由于环糊精葡萄糖基转移酶(CGT酶)作用淀粉合成环糊精反应中存在较强的产物抑制，造成环糊精得率较低、生产成本偏高，因此，着力于对产物抑制进行调控显得尤为重要。本项目以CGT酶为研究对象，首先，通过动力学方程分析不同类型环糊精引发产物抑制的作用方式，比较其差异，探究不同来源CGT酶催化反应中产物抑制的规律；然后，利用结构分析、计算机模拟和定点突变等技术，解析与CGT酶产物抑制相关的一级结构特征，阐明重要氨基酸残基对产物抑制产生影响的规律及机制；最后，构建具有较低产物抑制、能高产环糊精的CGT酶突变体，总结出基于CGT酶本身的产物抑制调控策略，从根本上提高环糊精得率、降低生产成本，并为其他淀粉酶促反应产物抑制调控提供理论基础和实践指导。

Strong product inhibition in enzymatic reaction for cyclodextrin synthesis from starch by cyclodextrin glycosyltransferase (CGTase) has resulted in relatively low yield and high production cost of cyclodextrin, so it is particularly important to regulate products inhibition. The item focuses on the CGTases. Firstly, the inhibition modes for different types of cyclodextrin will be investigated by the kinetic equations to find the regular pattern of product inhibition in enzymatic reaction for cyclodextrin synthesis. Then, the primary structure characteristics of CGTase related to cyclodextrin product inhibition will be analyzed by structural alignment, computer simulation, and site-directed mutagenesis. Effects of important amino acid residues on product inhibition are subsequently studied. Finally, the CGTase mutants can be constructed to lower product inhibition and enhance cyclodextrin production. In addition, Based on these researches, regulation strategies for product inhibition in enzymatic reaction for cyclodextrin synthesis are summarized, which helps to significantly enhance the cyclodextrin yield and reduce the production cost, and then provide theoretical basis and practice guidance for regulating products inhibition in other amylase-catalyzed reactions.