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

Glutathione and cysteine bind to the heme of lactoperoxidase, thereby causing a red shift of the Soret band which is reversed upon addition of iodide or guaiacol, two substrates for lactoperoxidase. The rate of formation of the enzyme-thiol complex is enhanced by diiodotyrosine. Binding of diiodotyrosine to lactoperoxidase does not cause a shift of the Soret band which indicates binding to the protein of the enzyme. At neutral pH and low ionic strength, lactoperoxidase is adsorbed on insolubilized diiodotyrosine (diiodotyrosine-agarose). It can be eluted at slightly increased ionic strength which shows that the binding is weak. In the presence of 5 X 10(-4) M glutathione, however, the binding of the enzyme to diiodotyrosine-agarose becomes much stronger so that a high salt concentration is required for elution. Lactoperoxidase is also adsorbed on insolubilized thiols (thiol-agarose). The presence of diiodotyrosine is not required for strong binding. A simple method for the preparation of lactoperoxidase from milk by affinity chromatography is based on the interactions of the enzyme with the two ligands, thiols and diiodotyrosine.
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PMID:Interaction of lactoperoxidase with thiols and diiodotyrosine. 3 12

A method has been developed for the dual staining of neutral complex carbohydrates in light microscopy. It combines a concanavalin A-peroxidase-diaminobenzidine (Con A-PO-DAB) method with a period acid-m-aminophenol-Fast Black salt K (PA-AP-FBK) sequence. With the combined method it is possible to stain alpha-D-glycosyl and alpha-D-mannosyl residues brown and 1,2-glycol groups of neutral complex carbohydrates blackish purple. The validity of the method has been confirmed with appropriate histochemical controls and enzyme digestions on test tissues.
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PMID:Concanavalin A-peroxidase-diaminobenzidine-periodic acid-m-aminophenol-fast black salt K: a method for the dual staining of neutral complex carbohydrates. 8 Mar 96

Recent experiments in primates indicate that the phenothiazine drug chlorpromazine hydrochloride inhibits both bile salt-dependent and -independent bile flow in a predictable fashion. Because a significant fraction of bile salt-independent bile flow is postulated to depend upon the activity of a canalicular membrane Na+,K+-ATPase, we have examined the effects chlorpromazine hydrochloride and its metabolites on the ATPase activities of canalicular-enriched rat liver plasma membranes. Chlorpromazine inhibited the activities of both Mg2+- and Na+,K+-ATPases with a linear dose-response relationship between 10 and 100 micronM. The inhibition of Na+,K+-ATPase was pH dependent, showing a maximal inhibition at pH 7.8. Over the pH range 7.0 to 8.2, the inhibition was significantly reduced with the addition of glutathione and was augmented under experimental conditions (ultraviolet irradiation and peroxidase-H2O2) that promote the formation of the chlorpromazine semiquinone free radical. The 7-hydroxychlorpromazine metabolite was as active an inhibitor as the parent drug; however, two sulfoxide metabolites, chlorpromazine sulfoxide and 7-hydroxychlorpromazine sulfoxide, were less effective inhibitors of Na+, K+-ATPase. Our data are consistent with the hypothesis that chlorpromazine cholestasis may be a result of a direct toxic effect on the ATPase activities of hepatic canalicular membranes. Our results further suggest that if chlorpromazine cholestasis occurs through an interaction with canalicular membrane ATPases, the degree of cholestasis may well be influenced by the extent of the conversion of the drug to its more active (free radical) or minimally active (sulfoxide) metabolites and by the local environment (pH and glutathione concentration) of the canalicular membrane.
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PMID:Effects of chlorpromazine hydrochloride and its metabolites on Mg2+- and Na+,K+-ATPase activities of canalicular-enriched rat liver plasma membranes. 14 85

At least three groups of polypeptides of the inner membrane of rat liver mitochondria have been shown to be exposed to the exterior surface by several techniques: lactoperoxidase-catalyzed iodination of mitochondria and inner membrane/matrix vesicles (mitoplasts), reaction of mitochondria and mitoplasts with the membrane-impermeable diazonium salt of sulfanilic acid, and controlled proteolysis of mitoplasts. These classes of proteins, separated by dodecyl sulfate gel electrophoresis, have polypeptide molecular weights of 73,000, 31,000, and 26,000. In addition, four other groups have been shown to be exposed to the exterior surface by at least one of these techniques: these components have polypeptide molecular weights of 130,000, 87,000, 16,000, and 10,500. A class of proteins, which makes up 50 to 60% of the total mitochondrial protein and which can be easily extracted from mitoplasts by freeze-thaw fractionation or other procedures designed to separate "matrix" protein from "membrane" protein, is shown not to be exposed to the outer surface of the inner membrane by these techniques. This class of proteins contains polypeptides of various molecular weights and includes the major 165,000 molecular weight polypeptide, identified with carbamyl phosphate synthetase.
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PMID:Protein asymmetry in the inner membrane of rat liver mitochondria. 17 48

A successive triple introduction of organophosphorus complexon DTPP (sodium-dicalcium salt of diethylene-triaminopentamethylphosphonic acid) in a dose of 500 mg/kg to albino male rats did not produce any marked effect on the composition of the peripheral blood. Some shortening of the initial period in blood coagulation process was noted. DTPP produced a moderate stimulation of the iron-containing enzymes (catalase, peroxidase, cytochroxidase) which led to an increased oxygen consumption. The blood serum and urine potassium, sodium and calcium content did not undergo any significant changes, while the magnesium concentration in the blood serum dropped by 37 pc and in the urine rose by as much as twice as compared to controls. This bears evidence to an elevated discharge of magnesium from the organism following the action of the DTPP complexon.
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PMID:[Effect of diethylene-triaminopentamethylphosphonic acid complex on various hematologic and biochemical indicators in experimental animals]. 19 88

