Effect of Thiolactomycin on de novo Fatty Acid Biosynthesis in Plants

1990 ◽  
Vol 45 (5) ◽  
pp. 518-520 ◽  
Author(s):  
Manfred Focke ◽  
Andrea Feld ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Acetate Incorporation ◽  
Acid Biosynthesis ◽  
Acetyl Coa ◽  
Malonyl Coa ◽  
Total Fatty Acids

Thiolactomycin was shown to be a potent inhibitor of de novo fatty acid biosynthesis in intact isolated chloroplasts (measured as [14C]acetate incorporation into total fatty acids). In our attempt to further localize the inhibition site we confirmed the inhibition with a fatty acid synthetase preparation, measuring the incorporation of [14C]malonyl-CoA into total fatty acids. From the two proposed enzymic targets of the fatty acid synthetase by thiolactomycin we could exclude the acetyl-CoA: ACP transacetylase. It appears that the inhibition by thiolactomycin occurs on the level of the condensing enzymes, i.e. the 3-oxoacyl-ACP synthases. We also demonstrated that the two starting enzymes of de novo fatty acid biosynthesis, the acetyl-CoA synthetase and the acetyl-CoA carboxylase, are not affected by thiolactomycin.

Notes: Inhibition of the Acetyl-CoA Carboxylase of Barley Chloroplasts by Cycloxydim and Sethoxydim

1987 ◽  
Vol 42 (11-12) ◽  
pp. 1361-1363 ◽  
Author(s):  
Manfred Focke ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Enzyme Preparation ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Acetyl Coa Carboxylase ◽  
Acid Biosynthesis ◽  
Hordeum Vulgare L ◽  
Acetyl Coa ◽  
Malonyl Coa

The effect of the three cyclohexane-1,3-dione derivatives cycloxydim, sethoxydim and clethodim on the incorpora­tion of 14C-labelled acetate, malonate. acctyl-CoA or malonyl-CoA into fatty acids was studied in an enzyme preparation isolated from barley chloroplasts (Hordeum vulgare L. var. “Alexis”). The herbicides cycloxydim, clethodim and sethoxydim block the de novo fatty acid biosynthesis from [2-14C]acetatc and [1-14C]acetyl-CoA, whereas that of [2-14C]malonatc and [2-14C)malonyl-CoA is not affected. The data indicate that the mode of action of the cyclohexane-1,3-dione derivatives in the sensitive bar­ley plant consists in the inhibition of de novo fatty acid biosynthesis by blocking the acetyl-CoA carboxylase (EC 6.4.1.2.).

Studies on the Inhibition of Biotin-Containing Carboxylases by Acetyl-CoA Carboxylase Inhibitors

1993 ◽  
Vol 48 (3-4) ◽  
pp. 294-300 ◽  
Author(s):  
Anja Motel ◽  
Simone Günther ◽  
Martin Clauss ◽  
Klaus Kobek ◽  
Manfred Focke ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Higher Plants ◽  
Acetate Incorporation ◽  
Acetyl Coa Carboxylase ◽  
Acid Biosynthesis ◽  
Acetyl Coa ◽  
Malonyl Coa ◽  
Key Enzyme

In higher plants the biosynthetic machinery of de novo fatty acid biosynthesis, measured as [14C]acetate incorporation into fatty acids, is predominantly located in plastids. A key enzyme in this pathway is the biotin-containing acetyl-CoA carboxylase (ACC , EC 6.4.1.2) which catalyzes the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. The ACC from Poaceae is very efficiently blocked by two herbicide classes, the cyclohexane-1,3-diones (e.g. sethoxydim, cycloxydim) and the aryloxyphenoxy-propionic acids (e.g. diclofop, fluazifop). It is shown that within the Poaceae not only different species but also different varieties exist which exhibit an altered sensitivity and tolerance towards both herbicide classes, which points to a mutation of the target enzyme ACC. In purifying the ACC we extended our research to the possible presence of other biotin-containing plant enzymes. In protein preparations from maize, oat, barley, pea and lentil we were able to demonstrate the carboxylation of acetyl-CoA, propionyl-CoA and methylcrotonyl-CoA. The two herbicide classes not only block the ACC, but also the activity of the propionyl-CoA carboxylase (PCC ), whereas the methylcrotonyl- CoA carboxylase (MCC ), a distinct biotin-containing enzyme from mitochondria, is not affected. MCC may play a role in isoprenoid catabolism. Whether PCC is a separate plastid enzyme or only a side activity of ACC is under current investigation. The efficiency of the graminicides in sensitive Poaceae is then not only determined by the inhibition of ACC, malonyl-CoA and fatty acid biosynthesis, but also by the exclusion of the PCC-catalyzed metabolic pathways of the plant cell.

