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)

Effects of human lysozyme (HLZ) combined with thiocyanate (SCN-) ions on mutans streptococci, both in physiologic salivary concentrations, were studied. The bacteria were incubated for 75 min either in HLZ-supplemented sterilized human whole saliva (pH 5 and 7) or in neutral buffer in the presence or absence of HLZ (30 mg/l)-SCN- (1-5 mM) combinations. HLZ had no inhibitory effect on the viability of Streptococcus mutans, serotype c, either in saliva or in buffer, not even at pH 5, in the presence of salivary bicarbonate or in higher (up to 240 mg/l) concentrations of HLZ. In contrast, HLZ significantly decreased the viability of S. rattus in both media. HLZ also effectively blocked the lactic acid production of S. rattus but not that of S. mutans. Thiocyanate ions, which have been proposed to enhance the antimicrobial activity of lysozyme, did not affect the antibacterial activity of HLZ or HLZ-HCO3- combinations. It is concluded that the in vivo levels of SCN- ions, which constitute an integral part of the peroxidase antimicrobial system in saliva, may not be high enough to trigger the lysis of S. mutans by lysozyme in human saliva. The very low prevalence of S. rattus compared with S. mutans in human populations may be associated with their different susceptibility to lysozyme-mediated inhibition in saliva.
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PMID:Effects of lysozyme-thiocyanate combinations on the viability and lactic acid production of Streptococcus mutans and Streptococcus rattus. 188 53

Increased synthesis of so-called glucose-regulated proteins (grp) of 78 and 94 kDa occurs in mammalian cells exposed to a variety of agents, including 2-mercaptoethanol, tunicamycin, agents which perturb calcium homeostasis, and amino acid analogs. Herein we describe a number of properties of 94-kDa grp (grp 94) and present a method for its purification to homogeneity. The protein, within the endoplasmic reticulum (ER), is modified by the addition of high mannose-containing oligosaccharides. The predicted amino acid sequence of grp 94, as determined by others, has revealed the protein to contain a putative transmembrane domain near its amino terminus, but in addition, a potential endoplasmic reticulum retention sequence (KDEL) at its COOH terminus. Consequently, the question of whether grp 94 exists as a transmembrane or luminal protein of the ER remains controversial. Results using isolated microsomes subjected to either limited proteolysis or lactoperoxidase-mediated iodination were consistent with the idea that the grp is a transmembrane protein. On the other hand, using the method of sodium carbonate extraction, grp 94 exhibited properties of both a luminal and integral membrane protein. These results raise the question of whether there exist two different forms of grp 94 within the ER.
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PMID:Characterization and purification of the 94-kDa glucose-regulated protein. 190 Aug 37

For various reasons extraction of proteins from plant material is difficult. In particular phenolic compounds and polyanionic cell-wall mucilages render conventional procedures of extraction and purification much more difficult. In this respect, aqueous polymer two-phase systems are presented as a powerful technique in extraction of vanadate-dependent bromoperoxidases from the brown macroalga Laminaria digitata, a seaweed extremely rich in mucilages. Little bromoperoxidase activity was obtained when fresh thallus material was extracted in Tris buffer. Extraction from freeze-dried and powdered material was more efficient but only satisfactory when partitioning in an aqueous polymer two-phase system was employed. Among several two-phase systems tested, one composed of poly(ethylene glycol) (PEG 1550) and potassium carbonate proved most successful (phase system-1). A rapid and efficient extraction procedure was developed with special regard for suitability in large scale processes. Staining for catalytic activity after PAGE revealed a pattern of several bromoperoxidase isoforms. Bromoperoxidases extracted in phase system-1 were fractionated into two groups of isoforms by partitioning in a second system (phase system-2) indicating that isoforms from both groups differ significantly in surface properties. Subsequently, one purification step by hydrophobic interaction chromatography was sufficient to remove residual non-peroxidase proteins as well as remaining polysaccharides from bromoperoxidases of both groups. Thus, consideration of aqueous two-phase systems as a technique for extraction and purification of plant proteins can be recommended, whenever inconveniant amounts of phenolic compounds, mucilages or pigments are present.
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PMID:Extraction of proteins from material rich in anionic mucilages: partition and fractionation of vanadate-dependent bromoperoxidases from the brown algae Laminaria digitata and L. saccharina in aqueous polymer two-phase systems. 199 Nov 50

