Cytochrome oxidase and ascorbic acid in the normal and regenerating tail of the Scincid lizard, Mabuya carinata

1975 ◽  
Vol 93 (3) ◽  
pp. 411-420 ◽  
Author(s):  
A.V. Ramachandran ◽  
N. Radhakrishnan ◽  
R.V. Shah
Keyword(s):  
Ascorbic Acid ◽  
Cytochrome Oxidase

The Conformational States of Oxidized and Oxygenated Beef-Heart Cytochrome c Oxidase

1975 ◽  
Vol 53 (4) ◽  
pp. 461-466 ◽  
Author(s):  
Jack A. Kornblatt ◽  
D. I. C. Kells ◽  
G. R. Williams
Keyword(s):  
Ascorbic Acid ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Cytochrome C Oxidase ◽  
Sedimentation Velocity ◽  
Beef Heart ◽  
Conformational States

1. The "oxygenated" form of cytochrome oxidase has been generated by treatment of the enzyme with ascorbic acid.2. "Oxygenated oxidase" so generated is stable over long periods (24 h).3. Sedimentation velocity experiments have shown the "oxygenated oxidase to be a less compact molecule than the oxidized.

Oxygen uptake and evolution by iron porphyrin enzymes

1959 ◽  
Vol 12 (1) ◽  
pp. 47
Author(s):  
NK King ◽  
ME Winfield
Keyword(s):  
Ascorbic Acid ◽  
Carbon Atom ◽  
Oxygen Uptake ◽  
Cytochrome Oxidase ◽  
Metal Atom ◽  
Iron Porphyrin ◽  
Reduction Step ◽  
The Third ◽  
Catalase Peroxidase ◽  
Electron Deficiency

Three detailed mechanisms are considered for the catalatic decomposition of H2O2. It is shown that the first of these, akin to the earlier hypotheses for catalase action, cannot satisfy the magnetic, titrimetric, and kinetic evidence. The second mechanism involves oxidation of the FeIII porphyrin to the equivalent of FeV. The electron deficiency is distributed over the ligands so that even in the most oxidized complex the iron is in the FeIV or possibly even the FeIII state. In the third scheme it is suggested that the reduction step (in which O2 is liberated) takes place at a carbon atom, while the site of the oxidation is the metal atom as commonly supposed. The liberation of O2 from H2O2 can be catalysed by 6-coordinate ruthenium II complexes. In the catalytic cycle, the metal appears to be oxidized to Rdv, then reduced to RuII. Ethanol or ascorbic acid can substitute for H2O2 in the reduction. Evidence for H2O2 attack on the ligands is suggestive but not conclusive. A brief comment is made on the bonding of oxygen to haemoglobin and myoglobin. The accumulated evidence for the structures of catalase, peroxidase, and myoglobin complexes is utilized in a scheme for the uptake of oxygen by cytochrome oxidase.

scholarly journals STUDIES IN BIOCHEMICAL GENETICS IN DROSOPHILA

1948 ◽  
Vol 31 (4) ◽  
pp. 337-345 ◽  
Author(s):  
Claude A. Villee
Keyword(s):  
Ascorbic Acid ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Imaginal Discs ◽  
Wing Disc ◽  
Biochemical Genetics ◽  
Wild Type ◽  
Respiratory Enzymes ◽  
Copper Porphyrin ◽  
Wing Discs

The metabolism of the imaginal discs of wild type, miniature, vestigial, and four-jointed varieties of Drosophila was investigated using the Cartesian diver ultramicrorespirometer. Wild type and vestigial wing disc respiration is inhibited by cyanide and azide and thus is mediated by an iron or copper porphyrin system, presumable cytochrome-cytochrome oxidase. Respiration is also inhibited by certain hydroxynaphthoquinones, believed to inactivate some enzyme between cytochromes b and c. The respiration of the vestigial and miniature wing discs is increased to normal by the addition of ascorbic acid and to a lesser extent by p-phenylenediamine and hydroquinone, hence the cytochrome oxidase and cytochrome c systems of vestigial and miniature wing discs are normal and the effects of these genes are on enzymes below cytochrome c in the respiratory chain. The respiratory enzymes of the developing imaginal discs of insects are similar to those of a wide variety of cells from bacteria to mammals. The correlation of these biochemical findings with embryological studies of the discs is discussed.

