Purification and biochemical characterization of rat skin cathepsin D

The hemoglobin-hydrolyzing, acidic proteinase activity of rat skin was purified by using ammonium sulfate precipitation. Sephadex G-100 gel column chromatography, acid treatment, and DEAE-cellulose column chromatography, giving a purification coefficient of 182. The pH optimum, molecular size, substrate specificity, as well as inhibitor and activator sensitivity of the enzyme preparation, corresponded closely to those of cathepsin D. The enzyme activity was separated from cathepsin B1. The present status of the knowledge of skin cathespins is reviewed.