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)

The amino acid sequence of the neutral zinc protease from Bacillus mesentericus strain 76 (MCP 76) has been determined by using peptides derived from digests with trypsin, chymotrypsin, and cyanogen bromide and from cleavage with o-iodosobenzoic acid. The peptides were purified by means of gel filtration and reversed-phase high-performance liquid chromatography and analyzed by automatic sequencing. The protein contains 300 amino acid residues. It proved to be identical with the neutral protease deduced from the DNA precursor sequence of Bacillus subtilis. The residues for zinc and substrate binding are conserved, whereas the number of calcium binding sites is reduced compared to thermolysin. A classification of the neutral zinc protease is discussed.
...
PMID:Primary structure of a zinc protease from Bacillus mesentericus strain 76. 230 86

Six basic proteins of 26 to 38 kDa with isoelectric points (pI) > or = 8.5 were abundant in proteins separated by two-dimensional SDS-PAGE from adult rat peritoneal mast cells (MC). One was identified previously as rat mast cell proteinase (RMCP) 1, a chymase of 26 to 28 kDa, pI > 9.0. Microsequence analyses showed that two polypeptides of about 29 and 30 kDa had NH2 terminal amino acid sequences homologous to mouse MC proteinase 5 (MCP-5), whereas the amino terminals of the 33, 35, and 36 kDa proteins were homologous to MC carboxypeptidase A (MC-CPA). Rabbit Abs produced against synthetic peptides of the identified NH2 terminal sequences were used in immunoblot studies. At least three proteins reacted with Abs to MC-CPA, whereas Abs to MCP-5 detected three adjacent polypeptides, rather than just the two identified by using microsequence analysis. Removal of oligosaccharide side chains using peptide:N-glycosidase F reduced the heterogeneity of each set of three polypeptides (MCP-5 and MC-CPA) to a band of each protein of a lower M(r). The serine proteinase inhibitor [3H]diisopropylfluorophosphate ([3H]DFP) bound to a proteinase of 30 to 35 kDa, which is probably MC tryptase (pI < or = 6.0). Immunoblot analysis of proteins from intestinal mucosal mast cells showed RMCP-2, but not RMCP-1, MCP-5, or MC-CPA. This is the first report of MCP-5 in the rat and of clearly distinguishable glycosylated forms of MC CPA. These proteinases appear to be restricted in their distribution to selected MC populations, but little is known about their functions.
...
PMID:Proteinases of rat mast cells. Peritoneal but not intestinal mucosal mast cells express mast cell proteinase 5 and carboxypeptidase A. 759 1

The multicatalytic proteinase (MCP or proteasome) is a large proteolytic complex that contains at least five catalytic components: the trypsin-like, chymotrypsin-like, peptidylglutamyl-peptide hydrolase (PGPH), branched-chain-amino-acid-preferring (BrAAP) and small-neutral-amino-acid-preferring activities. We have shown that brief heating of the lobster muscle proteasome activates a proteolytic activity that degrades casein and myofibrillar proteins and is distinct from the trypsin-like, chymotrypsin-like and PGPH components. Here we identify the BrAAP activity as a catalytic component involved in the initial degradation of myofibrillar proteins in vitro. This conclusion is based on the following. (1) The BrAAP component was activated by heat-treatment, whereas the other four peptidase activities were not. (2) The BrAAP and proteolytic activities showed similar sensitivities to cations and protease inhibitors: both were inhibited by 3,4-dichloroisocoumarin, chymostatin, N-ethylmaleimide and Mg2+, but were not affected by leupeptin, phenylmethanesulphonyl fluoride or Li+. (3) The BrAAP activity was inhibited most strongly by casein substrates and troponin; conversely, the troponin-degrading activity was inhibited by the BrAAP substrate. Another significant finding was that incubation of the heat-activated MCP in the presence of chymostatin resulted in the limited cleavage of troponin-T2 (45 kDa) to two fragments of 41 and 42 kDa; this cleavage was completely suppressed by leupeptin. These results suggest that under certain conditions the trypsin-like component can cleave endogenous protein.
...
PMID:Branched-chain-amino-acid-preferring peptidase activity of the lobster multicatalytic proteinase (proteasome) and the degradation of myofibrillar proteins. 786 22

