Identification of a Novel Parallel β-Strand Conformation within Molecular Monolayer of Amyloid Peptide.
The differentiation of protein properties and biological functions arises from the variation in the primary and secondary structure. Specifically, in abnormal assemblies of protein, such as amyloid peptide, the secondary structure is closely correlated with the stable ensemble and the cytotoxicity. In this work, the early Aβ33-42aggregates forming the molecular monolayer at hydrophobic interface are investigated. The molecular monolayer of amyloid peptide Aβ33-42consisting of novel parallel β-strand-like structure is further revealed by means of a quantitative nanomechanical spectroscopy technique with force controlled in pico-Newton range, combining with molecular dynamic simulation. The identified parallel β-strand-like structure of molecular monolayer is distinct from the antiparallel β-strand structure of Aβ33-42amyloid fibril. This finding enriches the molecular structures of amyloid peptide aggregation, which could be closely related to the pathogenesis of amyloid disease.
Institute for Advanced Materials Jiangsu University Zhenjiang 212013 P. R. China; Interdisciplinary Nanoscience Center (iNANO) Aarhus University Aarhus CDK-8000 Denmark.
Lei
L
Liu
Interdisciplinary Nanoscience Center (iNANO) Aarhus University Aarhus C DK-8000 Denmark.
Qiang
Q
Li
Interdisciplinary Nanoscience Center (iNANO) Aarhus University Aarhus C DK-8000 Denmark.
Shuai
S
Zhang
Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 P. R. China.
Xiaofeng
X
Wang
Department of Physics and Astronomy Aarhus University Aarhus C DK 8000 Denmark.
Søren Vrønning
SV
Hoffmann
Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 P. R. China.
Jingyuan
J
Li
Center for Programmable Materials School of Materials Science and Engineering Nanyang Technological University Singapore Singapore 639798 Singapore.
Zheng
Z
Liu
Interdisciplinary Nanoscience Center (iNANO) Aarhus University Aarhus C DK-8000 Denmark.
Flemming
F
Besenbacher
Interdisciplinary Nanoscience Center (iNANO) Aarhus University Aarhus C DK-8000 Denmark.
Mingdong
M
Dong
amyloid peptide aggregation; atomic force microscopy; secondary structure of amyloid peptide