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)

Catalase, glycolate oxidase, and hydroxypyruvate reductase, enzymes which are located in the microbodies of leaves, show different developmental patterns in the shoots of wheat seedlings. Catalase and hydroxypyruvate reductase are already present in the shoots of ungerminated seeds. Glycolate oxidase appears later. All three enzymes develop in the dark, but glycolate oxidase and hydroxypyruvate reductase have only low activities. On exposure of the seedlings to continuous white light (14.8 x 10(3) ergs cm(-2) sec(-1)), the activity of catalase is doubled, and glycolate oxidase and hydroxypyruvate reductase activities increase by 4- to 7-fold. Under a higher light intensity, the activities of all three enzymes are considerably further increased. The activities of other enzymes (cytochrome oxidase, fumarase, glucose-6-phosphate dehydrogenase) are unchanged or only slightly influenced by light. After transfer of etiolated seedlings to white light, the induced increase of total catalase activity shows a much longer lag-phase than that of glycolate oxidase and hydroxypyruvate reductase. It is concluded that the light-induced increases of the microbody enzymes are due to enzyme synthesis. The light effect on the microbody enzymes is independent of chlorophyll formation or the concomitant development of functional chloroplasts. Short repeated light exposures which do not lead to greening are very effective. High activities of glycolate oxidase and hydroxypyruvate reductase develop in the presence of 3-amino-1,2,4-triazole which blocks chloroplast development. The effect of light is not exerted through induced glycolate formation and appears instead to be photomorphogenetic in character.In senescing leaves excised from the plants decreases in activity of glycolate oxidase, and hydroxypyruvate reductase follow with some delay the decrease in chlorophyll content. The activity of catalase, however, is maintained at high levels, especially when the detached shoots are kept in light.
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PMID:Developmental studies on microbodies in wheat leaves : I. Conditions influencing enzyme development. 1665 92

Organelles in homogenates from autotrophic cells of Chlorogonium elongatum were separated on linear sucrose gradients. The distribution of enzymes typical of leaf peroxisomes was determined.Whereas more than 60% of the catalase activity was particulate and recovered in microbodies at a mean density of 1.225 g/cm(3) within the gradient, in most experiments only 5 to 10% (as a maximum 30%) of the NAD-dependent hydroxypyruvate reductase was particulate, and this was recovered principally at density 1.19 g/cm(3). This distribution coincides with that of cytochrome oxidase, malate dehydrogenase, and isocitrate dehydrogenase, the mitochondrial markers. Glyoxylate-glutamate aminotransferase and glycolate dehydrogenase showed a similar distribution pattern to that of NAD-dependent hydroxypyruvate reductase. Thus in Chlorogonium the enzymes of the glycolate pathway are not associated with the microbodies that are recovered at density 1.225 g/cm(3).The single large chloroplasts of the Chlorogonium cells are broken during grinding, and this probably accounts for the finding that NADP-glyoxylate reductase was recovered only in the soluble fractions of the gradient.
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PMID:Localization of Enzymes of Glycolate Metabolism in the Alga Chlorogonium elongatum. 1665 1

The crude homogenate of cells from Chlamydomonas reinhardii was placed on a linear gradient from 30% to 60% sucrose and centrifuged for 4 hours at 60 000 g. After fractionation of the gradient the distribution of enzymes was determined. Hydroxypyruvate reductase and glycolate dehydrogenase, two markers for peroxisomes, appeared with one sharp peak at density 1.185 g/cm(3) within the gradient. Twenty-five percent of the hydroxypyruvate reductase was particulate and 75% was found as solubles in the top fractions. The peaks of both enzymes matched exactly the peak of the cytochrome oxidase which is a marker for mitochondria. The profile for malate dehydrogenase was the same as that for hydroxypyruvate reductase. Catalase, however, showed two peaks. One coincided with the peak of cytochrome oxidase and the other appeared at density 1.22 g/cm(3). More than 50% of the catalase moved into the gradient during centrifugation.
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PMID:[Distribution of microbody enzymes from Chlamydomonas on sucrose gradients]. 2444 97