A plasminogen activator inhibitor-2 from a promyelocytic leukemia cell line, PL-21, binds to the carboxy-terminal chain of plasminogen activators.
A promyelocytic leukemia cell line, PL-21, was found to produce an inhibitor of plasminogen activators (PAI). The PAI reacted to anti-PAI-2 but not anti-PAI-1 anti-serum and had an apparent molecular weight of 43 kDa on unreduced SDS-PAGE. The PAI inhibited not only urokinase-type plasminogen activator (u-PA) but single- and two-chain tissue-type plasminogen activators (t-PAs) on plasminogen-containing fibrin plate. It formed SDS-stable complexes with both t-PA and u-PA but not with prourokinase as demonstrated by both fibrin zymography and immunoblotting using anti-PA and anti-PAI-2 antisera after SDS-PAGE. These complexes were still present even after reduction with dithiothreitol. The PAI appears to bind to the carboxy-terminal chain of both PAs, because the part of the band corresponding to the carboxy-terminal chain of PAs moved to an upper position as a result of complex formation when two-chain form of PAs were incubated with the PAI and analyzed by SDS-PAGE followed by immunoblotting.
Takeuchi
T
T
Department of Medicine, Kochi Medical School, Japan.
Niiya
K
K
Kubonishi
I
I
Miyoshi
I
I
D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D005337:Fibrin; D006801:Humans; D015151:Immunoblotting; D015473:Leukemia, Promyelocytic, Acute / Q000378:metabolism*; D008969:Molecular Sequence Data; D010960:Plasminogen Activators / Q000378:metabolism*; D015849:Plasminogen Inactivators / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D014407:Tumor Cells, Cultured
D015849:Plasminogen Inactivators; D005337:Fibrin; D010960:Plasminogen Activators