This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (124) Citing Articles via Google Scholar Google Scholar Articles by Ting, I. P. Articles by Osmond, C. B. Search for Related Content PubMed PubMed Citation Articles by Ting, I. P. Articles by Osmond, C. B. Agricola Articles by Ting, I. P. Articles by Osmond, C. B.

Articles

Multiple Forms of Plant Phosphoenolpyruvate Carboxylase Associated with Different Metabolic Pathways ¹

^a Department of Biology, University of California, Riverside, California 92502, ^b Department of Environmental Biology, Research School of Biological Sciences, A.N.U., Canberra, 2601, Australia

The physical and kinetic properties of multiple forms of phosphoenolpyruvate carboxylase were studied in leaves of C₄ and C₃ species, their F₁ and F₃ hybrids, in greening maize leaves, in Crassulacean acid metabolism plants, and in nongreen root tissues. Four different forms are suggested: a C₄ photosynthetic phosphoenolpyruvate carboxylase with high Km for phosphoenolpyruvate (0.59 mM), Km Mg (0.5 mM), and V_max (29 micromoles per minute per milligram of chlorophyll); a C₃ photosynthetic phosphoenolpyruvate carboxylase with low Km for phosphoenolpyruvate (0.14 mM), Km for Mg (0.097 mM), and V_max (1.5); a Crassulacean acid metabolism type with low Km for phosphoenolpyruvate (0.14 mM), and high V_max (14 micromoles per minute per milligram of chlorophyll); and a nongreen or nonautotrophic type with low Km for phosphoenolpyruvate, Km for Mg, and low V_max. In closely related species or within species, the types can be differentiated by anion exchange column chromatography. Each of the four forms is associated with a different metabolic pathway: the phosphoenolpyruvate carboxylase of C₄ species for malate generation as a photosynthetic intermediate, the phosphoenolpyruvate carboxylase of C₃ species in malate generation as a photosynthetic product, the phosphoenolpyruvate carboxylase of Crassulacean acid metabolism species in malate generation as a CO₂ donor for photosynthesis during the subsequent light period, and a nongreen or root type producing malate for ionic balance and reduced nicotinamide adenine dinucleotide phosphate generation. The data in this paper in conjunction with published information support the notion of different molecular forms of a protein functioning in different metabolic pathways which have common enzymic steps.

This article has been cited by other articles:

				T. J. G. Ettema, K. S. Makarova, G. L. Jellema, H. J. Gierman, E. V. Koonin, M. A. Huynen, W. M. de Vos, and J. van der Oost Identification and Functional Verification of Archaeal-Type Phosphoenolpyruvate Carboxylase, a Missing Link in Archaeal Central Carbohydrate Metabolism J. Bacteriol., November 15, 2004; 186(22): 7754 - 7762. [Abstract] [Full Text] [PDF]

				P. WESTHOFF and U. GOWIK Evolution of C4 Phosphoenolpyruvate Carboxylase. Genes and Proteins: a Case Study with the Genus Flaveria Ann. Bot., January 1, 2004; 93(1): 13 - 23. [Abstract] [Full Text] [PDF]