Aravinda, S and Shamala, N and Pramanik, Animesh and Das, Chittaranjan and Balaram, P (2000) An Unusual C–H . . . O Hydrogen Bond Mediated Reversal of Polypeptide Chain Direction in a Synthetic Peptide Helix. In: Biochemical and Biophysical Research Communications, 273 (3). pp. 933-936.
Restricted to Registered users only
Download (65Kb) | Request a copy
An unusual C-terminal conformation has been detected in a synthetic decapeptide designed to analyze the stereochemistry of helix termination in polypeptides. The crystal structure of the decapeptide Boc-Leu-Aib-Val-Ala-Leu-Aib-Val-DAla-DLeu-Aib-OMe reveals a helical segment spanning residues 1–7 and helix termination by formation of a Schellman motif, generated by DAla(8) adopting the left-handed helical (aL) conformation. The extended conformation at DLeu(9) results in a compact folded structure, stabilized by a potentially strong C-H . . . O hydrogen bond between Ala(4) CaH and DLeu(9) CO. The parameters for C-H . . . O interaction are Ala(4) CaH. . O=C DLeu(9) distance 3.27 Å, Ca-H . . O angle 176°, and O . . Ha distance 2.29 Å. This structure suggests that insertion of contiguous D-residues may provide a handle for the generation of designed structures containing more than one helical segment folded in a compact manner.
|Item Type:||Journal Article|
|Additional Information:||Copyright for this article belongs to Academic Press|
|Keywords:||C-H . . . O hydrogen bond;Conformational analysis;Helix termination;Peptide design;Schellman motif;X-ray structure|
|Department/Centre:||Division of Biological Sciences > Molecular Biophysics Unit
Division of Physical & Mathematical Sciences > Physics
|Date Deposited:||26 Aug 2004|
|Last Modified:||19 Sep 2010 04:14|
Actions (login required)