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Murthy NS, Wang W, Kamath Y. Structure of intermediate filament assembly in hair deduced from hydration studies using small-angle neutron scattering. J Struct Biol 2019; 206:295-304. [PMID: 30951823 DOI: 10.1016/j.jsb.2019.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/30/2019] [Accepted: 04/01/2019] [Indexed: 11/27/2022]
Abstract
Intermediate filaments (IFs) are ubiquitous in biological structures including hair. Small-angle neutron scattering (SANS) data from hydrated samples were used in this study to investigate the distribution of water in hair, and model the structure of the IF assembly. A main diffraction peak at a d-spacing of ∼90 Å, and two weaker reflections show that IFs are arranged in a ∼105 Å quasi-hexagonal lattice. Changes in the diffraction peaks show that only a small fraction of the water absorbed by hair enters between the IFs, and little water diffuses into the core of the IFs. The amount of water in the IF assembly increases rapidly up to 10% relative humidity (RH), and then slowly with further increase in RH. Most of the water appears to reside outside the IF assembly, in the voids and at the interfaces, and contribute to the central diffuse scattering. The IF assembly in the decuticled hair absorbs more water and is more ordered than that the native hair. This suggests that cuticle acts as a barrier, and might constrain the structure by compressing the cortex radially. Treatments with oils that are hydrophobic, heat treatment, and reduction of the S-S linkages that opens up the matrix by disulfide bond cleavage, all affect structure and water permeability. Coconut oil was found to impede hydration more than the soybean oil because of its ability to penetrate deeper into hair. A new model for the IF assembly that is sterically more favorable than the previous models is proposed.
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Affiliation(s)
- N Sanjeeva Murthy
- New Jersey Center for Biomaterials, Rutgers University, Piscataway, NJ 08854, USA.
| | - Wenjie Wang
- Ames Laboratory, Iowa State University, Ames, IA 50011, USA
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Bryson WG, Harland DP, Caldwell JP, Vernon JA, Walls RJ, Woods JL, Nagase S, Itou T, Koike K. Electron microscopy and tomography reveal that sodium 2-naphthalene sulfonate incorporated into perming solutions swells and tilts trichocyte intermediate filaments causing straightening of curly Japanese human hair. Int J Cosmet Sci 2019; 41:132-146. [PMID: 30719733 DOI: 10.1111/ics.12517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/30/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVE A new hair-care process has been specifically developed for the straightening of curved Japanese woman's hair . The process included sodium 2-naphthalene sulfonate (SNS) in the reduction and oxidation steps of a conventional perming process. Our objective was to develop an understanding of how this process caused hair straightening by measuring the changes to morphology and ultrastructure between untreated, conventionally permed and SNS permed hair. Untreated and SNS permed Merino wool fibres were used to confirm structural changes. METHODS Japanese hair samples were measured for single-fibre curvature before and after perming treatments. A silver staining method was developed to stain hair fibres without changing fibre curvature so that transmission electron microscopy could be used to measure changes in the lateral dimensions of all structural components from the cellular to protein filament level. Electron tomography determined intermediate filament slopes and slope changes after SNS perming relative to the central longitudinal axis of the fibre. RESULTS SNS perming was found to cause greater lateral swelling than conventional perming of: the paracortical cells of wool; the cuticle, the cuticular cell membrane complex and the macrofibrillar centre-to-centre distance of hair; and of the intermediate filaments in wool and hair. In curved hair, SNS perming caused the intermediate filaments of the helical macrofibrils to simultaneously swell and to tilt further, resulting in the slight longitudinal contraction of the macrofibrils. The overall swelling and tilting was greatest in the helical macrofibrils of Type B cortical cells predominately located in the convex fibre half. The presence of a higher percentage of helical macrofibrils in the convex fibre half than in the concave fibre half caused a contraction differential between the two halves leading to straighten of the curved fibre. A mechanical model was proposed to explain how SNS perming straightened curly hair. CONCLUSION The effects of conventional and SNS perming on the morphological and ultrastructural components of curved Japanese hair and high-curl Merino wool fibres have given clear insights into understanding the mechanism of fibre curvature change.
