Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A procedure is described for purification of pertussis heat-labile toxin (PEHLT) from cells of Bordetella pertussis. The purification procedure, performed in the cold and in the presence of protease inhibitors, gives 1,350-fold purification with yields of about 60%. The toxin was shown to be a single-chain polypeptide of 140 kDa, pI 6.02. It was completely inactivated by heating at 56 degrees C for 60 min. Rabbit antiserum prepared against PEHLT neutralized the toxin and gave a single precipitin line on immunodiffusion. In immunodiffusion assays, this anti-PEHLT serum did not react with pertussis toxin, filamentous hemagglutinin, or preparations of pertussis adenylate cyclase. Purified PEHLT elicited dermonecrosis and atrophy of the spleen. PEHLT is extraordinarily active; 0.4 X 10(-12) g caused necrotic lesions in newborn mice, and with 18- to 20-g mice the 50% lethal dose was about 11 X 10(-9) g.
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PMID:Purification and characterization of the heat-labile toxin of Bordetella pertussis. 189 74

Rabbit antiserum and murine monoclonal antibodies were raised against a strain of Haemophilus ducreyi. The antiserum gave high immunofluorescence titres and strong dot blot reactions with all H. ducreyi strains tested and the only cross reaction was with Bordetella pertussis. Three monoclonal antibodies, all of isotype IgG2a, also gave high immunofluorescence titres with H. ducreyi but did not cross react with any other species tested. Immunoblotting showed the monoclonal antibodies to react with a single polypeptide band of mol. wt 29,000 in the outer-membrane fraction of H. ducreyi. These antibodies have potential for use as diagnostic reagents and for investigating the pathogenicity of H. ducreyi.
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PMID:The production and characterisation of rabbit antiserum and murine monoclonal antibodies to Haemophilus ducreyi. 217 58

The extracellular calmodulin-sensitive adenylate cyclase produced by Bordetella pertussis is synthesized as a 215-kDa precursor. This polypeptide is transported to the outer membrane of the bacteria where it is proteolytically processed to a 45-kDa catalytic subunit which is released into the culture supernatant [Masure, H.R., & Storm, D.R. (1989) biochemistry 28, 438-442]. The gene encoding this enzyme, cyaA, is part of the cya operon that also includes the genes cyaB, cyaD, and cyaE. A comparison of the predicted amino acid sequences encoded by cyaA, cyaB, and cyaD with the amino acid sequences encoded by hlyA, hlyB, and hlyD genes from the hemolysin (hly) operon from Escherichia coli shows a large degree of sequence similarity [Glaser, P., Sakamoto, H., Bellalou, J., Ullmann, A., & Danchin, A. (1988) EMBO J. 7, 3997-4004]. Complementation studies have shown that HlyB and HlyD are responsible for the secretion of HlyA (hemolysin) from E. coli. The signal sequence responsible for secretion of hemolysin has been shown to reside in its C-terminal 27 amino acids. Similarly, CyaB, CyaD, and CyaE are required for the secretion of CyaA from Bordetella pertussis. We placed the cyaA gene and a truncated cyaA gene that lacks the nucleotides that code for a putative C-terminal secretory signal sequence under the control of the lac promoter in the plasmid pUC-19. These plasmids were transformed into strains of E. coli which contained the hly operon. The truncated cyaA gene product, lacking the putative signal sequence, was not secreted but accumulated inside the cell.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Secretion of the Bordetella pertussis adenylate cyclase from Escherichia coli containing the hemolysin operon. 218 14

