Cyclopropane ring formation in membrane lipids of bacteria

1997 ◽  
Vol 61 (4) ◽  
pp. 429-441 ◽  
Author(s):  
D W Grogan ◽  
J E Cronan
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Lipid Bilayers ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Cyclopropane Ring ◽  
Saturated Fatty Acids ◽  
Physiological Role ◽  
Phospholipid Bilayer ◽  
Valuable Insight

It has been known for several decades that cyclopropane fatty acids (CFAs) occur in the phospholipids of many species of bacteria. CFAs are formed by the addition of a methylene group, derived from the methyl group of S-adenosylmethionine, across the carbon-carbon double bond of unsaturated fatty acids (UFAs). The C1 transfer does not involve free fatty acids or intermediates of phospholipid biosynthesis but, rather, mature phospholipid molecules already incorporated into membrane bilayers. Furthermore, CFAs are typically produced at the onset of the stationary phase in bacterial cultures. CFA formation can thus be considered a conditional, postsynthetic modification of bacterial membrane lipid bilayers. This modification is noteworthy in several respects. It is catalyzed by a soluble enzyme, although one of the substrates, the UFA double bond, is normally sequestered deep within the hydrophobic interior of the phospholipid bilayer. The enzyme, CFA synthase, discriminates between phospholipid vesicles containing only saturated fatty acids and those containing UFAs; it exhibits no affinity for vesicles of the former composition. These and other properties imply that topologically novel protein-lipid interactions occur in the biosynthesis of CFAs. The timing and extent of the UFA-to-CFA conversion in batch cultures and the widespread distribution of CFA synthesis among bacteria would seem to suggest an important physiological role for this phenomenon, yet its rationale remains unclear despite experimental tests of a variety of hypotheses. Manipulation of the CFA synthase of Escherichia coli by genetic methods has nevertheless provided valuable insight into the physiology of CFA formation. It has identified the CFA synthase gene as one of several rpoS-regulated genes of E. coli and has provided for the construction of strains in which proposed cellular functions of CFAs can be properly evaluated. Cloning and manipulation of the CFA synthase structural gene have also enabled this novel but extremely unstable enzyme to be purified and analyzed in molecular terms and have led to the identification of mechanistically related enzymes in clinically important bacterial pathogens.

scholarly journals Influences of 1-methylcyclopropene-containing papers on the metabolisms of membrane lipids in Anxi persimmons during storage

2020 ◽  
Vol 4 (3) ◽  
pp. 143-150
Author(s):  
Hui Wang ◽  
Guo Chen ◽  
Lili Shi ◽  
Hetong Lin ◽  
Yihui Chen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Electric Conductivity ◽  
Electrolyte Leakage ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Saturated Fatty Acids ◽  
Cellular Membrane ◽  
Leakage Rate ◽  
Diospyros Kaki ◽  
Gas Chromatograph

Abstract Objectives The aim of this work was to analyse the effects of 1-methylcyclopropene (1-MCP) treatment on the metabolisms of membrane lipids in postharvest Anxi persimmons during storage. Materials and methods Anxi persimmon (Diospyros kaki L. f. cv. Anxi) fruits were treated by paper containing 1-MCP with a concentration of 1.35 μl/l. The cellular membrane permeability was analysed by the electric conductivity meter. The activities of lipoxygenase (LOX), phospholipase (PLD) and lipase were determined by spectrophotometry. The component and relative amounts of membrane fatty acids were determined using gas chromatograph (GC). Results The 1-MCP-treated Anxi persimmons manifested a lower electrolyte leakage rate, lower LOX, PLD and lipase activities, higher levels of unsaturated fatty acids (USFAs), higher ratio of USFAs to saturated fatty acids (SFAs) (U/S), higher index of USFAs (IUFA), but lower levels of SFAs. Conclusions The degradation and the metabolisms of membrane lipids could be suppressed by 1-MCP treatment, which might be accountable for the delaying softening of postharvest Anxi persimmons during storage.

scholarly journals Revealing Further Insights on Chilling Injury of Postharvest Bananas by Untargeted Lipidomics

Foods ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 894 ◽  
Author(s):  
Juan Liu ◽  
Qingxin Li ◽  
Junjia Chen ◽  
Yueming Jiang
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Saturated Fatty Acids ◽  
Chilling Injury ◽  
Membrane Damage ◽  
Membrane Lipid ◽  
Banana Fruit ◽  
Control Fruit

