An unusual C-H center dot center dot center dot O hydrogen bond mediated reversal of polypeptide chain direction in a synthetic peptide helix


Autoria(s): Aravinda, S; Shamala, N; Pramanik, Animesh; Das, Chittaranjan; Balaram, P
Data(s)

14/07/2000

Resumo

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-(D)Ala-(D)Leu-Aib-OMe reveals a helical segment spanning residues 1-7 and helix termination by formation of a Schellman motif, generated by (D)Ala(8) adopting the left-handed helical (alpha(L)) conformation. The extended conformation at (D)Leu(9) results in a compact folded structure, stabilized by a potentially strong C-H ... O hydrogen bond between Ala(4) (CH)-H-alpha and (D)Leu(9)CO. The parameters for C-H ... O interaction are Ala(4) (CH)-H-alpha .. O=C (D)Leu(9) distance 3.27 Angstrom C-alpha-H .. O angle 176 degrees, and O .. H-alpha distance 2.29 Angstrom. 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. (C) 2000 Academic Press.

Formato

application/pdf

Identificador

http://eprints.iisc.ernet.in/31433/1/bond.pdf

Aravinda, S and Shamala, N and Pramanik, Animesh and Das, Chittaranjan and Balaram, P (2000) An unusual C-H center dot center dot center dot 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.

Publicador

Elsevier Science

Relação

http://dx.doi.org/10.1006/bbrc.2000.3026

http://eprints.iisc.ernet.in/31433/

Palavras-Chave #Molecular Biophysics Unit #Physics
Tipo

Journal Article

PeerReviewed