Mitochondrial fraction catalase

Table I. Photoinactivation of Mitochondrial Fraction Catalase. Specificity of Protection3...

Subchronic exposure to MnCb for 7 days (total dose 1750 pmol/kg) by means of mini-osmotic pumps inplanted s.c. produced significant reduction in GSH-peroxidase (EC 1.11.1.9) activity in the cytosol and mitochondrial fractions of the whole rat brain and the striatum (Liccione and Maines 1988). The decrease in GSH-peroxidase was most pronounced in the mitochondrial fraction of the striatum where the activity was reduced to 35 % of the control. Catalase (EC 1.11.1.6) activity was also decreased in the striatum of rats treated with Mn but not in the whole brain. GSH content was markedly depleted (20 % of the control) in the striatum, although only modestly decreased in the whole brain (80% of the control). The treatment of rats with Mn also decreased the activity of oxidised glutathione reductase (EC 1.6.4.2) the same treatment increased the activity of y-glutamyltranspeptidase (EC 2.3.2.2). The activity of y-glutamylcysteine synthetase was not altered by Mn. 

Liver subfractionation experiments (2) showed that the protein content of all fractions was increased in the animals treated with clofibrate - most pronounced for the mitochondrial fraction. Also the amount of peroxisomes was probably increased since the amount of catalase was rather high both in the mitochondrial and in the lysosomal fraction. Total CoA (and long-chain acyl CoA) was increased in all fractions - most in the mitochondrial and lysosomal fractions/ where about 5— fold of the amounts in these fractions from the control rats were found. 

Cytochrome oxidase (cytochrome aa3) represents the most important cytochrome of the a class. This is the terminal oxidase used in animals, plants, yeasts, algae and some bacteria. It contains two copper centres, giving four redox groups in total. This oxidase is discussed with other cytochromes that have a terminal oxidase function in Sections 62.1.12.4 and 62.1.12.5. These are cytochromes o, d and cd,. The oxidases fed719 and ax are not included in that discussion. The situation regarding cytochrome ax has been confused, partly due to uncertainty in the definition of this cytochrome. In some respects, the properties of cytochrome ax resemble those of mitochondrial and bacterial aa3. It functions as a terminal oxidase in some bacteria,720 but its role in E. coli is unknown. A soluble fraction from disrupted E. coli cells grown anaerobically on glycerol and fumarate contains a hemoprotein similar to cytochrome ax, which has catalase and peroxidase activity.721... 

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