Activated C1s, Kallikrein, Factor XIIa, Factor XIa (N/A)

The target as given refers to four distinct serine proteases: Activated C1s, plasma kallikrein, coagulation Factor XIIa, and coagulation Factor XIa. - C1s is a component of the C1 complex of the classical complement system, initiating complement activation by cleaving C4 and C2. - Kallikrein (plasma kallikrein) is a key enzyme in the kallikrein-kinin system, generating bradykinin from high-molecular-weight kininogen, affecting inflammation and vascular permeability. - Factor XIIa is an activated serine protease that initiates contact activation in blood coagulation and activates kallikrein and Factor XI. - Factor XIa is the activated form of Factor XI, crucial in the intrinsic coagulation pathway by activating Factor IX and propagating thrombin generation. These proteins interact in the initiation and amplification of blood coagulation, complement activation, and inflammatory kinin generation. Collectively, they play essential roles in thrombosis, inflammation, and host defense. Grouping them as a single target is incorrect; therapies may selectively target one or more of these for distinct clinical indications, primarily cardiovascular and inflammatory diseases.

Other names

C1sComplement C1s subcomponentPlasma kallikreinKLKB1Fletcher factorActivated Factor XIIHageman factorActivated Factor XI

Enzyme inhibition (block active site or zymogen activation); Inhibition of coagulation cascade (Factor XIIa and XIa); Inhibition of kinin generation (kallikrein); Blockade of complement activation (C1s inhibitors)