scholarly journals Transport of long-chain fatty acids in Escherichia coli. Evidence for role of fadL gene product as long-chain fatty acid receptor.

1986 ◽  
Vol 261 (1) ◽  
pp. 167-171 ◽  
Author(s):  
W D Nunn ◽  
R W Colburn ◽  
P N Black
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Gene Product ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acids ◽  
Long Chain Fatty Acid ◽  
Acid Receptor ◽  
Long Chain

Membrane permeation and intracellular trafficking of long chain fatty acids: insights fromEscherichia coliand 3T3-L1 adipocytes

1995 ◽  
Vol 73 (5-6) ◽  
pp. 223-234 ◽  
Author(s):  
Dev Mangroo ◽  
Bernardo L. Trigatti ◽  
Gerhard E. Gerber
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Uptake ◽  
Chain Fatty Acid ◽  
Acid Uptake ◽  
Long Chain Fatty Acids ◽  
Long Chain Fatty Acid ◽  
Long Chain ◽  
Chain Fatty Acids

Long chain fatty acids are important substrates for energy production and lipid synthesis in prokaryotes and eukaryotes. Their cellular uptake represents an important first step leading to metabolism. This step is induced in Escherichia coli by growth in medium containing long chain fatty acids and in murine 3T3-L1 cells during differentiation to adipocytes. Consequently, these have been used extensively as model systems to study the cellular uptake of long chain fatty acids. Here, we present an overview of our current understanding of long chain fatty acid uptake in these cells. It consists of several distinct steps, mediated by a combination of biochemical and physico-chemical processes, and is driven by conversion of long chain fatty acids to acyl-CoA by acyl-CoA synthetase. An understanding of long chain fatty acid uptake may provide valuable insights into the roles of fatty acids in the regulation of cell signalling cascades, in the regulation of a variety of metabolic and transport processes, and in a variety of mammalian pathogenic conditions such as obesity and diabetes.Key words: acyl-CoA synthetase, adipocyte, Escherichia coli, fatty acid, transport, uptake.

scholarly journals Evidence that His110 of the protein FadL in the outer membrane of Escherichia coli is involved in the binding and uptake of long-chain fatty acids: possible role of this residue in carboxylate binding

1995 ◽  
Vol 310 (2) ◽  
pp. 389-394 ◽  
Author(s):  
P N Black ◽  
Q Zhang
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Outer Membrane ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acids ◽  
Wild Type ◽  
Long Chain Fatty Acid ◽  
Histidine Residues ◽  
Long Chain

The binding of exogenous fatty acids to the outer-membrane protein FadL of Escherichia coli is specific for long-chain fatty acids (C14-C18). Oleoyl alcohol [(Z)-9-octadecen-1-ol] and methyl oleate were unable to displace FadL-specific binding of [3H]oleate (C18:1), suggesting that the carboxylate of the long-chain fatty acid was required for binding. Therefore the binding of exogenous fatty acids to FadL is governed, in part, by the carboxy group of the long-chain fatty acid. Treatment of whole cells with 1 mM diethyl pyrocarbonate (DEPC) depressed binding by 43-73% over the range of oleate concentrations used (10-500 nM). On the basis of these results and the notion that histidine residues often play a role involving proton transfer and charge-pairing, the five histidine residues within FadL (His110, His226, His327, His345 and His418) were replaced by alanine using site-directed mutagenesis. Altered FadL proteins were correctly localized in the outer membrane at wild-type levels and retained the heat-modifiable property characteristic of the wild-type protein. Initial screening of these fadL mutants revealed that the replacement of His110 by Ala resulted in a decreased growth rate on minimal oleate/agar plates. The rates of long-chain fatty acid transport for delta fadL strains harbouring each mutation on a plasmid, with the exception of fadLH110A, were the same, or nearly the same, as those for the wild-type. fadLH110A was also defective in binding, arguing that the functional effect of this mutation was at the level of long-chain-fatty-acid binding.(ABSTRACT TRUNCATED AT 250 WORDS)

The Very-Long-Chain Fatty Acid Synthase Is Inhibited by Chloroacetamides

2004 ◽  
Vol 59 (7-8) ◽  
pp. 549-553 ◽  
Author(s):  
Thomas Götz ◽  
Peter Böger
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acids ◽  
Irreversible Binding ◽  
Long Chain Fatty Acid ◽  
Malonyl Coa ◽  
Elongation Step ◽  
Long Chain

AbstractThe first elongation step to form very-long-chain fatty acids (VLCFAs) is catalyzed by the VLCFA-synthase. CoA-activated fatty acids react with malonyl-CoA to condense a C2-unit. As shown with recombinant enzyme this reaction is specifically inhibited by chloroacetamide herbicides. The inhibition is alleviated when the inhibitor (e.g. metazachlor) is incubated together with adequate concentrations of the substrate (e.g. oleoyl-CoA). Malonyl-CoA has no influence. However, once a chloroacetamide has been tightly bound to the synthase after an appropriate time it cannot be displaced anymore by the substrate. In contrast, oleoyl- CoA, is easily removed from the synthase by metazachlor. The irreversible binding of the chloroacetamides and their competition with the substrate explains the very low half-inhibition values of 10-8 м and below. Chiral chloroacetamides like metolachlor or dimethenamid give identical results. However, only the (S)-enantiomers are active.

