The plasminogen/plasmin system plays a crucial role in fibrinolysis and regulation of cell functions in a wide range of normal and pathological processes. Investigation of plasminogen/plasmin functions requires the availability of well-characterized and effective molecular tools, such as antibodies. In the present work, the isolation and characterization of rabbit polyclonal antibodies against human plasminogen are described and approaches for the identification of plasminogen and its fragments using the purified antibodies are demonstrated. For the antibodies isolation, standard animal immunization and blood collection procedures, serum isolation, protein salting out and affinity chromatography were performed. For the antibodies characterization and application, the following methods were used: enzyme linked immunoassay (ELISA), Western blotting, FITC-protein conjugation, flow cytometry and spectrofluorometry. The obtained polyclonal rabbit anti-human plasminogen antibodies interacted with human Glu- and Lys-plasminogen, kringles 1-3 and 1-4 of plasminogen, mini-plasminogen, the heavy and light chain of plasmin. We propose the application of anti-plasminogen antibodies for the direct ELISA, Western blot analysis, and for flow cytometry and spectrofluorometric analysis of plasminogen binding with cells. The obtained anti-plasminogen antibodies are promising tools for the investigation of plasminogen/plasmin system functions, either fibrinolytic or signaling.
Isolation and Characterization of Bovine Plasminogen Activator from a Human Plasminogen-Streptokinase Mixture
