麦芽糖淀粉酶是一种重要的工业用酶，在食品、饲料、酿酒和医药工业等领域具有广泛的应用，发掘性能优良催化机制明确的麦芽糖淀粉酶具有十分重要的意义。本课题组前期获得一种来源于粘细菌的具有较高催化效率的新型麦芽糖淀粉酶，其淀粉水解产物中麦芽糖含量高达90%且不含葡萄糖。在以低浓度（2 mM）和高浓度（200 mM）麦芽三糖为底物时，该酶均能够高效产生麦芽糖且终产物中无葡萄糖产生，表明该淀粉酶水解过程中可能存在一种与已报道淀粉酶不同的催化机制。本项目拟对该麦芽糖淀粉酶产高纯度麦芽糖的催化机制进行研究，利用高效液相色谱、甲基化修饰以及14C放射性同位素标记技术分析酶解产物，阐明该麦芽糖淀粉酶产麦芽糖过程中底物识别和多分子催化反应过程。通过序列分析和酶晶体结构解析，确定参与催化反应的关键氨基酸的催化功能。本研究将阐明麦芽糖淀粉酶产高纯度麦芽糖的催化机制，以期为麦芽糖淀粉酶的后续应用奠定基础。

Amylolytic enzymes are important industrial enzymes which are widely applied in food, animal nutrition and medical industry, exploring excellent amylolytic enzymes becoming more and more popular and significant. In our previous research we cloned a new maltose-producing α-amylase from myxobacterium Corallococcus sp. EGB, about 90% level of maltose was produced without glucose during the hydrolysis reactions. High-efficiency catalytic reactions were achieved with the 2 mM and 200 mM maltotriose, which indicated that novel catalytic mechanism may exist, which is different from the reported amylases. In this research, the catalytic mechanism that involved in the production of high purity maltose is studied, the process of the molecular catalysis will be clarified by product analysis and methylation modification and 14C radioisotope labeling. The key functional amino acids also be researched based on sequence analysis and crystal structure analysis. The catalytic mechanism that involved in the production of high purity maltose will be clarified from the research. Our research will provide theory evidence for the application of AmyZ in the future.