Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have purified CR3 to homogeneity by affinity chromatography on C3bi-Sepharose and elution with EDTA. C3bi-coated erythrocytes bound to this purified CR3, and binding was dependent on the concentration of both C3bi and CR3, as well as on temperature and the presence of divalent cations. Moreover, binding could be blocked by mAb against CR3 or C3bi and could be enhanced by the addition of integrin modulating factor-1. We used the purified CR3 to test whether several putative ligands of CR3 directly bound the receptor. The interaction of purified CR3 with fibrinogen, filamentous hemagglutinin of Bordetella pertussis, lipophosphoglycan and glycoprotein 63 of Leishmania mexicana, and lipopolysaccharide from Escherichia coli was confirmed. However the interaction of CR3 with zymosan or its major component, beta-glucan, was not observed in these assays. Previous studies showed that binding of C3bi to PMN could be blocked with Arg-Gly-Asp (RGD) containing peptides and were interpreted to indicate that the RGD sequence in C3bi interacts directly with CR3. We found, however, that RGD containing peptides were unable to block the interaction of C3bi with purified CR3, yet retained the ability to block binding of C3bi to cells. We conclude that RGD-peptides do not directly bind CR3, but instead indirectly effect CR3 function. Inasmuch as the effect of RGD-peptides could be mimicked with antibodies against leukocyte response integrin, we suggest that RGD-peptides may bind to leukocyte response integrin on polymorphonuclear leukocytes and influence CR3 activity via this receptor.
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PMID:Ligand specificity of purified complement receptor type three (CD11b/CD18, alpha m beta 2, Mac-1). Indirect effects of an Arg-Gly-Asp (RGD) sequence. 837 80

Using radioiodinated, photoactivable, reducible cross-linker conjugated bacterial endotoxic lipopolysaccharide (125I-ASD-LPS), we have demonstrated that LPS selectively binds to the S2 subunit of pertussis toxin (PT). Since LPS also interacts with the S2 subunit of the B-oligomer of the toxin, the binding of LPS to PT is not A-protomer (S1 subunit) dependent. The binding can be inhibited with native underivatized LPS and with purified lipid A, suggesting that the binding is mediated through the lipid A moiety of the LPS molecule. The binding of PT to LPS can be inhibited by bovine fetuin glycoprotein. Since PT has been demonstrated to interact specifically with N-linked oligosaccharide side chains of fetuin, the interaction of LPS with the S2 subunit of PT may involve carbohydrate-dependent interactions of the disaccharide backbone of lipid A with S2. Additional studies have documented that LPS binding to PT may be competitively inhibited by lysozyme but not by polymyxin B. Sequence analysis has allowed identification of a high degree of amino acid sequence similarity between the S2 subunit of PT and hen egg white lysozyme at the N-terminal 80-residue regions. Shared N-terminal sequence similarity between lysozyme, PT-S2, and a third LPS-binding protein alpha-lactalbumin allows tentative identification of a second family of LPS binding proteins.
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PMID:Lipopolysaccharide interaction with S2 subunit of pertussis toxin. 841 48

We have investigated the mechanisms by which insulin and insulin-like growth factor-I (IGF-I) regulate the synthesis of progesterone by swine ovary granulosa cells. Analysis of the cell density dependence of the effects of insulin and IGF-I showed that the induction of progesterone synthesis by these growth factors is consistent with an autocrine or paracrine model of action, which involves the insulin- and IGF-I-stimulated release of a soluble factor(s) into the culture medium. We have tested the hypothesis that this soluble factor(s) may be structurally related to inositol phosphoglycans, a class of putative second messengers of the action of insulin. Consistent with this hypothesis, we isolated an activator of pyruvate dehydrogenase (PDH) phosphatase from culture medium obtained from cells treated with insulin or IGF-I. Further analysis showed that specific antibodies raised against the inositol phosphoglycan anchor of the variant surface glycoprotein of Trypanosoma brucei blocked the activation of PDH phosphatase by the material isolated from the culture medium, suggesting a close structural relationship between this putative PDH phosphatase activator and inositol phosphaglycans. Pertussis toxin treatment, shown to inhibit the generation of inositol phosphoglycans in other systems, was found to inhibit the effects of insulin on progesterone synthesis in granulosa cells. Finally, the stimulatory effects of insulin and IGF-I on progesterone synthesis by intact granulosa cells were markedly inhibited by the addition of antiinositol phosphoglycan antibodies to the culture medium. Based on these observations, we propose that the release of inositol phosphoglycans into the extracellular medium plays an important role in the signaling mechanisms by which insulin and IGF-I regulate the synthesis of progesterone in swine ovary granulosa cells.
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PMID:The involvement of inositol phosphoglycan mediators in the modulation of steroidogenesis by insulin and insulin-like growth factor-I. 846 54

