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Sample records for carrier protein desaturase

  1. Fat Metabolism in Higher Plants: LXII. Stearl-acyl Carrier Protein Desaturase from Spinach Chloroplasts.

    Science.gov (United States)

    Jacobson, B S; Jaworski, J G; Stumpf, P K

    1974-10-01

    Stearyl-acyl carrier protein desaturase (EC 1.14.99.6), present in the stroma fraction of spinach (Spinacia oleracea) chloroplasts, rapidly desaturated enzymatically prepared stearyl-acyl carrier protein to oleic acid. No other substrates were desaturated. In addition to stearyl-acyl carrier protein, reduced ferredoxin was an essential component of the system. The electron donor systems were either ascorbate, dichlorophenolindophenol, photosystem I and light, or NADPH and ferredoxin-NADP reductase. The desaturase was more active in extracts prepared from chloroplasts obtained from immature spinach leaves than from mature leaves. Stearyl-acyl carrier protein desaturase also occurs in soluble extracts of avocado (Persea americana Mill.) mesocarp and of developing safflower (Carthamus tinctorius) seeds.

  2. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs.

    Science.gov (United States)

    Shanklin, J; Somerville, C

    1991-03-15

    Stearoyl-acyl-carrier-protein (ACP) desaturase (EC 1.14.99.6) was purified to homogeneity from avocado mesocarp, and monospecific polyclonal antibodies directed against the protein were used to isolate full-length cDNA clones from Ricinus communis (castor) seed and Cucumis sativus (cucumber). The nucleotide sequence of the castor clone pRCD1 revealed an open reading frame of 1.2 kilobases encoding a 396-amino acid protein of 45 kDa. The cucumber clone pCSD1 encoded a homologous 396-amino acid protein with 88% amino acid identity to the castor clone. Expression of pRCD1 in Saccharomyces cerevisiae resulted in the accumulation of a functional stearoyl-ACP desaturase, demonstrating that the introduction of this single gene product was sufficient to confer soluble desaturase activity to yeast. There was no detectable identity between the deduced amino acid sequences of the castor delta 9-stearoyl-ACP desaturase and either the delta 9-stearoyl-CoA desaturase from rat or yeast or the delta 12 desaturase from Synechocystis, suggesting that these enzymes may have evolved independently. However, there was a 48-residue region of 29% amino acid sequence identity between residues 53 and 101 of the castor desaturase and the proximal border of the dehydratase region of the fatty acid synthase from yeast. Stearoyl-ACP mRNA was present at substantially higher levels in developing seeds than in leaf and root tissue, suggesting that expression of the delta 9 desaturase is developmentally regulated.

  3. Stearoyl-acyl carrier protein desaturases are associated with floral isolation in sexually deceptive orchids

    Energy Technology Data Exchange (ETDEWEB)

    Schluter, P.M.; Shanklin, J.; Xu, S.; Gagliardini, V.; Whittle, E.; Grossniklaus, U.; Schiestl, F. P.

    2011-04-05

    The orchids Ophrys sphegodes and O. exaltata are reproductively isolated from each other by the attraction of two different, highly specific pollinator species. For pollinator attraction, flowers chemically mimic the pollinators sex pheromones, the key components of which are alkenes with different double-bond positions. This study identifies genes likely involved in alkene biosynthesis, encoding stearoyl-acyl carrier protein (ACP) desaturase (SAD) homologs. The expression of two isoforms, SAD1 and SAD2, is flower-specific and broadly parallels alkene production during flower development. SAD2 shows a significant association with alkene production, and in vitro assays show that O. sphegodes SAD2 has activity both as an 18:0-ACP {Delta}{sup 9} and a 16:0-ACP {Delta}{sup 4} desaturase. Downstream metabolism of the SAD2 reaction products would give rise to alkenes with double-bonds at position 9 or position 12, matching double-bond positions observed in alkenes in the odor bouquet of O. sphegodes. SAD1 and SAD2 show evidence of purifying selection before, and positive or relaxed purifying selection after gene duplication. By contributing to the production of species-specific alkene bouquets, SAD2 is suggested to contribute to differential pollinator attraction and reproductive isolation among these species. Taken together, these data are consistent with the hypothesis that SAD2 is a florally expressed barrier gene of large phenotypic effect and, possibly, a genic target of pollinator-mediated selection.

  4. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs

    Energy Technology Data Exchange (ETDEWEB)

    Shanklin, J.; Somerville, C. (Michigan State Univ., East Lansing (United States))

    1991-03-15

    Stearoyl-acyl-carrier-protein (ACP) desaturase was purified to homogeneity from avocado mesocarp, and monospecific polyclonal antibodies directed against the protein were used to isolate full-length cDNA clones from Ricinus communis (castor) seed and Cucumis sativus (cucumber). The nucleotide sequence of the castor clone pRCD1 revealed an open reading frame of 1.2 kilobases encoding a 396-amino acid protein of 45 kDa. The cucumber clone pCSD1 encoded a homologous 396-amino acid protein with 88% amino acid identity to the castor clone. Expression of pRCD1 in Saccharomyces cerevisiae resulted in the accumulation of a functional stearoyl-ACP desaturase, demonstrating that the introduction of this single gene product was sufficient to confer soluble desaturase activity to yeast. There was a 48-residue region of 29% amino acid sequence identity between residues 53 and 101 of the castor desaturase and the proximal border of the dehydratase region of the fatty acid synthase from yeast. Stearoyl-ACP mRNA was present at substantially higher levels in developing seeds than in leaf and root tissue, suggesting that expression of the {Delta}{sup 9} desaturase is developmentally regulated.

  5. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs

    International Nuclear Information System (INIS)

    Stearoyl-acyl-carrier-protein (ACP) desaturase was purified to homogeneity from avocado mesocarp, and monospecific polyclonal antibodies directed against the protein were used to isolate full-length cDNA clones from Ricinus communis (castor) seed and Cucumis sativus (cucumber). The nucleotide sequence of the castor clone pRCD1 revealed an open reading frame of 1.2 kilobases encoding a 396-amino acid protein of 45 kDa. The cucumber clone pCSD1 encoded a homologous 396-amino acid protein with 88% amino acid identity to the castor clone. Expression of pRCD1 in Saccharomyces cerevisiae resulted in the accumulation of a functional stearoyl-ACP desaturase, demonstrating that the introduction of this single gene product was sufficient to confer soluble desaturase activity to yeast. There was a 48-residue region of 29% amino acid sequence identity between residues 53 and 101 of the castor desaturase and the proximal border of the dehydratase region of the fatty acid synthase from yeast. Stearoyl-ACP mRNA was present at substantially higher levels in developing seeds than in leaf and root tissue, suggesting that expression of the Δ9 desaturase is developmentally regulated

  6. The stearoyl-acyl-carrier-protein desaturase promoter (Des) from oil palm confers fruit-specific GUS expression in transgenic tomato.

    Science.gov (United States)

    Saed Taha, Rima; Ismail, Ismanizan; Zainal, Zamri; Abdullah, Siti Nor Akmar

    2012-09-01

    The stearoyl-acyl-carrier-protein (ACP) desaturase is a plastid-localized enzyme that catalyzes the conversion of stearoyl-ACP to oleoyl-ACP and plays an important role in the determination of the properties of the majority of cellular glycerolipids. Functional characterization of the fatty acid desaturase genes and their specific promoters is a prerequisite for altering the composition of unsaturated fatty acids of palm oil by genetic engineering. In this paper, the specificity and strength of the oil palm stearoyl-ACP desaturase gene promoter (Des) was evaluated in transgenic tomato plants. Transcriptional fusions between 5' deletions of the Des promoter (Des1-4) and the β-glucuronidase (GUS) reporter gene were generated and their expression analyzed in different tissues of stably transformed tomato plants. Histochemical analysis of the Des promoter deletion series revealed that GUS gene expression was confined to the tomato fruits. No expression was detected in vegetative tissues of the transgenic plants. The highest levels of GUS activity was observed in different tissues of ripe red fruits (vascular tissue, septa, endocarp, mesocarp and columella) and in seeds, which harbored the promoter region located between -590 and +10. A comparison of the promoter-deletion constructs showed that the Des4 promoter deletion (314bp) produced a markedly low level of GUS expression in fruits and seeds. Fluorometric analysis of the GUS activity revealed a 4-fold increase in the activity of the full-length Des promoter compared to the CaMV35S promoter. RNA-hybridization analyses provided additional evidence of increased GUS expression in fruits driven by a Des fragment. Taken together, these results demonstrate the potential of the Des promoter as a tool for the genetic engineering of oil palms and other species, including dicots, in improving the quality and nutritional value of the fruits. PMID:22658816

  7. ACYL-ACYL CARRIER PROTEIN DESATURASE2 and 3 Are Responsible for Making Omega-7 Fatty Acids in the Arabidopsis Aleurone.

    Science.gov (United States)

    Bryant, Fiona M; Munoz-Azcarate, Olaya; Kelly, Amélie A; Beaudoin, Frédéric; Kurup, Smita; Eastmond, Peter J

    2016-09-01

    Omega-7 monounsaturated fatty acids (ω-7s) are specifically enriched in the aleurone of Arabidopsis (Arabidopsis thaliana) seeds. We found significant natural variation in seed ω-7 content and used a Multiparent Advanced Generation Inter-Cross population to fine-map a major quantitative trait loci to a region containing ACYL-ACYL CARRIER PROTEIN DESATURASE1 (AAD1) and AAD3 We found that AAD3 expression is localized to the aleurone where mutants show an approximately 50% reduction in ω-7 content. By contrast, AAD1 is localized to the embryo where mutants show a small reduction in ω-9 content. Enzymatic analysis has previously shown that AAD family members possess both stearoyl- and palmitoyl-ACP Δ(9) desaturase activity, including the predominant isoform SUPPRESSOR OF SALICYLIC ACID INSENSITIVE2. However, aad3 ssi2 aleurone contained the same amount of ω-7s as aad3 Within the AAD family, AAD3 shares the highest degree of sequence similarity with AAD2 and AAD4. Mutant analysis showed that AAD2 also contributes to ω-7 production in the aleurone, and aad3 aad2 exhibits an approximately 85% reduction in ω-7s Mutant analysis also showed that FATTY ACID ELONGASE1 is required for the production of very long chain ω-7s in the aleurone. Together, these data provide genetic evidence that the ω-7 pathway proceeds via Δ(9) desaturation of palmitoyl-ACP followed by elongation of the product. Interestingly, significant variation was also identified in the ω-7 content of Brassica napus aleurone, with the highest level detected being approximately 47% of total fatty acids. PMID:27462083

  8. ACYL-ACYL CARRIER PROTEIN DESATURASE2 and 3 Are Responsible for Making Omega-7 Fatty Acids in the Arabidopsis Aleurone.

    Science.gov (United States)

    Bryant, Fiona M; Munoz-Azcarate, Olaya; Kelly, Amélie A; Beaudoin, Frédéric; Kurup, Smita; Eastmond, Peter J

    2016-09-01

    Omega-7 monounsaturated fatty acids (ω-7s) are specifically enriched in the aleurone of Arabidopsis (Arabidopsis thaliana) seeds. We found significant natural variation in seed ω-7 content and used a Multiparent Advanced Generation Inter-Cross population to fine-map a major quantitative trait loci to a region containing ACYL-ACYL CARRIER PROTEIN DESATURASE1 (AAD1) and AAD3 We found that AAD3 expression is localized to the aleurone where mutants show an approximately 50% reduction in ω-7 content. By contrast, AAD1 is localized to the embryo where mutants show a small reduction in ω-9 content. Enzymatic analysis has previously shown that AAD family members possess both stearoyl- and palmitoyl-ACP Δ(9) desaturase activity, including the predominant isoform SUPPRESSOR OF SALICYLIC ACID INSENSITIVE2. However, aad3 ssi2 aleurone contained the same amount of ω-7s as aad3 Within the AAD family, AAD3 shares the highest degree of sequence similarity with AAD2 and AAD4. Mutant analysis showed that AAD2 also contributes to ω-7 production in the aleurone, and aad3 aad2 exhibits an approximately 85% reduction in ω-7s Mutant analysis also showed that FATTY ACID ELONGASE1 is required for the production of very long chain ω-7s in the aleurone. Together, these data provide genetic evidence that the ω-7 pathway proceeds via Δ(9) desaturation of palmitoyl-ACP followed by elongation of the product. Interestingly, significant variation was also identified in the ω-7 content of Brassica napus aleurone, with the highest level detected being approximately 47% of total fatty acids.

  9. Stearoyl CoA Desaturase Is Required to Produce Active, Lipid-Modified Wnt Proteins

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    Jessica Rios-Esteves

    2013-09-01

    Full Text Available Wnt proteins contain palmitoleic acid, an unusual lipid modification. Production of an active Wnt signal requires the acyltransferase Porcupine and depends on the attachment of palmitoleic acid to Wnt. The source of this monounsaturated fatty acid has not been identified, and it is not known how Porcupine recognizes its substrate and whether desaturation occurs before or after fatty acid transfer to Wnt. Here, we show that stearoyl desaturase (SCD generates a monounsaturated fatty acid substrate that is then transferred by Porcupine to Wnt. Treatment of cells with SCD inhibitors blocked incorporation of palmitate analogs into Wnt3a and Wnt5a and reduced Wnt secretion as well as autocrine and paracrine Wnt signaling. The SCD inhibitor effects were rescued by exogenous addition of monounsaturated fatty acids. We propose that SCD is a key molecular player responsible for Wnt biogenesis and processing and that SCD inhibition provides an alternative mechanism for blocking Wnt pathway activation.

  10. A new F131V mutation in Chlamydomonas phytoene desaturase locates a cluster of norflurazon resistance mutations near the FAD-binding site in 3D protein models.

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    Julio V Suarez

    Full Text Available The green alga Chlamydomonas reinhardtii provides a tractable genetic model to study herbicide mode of action using forward genetics. The herbicide norflurazon inhibits phytoene desaturase, which is required for carotenoid synthesis. Locating amino acid substitutions in mutant phytoene desaturases conferring norflurazon resistance provides a genetic approach to map the herbicide binding site. We isolated a UV-induced mutant able to grow in very high concentrations of norflurazon (150 µM. The phytoene desaturase gene in the mutant strain contained the first resistance mutation to be localised to the dinucleotide-binding Rossmann-likedomain. A highly conserved phenylalanine amino acid at position 131 of the 564 amino acid precursor protein was changed to a valine in the mutant protein. F131, and two other amino acids whose substitution confers norflurazon resistance in homologous phytoene desaturase proteins, map to distant regions in the primary sequence of the C. reinhardtii protein (V472, L505 but in tertiary models these residues cluster together to a region close to the predicted FAD binding site. The mutant gene allowed direct 5 µM norflurazon based selection of transformants, which were tolerant to other bleaching herbicides including fluridone, flurtamone, and diflufenican but were more sensitive to beflubutamid than wild type cells. Norflurazon resistance and beflubutamid sensitivity allow either positive or negative selection against transformants expressing the mutant phytoene desaturase gene.

  11. Phytoene desaturase is present in a large protein complex in the plastid membrane

    Science.gov (United States)

    Phytoene desaturase (PDS, EC 1.14.99.-) represents one of the key enzymes in the carotenoid biosynthetic pathway and is present in nearly all types of plastids in plants. To further characterize PDS, we isolated the PDS cDNA from cauliflower (BoPDS) and confirmed its function by heterologous express...

  12. Oxygen induction of a novel fatty acid n-6 desaturase in the soil protozoon, Acanthamoeba castellanii.

    Science.gov (United States)

    Rutter, Andrew J; Thomas, Katie L; Herbert, Derek; Henderson, R James; Lloyd, David; Harwood, John L

    2002-11-15

    Induction of fatty acid desaturation is very important for the temperature adaptation of poikilotherms. However, in oxygen-limited late-exponential-phase Acanthamoeba castellanii cultures, oxygen alone was able to induce increased activity of a fatty acid desaturase that converts oleate into linoleate and which has been implicated in the temperature adaptation of this organism. Experiments with Delta(10)-nonadecenoate showed that the enzyme is an n -6 desaturase rather than a Delta(12)-desaturase. It also used preferentially 1-acyl-2-oleoyl-phosphatidylcholine as substrate and NAD(P)H as electron donor. The involvement of cytochrome b (5) as an intermediate electron carrier was shown by difference spectra measurements and anti-(cytochrome b (5)) antibody experiments. Of the three protein components of the desaturase complex, oxygen only increased the activity of the terminal (cyanide-sensitive) protein during n -6 desaturase induction. The induction of this terminal protein paralleled well the increase in overall oleate n -6 desaturation. The ability of oxygen to induce oleate desaturase independently of temperature in this lower eukaryotic animal model is of novel intrinsic interest, as well as being important for the design of future experiments to determine the molecular mechanism of temperature adaptation in poikilotherms. PMID:12153399

  13. Legionella pneumophila Secretes a Mitochondrial Carrier Protein during Infection

    OpenAIRE

    Pavel Dolezal; Margareta Aili; Janette Tong; Jhih-Hang Jiang; Marobbio, Carlo M.T.; Sau Fung Lee; Ralf Schuelein; Simon Belluzzo; Eva Binova; Aurelie Mousnier; Gad Frankel; Giulia Giannuzzi; Ferdinando Palmieri; Kipros Gabriel; Thomas Naderer

    2012-01-01

    Author Summary Mitochondrial carrier proteins evolved during endosymbiosis to transport substrates across the mitochondrial inner membrane. As such the proteins are associated exclusively with eukaryotic organisms. Despite this, we identified putative mitochondrial carrier proteins in the genomes of different intracellular bacterial pathogens, including Legionella pneumophila, the causative agent of Legionnaire's disease. We named the mitochondrial carrier protein from L. pneumophila LncP and...

  14. Trapping of the Enoyl-Acyl Carrier Protein Reductase-Acyl Carrier Protein Interaction.

    Science.gov (United States)

    Tallorin, Lorillee; Finzel, Kara; Nguyen, Quynh G; Beld, Joris; La Clair, James J; Burkart, Michael D

    2016-03-30

    An ideal target for metabolic engineering, fatty acid biosynthesis remains poorly understood on a molecular level. These carrier protein-dependent pathways require fundamental protein-protein interactions to guide reactivity and processivity, and their control has become one of the major hurdles in successfully adapting these biological machines. Our laboratory has developed methods to prepare acyl carrier proteins (ACPs) loaded with substrate mimetics and cross-linkers to visualize and trap interactions with partner enzymes, and we continue to expand the tools for studying these pathways. We now describe application of the slow-onset, tight-binding inhibitor triclosan to explore the interactions between the type II fatty acid ACP from Escherichia coli, AcpP, and its corresponding enoyl-ACP reductase, FabI. We show that the AcpP-triclosan complex demonstrates nM binding, inhibits in vitro activity, and can be used to isolate FabI in complex proteomes. PMID:26938266

  15. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco.

    Science.gov (United States)

    Cahoon, E B; Shanklin, J; Ohlrogge, J B

    1992-12-01

    Little is known about the metabolic origin of petroselinic acid (18:1 delta 6cis), the principal fatty acid of the seed oil of most Umbelliferae, Araliaceae, and Garryaceae species. To examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (ACP) desaturase, Western blots of coriander and other Umbelliferae seed extracts were probed with antibodies against the delta 9-stearoyl-ACP desaturase of avocado. In these extracts, proteins of 39 and 36 kDa were detected. Of these, only the 36-kDa peptide was specific to tissues which synthesize petroselinic acid. A cDNA encoding the 36-kDa peptide was isolated from a coriander endosperm cDNA library, placed under control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Expression of this cDNA in transgenic tobacco callus was accompanied by the accumulation of petroselinic acid and delta 4-hexadecenoic acid, both of which were absent from control callus. These results demonstrate the involvement of a 36-kDa putative acyl-ACP desaturase in the biosynthetic pathway of petroselinic acid and the ability to produce fatty acids of unusual structure in transgenic plants by the expression of the gene for this desaturase.

  16. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco

    Energy Technology Data Exchange (ETDEWEB)

    Cahoon, E.B.; Shanklin, J.; Ohlrogge, J.B. (Michigan State Univ., East Lansing (United States))

    1992-12-01

    Little is known about the metabolic origin of petroselinic acid (18:1[Delta][sup 6cis]), the principal fatty acid of the seed oil of most Umbelliferae, Araliaceae, and Garryaceae species. To examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (ACP) desaturase, Western blots of coriander and other Umbelliferae seed extracts were probed with antibodies against the [Delta][sup 9]-stearoyl-ACP desaturase of avocado. In these extracts, proteins of 39 and 36 kDa were detected. Of these, only the 36-kDa peptide was specific to tissues which synthesize petroselinic acid. A cDNA encoding the 36-kDa peptide was isolated from a coriander endosperm cDNA library, placed under control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Expression of this cDNA in transgenic tobacco callus was accompanied by the accumulation of petroselinic acid and [Delta][sup 4]-hexadecenoic acid, both of which were absent from control callus. These results demonstrate the involvement of a 36-kDa putative acyl-ACP desaturase in the biosynthetic pathway of petroselinic acid and the ability to produce fatty acids of unusual structure in transgenic plants by the expression of the gene for this desaturase. 27 refs., 5 figs.

  17. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase

    Science.gov (United States)

    Thomas, Jacob

    2009-01-01

    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  18. Expression and purification of integral membrane fatty acid desaturases.

    Directory of Open Access Journals (Sweden)

    Haiqin Chen

    Full Text Available Fatty acid desaturase enzymes perform dehydrogenation reactions leading to the insertion of double bonds in fatty acids, and are divided into soluble and integral membrane classes. Crystal structures of soluble desaturases are available; however, membrane desaturases have defied decades of efforts due largely to the difficulty of generating recombinant desaturase proteins for crystallographic analysis. Mortierella alpina is an oleaginous fungus which possesses eight membrane desaturases involved in the synthesis of saturated, monounsaturated and polyunsaturated fatty acids. Here, we describe the successful expression, purification and enzymatic assay of three M. alpina desaturases (FADS15, FADS12, and FADS9-I. Estimated yields of desaturases with purity >95% are approximately 3.5% (Ca. 4.6 mg/L of culture for FADS15, 2.3% (Ca. 2.5 mg/L of culture for FADS12 and 10.7% (Ca. 37.5 mg/L of culture for FADS9-I. Successful expression of high amounts of recombinant proteins represents a critical step towards the structural elucidation of membrane fatty acid desaturases.

  19. Biotin Carboxyl Carrier Protein in Barley Chloroplast Membranes

    DEFF Research Database (Denmark)

    Kannangara, C. G.; Jense, C J

    1975-01-01

    Biotin localized in barley chloroplast lamellae is covalently bound to a single protein with an approximate molecular weight of 21000. It contains one mole of biotin per mole of protein and functions as a carboxyl carrier in the acetyl-CoA carboxylase reaction. The protein was obtained by solubil......Biotin localized in barley chloroplast lamellae is covalently bound to a single protein with an approximate molecular weight of 21000. It contains one mole of biotin per mole of protein and functions as a carboxyl carrier in the acetyl-CoA carboxylase reaction. The protein was obtained...

  20. Preclinical studies on new proteins as carrier for glycoconjugate vaccines.

    Science.gov (United States)

    Tontini, M; Romano, M R; Proietti, D; Balducci, E; Micoli, F; Balocchi, C; Santini, L; Masignani, V; Berti, F; Costantino, P

    2016-07-29

    Glycoconjugate vaccines are made of carbohydrate antigens covalently bound to a carrier protein to enhance their immunogenicity. Among the different carrier proteins tested in preclinical and clinical studies, five have been used so far for licensed vaccines: Diphtheria and Tetanus toxoids, the non-toxic mutant of diphtheria toxin CRM197, the outer membrane protein complex of Neisseria meningitidis serogroup B and the Protein D derived from non-typeable Haemophilus influenzae. Availability of novel carriers might help to overcome immune interference in multi-valent vaccines containing several polysaccharide-conjugate antigens, and also to develop vaccines which target both protein as well saccharide epitopes of the same pathogen. Accordingly we have conducted a study to identify new potential carrier proteins. Twenty-eight proteins, derived from different bacteria, were conjugated to the model polysaccharide Laminarin and tested in mice for their ability in inducing antibodies against the carbohydrate antigen and eight of them were subsequently tested as carrier for serogroup meningococcal C oligosaccharides. Four out of these eight were able to elicit in mice satisfactory anti meningococcal serogroup C titers. Based on immunological evaluation, the Streptococcus pneumoniae protein spr96/2021 was successfully evaluated as carrier for serogroups A, C, W, Y and X meningococcal capsular saccharides. PMID:27317455

  1. Ribonuclease S-peptide as a carrier in fusion proteins.

    OpenAIRE

    J.S. Kim; Raines, R. T.

    1993-01-01

    S-peptide (residues 1-20) and S-protein (residues 21-124) are the enzymatically inactive products of the limited digestion of ribonuclease A by subtilisin. S-peptide binds S-protein with high affinity to form ribonuclease S, which has full enzymatic activity. Recombinant DNA technology was used to produce a fusion protein having three parts: carrier, spacer, and target. The two carriers used were the first 15 residues of S-peptide (S15) and a mutant S15 in which Asp 14 had been changed to Asn...

  2. Cellular uptake of steroid carrier proteins – mechanisms and implications

    OpenAIRE

    Willnow, T E; Nykjaer, A

    2009-01-01

    Abstract Steroid hormones are believed to enter cells solely by free diffusion through the plasma membrane. However, recent studies suggest the existence of cellular uptake pathways for carrier-bound steroids. Similar to the clearance of cholesterol via lipoproteins, these pathways involve the recognition of carrier proteins by endocytic receptors on the surface of target cells, followed by internalization and cellular delivery of the bound sterols. Here, we discuss the emerging co...

  3. Sterol carrier protein-x gene and effects of sterol carrier protein-2 inhibitors on lipid uptake in Manduca sexta

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    Lan Que

    2010-06-01

    Full Text Available Abstract Background Cholesterol uptake and transportation during the feeding larval stages are critical processes in insects because they are auxotrophic for exogenous (dietary cholesterol. The midgut is the main site for cholesterol uptake in many insects. However, the molecular mechanism by which dietary cholesterol is digested and absorbed within the midgut and then released into the hemolymph for transportation to utilization or storage sites is poorly understood. Sterol carrier proteins (SCP, non-specific lipid transfer proteins, have been speculated to be involved in intracellular cholesterol transfer and metabolism in vertebrates. Based on the high degree of homology in the conserved sterol transfer domain to rat and human SCP-2, it is supposed that insect SCP-2 has a parallel function to vertebrate SCP-2. Results We identified the Manduca sexta sterol carrier protein-x and the sterol carrier protein-2 (MsSCP-x/SCP-2 gene from the larval fat body and the midgut cDNAs. The MsSCP-x/SCP-2 protein has a high degree of homology in the SCP-2 domain to other insects' SCP-2. Transcripts of MsSCP-2 were detected at high levels in the midgut and the fat body of M. sexta during the larval stages. Recombinant MsSCP-2 bound to NBD-cholesterol with high affinity, which was suppressed by sterol carrier protein-2 inhibitors. Conclusions The results suggest that MsSCP-2 may function as a lipid carrier protein in vivo, and targeting insect SCP-2 may be a viable approach for the development of new insecticides.

  4. Protein carriers of conjugate vaccines: characteristics, development, and clinical trials.

    Science.gov (United States)

    Pichichero, Michael E

    2013-12-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

  5. Legionella pneumophila secretes a mitochondrial carrier protein during infection.

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    Pavel Dolezal

    2012-01-01

    Full Text Available The Mitochondrial Carrier Family (MCF is a signature group of integral membrane proteins that transport metabolites across the mitochondrial inner membrane in eukaryotes. MCF proteins are characterized by six transmembrane segments that assemble to form a highly-selective channel for metabolite transport. We discovered a novel MCF member, termed Legionellanucleotide carrier Protein (LncP, encoded in the genome of Legionella pneumophila, the causative agent of Legionnaire's disease. LncP was secreted via the bacterial Dot/Icm type IV secretion system into macrophages and assembled in the mitochondrial inner membrane. In a yeast cellular system, LncP induced a dominant-negative phenotype that was rescued by deleting an endogenous ATP carrier. Substrate transport studies on purified LncP reconstituted in liposomes revealed that it catalyzes unidirectional transport and exchange of ATP transport across membranes, thereby supporting a role for LncP as an ATP transporter. A hidden Markov model revealed further MCF proteins in the intracellular pathogens, Legionella longbeachae and Neorickettsia sennetsu, thereby challenging the notion that MCF proteins exist exclusively in eukaryotic organisms.

  6. Squalane as a possible carrier of bone morphogenetic protein.

    Science.gov (United States)

    Kawakami, T; Uji, H; Antoh, M; Hasegawa, H; Kise, T; Eda, S

    1993-07-01

    Gelatin capsules containing squalane partially purified bone morphogenetic protein (BMP) complex were placed on the perimuscular membrane of rats. Two kinds of control, gelatin capsules containing only BMP and those bearing squalane only, were used. The embedded areas were histopathologically examined at 3 and 6 wk after the operation. The observations revealed that the squalane/BMP complex elicited wide heterotopic bone formation with bone marrow tissue, suggesting that squalane is a possible carrier of BMP for clinical applications.

  7. A Δ-9 Fatty Acid Desaturase Gene in the Microalga Myrmecia incisa Reisigl: Cloning and Functional Analysis.

    Science.gov (United States)

    Xue, Wen-Bin; Liu, Fan; Sun, Zheng; Zhou, Zhi-Gang

    2016-01-01

    The green alga Myrmecia incisa is one of the richest natural sources of arachidonic acid (ArA). To better understand the regulation of ArA biosynthesis in M. incisa, a novel gene putatively encoding the Δ9 fatty acid desaturase (FAD) was cloned and characterized for the first time. Rapid-amplification of cDNA ends (RACE) was employed to yield a full length cDNA designated as MiΔ9FAD, which is 2442 bp long in sequence. Comparing cDNA open reading frame (ORF) sequence to genomic sequence indicated that there are 8 introns interrupting the coding region. The deduced MiΔ9FAD protein is composed of 432 amino acids. It is soluble and localized in the chloroplast, as evidenced by the absence of transmembrane domains as well as the presence of a 61-amino acid chloroplast transit peptide. Multiple sequence alignment of amino acids revealed two conserved histidine-rich motifs, typical for Δ9 acyl-acyl carrier protein (ACP) desaturases. To determine the function of MiΔ9FAD, the gene was heterologously expressed in a Saccharomyces cerevisiae mutant strain with impaired desaturase activity. Results of GC-MS analysis indicated that MiΔ9FAD was able to restore the synthesis of monounsaturated fatty acids, generating palmitoleic acid and oleic acid through the addition of a double bond in the Δ9 position of palmitic acid and stearic acid, respectively. PMID:27438826

  8. A Δ-9 Fatty Acid Desaturase Gene in the Microalga Myrmecia incisa Reisigl: Cloning and Functional Analysis

    Directory of Open Access Journals (Sweden)

    Wen-Bin Xue

    2016-07-01

    Full Text Available The green alga Myrmecia incisa is one of the richest natural sources of arachidonic acid (ArA. To better understand the regulation of ArA biosynthesis in M. incisa, a novel gene putatively encoding the Δ9 fatty acid desaturase (FAD was cloned and characterized for the first time. Rapid-amplification of cDNA ends (RACE was employed to yield a full length cDNA designated as MiΔ9FAD, which is 2442 bp long in sequence. Comparing cDNA open reading frame (ORF sequence to genomic sequence indicated that there are 8 introns interrupting the coding region. The deduced MiΔ9FAD protein is composed of 432 amino acids. It is soluble and localized in the chloroplast, as evidenced by the absence of transmembrane domains as well as the presence of a 61-amino acid chloroplast transit peptide. Multiple sequence alignment of amino acids revealed two conserved histidine-rich motifs, typical for Δ9 acyl-acyl carrier protein (ACP desaturases. To determine the function of MiΔ9FAD, the gene was heterologously expressed in a Saccharomyces cerevisiae mutant strain with impaired desaturase activity. Results of GC-MS analysis indicated that MiΔ9FAD was able to restore the synthesis of monounsaturated fatty acids, generating palmitoleic acid and oleic acid through the addition of a double bond in the Δ9 position of palmitic acid and stearic acid, respectively.

  9. Bone Regeneration Using Bone Morphogenetic Proteins and Various Biomaterial Carriers

    Directory of Open Access Journals (Sweden)

    Zeeshan Sheikh

    2015-04-01

    Full Text Available Trauma and disease frequently result in fractures or critical sized bone defects and their management at times necessitates bone grafting. The process of bone healing or regeneration involves intricate network of molecules including bone morphogenetic proteins (BMPs. BMPs belong to a larger superfamily of proteins and are very promising and intensively studied for in the enhancement of bone healing. More than 20 types of BMPs have been identified but only a subset of BMPs can induce de novo bone formation. Many research groups have shown that BMPs can induce differentiation of mesenchymal stem cells and stem cells into osteogenic cells which are capable of producing bone. This review introduces BMPs and discusses current advances in preclinical and clinical application of utilizing various biomaterial carriers for local delivery of BMPs to enhance bone regeneration.

  10. Versatility of acyl-acyl carrier protein synthetases.

    Science.gov (United States)

    Beld, Joris; Finzel, Kara; Burkart, Michael D

    2014-10-23

    The acyl carrier protein (ACP) requires posttranslational modification with a 4'-phosphopantetheine arm for activity, and this thiol-terminated modification carries cargo between enzymes in ACP-dependent metabolic pathways. We show that acyl-ACP synthetases (AasSs) from different organisms are able to load even, odd, and unnatural fatty acids onto E. coli ACP in vitro. Vibrio harveyi AasS not only shows promiscuity for the acid substrate, but also is active upon various alternate carrier proteins. AasS activity also extends to functional activation in living organisms. We show that exogenously supplied carboxylic acids are loaded onto ACP and extended by the E. coli fatty acid synthase, including unnatural fatty acid analogs. These analogs are further integrated into cellular lipids. In vitro characterization of four different adenylate-forming enzymes allowed us to disambiguate CoA-ligases and AasSs, and further in vivo studies show the potential for functional application in other organisms. PMID:25308274

  11. Amino Acid Change in an Orchid Desaturase Enables Mimicry of the Pollinator's Sex Pheromone.

    Science.gov (United States)

    Sedeek, Khalid E M; Whittle, Edward; Guthörl, Daniela; Grossniklaus, Ueli; Shanklin, John; Schlüter, Philipp M

    2016-06-01

    Mimicry illustrates the power of selection to produce phenotypic convergence in biology [1]. A striking example is the imitation of female insects by plants that are pollinated by sexual deception of males of the same insect species [2-4]. This involves mimicry of visual, tactile, and chemical signals of females [2-7], especially their sex pheromones [8-11]. The Mediterranean orchid Ophrys exaltata employs chemical mimicry of cuticular hydrocarbons, particularly the 7-alkenes, in an insect sex pheromone to attract and elicit mating behavior in its pollinators, males of the cellophane bee Colletes cunicularius [11-13]. A difference in alkene double-bond positions is responsible for reproductive isolation between O. exaltata and closely related species, such as O. sphegodes [13-16]. We show that these 7-alkenes are likely determined by the action of the stearoyl-acyl-carrier-protein desaturase (SAD) homolog SAD5. After gene duplication, changes in subcellular localization relative to the ancestral housekeeping desaturase may have allowed proto-SAD5's reaction products to undergo further biosynthesis to both 7- and 9-alkenes. Such ancestral coproduction of two alkene classes may have led to pollinator-mediated deleterious pleiotropy. Despite possible evolutionary intermediates with reduced activity, amino acid changes at the bottom of the substrate-binding cavity have conferred enzyme specificity for 7-alkene biosynthesis by preventing the binding of longer-chained fatty acid (FA) precursors by the enzyme. This change in desaturase function enabled the orchid to perfect its chemical mimicry of pollinator sex pheromones by escape from deleterious pleiotropy, supporting a role of pleiotropy in determining the possible trajectories of adaptive evolution. PMID:27212404

  12. The Crystal Structure of the Ivy delta4-16:0-ACP Desaturase Reveals Structural Details of the Oxidized Active Site and Potential Determinants of Regioselectivity

    Energy Technology Data Exchange (ETDEWEB)

    Guy,J.; Whittle, E.; Kumaran, D.; Lindqvist, Y.; Shanklin, J.

