Publications

• Human fatty acid synthase: properties and molecular cloning.

  Jayakumar A., Tai M.-H., Huang W.-Y., Al-Feel W., Hsu M., Abu-Elheiga L., Chirala S.S., Wakil S.J.

  Fatty acid synthase (FAS; EC 2.3.1.85) was purified to near homogeneity from a human hepatoma cell line, HepG2. The HepG2 FAS has a specific activity of 600 nmol of NADPH oxidized per min per mg, which is about half that of chicken liver FAS. All the partial activities of human FAS are comparable ... >> More

  Fatty acid synthase (FAS; EC 2.3.1.85) was purified to near homogeneity from a human hepatoma cell line, HepG2. The HepG2 FAS has a specific activity of 600 nmol of NADPH oxidized per min per mg, which is about half that of chicken liver FAS. All the partial activities of human FAS are comparable to those of other animal FASs, except for the beta-ketoacyl synthase, whose significantly lower activity is attributable to the low 4'-phosphopantetheine content of HepG2 FAS. We cloned the human brain FAS cDNA. The cDNA sequence has an open reading frame of 7512 bp that encodes 2504 amino acids (M(r), 272,516). The amino acid sequence of the human FAS has 79% and 63% identity, respectively, with the sequences of the rat and chicken enzymes. Northern analysis revealed that human FAS mRNA was about 9.3 kb in size and that its level varied among human tissues, with brain, lung, and liver tissues showing prominent expression. The nucleotide sequence of a segment of the HepG2 FAS cDNA (bases 2327-3964) was identical to that of the cDNA from normal human liver and brain tissues, except for a 53-bp sequence (bases 3892-3944) that does not alter the reading frame. This altered sequence is also present in HepG2 genomic DNA. The origin and significance of this sequence variance in the HepG2 FAS gene are unclear, but the variance apparently does not contribute to the lower activity of HepG2 FAS. << Less

  Proc. Natl. Acad. Sci. U.S.A. 92:8695-8699(1995) [PubMed] [EuropePMC]

  This publication is cited by 38 other entries.

• Purification and properties of fatty acyl thioesterase I from Escherichia coli.

  Bonner W.M., Bloch K.

  J. Biol. Chem. 247:3123-3133(1972) [PubMed] [EuropePMC]

  This publication is cited by 9 other entries.

• Characterization of substrate specificity of plant FatA and FatB acyl-ACP thioesterases.

  Salas J.J., Ohlrogge J.B.

  The specificity of plant acyl-acyl carrier protein (ACP) thioesterases is the major determinant of the chain length and level of saturated fatty acids found in most plant tissues. Although these enzymes have been previously characterized from a number of sources, information on kinetic parameters ... >> More

  The specificity of plant acyl-acyl carrier protein (ACP) thioesterases is the major determinant of the chain length and level of saturated fatty acids found in most plant tissues. Although these enzymes have been previously characterized from a number of sources, information on kinetic parameters for a wide range of substrates with cloned enzymes is lacking. In the present study the substrate specificity of recombinant FatA thioesterase isoforms from Arabidopsis (AtFatA) and coriander (CsFatA) and FatB from Arabidopsis (AtFatB) have been re-examined with a comprehensive range of substrates including 14:1-ACP and 16:1-ACP. AtFatA displayed the highest catalytic efficiencies (kcat/Km) towards oleoyl-ACP with activities at least 20-fold lower for all other tested substrates and 75-fold lower with palmitoyl-ACP. Both chain length and double bond presence strongly influenced kcat of FatA with minor influence on Km. Arabidopsis FatB substrate specificity was found to differ from previous reports and this difference could be attributed to the influence of ACP structure. FatB activity with palmitoyl-ACP was 2.5-fold higher and the ratio of 16:0-ACP/14:0-ACP hydrolysis was 6.4-fold higher with spinach ACP compared to E. coli ACP. Additionally, the influence of amino acid domains from both AtFatA and AtFatB on their substrate specificity was studied by utilizing a domain-swapping approach. The characterization of the resulting chimeric enzymes pointed to the N-terminus as a determinant of the substrate specificity for both FatA and FatB acyl-ACP thioesterases. << Less

  Arch. Biochem. Biophys. 403:25-34(2002) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Fat metabolism in higher plants. Characterization of plant acyl-ACP and acyl-CoA hydrolases.

  Ohlrogge J.B., Shine W.E., Stumpf P.K.

  Arch Biochem Biophys 189:382-391(1978) [PubMed] [EuropePMC]

• Hexanoate synthase, a specialized type I fatty acid synthase in aflatoxin B1 biosynthesis.

  Hitchman T.S., Schmidt E.W., Trail F., Rarick M.D., Linz J.E., Townsend C.A.

  In fungi, fatty acids are biosynthesized by large multifunctional enzyme complexes, the fatty acid synthases (FASs), which catalyze chain assembly in an iterative manner. Many fungal secondary metabolites contain fatty acid moieties, and it is often unclear whether they are recruited from primary ... >> More

  In fungi, fatty acids are biosynthesized by large multifunctional enzyme complexes, the fatty acid synthases (FASs), which catalyze chain assembly in an iterative manner. Many fungal secondary metabolites contain fatty acid moieties, and it is often unclear whether they are recruited from primary metabolism or are biosynthesized de novo by secondary metabolic FASs. The most convincing evidence of such a dedicated FAS comes from the biosyntheses of aflatoxin (AF) and sterigmatocystin (ST) in certain species of the filamentous fungus Aspergillus. Incorporation studies in AF and genetic analyses of ST and AF biosynthesis strongly suggest that their biosyntheses begin with the production of a C6 fatty acid by a specialized FAS. The genes encoding the alpha (hexA) and beta (hexB) subunits of this hexanoate synthase (HexS) from the AF pathway in Aspergillus parsiticus SU-1 were cloned and both their gDNAs and cDNAs were sequenced and their transcriptional ends analyzed. Translated amino acid sequences are predicted to result in proteins of 181.3 and 210.5 kDa, for HexA and HexB, respectively. Comparison of the HexA and HexB sequences with those of the ST FAS subunits and primary metabolic FASs indicated that the secondary metabolic enzymes are members of a well-defined subclass of the FAS family. Phylogenetic predictions and an analysis of GC-bias in AF and ST pathway genes compared with primary metabolic Aspergillus genes were used as a basis to propose a route for the evolution of the AF and ST clusters. << Less

  Bioorg. Chem. 29:293-307(2001) [PubMed] [EuropePMC]

• Fat metabolism in higher plants. The function of acyl thioesterases in the metabolism of acyl-coenzymes A and acyl-acyl carrier proteins.

  Shine W.E., Mancha M., Stumpf P.K.

  Arch Biochem Biophys 172:110-116(1976) [PubMed] [EuropePMC]