title: The structure of the "amorphous" matrix of keratins.
abstract: Various keratin fibers, particularly human hairs, were investigated by transmission electron microscopy, TEM, solid-state1H NMR and Transient Electro-Thermal Technique, TET. The results converge to suggest that the matrix of keratin fiber cortex, far from being amorphous, has a well-defined nano-scale grainy structure, the size of these grains being around 2-4nm. The size of the grains appears to strongly depend on the chemical treatment of the fiber, on the temperature and on the relative humidity of the environment, as well as on the physiological factors at the level of fiber production in follicle. By suggesting an organization at the nano-scale of the protein chains in these grains, likely to be Keratin Associated Proteins, the results challenge the view of matrix as a homogeneous glassy material. Moreover, they indicate the potential of further investigating the purpose of this structure that appears to reflect not only chemical treatments of keratins but also biological processes at the level of the follicle.
authors.affiliation: Lubrizol Advanced Materials, Inc., 9911 Brecksville Road, Brecksville, OH 44141, USA. Electronic address: murat.kadir@lubrizol.com.
authors.forename: Murat
authors.initials: M
authors.lastname: Kadir
authors.affiliation: Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, IA 50011, USA. Electronic address: xwang3@iastate.edu.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, IA 50011, USA.
authors.forename: Bowen
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, IA 50011, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: AgResearch Limited, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand. Electronic address: duane.harland@agresearch.co.nz.
authors.forename: Duane
authors.initials: D
authors.lastname: Harland
authors.affiliation: KAO Germany GmbH, Pfungstädterstr. 98-100, D-64297 Darmstadt, Germany. Electronic address: crisan.popescu@kao.com.
authors.forename: Crisan
authors.initials: C
authors.lastname: Popescu
mesh_terms: D000818:Animals; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000648:ultrastructure; D006197:Hair / Q000737:chemistry; D006801:Humans; D007633:Keratins / Q000737:chemistry / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D019906:Nuclear Magnetic Resonance, Biomolecular; D055503:Protein Multimerization
chemical_list: D003598:Cytoskeletal Proteins; D007633:Keratins
keywords: Keratin; Matrix; Phonon; Spin-diffusion; Transmission electron microscopy