title: Synthesis and interaction with metal ions of cyclic oligopeptides bearing carboxyl groups.
abstract: Cyclic di- and tetrapeptides bearing carboxyl or carboxylate groups, cyclo[Glu(OBzl)-Glu(OMe)], cyclo[Glu-Glu(OMe)], cyclo(Glu-Glu), cyclo[Glu(OMe)-Pro)2, and cyclo(Glu-Pro)2, were synthesized and investigated on the intramolecular interaction of carboxyl side chains in the complexation with metal ions in relation with the conformation. The three kinds of cyclic dipeptides were found to take a flagpole boat conformation. Folded conformation of side chains was predominant for cyclo[Glu(OBzl)-Glu(OMe)] and cyclo[Glu-Glu(OMe)]. However, cyclo(Glu-Glu) took an unfolded conformation. Intramolecular interaction of carboxyl groups was observed neither in free state nor in complexation with metal ions. The intramolecular interaction of carboxyl groups was observed in the case of cyclo(Glu-Pro)2 in the absence of metal ions added. Cyclo[Glu(OMe)-Pro]2 and cyclo(Glu-Pro)2 formed a complex with Ca2+ and Ba2+ without participation of side chains.
authors: Department of Polymer Chemistry, Kyoto University, Japan.
authors: Y
authors: Y
authors: Fusaoka
authors: E
authors: E
authors: Ozeki
authors: S
authors: S
authors: Kimura
authors: Y
authors: Y
authors: Imanishi
mesh_terms: D004151:Dipeptides / Q000138:chemical synthesis; D009682:Magnetic Resonance Spectroscopy; D008674:Metals, Rare Earth; D009842:Oligopeptides / Q000138:chemical synthesis*; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D004151:Dipeptides; D008674:Metals, Rare Earth; D009842:Oligopeptides; D010456:Peptides, Cyclic