Conformational perturbations in retro-analogs of the tBuCO-Ala-Gly-NHiPr dipeptide. Crystal structure of the retro-dipeptide with a reversed Ala-Gly amide bond.
The three retro-analogs of the tBuCO-Ala-Gly-NHiPr dipeptide, in which each amide bond had been successively reversed, were studied in solution by 1H-n.m.r. and i.r. spectroscopy with reference to the conformational properties of their parent dipeptide. Reversal of the Ala-Gly amide bond proved to perturb the folding tendency of the backbone less than the inversion of either of the terminal amide bonds. The crystal structure of the retro-peptide containing a reversed Ala-Gly amide bond was also solved by X-ray diffraction and constitutes the first available data for this retro-peptide series. In contrast to the beta II-folded structure of the parent dipeptide, the retro-peptide molecule adopts an open conformation in the crystal.
Gomez
E J
EJ
UA-CNRS-494, ENSIC-INPL, Nancy, France.
Vitoux
B
B
Marraud
M
M
Sakarellos
C
C
el Masdouri
L
L
Aubry
A
A
D004151:Dipeptides; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010456:Peptides, Cyclic; D011487:Protein Conformation; D012996:Solutions; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
D004151:Dipeptides; D010456:Peptides, Cyclic; D012996:Solutions; C063947:tert-butoxycarbonyl-alanyl-glycyl-isopropylamide