Protein inhibitors blocking human PR3 activity Boldface represents reactive center loop residues. Underlining represents substitutions.
| Inhibitor | Reactive Center Sequence | Rate Constant | Reference | |
|---|---|---|---|---|
| PR3 | HNE | |||
| Serpins, kass (M−1s−1) | ||||
| α1PI | GTEAAGAMFLEAIPM SIPPE | 4.5 × 105 | 6.5 × 107 | Epinette et al., unpublished data; Beatty et al., 1980 for PR3 and HNE, respectively |
| ACT(IPM/SIP) | GTEASAATAVKIIPM SIPVE | 1.9 × 105 | 1.0 × 106 | Groutas et al., 1997 |
| SerpinB1 | GTEAAAATAGIATFC MLMPE | 3 × 104 | 3.4 × 107 | Jégot et al., 2011 and Cooley et al., 2001 for PR3 and HNE, respectively |
| SerpinB1(STDA/R) | GTEAAAATAGISTDA RLMPE | 1.4 × 107 | Jégot et al., 2011 | |
| Canonical inhibitors, Ki (M) | ||||
| Elafin | LIRCA ML | 1.2 × 10−10 | 0.8 × 10−10 | Zani et al., 2004 |
| Elaf-SLPI2 | LIRCA ML | 7.6 × 10−11 | 2.2 × 10−11 | Zani et al., 2009 |
| SLPI2-Elaf | LIRCA ML | 43 × 10−11 | 5.2 × 10−11 | Zani et al., 2009 |
| Trappin-2 | LIRCA ML | 1.8 × 10−10 | 0.3 × 10−10 | Zani et al., 2004 |
| Trappin-2 A62L | LIRCL ML | 3.7 × 10−9 | 1.5 × 10−11 | Zani et al., 2009 |
| α2-M, kass (M−1s−1) | 39-residue bait region: Pro690-Thr728 | 1.1 × 107 | 4.1 × 107 | Rao et al., 1991 and Virca and Travis, 1984 for PR3 and HNE, respectively |
| Antibodies, Ki (nM) | ||||
| MCPR3-7 | Binding site: ScFv | N.I. | ||
| hAb-EI-L7 | Binding site: TSVHQET-MCTA SIPPQCY-YEWHVDV | >300 | 0.83 | Liu et al., 2015 |
ACT, antichymotrypsin; N.I., not identified.