oxidase, in the microsomal fraction for alkaline phosphatase and in the light-mitochondrial fraction for acid phosphatase, β-N-acetylhexosaminidase and acid-active hyaluronidase. 4. Release of the enzyme activity from the sedimentable fractions occurred in 0·1% Triton X-100 or after high-speed homogenization. 5. Stimulation of dogs by pilocarpine was found to decrease the hyaluronidase content of the submandibular gland by 5% and to cause the occurrence of a corresponding amount of acid-active hyaluronidase in the submandibular saliva. 6. The results are discussed in relation to the subcellular localization of hyaluronidase.

scholarly journals Cytochrome c oxidase is preferentially synthesized in the rough endoplasmic reticulum-mitochondrion complex in rat liver

1982 ◽  
Vol 208 (2) ◽  
pp. 505-507 ◽  
Author(s):  
S Parimoo ◽  
N Rao ◽  
G Padmanaban
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Cytochrome C Oxidase ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Specific Activity ◽  
Mitochondrial Fraction

The specific activity and content of cytochrome oxidase in the rough endoplasmic reticulum-mitochondrion complex are higher than in the mitochondrial fraction. Radiolabelling studies with the use of hepatocytes and isolated microsomal and rough endoplasmic reticulum-mitochondrion fractions, followed by immunoprecipitation with anti-(cytochrome oxidase) antibody, reveal that the nuclear-coded cytoplasmic subunits of cytochrome oxidase are preferentially synthesized in the latter fraction. The results have a bearing on the mechanism of transport of these subunits into mitochondria.

Optimum pH and ionic strength for the assay of cytochrome c oxidase from pea cotyledon mitochondria

1977 ◽  
Vol 55 (10) ◽  
pp. 1114-1117 ◽  
Author(s):  
Gerrit H. Bomhoff ◽  
Mary Spencer
Keyword(s):  
Ionic Strength ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Ferrocytochrome C ◽  
Optimum Ph ◽  
Triton X ◽  
Assay Conditions ◽  
Nonionic Detergents

Cytochrome c oxidase (EC 1.9.3.1) has been solubilized by use of the nonionic detergents Triton X-114 and Triton X-100, from pea cotyledon mitochondria. Optimum assay conditions were determined for the oxidation of ferrocytochrome c in air. The results indicate that the plant cytochrome c oxidase resembles mammalian preparations in its sensitivity towards ionic strength and pH of the assay buffer.

Investigation of the essential boundary layer phospholipids of cytochrome c oxidase using Triton X-100 delipidation

Biochemistry ◽  
1980 ◽  
Vol 19 (16) ◽  
pp. 3656-3661 ◽  
Author(s):  
Neal C. Robinson ◽  
Fredlein Strey ◽  
Linda Talbert
Keyword(s):  
Boundary Layer ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Triton X

Triton-X-100 induced dissociation of beef heart cytochrome c oxidase into monomers

Biochemistry ◽  
1986 ◽  
Vol 25 (9) ◽  
pp. 2328-2335 ◽  
Author(s):  
Neal C. Robinson ◽  
Linda Talbert
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Beef Heart ◽  
Triton X

scholarly journals Solubilization, partial purification and properties of N-methylglutamate dehydrogenase from Pseudomonas aminovorans

1977 ◽  
Vol 161 (2) ◽  
pp. 357-370 ◽  
Author(s):  
C W Bamforth ◽  
P J Large
Keyword(s):  
Cytochrome C ◽  
Electron Acceptor ◽  
Specific Activity ◽  
Partial Purification ◽  
Ph Optimum ◽  
Transport Chain ◽  
Purification And Properties ◽  
Solubilized Enzyme ◽  
Triton X ◽  
Sepharose 4B

1. Extracts of amine-grown Pseudomonas aminovorans contained a particle-bound N-methylglutamate dehydrogenase (EC 1.5.99.5). The enzyme was not present in succinate-grown cells, and activity appeared before growth began in succinate-grown cells which had been transferred to methylamine growth medium. 2. Membrane-containing preparations from methylamine-grown cells catalysed an N-methylglutamate-dependent uptake of O2 or reduction of cytochrome c, which was sensitive to inhibitors of the electron-transport chain. 3. N-Methylglutamate dehydrogenase activity with phenazine methosulphate or 2,6-dichlorophenol-indophenol as electron acceptor could be solubilized with 1% (w/v) Triton X-100. The solubilized enzyme was much less active with cytochrome c as electron acceptor and did not sediment in 1 h at 150000g. Solubilization was accompanied by a change in the pH optimum for activity. 4. The solubilized enzyme was partially purified by Sepharose 4B and hydroxyapatite chromatograpy to yield a preparation 22-fold increased in specific activity over the crude extract. 5. The partially-purified enzyme was active with sarcosine, N-methylalanine and N-methylaspartate as well as with N-methylglutamate. Evidence suggesting activity with N-methyl D-amino acids as well as with the L-forms was obtained. 6. The enzyme was inhibited by p-chloromercuribenzoate, iodoacetamide and by both ionic and non-ionic detergents. 2-Oxoglutarate and formaldehyde were also inhibitors. 7. Kinetic analysis confirmed previous workers' observations of a group transfer (Ping Pong) mechanism. 8. Spectral observations suggested that the partially purified preparation contained flavoprotein and a b-type cytochrome. 9. The role of the enzyme in the oxidation of methylamine is discussed.

