Amyloid fibrils are important components of tissue deposits in neurodegenerative and protein misfolding diseases. Because modified amyloid peptide subunits can be generated by synthetic methods and the nanometer-scale fibrils are stable under diverse conditions, amyloid fibrils have been suggested for use in nanotechnology applications. However, well-controlled and oriented growth of amyloid fibrils has not yet been accomplished. Here we show that amyloid β 25-35 (Aβ 25-35), a toxic fragment of Alzheimer's beta peptide, forms trigonally oriented fibrils on mica. Oriented binding depends on an apparently cooperative interaction of a positively charged moiety on the Aβ 25-35 peptide with the K+-binding pocket of the mica lattice. Time-lapse in situ AFM revealed that the formation of oriented fibrils is the result of epitaxial polymerization rather than binding of already assembled fibrils from solution. By varying the K+ concentration the growth rate and the mesh size of the oriented amyloid fibril network may be tuned. The K+-controlled oriented assembly of Aβ 25-35 fibrils could be utilized in nanotechnology applications such as formation of oriented tracks for molecular devices and generation of nanoelectronic circuits.
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering