Table 1.
Sequence Nameb | Sequence | ss Φem | ds Φem | ds λmax,abs/nm (ss) | ds λmax,em/nm (ss) | Tm (°C) | ΔTm (°C)c |
---|---|---|---|---|---|---|---|
GA | 5′-CGC-AGX-ATC-G-3′ | 0.020 | 0.050 | 422 (425) | 499 (499) | 50.7 | −5.1 |
CT | 5′-CGC-ACX-TTC-G-3′ | 0.020 | 0.025 | 414 (413) | 492 (495) | 54.7 | +2.0 |
GC | 5′-CGC-AGX-CTC-G-3′ | 0.032 | 0.12 | 348 (425) | 500 (499) | 49.1 | −14.5 |
CA | 5′-CGC-ACX-ATC-G-3′ | 0.014 | 0.017 | 410 (420) | 494 (493) | 57.4 | +2.1 |
GG | 5′-CGC-AGX-GTC-G-3′ | 0.027 | 0.056 | 400 (415) | 499 (498) | 58.2 | −7.0 |
CC | 5′-CGC-ACX-CTC-G-3′ | 0.013 | 0.024 | 413 (421) | 496 (496) | 60.2 | +6.7 |
TA | 5′-CGC-ATX-ATC-G-3′ | 0.014 | 0.026 | 420 (417) | 495 (495) | 48.7 | −1.6 |
TT | 5′-CGC-ATX-TTC-G-3′ | 0.025 | 0.041 | 416 (413) | 495 (495) | 48.5 | +0.2 |
AA | 5′-CGC-AAX-ATC-G-3′ | 0.008 | 0.042 | 410 (415) | 498 (497) | 48.4 | −2.6 |
AA mismatchd | 5′-CGC-AAX-ATC-G-3′ | 0.008 | 0.015 | 417 (415) | 501 (497) | 33.1 | +9.6 |
AA AP sitee | 5′-CGC-AAX-ATC-G-3′ | 0.008 | 0.007 | 421 (415) | 466 (497) | 36.9 | n.d.f |
tC parent AAg | 5′-CGC-AAtC-ATC-G-3′ | 0.11 | 0.11 | 389 (390) | 501 (502) | 55.3 | +4.3 |
Detailed procedures for photophysical measurements are given in the Supporting Information. Quantum yield measurements were performed at least in duplicate and the reported numbers are averaged. Typical errors based on standard deviation are approximately ±15%. ds = double-stranded; ss = single-stranded.
Sequences named for neighboring bases.
Tm for natural DNA duplex subtracted from Tm for the 8-DEA-tC-containing duplex.
AA sequenced annealed to 5′-CGA-TAT-TGC-G-3′ (8-DEA-tC opposite A).
AA sequenced annealed to 5′-CGA-T(dSpacer)T-TGC-G-3′ (8-DEA-tC opposite the dSpacer surrogate for an abasic site, AP).
Temperature-dependent CD changes were nonsigmoidal for the natural DNA strand and Tm could not be determined.
Sequence AA made with parent tC in place of 8-DEA-tC.