Overexpression of stearoyl-ACP desaturase enhances accumulations of oleic acid in the green alga Chlamydomonas reinhardtii

FAB2, which encodes stearoyl-acyl carrier protein desaturase, catalyzes the conversion of stearic acid (18:0) to oleic acid (18:1) in fatty acid biosynthesis. In this study, we isolated FAB2 from Chlamydomonas reinhardtii, named CrFAB2, and generated CrFAB2-overexpressing transgenic lines to identify a major role of CrFAB2 in fatty acid biosynthesis of C. reinhardtii. In CrFAB2-overexpressing lines, oleic acid (18:1) content was increased by approximately 2.4-fold compared to the wild-type control plants. Interestingly, CrFAB2 overexpression resulted in the induction of CrFAD2 expression. Consistent with this result, the induction of linoleic acid (18:2) was also detected in CrFAB2-overexpressing lines, and total fatty acid content in these lines was induced by approximately 28 % by CrFAB2 overexpression compared to the wild-type control. Our results indicate that CrFAB2 overexpression enhances the synthesis of oleic acid (18:1) and that CrFAB2 may also play a key role in regulating total fatty acid content in the green alga C. reinhardtii.     

Structure of the lipopolysaccharide core of Vibrio vulnificus type strain 27562

The structure of the lipopolysaccharide core of Vibrio vulnificus type strain 27562 is presented. LPS hydrolysis gave two oligosaccharides, OS-1 and OS-2, as well as lipid A. NMR spectroscopic data corresponded to the presence of one Kdo residue, one β-glucopyranose, three heptoses, one glyceric acid, one acetate, three PEtN, and one 5,7-diacylamido-3,5,7,9-tetradeoxynonulosonic acid residue (pseudaminic acid, Pse) in OS1. OS2 differed form OS 1 by the absence of glyceric acid, acetate, and Pse residues. Lipid A was analyzed for fatty acid composition and the following fatty acids were found: C14:0, C12:0-3OH, C16:0, C16:1, C14:0-3OH, C18:0, C18:1 in a ratio of 1:3:3:1:2.5:0.6:0.8.     

Mammalian-lung galactan

Exopolysaccharides of Agrobacterium tumefaciens and Rhizobium meliloti, containing d-glucose, d-galactose, pyruvic acid, and O-acetyl groups in the approximate proportions 6:1:1:1.5, were analysed by methylation. They were found to contain the following main structural units (all β-glycosidic): chain residues of (1→3)-linked d-glucose (24%), (1→3)-linked d-galactose (15%), (1→4)-linked d-glucose (20%), and (1→6)-linked d-glucose (18%); (1→4,1→6)-linked branching residues of d-glucose (12%), and terminal d-glucose residues substituted at positions 4 and 6 by pyruvate (11%). Uronic acid-containing exopolysaccharides of Rhizobium leguminosarum, R. phaseoli, and R. trifolii contained d-glucose, d-glucuronic acid, d-galactose, pyruvic acid, and O-acetyl groups in the approximate proportions 5:2:1:2:3. Methylation gave identical patterns of methylated sugar components, from which the following structural elements were deduced: chain residues of (1→3)-linked d-glucose substituted at positions 4 and 6 by pyruvate (13%), (1→4)-linked d-glucose (32%), and (1→4)-linked d-glucuronic acid (20%); (1→4,1→6)-linked branching residues of d-galactose and/or d-glucose (13%), and terminal d-glucose and/or d-galactose residues substituted at positions 4 and 6 by pyruvate (13%).     

The Effects of Cutaneous Fatty Acids on the Growth of Pseudogymnoascus destructans,the Etiological Agent of White-Nose Syndrome (WNS)

White Nose Syndrome (WNS) greatly increases the over-winter mortality of little brown (Myotis lucifugus), Indiana (Myotis sodalis), northern (Myotis septentrionalis), and tricolored (Perimyotis subflavus) bats. It is caused by a cutaneous infection with the fungus Pseudogymnoascus destructans (Pd). Big brown bats (Eptesicus fuscus) are much more resistant to cutaneous infection with Pd, however. We thus conducted analyses of wing epidermis from hibernating E. fuscus and M. lucifugus to determine their fatty acid compositions, and laboratory Pd culture experiments at 4.0–13.4°C to determine the effects of these fatty acids on Pd growth. Our analyses revealed that the epidermis of both bat species contain the same 7 fatty acid types (14:0, 15:0, 16:0. 16:1, 18:0, 18:1, & 18:2), but the epidermis of M. lucifugus contains: a) more stearic (18:0) acid, b) less palmitoleic (16:1) acid, c) less myristic (14:0) acid, and, d) less oleic (18:1) acid than that of E. fuscus. The growth of Pd was inhibited by: a) myristic and stearic acids at 10.5–13.4°C, but not at 4.0–5.0°C, b) oleic acid at 5.0–10.6°C, c) palmitoleic acid, and, d) linoleic (18:2) acid at 5.0–10.6°C. One set of factors that enables E. fuscus to better resist cutaneous P. destructans infections (and thus WNS) therefore appears to be the relatively higher myristic, palmitoleic, and oleic acid contents of the epidermis.     