We have recently described nongranular, cytosolic, high-molecular-weight trypsin-like (A-NKP 1) and chymotrypsin-like (A-NKP 2) proteases of interleukin-2-activated rat natural killer (A-NK) cells. A functional correlation between the inactivation of A-NKP 2 and the inhibition of rat A-NK cell-mediated cytotoxicity was found. Herein we describe the 6,000-fold purification of A-NKP 2 to apparent homogeneity following: isopycnic sucrose gradient fractionation of postnuclear supernatants, molecular sieve chromatography, and heparin-Sepharose chromatography. We also report the novel finding that A-NKP 2 as well as A-NKP 1, derived from either rat A-NK cells or the rat NK leukemic cell line CRNK-16, are constituents of the multicatalytic proteinase (MCP/proteasome) complexes of these cells. Characteristic biochemical, biophysical, and electron microscopic/ultrastructural similarity to the rat liver proteasome was observed. However, Western blot analysis using polyclonal antibodies to the rat liver proteasome clearly indicated differences in the rat hepatic proteasome and the CRNK-16-derived proteasomal subunits. The identification, characterization, and purification of A-NKP 1 and A-NKP 2, described herein, now allow for further investigation of the potential role of these proteasome components in NK cell function. Moreover, the proteasome of NK and A-NK cells can now be compared and contrasted to the granzymes of lytic granules with respect to their role in cell-mediated cytotoxicity.
...
PMID:Nongranular proteolytic enzymes of rat IL-2-activated natural killer cells. II. Purification and identification of rat A-NKP 1 and A-NKP 2 as constituents of the multicatalytic proteinase (proteasome) complex. 808 94

By using the combination of reverse-transcription CR and rapid amplification of cDNA ends methods, two distinct cDNAs encoding mast-cell proteases (chymases; MCPs), designated as gMCP-1 and -2, were successfully cloned and sequenced from the jejunum of Mongolian gerbil, Meriones unguiculatus, infected with Nippostrongylus brasiliensis. On the basis of a comparison of the deduced amino acid sequences with those of known rodent mast-cell chymases, gMCP-1 was found to be highly similar to mouse mast-cell protease (mMCP)-4 and rat mast-cell protease (rMCP)-1, while gMCP-2 was similar to mMCP-5 and rMCP-3. Alghough mMCP-4 and -5 and rMCP-1 and -3 were restrictedly or mainly expressed in connective-tissue mast cells and serosal mast cells, the gMCP-1 and -2 genes were mainly transcribed in the jejunal mucosa and to a lesser extent in the skin and tongue. Moreover, kinetic study after infection revealed that the amounts of the gMCP-1 and -2 mRNAs in jejunum paralleled well the degree of intestinal mastocytosis. The expression of gMCP-1 and -2 in mucosal mast cells of gerbil jejunum was also confirmed by in situ hybridization. Since a tryptase, another type of MCP, was also expressed in mucosal mast cells of gerbils but not in those of mice and rats, the expression of MPCs in mucosal mast cells of gerbils is different from those of mice and rats. The Mongolian gerbil would be a useful model with which to investigate the physiopathological role of MCPs.
...
PMID:Cloning of the cDNAs for mast-cell chymases from the jejunum of Mongolian gerbils, Meriones unguiculatus, and their sequence similarities with chymases expressed in the connective-tissue mast cells of mice and rats. 861 90

