PT - JOURNAL ARTICLE AU - Thierry Doco AU - Pascale Williams TI - Purification and Structural Characterization of a Type II Arabinogalactan-Protein from Champagne Wine AID - 10.5344/ajev.2013.13004 DP - 2013 Sep 01 TA - American Journal of Enology and Viticulture PG - 364--369 VI - 64 IP - 3 4099 - http://www.ajevonline.org/content/64/3/364.short 4100 - http://www.ajevonline.org/content/64/3/364.full SO - Am. J. Enol. Vitic.2013 Sep 01; 64 AB - Some arabinogalactan-proteins (AGPs) isolated from red wine have interesting physicochemical and sensory properties. An AGP was isolated from a Champagne wine by anion-exchange, affinity, and size exclusion chromatography. Glycosyl residue analysis showed that it included arabinose (12.8%), galactose (68.5%), glucuronic acid (5.9%), and trace rhamnose (0.7%). Champagne AGP reacted with Yariv reagent in gel diffusion tests. The protein part of the AGP primarily contained hydroxyproline (22% of 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 had a highly branched structure. The core consisted 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 occurred in terminal positions. Size exclusion chromatography with multiangle laser light scattering of the Champagne AGP revealed apparent average molecular weight mass of 1.1 × 105 g/mol, characterized by a narrow polydispersity index (Mw/Mn 1.09) and a very low intrinsic viscosity ([η] = 0.1 dL/g).