The biosynthesis of cyclopropane fatty acids. I. Feeding experiments with oleic acid-9,10-d2, oleic acid-8,8,11,11-d4, and L-methionine-methyl-d3

1981 ◽  
Vol 59 (5) ◽  
pp. 828-838 ◽  
Author(s):  
Peter H. Buist ◽  
David B. Maclean
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Double Bond ◽  
Cyclopropane Ring ◽  
Octadecenoic Acid ◽  
Cyclopropane Fatty Acid ◽  
Feeding Experiments ◽  
Cyclopropane Fatty Acids ◽  
Methylene Unit ◽  
Methylene Group

cis-9-Octadecenoic acid-9,10-d2 and cis-9-octadecenoic acid-8,8,11,11-d4 and L-methionine-methyl-d3 were administered to cultures of Lactobacillus plantarum and converted by the organism to the corresponding cyclopropyl compounds. The first experiment showed that no scrambling or loss of label occurred when a methylene unit was added across the double bond of the labelled substrate. In the second experiment, again, no loss or scrambling of label occurred, a result which ruled out any mechanism for biological cyclopropanation involving allylic activation of the double bond. The third experiment yielded a biosynthetic cyclopropane fatty acid containing deuterium located exclusively at the methylene group of the cyclopropane ring. Up to 17% of a d1-species accompanied the major dideuterated compound. The lone deuterium in the d1-cyclopropane fatty acid occupies both positions of the methylene group to the same extent. It has been shown that the extent to which d1-cyclopropane fatty acid is produced increases with cell growth. The extent of exchange was similar in the cyclopropanation of both the 9,10-and 11,12-isomers of cis-octadecenoic acid.

The biosynthesis of cyclopropane fatty acids. II. Mechanistic studies using methionine labelled with one, two, and three deuterium atoms in the methyl group

1982 ◽  
Vol 60 (4) ◽  
pp. 371-378 ◽  
Author(s):  
Peter H. Buist ◽  
David B. MacLean
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Cyclopropane Ring ◽  
Isotope Effects ◽  
Slow Step ◽  
Cyclopropane Fatty Acid ◽  
Methyl Group ◽  
Feeding Experiments ◽  
Cyclopropane Fatty Acids ◽  
Methyl Group Transfer

The mechanism of formation of monodeuterated cyclopropane fatty acids on administration of L-methione-methyl-d3 to L. plantarum has been investigated. It has been found that the extent of exchange is not affected by the presence of oxygen in the medium, that neither formate-d0 nor formaldehyde-d2 is significantly incorporated into the fatty acid, and that methionine reisolated from the intracellular pool does not contain any exchanged species. These experiments militate against any mechanism involving exchange prior to methyl group transfer. Parallel feeding experiments using methionine labelled in the methyl group with one, two, or three deuterium atoms were carried out and in this way that extent of exchange was quantitated. It was found that at least one-third of the cyclopropane fatty acid from methionine methyl-d3 experiments is derived from an exchanged methyl group. The intramolecular and intermolecular primary deuterium isotope effects for biological cyclopropane ring formation were measured and found to be 3.2 ± 0.5, and 1.01 ± 0.04, respectively. These results are consistent with a mechanism in which a methyl group is transferred in a slow step which is followed by a fast, partially reversible, protonation-deprotonation step.

scholarly journals Asymmetric and Regiospecific Synthesis of Isotopically Labelled Cyclopropane Fatty Acid (9R,10S)-Dihydrosterculic Acid: Overcoming Spontaneous Protonation During Lithium-Sulfoxide Exchange­

SynOpen ◽  
2018 ◽  
Vol 02 (02) ◽  
pp. 0168-0175
Author(s):  
Samuel Shields ◽  
Peter Buist ◽  
Jeffrey Manthorpe
Keyword(s):  
Fatty Acid ◽  
Total Synthesis ◽  
Cyclopropane Ring ◽  
Rapid Quenching ◽  
Cyclopropane Fatty Acid ◽  
Deuterium Incorporation ◽  
Biologically Relevant ◽  
Dihydrosterculic Acid

The total synthesis of isotopically labelled (9R,10S)-dihydro­sterculic acid, a usual cyclopropane fatty acid with biologically relevant toxicity upon desaturation in vivo, is reported. A diastereoselective Corey­–Chaykovsky reaction was employed to form the cyclopropane ring. Rapid quenching of a lithium-sulfoxide exchange was required to achieve the requisite high levels of deuterium incorporation.

scholarly journals Leaky β-Oxidation of atrans-Fatty Acid

2004 ◽  
Vol 279 (50) ◽  
pp. 52160-52167 ◽  
Author(s):  
Wenfeng Yu ◽  
Xiquan Liang ◽  
Regina E. Ensenauer ◽  
Jerry Vockley ◽  
Lawrence Sweetman ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Double Bond ◽  
Octadecenoic Acid ◽  
Liver Mitochondria ◽  
Gas Chromatography Mass Spectrometry ◽  
Rat Liver Mitochondria ◽  
Mitochondrial Matrix ◽  
Chain Acyl ◽  
Long Chain

