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Enzyme
Compound
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Query: EC:3.4.22.36 (
caspase-1
)
6,285
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Escherichia coli cells were found to contain a novel outer membrane-associated protease, designated
protease VII
(K. Sugimura and N. Higashi, J. Bacteriol. 170:3650-3654, 1988). This enzyme was purified to homogeneity and exhibited an apparent molecular weight of 36,000 on
sodium
dodecyl sulfate gels and 180,000 on a TSK G-3000SW column in the presence of Triton X-100. It was capable of cleaving several peptides at the center of paired basic residues but not at single basic residues, implying that it is distinct from trypsinlike proteases. Protease VII was most active at pH 6.0 and was sensitive to a serine protease inhibitor, diisopropylfluorophosphate, and to the bivalent cations Zn2+, Cu2+, and Fe2+. The nucleotide sequence of a
protease VII
gene-carrying DNA fragment, which had been cloned by complementation analysis (K. Sugimura, Biochem. Biophys. Res. Commun. 153:753-759, 1988) was determined. It carried two putative promoter regions and a putative Shine-Dalgarno sequence in addition to the complete structural gene, which encoded pre-
protease VII
of 317 amino acid residues, with the N-terminal 20 residues being a signal peptide. By comparing their amino acid sequences,
protease VII
and OmpT, which specifically cleaves ferric enterobactin receptor protein, were found to be identical.
...
PMID:Purification, characterization, and primary structure of Escherichia coli protease VII with specificity for paired basic residues: identity of protease VII and OmpT. 305 8
The allelically determined human salivary proteins, Ps 1 and 2, were purified on
sodium
dodecyl sulfate gels, eluted, and compared by limited proteolysis with Streptomyces griseus protease VI, Bacillus subtilis
protease VII
, and Staphylococcus aureus protease V8. Prior dansylation of the Ps isoproteins facilitated visualization of the peptides. Digestion patterns indicate considerable homology between the Ps isoproteins and support the conclusion [Azen, A. E., and Denniston, C. (1980). Biochem. Genet. 18:483] that there is an actual molecular weight difference between them. Further, the results suggest that this difference owes to an extension of the Ps 2 chain at one of its ends.
...
PMID:Human parotid size polymorphism (Ps): characterization of two allelic products, Ps 1 and 2, by limited proteolysis. 634 62
A technique is described to detect the activity of protease inhibitors present in
sodium
dodecyl sulfate (SDS)-polyacrylamide gels (PAG) containing a copolymerized enzyme substrate. The method involved (1) incorporation of substrate (gelatin or casein) into the SDS-PAG at the time of casting; (2) electrophoresis of the protease inhibitors in the presence of SDS; (3) removal of SDS by washing the gel in 2.5% (w/v) Triton X-100; (4) incubation of the gels in a solution containing the proteolytic enzyme at 37 degrees C for 16 h; and (5) staining undigested substrate with amido black. Standard inhibitors such as bovine pancreatic trypsin inhibitor (BPTI), soybean trypsin inhibitor (SBTI), alpha 1-antitrypsin inhibitor, and a protease inhibitor derived from human articular cartilage have been examined by this method and displayed sharp inhibition bands when the gels were treated with bovine trypsin, chymotrypsin, or other enzymes. The technique cannot be used for precise quantification of protease inhibitors. However, there is a relationship between the concentration of inhibitor used and the intensity of staining. By this means, it was possible to estimate the smallest amount of inhibitor that could be detected (against a particular enzyme) under a given set of conditions. Inhibition was detected when 10 ng of SBTI or 20 ng of BPTI were applied to the gels; human alpha 1-protease inhibitor could be detected at a level of 2-3 micrograms. The technique was used to investigate the effectiveness of the human cartilage inhibitor against a variety of proteolytic enzymes, including thermolysin, Pronase, neutral protease, elastase,
protease VII
, pepsin, bacterial collagenase, protease IV, and papain.
...
