Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China; KTH Royal Institute of Technology, Division of Glycoscience and Wallenberg Wood Science Centre (WWSC), AlbaNova University Centre, SE-106 91 Stockholm, Sweden; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane 4072, QLD, Australia.
The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane 4072, QLD, Australia.
Carbohydr Polym. 2014 Nov 26;113:539-51. doi: 10.1016/j.carbpol.2014.07.050. Epub 2014 Jul 31.
Two-dimensional (2D) structural distributions based on macromolecular size and branch chain-length are obtained for three maize starches with different amylose contents (one normal and two high-amylose varieties). Data were obtained using an analytical methodology combining chemical fractionation, enzymatic debranching, and offline 2D size-exclusion chromatography with multiple detection. The 2D distributions reveal novel features in the branching structure of high-amylose maize starches. Normal maize starch shows well-resolved structural topologies, corresponding to the amylopectin and amylose macromolecular populations. However, high-amylose maize starches exhibit very complex topologies with significant features between those of amylose and amylopectin, showing the presence of distinct intermediate components. These have the macromolecular size of amylose but similar branching structure to amylopectin, except for a higher proportion of longer branches. These structural features of the intermediate components can be related to a less tightly controlled biosynthesis of the branching structures in high-amylose maize starch mutants, which may prevent these molecules from maturing into full-size amylopectin. This altered macromolecular branched architecture of high-amylose starches probably contribute to their better nutritional properties.
三种不同直链淀粉含量的玉米淀粉（一种普通品种和两种高直链淀粉品种），基于大分子尺寸和支链长度的二维（2D）结构分布。数据是使用一种分析方法获得的，该方法结合了化学分级分离、酶解支、以及离线 2D 大小排阻色谱和多重检测。2D 分布揭示了高直链玉米淀粉分支结构的新特征。普通玉米淀粉显示出良好分辨的结构拓扑，对应于支链淀粉和直链淀粉的大分子群体。然而，高直链玉米淀粉表现出非常复杂的拓扑结构，在直链淀粉和支链淀粉之间具有显著的特征，表明存在明显的中间成分。这些中间成分具有直链淀粉的大分子尺寸，但分支结构类似于支链淀粉，除了更长分支的比例更高。这些中间成分的结构特征可能与高直链玉米淀粉突变体中分支结构的生物合成控制不那么严格有关，这可能阻止这些分子成熟为全尺寸支链淀粉。高直链淀粉淀粉的这种改变的大分子支化结构可能有助于其更好的营养特性。
