Cone-shaped lipids increase the susceptibility of phospholipids in bilayers to the action of phospholipases

1985 ◽  
Vol 63 (4) ◽  
pp. 263-267 ◽  
Author(s):  
James Thomas Buckley
Keyword(s):  
Fatty Acid ◽  
Snake Venom ◽  
Bilayer Lipid ◽  
Polar Head ◽  
Pancreatic Phospholipase ◽  
Head Groups ◽  
Nonbilayer Lipids ◽  
Monogalactosyl Diglyceride ◽  
Fatty Acid Compositions ◽  
Stimulation Of

Addition of cardiolipin or diacylglycerol to dispersions of phosphatidylcholine greatly increased hydrolysis by snake venom or pancreatic phospholipase A2, as well as by a microbial phospholipase. Monogalactosyl diglyceride which, like cardiolipin and diacylglycerol, will form nonbilayer hexagonal II structures also caused an increase in the breakdown of phosphatidylcholine. Addition of digalactosyl diglyceride, a bilayer lipid from the same source, had a much smaller effect on the three phospholipases, indicating that stimulation by the nonbilayer lipids was not due to their fatty acid compositions. Stimulation of the microbial phospholipase by cardiolipin did not require the presence of calcium, leading to the conclusion that the formation of nonbilayer structures was not necessary. The results suggest that cone-shaped lipids increase the accessibility of lipids in bilayers to phospholipases by decreasing the packing of the polar head groups.

Polar head groups are important for barrier-protective effects of oxidized phospholipids on pulmonary endothelium

2007 ◽  
Vol 292 (4) ◽  
pp. L924-L935 ◽  
Author(s):  
Anna A. Birukova ◽  
Panfeng Fu ◽  
Santipongse Chatchavalvanich ◽  
Dylan Burdette ◽  
Olga Oskolkova ◽  
...  
Keyword(s):  
Protective Effects ◽  
Oxidized Phospholipids ◽  
Barrier Dysfunction ◽  
Polar Head ◽  
Cell Counts ◽  
Head Groups ◽  
Stimulation Of

We have previously described protective effects of oxidized 1-palmitoyl-2-arachidonoyl- sn-glycero-3-phosphocholine (OxPAPC) on pulmonary endothelial cell (EC) barrier function and demonstrated the critical role of cyclopentenone-containing modifications of arachidonoyl moiety in OxPAPC protective effects. In this study we used oxidized phosphocholine (OxPAPC), phosphoserine (OxPAPS), and glycerophosphate (OxPAPA) to investigate the role of polar head groups in EC barrier-protective responses to oxidized phospholipids (OxPLs). OxPAPC and OxPAPS induced sustained barrier enhancement in pulmonary EC, whereas OxPAPA caused a transient protective response as judged by measurements of transendothelial electrical resistance (TER). Non-OxPLs showed no effects on TER levels. All three OxPLs caused enhancement of peripheral EC actin cytoskeleton. OxPAPC and OxPAPS completely abolished LPS-induced EC hyperpermeability in vitro, whereas OxPAPA showed only a partial protective effect. In vivo, intravenous injection of OxPAPS or OxPAPC (1.5 mg/kg) markedly attenuated increases in the protein content, cell counts, and myeloperoxidase activities detected in bronchoalveolar lavage fluid upon intratracheal LPS instillation in mice, although OxPAPC showed less potency. All three OxPLs partially attenuated EC barrier dysfunction induced by IL-6 and thrombin. Their protective effects against thrombin-induced EC barrier dysfunction were linked to the attenuation of the thrombin-induced Rho pathway of EC hyperpermeability and stimulation of Rac-mediated mechanisms of EC barrier recovery. These results demonstrate for the first time the essential role of polar OxPL groups in blunting the LPS-induced EC dysfunction in vitro and in vivo and suggest the mechanism of agonist-induced hyperpermeability attenuation by OxPLs via reduction of Rho and stimulation of Rac signaling.