The interaction of KB-V1, a multidrug resistant (MDR) variant of the KB-3-1 human oral carcinoma, with human complement was investigated. KB-V1 cells were found to be more sensitive than KB-3-1 cells to complement-mediated lysis. Detailed analysis of the capacity of KB cells to activate human complement demonstrated that both C3b deposition and formation of the membrane attack complex (MAC) are higher on KB-V1 than on KB-3-1 cells. Furthermore, the MAC formed on KB-V1 cells, but not on KB-3-1 cells, was found to be resistant to trypsin treatment, i.e. more stably inserted into the plasma membrane. Immunofluorescence analysis by flow cytometry showed that KB-V1 cells express less decay-accelerating factor (DAF, CD55) than KB-3-1 cells. Two other complement regulatory proteins, membrane cofactor protein (MCP, CD46) and CD59 are expressed to a similar extent on both KB-V1 and KB-3-1 cells. Treatment of KB-V1 cells with neutralizing anti-P-glycoprotein (P-gp) monoclonal antibodies reduced their sensitivity to complement. In addition, KB-V1 revertants which cease to express P-gp become more resistant to complement. These results indicate that multiple factors, such as reduced expression of DAF, enhanced deposition of C3b and increased binding and stability of the MAC may contribute to the increased complement sensitivity of KB-V1 cells. It is suggested that P-gp is responsible for the complement-sensitive phenotype of KB-V1 cells.
...
PMID:Enhanced sensitivity of P-glycoprotein-positive multidrug resistant tumor cells to complement-mediated lysis. 934 60

Recombinant mouse mast cell protease 6 (mMCP-6) was generated to study the role of this tryptase in inflammatory reactions. Seven to forty-eight hours after the i.p. injection of recombinant mMCP-6 into BALB/c, mast cell-deficient WCB6F1-Sl/Sl(d), C5-deficient, or mMCP-5-null mice, the number of neutrophils in the peritoneal cavity of each animal increased significantly by >50-fold. The failure of the closely related recombinant tryptase mMCP-7 to induce a comparable peritonitis indicates that the substrate specificities of the two tryptases are very different. Unlike most forms of acute inflammation, the mMCP-6-mediated peritonitis was relatively long lasting and neutrophil specific. Mouse MCP-6 did not induce neutrophil chemotaxis directly in an in vitro assay, but did promote chemotaxis of the leukocyte in the presence of endothelial cells. Mouse MCP-6 did not induce cultured human endothelial cells to express TNF-alpha, RANTES, IL-1alpha, or IL-6. However, the tryptase induced endothelial cells to express large amounts of IL-8 continually over a 40-h period. Neither enzymatically active mMCP-7 nor enzymatically inactive pro-mMCP-6 was able to induce endothelial cells to increase their expression of IL-8. Although the mechanism by which mMCP-6 induces neutrophil accumulation in tissues remains to be determined, the finding that mMCP-6 induces cultured human endothelial cells to selectively release large amounts of IL-8 raises the possibility that this tryptase regulates the steady state levels of neutrophil-specific chemokines in vivo during mast cell-mediated inflammatory events.
...
PMID:Induction of a selective and persistent extravasation of neutrophils into the peritoneal cavity by tryptase mouse mast cell protease 6. 946 53

Heat-shock protein 90 (Hsp 90) has been implicated in both protection against oxidative inactivation and inhibition of the multicatalytic proteinase (MCP, also known as 20 S proteasome). We report here that the protective and inhibitory effects of Hsp 90 depend on the activation state of the proteasome. Hsp 90 (and also alpha-crystallin) inhibits the N-Cbz-Leu-Leu-Leu-MCA-hydrolysing activity (Cbz=benzyloxycarbonyl; MCA=7-amido-4-methylcoumarin) when the rat liver MCP is in its latent form, but no inhibitory effects are observed when the MCP is in its active form. Metal-catalysed oxidation of the active MCP inactivates the Ala-Ala-Phe-MCA-hydrolysing (chymotrypsin-like), N-Boc-Leu-Ser-Thr-Arg-MCA-hydrolysing (trypsin-like; Boc=t-butyloxycarbonyl), N-Cbz-Leu-Leu-Glu-beta-naphthylamine-hydrolysing (peptidylglutamyl-peptide hydrolase) and N-Cbz-Leu-Leu-Leu-MCA-hydrolysing activities, whereas these activities are actually increased when the MCP is in its latent form. Hsp 90 protects against oxidative inactivation of the trypsin-like and N-Cbz-Leu-Leu-Leu-MCA-hydrolysing activities of the MCP active form, and alpha-crystallin protects the trypsin-like activity. The specificity of the Hsp 90-mediated protection was assessed by a quantitative analysis of the two-dimensional electrophoretic pattern of MCP subunits before and after oxidation of the MCP, in the presence or absence of Hsp 90. Treatment of the FAO hepatoma cell line with iron and ascorbate was found to inactivate the MCP. Hsp 90 overexpression obtained by challenging the cells with iron was associated with a decreased susceptibility to oxidative inactivation of the MCP trypsin-like activity. Depletion of Hsp 90 by using antisense oligonucleotides resulted in an increased susceptibility to oxidative inactivation of the MCP trypsin-like activity, providing evidence for the physiological relevance of Hsp 90-mediated protection of the MCP.
...
PMID:Protection from oxidative inactivation of the 20S proteasome by heat-shock protein 90. 965 82

