Abstract:

Enzymatic catalysis plays an increasing role in the development of bio-industry. However, there are still many problems in the application of some enzymes, which hinder the development of biocatalysis. This paper focused on the enzyme substrate specificity and reviewed the advantages of enzymes, such as high specificity, increased efficiency, and environmentally-friendly process. The applications of enzymes in fine chemistry and pharmaceutical synthesis were introduced. The paper also summarized the current methods used in engineering of enzyme substrate specificity, including chemical modification, irrational and rational design. Chemical reaction was a direct-viewing method applied in enzyme modification. Irrational design was often employed to obtain the better mutants with increased substrate specificity through error-prone PCR and DNA shuffling. In the rational design, enzyme engineering was based on their sequences and structures. Starting from reshaping the active pockets for increasing the substrate specificity and changing the enzymatic reaction type, this paper elaborated the methods of rational design to enhance the substrate specificity and provided a reference for future substrate specificity engineering.

Key words: biocatalysis, design of enzyme, substrate specificity, molecular modification

摘要：

随着生物产业的发展，生物酶催化发挥着越来越重要的作用。然而，部分酶在应用过程中仍然存在诸多问题，影响了生物催化的进一步发展。本文以酶的底物特异性为切入点，回顾了酶的专一性、高效性和环保性；介绍了酶在药物合成和天然产物改性领域的应用以及所遇到的问题；综述了酶的底物特异性改造过程中各种方法的应用，包括化学修饰、非理性和理性设计。化学修饰作为一种直观的修饰方法，通过化学反应对酶分子进行改造；非理性设计是利用易错PCR和DNA Shuffling等手段获得底物特异性提高的突变体；理性设计是基于序列和结构信息对酶分子进行改造。本文从重塑活性口袋提高酶的底物特异性和重塑活性口袋改变酶促反应类型两个方面出发，详述了理性设计改变酶的底物特异性的方法，为酶的特异性改造提供借鉴。

关键词: 生物催化, 酶设计, 底物特异性, 分子改造