Pd(gly- l-his- l-lys)Cl: Solution structure and ternary complex formation with mono- and tetranucleotides

Abstract

The tripeptide complex Pd(gly- l-his- l-lys)Cl (Pd(GHK)Cl. 1) has been studied by a variety of NMR techniques ( 1H, 1H E.COSY, 1H NOESY, 1H, 13C HMQC), by ESI-MS, as well as simulated annealing and molecular dynamics methods. Reactions of 1 with isolated 5′-deoxynucleotides of guanine, cytidine, adenine and thymine, alone and in competition, have been carried out in water and followed by 1H NMR spectroscopy. They reveal preferential binding of Pd(GHK) + to guanine N7 in weakly to moderately acidic solution and slow rotation of the Pd tripeptide entity about the metal-N7 bond below 276 K. The self-complementary tetranucleotide 5′-d(GTAC) reacts with 1 in D 2O, pD 3.5, at guanine N7.