ENTRY       EC 3.4.21.34
NAME        Plasma kallikrein
            Serum kallikrein
            Kininogenin
CLASS       Hydrolases
            Acting on peptide bonds (peptidases)
            Serine endopeptidases
REACTION    Selective cleavege of some Arg+ and Lys+ bonds, including Lys+Arg
            and Arg+Ser in (human) kininogen to release bradykinin
SUBSTRATE   Kininogen
            Polyarginine
            H2O
PRODUCT     Bradykinin
COMMENT     Formed from plasma prokallikrein (Fletcher factor) by Factor XIIa.
            Activates coagulation Factors XII, VII and plasminogen. Selective
            for Arg > Lys in P1, in small molecule substrates.  A homologue of
            chymotrypsin.  Formerly EC 3.4.4.21 and included in 3.4.21.8.
DISEASE     MIM: 229000  Kallikrein, plasma (Fletcher factor); Fletcher factor
                         deficiency (1)
MOTIF       PS: PS00134  [LIVM]-[ST]-A-[STAG]-H-C
            PS: PS00135  [DNSTAGC]-[GSTAPIMVQH]-x(2)-G-[DE]-S-G-[GS]-[SAPHV]-
                         [LIVMFYWH]-[LIVMFYSTANQH]
            PS: PS00495  C-x(3)-[LIVMFY]-x(5)-[LIVMFY]-x(3)-[DENQ]-[LIVMFY]-
                         x(10)-C-x(3)-C-T-x(4)-C-x-[LIVMFY]-F-x-[FY]-x(13,14)-C-
                         x-[LIVMFY]-[RK]-x-[ST]-x(14,15)-S-G-x-[ST]-[LIVMFY]-
                         x(2)-C
GENES       HSA: KLK3(Hs.1901)
DBLINKS     University of Geneva ENZYME DATA BANK: 3.4.21.34
            WIT (What Is There) Metabolic Reconstruction: 3.4.21.34
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