THE SIZE AND SHAPE OF AMYLOPECTIN - A STUDY USING ANALYTICAL ULTRACENTRIFUGATION
THE SIZE AND SHAPE OF AMYLOPECTIN - A STUDY USING ANALYTICAL ULTRACENTRIFUGATION
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DOI：
10.1016/s0008-6215(00)90262-3
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发表时间：
1986-10-01
影响因子：
3.1
通讯作者：
MARSDEN, K
中科院分区：
文献类型：
--
作者：
LELIEVRE, J;LEWIS, JA;MARSDEN, K
从在各种条件下生长的一系列小麦品种中分离淀粉。已知淀粉在加热时产生具有对比流变性质的糊。用分析超离心法研究了淀粉在二甲基亚砜中的溶液。沉积系数和归一化的重量-频率分布的限制沉积系数进行了测定。沉降系数数据证实支链淀粉在二甲基亚砜中的重均摩尔质量为约。第107章不管你是谁沉积系数值也与扩散系数数据相结合，并根据流体动力学理论进行评估，这表明支链淀粉具有半长轴和半短轴分别为45和1.2 nm的平片或盘状结构。支链淀粉样品的沉降系数的分布都是相似的，是单峰的、对称的，并且具有λ的峰宽半高。60 S.通过化学分级除去直链淀粉后得到的支链淀粉被证明是淀粉中总支链淀粉的代表。
Starch was isolated from a range of wheat cultivars grown under various conditions. The starches were known to produce pastes having contrasting rheological properties when heated. Solutions of the starch in dimethyl sulphoxide were investigated by analytical ultracentrifugation. Sedimentation coefficients and normalized weight-frequency distributions of limiting sedimentation-coefficients were determined. The sedimentation-coefficient data confirmed the weight-average molar mass of amylopectin in dimethyl sulphoxide to be .apprx. 107, irrespective of the source of the starch. The sedimentation-coefficient values were also combined with diffusion-coefficient data and evaluated according to hydrodynamic theory, this indicated that amylopectin has a flat-sheet or disc-like structure with semi-major and semi-minor axes of 45 and 1.2 nm, respectively. The distributions of sedimentation coefficients of the amylopectin samples were all similar, being unimodal, symmetrical, and having peak-width half-heights of .apprx. 60 S. The amylopectin obtained after removal of amylose by chemical fractionation was shown to be representative of the total amylopectin in starch.