TABLE 1

Proteinase families and their endogenous inhibitors

Enzyme Family InhibitedInhibitor ClassCommentReferences
Serine proteinasesSERPINs (serine proteinase inhibitors)Largest number of endogenous inhibitors; deficiencies cause lung and skin disease; upregulation involved in modulating neuropathic painPotempa et al., 1994; Law et al., 2006; Vicuña et al., 2015
Metalloproteinases (MMPs)TIMPs 1, 2, 3, and 4TIMPs elevated in cancer and inflammation; upregulation promotes fibrosisClark et al., 2008; Khokha et al., 2013; Arpino et al., 2015
Cysteine proteinasesCystatins, thyropinsIntracellular inhibitors regulate apoptosisTurk et al., 2002; Dubin, 2005; Magister and Kos, 2013
GeneralAlpha 2-macroglobulinAlpha 2-M preserves catalytic site function for smaller substratesBarrett and Starkey 1973; Barrett, 1981; Rehman et al., 2013