Self-assembly in aqueous solution of a modified amyloid beta peptide fragment

Castelletto, V., Hamley, I.W. ORCID: https://orcid.org/0000-0002-4549-0926 and Harris, P.J.F. (2008) Self-assembly in aqueous solution of a modified amyloid beta peptide fragment. Biophysical Chemistry, 138 (1-2). pp. 29-35. ISSN 0301-4622 doi: 10.1016/j.bpc.2008.08.007

Abstract/Summary

The self-assembly in films dried from aqueous solutions of a modified amyloid beta peptide fragment is studied. We focus on sequence A beta(16-20), KLVFF, extended by two alanines at the N-terminus to give AAKLVFF. Self-assembly into twisted ribbon fibrils is observed, as confirmed by transmission electron microscopy (TEM). Dynamic light scattering reveals the semi-flexible nature of the AAKLVFF fibrils, while polarized optical microscopy shows that the peptide fibrils crystallize after an aqueous solution of AAKLVFF is matured over 5 days. The secondary structure of the fibrils is studied by FT-IR, circular dichroism and X-ray diffraction (XRD), which provide evidence for beta-sheet structure in the fibril. From high resolution TEM it is concluded that the average width of an AAKLVFF fibril is (63 +/- 18) nm, indicating that these fibrils comprise beta-sheets with multiple repeats of the unit cell, determined by XRD to have b and c dimensions 1.9 and 4.4 nm with an a axis 0.96 nm, corresponding to twice the peptide backbone spacing in the antiparallel beta-sheet. (C) 2008 Elsevier B.V. All rights reserved.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/11097
Item Type	Article
Refereed	Yes
Divisions	Life Sciences Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry Interdisciplinary centres and themes > Chemical Analysis Facility (CAF)
Uncontrolled Keywords	Amyloid, Peptide, Fibrils, Self-assembly , DYNAMIC SCATTERING, SPECTROSCOPY, POLYPEPTIDES, POLYMERS, FIBRILS, SOLVENT
Publisher	Elsevier
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