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Updated: Aug 12, 2026

Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins
Published on: December 12, 2013
Differentiation between unlabeled and very-low-level fully 15N,13C-labeled nucleotides for resonance assignments in
Anh Tuân Phan1, Dinshaw J Patel
1Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. phantuan@sbnmr1.mskcc.org
Abstract:
Based on different characteristics between unlabeled and fully 15N,13C-labeled nucleotides, we develop a method for unambiguous resonance assignments in nucleic acids following site-specific fully 15N,13C isotope incorporation at very low levels. The J-couplings between heteronuclei provide for distinction between the NMR signals of the fully labeled nucleotides and those of the natural abundance nucleotides. The method is demonstrated for DNA oligonucleotides, in the dimeric G-quadruplex [d(GGGTTCAGG)]2 and in the 22-nucleotide human telomeric fragment d[AG3(TTAG3)3]. We expect this approach to be useful for selective monitoring of important functional domains and of their interactions in large nucleic acids.
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