Effects of Polyamino Acids and Polyelectrolytes on Amyloid 尾 Fibril Formation
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- 作者：Anna Assarsson ; Sara Linse ; Celia Cabaleiro-Lago
- 刊名：Langmuir
- 出版年：2014
- 出版时间：July 29, 2014
- 年：2014
- 卷：30
- 期：29
- 页码：8812-8818
- 全文大小：453K
- ISSN：1520-5827
文摘
The fibril formation of the neurodegenerative peptide amyloid 尾 (A尾42) is sensitive to solution conditions, and several proteins and peptides have been found to retard the process. A尾42 fibril formation was followed with ThT fluorescence in the presence of polyamino acids (poly-glutamic acid, poly-lysine, and poly-threonine) and other polymers (poly(acrylic acid), poly(ethylenimine), and poly(diallyldimethylammonium chloride). An accelerating effect on the A尾42 aggregation process is observed from all positively charged polymers, while no effect is seen from the negative or neutral polymers. The accelerating effect is dependent on the concentration of positive polymer in a highly reproducible manner. Acceleration is observed from a 1:500 polymer to A尾42 weight ratio and up. Polyamino acids and the other polymers exert quantitatively the same effect at the same concentrations based on weight. Fibrils are formed in all cases as verified by transmission electron microscopy. The concentrations of polymers required for acceleration are too low to affect the A尾42 aggregation process through increased ionic strength or molecular crowding effects. Instead, the acceleration seems to arise from the locally increased A尾42 concentration near the polymers, which favors association and affects the electrostatic environment of the peptide.