Yeast aminopeptidase II: rapid purification using affinity chromatography of the periplasmic enzyme.

Periplasmic aminopeptidase II of yeast was isolated from protoplast supernatants by ammonium sulfate precipitation, DEAE-Sephacel chromatography and affinity chromatography on immobilized bestatin. This isolation method is more rapid than conventional procedures and, in addition, avoids contact of the enzyme with yeast proteinases. Thus the preparation obtained is likely to represent the native periplasmic from of aminopeptidase II.