Search results

1

Detailed characterization of the substrate specificity of mouse wax synthase

100%

Miklaszewska M., Kawiński A., Banaś A.

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2013

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vol. 60

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issue 2

209-215

EN

Wax synthases are membrane-associated enzymes catalysing the esterification reaction between fatty acyl-CoA and a long chain fatty alcohol. In living organisms, wax esters function as storage materials or provide protection against harmful environmental influences. In industry, they are used as ingredients for the production of lubricants, pharmaceuticals, and cosmetics. Currently the biological sources of wax esters are limited to jojoba oil. In order to establish a large-scale production of desired wax esters in transgenic high-yielding oilseed plants, enzymes involved in wax esters synthesis from different biological resources should be characterized in detail taking into consideration their substrate specificity. Therefore, this study aims at determining the substrate specificity of one of such enzymes -; the mouse wax synthase. The gene encoding this enzyme was expressed heterologously in Saccharomyces cerevisiae. In the in vitro assays (using microsomal fraction from transgenic yeast), we evaluated the preferences of mouse wax synthase towards a set of combinations of 11 acyl-CoAs with 17 fatty alcohols. The highest activity was observed for 14:0-CoA, 12:0-CoA, and 16:0-CoA in combination with medium chain alcohols (up to 5.2, 3.4, and 3.3 nmol wax esters/min/mg microsomal protein, respectively). Unsaturated alcohols longer than 18°C were better utilized by the enzyme in comparison to the saturated ones. Combinations of all tested alcohols with 20:0-CoA, 22:1-CoA, or Ric-CoA were poorly utilized by the enzyme, and conjugated acyl-CoAs were not utilized at all. Apart from the wax synthase activity, mouse wax synthase also exhibited a very low acyl-CoA:diacylglycerol acyltransferase activity. However, it displayed neither acyl-CoA:monoacylglycerol acyltransferase, nor acyl-CoA:sterol acyltransferase activity.

2

Effects of high sucrose diet, gemfibrozil, and their combination on plasma paraoxonase 1 activity and lipid levels in rats

100%

Macan M., Vrkić N., Vrdoljak A. L., Radić B., Bradamante V.

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2010

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vol. 57

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issue 3

321-326

EN

We investigated the influence of high sucrose diet (HSD) after 3 or 5 weeks of administration on paraoxonase 1 (PON1) activity in plasma of normolipidemic rats and the relationship between serum PON1 activity, triacylglycerides (TGs), HDL and total cholesterol vs. the control group of rats fed normal, control diet (CD). Because the data about the influence of gemfibrozil (GEM) on PON1 activity are controversial, we also investigated its effects (administration in the 4th and 5th week in rats on HSD and CD) on plasma PON1 activity and lipid levels in normolipidemic rats, and in rats with hypertriglyceridemia caused by HSD. Our results obtained in rats on HSD show a significant increase of plasma TGs levels by 47% (P<0.05) after 5 weeks of treatment, and PON1 activity by 32% and 23% (P<0.05) after 3 and 5 weeks, but without change in lipid levels vs. rats on CD. In the rats on CD and HSD, GEM caused a significant decrease of PON1 activity by 44% and 33%, while a significant decrease of TGs level by 38% (P<0.05) was measured only in rats on CD. The effects of GEM on total cholesterol, HDL and LDL in both groups of rats were typical for its action on lipoprotein metabolism. Because GEM in the rat liver stimulates proliferation of peroxisomes, β oxidation, and production of H2O2, it is possible that the oxidative stress induced by GEM damages hepatocytes and lowers the synthesis of PON1.

3

Violaxanthin and diadinoxanthin de-epoxidation in various model lipid systems

100%

Latowski D., Goss R., Bojko M., Strzałka K.

