Table 2. IC50 values for hTACE truncates and C184A mutants.
hTACE activity was measured using a Dnp-labelled peptide containing the cleavage site of pro-TNFα in the presence and absence of three hydroxamic acid inhibitors, GW9471, GW4023 and GW1988. Each inhibitor was screened by the addition of the following concentrations to the reaction cocktail before a 1 h incubation at room temperature: 10, 1 μM, 100, 10, 1 nM and 100 pM. Dnp-labelled substrate and product were separated using reversed-phase HPLC and monitored at 350 nm.
| IC50 (nM) | |||
|---|---|---|---|
| TACE form | GW9471 | GW4023 | GW1988 |
| hR473 wild-type | 46.0±6.2 | 736±203 | 33.4±12.6 |
| hR473 C184A | 44.6±12.0 | 767±179 | 31.8±23.5 |
| hR651 wild-type | 48.2±5.6 | 851±94 | 34.4±13.0 |
| hR651 C184A | 48.7±5.3 | 836±407 | 43.2±13.5 |