Table 1. Counts of protein species, families and clans for proteolytic enzymes and protein inhibitors in the MEROPS database.
| MEROPS 9.9 | MEROPS 9.13 | |||
|---|---|---|---|---|
| Peptidases | Inhibitors | Peptidases | Inhibitors | |
| Sequences | 413 834 | 28 502 | 523 871 | 74 658 |
| Identifiers (Total) | 4384 | 712 | 4622 | 712 |
| experimentally characterized and sequenced | 2638 | 593 | 2794 | 597 |
| hypothetical from model organisms | 1352 | 0 | 1628 | 0 |
| not active as peptidase or inhibitor | 324 | 115 | 333 | 115 |
| experimentally characterized but unsequenced | 203 | 0 | 203 | 0 |
| pseudogenes | 70 | 0 | 70 | 0 |
| Compound and complex proteins | 16 | 49 | 16 | 56 |
| Families | 244 | 76 | 253 | 79 |
| Clans | 55 | 39 | 61 | 39 |
The numbers in Release 9.13 of MEROPS (July 2015) are compared to those in Release 9.9 of MEROPS (August 2013). A peptidase is referred to as ‘unsequenced’ when no sequence is known, or the known sequence fragments are insufficient to be able to assign the peptidase to a family.