Aβ-40 Y10F Increases βfibrils Formation but Attenuates the Neurotoxicity of Amyloid-β Peptide

International Journal of Molecular Sciences

Xueling Dai³  Ping Chang¹  Wenjuan Liu¹  Ke Xu²  Yaxuan Sun¹  Shigong Zhu³ 

[1] Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing 100191, China; E-Mails:;College of Life Science, Capital Normal University, Beijing 100048, China; E-Mail:;Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing 100191, China; E-Mail:

关键词: Alzheimer’s disease;    amyloid-β peptide;    βfibrils;    neurotoxicity;   

DOI  :  10.3390/ijms13055324

来源: mdpi

【 摘 要 】

Alzheimer’s disease (AD) is characterized by the abnormal aggregation of amyloid-β peptide (Aβ) in extracellular deposits known as senile plaques. The tyrosine residue (Tyr-10) is believed to be important in Aβ-induced neurotoxicity due to the formation of tyrosyl radicals. To reduce the likelihood of cross-linking, here we designed an Aβ-40 analogue (Aβ-40 Y10F) in which the tyrosine residue was substituted by a structurally similar residue, phenylalanine. The aggregation rate was determined by the Thioflavin T (ThT) assay, in which Aβ-40 Y10F populated an ensemble of folded conformations much quicker and stronger than the wild type Aβ. Biophysical tests subsequently confirmed the results of the ThT assay, suggesting the measured increase of β-aggregation may arise predominantly from enhancement of hydrophobicity upon substitution and thus the propensity of intrinsic β-sheet formation. Nevertheless, Aβ-40 Y10F exhibited remarkably decreased neurotoxicity compared to Aβ-40 which could be partly due to the reduced generation of hydrogen peroxide. These findings may lead to further understanding of the structural perturbation of Aβ to its fibrillation.

【 授权许可】

CC BY   
© 2012 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.