    2007-01-01

    The multifunctional acyl-acyl carrier protein (ACP) desaturase from Hedera helix (English ivy) catalyzes the {Delta}{sup 4} desaturation of 16:0-ACP and the{Delta}{sup 9} desaturation of 18:0-ACP and further desaturates{Delta}{sup 9}-16:1 or {Delta}{sup 9}-18:1 to the corresponding {Delta}{sup 4,9} dienes. The crystal structure of the enzyme has been solved to 1.95{angstrom} resolution, and both the iron-iron distance of 3.2{angstrom} and the presence of a {mu}-oxo bridge reveal this to be the only reported structure of a desaturase in the oxidized FeIII-FeIII form. Significant differences are seen between the oxidized active site and the reduced active site of the Ricinus communis (castor) desaturase; His{sup 227} coordination to Fe2 is lost, and the side chain of Glu{sup 224}, which bridges the two iron ions in the reduced structure, does not interact with either iron. Although carboxylate shifts have been observed on oxidation of other diiron proteins, this is the first example of the residue moving beyond the coordination range of both iron ions. Comparison of the ivy and castor structures reveal surface amino acids close to the annulus of the substrate-binding cavity and others lining the lower portion of the cavity that are potential determinants of their distinct substrate specificities. We propose a hypothesis that differences in side chain packing explains the apparent paradox that several residues lining the lower portion of the cavity in the ivy desaturase are bulkier than their equivalents in the castor enzyme despite the necessity for the ivy enzyme to accommodate three more carbons beyond the diiron site.

  13. Effects of Stearoyl-CoA Desaturase 1 and Sterol Regulatory Element Binding Protein Gene Polymorphisms on Milk Production, Composition and Coagulation Properties of Individual Milk of Brown Swiss Cows

    Directory of Open Access Journals (Sweden)

    Alice Maurmayr

    2011-10-01

    Full Text Available Associations between stearoyl-CoA desaturase (SCD and sterol regulatory element binding protein (SREBP-1 gene polymorphisms and milk production, composition (fat, protein, and casein content, acidity (pH and titratable acidity and coagulation properties (MCP, namely rennet coagulation time (RCT, min and curd firmness (a30, mm were investigated on individual Brown Swiss milk. A total of 294 cows from 16 herds and progeny of 15 sires were milk-sampled once. Th e additive effects of SCD and SREBP-1 genotypes on the aforementioned traits were analyzed through Bayesian linear models. The SCD gene was associated with protein content, casein content and a30. Lower protein, casein and a30 was observed for milk yielded by SCD V than A cows, whereas for other traits the effect was trivial. Animals carrying the L allele of SREBP-1 showed higher fat content than animals carrying the S allele. These results suggest a possible use of these loci in gene-assisted selection programs for the improvement of milk quality traits and MCP in Brown Swiss cattle, although large scale studies in different breeds are required.

  14. Effects of Stearoyl-CoA Desaturase 1 and Sterol Regulatory Element Binding Protein Gene Polymorphisms on Milk Production, Composition and Coagulation Properties of Individual Milk of Brown Swiss Cows

    Directory of Open Access Journals (Sweden)

    Alice Maurmayr

    2011-09-01

    Full Text Available Associations between stearoyl-CoA desaturase (SCD and sterol regulatory element binding protein (SREBP-1 gene polymorphisms and milk production, composition (fat, protein, and casein content, acidity (pH and titratable acidity and coagulation properties (MCP, namely rennet coagulation time (RCT, min and curd firmness (a30, mm were investigated on individual Brown Swiss milk. A total of 294 cows from 16 herds and progeny of 15 sires were milk-sampled once. Th e additive effects of SCD and SREBP-1 genotypes on the aforementioned traits were analyzed through Bayesian linear models. The SCD gene was associated with protein content, casein content and a30. Lower protein, casein and a30 was observed for milk yielded by SCD V than A cows, whereas for other traits the effect was trivial. Animals carrying the L allele of SREBP-1 showed higher fat content than animals carrying the S allele. These results suggest a possible use of these loci in gene-assisted selection programs for the improvement of milk quality traits and MCP in Brown Swiss cattle, although large scale studies in different breeds are required.

  15. cAMP response element binding protein1 is essential for activation of steroyl co-enzyme a desaturase 1 (Scd1 in mouse lung type II epithelial cells.

    Directory of Open Access Journals (Sweden)

    Nisha Antony

    Full Text Available Cyclic AMP Response Element-Binding Protein 1 (Creb1 is a transcription factor that mediates cyclic adenosine 3', 5'-monophosphate (cAMP signalling in many tissues. Creb1(-/- mice die at birth due to respiratory failure and previous genome-wide microarray analysis of E17.5 Creb1(-/- fetal mouse lung identified important Creb1-regulated gene targets during lung development. The lipogenic enzymes stearoyl-CoA desaturase 1 (Scd1 and fatty acid synthase (Fasn showed highly reduced gene expression in Creb1(-/- lungs. We therefore hypothesized that Creb1 plays a crucial role in the transcriptional regulation of genes involved in pulmonary lipid biosynthetic pathways during lung development. In this study we confirmed that Scd1 and Fasn mRNA levels were down regulated in the E17.5 Creb1(-/- mouse lung while the lipogenic-associated transcription factors SrebpF1, C/ebpα and Pparγ were increased. In vivo studies using germline (Creb1(-/- and lung epithelial-specific (Creb1(EpiΔ/Δ Creb1 knockout mice showed strongly reduced Scd1, but not Fasn gene expression and protein levels in lung epithelial cells. In vitro studies using mouse MLE-15 epithelial cells showed that forskolin-mediated activation of Creb1 increased both Scd1 gene expression and protein synthesis. Additionally, MLE15 cells transfected with a dominant-negative ACreb vector blocked forskolin-mediated stimulation of Scd1 gene expression. Lipid profiling in MLE15 cells showed that dominant-negative ACreb suppressed forskolin-induced desaturation of ether linked lipids to produce plasmalogens, as well as levels of phosphatidylethanolamine, ceramide and lysophosphatidylcholine. Taken together these results demonstrate that Creb1 is essential for the induction and maintenance of Scd1 in developing fetal mouse lung epithelial cells.

  16. Calcium Sulfate with Stearic Acid as an Encouraging Carrier for Reindeer Bone Protein Extract

    Directory of Open Access Journals (Sweden)

    Pekka Jalovaara

    2011-07-01

    Full Text Available Various bone proteins and growth factors in specific concentrations are required for bone formation. If the body cannot produce sufficient quantities of these factors, bone trauma can be healed with an implant that includes the required factors in a carrier. This study was designed to evaluate various calcium salt candidates that can be used as carrier with reindeer bone protein extract to induce ectopic bone formation in the muscle pouch model of mouse. The bone protein extract was either impregnated into the disc form of carrier or mixed with carrier powder before implantation. The radiographic analysis indicated increased bone formation in all of the active groups containing the bone protein extract compared to the controls within 21 days follow-up. The highest bone formation was seen in the group with calcium sulfate with stearic acid where new bone and calcified cartilage were clearly visible. The greatest bone formation occurred in the groups that had bone protein extract readily available. This indicates that the bone forming factors in sufficient concentrations are required at the early stage of bone formation. The calcium sulfate with stearic acid was the most suitable and effective carrier for reindeer bone protein extract.

  17. Stealth carriers for low-resolution structure determination of membrane proteins in solution

    DEFF Research Database (Denmark)

    Maric, Selma; Skar-Gislinge, Nicholas; Midtgaard, Søren;

    2014-01-01

    Structural studies of membrane proteins remain a great experimental challenge. Functional reconstitution into artificial nanoscale bilayer disc carriers that mimic the native bilayer environment allows the handling of membrane proteins in solution. This enables the use of small-angle scattering...... techniques for fast and reliable structural analysis. The difficulty with this approach is that the carrier discs contribute to the measured scattering intensity in a highly nontrivial fashion, making subsequent data analysis challenging. Here, an elegant solution to circumvent the intrinsic complexity......O at the length scales relevant to SANS. These 'stealth' carrier discs may be used as a general platform for low-resolution structural studies of membrane proteins using well established data-analysis tools originally developed for soluble proteins. © 2014 International Union of Crystallography....

  18. NMR structure of an acyl-carrier protein from Borrelia burgdorferi

    International Nuclear Information System (INIS)

    The high-resolution NMR structure of the acyl-carrier protein from the pathogen B. burgdorferi determined to a r.m.s. deviation of 0.4 Å over the protein backbone is reported. The NMR structure was determined using multidimensional NMR spectroscopy and consists of four α-helices and two 310-helices. Structural comparison reveals that this protein is highly similar to the acyl-carrier protein from A. aeolicus. Nearly complete resonance assignment and the high-resolution NMR structure of the acyl-carrier protein from Borrelia burgdorferi, a target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure-determination pipeline, are reported. This protein was chosen as a potential target for drug-discovery efforts because of its involvement in fatty-acid biosynthesis, an essential metabolic pathway, in bacteria. It was possible to assign >98% of backbone resonances and >92% of side-chain resonances using multidimensional NMR spectroscopy. The NMR structure was determined to a backbone r.m.s.d. of 0.4 Å and contained four α-helices and two 310-helices. A structure-homology search revealed that this protein is highly similar to the acyl-carrier protein from Aquifex aeolicus

  19. Possible pheromone-carrier function of two lipocalin proteins in the vomeronasal organ.

    OpenAIRE

    Miyawaki, A.; Matsushita, F; Ryo, Y; Mikoshiba, K

    1994-01-01

    We report the molecular cloning and characterization of two secretory proteins specifically expressed in vomeronasal and posterior glands of the nasal septum, the ducts of which open into the lumen of the vomeronasal organ. These two proteins are members of the lipocalin superfamily, consisting of hydrophobic ligand carriers. We immunohistochemically localized one of the proteins in the mucus covering the vomeronasal sensory epithelium, where the primary reception of pheromone takes place. Th...

  20. Cloning and expression analysis of phytoene desaturase and ζ-carotene desaturase genes in Carica papaya.

    Science.gov (United States)

    Yan, P; Gao, X Z; Shen, W T; Zhou, P

    2011-02-01

    The fruit flesh color of papaya is an important nutritional quality trait and is due to the accumulation of carotenoid. To elucidate the carotenoid biosynthesis pathway in Carica papaya, the phytoene desaturase (PDS) and the ζ-carotene desaturase (ZDS) genes were isolated from papaya (named CpPDS and CpZDS) using the rapid amplification of cDNA ends (RACE) approach, and their expression levels were investigated in red- and yellow-fleshed papaya varieties. CpPDS contains a 1749 bp open reading frame coding for 583 amino acids, while CpZDS contains a 1716 bp open reading frame coding for 572 amino acids. The deduced CpPDS and CpZDS proteins contain a conserved dinucleotide-binding site at the N-terminus and a carotenoid-binding domain at the C-terminus. Papaya genome sequence analysis revealed that CpPDS and CpZDS are single copy; the CpPDS was mapped to papaya chromosome LG6, and the CpZDS was mapped to chromosome LG3. Quantitative PCR showed that both CpPDS and CpZDS were expressed in all tissues examined with the highest expression in maturing fruits, and that the expression of CpPDS and CpZDS were higher in red-fleshed fruits than in yellow-fleshed fruits. These results indicated that the differential accumulation of carotenoids in red- and yellow-fleshed papaya varieties might be partly explained by the transcriptional level of CpPDS and CpZDS.

  1. Structural and bioinformatic characterization of an Acinetobacter baumannii type II carrier protein

    Energy Technology Data Exchange (ETDEWEB)

    Allen, C. Leigh; Gulick, Andrew M., E-mail: gulick@hwi.buffalo.edu [University at Buffalo, Buffalo, NY 14203 (United States)

    2014-06-01

    The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented. Microorganisms produce a variety of natural products via secondary metabolic biosynthetic pathways. Two of these types of synthetic systems, the nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), use large modular enzymes containing multiple catalytic domains in a single protein. These multidomain enzymes use an integrated carrier protein domain to transport the growing, covalently bound natural product to the neighboring catalytic domains for each step in the synthesis. Interestingly, some PKS and NRPS clusters contain free-standing domains that interact intermolecularly with other proteins. Being expressed outside the architecture of a multi-domain protein, these so-called type II proteins present challenges to understand the precise role they play. Additional structures of individual and multi-domain components of the NRPS enzymes will therefore provide a better understanding of the features that govern the domain interactions in these interesting enzyme systems. The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented here. Comparison with the closest structural homologs of other carrier proteins identifies the requirements for a conserved glycine residue and additional important sequence and structural requirements within the regions that interact with partner proteins.

  2. Mesoporous magnetic hollow nanoparticles—protein carriers for lysosome escaping and cytosolic delivery

    Science.gov (United States)

    Huang, Xinglu; Meng, Xianwei; Tang, Fangqiong; Li, Linlin; Chen, Dong; Liu, Huiyu; Zhang, Yanqi; Ren, Jun

    2008-11-01

    It is important for a controlled release system to determine whether nanoparticles can penetrate cell membranes and deliver protein into the nuclear or cytosolic compartments of cells, and thus function as carriers. Here, we prepared different functionalized mesoporous magnetic hollow nanoparticles (MMHs) and chose bovine serum albumin (BSA) as a model protein to detect the intracellular trafficking of MMHs. The results showed that MMHs modified with amino groups (AMMHs) were efficient in protein loading and that the loading was dependent on the pH, temperature and ionic strength. Furthermore, we found that the AMMHs not only transported BSA into the cells but also released the BSA carried into the nuclear or cytosolic compartments of the cells. In addition, the nanoparticles were biocompatible, and the encapsulation of BSA in AMMHs did not affect their bioactivity. Taken together, AMMHs are excellent carriers for releasing protein into the cytosol and nucleus, and they have the potential to be used in a controlled release system.

  3. The biological activity of a-mangostin, a larvicidal botanic mosquito sterol carrier protein-2 inhibitor

    Science.gov (United States)

    Alpha-mangostin derived from mangosteen was identified as a mosquito sterol carrier protein-2 inhibitor via high throughput insecticide screening. Alpha-mangostin was tested for its larvicidal activity against 3rd instar larvae of six mosquito species and the LC50 values range from 0.84 to 2.90 ppm....

  4. NMR structure of an acyl-carrier protein from Borrelia burgdorferi

    OpenAIRE

    Barnwal, Ravi P.; Van Voorhis, Wesley C.; Varani, G

    2011-01-01

    Nearly complete resonance assignment and the high-resolution NMR structure of the acyl-carrier protein from Borrelia burgdorferi, a target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure-determination pipeline, are reported. This protein was chosen as a potential target for drug-discovery efforts because of its involvement in fatty-acid biosynthesis, an essential metabolic pathway, in bacteria. It was possible to assign >98% of backbone resonances and >92% ...

  5. Diversity in transcripts and translational pattern of stress proteins in marine extremophiles

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, I.V.A.; LokaBharathi, P.A.

    -shocked cells by decreasing the membrane fluidity and acting as RNA chaperones (Yamanaka et al., 1998). They are different from CAPs. CSPs are induced in response to a sudden shock to a low temperature, whereas CAPs are specifically synthesized to acclimatize.... Lipid desaturases and genes involved in the maintenance of cell membrane fluidity have been found in the P. haloplanktis genome. Proteins concerned with membrane fluidity- β-keto-acyl-carrier proteins, β-keto-acyl-CoA synthetases and fatty acid cis...

  6. Evaluation of Salmonella enterica type III secretion system effector proteins as carriers for heterologous vaccine antigens.

    Science.gov (United States)

    Hegazy, Wael Abdel Halim; Xu, Xin; Metelitsa, Leonid; Hensel, Michael

    2012-03-01

    Live attenuated strains of Salmonella enterica have a high potential as carriers of recombinant vaccines. The type III secretion system (T3SS)-dependent translocation of S. enterica can be deployed for delivery of heterologous antigens to antigen-presenting cells. Here we investigated the efficacy of various effector proteins of the Salmonella pathogenicity island (SPI2)-encoded T3SS for the translocation of model antigens and elicitation of immune responses. The SPI2 T3SS effector proteins SifA, SteC, SseL, SseJ, and SseF share an endosomal membrane-associated subcellular localization after translocation. We observed that all effector proteins could be used to translocate fusion proteins with the model antigens ovalbumin and listeriolysin into the cytosol of host cells. Under in vitro conditions, fusion proteins with SseJ and SteC stimulated T-cell responses that were superior to those triggered by fusion proteins with SseF. However, in mice vaccinated with Salmonella carrier strains, only fusion proteins based on SseJ or SifA elicited potent T-cell responses. These data demonstrate that the selection of an optimal SPI2 effector protein for T3SS-mediated translocation is a critical parameter for the rational design of effective Salmonella-based recombinant vaccines.

  7. Identification and Characterization of Inhibitors of Bacterial Enoyl-Acyl Carrier Protein Reductase

    OpenAIRE

    Ling, Losee L.; Xian, Jun; Ali, Syed; Geng, Bolin; Fan, Jun; Mills, Debra M.; Arvanites, Anthony C.; Orgueira, Hernan; Ashwell, Mark A.; Carmel, Gilles; Xiang, Yibin; Moir, Donald T.

    2004-01-01

    Bacterial enoyl-acyl carrier protein reductase (ENR) catalyzes an essential step in fatty acid biosynthesis. ENR is an attractive target for narrow-spectrum antibacterial drug discovery because of its essential role in metabolism and its sequence conservation across many bacterial species. In addition, the bacterial ENR sequence and structural organization are distinctly different from those of mammalian fatty acid biosynthesis enzymes. High-throughput screening to identify inhibitors of Esch...

  8. Induction of the lac carrier and an associated membrane protein in Escherichia coli

    International Nuclear Information System (INIS)

    Induction of the lac operon in wild type Escherichia coli strains results in synthesis of a 16 kilodalton inner membrane protein in addition to the known products of the lacZ, lacY and lacA genes. Cells carrying the lacY gene on a plasmid over produce this 16 kilodalton polypeptide as well as the Lac carrier, the membrane protein product of the lacY gene. However, [35S]methionine labeling of minicells carrying the lacY plasmid shows that the 16 kDa protein is not synthesized from the plasmid DNA. The 16 kDa protein was purified and partially characterized. It is an acidic membrane protein of apparent molecular weight 15,800 whose amino terminal sequence (NH2-Met-Arg-Asn-Phe-Asp-Leu-) does not correspond to any nucleotide sequence known in lac operon DNA. Using antibody prepared to the purified 16 kDa protein, a quantitative analysis of conditions under which this protein is made was accomplished, and reveals that the amount of 16 kDa protein which appears in the membrane is proportional to lac operon expression. Hybridization of a synthetic oligonucleotide probe complementary to the 5' end of 16 kDa protein mRNA shows that its synthesis is regulated at the level of transcription. A description of attempts to clone this gene is given. Possible functional roles for the 16 kDa protein are discussed

  9. Participation of Low Molecular Weight Electron Carriers in Oxidative Protein Folding

    Directory of Open Access Journals (Sweden)

    József Mandl

    2009-03-01

    Full Text Available Oxidative protein folding is mediated by a proteinaceous electron relay system, in which the concerted action of protein disulfide isomerase and Ero1 delivers the electrons from thiol groups to the final acceptor. Oxygen appears to be the final oxidant in aerobic living organisms, although the existence of alternative electron acceptors, e.g. fumarate or nitrate, cannot be excluded. Whilst the protein components of the system are well-known, less attention has been turned to the role of low molecular weight electron carriers in the process. The function of ascorbate, tocopherol and vitamin K has been raised recently. In vitro and in vivo evidence suggests that these redox-active compounds can contribute to the functioning of oxidative folding. This review focuses on the participation of small molecular weight redox compounds in oxidative protein folding.

  10. Development of a stealth carrier system for structural studies of membrane proteins in solution

    DEFF Research Database (Denmark)

    Maric, Selma

    Structural studies of membrane proteins remain a great experimental challenge. Functional reconstitution into artificial carriers that mimic the native bilayer environment allows for the handling of membrane proteins in solution and enables the use of small-angle scattering techniques for fast...... which can be used for SANS structural analysis of membrane proteins in solution. In combination with the D2O/H2O-based contrast variation method it is demonstrated that it is possible to prepare specifically deuterated analogues of the nanodisc, which give minimal contribution to the neutron scattering...... scaffolding protein. To obtain physiologically relevant deuterated phosphatidylcholine (PC) species with the required scattering length density a novel method for deuteration of PC was developed to separately control the deuteration levels of three different parts of the phospholipid molecule: the lipid head...

  11. Functional identification of a delta8-sphingolipid desaturase from Borago officinalis.

    Science.gov (United States)

    Sperling, P; Libisch, B; Zähringer, U; Napier, J A; Heinz, E

    2001-04-15

    The similarities between delta12- and delta5-fatty acyl desaturase sequences were used to construct degenerate primers for PCR experiments with cDNA transcribed from mRNA of developing borage seeds. Screening of a borage seed cDNA library with an amplified DNA fragment resulted in the isolation of a full-length cDNA corresponding to a deduced open-reading frame of 446 amino acids. The protein showed high similarity to plant delta8-sphingolipid desaturases as well as to the delta6-fatty acyl desaturase from Borago officinalis. The sequence is characterized by the presence of a N-terminal cytochrome b5 domain. Expression of this open-reading frame in Saccharomyces cerevisiae resulted in the formation of delta8-trans/cis-phytosphingenines not present in wild-type cells, as shown by HPLC analysis of sphingoid bases as their dinitrophenyl derivatives. GLC-MS analysis of the methylated di-O-trimethylsilyl ether derivatives confirmed the presence of delta8-stereoisomers of C18- and C20-phytosphingenine. Furthermore, Northern blotting showed that the gene encoding a stereo-unselective delta8-sphingolipid desaturase is primarily expressed in young borage leaves. PMID:11368168

  12. A Δ11 desaturase gene genealogy reveals two divergent allelic classes within the European corn borer (Ostrinia nubilalis

    Directory of Open Access Journals (Sweden)

    Harrison Richard G

    2010-04-01

    Full Text Available Abstract Background Moth pheromone mating systems have been characterized at the molecular level, allowing evolutionary biologists to study how changes in protein sequence or gene expression affect pheromone phenotype, patterns of mating, and ultimately, the formation of barriers to gene exchange. Recent studies of Ostrinia pheromones have focused on the diversity of sex pheromone desaturases and their role in the specificity of pheromone production. Here we produce a Δ11 desaturase genealogy within Ostrinia nubilalis. We ask what has been the history of this gene, and whether this history suggests that changes in Δ11 desaturase have been involved in the divergence of the E and Z O. nubilalis pheromone strains. Results The Δ11 desaturase gene genealogy does not differentiate O. nubilalis pheromone strains. However, we find two distinct clades, separated by 2.9% sequence divergence, that do not sort with pheromone strain, geographic origin, or emergence time. We demonstrate that these clades do not represent gene duplicates, but rather allelic variation at a single gene locus. Conclusions Analyses of patterns of variation at the Δ11 desaturase gene in ECB suggest that this enzyme does not contribute to reproductive isolation between pheromone strains (E and Z. However, our genealogy reveals two deeply divergent allelic classes. Standing variation at loci that contribute to mate choice phenotypes may permit novel pheromone mating systems to arise in the presence of strong stabilizing selection.

  13. Fatty acid biosynthesis in Pseudomonas aeruginosa: cloning and characterization of the fabAB operon encoding beta-hydroxyacyl-acyl carrier protein dehydratase (FabA) and beta-ketoacyl-acyl carrier protein synthase I (FabB).

    OpenAIRE

    Hoang, T.T.; Schweizer, H P

    1997-01-01

    The Pseudomonas aeruginosa fabA and fabB genes, encoding beta-hydroxyacyl-acyl carrier protein dehydratase and beta-ketoacyl-acyl carrier protein synthase I, respectively, were cloned, sequenced, and expressed in Escherichia coli. Northern analysis demonstrated that fabA and fabB are cotranscribed and most probably form a fabAB operon. The FabA and FabB proteins were similar in size and amino acid composition to their counterparts from Escherichia coli and to the putative homologs from Haemop...

  14. Rational Design of a Carrier Protein for the Production of Recombinant Toxic Peptides in Escherichia coli

    Science.gov (United States)

    Pizzo, Elio; Varcamonti, Mario; Zanfardino, Anna; Sgambati, Valeria; Di Maro, Antimo; Carpentieri, Andrea; Izzo, Viviana; Di Donato, Alberto; Cafaro, Valeria; Notomista, Eugenio

    2016-01-01

    Commercial uses of bioactive peptides require low cost, effective methods for their production. We developed a new carrier protein for high yield production of recombinant peptides in Escherichia coli very well suited for the production of toxic peptides like antimicrobial peptides. GKY20, a short antimicrobial peptide derived from the C-terminus of human thrombin, was fused to the C-terminus of Onconase, a small ribonuclease (104 amino acids), which efficiently drove the peptide into inclusion bodies with very high expression levels (about 200–250 mg/L). After purification of the fusion protein by immobilized metal ion affinity chromatography, peptide was obtained by chemical cleavage in diluted acetic acid of an acid labile Asp-Pro sequence with more than 95% efficiency. To improve peptide purification, Onconase was mutated to eliminate all acid labile sequences thus reducing the release of unwanted peptides during the acid cleavage. Mutations were chosen to preserve the differential solubility of Onconase as function of pH, which allows its selective precipitation at neutral pH after the cleavage. The improved carrier allowed the production of 15–18 mg of recombinant peptide per liter of culture with 96–98% purity without the need of further chromatographic steps after the acid cleavage. The antimicrobial activity of the recombinant peptide, with an additional proline at the N-terminus, was tested on Gram-negative and Gram-positive strains and was found to be identical to that measured for synthetic GKY20. This finding suggests that N-terminal proline residue does not change the antimicrobial properties of recombinant (P)GKY20. The improved carrier, which does not contain cysteine and methionine residues, Asp-Pro and Asn-Gly sequences, is well suited for the production of peptides using any of the most popular chemical cleavage methods. PMID:26808536

  15. Rational Design of a Carrier Protein for the Production of Recombinant Toxic Peptides in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Katia Pane

    Full Text Available Commercial uses of bioactive peptides require low cost, effective methods for their production. We developed a new carrier protein for high yield production of recombinant peptides in Escherichia coli very well suited for the production of toxic peptides like antimicrobial peptides. GKY20, a short antimicrobial peptide derived from the C-terminus of human thrombin, was fused to the C-terminus of Onconase, a small ribonuclease (104 amino acids, which efficiently drove the peptide into inclusion bodies with very high expression levels (about 200-250 mg/L. After purification of the fusion protein by immobilized metal ion affinity chromatography, peptide was obtained by chemical cleavage in diluted acetic acid of an acid labile Asp-Pro sequence with more than 95% efficiency. To improve peptide purification, Onconase was mutated to eliminate all acid labile sequences thus reducing the release of unwanted peptides during the acid cleavage. Mutations were chosen to preserve the differential solubility of Onconase as function of pH, which allows its selective precipitation at neutral pH after the cleavage. The improved carrier allowed the production of 15-18 mg of recombinant peptide per liter of culture with 96-98% purity without the need of further chromatographic steps after the acid cleavage. The antimicrobial activity of the recombinant peptide, with an additional proline at the N-terminus, was tested on Gram-negative and Gram-positive strains and was found to be identical to that measured for synthetic GKY20. This finding suggests that N-terminal proline residue does not change the antimicrobial properties of recombinant (PGKY20. The improved carrier, which does not contain cysteine and methionine residues, Asp-Pro and Asn-Gly sequences, is well suited for the production of peptides using any of the most popular chemical cleavage methods.

  16. Rational Design of a Carrier Protein for the Production of Recombinant Toxic Peptides in Escherichia coli.

    Science.gov (United States)

    Pane, Katia; Durante, Lorenzo; Pizzo, Elio; Varcamonti, Mario; Zanfardino, Anna; Sgambati, Valeria; Di Maro, Antimo; Carpentieri, Andrea; Izzo, Viviana; Di Donato, Alberto; Cafaro, Valeria; Notomista, Eugenio

    2016-01-01

    Commercial uses of bioactive peptides require low cost, effective methods for their production. We developed a new carrier protein for high yield production of recombinant peptides in Escherichia coli very well suited for the production of toxic peptides like antimicrobial peptides. GKY20, a short antimicrobial peptide derived from the C-terminus of human thrombin, was fused to the C-terminus of Onconase, a small ribonuclease (104 amino acids), which efficiently drove the peptide into inclusion bodies with very high expression levels (about 200-250 mg/L). After purification of the fusion protein by immobilized metal ion affinity chromatography, peptide was obtained by chemical cleavage in diluted acetic acid of an acid labile Asp-Pro sequence with more than 95% efficiency. To improve peptide purification, Onconase was mutated to eliminate all acid labile sequences thus reducing the release of unwanted peptides during the acid cleavage. Mutations were chosen to preserve the differential solubility of Onconase as function of pH, which allows its selective precipitation at neutral pH after the cleavage. The improved carrier allowed the production of 15-18 mg of recombinant peptide per liter of culture with 96-98% purity without the need of further chromatographic steps after the acid cleavage. The antimicrobial activity of the recombinant peptide, with an additional proline at the N-terminus, was tested on Gram-negative and Gram-positive strains and was found to be identical to that measured for synthetic GKY20. This finding suggests that N-terminal proline residue does not change the antimicrobial properties of recombinant (P)GKY20. The improved carrier, which does not contain cysteine and methionine residues, Asp-Pro and Asn-Gly sequences, is well suited for the production of peptides using any of the most popular chemical cleavage methods. PMID:26808536

  17. Structural characterization and comparison of three acyl-carrier-protein synthases from pathogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Halavaty, Andrei S. [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States); Kim, Youngchang [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Minasov, George; Shuvalova, Ludmilla; Dubrovska, Ievgeniia; Winsor, James [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States); Zhou, Min [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Onopriyenko, Olena; Skarina, Tatiana [Center for Structural Genomics of Infectious Diseases, (United States); University of Toronto, Toronto, Ontario M5G 1L6 (Canada); Papazisi, Leka; Kwon, Keehwan; Peterson, Scott N. [Center for Structural Genomics of Infectious Diseases, (United States); J. Craig Venter Institute, Rockville, MD 20850 (United States); Joachimiak, Andrzej [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Savchenko, Alexei [Center for Structural Genomics of Infectious Diseases, (United States); University of Toronto, Toronto, Ontario M5G 1L6 (Canada); Anderson, Wayne F., E-mail: wf-anderson@northwestern.edu [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States)

    2012-10-01

    The structural characterization of acyl-carrier-protein synthase (AcpS) from three different pathogenic microorganisms is reported. One interesting finding of the present work is a crystal artifact related to the activity of the enzyme, which fortuitously represents an opportunity for a strategy to design a potential inhibitor of a pathogenic AcpS. Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpS{sub SA}), Vibrio cholerae (AcpS{sub VC}) and Bacillus anthracis (AcpS{sub BA}) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpS{sub BA} is emphasized because of the two 3′, 5′-adenosine diphosphate (3′, 5′-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3′, 5′-ADP is bound as the 3′, 5′-ADP part of CoA in the known structures of the CoA–AcpS and 3′, 5′-ADP–AcpS binary complexes. The position of the second 3′, 5′-ADP has never been described before. It is in close proximity to the first 3′, 5′-ADP and the ACP-binding site. The coordination of two ADPs in AcpS{sub BA} may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP.

  18. Cloning and characterization of a stearoyl-ACP desaturase gene from Jatropha curcas%麻疯树硬酯酰-酰基载体蛋白脱饱和酶基因的克隆及特征

    Institute of Scientific and Technical Information of China (English)

    罗通; 马丹炜; 徐莺; 邓骛远; 肖猛; 卿人韦; 陈放

    2007-01-01

    Using degenerate primers and RT-PCR, RACE techniques, a 1491 bp cDNA segment of stearoyl-acyl carrier protein desaturase (SAD) is cloned from developing seeds of Jatropha curcas L. The segment contains a 1191 bp of complete open reading frame (ORF). Analysis in the BLAST on NCBI shows that Jatropha curcas SAD (JSAD) gene encodes a protein precursor composed of a signal peptide of 33 amino acids and a mature peptide of 363 amino acids. The homological analysis shows that JSAD has high level of homology both in nucleotide sequence and in amino acid sequence to other plants SADs. The nucleotide and peptide identity of JSAD to Ricinus communis SAD (RSAD) is up to 89% and 96.2% respectively. Molecular modeling of JSAD indicates that its three-dimensional structure strongly resembled the crystal structure of RSAD.

  19. Role of acyl carrier protein isoforms in plant lipid metabolism: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Ohlrogge, J.B.

    1989-01-01

    Previous research from my lab has revealed that several higher plant species have multiple isoforms of acyl carrier protein (ACP) and therefore this trait appears highly conserved among higher plants. This level of conservation suggests that the existence of ACP isoforms is not merely the results of neutral gene duplications. We have developed techniques to examine a wider range of species. Acyl carrier proteins can be labelled very specifically and to high specific activity using H-palmitate and the E. coli enzyme acyl-ACP synthetase. Isoforms were then resolved by western blotting and native PAGE of H-palmitate labelled ACP's. Multiple isoforms of ACP were observed the leaf tissue of the monocots Avena sativa and Hordeum vulgare and dicots including Arabidopsis thallina, Cuphea wrightii, and Brassica napus. Lower vascular plants including the cycad, Dioon edule, Ginkgo biloba, the gymnosperm Pinus, the fern Anernia phyllitidis and Psilotum nudum, the most primitive known extant vascular plant, were also found to have multiple ACP isoforms as were the nonvascular liverwort, Marchantia and moss, Polytrichum. Therefore, the development of ACP isoforms occurred early in evolution. However, the uniellular alge Chlamydomonas and Dunaliella and the photosynthetic cyanobacteria Synechocystis and Agmnellum have only a single elecrophotetic form of ACP. Thus, multiple forms of ACP do not occur in all photosynthetic organisms but may be associated with multicellular plants.

  20. Humoral Immune Response to Keyhole Limpet Haemocyanin, the Protein Carrier in Cancer Vaccines

    Directory of Open Access Journals (Sweden)

    A. Kantele

    2011-01-01

    Full Text Available Keyhole limpet haemocyanin (KLH appears to be a promising protein carrier for tumor antigens in numerous cancer vaccine candidates. The humoral immune response to KLH was characterized at the single-cell level with ELISPOT combined with separations of cell populations according to their expression of homing receptors (HRs. The analysis of HR expressions is expected to reveal the targeting of the immune response in the body. Eight orally primed and four nonprimed volunteers received KLH-vaccine subcutaneously. Circulating KLH-specific plasmablasts were found in all volunteers, 60 KLH-specific plasmablasts/106 PBMC in the nonprimed and 136/106 in the primed group. The proportion of L-selectin+ plasmablasts proved high and integrin α4β7+ low. KLH serving as protein carrier in several vaccines, the homing profile of KLH-specific response may be applicable to the cancer antigen parts in the same vaccines. The present data reflect a systemic homing profile, which appears advantageous for the targeting of immune response to cancer vaccines.

  1. Purification of nonspecific lipid transfer protein (sterol carrier protein 2) from human liver and its deficiency in livers from patients with cerebro-hepato-renal (Zellweger) syndrome

    NARCIS (Netherlands)

    Amerongen, A. van; Helms, J.B.; Krift, T.P. van der; Schutgens, R.B.H.; Wirtz, K.W.A.

    1987-01-01

    The nonspecific lipid transfer protein (i.e., sterol carrier protein 2) from human liver was purified to homogeneity using ammonium sulfate precipitation, CM-cellulose chromatography, molecular sieve chromatography and fast protein liquid chromatography. Its amino acid composition was determined and

  2. Delta-8 desaturation activity varies among fatty acyl desaturases of teleost fish: high activity in delta-6 desaturases of marine species.

    Science.gov (United States)

    Monroig, Oscar; Li, Yuanyou; Tocher, Douglas R

    2011-08-01

    The benefits of dietary fish and fish oil are derived from n-3 long-chain polyunsaturated fatty acids (LC-PUFA) that have beneficial effects in a range of human diseases and pathologies such as cardiovascular and other inflammatory disorders, neural development and neurological pathologies. The precursor of n-3 LC-PUFA, 18:3n-3 does not have the same beneficial effects prompting interest in the pathways of endogenous synthesis of LC-PUFA in vertebrates. The LC-PUFA biosynthesis pathway classically involves Δ6 and Δ5 fatty acyl desaturases (Fad), but it was recently shown that Δ6 Fad in mammals also displayed Δ8 activity demonstrating a possible alternative "Δ8-pathway" for the synthesis of LC-PUFA. Our primary hypothesis was that Δ8 desaturase activity would be a common feature of vertebrate Δ6 Fads, and so the aim of the present study was to determine the ability of teleostei Fads for Δ8 desaturation activity. To this end, cDNAs for Fads from a range of freshwater, diadromous and marine teleost fish species were assayed for Δ8 activity in the heterologous yeast expression system. In summary, the present study has demonstrated that Δ8 desaturation activity was also a characteristic of fish orthologs, although the activity varied notably between freshwater/diadromous and marine fish species, with the latter possessing Fads2-like proteins with Δ8 activity far higher than mammalian FADS2. The data showed that, generally, the fish Fad are technically υ-3 desaturases, with new double bonds introduced 3C beyond a pre-existing double bond. However, the ability of zebrafish and rabbitfish Fads, previously characterised as Δ6/Δ5 bifunctional desaturases, to introduce non-methylene interrupted double bonds in 20:3n-3 and 20:2n-6 suggested that a novel combination of regioselectivity modes operates within these enzymes.

