Compatibility of the thioamide functional group with beta-sheet secondary structure: incorporation of a thioamide linkage into a beta-hairpin peptide.
[structure: see text]. We report the incorporation of a thioamide linkage between the i + 2 and i + 3 residues of the type II' beta-turn of a peptide known to fold into a beta-hairpin conformation. Two-dimensional NMR spectroscopy and circular dichroism spectroscopy indicate that the thioxo peptide adopts a hairpin conformation similar to that of the oxo peptide and that the hairpin conformation persists at elevated temperatures. The results show that a thioamide linkage is compatible with beta-sheet secondary structure.
Miwa
J H
JH
Department of Chemistry, Wellesley College, Wellesley, Massachusetts 02481, USA. jmiwa@wellesley.edu
Patel
A K
AK
Vivatrat
N
N
Popek
S M
SM
Meyer
A M
AM
D002942:Circular Dichroism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D011489:Protein Denaturation / Q000187:drug effects; D017433:Protein Structure, Secondary / Q000187:drug effects; D013696:Temperature; D013854:Thioamides / Q000737:chemistry* / Q000494:pharmacology
D010455:Peptides; D013854:Thioamides