Ethanol Tolerance in the Yeast Saccharomyces cerevisiae Is Dependent on Cellular Oleic Acid Content

In this investigation, we examined the effects of different unsaturated fatty acid compositions of Saccharomyces cerevisiae on the growth-inhibiting effects of ethanol. The unsaturated fatty acid (UFA) composition of S. cerevisiae is relatively simple, consisting almost exclusively of the mono-UFAs palmitoleic acid (Δ⁹Z-C_16:1) and oleic acid (Δ⁹Z-C_18:1), with the former predominating. Both UFAs are formed in S. cerevisiae by the oxygen- and NADH-dependent desaturation of palmitic acid (C_16:0) and stearic acid (C_18:0), respectively, catalyzed by a single integral membrane desaturase encoded by the OLE1 gene. We systematically altered the UFA composition of yeast cells in a uniform genetic background (i) by genetic complementation of a desaturase-deficient ole1 knockout strain with cDNA expression constructs encoding insect desaturases with distinct regioselectivities (i.e., Δ⁹ and Δ¹¹) and substrate chain-length preferences (i.e., C_16:0 and C_18:0); and, (ii) by supplementation of the same strain with synthetic mono-UFAs. Both experimental approaches demonstrated that oleic acid is the most efficacious UFA in overcoming the toxic effects of ethanol in growing yeast cells. Furthermore, the only other UFA tested that conferred a nominal degree of ethanol tolerance is cis-vaccenic acid (Δ¹¹Z-C_18:1), whereas neither Δ¹¹Z-C_16:1 nor palmitoleic acid (Δ⁹Z-C_16:1) conferred any ethanol tolerance. We also showed that the most ethanol-tolerant transformant, which expresses the insect desaturase TniNPVE, produces twice as much oleic acid as palmitoleic acid in the absence of ethanol and undergoes a fourfold increase in the ratio of oleic acid to palmitoleic acid in response to exposure to 5% ethanol. These findings are consistent with the hypothesis that ethanol tolerance in yeast results from incorporation of oleic acid into lipid membranes, effecting a compensatory decrease in membrane fluidity that counteracts the fluidizing effects of ethanol.     

Expression of yeast acyl-CoA-∆9 desaturase leads to accumulation of unusual monounsaturated fatty acids in soybean seeds

An acyl-CoA-Δ9 desaturase from Saccharomyces cerevisiae was expressed by subcellular-targeting in soybean (Glycine max) seeds with the goal of increasing palmitoleic acid (16:1Δ9), a high-valued fatty acid (FA), and simultaneously decreasing saturated FA in oil. The expression resulted in the conversion of palmitic acid (16:0) to 16:1Δ9 in soybean seeds. 16:1Δ9 and its elongation product cis-vaccenic acid (18:1Δ11) were increased to 17 % of the total fatty acids by plastid-targeted expression of the enzyme. Other lipid changes include the decrease of polyunsaturated FA and saturated FA, suggesting that a mechanism exists downstream in oil biosynthesis to compensate the FA alternation. This is the first time a cytosolic acyl-CoA-?9 desaturase is functionally expressed in plastid and stronger activity was achieved than its cytosolic expression. The present study provides a new strategy for converting 16:0 to 16:1Δ9 by engineering acyl-CoA-Δ9 desaturase in commercialized oilseeds.     

Unsaturated fatty acid from seed oil of consolida regalis

Icosenoic acid [20:1(11)] was isolated from the seed oil of Consolida regalis. The seeds contain ca 30% of fatty oil which comprise ca 25% 20:1 (11). The structure of the fatty acid methyl ester having been isolated by column chromatography was determined by GC/MS, IR and ¹H NMR and was confirmed by HPLC analysis of the bromophenacyl ester derivative.     

