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

被引：51

作者：

Castelletto, V. ^{[1
]}

Hamley, I. W. ^{[1
]}

Harris, P. J. F. ^{[2
]}

机构：

[1] Univ Reading, Dept Chem, Reading RG6 6AD, Berks, England

[2] Univ Reading, Ctr Adv Microscopy, Reading RG6 6AF, Berks, England

来源：

BIOPHYSICAL CHEMISTRY | 2008年 / 138卷 / 1-2期

关键词：

Amyloid; Peptide; Fibrils; Self-assembly;

D O I：

10.1016/j.bpc.2008.08.007

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

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.

引用

页码：29 / 35

页数：7

共 25 条

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