Authors: Fiala, Radovan¹; Munzarová, Markéta; Sklenář, Vladimír²

Source: Journal of Biomolecular NMR, Volume 29, Number 4, August 2004 , pp. 477-490(14)

Publisher: Springer

Abstract:

The paper presents a set of triple-resonance two-dimensional experiments for correlating all quaternary carbons in RNA bases to one or more of the base protons. The experiments make use of either three-bond proton-carbon couplings and one selective INEPT step (the long-range selective HSQC experiment) to transfer the magnetization between a proton and the carbon of interest and back, or they rely on one- and/or two-bond heteronuclear (the H(CN)C and H(N)C experiments) or carbon-carbon (the H(C)C experiment) couplings and multiple INEPT transfer steps. The effect of the large one-bond carbon-carbon coupling in t₁ is removed by a constant time evolution or by a selective refocusing. The performance of the proposed approach is demonstrated on a 0.5 mM 25-mer RNA. The results show that the experiments are applicable to samples containing agents for weak molecular alignment. The design of the correlation experiments has been supported by ab initio calculations of scalar spin-spin couplings in the free bases and the AU and GC base pairs. The ab initio data reveal surprisingly high values of guanine ²J_N1C5 and uracil ²J_N3C5 couplings that are in a qualitative agreement with the experimental data. The sensitivity of the spin-spin couplings to base pairing as well as the agreement with the experiment depend strongly on the type of nuclei involved and the number of bonds separating them.

Keywords: ab initio; correlation; DFT; NMR; quaternary carbon; RNA; spin-spin coupling

Document Type: Research article

DOI: http://dx.doi.org/10.1023/B:JNMR.0000034358.12599.d1

Affiliations: 1: Email: fiala@ncbr.chemi.muni.cz 2: Email: sklenar@ncbr.chemi.muni.cz

Publication date: 2004-08-01

Related content

• In this: publication
• By this: publisher
• In this Subject: Anatomy & Physiology ,  Analytical Chemistry ,  Internal Medicine
• By this author: Fiala, Radovan ;  Munzarová, Markéta ;  Sklenář, Vladimír

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers