Infrared evidence of a β‐hairpin peptide structure in solution

Open Access
Publisher Website
Google Scholar
Abstract
The IR spectrum of an 16‐amino acid peptide corresponding, according to NMR studies, to a β‐hairpin has been analysed. Two characteristic features distinguish its spectrum from that of an antiparallel β‐sheet: the low‐frequency band that in a β‐sheet structure is located at 2 ∼ 1632 cm−1 appears here at 2∼ 1620 cm−1, and the high‐frequency component does not undergo the isotopic shift typical of β‐sheet from 1690 to 1675 cm−1 when transferred to D2O. The infrared characteristics associated with β‐hairpins have been described so far in two proteins, in one of which, whose three‐dimensional structure is known from X‐ray diffraction, a β‐hairpin has actually been detected.