Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Factor IX BM Nagoya (IX Nagoya) is a natural mutant of factor IX responsible for severe hemophilia B. A patient with this mutant is characterized by a markedly prolonged ox brain prothrombin time. IX Nagoya was purified from the patient's plasma by immunoaffinity chromatography with an anti-factor IX monoclonal antibody column. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that treatment of IX Nagoya with factor XIa/Ca2+ resulted in cleavage only at the Arg145-Ala146 bond. Reversed-phase high performance liquid chromatography of a trypsin digest of IX Nagoya showed an aberrant peptide, which was further digested with proteinase Asp-N. Primary structure analysis of one of the Asp-N peptides revealed that Arg180 is replaced by Trp. An essentially complete (99%) amino acid sequence of IX Nagoya was obtained by sequencing fragments derived from a lysyl endopeptidase digest in which no other substitutions in the catalytic triad or substrate binding site were found. We also found that IX Nagoya is activated by alpha-chymotrypsin or rat mast cell chymase by monitoring the rate of factor X activation using a fluorogenic peptide substrate in the presence of factor VIII, phospholipids, and Ca2+. These results indicate that the substitution of Arg180 by Trp impairs the cleavage by factor XIa required for activation of this zymogen and that the substitution causes hemophilia BM.
...
PMID:Blood clotting factor IX BM Nagoya. Substitution of arginine 180 by tryptophan and its activation by alpha-chymotrypsin and rat mast cell chymase. 259 73

Mast cells at immature stages of development were identified in human tissues by electron microscopic techniques. General morphologic criteria of immaturity (such as a high apparent nuclear:cytoplasmic ratio and small cell size), the presence of few granules (those present being smaller than those in mature mast cells) and a lack of features of mast cell activation were used together to determine the level of maturity. Mast cells were identified as being of the T or TC type by immunogold staining with polyclonal rabbit IgG anti-chymase and murine monoclonal anti-tryptase primary antibodies and the appropriate gold-labeled secondary antibodies. Only those cells with tryptase-positive granules were recognized as mast cells. Immature T mast cell granules contained the same characteristic discrete scrolls found in their mature counterparts and all stained positive for tryptase. The presence of trace amounts of chymase in a minority of these granules, as in mature T mast cells, could not be ruled out. The majority of granules in immature TC mast cells had one or more amorphous electron-dense cores rather than the grating and lattice substructures characteristic of granules in mature TC mast cells. Secretory granules in immature TC mast cells stained positively for tryptase and chymase. Occasional immature TC mast cells contained a complete granule or a portion of a granule with the substructure characteristic of mature TC mast cells, favoring the concept that these TC mast cell forms are developmentally related. Essentially all mast cells in foreskin of newborns appeared immature, whereas 10, 5, 10, and 15% of the mast cells in adult lung, foreskin, bowel mucosa and bowel submucosa, respectively, appeared immature. The distribution of T and TC types of immature mast cells seemed to parallel that of the mature mast cell types. These compositional and ultrastructural differences between immature T and TC types of mast cells suggest that from the time granule formation begins, and possibly before this time, each type of human mast cell follows a distinct developmental pathway.
...
PMID:Ultrastructural analysis of maturing human T and TC mast cells in situ. 264 87

Limited proteolysis of T-kininogen by heterologous and homologous endopeptidases (bovine trypsin, human leukocyte elastase, rat submaxillary gland endopeptidase k, and rat mast cell chymase) produced similar fragmentation. Amino-terminal sequence analysis of whole T-kininogen lysates and purified proteolytic fragments identified four susceptible regions which contained all the preferential cleavage sites for these proteinases. Two of these susceptible regions were close to the junction between heavy chain cystatin-like domains, the third was in the kinin-containing region, and the fourth was close to the carboxyl terminus of the T-kininogen light chain. There was only one primary site for each proteinase in the kinin-containing region, which explains why catalytic amounts of these proteinases did not release immunoreactive kinin from this kininogen. However, preferential cleavage of T-kininogen close to the junction between cystatin-like domains released fragments which, provided they included cystatin-like domains 2 and/or 3, strongly inhibited papain and cathepsin L. The fragments were inhibitory even when parts of the amino-terminal ends of the domains were lacking. The highly conserved glycyl residue, thought to be involved in the inhibitory reactive site of cystatin-like inhibitors, was not required in purified domain 3 for inhibition of cathepsin L.
...
PMID:Limited proteolysis of T-kininogen (thiostatin). Release of comparable fragments by different endopeptidases. 264 33