Chilling injury is especially prominent in postharvest bananas stored at low temperature below 13 °C. To elucidate better the relationship between cell membrane lipids and chilling injury, an untargeted lipidomics approach using ultra-performance liquid chromatography–mass spectrometry was conducted. Banana fruit were stored at 6 °C for 0 (control) and 4 days and then sampled for lipid analysis. After 4 days of storage, banana peel exhibited a marked chilling injury symptom. Furthermore, 45 lipid compounds, including glycerophospholipids, saccharolipids, and glycerolipids, were identified with significant changes in peel tissues of bananas stored for 4 days compared with the control fruit. In addition, higher ratio of digalactosyldiacylglycerol (DGDG) to monogalactosyldiacylglycerol (MGDG) and higher levels of phosphatidic acid (PA) and saturated fatty acids but lower levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and unsaturated fatty acids were observed in banana fruit with chilling injury in contrast to the control fruit. Meanwhile, higher activities of phospholipase D (PLD) and lipoxygenase (LOX) were associated with significantly upregulated gene expressions of MaPLD1 and MaLOX2 and higher malondialdehyde (MDA) content in chilling injury-related bananas. In conclusion, our study indicated that membrane lipid degradation resulted from reduced PC and PE, but accumulated PA, while membrane lipid peroxidation resulted from the elevated saturation of fatty acids, resulting in membrane damage which subsequently accelerated the chilling injury occurrence of banana fruit during storage at low temperature.

scholarly journals Coordinated response of phospholipids and acyl components of membrane lipids in Pseudomonas putida A (ATCC 12633) under stress caused by cationic surfactants

Microbiology ◽  
2014 ◽  
Vol 160 (12) ◽  
pp. 2618-2626 ◽  
Author(s):  
Romina Marisa Heredia ◽  
Paola Sabrina Boeris ◽  
María Alicia Biasutti ◽  
Gastón Alberto López ◽  
Natalia Soledad Paulucci ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Pseudomonas Putida ◽  
Acid Composition ◽  
Cationic Surfactant ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Saturated Fatty Acids ◽  
Tetradecyltrimethylammonium Bromide

The present study assessed the role of membrane components of Pseudomonas putida A (ATCC 12633) under chemical stress conditions originated by treatment with tetradecyltrimethylammonium bromide (TTAB), a cationic surfactant. We examined changes in fatty acid composition and in the fluidity of the membranes of cells exposed to TTAB at a specific point of growth as well as of cells growing with TTAB. The addition of 10–50 mg TTAB l−1 promoted an increase in the saturated/unsaturated fatty acid ratio. By using fluorescence polarization techniques, we found that TTAB exerted a fluidizing effect on P. putida A (ATCC 12633) membranes. However, a complete reversal of induced membrane fluidification was detected after 15 min of incubation with TTAB. Consistently, the proportion of unsaturated fatty acids was lower in TTAB-treated cells as compared with non-treated cells. In the presence of TTAB, the content of phosphatidylglycerol increased (120 %), whilst that of cardiolipin decreased (60 %). Analysis of the fatty acid composition of P. putida A (ATCC 12633) showed that phosphatidylglycerol carried the major proportion of saturated fatty acids (89 %), whilst cardiolipin carried an elevated proportion of unsaturated fatty acids (18 %). The increase in phosphatidylglycerol and consequently in saturated fatty acids, together with a decrease in cardiolipin content, enabled greater membrane resistance, reversing the fluidizing effect of TTAB. Therefore, results obtained in the present study point to changes in the fatty acid profile as an adaptive response of P. putida A (ATCC 12633) cells to stress caused by a cationic surfactant.

scholarly journals Esterification of stearic acid with lower monohydroxylic alcohols

2018 ◽  
Vol 24 (3) ◽  
pp. 283-291 ◽  
Author(s):  
Vlatko Kastratovic ◽  
Miljan Bigovic
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Stearic Acid ◽  
Everyday Life ◽  
Chemical Industry ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Molar Ratio ◽  
Monocarboxylic Acids ◽  
Chain Lengths