  3. Directed evolution increases desaturation of a cyanobacterial fatty acid desaturase in eukaryotic expression systems.

    Science.gov (United States)

    Bai, Shuangyi; Wallis, James G; Denolf, Peter; Browse, John

    2016-07-01

    Directed evolution of a cyanobacterial Δ9 fatty acid desaturase (DSG) from Synechococcus elongatus, PCC6301 created new, more productive desaturases and revealed the importance of certain amino acid residues to increased desaturation. A codon-optimized DSG open reading frame with an endoplasmic-reticulum retention/retrieval signal appended was used as template for random mutagenesis. Increased desaturation was detected using a novel screen based on complementation of the unsaturated fatty acid auxotrophy of Saccharomyces cerevisiae mutant ole1Δ. Amino acid residues whose importance was discovered by the random processes were further examined by saturation mutation to determine the best amino acid at each identified location in the peptide chain and by combinatorial analysis. One frequently-detected single amino acid change, Q240R, yielded a nearly 25-fold increase in total desaturation in S. cerevisiae. Several other variants of the protein sequence with multiple amino acid changes increased total desaturation more than 60-fold. Many changes leading to increased desaturation were in the vicinity of the canonical histidine-rich regions known to be critical for electron transfer mediated by these di-iron proteins. Expression of these evolved proteins in the seed of Arabidopsis thaliana altered the fatty acid composition, increasing monounsaturated fatty acids and decreasing the level of saturated fatty acid, suggesting a potential application of these desaturases in oilseed crops. Biotechnol. Bioeng. 2016;113: 1522-1530. © 2016 Wiley Periodicals, Inc. PMID:26724425

  4. The effect of the application of protein and cellulose preparations as iodine carriers on stability of thiamine in processed meats

    OpenAIRE

    Krystyna Szymandera-Buszka; Katarzyna Waszkowiak; Marzanna Hęś; Anna Jędrusek-Golińska

    2011-01-01

      Fortification of processed meat with iodised table salt was shown to increase thiamine losses, both during thermal processing and storage. Taking into consideration the fact, as well as the recommendation for reduction of consumption of table salt, alternative iodine carriers need to be searched for. Thus the aim of the study was to determine the effect of soy protein isolate (SPI) and wheat fibre (WF) as iodine salts’ (potassium iodide and iodate) carriers on thiamine stabil...

  5. Water-soluble chitosan nanoparticles as a novel carrier system for protein delivery

    Institute of Scientific and Technical Information of China (English)

    WANG Chun; FU Xiong; YANG LianSheng

    2007-01-01

    High MW chitosan (CS) solutions have already been proposed as vehicles for protein delivery. The aim of the present work is to investigate the potential utility of water-soluble chitosan (WSC) as vehicles to load and deliver proteins. WSC nanoparticles (WSC NP) with various formations were prepared based on ionic gelation of WSC with pentasodium tripolyphosphate (TPP) anions. Bovine serum albumin (BSA) was used as a model protein drug incorporated into the WSC nanoparticles. Blank and BSA-loaded WSC nanoparticles were examined and determined to have a spherical shape with diameters between 35-190 nm, and zeta potential between 35-42 mV. FTIF confirmed that the tripolyphosphoric groups of TPP linked to the ammonium groups of WSC in the nanoparticles. Some factors affecting delivery properties of BSA have been investigated. Altering the concentration of BSA from 0.05 to 1 mg/mL enhanced the loading capacity of BSA but decreased loading efficiency simultaneously.Also, with the introduction of poly ethylene glycol (PEG), BSA release accelerated. Nanoparticle preparation from WSC with various deacetylation degrees (DDs) from 72.6% to 90% and MWs ranging from 3.5 to 15.8 kDa promoted loading efficiency and decreased the release rate. These results indicate that WSC nanoparticles are promising carriers for protein delivery.

  6. Electrospun fish protein fibers as a biopolymer-based carrier – implications for oral protein delivery

    DEFF Research Database (Denmark)

    Boutrup Stephansen, Karen; García-Díaz, María; Jessen, Flemming;

    2014-01-01

    Purpose: Protein-based electrospun fibers have emerged as novel nanostructured materials for tissue engineering and drug delivery due to their unique structural characteristics, biocompatibility and biodegradability. The aim of this study was to explore the use of electrospun fibers based on fish...

  7. An evaluation of garlic lectin as an alternative carrier domain for insecticidal fusion proteins

    Institute of Scientific and Technical Information of China (English)

    Elaine Fitches; Judith Philip; Gareth Hinchliffe; Leisbeth Vercruysse; Nanasaheb Chougule; John A.Gatehouse

    2008-01-01

    The mannosc-binding lectin GNA(snowdrop lectin)is used as a"carrier"domain in insecticidal fusion proteins which cross the insect gut after oral ingestion.A similar lectin from garlic bulb,ASAII,has been evaluated as an altemative"carrieff".Recombinant ASAII delivered orally to larvae of cabbage moth(Mamestra brassica;Lepidoptera)Was subse-quently detected in haemolymph,demonstrating transport.Fusion proteins comprising an insect neurotoxin.ButaIT(Buthus tamulus insecticidal toxin;red scorpion toxin)linked to the C-terminal region of ASAII or GNA were produced as recombinant proteins(GNA/ButaIT and ASA/ButaIT)by expression in Pichia pastoris.In both cases the C-terminal sequence of the lectin was truncated to avoid post-translational proteolysis.The GNA-containing fusion protein was toxic by injection to cabbage moth larvae(LD50≈250μg/g),and when fed had a negative effect on survival and growth.It also decreased the survival of cereal aphids(Sitobion avenae;Homoptera)from neonate to adult by>70%when fed.In contrast,the ASA-ButaIT fusion protein was non-toxic to aphids,and had no effect on lepidopteran lalwae,either when injected or when fed.However,intact ASA-ButaIT fusion protein was present in the haemolymph of cabbage moth larvae following ingestion,showing that transport of the fusion had occurred.The stabilities of GNA/BUtaIT and ASA/ButaIT to proteolysis in vivo after injection or ingestion differed,and this may be a factor in determining insecticidal activities.

  8. Cloning and characterization of a delta-6 desaturase encoding gene from Nannochloropsis oculata

    Institute of Scientific and Technical Information of China (English)

    MA Xiaolei; YU Jianzhong; ZHU Baohua; PAN Kehou; PAN Jin; YANG Guanpin

    2011-01-01

    A gene (NANOC-D6D) encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a eDNA library of Nannochloropsis oculata (Droop)D. J. Hibberd (Eustigmatophyceae). The unicellular marine microalga N. oculata synthesizes rich long chain polyunsaturated fatty acids (LCPUFAs), including eicosapentaenoic acid (20:5n-3, EPA).The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains. The neighbor-joining phylogenetic tree indicates that NANOC-D6D is phylogenetically close to the delta-6 fatty acid desaturase of marine microalgae such as Glossomastix chrysoplasta, Thalassiosira pseudonana, and Phaeodactylum tricornutum. The gene was expressed in Saccharomyces cerevisiae INVSc1 to verify the substrate specificity of NANOC-D6D. Our results suggest that the recombinant NANOC-D6D simultaneously desaturates linoleic acid (LA) and α-linolenic acid (ALA).

  9. The mitochondrial acyl carrier protein (ACP) coordinates mitochondrial fatty acid synthesis with iron sulfur cluster biogenesis.

    Science.gov (United States)

    Van Vranken, Jonathan G; Jeong, Mi-Young; Wei, Peng; Chen, Yu-Chan; Gygi, Steven P; Winge, Dennis R; Rutter, Jared

    2016-01-01

    Mitochondrial fatty acid synthesis (FASII) and iron sulfur cluster (FeS) biogenesis are both vital biosynthetic processes within mitochondria. In this study, we demonstrate that the mitochondrial acyl carrier protein (ACP), which has a well-known role in FASII, plays an unexpected and evolutionarily conserved role in FeS biogenesis. ACP is a stable and essential subunit of the eukaryotic FeS biogenesis complex. In the absence of ACP, the complex is destabilized resulting in a profound depletion of FeS throughout the cell. This role of ACP depends upon its covalently bound 4'-phosphopantetheine (4-PP)-conjugated acyl chain to support maximal cysteine desulfurase activity. Thus, it is likely that ACP is not simply an obligate subunit but also exploits the 4-PP-conjugated acyl chain to coordinate mitochondrial fatty acid and FeS biogenesis. PMID:27540631

  10. Effect of increased CRM₁₉₇ carrier protein dose on meningococcal C bactericidal antibody response.

    Science.gov (United States)

    Lee, Lucia H; Blake, Milan S

    2012-04-01

    New multivalent CRM(197)-based conjugate vaccines are available for childhood immunization. Clinical studies were reviewed to assess meningococcal group C (MenC) antibody responses following MenC-CRM(197) coadministration with CRM(197)-based pneumococcal or Haemophilus influenzae type b conjugate vaccines. Infants receiving a total CRM(197) carrier protein dose of ∼50 μg and concomitant diphtheria-tetanus-acellular pertussis (DTaP)-containing vaccine tended to have lower MenC geometric mean antibody titers and continued to have low titers after the toddler dose. Nevertheless, at least 95% of children in the reported studies achieved a MenC serum bactericidal antibody (SBA) titer of ≥ 1:8 after the last infant or toddler dose. SBA was measured using an assay with a baby rabbit or human complement source. Additional studies are needed to assess long-term antibody persistence and MenC CRM(197) conjugate vaccine immunogenicity using alternative dosing schedules.

  11. Binding of 7-dehydrocholesterol to sterol carrier protein and vitamin D3 effect

    International Nuclear Information System (INIS)

    It was confirmed that deltasup(5,7)-sterol delta7-reductase activity was suppressed by cholecalciferol (vitamin D3) in the enzyme system consisted of microsomes and sterol carrier protein (SCP). The enzyme activity was significantly decreased in the combination with microsomes obtained from either vitamin D-deficient or vitamin D3-treated rat liver and with SCP obtained from vitamin D3-treated rat. It was also demonstrated by the binding assay of the dextran-charcoal technique that 7-dehydrocholesterol binding to SCP could be specifically displaced by vitamin D3. The inhibition of cholecalciferol on 7-dehydro-cholesterol binding to liver SCP was confirmed to be non-competitive inhibition. (auth.)

  12. Characterization of the yellow fever mosquito sterol carrier protein-2 like 3 gene and ligand-bound protein structure

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, David H.; Vyazunova, Irina; Lorch, Jeffery M.; Forest, Katrina T.; Lan, Que; (UW)

    2009-06-12

    The sterol carrier protein-2 like 3 gene (AeSCP-2L3), a new member of the SCP-2 protein family, is identified from the yellow fever mosquito, Aedes aegypti. The predicted molecular weight of AeSCP-2L3 is 13.4 kDa with a calculated pI of 4.98. AeSCP-2L3 transcription occurs in the larval feeding stages and the mRNA levels decrease in pupae and adults. The highest levels of AeSCP-2L3 gene expression are found in the body wall, and possibly originated in the fat body. This is the first report of a mosquito SCP-2-like protein with prominent expression in tissue other than the midgut. The X-ray protein crystal structure of AeSCP-2L3 reveals a bound C16 fatty acid whose acyl tail penetrates deeply into a hydrophobic cavity. Interestingly, the ligand-binding cavity is slightly larger than previously described for AeSCP-2 (Dyer et al. J Biol Chem 278:39085-39091, 2003) and AeSCP-2L2 (Dyer et al. J Lipid Res M700460-JLR200, 2007). There are also an additional 10 amino acids in SCP-2L3 that are not present in other characterized mosquito SCP-2s forming an extended loop between {beta}3 and {beta}4. Otherwise, the protein backbone is exceedingly similar to other SCP-2 and SCP-2-like proteins. In contrast to this observed high structural homology of members in the mosquito SCP2 family, the amino acid sequence identity between the members is less than 30%. The results from structural analysis imply that there have been evolutionary constraints that favor the SCP-2 C{alpha} backbone fold while the specificity of ligand binding can be altered.

  13. Isolation and characterization of an enoyl-acyl carrier protein reductase gene from microalga Isochrysis galbana

    Science.gov (United States)

    Zheng, Minggang; Liang, Kepeng; Wang, Bo; Sun, Xiuqin; Yue, Yanyan; Wan, Wenwen; Zheng, Li

    2013-03-01

    In most bacteria, plants and algae, fatty acid biosynthesis is catalyzed by a group of freely dissociable proteins known as the type II fatty acid synthase (FAS II) system. In the FAS II system, enoylacyl carrier protein reductase (ENR) acts as a determinant for completing the cycles of fatty acid elongation. In this study, the cDNA sequence of ENR, designated as IgENR, was isolated from the microalga Isochrysis galbana CCMM5001. RACE (rapid amplification of cDNA ends) was used to isolate the full-length cDNA of IgENR (1 503 bp), which contains an open reading frame (ORF) of 1 044 bp and encodes a protein of 347 amino acids. The genomic DNA sequence of IgENR is interrupted by four introns. The putative amino acid sequence is homologous to the ENRs of seed plants and algae, and they contain common coenzymebinding sites and active site motifs. Under different stress conditions, real-time quantitative polymerase chain reaction (RT-qPCR) showed the expression of IgENR was upregulated by high temperature (35°C), and downregulated by depleted nitrogen (0 mol/L). To clarify the mechanism of lipids accumulating lipids, other genes involved in lipids accumulation should be studied.

  14. Isolation and characterization of an enoyl-acyl carrier protein reductase gene from microalga Isochrysis galbana

    Institute of Scientific and Technical Information of China (English)

    ZHENG Minggang; LIANG Kepeng; WANG Bo; SUN Xiuqin; YUE Yanyan; WAN Wenwen; ZHENG Li

    2013-01-01

    In most bacteria,plants and algae,fatty acid biosynthesis is catalyzed by a group of freely dissociable proteins known as the type Ⅱ fatty acid synthase (FAS Ⅱ) system.In the FAS Ⅱ system,enoylacyl carrier protein reductase (ENR) acts as a determinant for completing the cycles of fatty acid elongation.In this study,the cDNA sequence of ENR,designated as IgENR,was isolated from the microalga Isochrysis galbana CCMM5001.RACE (rapid amplification of cDNA ends) was used to isolate the full-length cDNA ofIgENR (1 503 bp),which contains an open reading frame (ORF) of 1 044 bp and encodes a protein of 347 amino acids.The genomic DNA sequence ofIgENR is interrupted by four introns.The putative amino acid sequence is homologous to the ENRs of seed plants and algae,and they contain common coenzymebinding sites and active site motifs.Under different stress conditions,real-time quantitative polymerase chain reaction (RT-qPCR) showed the expression ofIgENR was upregulated by high temperature (35℃),and downregulated by depleted nitrogen (0 mol/L).To clarify the mechanism of lipids accumulating lipids,other genes involved in lipids accumulation should be studied.

  15. Acyl-acyl carrier protein as a source of fatty acids for bacterial bioluminescence

    International Nuclear Information System (INIS)

    Pulse-chase experiments with [3H]tetradecanoic acid and ATP showed that the bioluminescence-related 32-kDa acyltransferase from Vibrio harveyi can specifically catalyze the deacylation of a 3H-labeled 18-kDa protein observed in extracts of this bacterium. The 18-kDa protein has been partially purified and its physical and chemical properties strongly indicate that it is fatty acyl-acyl carrier protein (acyl-ACP). Both this V. harveyi [3H]acylprotein and [3H]palmitoyl-ACP from Escherichia coli were substrates in vitro for either the V. harveyi 32-kDa acyltransferase or the analogous enzyme (34K) from Photobacterium phosphoreum. TLC analysis indicated that the hexane-soluble product of the reaction is fatty acid. No significant cleavage of either E. coli or V. harveyi tetradecanoyl-ACP was observed in extracts of these bacteria unless the 32-kDa or 34K acyltransferase was present. Since these enzymes are believed to be responsible for the supply of fatty acids for reduction to form the aldehyde substrate of luciferase, the above results suggest that long-chain acyl-ACP is the source of fatty acids for bioluminescence

  16. Comparative Analysis of Fatty Acid Desaturases in Cyanobacterial Genomes

    Directory of Open Access Journals (Sweden)

    Xiaoyuan Chi

    2008-01-01

    Full Text Available Fatty acid desaturases are enzymes that introduce double bonds into the hydrocarbon chains of fatty acids. The fatty acid desaturases from 37 cyanobacterial genomes were identified and classified based upon their conserved histidine-rich motifs and phylogenetic analysis, which help to determine the amounts and distributions of desaturases in cyanobacterial species. The filamentous or N2-fixing cyanobacteria usually possess more types of fatty acid desaturases than that of unicellular species. The pathway of acyl-lipid desaturation for unicellular marine cyanobacteria Synechococcus and Prochlorococcus differs from that of other cyanobacteria, indicating different phylogenetic histories of the two genera from other cyanobacteria isolated from freshwater, soil, or symbiont. Strain Gloeobacter violaceus PCC 7421 was isolated from calcareous rock and lacks thylakoid membranes. The types and amounts of desaturases of this strain are distinct to those of other cyanobacteria, reflecting the earliest divergence of it from the cyanobacterial line. Three thermophilic unicellular strains, Thermosynechococcus elongatus BP-1 and two Synechococcus Yellowstone species, lack highly unsaturated fatty acids in lipids and contain only one Δ9 desaturase in contrast with mesophilic strains, which is probably due to their thermic habitats. Thus, the amounts and types of fatty acid desaturases are various among different cyanobacterial species, which may result from the adaption to environments in evolution.

  17. Pregnancy zone protein is a carrier and modulator of placental protein-14 in T-cell growth and cytokine production.

    Science.gov (United States)

    Skornicka, Erin L; Kiyatkina, Nadya; Weber, Matthew C; Tykocinski, Mark L; Koo, Peter H

    2004-01-01

    A successful pregnancy can only occur when the maternal immune system fails to attack the allogeneic fetus. Two plasma proteins with described immunoregulatory activities, pregnancy zone protein (PZP) and placental protein-14 (PP14; also known as glycodelin-A), increase dramatically during pregnancy, prompting us to examine their potential role in mediating fetal protection. First, we demonstrated that both native PZP and its receptor-recognized monoamine-activated form (MA-PZP) bound non-covalently and specifically to PP14, exhibiting K(d) values greater than 3 microM, as determined by surface plasmon resonance. Our evidence further suggests that PZP is potentially a more effective carrier of PP14 than its relative alpha2-macroglobulin. Second, we found that T-cell activation, as measured by increased proliferation and IL-2 production, was inhibited by either PZP or PP14 in a dose-dependent manner. However, when PZP and PP14 were combined, they acted synergistically to inhibit T cell proliferation and IL-2 production. Interestingly, the combination of PZP and PP14 had little effect on the production of T(H)2 cytokine, IL-4. Based upon these findings, we hypothesize that PZP and PP14 form a stable complex in the plasma of pregnant women and together act synergistically to selectively modulate T-cell activation. Mechanistically, this activity appears to be independent of the PZP receptor (CD91) or PZP's anti-proteinase activity.

  18. Characterization of chicken riboflavin carrier protein gene structure and promoter regulation by estrogen

    Indian Academy of Sciences (India)

    Nandini Vasudevan; Urvashi Bahadur; Paturu Kondaiah

    2001-03-01

    The chicken riboflavin carrier protein (RCP) is an estrogen induced egg yolk and white protein. Eggs from hens which have a splice mutation in RCP gene fail to hatch, indicating an absolute requirement of RCP for the transport of riboflavin to the oocyte. In order to understand the mechanism of regulation of this gene by estrogen, the chicken RCP gene including 1 kb of the 5′ flanking region has been isolated. Characterization of the gene structure shows that it contains six exons and five introns, including an intron in the 5′ untranslated region. Sequence analysis of the 5′ flanking region does not show the presence of any classical, palindromic estrogen response element (ERE). However, there are six half site ERE consensus elements. Four deletion constructs of the 5′ flanking region with varying number of ERE half sites were made in pGL3 basic vector upstream of the luciferase-coding region. Transient transfection of these RCP promoter deletion constructs into a chicken hepatoma cell line (LMH2A) showed 6-12-fold transcriptional induction by a stable estrogen analogue, moxesterol. This suggests that the RCP gene is induced by estrogen even in the absence of a classical ERE and the half sites of ERE in this promoter may be important for estrogen induction.

  19. Cloning of a palmitoyl-acyl carrier protein thioesterase from oil palm.

    Science.gov (United States)

    Othman, A; Lazarus, C; Fraser, T; Stobart, K

    2000-12-01

    A palmitoyl-acyl carrier protein (ACP) thioesterase cDNA clone was isolated from an oil palm cDNA library. The cDNA was expressed in Escherichia coli as a glutathione S-transferase fusion protein and a crude bacterial extract was assayed for acyl-CoA-hydrolysing activity. The recombinant enzyme was able to hydrolyse medium- and long-chain acyl-CoAs. Northern-blot analysis showed a high level of gene expression in leaf, flower and 15-, 17- and 18-week mesocarp tissues. Low-level gene expression was detected in germinated seedlings and 8- and 12-week mesocarp tissues, but no transcript was detected in any kernel tissues. Southern-blot analysis indicated the presence of a single gene and we have also isolated a genomic clone using the cDNA as a probe. Two genomic fragments were subcloned and a 7 kb contiguous stretch of the oil palm genome was sequenced. Comparison of this sequence with the cDNA sequence identified a putative 93 amino acid transit peptide, most of which is missing from the cDNA. The coding region of the gene consisted of seven exons and six introns. PMID:11171146

  20. Potential of Translationally Controlled Tumor Protein-Derived Protein Transduction Domains as Antigen Carriers for Nasal Vaccine Delivery.

    Science.gov (United States)

    Bae, Hae-Duck; Lee, Joohyun; Jin, Xing-Hai; Lee, Kyunglim

    2016-09-01

    Nasal vaccination offers a promising alternative to intramuscular (i.m.) vaccination because it can induce both mucosal and systemic immunity. However, its major drawback is poor absorption of large antigens in the nasal epithelium. Protein transduction domains (PTDs), also called cell-penetrating peptides, have been proposed as vehicles for nasal delivery of therapeutic peptides and proteins. Here, we evaluated the potential of a mutant PTD derived from translationally controlled tumor protein (designated TCTP-PTD 13) as an antigen carrier for nasal vaccines. We first compared the l- and d-forms of TCTP-PTD 13 isomers (l- or d-TCTP-PTD 13) as antigen carriers. Studies in mice demonstrated that nasally administered mixtures of the model antigen ovalbumin (OVA) and d-TCTP-PTD 13 induced higher plasma IgG titers and secretory IgA levels in nasal washes than nasally administered OVA alone, OVA/l-TCTP-PTD 13, or i.m.-injected OVA. Plasma IgG subclass responses (IgG1 and IgG2a) of mice nasally administered OVA/d-TCTP-PTD 13 showed that the predominant IgG subclass was IgG1, indicating a Th2-biased immune response. We also used synthetic CpG oligonucleotides (CpG) as a Th1 immune response-inducing adjuvant. Nasally administered CpG plus OVA/d-TCTP-PTD 13 was superior in eliciting systemic and mucosal immune responses compared to those induced by nasally administered OVA/d-TCTP-PTD 13. Furthermore, the OVA/CpG/d-TCTP-PTD 13 combination skewed IgG1 and IgG2a profiles of humoral immune responses toward a Th1 profile. These findings suggest that TCTP-derived PTD is a suitable vehicle to efficiently carry antigens and to induce more powerful antigen-specific immune responses and a more balanced Th1/Th2 response when combined with a DNA adjuvant. PMID:27454469

  1. Evolution of hepatitis B virus surface gene and protein among Iranian chronic carriers from different provinces

    Directory of Open Access Journals (Sweden)

    Fatemeh Ramezani

    2015-11-01

    Full Text Available Background and Objectives:  Iranian chronic HBV carrier’s population has shown a unique pattern of genotype D distri- bution all around the country. The aim of this study was to explore more details of evolutionary history of carriers based on structural surface proteins from different provinces.Materials and Methods: Sera obtained from 360 isolates from 12 Different regions of country were used for amplificationand sequencing of surface proteins. A detailed mutational analysis was undertaken.Results: The total ratio for Missense/Silent nucleotide substitutions was 0.96. Sistan and Kermanshah showed the lowest rate of evolution between provinces (P = 0.055. On the other hand, Khorasan Razavi and Khoozestan contained the highest ratio (P = 0.055. The rest of regions were laid between these two extremes. Azarbayjan and Guilan showed the highest proportion of immune epitope distribution (91.3% and 96%, respectively. Conversely, Sistan and Tehran harbored the least percentage (66.6% and 68.8%, respectively. Kermanshah province contained only 5.2%, whereas Isfahan had 54.5% of B cell epitope distribution. In terms of T helper epitopes, all provinces showed a somehow homogeneity: 22.58% (Fars to 46.6% (Khuz- estan. On the other hand, distribution of substitutions within the CTL epitopes showed a wide range of variation between 6.6% (Khuzestan and 63% (Kermanshah.Conclusion: Further to low selection pressure found in Iranian population, the variations between different regions designate random genetic drift within the surface proteins. These finding would have some applications in terms of specific antiviral regimen, design of more efficient vaccine and public health issues.

  2. Self-assembled multicompartment liquid crystalline lipid carriers for protein, peptide, and nucleic acid drug delivery.

    Science.gov (United States)

    Angelova, Angelina; Angelov, Borislav; Mutafchieva, Rada; Lesieur, Sylviane; Couvreur, Patrick

    2011-02-15

    Lipids and lipopolymers self-assembled into biocompatible nano- and mesostructured functional materials offer many potential applications in medicine and diagnostics. In this Account, we demonstrate how high-resolution structural investigations of bicontinuous cubic templates made from lyotropic thermosensitive liquid-crystalline (LC) materials have initiated the development of innovative lipidopolymeric self-assembled nanocarriers. Such structures have tunable nanochannel sizes, morphologies, and hierarchical inner organizations and provide potential vehicles for the predictable loading and release of therapeutic proteins, peptides, or nucleic acids. This Account shows that structural studies of swelling of bicontinuous cubic lipid/water phases are essential for overcoming the nanoscale constraints for encapsulation of large therapeutic molecules in multicompartment lipid carriers. For the systems described here, we have employed time-resolved small-angle X-ray scattering (SAXS) and high-resolution freeze-fracture electronic microscopy (FF-EM) to study the morphology and the dynamic topological transitions of these nanostructured multicomponent amphiphilic assemblies. Quasi-elastic light scattering and circular dichroism spectroscopy can provide additional information at the nanoscale about the behavior of lipid/protein self-assemblies under conditions that approximate physiological hydration. We wanted to generalize these findings to control the stability and the hydration of the water nanochannels in liquid-crystalline lipid nanovehicles and confine therapeutic biomolecules within these structures. Therefore we analyzed the influence of amphiphilic and soluble additives (e.g. poly(ethylene glycol)monooleate (MO-PEG), octyl glucoside (OG), proteins) on the nanochannels' size in a diamond (D)-type bicontinuous cubic phase of the lipid glycerol monooleate (MO). At body temperature, we can stabilize long-living swollen states, corresponding to a diamond cubic phase

  3. Molecular Cloning and Functional Expression of a Δ9- Fatty Acid Desaturase from an Antarctic Pseudomonas sp. A3.

    Science.gov (United States)

    Garba, Lawal; Mohamad Ali, Mohd Shukuri; Oslan, Siti Nurbaya; Rahman, Raja Noor Zaliha Raja Abd

    2016-01-01

    Fatty acid desaturase enzymes play an essential role in the synthesis of unsaturated fatty acids. Pseudomonas sp. A3 was found to produce a large amount of palmitoleic and oleic acids after incubation at low temperatures. Using polymerase Chain Reaction (PCR), a novel Δ9- fatty acid desaturase gene was isolated, cloned, and successfully expressed in Escherichia coli. The gene was designated as PA3FAD9 and has an open reading frame of 1,185 bp which codes for 394 amino acids with a predicted molecular weight of 45 kDa. The activity of the gene product was confirmed via GCMS, which showed a functional putative Δ9-fatty acid desaturase capable of increasing the total amount of cellular unsaturated fatty acids of the E. coli cells expressing the gene. The results demonstrate that the cellular palmitoleic acids have increased two-fold upon expression at 15°C using only 0.1 mM IPTG. Therefore, PA3FAD9 from Pseudomonas sp.A3 codes for a Δ9-fatty acid desaturase-like protein which was actively expressed in E. coli. PMID:27494717

  4. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    Directory of Open Access Journals (Sweden)

    Je Min Lee

    2016-01-01

    Full Text Available Polyunsaturated fatty acids (PUFAs are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

  5. Acyl-acyl carrier protein thioesterase activity from sunflower (Helianthus annuus L.) seeds.

    Science.gov (United States)

    Martínez-Force, E; Cantisán, S; Serrano-Vega, M J; Garcés, R

    2000-10-01

    During sunflower (Helianthus annuus L.) seed formation there was an active period of lipid biosynthesis between 12 and 28 days after flowering (DAF). The maximum in-vitro acyl-acyl carrier protein (ACP) thioesterase activities (EC 3.1.2.14) were found at 15 DAF, preceding the largest accumulation of lipid in the seed. Data from the apparent kinetic parameters, Vmax and Km, from seeds of 15 and 30 DAF, showed that changes in acyl-ACP thioesterase activity are not only quantitative, but also qualitative, since, although the preferred substrate was always oleoyl-ACP, the affinity for palmitoyl-ACP decreased, whereas that for stearoyl-ACP increased with seed maturation. Bisubstrate assays carried out at 30 DAF seemed to indicate that the total activity found in mature seeds is due to a single enzyme with 100/75/15 affinity for oleoyl-ACP/stearoyl-ACP/ palmitoyl-ACP. In contrast, at 15 DAF, enzymatic data together with partial sequences from cDNAs indicated the presence of at least two enzymes with different properties, a FatA-like thioesterase, with a high affinity for oleoyl-ACP, plus a FatB-like enzyme, with preference for long-chain saturated fatty acids, both being expressed during the active lipid biosynthesis period. Competition assays carried out with CAS-5, a mutant with a higher content of palmitic acid in the seed oil, indicated that a modified FatA-type thioesterase is involved in the mutant phenotype.

  6. Plasma protein corona modulates the vascular wall interaction of drug carriers in a material and donor specific manner.

    Directory of Open Access Journals (Sweden)

    Daniel J Sobczynski

    Full Text Available The nanoscale plasma protein interaction with intravenously injected particulate carrier systems is known to modulate their organ distribution and clearance from the bloodstream. However, the role of this plasma protein interaction in prescribing the adhesion of carriers to the vascular wall remains relatively unknown. Here, we show that the adhesion of vascular-targeted poly(lactide-co-glycolic-acid (PLGA spheres to endothelial cells is significantly inhibited in human blood flow, with up to 90% reduction in adhesion observed relative to adhesion in simple buffer flow, depending on the particle size and the magnitude and pattern of blood flow. This reduced PLGA adhesion in blood flow is linked to the adsorption of certain high molecular weight plasma proteins on PLGA and is donor specific, where large reductions in particle adhesion in blood flow (>80% relative to buffer is seen with ∼60% of unique donor bloods while others exhibit moderate to no reductions. The depletion of high molecular weight immunoglobulins from plasma is shown to successfully restore PLGA vascular wall adhesion. The observed plasma protein effect on PLGA is likely due to material characteristics since the effect is not replicated with polystyrene or silica spheres. These particles effectively adhere to the endothelium at a higher level in blood over buffer flow. Overall, understanding how distinct plasma proteins modulate the vascular wall interaction of vascular-targeted carriers of different material characteristics would allow for the design of highly functional delivery vehicles for the treatment of many serious human diseases.

  7. [Cloning and functional characterization of phytoene desaturase in Andrographis paniculata].

    Science.gov (United States)

    Shen, Qin-qin; Li, Li-xia; Zhan, Peng-lin; Wang, Qiang

    2015-10-01

    A full-length cDNA of phytoene desaturase (PDS) gene from Andrographis paniculata was obtained through RACE-PCR. The cDNA sequence consists of 2 224 bp with an intact ORF of 1 752 bp (GeneBank: KP982892), encoding a ploypeptide of 584 amino acids. Homology analysis showed that the deduced protein has extensive sequence similarities to PDS from other plants, and contains a conserved NAD ( H) -binding domain of plant dehydrase cofactor binding-domain in N-terminal. Phylogenetic analysis demonstrated that ApPDS was more related to PDS of Sesamum indicum and Pogostemon cablin. The semi-quantitative RT-PCR analysis revealed that ApPDS expressed in whole aboveground tissues with the highest expression in leaves. Virus induced gene silencing (VIGS) was performed to characterize the functional of ApPDS in planta. Significant photobleaching was not observed in infiltrated leaves, while the PDS gene has been down-regulated significantly at the yellowish area. To the best of our knowledge, this represents the first report of PDS gene cloning and functional characterization from A. paniculata, which lays the foundation for further investigation of new genes, especially that correlative to andrographolide biosynthetic pathway. PMID:26975098

  8. Two Rab proteins, vesicle-associated membrane protein 2 (VAMP-2) and secretory carrier membrane proteins (SCAMPs), are present on immunoisolated parietal cell tubulovesicles.

    Science.gov (United States)

    Calhoun, B C; Goldenring, J R

    1997-01-01

    The tubulovesicles of gastric parietal cells sequester H+/K+-ATPase molecules within resting parietal cells. Stimulation of parietal cell secretion elicits delivery of intracellular H+/K+-ATPase to the apically oriented secretory canaliculus. Previous investigations have suggested that this process requires the regulated fusion of intracellular tubulovesicles with the canalicular target membrane. We have sought to investigate the presence of critical putative regulators of vesicle fusion on immunoisolated gastric parietal cell tubulovesicles. Highly purified tubulovesicles were prepared by gradient fractionation and immunoisolation on magnetic beads coated with monoclonal antibodies against the alpha subunit of H+/K+-ATPase. Western blot analysis revealed the presence of Rab11, Rab25, vesicle-associated membrane protein 2 (VAMP-2) and secretory carrier membrane proteins (SCAMPs) on immunoisolated vesicles. The same cohort of proteins was recovered on vesicles immunoisolated with monoclonal antibodies against SCAMPs and VAMP-2. In contrast, whereas immunoreactivities for syntaxin 1A/1B and synaptosome-associated protein (SNAP-25) were present in gradient-isolated vesicles, none of the immunoreactivity was associated with immunoisolated vesicles. The observation of VAMP-2 and two Rab proteins on immunoisolated H+/K+-ATPase-containing tubulovesicles supports the role for tubulovesicles in a regulated vesicle fusion process. In addition, the presence of SCAMPs along with Rab11 and Rab25 implicates the tubulovesicles as a critical apical recycling vesicle population. PMID:9230141

  9. The Bacillus subtilis Acyl Lipid Desaturase Is a Δ5 Desaturase

    Science.gov (United States)

    Altabe, Silvia G.; Aguilar, Pablo; Caballero, Gerardo M.; de Mendoza, Diego

    2003-01-01

    Bacillus subtilis was recently reported to synthesize unsaturated fatty acids (UFAs) with a double bond at positions Δ5, Δ7, and Δ9 (M. H. Weber, W. Klein, L. Muller, U. M. Niess, and M. A. Marahiel, Mol. Microbiol. 39:1321-1329, 2001). Since this finding would have considerable importance in the double-bond positional specificity displayed by the B. subtilis acyl lipid desaturase, we have attempted to confirm this observation. We report that the double bond of UFAs synthesized by B. subtilis is located exclusively at the Δ5 position, regardless of the growth temperature and the length chain of the fatty acids. PMID:12730185

  10. Novel Structural Components Contribute to the High Thermal Stability of Acyl Carrier Protein from Enterococcus faecalis.

