Electrostatic Channeling of Oxaloacetate in a Fusion Protein of Porcine Citrate Synthase and Porcine Mitochondrial Malate Dehydrogenase
| Autor: | Sandrine Lebreton, Paul A. Srere, Konstantin Shatalin, Magali Rault-Leonardon, Christian Vélot |
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| Přispěvatelé: | ProdInra, Migration, Unité mixte de recherche Ecologie des invertébrés (UAPV), Institut National de la Recherche Agronomique (INRA)-Avignon Université (AU) |
| Rok vydání: | 1998 |
| Předmět: |
Models
Molecular Oxaloacetic Acid Swine Recombinant Fusion Proteins [SDV]Life Sciences [q-bio] Static Electricity Electrostatic surface potential Mitochondria Liver Citrate (si)-Synthase Biochemistry Malate dehydrogenase Catalysis Cytosol Malate Dehydrogenase Animals Citrate synthase Computer Simulation Mitochondrial enzymes chemistry.chemical_classification biology Osmolar Concentration Fusion protein Yeast [SDV] Life Sciences [q-bio] Citric acid cycle Kinetics Enzyme chemistry biology.protein |
| Zdroj: | Biochemistry Biochemistry, American Chemical Society, 1999, 38, pp.881-889 |
| ISSN: | 1520-4995 0006-2960 |
| Popis: | Mitochondrial malate dehydrogenase and citrate synthase are sequential enzymes in the Krebs tricarboxylic acid cycle. We have shown [Lindbladh, C., Rault, M., Hagglund, C., Small, W. C., Mosbach, K., Bülow, L., Evans, C., and Srere, P.A (1994) Biochemistry 33, 11692-11698] that a fusion protein of yeast mitochondrial citrate synthase and yeast mitochondrial malate dehydrogenase channels oxaloacetate between the active sites. A Brownian dynamics simulation model of porcine mitochondrial enzymes of citrate synthase and malate dehydrogenase was used [Elcock, A. H., and McCammon, A. M. (1996) Biochemistry 35, 12652-12658], showing that a positive electrostatic surface potential between the active sites of the fusion protein could account for the channeling of oxaloacetate we observed with the yeast fusion protein. Since the data were established with a yeast fusion protein and the model was with porcine fusion protein, we have now prepared and studied the porcine fusion protein. The channeling of the oxaloacetate intermediate was the same for the porcine fusion protein as it was for the yeast fusion protein. This channeling behavior is eliminated at high ionic strength. A fusion protein of porcine citrate synthase and porcine cytosolic malate dehydrogenase does not exhibit any channeling of oxaloacetate. A model of the fusion protein with the cytosolic malate dehydrogenase shows no clear positive electrostatic potential surface between the two active sites, thus distinguishing it from the fusion protein with the mitochondrial malate dehydrogenase. These results establish the electrostatic nature of channeling in mitochondrial fusion proteins. |
| Databáze: | OpenAIRE |
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