Peptide-surfactant interactions: Consequences for the amyloid-beta structure

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• 作者：Sandra Rocha^a ; ^{sandra.rocha@fe.up.pt} ; Joana A. Loureiro^a ; Gerald Brezesinski^b ; Maria do Carmo Pereira^a
• 关键词：Conformation ; Amyloid-beta peptide ; Surfactants ; Micelles ; Sulfate monolayers ; Electrostatic interactions ; Hydrophobic effect
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2012
• 期刊代码：159_0006291x
• 类别：bio
• 出版时间：30 March, 2012
• 卷：420
• 期：1
• 页码：136-140
• 文件大小：622 K

摘要

The conformation of amyloid-beta peptide (A尾) determines if toxic aggregates are formed. The peptide structure by its turn depends on the environment and molecule-molecule interactions. We characterized the secondary structure of A尾-(1-40) in surfactant solutions and interacting with monolayers. The peptide adopts 尾-sheet structure in solutions of ionic surfactants at sub-micelle concentrations and 伪-helix in the presence of ionic micelles. Uncharged micelles induce 尾-sheets. A尾-(1-40) alters the critical micelle concentration value of the non-ionic surfactant, underlining hydrophobic interactions. At ionic monolayers the peptide forms 尾-sheets when its concentration at the surface is high enough. These results suggest that only electrostatic interactions of charged micelles that surround completely the peptide are able to induce non-aggregated 伪-helix structure.