title: Fatty acid transport by the lipophilic bacterium Nocardia asteroides.
abstract: Hexadecanoate was translocated in Nocardia asteroides by a constitutive transport system(s), which transported short, medium, and long-chain fatty acids. Inhibition of hexadenocanoate transport by homologues suggested that at least two systems are present: one specific for short-chain fatty acids and the other specific for medium- and long-chain fatty acids. Saturation kinetics typical of a carrier-mediated transport system (Kt = 870 muM)were observed, and concentration of fatty acids against a gradient was achieved. Inhibitor studies indicated that free sulfhydryl groups, a functional respiratory chain, and energy are required for translocation. Efflux of [14C]hexadecanoate in the presence of excess unlabeled hexadecanoate or 2,4-dinitrophenol and the cytoplasmic localization of acyl-coenzyme A synthetase (acid:coenzyme A ligase [adenosine monophosphate]; EC 6.2.1.3) (Calmes and Deal, 1973) are consistent with the hypothesis that fatty acids are transported and released intracellularly as free fatty acids.
mesh_terms: D000327:Adsorption; D001693:Biological Transport, Active; D002462:Cell Membrane / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D007700:Kinetics; D009616:Nocardia asteroides / Q000201:enzymology / Q000378:metabolism*; D010168:Palmitates / Q000378:metabolism; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D005227:Fatty Acids; D010168:Palmitates; D013439:Sulfhydryl Reagents; D014475:Uncoupling Agents; D003066:Coenzyme A Ligases