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Affiliation(s)
- W G Bryson
- Formerly of Canesis Network Limited, Lincoln, Canterbury, New Zealand
| | - D P Harland
- Formerly of Canesis Network Limited, Lincoln, Canterbury, New Zealand
| | - J P Caldwell
- Formerly of Canesis Network Limited, Lincoln, Canterbury, New Zealand
| | - J A Vernon
- Formerly of Canesis Network Limited, Lincoln, Canterbury, New Zealand
| | - R J Walls
- Formerly of Canesis Network Limited, Lincoln, Canterbury, New Zealand
| | - J L Woods
- Formerly of Canesis Network Limited, Lincoln, Canterbury, New Zealand
| | - S Nagase
- Hair Care Products Research Laboratories, Kao Corporation, 2-1-3, Bunka, Sumida, Tokyo, 131-8501, Japan
| | - T Itou
- Hair Care Products Research Laboratories, Kao Corporation, 2-1-3, Bunka, Sumida, Tokyo, 131-8501, Japan
| | - K Koike
- Hair Care Products Research Laboratories, Kao Corporation, 2-1-3, Bunka, Sumida, Tokyo, 131-8501, Japan
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Fraser RDB, Parry DAD. Structural Hierarchy of Trichocyte Keratin Intermediate Filaments. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1054:57-70. [PMID: 29797268 DOI: 10.1007/978-981-10-8195-8_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although trichocyte keratins (hair, wool, quill, claw) have been studied since the 1930s it is only over the last 30 years or so that major advances have been made in our understanding of the complex structural hierarchy of the filamentous component of this important filament-matrix composite. A variety of techniques, including amino acid sequence analysis, computer modelling, X-ray fibre diffraction and protein crystallography, various forms of electron microscopy, and crosslinking methods have now combined to reveal much of the structural detail. The heterodimeric structure of the keratin molecule is clear, as are the highly-specific modes by which these molecules aggregate to form functionally viable IF. The observation that hair keratin can adopt not one but two structurally-distinct conformations, one formed in the living cells at the base of the hair follicle in a reducing environment and the second in the fully differentiated hair in dead cells in an oxidized state, was unexpected but has major implications for the mechanism of hair growth. Insights have also been made into the mechanism of the uppermost level of hair superstructure, relating to the assembly of the IF in the paracortical and orthocortical macrofibrils.
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Affiliation(s)
- R D Bruce Fraser
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.,, Tewantin, QLD, Australia
| | - David A D Parry
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand. .,Riddet Institute, Massey University, Palmerston North, New Zealand.
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Fraser RB, Parry DA. Intermediate filament structure in fully differentiated (oxidised) trichocyte keratin. J Struct Biol 2017; 200:45-53. [DOI: 10.1016/j.jsb.2017.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/04/2017] [Accepted: 09/06/2017] [Indexed: 01/05/2023]
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Kadir M, Wang X, Zhu B, Liu J, Harland D, Popescu C. The structure of the "amorphous" matrix of keratins. J Struct Biol 2017; 198:116-123. [PMID: 28390956 DOI: 10.1016/j.jsb.2017.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 03/31/2017] [Accepted: 04/01/2017] [Indexed: 10/19/2022]
Abstract
Various keratin fibers, particularly human hairs, were investigated by transmission electron microscopy, TEM, solid-state 1H 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.
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Affiliation(s)
- Murat Kadir
- Lubrizol Advanced Materials, Inc., 9911 Brecksville Road, Brecksville, OH 44141, USA.
| | - Xinwei Wang
- Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, IA 50011, USA.
| | - Bowen Zhu
- Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, IA 50011, USA
| | - Jing Liu
- Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, IA 50011, USA
| | - Duane Harland
- AgResearch Limited, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand.
| | - Crisan Popescu
- KAO Germany GmbH, Pfungstädterstr. 98-100, D-64297 Darmstadt, Germany.
