Cryoprotective Effect of Saccharides on Denaturation of Catalase by Freeze-Drying
Cryoprotective Effect of Saccharides on Denaturation of Catalase by Freeze-Drying
复制标题
糖类对冷冻干燥过氧化氢酶变性的冷冻保护作用
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
K. Miyajima
中科院分区：
文献类型：
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作者：
Keiko Tanaka;T. Takeda;K. Miyajima
研究了在冷冻干燥过程中，海藻酸钠对过氧化氢酶的保护作用机理。通过改变过氧化氢酶和过氧化氢酶的浓度来测量变性率（D %）。依赖性的D %上的糖过氧化氢酶的重量比表明，它们直接相互作用。相互作用的模式可能是氢键。一个有效的氢键位点数为几个过氧化氢酶分子的表面上的氢结合位点的X-射线分析数据进行了评估。葡萄糖，麦芽糖和麦芽三糖表现出类似的保护效果比较的基础上，他们的重量，和葡萄糖甙基团占据约5个氢键位点的过氧化氢酶分子在最大的保护。具有较长糖苷链的糖苷类化合物具有较小的保护作用，这取决于它们的分子量。从以上结果可以看出，过氧化氢酶与水化酶的结合是以单分子层的形式存在的，该单分子层代替水化单分子层保护过氧化氢酶不被变性。
A mechanism of the cryoprotective effect of saccharides on the denaturation of catalase in the freeze-drying process was studied. Denaturation percents (D%) were measured by changing concentrations of saccharides and catalase. Dependence of D% on a weight ratio of saccharide to catalase suggested that they interact directly with each other. The mode of interaction is probably hydrogen-bonding. An effective number of hydrogen-bonding sites for several saccharides on the surface of the catalase molecule was evaluated by reference to the X-ray analysis data. Glucose, maltose and maltotriose showed a similar protective effect compared on the basis of their weights, and a glucoside group of those saccharides occupied about 5 hydrogen-bonding sites on a catalase molecule at the maximum protection. Saccharides with longer glucoside chains have less protection effect depending on their molecular weights. Judging from the above results, saccharides are bound to catalase as a monomolecualr layer and this layer protects catalase from being denatured instead of the hydration monolayer.