Pea xyloglucan and cellulose : I. Macromolecular organization.
Pea xyloglucan and cellulose : I. Macromolecular organization.
复制标题
豌豆木葡聚糖和纤维素：I.大分子组织。
DOI：
10.1104/pp.75.3.596
复制
发表时间：
1984
期刊：
影响因子：
7.4
通讯作者：
G. Maclachlan
中科院分区：
文献类型：
--
作者：
Takahisa Hayashi;G. Maclachlan
从黄化豌豆(Pisum sativum L.var.)的伸长区获得了木聚糖和纤维素组成的大分子复合体。阿拉斯加)茎。用24%KOH-0.1%NaBH(4)提取该复合体或用内切-1，4-β-葡聚糖酶延长处理可使木聚糖溶解。经超速离心和SepharoseCL-6B凝胶过滤，得到了均一的多糖，相对分子质量为330,000。通过酶解产物的裂解分析、甲基化分析和岩藻糖或半乳糖结合凝集素的沉淀试验，对豌豆木聚糖的结构进行了鉴定。该多糖由两个亚基组成，一个非糖(葡萄糖/木糖/半乳糖/岩藻糖，4：3：1：1)和一个七糖(葡萄糖/木糖，4：3)，呈随机分布，但主要按交替顺序排列。用碘染色光镜、[~(3)H]岩藻糖标记后的放射自显影、以荧光素-凝集素(岩藻糖结合)为探针的荧光显微镜和阴影后的电子显微镜观察木葡聚糖-纤维素复合体。这些技术都表明，大分子存在于细胞形状的文件中，这里称为细胞壁；幽灵，其中木葡聚糖定位在纤维素微纤维上和纤维之间。由于豌豆木葡聚糖的平均链长是纤维素微纤维直径的数倍，它可以通过与相邻的纤维结合而引入交联剂，从而增加壁面的刚性。
A macromolecular complex composed of xyloglucan and cellulose was obtained from elongating regions of etiolated pea (Pisum sativum L. var. Alaska) stems. Xyloglucan could be solubilized by extraction of this complex with 24% KOH-0.1% NaBH(4) or by extended treatment with endo-1,4-beta-glucanase. The polysaccharide was homogeneous by ultracentrifugal analysis and gel filtration on Sepharose CL-6B, molecular weight 330,000. The structure of pea xyloglucan was examined by fragmentation analysis of enzymic hydrolysates, methylation analysis, and precipitation tests with fucose- or galactose-binding lectins. The polysaccharide was composed of equal amounts of two subunits, a nonasaccharide (glucose/xylose/galactose/fucose, 4:3:1:1) and a heptasaccharide (glucose/xylose, 4:3), which appeared to be distributed at random, but primarily in alternating sequence. The xyloglucan:cellulose complex was examined by light microscopy using iodine staining, by radioautography after labeling with [(3)H]fucose, by fluorescence microscopy using a fluorescein-lectin (fucose-binding) as probe, and by electron microscopy after shadowing. The techniques all demonstrated that the macromolecule was present in files of cell shapes, referred to here as cell-wall ;ghosts,' in which xyloglucan was localized both on and between the cellulose microfibrils. Since the average chain length of pea xyloglucan was many times the diameter of cellulose microfibrils, it could introduce cross-links by binding to adjacent fibrils and thereby contribute rigidity to the wall.