Serine proteinases | SERPINs (serine proteinase inhibitors) | Largest number of endogenous inhibitors; deficiencies cause lung and skin disease; upregulation involved in modulating neuropathic pain | Potempa et al., 1994; Law et al., 2006; Vicuña et al., 2015 |
Metalloproteinases (MMPs) | TIMPs 1, 2, 3, and 4 | TIMPs elevated in cancer and inflammation; upregulation promotes fibrosis | Clark et al., 2008; Khokha et al., 2013; Arpino et al., 2015 |
Cysteine proteinases | Cystatins, thyropins | Intracellular inhibitors regulate apoptosis | Turk et al., 2002; Dubin, 2005; Magister and Kos, 2013 |
General | Alpha 2-macroglobulin | Alpha 2-M preserves catalytic site function for smaller substrates | Barrett and Starkey 1973; Barrett, 1981; Rehman et al., 2013 |