title: Subcellular distribution and kinetic parameters of HS mouse liver aldehyde dehydrogenase.
abstract: 1. Aldehyde dehydrogenase subcellular distribution studies were performed in a heterogeneous stock (HS) of male and female mice (Mus musculus) with propionaldehyde (5 mM and 50 microM) and formaldehyde (1 mM) and NAD+ or NADP+. 2. The relative percents of distribution were: cytosolic 55-68%, mitochondrial 12-20%, microsomal 9-18% and lysosomal 3-15% for both propionaldehyde concentrations and NAD+. 3. Kinetic experiments using propionaldehyde and acetaldehyde with NAD+ revealed two separate enzymes, Enzyme I (low Km) and Enzyme II (high Km) in the cytosolic and mitochondrial fractions. 4. The kinetic data also indicated a spectrum of cytosolic low Km values that exhibited a bimodal distribution with one congruent to 40 microM and one congruent to 5 microM. 5. It was concluded that there was no significant difference in aldehyde-metabolizing capability between male and female HS mice, compared on a per gram of liver basis. The cytosolic low Km enzyme plays a major role in aldehyde oxidation at moderate to low aldehyde concentrations.
mesh_terms: D000444:Aldehyde Dehydrogenase; D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D000818:Animals; D005260:Female; D005557:Formaldehyde / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D009243:NAD / Q000378:metabolism; D012737:Sex Factors; D013347:Subcellular Fractions / Q000201:enzymology; D014018:Tissue Distribution
chemical_list: D009243:NAD; D005557:Formaldehyde; D000445:Aldehyde Oxidoreductases; D000444:Aldehyde Dehydrogenase