Wikman Jeanette, Blennow Andreas, Bertoft Eric
Department of Biosciences, Åbo Akademi University, FI-20520 Turku, Finland.
Biopolymers. 2013 Jan;99(1):73-83. doi: 10.1002/bip.22145.
The effect of amylose deposition on the amylopectin crystalline lamellar organization in potato starch granules was studied by mild acid, so-called lintnerization, of potato tuber starch transgenically engineered to deposit different levels of amylose. The starch granules were subjected to lintnerization at different temperatures (25, 35, and 45°C) and to two levels of solubilization, ∼ 45 and 80%. The rate of the lintnerization increased with temperature but was suppressed by amylose. The molecular size of the lintner dextrins increased with temperature, but this effect was suppressed by the presence of amylose. At high temperatures and low-amylose content, the degree of branches was high with the concomitant increase in size in the dextrins. A portion of the branches was resistant to debranching enzymes possibly due to specific structural formations. The effects of temperature suggested a unique granular architecture of potato starch, and a model showing the dependence of temperature on the dynamic arrangement of amylopectin and amylose in the crystalline and amorphous lamellae for the potato starch is suggested.
通过对转基因工程马铃薯块茎淀粉进行温和酸处理（即所谓的糊精化），研究了直链淀粉沉积对马铃薯淀粉颗粒中支链淀粉结晶层状结构的影响，这些转基因马铃薯淀粉沉积了不同水平的直链淀粉。淀粉颗粒在不同温度（25、35和45°C）下进行糊精化处理，并进行两种水平的溶解，即约45%和80%。糊精化速率随温度升高而增加，但受直链淀粉抑制。糊精化糊精的分子大小随温度增加，但这种效应受直链淀粉的存在抑制。在高温和低直链淀粉含量下，分支度较高，同时糊精大小增加。一部分分支可能由于特定的结构形成而对脱支酶具有抗性。温度的影响表明马铃薯淀粉具有独特的颗粒结构，并提出了一个模型，该模型显示了温度对马铃薯淀粉结晶和无定形薄片中支链淀粉和直链淀粉动态排列的依赖性。
