AA9家族多糖裂解单加氧酶(LPMO)可氧化断裂多糖糖苷键助力糖苷酶水解，协同使用可大幅提高纤维素酶效率。依据AA9LPMO对葡萄糖C1和C4位的氧化偏好，可分为1、2、3亚家族。AA9LPMO底物结合方式影响其活性及氧化选择性，但缺乏深入研究，最新研究进展提示纤维素结合域CBM1、糖基化修饰、酶与底物接触平面的芳香族氨基酸及各亚家族保守氨基酸是影响AA9LPMO与底物结合的关键因素。本项目首先获得嗜热毁丝霉中所有含CBM1域的AA9LPMO（共4个，涵盖3个亚家族），明确其功能及性质；重点研究CBM1域、糖基化、关键氨基酸对其与底物结合进而对催化能力的影响；进一步获得其AA9催化域、CBM1域及其与底物共结晶晶体结构，直观解析其催化域、结合域与底物结合机制；利用上述信息指导分子改造，获得高效LPMO。本项目通过从多角度研究LPMO底物结合机制这一科学问题，加深对LPMO催化机制的认识。

Auxiliary activities family (AA) 9 lytic polysaccharide monooxygenases (LPMO) have the ability to oxidative cleavages the glycosidic bonds of cellulose polysaccharides. The synergy of AA9LPMO and cellulase mixture will great promote the cellulase degradation efficiency. According the AA9 LPMO oxidation selectivity on glucose C1 or C4, AA9 LPMOs could be divided into three sub-families named AA9 LPMO1, AA9 LPMO2 and AA9 LPMO3. The substrate binding mechanism of AA9 LPMO is important to its activity and oxidation selectivity, but lack of in-depth research. Recent research advances suggest that the substrate binding of AA9 LPMO with cellulose is affected by three important factors: the cellulose binding CBM1 domain of LPMO, the glycosylation of the protein, the important amino acids of the protein. In this study, all the CBM1-containing AA9 LPMOs of the efficient cellulose degradation fungus Myceliophthora thermophila will be cloned and charactered. Two of the four CBM1 contained MtLPMOs belong to AA9 LPMO1, one belong to AA9 LPMO2 and one belong to AA9 LPMO3.The effect of the CBM1 domain, N-glycosylation and the important amino acids on substrate binding and catalytic activity of MtLPMOs will be studied carefully. The crystal structures of the AA9 catalytic domain of MtLPMOs (MtLPMO-AA9) and CBM1 domain of MtLPMOs (MtLPMO-CBM1) as well as the MtLPMO-AA9-substrate and MtLPMO-CBM-substrate complex will be obtained and analyzed. Based on these results, the MtLPMOs will be molecular modified to obtain high activity LPMOs. This work will elucidate the substrate binding mechanism of MtLPMOs from several aspects and deepen the knowledge of the LPMO substrate selectivity and catalytic mechanism.