scholarly journals Enterococcus faecalis Readily Adapts Membrane Phospholipid Composition to Environmental and Genetic Perturbation

2021 ◽  
Vol 12 ◽  
Author(s):  
Brittni M. Woodall ◽  
John R. Harp ◽  
William T. Brewer ◽  
Eric D. Tague ◽  
Shawn R. Campagna ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Enterococcus Faecalis ◽  
Lipid Composition ◽  
Lipid Membrane ◽  
High Resolution Mass Spectrometry ◽  
Phospholipid Composition ◽  
Specific Gene ◽  
Polar Head ◽  
Head Groups

The bacterial lipid membrane, consisting both of fatty acid (acyl) tails and polar head groups, responds to changing conditions through alteration of either the acyl tails and/or head groups. This plasticity is critical for cell survival as it allows maintenance of both the protective nature of the membrane as well as functioning membrane protein complexes. Bacteria that live in fatty-acid rich environments, such as those found in the human host, can exploit host fatty acids to synthesize their own membranes, in turn, altering their physiology. Enterococcus faecalis is such an organism: it is a commensal of the mammalian intestine where it is exposed to fatty-acid rich bile, as well as a major cause of hospital infections during which it is exposed to fatty acid containing-serum. Within, we employed an untargeted approach to detect the most common phospholipid species of E. faecalis OG1RF via ultra-high performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). We examined not only how the composition responds upon exposure to host fatty acids but also how deletion of genes predicted to synthesize major polar head groups impact lipid composition. Regardless of genetic background and differing basal lipid composition, all strains were able to alter their lipid composition upon exposure to individual host fatty acids. Specific gene deletion strains, however, had altered survival to membrane damaging agents. Combined, the enterococcal lipidome is highly resilient in response to both genetic and environmental perturbation, likely contributing to stress survival.

The roles of the diversity of amphipathic lipids in shaping membranes by membrane-shaping proteins

2020 ◽  
Vol 48 (3) ◽  
pp. 837-851
Author(s):  
Manabu Kitamata ◽  
Takehiko Inaba ◽  
Shiro Suetsugu
Keyword(s):  
Fatty Acid ◽  
Lipid Composition ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Membrane Lipids ◽  
Cell Types ◽  
Cellular Lipid ◽  
Head Groups ◽  
Packing Defects ◽  
Membrane Bending

Lipid compositions of cells differ according to cell types and intracellular organelles. Phospholipids are major cell membrane lipids and have hydrophilic head groups and hydrophobic fatty acid tails. The cellular lipid membrane without any protein adapts to spherical shapes, and protein binding to the membrane is thought to be required for shaping the membrane for various cellular events. Until recently, modulation of cellular lipid membranes was initially shown to be mediated by proteins recognizing lipid head groups, including the negatively charged ones of phosphatidylserine and phosphoinositides. Recent studies have shown that the abilities of membrane-deforming proteins are also regulated by the composition of fatty acid tails, which cause different degrees of packing defects. The binding of proteins to cellular lipid membranes is affected by the packing defects, presumably through modulation of their interactions with hydrophobic amino acid residues. Therefore, lipid composition can be characterized by both packing defects and charge density. The lipid composition regarding fatty acid tails affects membrane bending via the proteins with amphipathic helices, including those with the ArfGAP1 lipid packing sensor (ALPS) motif and via membrane-deforming proteins with structural folding, including those with the Bin–Amphiphysin–Rvs167 (BAR) domains. This review focuses on how the fatty acid tails, in combination with the head groups of phospholipids, affect protein-mediated membrane deformation.

scholarly journals Insights Into Walnut Lipid Metabolism From Metabolome and Transcriptome Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Suxian Yan ◽  
Xingsu Wang ◽  
Chenkang Yang ◽  
Junyou Wang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Transcriptome Analysis ◽  
High Resolution Mass Spectrometry ◽  
Essential Fatty Acids ◽  
Ultra Performance Liquid Chromatography ◽  
Systematic Evaluation ◽  
Specific Gene ◽  
Walnut Oil

