ORGN 740 |
| Protein synthesis is a fundamental biological process. A mechanistic characterization of ribosome-catalyzed peptidyl bond formation has been a long term goal of biochemical research, which is still far from achieved, and knowledge of the transition state structure of this acyl transfer reaction may lead to extremely strong inhibitors which are potential antibiotics. However, the transition state is largely intractable to direct experimental observation because of its fleeting lifetime. Kinetic isotope effect (KIE) permits experimental access to the transition state structure, and are the only experimental methods currently available to obtain its detailed physical-chemical features. A modified fragment assay has been developed in our lab, and has been successfully used to measure the KIE of nucleophilic amine of the A-site substrate. To further determine KIEs of the P-site substrate, the synthesis of the trinucleotide conjugate (CCA-Phe-cap-biotin) has been developed, and is very efficient for incorporation of isotopes at various sites. The P-site substrate has been prepared in 26 steps with an overall yield of 18%(11 linear steps), starting from biotin. The success of synthesis relies on the judicious selection of orthogonal protecting groups for 5'-hydroxyls and other active sites and both 3'-esterification and nucleotide coupling by activation via imidazolium ions. |
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Lipids, Nucleotides, Biosynthesis, and Mimetics
8:00 AM-12:00 PM, Thursday, 1 September 2005 Washington DC Convention Center -- 202B, Oral
Division of Organic Chemistry |