Gene/Protein Disease Symptom Drug 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)

Brief periods of in vitro hypoxia/ischemia induce apoptosis of cultured renal epithelial cells, but the underlying mechanisms remain unknown. We show that partial ATP depletion (approximately 10-65% of control) results in a duration-dependent induction of apoptosis in Madin-Darby canine kidney (MDCK) cells, as evidenced by internucleosomal DNA cleavage (DNA laddering and in situ nick end labeling), morphological changes (cell shrinkage), and plasma membrane alterations (externalization of phosphatidylserine). The ATP-depleted cells display a significant upregulation of Fas, Fas ligand, and the Fas-associating protein with death domain (FADD). Exogenous application of stimulatory Fas monoclonal antibodies also induces apoptosis in nonischemic MDCK cells, indicating that they retain Fas-dependent pathways of programmed cell death. Furthermore, cleavage of poly(ADP)ribose polymerase (PARP) is evident after ATP depletion, indicating activation of caspases. Indeed, the apoptotic cells display a significant increase in caspase-8 (FLICE) activity. Finally, apoptosis induced by ATP depletion is ameliorated by pretreatment with inhibitors of caspase-8 (IETD), caspase-1 (YVAD), or caspase-3 (DEVD) but is not affected by inhibitors of serine proteases (TPCK). Our results indicate that partial ATP depletion of MDCK cells results in apoptosis and that Fas- and caspase-mediated pathways may play a critical role.
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PMID:Partial ATP depletion induces Fas- and caspase-mediated apoptosis in MDCK cells. 1036 72

Interleukin-1 beta (IL-1 beta)-converting enzyme (ICE, caspase-1) processes the IL-1 beta precursor to mature inflammatory cytokine IL-1 beta. ICE has been identified as a unique cysteine protease, which cleaves Asp-X bonds, shows resistance to E-64 (an inhibitor of most cysteine proteases) and has a primary structure that is homologous to CED-3, a protein required for apoptosis (programmed cell death) in the nematode Caenorhabditis elegans, and to mammalian cysteine proteases that initiate and execute apoptosis, e.g., apopain/CPP32/caspase-3. The inhibitors of the ICE/CED-3 family or caspases, as they are called recently, may constitute therapeutic agents for amelioration of inflammatory and apoptosis-associated diseases. The most efficient ICE inhibitors are peptide aldehydes and peptidyl chloro or (acyloxy)methanes. A recent study revealed that both D- and L-Asp are accepted by ICE at the P1 of such inhibitors, and the peptidyl (acyloxy)methane analogues having the beta-homo-aspartyl residue [-NH-CH(CH2COOH)-CH2CO-] are inactive. These findings we reexamined in terms of two issues. (a) ICE's resistance to E-64. Since it was thought to be caused by the enzyme's unique substrate specificity, we prepared substrate-based analogues, which were not inhibitory suggesting significant structural difference between the active centers of ICE and papain-like enzymes. (b) Tolerance for D-stereochemistry at the P1 of these inhibitors. In view of the mechanism of cysteine protease inhibition by peptidyl X-methanes, we thought that this phenomenon should be a general characteristic of cysteine proteases and the hAsp-containing analogues should behave as reversible inhibitors. Here, we analyzed the inhibition of ICE and apopain in comparison with that of papain, thrombin, and trypsin by peptide L/D-alpha-aldehydes and their L-beta-homo-aldehyde [-NH-CH(R)-CH2-CHO] analogues. The following results were found. (1) The peptidyl L-beta-homo-aspartals are potent inhibitors for caspases. (2) The L-beta-homo analogues of peptide aldehyde inhibitors designed for other proteases are not inhibitory. (3) Unlike trypsin and thrombin (serine proteases), papain (cysteine protease) shows tolerance for D-stereochemistry at the P1 site of peptide aldehydes in proportion to the lability of the alpha-hydrogen of the P1-D-residue. The complete tolerance of ICE for P1-D-Asp may arise from this residue's high tendency to epimerization. (4) Reaction of cysteine proteases with peptide aldehyde or peptidyl X-methane inhibitors containing P1-D-residues may include alpha-proton abstraction followed by asymmetric induction leading to P1-L-residue-containing products.
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PMID:Peptidyl beta-homo-aspartals (3-amino-4-carboxybutyraldehydes): new specific inhibitors of caspases. 1038 Mar 58

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.
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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

