title: Stereochemistry rules: a single stereocenter changes the conformation of a cyclic tetrapeptide.
abstract: Two novel cyclo(Boc-Cys-Pro-Leu-Cys-OMe) peptides 1 and 2 containing the enantiomeric amino acids d-Leu and l-Leu, respectively, were synthesized to investigate the effect of chiral centers on peptide conformations. By combining a variety of experimental techniques (X-ray crystallography, 2D NMR spectroscopy, temperature-dependent (1)H NMR and IR spectroscopy, and UV-CD spectroscopy) with replica exchange molecular dynamics (REMD) techniques and quantum mechanics/molecular dynamics (QM/MM) calculations, we establish that the stereochemistry of just one residue can noticeably influence the properties of the whole peptide and rationalize the origins of this effect, with potential implications for the rational design of peptides of chemical and biological relevance.
authors.affiliation: Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum , D-44801 Bochum, Germany.
authors.forename: Fee
authors.initials: F
authors.lastname: Li
authors.forename: Kenny
authors.initials: K
authors.lastname: Bravo-Rodriguez
authors.forename: Miguel
authors.initials: M
authors.lastname: Fernandez-Oliva
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ramirez-Anguita
authors.forename: Klaus
authors.initials: K
authors.lastname: Merz
authors.forename: Manuela
authors.initials: M
authors.lastname: Winter
authors.forename: Christian W
authors.initials: CW
authors.lastname: Lehmann
authors.forename: Wolfram
authors.initials: W
authors.lastname: Sander
authors.forename: Elsa
authors.initials: E
authors.lastname: Sanchez-Garcia
mesh_terms: D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D010456:Peptides, Cyclic / Q000737:chemistry*; D011487:Protein Conformation; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D010456:Peptides, Cyclic