Kinetics of denaturation and renaturation processes of double-stranded helical polysaccharide, xanthan in aqueous sodium chloride
Kinetics of denaturation and renaturation processes of double-stranded helical polysaccharide, xanthan in aqueous sodium chloride
复制标题
双链螺旋多糖黄原胶在氯化钠水溶液中变性和复性过程的动力学
DOI：
10.1016/j.carbpol.2021.118681
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
K. Terao
中科院分区：
文献类型：
--
作者：
Y. Tomofui;K. Matsuo;K. Terao
在快速温度变化后，对三种黄原胶样品（一种双螺旋多糖）在 5 或 10 mM 氯化钠水溶液中进行圆二色性 (CD) 和小角 X 射线散射 (SAXS) 测量，以研究有序状态和无序状态之间构象变化的动力学。快速加热后，主要反映侧链羰基的 CD 信号快速变化（<150 s），而 SAXS 的散射强度在 q（散射矢量的大小）= 1 nm−1 附近变化更逐渐，反映了主链构象。 CD 和 SAXS 之间的差异意味着中间构象可以被视为松散的双螺旋。快速冷却过程中的SAXS图谱显示，松散的双螺旋结构在150秒内构建完成，但CD信号在大约2天内缓慢变化，以恢复天然的紧密双螺旋。
Circular dichroism (CD) and small-angle X-ray scattering (SAXS) measurements were made for three xanthan samples, a double helical polysaccharide, in 5 or 10 mM aqueous NaCl after rapid temperature change to investigate the kinetics of the conformational change between the ordered and disordered states. After the rapid heating, the CD signal mainly reflecting the carbonyl groups on the side chains quickly changed (<150 s) while the scattering intensity from SAXS aroundq(magnitude of the scattering vector) = 1 nm−1changed more gradually, reflecting the main-chain conformation. The difference between CD and SAXS implies us the intermediate conformation which can be regarded as a loose double helix. The SAXS profile in the rapid cooling process showed that the loose double helical structure was constructed within 150 s, but the CD signal slowly changed with around 2 days to recover the native tight double helix.