Expedited Award for Novel Research: Enzyme Biocatalysis in Reverse Micelles: Thermodynamic and Kinetic Studies

新颖研究加急奖：反胶束中的酶生物催化：热力学和动力学研究

• 批准号: 8720267
• 负责人: John Prausnitz
• 金额: $ 3万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-02-01 至 1989-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8720267&HistoricalAwards=false
• 关键词: Expedited; Award; Novel; Research; Enzyme

The wider use of enzymes in organic syntheses, where their high degree of regio- and stereo-selectivity is difficult to achieve with conventional catalysts, is severely hampered by the low aqueous solubility of many substrates of interest. The encapsulation of enzymes in reverse micelles, which provides a method for stabilization of the enzyme, is a new and particularly promising approach for biological synthesis or transformation of organic compounds in organic solvents. This project concerns fundamental studies for the development of new bioreactors employing such encapsulated enzymes. It includes a study of the effect of encapsulation of dopamine beta- monooxygenase, a non-specific enzyme which hydroxylates ring- substituted phenethylamines, alkenes, aldehydes, amides and sulphides. The effect of micelle structure on the conformation of the enzyme is studied by use of ESR and kinetic measurements. A molecular- thermodynamic model, relating the properties of the aqueous miniphase to prevailing conditions, is also developed. The use of reverse micelles to protect the enzyme from the often denaturing influence of organic solvents is a new approach to enzyme stabilization. Current research has focussed on the use of reverse micelles for protein purification. The inner water pool of a reverse micelle can solubilize large protein molecules and the micelle provides a large surface area for transport of reactant and substrate to and from the enzyme. Little is understood of the behavior of enzymes within such micelles or of how their kinetic properties differ from enzymes in solution. The investigators create micelles using non-polar surfactants, so that transport of polar organic substrates can be enhanced by the addition of carrier molecules in the organic phase, such as quaternary alkyl amines. There is current interest in describing the behavior of water in reverse micelles from a phase equilibrium thermodynamic viewpoint. Of even greater importance is the development of a molecular-thermodynamic model to relate the properties of the aqueous miniphase to the external conditions, so that a predictive model can be employed for bioreactor design.

酶在有机合成中的广泛应用， 的区域和立体选择性是难以实现的， 传统催化剂，严重阻碍了低含水量 许多感兴趣的底物的溶解度。 的封装 反胶束中的酶，这提供了一种稳定 是一种新的，特别有前途的方法， 生物合成或有机化合物的生物转化 溶剂. 该项目涉及的基础研究 开发使用这种包封酶的新生物反应器。 它包括一项研究的影响，封装多巴胺β- 单加氧酶，一种非特异性的酶， 取代的苯乙胺、烯烃、醛、酰胺和硫化物。 胶束结构对酶构象的影响是 用ESR和动力学测量研究了它们的性质。 一种分子- 热力学模型，与水微相的性质相关 的条件下，也发展。 使用反胶束来保护酶不受通常的 有机溶剂的变性作用是研究酶的新途径 稳定化 目前的研究集中在使用反向 用于蛋白质纯化的胶束。 一个反向的内水池 胶束可以溶解大的蛋白质分子， 为反应物和底物的输送提供了大的表面积 和酶之间的联系 人们对这种行为知之甚少， 酶在这样的胶束或它们的动力学性质如何不同 从溶液中的酶。 研究人员使用 非极性表面活性剂，使极性有机基质的运输 可以通过在有机物中添加载体分子来增强 相，如季烷基胺。 目前有兴趣 描述水在反胶束中的行为 平衡热力学观点 更重要的是 一个分子热力学模型的发展， 水微相的性质的外部条件，所以 预测模型可用于生物反应器设计。