Bcl-2 family proteins and interleukin-1-beta converting enzyme/Caenorhabditis elegans cell death gene-3 (ICE/CED-3) family proteases (caspases) represent the basic regulators of apoptosis. However, the precise mechanism by which they interact is unclear. In this study, we found that gamma-radiation-induced apoptosis of leukemia cells was associated with activation of multiple caspases and bax up-regulation. Membrane changes and caspase activities were suppressed by specific caspase inhibitors. Similarly, the serine protease inhibitors z-Ala-Ala-Asp-cmk (AAD) and tosyl-lysine chloromethyl ketone (TLCK) also prevented caspase activation and poly(ADP-ribose) polymerase cleavage in vivo but had no effect on caspase activity in vitro. TLCK also prevented bax up-regulation as a result of its inhibitory effect on p53 function. Inhibitors of caspases and serine proteases partially prevented cell death, suggesting a caspase involvement in Bax-mediated cell death. We propose an ordering of signaling events in Bax-mediated cell death, including steps upstream and downstream of p53 and bax up-regulation.
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PMID:Ionizing radiation-induced, Bax-mediated cell death is dependent on activation of cysteine and serine proteases. 1043 17

The mechanism by which cycloheximide induces apoptosis in isolated rat hepatocytes was studied. Cycloheximide (1-300 microM) induced apoptosis within 3-4 hr in the hepatocytes. Specific apoptotic characteristics such as blebbing, phosphatidyl serine (PS) exposure, chromatin condensation, and nuclear fragmentation were induced. Cycloheximide (CHX) dose dependently activated the caspase-3-like proteases, but not the caspase-1-like proteases. Pretreatment of the hepatocytes with 100 microM of the caspase inhibitors z-Val-Ala-DL-Asp-fluoromethylketone or Ac-Asp-Glu-Val-Asp-aldehyde completely abrogated the caspase activation and the apoptosis. Addition of adenosine (100 microM) reduced phosphatidyl serine exposure and other morphological characteristics of apoptosis by 50%; however, it did not prevent the activation of the caspases, suggesting that adenosine inhibited downstream of caspase activation. The adenosine receptor antagonist 8-[4-[[[[(2-aminoethyl)amino]-carbonyl]methyl]oxy]phenyl]-1,3-dipropylxa nthine abolished the capacity of adenosine to prevent apoptosis, indicating that prevention was receptor-mediated. During apoptosis, the mitochondrial membrane potential in apoptotic cells (cells with PS exposition) was decreased to 50-60% of the control value; in the population viable cells, however, the mitochondrial membrane potential remained stable. Prevention of apoptosis by the caspase inhibitor z-Val-Ala-DL-Asp-fluoromethylketone or adenosine prevented the decrease in mitochondrial membrane potential. In conclusion, CHX rapidly induces apoptosis in isolated rat hepatocytes, which is inhibited by adenosine at a relatively late step.
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PMID:Prevention of cycloheximide-induced apoptosis in hepatocytes by adenosine and by caspase inhibitors. 1059 Nov 43

We have cloned and sequenced the cDNA encoding the major component (43-kDa peptide) of 30kP protease A which selectively hydrolyzes 30-kDa yolk proteins of the silkworm, Bombix mori. The deduced amino acid sequence consisted of 318 amino acids and shared sequences conserved in many serine proteases. Northern blot analysis using the cDNA as probe revealed that 43-kDa peptide mRNA began to rise at the last phase of embryogenesis and reached a maximum level at larval hatching. This level was maintained with some fluctuations throughout post-embryonic development. The concentration of 43-kDa peptide increased greatly toward larval hatching coinciding with the changing pattern of mRNA. When larvae were fed, the peptide concentration abruptly decreased and remained near zero throughout post-embryonic development. The decrease in peptide concentration did not occur, however, when the hatched larvae were starved. Thus, the nutritional shift from endogenous yolk to exogenous food plays a key role in 30kP protease A elimination from neonate larvae.
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PMID:The 30kP protease A responsible for 30-kDa yolk protein degradation of the silkworm, Bombyx mori: cDNA structure, developmental change and regulation by feeding. 1122 50

The ICE-like families of serine proteases (caspases) have integral roles in apoptosis. These studies were performed to further understand the role of two critical caspases in relation to apoptotic regulation of the alloimmune response. A novel three-color cytofluorographic technique was utilized for measuring intracellular (in situ) caspase-1-like and caspase-3-like enzyme activity in responding CD4(+) and CD8(+) T cells over several time points of human mixed lymphocyte reactions (MLR). We found that activity levels of caspase 3 in both CD4(+) and CD8(+) responder cells began rising at day 10 of the MLR and peaked at day 14. By comparison, caspase 1 demonstrated the highest activity at day 7 in both cell subpopulations. These results coincided with the appearance of apoptotic cells among the alloreactive cells in the MLR. These findings demonstrate that intracellular caspase-1- and -3-like enzyme activity increases in both CD4(+) and CD8(+) alloreactive T cells as the primary response to allostimulatory cells progresses. While the kinetic profiles for these enzymes differed, both had a temporal association with the appearance of apoptosis in the MLR-generated cells. In all cases, the highest enzyme activity and presence of apoptosis was seen subsequent to the peak proliferative period. These results support the concept that changes in the rate and amount of apoptosis in alloreactive T cells is one mechanism by which the response to alloantigens is attenuated (i.e., tolerance) or sustained.
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PMID:Differential kinetics of intracellular caspase-1-like and caspase-3-like enzyme activity in human alloreactive CD4(+) and CD8(+) T cells undergoing apoptosis. 1123 53