    Science.gov (United States)

    Park, Young-Guen; Jung, Min-Cheol; Song, Heesang; Jeong, Ki-Woong; Bang, Eunjung; Hwang, Geum-Sook; Kim, Yangmee

    2016-01-22

    Enterococcus faecalis is a Gram-positive, commensal bacterium that lives in the gastrointestinal tracts of humans and other mammals. It causes severe infections because of high antibiotic resistance. E. faecalis can endure extremes of temperature and pH. Acyl carrier protein (ACP) is a key element in the biosynthesis of fatty acids responsible for acyl group shuttling and delivery. In this study, to understand the origin of high thermal stabilities of E. faecalis ACP (Ef-ACP), its solution structure was investigated for the first time. CD experiments showed that the melting temperature of Ef-ACP is 78.8 °C, which is much higher than that of Escherichia coli ACP (67.2 °C). The overall structure of Ef-ACP shows the common ACP folding pattern consisting of four α-helices (helix I (residues 3-17), helix II (residues 39-53), helix III (residues 60-64), and helix IV (residues 68-78)) connected by three loops. Unique Ef-ACP structural features include a hydrophobic interaction between Phe(45) in helix II and Phe(18) in the α1α2 loop and a hydrogen bonding between Ser(15) in helix I and Ile(20) in the α1α2 loop, resulting in its high thermal stability. Phe(45)-mediated hydrophobic packing may block acyl chain binding subpocket II entry. Furthermore, Ser(58) in the α2α3 loop in Ef-ACP, which usually constitutes a proline in other ACPs, exhibited slow conformational exchanges, resulting in the movement of the helix III outside the structure to accommodate a longer acyl chain in the acyl binding cavity. These results might provide insights into the development of antibiotics against pathogenic drug-resistant E. faecalis strains.

  11. Moderate PEGylation of the carrier protein improves the polysaccharide-specific immunogenicity of meningococcal group A polysaccharide conjugate vaccine.

    Science.gov (United States)

    Zhang, Tingting; Yu, Weili; Wang, Yanfei; Hu, Tao

    2015-06-22

    Neisseria meningitidis can cause severe and fulminant diseases such as meningitis. Meningococcal capsular polysaccharide (PS) is a key virulence determinant that is not able to induce immunological memory. Conjugation of PS to a carrier protein can significantly increase the immunogenicity of PS and induce immunological memory. Due to the classically described carrier-induced epitopic suppression (CIES) mechanisms, a strong immune response against the carrier protein could suppress the immune response to PS after coadministration of free carrier protein with the conjugate vaccine. However, it was not clear whether suppressing or enhancing the protein-specific immunogenicity could improve the PS-specific immunogenicity of the conjugate vaccine. Thus, moderate PEGylation, extensive PEGylation and oligomerization were used to regulate the immunogenicity of tetanus toxoid (TT) in the conjugate vaccine (PS-TT). Moderate PEGylation led to a 2.7-fold increase in the PS-specific IgG titers elicited by PS-TT. In contrast, extensive PEGylation and oligomerization of TT led to 1.4-fold and 1.6-fold decrease in the PS-specific IgG titers elicited by PS-TT, respectively. The PS-specific immunogenicity of PS-TT can be increased by moderate PEGylation through mild suppression of the TT-specific immunogenicity. The PS-specific immunogenicity of PS-TT was decreased through significant suppression or enhancement of the TT-specific immunogenicity. Thus, our study contributes to understand the CIES mechanisms and improve the PS-specific immunogenicity of a meningococcal PS conjugate vaccine.

  12. cDNA cloning and expression analyses of phytoene synthase 1, phytoene desaturase and ζ-carotene desaturase genes from Solanum lycopersicum KKU-T34003

    Directory of Open Access Journals (Sweden)

    Krittaya Supathaweewat

    2013-10-01

    Full Text Available We report on the cloning of Psy1, Pds and Zds cDNAs encoding the enzymes responsible for lycopene biosynthesis,namely phytoene synthase 1 (PSY1, phytoene desaturase (PDS and -carotene desaturase (ZDS, respectively, from high-lycopene tomato cultivar, Solanum lycopersicum KKU-T34003. DNA sequence analyses showed that the complete openreading frames of Psy1, Pds and Zds cDNAs were 1,239, 1,752 and 1,767 base pairs in length and encoded proteins of 412,583 and 588 amino acids, respectively. Phylogenetic and the conserved domain analyses suggest that PSY1, PDS and ZDSfrom S. lycopersicum KKU-T34003 potentially have similar structures and biological functions to the corresponding proteinsfrom other plants. Gene expression studies showed that Psy1 was expressed only in the petal and the breaker fruit, whereasthe expressions of Pds and Zds were observed in the petal, the breaker fruit and the leaf. The highest expression level for allgenes was detected in the breaker-stage fruit, suggesting that carotenoid accumulation was developmentally regulated inthe chromoplast-containing tissues.

  13. Structure of 3-ketoacyl-(acyl-carrier-protein) reductase from Rickettsia prowazekii at 2.25 Å resolution

    International Nuclear Information System (INIS)

    The R. prowazekii 3-ketoacyl-(acyl-carrier-protein) reductase is similar to those from other prokaryotic pathogens but differs significantly from the mammalian orthologue, strengthening its case as a potential drug target. Rickettsia prowazekii, a parasitic Gram-negative bacterium, is in the second-highest biodefense category of pathogens of the National Institute of Allergy and Infectious Diseases, but only a handful of structures have been deposited in the PDB for this bacterium; to date, all of these have been solved by the SSGCID. Owing to its small genome (about 800 protein-coding genes), it relies on the host for many basic biosynthetic processes, hindering the identification of potential antipathogenic drug targets. However, like many bacteria and plants, its metabolism does depend upon the type II fatty-acid synthesis (FAS) pathway for lipogenesis, whereas the predominant form of fatty-acid biosynthesis in humans is via the type I pathway. Here, the structure of the third enzyme in the FAS pathway, 3-ketoacyl-(acyl-carrier-protein) reductase, is reported at a resolution of 2.25 Å. Its fold is highly similar to those of the existing structures from some well characterized pathogens, such as Mycobacterium tuberculosis and Burkholderia pseudomallei, but differs significantly from the analogous mammalian structure. Hence, drugs known to target the enzymes of pathogenic bacteria may serve as potential leads against Rickettsia, which is responsible for spotted fever and typhus and is found throughout the world

  14. Comparative experiment of four different materials as carriers of Bone morphogenetic protein to repair long bone defect

    Institute of Scientific and Technical Information of China (English)

    WEI Kuan-hai; PEI Guo-xian; YANG Run-gong

    2001-01-01

    @@ OBJECTIVE To investigate the effects of four different materials as carriers of bone morphogenetic protein (BMP) to repair long bone defect. METHODS 12 mm radius bone defects were made. They were divided into 4 groups in random and repaired respectively with the vascular muscle flap combined with FS/BMP (group A), vascular muscle flap/BMP (group B), bloodless muscle flap/BMP (group C) and autolyzed antigen-extracted allogeneic bone (AAA)/BMP (group D).Their abilities of bone forming to repair bone defects were observed.

  15. Effect of sterol carrier protein-2 gene ablation on HDL-mediated cholesterol efflux from cultured primary mouse hepatocytes

    OpenAIRE

    Storey, Stephen M.; Atshaves, Barbara P.; McIntosh, Avery L.; Kerstin K. Landrock; Martin, Gregory G.; Huang, Huan; Ross Payne, H.; Johnson, Jeffery D.; Macfarlane, Ronald D.; Kier, Ann B.; Schroeder, Friedhelm

    2010-01-01

    Although HDL-mediated cholesterol transport to the liver is well studied, cholesterol efflux from hepatocytes back to HDL is less well understood. Real-time imaging of efflux of 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino)-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol), which is poorly esterified, and [3H]cholesterol, which is extensively esterified, from cultured primary hepatocytes of wild-type and sterol carrier protein-2 (SCP-2) gene-ablated mice showed that 1) NBD-cholesterol efflux w...

  16. Construction of efficient and effective transformation vectors for palmitoyl-acyl carrier protein thioesterase gene silencing in oil palm

    OpenAIRE

    Bhore, Subhash Janardhan; Shah, Farida Habib

    2011-01-01

    Palm oil obtained from E. guineensis Jacq. Tenera is known to have about 44% of palmitic acid (C16:0). Palmitoyl-Acyl Carrier Protein Thioesterase (PATE) is one of the key enzymes involved in plastidial fatty acid biosynthesis; and it determines the level of the C16:0 assimilation in oilseeds. This enzyme's activity in oil palm is responsible for high (> 44 % in E. guineensis Jacq. Tenera and 25 % in E. oleifera) content of C16:0 in its oil. By post-transcriptional PATE gene silencing, C16:0 ...

  17. A fatty acyl desaturase (fads2) with dual Δ6 and Δ5 activities from the freshwater carnivorous striped snakehead Channa striata.

    Science.gov (United States)

    Kuah, Meng-Kiat; Jaya-Ram, Annette; Shu-Chien, Alexander Chong

    2016-11-01

    There is a lack of understanding on how the environment and trophic niche affect the capability of long-chain polyunsaturated fatty acids (LC-PUFA) in freshwater carnivorous teleost. In this present study, we isolated and functionally characterised a fatty acyl desaturase (Fads) from the striped snakehead Channa striata. Sequence comparison and phylogenetic analysis suggested a Fads2 protein that is closely related to previously characterised Fads2 proteins from freshwater carnivorous and marine herbivorous fish species. We further demonstrated the capacity of Δ6 and Δ5 desaturation activities for this particular desaturase, with highest activities towards the conversion of omega-3 (n-3) polyunsaturated fatty acids (PUFA). Low Δ4 desaturation activity was also detected, although the significance of this at a physiological level remains to be studied. The expression of this striped snakehead Δ6/Δ5 fads2 gene was highest in brain, followed by liver and intestine. In liver, diet fortified with high LC-PUFA concentration impeded the expression of Δ6/Δ5 fads2 gene compared to vegetable oil (VO) based diets. The discovery of Δ6/Δ5 Fads2 desaturase here complements the previous discovery of a Δ4 Fads2 desaturase and an Elovl5 elongase, lending proof to the existence of all the required enzymatic machinery to biosynthesise LC-PUFA from C18 PUFA in a freshwater carnivorous species.

  18. Structure of the complex between teicoplanin and a bacterial cell-wall peptide: use of a carrier-protein approach

    Energy Technology Data Exchange (ETDEWEB)

    Economou, Nicoleta J.; Zentner, Isaac J. [Drexel University College of Medicine, 245 North 15th Street, Philadelphia, PA 19102 (United States); Lazo, Edwin; Jakoncic, Jean; Stojanoff, Vivian [Brookhaven National Laboratory, Upton, NY 11973 (United States); Weeks, Stephen D.; Grasty, Kimberly C.; Cocklin, Simon; Loll, Patrick J. [Drexel University College of Medicine, 245 North 15th Street, Philadelphia, PA 19102 (United States)

    2013-04-01

    Using a carrier-protein strategy, the structure of teicoplanin bound to its bacterial cell-wall target has been determined. The structure reveals the molecular determinants of target recognition, flexibility in the antibiotic backbone and intrinsic radiation sensitivity of teicoplanin. Multidrug-resistant bacterial infections are commonly treated with glycopeptide antibiotics such as teicoplanin. This drug inhibits bacterial cell-wall biosynthesis by binding and sequestering a cell-wall precursor: a d-alanine-containing peptide. A carrier-protein strategy was used to crystallize the complex of teicoplanin and its target peptide by fusing the cell-wall peptide to either MBP or ubiquitin via native chemical ligation and subsequently crystallizing the protein–peptide–antibiotic complex. The 2.05 Å resolution MBP–peptide–teicoplanin structure shows that teicoplanin recognizes its ligand through a combination of five hydrogen bonds and multiple van der Waals interactions. Comparison of this teicoplanin structure with that of unliganded teicoplanin reveals a flexibility in the antibiotic peptide backbone that has significant implications for ligand recognition. Diffraction experiments revealed an X-ray-induced dechlorination of the sixth amino acid of the antibiotic; it is shown that teicoplanin is significantly more radiation-sensitive than other similar antibiotics and that ligand binding increases radiosensitivity. Insights derived from this new teicoplanin structure may contribute to the development of next-generation antibacterials designed to overcome bacterial resistance.

  19. Gene cloning, expression analysis of JcACP (Acyl Carrier Protein) in Jatropha curcas L. and its prokaryotical expression

    Institute of Scientific and Technical Information of China (English)

    JIANG Lu-ding; LI Xiao-hui

    2008-01-01

    Objective To clone the ACP (acyl carrier protein) gene in Jatropha curcas L., a potential antitumour and anti-fungal plant. And to determinate the expression of ACP in Jatropha curcas L. Methods A cDNA clone encoding ACP (acyl carrier protein) was isolated from Jatropha curcas L. endosperm eDNA library by random sequencing. The expression of ACP gene was investigated by semi-quantitative RT-PCR in leaves, stems and seeds of J. curca. The expression of ACP was also investigated in germinating seeds. The fragment encoding ACP protein in J. curca, was inserted into a prokaryotic expression vector pET28a( + ). The gene was overexpressed in E. coli BL21 to produce abundant protein. Immunohistochemical analysis was used to detect the expression of ACP in different tissues of J. curca. Results The cDNA sequence was 806 bp in length and the ORF was 393 bp. The predicted molecular weight of the putative protein was 14.4 kD, pI = 5.2. It contained a 4'-phosphopantetheine-binding motif. This prosthetic group can be combined with Serine of ACP protein. Semi-quantitative RT-PCR analysis showed that ACP gene was expressed in leaves, stems and seeds of J. curcas. The expression level of ACP was the highest in seeds and it was not detected in roots. After seeds germinated, the expression level of ACP in seeds increased progressively and reached a peak at 96 h. After induced by IPTG, SDS-PAGE analysis showed that the ACP protein of 20 kD was expressed. Immunohistochemical analysis showed that ACP specifical expressed abundantly in embyo of the seeds, and it was not detected in roots and the emdosperm while expressed in leaves and stems. Conclusions A cDNA clone encoding ACP which had all the typical characteristics of ACPs was isolated. It was expressed successfully in E. coli. The results of semi-quantitative RT-PCR analysis and immunohistochemieal analysis were very similar, which showed that the expression of ACP in J. curcas, was abundant in seeds. The results indicated the

  20. Determining and characterizing hapten loads for carrier proteins by MALDI-TOF MS and MALDI-TOF/RTOF MS.

    Science.gov (United States)

    Marchetti-Deschmann, Martina; Stephan, Christopher; Häubl, Georg; Allmaier, Günter; Krska, Rudolf; Cvak, Barbara

    2016-07-15

    The increasing number of bioconjugates used for bioanalytical purposes and in pharmaceutical industries has led to an increasing demand for robust quality control of products derived from covalently linking small molecules to proteins. Here we report, for the first time, a matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF)-based method to determine the quantity and location of the hapten zearalenone (ZEN) introduced to the carrier protein conalbumin (Con). This bioconjugate is of special interest because of its application in lateral flow immunoassays commercially available for fast testing of food and feed for the presence of ZEN, a common contaminant of all major cereal grains worldwide. Mass spectrometry (MS) analysis of the intact protein turned out to be highly reproducible allowing for the determination of the average hapten load of the carrier protein. In that way an easy and fast method to screen for changes in ZEN load after bioconjugate synthesis was established. For a more detailed hapten load characterization, measurements at the peptide level were of importance. Systematic studies, implementing post-source decay (PSD) and high- and low-energy collision-induced dissociation (CID), showed characteristic fragmentation pattern for three model peptides carrying between one and three lysines (the primary target for the ZEN modification) besides other, less obvious modification sites (serine, arginine and the N-terminus). By this, indicative reporter ions (m/z 203 and 316) and neutral losses (Δm/z 373 and 317) for the ZEN modification in general, plus immonium ions (m/z 87, 142 and 159) for the lysine modification in particular were identified. Based on these findings, proteolytic peptides, tentatively assigned to be modified, were unequivocally confirmed to be affected by bioconjugation. For a protein carrying on average only 2-3 modifications per molecule 29 Lys out of 59 potential modifications sites were actually modified

  1. Cloning, Expression of Crocus sativus Phytoene Desaturase Gene and Preparation of Antiserum against It

    Institute of Scientific and Technical Information of China (English)

    Bai Jie; Miao Chen; Xu Ying; Tang Lin; Wang Zhi-tao; Chen Fang

    2004-01-01

    A 2 149 bp full length phytoene desaturase (PDS) cDNA was first cloned from saffron (Crocus sativus L.) stigma using RT-PCR technique and a rapid amplification of cDNA end (RACE) strategy. The cDNA has an open reading frame of 1 697 bp, which encodes a polypeptide of 565 amino acids. The coding region of the cDNA was inserted into a prokaryotic expression vector pET -21a(+) and overexpressed in E. coli BL21 (DE3). The fusion proteins were found largely in an insoluble inclusion bodies. The purified fusion protein was used to immunize rabbits to obtain polyclonal antiserum with titer of 1×105. Western blot analysis by using this particular antiserum showed that the higher expression level of PDS in mature stigma than in leaves and stamen, and the higher expression level of PDS in mature stigma than in young stigma.

  2. Identification of a novel C22-∆4-producing docosahexaenoic acid (DHA) specific polyunsaturated fatty acid desaturase gene from Isochrysis galbana and its expression in Saccharomyces cerevisiae.

    Science.gov (United States)

    Shi, Tonglei; Yu, Aiqun; Li, Ming; Ou, Xiuyuan; Xing, Laijun; Li, Mingchun

    2012-12-01

    Isochrysis galbana, produces long chain polyunsaturated fatty acids including docosahexaenoic acid (DHA, 22:6n-3). A novel gene (IgFAD4-2), encoding a C22-∆4 polyunsaturated fatty acid specific desaturase, has been isolated and characterized from I. galbana. A full-length cDNA of 1,302 bp was cloned by LA-PCR technique. The IgFAD4-2 encoded a protein of 433 amino acids that shares 78 % identity with a previously reported ∆4-desaturase (IgFAD4-1) from I. galbana. The function of IgFAD4-2 was deduced by its heterologous expression in Saccharomyces cerevisiae, which then desaturated docosapentaenoic acid (DPA, 22:5n-3) to DHA. The conversion ratio of DPA to DHA was 34 %, which is higher than other ∆4-desaturases cloned from algae. However, IgFAD4-2 did not catalyze the desaturation or elongation reactions with other fatty acids. These results confirm that IgFAD4-2 has C22-∆4-PUFAs-specific desaturase activity.

  3. Effect of the feeding system on the fatty acid composition, expression of the Δ9-desaturase, Peroxisome Proliferator-Activated Receptor Alpha, Gamma, and Sterol Regulatory Element Binding Protein 1 genes in the semitendinous muscle of light lambs of the Rasa Aragonesa breed

    Directory of Open Access Journals (Sweden)

    Rodellar Clementina

    2010-07-01

    Full Text Available Abstract Background Conjugated linoleic acids (CLAs are receiving increasing attention because of their beneficial effects on human health, with milk and meat products derived from ruminants as important sources of CLA in the human diet. SCD gene is responsible for some of the variation in CLA concentration in adipose tissues, and PPARγ, PPARα and SREBP1 genes are regulator of SCD gene. The aim of this work was to evaluate the effect of the feeding system on fatty acid composition, CLA content and relative gene expression of Δ9-desaturase (SCD, Peroxisome Proliferator-Activated Receptor Gamma (PPARγ, Peroxisome Proliferator-Activated Receptor Alpha, (PPARα and Sterol Regulatory Element Binding Protein (SREBP1 in Rasa Aragonesa light lambs in semitendinous muscle. Forty-four single-born male lambs were used to evaluate the effect of the feeding system, varying on an intensity gradient according to the use of concentrates: 1. grazing alfalfa, 2. grazing alfalfa with a supplement for lambs, 3. indoor lambs with grazing ewes and 4. drylot. Results Both grazing systems resulted in a higher concentration of vaccenic acid (VA, CLA, CLA/VA acid ratio, and a lower oleic content, oleic acid (C18:1/stearic acid (C18:0 ratio, PUFA n-6/n-3 ratio and SCD expression compared to other diets. In addition feeding system affected the fatty acid composition and SCD expression, possibly due to CLA concentration or the PUFA n-6/n-3 ratio. Both expression of the SCD gene and the feeding system were important factors affecting CLA concentration in the animal's semitendinous muscle. PPARγ, PPARα and SREBP1 expression seemed to be unaffected by the feeding system. Although no significant results were found, PPARγ, PPARα and SREBP1 showed similar expression pattern as SCD. Moreover, the correlation results between SCD expression and PPARγ (p SREBP1 (p SCD expression in a different way. Conclusions The data indicated that the feeding system is the main factor

  4. A vesicle carrier that mediates peroxisome protein traffic from the endoplasmic reticulum.

    Science.gov (United States)

    Lam, Sheung Kwan; Yoda, Naofumi; Schekman, Randy

    2010-12-14

    Pex19p, a soluble cytoplasmic transport protein, is required for the traffic of the peroxisomal membrane proteins Pex3p and Pex15p from the endoplasmic reticulum (ER) to the peroxisome. We documented Pex15p traffic from the ER using a chimeric protein containing a C-terminal glycosylation acceptor peptide. Pex15Gp expressed in wild-type yeast cells is N-glycosylated and functions properly in the peroxisome. In contrast, pex19Δ-mutant cells accumulate the glycoprotein Pex15Gp in the ER. We developed a cell-free preperoxisomal vesicle-budding reaction in which Pex15Gp and Pex3p are packaged into small vesicles in the presence of cytosol, Pex19p, and ATP. Secretory vesicle budding (COPII) detected by the packaging of a SNARE protein (soluble N-ethylmaleimide-sensitive attachment protein receptor) occurs in the same incubation but does not depend on Pex19p. Conversely a dominant GTPase mutant Sar1p which inhibits COPII has no effect on Pex3p packaging. Pex15Gp and Pex3p budded vesicles sediment as low-buoyant-density membranes on a Nycodenz gradient and copurify by affinity isolation using native but not Triton X-100-treated budded vesicles. ER-peroxisome transport vesicles appear to rely on a novel budding mechanism requiring Pex19p and additional unknown factors.

  5. Identification of a mitochondrial target of thiazolidinedione insulin sensitizers (mTOT--relationship to newly identified mitochondrial pyruvate carrier proteins.

    Directory of Open Access Journals (Sweden)

    Jerry R Colca

    Full Text Available Thiazolidinedione (TZD insulin sensitizers have the potential to effectively treat a number of human diseases, however the currently available agents have dose-limiting side effects that are mediated via activation of the transcription factor PPARγ. We have recently shown PPARγ-independent actions of TZD insulin sensitizers, but the molecular target of these molecules remained to be identified. Here we use a photo-catalyzable drug analog probe and mass spectrometry-based proteomics to identify a previously uncharacterized mitochondrial complex that specifically recognizes TZDs. These studies identify two well-conserved proteins previously known as brain protein 44 (BRP44 and BRP44 Like (BRP44L, which recently have been renamed Mpc2 and Mpc1 to signify their function as a mitochondrial pyruvate carrier complex. Knockdown of Mpc1 or Mpc2 in Drosophila melanogaster or pre-incubation with UK5099, an inhibitor of pyruvate transport, blocks the crosslinking of mitochondrial membranes by the TZD probe. Knockdown of these proteins in Drosophila also led to increased hemolymph glucose and blocked drug action. In isolated brown adipose tissue (BAT cells, MSDC-0602, a PPARγ-sparing TZD, altered the incorporation of (13C-labeled carbon from glucose into acetyl CoA. These results identify Mpc1 and Mpc2 as components of the mitochondrial target of TZDs (mTOT and suggest that understanding the modulation of this complex, which appears to regulate pyruvate entry into the mitochondria, may provide a viable target for insulin sensitizing pharmacology.

  6. Structure-based analysis of the molecular interactions between acyltransferase and acyl carrier protein in vicenistatin biosynthesis.

    Science.gov (United States)

    Miyanaga, Akimasa; Iwasawa, Shohei; Shinohara, Yuji; Kudo, Fumitaka; Eguchi, Tadashi

    2016-02-16

    Acyltransferases (ATs) are key determinants of building block specificity in polyketide biosynthesis. Despite the importance of protein-protein interactions between AT and acyl carrier protein (ACP) during the acyltransfer reaction, the mechanism of ACP recognition by AT is not understood in detail. Herein, we report the crystal structure of AT VinK, which transfers a dipeptide group between two ACPs, VinL and VinP1LdACP, in vicenistatin biosynthesis. The isolated VinK structure showed a unique substrate-binding pocket for the dipeptide group linked to ACP. To gain greater insight into the mechanism of ACP recognition, we attempted to crystallize the VinK-ACP complexes. Because transient enzyme-ACP complexes are difficult to crystallize, we developed a covalent cross-linking strategy using a bifunctional maleimide reagent to trap the VinK-ACP complexes, allowing the determination of the crystal structure of the VinK-VinL complex. In the complex structure, Arg-153, Met-206, and Arg-299 of VinK interact with the negatively charged helix II region of VinL. The VinK-VinL complex structure allows, to our knowledge, the first visualization of the interaction between AT and ACP and provides detailed mechanistic insights into ACP recognition by AT. PMID:26831085

  7. Sterol carrier protein 2 regulates proximal tubule size in the Xenopus pronephric kidney by modulating lipid rafts.

    Science.gov (United States)

    Cerqueira, Débora M; Tran, Uyen; Romaker, Daniel; Abreu, José G; Wessely, Oliver

    2014-10-01

    The kidney is a homeostatic organ required for waste excretion and reabsorption of water, salts and other macromolecules. To this end, a complex series of developmental steps ensures the formation of a correctly patterned and properly proportioned organ. While previous studies have mainly focused on the individual signaling pathways, the formation of higher order receptor complexes in lipid rafts is an equally important aspect. These membrane platforms are characterized by differences in local lipid and protein compositions. Indeed, the cells in the Xenopus pronephric kidney were positive for the lipid raft markers ganglioside GM1 and Caveolin-1. To specifically interfere with lipid raft function in vivo, we focused on the Sterol Carrier Protein 2 (scp2), a multifunctional protein that is an important player in remodeling lipid raft composition. In Xenopus, scp2 mRNA was strongly expressed in differentiated epithelial structures of the pronephric kidney. Knockdown of scp2 did not interfere with the patterning of the kidney along its proximo-distal axis, but dramatically decreased the size of the kidney, in particular the proximal tubules. This phenotype was accompanied by a reduction of lipid rafts, but was independent of the peroxisomal or transcriptional activities of scp2. Finally, disrupting lipid micro-domains by inhibiting cholesterol synthesis using Mevinolin phenocopied the defects seen in scp2 morphants. Together these data underscore the importance for localized signaling platforms in the proper formation of the Xenopus kidney.

  8. Dextran or hydroxyethyl starch in spray-freeze-dried trehalose/mannitol microparticles intended as ballistic particulate carriers for proteins.

    Science.gov (United States)

    Rochelle, Christian; Lee, Geoffrey

    2007-09-01

    The goal of this study was to clarify the effects of dextran 10 kDa on the properties of spray-freeze-dried microparticles for use with ballistic injectors. A novel carrier of trehalose, mannitol, and the polymer is known to maximize particle density. Measurements of T'(g) showed that the dextran anti-plasticizes the trehalose/mannitol, but also undergoes phase separation. The product temperature exceeded T'(g) during primary drying. The collapsed particles can therefore be explained by plastic flow of the freeze concentrate. DSC of the powder showed T(g) at 45 degrees C and, in the first scan, a wide endothermic melting peak caused by mannitol recrystallization. Catalase showed 35% activity loss on rehydration of its spray freeze-drying (SFD) powder, which was improved in the TM/D (3:3:4) formulation, but not up to that level seen with either trehalose or mannitol alone. The dextran 10 kDa, which is vital to maximize particle density, was therefore detrimental to protein integrity during SFD, as also found with a 65-72 kDa dextran. Hydroxyethyl starch (HES) 200 kDa gave similar, limited stabilizing effects on the protein. The proportion of polymer in the formulation should be low to minimize protein damage, whilst high enough to give required particle morphology and density. PMID:17274046

  9. Reprogramming Acyl Carrier Protein Interactions of an Acyl-CoA Promiscuous trans-Acyltransferase

    DEFF Research Database (Denmark)

    Ye, Zhixia; Musiol-Kroll, Ewa Maria; Weber, Tilmann;

    2014-01-01

    on the ACP surface that contribute to specific recognition by KirCII. This information proved sufficient to modify a noncognate ACP from a different biosynthetic system to be a substrate for KirCII. The findings form a foundation for further understanding the specificity of trans-AT:ACP protein interactions...... and for engineering modular polyketide synthases to produce analogs....

  10. Hydrogel based drug carriers for controlled release of hydrophobic drugs and proteins

    NARCIS (Netherlands)

    Ke Peng,

    2011-01-01

    The aim of this study is to prepare in situ forming hydrogels based on biocompatible polymers for the controlled release of hydrophobic drug and proteins. In order to load hydrophobic drug to the hydrophilic hydrogel matrix, beta-cyclodextrin and human serum albumin was introduced to the hydrogel ne

  11. Male Sterile2 Encodes a Plastid-Localized Fatty Acyl Carrier Protein Reductase Required for Pollen Exine Development in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.; Shanklin, J.; Yu, X.-H.; Zhang, K.; Shi, J.; De Oliveira, S.; Schreiber, L.; Zhang, D.

    2011-10-01

    Male Sterile2 (MS2) is predicted to encode a fatty acid reductase required for pollen wall development in Arabidopsis (Arabidopsis thaliana). Transient expression of MS2 in tobacco (Nicotiana benthamiana) leaves resulted in the accumulation of significant levels of C16 and C18 fatty alcohols. Expression of MS2 fused with green fluorescent protein revealed that an amino-terminal transit peptide targets the MS2 to plastids. The plastidial localization of MS2 is biologically important because genetic complementation of MS2 in ms2 homozygous plants was dependent on the presence of its amino-terminal transit peptide or that of the Rubisco small subunit protein amino-terminal transit peptide. In addition, two domains, NAD(P)H-binding domain and sterile domain, conserved in MS2 and its homologs were also shown to be essential for MS2 function in pollen exine development by genetic complementation testing. Direct biochemical analysis revealed that purified recombinant MS2 enzyme is able to convert palmitoyl-Acyl Carrier Protein to the corresponding C16:0 alcohol with NAD(P)H as the preferred electron donor. Using optimized reaction conditions (i.e. at pH 6.0 and 30 C), MS2 exhibits a K{sub m} for 16:0-Acyl Carrier Protein of 23.3 {+-} 4.0 {mu}m, a V{sub max} of 38.3 {+-} 4.5 nmol mg{sup -1} min{sup -1}, and a catalytic efficiency/K{sub m} of 1,873 m{sup -1} s{sup -1}. Based on the high homology of MS2 to other characterized fatty acid reductases, it was surprising that MS2 showed no activity against palmitoyl- or other acyl-coenzyme A; however, this is consistent with its plastidial localization. In summary, genetic and biochemical evidence demonstrate an MS2-mediated conserved plastidial pathway for the production of fatty alcohols that are essential for pollen wall biosynthesis in Arabidopsis.

  12. Applicability of avidin protein coated mesoporous silica nanoparticles as drug carriers in the lung

    Science.gov (United States)

    van Rijt, S. H.; Bölükbas, D. A.; Argyo, C.; Wipplinger, K.; Naureen, M.; Datz, S.; Eickelberg, O.; Meiners, S.; Bein, T.; Schmid, O.; Stoeger, T.

    2016-04-01

    Mesoporous silica nanoparticles (MSNs) exhibit unique drug delivery properties and are thus considered as promising candidates for next generation nano-medicines. In particular, inhalation into the lungs represents a direct, non-invasive delivery route for treating lung disease. To assess MSN biocompatibility in the lung, we investigated the bioresponse of avidin-coated MSNs (MSN-AVI), as well as aminated (uncoated) MSNs, after direct application into the lungs of mice. We quantified MSN distribution, clearance rate, cell-specific uptake, and inflammatory responses to MSNs within one week after instillation. We show that amine-functionalized (MSN-NH2) particles are not taken up by lung epithelial cells, but induced a prolonged inflammatory response in the lung and macrophage cell death. In contrast, MSN-AVI co-localized with alveolar epithelial type 1 and type 2 cells in the lung in the absence of sustained inflammatory responses or cell death, and showed preferential epithelial cell uptake in in vitro co-cultures. Further, MSN-AVI particles demonstrated uniform particle distribution in mouse lungs and slow clearance rates. Thus, we provide evidence that avidin functionalized MSNs (MSN-AVI) have the potential to serve as versatile biocompatible drug carriers for lung-specific drug delivery.Mesoporous silica nanoparticles (MSNs) exhibit unique drug delivery properties and are thus considered as promising candidates for next generation nano-medicines. In particular, inhalation into the lungs represents a direct, non-invasive delivery route for treating lung disease. To assess MSN biocompatibility in the lung, we investigated the bioresponse of avidin-coated MSNs (MSN-AVI), as well as aminated (uncoated) MSNs, after direct application into the lungs of mice. We quantified MSN distribution, clearance rate, cell-specific uptake, and inflammatory responses to MSNs within one week after instillation. We show that amine-functionalized (MSN-NH2) particles are not taken up

  13. Crystallization and X-ray diffraction analysis of the beta-ketoacyl-acyl carrier protein reductase FabG from Aquifex aeolicus VF5.

    Science.gov (United States)

    Mao, Qilong; Duax, William L; Umland, Timothy C

    2007-02-01

    The gene product of fabG from Aquifex aeolicus has been heterologously expressed in Escherichia coli. Purification of the protein took place using anion-exchange and size-exclusion chromatography and the protein was then crystallized. Diffraction data were collected to a maximum resolution of 1.8 A and the initial phases were determined by molecular replacement. The A. aeolicus FabG protein is a putative beta-ketoacyl-acyl carrier protein reductase. Structure-function studies of this protein are being performed as part of a larger project investigating naturally occurring deviations from highly conserved residues within the short-chain oxidoreductase (SCOR) family.

  14. Cloning and Characterization of the -Carotene Desaturase Gene from Chlorella protothecoides CS-41

    Directory of Open Access Journals (Sweden)

    Meiya Li

    2011-01-01

    Full Text Available To elucidate the lutein biosynthesis pathway in the lutein-producing alga, Chlorella protothecoides CS-41, the -carotene desaturase gene (zds was isolated from Chlorella protothecoides using the approach of rapid amplification of cDNA ends. The full-length cDNA sequence was 2031 bp and contained 1755 bp putative open reading frame which encodes a 584 amino acid deduced polypeptide whose computed molecular weight was 63.7 kDa. Sequence homology research indicated that the nucleotide and putative protein had sequence identities of 72.5% and 69.5% with those of the green alga Chlamydomonas reinhardtii, respectively. Phylogenetic analysis demonstrated that the ZDS from C. protothecoides CS-41 had a closer relationship with those of chlorophyta and higher plants than with those of other species. In addition, we also found that the zds gene expression was upregulated in response to light.

  15. A novel cell penetrating peptide carrier for the delivery of nematocidal proteins drug

    Science.gov (United States)

    Kim, Jea Hyun

    Nematodes have recently become a primary source of harmful diseases to the environment that inflict harsh damages to pine trees and marine species. However, nematodes cannot be killed by normal pesticides or chemicals due to their thick outer protective layer mainly composed of collagen and cuticles. Thus, a novel approach to trigger intracellular delivery of chemicals through the layers of nematodes is required. In this study, the selection of the novel CPP was carefully progressed through protein database and serial digested fragmentation, internalization of each amino sequence was analyzed through flow cytometry and confocal microscope. As one of the most effective CPP material, JH 1.6 was compared with other major CPPs and its cellular toxicity was investigated. Furthermore, JH 1.6 was attached to various RNA, DNA, and proteins and internalization efficiency was evaluated for mammalian cells. To examine its effects on nematodes in vivo, JH 1.6 was conjugated with nematocidal protein - botulinum neurotoxin (BnT) and treated in C.elegans as a model animal. The results showed that JH 1.6 had high relative internalization rate and low cellular toxicity compared to other major CPP such as TAT and GV1001 peptides.

  16. Genes encoding Δ(8)-sphingolipid desaturase from various plants: identification, biochemical functions, and evolution.

