Kinetic and Interaction Studies of Adenosine-5′-Triphosphate (ATP) Hydrolysis with Polyoxovanadates

The reactivity of polyoxovanadates towards adenosine-5 & PRIME;-triphosphate (ATP) hydrolysis at pH 2, 4, 6 and 7 is reported. Detailed kinetic investigation of ATP hydrolysis in the presence of polyoxovanadates was performed through multinuclear nuclear magnetic resonance (NMR) spectroscopy. In general, rate acceleration of up to five orders of magnitude was observed in the presence of vanadates compared to spontaneous ATP hydrolysis, with the greatest acceleration observed for reactions carried out at pH 2. Interestingly, the effectiveness of vanadates in promoting ATP hydrolysis decreased as the pH of the reaction solution increased; nevertheless, at pH = 7, the rate increase of one order of magnitude in comparison to blank reactions was still observed. Interactions between vanadate species in solution and ATP were investigated by means of P-31 and V-51 NMR spectroscopy, and this pointed towards the preferential interaction of vanadium with the phosphate groups rather than other regions of the ATP molecule.

Automated summary

The reactivity of polyoxovanadates towards ATP hydrolysis was studied at different pH levels, showing significant acceleration in lower pH conditions. However, the effectiveness decreased as the pH of the reaction solution increased, with still observable rate increase at pH=7 compared to blank reactions. Interactions between vanadate species and ATP mainly occurred with phosphate groups rather than other regions of the ATP molecule, as revealed by NMR spectroscopy.