Unit Definition One unit will produce an increase in A280 of 1.0 per min per mL at pH 3.0 at 37 °C measured as TCA-soluble products using hemoglobin as substrate (1 cm light path).
Physical form Lyophilized powder containing citrate buffer salts
Biochem/physiol Actions Cathepsin D is an endosomal-lysosomal aspartic protease implicated in breast cancer metastasis and Alzheimer’s disease. Lysosomal release of cathepsin D has been found to precede cytochrome c release and loss of membrane potential in apoptotic human foreskin fibroblasts. Cathepsin D levels in PC12 cells increase 12 to 24 hours after apoptosis is induced.