Acetaldehyde-dependent oxidation of glutathione catalyzed by rat liver cytosol.
We have identified a novel reaction in which acetaldehyde promotes rat hepatic cytosolic catalysis of O2 consumption coupled with glutathione oxidation without apparent release of activated forms of O2. Acetaldehyde is not consumed in the reaction. The reaction (O2 consumption or oxidized glutathione production) is saturable with respect to varying glutathione (K'm congruent to 20-45 microM) but not at high acetaldehyde concentrations. However, activity in the range of acetaldehyde found in liver from alcohol metabolism (10-100 microM) appeared to be saturable (K'm congruent to 25-50 microM). Since neither acetaldehyde-dependent glutathione loss nor O2 consumption is detectable in guinea pig hepatic cytosol or hepatic cytosol from selenium-deficient rats, we propose that acetaldehyde interacts with glutathione peroxidase, converting the enzyme into a glutathione oxidase.
D000079:Acetaldehyde / Q000494:pharmacology*; D000693:Anaerobiosis; D000818:Animals; D003600:Cytosol / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D019803:Glutathione Disulfide; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains
D005978:Glutathione; D000079:Acetaldehyde; D019803:Glutathione Disulfide