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Low-temperature kinetics of the reaction of oxygen and solubilized cytochrome oxidase.

ABSTRACT: The reaction of solubilized cytochrome oxidase in the fully reduced state with O2 at low temperatures reveals components with characteristics similar to those observed with the membrane-bound oxidase, namely compounds A and B, which are proposed to be 'oxy' and 'peroxy' compounds respectively. Similar species are identified in both solubilized and membrane-bound oxidases; the reaction velocity constant for the reation with O2 and the dissociation constant are decreased 2-3-fold in the solubilied preparation as compared with the membrane-bound species, owing to decreased reactivity towards O2 in the former. The oxidase prepared in the mixed-valence state shows the distinctive absorption band characteristic of compound C, identified in the membrane-bound oxidase. The assignment of the alpha, beta, gamma and near-i.r. absorption bands to possible valence states of these compounds is made.

SUBMITTER: Chance B

PROVIDER: S-EPMC1184028 | biostudies-other | 1978 Jun

REPOSITORIES: biostudies-other

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Low-temperature kinetics of the reactions of fully reduced membrane-bound cytochrome oxidase with oxygen in the Soret, alpha and near-infrared regions.

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2020-10-07 | GSE159080 | GEO

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