title: Experimental and theoretical NMR studies of interaction between phenylalanine derivative and egg yolk lecithin.
abstract: The interaction of phenylalanine diamide (Ac-Phe-NHMe) with egg yolk lecithin (EYL) in chloroform was studied by (1)H and (13)C NMR. Six complexes EYL-Ac-Phe-NHMe, stabilized by N-H···O or/and C-H···O hydrogen bonds, were optimized at M06-2X/6-31G(d,p) level. The assignment of EYL and Ac-Phe-NHMe NMR signals was supported using GIAO (gauge including atomic orbital) NMR calculations at VSXC and B3LYP level of theory combined with STO-3Gmag basis set. Results of our study indicate that the interaction of peptides with lecithin occurs mainly in the polar 'head' of the lecithin. Additionally, the most probable lecithin site of H-bond interaction with Ac-Phe-NHMe is the negatively charged oxygen in phosphate group that acts as proton acceptor.
authors.affiliation: Faculty of Chemistry, University of Opole, Oleska 48 Str., 45-052, Opole, Poland.
authors.forename: Roksana
authors.initials: R
authors.lastname: Wałęsa
authors.forename: Tomasz
authors.initials: T
authors.lastname: Ptak
authors.forename: Dawid
authors.initials: D
authors.lastname: Siodłak
authors.forename: Teobald
authors.initials: T
authors.lastname: Kupka
authors.forename: Małgorzata A
authors.initials: MA
authors.lastname: Broda
mesh_terms: D000818:Animals; D001665:Binding Sites; D002645:Chickens; D003198:Computer Simulation; D004530:Egg Yolk / Q000737:chemistry*; D054709:Lecithins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010649:Phenylalanine / Q000032:analysis / Q000737:chemistry*
chemical_list: D054709:Lecithins; D010649:Phenylalanine
keywords: DFT; NMR; hydrogen bond; intermolecular interactions; lecithin; peptide