Fatty-acid biosynthesis and acetyl-coa carboxylase as a target of diclofop, fenoxaprop and other aryloxy-phenoxy-propionic acid herbicides

1988 ◽  
Vol 43 (1-2) ◽  
pp. 47-54 ◽  
Author(s):  
Klaus Kobek ◽  
Manfred Focke ◽  
K. Lichtenthaler Botanisches
Keyword(s):  
Fatty Acid ◽  
Propionic Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Free Acid ◽  
Acetate Incorporation ◽  
Acetyl Coa Carboxylase ◽  
Acid Biosynthesis ◽  
Acetyl Coa ◽  
Acid Herbicides

The effect of the herbicides and aryloxy-phenoxy-propionic acid derivatives diclofop, fenoxaprop, fluazifop and haloxyfop and their ethyl, methyl or butyl esters on the de novo fatty-acid biosynthesis of isolated chloroplasts was investigated with intact chloroplasts isolated from sensitive grasses (Poaceae) and tolerant dicotyledonous plants (Pisum, Spinacia). The 4 herbicides (free-acid form) block the de novo fatty-acid biosynthesis ([2-14C]acetate incorporation into the total fatty-acid fraction) of the sensitive Avena chloroplasts in a dose-dependent manner. The I50- values (a 50% inhibition of the [14C]acetate incorporation) lie in the range of 10-7 to 2 x 10-6 ᴍ. The ethyl or methyl esters (diclofop, fenoxaprop, haloxyfop) and butyl ester (fluazifop) do not affect the de novo fatty-acid biosynthesis of isolated chloroplasts or only at a very high concentration of ca. 10-4 ᴍ. In contrast, the de novo fatty-acid biosynthesis of the tolerant dicotyledonous species (pea, spinach) is not affected by the 4 aryloxy-phenoxy-propionic acid herbicides. In an enzyme preparation isolated from chloroplasts of the herbicide-sensitive barley plants the de novo fatty-acid biosynthesis from [14C]acetate and [14C]acetyl-CoA is blocked by all 4 herbicides (free acids), whereas that of [14C]malonate and [14C]malonyl-CoA is not affected. This strongly suggests that the target of all 4 herbicides (free-acid form) is the acetyl-CoA carboxylase within the chloroplasts. The applied ester derivatives, in turn, which are ineffective in the isolated chloroplast test system, have equally little or no effect on the activity of the acetyl-CoA carboxylase. It is assumed that the acetyl-CoA carboxylase of the tolerant dicot plants investigated is modified in such a way that the 4 herbicides cannot bind to and affect the target

scholarly journals The synthesis of fatty acids in avocado mesocarp and cauliflower bud tissue

1975 ◽  
Vol 146 (2) ◽  
pp. 425-437 ◽  
Author(s):  
P J Weaire ◽  
R G Kekwick
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Gradient Centrifugation ◽  
Fatty Acid Synthetase ◽  
Synthetase Activity ◽  
Acid Biosynthesis ◽  
Avocado Fruit ◽  
Malonyl Coa ◽  
Fatty Acid Synthetase Activity

1. Plastid and mitochondrial preparations were obtained by density-gradient centrifugation of homogenates made by gentle disintergration of avocado fruit mesocarp and cauliflower bud tissue. 2. The mitochondrial preparations had respiratory activity but did not incorporate [1-14C]acetate into fatty acids. 3. The plastid preparations incorporated [1-14C]acetate into the range of fatty acids found in the parent tissue. No fatty acid synthetase activity could be detected in the 12000g supernatant of these homogenates. 4. Homogenates produced by rupture of the tissue in an Ato-Mix blender and plastid preparations disintegrated by ultrasonic treatment both had fatty acid synthetase activity which did not sediment at 105000g and which formed mainly [14-C]stearate from [2-14C]malonyl-CoA. 5. It is concluded that the plastids are the principal site of fatty acid biosynthesis in the tissues studied.

scholarly journals Elongation of fatty acids by microsomal fractions from the brain of the developing rat

1975 ◽  
Vol 152 (3) ◽  
pp. 495-501 ◽  
Author(s):  
P J Brophy ◽  
D E Vance
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rat Brain ◽  
Microsomal Fraction ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Soluble Fraction ◽  
Residual Activity ◽  
Acid Biosynthesis ◽  
Malonyl Coa

