Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.3.1 (NADPH oxidase)
 11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When exposed to hen ovalbumin (OA)-complexed IgG antibodies, guinea-pig macrophages undergo O2- generation and a rapid rise in the intracellular concentration of free Ca2+ ((Ca2+]i). These responses were found to depend on the IgG isotype of antibodies used; OA-complexed IgG2 antibody (OA gamma 2) induced these responses 3-5 times more intensively than did OA-complexed IgG1 antibody (OA gamma 1). The inhibitory effects of monoclonal antibody to Fc gamma receptor for IgG2 alone (Fc gamma 2R) and that to Fc gamma receptor for both IgG1 and IgG2 (Fc gamma 1/gamma 2R) showed that Fc gamma 2R triggered both an increase in [Ca2+]i and activation of the respiratory burst NADPH oxidase more effectively than did Fc gamma 1/gamma 2R. As the number of Fc gamma 2R molecules per macrophage is about one-half that of Fc gamma 1/gamma 2R molecules, the ability of Fc gamma 2R to trigger these responses may be much higher than that of Fc gamma 1/gamma 2R. This difference between their abilities was further demonstrated by measuring the responses induced by cross-linking of Fc gamma 2R or Fc gamma 1/gamma 2R molecules. In addition, the O2- generation with OA gamma 1 was found to be enhanced with cytochalasin B, and to be lowered by depletion of the intracellular Ca2+ of macrophages with Ionomycin and EGTA, though cytochalasin B and the Ca2+ depletion did not affect the O2- generation with OA gamma 2. These results suggest that the mechanisms of Fc gamma 2- and Fc gamma 1/gamma 2 R-mediated signal transmission leading to activation of the NADPH oxidase also differ from each other.
Mol Immunol 1990 Sep
PMID:Different abilities of two types of Fc gamma receptor on guinea-pig macrophages to trigger the intracellular Ca2+ mobilization and O2- generation. 214 7

To determine the role of oxygen radicals in the killing of Mycobacterium tuberculosis by neutrophils, the effects of free-radical inhibitors and enzymes, catalase, superoxide dismutase, taurine, deferoxamine, and histidine were evaluated. Changes in the viability of M. tuberculosis were determined by agar plate colony counts and a radiometric assay. No impairment in killing was seen with any of the inhibitors or enzymes. Patients with chronic granulomatous disease (CGD) have a defect in the NADPH oxidase pathway, causing their neutrophils to be unable to generate oxygen radicals. If these radicals are involved in killing, then CGD neutrophils should be less effective killers of M. tuberculosis than normal neutrophils. There was no evidence by either measure of M. tuberculosis viability that CGD neutrophils were less bactericidal than normal neutrophils. Killing by normal neutrophils was also effective in the absence of serum. These results lead to the conclusion that the mechanism by which M. tuberculosis is killed by neutrophils is independent of the oxygen metabolic burst.
J Infect Dis 1990 Sep
PMID:Killing of Mycobacterium tuberculosis by neutrophils: a nonoxidative process. 190 38

The effects of quinones (benzoquinone, menadione, and doxorubicin) on the superoxide production in cell free systems (xanthine oxidase and rat liver microsomes) and of polycationic electrolyte- and latex-stimulated rat peritoneal macrophages have been studied. Contradictory results were obtained in cell free systems when two traditional assays for detection of superoxide ion, the cytochrome c reduction and the lucigenin-dependent chemiluminescence (CL), were used: all quinones inhibited the lucigenin-dependent CL at sufficiently large concentrations, but they did not inhibit at all the reduction of cytochrome c. It was proposed that the cytochrome c assay gave erroneous results due to the reversibility of the interaction of semiquinones with dioxygen. The effect of quinones on the superoxide production by peritoneal macrophages was biphasic: all quinones stimulated the O2-. formation at low concentrations and inhibited it at elevated concentrations. It was concluded that among the quinones studied, only menadione was capable of stimulating the superoxide production via a one-electron transfer mechanism in cell free systems, while the stimulatory effect of small concentrations of quinones on the O2-. production in macrophages was possibly due to their action on the activation of NADPH oxidase.
Arch Biochem Biophys 1990 Sep
PMID:Are quinones producers or scavengers of superoxide ion in cells? 216 57