The 26S proteasome is the macromolecular assembly that mediates ATP- and ubiquitin-dependent extralysosomal intracellular protein degradation in eukaryotes. However, its contribution to the regulation of osteoblast proliferation and hormonal regulation remains poorly defined. Treating osteoblasts with MG-132 or lactacystin (membrane-permeable proteasome inhibitors) attenuates proliferation. Three proteasome activities (peptidylglutamyl-peptide bond hydrolase-, chymotrypsin-, and trypsin-like) were detected in osteoblasts. Catabolic doses of PTH stim-ulated these activities, and cotreatment with PTH and MG-132 blocked stimulation. The proteasome alpha- and beta-subunits, polyubiquitins, and large ubiquitin-protein conjugates were detected by Western blotting. A 90-min treatment with 10 nM PTH had no effect on the amount of proteasome alpha or beta subunit protein, but increased the relative amount of large ubiquitin-protein conjugates by 200%. MG-132 inhibited deubiquitination of large ubiquitin-protein conjugates. The protein kinase A inhibitor SQ22536 blocked much of the PTH-induced stimulation of MCP activities, while dibutyryl cAMP stimulated it, suggesting that protein kinase A-dependent phosphorylation is important in PTH stimulation of proteasome activities. In conclusion, the ubiquitin-proteasome system is essential for osteoblast proliferation under control and PTH-treated conditions. PTH mediates its metabolic effects on the osteoblast, in part, by enhancing ubiquitinylation of protein substrates and stimulating three major proteasome activities by a cAMP-dependent mechanism.
...
PMID:The ubiquitin-proteasome system and cellular proliferation and regulation in osteoblastic cells. 968 33

Expression of HPV16 early region genes in basal keratinocytes of transgenic mice elicits a multistage pathway to squamous carcinoma. We report that infiltration by mast cells and activation of the matrix metalloproteinase MMP-9/gelatinase B coincides with the angiogenic switch in premalignant lesions. Mast cells infiltrate hyperplasias, dysplasias, and invasive fronts of carcinomas, but not the core of solid tumors, where they degranulate in close apposition to capillaries and epithelial basement membranes, releasing mast-cell-specific serine proteases MCP-4 (chymase) and MCP-6 (tryptase). MCP-6 is shown to be a mitogen for dermal fibroblasts that proliferate in the reactive stroma, whereas MCP-4 can activate progelatinase B and induce hyperplastic skin to become angiogenic in an in vitro bioassay. Notably, premalignant angiogenesis is abated in a mast-cell-deficient (KITW/KITWWv) HPV16 transgenic mouse. The data indicate that neoplastic progression in this model involves exploitation of an inflammatory response to tissue abnormality. Thus, regulation of angiogenesis during squamous carcinogenesis is biphasic: In hyperplasias, dysplasias, and invading cancer fronts, inflammatory mast cells are conscripted to reorganize stromal architecture and hyperactivate angiogenesis; within the cancer core, upregulation of angiogenesis factors in tumor cells apparently renders them self-sufficient at sustaining neovascularization.
...
PMID:Inflammatory mast cells up-regulate angiogenesis during squamous epithelial carcinogenesis. 1036 56


1 2 Next >>

---