Binding Forces of Cellulose Binding Modules on Cellulosic Nanomaterials

Abstract

In this study, the interaction forces between different cellulosic nanomaterials and a protein domain belonging to cellulose binding modules family 1 (CBM1) were investigated at the molecular scale. Cellulose binding modules are protein domains found in carbohydrate active enzymes having an affinity toward cellulosic materials. Here, the binding force of a fusion protein containing a cellulose binding module (CBM1) produced recombinantly in E. coli was quantified on different cellulose nanocrystals immobilized on surfaces. Adhesion of the CBM on cellulose with different degrees of crystallinity as well as on chitin nanocrystals was examined. This study was carried out by single molecule force spectroscopy using an atomic force microscope, which enables the detection of binding force of individual molecules. The study contains a preliminary quantification of the interactions at the molecular level that sheds light on the development of new nanocellulose-based nanocomposites with improved strength and elasticity.

Structural Dynamics of Lytic Polysaccharide Monooxygenase during Catalysis

“…The same reasoning could explain the negligible effect of crystalline cellulose on CBM. It is known from the literature that CBM binding to cellulose surface is mediated via side chains of aromatic residues [53,54]. Since the overall fold of CBM is highly compact, it is not likely that side-chain mediated cellulose-binding may induce significant changes in CBM hydrogen bonding or solvent protection detectable by HDX-MS.…”

High force catch bond mechanism of bacterial adhesion in the human gut

“…This complex anchors the base of the cellulosome network to the cell surface, and is required in vivo to maintain cell adhesion under hydrodynamic flow and applied shear stress. Single-molecule interactions between fiber substrates and cellulose-binding modules (CBMs) have been reported to rupture at moderate forces (~50 pN) 18,19 . However, due to the multivalency of interactions the mechanical requirements on the anchoring complex are more stringent.…”

Analysis of the phosphorylome of trichoderma reesei cultivated on sugarcane bagasse suggests post-translational regulation of the secreted glycosyl hydrolase Cel7A

“…Cellulose hydrolysis by T. reesei involves sequential steps, such as enzyme adsorption to the cellulose surface, formation of a complex between the catalytic domain (CD) and the cellulose reducing end, entry of cellulose into the catalytic tunnel for the hydrolysis itself, decomplexation, and detachment of the enzyme. The recognition and the attachment to the cellulose fiber by the CBD of the enzyme are crucial for the complexation of the CD with cellulose and, thus, cellulose hydrolysis [ 70 , 71 ]. Considering the importance of the interaction between the CBD and the cellulose fiber, we performed a docking analysis and verified that the phosphorylated form of Cel7A presents greater affinity for the cellulolytic fiber than the non-phosphorylated version, bearing in mind that the binding energy value increases with the size of the carbohydrate chain.…”