The Aqueous and Crystalline Forms of L-Alanine Zwitterion
The structural properties of L-alanine amino acid in aqueous solution and in crystalline phase have been studied by means of density-functional electronic-structure and molecular dynamics simulations. The solvated zwitterionic structure of L-alanine (+NH3-C2H4-COO−) was systematically compared to the structure of its zwitterionic crystalline analogue acquired from both computer simulations and experiments. It turns out that the structural properties of an alanine molecule in aqueous solution can differ significantly from those in crystalline phase, these differences being mainly attributed to hydrogen bonding interactions. In particular, we found that the largest difference between the two alanine forms can be seen for the orientation and bond lengths of the carboxylate (COO−) group: in aqueous solution the C—O bond lengths appear to strongly correlate with the number of water molecules which form hydrogen bonds with the COO− group. Furthermore, the hydrogen bond lengths are shorter and the hydrogen bond angles are larger for L-alanine in water as compared to crystal. Overall, our findings strongly suggest that the generally accepted approach of extending the structural information acquired from crystallographic data to a L-alanine molecule in aqueous solution should be used with caution.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: March 1, 2008
More about this publication?
- Journal of Computational and Theoretical Nanoscience is an international peer-reviewed journal with a wide-ranging coverage, consolidates research activities in all aspects of computational and theoretical nanoscience into a single reference source. This journal offers scientists and engineers peer-reviewed research papers in all aspects of computational and theoretical nanoscience and nanotechnology in chemistry, physics, materials science, engineering and biology to publish original full papers and timely state-of-the-art reviews and short communications encompassing the fundamental and applied research.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites