4-Bromocrotonic acid was found to effectively inhibit respiration supported by either palmitoylcarnitine or acetoacetate in coupled rat heart mitochondria. Partial inhibition was observed when 3-hydroxybutyrate served as a substrate, whereas pyruvate-supported r spiration was unaffected by the inhibitor. Thus, 4-bromocrotonic acid inhibits fatty acid oxidation a d ketone body degradation. W...

We examined the enzyme protein and biosynthesis of human trifunctional protein harboring enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and 3-ketoacyl-CoA thiolase activity in cultured skin fibroblasts from two patients with longchain 3-hydroxyacyl-CoA dehydrogenase deficiency. The following results were obtained. (a) In cells from patient 1, immunoblot analysis and pulse-chase experimen...

The biophysical properties of membrane phospholipids are controlled by the composition of their constituent fatty acids and are tightly regulated in Escherichia coli. The FabR (fatty acid biosynthesis repressor) transcriptional repressor controls the proportion of unsaturated fatty acids in the membrane by regulating the expression of the fabB (beta-ketoacyl-ACP synthase I) and fabA (beta-hydro...

Mitochondrial fatty-acid beta-oxidation (mFAO) plays a central role in mammalian energy metabolism. Multiple severe diseases are associated with defects in this pathway. Its kinetic structure is characterized by a complex wiring of which the functional implications have hardly been explored. Repetitive cycles of reversible reactions, each cycle shortening the fatty acid by two carbon atoms, evo...

Polyketides (PK), nonribosomal peptides (NRP) and their hybrids (PK/NRP) are classes of secondary metabolites whose members exhibit valuable activities with high potential for therapeutic applications. The program governing PK/NRP assembly is typically encoded within modular megasynthetases on which consecutive condensations of activated short-chain carboxylic acids (catalyzed by polyketide syn...

The dimeric, peroxisomal 3-ketoacyl-CoA thiolase catalyses the conversion of 3-ketoacyl-CoA into acyl-CoA, which is shorter by two carbon atoms. This reaction is the last step of the beta-oxidation pathway. The crystal structure of unliganded peroxisomal thiolase of the yeast Saccharomyces cerevisiae has been refined at 1.8 A resolution. An unusual feature of this structure is the presence of t...

This over-all equation is thought to consist of the repetition of a series of reactions, each series being initiated by the condensation of malonyl coenzyme A with an unsubstituted straight chain acyl compound to form ,&ketoacyl-S-enzyme (5, 8). A series is then presumably concluded by reactions in which the P-ketoacyl compound is reduced and dehydrated to form an acyl compound 2 carbon atoms l...

Genome-wide analysis has revealed abundant FabG (beta-ketoacyl-ACP reductase) paralogs, with uncharacterized biological functions, in several halophilic archaea. In this study, we identified for the first time that the fabG1 gene, but not the other five fabG paralogs, encodes the polyhydroxyalkanoate (PHA)-specific acetoacetyl coenzyme A (acetoacetyl-CoA) reductase in Haloarcula hispanica. Alth...

The seed oil of meadowfoam, a new crop in the Limnanthaceae family, is highly enriched in very long chain fatty acids that are desaturated at the Δ5 position. The unusual oil is desirable for cosmetics and innovative industrial applications and the seed meal remaining after oil extraction contains glucolimnanthin, a methoxylated benzylglucosinolate whose degradation products are herbicidal and ...