Cellulose is a major component of plant cell wall and the most abundant biomass on earth. Efficient degradation of cellulose makes it possible to produce fuels and chemicals from plant resources for the achievement of Bioeconomy. Cellobiohydrolases (CBHs) are types of cellulases hydrolyzing crystalline cellulose to soluble oligosaccharides, and one of the key enzymes in the biochemical conversion of cellulose. CBHs share a common two-domain structure, cellulose-binding domain and catalytic domain, and these domains cooperatively function for the effective hydrolysis of crystalline cellulose.
Dr. Igarashi recently reported the real-time visualization of crystalline cellulose degradation by individual cellulase molecules using high-speed atomic force microscopy. Such molecules were observed to slide unidirectionally along the crystalline cellulose surface, but at some points the movement of individual molecules was halted, leading to the appearance of traffic jams of enzyme molecules. In this lecture, he will present his findings and will discuss possible molecular mechanisms involved in the natural degradation of crystalline cellulose. He will also introduce neutron crystallography to clarify the detailed hydrolytic mechanisms of inverting cellulases and the application of a traffic simulator to the analysis of molecular behavior of cellulases towards connecting the mesoscopic gap between biochemical and single molecular analysis.