Computational simulations of the Trichoderma reesei cellobiohydrolase I acting on microcrystalline cellulose Iβ: the enzyme–substrate complex
| Autor: | Peter I. Hansen, John W. Brady, William S. Adney, Joseph M. Cleary, James F. Matthews, Mark R. Nimlos, Linghao Zhong, Charles L. Brooks, Ross C. Walker, Michael E. Himmel, Michael F. Crowley |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Cellulase
Biochemistry Protein Structure Secondary Analytical Chemistry chemistry.chemical_compound Cellodextrin Cellulose 1 4-beta-Cellobiosidase Computer Simulation Cellulose Trichoderma reesei Trichoderma Enzyme substrate complex Binding Sites Molecular Structure biology Organic Chemistry Substrate (chemistry) General Medicine biology.organism_classification Cellulose microfibril Microcrystalline cellulose Kinetics Models Chemical chemistry Chemical engineering biology.protein Thermodynamics |
| Zdroj: | Carbohydrate Research. 344:1984-1992 |
| ISSN: | 0008-6215 |
| DOI: | 10.1016/j.carres.2009.07.005 |
| Popis: | Cellobiohydrolases are the dominant components of the commercially relevant Trichoderma reesei cellulase system. Although natural cellulases can totally hydrolyze crystalline cellulose to soluble sugars, the current enzyme loadings and long digestion times required render these enzymes less than cost effective for biomass conversion processes. It is clear that cellobiohydrolases must be improved via protein engineering to reduce processing costs. To better understand cellobiohydrolase function, new simulations have been conducted using CHARMM of cellobiohydrolase I (CBH I) from T. reesei interacting with a model segment (cellodextrin) of a cellulose microfibril in which one chain from the substrate has been placed into the active site tunnel mimicking the hypothesized configuration prior to final substrate docking (i.e., the +1 and +2 sites are unoccupied), which is also the structure following a catalytic bond scission. No tendency was found for the protein to dissociate from or translate along the substrate surface during this initial simulation, nor to align with the direction of the cellulose chains. However, a tendency for the decrystallized cellodextrin to partially re-anneal into the cellulose surface hints that the arbitrary starting configuration selected was not ideal. |
| Databáze: | OpenAIRE |
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