Copper(II) Complexes of Tyrosine-Containing Di- and Tripeptides

Abstract
Tyrosine is a constituent of many neuropeptides, and it may be assumed that it plays a fundamental role in the activity of these compounds. Recent studies on tyrosine-containing oligopeptides has established that the direct participation of the side-chain phenolate groups in metal ion binding depended considerably on the position of the tyrosine in the peptide molecule.1-5 In this note the stability constants and the binding modes of the proton and copper(II) complexes of S-tyrosyl-S-tyrosine (TyrTyr) and S-tyrosyl-S-tyrosyl-S-tyrosine (TyrTyrTyr) are presented.