Complex formation between uranium(VI) and adenosine triphosph

Adenosine triphosphate is an important enzymatic compound, which is able to transfer the phosphate and diphosphate group between molecules. Heavy metal ions bound to the adenosine phosphates can be transported into living cells and than deposited.
In addition to studies of the soil-to-plant transfer factors /1/ and the interaction of the uranyl ion with microorganisms /2/ we studied the complex formation of the uranyl ion with adenosine triphosphate (ATP).
We found that adenosine phosphates are very strong quenchers of the fluorescence of the uranyl ion and also of the formed complexes. In the uranyl - adenosine monophosphate (AMP) system UV-vis measurements were carried out in the wavelength range from 180 nm to about 300 nm using a CARY5G spectrometer (VARIAN, Canberra). The adenosine monophosphate shows a strong absorption in this range and no fluorescence could be observed at all.
In the uranyl - adenosine triphosphate system fluorescence emission was observed only in a small range of the adenosine concentration. The deconvoluted fluorescence spectra show different emission maxima compared both to the uranyl ion and to phosphate complexes. This leads to the conclusion that a complex between uranyl and adenosine triphosphate is formed.