Activation of the phagocyte NADPH oxidase requires participation of membrane-bound cytochrome b558 and cytosol proteins of 47 kDa (p47) and 67 kDa (p67). We examined the sequence of participation of p47 and p67 in activation of the oxidase using an arachidonate-activated cell-free superoxidase (O2-) generating assay requiring phagocyte membrane and cytosol. Neutrophil cytosol from patients with certain forms of autosomal recessive chronic granulomatous disease (CGD) lack either p47 or p67. Initial incubation of membrane and arachidonate with CGD cytosol deficient in either p47 or p67 fails to generate superoxide in the cell-free assay until addition of complementary cytosol. CGD cytosol was incubated with arachidonate and membrane for 5-15 min and the lag time of O2- generation was measured after addition of complementary CGD cytosol. The lag time is shortened when p47, but not p67, is present in the initial incubation. We have previously shown that the peptide, RGVHFIF, corresponding to a cytoplasmic carboxyl-terminal domain of the large subunit of cytochrome b558, inhibits activation of NADPH oxidase in the cell-free assay, but does not affect the enzyme activity of fully assembled oxidase. Experiments with sequential addition of complementary CGD cytosols were performed as above, except that RGVHFIF was added after the initial incubation. The peptide failed to inhibit when added after initial incubation if p47 was present during that incubation. In contrast, the peptide markedly inhibited oxidase activity if p47 was absent during the initial incubation. These results suggest that p47, but not p67, is a participant with membrane and/or other cytosol components in early arachidonate-dependent reactions. In the absence of p67, these reactions culminate in the irreversible formation of a metastable activation intermediate that is insensitive to inhibition by RGVHFIF. After addition of p67, this activation intermediate subsequently reacts to form the active NADPH oxidase.
J Biol Chem 1990 Sep 15
PMID:The phagocyte 47-kilodalton cytosolic oxidase protein is an early reactant in activation of the respiratory burst. 216 17

Neutrophil NADPH:O2 oxidoreductase activity, essential in the killing of bacteria by neutrophils, can be elicited in a cell-free system that requires plasma membranes, cytosol and sodium dodecyl sulfate. In addition, GTP or its nonhydrolyzable analog guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) enhances NADPH oxidase activity. We investigated the mechanism of this effect of GTP gamma S in the cell-free system. Cytosol from human neutrophils was separated in three different soluble oxidase components (SOC I, SOC II, and SOC III). Previously we (Bolscher, B. G. J. M., Van Zwieten, R., Kramer, I. J. M., Weening, R. S., Verhoeven, A. J., and Roos, D. (1989) J. Clin. Invest. 83, 757-763) reported that the cytosol contains two components which act synergistically. We now report that one component (previously labeled SOC II) contains two different components that can be separated by ion exchange chromatography. Immunoblotting with antiserum B-1 (Volpp, B. D., Nauseef, W. M., and Clark, R. A. (1988) Science 242, 1295-1297), directed against a cytosolic complex capable of activating latent membranes in the cell-free system, showed a 47-kDa protein in SOC II and a 67-kDa protein in SOC III. SOC II also contains the 47-kDa phosphoprotein, which indicates that this phosphoprotein and the protein recognized by the antiserum are identical. Low rates of NADPH-dependent O2 consumption can be elicited by SOC II and SOC III in the absence of SOC I. This activity is independent of GTP gamma S. Addition of SOC I increases this activity 3-4-fold, only when GTP gamma S is present. Plasma membranes, incubated with SOC I plus GTP gamma S and re-isolated, showed a similar 3-4-fold enhanced O2 consumption with SOC II and SOC III. The GTP gamma S effect is exerted primarily at the level of the plasma membrane. The concentration of GTP gamma S that causes a half-maximal stimulation was 0.4 mu M. It is concluded that SOC I is a functional component of the NADPH oxidase.
J Biol Chem 1990 Sep 15
PMID:The activity of one soluble component of the cell-free NADPH:O2 oxidoreductase of human neutrophils depends on guanosine 5'-O-(3-thio)triphosphate. 220 87

The effects of anti-inflammatory drugs (acetylsalicylic acid, ASA; salicylic acid, SA; indomethacin, IM; hydrocortisone, HC) on the respiratory burst oxidase (NADPH oxidase) from human neutrophils in both whole cell and fully soluble (cell-free) systems were investigated. These drugs were found to inhibit the superoxide generation by human neutrophils exposed to phorbol myristate acetate in a whole cell system and the activation of superoxide-generating NADPH oxidase by sodium dodecyl sulfate in cell-free systems. Concentrations of these drugs required for 50% inhibition of the oxidase (ID50) were; ASA (more than 3.0 mM in the whole cell system and 1.35 mM in the cell-free system), SA (more than 3.0 mM in the whole cell system and 1.30 mM in the cell-free system), IM (180 microM in both systems) and HC (50 microM in the whole cell system and 40 microM in the cell-free system). In addition, these drugs time-dependently inhibited the activation of NADPH oxidase in cell-free systems. In the cell-free system, all of the drugs did not change the Km values for NADPH of the oxidase. These results suggest that these anti-inflammatory drugs, especially HC and IM, inhibit the reconstitution (activation) of neutrophil NADPH oxidase enzyme in the cell-free (whole cell) system.
Kansenshogaku Zasshi 1990 Sep
PMID:[Studies on relationships between the inhibition of human neutrophil NADPH oxidase by anti-inflammatory drugs and development of bacterial infections]. 224 89

