PURIFICATION OF AN EXTRACELLULAR PROTEINASE FROM PENICILLIUM NOTATUM

An extracellular proteolytic enzyme from the culture medium of Penicillium notatum, obtained as a dry, tannin‐precipitated powder from a commercial source, has been isolated. The purification procedures used include extraction of the crude proteinase with buffer from the commercial product, precipitation with ammonium sulphate, chromatography on DEAE‐Sephadex A‐25, gel filtration on Sephadex G‐75, followed by ion‐exchange chromatography on SE‐Sephadex C‐50, and finally zone electrophoresis on a cellulose column. Sufficient evidence is presented to show the purity of the isolated proteinase. Arguments for and against the presence of two distinct proteolytic enzymes from the same source are also presented. Copyright © 1968, Wiley Blackwell. All rights reserved