Elongation of fatty acids by microsomal fractions obtained from rat brain was measured by the incorporation of [2-14C]malonyl-CoA into fatty in the presence of palmitoyl-CoA or stearoyl-CoA. 2. Soluble and microsomal fractions were prepared from 21-day-old rats; density gradient centrifugation demonstrated that the stearoyl-CoA elongation system was localized in the microsomal fraction whereas fatty acid biosynthesis de novo from acetyl-CoA occurred in the soluble fraction. The residual activity de novo in the microsomal fraction was attributed to minor contamination by the soluble fraction. 3. The optimum concentration of [2-14C]malonyl-CoA for elongation of fatty acids was 25 mum for palmitoyl-CoA or stearoyl-CoA, and the corresponding optimum concentrations for the two primer acyl-CoA esters were 8.0 and 7.2 muM respectively. 4. Nadph was the preferred cofactor for fatty acid formation from palmitoyl-CoA or stearoyl-CoA, although NADH could partially replace it. 5. The stearoyl-CoA elongation system required a potassium phosphate buffer concentration of 0.075M for maximum activity; CoA (1 MUM) inhibited this elongation system by approx. 30%. 6. The fatty acids formed from malonyl-CoA and palmitoyl-CoA had a predominant chain length of C18 whereas stearoyl-CoA elongation resulted in an even distribution of fatty acids with chain lengths of C20, C22 and C24. 7. The products of stearoyl-CoA elongation were identified as primarily unesterified fatty acids. 8. The developmental pattern of fatty acid biosynthesis by rat brain microsomal preparations was studied and both the palmitoyl-CoA and stearoyl-CoA elongation systems showed large increases in activity between days 10 and 18 after birth.

Inhibition of the Plastidic Pyruvate Dehydrogenase Complex in Isolated Plastids of Oat

1994 ◽  
Vol 49 (7-8) ◽  
pp. 421-426 ◽  
Author(s):  
Andrea Golz ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Pyruvate Dehydrogenase ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Pyruvate Dehydrogenase Complex ◽  
Dependent Manner ◽  
Acid Biosynthesis ◽  
Acetyl Coa ◽  
Dehydrogenase Complex

The activity of the plastidic pyruvate dehydrogenase complex (pPDHC) is one source of acetyl-CoA in plastids of higher plants needed for de novo fatty acid biosynthesis. This plastidic enzyme reaction is specifically inhibited by acetylmethylphosphinate (AMPI), a com ­ pound which had hitherto been known only as an inhibitor of the mitochondrial pyruvate dehydrogenase complex (mPDHC). In the test system of isolated intact oat plastids (Avena sativa) [2-14C]pyruvate was used for de novo fatty acid biosynthesis. The incorporation of label from [2-14C]pyruvate in fatty acids was inhibited by AMPI in a dose-dependent manner. The inhibition rose with increasing preincubation time of plastids with the inhibitor. I50 values for the inhibition of de novo fatty acid biosynthesis from [2-14C]pyruvate by AMPI for iso­lated etioplasts and chloroplasts were 4.5 and 80 μm , respectively. The activity of the pPDHC decreased during greening of oat seedlings, as is seen from the decreasing incorporation of [2-14C]pyruvate into fatty acids during the light-induced transformation of etioplasts into chloroplasts. In contrast to the decreasing pPDHC activity, the activity of the plastidic acetyl-C oA synthetase (ACS), which transfers acetate to acetyl-CoA, rose parallel to the transfor­mation of etioplasts into chloroplasts. During the assay time of 20 min we could not detect an incorporation of radiolabel from pyruvate or acetate into β-carotene or any other carotenoid

scholarly journals The fractionation of the fatty acid synthetase activities of avocado mesocarp plastids

1975 ◽  
Vol 146 (2) ◽  
pp. 439-445 ◽  
Author(s):  
P J Weaire ◽  
R G O Kekwick
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
De Novo ◽  
Acyl Carrier Protein ◽  
Fatty Acid Synthetase ◽  
Carrier Protein ◽  
Acetyl Coa ◽  
Principal Product ◽  
Absolute Requirement ◽  
Malonyl Coa

1. The range of fatty acids formed by preparations of ultrasonically ruptured avocado mesocarp plastids was dependent on the substrate. Whereas [1-14C]palmitate and [14C]oleate were the major products obtained from [-14C]acetate and [1-14C]acetyl-CoA, the principal product from [2-14C]malonyl-CoA was [14-C]stearate. 2. Ultracentrifugation of the ruptured plastids at 105000g gave a supernatant that formed mainly stearate from [2-14C]malonyl-CoA and to a lesser extent from [1-14C]acetate. The incorporation of [1-14C]acetate into stearate by this fraction was inhibited by avidin. 3. The 105000g precipitate of the disrupted plastids incorporated [1-14C]acetate into a mixture of fatty acids that contained largely [14C]plamitate and [14C]oleate. The formation of [14C]palmitate and [14C]oleate by disrupted plastids was unaffected by avidin. 4. The soluble fatty acid synthetase was precipitated from the 105000g supernatant in the 35-65%-saturated-(NH4)2SO4 fraction and showed an absolute requirement for acyl-carrier protein. 5. Both fractions synthesized fatty acids de novo.

