CARB 2 |
| RDCs (residual dipolar couplings) can be used to determine carbohydrate structure because they yield relative internuclear vector orientations. We determine five-membered carbohydrate ring pucker from a combination of 1H-13C one-bond, 1H-13C long-range, 13C-13C one-bond, and 1H-1H RDCs which fit the best structural model. Treating the five-membered ring as an isolated residue, 20 structures were generated, each with a different pucker and fit to RDCs. Best fits were found without NOEs or empirically parameterized Karplus curves. The pucker phase of the fructofuranosyl ring is between 20o and 70o, in agreement with previous studies. Furthermore, the analysis implies more than one stable pucker phase and rapid ring interconversion in this range. Thus, RDCs alone can reveal multiple puckers. We are currently applying the method to analyze the conformations of arabinofuranose rings from mycobacterium tuberculosis, and to the deoxyribose ring of nucleosides in DNA lesions. |
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Implications of Sugar Ring Conformations in Drug Design: A Symposium in Memory of Muttaiya Sundaralingam
9:00 AM-12:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- B409, Oral
Division of Carbohydrate Chemistry |