title: H and 13C nuclear magnetic resonance spectra of some peptides with fibrinogen-like reactivity.
abstract: The 1H and 13C spectra of four peptides, L-Phe-Val-Arg-pNA, D-Phe-Val-Arg-pNA, L-Phe-Pip-Arg-pNA and D-Phe-Pip-Arg-pNA (pNA = p-nitroaniline, Pip = pipecolic acid residue), have been examined, and deductions made about their conformation in solution. The D-Phe peptides, which are cleaved especially rapidly by thrombin in water, have structures (in deuterated DMSO) in which the aromatic ring of the D-Phe residue is folded back over the Val or Pip residue. This arrangement is not found in the L-Phe peptides. It is proposed that this feature (in which Phe could be situated near Val and near the Arg-Gly bond of the A alpha chain in the three-dimensional structure of fibrinogen) may be especially advantageous for binding to the enzyme.
mesh_terms: D000595:Amino Acid Sequence; D002247:Carbon Isotopes; D055598:Chemical Phenomena; D002621:Chemistry; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010455:Peptides; D013329:Structure-Activity Relationship
chemical_list: D002247:Carbon Isotopes; D010455:Peptides; D006859:Hydrogen