Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serine proteases (granzymes) contained within the cytoplasmic granules of cytotoxic T cells and natural killer cells play a variety of roles including the induction of target cell apoptosis, breakdown of extracellular matrix proteins and induction of cytokine secretion by bystander leukocytes. Different granzymes display proteolytic specificities that mimic the activities of trypsin or chymotrypsin, or may cleave substrates at acidic ("Asp-ase") or at long unbranched amino acids such as Met ("Met-ase"). Here, we report that recombinant granzyme H has chymotrypsin-like (chymase) activity, the first report of a human granzyme with this proteolytic specificity. Recombinant 32-kDa granzyme H expressed in the baculovirus vector pBacPAK8 was secreted from Sf21 cells and recovered by Ni-affinity chromatography, using a poly-His tag encoded at the predicted carboxyl terminus of full-length granzyme H cDNA. The granzyme H efficiently cleaved Suc-Phe-Leu-Phe-SBzl (v = 185 nM/s at [S] = 0.217 mM) and also hydrolyzed Boc-Ala-Ala-X-SBzl (X = Phe, Tyr, Met, Nle, or Nva) with slower rates but had little tryptase or Asp-ase activity. Enzymatic activity was inhibited completely by 0.1 mM 3,4-dichloroisocoumarin and 84% by 1.0 mM phenylmethylsulfonyl fluoride. Fluoresceinated granzyme H was internalized in a temperature-dependent manner by Jurkat cells into endosome-like vesicles, suggesting that it can bind to cell surface receptors similar to those that bind granzyme B. This suggests a hitherto unsuspected intracellular function for granzyme H.
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PMID:The human cytotoxic T cell granule serine protease granzyme H has chymotrypsin-like (chymase) activity and is taken up into cytoplasmic vesicles reminiscent of granzyme B-containing endosomes. 1052 26

Mast cell proteinases are important inflammatory mediators in man and other species, but until now there has been no investigation of the nature of equine mast cell proteinases. These studies describe the purification and characterisation of two proteolytic components from equine mastocytoma tissue, detected using chromogenic substrates for trypsin and chymotrypsin. Following chromatographic purification, the trypsin-like component was found to be equine mast cell tryptase by N-terminal amino acid sequencing, showing a close similarity with human tryptase-beta (85% identity over 20 residues). It also had similar subunit molecular size (34-36kDa by SDS-PAGE) and substantially similar cleavage specificity to human tryptase-beta with the substrates tested. A 32kDa chymotrypsin-like component was also purified from mastocytoma extract, and termed equine mast cell proteinase-1 (eqMCP-1). The N-terminal amino acid sequence of eqMCP-1 was very similar to human granzyme H (95% over 19 residues). Rabbit antisera directed against tryptase and eqMCP-1 both detected equine mast cells by immunohistochemistry, and will be of use in future clinical studies of the relevance of mast cell proteinases in equine allergic disease.
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PMID:Characterisation of tryptase and a granzyme H-like chymase isolated from equine mastocytoma tissue. 1173 Sep 33