Kallikrein protein (KLK)

Kallikreins are a family of secreted serine proteases involved in essential physiological processes, including regulation of blood pressure, inflammation, skin desquamation, semen liquefaction, and multiple cell signaling pathways. In humans, plasma kallikrein (encoded by KLKB1) participates in blood coagulation and inflammation via the kinin–kininogen system, while tissue kallikreins (KLK1–KLK15) have tissue-specific roles, particularly in skin and glands. Dysregulation of kallikrein activity is implicated in cancers, cardiovascular disorders, inflammatory and skin diseases, and they are both therapeutic targets and biomarkers. Certain kallikreins, especially PSA (KLK3), are widely used as tumor markers. Pharmacological interventions targeting kallikreins are in clinical use (e.g., in hereditary angioedema) and under investigation for broader indications, though high homology within the family poses specificity and safety challenges.

Other names

KallikreinKLKKLKB1 (for plasma kallikrein)tissue kallikreinglandular kallikreinkallikrein-related peptidaseskininogenasekininogeninkallidinogenase

Direct inhibition of serine protease activity (by reversible or irreversible binding to the active site); Blockade of kinin generation (thus reducing bradykinin/vasoactive peptide production); Immunomodulation (as in blockade to prevent angioedema attacks)