Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Free flow electrophoresis was used for the purification of human tissue plasminogen activator (t‐PA) produced by recombinant yeast cells. This method was employed for three principal reasons: (a) yeast t‐PA purified by immunoaffinity chromatography was not pure enough to carry out protein chemical characterization, (b) the amount of yeast t‐PA available for purification was extremely limited, (c) t‐PA has a strong tendency to adsorb to support material; a support‐free separation method therefore seemed to be a reasonable way to further purify the enzyme. Free flow electrophoresis was first performed using solutions containing the soluble proteins of yeast cell extract, and secondly, using t‐PA fractions prepared by immunoaffinity chromatography, Yeast t‐PA purified by immunoaffinity chromatography and then by free flow electrophoresis is more than 80% pure and suitable for characterization experiments such as glycosylation studies or N‐terminal sequence determination.</jats:p>