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    Thermodynamic Analysis of the Emergence of New Regulatory Properties in a Phosphoribulokinase-Glyceraldehyde 3-Phosphate Dehydrogenase Complex


    Graciet, Emmanuelle and Lebreton, Sandrine and Camadro, Jean-Michel and Gontero, Brigitte (2002) Thermodynamic Analysis of the Emergence of New Regulatory Properties in a Phosphoribulokinase-Glyceraldehyde 3-Phosphate Dehydrogenase Complex. Journal of Biological Chemistry, 277 (15). pp. 12697-12702. ISSN 0021-9258

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    Abstract

    Glyceraldehyde 3-phosphate dehydrogenase and phosphoribulokinase exist as stable enzymes and as part of a complex in Chlamydomonas reinhardtii. We show here that phosphoribulokinase exerts an imprinting on glyceraldehyde 3-phosphate dehydrogenase, which affects its catalysis by decreasing the energy barrier of the reactions with NADH or NADPH by 3.8 +/- 0.5 and 1.3 +/- 0.3 kJ.mol(-1). Phosphoribulokinase and glyceraldehyde 3-phosphate dehydrogenase within the complex are regulated by NADP(H) but not by NAD(H). The activities of the metastable phosphoribulokinase and glyceraldehyde 3-phosphate dehydrogenase released from the complex preincubated with NADP(H) are different from those of the metastable enzymes released from the untreated complex. NADP(H) increases phosphoribulokinase and NADPH-glyceraldehyde 3-phosphate dehydrogenase activities with a (~)K(0.5 (NADP)) of 0.68 +/- 0.16 mm and a (~)K(0.5 (NADPH)) of 2.93 +/- 0.87 mm and decreases NADH-dependent activity. 1 mm NADP increases the energy barrier of the NADH-glyceraldehyde 3-phosphate dehydrogenase-dependent reaction by 1.8 +/- 0.2 kJ.mol(-1) and decreases that of the reactions catalyzed by phosphoribulokinase and NADPH-glyceraldehyde 3-phosphate dehydrogenase by 3 +/- 0.2 and 1.2 +/- 0.3 kJ.mol(-1), respectively. These cofactors have no effect on the independent stable enzymes. Therefore, protein-protein interactions may give rise to new regulatory properties. Emmanuelle Graciet, Sandrine Lebreton, Jean-Michel Camadro, and Brigitte Gontero

    Item Type: Article
    Additional Information: This research was originally published in the Journal of Biological Chemistry. Emmanuelle Graciet, Sandrine Lebreton, Jean-Michel Camadro, and Brigitte Gontero (2002) 'Thermodynamic Analysis of the Emergence of New Regulatory Properties in a Phosphoribulokinase-Glyceraldehyde 3-Phosphate Dehydrogenase Complex', 277: 12689-12702
    Keywords: Thermodynamic Analysis; Regulatory Properties; Phosphoribulokinase-Glyceraldehyde 3-Phosphate Dehydrogenase Complex;
    Academic Unit: Faculty of Science and Engineering > Biology
    Item ID: 7439
    Identification Number: https://doi.org/10.1074/jbc.M111121200
    Depositing User: Emanuelle Graciet
    Date Deposited: 09 Sep 2016 15:13
    Journal or Publication Title: Journal of Biological Chemistry
    Publisher: American Society for Biochemistry and Molecular Biology
    Refereed: Yes
    URI:

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