Development of organic solvent stable enzymes by protein engineering

酶是非常好的催化剂，因为它们在温和的条件下有效和特异地催化许多类型的反应。这样他们就不会产生副产品，也不会消耗大量能源。当酶在化学过程中用作催化剂时，可以减少工艺步骤，提高产率，减少原料、废物、溶剂、能源、设备、公用事业、生产成本、环境污染，并增加利润和竞争力。然而，有时酶的一些优点变成了缺点。虽然酶在温和的条件下是活性的，但在极端条件下，如低pH、高pH和温度，以及在有机溶剂中，酶很容易变性并失去催化活性。特别是，尽管大多数精细化学品不溶于水，但它们可以溶于有机溶剂。然后，需要耐有机溶剂的酶作为催化剂来生产精细化学品。本研究对酶的有机耐溶剂性进行了澄清，并利用蛋白质工程技术开发了新型的有机耐溶剂酶。本研究的研究内容如下：(1)了解酶的耐溶剂性(2)耐有机溶剂酶的基因克隆(3)耐有机溶剂酶基因表达系统的构建(4)利用蛋白质工程技术建立具有有用底物专一性的耐有机溶剂酶

Enzymes are very good catalysts, because they effectively and specifically catalyze many kinds of reactions under mild conditions. Then they do not produce by-products and not consume a lot of energy. When enzyme are used as a catalyst in a chemical process, it is possible to reduce process steps, to increase yield, to reduce raw materials, waste materials, solvents, energy, equipment, utilities, production costs, environment pollution, and to increase profits and competitiveness. However, sometimes some advantages of enzymes become disadvantages. Although enzymes are active under mild condition, they are easily denatured and lose catalytic activity under extreme conditions, such as low pH, high pH and temperature, and also in the presence of organic solvents. Especially, although most fine chemicals are insoluble in water, they are soluble in organic solvents. Then organic solvent-tolerant enzymes are required as catalysts to produce fine chemicals. In this research, clarification of organic solvent-tolerance of enzymes and development of new organic solvent-tolerant enzymes using protein engineering were performed. The examined item in this research is as follows.(1) Understanding of the organic solvent-tolerance of enzyme(2) Gene cloning of the enzyme in which organic solvent tolerance is desired(3) Construction of the gene expression system of the organic solvent tolerant enzyme(4) Development of the organic solvent tolerant enzyme having useful substrate specificity by the protein engineering