title: Substrate specificity of rat liver mitochondrial carnitine palmitoyl transferase I: evidence against alpha-oxidation of phytanic acid in rat liver mitochondria.
abstract: The two branched chain fatty acids pristanic acid (2,6,10,14-tetramethylpentadecanoic acid) and phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) were converted to co-enzyme A thioesters by rat liver mitochondrial outer membranes. However, these branched chain fatty acids could not be converted to pristanoyl and phytanoyl carnitines, respectively, by mitochondrial outer membranes. As expected, the unbranched long chain fatty acids, stearic acid and palmitic acid, were rapidly converted to stearoyl and palmitoyl carnitines, respectively, by mitochondrial outer membranes. These observations indicate that the branched chain fatty acids could not be transported into mitochondria. The data presented strongly suggest that in rat liver, alpha-oxidation of phytanic acid occurs in organelles other than mitochondria.
authors.affiliation: Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, Australia.
authors.forename: H
authors.initials: H
authors.lastname: Singh
authors.forename: A
authors.initials: A
authors.lastname: Poulos
mesh_terms: D000818:Animals; D001692:Biological Transport; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D003065:Coenzyme A / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism; D008930:Mitochondria, Liver / Q000201:enzymology*; D010084:Oxidation-Reduction; D010831:Phytanic Acid / Q000378:metabolism*; D051381:Rats; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
chemical_list: D005227:Fatty Acids; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D010831:Phytanic Acid; C002844:pristanic acid; D002334:Carnitine O-Palmitoyltransferase; D003066:Coenzyme A Ligases; C090799:FAA2 protein, S cerevisiae; D000098859:Long-Chain-Fatty-Acid-CoA Ligase; D003065:Coenzyme A