Do interstrand hydrogen bonds contribute to β-hairpin peptide stability in solution? IR analysis of peptide folding in water
Abstract
The amide I carbonyl stretch in the IR spectrum, together with
1H NMR Hα chemical shifts, have been used to investigate
the folding of a 16-residue β-hairpin peptide in water: while Hα
shifts are consistent with a significant population of the folded state
(ca. 40%), we see no features in the IR spectrum in the amide I
region to suggest a significant contribution from interstrand hydrogen
bonds, although at high peptide concentration (10 mM) the appearance
of a new band at 1616 cm−1 is consistent with the onset of
irreversible peptide aggregation.