Table 3. Inhibition constants for tetrapeptides against XIAP BIR2 and XIAP BIR3.
The assay is a FRET-based assay measuring the displacement of an AVPI-derived peptide from the BIR domain (see 2). Asterisks denote peptides which have been soaked into XIAP BIR2 crystals.
| Tetrapeptide | BIR2 K i (M) | BIR3 K i (M) |
|---|---|---|
| ATAA* | 1.70 | >47 |
| AVAV | 1.87 | 26.08 |
| AIAV* | 1.87 | 28.2 |
| ATAV | 2.17 | 32.26 |
| AMRV* | 2.41 | 32.90 |
| AVVV | 2.54 | |
| AIPI | 3.11 | 0.08 |
| AMRI | 3.52 | 5.20 |
| AVPI* | 5.24 | 0.71 |
| ARPI | 10.17 | 0.12 |
| SVPI* | 12.02 | 4.62 |
| SMRV | 12.25 | >47 |
| SMPI | 33.97 | 12.54 |
| ARPR | >53 |