Orlowski, A,Artzi, L,Cazade, PA,Gunnoo, M,Bayer, EA,Thompson, D

2018

March

Physical chemistry chemical physics : PCCP

On the distinct binding modes of expansin and carbohydrate-binding module proteins on crystalline and nanofibrous cellulose: implications for cellulose degradation by designer cellulosomes

Published

()

MOLECULAR-DYNAMICS SIMULATIONS PLANT-CELL WALLS BACTERIAL EXPANSIN CLOSTRIDIUM-THERMOCELLUM AMORPHOUS CELLULOSE FORCE-FIELD BIOMASS RECALCITRANCE ENZYMATIC-HYDROLYSIS CELLOBIOHYDROLASE-I POTENTIAL FUNCTIONS

20

8278

8293

Transformation of cellulose into monosaccharides can be achieved by hydrolysis of the cellulose chains, carried out by a special group of enzymes known as cellulases. The enzymatic mechanism of cellulases is well described, but the role of non-enzymatic components of the cellulose-degradation machinery is still poorly understood, and difficult to measure using experiments alone. In this study, we use a comprehensive set of atomistic molecular dynamics simulations to probe the molecular details of binding of the family-3a carbohydrate-binding module (CBM3a) and the bacterial expansin protein (EXLX1) to a range of cellulose substrates. Our results suggest that CBM3a behaves in a similar way on both crystalline and amorphous cellulose, whereas binding of the dual-domain expansin protein depends on the substrate crystallinity, and we relate our computed binding modes to the experimentally measured features of CBM and expansin action on cellulose.

10.1039/c7cp07764e