title: Design of peptides with alpha,beta-dehydro residues: a dipeptide with a branched beta-carbon dehydro residue at the (i+1) position, methyl N-(benzyloxycarbonyl)-alpha,beta-didehydrovalyl-L-tryptophanate.
abstract: The structure of the title peptide, C(25)H(27)N(3)O(5), has been determined and its conformation analysed. Values of the standard peptide torsion angles are phi(1) = -44.2 (3) degrees, psi(1) = 135.9 (2) degrees, phi(2) = -141.6 (2) degrees and psi(2)(T) = 168.0 (2) degrees. The crystal structure is stabilized by an intermolecular hydrogen bond, with an N...O distance of 2.919 (3) A, which is formed between screw-axis-related NH and CO groups of dehydrovaline residues.
authors.affiliation: Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029, India.
authors.forename: R
authors.initials: R
authors.lastname: Vijayaraghavan
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: S
authors.initials: S
authors.lastname: Dey
authors.forename: T P
authors.initials: TP
authors.lastname: Singh
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011487:Protein Conformation; D014364:Tryptophan / Q000031:analogs & derivatives / Q000737:chemistry*
chemical_list: C441508:methyl N-(benzyloxycarbonyl)-didehydrovalyl-tryptophanate; D014364:Tryptophan