Disassembly of Amyloid Fibrils by Premicellar and Micellar Aggregates of a Tetrameric Cationic Surfactant in Aqueous Solution

• Published in: Langmuir 2011-04, Vol.27 (8), p.4551-4556
• Main Authors: He, Chengqian, Hou, Yanbo, Han, Yuchun, Wang, Yilin
• Format: Article
• Language: English
• Subjects: Amyloid - chemistry; Cations; Chemistry; Colloidal state and disperse state; Colloids: Surfactants and Self-Assembly, Dispersions, Emulsions, Foams; Dimerization; Exact sciences and technology; General and physical chemistry; Humans; Micelles; Micelles. Thin films; Quaternary Ammonium Compounds; Solutions; Static Electricity; Surface-Active Agents - chemistry; Water
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la200350j

We report a finding that not only the micelles but also the premicellar aggregates of a star-like tetrameric quaternary ammonium surfactant PATC can disassemble and clear mature β-amyloid Aβ(1−40) fibrils in aqueous solution. Different from other surfactants, PATC self-assembles into network-like aggregates below its critical micelle concentration (CMC). The strong self-assembly ability of PATC even below its CMC enables PATC to disaggregate the Aβ(1−40) fibrils far below the charge neutralization point of the Aβ(1−40) with PATC. There may be two key features of the fibril disassembly induced by the surfactant. First, the positively charged surfactant molecules bind with the negatively charged Aβ(1−40) fibrils through electrostatic interaction. Second, the self-assembly of the surfactant molecules bound onto the Aβ(1−40) fibrils disaggregate the fibrils, and the surfactant molecules form mixed aggregates with the Aβ(1−40) molecules. The result reveals a structural approach of constructing efficient disassembly agents to mature β-amyloid fibrils.