The Keratin Proteins of Wool, Horn and Hoof from Sheep

Marshall, Robert C.; Gillespie, J. M.

doi:10.1071/bi9770389

Cited by 58 publications

(42 citation statements)

References 16 publications

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“…7,33 Some amino acids similarly vary between previous reports, 7,33 and such differences may reflect individual wool samples, protein preparations, or analysis conditions. LC-MS/MS analysis identified six proteins in the a-keratose fraction (Table II).…”

mentioning

confidence: 59%

Photochemical crosslinking of soluble wool keratins produces a mechanically stable biomaterial that supports cell adhesion and proliferation

Sando

Kim

Colgrave

et al. 2010

J Biomedical Materials Res

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Keratins extracted from various "hard tissues" such as wool, hair, and nails are increasingly being investigated as a source of abundant, biocompatible materials. In this study we explored a recent photochemical method to crosslink solubilized wool keratoses, with the aim of producing a mechanically favorable biomaterial. Wool proteins were isolated by oxidizing the disulfides and extracting the resulting soluble keratoses. The α- and γ-keratose fractions were analyzed by liquid chromatography-mass spectrometry to identify their constituent proteins. Hydrogels were produced by covalent crosslinking of the α-keratoses via a photo-oxidative process catalyzed by blue light, a ruthenium complex, and persulfate. The presence of dityrosine crosslinks was demonstrated by high performance liquid chromatography and mass spectrometry analyses. The crosslinked α-keratose material had moderate tensile strength and elasticity, and high adhesive strength. The material displayed modest shrinking after crosslinking, however the shrinking could be prevented by crosslinking in the presence of 2.5% glycerol, resulting in gels that did not shrink or swell. Small solutes such as Tris and glycerol influenced the crosslink density and elastic modulus of the crosslinked material. The α-keratose was able to support adhesion and growth of NIH/3T3 fibroblasts in vitro. The fabrication of mechanically stable keratin biomaterials by this facile photo-crosslinking method may be useful for various tissue engineering applications.

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mentioning

confidence: 59%

Photochemical crosslinking of soluble wool keratins produces a mechanically stable biomaterial that supports cell adhesion and proliferation

Sando

Kim

Colgrave

et al. 2010

J Biomedical Materials Res

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“…Taking into account the 95% confidence limits of roughly f 1 0 % for the enthalpy of a given material (see Table I ) , and neglecting the error for the value of the water content, this range is in good agreement with the value of 40-65 J / g for the melting enthalpy of a similarly superstructured, fibrillar biopolymer, namely, c01lagen.l~ It is generally accepted2' that the IFs in keratins are formed by a fraction of proteins called low-sulfur (LS) proteins, which in purified form are about 63% a -h e l i~a l .~~ Taking the amino acid analysis of this fraction, as determined by Marshall and Gillespie, 33 and calculating the weighed mean gives a molecular weight of 114 g/mol. This value leads to an estimated range for the denaturation enthalpy of a-helical material in keratin between AH = 6.5 kJ/mol and A H = 7.8 kJ/mol, on the basis of 30 and 25% a-helical material, respectively.…”

Section: Discussionmentioning

confidence: 89%

Characterizing keratins using high‐pressure differential scanning calorimetry (HPDSC)

Wortmann¹,

Deutz²

1993

J of Applied Polymer Sci

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SYNOPSISApplying differential scanning calorimetry (DSC) for temperatures up to 18O"C, the denaturation transition of the a-helical material of various keratins in excess water was studied at conditions of equilibrium water vapor pressure (high-pressure DSC) . The results show a generally cystine content and material invariate denaturation range of 20-30°C with peak temperatures around 140°C. Though analysis of variance and multiple comparison tests show a pronounced inhomogeneity of the enthalpy data, the results generally support the material invariance of the denaturation enthalpy and hence of the helix content of the keratins. The denaturation enthalpy for the helical coiled-coil-structures in the intermediate filaments is determined as AH = 6.5-7.8 kJ/mol. A significant positive correlation was found between the denaturation temperatures and the cystine content. It is concluded, that the helix denaturation temperatures are kinetically controlled by the amount and/or the chemical composition of the surrounding nonhelical matrix, and that the double-peak endotherms observed for wool and other keratins originate from two cell types that are sufficiently different in sulfur content to allow endotherm separation. In the case of wool the cell types can be identified as "ortho-" and "paracortical" cells.

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“…One set of hair-specific keratins is present in the medulla, cortex, and cortex cuticle (Marshall and Gillespie 1977;Crewther et al 1983;French and Hewish 1986;Heid et al 1986;Ito et al 1986;Lynch et al 1986). Another set of keratinlike proteins in the inner root sheath has not yet been fully characterized but seems to be distinct from all previously reported keratins (Steinert et al 1971;Lynch et al 1986;Stark et al 1987).…”

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confidence: 99%

A new look into an old problem: keratins as tools to investigate determination, morphogenesis, and differentiation in skin.

Kopan¹,

Fuchs²

1989

Genes Dev.

147

109

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We have investigated keratin and keratin mRNA expression during (1) differentiation of stem cells into epidermis and hair follicles and (2) morphogenesis of follicles. Our results indicate that a type I keratin K14 is expressed early in embryonal basal cells. Subsequently, its expression is elevated in the basal layer of developing epidermis but suppressed in developing matrix cells. This difference represents an early and major biochemical distinction between the two diverging cell types. Moreover, because expression of this keratin is not readily influenced by extracellular regulators or cell culture, it suggests a well-defined and narrow window of development during which an irreversible divergence in basal and matrix cells may take place. In contrast to KI4, which is expressed very early in development and coincident with basal epidermal differentiation, a hairspecific type I keratin and its mRNA is expressed late in hair matrix development and well after follicle morphogenesis. Besides providing an additional developmental difference between epidermal and hair matrix cells, the hair-specific keratins provide the first demonstration that keratin expression may be a consequence rather than a cause of cell organization and differentiation.[Key Words: Hair-specific keratins; keratin mRNA expression; hair follicle morphogenesis]

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The Keratin Proteins of Wool, Horn and Hoof from Sheep

Cited by 58 publications

References 16 publications

Photochemical crosslinking of soluble wool keratins produces a mechanically stable biomaterial that supports cell adhesion and proliferation

Photochemical crosslinking of soluble wool keratins produces a mechanically stable biomaterial that supports cell adhesion and proliferation

Characterizing keratins using high‐pressure differential scanning calorimetry (HPDSC)

A new look into an old problem: keratins as tools to investigate determination, morphogenesis, and differentiation in skin.

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