TABLE 1.
Drug concentrations required to inhibit the activities of DNA ligases from E. coli, T4 bacteriophage, and humans (type I) by 50%, and specificity factors
| Druga | IC50 (μM) for:
|
SFa | ||
|---|---|---|---|---|
| E. coli ligase | T4 ligase | Human ligase I | ||
| Doxorubicin | 1.3 ± 0.3 | 2 ± 0.4 | 1.8 ± 0.4 | 1.5 |
| CQ | 53 ± 3 | >1,500 | 720 ± 80 | >28 |
| Hydroxychloroquine | 63 ± 6 | >2,000 | NDb | >31 |
| Quinacrine | 1.5 ± 0.2 | 23 ± 5 | ND | 16 |
| 6bisQ0 | 2.6 ± 0.4 | 14 ± 2 | 16 ± 2 | 5.4 |
| 6bisQ6 | 2.2 ± 0.3 | 18.2 ± 2 | 14.8 ± 3 | 8.3 |
| 6bisQ8 | 1.8 ± 0.2 | 16.8 ± 2 | 12.8 ± 2 | 9.3 |
| 8bisQ0 | 10.2 ± 2 | 33 ± 3 | 49 ± 9 | 3.2 |
| 8bisQ4 | 9 ± 2 | 44 ± 5 | 43 ± 7 | 4.9 |
| N,N′-bis[4-Chloroquinolin-8-yl]succinamide | >2,000 | >2,000 | >2,000 | ND |
| Quinine | >2,000 | >2,000 | >2,000 | ND |
| Cinchonidine | >5,000 | >5,000 | >5,000 | ND |
| 2-Amino-5-diethylaminopentane | 2,100 ± 180 | >16,000 | ND | >7.6 |
| Spermidine | 5,000 ± 580 | 23,000 ± 3,800 | ND | 4.6 |
| Putrescine | 9,200 ± 950 | >20,000 | ND | >2.2 |
a
SF, specificity factor (ratio of IC50s of drug for T4 and E. coli DNA ligases).
b
ND, not determined.