Variation of xyloglucan substitution pattern affects the sorption on celluloses with different degrees of crystallinity

Abstract

The sorption of xyloglucan (XG) on cellulose is a basic feature of the supramolecular assembly of plant cell walls. The binding to cellulose of xyloglucan fractions from Rubus fruticosus suspension-cultured cells with different substitution patterns was assayed on celluloses having various degrees of crystallinity between 20 and 95%. The primary structure of XGs differing in their Xyl/Glc ratio affected their binding to cellulose. The less substituted XGs gave the highest binding yields. Selective removal of the terminal fucosyl residues of XGs differentially affected the binding depending on the crystallinity of cellulose. The results showed large variations on the way cellulose crystallinity affects the binding interaction of XGs. Interestingly, one of the highest binding capacities was exhibited by the primary cell wall cellulose isolated from the actual R. fruticosus cells which also had the lowest crystallinity. Differences in binding to primary wall cellulose appeared to be inversely related to the global substitution of the glucan main chain of XGs.Abbreviations: XG -xyloglucan; XGn -native xyloglucan; XG-deF -de-fucosylated xyloglucan.

CHITINASE-LIKE1/POM-POM1 and Its Homolog CTL2 Are Glucan-Interacting Proteins Important for Cellulose Biosynthesis in Arabidopsis

“…In fact, we did observe a significant reduction in the crystalline cellulose content in the ctl double mutants (Figure 9). Previous in vitro results have shown that a decrease in cellulose crystallinity causes an increase in XG binding capacity to the cellulose (Chambat et al, 2005). Consistent with this and with the cellulose-hemicellulose interaction model suggested by Pauly et al (1999a), we observed a greater degree of hemicellulose-related sugars in the insoluble cell wall fraction in the ctl1 ctl2 mutant (Table 1).…”

“…These interactions are not constant along the fibrils, leading to crystalline fibrils interspersed by amorphous zones, in which hemicelluloses, mainly xyloglucans (XGs) in dicot plants, become entrapped (Pauly et al, 1999a;Cosgrove, 2005). XGs can influence the structure of cellulose crystals (Whitney et al, 1995), and low levels of cellulose crystallinity lead to increased XG binding capacity (Chambat et al, 2005). In addition, XGs can be associated with cellulose microfibrils via hydrogen bonds (Hayashi, 1989;Pauly et al, 1999a).…”

Cortical microtubules optimize cell‐wall crystallinity to drive unidirectional growth in Arabidopsis

“…Reduced crystallinity could therefore be an important adaptation for maintaining anisotropic expansion during rapid growth. In vitro adsorption analysis showed that the binding capacity of the hemicellulose xyloglucan is higher when cellulose has a low degree of crystallinity (Chambat et al, 2005). Thus, a higher proportion of amorphous cellulose during rapid wall expansion could promote a greater degree of tethering by xyloglucan.…”

“…The degree of crystallinity, a measure of the ratio of crystalline to amorphous cellulose in the whole cell wall, is one of the main characteristics determining the overall mechanical properties of cellulose microfibrils and the cell wall itself. High cellulose crystallinity makes microfibrils highly inextensible, but also limits cross-linking by hemicelluloses (Chambat et al, 2005), which is crucial for resisting mechanical stress during rapid cell expansion. In this study, we show that the proportion of crystalline cellulose decreases when cell elongation rates increase, but that, if the microtubule polymer mass is reduced, as occurs in the mor1-1 temperature-sensitive mutant, the proportion of crystalline cellulose remains high.…”

Revision of adsorption models of xyloglucan on microcrystalline cellulose

“…In the present study, Avicel cellulose was used, which is highly crystalline (53.8 %) and mostly contains the Ib structure (96 %) (Szymańska-Chargot et al 2011). Chambat et al (2005) showed the different cellulose structures, for which the crystallinity and specific surface area are key factors that potentially influence xyloglucan binding. Because the effective surface area for binding varies with xyloglucan size, the binding kinetics are complicated and partly limited by size-dependent xyloglucan diffusion into the pores of the particles (Park and Cosgrove 2015).…”