Purification of human plasminogen

Abstract

Plasminogen was purified from out-dated human plasma. A crude plasminogen (fraction P 1) was first precipitated after the removal of fibrinogen from plasma at pH 5.3, and a fraction P 2 obtained from this by treatment with citrate buffer. Fraction P 2 was dissolved in acetate-phosphate buffer, pH 4.0, and the plasminogen precipitated from the solution by adjusting it to pH 5.15, to give fraction P 3. By dissolving the fraction P 3 in phosphate-sodium chloride buffer, pH 8.0, and shaking the solution with excess of ether at -3[degree], lipid material and some inactive protein were removed, and plasminogen precipitated from the aqueous layer at pH 5.15 to give fraction BL. From both fractions P 3 and BL purified plasminogen fractions were obtained by batch adsorption on to diethylaminoethylcellulose resin followed by elution with lysine-containing buffers. The eluates obtained by the batch adsorption of fraction BL (fraction R) had a potency 190-315 times that of plasma, the preparation being soluble at neutral pH.