Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Saliva antimicrobial proteins may interact in a common system to influence the oral ecology. Clinical studies of antimicrobial protein action thus may require a multiple-protein approach. Multivariate statistical methods have been used to describe possible patterns of interaction for lysozyme, lactoferrin, salivary peroxidase and secretory IgA in stimulated parotid saliva. However, oral microbes are most likely to encounter antimicrobial proteins in mixed resting saliva. Relationships among levels of lysozyme, lactoferrin, salivary peroxidase, and secretory IgA therefore were investigated in whole saliva from 216 subjects, and an attempt made to relate interperson variation in those proteins to differences in health and status, and dental plaque accumulation and composition. All proteins were significantly (alpha = 0.05) correlated with each other (r = 0.38-0.52, p less than 0.001). There was only one axis of common variation among proteins, and that axis was significantly correlated (p less than 0.001) with total protein (r = 0.84) and flow rate (r = -0.56). That pattern deviated from the previous finding that proteins of acinar origin tended to vary independently from proteins of ductal origin in stimulated parotid saliva. The difference between parotid and whole saliva may reflect constitutive secretion of all proteins at low levels of stimulation. Common variation of unstimulated saliva proteins suggests that antimicrobial actions can be compared in subjects at population extremes. There were no significant associations between antimicrobial proteins in whole saliva and measures of health status or plaque accumulation. However, the proportions of Streptococcus sanguis were significantly correlated with lysozyme (r = -0.26), lactoferrin (r = -0.34), peroxidase (r = -0.30), total protein (r = -0.37), flow rate (r = 0.24) and principal-components scores (r = -0.33) in a subset of subjects (n = 85) where commercial biochemical tests were used to supplement species identification by colony morphology. Those findings may indicate that saliva antimicrobial proteins can affect the composition of dental plaque.
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PMID:Antimicrobial proteins in human unstimulated whole saliva in relation to each other, and to measures of health status, dental plaque accumulation and composition. 177 23

Immunoelectron microscopical studies performed in healthy human neutrophils showed the presence of glycosyl-phosphatidylinositol (GPI)-linked CD67 in granules. The use of immunogold double-labeling of CD67 and lactoferrin (LF; as marker for specific granules) or CD67 and myeloperoxidase (MPO; as marker for azurophilic granules) showed that CD67 occurred only in the specific granules. Furthermore, flow cytometry showed that CD67 has a low level of expression on the plasma membrane of these cells. In paroxsymal nocturnal hemoglobinuria (PNH)-affected neutrophils, CD67 was not detected in any intracellular compartment by immunoelectron microscopy, and flow cytometry showed no CD67 on the plasma membrane. In earlier studies, FcRIII was found on the plasma membrane, in electron-lucent vesicles, and in the Golgi complex of healthy neutrophils, and in the Golgi complex of some of the PNH-affected neutrophils. Here we have studied FcRIII in PNH-affected cells of three other patients and found, by immunoelectron microscopy, that the receptor can not be detected in these cells. However, flow cytometry showed that FcRIII was not completely absent on the plasma membrane of the affected cells, but that the level of expression on these cells was low. Thus, PNH patients can differ from one another with respect to the occurrence of affected neutrophils that have a detectable level of FcRIII in the Golgi complex. In summary, these findings show not only that the expression of the two GPI-linked proteins, CD67 and FcRIII, is markedly lower on the plasma membrane, but also that neither occurred in any of the intracellular compartments of affected neutrophils of the PNH patients examined in this study.
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PMID:Intracellular localization of glycosyl-phosphatidylinositol-anchored CD67 and FcRIII (CD16) in affected neutrophil granulocytes of patients with paroxysmal nocturnal hemoglobinuria. 183 13

