title: Tensile deformation and failure of amyloid and amyloid-like protein fibrils.
abstract: Here we report a series of full atomistic molecular dynamics simulations of six amyloid or amyloid-like protein fibrils in order to systematically understand the effect of different secondary structure motifs on the mechanical tensile and failure response of cross-β protein fibrils. We find a similar failure behavior across the six structures; an initial failure event occurs at small strains involving cooperative rupture of a group of hydrogen bonds, followed by a slow one-by-one hydrogen bond rupture process as the remaining β-sheets peel off with very low applied stress. We also find that the ultimate tensile strength of the protein fibrils investigated scales directly with the number of hydrogen bonds per unit area which break in the initial rupture event. Our results provide insights into structure-property relationships in protein fibrils important for disease and engineering applications and lay the groundwork for the development of materials selection criteria for the design of de novo amyloid-based functional biomaterials.
authors: Laboratory for Atomistic and Molecular Mechanics (LAMM), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA. Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA.
authors: Max
authors: M
authors: Solar
authors: Markus J
authors: MJ
authors: Buehler
mesh_terms: D000682:Amyloid / Q000737:chemistry*; D001696:Biomechanical Phenomena; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013718:Tensile Strength
chemical_list: D000682:Amyloid