Determination of orientations of aromatic groups in self-assembled peptide fibrils by polarised Raman spectroscopy

Rodrıguez-Perez, J. C., Hamley, I. W. ORCID: https://orcid.org/0000-0002-4549-0926 and Squires, A. M. (2013) Determination of orientations of aromatic groups in self-assembled peptide fibrils by polarised Raman spectroscopy. Physical Chemistry Chemical Physics, 33 (15). pp. 13940-13950. ISSN 1463-9076 doi: 10.1039/c3cp52595c

Abstract/Summary

In this paper we describe a novel combination of Raman spectroscopy, isotope editing and X-ray scattering as a powerful approach to give detailed structural information on aromatic side chains in peptide fibrils. The orientation of the tyrosine residues in fibrils of the peptide YTIAALLSPYS with respect to the fibril axis has been determined from a combination of polarised Raman spectroscopy and X-ray diffraction measurements. The Raman intensity of selected tyrosine bands collected at different polarisation geometries is related to the values and orientation of the Raman tensor for those specific vibrations. Using published Raman tensor values we solved the relevant expressions for both of the two tyrosine residues present in this peptide. Ring deuteration in one of the two tyrosine side chains allowed for the calculation to be performed individually for both, by virtue of the isotopic shift that eliminates band overlapping. Sample disorder was taken into account by obtaining the distribution of orientations of the samples from X-ray diffraction experiments. The results provide previously unavailable details about the molecular conformation of this peptide, and demonstrate the value of this approach for the study of amyloid fibrils.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/34123
Identification Number/DOI	10.1039/c3cp52595c
Refereed	Yes
Divisions	Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Publisher	Royal Society of Chemistry
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