    Science.gov (United States)

    Li, Shu-Fen; Zhang, Guo-Jun; Zhang, Xue-Jin; Yuan, Jin-Hong; Deng, Chuan-Liang; Hu, Zan-Min; Gao, Wu-Jun

    2016-09-01

    ∆(8)-sphingolipid desaturase catalyzes the C8 desaturation of a long chain base, which is the characteristic structure of various complex sphingolipids. The genes of 20 ∆(8)-sphingolipid desaturases from 12 plants were identified and functionally detected by using Saccharomyces cerevisiae system to elucidate the relationship between the biochemical function and evolution of this enzyme. Results showed that the 20 genes all can encode a functional ∆(8)-sphingolipid desaturase, which catalyzes different ratios of two products, namely, 8(Z) and 8(E)-C18-phytosphingenine. The coded enzymes could be divided into two groups on the basis of biochemical functions: ∆(8)-sphingolipid desaturase with a preference for an E-isomer product and ∆(8)-sphingolipid desaturase with a preference for a Z-isomer product. The conversion rate of the latter was generally lower than that of the former. Phylogenetic analysis revealed that the 20 desaturases could also be clustered into two groups, and this grouping is consistent with that of the biochemical functions. Thus, the biochemical function of ∆(8)-sphingolipid desaturase is correlated with its evolution. The two groups of ∆(8)-sphingolipid desaturases could arise from distinct ancestors in higher plants. However, they might have initially evolved from ∆(8)-sphingolipid desaturases in lower organisms, such as yeasts, which can produce E-isomer products only. Furthermore, almost all of the transgenic yeasts harboring ∆(8)-sphingolipid desaturase genes exhibit an improvement in aluminum tolerance. Our study provided new insights into the biochemical function and evolution of ∆(8)-sphingolipid desaturases in plants. PMID:27294968

  17. Hyaluronan microgel as a potential carrier for protein sustained delivery by tailoring the crosslink network

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Chunhong [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Zhao, Jianhao, E-mail: jhzhao@jnu.edu.cn [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Tu, Mei; Zeng, Rong; Rong, Jianhua [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China)

    2014-03-01

    Hyaluronan (HA) microgels with different crosslink network, i.e. HGPs-1, HGPs-1.5, HGPs-3, HGPs-6 and HGPs-15, were synthesized using divinyl sulfone (DVS) as the crosslinker in an inverse microemulsion system for controlling the sustained delivery of bovine serum albumin (BSA). With increasing the crosslinker content, the average particle size slightly increased from 1.9 ± 0.3 μm to 3.6 ± 0.5 μm by dynamic laser scattering analysis. However, the crosslinker content had no significant effect on the morphology of HA microgels by scanning and transmission electron microscopes. Fourier transform infrared spectroscopy and elemental analysis proved more sulfur participated in the crosslink reaction when raising the crosslinker amount. The water swelling test confirmed the increasing crosslink density with the crosslinker content by calculating the average molecular weight between two crosslink points to be 8.25 ± 2.51 × 10{sup 5}, 1.26 ± 0.43 × 10{sup 5}, 0.96 ± 0.09 × 10{sup 5}, 0.64 ± 0.03 × 10{sup 5}, and 0.11 ± 0.01 × 10{sup 5} respectively. The degradation of HA microgels by hyaluronidase slowed down by enhancing the crosslink density, only about 5% of HGPs-15 was degraded as opposed to over 90% for HGPs-1. BSA loading had no obvious influence on the surface morphology of HA microgels but seemed to induce their aggregation. The increase of crosslink density decreased the BSA loading capacity but facilitated its long-term sustained delivery. When the molar ratio of DVS to repeating unit of HA reached 3 or higher, similar delivery profiles were obtained. Among all these HA microgels, HGPs-3 was the optimal carrier for BSA sustained delivery in this system because it possessed both high BSA loading capacity and long-term delivery profile simultaneously. - Highlights: • HA microgels with different crosslink densities were prepared. • The crosslinker content had little effect on the morphology and size of HA microgels. • The crosslink density

  18. Coupling Peptide Antigens to Virus-Like Particles or to Protein Carriers Influences the Th1/Th2 Polarity of the Resulting Immune Response

    Directory of Open Access Journals (Sweden)

    Rattanaruji Pomwised

    2016-05-01

    Full Text Available We have conjugated the S9 peptide, a mimic of the group B streptococcal type III capsular polysaccharide, to different carriers in an effort to elicit an optimal immune response. As carriers, we utilized the soluble protein keyhole limpet hemocyanin and virus-like particles (VLPs from two plant viruses, Cowpea Chlorotic Mottle Virus and Cowpea Mosaic Virus. We have found that coupling the peptide to the soluble protein elicits a Th2 immune response, as evidenced by the production of the peptide-specific IgG1 antibody and IL-4/IL-10 production in response to antigen stimulation, whereas the peptide conjugated to VLPs elicited a Th1 response (IgG2a, IFN-γ. Because the VLPs used as carriers package RNA during the assembly process, we hypothesize that this effect may result from the presence of nucleic acid in the immunogen, which affects the Th1/Th2 polarity of the response.

  19. Properties of the mitochondrial carrier of adenine-nucleotide after purification. Study of the transport protein under isolated form and reincorporated form in phospho-lipidic vesicles

    International Nuclear Information System (INIS)

    The first part of this research thesis addresses the reconstitution of the ADP/ATP transport by incorporation of the specific carrier, isolated in presence of detergent, in phospholipids vesicles. Fundamental properties of the reconstituted transport are identical to that of transport in mitochondria, notably as far as the exchange stoichiometry, the turn over and the transport Km are concerned, as well as the asymmetric orientation of the carrier in the membrane. The second part of this research addresses the study of interactions of specific ligands with the ADP/ATP transport protein in presence of detergent. The study of the variations of the intrinsic fluorescence of the isolated ADP/ATP carrier highlights conformational changes exclusively induced by the presence of transportable nucleotides which are modulated in a different manner by carboxy-atractyloside or bongkrekic acid. Moreover, by using the isolated protein, a detailed analysis of binding parameters of fluorescent analogues of ATP is reported

  20. Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

    DEFF Research Database (Denmark)

    Houen, G.; Olsen, D.T.; Hansen, P.R.;

    2003-01-01

    protein was conjugated with glutathione, the conjugation ratio determined by acid hydrolysis, and amino acid analysis performed with quantification of carboxymethyl cysteine. Elution of conjugates from the resin by a salt gradient revealed considerable heterogeneity in the degree of derivatization......, and immunization experiments with the eluted conjugates showed that the more substituted conjugates gave rise to the highest titers of glutathione antibodies. Direct immunization with the conjugates adsorbed to the ion exchange matrix was possible and gave rise to high titers of glutathione antibodies. Conjugates...

  1. Immunogold localization of acyl carrier protein in plants and Escherichia coli: Evidence for membrane association in plants.

    Science.gov (United States)

    Slabas, A R; Smith, C G

    1988-08-01

    Immunogold labelling was used to study the distribution of acyl carrier protein (ACP) in Escherichia coli and a variety of plant tissues. In E. coli, ACP is distributed throughout the cytoplasm, confirming the observation of S. Jackowski et al. (1985, J. Bacteriol., 162, 5-8_. In the mesocarp of Avocado (Persea americana) and maturing seeds of oil-seed rape (Brassica napus cv. Jet Neuf), over 95% of the ACP is localised to plastids. The protein is almost exclusively located in the chloroplasts of leaf material from oil-seed rape. Approximately 80% of the gold particles associated with the ACP were further localized to the thylakoid membrane of the chloroplast. Since acetyl-CoA carboxylase has been reported to be localized to the thylakoid membrane (C.G. Kannangara and C.J. Jensen, 1975, Eur. J. Biochem., 54, 25-30), these results are consistent with the view that the two sequential enzymes in fatty-acid synthesis are in close spacial proximity.

  2. Functional characterization of solute carrier (SLC) 26/sulfate permease (SulP) proteins in membrane mimetic systems.

    Science.gov (United States)

    Srinivasan, Lakshmi; Baars, Tonie Luise; Fendler, Klaus; Michel, Hartmut

    2016-04-01

    Solute carrier (SLC) 26 or sulfate permease (SulP) anion transporters, belong to a phylogenetically ancient family of secondary active transporters. Members of the family are involved in several human genetic diseases and cell physiological processes. Despite their importance, the substrates for transport by this family of proteins have been poorly characterized. In this study, recombinant StmYchM/DauA, a SulP from Salmonella typhimurium was purified to homogeneity and functionally characterized. StmYchM/DauA was found to be a dimer in solution as determined by size exclusion chromatography coupled to multiple angle light scattering. We report a functional characterization of the SulP proteins in two membrane mimetic systems and reveal a dual nature of anionic substrates for SulP. StmYchM/DauA functionally incorporated into nanodiscs could bind fumarate with millimolar affinities (KD = 4.6 ± 0.29 mM) as detected by intrinsic tryptophan fluorescence quench studies. In contrast, electrophysiological experiments performed in reconstituted liposomes indicate a strong bicarbonate transport in the presence of chloride but no detectable electrogenic fumarate transport. We hence suggest that while SulP acts as an electrogenic bicarbonate transporter, fumarate may serve as substrate under different conditions indicating multiple functions of SulP. PMID:26774215

  3. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  4. Correlation of acidic and basic carrier ampholyte and immobilized pH gradient two-dimensional gel electrophoresis patterns based on mass spectrometric protein identification

    DEFF Research Database (Denmark)

    Nawrocki, A; Larsen, Martin Røssel; Podtelejnikov, A V;

    1998-01-01

    -MS) to determine the identities of 335 protein spots in these two 2-D gel systems, including a substantial number of basic proteins which had never been identified before. Proteins that were identified in both gel systems allowed us to cross-reference the gel patterns. Vector analysis of these cross......-references demonstrated that there is no obvious pattern by which the mobility of a protein in one gel system can be used to predict its mobility in the other. Thus, as laboratories adopt the immobilized pH gradient-based 2-D gel systems, the only reliable means of translating the data gained with the carrier ampholyte...

  5. Fatty Acid-binding Proteins (FABPs) Are Intracellular Carriers for Δ9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD)*

    Science.gov (United States)

    Elmes, Matthew W.; Kaczocha, Martin; Berger, William T.; Leung, KwanNok; Ralph, Brian P.; Wang, Liqun; Sweeney, Joseph M.; Miyauchi, Jeremy T.; Tsirka, Stella E.; Ojima, Iwao; Deutsch, Dale G.

    2015-01-01

    Δ9-Tetrahydrocannabinol (THC) and cannabidiol (CBD) occur naturally in marijuana (Cannabis) and may be formulated, individually or in combination in pharmaceuticals such as Marinol or Sativex. Although it is known that these hydrophobic compounds can be transported in blood by albumin or lipoproteins, the intracellular carrier has not been identified. Recent reports suggest that CBD and THC elevate the levels of the endocannabinoid anandamide (AEA) when administered to humans, suggesting that phytocannabinoids target cellular proteins involved in endocannabinoid clearance. Fatty acid-binding proteins (FABPs) are intracellular proteins that mediate AEA transport to its catabolic enzyme fatty acid amide hydrolase (FAAH). By computational analysis and ligand displacement assays, we show that at least three human FABPs bind THC and CBD and demonstrate that THC and CBD inhibit the cellular uptake and catabolism of AEA by targeting FABPs. Furthermore, we show that in contrast to rodent FAAH, CBD does not inhibit the enzymatic actions of human FAAH, and thus FAAH inhibition cannot account for the observed increase in circulating AEA in humans following CBD consumption. Using computational molecular docking and site-directed mutagenesis we identify key residues within the active site of FAAH that confer the species-specific sensitivity to inhibition by CBD. Competition for FABPs may in part or wholly explain the increased circulating levels of endocannabinoids reported after consumption of cannabinoids. These data shed light on the mechanism of action of CBD in modulating the endocannabinoid tone in vivo and may explain, in part, its reported efficacy toward epilepsy and other neurological disorders. PMID:25666611

  6. Fatty acid-binding proteins (FABPs) are intracellular carriers for Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD).

    Science.gov (United States)

    Elmes, Matthew W; Kaczocha, Martin; Berger, William T; Leung, KwanNok; Ralph, Brian P; Wang, Liqun; Sweeney, Joseph M; Miyauchi, Jeremy T; Tsirka, Stella E; Ojima, Iwao; Deutsch, Dale G

    2015-04-01

    Δ(9)-Tetrahydrocannabinol (THC) and cannabidiol (CBD) occur naturally in marijuana (Cannabis) and may be formulated, individually or in combination in pharmaceuticals such as Marinol or Sativex. Although it is known that these hydrophobic compounds can be transported in blood by albumin or lipoproteins, the intracellular carrier has not been identified. Recent reports suggest that CBD and THC elevate the levels of the endocannabinoid anandamide (AEA) when administered to humans, suggesting that phytocannabinoids target cellular proteins involved in endocannabinoid clearance. Fatty acid-binding proteins (FABPs) are intracellular proteins that mediate AEA transport to its catabolic enzyme fatty acid amide hydrolase (FAAH). By computational analysis and ligand displacement assays, we show that at least three human FABPs bind THC and CBD and demonstrate that THC and CBD inhibit the cellular uptake and catabolism of AEA by targeting FABPs. Furthermore, we show that in contrast to rodent FAAH, CBD does not inhibit the enzymatic actions of human FAAH, and thus FAAH inhibition cannot account for the observed increase in circulating AEA in humans following CBD consumption. Using computational molecular docking and site-directed mutagenesis we identify key residues within the active site of FAAH that confer the species-specific sensitivity to inhibition by CBD. Competition for FABPs may in part or wholly explain the increased circulating levels of endocannabinoids reported after consumption of cannabinoids. These data shed light on the mechanism of action of CBD in modulating the endocannabinoid tone in vivo and may explain, in part, its reported efficacy toward epilepsy and other neurological disorders. PMID:25666611

  7. Chitosan based nanoparticles as protein carriers for efficient oral antigen delivery.

    Science.gov (United States)

    Gao, Ping; Xia, Guixue; Bao, Zixian; Feng, Chao; Cheng, Xiaojie; Kong, Ming; Liu, Ya; Chen, Xiguang

    2016-10-01

    This study aimed to investigate the efficacy of nanoparticles based on chitosan as a vehicle for oral antigen delivery in fish vaccination. Carboxymethyl chitosan/chitosan nanoparticles (CMCS/CS-NPs) loaded extracellular products (ECPs) of Vibrio anguillarum were successfully developed by ionic gelation method. The prepared ECPs-loaded CMCS/CS-NPs were characterized for various parameters including morphology, particle size (312±7.18nm), zeta potential (+17.4±0.38mV), loading efficiency (57.8±2.54%) and stability under the simulated gastrointestinal (GI) tract conditions in turbot. The in vitro profile showed that the cumulative release of ECPs from nanoparticles was higher in pH 7.4 (58%) than in pH 2.0 (37%) and pH 4.5 (29%) after 48h. Fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) was used as model protein antigen and encapsulated in CMCS/CS-NPs for investigating the biodistribution of antigen after oral delivery to turbot in 24h. Oral immunization of ECPs-loaded CMCS/CS-NPs group in turbot showed elevated specific antibody and higher concentrations of lysozyme activity and complement activity in fish serum than ECPs solution. CMCS/CS-NPs loaded with ECPs could enhance both adaptive and innate immune responses than the group treated with ECPs solution and suggested to be a potential antigen delivery system. PMID:27287772

  8. Photoaffinity labeling of the dopamine reuptake carrier protein with 3-azido 3H GBR-12935

    International Nuclear Information System (INIS)

    A high affinity tritiated azido-diphenylpiperazine derivative, 3-azido 3H GBR-12935, was synthesized as a potential photoaffinity probe of the dopamine transporter. Initially, the reversible binding of 3-azido 3H GBR-12935 to crude synaptosomal membranes from the rat striatum was characterized. Specific binding was sodium dependent and inhibited by a variety of drugs that are known to potently inhibit dopamine uptake. Other neurotransmitter uptake inhibitors, as well as cis-flupenthixol, a potent inhibitor of 3H GBR-12935 binding to piperazine binding sites, failed to inhibit specific binding at concentrations of less than or equal to 10 microM. A good correlation was observed between the relative potencies of these drugs in inhibiting dopamine uptake into synaptosomes and in inhibiting specific 3-azido 3H GBR-12935 binding to rat striatal membranes. These data suggest that 3-azido 3H GBR-12935, like other diphenylpiperazines such as 3H GBR-12935 and 3H GBR-12909, binds primarily to the dopamine transporter under defined assay conditions. After UV photolysis of crude synaptosomal membranes preincubated with 3-azido 3H GBR-12935 (1-2 nM), a single radiolabeled polypeptide with an apparent molecular mass of 80 kDa was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Photoincorporation of 3-azido 3H GBR-12935 into this polypeptide was inhibited selectively by compounds that inhibit the uptake of dopamine and was completely dependent on the presence of Na+. No photolabeled proteins were observed when cerebellar membranes were substituted for striatal membranes. Essentially complete adsorption of the radiolabeled 80-kDa polypeptide to wheat germ agglutinin and elution with N-acetyl-D-glucosamine strongly suggest that the dopamine transporter polypeptide photolabeled by 3-azido 3H GBR-12935 is glycosylated

  9. Evaluation of Trichodysplasia Spinulosa-Associated Polyomavirus Capsid Protein as a New Carrier for Construction of Chimeric Virus-Like Particles Harboring Foreign Epitopes

    Directory of Open Access Journals (Sweden)

    Alma Gedvilaite

    2015-07-01

    Full Text Available Recombinant virus-like particles (VLPs represent a promising tool for protein engineering. Recently, trichodysplasia spinulosa-associated polyomavirus (TSPyV viral protein 1 (VP1 was efficiently produced in yeast expression system and shown to self-assemble to VLPs. In the current study, TSPyV VP1 protein was exploited as a carrier for construction of chimeric VLPs harboring selected B and T cell-specific epitopes and evaluated in comparison to hamster polyomavirus VP1 protein. Chimeric VLPs with inserted either hepatitis B virus preS1 epitope DPAFR or a universal T cell-specific epitope AKFVAAWTLKAAA were produced in yeast Saccharomyces cerevisiae. Target epitopes were incorporated either at the HI or BC loop of the VP1 protein. The insertion sites were selected based on molecular models of TSPyV VP1 protein. The surface exposure of the insert positions was confirmed using a collection of monoclonal antibodies raised against the intact TSPyV VP1 protein. All generated chimeric proteins were capable to self-assemble to VLPs, which induced a strong immune response in mice. The chimeric VLPs also activated dendritic cells and T cells as demonstrated by analysis of cell surface markers and cytokine production profiles in spleen cell cultures. In conclusion, TSPyV VP1 protein represents a new potential carrier for construction of chimeric VLPs harboring target epitopes.

  10. Triclosan Resistome from Metagenome Reveals Diverse Enoyl Acyl Carrier Protein Reductases and Selective Enrichment of Triclosan Resistance Genes.

    Science.gov (United States)

    Khan, Raees; Kong, Hyun Gi; Jung, Yong-Hoon; Choi, Jinhee; Baek, Kwang-Yeol; Hwang, Eul Chul; Lee, Seon-Woo

    2016-01-01

    Triclosan (TCS) is a widely used antimicrobial agent and TCS resistance is considered to have evolved in diverse organisms with extensive use of TCS, but distribution of TCS resistance has not been well characterized. Functional screening of the soil metagenome in this study has revealed that a variety of target enoyl acyl carrier protein reductases (ENR) homologues are responsible for the majority of TCS resistance. Diverse ENRs similar to 7-α-hydroxysteroid dehydrogenase (7-α-HSDH), FabG, or the unusual YX7K-type ENR conferred extreme tolerance to TCS. The TCS-refractory 7-α HSDH-like ENR and the TCS-resistant YX7K-type ENR seem to be prevalent in human pathogenic bacteria, suggesting that a selective enrichment occurred in pathogenic bacteria in soil. Additionally, resistance to multiple antibiotics was found to be mediated by antibiotic resistance genes that co-localize with TCS resistance determinants. Further comparative analysis of ENRs from 13 different environments has revealed a huge diversity of both prototypic and metagenomic TCS-resistant ENRs, in addition to a selective enrichment of TCS-resistant specific ENRs in presumably TCS-contaminated environments with reduced ENR diversity. Our results suggest that long-term extensive use of TCS can lead to the selective emergence of TCS-resistant bacterial pathogens, possibly with additional resistance to multiple antibiotics, in natural environments. PMID:27577999

  11. Triclosan Resistome from Metagenome Reveals Diverse Enoyl Acyl Carrier Protein Reductases and Selective Enrichment of Triclosan Resistance Genes

    Science.gov (United States)

    Khan, Raees; Kong, Hyun Gi; Jung, Yong-Hoon; Choi, Jinhee; Baek, Kwang-Yeol; Hwang, Eul Chul; Lee, Seon-Woo

    2016-01-01

    Triclosan (TCS) is a widely used antimicrobial agent and TCS resistance is considered to have evolved in diverse organisms with extensive use of TCS, but distribution of TCS resistance has not been well characterized. Functional screening of the soil metagenome in this study has revealed that a variety of target enoyl acyl carrier protein reductases (ENR) homologues are responsible for the majority of TCS resistance. Diverse ENRs similar to 7-α-hydroxysteroid dehydrogenase (7-α-HSDH), FabG, or the unusual YX7K-type ENR conferred extreme tolerance to TCS. The TCS-refractory 7-α HSDH-like ENR and the TCS-resistant YX7K-type ENR seem to be prevalent in human pathogenic bacteria, suggesting that a selective enrichment occurred in pathogenic bacteria in soil. Additionally, resistance to multiple antibiotics was found to be mediated by antibiotic resistance genes that co-localize with TCS resistance determinants. Further comparative analysis of ENRs from 13 different environments has revealed a huge diversity of both prototypic and metagenomic TCS-resistant ENRs, in addition to a selective enrichment of TCS-resistant specific ENRs in presumably TCS-contaminated environments with reduced ENR diversity. Our results suggest that long-term extensive use of TCS can lead to the selective emergence of TCS-resistant bacterial pathogens, possibly with additional resistance to multiple antibiotics, in natural environments. PMID:27577999

  12. Design and evaluation of lipoprotein resembling curcumin-encapsulated protein-free nanostructured lipid carrier for brain targeting.

    Science.gov (United States)

    Meng, Fanfei; Asghar, Sajid; Xu, Yurui; Wang, Jianping; Jin, Xin; Wang, Zhilin; Wang, Jing; Ping, Qineng; Zhou, Jianping; Xiao, Yanyu

    2016-06-15

    Many nanoparticle matrixes have been demonstrated to be efficient in brain targeting, but there are still certain limitations for them. To overcome the shortcomings of the existing nanoparticulate systems for brain-targeted delivery, a lipoprotein resembling protein-free nanostructured lipid carrier (PS80-NLC) loaded with curcumin was constructed and assessed for in vitro and in vivo performance. Firstly, single factor at a time approach was employed to investigate the effects of various formulation factors. Mean particle sizes of ≤100nm, high entrapment efficiency (EE, about 95%) and drug loading (DL, >3%) were obtained for the optimized formulations. In vitro release studies in the presence of plasma indicated stability of the formulation under physiological condition. Compared with NLC, PS80-NLC showed noticeably higher affinity for bEnd.3 cells (1.56 folds greater than NLC) but with lower uptake in macrophages. The brain coronal sections showed strong and widely distributed fluorescence intensity of PS80-NLC than that of NLC in the cortex. Ex vivo imaging studies further confirmed that PS80-NLC could effectively permeate BBB and preferentially accumulate in the brain (2.38 times greater than NLC). The considerable in vitro and in vivo performance of the safe and biocompatible PS80-NLC makes it a suitable option for further investigations in brain targeted drug delivery.

  13. Defective Pollen Wall is Required for Anther and Microspore Development in Rice and Encodes a Fatty Acyl Carrier Protein Reductase

    Energy Technology Data Exchange (ETDEWEB)

    Shi, J.; Shanklin, J.; Tan, H.; Yu, X.-H.; Liu, Y.; Liang, W.; Ranathunge, K.; Franke, R. B.; Schreiber, L.; Wang, Y.; Kai, G.; Ma, H.; Zhang, D.

    2011-06-01

    Aliphatic alcohols naturally exist in many organisms as important cellular components; however, their roles in extracellular polymer biosynthesis are poorly defined. We report here the isolation and characterization of a rice (Oryza sativa) male-sterile mutant, defective pollen wall (dpw), which displays defective anther development and degenerated pollen grains with an irregular exine. Chemical analysis revealed that dpw anthers had a dramatic reduction in cutin monomers and an altered composition of cuticular wax, as well as soluble fatty acids and alcohols. Using map-based cloning, we identified the DPW gene, which is expressed in both tapetal cells and microspores during anther development. Biochemical analysis of the recombinant DPW enzyme shows that it is a novel fatty acid reductase that produces 1-hexadecanol and exhibits >270-fold higher specificity for palmiltoyl-acyl carrier protein than for C16:0 CoA substrates. DPW was predominantly targeted to plastids mediated by its N-terminal transit peptide. Moreover, we demonstrate that the monocot DPW from rice complements the dicot Arabidopsis thaliana male sterile2 (ms2) mutant and is the probable ortholog of MS2. These data suggest that DPWs participate in a conserved step in primary fatty alcohol synthesis for anther cuticle and pollen sporopollenin biosynthesis in monocots and dicots.

  14. Bioinformatic evidence for a widely distributed, ribosomally produced electron carrier precursor, its maturation proteins, and its nicotinoprotein redox partners

    Directory of Open Access Journals (Sweden)

    Haft Daniel H

    2011-01-01

    as N,N-dimethyl-4-nitrosoaniline (NDMA for the enzyme to cycle. Conclusions Taken together, these findings suggest that the mycofactocin precursor is modified by the Rv0693 family rSAM protein and other enzymes in its cluster. It becomes an electron carrier molecule that serves in vivo as NDMA and other artificial electron acceptors do in vitro. Subclasses from three different nicotinoprotein families show "only-if" relationships to mycofactocin because they require its presence. This framework suggests a segregated redox pool in which mycofactocin mediates communication among enzymes with non-exchangeable cofactors.

  15. DAF-16 and Δ9 desaturase genes promote cold tolerance in long-lived Caenorhabditis elegans age-1 mutants.

    Directory of Open Access Journals (Sweden)

    Fiona R Savory

    Full Text Available In Caenorhabditis elegans, mutants of the conserved insulin/IGF-1 signalling (IIS pathway are long-lived and stress resistant due to the altered expression of DAF-16 target genes such as those involved in cellular defence and metabolism. The three Δ(9 desaturase genes, fat-5, fat-6 and fat-7, are included amongst these DAF-16 targets, and it is well established that Δ(9 desaturase enzymes play an important role in survival at low temperatures. However, no assessment of cold tolerance has previously been reported for IIS mutants. We demonstrate that long-lived age-1(hx546 mutants are remarkably resilient to low temperature stress relative to wild type worms, and that this is dependent upon daf-16. We also show that cold tolerance following direct transfer to low temperatures is increased in wild type worms during the facultative, daf-16 dependent, dauer stage. Although the cold tolerant phenotype of age-1(hx546 mutants is predominantly due to the Δ(9 desaturase genes, additional transcriptional targets of DAF-16 are also involved. Surprisingly, survival of wild type adults following a rapid temperature decline is not dependent upon functional daf-16, and cellular distributions of a DAF-16::GFP fusion protein indicate that DAF-16 is not activated during low temperature stress. This suggests that cold-induced physiological defences are not specifically regulated by the IIS pathway and DAF-16, but expression of DAF-16 target genes in IIS mutants and dauers is sufficient to promote cross tolerance to low temperatures in addition to other forms of stress.

  16. Preparation and testing of a Vi conjugate vaccine using pneumococcal surface protein A (PspA) from Streptococcus pneumoniae as the carrier protein.

    Science.gov (United States)

    Kothari, Neha; Genschmer, Kristopher R; Kothari, Sudeep; Kim, Jeong Ah; Briles, David E; Rhee, Dong Kwon; Carbis, Rodney

    2014-09-29

    In the current study pneumococcal surface protein A (PspA) was conjugated to Vi capsular polysaccharide from Salmonella Typhi to make available a vaccine against typhoid fever that has the potential to also provide broad protection from Streptococcus pneumoniae. High yielding production processes were developed for the purification of PspAs from families 1 and 2. The purified PspAs were conjugated to Vi with high recovery of both Vi and PspA. The processes developed especially for PspA family 2 could readily be adapted for large scale production under cGMP conditions. Previously we have shown that conjugation of diphtheria toxoid (DT) to Vi polysaccharide improves the immune response to Vi but can also enhance the response to DT. In this study it was shown that conjugation of PspA to Vi enhanced the anti-PspA response and that PspA was a suitable carrier protein as demonstrated by the characteristics of a T-cell dependent response to the Vi. We propose that a bivalent vaccine consisting of PspA from families 1 and 2 bound to Vi polysaccharide would protect against typhoid fever and has the potential to also protect against pneumococcal disease and should be considered for use in developing countries.

  17. A novel approach for measuring sphingosine-1-phosphate and lysophosphatidic acid binding to carrier proteins using monoclonal antibodies and the Kinetic Exclusion Assay.

    Science.gov (United States)

    Fleming, Jonathan K; Glass, Thomas R; Lackie, Steve J; Wojciak, Jonathan M

    2016-09-01

    Sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) are bioactive signaling lysophospholipids that activate specific G protein-coupled receptors on the cell surface triggering numerous biological events. In circulation, S1P and LPA associate with specific carrier proteins or chaperones; serum albumin binds both S1P and LPA while HDL shuttles S1P via interactions with apoM. We used a series of kinetic exclusion assays in which monoclonal anti-S1P and anti-LPA antibodies competed with carrier protein for the lysophospholipid to measure the equilibrium dissociation constants (Kd) for these carrier proteins binding S1P and the major LPA species. Fatty acid-free (FAF)-BSA binds these lysophospholipids with the following Kd values: LPA(16:0), 68 nM; LPA(18:1), 130 nM; LPA(18:2), 350 nM; LPA(20:4), 2.2 μM; and S1P, 41 μM. FAF human serum albumin binds each lysophospholipid with comparable affinities. By measuring the apoM concentration and expanding the model to include endogenous ligand, we were able to resolve the Kd values for S1P binding apoM in the context of human HDL and LDL particles (21 nM and 2.4 nM, respectively). The novel competitive assay and analysis described herein enables measurement of Kd values of completely unmodified lysophospholipids binding unmodified carrier proteins in solution, and thus provide insights into S1P and LPA storage in the circulation system and may be useful in understanding chaperone-dependent receptor activation and signaling. PMID:27444045

  18. Crystal Structure of Epiphyas Postvittana Takeout 1 With Bound Ubiquinone Supports a Role As Ligand Carriers for Takeout Proteins in Insects

    Energy Technology Data Exchange (ETDEWEB)

    Hamiaux, C.; Stanley, D.; Greenwood, D.R.; Baker, E.N.; Newcomb, R.D.

    2009-05-19

    Takeout (To) proteins are found exclusively in insects and have been proposed to have important roles in various aspects of their physiology and behavior. Limited sequence similarity with juvenile hormone-binding proteins (JHBPs), which specifically bind and transport juvenile hormones in Lepidoptera, suggested a role for To proteins in binding hydrophobic ligands. We present the first crystal structure of a To protein, EpTo1 from the light brown apple moth Epiphyas postvittana, solved in-house by the single-wavelength anomalous diffraction technique using sulfur anomalous dispersion, and refined to 1.3 {angstrom} resolution. EpTo1 adopts the unusual {alpha}/{beta}-wrap fold, seen only for JHBP and several mammalian lipid carrier proteins, a scaffold tailored for the binding and/or transport of hydrophobic ligands. EpTo1 has a 45 {angstrom} long, purely hydrophobic, internal tunnel that extends for the full length of the protein and accommodates a bound ligand. The latter was shown by mass spectrometry to be ubiquinone-8 and is probably derived from Escherichia coli. The structure provides the first direct experimental evidence that To proteins are ligand carriers; gives insights into the nature of endogenous ligand(s) of EpTo1; shows, by comparison with JHBP, a basis for different ligand specificities; and suggests a mechanism for the binding/release of ligands.

  19. Effect of conjugated linoleic acid on fungal delta6-desaturase activity in a transformed yeast system.

    Science.gov (United States)

    Chuang, L T; Thurmond, J M; Liu, J W; Kirchner, S J; Mukerji, P; Bray, T M; Huang, Y S

    2001-02-01

    Conjugated linoleic acid (CLA; 18:2), a group of positional and geometric isomers of linoleic acid (LA; 18:2n-6), has been shown to modulate immune function through its effect on eicosanoid synthesis. This effect has been attributed to a reduced production of n-6 polyunsaturated fatty acid (PUFA), the precursor of eicosanoids. Since delta6-desaturase is the rate-limiting enzyme of the n-6 PUFA production, it is our hypothesis that CLA, which has similar chemical structure to LA, interacts directly with delta6-desaturase. A unique and simple model, i.e., baker's yeast (Saccharomyces cerevisiae) transformed with fungal delta6-desaturase gene, previously established, was used to investigate the direct effect of CLA on delta6-desaturase. This model allows LA to be converted to y-linolenic acid (GLA; 18:3n-6) but not GLA to its metabolite(s). No metabolites of CLA were found in the lipids of the yeast transformed with delta6-desaturase. The inability to convert CLA to conjugated GLA was not due to the failure of yeast cells to take up the CLA isomers. CLA mixture and individual isomers significantly inhibited the activity of delta6-desaturase of the transformed yeast in vivo. Even though its uptake by the yeast was low, CLA c9,t11 isomer was found to be the most potent inhibitor of the four isomers tested, owing to its high inhibitory effect on delta6-desaturase. Since CLA did not cause significant changes in the level of delta6-desaturase mRNA, the inhibition of GLA production could not be attributed to suppression of delta6-desaturase gene expression at the transcriptional level.

  20. Peroxisome proliferators induce mouse liver stearoyl-CoA desaturase 1 gene expression.

    OpenAIRE

    Miller, C. W.; Ntambi, J M

    1996-01-01

    Peroxisome proliferators induce stearoyl-CoA desaturase activity (EC 1.14.99.5) in liver [Kawashima, Y., Hanioka, N., Matsumura, M. & Kozuka, H. (1983) Biochim. Biophys. Acta 752, 259-264]. We analyzed the changes in stearoyl-CoA desaturase 1 (SCD1) mRNA to further define the molecular mechanism for the induction of stearoyl-CoA desaturase by peroxisome proliferators. SCD1 mRNA was analyzed from the livers of BALB/c mice that had been fed diets supplemented with clofibrate or gemfibrozil. Clo...

  1. Studies of Toxoplasma gondii and Plasmodium falciparum enoyl acyl carrier protein reductase and implications for the development of antiparasitic agents

    Energy Technology Data Exchange (ETDEWEB)

    Muench, Stephen P. [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom); Prigge, Sean T. [Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); McLeod, Rima [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Rafferty, John B. [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom); Kirisits, Michael J. [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Roberts, Craig W. [Department of Immunology, University of Strathclyde, Glasgow G4 0NR, Scotland (United Kingdom); Mui, Ernest J. [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Rice, David W., E-mail: d.rice@sheffield.ac.uk [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom)

    2007-03-01

    The crystal structures of T. gondii and P. falciparum ENR in complex with NAD{sup +} and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. Recent studies have demonstrated that submicromolar concentrations of the biocide triclosan arrest the growth of the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii and inhibit the activity of the apicomplexan enoyl acyl carrier protein reductase (ENR). The crystal structures of T. gondii and P. falciparum ENR in complex with NAD{sup +} and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. The structures of T. gondii ENR have revealed that, as in its bacterial and plant homologues, a loop region which flanks the active site becomes ordered upon inhibitor binding, resulting in the slow tight binding of triclosan. In addition, the T. gondii ENR–triclosan complex reveals the folding of a hydrophilic insert common to the apicomplexan family that flanks the substrate-binding domain and is disordered in all other reported apicomplexan ENR structures. Structural comparison of the apicomplexan ENR structures with their bacterial and plant counterparts has revealed that although the active sites of the parasite enzymes are broadly similar to those of their bacterial counterparts, there are a number of important differences within the drug-binding pocket that reduce the packing interactions formed with several inhibitors in the apicomplexan ENR enzymes. Together with other significant structural differences, this provides a possible explanation of the lower affinity of the parasite ENR enzyme family for aminopyridine-based inhibitors, suggesting that an effective antiparasitic agent may well be distinct from equivalent antimicrobials.

  2. Chlamydia trachomatis Scavenges Host Fatty Acids for Phospholipid Synthesis via an Acyl-Acyl Carrier Protein Synthetase.

