Structural patterns of rhamnogalacturonans modulating Hsp-27 expression in cultured human keratinocytes.
Polysaccharide extracts were obtained from chestnut bran (Castanea sativa), grape marc (Vitis vinifera) and apple marc (Malus spp.) and fractionated by size exclusion chromatography after endopolygalacturonase degradation. Compositional and linkage analyses by GC and GC-MS showed the characteristic rhamnogalacturonan structure with specific arabinan (apple marc) and type II arabinogalactan (chestnut bran, grape marc) side chains. Type II arabinogalactan rhamnogalacturonan from chestnut bran significantly stimulated the in vitro differentiation of human keratinocytes, giving evidence of a tight structure-function relationship. This molecule comprises short and ramified 3- and 3,6-beta- D-galactan and 5- and 3,5-alpha-L-arabinan side chains, but also contains significant amounts of t-Xyl and 4-Xyl with a characteristic 2:1 ratio. Enzymatic hydrolysis of this polysaccharide produced fragments of lower molecular weight with unchanged xylose content which conserved the same ability to stimulate human keratinocyte differentiation. It could be then speculated that dimeric xylosyl-xylose and/or longer oligomeric xylose side chains attached to a galacturonan and closely associated to hairy rhamno-galacturonan domains are essential patterns that could determine the biological activity of pectins.
Laboratoire de Chimie des Substances Naturelles (UPRES-EA 1069), Université de Limoges, Faculté des Sciences et Techniques, 123 rue A. Thomas, 87060 Limoges, France. vincent.gloaguen@unilim.fr
Vincent
V
Gloaguen
Pierre
P
Krausz
Véronique
V
Brudieux
Brigitte
B
Closs
Yves
Y
Leroy
Yann
Y
Guerardel
D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D018832:Molecular Chaperones; D009005:Monosaccharides / Q000032:analysis; D009363:Neoplasm Proteins / Q000378:metabolism*; D010368:Pectins / Q000737:chemistry* / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D011134:Polysaccharides / Q000302:isolation & purification
D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009005:Monosaccharides; D009363:Neoplasm Proteins; D010936:Plant Extracts; D011134:Polysaccharides; C042491:rhamnogalacturonan I; C042492:rhamnogalacturonan II; D010368:Pectins