Activation of glycolic acid oxidase in plants.
نویسندگان
چکیده
The enzyme which oxidizes glycolic acid to glyoxylic acid is present in sufficient concentrations to support active respiration in a wide variety of plants (1). Glycolic acid itself is present in plants in small amounts (2), and, as yet, it has been the only 2-carbon organic acid which has been found to accumulate Cl4 during short time photosynthesis experiments with Cl402 (3). Thus both the free acid and phosphoglycolic acid have been associated with the photosynthesis process. The enzyme which oxidizes glycolic acid has not been found in roots, and, in plants germinated and grown in total darkness, little enzyme activity is found in the leaves (4). These etiolated plants rapidly form the enzyme when they are placed in light, and this phenomenon has been thought of as “light activation.” Evidence is presented to show that the great increase in glycolic acid oxidase activity which occurs when an etiolated plant is placed in the light is substrate activation and not light activation in a physical sense. This is the first known case of adaptive enzyme formation in higher plants. The enzyme functions both as a dehydrogenase (5) and as an oxidase (1). Since all measurements in this paper are aerobic, the enzyme will be referred to as glycolic acid oxidase.
منابع مشابه
Oxidation and reduction of glycolic and glyoxylic acids in plants. II. Glyoxylic acid reductase.
Clagett, Tolbert, and Burris (1) discovered an enzyme of wide-spread occurrence in the green parts of many plants which catalyzes the oxidation of glycolic and L-lactic acids. The enzyme, which was partially purified from tobacco leaves, seemed to catalyze the oxidation of glycolic acid, through glyoxylic acid, to formic acid and CO, (2). In view of the possible importance of glycolic acid oxid...
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An enzyme catalyzing the oxidation of I-cr-hydroxymonocarboxylic acids has been reported earlier (1). It oxidizes glycolic acid (optimum pH range 7.8 to 8.6) about three times as rapidly as Z-lactic acid (optimum pH 7.6). The enzyme is of particular interest because of its high activity, its wide distribution among green plants, its absence from etiolated plants, its unusually low energy of act...
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9. SCHOU, L., BENSON, A. A., BASSHAM, J. A., and CALVIN, M. The path of carbon in photosynthesis. XI. The role of glycolic acid. Physiol. Plantarum 3: 487-495. 1950. 10. THIMANN, K. V. and BONNER, W. D., JR. Organic acid metabolism. Ann. Rev. Plant Physiol. 1: 75-108. 1950. 11. TOLBERT, N. E. and BURRIS, R. H. Light activation of the plant enzyme which oxidizes glycolic acid. Jour. Biol. Chem. ...
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عنوان ژورنال:
- The Journal of biological chemistry
دوره 204 2 شماره
صفحات -
تاریخ انتشار 1953