Association of herpes simplex virus (HSV)-related antigens with chromosomes was demonstrated in human and mouse cells biochemically transformed by HSV that had been irradiated with ultraviolet light. This was accomplished by using peroxidase-anti-peroxidase immunological staining with rabbit antisera that had high neutralizing titers against both HSV-specific thymidine kinase activity and virus infectivity. Antisera-against HSV did not react with chromosomes of uninfected cells nor did normal sera react with any of the constitutents of biochemically transformed cells. Methanol/acetic acid treatment of biochemically transformed cells eliminated their nuclear staining for HSV-related antigens. In vitro binding of HSV-related antigens to chromosomes was demonstrated by incubating soluble antigens from high salt extracts of HSV-infected cells with methanol/acetic acid-fixed chromosomes of biochemically transformed or uninfected cells, followed by exposure to antiserum against HSV and peroxidase-anti-peroxidase staining. There was no staining when soluble extracts from uninfected cells were substituted for those from HSV-infected cells. The results show that cells biochemically transformed and lytically infected by HSV, respectively, contain antigens, which like the Epstein-Barr virus-associated nuclear antigen (EBNA), bind to chromosomes in vivo and in vitro.
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PMID:Binding to chromosomes of herpes simplex-related antigens in biochemically transformed cells. 21 Apr 57

Unique fusiform or spindle-shaped particles (Phi bodies) and rods with hydroperoxidase (catalase and/or peroxidase) activity are present in human granulocyte precursors only in acute myelogenous leukemia (AML). These newly recognized particles are much more numerous and prominent than Auer rods. They may be rapidly and readily identified using the microscope in marrow or peripheral blood films when the procedures recommended in this paper for fixation, incubation for hydroperoxidase demonstration in 3,3'-diaminobenzidine (DAB)/H2O2 medium, copper salt treatment and counterstaining (optional) with the Papanicolaou method are employed. Films prepared in the same manner but treated with benzidine/H2O2 medium for myeloperoxidase did not reveal these particles. We believe that Phi bodies are pathognomonic of AML since they are almost invariably present in AML patients with active disease. Their presence serves to distinguish AML from acute lymphocytic leukemia and from chronic granulocytic leukemia in blast crisis. Since the particles disappear in disease remission and reappear upon relapse, the recommended procedure is not only useful in diagnosis but in guiding therapy. When a very rapid diagnosis is needed, it is not necessary to counterstain the preparations, but the nuclei, cytoplasm and plasmalemma can readily be observed in the granulocyte precursors when they are counterstained by the Papanicolaou method. This treatment does not diminish the clarity of the Phi bodies and rods which stain by virtue of their peroxidatic activity. This cytochemical diagnostic procedure should be considered for adoption by hematology laboratories.
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PMID:The light microscopic demonstration of hydroperoxidase-positive Phi bodies and rods in leukocytes in acute myeloid leukemia. 21 54

The chromogen ABTS is the di-ammonium salt of 2,2'-azino-di[3-ethyl-benzthiazolin-sulfonic acid (6)] routinely used in the "glucose-oxidase assay" with the peroxidase (GOD-Perid method, Boehringer). 1. The specific property of ABTS to give a stable radical cation by oxidation with hydrogen peroxide in the presence of peroxidase was used to design a kinetic method, for enzyme-activity determinations. 2. The assay is suitable for the specific oxido-reductase using oxygen as acceptor, known also as "aerobic transhydrogenases" which are H2O2 formers (EC 1.-.3.-). 3. L-Amino acid: oxygen oxidoreductase (deaminating) (EC 1.4.3.2), was used throughout, being a representative model for such determinations.
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PMID:[A kinetic method for the determination of the activity of "aerobic transhydrogenases" (author's transl)]. 24 20

alpha1-Acid glycoprotein, a major human serum glycoprotein was detected and localized in human liver parenchymal cells of a biopsy specimen. A heavy metal salt containing fixative was required to retain sufficient antigen determinants of alpha1-acid glycoprotein in order to visualize this protein by the peroxidase-anti-peroxidase unlabeled antibody enzyme method.
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PMID:Immunohistochemical localization of alpha1-acid-glycoprotein in human liver parenchymal cells. 32 2

1. Lysophospholipase activity solubilized from bovine liver microsomes could be precipitated for more than 80% by antibodies evoked in rabbits against the purified bovine liver lysophospholipase II. 2. After solubilization of the microsomes in 1.5% sodium deoxycholate, an immunoprecipitate containing lysophospholipase II in enzymically active form could be isolated. 3. Microsomal lysophospholipase activity was completely inhibited by [3H]diisopropylphosphofluoridate. Enzyme labelled in this way was isolated by immunoprecipitation from control and chymotrypsin-treated microsomes. Sodium dodecyl sulfate disc gel electrohporesis of the immunoprecipitates showed that chymotrypsin treatment of intact microsomes had no influence on the molecular weight of the enzyme. 4. Attempts to label the lysophospholipase II in microsomes by lactoperoxidase catalyzed iodination or by reaction with the diazonium salt of [125I]iodosulfanilic acid were negative, although both techniques labelled other microsomal proteins efficiently. 5. Antibody absorption experiments gave no indication for the presence of lysophospholipase antigenic sites on the outside surface of microsomes. 6. These experiments are interpreted to indicate that lysophospholipase II is exclusively located at the luminal side of the microsomal membrane.
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PMID:Studies on the transverse localization of lysophospholipase II in bovine liver microsomes by immunological techniques. 50 78


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