alpha-Aminoisobutyric acid modified protected analogues of beta-amyloid residue 17-20: a change from sheet to helix

Haldar, D., Drew, M.G.B. and Banerjee, A. (2006) alpha-Aminoisobutyric acid modified protected analogues of beta-amyloid residue 17-20: a change from sheet to helix. Tetrahedron, 62 (26). pp. 6370-6378. ISSN 0040-4020 doi: 10.1016/j.tet.2006.04.036

Abstract/Summary

The strong intermolecular interactions mediated by short hydrophobic sequences (e.g., 17-20, -L-Leu-L-Val-L-Phe-L-Phe-) in the middle of A beta are known to play a crucial role in the neuropathology of Alzheimer's disease. FTIR, TEM and Congo red binding studies indicated that a series of L-Ala substituted terminally protected peptides related to the sequence 17-20 of the beta-amyloid peptide, adopted D-sheet conformations. However, the Aib-modified analogues disrupt the D-sheet structure and switch over to a 310 helix with increasing number of Aib residues. X-ray crystallography shed some light on the change from sheet to helix at atomic resolution. (c) 2006 Elsevier Ltd. All rights reserved.