Modulation by dietary oils and clofibric acid of arachidonic acid content in phosphatidylcholine in liver and kidney of rat: Effects on prostaglandin formation in kidney

The manipulation of 20:4(n − 6) contents in phosphatidylcholine of liver and kidney of rats by dietary oils and p-chloropheno-xyisobutyric acid (clofibric acid) as well as the effects on the formation of prostaglandin E₂ in kidney were studied. Three groups of rats were fed diets that contained either safflower oil (SO) or perilla oil (PO) or fish oil (FO) for 1 week. Each dietary group was divided into two groups. One group continued the same diet for another 1 week; the second group continued the same diet and received subcutaneous injections of clofibric acid once a day for 1 week. The content of 20:4(n − 6) in hepatic phosphatidylcholine was markedly lowered by feeding either FO or PO and was further decreased by the administration of clofibric acid. Feeding either FO or PO lowered the content of 20:4(n − 6) in hepatic phosphatidylethanolamine, whereas clofibric acid increased it. The decrease in the level of 20:4(n − 6) in serum phospholipid was produced by feeding either FO or PO and by the administration of clofibric acid as well. There was a high correlation for the levels of 20:4(n − 6) between hepatic phosphatidylcholine and serum phospholipid. The changes brought about by dietary oils and clofibric acid in renal phosphatidylcholine was similar to those observed in liver. The content of 20:4(n − 6) in renal phosphatidylcholine was highly correlated with the level of 20:4(n − 6) in serum phospholipid. Other phospholipids in kidney responded less sensitively to the manipulation by dietary oils and clofibric acid. These results suggest that the level of 20:4(n − 6) in renal phosphatidylcholine is regulated by the level of 20:4(n − 6) in hepatic phosphatidylcholine through the changes in serum level of 20:4(n − 6). Formation of prostaglandin E₂ in kidney slices was dependent on the content of 20:4(n − 6) in renal phosphatidylcholine.     

Characterization of cis-9 trans-11 trans-15 C18:3 in milk fat by GC and covalent adduct chemical ionization tandem MS

Rumen biohydrogenation of dietary α-linolenic acid gives rise in ruminants to accumulation of fatty acid intermediates, some of which may be transferred into milk. Rumelenic acid [cis-9 trans-11 cis-15 C18:3 (RLnA)] has recently been characterized, but other C18:3 minor isomers are still unknown. The objective of this work was to identify a new isomer of octatridecenoic acid present in milk fat from ewes fed different sources of α-linolenic acid. Structural characterization of this fatty acid was achieved by GC-MS. Analysis of dimethyloxazoline and picolinyl ester derivatives allowed for location of the double bond positions. Covalent adduct chemical ionization tandem mass spectrometry confirmed the positional structure 9-11-15, identical to RLnA, and helped to establish double bond geometry (cis-trans-trans). This new C18:3 isomer could be formed by isomerization of cis-15 bond of RLnA and subsequently converted by hydrogenation to trans-11 trans-15 C18:2, an octadecadienoic acid also detected in this study.     

Improvement of the Fatty Acid Composition of an Oil-Producing Filamentous Fungus, Mortierella alpina 1S-4, through RNA Interference with Δ12-Desaturase Gene Expression

An oleaginous fungus, Mortierella alpina 1S-4, is used commercially for arachidonic acid production. Δ12-Desaturase, which desaturates oleic acid (18:1n-9) to linoleic acid (18:2n-6), is a key enzyme in the arachidonic acid biosynthetic pathway. To determine if RNA interference (RNAi) by double-stranded RNA occurs in M. alpina 1S-4, we silenced the Δ12-desaturase gene. The silenced strains accumulate 18:2n-9, 20:2n-9, and Mead acid (20:3n-9), which are not detected in either the control strain or wild type strain 1S-4. The fatty acid composition of stable transformants was similar to that of Δ12-desaturation-defective mutants previously identified. Thus, RNAi occurs in M. alpina and could be used to alter the types and relative amounts of fatty acids produced by commercial strains of this fungus without mutagenesis or other permanent changes in the genetic background of the producing strains.     

