Quantitative aspects of intramolecular interactions involving cobalt(II), copper(II), zinc(II), nucleotides and dipeptides

1157-1163Interaction of bivalent metal ions (Co2+, Cu2+, Zn2+) with purine nucleotides (5'-guanosine monophosphate and 5'inosine monophosphate)and dipeptides (DL-alanyl-alanine and DL-alanyl-phenylalanine) in binary and ternary mode has been investigated in stoichiometric ratios by pH measurements. The formation constants of various systems have been determined by a computer program. The stabilization in ternary complexes is expressed in terms of Δlog K1.The stacking interactions associated with nucleotidcs and dipeptides have been identified with parameters2 like ΔΔlog K, K1 % of (MLA)st and ΔG0x. The pH profiles of various species have been constructed in order to identify the stable species, in particular at biological pH. The thermodynamic parameters associated with the above systems have also been evaluated for a comprehensive understanding of these reactions in solution