Description
Principle of the Assay::The Human Cathepsin E ELISA (Enzyme-Linked Immunosorbent Assay) kit is an in vitro enzyme-linked immunosorbent assay for the quantitative measurement of Human Cathepsin E in Cell Culture Supernatants, Serum, Plasma. This assay employs an antibody specific for Human Cathepsin E coated on a 96-well plate. Standards and samples are pipetted into the wells and Cathepsin E present in a sample is bound to the wells by the immobilized antibody. The wells are washed and biotinylated anti-Human Cathepsin E antibody is added. After washing away unbound biotinylated antibody, HRP-conjugated streptavidin is pipetted to the wells. The wells are again washed, a TMB substrate solution is added to the wells and color develops in proportion to the amount of Cathepsin E bound. The Stop Solution changes the color from blue to yellow, and the intensity of the color is measured at 450 nm.
Background/Introduction: Cathepsin E is a protein that in humans is encoded by the CTSE gene. It is mapped to 1q32.1. The protein encoded by this gene is a gastric aspartyl protease that functions as a disulfide-linked homodimer. This protease, which is a member of the peptidase C1 family, has a specificity similar to that of pepsin A and cathepsin D. It is an intracellular proteinase that does not appear to be involved in the digestion of dietary protein and is found in highest concentration in the surface of epithelial mucus-producing cells of the stomach. Cathepsin E is the first aspartic proteinase expressed in the fetal stomach and is found in more than half of gastric cancers. It appears, therefore, to be an oncofetal antigen, and it also has an important role in immune responses