A fibroblast-derived urokinase-inhibitor differing from protease nexin.
UK-I, a 60-kDa urokinase-inhibitor derived from human fibroblasts, inhibited 54-kDa urokinase (EC 3.4.21.31) activity dose-dependently on ordinary fibrin-agar autograms. This UK-I formed an SDS-stable approximately 75-kDa complex with radioiodinated urokinase (33 kDa) on an autoradiogram following SDS/polyacrylamide gel electrophoresis. Benzamidine hydrochloride inhibited its formation, indicating UK-I to bind at the active site of urokinase and form an inactive complex. UK-I did not form a complex with [125I]thrombin (EC 3.4.21.5). It is thus evident that UK-I is one type of urokinase-inhibitor derived from human fibroblasts with properties differing from protease nexin, another urokinase-inhibitor derived from the same source.
Masuzawa
M
M
Department of Dermatology, Kitasato University School of Medicine, Kanagawa, Japan.
Hamazaki
H
H
Nishioka
K
K
Nishiyama
S
S
Ryan
T J
TJ
D016564:Amyloid beta-Protein Precursor; D002352:Carrier Proteins; D002478:Cells, Cultured; D005347:Fibroblasts / Q000032:analysis*; D006801:Humans; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D013917:Thrombin / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors* / Q000378:metabolism
D016564:Amyloid beta-Protein Precursor; D002352:Carrier Proteins; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D013917:Thrombin; D014568:Urokinase-Type Plasminogen Activator