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2012

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vol. 59

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issue 1

101-103

EN

The xanthophyll cycle is an important photoprotective process functioning in plants. One of its forms, the violaxanthin (Vx) cycle, involves interconversion between: Vx, antheraxanthin (Ax) and zeaxanthin (Zx). Another kind of the xanthophyll cycle is the diadinoxanthin (Ddx) cycle in which interconversion between Ddx and diatoxanthin (Dtx) occurs. In this study an information on molecular mechanism and regulation of these two types of the xanthophyll cycle is presented. The influence of lipids on the de-epoxidation of the xanthophyll cycle pigments was investigated, with special focus put on the significance of physical properties of the aggregates formed by inverted lipid micelles, which are necessary for activity of the xanthophyll cycle enzymes. In particular, thickness of the hydrophobic fraction of the aggregates, size of the inverted micelles, suggested by mathematical description of the structures and solubility of Vx and Ddx in various kind of lipids were studied. Obtained results show that the rate of de-epoxidation is strongly dependent on the physicochemical properties of the lipids used. The key role for enzyme activation play non-bilayer lipids and the parameters of inverted micelles such as thickness, fluidity of hydrophobic core and their diameter. The presented results show that MGDG and other non-lamellar lipids like different forms of phosphatidylethanolamine are necessary for the Vx and Ddx de-epoxidation because they provide the three-dimensional structures, which are needed for the binding of de-epoxidases and for the accessibility of Vx and Ddx to these enzymes.

4

Dopamine and iron mediated fragmentation of galactocerebroside and cardiolipin in micelles

100%

Yurkova I., Kisel M., Arnhold J., Shadyro O.

Open Chemistry

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2007

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vol. 5

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issue 4

970-980

EN

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and thin-layer chromatography (TLC) have been used to study dopamine and iron mediated free-radical transformation of lipids in their hydrophilic parts. It has been shown that the action of the dopamine/Fe2+ system on galactocerebroside or cardiolipin, which are the components of mixed micelles, results in formation of ceramide or phosphatidic acid and phosphatidylhydroxyacetone, respectively. These data, when combined with results obtained using the ascorbate/Fe2+/H2O2 oxidizing system with the same substrates, demonstrate that the formation of these products proceeds via an OH-radical induced fragmentation taking place in polar moiety of the starting lipids. [...]

5

The oxidability of krill lipids

100%

Kołakowska A., Kołakowska A.

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issue 1

6

The influence of sex and maturity stage of krill (Euphausia superba Dana) upon the content and composition of its lipids

100%

Kołakowska A., Kołakowska A.

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issue 1

7

Spin trapping studies of essential oils in lipid systems

100%

Makarova K., Drązikowska K., Suska B., Zawada K., Wawer I.

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issue 3

461-468

EN

In the present work, we report the results of a spin trapping ESR study of four essential oils widely used for skin care products such as creams and bath salts. The studied essential oils are Rosmarini aetheroleum (rosemary), Menthae piperitae aetheroleum (mint), Lavandulae aetheroleum (lavender), and Thymi aetheroleum (thyme). Fenton reaction in the presence of ethanol was used to generate free radicals. The N-tert-butyl-α-phenylnitrone (PBN) was used as a spin trap. In the Fenton reaction, the rosemary oil had the lowest effect on radical adduct formation as compared to the reference Fenton system. Since essential oils are known to be lipid soluble, we also conducted studies of essential oils in Fenton reaction in the presence of lipids. Two model lipids were used, namely 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). The obtained results suggested that in the presence of DOPC lipids, the •OH and PBN/•CHCH3(OH) radicals are formed in both phases, that is, water and lipids, and all the studied essential oils affected the Fenton reaction in a similar way. Whereas, in the DPPC system, the additional type of PBN/X (aN = 16.1 G, aH = 2.9 G) radical adduct was generated. DFT calculations of hyperfine splittings were performed at B3LYP/6-311+G(d,p)/EPR-II level of theory for the set of c-centered PBN adducts in order to identify PBN/X radical.