Inhibition of de novo Fatty-Acid Biosynthesis in Isolated Chloroplasts by the Antibiotic Cerulenin and Its Synthetic Derivatives

1992 ◽  
Vol 47 (5-6) ◽  
pp. 382-386 ◽  
Author(s):  
Bernd List ◽  
Andrea Golz ◽  
Wilhelm Boland ◽  
Hartmut K. Lichtenthaler
Keyword(s):  
Fatty Acid ◽  
Inhibitory Activity ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Specific Inhibitor ◽  
Hydrocarbon Chain ◽  
Acetate Incorporation ◽  
Acid Biosynthesis ◽  
Structural Element ◽  
Isolated Chloroplasts

The antibiotic cerulenin was shown to be a potent dose-dependent inhibitor of de novo fattyacid biosynthesis in intact isolated chloroplasts of different plants (measured as [14C]acetate incorporation into the total fatty-acid fraction). Various chemical derivatives of cerulenin were synthesized and tested in the chloroplast assay-system of oat, spinach and pea. Modifications of the hydrocarbon chain of cerulenin (e.g. tetrahydro-cerulenin and its short-chain cis-2,3-epoxy-4-oxoheptanamide derivative) decreased the inhibitory activity of cerulenin, whereas variations of the epoxy-oxo-amide structural element led to a complete loss of inhibition potency. The results indicate that the naturally occurring antibiotic cerulenin is the most active specific inhibitor of de novo fatty-acid biosynthesis, but the formation of the hydroxylactam ring seems to be an essential requirement for the inhibitory activity. Those structural analogues of cerulenin, which can no longer form a hydroxylactam ring, do not possess any inhibitory capacity.

SYNTHESIS OF FATTY ACIDS BY TESTICULAR TISSUE IN VITRO

1963 ◽  
Vol 41 (1) ◽  
pp. 1267-1274
Author(s):  
Peter F. Hall ◽  
Edward E. Nishizawa ◽  
Kristen B. Eik-Nes
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Fatty Acid Fraction ◽  
Testicular Tissue ◽  
Acid Biosynthesis ◽  
Adrenal Tissue ◽  
Substrate Fatty Acid

The fatty acids palmitic, palmitoleic, stearic, and oleic have been isolated from rabbit testis and evidence for the synthesis of palmitic and stearic acids de novo from acetate-1-C14is presented. ICSH did not produce demonstrable stimulation of the synthesis of these acids in vitro although the hormone stimulated the production of testosterone-C14by the same tissue. Adrenal tissue was shown to contain palmitic, stearic, and oleic acids, and ACTH did not increase the incorporation of acetate-1-C14into a fatty acid fraction extracted following incubation of adrenal tissue in the presence of this substrate. Fatty acid biosynthesis, therefore, is probably not influenced by the mechanisms by which tropic hormones increase steroid formation.

scholarly journals Reconstruction of the Fatty Acid Biosynthetic Pathway ofExiguobacterium antarcticumB7 Based on Genomic and Bibliomic Data

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Regiane Kawasaki ◽  
Rafael A. Baraúna ◽  
Artur Silva ◽  
Marta S. P. Carepo ◽  
Rui Oliveira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Short Chain Fatty Acids ◽  
Hexadecenoic Acid ◽  
Biosynthesis Pathway ◽  
Acid Biosynthesis ◽  
Cold Environments ◽  
Fatty Acid Biosynthesis Pathway

Exiguobacterium antarcticumB7 is extremophile Gram-positive bacteria able to survive in cold environments. A key factor to understanding cold adaptation processes is related to the modification of fatty acids composing the cell membranes of psychrotrophic bacteria. In our study we show thein silicoreconstruction of the fatty acid biosynthesis pathway ofE. antarcticumB7. To build the stoichiometric model, a semiautomatic procedure was applied, which integrates genome information using KEGG and RAST/SEED. Constraint-based methods, namely, Flux Balance Analysis (FBA) and elementary modes (EM), were applied. FBA was implemented in the sense of hexadecenoic acid production maximization. To evaluate the influence of the gene expression in the fluxome analysis, FBA was also calculated using thelog2⁡FCvalues obtained in the transcriptome analysis at 0°C and 37°C. The fatty acid biosynthesis pathway showed a total of 13 elementary flux modes, four of which showed routes for the production of hexadecenoic acid. The reconstructed pathway demonstrated the capacity ofE. antarcticumB7 tode novoproduce fatty acid molecules. Under the influence of the transcriptome, the fluxome was altered, promoting the production of short-chain fatty acids. The calculated models contribute to better understanding of the bacterial adaptation at cold environments.

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