Copper(II) Complexes of Opiate-like Food Peptides.
The alpha-casein peptide fragment (90-96) Arg-Tyr-Leu-Gly-Tyr-Leu-Glu, one of the exorphins called "food hormones", is an efficient ligand for Cu(II) ions. Potentiometric and spectroscopic studies on aqueous solutions indicate that, depending on the pH range, complex species with different coordination modes (involving the amino and the deprotonated amide groups) are formed. The phenolate side chain of the Tyr residue is not involved in the metal coordination.
Lodyga-Chruscinska
E
Institute of General Food Chemistry, Technical University of Lodz, Stefanowski Street 4/10, 90-924 Lodz, Poland; Dipartimento di Chimica, Università di Sassari, Via Vienna 2, 07100 Sassari, Italy; and Institute of Radiation Chemistry, Technical University of Lodz, Wroblewskiego Street 15, 90-924 Lodz, Poland.
Micera
G
Szajdzinska-Piêtek
E
Sanna
D