Critical role of γ-phosphate in structural transition of Na,K-ATPase upon ATP binding
| Autor: | Irina Yu. Petrushanko, Anastasia A. Anashkina, E. A. Dergousova, E. A. Klimanova, Vladimir A. Mitkevich, Alexander A. Makarov, Olga D. Lopina |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Models
Molecular Protein Conformation Sodium-Potassium-Exchanging ATPase Article Phosphates chemistry.chemical_compound Adenosine Triphosphate Adenine nucleotide Computer Simulation Nucleotide Binding site Na+/K+-ATPase chemistry.chemical_classification Binding Sites Multidisciplinary Adenine Temperature Isothermal titration calorimetry Enzyme Activation Models Chemical Biochemistry chemistry Biophysics ADP binding Adenosine triphosphate Protein Binding |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | Active transport of sodium and potassium ions by Na,K-ATPase is accompanied by the enzyme conformational transition between E1 and E2 states. ATP and ADP bind to Na,K-ATPase in the E1 conformation with similar affinity but the properties of enzyme in complexes with these nucleotides are different. We have studied thermodynamics of Na,K-ATPase binding with adenine nucleotides at different temperatures using isothermal titration calorimetry. Our data indicate that β-phosphate is involved in complex formation by increasing the affinity of adenine nucleotides to Na,K-ATPase by an order of magnitude, while γ-phosphate does not affect it. ATP binding to Na,K-ATPase in contrast to ADP binding generates a structural transition in the enzyme, which is consistent with the movement of a significant portion of the surface area to a solvent-protected state. We propose that ATP binding leads to convergence of the nucleotide-binding and phosphorylation domains transferring the enzyme from the "E1-open" to "E1-closed" conformation ready for phosphorylation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|