Carbonyl Iron
Mostrando 25-36 de 60 artigos, teses e dissertações.
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25. Alterations in the structure, physicochemical properties, and pH of hepatocyte lysosomes in experimental iron overload.
While hemochromatosis is characterized by sequestration of iron-protein complexes in hepatocyte lysosomes, little is known about the effects of excess iron on these organelles. Therefore, we studied the effects of experimental iron overload on hepatocyte lysosomal structure, physicochemical properties, and function in rats fed carbonyl iron. A sixfold increa
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26. Siderophore activity of myo-inositol hexakisphosphate in Pseudomonas aeruginosa.
myo-Inositol hexakisphosphate (InsP6), which is found in soil and most, if not all, plant and animal cells, has been estimated to have an affinity for Fe3+ in the range of 10(25) to 10(30) M-1. In this report, we demonstrate that the Fe-InsP6 complex has siderophore activity and is able to reverse the iron-restricted growth inhibition of Pseudomonas aerugino
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27. Iron transport in Streptomyces pilosus mediated by ferrichrome siderophores, rhodotorulic acid, and enantio-rhodotorulic acid.
Streptomyces pilosus is one of several microbes which produce ferrioxamine siderophores. In the accompanying paper (G. Müller and K. Raymond, J. Bacteriol. 160:304-312), the mechanism of iron uptake mediated by the endogenous ferrioxamines B, D1, D2, and E was examined. Here we report iron transport behavior in S. pilosus as mediated by the exogenous sidero
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28. Transferrin receptor 2: Continued expression in mouse liver in the face of iron overload and in hereditary hemochromatosis
Hereditary hemochromatosis (HH) is a common autosomal recessive disorder characterized by excess absorption of dietary iron and progressive iron deposition in several tissues, particularly liver. Liver disease resulting from iron toxicity is the major cause of death in HH. Hepatic iron loading in HH is progressive despite down-regulation of the classical tra
The National Academy of Sciences.
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29. Coupling between oxidation state and hydrogen bond conformation in heme proteins
In all heme proteins for which crystal structures are available, the Nε of a histidyl residue is bonded to the heme iron and Nδ is hydrogen bonded to a carbonyl oxygen of the peptide backbone. We investigate here the possibility that a change in oxidation state of the iron or a change in the geometry of this hydrogen bond might change the hydrogen bond str
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30. Purification and properties of ferredoxin and rubredoxin from Butyribacterium methylotrophicum.
A ferredoxin and a rubredoxin from Butyribacterium methylotrophicum, which displays a carbonyl-dependent acetyl-coenzyme A synthesis, were purified to electrophoretic homogeneity. The two electron carriers showed absorption spectra similar to those in Clostridium species. The ferredoxin displayed absorption peaks at 280 and 391 nm, while rubredoxin displayed
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31. Depression of B-lymphocyte levels in the peripheral blood of cows with mastitis.
The levels of B-lymphocytes in the peripheral blood of normal and mastitic cows were evaluated by fluorescent-antibody and erythrocyte-antibody-complement-rosetting techniques. Normal cows (N = 8) had 26.9 +/- 4.4% surface membrane immunoglobulin-positive lymphocytes, whereas mastitic cows (N = 6) had only 16.3 +/- 3.6% similar cells among lymphocyte prepara
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32. Transfer of oxygen from an artificial protease to peptide carbon during proteolysis.
Site-specific cleavage of proteins with metal chelates is an approach for designing artificial proteolytic reagents that are directed by proximity to a peptide bond rather than by an amino acid residue type. In the presence of ascorbate and H2O2, an iron chelate attached to Cys-212 of the enzyme human carbonic anhydrase I quickly cleaved the protein between
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33. Evidence from bond lengths and bond angles for enneacovalence of cobalt, rhodium, iridium, iron, ruthenium, and osmium in compounds with elements of medium electronegativity
Enneacovalence of neutral atoms can be achieved for Co, Rh, and Ir by promoting some electrons from the nd orbital to the (n + 1)s and (n + 1)p orbitals and for Fe, Ru, and Os by a similar promotion together with the addition of an electron, which may be provided by an electron pair from a singly bonded carbonyl group or other group. The bond lengths and bon
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34. Bond angles in transition-metal tricarbonyl compounds: A test of the theory of hybrid bond orbitals*
The theory of hybrid bond orbitals is used to calculate equations giving the value of the bond angle OC—M—CO in relation to the bond number of the metal—carbonyl bond for tricarbonyl groups in which the transition-metal atom is enneacovalent or octacovalent and the group has approximate trigonal symmetry. For cobalt and iron and their congeners the ave
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35. Changing the invariant proline-30 of rat and Drosophila melanogaster cytochromes c to alanine or valine destabilizes the heme crevice more than the overall conformation.
Drosophila melanogaster and rat cytochromes c in which proline-30 was converted to alanine or valine were expressed in a strain of baker's yeast, Saccharomyces cerevisiae, where they sustained aerobic growth. The mutations had no significant effect on the spectra or redox potentials but altered drastically the stability of the bond between the methionine-80
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36. Characterization of the iron-sulfur clusters in ferredoxin from acetate-grown Methanosarcina thermophila.
Ferredoxin from Methanosarcina thermophila is an electron acceptor for the CO dehydrogenase complex which decarbonylates acetyl-coenzyme A and oxidizes the carbonyl group to carbon dioxide in the pathway for conversion of the methyl group of acetate to methane (K. C. Terlesky and J. G. Ferry, J. Biol. Chem. 263:4080-4082, 1988). Resonance Raman spectroscopy