Speciation in Vanadium Bioinorganic Systems. 4. Interactions between Vanadate, Adenosine, and ImidazoleAn Aqueous Potentiometric and 51V NMR Study
| Autor: | Lage Pettersson, Debbie C. Crans, Katarina Elvingson |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Aqueous solution
Chemistry Inorganic chemistry Potentiometric titration Vanadium chemistry.chemical_element Bioinorganic chemistry General Chemistry Nuclear magnetic resonance spectroscopy Biochemistry Glass electrode Catalysis law.invention Colloid and Surface Chemistry Stability constants of complexes law Vanadate |
| Zdroj: | Journal of the American Chemical Society. 119:7005-7012 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja9630497 |
| Popis: | The potential biological activity of vanadium analogs of AMP, ADP, ATP, 2‘,3‘-cAMP, and 3‘,5‘-cAMP stimulated the full speciation study of the vanadate−adenosine(AdH) and vanadate−adenosine−imidazole(ImH) systems in aqueous solution, using a combination of potentiometry (glass electrode) and 51V NMR spectroscopy. The study of the H+−H2VO4-−AdH−ImH system was performed in 0.600 M Na(Cl) medium at 25 oC in the pH range 2−11. In the vanadate−adenosine system V2Ad22- and a new complex, V2Ad2-, with log β = 7.68 ± 0.01 and 11.89 ± 0.08, respectively (pKa = 4.21), explained all experimental observations. Although the V2Ad2--type complex has previously been reported in the vanadate−AMP system, the existence of such a complex in a vanadate−nucleoside system was not previously appreciated. In the vanadate−adenosine−imidazole system a ternary mixed ligand complex, VAdIm-, forms in addition to the V2Ad22- and V2Ad2- species. It exists between pH 5.5 and 11 and has a formation constant log β = 3.04 ± 0.02. This is th... |
| Databáze: | OpenAIRE |
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