scholarly journals Copper deficiency in chicks: effects of ascorbic acid on iron, copper, cytochrome oxidase activity, and aortic mucopolysaccharides

1970 ◽  
Vol 24 (3) ◽  
pp. 607-614 ◽  
Author(s):  
C. E. Hunt ◽  
Joanne Landesman ◽  
P. M. Newberne
Keyword(s):  
Ascorbic Acid ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Copper Deficiency ◽  
Chondroitin Sulphate ◽  
Aortic Rupture ◽  
Control Diet ◽  
Cytochrome Oxidase Activity ◽  
Cu Deficiency ◽  
Acid Mucopolysaccharides

1. Copper deficiency was induced in newly hatched chicks by feeding on a milk-based diet for 12 d; effects of supplementation with ascorbic acid were studied.2. Cu deficiency alone resulted in 30% mortality from aortic rupture. This was associated with a 20% increase in total acid mucopolysaccharides in the aorta, manifested as an increase in chondroitin sulphate and a relative decrease in hyaluronic acid. Cytochrome oxidase activity of liver and heart was less than half that of the controls.3. Supplementing the Cu-deficient diet with 0.5 % L-ascorbic acid increased mortality to 40%, raised total aortic acid mucopolysaccharides to a higher level, and increased liver iron by 36%.4. Supplementing the control diet with ascorbic acid decreased liver Cu by 30% and significantly reduced total aortic acid mucopolysaccharides.5. The enhancement of the Cu-deficiency effect by ascorbic acid probably results from interactions between ascorbic acid and absorption or metabolism of Cu; untoward effects of supplementing the control diet with ascorbic acid may be interpreted as manifestations of ascorbic acid toxicity per se.

scholarly journals Interrelationships between copper deficiency and dietary ascorbic acid in the rabbit

1970 ◽  
Vol 24 (1) ◽  
pp. 61-69 ◽  
Author(s):  
C. E. Hunt ◽  
W. W. Carlton ◽  
P. M. Newberne
Keyword(s):  
Ascorbic Acid ◽  
Cortical Bone ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Copper Deficiency ◽  
Acid Supplementation ◽  
Cytochrome Oxidase Activity ◽  
Cu Deficiency ◽  
Calcium And Phosphorus ◽  
Ascorbic Acid Supplementation

1. Copper deficiency was induced in growing rabbits and the effects of ascorbic acid supplementation were studied.2. Signs of Cu deficiency, including reduced growth, achromotrichia and alopecia, anaemia, and gross alterations in the bones of the forelimbs, developed most rapidly in those animals fed ascorbic acid.3. Microscopic lesions in ossification centres were seen only in bones of rabbits which hadm received the vitamin.4. Calcium and phosphorus contents of ash from cortical bone were not changed.5. Compared with the controls, the concentration of liver Cu decreased and that of iron increased (> 50%) in Cu-deficient animals.6. Cytochrome oxidase activity was reduced in liver and heart in Cu-deficient animals; this effect was accentuated in heart preparations from animals fed ascorbic acid.

Initial Polymerization Sites Indicated During Mitochondrial Oxidation of Diaminobenzidine after Toluene Treatment

1977 ◽  
Vol 35 ◽  
pp. 408-409
Author(s):  
W. A. Shannon ◽  
M. A. Matlib
Keyword(s):  
Membrane Permeability ◽  
Cytochrome Oxidase ◽  
Rat Liver ◽  
Precise Definition ◽  
Cytochemical Localization ◽  
Oxidative Reaction ◽  
Mitochondrial Oxidation ◽  
Definition Of ◽  
Exogenous Substrates

Numerous studies have dealt with the cytochemical localization of cytochrome oxidase via cytochrome c. More recent studies have dealt with indicating initial foci of this reaction by altering incubation pH (1) or postosmication procedure (2,3). The following study is an attempt to locate such foci by altering membrane permeability. It is thought that such alterations within the limits of maintaining morphological integrity of the membranes will ease the entry of exogenous substrates resulting in a much quicker oxidation and subsequently a more precise definition of the oxidative reaction.The diaminobenzidine (DAB) method of Seligman et al. (4) was used. Minced pieces of rat liver were incubated for 1 hr following toluene treatment (5,6). Experimental variations consisted of incubating fixed or unfixed tissues treated with toluene and unfixed tissues treated with toluene and subsequently fixed.

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