Esters play a significant role in everyday life but also in the chemical industry. The aim of this study is to investigate the influence of different parameters on the process of esterification of higher monocarboxylic acids with lower monohydroxylic alcohols. We examined the influences of the following variables: the type and amount of the catalyst, the structure of alcohols and fatty acids, the acid/alcohol molar ratio, and the temperature of the esterification process. The descending order of reactivity found alcohols is: 1-butanol > 1-propanol > 2-methyl-1-propanol > ethanol > 2-butanol >2-propanol > 2-methyl-2-propanol. The results of this study show no significant effect of chain lengths of saturated fatty acids on the speed and yield of esterification. The presence of the double bond in unsaturated fatty acids reduces the acid to ester conversion. The highest yield (99%) was obtained in the reaction of stearic acid and 1-butanol with an acid/alcohol/catalyst (H2SO4) mole ratio 1/15/0.75 and at a temperature of 65?C.

scholarly journals Adaptive Changes in Membrane Lipids of Barophilic Bacteria in Response to Changes in Growth Pressure

1998 ◽  
Vol 64 (2) ◽  
pp. 479-485 ◽  
Author(s):  
Yutaka Yano ◽  
Akihiko Nakayama ◽  
Kenji Ishihara ◽  
Hiroaki Saito
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Saturated Fatty Acids ◽  
Hexadecenoic Acid ◽  
Bacterial Strains ◽  
Growth Pressure ◽  
Adaptive Changes ◽  
Total Fatty Acids

ABSTRACT The lipid compositions of barophilic bacterial strains which contained docosahexaenoic acid (DHA [22:6n-3]) were examined, and the adaptive changes of these compositions were analyzed in response to growth pressure. In the facultatively barophilic strain 16C1, phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were major components which had the same fatty acid chains. However, in PE, monounsaturated fatty acids such as hexadecenoic acid were major components, and DHA accounted for only 3.7% of the total fatty acids, while in PG, DHA accounted for 29.6% of the total fatty acids. In response to an increase in growth pressure in strain 16C1, the amounts of saturated fatty acids in PE were reduced, and these decreases were mainly balanced by an increase in unsaturated fatty acids, including DHA. In PG, the decrease in saturated fatty acids was mainly balanced by an increase in DHA. Similar adaptive changes in fatty acid composition were observed in response to growth pressure in obligately barophilic strain 2D2. Furthermore, these adaptive changes in response were also observed in response to low temperature in strain 16C1. These results confirm that the general shift from saturated to unsaturated fatty acids including DHA is one of the adaptive changes in response to increases in pressure and suggest that DHA may play a role in maintaining the proper fluidity of membrane lipids under high pressure.

DEVELOPMENT OF AN EXPERIMENTAL MODEL OF AVITAMINOSIS F

2020 ◽  
Vol 20 (2) ◽  
pp. 38-40
Author(s):  
A. Levitsky ◽  
A. Lapinska ◽  
I. Selivanskaya
Keyword(s):  
Fatty Acids ◽  
Experimental Model ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Coconut Oil ◽  
The Body ◽  
Regulatory Function ◽  
Omega 3 ◽  
White Rats ◽  
Arachidonic Acids

The article analyzes the role of essential polyunsaturated fatty acids (PUFA), especially omega-3 series in humans and animals. The biosynthesis of essential PUFA in humans and animals is very limited, so they must be consumed with food (feed). Тhe ratio of omega-3 and omega-6 PUFA is very important. Biomembranes of animal cells contain about 30% PUFA with a ratio of ω-6/ ω-3 1-2. As this ratio increases, the physicochemical properties of biomembranes and the functional activity of their receptors change. The regulatory function of essential PUFA is that in the body under the action of oxygenase enzymes (cyclooxygenase, lipoxygenase) are formed extremely active hormone-like substances (eicosanoids and docosanoids), which affect a number of physiological processes: inflammation, immunity, metabolism. Moreover, ω-6 PUFA form eicosanoids, which have pro-inflammatory, immunosuppressive properties, and ω-3 PUFAs form eicosanoids and docosanoids, which have anti-inflammatory and immunostimulatory properties. Deficiency of essential PUFA, and especially ω-3 PUFA, leads to impaired development of the body and its state of health, which are manifestations of avitaminosis F. Prevention and treatment of avitaminosis F is carried out with drugs that contain PUFA. To create new, more effective vitamin F preparations, it is necessary to reproduce the model of vitamin F deficiency. An experimental model of vitamin F deficiency in white rats kept on a fat –free diet with the addition of coconut oil, which is almost completely free of unsaturated fatty acids, and saturated fatty acids make up almost 99 % of all fatty acids was developed. The total content of ω-6 PUFA (sum of linoleic and arachidonic acids), the content of ω-3 PUFA (α-linolenic, eicosapentaenoic and docosahexaenoic acids) in neutral lipids (triglycerides and cholesterol esters) defined. Тhe content of ω-6 PUFA under the influence of coconut oil decreased by 3.3 times, and the content of ω-3 PUFA - by 7.5 times. Тhe influence of coconut oil, the content of ω-6 PUFA decreased by 2.1 times, and the content of ω-3 PUFA - by 2.8 times. The most strongly reduces the content of ω-3 PUFA, namely eicosapentaenoic, coconut oil, starting from 5 %. Consumption of FFD with a content of 15 % coconut oil reduces the content of eicosapentaenoic acid to zero, ie we have an absolute deficiency of one of the most important essential PUFAs, which determined the presence of vitamin F deficiency.

