Jh. Miwa et al., Compatibility of the thioamide functional group with beta-sheet secondary structure: Incorporation of a thioamide linkage into a beta-hairpin peptide, ORG LETT, 3(21), 2001, pp. 3373-3375
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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 b
eta -hairpin conformation. Two-dimensional NMR spectroscopy and circular di
chroism spectroscopy indicate that the thioxo peptide adopts a hairpin conf
ormation similar to that of the oxo peptide and that the hairpin conformati
on persists at elevated temperatures. The results show that a thioamide lin
kage is compatible with beta -sheet secondary structure.