Table 3.

Steady-state equilibrium dissociation constants (K_d) of Hg^II binding to ^DMAT–C,^DMAC–T, ^DMAT–T or wild-type C–T in duplex DNA^a

Sequence	Temperature	K d (nM) non-specificb	K d (nM) mismatch specificc
X13 DMAT–C	25°C	-	152 ± 4
X13 DMAT–C	15°C	-	107 ± 4
X13 DMAT–C	4°C	-	56 ± 4
X15 DMAT–C	25°C	1300 ± 300	123 ± 76
X15 DMAC–T	25°C	2300 ± 300	153 ± 27
X15 DMAC–G, X14 C–T	25°C	2200 ± 400	107 ± 45
X15 DMAC–G	25°C	2260 ± 130	-
X13 DMA T–T	25°C	-	77 ± 4
X13 DMA T–T	15°C	-	122 ± 11
X13 DMA T–T	4°C	-	144 ± 27

^a Reported values = mean ± standard deviation from three independent measurements. Samples contained 25 nM of DNA in an aqueous buffer containing 200 mM Na₂HPO₄, 100 mM citric acid and 100 mM NaNO₃ (pH 7.35). K_d values were calculated by fitting quenching data to either a monoexponential curve (eq 11, SI) or to a biphasic curve (eq 12, SI). All R² values were ≥ 0.97 (Supplementary Figures S16 and S17, SI). For duplex sequences see Supplementary Table S1, SI.

^b Represents local, mismatch-independent binding to duplex DNA.

^c Represents local, mismatch-dependent binding to duplex DNA.