title: A family of serine esterases in lytic granules of cytolytic T lymphocytes.
abstract: Cytoplasmic granules of cytolytic T lymphocytes (CTLs) contain, in addition to the pore-forming protein perforin, a family of highly homologous serine esterases, granzymes A-H. The serine esterase affinity label diisopropyl fluorophosphate reacts strongly with granzymes A and D, to a lesser extent with B, E, F, G, and H, and not at all with C and F. For granzymes A and D, synthetic substrates have been found. Antibodies raised against granzyme B strongly cross-react with A, G, and H, and antibodies to granzyme D recognize C, E, and F. These antigenic relationships correlate with similarities in the N-terminal amino acid sequences. At least 60% homology is observed between the eight proteins, and all are similar to rat mast cell protease 2. Sequence analysis suggests the identity of granzyme A with a protease predicted from a CTL-specific cDNA clone (H factor) and of granzyme B, G, or H with a protein encoded by the CTL-specific cDNA clone CTLA 1/CCP 1.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003594:Cytoplasmic Granules / Q000201:enzymology*; D010450:Endopeptidases / Q000378:metabolism; D004950:Esterases / Q000235:genetics / Q000378:metabolism*; D053804:Granzymes; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D012697:Serine Endopeptidases; D013602:T-Lymphocytes, Cytotoxic / Q000201:enzymology*
chemical_list: D004950:Esterases; C022635:serine esterase; D010450:Endopeptidases; D053804:Granzymes; D012697:Serine Endopeptidases