title: Oriented epitaxial growth of amyloid fibrils of the N27C mutant beta 25-35 peptide.
abstract: Amyloid fibrils are present in the extracellular space of various tissues in neurodegenerative and protein misfolding diseases. Amyloid fibrils may be used in nanotechnology applications, because of their self-assembly properties and stability, if their growth and orientation can be controlled. Recently, we have shown that amyloid beta 25-35 (A beta 25-35) forms a highly oriented, K(+)-dependent network on mica. Here, we analyzed the properties of A beta 25-35_N27C, the cysteine residue of which may be used for subsequent chemical modifications. We find that A beta 25-35_N27C forms epitaxially growing fibrils on mica, which evolve into a trigonally oriented branched network. The binding is apparently more sensitive to cation concentration than that of the wild-type peptide. By nanomanipulating A beta 25-35_N27C fibrils with a gold-coated AFM tip, we show that the sulfhydryl of Cys27 is reactive and accessible from the solution. The oriented network of A beta 25-35_N27C fibrils can therefore be specifically labeled and may be used for constructing nanobiotechnological devices.
authors.affiliation: Department of Biophysics, Faculty of Medicine, University of Pécs, Szigeti u. 12, H-7624, Pécs, Hungary.
authors.forename: Arpád
authors.initials: A
authors.lastname: Karsai
authors.forename: Unige
authors.initials: U
authors.lastname: Murvai
authors.forename: Katalin
authors.initials: K
authors.lastname: Soós
authors.forename: Botond
authors.initials: B
authors.lastname: Penke
authors.forename: Miklós S Z
authors.initials: MS
authors.lastname: Kellermayer
mesh_terms: D000538:Aluminum Silicates; D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001696:Biomechanical Phenomena; D002412:Cations / Q000494:pharmacology; D003545:Cysteine; D018625:Microscopy, Atomic Force; D009154:Mutation; D036103:Nanotechnology; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; D000682:Amyloid; D016229:Amyloid beta-Peptides; D002412:Cations; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35); D003545:Cysteine; C011934:mica