ISOLATION AND PURIFICATION OF A KRINGLE 5 FROM HUMAN PLASMINOGEN USING AH-SEPHAROSE

Abstract

Our aim was to develop a method for isolation of human plasminogen kringle 5 possessing functional activity. The proposed method includes the following steps: hydrolysis of plasminogen with elastase, separation of mini-plasminogen from kringle fragments 1–3 and 4 on Lys-Sepharose, mini-plasminogen hydrolysis with pepsin, affinity chromatography on AH-Sepharose and polyacrilamide gel electrophoresis. We obtained the electrophoretically pure fragment of human plasminogen kringle 5 showing functional activity towards the ligands with high and low molecular mass. Weight yield was 3.8% that corresponds to 25.3% of the theoretically possible. It was established that affinity chromatography on AH-Sepharose was the sufficient step to isolate kringle 5 from mini-plasminogen hydrolysate with pepsin. This approach does not require additional purification steps while the ability of kringle 5 to bind specifically to AH-Sepharose demonstrates the functional activity of the kringle.

Keywords

• plasminogen
• fragments of plasminogen
• kringle 5
• angiostatins