Abstract
Reduced glutathione, but not mercaptoethanol or dithiothreitol, inhibits phosphoenolpyruvate carboxylase (PEPC) in desalted leaf extracts from Sedum praealtum D.C. The inhibition is more evident at low pH values (< 7.2) and becomes increasingly smaller at higher pH. In the presence of the inhibitor, the hyperbolic rate curve of night PEPC is transformed to sigmoid and the S0.5 is increased. When the enzyme is extracted during the day, the rate curve is sigmoid and it is not changed by the inhibitor, though the S0.5 is further increased. Oxidized glutathione is completely inactive. Levels of reduced glutathione in leaf tissue are distinctly higher in the light. A role of photosynthetically reduced glutathione in the regulation of PEPC in Crassulacean acid metabolism species appears probable.
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- BANDURSKI R. S. Further studies on the enzymatic synthesis of oxalacetate from phosphorylenolpyruvate and carbon dioxide. J Biol Chem. 1955 Nov;217(1):137–150. [PubMed] [Google Scholar]
- MARUYAMA H., LANE M. D. Purification and properties of phosphoenolpyruvate carboxylase from the germinating peanut cotyledon. Biochim Biophys Acta. 1962 Dec 4;65:207–218. doi: 10.1016/0006-3002(62)91040-5. [DOI] [PubMed] [Google Scholar]
- Spalding M. H., Schmitt M. R., Ku S. B., Edwards G. E. Intracellular Localization of Some Key Enzymes of Crassulacean Acid Metabolism in Sedum praealtum. Plant Physiol. 1979 Apr;63(4):738–743. doi: 10.1104/pp.63.4.738. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winter K. Day/Night Changes in the Sensitivity of Phosphoenolpyruvate Carboxylase to Malate during Crassulacean Acid Metabolism. Plant Physiol. 1980 May;65(5):792–796. doi: 10.1104/pp.65.5.792. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winter K., Foster J. G., Edwards G. E., Holtum J. A. Intracellular Localization of Enzymes of Carbon Metabolism in Mesembryanthemum crystallinum Exhibiting C(3) Photosynthetic Characteristics or Performing Crassulacean Acid Metabolism. Plant Physiol. 1982 Feb;69(2):300–307. doi: 10.1104/pp.69.2.300. [DOI] [PMC free article] [PubMed] [Google Scholar]