Insights on the Mechanical Behavior of Keratin Fibrils

A computational molecular model of a truncated keratin protofibril was used to run steered molecular dynamics simulations, producing strain-stress curves that were compared with experimental mechanical data on hair fibers. The simulations, particularly those done in vacuum, aligned well with experimental Young's Modulus (YM) values. The study evaluated the impact of hydrogen bonds and keratin's secondary structure on its mechanical properties. Additionally, incubation with the SPD-2 peptide (QAAFSQ) improved the YM of hair keratin, as shown by both simulations and experimental data. This research provided mechanistic insights into the microscopic mechanical properties of keratin protofibrils.