Monoclonal Antibody B9-2 Recognizes an 8 Amino Acid Sequence that Spans an Autocatalytic Cleavage Site Between the Two Subunits of Human Procaspase 8

Caspase 8 is synthesized in a zymogen form and must be proteolytically cleaved to be activated. The catalytically active enzyme is composed of two of the four cleavage products. We have determined that the monoclonal antibody B9-2 recognizes the octomer EMDLSSPQ. This sequence is shared by two of the cleavage products: a decamer linker region released after autocatalysis and the smaller subunit of the active enzyme.