Influence of Au nanoparticles on the aggregation of amyloid-β-(25-35) peptides.
The influence of Au nanoparticles (Au NPs) on the aggregation of amyloid-β-(25-35) peptides (Aβ25-35) is investigated by atomic force microscopy and Thioflavin T fluorescence measurements. It is found that, without Au NPs, the Aβ25-35 peptides aggregate gradually from monomers and oligomers to long fibrils with the incubation time. In contrast, short protofibrils are formed quickly after Au NPs are added to the Aβ25-35 solution, which can be further aggregated to form short fibril bundles or even bundle conjunctions. To reveal the origin of Au NPs on the aggregation of Aβ25-35, electrostatic force microscopy and scanning Kelvin microscopy are employed to investigate the electrical properties of the Aβ25-35 fibrils with and without Au NPs. Due to the significant difference of the electrical properties between the Aβ25-35 fibrils and Au NPs, the locations of Au NPs inside the Aβ25-35 fibril bundles can be revealed and hence a possible influence mechanism of Au NPs on the aggregation of Aβ25-35 is suggested.
State Key Laboratory of Surface Physics and Physics Department, Fudan University, Shanghai 200433, P. R. China. xjyang@fudan.edu.cn.
Qianqian
Q
Ma
Guanghong
G
Wei
Xinju
X
Yang
D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000378:metabolism; D052160:Benzothiazoles; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D055672:Static Electricity; D013844:Thiazoles / Q000737:chemistry
D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D010446:Peptide Fragments; D013844:Thiazoles; C074636:amyloid beta-protein (25-35); C009462:thioflavin T; D006046:Gold