Table 2.
Thermal Melting Temperatures (Tm) of Oligonucleotide Duplexes Containing the N2-IQ Adduct
| Oligonucleotides a | Tm (ΔTm)b,c | |||
|---|---|---|---|---|
| dGuo-N2-IQd | dGuo-C8-IQe | |||
| a | 5′-CTC GGC GCC ATC-3′ | (12) | 38° (−27°) | 58° (−7°) |
| 3′-GAG CCG CGG TAG-5′ | ||||
| b | 5′-CTC GGC GCC ATC-3′ | (13) | 40° (−25°) | 60° (−5°) |
| 3′-GAG CCG CGG TAG-5′ | ||||
| c | 5′-CTC GGC GCC ATC-3′ | (14) | 44° (−21°) | 61° (−4°) |
| 3′-GAG CCG CGG TAG-5′ | ||||
| d | 5′-CTC GGC GCC ATC-3′ | (14) | 54° (+16°) | 48° (+10°) |
| 3′-GAG CCG --G TAG-5′ | ||||
| e | 5′-G GCA GGT GGT G-3′ | (15) | 48° (−12°) | 51° (−9°) |
| 3′-C CGT CCA CCA C-5′ | ||||
a
G is the modified dGuo.
b
ΔTm = Tm (modified) − Tm (unmodified). The Tm for the unmodified NarI duplex is 65 °C. The Tm for the unmodified NarI oligonucleotide opposite a two-base deletion (entry d) is 38 °C.
c
Conditions: 10 mM phosphate buffer (pH 7.0) containing 100 mM NaCl, 0.05 mM EDTA, and 0.5 A260/mL of each oligonucleotide. The temperature was raised 1 °C min−1.
d
This work.