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Structural Transition of Trichocyte Keratin Intermediate Filaments During Development in the Hair Follicle. Subcell Biochem 2017; 82:131-149. [PMID: 28101861 DOI: 10.1007/978-3-319-49674-0_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The intermediate filaments (IF) in trichocyte (hard α-) keratin are unique amongst the various classes of IF in having not one but two topologically-distinct structures. The first is formed at an early stage of hair development in a reducing environment within the cells in the lower part of the follicle. The second structure occurs at a later stage of hair development in the upper part of the follicle, where there is a transition to an oxidizing environment. Crosslinking studies reveal that molecular slippage occurs within the IF upon oxidation and that this results in many cysteine residues lying in near axial alignment, thereby facilitating disulphide bond formation. The disulphide bonds so formed stabilize the assembly of IF molecules and convert the keratin fibre into a tough, resilient and insoluble structure suitable for its function in vivo as a thermo-regulator and a protector of the animal against its external environment.
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Rafik ME, Briki F, Burghammer M, Doucet J. In vivo formation steps of the hard alpha-keratin intermediate filament along a hair follicle: evidence for structural polymorphism. J Struct Biol 2006; 154:79-88. [PMID: 16458019 DOI: 10.1016/j.jsb.2005.11.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 11/18/2005] [Accepted: 11/22/2005] [Indexed: 10/25/2022]
Abstract
Several aspects of the intermediate filaments' molecular architecture remain mysterious despite decades of study. The growth process and the final architecture may depend on the physical, chemical, and biochemical environment. Aiming at clarifying this issue, we have revisited the structure of the human hair follicle by means of X-ray microdiffraction. We conclude that the histology-based growth zones along the follicle are correlated to the fine architecture of the filaments deduced from X-ray microdiffraction. Our analysis reveals the existence of two major polymorph intermediate filament architectures. Just above the bulb, the filaments are characterized by a diameter of 100 Angstroms and a low-density core. The following zone upwards is characterized by the lateral aggregation of the filaments into a compact network of filaments, by a contraction of their diameter (to 75 Angstroms) and by the setting up of a long-range longitudinal ordering. In the upper zone, the small structural change associated with the tissue hardening likely concerns the terminal domains. The architecture of the intermediate filament in the upper zones could be specific to hard alpha-keratin whilst the other architecture found in the lower zone could be representative for intermediate filaments in a different environment.
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Affiliation(s)
- Mériem Er Rafik
- Laboratoire de Physique des Solides, Bât 510, Université Paris-11, F-91405 Orsay, France
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Er Rafik M, Doucet J, Briki F. The intermediate filament architecture as determined by X-ray diffraction modeling of hard alpha-keratin. Biophys J 2005; 86:3893-904. [PMID: 15189886 PMCID: PMC1304291 DOI: 10.1529/biophysj.103.034694] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite investigation since the 1950s, the molecular architecture of intermediate filaments has not yet been fully elucidated. Reliable information about the longitudinal organization of the molecules within the filaments and about the lateral interfilament packing is now available, which is not the case for the transverse architecture. Interesting results were recently obtained from in vitro microscopy observations and cross-linking of keratin, desmin, and vimentin analyses. The structural features that emerge from these analyses could not be fully representative of the in vivo architecture because intermediate filaments are subject to polymorphism. To bring new light to the transverse intermediate filament architecture, we have analyzed the x-ray scattering equatorial profile of human hair. Its comparison with simulated profiles from atomic models of a real sequence has allowed results to be obtained that are representative of hard alpha-keratin intermediate filaments under in vivo conditions. In short, the alpha-helical coiled coils, which are characteristic of the central rod of intermediate filament dimers, are straight and not supercoiled into oligomers; the radial density across the intermediate filament section is fairly uniform; the coiled coils are probably assembled into tetrameric oligomers, and finally the oligomer positions and orientations are not regularly ordered. These features are discussed in terms of filament self-assembling and structural variability.