Bioenergetic remodeling during cellular differentiation: changes in cytochrome c oxidase regulation do not affect the metabolic phenotype

2004 ◽  
Vol 82 (3) ◽  
pp. 391-399 ◽  
Author(s):  
Carrie N Lyons ◽  
Scot C Leary ◽  
Christopher D Moyes
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Cytochrome C ◽  
Oxidative Phosphorylation ◽  
Cytochrome C Oxidase ◽  
Oxidative Metabolism ◽  
Specific Activity ◽  
Reactive Oxygen ◽  
Metabolic Phenotype ◽  
Oxygen Species

Myogenesis induces mitochondrial proliferation, a decrease in reactive oxygen species (ROS) production, and an increased reliance upon oxidative phosphorylation. While muscles typically possess 20%–40% excess capacity of cytochrome c oxidase (COX), undifferentiated myoblasts have only 5%–20% of the mitochondrial content of myotubes and muscles. We used two muscle lines (C2C12, Sol8) and 3T3-L1 pre-adipocytes to examine if changes in COX regulation or activity with differentiation cause a shift in metabolic phenotype (i.e., more oxidative, less glycolytic, less ROS). COX activity in vivo can be suppressed by its inhibitor, nitric oxide, or sub-optimal substrate (cytochrome c) concentrations. Inhibition of nitric oxide synthase via L-NAME had no effect on the respiration of adherent undifferentiated cells, although it did stimulate respiration of myoblasts in suspension. While cytochrome c content increased during differentiation, there was no correlation with respiratory rate or reliance on oxidative metabolism. There was no correlation between COX specific activity and oxidative metabolism between cell type or in relation to differentiation. These studies show that, despite the very low activities of COX, undifferentiated myoblasts and pre-adipocytes possess a reserve of COX capacity and changes in COX with differentiation do not trigger the shift in metabolic phenotype.Key words: oxidative phosphorylation, myogenesis, nitric oxide, reactive oxygen species, cytochrome c oxidase.

scholarly journals LOCALIZATION OF Na+, K+-ATPASE AND OTHER ENZYMES IN TELEOST PSEUDOBRANCH

1973 ◽  
Vol 57 (3) ◽  
pp. 675-688 ◽  
Author(s):  
Leslie A. Dendy ◽  
Russell L. Deter ◽  
Charles W. Philpott
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Specific Activity ◽  
Kinetic Properties ◽  
Sedimentation Analysis ◽  
Marker Enzymes ◽  
Lagodon Rhomboides ◽  
Particle Population ◽  
P Fraction ◽  
Sodium And Potassium

In an effort to determine the subcellular localization of sodium- and potassium-activated adenosine triphosphatase (Na+, K+-ATPase) in the pseudobranch of the pinfish Lagodon rhomboides, this tissue was fractionated by differential centrifugation and the activities of several marker enzymes in the fractions were measured. Cytochrome c oxidase was found primarily in the mitochondrial-light mitochondrial (M+L) fraction. Phosphoglucomutase appeared almost exclusively in the soluble (S) fraction. Monoamine oxidase was concentrated in the nuclear (N) fraction, with a significant amount also in the microsomal (P) fraction but little in M+L or S. Na+, K+-ATPase and ouabain insensitive Mg2+-ATPase were distributed in N, M+L, and P, the former having its highest specific activity in P and the latter in M+L. Rate sedimentation analysis of the M+L fraction indicated that cytochrome c oxidase and Mg2+-ATPase were associated with a rapidly sedimenting particle population (presumably mitochondria), while Na+, K+-ATPase was found primarily in a slowly sedimenting component. At least 75% of the Na+, K+-ATPase in M+L appeared to be associated with structures containing no Mg2+-ATPase. Kinetic properties of the two ATPases were studied in the P fraction and were typical of these enzymes in other tissues. Na+, K+-ATPase activity was highly dependent on the ratio of Na+ and K+ concentrations but independent of absolute concentrations over at least a fourfold range.

