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High‐molecular‐weight kininogen is a binding protein for tissue prokallikrein
Author(s) -
Raab Armin,
Kemme Michael
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01141-8
Subject(s) - high molecular weight kininogen , kininogen , zymogen , kallikrein , chemistry , prekallikrein , biochemistry , kinin , factor xii , biotinylation , microbiology and biotechnology , receptor , enzyme , medicine , biology , bradykinin , coagulation
Human tissue prokallikrein, a zymogen of the kallikrein‐kinin system, circulates in plasma bound to neutrophils. Because plasma kininogens contribute to the assembly of kinin‐generating components on blood cells, these proteins were assessed for their ability to complex the kallikrein precursor. Using ligand blot and direct binding assays, biotinylated prokallikrein was found to bind only to high‐molecular‐weight kininogen and not to the low‐molecular‐weight form. The interaction was specific, reversible, and saturable yielding an estimated dissociation constant K D =690 nM and a 1:1 stoichiometry. Specific kininogen binding of tissue prokallikrein also occurred at physiological plasma protein concentrations. These results provide the first evidence for a novel function of high‐molecular‐weight kininogen as a binding protein for tissue prokallikrein that could serve to localize the kallikrein precursor on the neutrophil surface.