How protein materials balance strength, robustness and adaptability

Sinan Keten, Markus J. Buehler

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We report a theoretical fracture mechanics framework for describing underlying physical mechanism of H-bond rupture events that control the strength of beta-sheet protein structures found in materials such as silk, muscle and amyloid fibers. Using large-scale atomistic simulation and theory, we show that rupture of H-bonds assemblies is governed by geometric confinement effects, suggesting that clusters of at most 3-4 H-bonds break concurrently, even under uniform shear loading of a large number of H-bonds. This universal result leads to an intrinsic size-dependent strength limit that suggests that shorter beta-strands with less H-bonds achieve the highest shear strength, which is comparable to theoretical values obtained for metals. The asymptotical near-equilibrium strength limit predicted by our theory agrees very well with single-biomolecule experiments on beta-proteins. Our results also explain recent experimental proteomics data, suggesting a correlation between strength and the prevalence of beta-strand lengths in biology.

Original languageEnglish (US)
Title of host publicationSociety for Experimental Mechanics - 11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
Pages800-806
Number of pages7
StatePublished - Dec 22 2008
Event11th International Congress and Exhibition on Experimental and Applied Mechanics 2008 - Orlando, FL, United States
Duration: Jun 2 2008Jun 5 2008

Publication series

NameSociety for Experimental Mechanics - 11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
Volume2

Other

Other11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
CountryUnited States
CityOrlando, FL
Period6/2/086/5/08

Keywords

  • Beta-sheet
  • H-bonds
  • Mechanics
  • Protein
  • Shear strength
  • Size-effect

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials

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