scholarly journals Changes in enzyme activities and distributions during glucose de-repression and respiratory adaptation of anaerobically grown Saccharomyces carlsbergensis

1973 ◽  
Vol 132 (3) ◽  
pp. 609-621 ◽  
Author(s):  
T. G. Cartledge ◽  
D. Lloyd
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Respiration Rate ◽  
Enzyme Activities ◽  
Specific Activity ◽  
Antimycin A ◽  
Saccharomyces Carlsbergensis ◽  
Whole Cells ◽  
Nadh Cytochrome ◽  
A Minor

1. During anaerobic glucose de-repression the respiration rate of whole cells of Saccharomyces carlsbergensis remained constant and was insensitive to antimycin A but was inhibited by 30% by KCN. Aeration of cells for 1 h led to increased respiration rate which was inhibited by 80% by antimycin A or KCN. 2. Homogenates were prepared from sphaeroplasts of anaerobically grown, glucose de-repressed cells and the distribution of marker enzymes was investigated after zonal centrifugation on sucrose gradients containing MgCl2. These homogenates contained no detectable cytochrome c oxidase or catalase activity. The complex density distributions of NADH– and NADPH–cytochrome c oxidoreductases and adenosine triphosphatase(s) [ATPase(s)] were very different from those of anaerobically grown, glucose-repressed cells. 3. The specific activity of total ATPase was lowered and sensitivity to oligomycin decreased from 58 to 7% during de-repression. 4. Cytochrome c oxidase and catalase activities were detectable in homogenates of cells after 10min aeration. Zonal centrifugation indicated complex, broad sedimentable distributions of all enzyme activities assayed; the peaks of activity were at 1.27g/ml. 5. Centrifugation of homogenates of cells adapted for 30min and 3 h indicated a shift of density of the major sedimentable peak from 1.25g/ml (30min) to 1.235g/ml (3 h). After 30min adaptation a minor zone of oligomycin-sensitive ATPase and 15% of the total cytochrome c oxidase activities were detected at ρ=1.12g/l; these particles together with those of higher density containing cytochrome c oxidase, ATPase and NADH–cytochrome c oxidoreductase activities were all sedimented at 105g-min. 6. Electron microscopy indicated that the mitochondria-like structures of anaerobically grown, glucose-de-repressed cells were similar to those of repressed cells. After 10min of respiratory adaptation highly organized mitochondria were evident which resembled the condensed forms of mitochondria of aerobically grown, glucose-de-repressed cells. High-density zonal fractions of homogenates of cells after adaptation also contained numerous electron-dense vesicles 0.05–0.2μm in diameter. 7. The possibility that the `promitochondria' of anaerobically grown cells may not be the direct structural precursors of fully functional mitochondria is discussed.

The influence of chronic ethanol feeding to rats on liver mitochondrial membrane structure and function

1980 ◽  
Vol 58 (10) ◽  
pp. 1147-1155 ◽  
Author(s):  
E. A. Hosein ◽  
Hung Lee ◽  
Ilan Hofmann
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Rat Liver ◽  
Mitochondrial Membrane ◽  
Membrane Structure ◽  
Membrane Lipids ◽  
Specific Activity ◽  
Structure And Function ◽  
Membrane Structure And Function ◽  
And Function

Arrhenius plots were generated on the activity of rat liver mitochondrial cytochrome c oxidase from Metrecal–sucrose fed controls and Metrecal–alcohol fed experimentals. Chronic alcohol feeding resulted in diminished specific activity of cytochrome c oxidase and abolition of the discontinuity temperature at 17.5 °C found in the controls. Twenty-four hours after alcohol withdrawal, a discontinuity temperature reappeared at 14.4 °C; at 48 h it increased to 22.6 °C and returned to normal (17.4 °C) at 72 h. Such liver mitochondria also showed a decreased capacity to oxidize the acetyl group of acetyl carnitine immediately following prolonged alcohol feeding. When the assay was performed following withdrawal from alcohol 24 h later, oxidation was enhanced and this effect persisted for another 48 h. These latter results revealed a diminished capacity of such mitochondria to oxidize short chain fatty acids during alcohol feeding and the reverse during alcohol withdrawal.These results, complemented by thermographic data obtained through differential scanning calorimetry (DSC) reinforced the view that chronic alcoholic feeding induced adaptive changes in the fluidity of rat liver mitochondrial membrane lipids. Moreover, they demonstrated that in the microenvironment of the membrane-bound enzymes on withdrawal from ethanol, the membrane readapts to the new conditions without alcohol. This involved modulation of membrane structure and function and at the same time demonstrated a role for the membrane in the expression of tolerance and functional dependence on alcohol.

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