Tissue kallikrein (Kallikrein-1) (KLK1)

Arginine ester hydrolases are a group of serine proteases that specifically catalyze the hydrolysis of ester bonds in arginine-containing substrates (UniProt: P06870). In human physiology, this functional term is most frequently associated with the tissue kallikrein family, particularly Kallikrein-1 (KLK1), which is the primary enzyme responsible for arginine esterase activity in various tissues (NCBI: Gene ID 3816). These enzymes are central to the kallikrein-kinin system, where they cleave low-molecular-weight kininogen to release the potent vasodilator kallidin (lysyl-bradykinin) (PubMed: 10749679). This pathway is vital for regulating systemic blood pressure, local blood flow, and inflammatory responses (PubMed: 15657206). Therapeutically, these enzymes are targeted by inhibitors like aprotinin and nafamostat to manage systemic inflammatory responses and excessive bleeding during surgery, while purified or recombinant forms like kallidinogenase are used to treat conditions such as hypertension and ischemic stroke by promoting vasodilation (DrugBank: DB00033). Additionally, their activity serves as a key biomarker in diagnostic contexts, including the assessment of renal function and certain cardiovascular pathologies (PubMed: 12117406).

Other names

Arginine esteraseGlandular kallikreinUrinary kallikreinKininogeninArginine ester hydrolasehK1Kallikrein-1

Inhibition of serine protease activity to prevent the formation of kinins and other inflammatory mediators, or exogenous supplementation of the enzyme to promote kinin-mediated vasodilation and improve microcirculation.