Table 1.

Summary of NER susceptibilities and T_m melting points of 11-mer duplexes.

Adduct	Relative NER efficiencya (135-mers)	Conformationb	ΔTm (°C) (11-mers)c	Tm (°C)d
10R cis-B[a]P-N2-dG	5.2 ± 0.5	Base-displaced intercalation; W-C pairing ruptured	−12e	39.4 ± 0.8e
14R DB[a,l]P-N2-dG	3.4 ± 0.1	3′-intercalation from the minor groove; W-C pairing at lesion site disrupted; but the bases are not displaced	−10	40.7 ± 0.3
14S DB[a,l]P-N2-dG	1.0 ± 0.1	Conformational heterogeneity; 5′-minor groove aligned with two W-C pairs ruptured;	−2	49.2 ± 0.1
14R DB[a,l]P-N6-dA	≥ 0.10	5′-intercalation from the major groove	+10	56.2 ± 0.2
14S DB[a,l]P-N6-dA	≥ 0.07	3′-intercalation from the major groove	−3	42.7 ± 0.3

^a% min⁻¹ (estimated from the slopes of Figure 2B, and assigning a value of 100% to the magnitude of the dual incisions at the 30 min time point for the 135-mer duplex with the 14R DB[a,l]P-N²-dG adduct). The averages are results of 5 independent experiments in different cell extract preparations.

^bStructural properties were obtained via high resolution NMR for the R-cis-B[a]P-N²-dG ⁷³, and R-DB[a,l]P-N²-dG ⁵⁹ adducts. Structural properties were obtained from MD simulations based on NMR studies for the the S-DB[a,l]P-N²-dG ^{60, 61}. Structural properties for the R- and S- DB[a,l]P-N⁶-dA adducts ⁵⁸ were obtained from MD simulations based on NMR studies for the stereochemically identical fjord region R- and S- B[c]Ph-N⁶-dA adducts. ¹⁸

^cΔT_m (°C) = T_m (Lesion-containing duplex) − T_m (Unmodified).

^dFor the unmodified duplex of 5′-d(CCATC XCTACC)•5′-d(GGTAGYGATGG), T_m is 51 ± 0.5 °C when X = G, and Y= C; T_m is 45.7 ± 0.1 °C when X = A, and Y= T.

^eData from ¹⁷