Isolation and Characterization of Two Cathepsins from Muscle of Carassius auratus gibelio

Abstract

Two cathepsins were identified in the white skeletal muscle from Carassius 
auratus gibelio. One of these, cathepsin D, has optimal activity at pH 3.5 with 
hemoglobin as substrate and a molecular weight 38,200 Da. The second, cathepsin E, is a protein with a molecular weight of 82,000 Da and an optimum pH 2.5. Both of the enzymes were strongly inhibited by pepstatin, a specific inhibitor for aspartic proteinases.