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

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

Boivin extracts of Bordetella bronchiseptica inhibited or uncoupled the energized processes of bovine heart and pig heart mitochondria. Energy-dependent accumulation of calcium phosphate by both types of mitochondria was markedly inhibited by the extracts. The thesis is advanced that Boivin extracts of B. bronchiseptica may contain the membrane-damaging component responsible for infectious atrophic rhinitis. The action of the extracts was decreased by heat but seemed rather insensitive to digestion by trypsin or extraction by lipid solvents. Attempts to resolve the active component from the extracts were unsuccessful.
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PMID:A suggested mechanism for the pathogenesis of infectious atrophic rhinitis. 426 Sep 46

Of the 24 strains of Bordetella pertussis examined, 2 produced bacteriocins that inhibited the growth of all but 2 other strains of this species. The two strains producing the bacteriocin and the two resistant strains were rough, whereas all susceptible strains were smooth. The bacteriocin was not active on the B. parapertussis or B. bronchiseptica strains tested. These bacteriocins appeared to be protein in nature, since they were heat-labile and partially inactivated by trypsin. They were antigenic but the neutralizing antibodies did not precipitate the antigens. Absorption of the antiserum with homologous cell suspensions removed the agglutinating, but not the neutralizing, antibody.
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PMID:Bacteriocin produced by Bordetella pertussis. 429 May 77

Dermonecrotic toxin (DNT) produced by serotype D strains of Pasteurella multocida, isolated from pigs, was characterized and compared with DNT produced by Bordetella bronchiseptica. The DNT prepared by sonication from P multocida or B bronchiseptica had dermonecrotic activity and lethal toxicity for guinea pigs and mice, and also induced marked atrophy of spleens in the mice. Toxicity of P multocida or B bronchiseptica DNT was completely inactivated by heating at 70 C for 30 minutes, and was reduced by treatment with trypsin, formalin, or glutaraldehyde, indicating that the DNT may be a protein. Although biologic and toxic properties of P multocida DNT were similar to those of B bronchiseptica DNT, cross-neutralization tests between P multocida and B bronchiseptica indicated that DNT from the 2 bacterial species were serologically distinct.
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PMID:Characterization of dermonecrotic toxin produced by serotype D strains of Pasteurella multocida. 644 88

Stimulation of normal rat splenic T cells with pertussigen (lymphocytosis-promoting factor, LPF, from Bordetella pertussis) resulted in the release of a soluble factor that enhanced the glycosylation of IgE-binding factors during their biosynthesis. The soluble factor was detected by the ability of a culture filtrate of LPF-stimulated spleen cells to switch a T cell hybridoma, 23A4, from the formation of unglycosylated IgE-binding factor to the formation of glycosylated IgE-binding factor. The glycosylation-enhancing factor (GEF) had affinity for D-galactose, and the binding of the factor to hybridoma cells via a cell surface galactose was essential for modulation of IgE-binding factors. The GEF was inactivated by irreversible inhibitors of serine proteases such as phenylmethylsulfonyl fluoride, diisopropylfluorophosphate, and p-nitrophenyl ethylpentylphosphonate but was not affected by nonphosphorylating analogues of the organophosphorus compounds. Benzamidine, a competitive and reversible inhibitor of trypsin, also inhibited the glycosylation of IgE-binding factors by GEF. The factor could be purified by absorption to p-aminobenzamidine agarose followed by elution with benzamidine. The capacity of GEF to enhance the glycosylation of IgE-binding factors was inhibited by synthetic substrates of trypsin but not by substrates of chymotrypsin, indicating that GEF is a trypsin-like enzyme. Indeed, trypsin, plasmin, and kallikrein enhanced the glycosylation of IgE-binding factors during their biosynthesis. An inhibitor of trypsin-like enzyme(s), N-alpha-p-tosyl-L-lysine chloromethylketone (TLCK), inhibited trypsin and plasmin but not kallikrein, and TLCK failed to inhibit the GEF-mediated enhancement of glycosylation. It was also found that bradykinin, the biologically active product of cleavage of kininogen by kallikrein, enhanced the glycosylation of IgE-binding factors. The results indicate that GEF is a kallikrein-like enzyme.
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PMID:Modulation of the biologic activities of IgE-binding factor. IV. Identification of glycosylation-enhancing factor as a kallikrein-like enzyme. 655 15