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Affiliation(s)
- Meriem Er Rafik
- Laboratoire d'Utilisation du Rayonnement Electromagnetique, Centre Universitaire Paris-Sud, Orsay, France
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Fraser RDB, Steinert PM, Parry DAD. Structural changes in trichocyte keratin intermediate filaments during keratinization. J Struct Biol 2003; 142:266-71. [PMID: 12713954 DOI: 10.1016/s1047-8477(02)00636-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The so-called hard alpha-keratins, such as quill and hair, have a composite structure in which intermediate filaments (IF) are embedded in a sulfur-rich matrix. Recent studies of these trichocyte keratin IF have revealed that substantial changes in the molecular architecture take place when oxidation of the cysteine residues occurs as part of the terminal differentiation/keratinization process. Recent cryoelectron microscope studies suggest that the IF has a tubular structure prior to keratinization, but transmission electron micrographs of thin sections of fully keratinized fibers exhibit a "ring-core" structure. In the present contribution we develop a generic model for the IF in the reduced state based on cross-linking studies and discuss two possibilities for the way in which this structure may be modified during the keratinization process.
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Affiliation(s)
- R D Bruce Fraser
- Institute of Fundamental Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
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Abstract
This chapter is concerned with the structure of the mature human hair shaft and the chemical composition of its subcomponents as adduced from the examination of fibres mainly with the conventional transmission electron microscope (TEM). The broad outlines of the techniques used in the study of hair are reviewed, with particular attention being paid to the processes of chemical staining which enable one to define various aspects of the chemical composition of the hair's microscopic sub-components. Against this background the internal structure of normal undamaged hair is described.
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Affiliation(s)
- J A Swift
- Department of Textiles and Fashion, De Montfort University, Leicester, England
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Jones LN, Pope FM. Isolation of intermediate filament assemblies from human hair follicles. J Cell Biol 1985; 101:1569-77. [PMID: 2413046 PMCID: PMC2113906 DOI: 10.1083/jcb.101.4.1569] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We used developing human hair follicle cells for the isolation of hard alpha-keratin structural components. Intracellular dispersions examined by electron microscopy contained both individual alpha-keratin filaments and the tactoid-like filament assemblies observed in situ organized along subfibrillar arms of macrofibrils. The assemblies of average width 47 nm were composed of closely packed alpha-keratin filaments and originated from the initial filament arrays observed in sections of developing mammalian hair follicles. We have distinguished two types of assemblies: the para-like or hexagonally packed and the ortho-like spiral or whorl type. Axial banding extended across the width of filament assemblies, which suggested that hard alpha-keratin filaments pack in lateral register and form a lattice that contains interfilamentous bridges. We observed axial banding patterns with periods ranging from 20 to 22 nm, consistent with the 22-nm periodic structure deduced from x-ray diffraction studies and present in models proposed for hard alpha-keratin and other intermediate filaments. Preliminary biochemical studies of filaments and filament assemblies indicate that they consist of the closely related group of proteins (low-sulfur proteins) ubiquitous among extracts of hard mammalian keratins. Isolated hard alpha-keratin filament assemblies provide a new and valuable structural entity for investigating the assembly mechanisms involved in the formation of the filament-matrix framework found in hard mammalian keratin appendages.
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Abstract
Quantitative measurements of the intensity of the meridional reflections in the X-ray-diffraction pattern of alpha-keratin are shown to be consistent with a microfibril structure in which a surface lattice with an axially projected period around 200 A is subject to a periodic interruption with an axially projected period of 470 A. Taken in conjunction with recent evidence on the chemical structure of alpha-keratin and other intermediate filaments this finding enables an elaboration to be made of a model proposed earlier by RDB Fraser, TP MacRae, & E Suzuki (J. Mol. Biol. 108, 435-452, 1976) for the alpha-helical framework of the microfibril. The disposition and connectivity of the helical segments suggested here provides a straightforward explanation of a number of recent physicochemical and electron-microscopical observations on intermediate filaments and provides a starting point for the development of models for the framework of other intermediate filaments.