8

A biochemical study on the level of lipids and glycoproteins in the serum and platelets of liver cirrhotic bleeders

88%

Vijayalakshmi S., Geetha A., Jeyachristy S. A.

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2006

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vol. 53

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issue 1

213-220

EN

Bleeding complication and abnormal platelet functions are associated with liver cirrhosis. The aim of the present investigation was to assess the functional integrity of platelets in terms of lipids like cholesterol and phospholipids, glycoproteins and membrane-bound enzymes. Liver cirrhotic patients with bleeding complications were studied. Age and sex matched normal healthy volunteers were also involved in this study as a control group. Levels of cholesterol, phospholipids, glycoproteins and adenosine triphosphatases were assessed in isolated platelet membrane fraction. The level of glycoproteins and the activity of adenosine triphosphatases were found to be decreased significantly in cirrhotic patients. The cholesterol/phospholipid ratio was found to be altered significantly, indicating an alteration in the fluidity of platelet membrane. The results of this study reveal that the functional impairment of platelets in liver cirrhotic patients which is responsible for their bleeding tendency might also be due to altered lipid and enzyme levels in platelet membrane.

9

Antihyperlipidemic and antiatherogenic activity of simvastatin may involve modulation of the expression of lecithin:cholesterol acyl transferase

88%

Adekunle A., Fatoki J., Adelusi T.

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2013

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vol. 60

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issue 4

579-583

EN

Introduction: The statin-induced effects on high density lipoprotein (HDL) are relatively small compared with those of low density lipoprotein (LDL) and, as a result, most clinical trials of statins are underpowered with respect to HDL parameters. This study experimentally investigated, the effects of statin on serum lipids, atherogenic index and examined the possibility of a relationship amongst serum concentrations of HDL-C, atherogenic index and activity of lecithin:cholesterol acyl transferase. Method: Thirty albino rats equally divided into 2 groups were used for the study. Group 1 was given 0.05mg/g of statin daily for 28 days, while group 2 served as control. HDL concentration was determined as a measure of HDL-C. Total cholesterol (TC), triglyceride (TG) and HDL-C were determined spectrophotometrically while LDL-C was calculated using the Frieldwald formula. Effect on the activity of lecithin:cholesterol acyl transferase was determined by the difference between the amount of free cholesterol converted to cholesteryl ester in the two experimental groups. Effects on body and relative organs weights were also determined. Results: The administration of statin caused a significant increase in serum concentration of HDL-C, while levels of LDL-C, triglyceride and total cholesterol were reduced. Simvastatin caused a significant reduction in the atherogenic index (TC/HDL-C; LDLC/HDL-C). The administration of statin significantly induced the activity of lecithin:cholesterol acyl transferase (LCAT) as evident by reduced serum concentration of free cholesterol when compared with control. The administration of statin caused reduced body and relative organs weights. Conclusion: The study showed that serum antihyperlipidemic and antiatherogenic activity of statin may involve the induction of LCAT.

10

The lipid compositionof some Antarctic Crustacea

88%

Kołakowska A., Kołakowska A.

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issue 1

11

The reactions of hypochlorous acid, the reactive oxygen species produced by myeloperoxidase, with lipids.

75%

Spickett C. M., Jerlich A., Panasenko O. M., Arnhold J., Pitt A. R., Stelmaszyńska T., Joerg Schaur R.