Granulocyte activation during cardiopulmonary bypass (CPB), resulting in degranulation, may have adverse effects. Fresh whole human blood and priming solution was circulated through oxygenator/tubing sets coated with functional heparin (n = 7) and through uncoated sets (n = 7) in model CPB. Plasma concentrations of the primary granule protein myeloperoxidase (MPO) and the secondary granule protein lactoferrin (LF) were measured in radioimmunoassays, and the neutrophils were counted. After 120 min, seven to nine times baseline concentrations of LF (p less than 0.0001) were observed with both devices. Increases of MPO were also significant, but significantly larger (p less than 0.01) with the uncoated devices. There was an equivalent reduction in neutrophil numbers in both groups. MPO did not bind to heparin-coated Sephadex particles in gel chromatography. Thus, the heparin coating most likely prevented the release of potentially harmful primary granule proteins, indicating improved biocompatibility. Adhesion of neutrophils and exocytosis of LF, which may be involved in adhesion, were unaffected.
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PMID:Reduced granulocyte activation with a heparin-coated device in an in vitro model of cardiopulmonary bypass. 185 53

The purpose of this study was to determine whether granule fractions of human neutrophils differentially kill Actinobacillus actinomycetemcomitans and Capnocytophaga spp. Granule extracts were subjected to gel filtration, and seven fractions (designated A through G) were obtained. Under aerobic conditions at pH 7.0, representative strains of A. actinomycetemcomitans were killed by fraction D and variably by fraction B. In contrast, the Capnocytophaga spp. were killed by fractions C, D, F, and G. Fractions A (containing lactoferrin and myeloperoxidase) and E (containing lysozyme) exerted little bactericidal activity under these conditions. Anaerobiosis had little effect on the bactericidal activity of fractions D and F but inhibited that of fractions B and C. Electrophoresis, zymography, determination of amino acid composition, and N-terminal sequence analysis revealed that fraction C contained elastase, proteinase 3, and azurocidin. Fraction D contained lysozyme, elastase, and cathepsin G. Subfractions of C and D containing elastase (subfraction C4), a mixture of elastase and azurocidin (subfraction C5), and cathepsin G (subfraction D9) were found to be bactericidal. The bactericidal effects of fraction D and subfraction D9 against A. actinomycetemcomitans was not inhibited by heat inactivation, phenylmethylsulfonyl fluoride, or N-benzyloxycarbonylglycylleucylphenylalanylchloromethyl ketone. We conclude that (i) A. actinomycetemcomitans and Capnocytophaga spp. were sensitive to the bactericidal effects of different neutrophil granule components, (ii) both were sensitive to the bactericidal effects of neutral serine proteases, and (iii) the killing of A. actinomycetemcomitans by cathepsin G-containing fractions was independent of oxygen and neutral serine protease activity.
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PMID:Differential killing of Actinobacillus actinomycetemcomitans and Capnocytophaga spp. by human neutrophil granule components. 189 75

Many antimicrobial agents in human saliva are known to have bacteriostatic or bactericidal effects on cariogenic bacteria, in particular against Streptococcus mutans. Studies have usually been conducted with purified agents (proteins) in vitro. Very little proof exists to show that they also affect oral cariogenic flora in vivo. Recent studies have shown that some salivary systems can act synergistically against Streptococcus mutans. Such synergistic antibacterial activity is likely to exist in the human mouth. Attempts to enhance the anticariogenic properties of saliva have been made by adding antimicrobial proteins such as peroxidase, lactoferrin and lysozyme to oral health products. Although clinical evidence is still limited, the idea of using such antimicrobial agents--"natural antibiotics"--rather than synthetic agents against cariogenic bacteria seems promising.
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PMID:Salivary lysozyme, lactoferrin and peroxidases: antibacterial effects on cariogenic bacteria and clinical applications in preventive dentistry. 189 32

1. The biochemical properties of bovine, goat and sheep lactoferrin were compared. Molecular weights of the three lactoferrins were estimated to be 78,000 to 80,000 as determined by SDS-PAGE. By IEF, microheterogeneity was observed for all of them. 2. Partial antigenic identity was observed between bovine lactoferrin and goat or sheep lactoferrin by immunodiffusion method. 3. CD spectra at the u.v. region of the three lactoferrins suggested their similar secondary and tertiary structural profiles. 4. Reactivities with peroxidase-conjugated lectins showed that the carbohydrate compositions of the three ruminants' lactoferrin were the same but not identical with that of human lactoferrin.
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PMID:Comparison of bovine, sheep and goat milk lactoferrins in their electrophoretic behavior, conformation, immunochemical properties and lectin reactivity. 190 66