To determine whether antibodies to the B oligomer of pertussis toxin (PT) were present in patients diagnosed with pertussis or vaccinees who had received diphtheria-tetanus-whole-cell pertussis vaccine, we analyzed serum samples from 5 patients and 10 vaccinees by both enzyme-linked immunosorbent assay (ELISA) and Western immunoblotting techniques. Antibodies to the B oligomer were detected by ELISA in all samples containing antibodies to holotoxin. Western immunoblotting procedures were less efficient than ELISA techniques for detecting antibodies to the B oligomer. Antibodies which inhibit the ability of the B oligomer to agglutinate erythrocytes were detected in purified human immunoglobulin preparations. In addition, serum samples containing antibodies to PT inhibited the binding of purified B oligomer and holotoxin to a 165-kDa glycoprotein which has been considered a potential PT receptor in Chinese hamster ovary (CHO) cells. These results suggest that antibodies to the B oligomer contribute to the human serologic response to PT, but their detection and characterization require appropriate methods.
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PMID:Human antibody response to the B oligomer of pertussis toxin. 855 12

We studied the mechanism of anti-tumour action of sulphydryl glycoprotein (SAGP) purified from an extract of Streptococcus pyogenes in vitro. SAGP rapidly inhibited the incorporation of nucleic acid precursors into murine fibrosarcoma (Meth A) cells before it inhibited the cell growth. SAGP-induced cell growth inhibition was diminished by incubating the cells with pertussis toxin (IAP), whereas the SAGP activity was augmented by incubating the cells with cholera toxin (CTX). Meth A cells exposed to SAGP underwent an increase in labelling of the alpha-subunit of an inhibitory guanine nucleotide-binding (Gi) protein in a subsequent IAP-catalysed [32P]ADP ribosylation of the cell membrane fraction. Gi alpha labelling was not increased either in the membrane from the Meth A cells exposed to heat-inactivated SAGP or in the membrane from L929 cells exposed to SAGP, in which growth was also unaffected. By contrast, SAGP caused no alteration in labelling the alpha-subunit of stimulatory guanine nucleotide-binding (Gs) protein in a subsequent CTX-catalysed ADP ribosylation of membrane fractions of Meth A and L929 cells. The amount of intracellular cAMP was decreased slightly in Meth A cells incubated with SAGP. Although the precise roles of Gs protein and adenylate cyclase in the cell growth inhibition induced by SAGP are not clear, these findings suggested that the modulation of Gi protein is involved in such SAGP-induced cellular events as the inhibition of nucleic acid synthesis and cell growth inhibition.
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PMID:Streptococcal glycoprotein-induced tumour cell growth inhibition involves the modulation of a pertussis toxin-sensitive G protein. 861 26

Recently it was demonstrated that the metabolism of both glycoproteins and sphingo(glyco)lipids is dependent upon the state of enterocytic differentiation of HT-29 cells. Furthermore, it was shown that undifferentiated HT-29 cells display an important autophagic sequestration, controlled by a heterotrimeric Gi3 protein. In order to correlate the metabolism of sphingo(glyco)lipids with the extent of autophagic sequestration, we have incubated undifferentiated and differentiated HT-29 cells with tritium-labelled GM1 ganglioside and sphingosine in the absence and presence of pertussis toxin (an inhibitor of autophagic sequestration) or asparagine (an inhibitor of autophagic vacuole maturation). In addition, undifferentiated HT-29 cells transfected with a cDNA encoding the G alpha i3 protein (cells expressing an amplified autophagic pathway) were labelled with both GM1 and sphingosine. The results show that the catabolism of sphingo(glyco)lipids is dramatically enhanced in parallel with the increase of the autophagic pathway while at the same time their biosynthesis is reduced. The inhibition of autophagy in both undifferentiated cells and alpha i3-overexpressing cells restores sphingo(glyco)lipid metabolism, as normally expressed in differentiated cells, as well as in other mammalian cell types. We conclude that autophagy plays an important role in governing the metabolic fate of sphingo(glyco)lipids in HT-29 cells. Since autophagy regulates the N-linked glycoprotein metabolism in this cell line, our results corroborate the idea that glycolipid and glycoprotein metabolisms are controlled by similar mechanisms.
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PMID:The metabolism of sphingo(glyco)lipids is correlated with the differentiation-dependent autophagic pathway in HT-29 cells. 864 85

The sperm acrosome reaction is a Ca(2+)-dependent secretory event required for fertilization. Adhesion to the egg's zona pellucida promotes Ca2+ influx through voltage-sensitive channels, thereby initiating secretion. We used potentiometric fluorescent probes to determine the role of sperm membrane potential in regulating Ca2+ entry. ZP3, the glycoprotein agonist of the zona pellucida, depolarizes sperm membranes by activating a pertussis toxin-insensitive mechanism with the characteristics of a poorly selective cation channel. ZP3 also activates a pertussis toxin-sensitive pathway that produces a transient rise in internal pH. The concerted effects of depolarization and alkalinization open voltage-sensitive Ca2+ channels. These observations suggest that mammalian sperm utilize membrane potential-dependent signal transduction mechanisms and that a depolarization pathway is an upstream transducing element coupling adhesion to secretion during fertilization.
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PMID:ZP3-dependent activation of sperm cation channels regulates acrosomal secretion during mammalian fertilization. 870 44