Tumor necrosis factors alpha and beta (TNF-alpha and TNF-beta) are multifaceted polypeptide cytokines which may mediate some of the significant changes in cellular homeostasis which accompany the invasion of the mammalian host by viruses, bacteria, and parasites. Although it is well established that bacterial lipopolysaccharide is a potent inducer of TNF-alpha, there is still very little known of the types of agents which can trigger the production of TNFs in mononuclear leukocytes. Using an enzyme-linked immunosorbent assay for measuring TNF-alpha and TNF-beta, we examined the capacity of various T-lymphocyte and beta-lymphocyte mitogens as well as microbial components to stimulate production of these cytokines in culture. The mitogens phytohemagglutinin, concanavalin A, and pokeweed mitogen induced production of both TNF-alpha and TNF-beta, while whole-killed Staphylococcus aureus and Bordetella pertussis, like lipopolysaccharide, were potent inducers of TNF-alpha but failed to stimulate TNF-beta production. TNF-alpha production was detectable within 1 h after stimulation, while TNF-beta production was not detected until after 8 h of culture. The bacterial products tetanus toxoid, purified protein derivative, pertussis filamentous hemagglutinin, and pertussis toxin were all able to induce TNF-alpha and TNF-beta production. Disrupted (frozen-thawed) Plasmodium falciparum-infected erythrocytes were also potent inducers of TNF-alpha and TNF-beta. The results demonstrated that a wide variety of microbial components are inducers of TNF-alpha. Some may not only be more effective than lipopolysaccharide but can also induce TNF-beta production. Furthermore, evidence is presented showing that TNF-beta but not TNF-alpha production correlates with lymphoproliferation.
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PMID:Production of tumor necrosis factors alpha and beta by human mononuclear leukocytes stimulated with mitogens, bacteria, and malarial parasites. 225 24

Differences in susceptibility to experimental autoimmune uveitis (EAU) among rats of various strains have been reported. The present study was aimed at separating the effects of the major histocompatibility antigen complex (MHC) and non-MHC genes on the development of EAU. EAU-susceptible LEW, EAU-resistant WKAH, WKAH, 1L MHC congenic strain rats representing MHC of LEW on WKAH genetic background, and other nine inbred strains of rats were examined for their ability to develop EAU by immunization with bovine S-Ag or peptide M, an synthetic polypeptide corresponding to position 303 to 320 in bovine S-Ag. We found that only LEW rats developed S-Ag induced-EAU, where WKAH, 1L congenic and other rats did not. However, when an additional injection of Bordetella pertussis (BP) was given, all rat strains developed S-Ag induced-EAU. In contrast, only LEW, WKAH, 1L,F344, and NIG-III rats, which have haplotype 1 at RT1 class II subregions developed EAU by immunization with peptide M and BP. The present findings showed that the susceptibility to EAU in rats was controlled by both MHC and non-MHC genes. Eventual development of EAU in rats was governed by non-MHC gene (s). However, this effect of non-MHC gene (s) could no longer be observed when an additional injection of BP was administered. MHC class II (RT1(1] restricted the susceptibility to peptide M induced-EAU. However, this MHC restriction was not observed when multideterminant S-Ag was used as an immunogen.
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PMID:[Genetic control of experimental autoimmune uveitis in rats]. 226 20

Bordetella pertussis, the etiological agent of whooping cough, synthesizes a calmodulin-sensitive adenylate cyclase that is suspected to play a major role in the virulence of this bacterium. We show that adenylate cyclase synthesized as a 200-kilodalton protein is the product of the cyaA gene and that various virulent Bordetella species secrete this high-molecular-weight polypeptide without apparent proteolytic processing. When submitted to trypsin digestion, the 200-kilodalton protein was converted to a stable 45- to 50-kilodalton species. This corresponds to the size of the enzyme previously purified from a culture supernatant. The molecular heterogeneity reported for the various identified forms of adenylate cyclase could therefore result in part from proteolytic degradation or molecular aggregation of the major 200-kilodalton form of the enzyme.
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PMID:Synthesis and secretion of Bordetella pertussis adenylate cyclase as a 200-kilodalton protein. 232 14

The nucleotide sequence of the structural gene for filamentous haemagglutinin (FHA), fhaB, a crucial adherence factor for Bordetella pertussis, has been determined. Its 10774 nucleotides are far more than necessary to encode the 220 kD biologically active, mature polypeptide product, suggesting a role for co- or post-translational processing. Fusion proteins derived from various portions of the fhaB open reading frame (ORF) were used to generate polyclonal antisera. Western immunoblot analysis of purified FHA and Bordetella sp. whole cell extracts with these antisera indicated that the 220 kD product is encoded by the 5' portion of the ORF and that the smaller polypeptide species are breakdown products of this polypeptide. These data, as well as N-terminal amino acid sequencing of the major polypeptide species, suggest a scheme for the proteolytic processing of an FHA precursor polypeptide.
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PMID:Genetic characterization of Bordetella pertussis filamentous haemagglutinin: a protein processed from an unusually large precursor. 238 59