The usefulness of 1-naphthol as substrate for horseradish peroxidase (HRP) in immunohistochemistry was studied using the peroxidase-antiperoxidase (PAP) and avidin-biotin-complex (ABC) methods in the demonstration of glial fibrillary acidic protein (GFAP), vimentin, carbonic anhydrase C (CA.C), and factor VIII-related antigen (FVIII/RAg) in central nervous tissue and cerebral tumors. In the presence of ammonium carbonate, 1-naphthol is oxidized by HRP and hydrogen peroxide, producing a fine gray-violet precipitate. The oxidation product of 1-naphthol proved capable of binding a great number of basic dyes. For each stain the final reaction product had a characteristic color that was different from the spontaneous color of the dye and from the color displayed by nuclei. The final color obtained with this procedure was alcohol resistant and could be mounted in solvent-based mounting media. The results obtained with the 1-naphthol basic dye (1-NBD) method were compared with those obtained using the diaminobenzidine (DAB) reaction in the demonstration of GFAP-positive astrocytes. The DAB reaction produced a more intense staining but also a coarser precipitate than the 1-NBD reaction. The 1-NBD procedure showed more morphological detail of fine structures and did not obscure nuclei and mitosis. The very low toxicity of 1-naphthol compared with DAB (a suspected carcinogen) is an important advantage of the 1-NBD method, as is its high specificity and sensitivity.
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PMID:1-Naphthol basic dye (1-NBD). An alternative to diaminobenzidine (DAB) in immunoperoxidase techniques. 241 92

We have examined the development of microglia in the rat retina, using a peroxidase-conjugated lectin derived from Griffonia simplicifolia. Retinas were studied from animals aged from E(embryonic day)12, just after the invagination of the optic cup and prior to the closure of the optic fissure, to adulthood. The lectin also proved a sensitive label for the endothelial cells of the developing retina. Our results provide some support for the view that microglia are derived from the monocyte-macrophage series of blood cells. At E12, most labeled cells were found at the vitreal surface, suggesting that they had come from the hyaloid circulation, while some had entered the retina and appeared to be migrating towards its ventricular surface. From E14 to early postnatal ages, most labeled cells had processes and resembled the amoeboid microglial cells described in silver carbonate staining studies (Ling, 1982). The number of labeled cells rose from about 700 to E14 to a peak of about 27,000 at P(postnatal day)7, and fell to about 19,600 by P12. As early as E16, a regularity was apparent in the distribution of microglial cells over the surface of the retina, the cells tending to avoid each other. Microglial cells are found throughout the thickness of the very young retina, but as the layers of the retina differentiate, they are increasingly restricted to the inner half of the retina. Our findings indicate that microglia enter the retina well before the period of neuronal death, making it unlikely that they invade the retina solely in response to cell death. Our results confirm however that, once in the retina, microglia become associated with, and appear to phagocytose, the pyknotic debris which appears during the period of neuronal death. They also become closely associated with the retinal vasculature. In the adult, the intensity of the labeling of microglia was much reduced. Those cells which were labeled appeared more differentiated, resembling the "resting microglia" described in earlier studies.
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PMID:The appearance and distribution of microglia in the developing retina of the rat. 248 81

Addition of EGF to human epidermoid carcinoma A431 cells increases the rate of fluid-phase pinocytosis 6-10-fold as measured by horseradish peroxidase uptake (Haigler, H.T., J. A. McKanna, and S. Cohen. 1979. J. Cell Biol. 83:82-90). We show here that in the absence of extracellular Na+ or in the presence of amiloride the stimulation of pinocytosis by EGF is substantially reduced. Amiloride had no effect on the endocytosis of EGF itself or of transferrin, demonstrating that the receptor-mediated endocytotic pathway operated normally under conditions that blocked stimulated pinocytosis. Amiloride blocked EGF-stimulated pinocytosis in both HCO3(-)-containing and HCO3(-)-free media. The EGF-stimulated pinocytotic activity can frequently be localized to areas of the cell where membrane spreading and ruffling are taking place. These results demonstrate that (a) EGF induces a distinct amiloride-sensitive endocytotic pathway on A431 cells; (b) occupied EGF receptors do not utilize this pathway for their own entry; (c) endocytosis of occupied EGF receptors is not in itself sufficient to stimulate pinocytosis.
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PMID:Distinct endocytotic pathways in epidermal growth factor-stimulated human carcinoma A431 cells. 255 6

