V. Ramesh et al., SITE-SPECIFIC N-15-LABELING OF OLIGONUCLEOTIDES FOR NMR - THE TRP OPERATOR AND ITS INTERACTION WITH THE TRP REPRESSOR, FEBS letters, 363(1-2), 1995, pp. 61-64
A convenient and economical method is described for the site-specific
N-15-labelling of the 4-amino group of individual cytidine residues in
oligonucleotides. This is applied to a 20 base-pair oligonucleotide c
orresponding to the trp operator; this oligonucleotide and its complex
with the E. coli trp repressor are studied by NMR, using H-1-N-15 HMQ
C and N-15-edited H-1-H-1 NOESY experiments.