The degradation of elaidic acid (9-trans-octadecenoic acid), oleic acid, and stearic acid by rat mitochondria was studied to determine whether the presence of atransdouble bond in place of acisdouble bond or no double bond affects β-oxidation. Rat mitochondria from liver or heart effectively degraded the coenzyme A derivatives of all three fatty acids. However, with elaidoyl-CoA as a substrate, a major metabolite accumulated in the mitochondrial matrix. This metabolite was isolated and identified as 5-trans-tetradecenoyl-CoA. In contrast, little or none of the corresponding metabolites were detected with oleoyl-CoA or stearoyl-CoA as substrates. A kinetic study of long-chain acyl-CoA dehydrogenase (LCAD) and very long-chain acyl-CoA dehydrogenase revealed that 5-trans-tetradecenoyl-CoA is a poorer substrate of LCAD than is 5-cis-tetradecenoyl-CoA, while both unsaturated acyl-CoAs are poor substrates of very long-chain acyl-CoA dehydrogenase when compared with myristoyl-CoA. Tetradecenoic acid and tetradecenoylcarnitine were detected by gas chromatography/mass spectrometry and tandem mass spectrometry, respectively, when rat liver mitochondria were incubated with elaidoyl-CoA but not when oleoyl-CoA was the substrate. These observations support the conclusion that 5-trans-tetradecenoyl-CoA accumulates in the mitochondrial matrix, because it is less efficiently dehydrogenated by LCAD than is itscisisomer and that the accumulation of this β-oxidation intermediate facilitates its hydrolysis and conversion to 5-trans-tetradecenoylcarnitine thereby permitting a partially degraded fatty acid to escape from mitochondria. Analysis of this compromised but functional process provides insight into the operation of β-oxidation in intact mitochondria.

Lipid biosynthesis during the recovery of Salmonella typhimurium from thermal injury

1972 ◽  
Vol 18 (7) ◽  
pp. 1015-1021 ◽  
Author(s):  
Richard I. Tomlins ◽  
Gloria L. Vaaler ◽  
Z. John Ordal
Keyword(s):  
Fatty Acid ◽  
Salmonella Typhimurium ◽  
Total Lipid ◽  
Recovery Period ◽  
Fatty Acid Synthetase ◽  
Cyclopropane Fatty Acid ◽  
Normal Cells ◽  
Isotope Dilution Assay ◽  
Cyclopropane Fatty Acids ◽  
Fatty Acid Species

The heating of Salmonella typhimurium 7136 at 48C produced a sublethal injury. When injured cells were placed in fresh growth medium, they recovered within 3 h their normal tolerance to Levine Eosin Methylene Blue Agar containing 2% NaCl (EMBS). An isotope dilution assay demonstrated that 26.6% of the total lipid extracted from recovered cells was synthesized during the recovery period. Phospholipids synthesized during growth or recovery comprised about 90% of the total lipid. The concentrations of phosphatidyl ethanolamine and phosphatidyl glycerol synthesized during growth or recovery were similar; however, the amount of cardiolipin synthesized during recovery was greater than that obtained from normal cells. The fatty acid species synthesized during recovery were qualitatively similar but quantitatively dissimilar to the fatty acid profile of normal cells. The decreased concentrations of cyclopropane fatty acids with concomitant increases in their parent monoenoic acids gave presumptive evidence for the partial inactivation during injury of the enzyme cyclopropane fatty acid synthetase.

The effect of temperature and other growth conditions on the fatty acid composition of Escherichia coli

1981 ◽  
Vol 27 (8) ◽  
pp. 835-840 ◽  
Author(s):  
James T. McGarrity ◽  
John B. Armstrong
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Exponential Growth ◽  
Growth Conditions ◽  
Cyclopropane Fatty Acid ◽  
Cyclopropane Fatty Acids ◽  
K 12

During exponential growth, strain AW405 of Escherichia coli K-12 did not regulate the fatty acid composition of its lipids in response either to temperature or to the addition of NaCl, KCl, or MgCl2 to the medium. Growth was severely restricted at temperatures below 21 °C. Differential scanning calorimetry (DSC) of the isolated lipids from a culture with a typical exponential-phase composition yielded a broad transition, extending from approximately 0 to 33 °C, with a midpoint at 19 °C.During late stages of growth, the fatty acid composition changed. The percentage of palmitic acid increased and cyclopropane fatty acids replaced some of the equivalent unsaturated fatty acids. The increase in palmitate seemed largely independent of growth conditions, whereas the increase in the cyclopropane fatty acids was stimulated by the addition of salts or sucrose. Cultures grown in the presence of sucrose also had higher cyclopropane fatty acid levels during exponential growth. DSC of lipids from a sucrose culture, in which the compositional changes were most pronounced, yielded a much narrower transition with a midpoint at 27 °C.

