Structural and functional elucidation of basic branched polysaccharides capable of microtube formtion

2015 Fiscal Year Final Research Report

• Project/Area Number: 25450148
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Bioorganic chemistry
• Research Institution: Yokohama National University
• Principal Investigator: Takeda Minoru 横浜国立大学, 工学(系)研究科(研究院), 准教授 (40247507)
• Co-Investigator(Renkei-kenkyūsha): UEDA Kazuyoshi 横浜国立大学, 大学院工学研究院, 教授 (40223458) ; MATSUMOTO Shinya 横浜国立大学, 大学院環境情報研究院, 教授 (50345469)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: マイクロチューブ / 鞘 / 塩基性多糖 / Thiothrix / 希少糖 / 構造決定

Outline of Final Research Achievements

Sulfur-oxidizing bacterium, Thiothrix fructosivorans, forms a microtube (sheath) that encloses a line of cells. The sheath was prepared by selectively removing the cells. D-glucose, D-glucosamine, L-fucose, and D-perosamine (D-Rhap4N) were detected from the sheath. When the sheath was strongly treated with sodium hydroxide, the original microtube structure was lost and the sheath became soluble under acidic conditions, suggesting the importance of N-substitution in maintaining the sheath structure. According to 1H and 13C NMR analyses of the deacetylated sheath, the sheath-forming polymer (deacetylated form) of T. fructosivorans was found to have a main chain of [→4)-β-D-GlcpN-(1→4)-β-D-Glcp-(1→]n, to which disaccharide side chains of α-D-Rhap4N-(1→3)-α-L-Fucp-(1→ were attached at position 3 of Glc. Further detailed structural analysis revealed that GlcN is substoichiometrically (about 50%) N-acetylated and more than 80% of Rha4N is N-L-lactylated.

Free Research Field

天然高分子学