EFFECT OF GINGER, LEMURU FISH OIL SAPONIFICATION AND OLIVE OIL ON COMPOSITION FATTY ACID OF BEEF

2014 ◽  
Vol 4 (1) ◽  
pp. 31-39
Author(s):  
Siwitri Kadarsih
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fish Oil ◽  
Olive Oil ◽  
Rice Bran ◽  
Dry Matter ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Omega 3 ◽  
Omega 6

The objective was to get beef that contain unsaturated fatty acids (especially omega 3 and 6), so as to improve intelligence, physical health for those who consume. The study design using CRD with 3 treatments, each treatment used 4 Bali cattle aged approximately 1.5 years. Observations were made 8 weeks. Pasta mixed with ginger provided konsentrat. P1 (control); P2 (6% saponification lemuru fish oil, olive oil 1%; rice bran: 37.30%; corn: 62.70%; KLK: 7%, ginger paste: 100 g); P3 (lemuru fish oil saponification 8%, 2% olive oil; rice bran; 37.30; corn: 62.70%; KLK: 7%, ginger paste: 200 g). Konsentrat given in the morning as much as 1% of the weight of the cattle based on dry matter, while the grass given a minimum of 10% of the weight of livestock observation variables include: fatty acid composition of meat. Data the analyzies qualitative. The results of the study showed that the composition of saturated fatty acids in meat decreased and an increase in unsaturated fatty acids, namely linoleic acid (omega 6) and linolenic acid (omega 3), and deikosapenta deikosaheksa acid.Keywords : 

Differential Effects of Dietary Fatty Acids on Body Composition and Adiposity

2020 ◽  
Vol 16 (2) ◽  
pp. 142-154 ◽  
Author(s):  
Hadi Emamat ◽  
Zahra Yari ◽  
Hossein Farhadnejad ◽  
Parvin Mirmiran
Keyword(s):  
Fatty Acids ◽  
Body Composition ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Total Body Weight ◽  
Fat Distribution ◽  
Monounsaturated Fatty Acids ◽  
Dietary Fatty Acids ◽  
Dietary Fats ◽  
Total Body

Recent evidence has highlighted that fat accumulation, particularly abdominal fat distribution, is strongly associated with metabolic disturbance. It is also well-recognized that the metabolic responses to variations in macronutrients intake can affect body composition. Previous studies suggest that the quality of dietary fats can be considered as the main determinant of body-fat deposition, fat distribution, and body composition without altering the total body weight; however, the effects of dietary fats on body composition have controversial results. There is substantial evidence to suggest that saturated fatty acids are more obesogen than unsaturated fatty acids, and with the exception of some isomers like conjugate linoleic acid, most dietary trans fatty acids are adiposity enhancers, but there is no consensus on it yet. On the other hand, there is little evidence to indicate that higher intake of the n-3 and the n-6 polyunsaturated fatty acids can be beneficial in attenuating adiposity, and the effect of monounsaturated fatty acids on body composition is contradictory. Accordingly, the content of this review summarizes the current body of knowledge on the potential effects of the different types of dietary fatty acids on body composition and adiposity. It also refers to the putative mechanisms underlying this association and reflects on the controversy of this topic.

scholarly journals Explore the gene network regulating the composition of fatty acids in cottonseed

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Gene Network ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Accumulation Pattern ◽  
Time Points ◽  
Expression Characteristics

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.

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