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Updated: May 18, 2026

Synthesis of Keratin-based Nanofiber for Biomedical Engineering
Published on: February 7, 2016
Structure and mechanical properties of human trichocyte keratin intermediate filament protein
Chia-Ching Chou1, Markus J Buehler
1Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 1-235A,B, Cambridge, MA 02139, USA.
Abstract:
Keratin is a protein in the intermediate filament family and the key component of hair, nail, and skin. Here we report a bottom-up atomistic model of the keratin dimer, using the complete human keratin type k35 and k85 amino acid sequence. A detailed analysis of geometric and mechanical properties through full-atomistic simulation with validation against experimental results is presented. We introduce disulfide cross-links in a keratin tetramer and compare the mechanical behavior of the disulfide bonded systems with a system without disulfide bonds. Disulfide bond results in a higher strength (20% increase) and toughness (49% increase), but the system loses α-helical structures under loading, suggesting that disulfide bonds play a significant role in achieving the characteristic mechanical properties of trichocyte α-keratin. Our study provides general insight into the effect of disulfide cross-link on mechanical properties. Moreover, the availability of an atomistic model of this protein opens the possibility to study the mechanical properties of hair fibrils and other fibers from a bottom-up perspective.
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