We tested four synthetic substances for their histochemical value to demonstrate the catalytic activities of chymase or tryptase in mast cells in sections of human gut. Both Suc-Ala-Ala-Phe-4 methoxy-2-naphthylamide (MNA) and N-acetyl-L-methionine-alpha-naphthyl ester (alpha-N-O-Met) reacted with chymase but not tryptase in mast cells. Conversely, D-Val-Leu-Arg-MNA and Z-Ala-Ala-Lys-MNA were hydrolyzed by mast cell tryptase but not chymase. These results were confirmed by use of two inhibitors of chymotrypsin-like activity, chymostatin and Z-Gly-Leu-Phe-chloromethyl ketone (CK) and two inhibitors of trypsin-like activity, Tos-Lys-CK and D-Val-Leu-Arg-CK. Excellent staining reactions were obtained on cryostat sections of unfixed or aldehyde-fixed tissues and on paraffin sections of Carnoy-fixed tissues. For chymase, however, Suc-Ala-Ala-Phe-MNA is preferred on cryostat sections because it is more specific. On paraffin sections alpha-N-O-Met is preferred because other cells are not then stained. For tryptase, Z-Ala-Ala-Lys-MNA was more selective and more specific and is the preferred general purpose substrate on cryostat sections of aldehyde-fixed tissues and for paraffin sections. D-Val-Leu-Arg-MNA is the preferred substrate for cryostat sections of unfixed tissue. Only a limited number of mast cells showed a reaction for chymase, and these occurred mainly in the submucosa. All mast cells, however, gave a reaction for tryptase, and we recommend the use of either substrate for this enzyme for routine detection of mast cells in human tissues. Double staining for the two main mast cell proteases is most conveniently undertaken on paraffin sections of Carnoy-fixed tissues using MNA substrates for tryptase and alpha-N-O-Met for chymase.
...
PMID:Enzyme histochemical discrimination between tryptase and chymase in mast cells of human gut. 264 38

The mast cell proteases tryptase and chymase have long been known to constitute one-fifth of the total protein in mast cells. However, their biological functions have not been easy to study because of the difficulty in obtaining sufficient amounts of the enzymes to study their biological functions. Recently, we have been fortunate to have available a permanent line of dog mastocytoma cells to purify both enzymes to homogeneity, and we have used the purified enzymes in two ways. First, in a series of biological studies, we have discovered unique and potent actions of the enzymes that may provide important insights into the pathogenesis of diseases such as asthma and cystic fibrosis. Important biological activities are also likely to exist in other tissues. Because of their structures, mast cell proteases are likely to act in proximity to their sites of release. Thus, the presence and amounts of tryptase and chymase in specific loci may play important roles in tissue responses. In diseases such as asthma and cystic fibrosis, there is evidence that the expression of these mast cell enzymes changes, and these changes have important pathogenetic implications. Second, we have begun to perform structural studies of the enzymes. The recent cloning of tryptase by our group should assist in the better understanding of its functions. Crystallography of the pure proteins should provide further insights and could be the basis of rational development of potent and selective drugs that will inhibit their actions.
...
PMID:Roles of mast cell proteases in airways. 266 41

Mast cells are abundant and are widely distributed in airway tissues. They release their secretory products into microenvironments as diverse as epithelium, smooth muscle, and glands. The major secretory granule proteins of mast cells are proteases that are released outside of the cell with heparin, histamine, and other preformed mediators. In the past few years, investigations in a number of laboratories have rapidly increased our knowledge of the chemical and biological properties of the two major mast cell secretory proteases, tryptase and chymase. Recent experimental evidence suggests the possibility of biologically important roles for tryptase and chymase in the airways, particularly in the regulation of neuropeptide activity, bronchomotor tone, and submucosal gland secretion. The purpose of this commentary is to examine critically the evidence of participation of these mast cell proteases in molecular and physiological events in the airways.
...
PMID:Roles of mast cell tryptase and chymase in airway function. 266 22

The distribution of tryptase in various human tissue high-salt extracts (skin, lung, pancreas, liver, kidney, and spleen) was studied. Tryptase activity was compared with tissue histamine concentration, chymase activity, and cathepsin D, and histamine-N-methyltransferase (HMT) activities. Tryptase activity, found biochemically in tissue extracts, was localized in tissue sections by an enzyme-histochemical method using peptide 4-methoxy-2-naphthylamide substrates and Fast Garnet GBC as the chromogen. The highest levels of tryptase activity were found in lung and skin extracts. Liver, kidney, and spleen extracts displayed only a little activity. The distribution of histamine was similar to that of tryptase, whereas distributions of cathepsin D and HMT were quite different from that of tryptase. High-salt extracts of lung contained no detectable chymase activity, but in skin extracts this activity was high. Using an enzyme-histochemical method, the tryptase activity in tissue sections seemed solely to be confined to cells, which were granular and Giemsa positive after the red azo dye had been removed with Tween 20. Skin and lung sections contained the highest number of positively stained cells. The inhibition properties of tryptase, found in both tissue extracts and sections, and the substrate profile in tissue sections were identical. Human leukocyte preparation was negative for tryptase when stained enzyme-histochemically. The present results suggest that tryptase in human tissues is found only in the mast cells. The enzyme seems to be identical in the various human tissues studied because the different high-salt extracts were immunologically cross-reactive when tested with a rabbit polyclonal antibody against skin tryptase.
...
PMID:Biochemical and histochemical evaluation of tryptase in various human tissues. 267 65

