Hemoproteins
Mostrando 1-12 de 66 artigos, teses e dissertações.
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1. Hemoglobina extracelular gigante de Glossoscolex paulistus: um extraordinário sistema supramolecular hemoproteico
Giant extracellular hemoglobins are considered the summit of complexity in systems that carry oxygen, constituting an extraordinary model system to the study of hemoproteins. This class includes the hemoglobin of the annelid Glossoscolex paulistus that presents high cooperativity, great oligomeric and redox stabilities and ability of oligomeric reassociation
Química Nova. Publicado em: 2011
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2. Estudo comparativo entre diferentes nitrosil hemoproteinas por ressonância paramagnética eletrônica. / Electron paramagnetic resonance study between different nitrosyl hemoproteins.
As propriedades dos derivados nitrosilados de diferentes hemoproteínas em função da temperatura, da concentração de óxido nítrico (NO) e pH, foram investigadas utilizando a técnica de Ressonância Paramagnética Eletrônica (RPE). Nas hemoproteínas, o grupo heme está acomodado em um bolso: de um lado encontra-se a histidina proximal, de outro uma c
Publicado em: 1987
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3. Estudos estruturais das mioglobinas de "Aplysia Brasiliana" e "Dermochelis Coriacea " por técnicas ópticas e ressonância paramagnética eletrônica / Structural studies of Aplysia Brasiliana and Demochelis Coriacea myoglobins by optical techniques and electron paramagnetic resonance
Neste trabalho são estudadas as mioglobínas de Aplysía Brasiliana (MbApB) e da tartaruga marinha "Dermoche lis Coriacea" (MbT) focalizando a transição ácida alcalina (TAA), a interação com metais de transição e mudanças conformacionais induzidas - termicamente com objetivo de observar diferenças estruturais destas mioglobinas. A TAA da MbApB poss
Publicado em: 1984
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4. Interação hidrofóbica de mioglobina com spin label TEMPO. / Hydrophobic interaction od myoglobin with the spin label TEMPO.
Type A myoglobin single crystals were doped with the 2, 2, 6, 6 -tetramethyl - 1 - oxyl (TEMPO) spin label by a diffusion process. We observed one isotropic spin label type, and another anisotropic type which shows an axial symmetry with A// = 23,4 G, A⊥ = 20, 6 G and g = 2,0056. The rotational correlation times are estimated to be a τ// = 7,2.10-9s
Publicado em: 1980
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5. Binding of O2 and CO to hemes and hemoproteins.
Enthalpies and entropies have been determined for the reversible binding of O2 and CO to chelated protoheme, a compound having a covalently attached imidazole bound to the iron. The values, based upon 1 atm standard state, are delta HO2 = -14.0 kcal (1 kcal = 4.18 kJ)/mol, delta SO2 = -35 eu, delta HCO = -17.5 kcal/mol, delta SCO = -34 eu, delta H identical
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6. Carbon monoxide binding to iron porphyrins.
The carbon monoxide affinities of iron complexes of meso-tetra (alpha, alpha, alpha, alpha-o-pivalamidophenyl)porphyrin (the "picket fence" porphyrin) and of a "picket fence" porphyrin derivative with an appended axial base have been measured in solution and compared with the CO affinities of various hemoproteins. The model complexes bind CO with much greate
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7. Structural Measurements in Hemoproteins: Use of Spin-Labeled Protoheme as a Probe of Heme Environment
With the aid of two kinds of spin-labeled protohemins, the nature of the heme-protein interaction of various hemoproteins was investigated. Di- and mono-spin-labeled protohemins were prepared from protohemin and 2,2,5,5-tetramethyl-3-aminopyrrolidine-1-oxyl. The spin-labeled hemins were recombined with apoproteins of hemoglobin (Hb), myoglobin (Mb), cytochro
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8. Proton nuclear magnetic resonance characterization of heme disorder in hemoproteins.
A proton NMR method is described for determining the orientation of a porphyrin within the heme pocket of a hemoprotein. The pattern of the hyperfine-shifted heme methyl resonances in low-spin ferric model compounds is demonstrated to characteristically reflect the position of a localized low-symmetry perturbation on the pi system. The specific assignments v
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9. Nature of O2 and CO binding to metalloporphyrins and heme proteins.
The O2 vibration of dioxygen adducts of Fe and Co model complexes of alpha,alpha,alpha,alpha-tetrapivalamidophenylporphyrin ("picket fence" porphyrin, TpivPP) with 1-methylimidazole and 1-tritylimidazole as axial bases are reported, obtained with difference techniques between 16O2, 18O2, 169-18O, and NO with a Fourier transform infrared spectrometer. Assignm
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10. HEMATIN-REQUIRING PLASMODIAL MYXOMYCETE
Daniel, John W. (University of Wisconsin, Madison), Jacqueline Kelley, and Harold P. Rusch. Hematin-requiring plasmodial myxomycete. J. Bacteriol. 84:1104–1110. 1962.—The myxomycete Physarum polycephalum, previously shown to require chick embryo extract for growth on a partially defined, soluble medium, grows as well if hematin or certain hemoproteins ar
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11. Lack of heme synthesis in a free-living eukaryote
In most free-living eukaryotes studied thus far, heme is synthesized from a series of intermediates through a well defined evolutionarily conserved pathway. We found that free-living worms, including the model genetic organism Caenorhabditis elegans, and parasitic helminths are unable to synthesize heme de novo, even though these animals contain hemoproteins
National Academy of Sciences.
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12. Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses.
We have measured spectral and kinetic differences in protoheme, sperm whale or horse heart myoglobin and human hemoglobin following photodissociation induced by optical pulses of 80 fs duration. Full ligation was performed with oxygen or carbon monoxide. Femtosecond kinetics and transient difference spectra revealed the appearance of a deoxy species with tau