Abstract
Curdlan and other β-1,3-D-glucans form right-handed triple helices, and it has been believed that the intermolecular H-bond is present at the center of the helix to maintain the structure. In this H-bond model, three secondary OH groups form an inequilateral hexagonal shape perpendicular to the helix axis. This hexagonal form seems to be characteristic for β-1,3-D-glucans and is widely accepted. We carried out MOPAC and ab initio calculations for the curdlan helix, and we propose a new intermolecular H-bonding model. In our model, the H-bonds are formed between the O(2)-atoms on different x-y planes along the curdlan helix, hence the H-bonds are not perpendicular to the helix axis. The new H-bonds are connected along the helix, traversing three curdlan chains to make a left-handed helix. Therefore, the H-bonding array leads to a reverse helix of the main chain. According to our MOPAC calculation, this model is more stable than the previous one. We believe that the continuous H-bonding array is stabilized by cooperative phenomena in the polymeric system.
Original language | English |
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Pages (from-to) | 916-924 |
Number of pages | 9 |
Journal | Chemistry and Biodiversity |
Volume | 1 |
Issue number | 6 |
DOIs | |
Publication status | Published - Dec 1 2004 |
All Science Journal Classification (ASJC) codes
- Bioengineering
- Biochemistry
- Chemistry(all)
- Molecular Medicine
- Molecular Biology