Abstract
The chloroplastic and cytosolic forms of spinach (Spinacia oleracea cv Long Standing Bloomsdale) leaf NADH:dihydroxyacetone phosphate (DHAP) reductase were separated and partially purified. The chloroplastic form was stimulated by dithiothreitol, reduced thioredoxin, dihydrolipoic acid, 6-phosphogluconate, and phosphate; the cytosolic isozyme was stimulated by fructose 2,6-bisphosphate but not by reduced thioredoxin. End product components that severely inhibited both forms of the reductase included lipids and free fatty acids, membranes, and glycerol phosphate. In addition, two groups of inhibitory peptides were obtained from the fraction precipitated by 70 to 90% saturation with (NH4)2SO4. Chromatography of this fraction on Sephadex G-50 revealed a peptide peak of about 5 kilodaltons which inhibited the chloroplastic DHAP reductase and a second peak containing peptides of about 2 kilodaltons which inhibited the cytosolic form of the enzyme. Regulation of the reduction of dihydroxyacetone phosphate from the C3 photosynthetic carbon cycle or from glycolysis is a complex process involving activators such as thioredoxin or fructose 2,6-bisphosphate, peptide and lipid inhibitors, and intermediary metabolites. It is possible that fructose 2,6-bisphosphate increases lipid production by stimulating DHAP reductase for glycerol phosphate production as well as inhibiting fructose 1,6-bisphosphatase to stimulate glycolysis.
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- Gee R. W., Byerrum R. U., Gerber D. W., Tolbert N. E. Dihydroxyacetone phosphate reductase in plants. Plant Physiol. 1988 Jan;86(1):98–103. doi: 10.1104/pp.86.1.98. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huang A. H. Enzymes of glycerol metabolism in the storage tissues of Fatty seedlings. Plant Physiol. 1975 Mar;55(3):555–558. doi: 10.1104/pp.55.3.555. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McLoughlin D. J., Shahied I. I., MacQuarrie R. The interaction of fatty acids with rabbit liver and muscle glycerol-3-phosphate dehydrogenase. Biochim Biophys Acta. 1978 Nov 10;527(1):193–203. doi: 10.1016/0005-2744(78)90268-1. [DOI] [PubMed] [Google Scholar]
- Santora G. T., Gee R., Tolbert N. E. Isolation of a sn-glycerol 3-phosphate: NAD oxidoreductase from spinach leaves. Arch Biochem Biophys. 1979 Sep;196(2):403–411. doi: 10.1016/0003-9861(79)90291-1. [DOI] [PubMed] [Google Scholar]
- Smyth D. A., Wu M. X., Black C. C. Pyrophosphate and fructose 2,6-bisphosphate effects on glycolysis in pea seed extracts. Plant Physiol. 1984 Oct;76(2):316–320. doi: 10.1104/pp.76.2.316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stitt M. Fructose 2,6-bisphosphate and plant carbohydrate metabolism. Plant Physiol. 1987 Jun;84(2):201–204. doi: 10.1104/pp.84.2.201. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stitt M., Herzog B., Heldt H. W. Control of Photosynthetic Sucrose Synthesis by Fructose 2,6-Bisphosphate : I. Coordination of CO(2) Fixation and Sucrose Synthesis. Plant Physiol. 1984 Jul;75(3):548–553. doi: 10.1104/pp.75.3.548. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stitt M., Herzog B., Heldt H. W. Control of Photosynthetic Sucrose Synthesis by Fructose 2,6-Bisphosphate : V. Modulation of the Spinach Leaf Cytosolic Fructose 1,6-Bisphosphatase Activity in Vitro by Substrate, Products, pH, Magnesium, Fructose 2,6-Bisphosphate, Adenosine Monophosphate, and Dihydroxyacetone Phosphate. Plant Physiol. 1985 Nov;79(3):590–598. doi: 10.1104/pp.79.3.590. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stitt M., Kürzel B., Heldt H. W. Control of Photosynthetic Sucrose Synthesis by Fructose 2,6-Bisphosphate : II. Partitioning between Sucrose and Starch. Plant Physiol. 1984 Jul;75(3):554–560. doi: 10.1104/pp.75.3.554. [DOI] [PMC free article] [PubMed] [Google Scholar]