HEAT DENATURATION OF HUMAN OROSOMUCOID IN WATER-METHANOL MIXTURES
HEAT DENATURATION OF HUMAN OROSOMUCOID IN WATER-METHANOL MIXTURES
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DOI：
10.1016/0167-4838(94)00173-e
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发表时间：
1995-01-05
期刊：
影响因子：
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通讯作者：
KARPENKO, V
中科院分区：
文献类型：
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作者：
KODICEK, M;INFANZON, A;KARPENKO, V
用圆二色谱、本征蛋白质荧光和热差吸收光谱研究了类红粘蛋白在0-70%(v/v)甲醇溶液中的热变性。无论其含糖量高(40%)，在中性水溶液中，Orosomucid高度协同的变性转变是完全可逆的。成功地应用了二态模型；数值分析得到的热力学参数值与以前报道的量热法测量的实验数据非常吻合。然而，在含有微量甲醇(5%)的溶液中，热变性是不可逆的。变性蛋白质冷却后，复性后的分子显示出比天然分子更高的螺旋含量。讨论了甲醇与天然和变性蛋白质分子相互作用的可能性。
Heat denaturation of orosomucoid in solutions of methanol concentrations ranging from 0 to 70% (v/v) has been studied by using circular dichroism, intrinsic protein fluorescence and thermal difference absorption spectroscopy. Regardless of its high saccharide content (40%), the highly cooperative denaturation transition of orosomucoid is fully reversible in neutral water solution. A two-state model has been successfully applied; the numerical analysis results in thermodynamical parameter values that are in close agreement with previously reported experimental data from calorimetric measurements. However, in solutions containing even minute concentrations of methanol (5%) the heat denaturation is irreversible. After cooling of the denatured protein the refolded molecules exhibit a higher ct-helical content than the native one. Possibilities of methanol interaction with native and denatured protein molecule are discussed.