METHOD OF PRODUCING LYS-PLASMINOGEN

摘要

To produce lys-plasminogen having a specific activity of at least 17.5 caseinolytic units/mg protein and at least 50 .mu. moles/g protein nitrogen as well as an electrophoretic purity of at least 90 %, plasminogen from plasma, a plasminogen-containing fraction or a tissue culture is adsorbed on immobilized lysine for the purpose of purification, is eluted and is recovered from the eluate by a protein precipitating agent. A solution of the thus purified plasminogen is adjusted to a plasmin activity ranging between 0.005 and 0.2 .mu.moles/ml min relative to chromogenic substrate H-D-valyl-L-leucyl-L-lysine-p-nitroanilide dihydrochloride, is maintained at a temperature of from +1.degree.C to +20.degree.C for a period of from 6 to 60 hours in order to provoke an enzymatic-proteolytic conversion of plasminogen into lys-plasminogen, whereupon the enzymatic action is interrupted and lys-plasminogen is isolated.