Abstract
Chloroplastic respiration was monitored by measuring 14CO2 from 14C glucose in the darkened Chlamydomonas reinhardtii F-60 chloroplast. The patterns of 14CO2 evolution from labeled glucose in the absence and presence of the inhibitors iodoacetamide, glycolate-2-phosphate, and phosphoenolpyruvate were those expected from the oxidative pentose phosphate cycle and glycolysis. The Km for glucose was 56 micromolar and for MgATP was 200 micromolar. Release of 14CO2 was inhibited by phloretin and inorganic phosphate. Comparing the inhibition of CO2 evolution generated by pH 7.5 with respect to pH 8.2 (optimum) in chloroplasts given C-1, C-2, and C-6 labeled glucose indicated that a suboptimum pH affects the recycling of the pentose phosphate intermediates to a greater extent than CO2 evolution from C-1 of glucose. Respiratory inhibition by pH 7.5 in the darkened chloroplast was alleviated by NH4Cl and KCl (stromal alkalating agents), iodoacetamide (an inhibitor of glyceraldehyde 3-phosphate dehydrogenase), or phosphoenolpyruvate (an inhibitor of phosphofructokinase). It is concluded that the site which primarily mediates respiration in the darkened Chlamydomonas chloroplast is the fructose-1,6-bisphosphatase/phosphofructokinase junction. The respiratory pathways described here can account for the total oxidation of a hexose to CO2 and for interactions between carbohydrate metabolism and the oxyhydrogen reaction in algal cells adapted to a hydrogen metabolism.
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Selected References
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- Ahluwalia K. J., Willeford K. O., Gibbs M. Aerobic and anaerobic respiration in the intact spinach chloroplast. Plant Physiol. 1989 Jun;90(2):653–656. doi: 10.1104/pp.90.2.653. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Anderson L. E. Chloroplast and cytoplasmic enzymes. II. Pea leaf triose phosphate isomerases. Biochim Biophys Acta. 1971 Apr 14;235(1):237–244. doi: 10.1016/0005-2744(71)90051-9. [DOI] [PubMed] [Google Scholar]
- Anderson L. E., Ng T. C., Park K. E. Inactivation of pea leaf chloroplastic and cytoplasmic glucose 6-phosphate dehydrogenases by light and dithiothreitol. Plant Physiol. 1974 Jun;53(6):835–839. doi: 10.1104/pp.53.6.835. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Arnon D. I. COPPER ENZYMES IN ISOLATED CHLOROPLASTS. POLYPHENOLOXIDASE IN BETA VULGARIS. Plant Physiol. 1949 Jan;24(1):1–15. doi: 10.1104/pp.24.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belknap W. R. Partial Purification of Intact Chloroplasts from Chlamydomonas reinhardtii. Plant Physiol. 1983 Aug;72(4):1130–1132. doi: 10.1104/pp.72.4.1130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berkowitz G. A., Gibbs M. Effect of osmotic stress on photosynthesis studied with the isolated spinach chloroplast : generation and use of reducing power. Plant Physiol. 1982 Oct;70(4):1143–1148. doi: 10.1104/pp.70.4.1143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Erbes D. L., Gibbs M. Kinetics of the Oxyhydrogen Reaction in the Presence and Absence of Carbon Dioxide in Scenedesmus obliquus. Plant Physiol. 1981 Jan;67(1):129–132. doi: 10.1104/pp.67.1.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GIBBS M., HORECKER B. L. The mechanism of pentose phosphate conversion to hexose monophosphate. II. With pea leaf and pea root preparations. J Biol Chem. 1954 Jun;208(2):813–820. [PubMed] [Google Scholar]
- Gfeller R. P., Gibbs M. Fermentative Metabolism of Chlamydomonas reinhardtii: I. Analysis of Fermentative Products from Starch in Dark and Light. Plant Physiol. 1984 May;75(1):212–218. doi: 10.1104/pp.75.1.212. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HORWITZ L. Observations on the oxyhydrogen reaction in Scenedesmus and its relation to respiration and photosynthesis. Arch Biochem Biophys. 1957 Jan;66(1):23–44. doi: 10.1016/0003-9861(57)90534-9. [DOI] [PubMed] [Google Scholar]
- Kelly G. J., Latzko E. Chloroplast Phosphofructokinase: II. Partial Purification, Kinetic and Regulatory Properties. Plant Physiol. 1977 Aug;60(2):295–299. doi: 10.1104/pp.60.2.295. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klein U., Chen C., Gibbs M. Photosynthetic Properties of Chloroplasts from Chlamydomonas reinhardii. Plant Physiol. 1983 Jun;72(2):488–491. doi: 10.1104/pp.72.2.488. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klein U., Chen C., Gibbs M., Platt-Aloia K. A. Cellular Fractionation of Chlamydomonas reinhardii with Emphasis on the Isolation of the Chloroplast. Plant Physiol. 1983 Jun;72(2):481–487. doi: 10.1104/pp.72.2.481. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maury W. J., Huber S. C., Moreland D. E. Effects of Magnesium on Intact Chloroplasts : II. CATION SPECIFICITY AND INVOLVEMENT OF THE ENVELOPE ATPase IN (SODIUM) POTASSIUM/PROTON EXCHANGE ACROSS THE ENVELOPE. Plant Physiol. 1981 Dec;68(6):1257–1263. doi: 10.1104/pp.68.6.1257. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moll B., Levine R. P. Characterization of a Photosynthetic Mutant Strain of Chlamydomonas reinhardi Deficient in Phosphoribulokinase Activity. Plant Physiol. 1970 Oct;46(4):576–580. doi: 10.1104/pp.46.4.576. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Russell G. K., Gibbs M. Evidence for the participation of the reductive pentose phosphate cycle in photoreduction and the oxyhydrogen reaction. Plant Physiol. 1968 Apr;43(4):649–652. doi: 10.1104/pp.43.4.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schäfer G., Heber U. Glucose transport into spinach chloroplasts. Plant Physiol. 1977 Aug;60(2):286–289. doi: 10.1104/pp.60.2.286. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steup M., Peavey D. G., Gibbs M. The regulation of starch metabolism by inorganic phosphate. Biochem Biophys Res Commun. 1976 Oct 18;72(4):1554–1561. doi: 10.1016/s0006-291x(76)80191-x. [DOI] [PubMed] [Google Scholar]
- Stitt M., Rees T. A. Carbohydrate breakdown by chloroplasts of Pisum sativum. Biochim Biophys Acta. 1980 Jan 17;627(2):131–143. doi: 10.1016/0304-4165(80)90315-3. [DOI] [PubMed] [Google Scholar]
- Turner J. F., Copeland L. Hexokinase II of Pea Seeds. Plant Physiol. 1981 Nov;68(5):1123–1127. doi: 10.1104/pp.68.5.1123. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Werdan K., Heldt H. W., Milovancev M. The role of pH in the regulation of carbon fixation in the chloroplast stroma. Studies on CO2 fixation in the light and dark. Biochim Biophys Acta. 1975 Aug 11;396(2):276–292. doi: 10.1016/0005-2728(75)90041-9. [DOI] [PubMed] [Google Scholar]
- Willeford K. O., Gibbs M. Localization of the Enzymes Involved in the Photoevolution of H(2) from Acetate in Chlamydomonas reinhardtii. Plant Physiol. 1989 Jul;90(3):788–791. doi: 10.1104/pp.90.3.788. [DOI] [PMC free article] [PubMed] [Google Scholar]
