Molecular simulation study with complex models of the carbohydrate binding module of Cel6A and the cellulose I alpha crystal

作者：Shiiba Hirohide; Hayashi Sachio; Yui Toshifumi^*

来源：Cellulose, 2012, 19(3): 635-645.

DOI：10.1007/s10570-012-9671-y

• Carbohydrate binding module
• Cellulose
• Molecular dynamics
• Docking study

A computer docking study was carried out on the (110) crystal surface of the cellulose I alpha crystal model for the carbohydrate binding module (CBM) of cellobiohydrolase Cel6A, which is produced by the filamentous fungus Trichoderma reesei. Three-dimensional structures of the CBM were constructed by the homology modeling method using the Cel7A CBM, which is another cellobiohydrolase from T. reesei, as a template, and refined by molecular dynamics calculations in the solution state. Among the three models tested, those with three disulfide bonds were selected for a docking analysis. The binding free energy maps represented changes in non-covalent interactions and solvation free energies with respect to the CBM position. These indicated two minimum positions within the unit cell for both the parallel and antiparallel orientation modes of the CBM with respect to the cellulose fiber axis. Molecular dynamics calculations under an explicit solvent system were performed for the four complex models derived from the minimum positions of the binding free energy maps. The complex models with CBM in the parallel orientation had the lowest binding energies.

• 出版日期2012-6