Factors controlling the Pb(II) promoted dephosphorylation of nucleotides.

The conditions under which Pb(II) promotes dephosphorylation of nucleotides have been studied with the Pb(II) complexes of several isomers of AMP, dAMP, GMP, and dGMP. A number of factors which together control the dephosphorylation reaction have been identified. These include the tendency of Pb(II)-induced nucleotide base stacking, as evidenced by large enhancement in ultraviolet circular dichroism, to occur in the complexes and limit the reaction; hydroxylation of the metal, either with weakening of the lead-nucleotide binding, or eventually with displacement of the nucleotide; and the solubility of the complexes, which limits the reaction, but is increased by raising the temperature and by hydroxylation of the complexes. The pH range in which both base stacking and metal hydrolysis are minimized can define a "reaction window" for the complexes.