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)

The principle amatoxin, alpha-amanitin, is found to be extremely sensitive toward lactoperoxidase catalyzed degradation, rather than iodination, of the indole nucleus. Extensive attenuation of inhibitor potency against eukaryotic DNA-dependent RNA polymerase II accompanies the treatment of alpha-amanitin with lactoperoxidase, iodide and hydrogen peroxide.
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PMID:alpha-Amanitin: inactivation by bovine lactoperoxidase. 10 6

Reverse transcriptase activity was measured by incorporation of dUMP linked to digoxigenin into a suitable template-primer molecule. Incorporation was monitored by using peroxidase-conjugated Fab fragments directed against digoxigenin. The standard assay measuring incorporation of radiolabeled nucleotides into acid-precipitable material was compared with this new immunochemical assay with regard to its usefulness for testing inhibitors of reverse transcriptase.
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PMID:Measurement of HIV-1 reverse transcriptase by a nonradioactive assay system. 128 11

Partial amino acid sequence of human myeloperoxidase was determined, and a 41-base oligonucleotide containing deoxyinosines at four positions was chemically synthesized. By using the oligonucleotide as a probe, cDNA clones for human myeloperoxidase were isolated from a cDNA library constructed with mRNA from human promyelocytic leukemia HL-60 cells. One of the clones containing a 2.6-kilobase insert was subjected to nucleotide sequence analysis. The sequence was found to contain an open reading frame, 2,235 nucleotides coding for a protein of 745 amino acids with a calculated Mr of 83,868. The heavy chain of myeloperoxidase, consisting of 467 amino acids, was located on the COOH terminus half of the protein. The RNA specified by the cDNA was prepared using SP6 RNA polymerase and translated in rabbit reticulocyte lysates, and the product was identified as human myeloperoxidase by immunoprecipitation with rabbit anti-human myeloperoxidase antibody. By Northern hybridization analysis of RNA from leukemic cells, it was shown that myeloperoxidase mRNA is abundantly expressed in human promyelocytic HL-60 and mouse myeloid leukemia NFS-60 cells. Furthermore, the results of Southern hybridization analysis of human genomic DNA suggest that there are one or two genes for myeloperoxidase in the human haploid genome.
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PMID:Molecular cloning and characterization of cDNA for human myeloperoxidase. 302 27

We have developed general methods for joining together, via cleavable disulfide bonds, either two unprotected polynucleotides or a polynucleotide and a peptide or protein. To join two oligonucleotides, each is first converted to an adduct in which cystamine is joined to the 5'-terminal phosphate of the oligonucleotide by a phosphoramidate bond. The adducts are mixed and reduced with dithiothreitol. The dithiothreitol is then removed by dialysis. Oxidation by atmospheric oxygen occurs to yield the required dimer. To join an oligonucleotide to a cysteine-containing peptide or protein, the 5'-cystamine oligomer is first converted to a 2'-pyridyldisulfide adduct and then reacted with an excess of the peptide or protein. If the peptide does not contain a free cysteine residue, it is first treated with iminothiolane to introduce one or more sulfhydryl groups. We have used these procedures to join a 16 mer deoxynucleotide probe and MDV-1 RNA, a substrate of Q beta RNA polymerase. This adduct hybridizes with a complementary target DNA. We have also joined a 16mer probe to peroxidase and MDV-1 RNA to human IgG. The probe-peroxidase adduct maintains enzymatic activity and the MDV-1 RNA-IgG adduct binds to a complementary anti-IgG.
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PMID:Ligation of oligonucleotides to nucleic acids or proteins via disulfide bonds. 337 70

The localization of foot-and-mouth disease viral-induced RNA polymerase has been determined in situ and in partially fractionated cell components by using polymerase antisera tagged with either peroxidase or ferritin. Electron microscopic examination revealed the polymerase to be heavily concentrated on membranes of the smooth membranous vacuoles (SMV) which are newly formed during infection and which were previously shown to be the site where newly synthesized viral RNA appeared. Polymerase antigen was also seen to be associated with the endoplasmic reticulum (ER), the assumed site of original synthesis, and to a lesser extent with mitochondria and the Golgi apparatus. There was no significant polymerase attachment to nuclear and plasma membranes.
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PMID:Association of foot-and-mouth disease virus induced RNA polymerase with host cell organelles. 631 90

