Plasma kallikrein-IN-1 is a PKK inhibitor with an IC 50 value of 0.5 nM.

Berotralstat (BCX7353) is a second-generation, synthetic, and orally active plasma kallikrein inhibitor with low toxicity. It is highly specific and effectively used in the research of hereditary angioedema (HAE) attacks. Berotralstat functions by inhibiting the enzymatic activity of plasma kallikrein, which is responsible for the release of bradykinin. This blocking mechanism targets the major biologic peptide involved in the promotion of swelling and pain associated with HAE attacks[1][2].

D-Pro-Phe-Arg-Chloromethylketone, an inhibitor of coagulation factor XII and plasma kallikrein, is significant in the regulation of thrombosis and inflammation [1].

Plasma kallikrein-IN-3, a potent inhibitor ( IC 50 : 0.15 μM) of plasma kallikrein, finds application in research related to hereditary angioedema, diabetic macular edema, and diabetic retinopathy [1].

Kallikrein is capable of forming the kallikrenase kalinin system (KKS) in plasma and tissues, producing bradykinin and kalin peptides , respectively [1] .