Plasma kallikrein (KLKB1) serves as an enzyme, cleaving Lys-Arg and Arg-Ser bonds to release bradykinin from HMW kininogen. It plays a crucial role in the reciprocal activation of factor XII, especially upon binding to a negatively charged surface. Besides its role in the kinin system, KLKB1 may contribute to the renin-angiotensin system by converting prorenin into renin. Plasma kallikrein/KLKB1 Protein, Cynomolgus (HEK293, His) is the recombinant cynomolgus-derived Plasma kallikrein/KLKB1 protein, expressed by HEK293 , with C-His labeled tag.