Jia Zhonghua, Qin Qiang, Darvill Alan G, York William S
Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, 220 Riverbend Road, Athens, GA 30602-4712, USA.
Carbohydr Res. 2003 May 23;338(11):1197-208. doi: 10.1016/s0008-6215(03)00079-x.
The xyloglucan secreted by suspension-cultured tomato (Lycopersicon esculentum) cells was structurally characterized by analysis of the oligosaccharides generated by treating the polysaccharide with a xyloglucan-specific endoglucanase (XEG). These oligosaccharide subunits were chemically reduced to form the corresponding oligoglycosyl alditols, which were isolated by high-performance liquid chromatography (HPLC). Thirteen of the oligoglycosyl alditols were structurally characterized by a combination of matrix-assisted laser-desorption ionization mass spectrometry and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Nine of the oligoglycosyl alditols (GXGGol, XXGGol, GSGGol, XSGGol, LXGGol, XTGGol, LSGGol, LLGGol, and LTGGol, [see, Fry, S.C.; York, W.S., et al., Physiologia Plantarum 1993, 89, 1-3, for this nomenclature]) are derived from oligosaccharide subunits that have a cellotetraose backbone. Very small amounts of oligoglycosyl alditols (XGGol, XGGXXGGol, XXGGXGGol, and XGGXSGGol) derived from oligosaccharide subunits that have a cellotriose or celloheptaose backbone were also purified and characterized. The results demonstrate that the xyloglucan secreted by suspension-cultured tomato cells is very complex and is composed predominantly of 'XXGG-type' subunits with a cellotetraose backbone. The rigorous characterization of the oligoglycosyl alditols and assignment of their 1H and 13C NMR spectra constitute a robust data set that can be used as the basis for rapid and accurate structural profiling of xyloglucans produced by Solanaceous plant species and the characterization of enzymes involved in the synthesis, modification, and breakdown of these polysaccharides.
通过用木葡聚糖特异性内切葡聚糖酶（XEG）处理多糖所产生的寡糖进行分析，对悬浮培养的番茄（Lycopersicon esculentum）细胞分泌的木葡聚糖进行了结构表征。这些寡糖亚基经化学还原形成相应的寡糖基糖醇，通过高效液相色谱（HPLC）进行分离。通过基质辅助激光解吸电离质谱和二维核磁共振（NMR）光谱相结合的方法，对13种寡糖基糖醇进行了结构表征。其中9种寡糖基糖醇（GXGGol、XXGGol、GSGGol、XSGGol、LXGGol、XTGGol、LSGGol、LLGGol和LTGGol，[关于此命名法，见Fry, S.C.; York, W.S.等人，《植物生理学》1993年，89卷，1 - 3页]）源自具有纤维四糖主链的寡糖亚基。还纯化并表征了极少量源自具有纤维三糖或纤维七糖主链的寡糖亚基的寡糖基糖醇（XGGol、XGGXXGGol、XXGGXGGol和XGGXSGGol）。结果表明，悬浮培养的番茄细胞分泌的木葡聚糖非常复杂，主要由具有纤维四糖主链的“XXGG型”亚基组成。对寡糖基糖醇的严格表征及其1H和13C NMR光谱的归属构成了一个强大的数据集，可作为茄科植物产生的木葡聚糖快速准确结构分析以及参与这些多糖合成、修饰和分解的酶的表征的基础。
