A coarse-grain force-field for xylan and its interaction with cellulose

Area of Science:

• Biomolecular Modeling
• Materials Science
• Computational Chemistry

Background:

• Xylan and cellulose are key plant cell wall components.
• Understanding their interactions is crucial for biomass processing.
• Atomistic models are computationally expensive for large systems.

Purpose of the Study:

• To develop and validate a coarse-grain (CG) model for xylan adsorption on crystalline cellulose.
• To investigate the structural behavior of xylan on different cellulose surfaces using CG simulations.

Main Methods:

• A coarse-grain model representing xylosyl/glucosyl units as single beads was constructed.
• Force-field parameters were derived from atomistic simulations of xylan fragments.
• The CG model was validated against atomistic simulations and experimental data for isolated and adsorbed xylan.

Main Results:

• The CG model accurately reproduced xylan chain conformations in isolation and bulk.
• Simulations showed good agreement with experimental measurements for xylan adsorption on the cellulose (110) surface.
• Extended xylan structures were observed on cellulose, along with novel coiled conformations, particularly on hydrophobic surfaces.

Conclusions:

• The developed CG model provides an efficient and accurate tool for studying xylan-cellulose interactions.
• The model reveals that xylan can adopt diverse conformations, including coiled structures, on crystalline cellulose surfaces.
• This finding has implications for understanding biomass structure and developing new biomass utilization strategies.