title: Conformation characterization of cyclopentapeptide, L.Val-L.Pro-Gly-L.Val-Gly: a repeating analogue of elastin.
abstract: The cyclopentapeptide, L.Val1-L.Pro2-Gly3-L.Val4-Gly5, was synthesized and its conformational characterization was carried out using n.m.r. and theoretical energy calculations. The n.m.r. studies indicated the existence of a cis Val1-Pro2 peptide bond in water and a very strong intramolecular H-bond between the val1 NH and Gly3 C=O groups. This H-bond forms a beta-turn (type II) placing Val4 and Gly5 residues within the turn. Two minimum energy conformations were derived, one of which agrees very well with the solution conformation.
mesh_terms: D000595:Amino Acid Sequence; D004549:Elastin / Q000031:analogs & derivatives*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D010456:Peptides, Cyclic / Q000138:chemical synthesis; D011487:Protein Conformation
chemical_list: D010456:Peptides, Cyclic; C030028:cyclo(valyl-prolyl-glycyl-valyl-prolyl); D004549:Elastin