Mast cells contain spleen-type prostaglandin D synthetase.

摘要: Prostaglandin D synthetase activity in the cytosol (100,000 x g, 1-h supernatant) fraction of peritoneal mast cells adult rats (105.0 nmol/min/mg protein) was highest among such activities various rat tissues and cells. As judged by absolute requirement for glutathione reaction (Km = 300 microM), Km value prostaglandin H2 (200 insensitivity to 1 mM 1-chloro-2,4-dinitrobenzene, enzyme similar spleen differed from brain or S-transferase, all which catalyze isomerase D2. In immunotitration analyses, showed a titration curve exactly identical with that purified spleen-type almost completely absorbed an excess amount antibody against this enzyme, but it remained unchanged after incubation antibodies brain-type S-transferase isozymes thus far purified. Western blot two-dimensional electrophoresis crude extracts cells, single immunoreactive spot observed at same position as (Mr 26,000, pI 5.2). Furthermore, protein obtained peptide fingerprints those partial digestion Staphylococcus aureus V8 protease trypsin. immunoperoxidase staining, immunoreactivity found tissue organs thymus, intestine, stomach, skin rats. These findings indicate D2 is produced tissues.