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.

STEROIDS AND THE STIMULATION OF SEXUAL REPRODUCTION OF A SPECIES OF PYTHIUM

1964 ◽  
Vol 10 (2) ◽  
pp. 187-195 ◽  
Author(s):  
R. H. Haskins ◽  
A. P. Tulloch ◽  
R. G. Micetich
Keyword(s):  
Fatty Acid ◽  
Sexual Reproduction ◽  
Vegetable Oils ◽  
Seed Oil ◽  
Side Chain ◽  
Low Concentrations ◽  
High Concentrations ◽  
Related Compounds ◽  
Fatty Acid Compositions ◽  
Stimulation Of

The fatty acid compositions of the mycelia of a parasitic species of Pythium and of various hosts are reported. The Pythium spp. contained high concentrations of myristic acid and low concentrations of linoleic and linolenic acids in comparison with concentrations in other fungi tested. Appreciable amounts of unsaturated C20 acids, uncommon in fungi, were found in the Phycomycetes tested. Vegetable oils and other fats of widely varying fatty acid compositions were all effective in stimulating sexual reproduction of the Pythium sp. It was concluded that substance(s) other than fatty acids present in the vegetable oils were responsible for the stimulation observed. The most active fraction in sunflower seed oil was isolated and identified as a phytosterol, probably β-sitosterol. The results of testing for stimulatory activity a series of structurally related compounds indicated that the sexual reproduction of the Pythium sp. studied required the presence of a substance such as β-sitosterol or cholesterol or one with similar structure and which similarly satisfied certain specific structural requirements regarding length of the C17 side chain, stereochemistry, and position of the oxygenated function. β-Sitosterol and cholesterol were effective at 0.2 γ/ml in potato dextrose agar.

The influence of various lipids on the activity of bovine milk galactosyltransferase

1980 ◽  
Vol 58 (10) ◽  
pp. 809-814 ◽  
Author(s):  
M. M. Mitranic ◽  
M. A. Moscarello
Keyword(s):  
Phase Transition ◽  
Fatty Acid ◽  
Phosphatidic Acid ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Physical State ◽  
Bovine Milk ◽  
Head Group ◽  
Head Groups ◽  
Fatty Acid Compositions

Purified bovine milk galactosyltransferase was combined with liposomes of different lipid composition. The activity was markedly affected by the nature of the lipid used. Thus phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol stimulated the activity, while phosphatidic acid and phosphatidylserine inhibited the activity of the transferase. Phosphatidylcholine, phosphatidylglycerol, and phosphatidic acid had identical fatty acid compositions, yet phosphatidylcholine and phosphatidylglycerol stimulated the activity while phosphatidic acid inhibited the activity. The effect on the enzyme was probably related to the nature of the head group since the inhibition by phosphatidic acid could be converted to stimulation by methylating the phosphatidic acid. The properties of several of the head groups is discussed. The physical state of the lipid was shown to affect the activity markedly. When the enzyme was combined with dimyristylphosphatidylcholine the activity was markedly stimulated when the lipid was in the liquid-crystalline state i.e., above the phase transition.

Comparison of Fatty Acid Compositions and Tocopherols in Perilla germplasm of South Korea

2017 ◽  
Author(s):  
JS Sung ◽  
YJ Jeong ◽  
DJ Kim ◽  
YY Lee ◽  
YA Jeon ◽  
...  
Keyword(s):  
Fatty Acid ◽  
South Korea ◽  
Fatty Acid Compositions

Serum Fatty Acid Compositions and Lipid Concentrations and Their Correlations.