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2000

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vol. 47

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issue 4

889-899

EN

Myeloperoxidase (MPO), an abundant enzyme in phagocytes, has been implicated in the pathogenesis of various inflammatory diseases including atherosclerosis. The major oxidant produced by MPO, hypochlorous acid (HOCl), is able to modify a great variety of biomolecules by chlorination and/or oxidation. In this paper the reactions of lipids (preferentially unsaturated fatty acids and cholesterol) with either reagent HOCl or HOCl generated by the MPO-hydrogen peroxide-chloride system are reviewed. One of the major issues has been whether the reaction of HOCl with lipids of low density lipoprotein (LDL) yields predominantly chlorohydrins or lipid hydroperoxides. Electrospray mass spectrometry provided direct evidence that chlorohydrins rather than peroxides are the major products of HOCl- or MPO-treated LDL phosphatidylcholines. Nevertheless lipid peroxidation is a possible alternative reaction of HOCl with polyunsaturated fatty acids if an additional radical source such as pre-formed lipid hydroperoxides is available. In phospholipids carrying a primary amino group such as phosphatidylethanolamine chloramines are the preferred products compared to chlorohydrins. Cholesterol can be converted by HOCl to great variety of oxysterols besides three isomers of chlorohydrins. For the situation in vivo it appears that the type of reaction occurring between HOCl and lipids would very much depend on the circumstances, e.g. the pH and the presence of radical initiators. The biological effects of lipid chlorohydrins are not yet well understood. It has been shown that chlorohydrins of both unsaturated fatty acids as well as of cholesterol may cause lysis of target cells, possibly by disruption of membrane structures.

12

The Effects of Sprint Interval vs. Continuous Endurance Training on Physiological and Metabolic Adaptations in Young Healthy Adults

75%

Nalcakan G. R.

Journal of Human Kinetics

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2014

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vol. 44

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issue 1

97-109

EN

The purpose of this study was to compare the effects of sprint interval training (SIT) and continuous endurance training (CET) on selected anthropometric, aerobic, and anaerobic performance indices as well as the blood lipid profile, inflammatory and muscle damage markers in healthy young males. Fifteen recreationally active male volunteers (age: 21.7 ±2.2 years, body mass: 83.0 ±8.0 kg, body height: 1.82 ±0.05 m) were divided into two groups according to their initial VO2max levels. Training programs were conducted 3 times per week for 7 weeks. The SIT program consisted of 4-6 Wingate anaerobic sprints with a 4.5 min recovery, while CET consisted of 30-50 min cycling at 60% VO2max. Biochemical, anthropometric and fitness assessments were performed both pre and post-intervention. Significant improvements in VO2max, anaerobic power and capacity, and VO2 utilization during the submaximal workout and significant decreases in body fat and in waist circumference after the intervention occurred in both SIT and CET groups. Significantly greater gross efficiency was measured in the CET group. No differences in the lipid profile or serum levels of inflammatory, myocardial and skeletal muscle damage markers were observed after the training period. The study results agree with the effectiveness of a 30 s all-out training program with a reduced time commitment for anthropometric, aerobic and anaerobic adaptation and eliminate doubts about its safety as a model.

13

Molecular dynamics simulations of potassium channels

75%

Domene C.

Open Chemistry

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2007

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vol. 5

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issue 3

635-671

EN

Despite the complexity of ion-channels, MD simulations based on realistic all-atom models have become a powerful technique for providing accurate descriptions of the structure and dynamics of these systems, complementing and reinforcing experimental work. Successful multidisciplinary collaborations, progress in the experimental determination of three-dimensional structures of membrane proteins together with new algorithms for molecular simulations and the increasing speed and availability of supercomputers, have made possible a considerable progress in this area of biophysics. This review aims at highlighting some of the work in the area of potassium channels and molecular dynamics simulations where numerous fundamental questions about the structure, function, folding and dynamics of these systems remain as yet unresolved challenges. [...]

14

Cultivation of Chlorella sp. for biodiesel production using two farming wastewaters in eastern Colombia

75%

Urbina-Suarez N. A., Barajas-Solano A. F., Garcia-Martinez J. B., Lopez-Barrera G. L., Gonzalez-Delgado A. D., Urbina-Suarez N. A., Barajas-Solano A. F., Garcia-Martinez J. B., Lopez-Barrera G. L., Gonzalez-Delgado A. D.