A new enzyme linked immunosorbent assay (ELISA) method was assessed in parallel with an indirect immunofluorescence assay (IFA) for the serological testing of specimens submitted for detection of Lyme disease. Wells of an ELISA microtitre plate were coated with sonicated whole cells of Borrelia burgdorferi in carbonate buffer. After overnight incubation at 4 degrees C the plates were washed three times, then incubated at 37 degrees C for an hour sequentially with a blocking solution, diluted test serum, anti-human IgG horseradish peroxidase conjugate, and finally for half an hour at room temperature with o-phenylenediamine substrate before being read at 492 nm. Absorbance results were converted into arbitrary ELISA units. Of a total of 1760 sera, 146 (8.3%) were positive: of these 92 (63%) were positive by both methods, five (3.4%) by IFA alone, and 49 (33.6%) by ELISA alone. The ELISA was better suited for testing large numbers of specimens and easier to interpret than IFA.
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PMID:Comparison of immunofluorescence and enzyme linked immunosorbent assays for diagnosing Lyme disease. 267 Oct 54

The carcinogenic activity of the synthetic estrogen hexestrol was measured in male Syrian hamsters. Between 90% and 100% of the animals treated with hexestrol or with 3',3",5',5"-tetradeuteriohexestrol, implanted subcutaneously as 25-mg pellets, were found with renal carcinoma after 6-7 months. In vitro hexestrol metabolism, mediated by phenobarbital-induced rat liver microsomes, led to the formation of 3'-hydroxyhexestrol. This metabolite was identified by comparison with authentic reference material synthesized by oxidation of hexestrol with Fremy's salt. Diethylstilbestrol could not be detected as a metabolite. In urine of male Syrian hamsters, 3'-hydroxyhexestrol, 3'-methoxyhexestrol, 1-hydroxyhexestrol, and other hydroxylated and/or methoxylated hexestrol metabolites were identified. Again, diethylstilbestrol was not detectable as a hexestrol metabolite in vivo. The reactivity of 3'-hydroxyhexestrol was then studied to determine if this catechol estrogen played a role in hexestrol carcinogenicity. Horseradish peroxidase catalyzed the oxidation of 3'-hydroxyhexestrol to 3',4'-hexestrol quinone. This oxidation reaction could also be carried out non-enzymatically using silver oxide or silver carbonate on celite as oxidants. The quinone was unstable (t1/2 in methylene chloride: 53 min). It reacted with sulfur-containing compounds such as mercaptoethanol by Michael addition to form 3'-(2-hydroxyethylthio)-5'-hydroxyhexestrol. 3',4'-Hexestrol quinone reacted with simple amines such as ethylamine to form N-ethyl-aminohexestrol. The chemical reactions described above were carried out to test the reactivity of identified or suspected metabolic intermediates of hexestrol. It was concluded that carcinogenicity of hexestrol was not based on its conversion to diethylstilbestrol. Rather, catechol estrogen formation may be necessary for the carcinogenic action of hexestrol in analogy to events observed earlier with estradiol.
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PMID:Carcinogenicity and metabolic activation of hexestrol. 299 30

Conditions of the enzyme immunoassay for the detection of HSV-I by the "sandwich"-method at all stages of the testing were optimized using monoclonal antibodies (monoAB). When identical concentrations of monoclonal antibodies and durations of their adsorption on polystyrene plates were used, the signal in EIA (A405) with carbonate buffer was by 30% higher than that for PBS. A similar increase in the signal was observed at a temperature of incubation of 37 degrees C as compared with that at 4 degrees C. Even during 18-hour incubation at 37 degrees C no inactivation of monoAB occurred. It was further shown that saturation of the surface of wells with protein was achieved at a concentration of monoAB 5-10 micrograms/ml, and under these conditions the optimal dilution of the conjugate was that corresponding to antibody concentration of 1.5 micrograms/ml. When ABDC peroxidase and 5-aminosalycilic acid were used as the substrate, the presence of HSV-I was regularly detected even with a concentrated virus preparation diluted 500-1000-fold (corresponding to approximately 5.0 1g TCID50).
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PMID:[Development of an immunoenzyme test for determining herpes simplex type 1 virus using monoclonal antibodies]. 303 3

A comparison of the effects of different factors on the sensitivity of Western blotting technique to detect monoclonal antibodies is described. The major improvements were obtained by: A) renaturating the antigen in the gel before transferring it in carbonate buffer at pH 10 onto nitrocellulose and B) using alkaline-phosphatase-conjugated second antibody instead of peroxidase-conjugated second antibody.
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PMID:Improvements of Western blotting to detect monoclonal antibodies. 330 95


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