Interaction of ck-Pt(ino)2C12 with Amino Acids zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA A. Garoufis, R. Haran, M. Pasdeloup, J. P. Laussac, and N. Hadjiliadis AG, NH. Department of Chemistry, University of Ioannina, Greece.-RH, MP, JPL. Laboratoire de Chimie de Coordination du CNRS, Toulouse, France zyxwvutsrqponmlkjihgfedcb ABSTRACT The reactions of ci.s-Pt(ino)2C12 with the amino acids Gly, L-Ala, L-Val, L-Ileu, L-Phe and L-Pro were studied in methanolic solutions. The (1: 1) adducts of the formulas cis-[Pt(ino)z(am-ac)]C1 were isolated from these reactions in the solid state, which in turn produce the cis-[Pt(ino)z(am-acH)C1]C1 complexes, by treating the former with equivalent amounts of HCl, in aqueous solutions. The complexes were characterized with elemental analysis, conductivity measurements, IR, ‘H NMR, and 13C NMR spectra. The results show that the purine ring of inosine interacts with the aliphatic side chain of the amino acids. The platination increases the percentage of the C3 f -endo-anti conformation of the sugar part of inosine. INTRODUCTION Nucleic acids and proteins can recognize each other selectively in biological systems and interact through specific amino acid side-chains and nucleic acid bases [ 11. These specific interactions can in several cases be mediated through a metal ion, helping in the formation of ternary complexes [2, 31. For example, Cu+ z and Zn+’ ions can provoke interactions between polypeptides containing tyrosine and glutamic acid fragments and polynucleotides [4]. The various ligand-ligand interactions may be classified as (i) steric hindrance, (ii) electrostatic interactions and hydrogen bonds, (iii) hydrophobic interactions, and (iv) metal ion mediated electronic interactions [5]. Sigel et al. [l] studied the ternary complexes formed between ATP, the metal ions Mn+2, CU+~, Zn+2, Cd+2, and Pbf2 and various amino acids with increasing aliphatic Address reprint requests to Professor N. Hadjiliadis, University of Ioannina, Department of Chemistry, Laboratory of General and Inorganic Chemistry, Ioannina 45-332, Greece. Journal of Inorganic Biochemistry 31, 65-79 (1987) 65 @ 1987 Elsevier Science Publishing Co., Inc., 52 Vanderbilt Ave., New York, NY 10017 0162-0134/87/$3.50