1996 ◽  
Vol 20 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Toshichika TAKITA ◽  
Kahoru NAKAMURA ◽  
Mitsuru KIMIRA ◽  
Norihiro YAMADA ◽  
Yoshie KOBAYASHI ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Serum Fatty Acid ◽  
Fatty Acid Compositions

scholarly journals GPR40 Is Necessary but Not Sufficient for Fatty Acid Stimulation of Insulin Secretion In Vivo

Diabetes ◽  
2007 ◽  
Vol 56 (4) ◽  
pp. 1087-1094 ◽  
Author(s):  
M. G. Latour ◽  
T. Alquier ◽  
E. Oseid ◽  
C. Tremblay ◽  
T. L. Jetton ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Fatty Acid ◽  
Insulin Secretion In Vivo ◽  
Stimulation Of

Fatty Acid Data and Crop Surveys Indicate Sources of Red Sunflower Seed Weevil (Coleoptera: Curculionidae), Populations and Suggest Strategies for Management

2020 ◽  
Author(s):  
Jarrad R Prasifka ◽  
Beth Ferguson ◽  
James V Anderson
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Sunflower Seed ◽  
Cultural Practices ◽  
High Oleic ◽  
Fatty Acid Data ◽  
Smicronyx Fulvus ◽  
Combined Data ◽  
Fatty Acid Compositions

Abstract The red sunflower seed weevil, Smicronyx fulvus L., is a univoltine seed-feeding pest of cultivated sunflower, Helianthus annuus L. Artificial infestations of S. fulvus onto sunflowers with traditional (<25% oleic acid), mid-oleic (55–75%), or high oleic (>80%) fatty acid profiles were used to test if fatty acids could be used as natural markers to estimate the proportion of weevils developing on oilseed sunflowers rather than wild Helianthus spp. and confection (non-oil) types. Oleic acid (%) in S. fulvus confirmed the fatty acid compositions of mature larvae and weevil adults reflected their diets, making primary (oleic or linoleic) fatty acids feasible as natural markers for this crop-insect combination. Oleic acid in wild S. fulvus populations in North Dakota suggests at least 84 and 90% of adults originated from mid-oleic or high oleic sunflower hybrids in 2017 and 2018, respectively. Surveys in 2017 (n = 156 fields) and 2019 (n = 120 fields) extended information provided by S. fulvus fatty acid data; no significant spatial patterns of S. fulvus damage were detected in samples, damage to oilseed sunflowers was greater than confection (non-oil) types, and the majority of damage occurred in ≈10% of surveyed fields. Combined, data suggest a few unmanaged or mismanaged oilseed sunflower fields are responsible for producing most S. fulvus in an area. Improved management seems possible with a combination of grower education and expanded use of non-insecticidal tactics, including cultural practices and S. fulvus-resistant hybrids.

scholarly journals Evaluation of Chemical Variability of Cured Vanilla Beans (Vanilla tahitensis and Vanilla planifolia)

2009 ◽  
Vol 4 (10) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Christel Brunschwig ◽  
François Xavier Collard ◽  
Jean-Pierre Bianchini ◽  
Phila Raharivelomanana
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Dry Matter ◽  
Monounsaturated Fatty Acids ◽  
Vanilla Planifolia ◽  
Chemical Variability ◽  
Total Fatty Acids ◽  
Curing Method ◽  
Fatty Acid Compositions

In order to establish a chemical fingerprint of vanilla diversity, thirty samples of V. planifolia J. W. Moore and V. tahitensis G. Jackson cured beans from seven producing countries were examined for their aroma and fatty acid contents. Both fatty acid and aroma compositions were found to vary between vanilla species and origins. Vanillin was found in higher amounts in V. planifolia (1.7-3.6% of dry matter) than in V. tahitensis (1.0-2.0%), and anisyl compounds were found in lower amounts in V. planifolia (0.05%) than in V. tahitensis (1.4%-2.1%). Ten common and long chain monounsaturated fatty acids (LCFA) were identified and were found to be characteristic of the vanilla origin. LCFA derived from secondary metabolites have discriminating compositions as they reach 5.9% and 15.8% of total fatty acids, respectively in V. tahitensis and V. planifolia. This study highlights the role of the curing method as vanilla cured beans of two different species cultivated in the same country were found to have quite similar fatty acid compositions.

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