scholarly journals Mixed fatty acid-phospholipid protocell networks

2021 ◽  
Author(s):  
Inga Põldsalu ◽  
Elif Senem Köksal ◽  
Irep Gözen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Solid Surface ◽  
Mixed Fatty Acid ◽  
Early Earth ◽  
Phospholipid Membranes ◽  
Mixed Surfactant ◽  
Solid Substrates ◽  
Membrane Compartments ◽  
Structurally Stable

AbstractSelf-assembled membranes composed of both fatty acids and phospholipids are both permeable for solutes and structurally stable, which was likely an advantageous combination for the development of primitive cells on the early Earth. Here we report on the solid surface-assisted formation of primitive mixed-surfactant membrane compartments, i.e. model protocells, from multilamellar lipid reservoirs composed of different ratios of fatty acids and phospholipids. Similar to the previously discovered enhancement of model protocell formation on solid substrates, we achieve spontaneous multi-step self-transformation of mixed surfactant reservoirs into closed surfactant containers, interconnected via nanotube networks. Some of the fatty acid containing compartments in the networks exhibit colony-like growth. We demonstrate that the compartments generated from fatty acid-containing phospholipid membranes feature increased permeability coefficients for molecules in the ambient solution, for fluorescein up to 7*10-6 cm/s and for RNA up to 3.5*10-6 cm/s. Our findings indicate that surface-assisted autonomous protocell formation and development, starting from mixed amphiphiles, is a plausible scenario for the early stages of the emergence of primitive cells.

scholarly journals Mixed fatty acid-phospholipid protocell networks

2021 ◽  
Author(s):  
Inga Põldsalu ◽  
Elif Senem Köksal ◽  
Irep Gözen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Mixed Fatty Acid ◽  
Self Assembled ◽  
Structurally Stable

Self-assembled membranes composed of both fatty acids and phospholipids are permeable for solutes and structurally stable, which was likely an advantageous combination for the development of primitive cells on the...

scholarly journals Fatty acid remodeling by LPCAT3 enriches arachidonate in phospholipid membranes and regulates triglyceride transport

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Tomomi Hashidate-Yoshida ◽  
Takeshi Harayama ◽  
Daisuke Hishikawa ◽  
Ryo Morimoto ◽  
Fumie Hamano ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Physical Properties ◽  
High Density ◽  
Phospholipid Membranes ◽  
Biological Processes ◽  
Eicosanoid Synthesis ◽  
Lipoprotein Assembly ◽  
Deficient Mice

Polyunsaturated fatty acids (PUFAs) in phospholipids affect the physical properties of membranes, but it is unclear which biological processes are influenced by their regulation. For example, the functions of membrane arachidonate that are independent of a precursor role for eicosanoid synthesis remain largely unknown. Here, we show that the lack of lysophosphatidylcholine acyltransferase 3 (LPCAT3) leads to drastic reductions in membrane arachidonate levels, and that LPCAT3-deficient mice are neonatally lethal due to an extensive triacylglycerol (TG) accumulation and dysfunction in enterocytes. We found that high levels of PUFAs in membranes enable TGs to locally cluster in high density, and that this clustering promotes efficient TG transfer. We propose a model of local arachidonate enrichment by LPCAT3 to generate a distinct pool of TG in membranes, which is required for normal directionality of TG transfer and lipoprotein assembly in the liver and enterocytes.

scholarly journals The NADPH-oxidase-associated H+ channel is opened by arachidonate

1992 ◽  
Vol 283 (1) ◽  
pp. 171-175 ◽  
Author(s):  
L M Henderson ◽  
J B Chappell
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Membrane Potential ◽  
Nadph Oxidase ◽  
Phorbol Esters ◽  
Ph Gradient ◽  
Protonmotive Force ◽  
Phospholipid Membranes ◽  
Chemotactic Peptides ◽  
O2 Production

The H+ channel associated with the generation of O2.- by NADPH oxidase and the oxidase itself must both be activated in response to stimuli (e.g. phorbol esters, chemotactic peptides, certain fatty acids). We have investigated the effects of membrane potential, an imposed pH gradient and a combination of the two (the protonmotive force) on the H+ conductivity of the cytoplast membrane. H+ conductivity was observed only in the presence of arachidonate and not in its absence. In the presence of arachidonate, H+ movement was determined by the protonmotive force. The effect of arachidonate was probably on a channel, since this fatty acid did not significantly increase the H+ permeability of artificial phospholipid membranes. It appears, therefore, that arachidonate is required both for the activation of O2.- production and the associated H(+)-channel-mediated efflux.

scholarly journals Semipermeable Mixed Phospholipid-Fatty Acid Membranes Exhibit K+/Na+ Selectivity in the Absence of Proteins

Life ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 39
Author(s):  
Xianfeng Zhou ◽  
Punam Dalai ◽  
Nita Sahai
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Phospholipid Fatty Acid ◽  
External Environment ◽  
Mixed Fatty Acid ◽  
Ion Pumps ◽  
Semipermeable Membranes ◽  
Macromolecular Transport ◽  
Ion Gradients ◽  
Protein Channels

Two important ions, K+ and Na+, are unequally distributed across the contemporary phospholipid-based cell membrane because modern cells evolved a series of sophisticated protein channels and pumps to maintain ion gradients. The earliest life-like entities or protocells did not possess either ion-tight membranes or ion pumps, which would result in the equilibration of the intra-protocellular K+/Na+ ratio with that in the external environment. Here, we show that the most primitive protocell membranes composed of fatty acids, that were initially leaky, would eventually become less ion permeable as their membranes evolved towards having increasing phospholipid contents. Furthermore, these mixed fatty acid-phospholipid membranes selectively retain K+ but allow the passage of Na+ out of the cell. The K+/Na+ selectivity of these mixed fatty acid-phospholipid semipermeable membranes suggests that protocells at intermediate stages of evolution could have acquired electrochemical K+/Na+ ion gradients in the absence of any macromolecular transport machinery or pumps, thus potentially facilitating rudimentary protometabolism.

Evaluation of an Improved Sublimation Apparatus Utilizing Carbon-14 Labeled Methyl Esters of Fatty Acids

1963 ◽  
Vol 46 (6) ◽  
pp. 947-949
Author(s):  
A J Sheppard ◽  
L A Ford
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Mixed Fatty Acid ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Carbon 14 ◽  
Acid Methyl

Abstract An improved sublimation appparatus has been designed and tested. The unit was tested with carbon-14 labeled methyl esters of fatty acids up through 22 carbon chain length. Samples of 40 mg or less of mixed fatty acid methyl esters can be sublimed routinely with recoveries of approximately 100%.

Platelet Aggregation in Finnish Men and Its Relation to Fatty Acids in Platelets, Plasma and Adipose Tissue

1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Platelet Aggregation ◽  
Acid Composition ◽  
Saturated Fatty Acids ◽  
Free Living ◽  
Ω3 Fatty Acids ◽  
Induced Aggregation

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.

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