The polypeptide 3(10)-helix as a template for molecular recognition studies. Structural characterization of a side-chain functionalized octapeptide.
A N alpha-blocked, Aib-rich octapeptide methylamide containing two N omega-benzoylated L-Lys residues at positions 3 and 6 was synthesized by solution methods and fully characterized. A solution and crystal-state conformational analysis, performed by using FT-IR, 1H NMR, CD, and X-ray diffraction techniques, showed that the peptide is folded into a regular, right-handed 3(10)-helix stabilized by seven consecutive N-H...O=C intramolecular H-bonds of the beta-turn III type. The two benzamidobutyl L-Lys side chains, located on the same side of the helix after one complete turn, generate a cleft the minimal width of which was found to be 3.47 A.
Toniolo
C
C
Department of Organic Chemistry, University of Padova, Italy.
Bianco
A
A
Formaggio
F
F
Crisma
M
M
Bonora
G M
GM
Benedetti
E
E
Del Duca
V
V
Saviano
M
M
Di Blasio
B
B
Pedone
C
C
D000595:Amino Acid Sequence; D001665:Binding Sites; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013698:Templates, Genetic; D014961:X-Ray Diffraction
D009842:Oligopeptides