The effect of a blend of dietary unesterified and saturated long-chain fatty acids on the performance of dairy cows in mid-lactation

1990 ◽  
Vol 41 (1) ◽  
pp. 129 ◽  
Author(s):  
KR King ◽  
CR Stockdale ◽  
TE Trigg
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Dairy Cows ◽  
Milk Fat ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acids ◽  
Long Chain Fatty Acid ◽  
Long Chain ◽  
Chain Fatty Acids

This experiment studied the effects of feeding a supplement of a blend of unesterified and saturated long-chain fatty acids on the productivity of dairy cows in mid-lactation. Twenty-three cows in their fourth month of lactation were individually fed ad libitum, a mixed balanced ration based on maize silage, lucerne hay and rolled grain. Varying quantities, up to 1020 g cow-1 day-1 of the fatty acid supplement, were mixed into the ration. Yields of milk and milk products were linearly related to total long-chain fatty acid intake. Milk fat content increased linearly while milk protein content averaged 3.59 (s.d. � 0.15)%. The marginal returns from feeding 1 kg of the supplement were 3.3 kg milk, 0.33 kg fat and 0.07 kg protein. The proportions of C 10:0, C12:0 and C 14:0 fatty acids in milk were decreased, while those of C 18:0 and C18:1 were increased as the result of feeding long-chain fatty acids. The concentration of lipid in plasma was increased, but acetate and D-(3)-hydroxybutyrate levels in blood remained unchanged with increased levels of dietary long-chain fatty acid. Efficiency of milk production was increased by 11% from feeding 1 kg of the supplement. In vivo digestibilities of dry matter, neutral and acid detergent fibres, and dietary long-chain fatty acids were unaffected by supplement.

scholarly journals The effect of intracellular pH on long-chain fatty acid uptake in 3T3-L1 adipocytes: evidence that uptake involves the passive diffusion of protonated long-chain fatty acids across the plasma membrane

1996 ◽  
Vol 313 (2) ◽  
pp. 487-494 ◽  
Author(s):  
Bernardo L. TRIGATTI ◽  
Gerhard E. GERBER
Keyword(s):  
Fatty Acids ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acids ◽  
Cytoplasmic Ph ◽  
Long Chain Fatty Acid ◽  
Intact Cells ◽  
Fatty Acid Binding ◽  
Long Chain

To understand the mechanism of long-chain fatty acid permeation of the plasma membrane in mammalian cells, the effects of changes in the cytoplasmic pH on the internalization of physiologically relevant, submicromolar concentrations of uncomplexed long-chain fatty acids were investigated in 3T3-L1 adipocytes. The acidification of the cytoplasm upon NH4Cl prepulsing of intact cells was accompanied by a rapid reduction of cellular long-chain fatty acid uptake (measured as the total accumulation of [9,10-3H]oleate). This was followed by a slow recovery to normal levels of uptake as the cytoplasmic pH recovered. Conventional filtration assays do not distinguish between fatty acid movement across the plasma membrane and intracellular steps, such as binding to cytoplasmic fatty acid-binding proteins or metabolism. While the in vitro binding of a photoreactive fatty acid, 11-m-diazirinophenoxy[11-3H]undecanoate, to a cytoplasmic fatty acid-binding protein was insensitive to changes in pH from pH 7.5 to 5.5, the in vitro conversion of oleate into oleoyl-CoA by cellular acyl-CoA synthetase decreased dramatically. Therefore, the labelling of the 15 kDa cytoplasmic fatty acid-binding protein in intact cells by the photoreactive fatty acid was used as a more direct measure of the permeation of the probe across the plasma membrane. Acidification of the cytoplasm resulted in an immediate reduction in the labelling of this protein in intact adipocytes. Its photolabelling recovered, however, upon the recovery of the cytoplasmic pH to normal levels. This was due to effects of the cytoplasmic pH on the permeation of the photoreactive fatty acid across the plasma membrane rather than its binding to the 15 kDa protein or metabolism in vivo. This is the first demonstration that the movement of physiologically relevant, submicromolar concentrations of uncomplexed long-chain fatty acids across the plasma membrane of intact cells is coupled to the cytoplasmic pH and suggests that it occurs by the diffusion of the protonated long-chain fatty acid through the lipid bilayer.

