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:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A method using p-benzoquinone for coupling antigens and antibodies to enzymes and erythrocytes is described. The method involves the treatment of proteins (or polysaccharides) at pH 6 or 7 with an excess of p-benzoquinone. After removal of the unreacted reagent by gel filtration, the "activated" proteins were coupled at pH 8-9 with enzymes or erythrocytes. Biological activities of the proteins were not substantially modified by this treatment since 80-100% of the antigen binding capacity was found to be preserved in p-benzoquinone treated antibodies or Fab fragments. Anti-Ig antibodies (or Fab) were coupled by this procedure to peroxidase, alkaline phosphatase, lactoperoxidase, glucose oxidase and beta-galactosidase, and the conjugates obtained were found to be highly effective in detecting intracellular Ig by immunohistochemical techniques. Erythrocytes coated with sheep anti-mouse Ig antibody or Fab were used to titrate by passive hemagglutination serum Ig. The same erythrocytes were employed to detect by plaque assay mouse Ig secreting cells. Erythrocytes coated with peroxidase, alkaline phosphatase, bovine serum albumin, ribonuclease, Salmonella polysaccharide (B 27 +) and pneumoccocal polysaccharide SIII were employed to titrate serum antibody by passive hemagglutination and hemolysis and to detect mouse antibody secreting cells by plaque assay. All the antigens and antibodies coated erythrocytes prepared gave highly satisfactory and reproducible results.
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PMID:A new method using p-benzoquinone for coupling antigens and antibodies to marker substances. 0 79

Rat and rabbit IgG immunoglobulins conjugated to horseradiah peroxidase as a histochemical marker bind at 0 degrees C to the luminal surface of absorptive cells in isolated segments of jejunum from 10-12-day old rats. Binding is observed at pH 6.0, near the normal luminal pH of the duodenum and jejunum at this age, but not at pH 7.4. Furthermore, no binding occurs when cells are exposed at pH 6.0 to either free peroxidase or peroxidase conjugated to chicken or sheep IgG immunoglobulins or bovine serum albumin. The sensitivity of binding to pH suggests a means whereby immunoglobulins which are selectively absorbed by the cells can be released efficiently at the abluminal surface.
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PMID:pH-dependent binding of immunoglobulins to intestinal cells of the neonatal rat. 1 Dec 23

After primary immunization of mice, rats and rabbits with antigens (horse radish peroxidase, bovine serum albumin and muchroom tyrosinase) emulsified in complete or incomplete Freund's adjuvant, both cells synthesizing immunoglobulin without detectable antibody function and antibody-producing cells were detected. The first cells which appeared were synthesizing and secreting IgG and IgM immunoglobulins without antibody function. These cells were progressively replaced by cells synthesizing and secreting antibodies. In some plasma cells of mice, rats and rabbits immunized with peroxidase, antibody activity was detected only in restricted areas of the cytoplasm ; the remainder contained antigenic determinants of immunoglobulins. After secondary immunization the results were the following: in mice, both cells containing immunoglobulins without antibody function and antibody-containing cells appeared simultaneously and they were present in equal amount; in rats, only the antibody-containing cells were present in high number. Immunizations performed using different protein antigens (horse radish peroxidase, human and bovine serum albumin, aggregated and desaggregated human IgG, and ovalbumin) injected as a solution in saline have shown that after antigenic stimulation both populations of cells appeared, their number depending on the dose of the antigen injected. Further experiments carried out with tolerant mice, with germ-free animals and with "B" mice have shown that the appearance or not of antibody-producing cells was always related with respectively the presence or absence of cells synthesizing immunoglobulins without detectable antibody function. Finally experiments performed on rabbits have shown that some cells containing immunoglobulins without antibody function share idiotypic determinants in common with cells synthesizing antibodies.
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PMID:Development of immuneeoglobulin and antibody-forming cells in different stages of the immun response. 6 Sep 8

