title: Structures of ATP(adenosine triphosphate)-vanadyl complexes.
abstract: The state of existence of cytoplasmic vanadium ion is known to be important: vanadyl ion forms complexes with ATP and vanadate form inhibits (Na++K+)-ATPase. Therefore, the formation of complexes between ATP and vanadyl ion was investigated. Formations of three types of complex were observed: a blue 1:1 complex formed in acidic pH region; a blue 1:1 complex formed in neutral pH region; a green 2:1 complex formed in alkaline pH region. On the basis of the results on potentiometric titration, optical and EPR spectra and 31P- and 13C-NMR spectra, three characteristic types of coordination environment are proposed.
mesh_terms: D000255:Adenosine Triphosphate; D055598:Chemical Phenomena; D002621:Chemistry; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D011199:Potentiometry; D013329:Structure-Activity Relationship; D014638:Vanadates; D014639:Vanadium
chemical_list: D014639:Vanadium; D014638:Vanadates; D000255:Adenosine Triphosphate