Studies on the fine structure and functional role of plant cell-wall polysaccharides
Studies on the fine structure and functional role of plant cell-wall polysaccharides
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植物细胞壁多糖精细结构及功能作用研究
DOI：
10.5458/jag.55.35
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发表时间：
2008
影响因子：
1.1
通讯作者：
Y. Kato
中科院分区：
文献类型：
--
作者：
Y. Kato
本文介绍了高等植物初代细胞壁中重要的半纤维素——木葡聚糖和葡萄糖醛酸阿拉伯木聚糖的精细结构和功能的研究。木葡聚糖：1)采用高效阴离子交换色谱法和脉冲安培法，在纯化的异甲葡聚糖低聚寡糖水解酶（IPase）酶切前后，建立了快速鉴定6个最常见的木葡聚糖低聚单位：XXXG、XLXG、XXLG、XLLG、XXFG和XLFG的方法。从13种蔬菜和11种水果的细胞壁中分离的木葡聚糖的低聚糖单位的组成分析，有力地证实了该方法的可用性。在我们的连续实验中，大多数含焦木葡聚糖除了含有XXXG、XXFG和XLFG作为主要结构低聚糖单位外，还含有少量的XLLG、XLXG和XXLG。2)采用木葡聚糖特异性酶（木葡聚糖酶、IPase、低聚氧葡聚糖还原内切纤维生物水解酶）、β- d -葡萄糖苷酶和β- d -半乳糖糖苷酶对茄科（茄子、甜椒、红椒和番茄）和禾本科（大麦和竹笋）的木葡聚糖结构进行了研究。前者由六元-(XXGG)、七元-（XLGG、LXGG和XSGG）和八元糖（LSGG）组成，后者由四元-(XX)、五元-(XXG)、六元-(XXGG)、七元-（XXGGG和LXGG）、八元-（XLGGG、LXGGG、XXGGGG和GXXGGG）和非糖（XLGGGG、LXGGGG、GXLGGG、GLXGGG和XXGGG）组成。3)通过对不同发育阶段苹果果实细胞壁制备的木葡聚糖结构的比较研究表明，细胞壁木葡聚糖的结构修饰发生在苹果果实发育过程中。1)经纯化的内切-(1→4)-β- d -木聚糖酶处理后，从玉米茎细胞壁释放的阿魏酰化的葡萄糖醛酸-阿拉伯木聚糖具有木聚糖主链，其中含有（1→4）-β- d -木吡喃基残基，在C-2或C-3位置被阿拉伯糖、葡萄糖醛酸和其他取代基取代了60 ~ 70%。阿威酸发生在葡萄糖醛酸阿拉伯木聚糖中（1→4）-连接的β- d -木吡喃基残基线性骨架的3- o -阿拉伯糖基分支点上。2)发现多糖之间的阿魏酰和异魏酰酯参与了培养水稻细胞的聚集。3)用酸水解熟麦芽的根茎，然后用酶处理得到含阿魏酸的碳水化合物片段。从这些碎片的混合物中制备了阿魏氨酸化的单糖和三糖组分。研究了酯酶处理前后对人肿瘤细胞COLO 201生长的影响。阿魏酸单糖和三糖对细胞生长有抑制作用，尤其是阿魏酸三糖，而阿魏酸、单糖和三糖对细胞生长无抑制作用。
This paper describes our studies on the fine structures and functions of the important hemicellulose, xyloglucan and glucuronoarabinoxylan, of the primary cell-walls of all higher plants. Xyloglucan: 1) A method for rapidly identifying six of the most commonly found xyloglucan oligosaccharide units, XXXG, XLXG, XXLG, XLLG, XXFG and XLFG was developed by high-performance anion exchange chromatography with pulsed amperometric detection before and after digestion with purified isoprimeverose-producing oligoxyloglucan hydrolase (IPase). The usability of this method was confirmed strongly by the studies of the compositional analysis of oligosaccharide units of xyloglucans isolated from the cell-walls of thirteen vegetables and eleven fruits. In our sequential experiments, most fucose-containing xyloglucans were shown to have essentially a small quantity of XLLG, XLXG and XXLG besides XXXG, XXFG and XLFG as major structural oligosaccharide units. 2) The structures of xyloglucans from Solanaceae (eggplant, sweet pepper, red pepper and tomato) and Gramineae (barley and bamboo shoot) were investigated using xyloglucan-specific enzymes (xyloglucanase, IPase, oligoxyloglucan reducing endo-specific cellobiohydrolase), β-D-glucosidase and β-D-galactosidase. The former was built from hexa-(XXGG), hepta-(XLGG, LXGG, and XSGG) and octa-saccharide units (LSGG), and the latter was built from tetra-(XX), penta-(XXG), hexa-(XXGG), hepta-(XXGGG and LXGG), octa-(XLGGG, LXGGG, XXGGGG, and GXXGGG) and nona-saccharide units (XLGGGG, LXGGGG, GXLGGG, GLXGGG, and XXGGGGG). 3) A comparative study of the structures of xyloglucans prepared from the cell-walls of apple fruit obtained at various development stages showed that the structural modifications of cell-wall xyloglucan occur during development of apple fruit. Glucuronoarabinoxylan: 1) Feruloylated glucuronoarabinoxylan liberated from Zea shoot cell-walls by treatment with a purified endo-(1→4)-β-D-xylanase had a xylan backbone which contained (1→4)-β-D-xylopyranosyl residues, with 60 to 70% substitution at the C-2 or C-3 position with arabinose, glucuronic acid, and other substituents. Ferulic acid occurred at 3-O-arabinosyl branch-points of linear backbones of (1→4)-linked β-D-xylopyranosyl residues in the glucuronoarabinoxylan. 2) Feruloyl and diferuloyl esters between polysaccharides were found to be involved in the aggregation of cultured rice cells. 3) The rootlets from the kilned malt were hydrolyzed with acid followed by treatment with an enzyme to give carbohydrate fragments containing ferulic acid. Feruloylated mono- and tri-saccharide fractions were prepared from the mixture of fragments. These fractions were tested for effects on the growth of COLO 201 human tumor cells before and after treatment with esterase. The cell growth was reduced by feruloylated mono- and tri-saccharides, especially feruloylated tri-saccharide, and was not reduced by ferulic acid, monosaccharide or trisaccharide.