Spin Label
Mostrando 13-24 de 162 artigos, teses e dissertações.
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13. 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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14. 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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15. Neisseria gonorrhoeae membrane microenvironment studied by spin-label electron spin resonance: comparison of colony types.
Spin-label electron spin resonance was used to characterize the microenvironment around spin probes which localize (i) in membranes, (ii) at the membrane surface, or (iii) in the cytoplasm of living Neisseria gonorrhoeae. Four colony types (T1, T2, T3, and T4) of gonococci were compared on the basis of the electron spin resonance parameters 2T parallel to, S
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16. Determination of spin-label orientation within the myosin head.
Current methods of analyzing EPR spectra of spin-labeled muscle fibers allow the determination of spin-label orientation within the fiber, rather than the orientation of the myosin head itself. In order to describe the orientational distribution of spin labeled myosin heads within the muscle fibers, the orientation of the spin label within the myosin head mu
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17. A spin label study of the effects of asbestos, quartz, and titanium dioxide dusts on the bovine erythrocyte membrane.
The effects of five UICC asbestos samples, titanium dioxide, and quartz on the bovine red cell membrane have been studied in erythrocyte ghosts by the spin labelling technique. Analysis of the electron paramagnetic resonance (EPR) spectra of two sulphydryl reactive spin labels and one fatty acid spin label in red cell ghosts showed modifications in membrane
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18. Sendai virus-induced hemolysis: reduction in heterogeneity of erythrocyte lipid bilayer fluidity.
Hemolysis of human or chicken erythrocytes by Sendai virus causes a change in the structure of the erythrocyte membrane lipid bilayer that can be detected by spin label electron spin resonance. In the intact erythrocyte, the phosphatidylcholine derivative spin label exists in a more rigid environment than the corresponding phosphatidylethanolamine label. Vir
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19. Calculation of electron paramagnetic resonance spectra from Brownian dynamics trajectories: application to nitroxide side chains in proteins.
We present a method to simulate electron paramagnetic resonance spectra of spin-labeled proteins that explicitly includes the protein structure in the vicinity of the attached spin label. The method is applied to a spin-labeled polyleucine alpha-helix trimer. From short (6 ns) stochastic dynamics simulations of this trimer, an effective potential energy func
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20. A spin label study of the effect of chrysotile asbestos on erythrocyte membranes.
Alterations in erythrocyte membranes caused by UICC B chrysotile asbestos fibres were studied in red cell ghosts using the spin label technique. The electron paramagnetic resonance (EPR) spectra of two sulphydryl reactive spin labels and one fatty acid spin probe in erythrocyte ghosts showed membrane protein modifications but no changes in lipid fluidity cau
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21. Spin-labeling studies of the conformational changes in the vicinity of D36, D38, T46, and E161 of bacteriorhodopsin during the photocycle.
Electron paramagnetic resonance (EPR) spectroscopy of site-directed spin-labeled bacteriorhodopsin mutants is used to study structural changes during the photocycle. After exchange of the native amino acids D36 and D38 in the A-B loop, E161 in the E-F loop, and T46 in the putative proton channel by cysteines, these positions were modified by a methanethiosul
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22. SPIN-LABELED TRANSFER RNA*
The α-amino group of valyl-tRNA has been combined chemically with a nitroxide spin label through an amide linkage. This spin-labeled aminoacyl-tRNA has an electron paramagnetic resonance spectrum which reflects the mobility of the aminoacyl end of the tRNA molecule. The rate of tumbling of the spin label has been measured as a function of temperature and io
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23. Surface localization of sites of reduction of nitroxide spin-labeled molecules in mitochondria.
The relative rates of reduction of several spin-labeled molecules that partition differently across the hy-drophobic-interface of inner membranes from rat liver mitochondria were investigated. Spin labels localized either deep in the hydrophobic region or in the aqueous phase are only slowly reduced; however a spin-labeled analogue of the cationic detergent
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24. Sequence of oxygen binding by hemoglobin
A nitroxide spin-label probe was attached directly to a propionic acid group of heme in either the α or the β chain of hemoglobin. The electron paramagnetic resonance (EPR) spectrum of the spin label is altered by the spin-state change of the heme iron to which the spin label is attached. These hybrid hemoglobins showed normal optical and functional proper