Cathepsin D-like activity in neutrophils and monocytes.
Monocytes-macrophages and polymorphonuclear leukocytes contain an acid proteolytic enzyme that cleaves tritiated hemoglobin. The monocyte-macrophage-derived enzymatic activity was completely inhibited by pepstatin A, a property of cathepsin D. Monocyte-derived macrophages developed detectable cathepsin D-like activity after 5 days in culture, and this activity coincided with the appearance of other known indicators of macrophage maturation. The cathepsin D activity further increased significantly with time after day 5 of culture. The proteinase activity extracted from neutrophils was only partially inhibitable by pepstatin A, which indicates that this activity is contributed by more than one proteolytic enzyme, including cathepsin D. Cathepsin D activity demonstrated in neutrophils and macrophages may be an important marker of phagocyte function.
Levy
J
J
Division of Allergy-Immunology-Bone-Marrow Transplantation, Children's Hospital of Philadelphia, Pennsylvania.
Kolski
G B
GB
Douglas
S D
SD
D002402:Cathepsin D / Q000097:blood*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008264:Macrophages / Q000201:enzymology; D009000:Monocytes / Q000201:enzymology*; D009504:Neutrophils / Q000201:enzymology*
D006454:Hemoglobins; D002402:Cathepsin D