Immunological relationship between the fast-acting plasminogen activator inhibitors from plasma, blood platelets and endothelial cells demonstrated with a monoclonal antibody against an inhibitor from placenta.
Two plasminogen activator inhibitors (I and II) were demonstrated in human placenta. The complex between inhibitor I and tissue-type plasminogen activator was purified by immunoadsorption to solid-phase anti-activator antibodies. The purified complex (Mr 95.000) was used for immunization of mice and subsequent production of monoclonal antibodies. One antibody (F37), which reacted with both free and complex-bound inhibitor I, was used for further study by a method involving binding of the antibody to protein A-Sepharose, immunoadsorption of antigen and analysis of the resulting supernatant by SDS-polyacrylamide gel electrophoresis and enzymography. The analysis showed that F37 reacted with the fast-acting plasminogen activator inhibitors recently demonstrated in plasma, blood platelets and endothelial cells, indicating that these inhibitors and inhibitor I share a common epitope. Inhibitor II did not react with F37. Inhibitor II is identical to the placenta inhibitor previously described by others. It reacted selectively with polyclonal antibodies against that inhibitor.
D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D001792:Blood Platelets / Q000032:analysis* / Q000276:immunology; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D004727:Endothelium / Q000032:analysis / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D005260:Female; D006023:Glycoproteins / Q000097:blood / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007074:Immunoglobulin G / Q000145:classification; D008970:Molecular Weight; D010920:Placenta / Q000032:analysis* / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D015849:Plasminogen Inactivators; D011247:Pregnancy; D011485:Protein Binding; D014018:Tissue Distribution; D010959:Tissue Plasminogen Activator / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006023:Glycoproteins; D007074:Immunoglobulin G; D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator