title: Structural analysis of galactoarabinan from duckweed.
abstract: A highly branched galactoarabinan named DAG1 (Mw∼4.0×10(4) Da) was purified from Lemna aequinoctialis 6000 via 70% (v/v) ethanol extraction, followed by size-exclusion chromatography on Bio-Gel P2 and Superdex 75. Methylation analysis showed that DAG1 consisted of t-Araf, (1→5)-Araf, (1→2,5)-Araf, (1→3)-Galp, and (1→3,6)-Galp in a relative proportion of approximately 6:4:3:3:3, suggesting an arabinogalactan/galactoarabinan polysacchairde. With the aid of arabinan degrading enzymes, the structure of DAG1 repeating unit was further characterized by ELISA with specific monoclonal antibodies and Yariv reagent assay. Analyses indicated that the proposed repeating unit of DAG1 had a backbone composed of seven α-(1→5)-L-arabinofuranose residues where branching occurred at O-2 with either terminal arabinoses or arabinogalactan side chain. The arabinogalactan side chain was composed of six β-(1→3)-D-galactopyranose residues, half of which were ramified at O-6 with terminal arabinoses and the last galactose was terminated with arabinose.
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Yu
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Changjiang
authors.initials: C
authors.lastname: Yu
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Yubin
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China. Electronic address: zhougk@qibebt.ac.cn.
authors.forename: Gongke
authors.initials: G
authors.lastname: Zhou
mesh_terms: D029064:Araceae / Q000737:chemistry*; D002240:Carbohydrate Sequence; D006031:Glycosylation; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011134:Polysaccharides
keywords: Cell wall antibody; Duckweed; Galactoarabinan; Yariv assay; α-1,5-Arabinan backbone; β-1,3-Galactan side chain