ISSN:
1432-072X
Keywords:
Staphylococcus aureus
;
Electron transport
;
Branched respiratory chain
;
Cytochrome oxidase
;
Ethanol oxidation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Addition of ethanol and some other primary alcohols, except methanol, to cells and protoplasts (but not membrane particles) considerably stimulated the rate of oxygen consumption. This additional respiration was strongly inhibited by 0.1 mM KCN. The cyanide inhibition curve of endogenous substrate oxidation was slightly biphasic while in the presence of ethanol it became clearly biphasic having K i values of approx. 0.1 and 0.5 mM. Based on the steady-state cytochrome spectra in the presence of 0.1 mM KCN, we attributed the lower K i to cytochrome a 602. Proteolysis of protoplasts external membrane proteins did not change the rate of endogeneous substrate oxidation but prevented the inhibition of this respiration by low concentrations of KCN and stimulation of oxygen consumption by ethanol. The activity of NAD+-dependent ethanol dehydrogenase in the cytoplasm was found to be 520 nmol NADH-x min−1 x mg−1 protein. Proteolysis of external membrane proteins apparently inhibits the operation of the cytochrome a 602-containing electron transport branch inducing the suppression of electron flow from NADH to oxygen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00245268
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