NMR studies on binary and ternary Pd(II) complexes formed by the growth-modulating tripeptide glycylhistidyllysine and nucleotides

The mechanism of transport of Pt(II) and Pd(II) into tissues through blood and that of their elimination in kidney is incompletely known so far. In this respect, the binding of palladium by the tripeptide glycyl-L-histidyl-L-lysine (GHL), a constituent of the human plasma, as a binary complex, and by the nucleotides 5'-IMP and 5'-GMP, as ternary complexes, has been studied by 1H and 13C NMR spectroscopy. These studies have been conducted in aqueous media and at different ligand/metal ratios. At acidic pH, resonances were observed for binary and ternary kinetically stable complexes, and binding sites in these complexes were identified by the effect of binding on chemical shifts of protons and carbon resonances. From these data, stoichiometries and structures of these complexes were proposed.