    Science.gov (United States)

    Yao, Jiangwei; Dodson, V Joshua; Frank, Matthew W; Rock, Charles O

    2015-09-01

    The obligate intracellular parasite Chlamydia trachomatis has a reduced genome but relies on de novo fatty acid and phospholipid biosynthesis to produce its membrane phospholipids. Lipidomic analyses showed that 8% of the phospholipid molecular species synthesized by C. trachomatis contained oleic acid, an abundant host fatty acid that cannot be made by the bacterium. Mass tracing experiments showed that isotopically labeled palmitic, myristic, and lauric acids added to the medium were incorporated into C. trachomatis-derived phospholipid molecular species. HeLa cells did not elongate lauric acid, but infected HeLa cell cultures elongated laurate to myristate and palmitate. The elongated fatty acids were incorporated exclusively into C. trachomatis-produced phospholipid molecular species. C. trachomatis has adjacent genes encoding the separate domains of the bifunctional acyl-acyl carrier protein (ACP) synthetase/2-acylglycerolphosphoethanolamine acyltransferase gene (aas) of Escherichia coli. The CT775 gene encodes an acyltransferase (LpaT) that selectively transfers fatty acids from acyl-ACP to the 1-position of 2-acyl-glycerophospholipids. The CT776 gene encodes an acyl-ACP synthetase (AasC) with a substrate preference for palmitic compared with oleic acid in vitro. Exogenous fatty acids were elongated and incorporated into phospholipids by Escherichia coli-expressing AasC, illustrating its function as an acyl-ACP synthetase in vivo. These data point to an AasC-dependent pathway in C. trachomatis that selectively scavenges host saturated fatty acids to be used for the de novo synthesis of its membrane constituents. PMID:26195634

  3. Studies of Toxoplasma gondii and Plasmodium falciparum enoyl acyl carrier protein reductase and implications for the development of antiparasitic agents

    International Nuclear Information System (INIS)

    The crystal structures of T. gondii and P. falciparum ENR in complex with NAD+ and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. Recent studies have demonstrated that submicromolar concentrations of the biocide triclosan arrest the growth of the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii and inhibit the activity of the apicomplexan enoyl acyl carrier protein reductase (ENR). The crystal structures of T. gondii and P. falciparum ENR in complex with NAD+ and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. The structures of T. gondii ENR have revealed that, as in its bacterial and plant homologues, a loop region which flanks the active site becomes ordered upon inhibitor binding, resulting in the slow tight binding of triclosan. In addition, the T. gondii ENR–triclosan complex reveals the folding of a hydrophilic insert common to the apicomplexan family that flanks the substrate-binding domain and is disordered in all other reported apicomplexan ENR structures. Structural comparison of the apicomplexan ENR structures with their bacterial and plant counterparts has revealed that although the active sites of the parasite enzymes are broadly similar to those of their bacterial counterparts, there are a number of important differences within the drug-binding pocket that reduce the packing interactions formed with several inhibitors in the apicomplexan ENR enzymes. Together with other significant structural differences, this provides a possible explanation of the lower affinity of the parasite ENR enzyme family for aminopyridine-based inhibitors, suggesting that an effective antiparasitic agent may well be distinct from equivalent antimicrobials

  4. Hydroxyapatite/ovalbumin composite particles as model protein carriers for bone tissue engineering: I. Synthesis and characterization

    International Nuclear Information System (INIS)

    Hydroxyapatite (HAp) nanoparticles were synthesized from the co-precipitation reaction between calcium oxide from discarded egg shells and phosphoric acid in the absence and the presence of ovalbumin (OVA). 2-Amino-2-hydroxymethyl-propane-1,3-diol (tris-base) was used to control the pH during the co-precipitation (i.e., 7–9). The formation of HAp was confirmed by X-ray diffraction analysis, while both the Fourier-transform infrared spectroscopy and the thermogravimetric analysis confirmed the existence of OVA within the HAp–OVA particles. The crystallite sizes of the individual crystalline entities within the HAp and the HAp–OVA particles were approximated from the (002) reflection peaks by means of the Scherrer's equation. The average particle sizes of the HAp and the HAp–OVA particles were measured by particle size analysis. Transmission electron microscopy revealed that these particles were aggregates of rod-like HAp nanocrystals, whereas scanning electron microscopy revealed that these particles ultimately formed into larger aggregates. Lastly, the decrease in the pH during the precipitation process and the presence of OVA were responsible for the observed increase in the values of pore size, BET specific surface area, and pore volume of the resulting HAp particles. Highlights: ► CaO from discarded egg shells was used as the source of calcium. ► Precipitation of CaO with H3PO4 into HAp was achieved with tris-base ► Precipitation was done with or without ovalbumin (OVA) ► HAp–OVA composite particles are envisioned as model carriers of proteins ► 2nd work in the series showed that release of OVA was good for up to 21 days

  5. High-resolution structures of the D-alanyl carrier protein (Dcp) DltC from Bacillus subtilis reveal equivalent conformations of apo- and holo-forms.

    Science.gov (United States)

    Zimmermann, Stephan; Pfennig, Sabrina; Neumann, Piotr; Yonus, Huma; Weininger, Ulrich; Kovermann, Michael; Balbach, Jochen; Stubbs, Milton T

    2015-08-19

    D-Alanylation of lipoteichoic acids plays an important role in modulating the properties of Gram-positive bacteria cell walls. The D-alanyl carrier protein DltC from Bacillus subtilis has been solved in apo- and two cofactor-modified holo-forms, whereby the entire phosphopantetheine moiety is defined in one. The atomic resolution of the apo-structure allows delineation of alternative conformations within the hydrophobic core of the 78 residue four helix bundle. In contrast to previous reports for a peptidyl carrier protein from a non-ribosomal peptide synthetase, no obvious structural differences between apo- and holo-DltC forms are observed. Solution NMR spectroscopy confirms these findings and demonstrates in addition that the two forms exhibit similar backbone dynamics on the ps-ns and ms timescales. PMID:26193422

  6. High-resolution structures of the D-alanyl carrier protein (Dcp) DltC from Bacillus subtilis reveal equivalent conformations of apo- and holo-forms.

    Science.gov (United States)

    Zimmermann, Stephan; Pfennig, Sabrina; Neumann, Piotr; Yonus, Huma; Weininger, Ulrich; Kovermann, Michael; Balbach, Jochen; Stubbs, Milton T

    2015-08-19

    D-Alanylation of lipoteichoic acids plays an important role in modulating the properties of Gram-positive bacteria cell walls. The D-alanyl carrier protein DltC from Bacillus subtilis has been solved in apo- and two cofactor-modified holo-forms, whereby the entire phosphopantetheine moiety is defined in one. The atomic resolution of the apo-structure allows delineation of alternative conformations within the hydrophobic core of the 78 residue four helix bundle. In contrast to previous reports for a peptidyl carrier protein from a non-ribosomal peptide synthetase, no obvious structural differences between apo- and holo-DltC forms are observed. Solution NMR spectroscopy confirms these findings and demonstrates in addition that the two forms exhibit similar backbone dynamics on the ps-ns and ms timescales.

  7. Crystal structure of enoyl–acyl carrier protein reductase (FabK) from Streptococcus pneumoniae reveals the binding mode of an inhibitor

    OpenAIRE

    Saito, Jun; Yamada, Mototsugu; Watanabe, Takashi; Iida, Maiko; Kitagawa, Hideo; Takahata, Sho; Ozawa, Tomohiro; Takeuchi, Yasuo; Ohsawa, Fukuichi

    2008-01-01

    Enoyl–acyl carrier protein (ACP) reductases are critical for bacterial type II fatty acid biosynthesis and thus are attractive targets for developing novel antibiotics. We determined the crystal structure of enoyl–ACP reductase (FabK) from Streptococcus pneumoniae at 1.7 Å resolution. There was one dimer per asymmetric unit. Each subunit formed a triose phosphate isomerase (TIM) barrel structure, and flavin mononucleotide (FMN) was bound as a cofactor in the active site. The overall structure...

  8. Crystallization and X-ray diffraction analysis of the β-ketoacyl-acyl carrier protein reductase FabG from Aquifex aeolicus VF5

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Qilong [Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203 (United States); Duax, William L.; Umland, Timothy C., E-mail: umland@hwi.buffalo.edu [Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203 (United States); Department of Structural Biology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY (United States)

    2007-02-01

    FabG from A. aeolicus, a putative component of fatty-acid synthase II, has been overexpressed, purified and crystallized. Diffraction data have been collected to 1.8 Å resolution. The gene product of fabG from Aquifex aeolicus has been heterologously expressed in Escherichia coli. Purification of the protein took place using anion-exchange and size-exclusion chromatography and the protein was then crystallized. Diffraction data were collected to a maximum resolution of 1.8 Å and the initial phases were determined by molecular replacement. The A. aeolicus FabG protein is a putative β-ketoacyl-acyl carrier protein reductase. Structure–function studies of this protein are being performed as part of a larger project investigating naturally occurring deviations from highly conserved residues within the short-chain oxidoreductase (SCOR) family.

  9. Crystallization and X-ray diffraction analysis of the β-ketoacyl-acyl carrier protein reductase FabG from Aquifex aeolicus VF5

    International Nuclear Information System (INIS)

    FabG from A. aeolicus, a putative component of fatty-acid synthase II, has been overexpressed, purified and crystallized. Diffraction data have been collected to 1.8 Å resolution. The gene product of fabG from Aquifex aeolicus has been heterologously expressed in Escherichia coli. Purification of the protein took place using anion-exchange and size-exclusion chromatography and the protein was then crystallized. Diffraction data were collected to a maximum resolution of 1.8 Å and the initial phases were determined by molecular replacement. The A. aeolicus FabG protein is a putative β-ketoacyl-acyl carrier protein reductase. Structure–function studies of this protein are being performed as part of a larger project investigating naturally occurring deviations from highly conserved residues within the short-chain oxidoreductase (SCOR) family

  10. Molecular cloning and ontogenic mRNA expression of fatty acid desaturase in the carnivorous striped snakehead fish (Channa striata).

    Science.gov (United States)

    Jaya-Ram, Annette; Ishak, Sairatul Dahlianis; Enyu, Yee-Ling; Kuah, Meng-Kiat; Wong, Kah-Loon; Shu-Chien, Alexander Chong

    2011-04-01

    There is very little information on the capacity of freshwater carnivorous fish to biosynthesize highly unsaturated fatty acids (HUFA). The striped snakehead fish (Channa striata) is a carnivorous species cultured inland of several Southeast Asian countries due to its pharmaceutical properties in wound healing enhancement. We described here the full-length cDNA cloning of a striped snakehead fatty acid desaturase (fads), which is responsible for desaturation of unsaturated fatty acids in the HUFA biosynthesis. Bioinformatics analysis reveals a protein coding region with length of 445 amino acids containing all characteristic features of desaturase enzyme, including a cytochrome b5-domain with the heme-binding motif, two transmembrane domains and three histidine-rich regions. The striped snakehead fads amino acid sequence shares high similarity with known fads of other teleosts. The mRNA expression of striped snakehead fads also showed an ontogenic-related increase in expression in 0-20 days after hatch larva. Using ISH, we localized the presence of fads in larva brain, liver and intestinal tissues.

  11. Creation of glyphosate-resistant Brassica napus L. plants expressing DesC desaturase of cyanobacterium Synechococcus vulcanus

    Directory of Open Access Journals (Sweden)

    Goldenkova-Pavlova I. V.

    2012-12-01

    Full Text Available Aim. Creation of glyphosate-resistant canola plants expressing bifunctional hybrid desC::licBM3 gene. In the hybrid gene the sequence of DesC desaturase of cyanobacterium S. vulcanus without plastid targeting was fused with the sequence of thermostable lichenase reporter LicBM3 gene. Methods. Agrobacterium tumefaciens-mediated transformation, PCR, quantitative and qualitative determination of lichenase activity, genetic analysis. Results. Transgenic canola plants, carring the enolpyruvat shikimat phosphate syntase gene (epsps, conferring on plants resistance to phosphonomethyl glycine herbicides (Roundup, as well as the desC::licBM3 gene, were selected. The presence of transgenes was confimed by multiplex PCR. The epsps gene expression in canola was shown at the transcription level, during in vitro growth and after greenhouse herbicide treatment. Activity of the licBM3 gene product as a part of hybrid protein allowed quantitative and qualitative estimation of the desaturase gene expression. Inheritance of heterologous genes and their expression in the first generation were investigated. Conclusions. Transgenic canola plants were obtained, the presence of trangenes in plant genome was proved and expression of the target genes was detected.

  12. Molecular cloning and ontogenic mRNA expression of fatty acid desaturase in the carnivorous striped snakehead fish (Channa striata).

    Science.gov (United States)

    Jaya-Ram, Annette; Ishak, Sairatul Dahlianis; Enyu, Yee-Ling; Kuah, Meng-Kiat; Wong, Kah-Loon; Shu-Chien, Alexander Chong

    2011-04-01

    There is very little information on the capacity of freshwater carnivorous fish to biosynthesize highly unsaturated fatty acids (HUFA). The striped snakehead fish (Channa striata) is a carnivorous species cultured inland of several Southeast Asian countries due to its pharmaceutical properties in wound healing enhancement. We described here the full-length cDNA cloning of a striped snakehead fatty acid desaturase (fads), which is responsible for desaturation of unsaturated fatty acids in the HUFA biosynthesis. Bioinformatics analysis reveals a protein coding region with length of 445 amino acids containing all characteristic features of desaturase enzyme, including a cytochrome b5-domain with the heme-binding motif, two transmembrane domains and three histidine-rich regions. The striped snakehead fads amino acid sequence shares high similarity with known fads of other teleosts. The mRNA expression of striped snakehead fads also showed an ontogenic-related increase in expression in 0-20 days after hatch larva. Using ISH, we localized the presence of fads in larva brain, liver and intestinal tissues. PMID:21130179

  13. The role of ß-ketoacyl-acyl carrier protein synthase III in the condensation steps of fatty acid biosynthesis in sunflower

    DEFF Research Database (Denmark)

    González-Mellado, Damián; von Wettstein, Penny; Garcés, Rafael;

    2010-01-01

    The ß-ketoacyl-acyl carrier protein synthase III (KAS III; EC 2.3.1.180) is a condensing enzyme catalyzing the initial step of fatty acid biosynthesis using acetyl-CoA as primer. To determine the mechanisms involved in the biosynthesis of fatty acids in sunflower (Helianthus annuus L.) developing...... proteins infers its origin from cyanobacterial ancestors. A genomic DNA gel blot analysis revealed that HaKAS III is a single copy gene. Expression levels of this gene, examined by Q-PCR, revealed higher levels in developing seeds storing oil than in leaves, stems, roots or seedling cotyledons...

  14. Expression of cholera toxin B-lumbrokinase fusion protein in Pichia pastoris--the use of transmucosal carriers in the delivery of therapeutic proteins to protect rats against thrombosis.

    Science.gov (United States)

    Chunfeng, Guan; Xiaozhou, Li; Gang, Wang; Jing, Ji; Chao, Jin; Josine, Tchouopou Lontchi

    2013-01-01

    Cholera toxin B-subunit (CTB) has been widely used to facilitate antigen delivery by serving as an effective mucosal carrier molecule for the induction of oral tolerance. However, whether CTB can be used as a transmucosal carrier in the delivery of not only vaccines but also therapeutic proteins has not been widely studied. Thus, we investigate here the concept of receptor-mediated oral delivery of lumbrokinase (LK) proteins which is an important fibrinolytic enzyme derived from earthworm. CTB and LK, separated by a furin cleavage site, was expressed via Pichia pastoris. The activity and proper folding of recombinant protein in yeast were confirmed by Western blot analysis, fibrin plate assays, and G(M1)-ganglioside ELISA. Following oral administration of recombinant protein, the thrombosis model of rats and mice revealed that the oral treatment of rCTB-LK has a more significant anti-thrombotic effect on animals compared with rLK. It is possible to conclude that CTB can successfully enhance its fusion protein LK to be absorbed. The use of CTB as a transmucosal carrier in the delivery of not only vaccines but also therapeutic proteins was supported. PMID:23269637

  15. A phytoene desaturase homolog gene from the methanogenic archaeon Methanosarcina acetivorans is responsible for hydroxyarchaeol biosynthesis.

    Science.gov (United States)

    Mori, Takeshi; Isobe, Keisuke; Ogawa, Takuya; Yoshimura, Tohru; Hemmi, Hisashi

    2015-10-16

    Hydroxyarchaeols are the typical core structures of archaeal membrane lipids uniquely produced by a limited number of methanogenic lineages, which are mainly classified in orders Methanosarcinales and Methanococcales. However, the biosynthetic machinery that is used for the biosynthesis of hydroxyarcheol core lipids has not been discovered. In this study, the ma0127 gene from Methanosarcina acetivorans, which encodes a phytoene desaturase-like protein, was found to be responsible for the hydration of a geranylgeranyl group in an archaeal-lipid precursor, sn-2,3-O-digeranylgeranylglyceryl phosphoglycerol, produced in Escherichia coli cells expressing several archaeal enzymes. LC-ESI-tandem-MS analyses proved that hydration occurs at the 2',3'-double bond of the geranylgeranyl group, yielding a 3'-hydroxylated lipid precursor. This result suggests that the encoded protein MA0127 is a hydratase involved in hydroxyarchaeol biosynthesis, because M. acetivorans is known to produce hydroxyarchaeol core lipids with a 3'-hydroxyphytanyl group. Furthermore, the distribution of the putative orthologs of ma0127 among methanogens is generally in good agreement with that of hydroxyarchaeol producers, including anaerobic methanotrophs (ANMEs). PMID:26361140

  16. Stearoyl coenzyme A desaturase 1 is associated with hepatitis C virus replication complex and regulates viral replication

    DEFF Research Database (Denmark)

    Nguyen, LN; Lim, YS; Pham, Long;

    2014-01-01

    The hepatitis C virus (HCV) life cycle is tightly regulated by lipid metabolism of host cells. In order to identify host factors involved in HCV propagation, we have recently screened a small interfering RNA (siRNA) library targeting host genes that control lipid metabolism and lipid droplet...... formation using cell culture-grown HCV (HCVcc)-infected cells. We selected and characterized the gene encoding stearoyl coenzyme A (CoA) desaturase 1 (SCD1). siRNA-mediated knockdown or pharmacological inhibition of SCD1 abrogated HCV replication in both subgenomic replicon and Jc1-infected cells, while...... exogenous supplementation of either oleate or palmitoleate, products of SCD1 activity, resurrected HCV replication in SCD1 knockdown cells. SCD1 was coimmunoprecipitated with HCV nonstructural proteins and colocalized with both double-stranded RNA (dsRNA) and HCV nonstructural proteins, indicating that SCD1...

  17. Evolution of the insect desaturase gene family with an emphasis on social Hymenoptera.

    Science.gov (United States)

    Helmkampf, Martin; Cash, Elizabeth; Gadau, Jürgen

    2015-02-01

    Desaturase genes are essential for biological processes, including lipid metabolism, cell signaling, and membrane fluidity regulation. Insect desaturases are particularly interesting for their role in chemical communication, and potential contribution to speciation, symbioses, and sociality. Here, we describe the acyl-CoA desaturase gene families of 15 insects, with a focus on social Hymenoptera. Phylogenetic reconstruction revealed that the insect desaturases represent an ancient gene family characterized by eight subfamilies that differ strongly in their degree of conservation and frequency of gene gain and loss. Analyses of genomic organization showed that five of these subfamilies are represented in a highly microsyntenic region conserved across holometabolous insect taxa, indicating an ancestral expansion during early insect evolution. In three subfamilies, ants exhibit particularly large expansions of genes. Despite these expansions, however, selection analyses showed that desaturase genes in all insect lineages are predominantly undergoing strong purifying selection. Finally, for three expanded subfamilies, we show that ants exhibit variation in gene expression between species, and more importantly, between sexes and castes within species. This suggests functional differentiation of these genes and a role in the regulation of reproductive division of labor in ants. The dynamic pattern of gene gain and loss of acyl-CoA desaturases in ants may reflect changes in response to ecological diversification and an increased demand for chemical signal variability. This may provide an example of how gene family expansions can contribute to lineage-specific adaptations through structural and regulatory changes acting in concert to produce new adaptive phenotypes. PMID:25425561

  18. Somatomedin-1 binding protein-3: insulin-like growth factor-1 binding protein-3, insulin-like growth factor-1 carrier protein.

    Science.gov (United States)

    2003-01-01

    Somatomedin-1 binding protein-3 [insulin-like growth factor-1 binding protein-3, SomatoKine] is a recombinant complex of insulin-like growth factor-1 (rhIGF-1) and binding protein-3 (IGFBP-3), which is the major circulating somatomedin (insulin-like growth factor) binding protein; binding protein-3 regulates the delivery of somatomedin-1 to target tissues. Somatomedin-1 binding protein-3 has potential as replacement therapy for somatomedin-1 which may become depleted in indications such as major surgery, organ damage/failure and traumatic injury, resulting in catabolism. It also has potential for the treatment of osteoporosis; diseases associated with protein wasting including chronic renal failure, cachexia and severe trauma; and to attenuate cardiac dysfunction in a variety of disease states, including after severe burn trauma. Combined therapy with somatomedin-1 and somatomedin-1 binding protein-3 would prolong the duration of action of somatomedin-1 and would reduce or eliminate some of the undesirable effects associated with somatomedin-1 monotherapy. Somatomedin-1 is usually linked to binding protein-3 in the normal state of the body, and particular proteases clip them apart in response to stresses and release somatomedin-1 as needed. Therefore, somatomedin-1 binding protein-3 is a self-dosing system and SomatoKine would augment the natural supply of these linked compounds. Somatomedin-1 binding protein-3 was developed by Celtrix using its proprietary recombinant protein production technology. Subsequently, Celtrix was acquired by Insmed Pharmaceuticals on June 1 2000. Insmed and Avecia, UK, have signed an agreement for the manufacturing of SomatoKine and its components, IGF-1 and binding protein-3. CGMP clinical production of SomatoKine and its components will be done in Avecia's Advanced Biologics Centre, Billingham, UK, which manufactures recombinant-based medicines and vaccines with a capacity of up to 1000 litres. In 2003, manufacturing of SomatoKine is

  19. Binding of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100) and/or its metabolites to mammalian biliary carrier proteins

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.; Huwe, J.; Hakk, H. [USDA ARS Biosciences Research Lab, Fargo, ND (United States); Low, M.; Rutherford, D. [Concordia College, Moorhead, MN (United States)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in the textile and electronics industries and are globally produced in the range of 150,000 tons annually. Because they are very lipophilic, structurally similar to polychlorinated dibenzo-p-dioxins and biphenyls, environmentally persistent, and display an increasing number of toxicological effects, there is growing concern that this class of compounds may be emerging as a new environmental contaminant. Recent reports have documented their presence in human plasma, milk, and adipose tissue and in aquatic species such as sperm whales, harbor seals, and whitebeaked dolphins. Only a few PBDE congeners are consistently found and reported in the environment, e.g. BDE-47, 99, 100, 153 and 154, and 209. Of this group, only BDE-47 and 99 have been studied in mammals. Halogenated aromatic hydrocarbons can associate with endogenous carrier proteins in the urine and bile of rats, either as the parent or as metabolites. Toxic and non-toxic dioxins, PCB's, and PBDE's all have this capacity. Based on its lipophilicity, BDE-100 would be expected to require carrier proteins for mammalian in vivo transport. The purpose of the association has not been established but may be part of the process involved in mammalian elimination of these xenobiotics. However, the association may affect the normal function of these carrier proteins. One of the purposes of the present research was to administer a single oral dose of BDE-100 to male rats and measure the amount eliminated in the urine and bile, as well as characterize the nature and extent of binding to any proteins in these excreta.

  20. Radionuclide carriers

    International Nuclear Information System (INIS)

    A new carrier for radionuclide technetium 99m has been prepared for scintiscanning purposes. The new preparate consists of physiologically acceptable water-insoluble Tcsup(99m)-carrier containing from 0.2 to 0.8 weight percent of stannic ion as reductor, bound to an anionic starch derivative with about 1-20% of phosphate substituents. (EG)

  1. Inhibition of dihydroceramide desaturase activity by the sphingosine kinase inhibitor SKI II.

    Science.gov (United States)

    Cingolani, Francesca; Casasampere, Mireia; Sanllehí, Pol; Casas, Josefina; Bujons, Jordi; Fabrias, Gemma

    2014-08-01

    Sphingosine kinase inhibitor (SKI) II has been reported as a dual inhibitor of sphingosine kinases (SKs) 1 and 2 and has been extensively used to prove the involvement of SKs and sphingosine-1-phosphate (S1P) in cellular processes. Dihydroceramide desaturase (Des1), the last enzyme in the de novo synthesis of ceramide (Cer), regulates the balance between dihydroceramides (dhCers) and Cers. Both SKs and Des1 have interest as therapeutic targets. Here we show that SKI II is a noncompetitive inhibitor (Ki = 0.3 μM) of Des1 activity with effect also in intact cells without modifying Des1 protein levels. Molecular modeling studies support that the SKI II-induced decrease in Des1 activity could result from inhibition of NADH-cytochrome b5 reductase. SKI II, but not the SK1-specific inhibitor PF-543, provoked a remarkable accumulation of dhCers and their metabolites, while both SKI II and PF-543 reduced S1P to almost undetectable levels. SKI II, but not PF543, reduced cell proliferation with accumulation of cells in the G0/G1 phase. SKI II, but not PF543, induced autophagy. These overall findings should be taken into account when using SKI II as a pharmacological tool, as some of the effects attributed to decreased S1P may actually be caused by augmented dhCers and/or their metabolites.

  2. Structural Characterisation of the Beta-Ketoacyl-Acyl Carrier Protein Synthases, FabF and FabH, of Yersinia pestis

    OpenAIRE

    Jeffrey D. Nanson; Himiari, Zainab; Swarbrick, Crystall M. D.; Forwood, Jade K.

    2015-01-01

    Yersinia pestis, the causative agent of bubonic, pneumonic, and septicaemic plague, remains a major public health threat, with outbreaks of disease occurring in China, Madagascar, and Peru in the last five years. The existence of multidrug resistant Y. pestis and the potential of this bacterium as a bioterrorism agent illustrates the need for new antimicrobials. The β-ketoacyl-acyl carrier protein synthases, FabB, FabF, and FabH, catalyse the elongation of fatty acids as part of the type II f...

  3. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    in Asia and will balance the carrier acquisitions of the United States, the United Kingdom, Russia and India. China’s current military strategy is predominantly defensive, its offensive elements being mainly focused on Taiwan. If China decides to acquire a large carrier with offensive capabilities......, then the country will also acquire the capability to project military power into the region beyond Taiwan, which it does not possess today. In this way, China will have the military capability to permit a change of strategy from the mainly defensive, mainland, Taiwan-based strategy to a more assertive strategy...... to acquire a carrier, they can either buy one or build it themselves. The easiest way would be to buy a carrier, and if that is the chosen option, then Russia would be the most likely country to build it. Technologically, it will be a major challenge for them to build one themselves and it is likely...

  4. Evidence that the Yeast Desaturase Ole1p Exists as a Dimer In Vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Y.; Shanklin, J.

    2010-06-18

    Desaturase enzymes are composed of two classes, the structurally well characterized soluble class found predominantly in the plastids of higher plants and the more widely distributed but poorly structurally defined integral membrane class. Despite their distinct evolutionary origins, the two classes both require an iron cofactor and molecular oxygen for activity and are inhibited by azide and cyanide, suggesting strong mechanistic similarities. The fact that the soluble desaturase is active as a homodimer prompted us test the hypothesis that an archetypal integral membrane desaturase from Saccharomyces cerevisiae, the {Delta}{sup o}-acyl-Co-A desaturase Ole1p, also exhibits a dimeric organization. Ole1p was chosen because it is one of the best characterized integral membrane desaturase and because it retains activity when fused with epitope tags. FLAG-Ole1p was detected by Western blotting of immunoprecipitates in which anti-Myc antibodies were used for capture from yeast extracts co-expressing Ole1p-Myc and Ole1p-FLAG. Interaction was confirmed by two independent bimolecular complementation assays (i.e. the split ubiquitin system and the split luciferase system). Co-expression of active and inactive Ole1p subunits resulted in an {approx}75% suppression of the accumulation of palmitoleic acid, demonstrating that the physiologically active form of Ole1p in vivo is the dimer in which both protomers must be functional.

  5. Crystallization and preliminary X-ray crystallographic studies of a new class of enoyl-(acyl-carrier protein) reductase, FabV, from Vibrio fischeri

    International Nuclear Information System (INIS)

    An orthorhombic crystal of an enoyl-(acyl-carrier protein) reductase from V. fischeri was obtained and diffraction data were collected to 2.7 Å resolution. Enoyl-(acyl-carrier protein) reductase (ENR) catalyzes the last step of the fatty-acid elongation cycle of the bacterial fatty-acid biosynthesis (FAS II) pathway. Recently, a new class of ENR has been identified from Vibrio cholerae and was named FabV. In order to understand the molecular mechanism of the new class of ENR at the structural level, FabV from V. fischeri was overexpressed, purified and crystallized. Diffraction data were collected to 2.7 Å resolution from a native crystal. The crystal belonged to the orthorhombic space group P21212, with unit-cell parameters a = 123.53, b = 164.14, c = 97.07 Å. The presence of four molecules of FabV in the asymmetric unit gave a VM value of 2.81 Å3 Da−1, with a corresponding solvent content of 54.5%

  6. Staphylococcus aureus mutants lacking cell wall-bound protein A found in isolates from bacteraemia, MRSA infection and a healthy nasal carrier.

    Science.gov (United States)

    Sørum, Marit; Sangvik, Maria; Stegger, Marc; Olsen, Renate S; Johannessen, Mona; Skov, Robert; Sollid, Johanna U E

    2013-02-01

    Staphylococcus aureus is a major human pathogen and a multitude of virulence factors enables it to cause infections, from superficial lesions to life-threatening systemic conditions. Staphylococcal protein A (SpA) is a surface protein contributing to S. aureus pathogenesis by interfering with immune responses and activating inflammation. Seven isolates with frameshift mutations in the spa repeat region were investigated to determine whether these mutations lead to truncation and secretion of SpA into the extracellular environment. Five isolates originated from blood cultures, one from an MRSA infection and one from a persistent nasal carrier. Full-length spa genes from the seven isolates were sequenced, and Western blot experiments were performed to localize SpA. Three isolates had identical deviating 25-bp spa repeats, but all isolates displayed different repeat successions. The DNA sequence revealed that the frameshift mutations created premature stop codons in all seven isolates, resulting in truncated SpA of different lengths, however, all lacking the XC region with the C-terminal sorting signal. SpA was detected by Western blot in six of the seven isolates, mainly extracellularly. Our findings demonstrate that S. aureus isolates with truncated SpA, not anchored to the cell wall, can still be found in bacteraemia, infection and among carriers.

  7. Regiospecific chlorination of (S)-beta-tyrosyl-S-carrier protein catalyzed by SgcC3 in the biosynthesis of the enediyne antitumor antibiotic C-1027.

    Science.gov (United States)

    Lin, Shuangjun; Van Lanen, Steven G; Shen, Ben

    2007-10-17

    C-1027 is a potent antitumor antibiotic composed of an apo-protein and a reactive enediyne chromophore. The chromophore consists of four different chemical subunits including an (S)-3-chloro-4,5-dihydroxy-beta-phenylalanine moiety, the biosynthesis of which from l-alpha-tyrosine is catalyzed by six proteins, SgcC, SgcC1, SgcC2, SgcC3, SgcC4, and SgcC5. Biochemical characterization of SgcC3 unveiled the following: (i) SgcC3 is a flavin adenine dinucleotide (FAD)-dependent halogenase; (ii) SgcC3 acts only on the SgcC2 peptidyl carrier protein-tethered substrates; (iii) SgcC3-catalyzed halogenation requires O2 and reduced FAD and either the C-1027 pathway-specific flavin reductase SgcE6 or E. coli flavin reductase (Fre) can support the SgcC3 activity; (iv) SgcC3 also efficiently catalyzes bromination but not fluorination or iodination; (v) SgcC3 can utilize both (S)- and (R)-beta-tyrosyl-S-SgcC2 but not 3-hydroxy-beta-tyrosyl-S-SgcC2 as a substrate. These results establish that SgcC3 catalyzes the third enzymatic transformation during the biosynthesis of the (S)-3-chloro-4,5-dihydroxy-beta-phenylalanine moiety of C-1027 from l-alpha-tyrosine. SgcC3 now represents the second biochemically characterized flavin-dependent halogenase that acts on a carrier protein-tethered substrate. These findings will facilitate the engineering of new C-1027 analogs by combinatorial biosynthesis methods. PMID:17887753

  8. Cloning and functional characterization of Δ6 fatty acid desaturase (FADS2) in Eurasian perch (Perca fluviatilis).

    Science.gov (United States)

    Geay, F; Tinti, E; Mellery, J; Michaux, C; Larondelle, Y; Perpète, E; Kestemont, P

    2016-01-01

    The Eurasian perch (Perca fluviatilis) is a freshwater carnivorous species of high interest to diversify inland aquaculture. However, little is known about its ability to bioconvert polyunsaturated fatty acids (PUFAs) from plant oils into long chain polyunsaturated fatty acids (LC-PUFAs). In this study, special attention has been given to the fatty acid desaturase 2 (FADS2) which is commonly described to be a rate-limiting enzyme of the LC-PUFA biosynthesis. This work reports on the cloning, tissue expression and functional characterization of the Eurasian perch fads2, but also on the cloning of two alternative splicing transcripts named fads2-AS1 and fads2-AS2. The fads2 cDNA cloned is composed of an open reading frame (ORF) of 1338 nucleotides (nt) and encodes a protein of 445 amino acids. This deduced amino acid sequence displays the typical structure of microsomal FADS2 including two transmembrane domains and an N-terminal cytochrome b5 domain with the "HPGG" motif. Quantitative real-time PCR assay of fads2, fads2-AS1 and fads2-AS2 expressions revealed that the fads2 transcript was mainly expressed in the liver and intestine and exhibited a typical gene expression pattern of freshwater species while fads2-AS1 and fads2-AS2 genes were highly expressed in the brain, followed by the liver and intestine. Functional characterization of Eurasian perch FADS2 in transgenic yeast showed a fully functional Δ6 desaturation activity toward C18 PUFA substrates, without residual Δ5 and Δ8 desaturase activities.

  9. Cloning, functional characterization and nutritional regulation of Δ6 fatty acyl desaturase in the herbivorous euryhaline teleost Scatophagus argus.

    Science.gov (United States)

    Xie, Dizhi; Chen, Fang; Lin, Siyuan; Wang, Shuqi; You, Cuihong; Monroig, Óscar; Tocher, Douglas R; Li, Yuanyou

    2014-01-01

    Marine fish are generally unable or have low ability for the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA) from C18 PUFA precursors, with some notable exceptions including the herbivorous marine teleost Siganus canaliculatus in which such a capability was recently demonstrated. To determine whether this is a unique feature of S. canaliculatus or whether it is common to the herbivorous marine teleosts, LC-PUFA biosynthetic pathways were investigated in the herbivorous euryhaline Scatophagus argus. A putative desaturase gene was cloned and functionally characterized, and tissue expression and nutritional regulation were investigated. The full-length cDNA was 1972 bp, containing a 1338 bp open-reading frame encoding a polypeptide of 445 amino acids, which possessed all the characteristic features of fatty acyl desaturase (Fad). Functional characterization by heterologous expression in yeast showed the protein product of the cDNA efficiently converted 18:3n-3 and 18:2n-6 to 18:4n-3 and 18:3n-6, respectively, indicating Δ6 desaturation activity. Quantitative real-time PCR showed that highest Δ6 fad mRNA expression was detected in liver followed by brain, with lower expression in other tissues including intestine, eye, muscle, adipose, heart kidney and gill, and lowest expression in stomach and spleen. The expression of Δ6 fad was significantly affected by dietary lipid and, especially, fatty acid composition, with highest expression of mRNA in liver of fish fed a diet with a ratio of 18:3n-3/18:2n-6 of 1.72:1. The results indicated that S. argus may have a different LC-PUFA biosynthetic system from S. canaliculatus despite possessing similar habitats and feeding habits suggesting that LC-PUFA biosynthesis may not be common to all marine herbivorous teleosts.