Journal of Water and Land Development

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2021

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issue 50

15

Effect of fungal solid-state fermented product enriched with gamma-linolenic acid and ß-carotene on blood biochemistry and immunology of broiler chickens

75%

Bartkovský M., Mudroňová D., Marcinčáková D., Klempová T., Sesztáková E., Maskaľová I., Karaffová V., Jaďuttová I., Čertík M., Hudák M., Marcinčák S., Bartkovský M., Mudroňová D., Marcinčáková D., Klempová T., Sesztáková E., Maskaľová I., Karaffová V., Jaďuttová I., Čertík M., Hudák M., Marcinčák S.

Polish Journal of Veterinary Sciences

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2020

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vol. 23

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issue 2

16

Changes in the content of γ-linolenic C18:3 (n-6) and stearidonic C18:4 (n-3) acids in developing seeds of viper's bugloss Echium vulgare L.

63%

Stolyhwo A., Mol J.

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2007

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vol. 54

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issue 4

741-746

EN

Changes in the composition of fatty acids (FA) were determined in lipid extracts isolated from developing ovaries containing ovules and developing seeds of Echium vulgare L. The samples were collected successively over 20 days beginning with the first day after flowering. The contents of the n-6 FA family members, i.e., γ-linolenic (GLA) (C18:3) and linoleic (LA) (C18:2) acids changed in a parallel manner and reached the maximum of 13.9% and 24%, respectively, on the 12th day, after which they fell systematically down to 8.6% and 18.2%, respectively, on the 20th day after flowering. Starting with day 13, the content of α-linolenic acid (ALA) (C18:3 n-3) begins to grow intensively, from 24.2% to 39.3% on the 20th day after flowering. The increase in the content of stearidonic acid (SDA) (C18:4 n-3), up to 10.5% on the 20th day after flowering, occurred steadily as the seeds developed, and was independent of the changes in the content of GLA and LA. The pattern of changes in the content of SDA, GLA, LA and ALA during the development of seeds, and the occurrence of SDA in the seed oil of other plants, demonstrate that the biosynthesis of SDA in the seeds is critically dependent on the presence of ALA. The above condition indicates that SDA biosynthesis in the seeds of Echium vulgare follows the scheme LA → simultaneous, competitive, action of Δ6 and Δ15 desaturases, leading to the formation of GLA and ALA, respectively, and then ALA (Δ6 des) → SDA. The biosynthesis according to the scheme: GLA (Δ15 des) → SDA is highly unlikely.

17

Carrier-state of the A allele of – 455G>A polymorphism within the beta fibrinogen gene increases the risk of coronary artery disease in the presence of elevated concentration of serum triacylglycerols

63%

Sarecka-Hujar B., Zak I., Krauze J.

Annales Academiae Medicae Silesiensis

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2009

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vol. 63

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issue 5

41-49

EN

BACKGROUND Fibrinogen promotes development of atherosclerosis by directed integration in atherosclerotic lesions where it is converted into fi brin. The aim of the study was to assess a relationship between –455G>A polymorphism of beta fi brinogen (FGB) gene and coronary artery disease (CAD) in the Polish patients from Upper Silesia region and to establish whether there are any interactions between this polymorphism and traditional risk factors that infl uence the risk of CAD. METHODS We analyzed 191 patients with angiographically documented CAD and 203 blood donors. Genetic analysis was performed using PCR-RFLP method. RESULTS The frequency of FGB -455G>A genotypes was compatible with Hardy- Weinberg equilibrium. There was no signifi cant diff erences in the distribution of A allele and A allele carriers of FGB polymorphism between cases and controls. We observed a tendency to higher level of plasma fibrinogen in subjects with AA or GA genotypes than in GG homozygotes. We also found strong synergistic eff ects between A allele carrier-state and increased level of triacylglycerols (TG) in determining the risk of CAD (SI=5.97, SIM=2.63). Carriers of A allele with elevated level of TG were 3-fold more frequent among cases than in control group (12.0% vs 3.9%, p=0.003,OR=3.34). CONCLUSIONS There is a synergistic eff ect between –455G>A polymorphism of FGB gene and elevated concentration of serum triacylglycerols which determine the risk of CAD.

