Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Early development of peptide hydrolysis in the digestive tract was investigated in experiments with fasted and fed ad lib. chicks during the first decade of postnatal period. 2. Pancreatic carboxypeptidase A (CPA) activity was maximal at the moment of hatch. On the second day CPA activity considerably diminished in starved and fed animal groups; further starvation (3-4 days) led to the significant increase of CPA total and specific activity, whereas the amount of enzyme in pancreas of fed chicks was rather low. 3. Aminopeptidase (AP) activity of the small intestinal surface was less sensitive to starvation. The increase of activity in all intestinal parts was observed only on the 4th day of fasting. The most sensitive to starvation were dipeptidases. Changes in their activity (2-fold increase) were detected after 24 hr of starvation. 4. The formation of specific physiological proximo-distal gradient of intestinal exopeptidase activities began only after the moment of the first feeding. 5. This gives evidence that the development of peptide hydrolysis depends not only on the age of the animal but also on the normal physiological beginning of the process of exogenous nutrition.
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PMID:Effect of early postnatal long-term fasting on the development of peptide hydrolysis in chicks. 134 25

Sonicates of mouse bone marrow-derived mast cells (BMMC) differentiated in vitro and of mouse serosal mast cells differentiated in vivo contained small but approximately equal amounts of aminopeptidase activity, as determined by cleavage of leucine-beta-naphthylamide and resolution of the reaction products by reverse-phase high-performance liquid chromatography. Aminopeptidase activity was exocytosed from antigen-activated, IgE-sensitized BMMC in proportion to the secretory granule enzyme beta-hexosaminidase, thereby localizing approximately 60% of the total cell-associated aminopeptidase activity to the secretory granules of the mast cells. A prominent secretory granule location for aminopeptidase was confirmed by activity measurement in subcellular fractions of disrupted BMMC. The secretory granule aminopeptidase had a pH optimum of 6.0-8.0 and a Km of 0.36 +/- 0.06 mM (mean +/- SD; n = 3) for leucine-beta-naphthylamide. When various amino acid beta-naphthylamides were used as substrates, the preference of the secretory granule enzyme was Ala greater than Leu greater than Phe much greater than Arg much greater than Asp = Tyr. Most of the aminopeptidase activity that was exocytosed from calcium ionophore-activated BMMC was bound to 35S-labeled proteoglycans in complexes of greater than 1 x 10(7) kDa as defined by exclusion during Sepharose CL-2B gel-filtration chromatography. We postulate that the amino-peptidase in the mast cell protease/proteoglycan complexes allows the removal of N-terminal amino acids from peptides that are generated by the action of mast cell endopeptidases.
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PMID:Identification of aminopeptidase activity in the secretory granules of mouse mast cells. 206 74