S109: Understanding fungal glycoside hydrolases and oxidative enzymes with simulation and experiment

Fungal cellulases and the newly characterized oxidative GH61 enzymes form the basis of many industrial enzyme cocktails for biomass deconstruction. This talk will describe several computational and experimental studies aimed at understanding how the Trichoderma reesei cellulases Cel7A and Cel6A and oxidative enzymes deconstruct cellulose. The overall aim of these studies is to guide rational protein engineering efforts to improve enzyme performance. We show that O-glycosylation has a significant impact on cellulase binding affinity, and that product inhibition varies dramatically between processive and non-processive enzymes. We also predict that the Cel7A and Cel6A linkers may possess more function than previously considered. Additionally, a new experimental approach is presented to measure the amount of productively bound cellulase on cellulose, which is a key measurement for calculating the intrinsic kinetics of enzymes that work at solid-liquid interfaces. Lastly, we examine the effects of the recently characterized oxidative enzymes on cellulose with molecular simulation. Overall, these results provide new insights into our collective understanding of the mechanisms by which fungal enzymes deconstruct cellulose.