Beta-turn formation by a six-residue linear peptide in solution.
A model peptide AAGDYY-NH2 (B1), which is found to adopt a beta-turn conformation in the TEM-1 beta-lactamase inhibitor protein (BLIP) in the TEM-1/BLIP co-crystal, was synthesized to elucidate the mechanism of its beta-turn formation and stability. Its structural preferences in solution were comprehensively characterized using CD, FT-IR and 1H NMR spectroscopy, respectively. The set of observed diagnostic NOEs, the restrained molecular dynamics simulation, CD and FT-IR spectroscopy confirmed the formation of a beta-turn in solution by the model peptide. The dihedral angles [(phi3, phi3) (phi4, phi4)] of [(-52 degrees, -32 degrees ) (-38 degrees, -44 degrees )] of Gly-Asp fragment in the model peptide are consistent with those of a type III beta-turn. In a conclusion, the conformational preference of the linear hexapeptide B1 in solution was determined, and it would provide a simple template to study the mechanism of beta-turn formation and stability.
Gao
F
F
Institute of Physical Chemistry, Peking University, Beijing, China.
Wang
Y
Y
Qiu
Y
Y
Li
Y
Y
Sha
Y
Y
Lai
L
L
Wu
H
H
D002942:Circular Dichroism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases
D009842:Oligopeptides; D012996:Solutions; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1