We developed an improved immunohistochemical technique for distinguishing human mast cells of the MCT (tryptase-positive, chymase-negative) and MCTC (tryptase-positive, chymase-positive) types utilizing a biotinylated murine anti-chymase monoclonal antibody (MAb), termed B7, and an alkaline phosphatase-conjugated murine anti-tryptase MAb, termed G3. The B7 MAb also was used to show the selective presence of chymase in mast cells. The distribution of MCT and MCTC cells in Carnoy's fluid-fixed tissue sections of human lung, skin, small intestine, and tonsils was analyzed by the new technique and the results compared to those obtained with the older method using a rabbit polyclonal antichymase antibody and a mouse anti-tryptase MAb in indirect immunoperoxidase and indirect immunoalkaline phosphatase protocols, respectively. In tissues known to contain predominantly mature mast cells, there were no quantitative differences between the two techniques, although the staining intensity achieved with the anti-chymase MAb was greater and without development of high background, compared to results achieved with the polyclonal antibody. MCT cells were the predominant type seen in the alveoli of the lung (93%) and in the small intestinal mucosa (81%). MCTC cells predominanted in the skin (99%) and in the small intestinal submucosa (77%) and, to a lesser degree, in tonsils (60%). However, in newborn foreskin tissue which contains predominantly immature forms of mast cells, 75% of all mast cells were stained uniformly and intensely with B7, whereas only 43% were stained with the polyclonal anti-chymase antibody. Therefore, the use of MAb provides for better standardization of reagents and more accurate assessment of the distribution of human MCT and MCTC cells in tissues than previously available methods.
...
PMID:Detection of MCT and MCTC types of human mast cells by immunohistochemistry using new monoclonal anti-tryptase and anti-chymase antibodies. 267 73

Granules that are potently cytolytic in vitro can be obtained from cytotoxic lymphocytes that kill virally infected cells and tumor cells. These granules contain pore-forming proteins and several serine proteases. Here we indicate that at least two different proteases participate in the lysis mediated by granule proteins from RNK-16 rat leukemia cells. We report twelve different mechanism-based or "suicide" isocoumarin serine protease inhibitors which have different 3- and 7-substituents that confer selectivity and reactivity towards either the chymotrypsin- ("chymase") or trypsin-like ("tryptase") protease activities of RNK-16 cells. Second order inhibition rates of inactivation (kobsd/[I]) for the RNK-16 granule proteases ranged between 164 and 22,640 M-1s-1. These new, specific and highly reactive isocoumarin serine protease inhibitors also abrogated the cytolysis mediated by lymphocytes granule proteins. The eight inhibitors with large hydrophobic or basic substituents that conferred chymase or tryptase specificities were more effective at inactivating lytic function than the four elastase-directed inhibitors with smaller substituents. All twelve new isocoumarin inhibitors blocked cytolysis at lower concentrations than 3,4-dichloroisocoumarin, a potent general mechanism-based serine protease inhibitor that also blocks RNK-16 granule protease activities and lysis.
...
PMID:Selective isocoumarin serine protease inhibitors block RNK-16 lymphocyte granule-mediated cytolysis. 281 73

The skeletal muscle content of three rat proteinase inhibitors, a 1-proteinase inhibitor, contrapsin and a 1-cysteine proteinase inhibitor was measured by immunochemical techniques following streptozotocin-induced diabetes. When compared with normal rats, a 1-cysteine proteinase inhibitor and a 1-proteinase inhibitor levels remained essentially unchanged, whereas the content of rat contrapsin was reduced by nearly 80% after the onset of diabetes. Similarly, fasting of rats for three days resulted in a lowering of the levels of contrapsin in skeletal muscles. Under these conditions, levels of chymotrypsin-like activity (chymase) were increased by 150%, whereas the content of the trypsin-like, neutral proteinase was unchanged. Kinetic studies in vitro with Tosyl-Gly-Pro-Arg-4-nitroanilide as substrate showed no inhibition of the trypsin-like proteinase by a 1-proteinase inhibitor, while contrapsin inhibited the enzyme with a Ki value of 40nM. The changing pattern of these proteinases and their potential inhibitors (chymase/a 1-proteinase inhibitor and trypsin-like proteinase/contrapsin) may be a factor contributing to muscle wasting as observed in diabetes and fasting.
...
PMID:Changes in proteinase/proteinase inhibitor levels in rat skeletal muscle tissue during diabetes and fasting. 306 Jan 41


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---