Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The anti-inflammatory activity of FL 70, a derivative of 2,5-dihydroxy-benzoic acid, was examined in a number of conventional experimental models. In addition, FL-70 was tested for its inhibitory action on enzymes. The results were as follows: 1. The induction of a local inflammatory reaction and the subsequent i.v. injection of trypan blue showed that FL 70 reduces the capillary permeability. 2, FL-70 significantly suppresses exudation in the formalin-induced peritonitis of the rat. 3. A slight inhibition of an edema in the footpad of the rat induced by formalin-dextran was not shown to be statistically significant. 4. Local swelling could be markedly inhibited in the turpentine-oil induced inflammatory reaction of the rabbit. 5. Exudation and formation of granulomatous tissue was inhibited in Selye's granuloma. 6. FL-70 markedly inhibited the local inflammatory reaction accompanying the cutaneous reaction in experimental vaccinia infection of the rabbit skin. The size of the infiltration after intracutaneous infection of the virus was not reduced. 7. FL-70 could not prevent the onset of clinical signs, if administered in experimental allergic encephalitis. 8. The activity of acid phosphatase was inhibited by FL-70. Alcaline phosphatase, cholinesterase, leucin aminopeptidase, glucose-6- phosphatase-dehydrogenase (G-6-PDH), trypsin and chymotrypsin were unaffe-ted. FL-70 inhibits the following, G-6-PDH activated reduction process: glucose-6-phosphate (see article).
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PMID:[Anti-inflammatory activity of a new quinoid polyradical (FL-70)]. 16 92

Isolates of tick-borne encephalitis (TBE) virus from Finland, Germany, Czechoslovakia, Switzerland and Austria were compared with strains of the Far Eastern subtype isolated in Russia as well as Louping ill virus and other flaviviruses belonging to a different serocomplex: West Nile, Murray Valley encephalitis and Rocio viruses. Analysis of the structural polypeptides by SDS--polyacrylamide gel electrophoresis (SDS--PAGE) revealed identical mol. wt. of the glycoprotein E (mol. wt. 55 000) and the core protein C (mol. wt. 15 000) for all the TBE virus strains analysed. However, the small envelope protein M from viruses isolated in Germany, Switzerland and Austria migrated slightly slower (apparent mol. wt. 7500) compared to M from viruses isolated in Finland, Czechoslovakia or the Far Eastern subtype strains (apparent mol. wt. 6500 to 7000). The structural glycoproteins were isolated from purified [35S]methionine-labeled virions and subjected to peptide mapping by limited proteolysis with alpha-chymotrypsin or V8 protease followed by SDS--PAGE of the resulting cleavage products. With both proteases a remarkably homogeneous pattern was obtained for all the European isolates with only very minor deviations from a common pattern in single cases. Similar but distinguishable patterns were obtained for the Far Eastern subtype strains and also Louping ill virus, which, in addition, differed in the mol. wt. of its core protein C (mol. wt. 16 000) and the small membrane protein M (mol. wt. 9000). These almost identical peptide maps observed with the TBE virus strains were in sharp contrast to the unrelated patterns obtained with the glycoproteins from West Nile, Murray Valley encephalitis and Rocio viruses. Although these viruses are serologically closely related and members of the same serocomplex of flaviviruses their glycoprotein peptide maps were completely different from one another. In a competitive radioimmunoassay all European TBE virus isolates showed identical immunological reactivity which further points to the great stability of this type of virus.
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PMID:Homogeneity of the structural glycoprotein from European isolates of tick-borne encephalitis virus: comparison with other flaviviruses. 617 53

