Potentiometric and spectroscopic data including CD and EPR results as well as theoretical calculations have shown that the insertion of the tetrazole ring [-psi (CN4)-] in the tetraalanine sequence leads to a very effective peptide chelating agent towards Cu(II) ions. The [-psi (CN4)-] moiety induces a specific peptide conformation which favours the formation of one or two stable chelating rings stabilising a bent structure, with the coordination of 1N-type in Cut or 3N-type in both CuH-1L and CuH-2L species. It is worth noting that the Cu(II)-N-tetr bond does not undergo the hydrolysis process even at high pH although the N-tetr donor is weakly basic. (C) 2001 Elsevier Science Ltd. All rights reserved.
A new class of peptide chelating agents towards copper(II) ions / Lodyga-Chruscinska E; Micera G; Sanna D; Olczak J; Zabrocki J. - In: POLYHEDRON. - ISSN 0277-5387. - 20:15-16(2001), pp. 1915-1923. [10.1016/S0277-5387(01)00779-3]