Hydrogen bonds and twist in cellulose microfibrils.

Autor: Kannam SK; Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria 3122, Australia., Oehme DP; ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia., Doblin MS; ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia., Gidley MJ; ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, The University of Queensland, St Lucia, QLD 4072, Australia., Bacic A; ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia., Downton MT; IBM Research Australia, Level 5, 204 Lygon Street, 3053 Carlton, Victoria, Australia. Electronic address: mattdton@au1.ibm.com.
Jazyk: angličtina
Zdroj: Carbohydrate polymers [Carbohydr Polym] 2017 Nov 01; Vol. 175, pp. 433-439. Date of Electronic Publication: 2017 Jul 31.
DOI: 10.1016/j.carbpol.2017.07.083
Abstrakt: There is increasing experimental and computational evidence that cellulose microfibrils can exist in a stable twisted form. In this study, atomistic molecular dynamics (MD) simulations are performed to investigate the importance of intrachain hydrogen bonds on the twist in cellulose microfibrils. We systematically enforce or block the formation of these intrachain hydrogen bonds by either constraining dihedral angles or manipulating charges. For the majority of simulations a consistent right handed twist is observed. The exceptions are two sets of simulations that block the O2-O6' intrachain hydrogen bond, where no consistent twist is observed in multiple independent simulations suggesting that the O2-O6' hydrogen bond can drive twist. However, in a further simulation where exocyclic group rotation is also blocked, right-handed twist still develops suggesting that intrachain hydrogen bonds are not necessary to drive twist in cellulose microfibrils.
(Copyright © 2017 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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