Patent ID: 6284874
Filing Date: 2001-09-04
Classification: C07K

Abstract:
A process for purifying .alpha..sub.1 -proteinase inhibitor comprising:providing an impure protein fraction comprising .alpha..sub.1 -proteinase inhibitor;suspending the impure protein fraction comprising .alpha..sub.1 -proteinase inhibitor in water;precipitating the impure protein fraction comprising .alpha..sub.1 -proteinase inhibitor with a precipitant comprising polyethylene glycol (PEG) and ZnCl.sub.2 ;collecting the supernatant from the PEG/ZnCl.sub.2 precipitation, wherein the supernatant comprises .alpha..sub.1 -proteinase inhibitor;precipitating .alpha..sub.1 -proteinase inhibitor from the PEG/ZnCl.sub.2 supernatant with ZnCl.sub.2 at a concentration of 5 to 15 mM to thereby provide an .alpha..sub.1 -proteinase inhibitor precipitate;resuspending the .alpha..sub.1 -proteinase inhibitor precipitate in an aqueous medium;applying the resuspended .alpha..sub.1 -proteinase inhibitor to an anion-exchange chromatography medium;applying .alpha..sub.1 -proteinase inhibitor recovered from the anion-exchange chromatography medium to a metal chelate medium; andrecovering a fraction comprising .alpha..sub.1 -proteinase inhibitor from the metal chelate medium.