PD(GLY-L-HIS-L-LYS)CL - SOLUTION STRUCTURE AND TERNARY COMPLEX-FORMATION WITH MONO-AND TETRANUCLEOTIDES

The tripeptide complex Pd(gly-L-his-L-lys)Cl (Pd(GHK)Cl, 1) has been s tudied by a variety of NMR techniques (H-1, H-1 E.COSY, H-1 NOESY, H-1 ,C-13 HMQC), by ESI-MS, as well as simulated annealing and molecular d ynamics methods. Reactions of 1 with isolated 5'-deoxynucleotides of g uanine, cytidine, adenine and thymine, alone and in competition, have been carried out in water and followed by H-1 NMR spectroscopy. They r eveal preferential binding of Pd(GHK)(+) to guanine N7 in weakly to mo derately acidic solution and slow rotation of the Pd tripeptide entity about the metal-N7 bond below 276 K. The self-complementary tetranucl eotide 5'-d(GTAC) reacts with 1 in D2O, pD 3.5, at guanine N7. (C) 199 8 Elsevier Science S.A. All rights reserved.