A model showing the topological distribution, functions, and serological specificities of eight distinct, monoclonal antibody-defined epitopes on the tick-borne encephalitis (TBE) virus glycoprotein has been presented in a previous publication (F. X. Heinz, R. Berger, W. Tuma, and Ch. Kunz (1983). Virology 126, 525-537.) In the present report the influence of conformational change, chemical modification, and fragmentation on the antigenic reactivity of each epitope has been analyzed by the use of blocking enzyme immunoassays and "Western blotting." One of the two major antigenic domains (A), composed of three different epitopes, completely lost its antigenicity upon incubation at pH 5.0 or by treatment with guanidine-HCl/urea, SDS, reduction and carboxymethylation, as well as by proteolytic (trypsin, alpha-chymotrypsin, thermolysin) and chemical (CNBr) fragmentation. The second major antigenic domain (B), however, defined by four distinct monoclonal antibodies, three of which are hemagglutination (HA)-inhibiting, neutralizing, and protective, was shown to be resistant to low pH, guanidine-HCl/urea treatment, and proteolytic cleavage of the native protein. Also, polyclonal immune sera from mice and rabbits contained antibody populations reactive with antigenic determinants which are resistant and others which are sensitive to conformational change and fragmentation. Glycoprotein fragments with molecular weights of about 9000, generated by proteolysis of the native protein, were immunoreactive with neutralizing and protective monoclonal antibodies (defining domain B) as well as with a polyclonal mouse immune serum. Thus, these fragments appear to contain antigenic determinants which are immunodominant on the native protein and play an important role in the induction of a protective immune response against TBE virus. In addition, these results show that antibody binding to antigenic domains which are topologically and structurally completely unrelated may result in neutralization and/or HA inhibition. As the presence of two receptor-binding sites is unlikely, different effector mechanisms may account for the effects of these antibodies. The antigenic reactivity of domain A is sensitive to the same treatments which also inactivate HA activity of TBE virus, whereas domain B is resistant. These treatments include a change of domain A induced by incubation at slightly acidic pH which also results in inactivation of virus infectivity. Antibodies to domain A therefore presumably block viral activities by direct binding at or near the putative receptor-binding site whereas antibodies to domain B may cause loss of biological activities by inducing a conformational change of the receptor-binding site.
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PMID:Location of immunodominant antigenic determinants on fragments of the tick-borne encephalitis virus glycoprotein: evidence for two different mechanisms by which antibodies mediate neutralization and hemagglutination inhibition. 619 9

After digestion with trypsin, alpha-chymotrypsin, or chemical cleavage using CNBr, fragments of the tick-borne encephalitis (TBE) virus glycoprotein were isolated which retained their reactivity with neutralizing monoclonal antibodies defining a denaturation-resistant antigenic domain. Upon immunization of mice, these fragments induced antibodies reactive with the immunizing peptide, the denatured glycoprotein and the native glycoprotein as a constituent of the whole virus. The immune sera revealed the same properties as the monoclonal antibodies that were used to select the fragments for immunization: neutralizing activity; haemagglutination-inhibiting activity; blocking of the binding of antibodies used for selection; enhancement of the binding of other monoclonal antibodies defining a denaturation-sensitive antigenic domain. It was shown that the natural immune response against certain functionally important, denaturation-resistant immunogenic domains on the native protein can be closely mimicked by immunization with defined protein fragments. Antigenic sites present on these fragments may therefore represent essential constituents of a synthetic vaccine. The fine specificities of antibody populations in anti-peptide or anti-protein immune sera were analysed on the basis of single antigenic determinants by blocking assays using radiolabelled monoclonal antibodies that define eight distinct epitopes on the TBE virus glycoprotein. Quantitative differences in the blocking of certain monoclonal antibodies were also observed between human convalescent sera. The establishment of such blocking profiles using a panel of well-characterized monoclonal antibodies may represent a general method for dissecting the specificities of antibody populations present in polyclonal immune sera and could allow investigations on determinant-restricted differences of immune responses and its possible implications for the course of the disease.
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PMID:Immunogenicity of tick-borne encephalitis virus glycoprotein fragments: epitope-specific analysis of the antibody response. 620 62