  10. Stearoyl-CoA desaturase is an essential enzyme for the parasitic protist Trypanosoma brucei

    Energy Technology Data Exchange (ETDEWEB)

    Alloatti, Andres [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina); Gupta, Shreedhara; Gualdron-Lopez, Melisa; Nguewa, Paul A. [Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Universite Catholique de Louvain, Brussels (Belgium); Altabe, Silvia G. [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina); Deumer, Gladys; Wallemacq, Pierre [Department of Clinical Chemistry, Cliniques Universitaires Saint-Luc, LTAP, Universite Catholique de Louvain, Brussels (Belgium); Michels, Paul A.M. [Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Universite Catholique de Louvain, Brussels (Belgium); Uttaro, Antonio D., E-mail: toniuttaro@yahoo.com.ar [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina)

    2011-08-26

    Highlights: {yields} Inhibiting {Delta}9 desaturase drastically changes T. brucei's fatty-acid composition. {yields} Isoxyl specifically inhibits the {Delta}9 desaturase causing a growth arrest. {yields} RNA interference of desaturase expression causes a similar effect. {yields} Feeding T. brucei-infected mice with Isoxyl decreases the parasitemia. {yields} 70% of Isoxyl-treated mice survived the trypanosome infection. -- Abstract: Trypanosoma brucei, the etiologic agent of sleeping sickness, is exposed to important changes in nutrients and temperature during its life cycle. To adapt to these changes, the fluidity of its membranes plays a crucial role. This fluidity, mediated by the fatty-acid composition, is regulated by enzymes named desaturases. We have previously shown that the oleoyl desaturase is essential for Trypanosoma cruzi and T. brucei. In this work, we present experimental support for the relevance of stearoyl-CoA desaturase (SCD) for T. brucei's survival, in both its insect or procyclic-form (PCF) and bloodstream-form (BSF) stages. We evaluated this essentiality in two different ways: by generating a SCD knocked-down parasite line using RNA interference, and by chemical inhibition of the enzyme with two compounds, Isoxyl and a thiastearate with the sulfur atom at position 10 (10-TS). The effective concentration for 50% growth inhibition (EC{sub 50}) of PCF was 1.0 {+-} 0.2 {mu}M for Isoxyl and 5 {+-} 2 {mu}M for 10-TS, whereas BSF appeared more susceptible with EC{sub 50} values 0.10 {+-} 0.03 {mu}M (Isoxyl) and 1.0 {+-} 0.6 {mu}M (10-TS). RNA interference showed to be deleterious for both stages of the parasite. In addition, T. brucei-infected mice were fed with Isoxyl, causing a reduction of the parasitemia and an increase of the rodents' survival.

  11. Isolation and Functional Characterisation of the Genes Encoding △8-Sphingolipid Desaturase from Brassica rapa

    Institute of Scientific and Technical Information of China (English)

    Shu-Fen Li; Li-Ying Song; Wei-Bo Yin; Yu-Hong Chen; Liang Chen; Ji-Lin Li; Richard R.-C. Wang; Zan-Min Hu

    2012-01-01

    △8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants.There have been no previous studies on the genes encoding △8-sphingolipid desaturases in Brassica rapa.In this study,four genes encoding △8-sphingolipid desaturases from B.rapa were isolated and characterised.Phylogenetic analyses indicated that these genes could be divided into two groups:BrD8A,BrD8C and BrD8D in group Ⅰ,and BrD8B in group Ⅱ.The two groups of genes diverged before the separation of Arabidopsis and Brassica.Though the four genes shared a high sequence similarity,and their coding desaturases all located in endoplasmic reticulum,they exhibited distinct expression patterns.Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse △8-sphingolipid desaturases that catalyse different ratios of the two products 8(Z)- and 8(E)-C18-phytosphingenine.The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells.Expression of BrD8A in A rabidopsis changed the ratio of 8(Z):8(E)-C 18-phytosphingenine in transgenic plants.The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of △8-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8(Z)- and 8(E)-C18-phytosphingenine biosynthesis.

  12. The regulation of lipid droplet size and phospholipid composition by stearoyl-CoA desaturase

    DEFF Research Database (Denmark)

    Shi, Xun; Li, Juan; Zou, Xiaoju;

    2013-01-01

    desaturase mutants, independently, and in combination with mutants disrupted in conserved lipid metabolic pathways. C. elegans with impaired SCD activity displayed both reduced fat stores and decreased lipid droplet size. Mutants in the daf-2 (insulin-like growth factor receptor), rsks-1 (homolog of p70S6......Fatty acid desaturation regulates membrane function and fat storage in animals. To determine the contribution of stearoyl-CoA desaturase (SCD) activity on fat storage and development in the nematode Caenorhabditis elegans, we analyzed the lipid composition and lipid droplet size in the fat-6;fat-7...

  13. A Proposed Role for the Azotobacter vinelandii NfuA Protein as an Intermediate Iron-Sulfur Cluster Carrier*

    OpenAIRE

    Bandyopadhyay, Sibali; Naik, Sunil G.; O'Carroll, Ina P.; Huynh, Boi-Hanh; Dean, Dennis R.; Johnson, Michael K.; Dos Santos, Patricia C.

    2008-01-01

    Iron-sulfur clusters ([Fe-S] clusters) are assembled on molecular scaffolds and subsequently used for maturation of proteins that require [Fe-S] clusters for their functions. Previous studies have shown that Azotobacter vinelandii produces at least two [Fe-S] cluster assembly scaffolds: NifU, required for the maturation of nitrogenase, and IscU, required for the general maturation of other [Fe-S] proteins. A. vinelandii also encodes a protein designated NfuA, which shares amino acid sequence ...

  14. Bile salts-containing vesicles: promising pharmaceutical carriers for oral delivery of poorly water-soluble drugs and peptide/protein-based therapeutics or vaccines.

    Science.gov (United States)

    Aburahma, Mona Hassan

    2016-07-01

    Most of the new drugs, biological therapeutics (proteins/peptides) and vaccines have poor performance after oral administration due to poor solubility or degradation in the gastrointestinal tract (GIT). Though, vesicular carriers exemplified by liposomes or niosomes can protect the entrapped agent to a certain extent from degradation. Nevertheless, the harsh GIT environment exemplified by low pH, presence of bile salts and enzymes limits their capabilities by destabilizing them. In response to that, more resistant bile salts-containing vesicles (BS-vesicles) were developed by inclusion of bile salts into lipid bilayers constructs. The effectiveness of orally administrated BS-vesicles in improving the performance of vesicles has been demonstrated in researches. Yet, these attempts did not gain considerable attention. This is the first review that provides a comprehensive overview of utilizing BS-vesicles as a promising pharmaceutical carrier with a special focus on their successful applications in oral delivery of therapeutic macromolecules and vaccines. Insights on the possible mechanisms by which BS-vesicles improve the oral bioavailability of the encapsulated drug or immunological response of entrapped vaccine are explained. In addition, methods adopted to prepare and characterize BS-vesicles are described. Finally, the gap in the scientific researches tackling BS-vesicles that needs to be addressed is highlighted. PMID:25390191

  15. Analysis of the expression pattern of the carrier protein transthyretin and its receptor megalin in the human scalp skin and hair follicles: hair cycle-associated changes.

    Science.gov (United States)

    Adly, Mohamed A

    2010-12-01

    Transthyretin is a serum and cerebrospinal fluid protein synthesized early in development by the liver, choroid plexus and several other tissues. It is a carrier protein for the antioxidant vitamins, retinol, and thyroid hormones. Transthyretin helps internalize thyroxine and retinol-binding protein into cells by binding to megalin, which is a multi-ligand receptor expressed on the luminal surface of various epithelia. We investigated the expression of transthyretin and its receptor megalin in the human skin; however, their expression pattern in the hair follicle is still to be elucidated. This study addresses this issue and tests the hypothesis that "the expression of transthyretin and megalin undergoes hair follicle cycle-dependent changes." A total of 50 normal human scalp skin biopsies were examined (healthy females, 53-62 years) using immunofluorescence staining methods and real-time PCR. In each case, 50 hair follicles were analyzed (35, 10, and 5 follicles in anagen, catagen, and telogen, respectively). Transthyretin and megalin were prominently expressed in the human scalp skin and hair follicles, on both gene and protein levels. The concentrations of transthyretin and megalin were 0.12 and 0.03 Ul/ml, respectively, as indicated by PCR. The expression showed hair follicle cycle-associated changes i.e., strong expression during early and mature anagen, very weak expression during catagen and moderate expression during telogen. The expression values of these proteins in the anagen were statistically significantly higher than those of either catagen or telogen hair follicles (P ≤ 0.001). This study provides the first morphologic indication that transthyretin and megalin are variably expressed in the human scalp skin and hair follicles. It also reports variations in the expression of these proteins during hair follicle cycling. The clinical ramifications of these findings are open for further investigations.

  16. Docking studies of flavonoid compounds as inhibitors of β-ketoacyl acyl carrier protein synthase I (Kas I) of Escherichia coli.

    Science.gov (United States)

    Sabbagh, Ghalia; Berakdar, Noura

    2015-09-01

    Escherichia coli is one of the most frequent causes of many common bacterial infections, including cholecystitis, bacteremia, cholangitis, urinary tract infection (UTI), traveler's diarrhea and other clinical infections such as neonatal meningitis and pneumonia. The fatty acid biosynthesis is essential for the bacterial viability and growth. There are three types of β-ketoacyl acyl carrier protein synthase (KAS) which are important for overcoming the bacterial resistance problem. β-ketoacyl acyl carrier protein synthase I (KAS I) is member of the condensing enzyme family, which is a key catalyst in bacterial fatty acid biosynthesis, and thus an attractive target for novel antibioticsis related to the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and can be a good therapeutic target of designing novel antibiotics. In this report, we performed docking study of E. coli (KAS I) and 50 flavonoids. Out of these 50 flavonoids, there are two compounds, genistein and isorhamnetin, that showed the superior binding energy while fully satisfying the conditions of drug likeliness. The predicted binding energy of genistein and isorhamnetin toward KAS I are -135.76kcal/mol and -132.42kcal/mol, respectively. These energies favorably compare to the biding energy of known drugs thiolactomicin and cerulenin that are -90.26kcal/mol and -99.64kcal/mol, respectively. The method used was docking with the selected E. coli (KAS I-PDB ID-1FJ4) using iGemdock. This was also found to obey the Lipinski's guidelines of five and to show the drug likeliness and bioavailability. PMID:26292066

  17. Solution structure of the tandem acyl carrier protein domains from a polyunsaturated fatty acid synthase reveals beads-on-a-string configuration.

    Directory of Open Access Journals (Sweden)

    Uldaeliz Trujillo

    Full Text Available The polyunsaturated fatty acid (PUFA synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect and in structural stabilization of the multidomain protein (synergistic effect. While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of

  18. Solution Structure of the Tandem Acyl Carrier Protein Domains from a Polyunsaturated Fatty Acid Synthase Reveals Beads-on-a-String Configuration

    KAUST Repository

    Trujillo, Uldaeliz

    2013-02-28

    The polyunsaturated fatty acid (PUFA) synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP) domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect) and in structural stabilization of the multidomain protein (synergistic effect). While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS) revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of multiple ACP

  19. Lysine63-linked ubiquitylation of PIN2 auxin carrier protein governs hormonally controlled adaptation of Arabidopsis root growth.

    Science.gov (United States)

    Leitner, Johannes; Petrášek, Jan; Tomanov, Konstantin; Retzer, Katarzyna; Pařezová, Markéta; Korbei, Barbara; Bachmair, Andreas; Zažímalová, Eva; Luschnig, Christian

    2012-05-22

    Cross-talk between plant cells and their surroundings requires tight regulation of information exchange at the plasma membrane (PM), which involves dynamic adjustments of PM protein localization and turnover to modulate signal perception and solute transport at the interface between cells and their surroundings. In animals and fungi, turnover of PM proteins is controlled by reversible ubiquitylation, which signals endocytosis and delivery to the cell's lytic compartment, and there is emerging evidence for related mechanisms in plants. Here, we describe the fate of Arabidopsis PIN2 protein, required for directional cellular efflux of the phytohormone auxin, and identify cis- and trans-acting mediators of PIN2 ubiquitylation. We demonstrate that ubiquitin acts as a principal signal for PM protein endocytosis in plants and reveal dynamic adjustments in PIN2 ubiquitylation coinciding with variations in vacuolar targeting and proteolytic turnover. We show that control of PIN2 proteolytic turnover via its ubiquitylation status is of significant importance for auxin distribution in root meristems and for environmentally controlled adaptations of root growth. Moreover, we provide experimental evidence indicating that PIN2 vacuolar sorting depends on modification specifically by lysine(63)-linked ubiquitin chains. Collectively, our results establish lysine(63)-linked PM cargo ubiquitylation as a regulator of polar auxin transport and adaptive growth responses in higher plants.

  20. Inventory of Fatty Acid Desaturases in the Pennate Diatom Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    Lina-Juana Dolch

    2015-03-01

    Full Text Available The diatom Phaeodactylum is rich in very long chain polyunsaturated fatty acids (PUFAs. Fatty acid (FA synthesis, elongation, and desaturation have been studied in depth in plants including Arabidopsis, but for secondary endosymbionts the full picture remains unclear. FAs are synthesized up to a chain length of 18 carbons inside chloroplasts, where they can be incorporated into glycerolipids. They are also exported to the ER for phospho- and betaine lipid syntheses. Elongation of FAs up to 22 carbons occurs in the ER. PUFAs can be reimported into plastids to serve as precursors for glycerolipids. In both organelles, FA desaturases are present, introducing double bonds between carbon atoms and giving rise to a variety of molecular species. In addition to the four desaturases characterized in Phaeodactylum (FAD2, FAD6, PtD5, PtD6, we identified eight putative desaturase genes. Combining subcellular localization predictions and comparisons with desaturases from other organisms like Arabidopsis, we propose a scheme at the whole cell level, including features that are likely specific to secondary endosymbionts.

  1. Fatty acid desaturase gene variants, cardiovascular risk factors, and myocardial infarction in the costa rica study

    Science.gov (United States)

    Genetic variation in fatty acid desaturases (FADS) has previously been linked to long-chain polyunsaturated fatty acids (PUFAs) in adipose tissue and cardiovascular risk. The goal of our study was to test associations between six common FADS polymorphisms (rs174556, rs3834458, rs174570, rs2524299, r...

  2. An oleate 12-hydroxylase from Ricinus communis L. is a fatty acyl desaturase homolog

    Energy Technology Data Exchange (ETDEWEB)

    Van De Loo, F.J. [Univ. of Kentucky, Lexington, KY (United States); Broun, P.; Turner, S.; Somerville, C. [Carnegie Institution of Washington, Stanford, CA (United States)

    1995-07-18

    Recent spectroscopic evidence implicating a binuclear iron site at the reaction center of fatty acyl desaturases suggested to us that certain fatty acyl hydroxylases may share significant amino acid sequence similarity with desaturases. To test this theory, we prepared a cDNA library from developing endosperm of the castor-oil plant (Ricinus communis L.) and obtained partial nucleotide sequences for 468 anonymous clones that were not expressed at high levels in leaves, a tissue deficient in 12-hydroxyoleic acid. This resulted in the identification of several cDNA clones encoding a polypeptide of 387 amino acids with a predicted molecular weight of 44,407 and with {approx}67% sequence homology to microsomal oleate desaturase from Arabidopsis. Expression of a full-length clone under control of the cauliflower mosaic virus 35S promoter in transgenic tobacco resulted in the accumulation of low levels of 12-hydroxyoleic acid in seeds, indicating that the clone encodes the castor oleate hydroxylase. These results suggest that fatty acyl desaturases and hydroxylases share similar reaction mechanisms and provide an example of enzyme evolution. 26 refs., 6 figs., 1 tab.

  3. A single desaturase gene from red yeast Sporidiobolus pararoseus is responsible for both four- and five-step dehydrogenation of phytoene.

    Science.gov (United States)

    Li, Chunji; Zhang, Ning; Song, Jia; Wei, Na; Li, Bingxue; Zou, Hongtao; Han, Xiaori

    2016-09-15

    Carotenoids are one of the most common classes of natural pigments widely occurring within organisms. These structurally diverse pigments are of great importance in different processes such as nutrition, vision, cellular growth and development. While found in various yeast strains, one of the best-studied carotenoid producer is the pigmented species Sporidiobolus pararoseus. However, the precise nature of the genes involved in the biosynthesis of carotenoids in this species remains unclear. Here, we cloned a cDNA copy of the phytoene desaturase gene crtI from Sporidiobolus pararoseus CGMCC 2.5280. The crtI full-length genomic DNA and cDNA are 2330bp and 1683bp, respectively. This gene encodes a 560-amino acid protein with a predicted molecular mass of 62.28 kDa and a pI of 7.27. Functional identification of the gene was performed using heterologous complementation detection in Escherichia coli. Our experimental findings indicate that the enzymatic conversion of phytoene to lycopene (fourth step product) and 3,4-didehydrolycopene (fifth step product) is catalyzed by this phytoene desaturase of S. pararoseus through consecutive dehydrogenation. Furthermore, our findings suggest that the crtI gene of S. pararoseus represents an alternative gene source for the reconstruction of carotenogenic pathways vital for the production of engineered carotenoids. PMID:27346167

  4. Disrupting the Acyl Carrier Protein/SpoT interaction in vivo: identification of ACP residues involved in the interaction and consequence on growth.

    Directory of Open Access Journals (Sweden)

    Sandra Angelini

    Full Text Available In bacteria, Acyl Carrier Protein (ACP is the central cofactor for fatty acid biosynthesis. It carries the acyl chain in elongation and must therefore interact successively with all the enzymes of this pathway. Yet, ACP also interacts with proteins of diverse unrelated function. Among them, the interaction with SpoT has been proposed to be involved in regulating ppGpp levels in the cell in response to fatty acid synthesis inhibition. In order to better understand this mechanism, we screened for ACP mutants unable to interact with SpoT in vivo by bacterial two-hybrid, but still functional for fatty acid synthesis. The position of the selected mutations indicated that the helix II of ACP is responsible for the interaction with SpoT. This suggested a mechanism of recognition similar to one used for the enzymes of fatty acid synthesis. Consistently, the interactions tested by bacterial two-hybrid of ACP with fatty acid synthesis enzymes were also affected by the mutations that prevented the interaction with SpoT. Yet, interestingly, the corresponding mutant strains were viable, and the phenotypes of one mutant suggested a defect in growth regulation.

  5. Preconception Carrier Screening

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Preconception Carrier Screening Home For Patients Search FAQs Preconception Carrier Screening ... Screening FAQ179, August 2012 PDF Format Preconception Carrier Screening Pregnancy What is preconception carrier screening? What is ...

  6. Changes in blood levels of proteinase inhibitors, pregnancy zone protein, steroid carriers and complement factors induced by oral contraceptives

    DEFF Research Database (Denmark)

    Nielsen, C H; Poulsen, H K; Teisner, B;

    1993-01-01

    levels of antithrombin III (AT III), alpha 2-macroglobulin (alpha 2M) alpha 1-antitrypsin (alpha 1at), complement factors (factor B, C3, C4), pregnancy zone protein (PZP), corticosteroid binding globulin (CBG), sex hormone binding globulin (SHBG) and albumin were measured before treatment and during...... the first and third treatment cycles. AT III levels decreased and alpha 1at levels increased in all three groups during treatment. alpha 2M increased during cycle 3 in the Trinordiol and Gynatrol groups. CBG, PZP and SHBG levels increased in all 3 groups, the CBG and PZP increase being higher...... in the Marvelon group than in the Gynatrol group. Increases in SHBG levels were found in the order Marvelon > Trinordiol > Gynatrol. Plasma levels of complement factors B, C3 and C4 remained unchanged. It is concluded that the increase in alpha 1at partly compensates for the fall in AT III, that the rise in PZP...

  7. Characterization of SLCO5A1/OATP5A1, a solute carrier transport protein with non-classical function.

    Directory of Open Access Journals (Sweden)

    Katrin Sebastian

    Full Text Available Organic anion transporting polypeptides (OATP/SLCO have been identified to mediate the uptake of a broad range of mainly amphipathic molecules. Human OATP5A1 was found to be expressed in the epithelium of many cancerous and non-cancerous tissues throughout the body but protein characterization and functional analysis have not yet been performed. This study focused on the biochemical characterization of OATP5A1 using Xenopus laevis oocytes and Flp-In T-REx-HeLa cells providing evidence regarding a possible OATP5A1 function. SLCO5A1 is highly expressed in mature dendritic cells compared to immature dendritic cells (∼6.5-fold and SLCO5A1 expression correlates with the differentiation status of primary blood cells. A core- and complex- N-glycosylated polypeptide monomer of ∼105 kDa and ∼130 kDa could be localized in intracellular membranes and on the plasma membrane, respectively. Inducible expression of SLCO5A1 in HeLa cells led to an inhibitory effect of ∼20% after 96 h on cell proliferation. Gene expression profiling with these cells identified immunologically relevant genes (e.g. CCL20 and genes implicated in developmental processes (e.g. TGM2. A single nucleotide polymorphism leading to the exchange of amino acid 33 (L→F revealed no differences regarding protein expression and function. In conclusion, we provide evidence that OATP5A1 might be a non-classical OATP family member which is involved in biological processes that require the reorganization of the cell shape, such as differentiation and migration.

  8. Polymorphisms in Fatty Acid Desaturase (FADS Gene Cluster: Effects on Glycemic Controls Following an Omega-3 Polyunsaturated Fatty Acids (PUFA Supplementation

    Directory of Open Access Journals (Sweden)

    Patrick Couture

    2013-09-01

    Full Text Available Changes in desaturase activity are associated with insulin sensitivity and may be associated with type 2 diabetes mellitus (T2DM. Polymorphisms (SNPs in the fatty acid desaturase (FADS gene cluster have been associated with the homeostasis model assessment of insulin sensitivity (HOMA-IS and serum fatty acid composition. Objective: To investigate whether common genetic variations in the FADS gene cluster influence fasting glucose (FG and fasting insulin (FI responses following a 6-week n-3 polyunsaturated fatty acids (PUFA supplementation. Methods: 210 subjects completed a 2-week run-in period followed by a 6-week supplementation with 5 g/d of fish oil (providing 1.9 g–2.2 g of EPA + 1.1 g of DHA. Genotyping of 18 SNPs of the FADS gene cluster covering 90% of all common genetic variations (minor allele frequency ≥ 0.03 was performed. Results: Carriers of the minor allele for rs482548 (FADS2 had increased plasma FG levels after the n-3 PUFA supplementation in a model adjusted for FG levels at baseline, age, sex, and BMI. A significant genotype*supplementation interaction effect on FG levels was observed for rs482548 (p = 0.008. For FI levels, a genotype effect was observed with one SNP (rs174456. For HOMA-IS, several genotype*supplementation interaction effects were observed for rs7394871, rs174602, rs174570, rs7482316 and rs482548 (p = 0.03, p = 0.01, p = 0.03, p = 0.05 and p = 0.07; respectively. Conclusion: Results suggest that SNPs in the FADS gene cluster may modulate plasma FG, FI and HOMA-IS levels in response to n-3 PUFA supplementation.

  9. Genome-wide screening and transcriptional profile analysis of desaturase genes in the European corn borer moth

    Institute of Scientific and Technical Information of China (English)

    Bingye Xue; Alejandro P. Rooney; Wendell L. Roelofs

    2012-01-01

    Acyl-coenzyme A (Acyl-CoA) desaturases play a key role in the biosynthesis of female moth sex pheromones.Desaturase genes are encoded by a large multigene family,and they have been divided into five subgroups on the basis of biochemical functionality and phylogenetic affinity.In this study both copy numbers and transcriptional levels of desaturase genes in the European corn borer (ECB),Ostrinia nubilalis,were investigated.The results from genome-wide screening of ECB bacterial artificial chromosome (BAC)library indicated there are many copies of some desaturase genes in the genome.An open reading frame (ORF) has been isolated for the novel desaturase gene ECB ezi-△11β from ECB gland complementary DNA and its functionality has been analyzed by two yeast expression systems.No functional activities have been detected for it.The expression levels of the four desaturase genes both in the pheromone gland and fat body of ECB and Asian corn borer (ACB),O.furnacalis,were determined by real-time polymerase chain reaction.In the ECB gland,△ 11 is the most abundant,although the amount of △14 is also considerable.In the ACB gland,△14 is the most abundant and is 100 times more abundant than all the other three combined.The results from the analysis of evolution of desaturase gene transcription in the ECB,ACB and other moths indicate that the pattern of △ 11 gene transcription is significantly different from the transcriptional patterns of other desaturase genes and this difference is tied to the underlying nucleotide composition bias of the genome.

  10. Markers of endogenous desaturase activity and risk of coronary heart disease in the CAREMA cohort study.

    Directory of Open Access Journals (Sweden)

    Yingchang Lu

    Full Text Available BACKGROUND: Intakes of n-3 polyunsaturated fatty acids (PUFAs, especially EPA (C20:5n-3 and DHA (C22:6n-3, are known to prevent fatal coronary heart disease (CHD. The effects of n-6 PUFAs including arachidonic acid (C20:4n-6, however, remain unclear. δ-5 and δ-6 desaturases are rate-limiting enzymes for synthesizing long-chain n-3 and n-6 PUFAs. C20:4n-6 to C20:3n-6 and C18:3n-6 to C18:2n-6 ratios are markers of endogenous δ-5 and δ-6 desaturase activities, but have never been studied in relation to incident CHD. Therefore, the aim of this study was to investigate the relation between these ratios as well as genotypes of FADS1 rs174547 and CHD incidence. METHODS: We applied a case-cohort design within the CAREMA cohort, a large prospective study among the general Dutch population followed up for a median of 12.1 years. Fatty acid profile in plasma cholesteryl esters and FADS1 genotype at baseline were measured in a random subcohort (n = 1323 and incident CHD cases (n = 537. Main outcome measures were hazard ratios (HRs of incident CHD adjusted for major CHD risk factors. RESULTS: The AA genotype of rs174547 was associated with increased plasma levels of C204n-6, C20:5n-3 and C22:6n-3 and increased δ-5 and δ-6 desaturase activities, but not with CHD risk. In multivariable adjusted models, high baseline δ-5 desaturase activity was associated with reduced CHD risk (P for trend = 0.02, especially among those carrying the high desaturase activity genotype (AA: HR (95% CI = 0.35 (0.15-0.81 for comparing the extreme quintiles. High plasma DHA levels were also associated with reduced CHD risk. CONCLUSION: In this prospective cohort study, we observed a reduced CHD risk with an increased C20:4n-6 to C20:3n-6 ratio, suggesting that δ-5 desaturase activity plays a role in CHD etiology. This should be investigated further in other independent studies.

  11. Structure and function of sterol carrier proteins in insects%昆虫固醇转运蛋白的结构与功能

    Institute of Scientific and Technical Information of China (English)

    张丽丽; 郭兴荣; 冯启理; 郑思春

    2011-01-01

    In insects, cholesterol is not only one of the main components of cell membranes, but also a precursor of ecdysone biosynthesis. However, because insects lack two key enzymes for cholesterol biosynthesis, they can not autonomously synthesize cholesterol from simple compounds and therefore have to obtain sterols from their diet. Insects must convert food sterols into cholesterol to meet the requirements of growth, development and reproduction. Sterol carrier proteins (SCPs) are main transport proteins for sterol absorption and transport in insects. It is critical to study the relationship between structure and function of SCPs for understanding the roles of SCPs in sterol transport. In this review, recent progress in the study of the structure, expression and distribution of SCP genes and proteins, post-translation modification, crystal structure, ligand-binding specificity and possible absorption and transport pathways of insect SCPs was summarized and the potential of using SCPs as a molecular target for pest insect control was also discussed.Studies indicate that transcript expression of SCP genes and post-translation modifications of SCP proteins vary depending on different species. In dipteran insects such as Aedes aegypti and Drosophila melangoster SCP-x gene encodes SCP-x and SCP-2 proteins, while there are additional SCP-2 genes and SCP-2-1ike genes encoding SCP-2 and SCP-2-1ike proteins, respectively. In lepidopteran insects such as Spodoptera littoralis,Spodoptera litura and Bombyx mori, the transcript expression and translation processes of SCP-x gene are similar to those in vertebrates, in which SCP-2 protein is produced after post transcription and translation modifications of a unique SCP-x gene. SCP-x and SCP-2 proteins are localized in peroxisomes. SCP-2 protein consists of 5 αt-helixes and 5 β-sheets and the αS-helix appears to impact the binding of the protein to substrates. SCP-2 protein can bind with different affinity to cholesterol

  12. Intestinal solute carriers

    DEFF Research Database (Denmark)

    Steffansen, Bente; Nielsen, Carsten Uhd; Brodin, Birger;

    2004-01-01

    membrane transporters in the small intestine in order to increase oral bioavailabilities of drug or prodrug, the major influence on in vivo pharmacokinetics is suggested to be dose-dependent increase in bioavailability as well as prolonged blood circulation due to large capacity facilitated absorption......A large amount of absorptive intestinal membrane transporters play an important part in absorption and distribution of several nutrients, drugs and prodrugs. The present paper gives a general overview on intestinal solute carriers as well as on trends and strategies for targeting drugs and....../or prodrugs to these carriers in order to increasing oral bioavailability and distribution. A number of absorptive intestinal transporters are described in terms of gene and protein classification, driving forces, substrate specificities and cellular localization. When targeting absorptive large capacity...

  13. Unexpected functional diversity in the fatty acid desaturases of the flour beetle Tribolium castaneum and identification of key residues determining activity.

    Science.gov (United States)

    Haritos, Victoria S; Horne, Irene; Damcevski, Katherine; Glover, Karen; Gibb, Nerida

    2014-08-01

    Desaturases catalyse modifications to fatty acids which are essential to homeostasis and for pheromone and defensive chemical production. All desaturases of the flour beetle Tribolium castaneum were investigated via query of the sequenced genome which yielded 15 putative acyl-Coenzyme A genes. Eleven desaturase mRNA were obtained in full length and functionally expressed in yeast. Phylogenetic analysis separated the desaturases into 4 distinct clades; one clade contained conserved beetle Δ9 desaturases, second clade was Tribolium-specific having diverse activities including Δ5, Δ9 and Δ12 desaturation and the other 2 clades had mixed insect representatives. Three members of this clade contained unusual inserted sequences of ∼20 residues in the C-terminal region and were related to desaturases that all contained similar inserts. Deletion of the entirety of the insert in the flour beetle Δ12 desaturase abolished its activity but this was partially restored by the reintroduction of two histidine residues, suggesting the histidine(s) are required for activity but the full length insert is not. Five new desaturase activities were discovered: Δ9 desaturation of C12:0-C16:0 substrates; two unprecedented Δ5 enzymes acting on C18:0 and C16:0; Δ9 activity exclusively on C16:0 and a further stearate Δ9 desaturase. qPCR analysis ruled out a role in sex pheromone synthesis for the Δ5 and Δ9/C16:0 desaturases. The flour beetle genome has underpinned an examination of all transcribed desaturases in the organism and revealed a diversity of novel and unusual activities, an improved understanding of the evolutionary relationships among insect desaturases and sequence determinants of activity.

  14. Biomimetic coating of organic polymers with a protein-functionalized layer of calcium phosphate: the surface properties of the carrier influence neither the coating characteristics nor the incorporation mechanism or release kinetics of the protein.

    Science.gov (United States)

    Wu, Gang; Liu, Yuelian; Iizuka, Tateyuki; Hunziker, Ernst B

    2010-12-01

    Polymers that are used in clinical practice as bone-defect-filling materials possess many essential qualities, such as moldability, mechanical strength and biodegradability, but they are neither osteoconductive nor osteoinductive. Osteoconductivity can be conferred by coating the material with a layer of calcium phosphate, which can be rendered osteoinductive by functionalizing it with an osteogenic agent. We wished to ascertain whether the morphological and physicochemical characteristics of unfunctionalized and bovine-serum-albumin (BSA)-functionalized calcium-phosphate coatings were influenced by the surface properties of polymeric carriers. The release kinetics of the protein were also investigated. Two sponge-like materials (Helistat® and Polyactive®) and two fibrous ones (Ethisorb™ and poly[lactic-co-glycolic acid]) were tested. The coating characteristics were evaluated using state-of-the-art methodologies. The release kinetics of BSA were monitored spectrophotometrically. The characteristics of the amorphous and the crystalline phases of the coatings were not influenced by either the surface chemistry or the surface geometry of the underlying polymer. The mechanism whereby BSA was incorporated into the crystalline layer and the rate of release of the truly incorporated depot were likewise unaffected by the nature of the polymeric carrier. Our biomimetic coating technique could be applied to either spongy or fibrous bone-defect-filling organic polymers, with a view to rendering them osteoconductive and osteoinductive.

  15. Enhanced production of branched-chain fatty acids by replacing β-ketoacyl-(acyl-carrier-protein) synthase III (FabH).

    Science.gov (United States)

    Jiang, Wen; Jiang, Yanfang; Bentley, Gayle J; Liu, Di; Xiao, Yi; Zhang, Fuzhong

    2015-08-01

    Branched-chain fatty acids (BCFAs) are important precursors for the production of advanced biofuels with improved cold-flow properties. Previous efforts in engineering type II fatty acid synthase (FAS) for BCFA production suffered from low titers and/or the co-production of a large amount of straight-chain fatty acids (SCFAs), making it nearly impossible for further conversion of BCFAs to branched biofuels. Synthesis of both SCFAs and BCFAs requires FabH, the only β-ketoacyl-(acyl-carrier-protein) synthase in Escherichia coli that catalyzes the initial condensation reaction between malonyl-ACP and a short-chain acyl-CoA. In this study, we demonstrated that replacement of the acetyl-CoA-specific E. coli FabH with a branched-chain-acyl-CoA-specific FabH directed the flux to the synthesis of BCFAs, resulting in a significant enhancement in BCFA titer compared to a strain containing both acetyl-CoA- and branched-chain-acyl-CoA-specific FabHs. We further demonstrated that the composition of BCFAs can be tuned by engineering the upstream pathway to control the supply of different branched-chain acyl-CoAs, leading to the production either even-chain-iso-, odd-chain-iso-, or odd-chain-anteiso-BCFAs separately. Overall, the top-performing strain from this study produced BCFAs at 126 mg/L, comprising 52% of the total free fatty acids. PMID:25788017

  16. Distribution of sterol carrier protein2 (SCP2) in rat tissues and evidence for slow turnover in liver and adrenal cortex

    International Nuclear Information System (INIS)

    Sterol carrier protein2 (SCP2) has been implicated in the regulation of the terminal stages of hepatic cholesterol biosynthesis, and in sterol utilization for adrenal steroid hormone and hepatic bile acid synthesis. In the present studies, a highly sensitive radioimmunoassay, using [125I] SCP2, has been developed. Highest levels of SCP2 were found in rat liver with progressively lower levels in intestinal mucosa, adrenal, kidney, lung and testis. SCP2 levels were low or absent in heart, brain, skeletal muscle and serum. Liver SCP2 was largely (44%) associated with the microsomal fraction, while in adrenal, 46% was associated with mitochondria, a distribution which is consistent with the proposed roles for SCP2 in these tissues. Levels of SCP2 in AS 30D hepatoma cells were only 5% of those in normal liver. In liver there was no indication of diurnal rhythm of SCP2 in the cytosol and only slight variation of the microsomal SCP2 levels. Fasting has only slight effects on SCP2 concentration of rat liver microsomes and cytosol. Neither ACTH nor cycloheximide treatment of rats had a significant effect on SCP2 distribution in the adrenal. In general, these findings indicate that SCP2 has a low turn-over rate

  17. Broad-range and binary-range acyl-acyl-carrier protein thioesterases suggest an alternative mechanism for medium-chain production in seeds.

    Science.gov (United States)

    Voelker, T A; Jones, A; Cranmer, A M; Davies, H M; Knutzon, D S

    1997-06-01

    In the current model of medium-chain (C8-14) fatty acid biosynthesis in seeds, specialized FatB acyl-acyl-carrier-protein (ACP) thioesterases are responsible for the production of medium chains. We have isolated and characterized FatB cDNAs from the maturing seeds of elm (Ulmus americana) and nutmeg (Myristica fragrans), which accumulate predominantly caprate (10:0)- and myristate (14:0)-containing oils, respectively. In neither species were we able to find cDNAs encoding enzymes specialized for these chain lengths. Nutmeg FatB hydrolyses C14-18 substrates in vitro and expression in Brassica napus seeds leads to an oil enriched in C14-18 saturates. Elm FatB1 displays a binary specificity: one activity is centered on 10:0-ACP, and a second is centered on palmitate (16:0)-ACP. After expression in B. napus seeds the oil is enriched in C10-18 saturates, predominantly 16:0, 14:0, and 10:0. The composition of free fatty acids produced by elm FatB1 in Escherichia coli shifts from C14-16 to mostly C8-10 by increasing the rate of chain termination by this enzyme. These results suggest the existence of an alternative mechanism used in the evolution of medium-chain production, a model of which is presented. PMID:9193098

  18. Overexpression of the olive acyl carrier protein gene (OeACP1) produces alterations in fatty acid composition of tobacco leaves.

