ORGN 397 |
| Studies on chemical modifications of non-canonical base pairs in RNA are of fundamental biochemical interest and may yield novel RNA analogues for practical applications in biotechnology. We synthesized and studied several short RNA fragments containing G-U wobble base pairs having imidazole attached to the C5-position of uracyl. UV melting studies showed that imidazole modified sequences were somewhat thermally less stable (about 0.4 kcal mol-1 per modification) than the sequences having non-modified G-U base pairs. We also used CD spectroscopy and osmotic stress to study the effect of imidazole on structure and hydration of the modified G-U base pairs. Osmotic stress is a thermodynamic method to evaluate the trends in hydration and allows to determine the number of water molecules involved in the double helix and are released upon its melting. Our results showed that the imidazole modification generally caused small changes in structure and hydration. However, in one case a relatively larger reduction in thermal stability was accompanied by a more significant loss of hydration. The results point out the important role hydration plays in structure and function of nucleic acids.
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New Reactions and Methodology, Bioorganic Chemistry, Molecular Recognition and Self Assembly
8:00 PM-10:00 PM, Tuesday, 28 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Sci-Mix
Division of Organic Chemistry |