Bordetella bronchiseptica and Pasteurella multocida have been impLicated in the aetiology of atrophic rhinitis of pigs but the precise cause and pathogenesis of field outbreaks have still to be clarified. The virulence of 11 strains of P multocida was investigated by intraperitoneal injection of culture filtrates in BALB/C mice, or by infection of gnotobiotic piglets given B bronchiseptica five days previously. Three of four type D strains of P multocida were lethal for mice and caused severe turbinate lesions and shortening of the snout with B bronchiseptica in gnotobiotic pigs; large numbers of P multocida and B bronchiseptica persisted for 64 days in the nasal cavity of these pigs. The fourth strain caused moderately severe turbinate lesions in gnotobiotic pigs infected with B bronchiseptica; small numbers of P multocida were found in these pigs and the lesions were attributed mainly to B bronchiseptica. Filtrates from seven strains of P multocida (four type A and three type D) were not lethal for mice and these strains with B bronchiseptica caused moderately severe turbinate lesions in gnotobiotic pigs; five of them colonised the nasal cavity reasonably well for 35 days but the lesions were attributed mainly to B bronchiseptica. The turbinate bones had regenerated by 64 days in pigs given type A strains of P multocida whereas the lesions persisted in pigs given type D strains. Antibodies to P multocida were detected in sera from infected gnotobiotic pigs by acid agglutination but not by indirect haemagglutination tests; neutralising activity to the mouse lethal toxin was detected in serum from one of five piglets at 64 days. The lethal toxin was inactivated at 56 degrees C for 30 minutes, by incubation with protease K for two hours and by 0.2 per cent formalin for 18 hours at 37 degrees C but not by trypsin; it was precipitated by 30 to 40 per cent saturation with ammonium sulphate and remained in the supernatant after centrifugation at 150,000 g. It was concluded that infection with virulent, type D strains of P multocida and B bronchiseptica could explain severe outbreaks of atrophic rhinitis; large numbers of both organisms persisted in the nasal cavity of gnotobiotic pigs with severe lesions; and that a soluble, heat-labile toxin may be an important virulence determinant in the type D strains of P multocida that cause severe atrophic rhinitis.
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PMID:Virulence of Pasteurella multocida in atrophic rhinitis of gnotobiotic pigs infected with Bordetella bronchiseptica. 687 79

Proteins to be used as vaccines are frequently treated with formaldehyde, although little is known about the effects of this treatment on protein antigenicity. To investigate the effect of formaldehyde treatment on antigen recognition by T cells, we compared the in vitro T-cell response to proteins that have been formaldehyde treated with the response to untreated proteins. We found that peripheral blood mononuclear cells from individuals vaccinated with three formaldehyde-treated proteins (pertussis toxin, filamentous hemagglutinin, pertactin) of Bordetella pertussis showed little or no response to the formaldehyde-treated proteins but proliferated very well in response to the corresponding untreated protein. These findings were further confirmed with CD4+ T-cell clones specific for defined epitopes of the bacterial proteins. We found that some epitopes are presented poorly or not at all when formaldehyde-treated proteins are used, whereas other epitopes are equally presented to T-cell clones when either formaldehyde-treated or untreated antigens are used. However, T-cell recognition could be restored by either antigen degradation before formaldehyde treatment or heat denaturation after such treatment. Parallel digestion with trypsin of both formaldehyde-treated and untreated proteins showed that fragments generated from the two forms of the same antigen were different in size. These results demonstrate that formaldehyde treatment can constrain antigen presentation to T cells and that this may be due to an altered proteolytic processing of formaldehyde-treated proteins.
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PMID:Formaldehyde treatment of proteins can constrain presentation to T cells by limiting antigen processing. 751 7

Microbial adherence to epithelial cell surfaces has been implicated as the first step in the initiation of several infectious diseases. The ability of antibiotics to affect the properties of bacterial adherence to cell surfaces may be a criterion in selecting antibiotics for therapy. This study was performed in order to investigate the activity of amoxicillin, chloramphenicol, and clarithromycin in modifying the adhering activity of Bordetella pertussis to human epithelial cells. The actions of antibiotics, alone or combined with aprotinin, were compared with that of trypsin, aprotinin and trypsin+aprotinin, to investigate the chemical nature of the ligand where antibiotics could act. The adhering activity was evaluated on human epithelial cells, collected from the oral mucosa, challenged with B. pertussis A2963 previously incubated in the presence of the tested substances for 1 h at 37 degrees C in a shaker incubator. After staining, the percentage of mucosal cells with more than 50 adhering bacteria was evaluated. Under the described experimental conditions, trypsin significantly reduced the adherence of B. pertussis. Aprotinin had no effect but was able to counteract the inhibitory action of trypsin. Both clarithromycin and chloramphenicol markedly reduced adhering activity and their actions were not counteracted by aprotinin. Amoxicillin was without effect. It was hypothesized that chloramphenicol and clarithromycin, exerting their antimicrobial action by inhibiting bacterial protein synthesis, affected bacterial adhesion through an unknown mechanism without proteolytic effect.
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PMID:Effect of antibiotics on Bordetella pertussis adhering activity: hypothesis regarding mechanism of action. 751 82