PMID:Detection of protease inhibitors using substrate-containing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 635 99
Four zymogens of acidic proteases A, B, C, and D were isolated from the gastric mucosa of harp seals by ion-exchange chromatography on a diethylaminoethyl-Sephadex A-50 column. The major zymogens were A and C, and the ratio of zymogen A to zymogen C was greater in extracts from 1-week-old animals than in extracts from adult animals. Zymogens A and C were further purified by affinity chromatography using carbobenzoxy-D-phenylalaninetriethylene tetramine Sepharose and gel filtration on a Sephadex G-100 column. Certain physical and catalytic properties of proteases A and C were compared with those of calf chymosin (EC 3.4.23.4) and porcine pepsin (EC 3.4.23.1). Zymogen C and the corresponding enzyme were homogeneous on analytical polyacrylamide gel electrophoresis. Zymogen A was homogeneous as judged by
sodium
dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis and high performance liquid chromatography, but was heterogeneous by polyacrylamide gel electrophoresis at pH 8.3. Zymogens A and C had molecular weights of 33 800 and 44 000, respectively, as estimated by SDS-polyacrylamide gel electrophoresis. Protease A had an isoelectric point of 4.90. Protease A was similar to calf chymosin with respect to several criteria. It had a higher ratio of milk-clotting to proteolytic activity than those of seal protease C and porcine pepsin and had a pH optimum of 2.2-3.5 for hemoglobin hydrolysis. It did not inactivate ribonuclease, had very low activity on N-acetyl-L-phenylalanyl-3,5-diiodo-L-tyrosine and lost activity in 6 M urea. These results indicate
protease A
is chymosinlike.
...
PMID:Purification and characterization of a chymosinlike protease from the gastric mucosa of harp seal (Pagophilus groenlandicus). 643 45
Apoptosis induced in rat hepatocytes by transforming growth factor beta1 (TGF-beta1) was accompanied by the activation of
interleukin-1beta converting enzyme
(
ICE
)-like proteases. Cell lysates were isolated at various times after TGF-beta1 treatment and analyzed for
ICE
and CPP32-like activity, using N-acetyl-Tyr-Val-Ala-Asp-7-amino-4-methylcoumarin (Ac-YVAD.AMC) and benzyloxycarbonyl-Asp-Glu-Val-Asp-7-amino-4-trifluoromethylcoumarin (Z-DEVD.AFC), respectively. CPP32-like but not
ICE
protease activity increased in a time dependent manner and preceded the onset of apoptosis. Kinetic studies in cell lysates indicated that more than one CPP32-like protease was being activated. This was confirmed by
sodium
dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting of TGF-beta1-treated cells, which showed limited processing of CPP32 as shown by the appearance of the catalytically active p17 subunit. Loss of pro-Mch3alpha was also observed but the catalytically active p19 subunit was not detected. Staurosporine, which induced a much greater level of hepatocyte apoptosis, produced a concomitant increase in CPP32/Mch3alpha processing as shown by the appearance of the p17/p19 subunits and the corresponding increase in CPP32-like protease activity. Apoptosis, CPP32/Mch3alpha processing and the increase in CPP32-like protease activity induced by TGF-beta1 and staurosporine were abolished in hepatocytes pretreated with Z-Asp-Glu-Val-Asp (OMe) fluoromethylketone (Z-DEVD.FMK) or Z-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK). These peptide analogues were potent inhibitors of CPP32-like protease activity in lysates. Pretreatment of hepatocytes with cycloheximide also blocked TGF-beta1-induced apoptosis and the increase in CPP32-like activity. Unlike Z-VAD.FMK and Z-DEVD.FMK, cycloheximide did not inhibit CPP32-like protease activity in cell lysates. Thus, cycloheximide may block apoptosis by inhibiting the synthesis of a protein, which is involved in the upstream events responsible for the activation of the CPP32-like protease activity. Our studies have identified two of the CPP32-like proteases, namely CPP32 and Mch3alpha, which are activated during the execution phase of hepatocyte apoptosis.
...