Rat adipose tissue possesses two Bordetella pertussis toxin (PTX) substrates and, in the same 39-41 kDa molecular mass range, positive immunoreactivity has also been reported with antibodies against the alpha subunit of Go, the major brain GTP-binding protein (G-protein). In this study, the presence of the brain Go alpha subunit at 39 kDa in adipocytes was reassessed, since direct correspondence between PTX substrates and Go alpha immunoreactivity has not yet been clearly established. On resolutive SDS/polyacrylamide-gel electrophoresis, the PTX substrates of human adipocytes were compared with the three PTX substrates found in brain. No ADP-ribosylated substrate at the level of the 39 kDa brain Go alpha could be detected in adipocyte membranes. Immunoblotting of human adipocyte membranes stained with our anti-Go alpha antibodies confirmed the presence of a positive immunoreactivity in this tissue, but the apparent molecular mass of the immunoreactive polypeptide in adipocytes was higher than that found in nervous tissues. Taken together, these results indicate that the brain Go alpha subunit is not present in adipose tissue. They also suggest the existence of a G-protein in adipocytes which is immunologically related to Go alpha but having a slightly higher molecular mass.
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PMID:The adipocyte Go alpha-immunoreactive polypeptide is different from the alpha subunit of the brain Go protein. 250 50

A 2.7-kb cya A gene fragment encoding the amino-terminal end of the calmodulin-sensitive adenylate cyclase from Bordetella pertussis has been placed under the control of the lac promoter for expression in Escherichia coli. Following induction with isopropyl beta-D-thiogalactoside, calmodulin-sensitive adenylate cyclase activity was detected in a cell extract from E. coli. The expression vector directed the synthesis of a 90-kDa polypeptide that was recognized by rabbit polyclonal antibodies raised against the catalytic subunit of B. pertussis adenylate cyclase. Inspection of the deduced amino acid sequence of the cya A gene product revealed a sequence with homology to consensus sequences for an ATP-binding domain found in many ATP-binding proteins. On the basis of the analysis of nucleotide binding proteins, a conserved lysine residue has been implicated in the binding of ATP. A putative ATP-binding domain in the B. pertussis adenylate cyclase possesses an analogous lysine residue at position 58. To test whether lysine 58 of the B. pertussis adenylate cyclase is a crucial residue for enzyme activity, it was replaced with methionine by oligonucleotide-directed mutagenesis. E. coli cells were transformed with the mutant cya A gene, and the expressed gene product was characterized. The mutant protein exhibited neither basal nor calmodulin-stimulated enzyme activity, indicating that lysine 58 plays a critical role in enzyme catalysis.
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PMID:Site-directed mutagenesis of lysine 58 in a putative ATP-binding domain of the calmodulin-sensitive adenylate cyclase from Bordetella pertussis abolishes catalytic activity. 254 36

Bordetella pertussis adenylate cyclase (AC) toxin is a calmodulin-activated adenylate cyclase enzyme which has the capacity to enter eukaryotic target cells and catalyze the conversion of endogenous ATP into cyclic AMP. In this work, the AC holotoxin molecule is identified and isolated. It is a single polypeptide of apparent 216 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Monoclonal antibodies which immunoprecipitate AC activity from extracts of wild type B. pertussis (BP338) react with this 216-kDa band on Western blots, and it is absent from a transposon Tn5 mutant (BP348) specifically lacking AC toxin. Isolation of the 216-kDa protein to greater than 85% purity by hydrophobic chromatography, preparative sucrose gradient centrifugation, and affinity chromatography using either calmodulin-Sepharose or monoclonal antibody coupled to Sepharose 4B yields stepwise increases in AC toxin potency, to a maximum of 88.3 mumol of cAMP/mg of target cell protein/mg of toxin. Electroelution of the 216-kDa band following sodium dodecyl sulfate-polyacrylamide gel electrophoresis yields a preparation with both AC enzyme and toxin activities. These data indicate that this protein represents the AC holotoxin molecule.
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PMID:Adenylate cyclase toxin from Bordetella pertussis. Identification and purification of the holotoxin molecule. 255 37


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