This Article Full Text (PDF) A correction has been published 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 (202) Citing Articles via Google Scholar Google Scholar Articles by Uedan, K. Articles by Sugiyama, T. Search for Related Content PubMed PubMed Citation Articles by Uedan, K. Articles by Sugiyama, T. Agricola Articles by Uedan, K. Articles by Sugiyama, T.

Articles

Purification and Characterization of Phosphoenolpyruvate Carboxylase from Maize Leaves ¹

^a Department of Agricultural Chemistry, School of Agriculture, Shizuoka University, Ohya 836, Shizuoka 422, Japan

Phosphoenolpyruvate carboxylase has been purified to homogeneity from maize (Zea mays L. var. Golden Cross Bantam T51) leaves. The ratio of specific activities in crude extracts and the purified enzyme suggests that the enzyme is a major soluble protein in the tissue. The enzyme has a sedimentation coefficient (s_20,w) of 12.3S and a molecular weight, determined by sedimentation equilibrium, of 400,000 daltons. Dissociation of the enzyme and electrophoresis on dodecyl sulfate polyacrylamide gels yields a single stained band which corresponds to a subunit weight of 99,000 daltons. Thus it appears that the native enzyme is composed of four identical or similar polypeptide chains.

The enzyme yields cooperative rate-concentration plots (Hill number of 2) with phosphoenolpyruvate as the variable substrate at pH 7. This cooperativity disappears in the presence of an activator, glucose-6-P, or by raising the pH of the assay mixture to 8. Glycerol (20%, v/v) exerts a similar effect. The enzyme is also activated in the presence of glycine which causes an increase in V_max without significant effect on the apparent Km for phosphoenolpyruvate and Hill number. The apparent Km for HCO₃^– is 0.02 mM, and the activation constant for Mg²⁺ is 1.54 mM at pH 7. There is an abrupt discontinuity in Arrhenius plots and an associated increase in activation energy below 10.8 C.

This article has been cited by other articles:

				Y. Gibon, O. E. Blaesing, J. Hannemann, P. Carillo, M. Hohne, J. H.M. Hendriks, N. Palacios, J. Cross, J. Selbig, and M. Stitt A Robot-Based Platform to Measure Multiple Enzyme Activities in Arabidopsis Using a Set of Cycling Assays: Comparison of Changes of Enzyme Activities and Transcript Levels during Diurnal Cycles and in Prolonged Darkness PLANT CELL, December 1, 2004; 16(12): 3304 - 3325. [Abstract] [Full Text] [PDF]

				A. Makino, H. Sakuma, E. Sudo, and T. Mae Differences between Maize and Rice in N-use Efficiency for Photosynthesis and Protein Allocation Plant Cell Physiol., September 15, 2003; 44(9): 952 - 956. [Abstract] [Full Text] [PDF]

				A. Tovar-Méndez, C. Mújica-Jiménez, and R. A. Muñoz-Clares Physiological Implications of the Kinetics of Maize Leaf Phosphoenolpyruvate Carboxylase Plant Physiology, May 1, 2000; 123(1): 149 - 160. [Abstract] [Full Text]

				K. J. Bailey, A. Battistelli, L. V. Dever, P. J. Lea, and R. C. Leegood Control of C4 photosynthesis: effects of reduced activities of phosphoenolpyruvate carboxylase on CO2 assimilation in Amaranthus edulis L. J. Exp. Bot., February 1, 2000; 51(90001): 339 - 346. [Abstract] [Full Text]

				S.-i. Maeda, G. D. Price, M. R. Badger, C. Enomoto, and T. Omata Bicarbonate Binding Activity of the CmpA Protein of the Cyanobacterium Synechococcus sp. strain PCC 7942 Involved in Active Transport of Bicarbonate J. Biol. Chem., June 30, 2000; 275(27): 20551 - 20555. [Abstract] [Full Text] [PDF]