The first example of sequence-specific non-uniformly 13C5 labelled RNA: Synthesis of the 29mer HIV-1 TAR RNA with 13C relaxation window

Article abstract of DOI:10.1016/S0040-4020(99)00294-X

A complete synthetic protocol as well as ¹H- and ¹³C-NMR data on the monomer building blocks used for the solid-phase synthesis of specifically ¹³C-labelled (99 atom % ¹³C) stem (²⁷A and ⁴³G), bulge (²⁴C) and loop (³¹U) regions of 29mer HIV-1 TAR RNA hairpin starting from the ¹³C₆-D-glucose are presented. The complex NMR spectra of ¹³C-labelled monomer building blocks, due to the interaction of various ¹³C and ¹H spins, have been assigned. It has been demonstrated by heteronuclear 2D NMR that the non-uniform labelling of the HIV-1 TAR 29mer RNA achieved herein by chemical synthesis provides an optimal opportunity to perform full T₁ and T₂ relaxation measurements (the 'NMR Relaxation Window') of each type of sugar-carbons for all four strategically placed ¹³C-labelled residues in a unique and unprecedented manner because of minimal overlap of ¹³C resonances compared to uniformly labelled oligo-RNA.