title: Insights on the mechanical behavior of keratin fibrils.
abstract: A computational molecular model of a truncated keratin protofibril (8 chains of hair keratin, PDB provided in Supplementary material) was used, to run a series of steered molecular dynamics simulations obtaining strain-stress curves. These results were compared with experimental mechanical data on hair fibers. Our data demonstrate that the molecular dynamics simulations can model hair mechanical properties. Simulations done in vacuum showed a better agreement with experimental Young's Modulus (YM) values. The role of hydrogen bonds and the secondary structure of keratin on the mechanical properties was evaluated in detail. The incubation with a fragment of one surfactant protein, the SPD-2 peptide (QAAFSQ), showed the improvement of YM of the hair keratin either by simulations and experimental data. For the first, our research provides mechanistic insights on mechanical microscopic properties of keratin protofibrils through molecular dynamics simulations.
authors.affiliation: CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: Egipto
authors.initials: E
authors.lastname: Antunes
authors.affiliation: CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: Célia F
authors.initials: CF
authors.lastname: Cruz
authors.affiliation: CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors.forename: Nuno G
authors.initials: NG
authors.lastname: Azoia
authors.affiliation: CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal. Electronic address: artur@deb.uminho.pt.
authors.forename: Artur
authors.initials: A
authors.lastname: Cavaco-Paulo
mesh_terms: D006197:Hair / Q000737:chemistry* / Q000648:ultrastructure; D006860:Hydrogen Bonding; D007633:Keratins / Q000737:chemistry* / Q000648:ultrastructure; D056004:Molecular Dynamics Simulation; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D007633:Keratins
keywords: Hair; Keratin; Molecular dynamics; Pulling; Young’s Modulus