New investigations of the structure of grape arabinogalactan-protein.
The structure of an arabinogalactan-protein (AGP) isolated from grape juice was studied by methylation analysis, n.m.r. spectroscopy, and interactions with peanut lectin, after specific degradation with purified enzymes and/or Smith degradation. AGP appeared to be homogeneous with a weight-average molecular weight of 110,000. Treatment of AGP with arabinofuranosidase released 88% of the arabinose and left GP1. Hydrolysis of GP1 with an endo-(1----6)-beta-D-galactanase removed 50% of the galactose and left GP2. Smith degradation of GP1 gave a 3-linked galactan that still contained 3,6-linked residues. Endogalactanase- and Smith-degraded GP1, but not AGP and GP1, reacted strongly with peanut lectin. Thus, AGP is a 3-linked galactan cross-linked at positions 6. The core also carries, at positions 6, 6-linked galactan chains heavily 3-substituted with arabinofuranose residues.
Saulnier
L
L
Institut National de la Recherche Agronomique, Laboratoire des Polymères et des Techniques Physico-Chimiques, Montpellier, France.
Brillouet
J M
JM
Moutounet
M
M
Hervé du Penhoat
C
C
Michon
V
V
D002240:Carbohydrate Sequence; D005638:Fruit / Q000737:chemistry*; D005685:Galactans / Q000737:chemistry* / Q000302:isolation & purification; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D006026:Glycoside Hydrolases / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis; D019887:Peanut Agglutinin; D037121:Plant Lectins
D005685:Galactans; D006023:Glycoproteins; D037102:Lectins; D009005:Monosaccharides; D019887:Peanut Agglutinin; D037121:Plant Lectins; D006026:Glycoside Hydrolases; C005653:arabinogalactan