title: Identification and partial characterization of proteins and proteoglycans encrusting the secondary cell walls of flax fibres.
abstract: Four proteins were isolated from depectinised elementary fibres of flax (Linum usitatissimum L.), using either alkali or cellulase digestion treatments. All the four proteins were characterized by a deficiency or low contents of hydroxyproline and by high levels of glutamic acid/glutamine and/or aspartic acid/asparagine. The two proteoglycans solubilized with cellulase strongly reacted with beta-glucosyl Yariv reagent but not with alpha-glucosyl Yariv reagent and contained appreciable amounts of alanine, glycine, serine and threonine, suggesting a relationship with cell wall hydroxyproline-deficient arabinogalactan-proteins. The two alkali-extracted proteins did not show any reaction with beta-glucosyl Yariv dye. Due to the harsh treatment, they might only partially represent the original proteins. Due to its high level of glycine (41%), one of these proteins might be classified as a glycine-rich protein. The latter polypeptide, of low molecular molar mass, contained 14.6% leucine and might consist of a domain related to leucine-rich proteins. The data show that these proteins and arabinogalactan-protein-like proteoglycans were strongly associated with the secondary walls of flax fibres. Their presence in small amounts (0.1-0.4%), raises the problem of their putative structural role.
authors.affiliation: SCUEOR ESA 6037 CNRS, University of Rouen, Mont Saint Aignan, France.
authors.forename: R
authors.initials: R
authors.lastname: Girault
authors.forename: I
authors.initials: I
authors.lastname: His
authors.forename: C
authors.initials: C
authors.lastname: Andeme-Onzighi
authors.forename: A
authors.initials: A
authors.lastname: Driouich
authors.forename: C
authors.initials: C
authors.lastname: Morvan
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002473:Cell Wall / Q000737:chemistry; D004587:Electrophoresis, Agar Gel; D019597:Flax / Q000737:chemistry* / Q000648:ultrastructure*; D007202:Indicators and Reagents; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D011509:Proteoglycans / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D007202:Indicators and Reagents; D010940:Plant Proteins; D011509:Proteoglycans