PMID:Processing/activation of CPP32-like proteases is involved in transforming growth factor beta1-induced apoptosis in rat hepatocytes. 918 77
Excitotoxic mechanisms are believed to be involved in the death of neurons after trauma, epileptic seizures and cerebral ischaemia. We investigated the role of mitochondrial superoxide production in excitotoxic cell death of cultured rat hippocampal neurons. Brief exposure to the selective glutamate agonist N-methyl-D-aspartate (NMDA; 100-300 microM, 10 min) induced significant neuronal death, which was sensitive to cycloheximide (1 microM) and the
caspase-1
inhibitor, acetyl-Tyr-Val-Ala-Asp-chloromethylketone (10 microM). Intracellular superoxide production was monitored semiquantitatively on sister cultures from the same platings using the oxidation-sensitive probe, hydroethidine. Brief exposures to toxic NMDA concentrations induced significant increases in superoxide production which correlated with the degree of neuronal injury. However, subtoxic NMDA exposures also produced moderate, yet statistically significant increases in superoxide production. Both NMDA-induced superoxide production and neurotoxicity were reduced by inhibition of mitochondrial electron transport using either
sodium
cyanide (1 mM), or a combination of rotenone (2 microM) and oligomycin (2 microM). The mitochondrial uncoupler carbonyl cyanide p-trifluoromethoxy-phenylhydrazone (FCCP, 1 microM) mimicked the effect of NMDA on mitochondrial superoxide production. Both NMDA-induced superoxide production and neurotoxicity were potentiated by FCCP (1 microM). Exposure to FCCP alone (1-10 microM, 10 min), however, failed to produce any toxicity. Our data suggest that mitochondrial superoxide production per se is not sufficient to trigger the degeneration of cultured hippocampal neurons, but that manipulation of mitochondrial activity alters NMDA-induced superoxide production and neurotoxicity.
...
PMID:NMDA-induced superoxide production and neurotoxicity in cultured rat hippocampal neurons: role of mitochondria. 975 Nov 60
Lipopolysaccharide-activated human monocytes produce prointerleukin (pro-IL)-1beta but release little of this inflammatory cytokine as the biologically active species. Efficient externalization of mature 17-kDa cytokine requires that the activated monocytes encounter a secondary stimulus such as ATP. To identify cation requirements of the ATP-induced process, lipopolysaccharide-activated monocytes were treated with ATP in media containing different Cl- salts or sucrose. Media devoid of
Na+
did not support IL-1beta processing. Titration of NaCl into choline chloride- or sucrose-based media restored 17-kDa IL-1beta production.
Na+
replacement, however, was not sufficient to support ATP-induced production of 17-kDa IL-1beta in the presence of >/=37 mM extracellular K+ or Li+. Inhibition by K+ suggests that efflux of this cation is a necessary component of the stimulus-coupled response. The inhibitory effect achieved by
Na+
depletion is not due to inactivation of the ATP receptor and is distinct from a
caspase-1
inhibitor. Stimulus-coupled IL-1beta posttranslational processing, therefore, requires extracellular
Na+
for a step downstream of the initiating stimulus but preceding
caspase-1
activation.
...
PMID:Human monocyte stimulus-coupled IL-1beta posttranslational processing: modulation via monovalent cations. 984 15
To continue elucidation of the biochemical and molecular pathways involved in the induction of apoptosis in granulosa cells (GC) of ovarian follicles destined for atresia, we characterized the occurrence and protease modulation of high and low molecular weight (MW) DNA fragmentation during rat GC death. Atresia of ovarian follicles, occurring either spontaneously in vivo or induced in vitro, was associated with both high MW and internucleosomal (low MW) DNA cleavage. Incubation of follicles in the presence of a putative irreversible and non-competitive inhibitor of
caspase-1
(interleukin-1beta-converting enzyme or
ICE
),
sodium
aurothiomalate (SAM), completely prevented internucleosomal, but not high MW, DNA cleavage. As reported previously, morphological features of apoptosis (pyknosis, cellular condensation) and atresia (granulosa cell disorganization, oocyte pseudomaturation) remained detectable in SAM-treated follicles. The potential involvement of proteases in endonuclease activation was further analyzed in cell-free assays using nuclei from both GC (which autodigest their DNA) and HeLa cells (HC, which do not autodigest their DNA unless incubated with extracts prepared from other cell types). Crude cytoplasmic extracts prepared from GC induced both high MW and internucleosomal DNA cleavage in HC nuclei. The induction of low, but not high, MW DNA cleavage in HC nuclei by GC extracts was suppressed by pretreatment of the extracts with SAM or with any one of the serine protease inhibitors, dichloroisocoumarin (DCI), N-tosyl-L-leucylchloromethylketone (TLCK) or N-tosyl-L-phenylchloromethylketone (TPCK). Interestingly, SAM and DCI also prevented cation-induced low MW DNA fragmentation in GC nuclei; however, TLCK and TPCK were without effect. Our results support a role for cytoplasmic and nuclear serine proteases in the activation of the endonuclease(s) responsible for internucleosomal DNA cleavage during apoptosis.
