纤维素酶解速度的可视化表征与限制因素分析

纤维素酶解效率是木质纤维素高效生物转化的限制瓶颈,利用原子力显微镜(atomic force microscope,AFM)可以在水相中原位可视化表征纤维素酶分子运动行为,分析单个酶分子的运动速度及其影响因素.研究发现,高效降解结晶纤维素酶分子仅结合于特定结晶表面上的特定位点上,通过单方向运动完成逐层降解,过量酶分子结合于特定表面上会导致持续性运动"塞车"现象.结晶微纤丝的降解不仅取决于酶分子运动速度及其糖苷键断裂效率,更取决于酶分子可及底物的晶面大小及其晶面氢键解聚程度.以新结合模式、新运动模式或新组织模式的纤维素酶系或复合体应是纤维素酶研究的重点方向.

The Visual Representation for Cellulase Degradation Velocity and The Analysis for Limiting Factor

The efficient bioconversion of lignocelluloses is limited by the enzymatic hydrolysis efficiency, atomic force microscope (AFM) enables us to represent the Real-time motion behavior of the cellulase in the aqueous solution, to analysis the moving velocity and limiting factors. Cellobiohydrolase (CBH) is demonstrated to combine to specific site of the crystal face, to move unidirectionally and accomplish the degradation layer by layer. Over-dose cellobiohydrolase which combine to special face results in the "traffic jam" phenomenon. The degradation efficiency of crystal cellulose not only depends on the moving velocity of the enzyme molecule and the cleavage of glycosidic bond, but also lies on the crystal surface area of accessible substrate and the breakdown of hydrogen bonds on the crystal face. The novel cellulase complex or system with different combining mode, different movement mode or composition mode should be an important research aspect in the future.