Invitrogen™ Perforin Monoclonal Antibody (CB5.4)

Perforin is one of the major cytolytic proteins of cytolytic granules. Perforin is a cytolytic mediator and is stored in and released by cytoplasmic granules. Moreover, perforin is involved in immune defense against tumors and virus infections as mediated by cytotoxic lymphocytes. Perforin is a 555 amino acid protein with a 21 amino acid signal peptide, and has a molecular weight of 70 to 75 kD. Perforin is a pore forming protein with a mechanism of transmembrane channel formation similar to C9, and homology between perforin and C9 have been demonstrated. Studies show that perforin is expressed only in killer cell lines and not in helper T lymphocytes or other tumor cells tested. Perforin is known to be a key effector molecule for T-cell- and natural killer-cell-mediated cytolysis. Defects in the perforin gene cause familial hemophagocytic lymphohistiocytosis type 2 (HPLH2), a rare and lethal autosomal recessive disorder of early childhood. Alternative splicing results in multiple transcript variants of perforin.