Isolation of Cathepsin D by Affinty Chromatography on Immobilized Pepstatin

Affinity chromatography with an immobilized substrate proved to be a successful tool in the preparation of pure and undegraded cathepsin D (1). Immobilized reversible inhibitors are even more suitable for the isolation because the enzyme remains inactive during the affinity chromatography procedure. Pepstatin is known as a strong inhibitor of carboxyl proteases (2) and we wanted to make use of its inhibitory property for the isolation of cathepsin D. In this report, a method for isolation of cathepsin D is described using affinity chromatography on pepstatin-agarose.