Nine virus-specified proteins were identified by SDS-polyacrylamide gel electrophoresis in [35S]methionine-labelled chick embryo cells infected with tick-borne encephalitis (TBE) virus by comparison with mock-infected cells. These proteins were designated P91, p74, p72, P67, GP53(E), P47, p25, P15(C) and P14.5 according to their molecular weights. Peptide mapping of P91, P67, GP53(E) and P47 from TBE virus-infected cells, as well as those of the corresponding proteins from West Nile virus (WNV)-infected cells (previously termed NV5, NV4, V3 and NV3), demonstrated the uniqueness of these proteins. Almost no subtype variability, with respect to the pattern of intracellular proteins, was found when isolates of TBE virus from Austria, Switzerland, Germany, Finland and Czechoslovakia were compared. Peptide mapping of NV5 (P91) and NV4 (P67) from all these isolates using limited proteolysis with alpha-chymotrypsin and V8 protease revealed completely identical patterns, thus extending our observations that TBE virus seems to represent a very stable member of the flavivirus genus, which was based on the lack of variation found with the structural glycoprotein. On the other hand, the Far Eastern subtype of TBE virus and the closely related louping-ill virus could not only be differentiated from the Western subtype by differences in the peptide maps of their structural glycoprotein but also in those of the non-structural protein NV5, i.e. subtype or subgroup variations are not confined to the virion surface glycoprotein. WNV and Murray Valley encephalitis virus (MVEV) revealed the expected heterogeneity of virus-specified proteins found in cells infected with different flaviviruses. It is especially interesting that also the largest non-structural protein, NV5, is subject to this heterogeneity, ranging in mol. wt. from 91 000 for TBE virus to 98 000 for MVEV and that also the peptide maps of NV5, as well as those of NV4, were unrelated. These proteins, therefore, revealed a variability between serologically distinct flaviviruses similar to that observed with the structural glycoprotein.
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PMID:Molecular epidemiology of tick-borne encephalitis virus: peptide mapping of large non-structural proteins of European isolates and comparison with other flaviviruses. 629 51

Cerebrospinal fluids (CSFs) from 9 Pug dogs with necrotizing meningoencephalitis (NME: Pug dog encephalitis) were examined to identify the antigens for anti-astrocyte autoantibodies. Each CSF exhibited a positive reaction to the cytoplasm of cultured canine astrocytes by an indirect fluorescent antibody test. In an immunoblotting analysis on normal canine brain proteins, eight of 9 CSFs showed a common band of 52 kDa, corresponding to glial fibrillary acidic protein (GFAP), and all of 9 CSFs reacted with purified bovine GFAP. From these results, GFAP is one of the common autoantigens in Pug dogs with NME. On the other hand, the reactivity of CSFs to chymotrypsin-digested bovine GFAP fragments were variable among dogs, indicating that the antibodies in the CSFs recognized different epitopes on GFAP.
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PMID:Autoantibodies against glial fibrillary acidic protein (GFAP) in cerebrospinal fluids from Pug dogs with necrotizing meningoencephalitis. 1740 38

The infectivity of flavivirus particles depends on a maturation process that is triggered by the proteolytic cleavage of the precursor of the M protein (prM). This activation cleavage is naturally performed by ubiquitous cellular proteases of the furin family, which typically recognize the multibasic sequence motif R-X-R/K-R. Previously, we demonstrated that a tick-borne encephalitis virus (TBEV) mutant with an altered cleavage motif, R-X-R, produced immature, noninfectious particles that could be activated by exogenous trypsin, which cleaves after single basic residues. Here, we report the adaptation of this mutant to chymotrypsin, a protease specific for large, hydrophobic amino acid residues. Using selection pressure in cell culture, two different mutations conferring a chymotrypsin-dependent phenotype were identified. Surprisingly, one of these mutations (Ser85Phe) occurred three positions upstream of the natural cleavage site. The other mutation (Arg89His) arose at the natural cleavage position but involved a His residue, which is not a typical chymotrypsin cleavage site. Efficient cleavage of protein prM and activation by the heterologous protease were confirmed using various recombinant TBEV mutants. Mutants with only the originally selected mutations exhibited unimpaired export kinetics and were genotypically stable during at least six cell culture passages. However, in contrast to the wild-type virus or trypsin-dependent mutants, chymotrypsin-dependent mutants were not neurovirulent in suckling mice. Our results demonstrate that flaviviruses with altered protease specificities can be generated and suggest that this approach can be used for the construction of viral mutants or vectors that can be activated on demand and have restricted tissue tropism and virulence.
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PMID:Changing the protease specificity for activation of a flavivirus, tick-borne encephalitis virus. 1856 34