Purification of Cathepsin D by Ah-Sepharose Affinity Chromatography

A rapid and reliable method for coupling the protease in-hibitor pepstatin to AH-Sepharose 4B was developed. The matrix prepared was used to purify cathepsin D from rat liver. The enzyme was eluted in one fraction and proved to be pure by gel electrophoresis, two types of ion exchange chromatography, molecular sieve chromatography, and immunologically homogenous by Immunoelectrophoresis. This method is more rapid and gives a higher yield than previous techniques. The possibility to use this technique for the purification of other enzymes inhibitable by pepstatin should be considered.