Electron paramagnetic resonance studies on nitrogenase
نویسندگان
چکیده
منابع مشابه
Electron paramagnetic resonance studies on nitrogenase. I. The properties of molybdoferredoxin and azoferredoxin.
Both molybdoferredoxin and azoferredoxin exhibit Jl:PR signals. Reduced MOferredoxin has a q = 1.94 type signal characteristic of nonheme iron proteins. Kednced molybdoferredoxin has P;PR signals with y-values of 2.01, 3.78 and 4.27. This resonance appears to be dne to an antiferromagnetically coupled system of iron atoms with an effective spin of 34 which has been snbjec~ted to both axial and ...
متن کاملElectron paramagnetic resonance of nitrogenase and nitrogenase components from Clostridium pasteurianum W5 and Azotobacter vinelandii OP.
The electron paramagnetic resonance of nitrogenase components, separately and together with the other reactants in the nitrogenase system (namely, reductant and Mg.ATP), have been examined at low temperatures (<20 degrees K). The MoFe protein, component I or molybdoferredoxin, in the oxidized (but not oxygen-inactivated) state yields signals with g-values of 4.3, 3.7, and 2.01, and when reduced...
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Studies of the effect of substitution with 170 on the e.p.r. spectra at 9 and 35 GHz of Mo(V) in the phosphate complex of sulphite oxidase are reported. Substitution of '7O-enriched water for normal water, for samples of the enzymes reduced by sulphite in the presence of normal phosphate, produced no detectable effect on the e.p.r. signal. If phosphate substituted with 170 was used, coupling du...
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The aim of this review is to show how Electron Paramagnetic Resonance (EPR) and related methods such as dynamic nuclear polarisation (DNP) can be used to detect, localize and quantify oxygen concentration in biological tissues. Several applications will be described with special emphasis on tumor oxygenation. Introduction It is well established that the partial pressure of oxygen (pO2) plays im...
متن کاملElectron paramagnetic resonance studies on the ferredoxin from Clostridium pasteurianum.
We have recently demonstrated an EPR signal in spinach ferredoxin on reduction either enzymically or with dithionite (Palmer and Sands, 1966). It is the purpose of this communication to report on the EPR spectrum found in the ferredoxin obtained from the bacterium C. pasteurianum. The ferredoxin was purified by the method of Mortenson (1964) and had an absorbancy ratio 285 rnp; 3QO rnF of 0.82....
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ژورنال
عنوان ژورنال: Archives of Biochemistry and Biophysics
سال: 1972
ISSN: 0003-9861
DOI: 10.1016/0003-9861(72)90452-3