Biochemical Characterization of the Oxygenation of Unsaturated Fatty Acids by the Dioxygenase and Hydroperoxide Isomerase of Pseudomonas aeruginosa 42A2

We have studied oxygenation of fatty acids by cell extract of Pseudomonas aeruginosa 42A2. Oleic acid ((9Z)-18:1) was transformed to (10S)-hydroperoxy-(8E)-octadecenoic acid ((10S)-HPOME) and to (7S,10S)-dihydroxy-(8E)-octadecenoic acid (7,10-DiHOME). Experiments under oxygen-18 showed that 7,10-DiHOME contained oxygen from air and was formed sequentially from (10S)-HPOME by isomerization. (10R)-HPOME was not isomerized. The (10S)-dioxygenase and hydroperoxide isomerase activities co-eluted on ion exchange chromatography and on gel filtration with an apparent molecular size of ∼50 kDa. 16:1n-7, 18:2n-6, and 20:1n-11 were also oxygenated to 7,10-dihydroxy fatty acids, and (8Z)-18:1 was oxygenated to 6,9-dihydroxy-(7E)-octadecenoic acid. A series of fatty acids with the double bond positioned closer to ((6Z)-18:1, (5Z,9Z)-18:2) or more distant from the carboxyl group ((11Z)-, (13Z)-, and (15Z)-18:1) were poor substrates. The oxygenation mechanism was studied with [7S-²H]18:1n-9, [7R-²H]18:2n-6, and [8R-²H]18:2n-6 as substrates. The pro-R hydrogen at C-8 was lost in the biosynthesis of (10S)-HPODE, whereas the pro-S hydrogen was lost and the pro-R hydrogen was retained at C-7 during biosynthesis of the 7,10-dihydroxy metabolites. Analysis of the fatty acid composition of P. aeruginosa revealed relatively large amounts of (9E/Z)-16:1 and (11E/Z)-18:1 and only traces of 18:1n-9. We found that (11Z)-18:1 (vaccenic acid) was transformed to (11S,14S)-dihydroxy-(12E)-octadecenoic acid and to a mixture of 11- and 12-HPOME, possibly due to reverse orientation of (11Z)-18:1 at the active site compared with oleic acid. The reaction mechanism of the hydroperoxide isomerase suggests catalytic similarities to cytochrome P450.     

Alterations of the fatty acid composition and lipid metabolome of breast muscle in chickens exposed to dietary mixed edible oils

The fatty acid composition of chicken’s meat is largely influenced by dietary lipids, which are often used as supplements to increase dietary caloric density. The underlying key metabolites and pathways influenced by dietary oils remain poorly known in chickens. The objective of this study was to explore the underlying metabolic mechanisms of how diets supplemented with mixed or a single oil with distinct fatty acid composition influence the fatty acid profile in breast muscle of Qingyuan chickens. Birds were fed a corn-soybean meal diet supplemented with either soybean oil (control, CON) or equal amounts of mixed edible oils (MEO; soybean oil : lard : fish oil : coconut oil = 1 : 1 : 0.5 : 0.5) from 1 to 120 days of age. Growth performance and fatty acid composition of muscle lipids were analysed. LC-MS was applied to investigate the effects of CON v. MEO diets on lipid-related metabolites in the muscle of chickens at day 120. Compared with the CON diet, chickens fed the MEO diet had a lower feed conversion ratio (P < 0.05), higher proportions of lauric acid (C12:0), myristic acid (C14:0), palmitoleic acid (C16:1n-7), oleic acid (C18:1n-9), EPA (C20:5n-3) and DHA (C22:6n-3), and a lower linoleic acid (C18:2n-6) content in breast muscle (P < 0.05). Muscle metabolome profiling showed that the most differentially abundant metabolites are phospholipids, including phosphatidylcholines (PC) and phosphatidylethanolamines (PE), which enriched the glycerophospholipid metabolism (P < 0.05). These key differentially abundant metabolites – PC (14:0/20:4), PC (18:1/14:1), PC (18:0/14:1), PC (18:0/18:4), PC (20:0/18:4), PE (22:0/P-16:0), PE (24:0/20:5), PE (22:2/P-18:1), PE (24:0/18:4) – were closely associated with the contents of C12:0, C14:0, DHA and C18:2n-6 in muscle lipids (P < 0.05). The content of glutathione metabolite was higher with MEO than CON diet (P < 0.05). Based on these results, it can be concluded that the diet supplemented with MEO reduced the feed conversion ratio, enriched the content of n-3 fatty acids and modified the related metabolites (including PC, PE and glutathione) in breast muscle of chickens.     