PL

WSTĘP Fibrynogen promuje rozwój zmian miażdżycowych przez przyleganie do zmienionej ściany tętnic gdzie jest przekształcany w fibrynę. Celem niniejszej pracy była ocena związku między polimorfi zmem –455G>A genu kodującego łańcuch beta fibrynogenu (FGB) a ryzykiem choroby wieńcowej (CAD, ang. coronary artery disease) w grupie pacjentów z Górnego Śląska i ustalenie czy istnieją interakcje między tym polimorfi zmem a tradycyjnymi czynnikami ryzyka miażdżycy w determinowaniu ryzyka CAD. MATERIAŁ I METODY Grupę badaną stanowiło: 191 pacjentów z potwierdzoną koronarografi cznie CAD oraz 203 krwiodawców bez obciążeń chorobami sercowo-naczyniowymi. Polimorfi zm –455G>A genu FGB genotypowano metodą RFLP-PCR. Wyniki. Częstości genotypów polimorfi zmu -455G>A genu FGB były zgodne z równowagą Hardy-Weinberg’a. Nie stwierdzono znamiennych różnic w częstości allela A i nosicieli allela A polimorfi zmu genu FGB między pacjentami a grupą kontrolną. Obserwowano tendencję do występowania wyższego poziomu fi brynogenu w osoczu osób z genotypami AA i GA w porównaniu do poziomu fibrynogenu w osoczu osób z genotypem GG. Stwierdzono również silny synergiczny efekt między nosicielstwem allela A a podwyższonym poziomem triglicerydów w determinowaniu ryzyka CAD (indeksy synergii SI=5.97, SIM=2.63). Nosiciele allela A charakteryzujący się podwyższonym poziomem triglicerydów występowali trzykrotnie częściej w grupie chorych niż w kontroli (12.0% vs 3.9%, p=0.003,OR=3.34). WNIOSKI Przedstawione wyniki wskazują na synergiczny związek nosicielstwa allela A polimorfi zmu – 455G>A genu FGB z ponadnormatywnym stężeniem triglicerydów w surowicy krwi w kształtowaniu ryzyka CAD w populacji pacjentów z Górnego Śląska.

Refine search results

Detailed characterization of the substrate specificity of mouse wax synthase

Effects of high sucrose diet, gemfibrozil, and their combination on plasma paraoxonase 1 activity and lipid levels in rats

Violaxanthin and diadinoxanthin de-epoxidation in various model lipid systems

Dopamine and iron mediated fragmentation of galactocerebroside and cardiolipin in micelles

The oxidability of krill lipids

The influence of sex and maturity stage of krill (Euphausia superba Dana) upon the content and composition of its lipids

Spin trapping studies of essential oils in lipid systems

A biochemical study on the level of lipids and glycoproteins in the serum and platelets of liver cirrhotic bleeders

Antihyperlipidemic and antiatherogenic activity of simvastatin may involve modulation of the expression of lecithin:cholesterol acyl transferase

The lipid compositionof some Antarctic Crustacea

The reactions of hypochlorous acid, the reactive oxygen species produced by myeloperoxidase, with lipids.

The Effects of Sprint Interval vs. Continuous Endurance Training on Physiological and Metabolic Adaptations in Young Healthy Adults

Molecular dynamics simulations of potassium channels

Cultivation of Chlorella sp. for biodiesel production using two farming wastewaters in eastern Colombia

Effect of fungal solid-state fermented product enriched with gamma-linolenic acid and ß-carotene on blood biochemistry and immunology of broiler chickens

Changes in the content of γ-linolenic C18:3 (n-6) and stearidonic C18:4 (n-3) acids in developing seeds of viper's bugloss Echium vulgare L.

Carrier-state of the A allele of – 455G>A polymorphism within the beta fibrinogen gene increases the risk of coronary artery disease in the presence of elevated concentration of serum triacylglycerols