AbstractDouble helical polysaccharide, xanthan samples with varying molar mass were thermally denatured and renatured in dilute solutions. Both the weight average molar mass, which was determined by size exclusion chromatography (SEC), and viscosity average molar mass decreased after denaturation and renaturation for samples with an initial molar mass of 106 g mol−1, but those for the samples with an initial molar mass of 105 or 107 g mol−1 decreased only slightly. Although the double helices of xanthan only partially dissociated into single chains, the molar mass distribution estimated by SEC did not broaden drastically by the denaturation and renaturation. These results can be explained by the formation of hairpin structures by the single chains, which are restricted to xanthan with a molar mass of 105 g mol−1 by the strain of the hairpin loop, and for xanthan molar masses of 107 g mol−1 by the incomplete dissociation of its long polymer chains.Double helical polysaccharide, xanthan samples with varying molar mass were thermally denatured and renatured in dilute solutions. The molar mass decreased after denaturation and renaturation for samples with an initial molar mass of 106 g mol−1, but those for the samples with an initial molar mass of 105 or 107 g mol−1 decreased only slightly. A model explaining this molar mass dependence of the denaturation and renaturation behaviors was proposed based on the experimental results.

中文翻译：

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在稀溶液中热变性和复性的黄原胶结构的摩尔质量依赖性

摘要 双螺旋多糖、不同摩尔质量的黄原胶样品在稀溶液中进行热变性和复性。对于初始摩尔质量为 106 g mol−1 的样品，通过尺寸排阻色谱 (SEC) 测定的重均摩尔质量和粘均摩尔质量在变性和复性后均有所降低，但对于初始摩尔质量为 106 105 或 107 g mol-1 的摩尔质量仅略有下降。尽管黄原胶的双螺旋仅部分解离成单链，但 SEC 估计的摩尔质量分布并未因变性和复性而急剧扩大。这些结果可以通过单链形成发夹结构来解释，由于发夹环的应变，这些单链被限制为摩尔质量为 105 g mol-1 的黄原胶，对于 107 g mol-1 的黄原胶摩尔质量，由于其长聚合物链的不完全解离。双螺旋多糖，具有不同摩尔质量的黄原胶样品在稀溶液中进行热变性和复性。初始摩尔质量为 106 g mol-1 的样品在变性和复性后摩尔质量下降，但初始摩尔质量为 105 或 107 g mol-1 的样品仅略有下降。基于实验结果提出了解释这种变性和复性行为的摩尔质量依赖性的模型。初始摩尔质量为 106 g mol-1 的样品在变性和复性后摩尔质量下降，但初始摩尔质量为 105 或 107 g mol-1 的样品仅略有下降。基于实验结果提出了解释这种变性和复性行为的摩尔质量依赖性的模型。初始摩尔质量为 106 g mol-1 的样品在变性和复性后摩尔质量下降，但初始摩尔质量为 105 或 107 g mol-1 的样品仅略有下降。基于实验结果提出了解释这种变性和复性行为的摩尔质量依赖性的模型。