Chronic granulomatous disease (CGD) is a heterogeneous group of inherited disorders of impaired superoxide production in phagocytes. The most common X-linked recessive form involves the CYBB locus in band Xp21.1 that encodes the membrane-bound beta subunit of the cytochrome b558 complex. Two autosomal recessive forms of CGD result from defects in cytosolic components of the phagocyte NADPH oxidase system, p47phox (NCF1) and p67phox (NCF2). By using human cDNA probes we have mapped the genes for these proteins to chromosomal sites. The combined data from Southern analysis of somatic cell hybrid lines and chromosomal in situ hybridization localize NCF1 to 7q11.23 and NCF2 to band 1q25. The NCF1 localization corrects an erroneous preliminary assignment to chromosome 10. In the mouse, the locus corresponding to NCF2 (Ncf-2) was mapped with somatic cell hybrid panels and recombinant inbred strains to mouse chromosome 1 near Xmv-21 within a region of conserved homology with human chromosome 1 region q21-q32. A second site, probably a processed pseudogene, was identified on mouse chromosome 13.
Am J Hum Genet 1990 Sep
PMID:Genes for two autosomal recessive forms of chronic granulomatous disease assigned to 1q25 (NCF2) and 7q11.23 (NCF1). 239 22

The neuropeptide substance P (SP), which has been suggested to mediate neurogenic inflammation, induces in human neutrophils the activation of the respiratory burst measured as O2 consumption and H2O2 production, and a cytochalasin B-dependent secretion of specific and azurophilic granules. The SP(4-11) fragment is much more stimulant than the entire molecule, whereas the SP(1-4) fragment is inactive. The respiratory and secretory response to SP are associated with an activation of phosphoinositide turnover, of Ca2+ influx and release from intracellular stores. Pertussis toxin inhibits 70% of the respiratory response and the residual 30% activity remains, even increasing 10-fold the concentration of the toxin. 1-(5-Isoquinolinesulfonyl)-2-methylpiperazine, a putative inhibitor of protein kinase C, does not modify the respiratory response to SP. Cytochalasin B significantly depresses the activation of the respiration by SP, whereas it moderately enhances the activation of phosphoinositide turnover and potentiates the increase of intracellular Ca2+ concentration. The results are discussed in relation to the receptor apparatus involved in SP activity, the signal transduction sequence activated by SP for the stimulation of NADPH oxidase, and the role of cell response to SP in the inflammatory process.
J Immunol 1988 Sep 15
PMID:Activation of human neutrophils by substance P. Effect on oxidative metabolism, exocytosis, cytosolic Ca2+ concentration and inositol phosphate formation. 245

Neutrophil NADPH oxidase is a multicomponent enzyme that is activated to generate superoxide anion and is defective in the cells of patients with chronic granulomatous disease. It requires both membrane and cytosolic components, the latter including 47- and 67-kDa proteins recognized by the polyclonal antiserum B-1. Immunoscreening of an induced HL-60 lambda ZAP cDNA library yielded seven cross-hybridizing cDNAs encoding the 47-kDa component. Fusion proteins of 22-50 kDa were recognized by B-1. Antiserum against a fusion protein recognized a 47-kDa protein in normal neutrophils but not in those from patients with autosomal chronic granulomatous disease who lack the 47-kDa cytosolic oxidase component. In a cell-free NADPH oxidase system full-length and C-terminal fusion proteins augmented superoxide generation and reconstituted the cytosolic defect of a patient missing the 47-kDa protein. The cDNA hybridized with a 1.4-kilobase mRNA from induced HL-60 cells. The longest cDNA contained an open reading frame encoding a protein of 41,440 Da with a calculated pI of 10.4, an N-terminal glycine, sites favorable for phosphorylation, a nucleotide binding domain, and a region of homology to the src protein kinases, phospholipase C, and alpha-fodrin. These structural features are pertinent to proposed functional roles of the protein in the respiratory burst oxidase.
Proc Natl Acad Sci U S A 1989 Sep
PMID:Cloning of the cDNA and functional expression of the 47-kilodalton cytosolic component of human neutrophil respiratory burst oxidase. 255 Sep 33

A superoxide-generating NADPH oxidase was solubilized from phorbol 12-myristate 13-acetate-activated human neutrophils with a mixture of sodium deoxycholate (0.125%, w/v) and Lubrol-PX (0.125%, v/v). The solubilized preparation contained FAD (577 pmol/mg of protein) and cytochrome b-245 (479 pmol/mg of protein) and produced 11.61 mol of O2-./s per mol of cytochrome b (340 nmol of O2-./min per mg of protein). On addition of NADPH, the cytochrome b-245 was reduced by 7.9% and the FAD by 38% in the aerobic steady state; NADH addition caused little steady-state reduction of cytochrome b and FAD. In this preparation, and several others, the measured rate of O2-. production correlated with the turnover of cytochrome b calculated from the extent of cytochrome b-245 reduction under aerobic conditions. Addition of diphenyleneiodonium abolished the reduction of both the FAD and cytochrome b-245 components and inhibited O2-. production. The haem ligand imidazole inhibited O2-. generation and cytochrome b reduction while permitting FAD reduction. These results support the suggestion that the human neutrophil NADPH oxidase has the electron-transport sequence: NADPH----FAD----cytochrome b-245----O2.
Biochem J 1989 Sep 01
PMID:Studies on the electron-transfer mechanism of the human neutrophil NADPH oxidase. 255 3


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