Transformation of lipids in activated sludge

2001 ◽  
Vol 43 (1) ◽  
pp. 165-172 ◽  
Author(s):  
T. E. Dueholm ◽  
K. H. Andreasen ◽  
P. H. Nielsen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Activated Sludge ◽  
Chain Fatty Acid ◽  
Hydrolysis Rate ◽  
Long Chain Fatty Acids ◽  
Long Chain Fatty Acid ◽  
Sludge Flocs ◽  
Uptake Rates ◽  
Long Chain

Transformation of lipids in activated sludge treatment plants is of interest for two reasons: lipids contribute 30–40% of the chemical oxygen demand (COD) in wastewater, and they may stimulate the growth of filamentous microorganisms in nutrient removal activated sludge plants. The transformation of lipids was investigated under aerobic and anoxic conditions by measuring the oxygen and nitrate uptake rates (OUR and NUR). The maximal OUR and NUR of long-chain fatty acid was found to be at the same level as acetate indicating that long-chain fatty acid was as easily consumable. However, the adsorption of long-chain fatty acid to surfaces of sludge flocs made it difficult to determine initial uptake rates of long-chain fatty acids. It was not possible to describe the hydrolysis rate of triacylglyceride by OUR and NUR to long-chain fatty acids because the hydrolysis rate was very slow. For a better description of the processes involved in transformation of lipids, a conceptual model was suggested. The processes in the suggested model were the adsorption/desorption of both triacylglyceride, and long-chain fatty acid onto surfaces of sludge flocs, hydrolysis of triacylglyceride by lipases and the uptake of long-chain fatty acid by bacteria under various conditions. The model can be helpful to structure design and evaluation of activated sludge experiment with lipids.

scholarly journals The Canonical Long-Chain Fatty Acid Sensing Machinery Processes Arachidonic Acid To Inhibit Virulence in Enterohemorrhagic Escherichia coli

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Melissa Ellermann ◽  
Angel G. Jimenez ◽  
Reed Pifer ◽  
Nestor Ruiz ◽  
Vanessa Sperandio
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Transcription Factor ◽  
Arachidonic Acid ◽  
Fatty Acid ◽  
Chain Fatty Acid ◽  
Host Immunity ◽  
Long Chain Fatty Acid ◽  
Content Type ◽  
Long Chain

ABSTRACT The mammalian gastrointestinal tract is a complex biochemical organ that generates a diverse milieu of host- and microbe-derived metabolites. In this environment, bacterial pathogens sense and respond to specific stimuli, which are integrated into the regulation of their virulence programs. Previously, we identified the transcription factor FadR, a long-chain fatty acid (LCFA) acyl coenzyme A (acyl-CoA) sensor, as a novel virulence regulator in the human foodborne pathogen enterohemorrhagic Escherichia coli (EHEC). Here, we demonstrate that exogenous LCFAs directly inhibit the locus of enterocyte effacement (LEE) pathogenicity island in EHEC through sensing by FadR. Moreover, in addition to LCFAs that are 18 carbons in length or shorter, we introduce host-derived arachidonic acid (C20:4) as an additional LCFA that is recognized by the FadR system in EHEC. We show that arachidonic acid is processed by the acyl-CoA synthetase FadD, which permits binding to FadR and decreases FadR affinity for its target DNA sequences. This interaction enables the transcriptional regulation of FadR-responsive operons by arachidonic acid in EHEC, including the LEE. Finally, we show that arachidonic acid inhibits hallmarks of EHEC disease in a FadR-dependent manner, including EHEC attachment to epithelial cells and the formation of attaching and effacing lesions. Together, our findings delineate a molecular mechanism demonstrating how LCFAs can directly inhibit the virulence of an enteric bacterial pathogen. More broadly, our findings expand the repertoire of ligands sensed by the canonical LFCA sensing machinery in EHEC to include arachidonic acid, an important bioactive lipid that is ubiquitous within host environments. IMPORTANCE Polyunsaturated fatty acids (PUFAs) play important roles in host immunity. Manipulation of lipid content in host tissues through diet or pharmacological interventions is associated with altered severity of various inflammatory diseases. Our work introduces a defined host-pathogen interaction by which arachidonic acid, a host-derived and dietary PUFA, can impact the outcome of enteric infection with the human pathogen enterohemorrhagic Escherichia coli (EHEC). We show that long-chain fatty acids including arachidonic acid act as signaling molecules that directly suppress a key pathogenicity island in EHEC following recognition by the fatty acyl-CoA-responsive transcription factor FadR. Thus, in addition to its established effects on host immunity and its bactericidal activities against other pathogens, we demonstrate that arachidonic acid also acts as a signaling molecule that inhibits virulence in an enteric pathogen.

Biocatalytic synthesis of ultra-long-chain fatty acid sugar alcohol monoesters

2015 ◽  
Vol 17 (6) ◽  
pp. 3475-3489 ◽  
Author(s):  
Wei Wei ◽  
Fengqin Feng ◽  
Bianca Perez ◽  
Mingdong Dong ◽  
Zheng Guo
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Solid Lipid Nanoparticles ◽  
Lipid Nanoparticles ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acids ◽  
Sugar Alcohol ◽  
Sugar Alcohols ◽  
Long Chain Fatty Acid ◽  
Long Chain

The enzymatic conjugation of ultra-long-chain fatty acids with a variety of sugar alcohols creates an array of molecules that could be used for multipurpose applications, from orthorhombic packing enhancers to excipients for the preparation of surfactant-free solid lipid nanoparticles (SLNs).

Sign in / Sign up

Export Citation Format

Share Document