title: Characterization of the nanoscale properties of individual amyloid fibrils.
abstract: We report the detailed mechanical characterization of individual amyloid fibrils by atomic force microscopy and spectroscopy. These self-assembling materials, formed here from the protein insulin, were shown to have a strength of 0.6 +/- 0.4 GPa, comparable to that of steel (0.6-1.8 GPa), and a mechanical stiffness, as measured by Young's modulus, of 3.3 +/- 0.4 GPa, comparable to that of silk (1-10 GPa). The values of these parameters reveal that the fibrils possess properties that make these structures highly attractive for future technological applications. In addition, analysis of the solution-state growth kinetics indicated a breakage rate constant of 1.7 +/- 1.3 x 10(-8) s(-1), which reveals that a fibril 10 mum in length breaks spontaneously on average every 47 min, suggesting that internal fracturing is likely to be of fundamental importance in the proliferation of amyloid fibrils and therefore for understanding the progression of their associated pathogenic disorders.
authors.affiliation: Nanoscience Centre, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0FF, United Kingdom.
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Smith
authors.forename: Tuomas P J
authors.initials: TP
authors.lastname: Knowles
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Dobson
authors.forename: Cait E
authors.initials: CE
authors.lastname: Macphee
authors.forename: Mark E
authors.initials: ME
authors.lastname: Welland
mesh_terms: D000682:Amyloid / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure*; D000818:Animals; D002417:Cattle; D007328:Insulin / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding
chemical_list: D000682:Amyloid; D007328:Insulin