The unstimulated and stimulated whole saliva of patients with a very high caries experience were used for the determination of the flow rate, total protein, and the antibacterial proteins lysozyme, S-IgA and lactoferrin as well as the peroxidase and thiocyanate being components of the salivary peroxidase system. The concentration, the specific concentration and the secretion rate were calculated.
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PMID:[The quantitative determination of resistance factors in the saliva of patients with very high caries involvement]. 193 28

Granulocyte-mediated reactions such as opsonization, chemotaxis, and release of granulocyte myeloperoxidase and lactoferrin were studied in properdin-deficient and normal human serum incubated with serogroup A and W-135 meningococci. There were no differences between the sera when serogroup A meningococci were studied. Opsonic and chemotactic activity were impaired against serogroup W-135 meningococci in properdin-deficient serum. Restitution with properdin restored both activities. We found similar release of myeloperoxidase and lactoferrin from granulocytes challenged with serogroup A or W-135 meningococci in either sera. These findings are in accordance with the clinical observations of meningococcal infections caused by serogroup W-135 in properdin-deficient patients as well as the absence of infections caused by serogroup A meningococci.
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PMID:Granulocyte functions and Neisseria meningitidis: influence of properdin-deficient serum. 195 52

In this study of one-step and two different two-step non-competitive avidin-biotin assays (NABAs) were developed for the measurement of a monomeric antigen (lactoferrin, LF) using polyclonal antibodies and the detection of a heterodimeric antigen (lutropin. LH) using monoclonal antibodies. The assays were based on the use of performed complexes of biotinylated antibody and avidin-peroxidase conjugate. The detection limits and intra-assay CVs of the one- and two-step NABAs were 0.1-0.5 mg/ml and 2.6-5.1% for LF, and 0.1-0.2 IU/l and 2.3-3.7% for LH, respectively. The working range was 1-100 ng/ml for the LF assay and 1-100 IU/l for the LH assay. A linear relationship with high correlation coefficients (0.979-0.992 for LF-NABAs: 0.949-0.990 for LH-NABAs) and good agreement was observed between the one- and two-step assays and the corresponding three-step NABAs used as reference methods. However, under stringent conditions the one-step assay for heterodimeric antigen was found to be sensitive to interference. The results indicate that it is possible to perform the multistep NABAs using convenient one- and two-step protocols. The one- and two-step assays also retained the advantages of the avidin-biotin system: rapidity and good sensitivity.
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PMID:One- and two-step non-competitive avidin-biotin immunoassays for monomeric and heterodimeric antigen. 199 14

Exposure of the respiratory mucosa to oxygen-enriched air contributes to the generation of the lung damage in both adult respiratory distress syndrome and bronchopulmonary dysplasia. Recent work has identified the nasal submucosal gland as the source of diverse molecules important in mucous membrane host defense. We searched for the presence of antioxidant activity in nasal glandular secretions, the absence of which could possibly predispose to oxygen-induced injury. Employing a low molecular weight preparation of nasal secretions (a pooled concentrate passed over a 10,000-dalton molecular sieve), antioxidant activity capable of inhibiting both horseradish peroxidase and Fenton reagent reactions was discovered. The following lines of evidence suggest that submucosal glands are the source of this activity. (1) Antioxidant activity present in resting, baseline nasal washings is significantly increased after cholinergic stimulation either in response to topical methacholine or induced by a gustatory reflex. (2) Application of atropine reduced the antioxidant activity to baseline levels after either of the cholinergic stimuli. (3) Levels of antioxidant activity correlated very closely with the secretion of lactoferrin, a recognized product secreted solely from the serous cell of the submucosal gland. The antioxidant activity is due to novel, previously unrecognized molecules. This activity is found in nasal secretions containing molecules less than 10,000 daltons, is unaffected by N-ethyl maleimide (which inactivates glutathione, another low molecular weight antioxidant), is not associated with the capacity to reduce cytochrome c (as seen with ascorbic acid), and resides in the water soluble pool of secretions (in contrast to vitamin E, another putative antioxidant).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Human nasal glandular secretion of novel antioxidant activity: cholinergic control. 200 Oct 65


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