Filamentous hemagglutinin (FHA) is a major adhesin produced by Bordetella pertussis, the etiologic agent of whooping cough. FHA has been shown to be surface associated but is also secreted by virulent bacteria. Microscopic observations of lungs of mice infected with B. pertussis showed that the bacteria grow as clusters within the alveolar lumen. When B. pertussis was cultivated in vitro with chemically defined medium, bacteria grew as aggregates, mimicking growth observed in vivo. This aggregation was abolished by the addition of cyclodextrin (CDX) to the growth medium and depended on the production of FHA, because a mutant lacking the FHA structural gene failed to form aggregates in a CDX-free medium. Western blot (immunoblot) analyses revealed that, in the absence of CDX, FHA was attached to the bacterial surface and was not efficiently released into the growth medium. Hydrophobic chromatography of FHA showed that CDX drastically reduced the hydrophobicity of FHA, suggesting a direct binding of CDX to FHA, which was further supported by the partial protection of FHA from trypsin digestion in the presence of CDX. In addition, free FHA can interact in a CDX-inhibitable manner with solid phase-immobilized FHA. It can therefore be postulated that the B. pertussis aggregates are most likely due to direct FHA-FHA interaction.
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PMID:Surface-associated filamentous hemagglutinin induces autoagglutination of Bordetella pertussis. 792 83

The molecular basis for direct bacteria-macrophage interactions that distinguishes nontypeable (NT) Haemophilus influenzae from type b organisms is not known. Because of similarities between filamentous hemagglutinin (FHA) adhesin of Bordetella pertussis and high-molecular-weight (HMW) proteins commonly expressed by NT H. influenzae, the role that HMW proteins play in determining NT H. influenzae-macrophage interactions was assessed. In tests with genetically engineered organisms, HMW protein-expressing bacteria bound significantly better than isogenic HMW protein-deficient bacteria to macrophages. HMW protein-dependent binding to macrophages is trypsin-sensitive, is independent of divalent cations, does not occur via the leukocyte integrin CD11b/CD18, and is not affected by galactose-containing carbohydrates. Organisms bound via HMW proteins remain largely extracellular and viable. Like FHA of Bordetella organisms, HMW proteins mediate binding of NT H. influenzae to macrophages. However, unlike the interaction determined by FHA, this interaction is characteristically one of adhesion and requires additional serum opsonization for efficient killing of bacteria by macrophages.
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PMID:High-molecular-weight surface-exposed proteins of Haemophilus influenzae mediate binding to macrophages. 810 76

The catalytic domain of Bordetella pertussis adenylate cyclase, a calmodulin-activated enzyme with toxic properties, is a modular construct cleaved by trypsin into two subdomains of 224 (T25) and 175 (T18) amino acids. The calmodulin-binding locus of the bacterial enzyme consists of approximately 70 amino acids and overlaps the C-terminus of T25 and the N-terminus of T18. This region, exposed to the solvent or proteases, also exhibits an unusual high flexibility and allows, as demonstrated in this study, reconstitution in the presence of calmodulin of active species of adenylate cyclase from overlapping inactive fragments of the enzyme. Moreover, several combinations of inactive variants of the bacterial enzyme obtained by site-directed mutagenesis can yield active species. Heterodimers, resulting from a few selected combinations of inactive species of adenylate cyclase, exhibit specific activity similar to that of the native enzyme. Productive complementation from inactive fragments is a unique phenomenon among calmodulin-activated enzymes and represents a new and helpful tool in the understanding of the molecular mechanism of activation of B. pertussis adenylate cyclase upon binding of calmodulin.
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PMID:Structural flexibility of the calmodulin-binding locus in Bordetella pertussis adenylate cyclase. Reconstitution of catalytically active species from fragments or inactive forms of the enzyme. 822 1


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