The proteolytic enzymes that depend upon a cysteine residue for activity have come from at least seven different evolutionary origins, each of which has produced a group of cysteine peptidases with distinctive structures and properties. We show here that the characteristic molecular topologies of the peptidases in each evolutionary line can be seen not only in their three-dimensional structures, but commonly also in the two-dimensional structures. Clan CA contains the families of papain (C1), calpain (C2), streptopain (C10) and the ubiquitin-specific peptidases (C12, C19), as well as many families of viral cysteine endopeptidases. Clan CD contains the families of clostripain (C11), gingipain R (C25), legumain (C13), caspase-1 (C14) and separin (C50). These enzymes have specificities dominated by the interactions of the S1 subsite. Clan CE contains the families of adenain (C5) from adenoviruses, the eukaryotic Ulp1 protease (C48) and the bacterial YopJ proteases (C55). Clan CF contains only pyroglutamyl peptidase I (C15). The picornains (C3) in clan PA have probably evolved from serine peptidases, which still form the majority of enzymes in the clan. The cysteine peptidase activities in clans PB and CH are autolytic only. In conclusion, we suggest that although almost all the cysteine peptidases depend for activity on catalytic dyads of cysteine and histidine, it is worth noting some important differences that they have inherited from their distant ancestral peptidases.
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PMID:Evolutionary lines of cysteine peptidases. 1151 25

Two novel extracellular serine proteases were purified to homogeneity from the cell-free culture filtrate of an obligate alkalophilic Bacillus sphaericus by a combination of ultrafiltration, ammonium sulfate precipitation and chromatographic methods. The enzymes showed similar substrate specificities, but differed in hydrophobicity and molecular mass. Protease A was a monomeric protease with a relative molecular mass (M(r)) of 28.7 kDa, whereas protease B, with a M(r) of 68.0 kDa, apparently consisted of smaller subunits. The purified protease A had a specific activity on hemoglobin of 5.1 U/mg protein compared to 40.9 U/mg protein in the case of protease B. Both proteases were most active on SAAPF-pNa, a substrate for chymotrypsin-like serine proteases. However, the K(m) values of these two proteases on SAAPF-pNa were higher than that for alpha-chymotrypsin, indicating a lower affinity of proteases A and B for this substrate compared to chymotrypsin. Unlike other Bacillus serine proteases, neither protease A nor B stained with Coomasie blue R-250, even with loading of a large amount of protein, and they stained poorly with the silver staining method. However, NH(2)-terminal amino acid sequencing of protease B revealed a high similarity with subtilisin Carlsberg (67% homology). Almost total inhibition of both proteases by PMSF, but very little/no inhibition by trypsin and chymotrypsin inhibitors (TPCK and TLCK) or thiol reagents (PCMB and iodoacetic acid), further supported the view that the enzyme belonged to the serine protease family.
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PMID:Purification and characterization of two extracellular alkaline proteases from a newly isolated obligate alkalophilic Bacillus sphaericus. 1157 23

IL-18, a potent IFN-gamma-inducing cytokine, is expressed by various nonimmune cells as well as macrophages, suggesting that it has important physiological and immunological roles. The present study focused on the mechanism of active IL-18 induction from human oral epithelial cells. The epithelial cells and the cell lines constitutively express IL-18 mRNA and the 24-kDa precursor form of IL-18. Bioactive IL-18 exhibiting IFN-gamma-inducing activity was detected in the supernatant of the cells on costimulation with neutrophil proteinase 3 (PR3) and LPS for 24 h after IFN-gamma-priming for 3 days. An active 18-kDa form of IL-18 was detected in lysate and supernatant of the cells only after the above treatment and the induction was inhibited by cycloheximide and by serine proteinase inhibitors. After the treatment, lactate dehydrogenase activity was not detected in the cell culture supernatant, and PR3 was detected only in the membrane and not in cytoplasm fractions of the cells. Caspase-1 was not detected in the cells even after the treatment and the IL-18 induction was not inhibited by a caspase-1 inhibitor. These results suggest that the PR3-mediated induction of bioactive IL-18 secretion from oral epithelial cells in combination with LPS after IFN-gamma-priming occurred via a caspase-1-independent pathway, and provide new insight into the possible involvement of a neutrophil proteinase in the induction of bioactive IL-18 in oral inflammation such as periodontitis.
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PMID:Neutrophil proteinase 3-mediated induction of bioactive IL-18 secretion by human oral epithelial cells. 1171 26


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