Intraorganellar localization of CoASH-independent phytanic acid oxidation in human liver peroxisomes.
In human tissues phytanic acid is alpha-oxidized to pristanic acid in peroxisomes. Studies of the intraorganellar site of alpha-oxidation of [1-14C]phytanic acid to pristanic acid in peroxisomes isolated from human liver demonstrate that phytanoyl-CoA ligase is present in the peroxisomal membrane and that the enzyme system for alpha-oxidation of phytanic acid to pristanic acid is in the peroxisomal matrix. In contrast to the beta-oxidation system for fatty acids, the substrate for alpha-oxidation is free phytanic acid. The studies described in this manuscript report a novel fatty acid oxidation system where the substrate for the enzyme system is free fatty acid; however, phytanoyl-CoA ligase regulates the alpha-oxidation of phytanic acid at the organellar (peroxisomal) level.
Pahan
K
K
Department of Pediatrics, Medical University of South Carolina, Charleston 29425.
Singh
I
I
D003065:Coenzyme A / Q000378:metabolism*; D003066:Coenzyme A Ligases / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008830:Microbodies / Q000378:metabolism*; D010084:Oxidation-Reduction; D010831:Phytanic Acid / Q000378:metabolism*
D010831:Phytanic Acid; D003066:Coenzyme A Ligases; C080977:phytanoyl-CoA ligase; D003065:Coenzyme A