Previous investigations have shown that tetanus toxin is transported retrogradely in all peripheral neurons whereas the transport of NGF is confined to adrenergic and sensory neurons. Other macromolecules with molecular weights and general physiochemical properties similar to NGF and tetanus toxin (e.g., cytochrome C, insulin, horseradish peroxidase and bovine serum albumin) are not transported to a detectable extent if injected in comparable molar concentrations. For tetanus toxin, which is transported in all peripheral neurons, it has be assumed that it's retrograde transport depends on properties common to all neurons. In view of the relatively high ganglioside content of the neurons and the high affinity of tetanus toxin for the trisialoganglioside GT1, we studied the influence of gangliosides on the retrograde transport of tetanus toxin as compared to NGF. We included into the study cholera toxin which is known to have a high affinity for the monosialoganglioside GM1 and wheat germ agglutinatinin, a lectin with specific affinity for glycoproteins with N-acetyl-glucosamine residues. Both cholera toxin and wheat germ agglutinin were transported efficiently in all peripheral neurons. Preincubation of 125I-cholera toxin with monosialoganglioside GM1 completely blocked its retrograde axonal transport. The transport of NGF and wheat germ agglutinin was affected neither by various purified gangliosides nor by a mixture of bovine brain gangliosides. The transport of tetanus toxin was only reduced by 50% both by the trisialoganglioside GT1 and the bovine ganglioside mixture.
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PMID:Role of gangliosides in the uptake and retrograde axonal transport of cholera and tetanus toxin as compared to nerve growth factor and wheat germ agglutinin. 7 Feb 59

Thyrotropin-releasing hormone (TRH) immunoreactivity was localized in the rat anterior pituitary with rabbit anti-TRH sera and the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique. Stain was present in secretory granules of cells possessing morphological characteristics of thyrotropes, gonadotropes and lactotropes. Antibody absorption studies with anti-TRH sera absorbed with TRH, 3 diastereoisomeric analogues of TRH, gonadotropin-releasing hormone (GnRH), bovine serum albumin, thyrotropin, prolactin, adrenocorticotropin, luteinizing hormone, follicle stimulating hormone were performed to determine the specificity of the staining reaction. Only absorption with TRH resulted in a significant reduction in staining intensity. In vitro experiments were then begun with hemipituitaries to ascertain if intrapituitary TRH might originate by sequestration of exogenous, plasma membrane bound TRH or by de novo synthesis. The results suggest that anterior pituitary TRH is of endogenous origin.
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PMID:Endogenous thyrotropin-releasing hormone in the anterior pituitary: sites of activity as identified by immunocytochemical staining. 8 70

Viable leucocytes obtained fresh from normal human subjects were shown to be able to catalyse the in vitro iodination of bovine serum albumin (BSA) in a H2O2-generating system. The rate and degree of iodination were greatly improved by sonication of the cells. A balanced salt solution was a more favourable medium than phosphate buffer for the myeloperoxidase (MPO)-catalysed iodination of whole cells and sonicated cells. Reactions known to be catalysed by other peroxidases (e.g. thyroid peroxidase (TPO) and lactoperoxidase), such as inorganic iodide exchange for organic iodine in di-iodotyrosine (DIT) and the de-iodination of thyroxine (T4), were also catalysed by the sonicated leucocyte suspension in the system used. The non-steroidal anti-inflammatory drugs indomethacin, flufenamic acid and naproxen were far less effective inhibitors of MPO-catalysed BSA iodination of sonicated leucocytes at concentrations expected in blood with therapeutic dose levels than was observed earlier with TPO-catalysed in vitro iodination of BSA. The antithyroid drug methylmercapto-imidazole (MMI) inhibited in vitro MPO-catalysed 131I delabelling of 131I-DIT at all concentrations between 10(-7) and 10(-2)M, whereas 131I-T4 delabelling was markedly stimulated at the same drug concentrations. On the other hand, 125I incorporation into 131I-DIT was not affected by increased concentrations of MMI up to 10(-5)M. At higher drug concentrations the drug caused inhibition of MPO-catalysed exchange of inorganic iodide for organic iodine in DIT.
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PMID:The influence of non-steroidal anti-inflammatory and antithyroid agents on myeloperoxidase-catalysed activities of human leucocytes. 8 4

The bilirubin-binding ability of human alpha-fetoproteins, which were purified from fetal cord serum and from ascites fluid of a hepatoma-bearing patient, was examined by the difference spectrum and the Jacobsen peroxidase methods. The difference spectrum observed as a result of the specific binding of bilirubin to alpha-fetoprotein had a maximum at 482 nm, and this pattern was quite similar to that observed for serum albumin. The result obtained by the difference spectrum method showed that 1 mol of each alpha-fetoprotein bound 1 mol of bilirubin at pH 8.3 and that the dissociation constants of the complexes of bilirubin with fetal alpha-fetoprotein and hepatoma-derived alpha-fetoprotein were 2.6 x 10(-7) and 5.0 x 10(-7) M, respectively. The Jacobsen enzymatic method using horseradish peroxidase gave the same values for molar binding ratios and similar dissociation constants, 7.1 x 10(-7) M for fetal alpha-fetoprotein and 7.4 x 10(-7) M for hepatoma-derived alpha-fetoprotein. These results indicate that alpha-fetoprotein may function as a carrier protein for bilirubin as has been shown for serum albumin.
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PMID:alpha-Fetoprotein as a carrier protein in plasma and its bilirubin-binding ability. 8

