Synthesis and biochemical use of 2-trifluoromethylinosine for RNA structural analysis

CHED 869

Darren G. Stoub1, Marko Stankic1, and Peter A. Beal2. (1) Department of Chemistry, Whittier College, 13406 Philadelphia Street, Whittier, CA 90608, (2) Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, UT 84112
Protein-nucleotide interactions, such as found in RNA Adenosine Deaminase (ADAR-1) and RNA-Activated Protein Kinase (PKR), have recently received great interest. Mechanistic investigations have been hindered by the lack of effective tools to probe the three-dimensional structure of these important complexes. One available tool utilizes the NMR properties of fluorinated nucleotides; however, only one such nucleotide has been reported. We report our efforts towards the synthesis and structural implications of 2-trifluoromethylinosine, a novel nucleotide analog that can be used as an NMR probe for RNA/Protein interactions. Synthesis of the nucleotide is accomplished via bromination of protected guanosine, copper-mediated trifluoromethylation, followed by deprotection. The effect of the nucleotides structure on RNA duplex stability was determined. The use of the analog as an NMR probe was investigated. 6-trifluoromethylinosine represents a novel nucleotide analog suitable for the investigation of complex RNA structures including RNA/protein complexes.