Small numbers of CD34+ primitive hematopoietic progenitors are found in normal human peripheral blood. These cells differentiate to myeloid or lymphoid lineage under the influence of different growth factors. We investigated the effects of IL5 and other growth factors on the production of eosinophils from peripheral blood CD34+ cells. CD34+ cells were enriched from normal donors by apheresis and positive selection using an affinity column and plated in agarose with different combinations of cytokines. At 14 days of growth a triple stain technique was used to identify eosinophil, monocyte, and neutrophil colonies. IL5 alone did not support colony growth from CD34+ cells. In contrast, GM-CSF and IL3 alone or together without added IL5 supported the generation of more than 50% pure eosinophil colonies. Addition of IL5 did not change the total number of colonies, but increased the fraction of pure eosinophil colonies to over 70%. Addition of G-CSF reduced the percentage of eosinophil colonies and increased the percentage of neutrophil colonies. Under the best conditions for eosinophil colony growth (IL3+GM-CSF+IL5), the addition of interferon-alpha or bacterial lipopolysaccharide inhibited colony growth by 51 and 58%, respectively. Addition of interferon-gamma, tumor necrosis factor-alpha, or dexamethasone had no effect on eosinophil colonies. Since IL5 alone did not support colony growth from CD34+ cells, we determined when IL5-responsive cells appeared in culture. Cells were grown initially with IL3 + GM-CSF in suspension, washed, and plated in agarose with IL5 alone. Only when progenitors were grown at least 3 days could IL5 serve as the single growth factor supporting pure eosinophil colony growth (47 colonies/10(4) cells plated at Day 3 and 134 colonies/10(4) cells at Day 7). We used neutralizing anti-IL5 antibodies to demonstrate that this late acting IL5 growth effect was specific, and that differentiation of eosinophils in the presence of IL3 + GM-CSF was IL5 independent. Using reverse-transcriptase polymerase chain reaction, the mRNA encoding the eosinophil-specific protein eosinophil peroxidase (EPO) was not detected in Day 0 CD34+ cells, but was demonstrated by Day 3 of culture. We conclude that within 3 days of culture, peripheral blood CD34+ cells can become committed to the eosinophil lineage as demonstrated by responsiveness to IL5 and production of EPO transcripts.
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PMID:Modulation of growth and differentiation of eosinophils from human peripheral blood CD34+ cells by IL5 and other growth factors. 753 Nov 18

A simple multiplex riboprobe system for detection of virulent Yersinia enterocolitica was developed using a pool of RNA probes specific for various chromosomal and plasmid-borne virulence gene sequences (yadA, virC, ail and yst). Riboprobes were synthesized by a rapid, simple and efficient technique involving in vitro transcription of polymerase chain reaction-generated templates incorporating bacteriophage T7 RNA polymerase promoter sequences in one of the priming oligonucleotides. After dot blotting target DNA samples on nitrocellulose and hybridization with the riboprobes, the RNA: DNA hybrids formed were detected by a simple immunoenzymic assay involving sequential reactions with an anti-RNA : DNA hybrid monoclonal antibody, anti-mouse Ig-peroxidase conjugate and chromogenic or chemiluminescent enzyme substrate solution. This multiplex riboprobe system targeting both chromosomal and plasma-borne sequences permitted detection of virulent Y. enterocolitica, regardless of plasmid loss during handling of cultures, and was unreactive with a virulent Y. enterocolitica, other Yersinia and other bacteria. This system resulted in a significant improvement in the limit of detection in comparison to that obtained with individual probes.
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PMID:Multiplex riboprobes for the detection of virulent Yersinia enterocolitica and simple methods for their preparation. 759 16

