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Novel enzyme materials-utilizing in organic media

新型酶材料——在有机介质中的应用

基本信息

批准号：
07555245
负责人：
NAKASHIO Fumiyuki
金额：
$ 4.61万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

The utility of enxymes in organic media has attracted much interest during the last ten years due to some remarkable novel properties compared to those in water. Biocatalyst engineering has been used successfully to improve biocatalysis in organic media and obtaining stable biocatalysts is a main target of biotechnology. Enzymes in nonaqueous solvents can catalyze a synthesis reaction of hydrophobic compounds such as esterification, steroid conversions and peptide formation. The substrate specificity and reactivity in an enzyme conversion are extremely high compared with those of conventional chemical synthesis. Thus an application of enzymatic reaction has been expected to produce optically active materials with an industrial scale.However, in order to take full advantage of the biocatalysis in organic media, it is necessary to modify the enzyme to be soluble in an organic solvent from the viewpoint of reduced diffusional limitations of substrates and increase in the reaction rate. Al … More though using a powder enzyme in a suspension state is simple, the reaction rate is usually very low due to the heterogeneity and several days are required to attain a high reaction yield. In this study, a novel preparation method for surfactant-enzyme complexes has been developed utilizing water-in-oil emulsions. Preparation conditions to obtain a suitable surfactant-lipase complex were investigated. Using the surfactant-lipase complexes, the estarification of benzyl alcohol with lauric acid was conducted in organic solvents. The enzymatic activity of lipase in a hydrophobic organic solvent was significantly enhanced by entrapping in a surfactant matrix. The surfactant-lipase complex catalyzed the esterification effect ively in organic media. The esterification rate from the surfactant-lipase complex was much higher than that from the powder lipase. The activity of the lipase complex strongly depends on the entrapping surfactant and the aqueous pH in the preparation. The surfactant-lipase complexes were thermostable at high temperature compared to the native lipase. Furthermore, the lipase complex showed a high storage stability. This modification method will enable us to utilize a lot of enzymes as new biocatalysts which had not shown enzymatic activity in organic media. Less

酶在有机介质中的应用在过去的十年中引起了人们的极大兴趣，由于一些显着的新性质相比，在水中。生物催化剂工程已成功地应用于有机介质中的生物催化，获得稳定的生物催化剂是生物技术的主要目标。非水溶剂中的酶可以催化疏水化合物的合成反应，例如酯化、类固醇转化和肽形成。与常规化学合成相比，酶转化中的底物特异性和反应性极高。因此，利用酶催化反应可以工业规模地生产光学活性物质，但是为了充分利用有机介质中的生物催化，从降低底物的扩散限制和提高反应速度的观点出发，需要将酶改性为可溶于有机溶剂。Al ...更多信息虽然使用悬浮状态的粉末酶很简单，但由于不均匀性，反应速率通常很低，并且需要几天才能达到高反应产率。在这项研究中，一种新的制备方法的表面活性剂-酶复合物已开发利用油包水乳液。研究了表面活性剂-脂肪酶复合物的制备条件。利用表面活性剂-脂肪酶复合物，在有机溶剂中进行了苯甲醇和月桂酸的酯化反应。脂肪酶在疏水性有机溶剂中的酶活性通过表面活性剂基质包埋而显著增强。在有机介质中，表面活性剂-脂肪酶复合物能有效地催化酯化反应。结果表明，表面活性剂-脂肪酶复合物的酯化率远高于粉末脂肪酶。脂肪酶复合物的活性强烈地依赖于包封表面活性剂和制备中的水溶液pH。与天然脂肪酶相比，表面活性剂-脂肪酶复合物在高温下是热稳定的。此外，脂肪酶复合物显示出高的储存稳定性。这种修饰方法将使我们能够利用许多在有机介质中没有表现出酶活性的酶作为新的生物催化剂。少