| NMR Experiment |
|---|
| Experiment | Type | Sample Contents | Solvent | Ionic Strength | pH | Pressure | Temperature (K) | Spectrometer |
|---|
| 1 | 2D NOESY | Single-stranded oligodeoxyribonucleotides, d(5-GCTAAGGAAAGCC-3) and the complementary strand d(5-GGCTTTCCTTAGC-3), were synthesized using standard phosphoramidite chemistry. The thioG-modified oligodeoxyribonucleotide, d(5-GCTAAGthioGAAAGCC-3), was commercially synthesized (Trilink Biotechnologies) using 6-thio-deoyxguanosine-cyanoethyl phosphoramidite(Glen Research). Single-stranded DNA molecules were purified using anion exchange chromatography (MonoQ HR 5/5, Pharmacia Biotech). Purity was confirmed by UV spectroscopy, analytical anion exchange chromatography, and mass spectrometry. The GC and thioGC DNA duplexes were each prepared by annealing either equimolar amounts of complimentary strands or a 1.2 molar excess of the unmodified strand to the modified strand in Buffer A (10 mM sodium phosphate, 50 mM NaCl, pH 7.0) at 70 C for 5 min., followed by slow cooling over 12 hours to room temperature. DNA duplexes were purified using gel filtration chromatography (Superdex Peptide HR 10/30, Pharmacia Biotech) in Buffer A. | Buffer A (10 mM sodium phosphate, 50 mM NaCl, pH 7.0) | approx. 65 mM | 7.0 | ambient | 293 | |
| 2 | 2D TOCSY | Single-stranded oligodeoxyribonucleotides, d(5-GCTAAGGAAAGCC-3) and the complementary strand d(5-GGCTTTCCTTAGC-3), were synthesized using standard phosphoramidite chemistry. The thioG-modified oligodeoxyribonucleotide, d(5-GCTAAGthioGAAAGCC-3), was commercially synthesized (Trilink Biotechnologies) using 6-thio-deoyxguanosine-cyanoethyl phosphoramidite(Glen Research). Single-stranded DNA molecules were purified using anion exchange chromatography (MonoQ HR 5/5, Pharmacia Biotech). Purity was confirmed by UV spectroscopy, analytical anion exchange chromatography, and mass spectrometry. The GC and thioGC DNA duplexes were each prepared by annealing either equimolar amounts of complimentary strands or a 1.2 molar excess of the unmodified strand to the modified strand in Buffer A (10 mM sodium phosphate, 50 mM NaCl, pH 7.0) at 70 C for 5 min., followed by slow cooling over 12 hours to room temperature. DNA duplexes were purified using gel filtration chromatography (Superdex Peptide HR 10/30, Pharmacia Biotech) in Buffer A. | Buffer A (10 mM sodium phosphate, 50 mM NaCl, pH 7.0) | approx. 65 mM | 7.0 | ambient | 293 | |
| 3 | DQF-COSY | Single-stranded oligodeoxyribonucleotides, d(5-GCTAAGGAAAGCC-3) and the complementary strand d(5-GGCTTTCCTTAGC-3), were synthesized using standard phosphoramidite chemistry. The thioG-modified oligodeoxyribonucleotide, d(5-GCTAAGthioGAAAGCC-3), was commercially synthesized (Trilink Biotechnologies) using 6-thio-deoyxguanosine-cyanoethyl phosphoramidite(Glen Research). Single-stranded DNA molecules were purified using anion exchange chromatography (MonoQ HR 5/5, Pharmacia Biotech). Purity was confirmed by UV spectroscopy, analytical anion exchange chromatography, and mass spectrometry. The GC and thioGC DNA duplexes were each prepared by annealing either equimolar amounts of complimentary strands or a 1.2 molar excess of the unmodified strand to the modified strand in Buffer A (10 mM sodium phosphate, 50 mM NaCl, pH 7.0) at 70 C for 5 min., followed by slow cooling over 12 hours to room temperature. DNA duplexes were purified using gel filtration chromatography (Superdex Peptide HR 10/30, Pharmacia Biotech) in Buffer A. | Buffer A (10 mM sodium phosphate, 50 mM NaCl, pH 7.0) | approx. 65 mM | 7.0 | ambient | 293 | |