Walnut oil is an excellent source of essential fatty acids. Systematic evaluation of walnut lipids has significance for the development of the nutritional and functional value of walnut. Ultra-performance liquid chromatography/Orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap HRMS) was used to characterize the lipids of walnut. A total of 525 lipids were detected and triacylglycerols (TG) (18:2/18:2/18:3) and diacylglycerols (DG) (18:2/18:2) were the main glycerolipids present. Essential fatty acids, such as linoleic acid and linolenic acid, were the main DG and TG fatty acid chains. Many types of phospholipids were observed with phosphatidic acid being present in the highest concentration (5.58%). Using a combination of metabolome and transcriptome analysis, the present study mapped the main lipid metabolism pathway in walnut. These results may provide a theoretical basis for further study and specific gene targets to enable the development of walnut with increased oil content and modified fatty acid composition.

scholarly journals Fatty acid positional distribution (sn-2 fatty acids) and phospholipid composition in Chinese breast milk from colostrum to mature stage

2018 ◽  
Vol 121 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Ke Wu ◽  
Runying Gao ◽  
Fang Tian ◽  
Yingyi Mao ◽  
Bei Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Fatty Acid Profile ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Content ◽  
Positional Distribution ◽  
Phospholipid Composition ◽  
Mature Stage ◽  
Feeding Time

AbstractThis study quantified the fatty acid profile with emphasis on the stereo-specifically numbered (sn) 2 positional distribution in TAG and the composition of main phospholipids at different lactation stages. Colostrum milk (n 70), transitional milk (n 96) and mature milk (n 82) were obtained longitudinally from healthy lactating women in Shanghai. During lactation, total fatty acid content increased, with SFA dominating in fatty acid profile. A high ratio of n-6:n-3 PUFA was observed as 11:1 over lactation due to the abundance of linoleic acid in Chinese human milk. As the main SFA, palmitic acid showed absolute sn-2 selectivity, while oleic acid, linoleic acid and α-linolenic acid, the main unsaturated fatty acids, were primarily esterified at the sn-1 and sn-3 positions. Nervonic acid and C22 PUFA including DHA were more enriched in colostrum with an sn-2 positional preference. A total of three dominant phospholipids (phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM)) were analysed in the collected samples, and each showed a decline in amount over lactation. PC was the dominant compound followed by SM and PE. With prolonged breast-feeding time, percentage of PE in total phospholipids remained constant, but PC decreased, and SM increased. Results from this study indicated a lipid profile different from Western reports and may aid the development of future infant formula more suitable for Chinese babies.

Abstract 631: Lipid Composition of Gold Nanoparticle-Templated High-Density Lipoprotein Analogs Dictates Cholesterol Efflux Function

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
R Kannan Mutharasan ◽  
Amritha T Singh ◽  
Kaylin M McMahon ◽  
C Shad Thaxton
Keyword(s):  
Fatty Acid ◽  
Lipid Content ◽  
Lipid Composition ◽  
Reverse Cholesterol Transport ◽  
Cholesterol Efflux ◽  
Lipid Membrane ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Cholesterol Transport

