Table 1. Fluorescence Titrations Confirm N-Methyl Analogs Have Higher Affinity and Selectivity for HIV-1 FSS RNAa.
| sequence, KD (nM) |
|||||
|---|---|---|---|---|---|
| compound | FSS-RNA | FSS-DNA | yeast tRNA | FSS RNA: FSS DNA selectivity | FSS RNA: tRNA selectivity |
| 1E | 100 ± 30 | 230 ± 20 | 220 ± 30 | 2.3:1 | 2.2:1 |
| 1Z | 66 ± 30 | 120 ± 20 | 330 ± 30 | 1.8:1 | 5:1 |
| 2E | 2.7 ± 1.0 | 81 ± 30 | 120 ± 40 | 30:1 | 44:1 |
| 2Z | 2.7 ± 0.7 | 65 ± 10 | 180 ± 20 | 24:1 | 67:1 |
| 3E | 3.0 ± 0.1 | 79 ± 10 | 90 ± 10 | 26:1 | 30:1 |
| 3Z | 1.1 ± 0.5 | 60 ± 8.0 | 67 ± 10 | 55:1 | 61:1 |
| 4E | 5.0 ± 2.0 | 34 ± 10 | 91 ± 20 | 6.8:1 | 18:1 |
a
Dissociation constants (KD) are reported in nanomolarity. Titrations were carried out in 20 mM HEPES, 150 mM NaCl, and 5 mM MgCl2. Each measurement was taken in triplicate to assure equilibrium was reached, and each titration was repeated twice. Data were fit to a single-site binding model. Error reported is the distance between values from complete titrations.