Rat IgM and IgG was determined by mechanized "sandwich" enzyme-linked immunosorbent assay (ELISA) using peroxidase labeled anti-rat-IgM and -IgG. Linear ranges in standard curves of a reference rat serum had a slope similar to the slopes found with sera of 25 rats of various age. IgM and IgG measurements by ELISA in these sera correlated well with results obtained by single radial immuno-diffusion (SRID). In addition, the precision of the enzyme immunoassay was the same as obtained with the SRID. Compared with SRID, ELISA is less time consuming and the amount of antiserum used in the macro-ELISA is one order of magnitude lower; and again 10 times lower in the mechanized micro-ELISA that is currently being developed. In conclusion, the ELISA is a specific, reliable, sensitive, and economic method for routine measurement of rat serum IgG and IgM e.g. in toxicity studies. In the second part of this study, ELISA and the passive hemagglutination test were compared to determine the primary and secondary antibody response to E. coli lipopolysaccharide (LPS) and tetanus toxoid in rats. In the ELISA, the antigens were bound to the wells of polystyrene microplates. Tetanus toxoid was coated directly, LPS after complexing with methylated bovine serum albumin. After incubation with dilutions of the rat sera, the amount of antibody bound to the solid phase was quantified by means of peroxidase-labeled antiimmunoglobulin. The specificity of the enzyme immunoassay was tested by absorption of the sera with the respective antigens. ELISA proved to be more sensitive than the hemagglution reaction, except when titers were determined during the secondary response to tetanus toxoid. Besides its specificity and sensitivity, ELISA is a convenient method for measuring both IgM and IgG antibodies. Finally, evidence is presented that in the rat, the humoral immune response to LPS is a thymus-independent phenomenon. Thus, by using the antibody response to LPS and tetanus toxoid in function studies of the immune system of the rat, insight can be obtained in the thymus-independent and thymus-dependent humoral immune response.
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PMID:Quantification of total IgM and IgG and specific IgM and IgG to a thymus-independent (LPS) and a thymus-dependent (tetanus toxoid) antigen in the rat by enzyme-linked immunosorbent assay (ELISA). 11 Feb

A new method for quantifying class-specific antibodies is presented. The method has been named Diffusion-In-Gel-Enzyme-Linked-ImmunoSorbentAssay (DIG-ELISA), and is briefly as follows. Antiserum ia allowed to diffuse from wells in a gel layered over an antigen-coated plastic surface. The gel is then removed and the preparation is incubated with enzyme-conjugated anti-immunoglobulin. The enzyme is then visualised in situ by a colour reaction produced by pouring a substrate-containing gel over the plastic surface. Bovine serum albumin and rabbit-anti-BSA were used as a model system, and horseradish peroxidase or alkaline phosphatase as enzymes for visualization.
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PMID:Diffusion in gel-enzyme linked immunosorbent assay (DIG-ELISA): a simple method for quantitation of class-specific antibodies. 11 55

Rat liver lysosomes were lysed and subfractionated by differential centrifugation through 0.2M-NaCl to yield a membranous pellet. This membrane fraction contains less than 20% of the lysosomal protein, adenosine triphosphatase activity of about 1.2mumol/min per mg of protein, 120nmol of thiol groups/mg of protein and at least 16 protein and glycoprotein bands on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The gel patterns of membranes isolated from lysosomes after treatment with (1) [125I]iodidehydrogen peroxide-lactoperoxidase, (2) toluene 2,4-di-isocyanate-activated bovine serum albumin, (3) trypsin and (4) subtilisin indicate that most of the membrane proteins are exposed to the cytoplasm. These exposed proteins are candidates for intracellular receptors which recognize either substances that are to be degraded or vesicles containing those substances.
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PMID:Properties of the membrane proteins of rat liver lysosomes. The majority of lysosomal membrane proteins are exposed to the cytoplasm. 15 36


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