SerpinB9: Proteins and Enzymes

SerpinB9 is a serine proteinase inhibitor of the ovalbumin like B clade of serpins. The mouse orthologue to PI9 is SPI-6. SerpinB9 was first discovered in human bone marrow in a search for serpins similar to SerpinB6. SerpinB9 was identified in lymphocytes, especially natural killer cells and cytotoxic T lymphocytes, cells which also produce and store the apoptosis-inducing enzyme Granzyme B. PI9 was shown to be a potent inhibitor of Granzyme B, working at picamolar efficiencies. PI9 was also ...