Mixed-valence cytochrome oxidase-formate complex. A steady-state intermediate
نویسندگان
چکیده
منابع مشابه
Mixed-Valence Cytochrome Oxidase-Formate Complex
At neutral pH, formate binds to the haem a3 component of cytochrome c oxidase to give a complex that reacts differently from the non-liganded enzyme with reducing agents. Addition of sodium dithionite to the formate complex leads directly to the formation of the fully reduced species, whereas reduction with ascorbate/tetramethylenephenylenediamine can lead to the production of a mixed-valence s...
متن کاملCO binding to mitochondrial mixed valence state cytochrome oxidase at low temperatures.
The kinetics and thermodynamics of the reaction of mixed valence state membrane-bound cytochrome oxidase with CO over the 178-203 K range has been studied by multichannel optical spectroscopy at three wavelength pairs (444-463 nm in the Soret region, and 590-630 and 608-630 nm in the alpha region) and analysed by non-linear optimization techniques. As in the case of the fully reduced membrane-b...
متن کاملDirect detection of a dioxygen adduct of cytochrome a3 in the mixed valence cytochrome oxidase/dioxygen reaction.
Time-resolved resonance Raman spectra have been recorded during the reaction of mixed valence (a3+ a2+(3)) cytochrome oxidase with dioxygen at room temperature. In the spectrum recorded at 10 microseconds subsequent to carbon monoxide photolysis, a mode is observed at 572 cm-1 that shifts to 548 cm-1 when the experiment is repeated with 18O2. The appearance of this mode is dependent upon the la...
متن کاملThe Cytochrome C-cytochrome Oxidase Complex
In the preceding paper the oxidation of substrates by “indophenol oxidase” was demonstrated to be a joint action of cytochrome and cytochrome oxidase. It was further shown that with a given amount of oxidase the velocity of hydroquinone oxidation reached a maximum as the amount of added cytochrome was increased. The latter fact immediately suggested the probability that the rapid aerobic oxidat...
متن کاملModulation of the electron redistribution in mixed valence cytochrome C oxidase by protein conformational changes.
The redistribution of two electrons in the four redox centers of cytochrome c oxidase following photodissociation of CO from the CO-bound mixed valence species has been examined by resonance Raman spectroscopy. To account for both the kinetic data, obtained from 5 micros to 2 ms, and the equilibrium results, a model is proposed in which the electron redistribution is modulated by a protein conf...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1977
ISSN: 0264-6021
DOI: 10.1042/bj1670531