RT Journal Article
SR Electronic
T1 Purification and Structural Characterization of a Type II Arabinogalactan-Protein from Champagne Wine
JF American Journal of Enology and Viticulture
JO Am. J. Enol. Vitic.
FD American Society for Enology and Viticulture
SP ajev.2013.13004
DO 10.5344/ajev.2013.13004
A1 Thierry Doco
A1 Pascale Williams
YR 2013
UL http://www.ajevonline.org/content/early/2013/04/18/ajev.2013.13004.abstract
AB Some AGPs isolated from red wine have interesting physicochemical and sensorial properties. An arabinogalactan-protein (AGP) was isolated from a Champagne wine by anion-exchange, affinity and size exclusion chromatography. Glycosyl residue analysis showed that it consists of arabinose (12.8%) and galactose (68.5%), lower amounts of glucuronic acid (5.9%) and traces of rhamnose (0.7%). Champagne AGP reacts with the Yariv reagent in gel diffusion tests. The protein part of the AGP mainly contains hydroxyproline (22 % of the total amino acids), serine (17.6 %), alanine (10.8 %), glutamic acid (10.3 %) and threonine (8.6 %). Methylation analysis revealed that the carbohydrate moiety of the glycoprotein has a highly branched structure. The core consists of 3-linked β-D-galactopyranose units carrying side chains of 6-linked β-D-galactopyranose, partly substituted in position 3 and 4 by L-arabinofuranosyl residues. Galactose and arabinose as well as rhamnose and glucuronic acid occur in terminal positions. Size exclusion chromatography (SEC) with multiangle laser light scattering (MALLS) of the Champagne AGP revealed apparent weight average molecular mass of 1.1 105 g/mol, characterized by a narrow polydispersity index (Mw/Mn 1.09), and with a very low intrinsic viscosity ([η] = 0.1 dL/g).