...
PMID:High and low molecular weight DNA cleavage in ovarian granulosa cells: characterization and protease modulation in intact cells and in cell-free nuclear autodigestion assays. 1020 Apr 44
The Serp2 protein encoded by the leporipoxvirus myxoma virus is essential for full virulence (F. Messud-Petit, J. Gelfi, M. Delverdier, M. F. Amardeilh, R. Py, G. Sutter, and S. Bertagnoli, J. Virol. 72:7830-7839, 1998) and, like crmA of cowpox virus (CPV), is reported to inhibit the interleukin-1beta-converting enzyme (
ICE
,
caspase-1
) (F. Petit, S. Bertagnoli, J. Gelfi, F. Fassy, C. Boucraut-Baralon, and A. Milon, J. Virol. 70:5860-5866, 1996). Serp2 and CrmA both contain Asp at the P1 position within the serpin reactive site loop and yet are only 35% identical overall. Serp2 protein was cleaved by
ICE
but, unlike CrmA, did not form a stable complex with
ICE
that was detectable by native gel electrophoresis. Attempts to covalently cross-link
ICE
-serpin inhibitory complexes were successful with CrmA, but no complex between
ICE
and Serp2 was visible after cross-linking. Purified His10-tagged Serp2 protein was a relatively poor inhibitor of
ICE
, with a Ki of 80 nM compared to 4 pM for CrmA. Serp2 protein resembled CrmA in that a stable complex with the serine proteinase granzyme B was detectable after
sodium
dodecyl sulfate-polyacrylamide gel electrophoresis. However, Serp2 was less effective at inhibiting granzyme B activity (Ki = 420 nM) than CrmA (Ki = 100 nM). Finally, Serp2 was tested for the ability to replace CrmA and inhibit apoptosis in LLC-PK1 cells infected with a CPV recombinant deleted for CrmA but expressing Serp2. Unlike wild-type-CPV-infected cells, apoptosis was readily observed in cells infected with the recombinant virus, as indicated by the induction of both nuclear fragmentation and caspase-mediated cleavage of DEVD-AMC [acetyl-Asp-Glu-Val-Asp-(amino-4-methyl coumarin)]. These results indicate that Serp2 is unable to functionally substitute for CrmA within the context of CPV and that the inhibition spectra for Serp2 and CrmA are distinct.
...
PMID:Myxoma virus Serp2 is a weak inhibitor of granzyme B and interleukin-1beta-converting enzyme in vitro and unlike CrmA cannot block apoptosis in cowpox virus-infected cells. 1040 Jul 32
Human normal and malignant T cells cease to proliferate, down-modulate Bcl-2 expression, and undergo apoptosis when cultured in the presence of NO-donor compounds (
sodium
nitroprusside and NOC12) for 48 h. At 72 h, cells that evade apoptosis start to proliferate again, overexpress both chains of the IFN-gammaR, and thus become susceptible to apoptosis in the presence of IFN-gamma. By contrast, in the presence of IFN-gamma, no apoptosis, but an increase of proliferation was displayed by control cultures of T cells not exposed to NO and not overexpressing IFN-gammaR chains. The NO-induced cell surface overexpression of IFN-gammaR chains did not affect the transduction of IFN-gamma-mediated signals, as shown by the expression of the transcription factor IFN regulatory factor 1 (IRF-1). However, transduction of these signals was quantitatively modified, because IFN-gamma induces enhanced levels of
caspase-1
effector death in NO-treated cells. These findings identify NO as one of the environmental factors that critically govern the response of T cells to IFN-gamma. By inducing the overexpression of IFN-gammaR chains, NO decides whether IFN-gamma promotes cell proliferation or the induction of apoptosis.
...
PMID:Nitric oxide suppresses human T lymphocyte proliferation through IFN-gamma-dependent and IFN-gamma-independent induction of apoptosis. 1051 Mar 54
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