Background: Reverse cholesterol transport, the process by which cholesterol is effluxed from cells to high-density lipoproteins (HDL) and is delivered to the liver for clearance, is a promising pathway to augment for treatment of atherosclerosis. Though structure-function relationships for nascent, discoidal HDL and cholesterol efflux have been well studied, how the lipid composition of spherical HDL species - which varies in pathophysiological conditions - impacts their ability to mediate cholesterol efflux has not been investigated. Methods and Results: Spherical gold nanoparticles (5 nm) were used to synthesize spherical HDL analogs (HDL-NP) by adding ApoAI protein, and various lipids. With this strategy a panel of HDL-NP varying in lipid content was generated. HDL-NP designs tested include: dipalmitylphosphatidylcholine (DPPC, saturated fatty acid), dioleoylphosphatidylcholine (DOPC, unsaturated fatty acid), sphingomyelin, lysophosphatidylcholine (LPC), and mixtures thereof. All of these species are found in natural HDL. After characterizing protein and lipid stoichiometry of the purified HDL-NP, these HDL-NP designs were tested in the cellular reverse cholesterol transport assay using J774 mouse macrophages. These studies demonstrate that all HDL-NP designs mediate more efflux than equimolar amounts of ApoAI protein control, and further demonstrate that HDL-NP designs incorporating unsaturated phospholipid (DOPC), sphingomyelin, and LPC - each of which can increase disorder in the lipid membrane and thus give rise to opportunity for cholesterol to intercalate and bind - enhance cholesterol efflux compared to saturated phospholipid (DPPC) design. Conclusion: In summary, these results demonstrate that lipid content of HDL-NP - analogs of spherical HDL - dictates cholesterol efflux function, a finding which sheds light on the functional importance of lipid content variation seen in mature, spherical HDL species.

scholarly journals Phenomics reveals a novel putative chloroplast fatty acid transporter in the marine diatom Skeletonema marinoi involved in temperature acclimation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Oskar N. Johansson ◽  
Mats Töpel ◽  
Jenny Egardt ◽  
Matthew I. M. Pinder ◽  
Mats X. Andersson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Temperature Acclimation ◽  
Marine Diatom ◽  
Specific Gene ◽  
Hypothetical Proteins ◽  
Omega 3 ◽  
Fatty Acid Transporter ◽  
Future Value ◽  
Acid Transporter

Abstract Diatoms are the dominant phytoplankton in temperate oceans and coastal regions and yet little is known about the genetic basis underpinning their global success. Here, we address this challenge by developing the first phenomic approach for a diatom, screening a collection of randomly mutagenized but identifiably tagged transformants. Based upon their tolerance to temperature extremes, several compromised mutants were identified revealing genes either stress related or encoding hypothetical proteins of unknown function. We reveal one of these hypothetical proteins is a novel putative chloroplast fatty acid transporter whose loss affects several fatty acids including the two omega-3, long-chain polyunsaturated fatty acids - eicosapentaenoic and docosahexaenoic acid, both of which have medical importance as dietary supplements and industrial significance in aquaculture and biofuels. This mutant phenotype not only provides new insights into the fatty acid biosynthetic pathways in diatoms but also highlights the future value of phenomics for revealing specific gene functions in these ecologically important phytoplankton.

Influence of Altered Fatty Acid Composition on Resistance of Listeria monocytogenes to Antimicrobials

1993 ◽  
Vol 56 (4) ◽  
pp. 302-305 ◽  
Author(s):  
V. K. JUNEJA ◽  
P. M. DAVIDSON
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Acid Composition ◽  
Lipid Composition ◽  
Antimicrobial Agents ◽  
Food Preservation ◽  
Gas Liquid Chromatography ◽  
Antimicrobial Compounds

The sensitivity of Listeria monocytogenes Scott A and ATCC 19114 to antimicrobial compounds was altered when bacterial membrane lipid composition was modified by growth in the presence of added fatty acids. Analysis of cellular fatty acid composition by gas-liquid chromatography indicated that L. monocytogenes Scott A cells contained 0.97, 2.32, 0.81, and 0.72% (relative) of C14:0, C16:0, C18:0, and C18:l, respectively. In the presence of exogenously supplied C14:0, C16:0, C18:0, and C18:l, the percentages increased to 14.03, 30.92, 16.30, and 27.90%. Average MICs for L. monocytogenes Scott A and ATCC 19114 to sodium chloride, tertiary butylhydroquinone, methyl paraben, and propyl paraben were 10.0%, 81, 1406, and 544 μg/ml, respectively. Growing either strain in the presence of 50 μg/ml of either exogenously added C14:0 or C18:0 fatty acids increased their resistance to the four antimicrobial compounds. However, growth in the presence of C18:1 led to increased sensitivity to the antimicrobial agents. The results indicate that the susceptibility of L. monocytogenes to antimicrobial agents is related to the lipid composition of the cell membrane. Consequently, food preservation processes which alter fatty acid composition of L. monocytogenes could result in changes in antimicrobial susceptibility.

