6533b85ffe1ef96bd12c1d3b
RESEARCH PRODUCT
Conformational investigation of α,β‐dehydropeptides Part VI. Molecular and crystal structure of benzyloxycarbonylglycyl‐(Z )‐dehydrophenylalanine
Małgorzata A. BrodaBarbara TrzeźwinskaAnna E. KoziolZdzisław GałdeckiJanina Karolak-wojciechowskaBarbara Rzeszotarskasubject
conformationdehydropeptidehydrogen bondProtein ConformationChemistryHydrogen bondhelical conformersIntermolecular forceDipeptidesCrystal structuredehydrophenylalanineBiochemistryZ‐Gly‐(Z )‐APheCrystallographyProtein structureX-Ray DiffractionIntramolecular forceSpectroscopy Fourier Transform InfraredX-ray crystallographyMoleculeinfrared spectroscopyX‐ray structure analysisMonoclinic crystal systemdescription
The structure of a peptide containing C-terminal dehydrophenylalanine, Z-Gly-(Z)-delta Phe (C19H18N2O5, MW = 354) was determined from single-crystal X-ray diffraction data. Needle-shaped crystals were grown from a 1:1 mixture of methanol-acetone in the monoclinic space group P2(1) with a = 14.717(4), b = 4.941(2), c = 12.073(4) A, beta = 103.72(4) degrees; V = 852.86(8) A3, Z = 2 and Dc = 1.32 g cm-3. The structure was solved by direct methods using SHELXS-86 and refined to a final R-index of 0.032 for 1714 observed reflections. The peptide adopts a conformation folded at the glycine residue, and principal torsion angles are omega 0 = -167.6(2) degrees, phi 1 = -71.8(3) degrees, psi 1 = -31.6(4) degrees, omega 1 = -165.7(3) degrees, phi 2 = 65.6(4) degrees, psi 1(2) = -174.4(3) degrees and psi 2(2) = 5.2(4) degrees. Two intermolecular hydrogen bonds, N1-H...O0' and O2-H...O1', join the folded molecules into columns and link columns to each other, respectively. FTIR spectroscopy shows the presence of three hydrogen bonds. This third one has been interpreted as an intramolecular hydrogen bond of the N2-H...N1 type.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1994-10-01 | International Journal of Peptide and Protein Research |