Fig. 2.

KKS organisation. Following alternate splicing of KNG gene, LMWK and HMWK are synthesized. Various physiological insults such as tissue damage leads to proteolytic activations of TK, which converts LMWK into LBK. Factor XII (Hageman factor) activates PK, that transforms HMWK to bradykinin. LBK and bradykinin are agonists for BDKRB2, and upon the action of carboxypeptidases like CPM/CPN can result in the formation of Des-Arg⁹-Kallidin and Des-Arg⁹-BK, members BDKRB1 agonists. Bradykinin can be broken down into inactive fractions by ACE and NEP and LBK converted into bradykinin by an aminopeptidase. (Notations: LMWK-Low-molecular-weight kininogen, HMWK-High-molecular-weight kininogen, PK-Plasma kallikrein, ACE-Angiotensin-converting enzyme, NEP-Neutral endopeptidase)