Table 1.
Representative examples of protease inhibitors
| Inhibitor | Family | Reactive site sequence | KD, M | Ref. |
|---|---|---|---|---|
| CI2 | Potato I | IVTM↓EYRI | 2 × 10−12/subtilisin | 12 |
| BPTI | Kunitz-BPTI | GPCK↓ARII | 6 × 10−14/trypsin | 41 |
| STI | Kunitz-STI | PSYR↓IRFI | 1 × 10−11/trypsin | 42 |
| OMTKY3 | Kazal | ACTL↓EYRP | 3 × 10−12/chymotrypsin | 43 |
| PSTI | Kazal | GCPR↓IYNP | 3 × 10−11/trypsin | 41 |
| BBI | Bowman–Birk | ACTK↓SNPP | 8 × 10−10/trypsin | 44 |
| BBI | Bowman–Birk | ICAL↓SYPA | 6 × 10−10/chymotrypsin | 44 |
| SSI | SSI | MCPM↓VYDP | 2 × 10−11/subtilisin | 18 |
| CMTI I | Squash seed | VCPR↓ILEM | 2 × 10−12/trypsin | 45 |
| SGTI | Grasshopper | ACTR↓KGCP | 3 × 10−12/trypsin | 46 |
| SFTI-1 | Sunflower | RCTK↓SIPP | 1 × 10−10/trypsin | 47 |
Amino acid sequences flanking the cleavage site (indicated by the arrow) are shown; in each case, the amino acid preceding the scissile bond (the major specificity residue) is typical of a good substrate for the respective enzyme. BPTI, bovine pancreatic trypsin inhibitor; STI, soybean trypsin inhibitor; OMTKY3, turkey ovomucoid third domain; PSTI, pancreatic secretory trypsin inhibitor; BBI, Bowman–Birk inhibitor; SSI, Streptomyces subtilisin inhibitor; CMTI I, Cucurbita maxima trypsin inhibitor I; SGTI, Schistocerca gregaria trypsin inhibitor; SFTI-1, sunflower trypsin inhibitor.