Determining the Crystal Structure of Cellulose III by Modeling

Recently, a one-chain monoclinic unit cell for Cellulose IIII having a single glucose in the asymmetric unit was proposed based on high-resolution diffraction patterns. The new work challenged a two-chain structure published 25 years earlier, although it did not provide new three-dimensional coordinates. Our goals were to solve the structure by modeling, find whether modeling would reject the previously determined two-chain unit cell, and compare the model with the anticipated experimental structure. Combinations of the O2, O3, and O6 hydroxyls produced 54 starting structures. Clusters of 13 cellotetraose chains terminated by methyl groups for each of the 54 starting structures were optimized with MM3(96). Hydroxyl groups on 16 of these 54 structures reoriented to give very similar hydrogenbonding schemes in the interiors, along with the lowest energies. The one-chain cell models had much lower energy. The eight best “up” one-chain models agree well with the structure newly determined by experiment.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year

2005

Author dc:creator

• Ford, Zakhia

Contributors dc:contributor

• Stevens, Edwin
• Thibodeaux, Devron
• Wiley, John

• Carbohydrate
• Molecular Mechanics
• Hydrogen bonding
• Packing

Repository record dc:identifier

https://scholarworks.uno.edu/td/291

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-1324