39 LIPID FINGERPRINTING OF INDIVIDUAL BOVINE BLASTOCYSTS BY DESORPTION IONIZATION ELECTROSPRAY MASS SPECTROMETRY

2012 ◽  
Vol 24 (1) ◽  
pp. 132 ◽  
Author(s):  
C. R. Ferreira ◽  
L. S. Eberlin ◽  
J. E. Hallett ◽  
R. G. Cooks
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Mass Spectrometer ◽  
Lipid Composition ◽  
Mass Spectra ◽  
Ms Analysis ◽  
Desi Ms ◽  
Complex Lipids

Mass spectrometry (MS) allows the detection and structural characterisation of intact molecules such as fatty acids and complex lipids. Desorption electrospray ionization (DESI) is an ambient ionization technique used for MS analysis and profiling and imaging of drugs, metabolites and lipids directly from biological samples with no sample preparation. With the recent introduction of morphologically friendly DESI-MS solvent systems, it is also possible to acquire DESI-MS data non-destructively. Due to the extractive nature of these solvent combinations, enough ion intensity can be generated to chemically profile samples of microscopic dimensions. The objective of this work was to perform chemical profiling on intact bovine blastocysts by DESI-MS, focusing on lipid distributions. Blastocysts produced in vitro were washed 3 times in PBS + 0.1% polyvinyl alcohol to remove lipids present in the culture medium, were placed in PBS/methanol 50% and stored under –20°C for 1 week. For DESI-MS analysis, the embryos were simply placed in glass slides and allowed to dry at room temperature. Mass spectra were acquired in the negative ion mode at the mass/charge range from m/z 150 to 1000, using as solvents a combination of 1:1 (vol/vol) ethanol:dimethylformamide (DMF) or acetonitrile:DMF. The mass spectrometer used was a LTQ linear ion trap mass spectrometer controlled by Xcalibur 2.0 software (Thermo Fisher Scientific, San Jose, CA, USA). The lipid species detected included deprotonated free fatty acids such as palmitic acid (m/z 255.2), stearic acid (m/z 283.2), arachidonic acid (m/z 311.2) and docosanoic acid (m/z 339.3). Free fatty acid dimers appear in the region from m/z 500 to 650 and complex lipids represented mainly by glycerophospholipid classes appear in the region from m/z 700 to 1000 and include phosphatidylinositols (PI 38:1; m/z 788.7), phosphatidylserines (PS 36:1, m/z 885.7) and also the chlorinated phosphatidylcholines (PC 36:1; m/z 794.7). After recording the mass spectra, embryos could still be observed in the glass slide with evident dehydration due to the action of the organic solvent. Since lipid composition of bovine embryos is closely related to cryosensitivity and due to the limited amount of analytes (each embryo is estimated to have a mass of 15 pg of total lipids) lipid analysis usually involves the pooling of individuals to have a large enough amount of analytes. Traditionally, gas chromatography is used for fatty acid residue analysis in oocytes and embryos pooled are submitted to lipid extraction and derivatization. Mass spectrometry by DESI, however, allows direct analysis of intact and single embryos and the profiling of not only free fatty acids but also complex lipids, represented mainly by 3 glycerophospholipid classes (PC, PI and PS). We envisage that DESI-MS will likely become a routine tool for the analysis of lipid composition in mammalian embryos and will contribute significantly to the development of culture systems that produce embryos with higher cryoresistance. Support from the Purdue University Center for Cancer Research Small Grants Program is gratefully acknowledged.

scholarly journals Release of Anti-Inflammatory Palmitoleic Acid and Its Positional Isomers by Mouse Peritoneal Macrophages

