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Comparison of H5 and H8 relaxation rates of a 2 H/ 13 C/ 15 N labeled RNA oligonucleotide with selective protonation at C5 and C8
Author(s) -
Nikonowicz E.P,
Kalurachchi K,
DeJong E
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)01034-x
Subject(s) - chemistry , protonation , deuterium , relaxation (psychology) , oligonucleotide , rna , nucleotide , ribonucleotide , molecule , guanine , nuclear magnetic resonance spectroscopy , tritium , nuclear magnetic resonance , analytical chemistry (journal) , crystallography , stereochemistry , biochemistry , organic chemistry , dna , biology , physics , ion , neuroscience , gene , nuclear physics , quantum mechanics
Uniformly 13 C/ 15 N enriched ribonucleotide monophosphates have been prepared with extensive deuterium enrichment of the non‐exchangeable positions. The purine C8 and pyrimidine C5 base positions were selectively protonated prior to incorporation of the individual nucleotide triphosphates into an RNA oligonucleotide. The longitudinal and transverse relaxation rates of the H8 and H5 resonances of this deuterated molecule were compared with the relaxation rates of the corresponding protonated, 13 C/ 15 N enriched RNA molecule. Deuteration disrupts the efficiency of 1 H– 1 H dipolar relaxation and reduces the longitudinal and transverse magnetization relaxation rates on average to 25% and 68%, respectively, of the values measured for the non‐deuterated RNA molecule. Importantly, the longitudinal relaxation rates remain sufficiently rapid (>1s −1 ) to permit the use of short recovery delays in multidimensional NMR experiments without significant loss of sensitivity.