Crystal structure of bacterial cyclopropane-fatty-acyl-phospholipid synthase with phospholipid

2019 ◽  
Vol 166 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Yulong Ma ◽  
Chunli Pan ◽  
Qihai Wang
Keyword(s):  
Crystal Structure ◽  
Active Site ◽  
Cyclopropane Ring ◽  
Fatty Acyl ◽  
Structural Basis ◽  
Cyclopropane Fatty Acid ◽  
Adverse Conditions ◽  
General Base ◽  
Acyl Chains ◽  
Methylene Group

AbstractThe lipids containing cyclopropane-fatty-acid (CFA) protect bacteria from adverse conditions such as acidity, freeze-drying desiccation and exposure to pollutants. CFA is synthesized when cyclopropane-fatty-acyl-phospholipid synthase (CFA synthase, CFAS) transfers a methylene group from S-adenosylmethionine (SAM) across the cis double bonds of unsaturated fatty acyl chains. Here, we reported a 2.7-Å crystal structure of CFAS from Lactobacillus acidophilus. The enzyme is composed of N- and C-terminal domain, which belong to the sterol carrier protein and methyltransferase superfamily, respectively. A phospholipid in the substrate binding site and a bicarbonate ion (BCI) acting as a general base in the active site were discovered. To elucidate the mechanism, a docking experiment using CFAS from L. acidophilus and SAM was carried out. The analysis of this structure demonstrated that three groups, the carbons from the substrate, the BCI and the methyl of S(CHn)3 group, were close enough to form a cyclopropane ring with the help of amino acids in the active site. Therefore, the structure supports the hypothesis that CFAS from L. acidophilus catalyzes methyl transfer via a carbocation mechanism. These findings provide a structural basis to more deeply understand enzymatic cyclopropanation.

scholarly journals Myosin Cross-reactive Antigen ofStreptococcus pyogenesM49 Encodes a Fatty Acid Double Bond Hydratase That Plays a Role in Oleic Acid Detoxification and Bacterial Virulence

2010 ◽  
Vol 285 (14) ◽  
pp. 10353-10361 ◽  
Author(s):  
Anton Volkov ◽  
Alena Liavonchanka ◽  
Olga Kamneva ◽  
Tomas Fiedler ◽  
Cornelia Goebel ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Double Bond ◽  
Bacterial Virulence

scholarly journals Profil FTIR Minyak Ikan dan Lemak Babi serta Perbandingannya sebagai Dasar Penentuan Autentifikasi Halal

ALCHEMY ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Dewi Sinta Megawati ◽  
Begum Fauziyah ◽  
Siti Maimunah ◽  
Abdul Wafi
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Double Bond ◽  
Ir Spectra ◽  
Fatty Acid Profile ◽  
Ftir Analysis ◽  
Tuna Oil ◽  
Significant Difference

<p>Research has been conducted on the determination of tuna oil and lard spectra using FTIR. This research aims to determine the IR spectra profile of lard and tuna oil and to compare both spectra profiles. Profile and comparison of lard and tuna oil IR spectra useful to determine whether an ingredient or a product contaminated with lard. The fatty acid profile of lard by FTIR analysis showed a significant difference in the absorption patterns of the spectra, especially at 3010-3000, 1680- 1600, and 968-966 cm-1 wavenumbers which represented the different composition and type of fatty acids in the lard and tuna oil. The absorption patterns at 3007 and 1653 cm-1 regions (double bond C=C cis) for tuna oil showed relatively high peaks if it is compared to lard samples because of the percentage of MUFA fatty acids (oleic acid) in tuna oil was much higher. </p><p> </p><p>Telah dilakukan penelitian mengenai penentuan spektra minyak ikan tuna dan lemak babi dengan menggunakan FTIR. Penelitian ini bertujuan untuk mengetahui profil spektra IR dari lemak babi dan minyak ikan tuna serta membandingkan kedua profil spektranya. Profil dan perbandingan spektra IR lemak babi dan minyak ikan tuna dapat digunakan sebagai dasar penentuan apakah suatu bahan atau produk terkontaminasi lemak babi. Profil asam lemak babi hasil analisis FTIR menunjukkan adanya perbedaan yang cukup signifikan pada pola-pola penyerapan spektra, khususnya pada bilangan gelombang 3010-3000, 1680-1600 dan 968-966 cm-1 yang merepresentasikan perbedaan komposisi dan jenis asam lemak pada sampel lemak babi dan minyak ikan tuna. Pola serapan pada bilangan gelombang 3007 dan 1653 cm-1 (ikatan rangkap C=C cis) untuk sampel minyak ikan tuna menunjukkan puncak yang relatif tinggi jika dibandingkan dengan sampel lemak babi karena persentase asam lemak MUFA (asam oleat) pada minyak ikan tuna jauh lebih tinggi. </p>

Raman spectroscopy as a tool for tracking cyclopropane fatty acids in genetically engineeredSaccharomyces cerevisiae

The Analyst ◽  
2019 ◽  
Vol 144 (3) ◽  
pp. 901-912 ◽  
Author(s):  
Kamila Kochan ◽  
Huadong Peng ◽  
Eunice S. H. Gwee ◽  
Ekaterina Izgorodina ◽  
Victoria Haritos ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Raman Spectroscopy ◽  
Fatty Acid ◽  
Cyclopropane Fatty Acid ◽  
Cyclopropane Fatty Acids

We demonstrate the first spectrum of cyclopropane fatty acid and track its presence in yeast using Raman spectroscopy and PLS-DA.

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