Subcellular distribution of aldehyde dehydrogenase activities in human liver.
The subcellular distributions of aldehyde dehydrogenase activities towards acetaldehyde have been determined in wedge-biopsy samples of human liver. A form with Km values of less than 1 microM and 285 microM towards acetaldehyde and NAD+ respectively was present in the mitochondrial fraction. This enzyme had no detectable activity towards N-tele-methylimidazole acetaldehyde, the aldehyde derived from the oxidation of N-tele-methylhistamine. The activity in the cytosol was more sensitive to inhibition by disulfiram and had Km values of 270 microM and 25 microM for acetaldehyde and NAD+, respectively. It was active towards N-tele-methylimidazole acetaldehyde with a Km value of 2.5 microM and a maximum velocity that was 40% of that determined with acetaldehyde. Both these cytosolic activities had alkaline pH optima.
D000444:Aldehyde Dehydrogenase / Q000032:analysis* / Q000037:antagonists & inhibitors; D003600:Cytosol / Q000201:enzymology; D004221:Disulfiram / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology; D013347:Subcellular Fractions / Q000201:enzymology
D000444:Aldehyde Dehydrogenase; D004221:Disulfiram