Table 1. Imino proton exchange rates (s–1) at 1°C: GTA triplex (upper row) and C+GC triplex (lower row).
T24 | C+25 | T26 | G27/C+27 | T28 | C+29 | T30 | T31 |
4.0 ± 0.4 | 7.6 ± 0.6 | 10–3 <kex <0.5 | 4.2 ± 0.2 | (3 ± 1) × 10–4 | 11.6 ± 0.3 | 10–3 <kex <0.5 | 11.2 ± 0.4 |
a |
12 ± 1 |
(3.8 ± 0.7) × 10–5 |
0.7 ± 0.4 |
(3.3 + 0.3) × 10–5 |
1.5 ± 0.3 |
10–3 <kex <0.5 |
10.5 ± 0.6 |
A1 | G2b | A3 | T4/G4b | A5 | G6b | A7 | A8 |
(9 ± 2) × 10–4 | (2.6 ± 0.8) × 10–4 | (9 ± 2) × 10–4 | |||||
|
(9.9 ± 0.3) × 10–5 |
|
(9.9 ± 0.3) × 10–5 |
|
(9.9 ± 0.3) × 10–5 |
|
|
T20 | C13 | T18c | A17/C17 | T16 | C15 | T14c | T13 |
1.8 ± 0.2 | 10–3 <kex <0.5 | (4.0 ± 1.0) × 10–4 | 10–3 <kex <0.5 | 1.1 ± 0.2 | |||
1.7 ± 0.2 | (3.0 ± 0.3) × 10–4 | (4.7 ± 0.3) × 10–5 | 10–3 <kex <0.5 | 1.1 ± 0.1 |
aThe imino proton resonance of T24 in the C+GC triplex is not observable (see text).
bIn the GTA triplex the imino proton resonance of G2 and G6 overlap (Fig. 2); similarly, in the C+GC triplex, the imino proton resonance of G2, G4 and G6 overlap (Fig. 2). The values of kex given were obtained from the overlapped resonances.
cIn the GTA triplex the imino proton resonance of T18 and T14 overlap (Fig. 2).