Table 1.
Time-resolved fluorescence decay and anisotropy parameters
| A1061AP TCSPC |
amplitude 1 (%) |
τ1 ns | amplitude 2 (%) |
τ2ns | amplitude 3 (%) |
τ3 ns |
|---|---|---|---|---|---|---|
| 30 °C, no Mg2+ |
28% | 6.4 | 21% | 2.3 | 51% | 0.19 |
| 30 °C, 8 mM Mg2+ |
6.4% | 7.2 | 23% | 1.8 | 71% | 0.34 |
| TRA | Ro | β1 | φ1 ns | β2 | φ2 ns | χ2 |
| 30 °C, no Mg2+ |
0.27 | 48% | 4.6 | 52% | 0.42 | 1.2 |
| 30 °C, 8 mM Mg2+ |
0.30 | 79% | 5.8 | 21% | 1.6 | 1.3 |
|
A1089AP TCSPC |
amplitude 1 (%) |
τ1 ns |
amplitude 2 (%) |
τ2ns |
amplitude 3 (%) |
τ3 ns |
| 30 °C, no Mg2+ |
24% | 7.6 | 26% | 2.3 | 50% | 0.3 |
| 30 °C, 8 mM Mg2+ |
16% | 7.7 | 30% | 2.1 | 55% | 0.25 |
| TRA | Ro | β1 | φ1 ns | β2 | φ2 ns | χ2 |
| 30 °C, no Mg2+ |
0.28 | 56% | 4.3 | 44% | 0.66 | 1.1 |
| 30 °C, 8 mM Mg2+ |
0.26 | 76% | 5.6 | 24% | 0.78 | 1.2 |
|
A1085AP TCSPC |
amplitude 1 (%) |
τ1 ns |
amplitude 2 (%) |
τ2ns |
amplitude 3 (%) |
τ3 ns |
| 30 °C, no Mg2+ |
20% | 7.8 | 37% | 2.3 | 42% | 0.34 |
| 30 °C, 8 mM Mg2+ |
23% | 7.5 | 37% | 3.0 | 40% | 0.59 |
| TRA | Ro | β1 | φ1 ns | β2 | φ2 ns | χ2 |
| 30 °C, no Mg2+ |
0.27 | 48% | 6.8 | 52% | 0.81 | 1.4 |
| 30 °C, 8 mM Mg2+ |
0.26 | 79% | 6.3 | 21% | 0.53 | 1.2 |
TCSPC Time-correlated single photon counting. TRA Time-resolved anisotropy. 10 mM sodium cacodylate, pH 6.5, 100 mM KCl. [RNA] = 2 μM. 2-aminopurine nucleotide alone has a single fluorescence lifetime of 10–11 ns, and a single time-resolved anisotropy decay of 9 ps. Support-plane data analysis provided errors for the decay lifetimes, which are not shown here. Typically, < 10% uncertainties are symmetric around the given lifetime.