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Affiliation(s)
- R D Fraser
- Division of Protein Chemistry, CSIRO, Parkville, Victoria, Australia
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Drochmans P, Freudenstein C, Wanson JC, Laurent L, Keenan TW, Stadler J, Leloup R, Franke WW. Structure and biochemical composition of desmosomes and tonofilaments isolated from calf muzzle epidermis. J Cell Biol 1978; 79:427-43. [PMID: 569157 PMCID: PMC2110254 DOI: 10.1083/jcb.79.2.427] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Complexes of plasma membrane segments with desmosomes and attached tonofilaments were separated from the stratum spinosum cells of calf muzzle by means of moderately alkaline buffers of low ionic strength and mechanical homogenization. These structures were further fractionated by the use of various treatments including sonication, sucrose gradient centrifugation, and extraction with buffers containing high concentrations of salt, urea, citric acid, or detergents. Subfractions enriched in desmosome-tonofilament-complexes and tonofilament fragments were studied in detail. The desmosome structures such as the midline, the trilaminar membrane profile, and the desmosomal plaque appeared well preserved and were notably resistant to the various treatments employed. Fractions containing desmosome-tonofilament complexes were invariably dominated by the nonmembranous proteins of the tonofilaments which appeared as five major polypeptide bands (apparent molecular weights: 48,000; 51,000; 58,000; 60,000; 68,000) present in molar ratios of approx. 2:1:1:2:2. Four of these polypeptide bands showed electrophoretic mobilities similar to those of prekeratin polypeptides from bovine hoof. However, the largest polypeptide (68,000 mol wt) migrated significantly less in polyacrylamide gels than the largest component of the hoof prekeratin (approximately 63,000 mol wt). In addition, a series of minor bands, including carbohydrate-containing proteins, were identified and concluded to represent constituents of the desmosomal membrane. The analysis of protein-bound carbohydrates (total 270 microgram/mg phospholipid in desmosome-enriched subfractions) showed the presence of relatively high amounts of glucosamine, mannose, galactose, and sialic acids. These data as well as the lipid composition (e.g., high ratio of cholesterol to phospholipids, relatively high contents of sphingomyelin and gangliosides, and fatty acid pattern) indicate that the desmosomal membrane is complex in protein and lipid composition and has a typical plasma membrane character. The similarity of the desmosome-associated tonofilaments to prekeratin filaments and other forms of intermediate-sized filaments is discussed.
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Franke WW, Weber K, Osborn M, Schmid E, Freudenstein C. Antibody to prekeratin. Decoration of tonofilament like arrays in various cells of epithelial character. Exp Cell Res 1978; 116:429-45. [PMID: 361424 DOI: 10.1016/0014-4827(78)90466-4] [Citation(s) in RCA: 380] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Abstract
alpha-Keratin microfibrils have been isolated from the presumptive cortex of developing mammalian hair follicles and purified by a centrifugation procedure. They have been obtained on a scale sufficient to enable their physical and chemical nature to be studied directly. The amino acid and protein compositions of the microfibril preparation closely resemble those of the low-sulphur protein fraction extracted from the fully keratinized fibre. High resolution electron microscopy of isolated microfibrils has indicated that they possess structural features in line with those observed in sectioned material.
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Jones LN. The isolation and characterization of alpha-keratin microfibrils. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 412:91-8. [PMID: 1191678 DOI: 10.1016/0005-2795(75)90342-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A method of isolating alpha-keratin microfibrils which avoids the degradation previously associated with the use of chemical, physical or enzymic procedures has been developed. Electron microscope studies of the isolation procedure establish that the microfibrils originate from the presumptive cortical cells. A purification procedure, monitored by electron microscopy, has enabled microfibrils to be isolated on a scale sufficient for chemical characterization. The amino acid composition of the microfibrils is very similar to that of low-sulphur protein fractions extracted from a range of hard mammalian keratins and thus provides direct experimental evidence for the assumption that the low-sulphur proteins comprise the microfibril in alpha-keratin.
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Millward GR, Reaveley DA. Electron microscope observations on the cell walls of some gram-positive bacteria. JOURNAL OF ULTRASTRUCTURE RESEARCH 1974; 46:309-26. [PMID: 4363809 DOI: 10.1016/s0022-5320(74)90059-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Hashimoto K. Ultrastructure of the human toenail. II. Keratinization and formation of the marginal band. JOURNAL OF ULTRASTRUCTURE RESEARCH 1971; 36:391-410. [PMID: 4106435 DOI: 10.1016/s0022-5320(71)80112-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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