title: 13C-direct detected NMR experiments for the sequential J-based resonance assignment of RNA oligonucleotides.
abstract: We present here a set of (13)C-direct detected NMR experiments to facilitate the resonance assignment of RNA oligonucleotides. Three experiments have been developed: (1) the (H)CC-TOCSY-experiment utilizing a virtual decoupling scheme to assign the intraresidual ribose (13)C-spins, (2) the (H)CPC-experiment that correlates each phosphorus with the C4' nuclei of adjacent nucleotides via J(C,P) couplings and (3) the (H)CPC-CCH-TOCSY-experiment that correlates the phosphorus nuclei with the respective C1',H1' ribose signals. The experiments were applied to two RNA hairpin structures. The current set of (13)C-direct detected experiments allows direct and unambiguous assignment of the majority of the hetero nuclei and the identification of the individual ribose moieties following their sequential assignment. Thus, (13)C-direct detected NMR methods constitute useful complements to the conventional (1)H-detected approach for the resonance assignment of oligonucleotides that is often hindered by the limited chemical shift dispersion. The developed methods can also be applied to large deuterated RNAs.
authors.affiliation: Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University Frankfurt, Frankfurt/M, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Richter
authors.forename: Helena
authors.initials: H
authors.lastname: Kovacs
authors.forename: Janina
authors.initials: J
authors.lastname: Buck
authors.forename: Anna
authors.initials: A
authors.lastname: Wacker
authors.forename: Boris
authors.initials: B
authors.lastname: Fürtig
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bermel
authors.forename: Harald
authors.initials: H
authors.lastname: Schwalbe
mesh_terms: D002247:Carbon Isotopes / Q000737:chemistry*; D009587:Nitrogen Isotopes / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D012313:RNA