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 Ki 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 Ki to cytochrome a602. 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 a602-containing electron transport branch inducing the suppression of electron flow from NADH to oxygen.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
