多模块糖苷水解酶一般由催化结构域与碳水化合物结合模块通过一段连接肽（linker）序列相连。糖苷水解酶的Linker及蛋白末端无序残基通常不具备稳定的3D结构，属于固有无序蛋白(Intrinsically disordered proteins, IDPs)。到目前为止，糖苷水解酶的IDPs氨基酸组成、长度和刚度对酶的热适应性进化、催化效率、酶与底物结合的影响，尚不清楚。本项目拟通过linker置换、关键氨基酸突变等，构建多模块糖苷水解酶突变体，运用小角X射线散射、单分子荧光、核磁共振等方法研究糖苷水解酶中linker在溶液中的瞬时构象变化，解析其对糖苷水解酶热稳定性、催化效率、酶与底物结合、持续性等的影响，阐明linker在酶构象平衡过程中作用。通过研究多模块糖苷水解酶IDPs在蛋白热适应性进化过程中的氨基酸组成优化机制，建立IDPs序列与功能之间的关系，为体外重构糖苷水解酶奠定基础。

Multimodular glycoside hydrolase contains multiple binding modules and catalytic domains which are connected by linker peptide. The linkers and terminal disordered residues have no single and stable 3D structures, which can be designated as intrinsically disordered proteins (IDPs). Till now, the roles for linker peptides and terminal disordered residues (amino acid composition, length, and stiffness) on cellulase properties (interdomain interaction, thermostability, conformation, and binding between enzyme and substrate) have not yet been determined. In this project, we will investigate the transition conformation of IDPs in solution by thermodynamic analysis, interdomain interaction determination, small angle x-ray scattering, single molecule fluorescence resonance energy transfer, and NMR. The relationship between IDPs and enzymatic properties of glycoside hydrolases (thermostability, substrate specificity, binding, sliding, and degrading between enzyme and substrate, and interdomain interaction) will be investigated. IDPs are optimized during enzyme evolution, which give us a clue on the function of IDPs. The relationship between the sequence and function of IDPs will be established, which will lay the foundation for designing and constructing industrial catalysts for efficient cellulose degradation.