A 78 year old female was found to have pancytopenia in February 1991. Bone marrow was normocellular with 11.7% blasts and showed dysmegakaryopoietic changes. A diagnosis of MDS (RAEB) was made and she was treated with transfusions and ubenimex. Leukemic transformation was noted in July. On Admission in October 1991, her laboratory examinations revealed the following: WBC 38,900/microliters with 93% blast, Hb 8.0 g/dl, Plt 2.1 x 10(4)/microliters, a hypercellular bone marrow with 74% blasts which were negative for myeloperoxidase (MPO) by light microscopy, but were positive by electron microscopy. Surface marker for CD13 was positive. These findings corresponded to M0 of the FAB subtype. Chromosome analysis revealed Ph1 chromosome with 46XX, t (9;22) (q34;q11) in 3 of 3 cells examined, Southern analysis showed the rearrangement of the break point cluster region (bcr). Reverse transcriptase polymerase chain reaction technique demonstrated the presence of major bcr/abl mRNA. She was treated with transfusions and methyl-prednisolone. Her blast counts declined and Ph1 chromosome was only positive in 1 of 12 metaphases examined. She died of pneumonia in December 1991. Eleven cases with MDS showing Ph1 chromosome have previously been reported. The observations indicate that Ph1 chromosome positive acute leukemias were heterogenous in nature.
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PMID:[RAEB transformed into AML (M0) showing Ph1 chromosome and rearrangement of major cluster region]. 825 8

Using the T7 RNA polymerase expression system, a modified plasmid vector has been developed which gives reliable, high level expression in Escherichia coli of the gene encoding streptococcal NADH peroxidase. The recombinant enzyme has been purified to homogeneity using a revised protocol which yields over 35 mg of pure protein per liter of culture. Recombinant NADH peroxidase is fully active and exhibits spectroscopic and redox properties identical to those for the enzyme purified from Streptococcus faecalis 10C1. Reductive titrations and thiol analyses confirm the presence of the unusual cysteine-sulfenic acid (Cys-SOH) redox center identified previously. N-terminal sequence analysis, analytical gel filtration, and preliminary x-ray diffraction data all confirm the structural identity of the recombinant and S. faecalis enzymes. Steady-state kinetic analysis of the peroxidase, coupled with results from static titration experiments is consistent with a limiting type of ternary complex mechanism and allows the determination of many of the corresponding kinetic constants. In addition, preliminary 1H NMR spectra of the enzyme at millimolar concentrations show good dispersion in the amide region and indicate that the recombinant peroxidase is suitable for one-dimensional NMR work with labeled amino acids.
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PMID:Purification and analysis of streptococcal NADH peroxidase expressed in Escherichia coli. 842 93

There is evidence suggesting the importance of the interleukin-1 receptor type I (IL-1Rtl) and interleukin-1 beta (IL-1 beta) as mediator in local intercellular interactions in endometrial tissue and embryonic implantation. To complete our understanding of the entire endometrial IL-1 system in humans, we have investigated the immunohistochemical distribution of IL-1 receptor antagonist (IL-1ra) in the human endometrium throughout the menstrual cycle. We have also identified the forms of IL-1ra present in human endometrial cells. Immunoreactive IL-1ra was found in both cryostat and paraffin-embedded sections of human endometrium using the alkaline phosphatase-peroxidase (A-P) method with two different IL-1ra antibodies. IL-1ra was present throughout the entire menstrual cycle, located primarily in the endometrial epithelium. However, IL-1ra staining was significantly higher during follicular phase in comparison with early and mid-late luteal phases. Reverse transcriptase polymerase chain reaction of cultured stromal and glandular cells showed that these cells express the intracellular form of IL-1ra mRNA (icIL-1ra). Our results demonstrate the regulated presence of the icIL-1ra in the human endometrium. This finding supports a possible autocrine-paracrine role for the IL-1 system in the human endometrium and embryonic implantation.
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PMID:Immunohistochemical localization, identification and regulation of the interleukin-1 receptor antagonist in the human endometrium. 853 Jun 93


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