Table 1. Sensitivity of rSmSP2 to protease inhibitors.
| Inhibitora | Target proteaseb | Concentration (μM) | Inhibition (%)c |
|---|---|---|---|
| Pefabloc SC | SP | 1000 | 100 |
| Benzamidine | SP | 1000 | 100 |
| 3,4-dichlorcoumarin | SP | 100 | 71.4 ± 3.3 |
| Antipain | SP, CP | 20 | 100 |
| Leupeptin | SP, CP | 20 | 100 |
| BPTI (Aprotinin) | SP | 10 | 87.0 ± 2.6 |
| STI | SP | 10 | 91.8 ± 0.9 |
| α-1-antichymotrypsin | SP | 1 | 13.2 ± 2.4 |
| α-1-antitrypsin | SP | 1 | 79.0 ± 0.9 |
| Antithrombin III | SP | 1 | 99.1 ± 0.3 |
| PAI-1 | SP | 1 | 100 |
| E-64 | CP | 10 | 7.2 ± 0.9 |
| Pepstatin A | AP | 1 | 0 |
| EDTA | MP | 1000 | 3.2 ± 0.9 |
| Bestatin | MP | 1 | 4.5 ± 2.0 |
| Phenanthroline | MP | 1000 | 26.9 ± 4.7 |
| α-2-macroglobulin | all types | 0.1 | 61.6 ± 0.4 |
a Abbreviations: BPTI (bovine pancreatic trypsin inhibitor), STI (soybean trypsin inhibitor), E64 (trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane), PAI-1 (plasminogen activator inhibitor-1).
b The target proteases are classified based on catalytic type into aspartic (AP), cysteine (CP), serine (SP) proteases and metalloproteases (MP).
c rSmSP2 was pre-incubated with the given inhibitor and remaining activity was measured in a kinetic assay with the fluorogenic substrate P-F-R-AMC. The mean values ± S.D. of three replicates are expressed as the percentage inhibition relative to uninhibited controls.