Abstract
Using small-angle neutron scattering (SANS), we have studied the suppression of fibril formation of β-amyloid peptide (A β ), a 1-40 amino acid peptide fragment derived from proteolytic cleavage of a large amyloid precursor protein, by an ionic surfactant, SDS. In comparison with the pure peptide in aqueous solutions which forms long and thin fibrils, A β forms smaller complex with SDS, which hinders partially the growth of long fibrils. With a selected deuteration of SDS for a contrast variation in SANS, we have extracted the structural information of the SDS/peptide complex, including a short rod-like shape, size, and an association ratio between SDS and the peptide. © 2006 Elsevier B.V. All rights reserved.