Expression and Characterization of CYP52 Genes Involved in the Biosynthesis of Sophorolipid and Alkane Metabolism from Starmerella bombicola

Three cytochrome P450 monooxygenase CYP52 gene family members were isolated from the sophorolipid-producing yeast Starmerella bombicola (former Candida bombicola), namely, CYP52E3, CYP52M1, and CYP52N1, and their open reading frames were cloned into the pYES2 vector for expression in Saccharomyces cerevisiae. The functions of the recombinant proteins were analyzed with a variety of alkane and fatty acid substrates using microsome proteins or a whole-cell system. CYP52M1 was found to oxidize C₁₆ to C₂₀ fatty acids preferentially. It converted oleic acid (C_18:1) more efficiently than stearic acid (C_18:0) and linoleic acid (C_18:2) and much more effectively than α-linolenic acid (C_18:3). No products were detected when C₁₀ to C₁₂ fatty acids were used as the substrates. Moreover, CYP52M1 hydroxylated fatty acids at their ω- and ω-1 positions. CYP52N1 oxidized C₁₄ to C₂₀ saturated and unsaturated fatty acids and preferentially oxidized palmitic acid, oleic acid, and linoleic acid. It only catalyzed ω-hydroxylation of fatty acids. Minor ω-hydroxylation activity against myristic acid, palmitic acid, palmitoleic acid, and oleic acid was shown for CYP52E3. Furthermore, the three P450s were coassayed with glucosyltransferase UGTA1. UGTA1 glycosylated all hydroxyl fatty acids generated by CYP52E3, CYP52M1, and CYP52N1. The transformation efficiency of fatty acids into glucolipids by CYP52M1/UGTA1 was much higher than those by CYP52N1/UGTA1 and CYP52E3/UGTA1. Taken together, CYP52M1 is demonstrated to be involved in the biosynthesis of sophorolipid, whereas CYP52E3 and CYP52N1 might be involved in alkane metabolism in S. bombicola but downstream of the initial oxidation steps.     

Biocatalyzed kinetic resolution of racemic mixtures of chiral α-aminophosphonic acids

Several fungal species namely: Aspergillus niger, Aspergillus parasiticus, Penicillium funiculosum, Trigonopsis variabilis and two different strains of Fusarium oxysporum were tested toward racemic mixtures of following phosphonic acids: 1-amino-2-methylpropanephosphonic acid, 1-aminophenylmethanephosphonic acid and 1-amino-2-phenylethanephosphonic acid. Application of F. oxysporum strain (UW1) allowed obtaining optically pure S-isomer of 1-aminophenylmethanephosphonic acid and R-isomer of 1-amino-2-phenylethanephosphonic acid, whereas biotransformation of racemic mixture of 1-amino-2-methylpropanephosphonic acid with F. oxysporum strain (DSM 12646) cells resulted in obtaining pure enantiomer of R-configuration.     

Characterization of anti-complementary acidic heteroglycans from the seed of Coix lacryma-jobi var. ma-yuen

The anti-complementary polysaccharides, CA-1 and CA-2, were purified from the seed of Coix lacryma-jobi L. var. ma-yuen. CA-1 consists of rhamnose, arabinose, xylose, galactose, galacturonic acid and glucuronic acid in molar ratios of 1.8:43.8:10.8:33.2:3.2:7.2, and CA-2 consists of rhamnose, arabinose, xylose, mannose, galactose, glucose, galacturonic acid and glucuronic acid in molar ratios of 2.4:37.0:11.8:1.7:35.6:2.9:2.6:6.0. CA-1 and CA-2 contained 8 ∼ 11% protein. Their M_rs were estimated to be 160 000 in CA-1 and 70 000 in CA-2 by gel filtration. CA-2 showed more potent anti-complementary activity than CA-1 in low dose.Methylation analysis of CA-1, its carboxyl-reduced products (reduced CA-1a and CA-1b) and CA-2 were carried out by the use of GC/MS and the results suggested that CA-1 has a very complicated and highly branched structure, and CA-2 is also composed of the same glycosidic linkages as CA-1 in different molar proportions. The results of exo α-L-arabinofuranosidase treatment and partial acid hydrolysis suggested that CA-1 and CA-2 contained arabino 3,6-galactan moiety and most of the arabinose was present as an α-L-furanosyl residues in the non-reducing terminals and (1 → 5)-linked side chains which mostly attached to the O-3 of (1 → 6)-linked galactopyranosyl residues. The results also suggested that CA-1 and CA-2 contained rhamnogalacturonan moiety which has a main chain consisting of (1 → 4)-linked galacturonic acid and (1 → 2)-linked rhamnose, and arabino 3,6- and 4-galactan might be attached to the rhamnosyl residue at the O-4. All glucuronic acid residues were present at the non-reducing terminals.     

