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Identification of prolylcarboxypeptidase as the cell matrix‐associated prekallikrein activator
Author(s) -
Moreira Claudia R,
Schmaier Alvin H,
Mahdi Fakhri,
da Motta Guacyara,
Nader Helena B,
Shariat-Madar Zia
Publication year - 2002
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(02)02980-0
Subject(s) - chemistry , antipain , bradykinin , angiotensin ii , prekallikrein , kallikrein , microbiology and biotechnology , factor xii , human umbilical vein endothelial cell , umbilical vein , leupeptin , biochemistry , medicine , protease , biology , enzyme , receptor , coagulation , in vitro
Investigations determined that the cell matrix‐associated prekallikrein (PK) activator is prolylcarboxypeptidase. PK activation on human umbilical vein endothelial cell (HUVEC) matrix is inhibited by antipain (IC 50 =50 μM) but not anti‐factor XIIa antibody, 3 mM benzamidine, 5 mM iodoacetic acid or iodoacetamide, or 3 mM N ‐ethylmaleimide. Corn trypsin inhibitor (IC 50 =100 nM) or Fmoc‐aminoacylpyrrolidine‐2‐nitrile (IC 50 =100 μM) blocks matrix‐associated PK activation. Angiotensin II (IC 50 =100 μM) or bradykinin (IC 50 =3 mM), but not angiotensin 1–7 or bradykinin 1–5, inhibits matrix‐associated PK activation. ECV304 cell matrix PK activator also is blocked by 100 μM angiotensin II, 1 μM corn trypsin inhibitor, and 50 μM antipain, but not angiotensin 1–7. 1 mM angiotensin II or 300 μM Fmoc‐aminoacylpyrrolidine‐2‐nitrile indirectly blocks plasminogen activation by inhibiting kallikrein formation for single chain urokinase activation. On immunoblot, prolylcarboxypeptidase antigen is associated with HUVEC matrix. These studies indicate that prolylcarboxypeptidase is the matrix PK activator.