SNIC SUPR
Molecular dynamics simulations of hydrated biomacromolecules
Dnr:

SNIC 2020/5-97

Type:

SNIC Medium Compute

Principal Investigator:

Lars Berglund

Affiliation:

Kungliga Tekniska högskolan

Start Date:

2020-03-01

End Date:

2021-03-01

Primary Classification:

10402: Physical Chemistry

Webpage:

Allocation

Abstract

Water constitutes a major limiting factor when it comes to exploiting cellulosic biomaterial in novel applications. The effect of water are ubiquitous but the molecular origins of those effects remain obscure. The project aim is to clarify those molecular origins by combining nuclear magnetic resonance NMR on the experimental side and molecular dynamics simulations MD on the interpretational side. Suitable scattering experiments will provide additional experimental support. MD simulations will be performed using established protocols [1-3] of model systems (such as hemicellulose/cellulose interfaces, chitin fibrils and fibril aggregates) at varying hydration. The generated molecular structure and dynamics will be compared directly to experimental data in the form of (i) calculated NMR relaxation times, (ii) calculated static and dynamic structure factors, and (iii) calculated self diffusion of water. Simulated properties are spatially resolved, in the sense that they can be used to interpret experimental data with respect variations in the local chemical environment from, e.g., heterogeneous chemical structure, presence of interfaces, defects in crystal structure, or hydration. [1] P. Chen et al. Quantifying Localized Macromolecular Dynamics within Hydrated Cellulose Fibril Aggregates. Macromolecules, 2019, 52, 7278-7288 [2] P. Chen et al. Hydration-Dependent Dynamical Modes in Xyloglucan from Molecular Dynamics Simulation of 13C NMR Relaxation Times and Their Distributions. Biomacromolecules, 2018, 19, 2567-2579 [3] Y. Wang et al. Swelling and dimensional stability of xyloglucan/montmorillonite nanocomposites in moist conditions from molecular dynamics simulations. Comput. Mater. Sci., 2017, 128, 191-197