GZMB codes for granzyme B.
Granzyme B (gzm B) is a peptidase that induces cytotoxic T lymphocyte (CTL)-mediated DNA fragmentation and apoptosis in allogeneic target cells. It cleaves after aspartic acid residues in substrates. Granzyme B-mediated release of mitochondrial cell death factors are required for the activation of caspase-3. Furthermore, the degradation of granzyme B is known to decrease the susceptibility of cancer cells to NK-cell-mediated lysis during hypoxia. Granzyme B activity assays can be used for studying T cell immunity, CTL responses, cell-mediated cytotoxicity, and apoptosis.
Gzm B is a pro-apoptotic member of the granzyme family. It is a neutral serine protease with Aspase activity. Gzm B is expressed exclusively in the granules of activated cytolytic T cells, natural killer cells and lymphokine-activated killer cells.
Granzyme B activity is determined using an enzyme-catalyzed reaction in which the non-fluorescent substrate, Ac-IEPD-AFC, is hydrolyzed resulting in the release of AFC (λex = 380/λem = 500 nm) proportional to the enzymatic activity present. One unit of granzyme B is the amount of enzyme that hydrolyzes 1 pmole of the substrate per minute at 37 °C.