Table 2.
Binding affinities to BIR2 or BIR3 domains of XIAP for tripeptide analogues where R4 = NHPh (2a, 8h–p).
| ||||
|---|---|---|---|---|
| Cmpds. | P3 | BIR2 Ki, μMa | BIR3 Ki, μMa | BIR2 vs BIR3 Selectivity |
| 2a | Pro | 0.39 (± 0.17) | 1.08 (± 0.06) | 3 : 1 |
| 8h | Ala | 2.29 (± 0.37) | 51.79 (± 2.16) | 22.6 : 1 |
| 8i | Val | 3.04 (± 0.28) | 65.62 (± 6.22) | 21.6 : 1 |
| 8j | ArgNO2 | 1.18 (± 0.11) | 8.79 (± 1.11) | 7.5 : 1 |
| 8k | Arg | 3.65 (± 0.23) | 21.15 (± 1.77) | 5.8 : 1 |
| 8l | Thr | 4.67 (± 0.37) | 30.07 (± 0.55) | 6.4 : 1 |
| 8m | OrnCBZ | 1 70 (± 01 3) | 9.82 (± 1.17) | 5.8 : 1 |
| 8n | Orn | 13.14 (± 1.19) | ~39 | 3 : 1 |
| 8o | Ser | 5.46 (± 0.56) | > 39 | > 7.1 : 1 |
| 8p | Lys | 1.88 (± 0.13) | 21.48 (± 1.52) | 11.4 : 1 |
a
Values are determined in duplicate and reported ± standard deviation which is given in parentheses.