Table 1.
From left to right, the table illustrates a specific PAD inhibitor, along with respective IC50 and Ki constant, and additionally displays PAD isozymes 1–4. Decreased IC50 values represent increased potency by requiring less inhibitor to produce half of a desired effect, while the inhibitory constant further demonstrates potency through analysis of the concentration required to produce half of the maximum inhibition. Notably, GSK484 and GSK 199 IC5o were collected in the absence of Ca2+, being that the ion acts as a competitive inhibitor for enzyme-substrate activity. ND represents “Not Determined”, which is applicable to more novel or less researched PAD inhibitors. PAD-selective IC50 or Ki information may be excluded from the table if isozyme specificity is unknown.
| PAD Inhibitor | PAD1 | PAD2 | PAD3 | PAD4 |
|---|---|---|---|---|
| Cl-Amidine | ||||
| IC50 (µM) | 0.8 ± 0.3 µM | 17 ± 3.1 µM | 6.2 ± 1.0 µM | 5.9 ± 0.3 µM |
| KI µM | 62 ± 11 µM | ND | 28 ± 7.3 µM | 180 ± 33 µM |
| TDFA | ||||
| IC50 (µM) | 8.5 ± 0.8 µM | 71 ± 4.4 µM | 26 ± 7.4 µM | 2.3 ± 0.2 µM |
| KI (µM) | ND | ND | 180 ± 60 µM | 16 ± 10 µM |
| F-Amidine | ||||
| IC50 (µM) | 30 ± 1.3 µM | 51 ± 9.0 µM | ≥350 µM | 22 ± 2.1 µM |
| KI (µM) | 110 ± 40 µM | ND | 290 ± 190 µM | 330 ± 90 µM |
| YW3-56 | ||||
| IC50 (µM) | ND | 0.5–1 µM | ND | 1–5 µM |
| KI (µM) | ND | ND | ND | ND |
| GSK484 | ||||
| IC50 (µM) | ND | ND | ND | 0.05 µM |
| KI (µM) | ND | ND | ND | ND |
| GSK199 | ||||
| IC50 (µM) | ND | ND | ND | |
| KI (µM) | ND | ND | ND | 0.2 µM |
| Paclitaxel (Taxol) | ||||
| IC50 (µM) | ND | ND | ND | 5 × 103 µM |
| KI (µM) | ND | ND | ND | ND |