title: Characteristic Raman optical activity signatures of protein β-sheets.
abstract: In this study, we compute and analyze theoretical Raman optical activity spectra of large model β-sheets in order to identify reliable signatures for this important secondary structure element. We first review signatures that have already been proposed to be indicative of β-sheets. From these signatures, we find that only the couplet in the amide I region can be regarded as a truly reliable signature. In addition, we propose a strong negative peak at ∼1350 cm(-1) to be another good signature for parallel as well as antiparallel β-sheets. We study the robustness of these signatures with respect to perturbations induced by the amino acid side chains, the overall conformation of the sheet structure, and microsolvation. It is found that the latter effects can be very well understood and separated employing the concept of localized modes. Finally, we investigate whether Raman optical activity is capable of discriminating between parallel and antiparallel β-sheets. The amide III region turns out to be most promising for this purpose.
authors.affiliation: Laboratorium für Physikalische Chemie, ETH Zurich , Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Weymuth
authors.forename: Markus
authors.initials: M
authors.lastname: Reiher
mesh_terms: D000577:Amides / Q000737:chemistry; D009904:Optical Rotation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D013059:Spectrum Analysis, Raman
chemical_list: D000577:Amides; D011506:Proteins