Aggregation and chemical reaction in hen lysozyme caused by heating at pH 6 are depressed by osmolytes, sucrose and trehalose.
Aggregation and chemical reaction in hen lysozyme caused by heating at pH 6 are depressed by osmolytes, sucrose and trehalose.
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渗透剂、蔗糖和海藻糖抑制在 pH 6 下加热引起的母鸡溶菌酶的聚集和化学反应。
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
Taiji Imoto
中科院分区：
文献类型：
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作者：
Tadashi Ueda;Makiko Nagata;Taiji Imoto
我们研究了渗透剂，蔗糖和海藻糖，对作为模型蛋白质的鸡溶菌酶的劣化的影响。蔗糖和海藻糖抑制溶菌酶分子的聚集所造成的加热在100摄氏度，pH值为6。由于溶菌酶在这些条件下完全变性，蔗糖和海藻糖对溶菌酶的变性状态的影响进行了研究，使用还原S-烷基化溶菌酶，变性鸡溶菌酶的模型。圆二色谱和荧光光谱分析表明，蔗糖和海藻糖诱导还原型S-烷基化溶菌酶中色氨酸残基周围形成α-螺旋构象和一些三级结构。此外，这些化合物还抑制了还原的S-烷基化溶菌酶的化学反应，如脱酰胺和外消旋，这些反应通常会导致蛋白质的劣化。因此，数据表明，蔗糖和海藻糖具有通过诱导多肽链中的某些三级结构（包括α-螺旋结构）来抑制蛋白质分子聚集或蛋白质中的化学反应等劣化的倾向。
We examined the effects of osmolytes, sucrose and trehalose, on the deterioration of hen lysozyme as a model protein. Sucrose and trehalose depressed the aggregation of lysozyme molecules caused by heating at 100 degrees C at pH 6. Since lysozyme was fully denatured under these conditions, the effects of sucrose and trehalose on the denatured state of lysozyme were investigated using reduced S-alkylated lysozyme, a model of denatured hen lysozyme. From analyses of circular dichroism spectra and fluorescence spectra, sucrose and trehalose were found to induce alpha-helical conformations and some tertiary structures around tryptophan residues in the reduced S-alkylated lysozyme. Moreover, these compounds also depressed chemical reactions such as deamidation and racemization, which often cause the deterioration of proteins, on the reduced S-alkylated lysozyme. Therefore, the data suggest that sucrose and trehalose have a propensity to depress such deterioration as the aggregation of protein molecules or chemical reactions in proteins by inducing some tertiary structures (including alpha-helical structures) in the polypeptide chain.