High-throughput approaches in enzyme discovery and engineering

酶是非凡的生物催化剂，它们是细胞工厂的机器，由大自然在亿万年的进化过程中精心打造。在自然界，酶催化生物体内的化学反应，而在生物技术应用中，它们被从自然环境中提取出来，用于许多行业中重要的化学过程。由于工业生物催化中的酶经常在不同于它们进化的自然环境和功能的条件和目的下使用，因此在这些过程中有很大的空间来改进它们的性能。通过酶工程的努力，例如定向进化，酶在生物工业应用中的潜力得到了极大的扩展。我提出了一项研究计划，重点是发现和设计用于生产高价值生物活性化合物的酶生物催化剂，以及作为石油产品替代品的生物可再生化学品。这将通过最初针对两类酶来实现：将糖单元连接到天然产品支架上以产生生物活性糖基化小分子的糖基转移酶；参与将脂肪酸转化为碳氢化合物的脱羧酶，这些碳氢化合物可能被用作燃料和化学构建块来取代石化产品。我们将开发方法，使我们不仅能够发现，而且能够设计产生这些有价值化合物的酶。利用定向进化，我们将提高这些酶生物催化剂生产此类化合物的效率，并改变它们的特异性，以扩大它们可以产生的分子种类。生产可再生资源和高价值生物活性化学品的生物催化工具的工程将具有重大的社会和经济效益。

Enzymes are extraordinary biocatalysts they are the machinery of cell factories, crafted by Nature over aeons of evolution. In Nature, enzymes catalyze the chemical reactions within living organisms, whereas in biotechnological applications, they are taken out of their natural context and used for chemical processes that are important in many industries. Since enzymes in industrial biocatalysis are often used in conditions and for purposes quite different from the natural context and function for which they have evolved, there is much room to improve their performance in these processes. The potential of enzymes in bioindustrial applications is greatly expanded through enzyme engineering efforts, such as directed evolution. I propose a research program focused on the discovery and engineering of enzyme biocatalysts for the production of high-value bioactive compounds and of biorenewable chemicals as alternatives to petroleum products. This will be achieved by initially targeting two classes of enzymes: glycosyltransferases that attach sugar units onto natural product scaffolds to produce bioactive glycosylated small molecules; and decarboxylases involved in the conversion of fatty acids into hydrocarbons that can potentially be used to replace petrochemicals as fuels and chemical building blocks. We will develop methods that will enable us not only to discover, but to engineer the enzymes that produce these valuable compounds. Using directed evolution we will improve the efficiency of these enzyme biocatalysts in producing such compounds, and alter their specificity to expand the kinds of molecules that they can produce. The engineering of biocatalyst tools for producing renewable resources and high-value bioactive chemicals will be of significant social and economic benefit.