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Investigating Receptor-ligand Systems of the Cellulosome with AFM-based Single-molecule Force Spectroscopy
Published on: December 20, 2013
Force pulling of single cellulose chains at the crystalline cellulose-liquid interface: a molecular dynamics study
Malin Bergenstråhle1, Esben Thormann, Niklas Nordgren
1Department of Fibre and Polymer Technology, Royal Institute of Technology, Teknikringen 58, SE-10044 Stockholm, Sweden. malbe@kth.se
Langmuir : the ACS Journal of Surfaces and Colloids
|February 24, 2009
Summary
Molecular dynamics simulations reveal solvent effects on pulling single cellulose molecules. Cyclohexane requires higher forces and energies than water for cellulose desorption, impacting atomic force microscopy interpretations.
Area of Science:
- Biomolecular simulations
- Materials science
- Surface chemistry
Background:
- Cellulose is a key biopolymer with crystalline structures.
- Atomic force microscopy (AFM) is used to probe single-molecule interactions.
- Understanding cellulose desorption is crucial for materials science applications.
Purpose of the Study:
- To model the pulling of single cellulose molecules from crystalline surfaces using molecular dynamics (MD) simulations.
- To investigate cellulose interactions during desorption in different solvents.
- To analyze the influence of initial octamer conformation and orientation on pull-off forces.
Main Methods:
- Molecular dynamics (MD) simulations were employed to mimic AFM experiments.
- Simulations were conducted in water and the organic solvent cyclohexane.
- Analysis included normal and lateral forces, pull-off energies, and hydrogen bond interactions.
Main Results:
- Solvent significantly affects cellulose desorption forces and energies.
- Higher forces (200-500 pN) and energies (43.5+/-6.0 kJ/mol) were observed in cyclohexane compared to water (58 pN, 18.2+/-3.6 kJ/mol).
- Lateral force components provide insights into initial molecular conformation and orientation.
Conclusions:
- MD simulations offer detailed insights into cellulose desorption processes.
- Findings aid in the interpretation of experimental AFM data for cellulose.
- Solvent choice critically influences the mechanics of single cellulose molecule extraction.
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