Pancreastatin is a 49 amino acid peptide first isolated, purified and characterized from porcine pancreas. Its biological activity in different tissues can be assigned to the C-terminal part of the molecule. Pancreastatin has a prohormonal precursor, chromogranin A, which is a glycoprotein present in neuroendocrine cells, including the endocrine pancreas. We have been interested in pancreastatin action in the liver. We found that pancreastatin has a glycogenolytic effect in the hepatocyte both in vivo and in vitro. We then studied and characterized the specific pancreastatin receptor in the rat liver plasma membrane, as well as the specific signal transduction. This receptor appears to be coupled to two different G proteins. A pertussis toxin-insensitive G proteins leads to the activation of phospholipase C, and therefore mediates the glycogenolytic effect in the liver by increasing cytoplasmic free calcium and stimulating protein kinase C. The role of cyclic GMP in the action of pancreastatin is not known yet, although it seems to regulate negatively the activation of phospholipase C. The precise mechanism by which pancreastatin stimulates guanylate cyclase activity remains to be studied.
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PMID:Pancreastatin action in the liver: dual coupling to different G proteins. 877 44

Galectin-3, a mammalian galactoside-binding protein, is not expressed in the Jurkat T-lymphoblastoid cell line. However, Jurkat cells express surface glycoprotein receptors for galectin-3, one of which is shown to be the glycosylated heavy chain of CD98 (4F2 antigen), a T-cell activation marker. Addition of galectin-3 to Jurkat cells triggers a sustained influx of extracellular Ca2+ in a concentration dependent manner. The induced increase in cytosolic [Ca2+]i is blocked by sugar hapten inhibitors of galectin-3. The galectin-3-induced effect is insensitive to voltage-gated Ca2+ channel antagonists such as prenylamine, nifedipine and diltiazem and to pertussis toxin but is inhibited by cholera toxin. The results suggest that galectin-3 released by accessory cells such as macrophages may bind in vivo to T-cell activation antigens and also participate in Ca2+ signalling.
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PMID:Galectin-3 stimulates uptake of extracellular Ca2+ in human Jurkat T-cells. 889 87

Autotaxin (ATX) is an extracellular enzyme and an autocrine motility factor that stimulates pertussis toxin-sensitive chemotaxis in human melanoma cells at picomolar to nanomolar concentrations. This 125-kDa glycoprotein contains a peptide sequence identified as the catalytic site in type I alkaline phosphodiesterases (PDEs), and it possesses 5'-nucleotide PDE (EC 3.1.4.1) activity (Stracke, M. L., Krutzsch, H. C., Unsworth, E. J., Arestad, A., Cioce, V., Schiffmann, E., and Liotta, L. (1992) J. Biol. Chem. 267, 2524-2529; Murata, J., Lee, H. Y., Clair, T., Krutsch, H. C., Arestad, A. A., Sobel, M. E., Liotta, L. A., and Stracke, M. L. (1994) J. Biol. Chem. 269, 30479-30484). ATX binds ATP and is phosphorylated only on threonine. Thr210 at the PDE active site of ATX is required for phosphorylation, 5'-nucleotide PDE, and motility-stimulating activities (Lee, H. Y., Clair, T., Mulvaney, P. T., Woodhouse, E. C., Aznavoorian, S., Liotta, L. A., and Stracke, M. L. (1996) J. Biol. Chem. 271, 24408-24412). In this article we report that the phosphorylation of ATX is a transient event, being stable at 0 degrees C but unstable at 37 degrees C, and that ATX has adenosine-5'-triphosphatase (ATPase; EC 3.6.1.3) and ATP pyrophosphatase (EC 3.6.1.8) activities. Thus ATX catalyzes the hydrolysis of the phosphodiester bond on either side of the beta-phosphate of ATP. ATX also catalyzes the hydrolysis of GTP to GDP and GMP, of either AMP or PPi to Pi, and the hydrolysis of NAD to AMP, and each of these substrates can serve as a phosphate donor in the phosphorylation of ATX. ATX possesses no detectable protein kinase activity toward histone, myelin basic protein, or casein. These results lead to the proposal that ATX is capable of at least two alternative reaction mechanisms, threonine (T-type) ATPase and 5'-nucleotide PDE/ATP pyrophosphatase, with a common site (Thr210) for the formation of covalently bound reaction intermediates threonine phosphate and threonine adenylate, respectively.
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PMID:Autotaxin is an exoenzyme possessing 5'-nucleotide phosphodiesterase/ATP pyrophosphatase and ATPase activities. 899 94


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