Biomedicines ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 480
Author(s):  
Alma M. Astudillo ◽  
Clara Meana ◽  
Miguel A. Bermúdez ◽  
Alfonso Pérez-Encabo ◽  
María A. Balboa ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Palmitoleic Acid ◽  
Peritoneal Macrophages ◽  
Fatty Acid Esters ◽  
Specific Gene ◽  
Hexadecenoic Acid ◽  
Positional Isomers ◽  
Anti Inflammatory ◽  
Mouse Peritoneal Macrophages

Positional isomers of hexadecenoic acid are considered as fatty acids with anti-inflammatory properties. The best known of them, palmitoleic acid (cis-9-hexadecenoic acid, 16:1n-7), has been identified as a lipokine with important beneficial actions in metabolic diseases. Hypogeic acid (cis-7-hexadecenoic acid, 16:1n-9) has been regarded as a possible biomarker of foamy cell formation during atherosclerosis. Notwithstanding the importance of these isomers as possible regulators of inflammatory responses, very little is known about the regulation of their levels and distribution and mobilization among the different lipid pools within the cell. In this work, we describe that the bulk of hexadecenoic fatty acids found in mouse peritoneal macrophages is esterified in a unique phosphatidylcholine species, which contains palmitic acid at the sn-1 position, and hexadecenoic acid at the sn-2 position. This species markedly decreases when the macrophages are activated with inflammatory stimuli, in parallel with net mobilization of free hexadecenoic acid. Using pharmacological inhibitors and specific gene-silencing approaches, we demonstrate that hexadecenoic acids are selectively released by calcium-independent group VIA phospholipase A2 under activation conditions. While most of the released hexadecenoic acid accumulates in free fatty acid form, a significant part is also transferred to other phospholipids to form hexadecenoate-containing inositol phospholipids, which are known to possess growth-factor-like-properties, and are also used to form fatty acid esters of hydroxy fatty acids, compounds with known anti-diabetic and anti-inflammatory properties. Collectively, these data unveil new pathways and mechanisms for the utilization of palmitoleic acid and its isomers during inflammatory conditions, and raise the intriguing possibility that part of the anti-inflammatory activity of these fatty acids may be due to conversion to other lipid mediators.

scholarly journals Lipid composition of the isolated rat intestinal microvillus membrane

1968 ◽  
Vol 109 (1) ◽  
pp. 51-59 ◽  
Author(s):  
G. G. Forstner ◽  
K. Tanaka ◽  
K. J. Isselbacher
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Neutral Lipid ◽  
Lipid Composition ◽  
Plasma Membranes ◽  
Membrane Lipids ◽  
Saturated Fatty Acids ◽  
Polar Lipids ◽  
Published Data ◽  
Microvillus Membrane

1. Rat intestinal microvillus plasma membranes were prepared from previously isolated brush borders and the lipid composition was analysed. 2. The molar ratio of cholesterol to phospholipid was greatest in the membranes and closely resembled that reported for myelin. 3. Unesterified cholesterol was the major neutral lipid. However, 30% of the neutral lipid fraction was accounted for by glycerides and fatty acid. 4. Five phospholipid components were identified and measured, including phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, sphingomyelin and lysophosphatidylcholine. Though phosphatidylethanolamine was the chief phospholipid, no plasmalogen was detected. 5. In contrast with other plasma membranes in the rat, the polar lipids of the microvillus membrane were rich in glycolipid. The cholesterol:polar lipid (phospholipid+glycolipid) ratio was about 1:3 for the microvillus membrane. Published data suggest that this ratio resembles that of the liver plasma membrane more closely than myelin or the erythrocyte membrane. 6. The fatty acid composition of membrane lipids was altered markedly by a single feeding of safflower oil. Membrane polar lipids did not contain significantly more saturated fatty acids than cellular polar lipids. Differences in the proportion of some fatty acids in membrane and cellular glycerides were noted. These differences may reflect the presence of specific membrane glycerides.

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