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Characterization of the exocuticle a‐layer proteins of wool
Author(s) -
Bringans Scott D.,
Plowman Jeffrey E.,
Dyer Jolon M.,
Clerens Stefan,
Ver James A.,
Bryson Warren G.
Publication year - 2007
Publication title -
experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 96
eISSN - 1600-0625
pISSN - 0906-6705
DOI - 10.1111/j.1600-0625.2007.00610.x
Subject(s) - wool , cysteine , chemistry , layer (electronics) , biochemistry , amino acid , digestion (alchemy) , cuticle (hair) , biophysics , chromatography , biology , organic chemistry , materials science , anatomy , enzyme , composite material
The outermost protein layer of wool cuticle cells is known as the exocuticle a‐layer. This layer is a resistant barrier to the degradation of the fibre and, as a result, little is known of its proteinaceous composition. Merino wool fibres were subjected to both proteolytic and chemical digestion and the resulting material was found by transmission electron microscopy to be highly enriched in a‐layer. Amino acid analysis revealed a high cysteine and glycine content, with a close, but not exact, match to the Allwörden membrane. Subsequent digestion of the a‐layer preparation by 2‐nitro‐5‐thiocyano‐benzoic acid produced a large number of short peptides, and analysis by mass spectrometry revealed peptides with strong homologies to cuticular ultra‐high sulphur proteins of sheep wool and cuticular ultra‐high and high‐sulphur proteins of human hair, thus supporting other evidence for the presence of these sulphur‐rich proteins in the a‐layer.