title: Identification of two types of protein immunochemically related to urinary urokinase occurring in human plasma.
abstract: Plasma urokinase, a plasminogen activator immunochemically related to urinary urokinase (UK), was removed from human plasma (3.5 ng/ml) by immuno-depletion with antibodies raised against UK. The remaining plasminogen activator activity of the depleted plasma could not be inhibited by anti-UK antibodies and a sensitive ELISA for UK did not detect any UK levels that were higher than the background of the assay (0.1 ng/ml). However, when the depleted plasma was subjected to SDS-PAGE, substantial amounts of protein were found hereafter around 110 and 46 kD which now gave a positive reaction in the ELISA (35-350 ng/ml plasma). From these observations it is concluded that in human plasma two types of UK-related protein occur: Type I, among which the plasma urokinase, has antigenic determinants which are directly accessible to the anti-UK antibodies, Type II has determinants in a latent form. The function of the 110 kD type-II protein is that of a plasminogen activator; that of the 46 kD protein is not yet clear.
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D006801:Humans; D008970:Molecular Weight; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D010959:Tissue Plasminogen Activator / Q000032:analysis; D014568:Urokinase-Type Plasminogen Activator / Q000097:blood* / Q000145:classification / Q000276:immunology
chemical_list: D012967:Sodium Dodecyl Sulfate; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator