Studies on the peroxisomal oxidation of palmitate and lignocerate in rat liver.
We have investigated the pathways involved in the peroxisomal oxidation of palmitate and lignocerate, measured as the cyanide-insensitive formation of acetyl units, in rat-liver homogenates. The peroxisomal beta-oxidation of both fatty acids is dependent on the presence of ATP, coenzyme A, NAD+ and Mg2+. However, there is a striking difference in the dependence of the rate of oxidation of the two substrates on the concentration of the individual cofactors, especially ATP. The peroxisomal beta-oxidation of lignocerate was inhibited to a progressively greater extent by increasing concentrations of palmitate and vice versa. Activation of lignoceric acid to lignoceroyl-CoA, however, was not inhibited by increasing concentrations of palmitate, and vice versa. It can be concluded that the peroxisomal palmitate and lignocerate beta-oxidation pathways differ in at least one enzymic reaction (the synthetase), but that the two pathways share at least one common step.
D000818:Animals; D003066:Coenzyme A Ligases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008830:Microbodies / Q000378:metabolism*; D010084:Oxidation-Reduction; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism*; D051381:Rats; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
D005227:Fatty Acids; D010169:Palmitic Acids; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D019308:Palmitic Acid; D003066:Coenzyme A Ligases; C044125:lignoceroyl-CoA ligase; C090799:FAA2 protein, S cerevisiae; D000098859:Long-Chain-Fatty-Acid-CoA Ligase; C010210:lignoceric acid