Yeast engineering to express sex pheromone gland genes of the oriental fruit moth,Grapholita molesta

Mating disruption by using sex pheromone is an ecofriendly alternative way to control insect pests. To be effective, large amounts of sex pheromone are needed, leading to a relatively high production cost. To reduce the cost for chemical synthesis of sex pheromone, yeast engineering technology has been devised. This study used a baker's yeast, Saccharomyces cerevisiae, to express genes associated with sex pheromone biosynthesis of the Oriental fruit moth, Grapholita molesta. Compared to other fatty acid biosynthetic pathways, two steps that are unique to pheromone gland of G. molesta are proposed: desaturation at even number catalyzed by desaturase (Gm-DES) and terminal reduction catalyzed by fatty acyl reductase (Gm-FAR). Gm-DES and Gm-FAR were cloned into a yeast expression vector, pYES2.1. They were used to transform S. cerevisiae by a double transfection method. The transformed yeast was induced with 2% galactose to over-express these two exogenous genes. Their expression was confirmed by RT-PCR and western blotting. To facilitate pheromone production, transformed yeasts were supplied with myristic acid during over-expression. Resulting fatty acid composition was analyzed by GC-MS after fatty acid methyl ester derivatization. Control yeast produced mostly saturated fatty acids. However, a single gene (Gm-DES)-transformed yeast produced unsaturated fatty acids at ∆9 such as Z9-tetradecenoic acid (Z9-14:1), palmitoleic acid (Z9-16:1), and oleic acid (Z9-18:1) in addition to saturated fatty acids. The double-transformed yeast produced an additional component, alcohol form of oleic acid (Z9-18:OH). These results suggest that Gm-DES can catalyze desaturation of fatty acids at ∆9 and Gm-FAR can reduce terminal carboxylic acid into alcohol.     

Reduced protein oxidation in Wistar rats supplemented with marine ω3 PUFAs

The potential effects of various dietary eicosapentaenoic acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6) ratios (1:1, 2:1, and 1:2, respectively) on protein redox states from plasma, kidney, skeletal muscle, and liver were investigated in Wistar rats. Dietary fish oil groups were compared with animals fed soybean and linseed oils, vegetable oils enriched in ω6 linoleic acid (LA; 18:2) and ω3 α-linolenic acid (ALA; 18:3), respectively. Fish oil treatments were effective at reducing the level of total fatty acids in plasma and enriching the plasmatic free fatty acid fraction and erythrocyte membranes in EPA and DHA. A proteomic approach consisting of fluorescein 5-thiosemicarbazide (FTSC) labeling of protein carbonyls, FTSC intensity visualization on 1-DE or 2-DE gels, and protein identification by MS/MS was used for the protein oxidation assessment. Albumin was found to be the most carbonylated protein in plasma for all dietary groups, and its oxidation level was significantly modulated by dietary interventions. Supplementation with an equal EPA:DHA ratio (1:1) showed the lowest oxidation score for plasma albumin, followed in increasing order of carbonylation by 1:2 <2:1 ≈ linseed < soybean. Oxidation patterns of myofibrillar skeletal muscle proteins and cytosolic proteins from kidney and liver also indicated a protective effect on proteins for the fish oil treatments, the 1:1 ratio exhibiting the lowest protein oxidation scores. The effect of fish oil treatments at reducing carbonylation on specific proteins from plasma (albumin), skeletal muscle (actin), and liver (albumin, argininosuccinate synthetase, 3-α-hydroxysteroid dehydrogenase) was remarkable. This investigation highlights the efficiency of dietary fish oil at reducing in vivo oxidative damage of proteins compared to oils enriched in the 18-carbon polyunsaturated fatty acids ω3 ALA and ω6 LA, and such antioxidant activity may differ among different fish oil sources because of variations in EPA/DHA content.     

A fatty acid elongase ELO with novel activity from Dictyostelium discoideum

Fatty acid elongation was examined in the cellular slime mold, Dictyostelium discoideum. Profiling of the total fatty acid content of D. discoideum indicated that fatty acid elongation is active. Orthologs of the fatty acid elongase ELO family were identified in the D. discoideum genome and the cDNA for one, eloA, was cloned and functionally characterized by expression in yeast. EloA is a highly active ELO with strict substrate specificity for monounsaturated fatty acids, in particular 16:1^Δ9 to produce the unusual 18:1^Δ11 fatty acid. This is the first report on fatty acid elongation in a cellular slime mold.