Possible active sites in nitrite reductase and hydroxylamine reductases from vegetable marrow (Cucurbita pepo L.)
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چکیده
منابع مشابه
Third-harmonic detection of electron-paramagnetic-resonance spectra: resolution of the hyperfine splitting in nitrosylated nitrite reductase from vegetable marrow (Cucurbita pepo).
Derivative spectroscopy has often been used in n.m.r. and optical-absorption spectroscopy as a means of resolving narrow features obscured by broad lineshapes. E.p.r. spectra are normally presented as the first-harmonic (first derivative) form, but higher harmonics can readily be generated by modulating the magnetic field at a subharmonic frequency and operating the phase-sensitive detector at ...
متن کاملThe Reduction of Nitrate, Nitrite and Hydroxylamine to Ammonia by Enzymes from Cucurbita Pepo L. in the Presence of Reduced Benzyl Viologen as Electron Donor.
1. Enzyme systems from Cucurbita pepo have been shown to catalyse the reduction of nitrite and hydroxylamine to ammonia in yields about 90-100%. 2. Reduced benzyl viologen serves as an efficient electron donor for both systems. Activity of the nitrite-reductase system is directly related to degree of dye reduction when expressed in terms of the function for oxidation-reduction potentials, but a...
متن کاملHydroxylamine reductase enzymes from maize scutellum and their relationship to nitrite reductase.
Three enzymes contribute to the total hydroxylamine reductase activity of corn (Zea mays L.) scutellum extracts. Two of these resemble enzymes previously prepared from leaves, while the third, which accounts for a major part of the activity, appears to have no counterpart in leaf tissue. One of the hydroxylamine reductases found only in small amounts is associated with nitrite reductase and is ...
متن کاملl-Ornithine:2-Oxoacid Aminotransferase from Squash (Cucurbita pepo, L.) Cotyledons: Purification and Properties.
ORNITHINE: 2-oxoacid aminotransferase (EC 2.6.1.13) has been purified over 400-fold with a total recovery of 14% from acetone powders of cotyledons of germinating squash (Cucurbita pepo, L.) seedlings. The pH optimum of the transamination between l-ornithine and alpha-ketoglutarate is 8 and the Michaelis constants are 4.7 mm and 6.3 mm, respectively. The enzyme has a molecular weight of 48,000 ...
متن کاملRelationship of nitrite and hydroxylamine reductases to nitrate assimilation and nitrogen fixation in Azotobacter agile.
The nitrogen fixation process has been recently reviewed by Wilson (1952), Burris (1956), Shug et al. (1956), and Gest et al. (1956). Although the characteristics of the over-all process in vivo are well known, neither the pathway nor the enzymatic steps has been established. On the other hand, a number of enzymes from bacteria, fungi and higher plants have been characterized which together can...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1970
ISSN: 0306-3283
DOI: 10.1042/bj1170030pa