    Science.gov (United States)

    De Marchis, Francesca; Valeri, Maria Cristina; Pompa, Andrea; Bouveret, Emmanuelle; Alagna, Fiammetta; Grisan, Simone; Stanzione, Vitale; Mariotti, Roberto; Cultrera, Nicolò; Baldoni, Luciana; Bellucci, Michele

    2016-02-01

    Taking into account that fatty acid (FA) biosynthesis plays a crucial role in lipid accumulation in olive (Olea europaea L.) mesocarp, we investigated the effect of olive acyl carrier protein (ACP) on FA composition by overexpressing an olive ACP cDNA in tobacco plants. The OeACP1.1A cDNA was inserted in the nucleus or in the chloroplast DNA of different tobacco plants, resulting in extensive transcription of the transgenes. The transplastomic plants accumulated lower olive ACP levels in comparison to nuclear-transformed plants. Moreover, the phenotype of the former plants was characterized by pale green/white cotyledons with abnormal chloroplasts, delayed germination and reduced growth. We suggest that the transplastomic phenotype was likely caused by inefficient olive ACP mRNA translation in chloroplast stroma. Conversely, total lipids from leaves of nuclear transformants expressing high olive ACP levels showed a significant increase in oleic acid (18:1) and linolenic acid (18:3), and a concomitant significant reduction of hexadecadienoic acid (16:2) and hexadecatrienoic acid (16:3). This implies that in leaves of tobacco transformants, as likely in the mesocarp of olive fruit, olive ACP not only plays a general role in FA synthesis, but seems to be specifically involved in chain length regulation forwarding the elongation to C18 FAs and the subsequent desaturation to 18:1 and 18:3. PMID:26560313

  19. Effect of seafood mediated PCB exposure on desaturase activity and PUFA profile in Faroese septuagenarians

    DEFF Research Database (Denmark)

    Tøttenborg, Sandra Søgaard; Choi, Anna L; Bjerve, Kristian S;

    2015-01-01

    increase in EA was also observed, though only in the third tertile of PCB exposure. Non-linear relationships between the exposure and the desaturase activity were not found. Consuming fish and seafood may not be translated into beneficial fatty acid profiles if the diet simultaneously causes exposure......Polychlorinated biphenyl (PCB) exposure may affect serum concentrations of polyunsaturated fatty acids (PUFAs) by inhibiting desaturases ∆5 and ∆6 that drive their synthesis from precursor fatty acids. Such changes in the composition of fatty acids may affect cardiovascular disease risk, which...... is thought to increase at elevated PCB exposures. This population-based cross-sectional study examined 712 Faroese men and women aged 70-74 years. The serum phospholipid fraction of fasting blood samples was used to determine the PUFA profile, including linoleic acid, dihomo-γ-linolenic acid, arachidonic...

  20. Isolation and Characterization of Phytoene Desaturase cDNA from Stigma of Crocus sativus

    Institute of Scientific and Technical Information of China (English)

    Bai Jie(白洁); Xu Ying; Tang Lin; Zeng Yu; Feng Yun; Wang Shenghua; Chen Fang

    2004-01-01

    Phytoene desaturase (PDS) has recently been identified as an important enzyme in carotenoid biosynthesis pathway. A cDNA clone encoding phytoene desaturase gene is isolated from stigma of saffron (Crocus sativus L.) using RT-PCR technique. Sequence analysis shows 83% similarity to Narcissus pseudonarcissus, 79% to Zea mays, 78% to Arabidopsis thaliana, 77% to Lycopersicon esculentum. A new full-length cDNA is obtained by 5'-RACE and 3' -RACE techniques. The cDNA is 2149bp long with an open reading frame of 1697bp, which encodes a polypeptide of 565 amino acids. Southern analysis shows that the PDS gene is a single copy in saffron. Northern blot analysis shows higher expression level of PDS gene in stigma and anther than in leaves and stem.

  1. Detection of Foot-and-mouth Disease Virus RNA and Capsid Protein in Lymphoid Tissues of Convalescent Pigs Does Not Indicate Existence of a Carrier State.

    Science.gov (United States)

    Stenfeldt, C; Pacheco, J M; Smoliga, G R; Bishop, E; Pauszek, S J; Hartwig, E J; Rodriguez, L L; Arzt, J

    2016-04-01

    A systematic study was performed to investigate the potential of pigs to establish and maintain persistent foot-and-mouth disease virus (FMDV) infection. Infectious virus could not be recovered from sera, oral, nasal or oropharyngeal fluids obtained after resolution of clinical infection with any of five FMDV strains within serotypes A, O and Asia-1. Furthermore, there was no isolation of live virus from tissue samples harvested at 28-100 days post-infection from convalescent pigs recovered from clinical or subclinical FMD. Despite lack of detection of infectious FMDV, there was a high prevalence of FMDV RNA detection in lymph nodes draining lesion sites harvested at 35 days post-infection, with the most frequent detection recorded in popliteal lymph nodes (positive detection in 88% of samples obtained from non-vaccinated pigs). Likewise, at 35 dpi, FMDV capsid antigen was localized within follicles of draining lymph nodes, but without concurrent detection of FMDV non-structural protein. There was a marked decline in the detection of FMDV RNA and antigen in tissue samples by 60 dpi, and no antigen or viral RNA could be detected in samples obtained at 100 dpi. The data presented herein provide the most extensive investigation of FMDV persistence in pigs. The overall conclusion is that domestic pigs are unlikely to be competent long-term carriers of infectious FMDV; however, transient persistence of FMDV protein and RNA in lymphoid tissues is common following clinical or subclinical infection. PMID:24943477

  2. THAP and ATF-2 regulated sterol carrier protein-2 promoter activities in the larval midgut of the yellow fever mosquito, Aedes aegypti.

    Science.gov (United States)

    Peng, Rong; Fu, Qiang; Hong, Huazhu; Schwaegler, Tyler; Lan, Que

    2012-01-01

    Expression of sterol carrier protein-2 (SCP-2) in Aedes aegypti shows a distinct temporal/spatial pattern throughout the life cycle. In order to identify the transcription factors responsible for the larval temporal/spatial regulation of AeSCP-2 transcription, AeSCP-2 promoter activities were studied in vivo via transient transfection of promoter/reporter gene assays. Regulatory sequences upstream -1.3 kb of the transcription start site of AeSCP-2 were found to be critical for the in vivo temporal/spatial promoter activity. Interestingly, the -1.6 kb promoter sequence efficiently drove the larval midgut-specific siRNA expression, indicating that the -1.6 kb upstream sequence is sufficient for temporal/spatial AeSCP-2 transcriptional activity. Four transcription factors were identified in the midgut nuclear extract from feeding larvae via labeled -1.6/-1.3 kb DNA probe pull-down and proteomic analysis. Co-transfection of the promoter/reporter gene with inducible siRNA expression of each transcription factor was performed to confirm the regulatory function of individual transcription factor on AeSCP-2 transcriptional activities in the larval midgut. The results indicate that two of the identified transcription factors, Thanatos-associated protein (THAP) and activating transcription factor-2 (ATF-2), antagonistically control AeSCP-2 transcriptional activity in the midgut of feeding larvae via the regulatory sequences between -1.6 to -1.3 kb 5' upstream of the transcription start site. In vivo expression knockdown of THAP and ATF-2 resulted in significant changes in developmental progression, which may be partially due to their effects on AeSCP-2 expression. PMID:23056538

  3. THAP and ATF-2 regulated sterol carrier protein-2 promoter activities in the larval midgut of the yellow fever mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Rong Peng

    Full Text Available Expression of sterol carrier protein-2 (SCP-2 in Aedes aegypti shows a distinct temporal/spatial pattern throughout the life cycle. In order to identify the transcription factors responsible for the larval temporal/spatial regulation of AeSCP-2 transcription, AeSCP-2 promoter activities were studied in vivo via transient transfection of promoter/reporter gene assays. Regulatory sequences upstream -1.3 kb of the transcription start site of AeSCP-2 were found to be critical for the in vivo temporal/spatial promoter activity. Interestingly, the -1.6 kb promoter sequence efficiently drove the larval midgut-specific siRNA expression, indicating that the -1.6 kb upstream sequence is sufficient for temporal/spatial AeSCP-2 transcriptional activity. Four transcription factors were identified in the midgut nuclear extract from feeding larvae via labeled -1.6/-1.3 kb DNA probe pull-down and proteomic analysis. Co-transfection of the promoter/reporter gene with inducible siRNA expression of each transcription factor was performed to confirm the regulatory function of individual transcription factor on AeSCP-2 transcriptional activities in the larval midgut. The results indicate that two of the identified transcription factors, Thanatos-associated protein (THAP and activating transcription factor-2 (ATF-2, antagonistically control AeSCP-2 transcriptional activity in the midgut of feeding larvae via the regulatory sequences between -1.6 to -1.3 kb 5' upstream of the transcription start site. In vivo expression knockdown of THAP and ATF-2 resulted in significant changes in developmental progression, which may be partially due to their effects on AeSCP-2 expression.

  4. Analysis of Mitochondrial Proteins in the Surviving Myocardium after Ischemia Identifies Mitochondrial Pyruvate Carrier Expression as Possible Mediator of Tissue Viability.

    Science.gov (United States)

    Fernández-Caggiano, Mariana; Prysyazhna, Oleksandra; Barallobre-Barreiro, Javier; CalviñoSantos, Ramón; Aldama López, Guillermo; Generosa Crespo-Leiro, Maria; Eaton, Philip; Doménech, Nieves

    2016-01-01

    The endogenous mechanisms contributing to tissue survival following myocardial infarction are not fully understood. We investigated the alterations in the mitochondrial proteome after ischemia-reperfusion (I/R) and its possible implications on cell survival. Mitochondrial proteomic analysis of cardiac tissue from an in vivo porcine I/R model found that surviving tissue in the peri-infarct border zone showed increased expression of several proteins. Notably, these included subunits of the mitochondrial pyruvate carrier (MPC), namely MPC1 and MPC2. Western blot, immunohistochemistry, and mRNA analysis corroborated the elevated expression of MPC in the surviving tissue. Furthermore, MPC1 and MPC2 protein levels were found to be markedly elevated in the myocardium of ischemic cardiomyopathy patients. These findings led to the hypothesis that increased MPC expression is cardioprotective due to enhancement of mitochondrial pyruvate uptake in the energy-starved heart following I/R. To test this, isolated mouse hearts perfused with a modified Krebs buffer (containing glucose, pyruvate, and octanoate as metabolic substrates) were subjected to I/R with or without the MPC transport inhibitor UK5099. UK5099 increased myocardial infarction and attenuated post-ischemic recovery of left ventricular end-diastolic pressure. However, aerobically perfused control hearts that were exposed to UK5099 did not modulate contractile function, although pyruvate uptake was blocked as evidenced by increased cytosolic lactate and pyruvate levels. Our findings indicate that increased expression of MPC leads to enhanced uptake and utilization of pyruvate during I/R. We propose this as a putative endogenous mechanism that promotes myocardial survival to limit infarct size.

  5. Exploring the potential of the bacterial carotene desaturase CrtI to increase the beta-carotene content in Golden Rice.

    Science.gov (United States)

    Al-Babili, Salim; Hoa, Tran Thi Cuc; Schaub, Patrick

    2006-01-01

    To increase the beta-carotene (provitamin A) content and thus the nutritional value of Golden Rice, the optimization of the enzymes employed, phytoene synthase (PSY) and the Erwinia uredovora carotene desaturase (CrtI), must be considered. CrtI was chosen for this study because this bacterial enzyme, unlike phytoene synthase, was expressed at barely detectable levels in the endosperm of the Golden Rice events investigated. The low protein amounts observed may be caused by either weak cauliflower mosaic virus 35S promoter activity in the endosperm or by inappropriate codon usage. The protein level of CrtI was increased to explore its potential for enhancing the flux of metabolites through the pathway. For this purpose, a synthetic CrtI gene with a codon usage matching that of rice storage proteins was generated. Rice plants were transformed to express the synthetic gene under the control of the endosperm-specific glutelin B1 promoter. In addition, transgenic plants expressing the original bacterial gene were generated, but the endosperm-specific glutelin B1 promoter was employed instead of the cauliflower mosaic virus 35S promoter. Independent of codon optimization, the use of the endosperm-specific promoter resulted in a large increase in bacterial desaturase production in the T(1) rice grains. However, this did not lead to a significant increase in the carotenoid content, suggesting that the bacterial enzyme is sufficiently active in rice endosperm even at very low levels and is not rate-limiting. The endosperm-specific expression of CrtI did not affect the carotenoid pattern in the leaves, which was observed upon its constitutive expression. Therefore, tissue-specific expression of CrtI represents the better option. PMID:16488912

  6. Chimeras of Delta6-fatty acid and Delta8-sphingolipid desaturases.

    Science.gov (United States)

    Libisch, B; Michaelson, L V; Lewis, M J; Shewry, P R; Napier, J A

    2000-12-29

    The Borago officinalis Delta6 fatty acid desaturase (Boofd6) shares 58% identity in its amino acid sequence with Boofd8, a Delta8 sphingolipid desaturase from the same plant species. In order to localise the distinct catalytic properties of Boofd6 and Boofd8 to individual regions within them, a set of chimeras of these two enzymes were constructed and expressed in yeast. Chimera 2 is different from the other chimeras and Boofd6 in that it did not have any detectable desaturase activity on 18 carbon fatty acids. However, it desaturated C16 palmitoleic and C14 myristoleic acid, and the conversion rate for the later one was more than three times higher than that of Boofd6. These results suggest that the predicted membrane helices 1 and 2 of Boofd6 are involved in forming the substrate-binding site. This site appears to place constraints on the chain length of fatty acid substrates, which is similar to hydrophobic substrate binding pockets. PMID:11162428

  7. Cloning and Characterization of the Phytoene Desaturase(pds) Gene-a Key Enzyme for Carotenoids Synthesis in Dunaliella (Chlorophyta)

    Institute of Scientific and Technical Information of China (English)

    SUN Guohua; SUI Zhenghong; ZHANG Xuecheng

    2008-01-01

    The unicellular green alga Dunaliella is outstanding for its ability of massive accumulation of carotenoids. To elucidate the carotenoids synthesis pathway in this alga, phytoene desaturase (pals) gene cDNA together with its DNA sequences were isolated and their structures and functions analyzed. The full-length pds cDNA of 2290 bp (GenBank Accession No. DQ243892) was de- duced from RACE results, including untranslated 21 bp 5'- and 520 bp 3'- flanking regions and an open reading frame of 582 amino acids, coding a protein of 64.196 kDa. The DNA sequence of 2908 bp (GenBank Accession No. DQ845248) including five introns was obtained. The fifth intron was uncompleted and complex, including two bases' perfect repeats (GT)10 and large different-sized repeats within the last 400 bp. The Southern blot hybridization result demonstrated that this gene occurred as a single copy in this species, and the quantitative RT-PCR result showed that the transcription of this gene was constitutive. The evolutional significance ofpds was discussed.

  8. Elevated delta-6 desaturase (FADS2) expression in the postmortem prefrontal cortex of schizophrenic patients: relationship with fatty acid composition.

    Science.gov (United States)

    Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; McNamara, Robert K

    2009-04-01

    Although emerging evidence suggests that schizophrenia (SZ) is associated with peripheral and central polyunsaturated fatty acid (PUFA) deficits, there is currently nothing known about the expression of genes that mediate PUFA biosynthesis in SZ patients. Here we determined Delta5 desaturase (FADS1), Delta6 desaturase (FADS2), elongase (HELO1 [ELOVL5]), peroxisomal (PEX19), and Delta9 desaturase (stearoyl-CoA desaturase, SCD) mRNA expression, and relevant fatty acid product:precursor ratios as estimates of enzyme activities, in the postmortem prefrontal cortex (PFC) of patients with SZ (n=20) and non-psychiatric controls (n=20). After correction for multiple comparisons, FADS2 mRNA expression was significantly greater in SZ patients relative to controls (+36%, p=0.002), and there was a positive trend found for FADS1 (+26%, p=0.15). No differences were found for HELO1 (+10%, p=0.44), PEX19 (+12%, p=0.44), or SCD (-6%, p=0.85). Both male (+34%, p=0.02) and female (+42%, p=0.02) SZ patients exhibited greater FADS2 mRNA expression relative to same-gender controls. Drug-free SZ patients (+37%, p=0.02), and SZ patients treated with typical (+40%, p=0.002) or atypical (+31%, p=0.04) antipsychotics, exhibited greater FADS2 mRNA expression relative to controls. Consistent with increased Delta6 desaturase activity, SZ patients exhibited a greater 20:3/18:2 ratio (+20%, p=0.03) and a positive trend was found for 20:4/18:2 (+13%, p=0.07). These data demonstrate abnormal, potentially compensatory, elevations in Delta6 desaturase (FADS2) expression in the PFC of SZ patients that are independent of gender and antipsychotic medications. Greater Delta6 desaturase expression and activity could have implications for central prostaglandin synthesis and proinflammatory signaling. PMID:19195843

  9. Identification and functional analysis of delta-9 desaturase, a key enzyme in PUFA Synthesis, isolated from the oleaginous diatom Fistulifera.

    Directory of Open Access Journals (Sweden)

    Masaki Muto

    Full Text Available Oleaginous microalgae are one of the promising resource of nonedible biodiesel fuel (BDF feed stock alternatives. Now a challenge task is the decrease of the long-chain polyunsaturated fatty acids (PUFAs content affecting on the BDF oxidative stability by using gene manipulation techniques. However, only the limited knowledge has been available concerning the fatty acid and PUFA synthesis pathways in microalgae. Especially, the function of Δ9 desaturase, which is a key enzyme in PUFA synthesis pathway, has not been determined in diatom. In this study, 4 Δ(9 desaturase genes (fD9desA, fD9desB, fD9desC and fD9desD from the oleaginous diatom Fistulifera were newly isolated and functionally characterized. The putative Δ(9 acyl-CoA desaturases in the endoplasmic reticulum (ER showed 3 histidine clusters that are well-conserved motifs in the typical Δ(9 desaturase. Furthermore, the function of these Δ(9 desaturases was confirmed in the Saccharomyces cerevisiae ole1 gene deletion mutant (Δole1. All the putative Δ(9 acyl-CoA desaturases showed Δ(9 desaturation activity for C16∶0 fatty acids; fD9desA and fD9desB also showed desaturation activity for C18∶0 fatty acids. This study represents the first functional analysis of Δ(9 desaturases from oleaginous microalgae and from diatoms as the first enzyme to introduce a double bond in saturated fatty acids during PUFA synthesis. The findings will provide beneficial insights into applying metabolic engineering processes to suppressing PUFA synthesis in this oleaginous microalgal strain.

  10. 细菌多糖结合疫苗载体蛋白的免疫原性干扰作用%Immune interference of carrier proteins in bacterial glycoconjugate vaccines

    Institute of Scientific and Technical Information of China (English)

    陈琼

    2013-01-01

    细菌多糖蛋白结合疫苗(b型流感嗜血杆菌、脑膜炎奈瑟菌和肺炎链球菌多糖结合疫苗)普遍用于2岁以下婴幼儿免疫.目前该类疫苗广泛使用的蛋白载体有破伤风类毒素(tetanus toxoid,TT)、白喉类毒素(diphtheria toxoid,DT)、CRM197(白喉毒素的一种突变体)和未分型流感嗜血杆菌蛋白D(nontypeable haemophilus influenzae protein D,PD).本文就目前这类疫苗免疫接种中载体特异的T辅助细胞刺激作用、载体诱导的表位抑制作用(carrier-inducedepitopic suppression,CIES)和旁观者干扰效应进行初步探讨.%The development of polysaccharide-protein conjugate vaccines has been instrumental in preventing potentially fatal disease due to Haemophilus influenzae (Hib),Neisseria meningitidis and Streptococcus pneumonioe in infants at ages of less than 2 years.The widely used carrier proteins include tetanus toxoid (TT),diphtheria toxoid (DT),diphtheria toxoid variant CRM197 protein and nontypeable Haemophilus influenzae protein D (PD).The mechanisms of interference on responses to conjugate vaccines,including carrier-specific enhancement of T-cell help,carrier-induced-epitopic suppression (CIES) and bystander interference,are reviewed in this paper.

  11. What Is Carrier Screening?

    Science.gov (United States)

    ... you want to learn. Search form Search Carrier screening You are here Home Testing & Services Testing for ... help you make the decision. What Is Carrier Screening? Carrier screening checks if a person is a " ...

  12. Fatty acid biosynthesis in Pseudomonas aeruginosa is initiated by the FabY class of β-ketoacyl acyl carrier protein synthases.

    Science.gov (United States)

    Yuan, Yanqiu; Sachdeva, Meena; Leeds, Jennifer A; Meredith, Timothy C

    2012-10-01

    The prototypical type II fatty acid synthesis (FAS) pathway in bacteria utilizes two distinct classes of β-ketoacyl synthase (KAS) domains to assemble long-chain fatty acids, the KASIII domain for initiation and the KASI/II domain for elongation. The central role of FAS in bacterial viability and virulence has stimulated significant effort toward developing KAS inhibitors, particularly against the KASIII domain of the β-acetoacetyl-acyl carrier protein (ACP) synthase FabH. Herein, we show that the opportunistic pathogen Pseudomonas aeruginosa does not utilize a FabH ortholog but rather a new class of divergent KAS I/II enzymes to initiate the FAS pathway. When a P. aeruginosa cosmid library was used to rescue growth in a fabH downregulated strain of Escherichia coli, a single unannotated open reading frame, PA5174, complemented fabH depletion. While deletion of all four KASIII domain-encoding genes in the same P. aeruginosa strain resulted in a wild-type growth phenotype, deletion of PA5174 alone specifically attenuated growth due to a defect in de novo FAS. Siderophore secretion and quorum-sensing signaling, particularly in the rhl and Pseudomonas quinolone signal (PQS) systems, was significantly muted in the absence of PA5174. The defect could be repaired by intergeneric complementation with E. coli fabH. Characterization of recombinant PA5174 confirmed a preference for short-chain acyl coenzyme A (acyl-CoA) substrates, supporting the identification of PA5174 as the predominant enzyme catalyzing the condensation of acetyl coenzyme A with malonyl-ACP in P. aeruginosa. The identification of the functional role for PA5174 in FAS defines the new FabY class of β-ketoacyl synthase KASI/II domain condensation enzymes.

  13. Crystal structure of enoyl-acyl carrier protein reductase (FabK) from Streptococcus pneumoniae reveals the binding mode of an inhibitor.

    Science.gov (United States)

    Saito, Jun; Yamada, Mototsugu; Watanabe, Takashi; Iida, Maiko; Kitagawa, Hideo; Takahata, Sho; Ozawa, Tomohiro; Takeuchi, Yasuo; Ohsawa, Fukuichi

    2008-04-01

    Enoyl-acyl carrier protein (ACP) reductases are critical for bacterial type II fatty acid biosynthesis and thus are attractive targets for developing novel antibiotics. We determined the crystal structure of enoyl-ACP reductase (FabK) from Streptococcus pneumoniae at 1.7 A resolution. There was one dimer per asymmetric unit. Each subunit formed a triose phosphate isomerase (TIM) barrel structure, and flavin mononucleotide (FMN) was bound as a cofactor in the active site. The overall structure was similar to the enoyl-ACP reductase (ER) of fungal fatty acid synthase and to 2-nitropropane dioxygenase (2-ND) from Pseudomonas aeruginosa, although there were some differences among these structures. We determined the crystal structure of FabK in complex with a phenylimidazole derivative inhibitor to envision the binding site interactions. The crystal structure reveals that the inhibitor binds to a hydrophobic pocket in the active site of FabK, and this is accompanied by induced-fit movements of two loop regions. The thiazole ring and part of the ureido moiety of the inhibitor are involved in a face-to-face pi-pi stacking interaction with the isoalloxazine ring of FMN. The side-chain conformation of the proposed catalytic residue, His144, changes upon complex formation. Lineweaver-Burk plots indicate that the inhibitor binds competitively with respect to NADH, and uncompetitively with respect to crotonoyl coenzyme A. We propose that the primary basis of the inhibitory activity is competition with NADH for binding to FabK, which is the first step of the two-step ping-pong catalytic mechanism. PMID:18305197

  14. Plant sterol metabolism. Δ7-Sterol-C5-Desaturase (STE1/DWARF7), Δ5,7-Sterol-Δ7-Reductase (DWARF5) and Δ24-Sterol-Δ24-Reductase (DIMINUTO/DWARF1) show multiple subcellular localizations in Arabidopsis thaliana (Heynh) L

    DEFF Research Database (Denmark)

    Silvestro, Daniele; Andersen, Tonni Grube; Schaller, Hubert;

    2013-01-01

    to contribute to cellular sterol homeostasis. To further document cellular aspects of sterol biosynthesis in plants, we addressed the question of the subcellular localization of the enzymes implicated in the final steps of the post-squalene biosynthetic pathway. In order to create a clear localization map...... of steroidogenic enzymes in cells, the coding regions of ¿(7)-sterol-C(5)-desaturase (STE1/DWARF7), ¿(24)-sterol-¿(24)-reductase (DIMINUTO/DWARF1) and ¿(5,7)-sterol-¿(7)-reductase (DWARF5) were fused to the yellow fluorescent protein (YFP) and transformed into Arabidopsis thaliana mutant lines deficient...... in the corresponding enzymes. All fusion proteins were found to localize in the endoplasmic reticulum in functionally complemented plants. The results show that both ¿(5,7)-sterol-¿(7)-reductase and ¿(24)-sterol-¿(24)-reductase are in addition localized to the plasma membrane, whereas ¿(7)-sterol-C(5)-desaturase...

  15. Production of γ-linolenic acid and stearidonic acid by Synechococcus sp. PCC7002 containing cyanobacterial fatty acid desaturase genes

    Science.gov (United States)

    Dong, Xuewei; He, Qingfang; Peng, Zhenying; Yu, Jinhui; Bian, Fei; Li, Youzhi; Bi, Yuping

    2016-07-01

    Genetic modification is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be used to modify fatty acid metabolism. Synechococcus sp. PCC7002, a fast-growing cyanobacterium, does not contain a Δ6 desaturase gene and is therefore unable to synthesize γ-linolenic acid (GLA) and stearidonic acid (SDA), which are important in human health. In this work, we constructed recombinant vectors Syd6D, Syd15D and Syd6Dd15D to express the Δ15 desaturase and Δ6 desaturase genes from Synechocystis PCC6803 in Synechococcus sp. PCC7002, with the aim of expressing polyunsaturated fatty acids. Overexpression of the Δ15 desaturase gene in Synechococcus resulted in 5.4 times greater accumulation of α-linolenic acid compared with the wild-type while Δ6 desaturase gene expression produced both GLA and SDA. Co-expression of the two genes resulted in low-level accumulation of GLA but much larger amounts of SDA, accounting for as much to 11.64% of the total fatty acid content.

  16. Does genetic variation in the Δ6-desaturase promoter modify the association between α-linolenic acid and the prevalence of metabolic syndrome?123

    OpenAIRE

    Truong, Hong; DiBello, Julia R; Ruiz-Narvaez, Edward; Kraft, Peter; Campos, Hannia; Baylin, Ana

    2009-01-01

    Background: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with protection against components of the metabolic syndrome, but the role of α-linolenic acid (ALA), the metabolic precursor of EPA and DHA, has not been studied. The Δ6-desaturase enzyme converts ALA into EPA and DHA, and genetic variation in the Δ6-desaturase gene (FADS2) may affect this conversion.

  17. Solution Nuclear Magnetic Resonance Studies of Sterol Carrier Protein 2 Like 2 (SCP2L2) Reveal the Insecticide Specific Structural Characteristics of SCP2 Proteins in Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Singarapu, Kiran Kumar; Ahuja, Ashish; Potula, Purushotam Reddy; Ummanni, Ramesh

    2016-09-01

    Sterol carrier protein 2 like 2 from Aedes aegypti (AeSCP2L2) plays an important role in lipid transport in mosquitoes for its routine metabolic processes. Repeated unsuccessful attempts to crystallize ligand free SCP2L2 prompted us to undertake nuclear magnetic resonance (NMR) spectroscopy to determine its three-dimensional structure. We report here the three-dimensional structures and dynamics of apo-AeSCP2L2 and its complex with palmitate. The (15)N heteronuclear single-quantum coherence spectrum of apo-AeSCP2L2 displayed multiple peaks for some of the amide resonances, implying the presence of multiple conformations in solution, which are transformed to a single conformation upon formation of the complex with plamitate. The three-dimensional structures of apo-AeSCP2L2 and palmitated AeSCP2L2 reveal an α/β mixed fold, with five β-strands and four α-helices, very similar to the other SCP2 protein structures. Unlike the crystal structure of palmitated AeSCP2L2, both solution structures are monomeric. It is further confirmed by the rotational correlation times determined by NMR relaxation times (T1 and T2) of the amide protons. In addition, the palmitated AeSCP2L2 structure contains two palmitate ligands, bound in the binding pocket, unlike the three palmitates bound in the dimeric form of AeSCP2L2 in the crystals. The relaxation experiments revealed that complex formation significantly reduces the dynamics of the protein in solution.

  18. Solution Nuclear Magnetic Resonance Studies of Sterol Carrier Protein 2 Like 2 (SCP2L2) Reveal the Insecticide Specific Structural Characteristics of SCP2 Proteins in Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Singarapu, Kiran Kumar; Ahuja, Ashish; Potula, Purushotam Reddy; Ummanni, Ramesh

    2016-09-01

    Sterol carrier protein 2 like 2 from Aedes aegypti (AeSCP2L2) plays an important role in lipid transport in mosquitoes for its routine metabolic processes. Repeated unsuccessful attempts to crystallize ligand free SCP2L2 prompted us to undertake nuclear magnetic resonance (NMR) spectroscopy to determine its three-dimensional structure. We report here the three-dimensional structures and dynamics of apo-AeSCP2L2 and its complex with palmitate. The (15)N heteronuclear single-quantum coherence spectrum of apo-AeSCP2L2 displayed multiple peaks for some of the amide resonances, implying the presence of multiple conformations in solution, which are transformed to a single conformation upon formation of the complex with plamitate. The three-dimensional structures of apo-AeSCP2L2 and palmitated AeSCP2L2 reveal an α/β mixed fold, with five β-strands and four α-helices, very similar to the other SCP2 protein structures. Unlike the crystal structure of palmitated AeSCP2L2, both solution structures are monomeric. It is further confirmed by the rotational correlation times determined by NMR relaxation times (T1 and T2) of the amide protons. In addition, the palmitated AeSCP2L2 structure contains two palmitate ligands, bound in the binding pocket, unlike the three palmitates bound in the dimeric form of AeSCP2L2 in the crystals. The relaxation experiments revealed that complex formation significantly reduces the dynamics of the protein in solution. PMID:27508310

  19. Fatty acid biosynthesis in eukaryotic photosynthetic microalgae: identification of a microsomal delta 12 desaturase in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Chi, Xiaoyuan; Zhang, Xiaowen; Guan, Xiangyu; Ding, Ling; Li, Youxun; Wang, Mingqing; Lin, Hanzhi; Qin, Song

    2008-04-01

    Polyunsaturated fatty acids (PUFAs) are important components of infant and adult nutrition because they serve as structural elements of cell membranes. Fatty acid desaturases are responsible for the insertion of double bonds into pre-formed fatty acid chains in reactions that require oxygen and reducing equivalents. In this study, the genome-wide characterization of the fatty acid desaturases from seven eukaryotic photosynthetic microalgae was undertaken according to the conserved histidine-rich motifs and phylogenetic profiles. Analysis of these genomes provided insight into the origin and evolution of the pathway of fatty acid biosynthesis in eukaryotic plants. In addition, the candidate enzyme from Chlamydomonas reinhardtii with the highest similarity to the microsomal delta 12 desaturase of Chlorella vulgaris was isolated, and its function was verified by heterologous expression in yeast (Saccharomyces cerevisiae). PMID:18545969

  20. Expression of a cyanobacterial {del}{sup 6}-desaturase gene results in {gamma}-linolenic acid production in transgenic plants

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, A.S.; Thomas, T.L. [Texas A & M Univ., College Station, TX (United States)

    1996-05-01

    Gamma-linolenic acid (GLA), a nutritionally important fatty acid in human and animal diets, is not produced in oil seed crops. Many oil seed plants, however, produce significant quantities of linoleic acid, a fatty acid that could be converted to GLA by the enzyme {del}{sup 6}-desaturase if it were present. As a first step to producing GLA in oil seed crops, we have cloned a cyanobacterial {del}{sup 6}-desaturase gene. Expression of this gene in transgenic tobacco resulted in GLA accumulation. Octadecatetraenoic acid, a highly unsaturated, industrially important fatty acid, was also found in transgenic tobacco plants expressing the cyanobacterial {del}{sup 6}-desaturase. This is the first example of engineering the production of `novel` polyunsaturated fatty acids in transgenic plants. 28 refs., 4 figs., 1 tab.

  1. Plasma fatty acids profile and estimated elongase and desaturases activities in Tunisian patients with the metabolic syndrome.

    Science.gov (United States)

    Sethom, M M; Fares, S; Feki, M; Hadj-Taieb, S; Elasmi, M; Omar, S; Sanhaji, H; Jemaa, R; Kaabachi, N

    2011-01-01

    This study aimed to determine plasma fatty acids pattern and to estimate desaturases activities in Tunisian subjects with metabolic syndrome (MetS). A total of 1975 adults were randomly selected from the Great Tunis region (Tunisia). MetS was defined according to the International Diabetes Federation criteria. Saturated and monounsaturated fatty acids levels and delta 9 desaturase activity were increased, but polyunsaturated fatty acids (PUFA) levels and delta 5 desaturase activity were decreased in patients with MetS. Using multivariate analysis, MetS was found inversely associated with PUFA; compared to first quartile, multi-adjusted odd ratios (95% confidence interval) of MetS were 0.80 (0.54-1.17), 0.47 (0.27-0.81) and 0.32 (0.15-0.68) for second, third and fourth quartiles of PUFA, respectively. Altered fatty acids pattern in MetS is likely related to both dietary and metabolic changes. PMID:21782403

  2. Regulation of growth, fatty acid composition and delta 6 desaturase expression by dietary lipids in gilthead seabream larvae (Sparus aurata).

    Science.gov (United States)

    Izquierdo, M S; Robaina, Lidia; Juárez-Carrillo, Eduardo; Oliva, V; Hernández-Cruz, Carmen María; Afonso, Juan Manuel

    2008-06-01

    The Delta6 and Delta5 desaturases and elongases show only very limited activity in marine fish, and little is known of the possibility of enhancing Delta6 desaturase gene expression in these fish. The use of plant oils in marine fish diets is limited by their lack of n-3 highly unsaturated fatty acids (HUFA) despite an abundant content of the 18C fatty acid precursor linoleic and alpha-linolenic acids. The objective of the present study was to determine the ability of larval gilthead seabream to utilize vegetable oils and assess the nutritional regulation of Delta6 desaturase gene expression. Seventeen-day-old gilthead seabream larvae were fed during a 17-day period with one of four different microdiets formulated with either sardine fish oil (FO), soybean, rapeseed or linseed oils, respectively, or a fifth diet containing defatted squid meal and linseed oil. Good larval survival and growth, both in terms of total length and body weight, were obtained by feeding the larvae either rapeseed, soybean or linseed oils. The presence of vegetable oils in the diet increased the levels of 20:2n-9 and 20:2n-6, 18:2n-9, 18:3n-6, 20:3n-6 and 20:4n-6, in larvae fed rapeseed and soybean oils in comparison to those fed FO. In addition, a sixfold increase in the relative expression of Delta6 desaturase-like gene was found in larvae fed rapeseed and soybean oils, denoting the nutritional regulation of desaturase activity through its gene expression in this fish species. However, feeding linseed oil did not increase the expression of the Delta6 desaturase gene to such a high extent.

  3. Relationship between Body Mass Index, C-Peptide, and Delta-5-Desaturase Enzyme Activity Estimates in Adult Males

    Science.gov (United States)

    Pickens, C. Austin; Matsuo, Karen H.; Fenton, Jenifer I.

    2016-01-01

    Obesity, in particular abdominal obesity, alters the composition of plasma and tissue fatty acids (FAs), which contributes to inflammation and insulin resistance. FA metabolism is modulated by desaturases and may affect adipokine and insulin secretion. Therefore, we examined relationships between adipokines, a marker of insulin production, and plasma FA desaturase enzyme activity estimates (EAEs) in obesity. Plasma phospholipid (PPL) FAs were isolated from 126 males (ages 48 to 65 years), derivatized, and analyzed using gas chromatography. Delta-6 desaturase (D6D) and delta-5 desaturase (D5D) EAEs were calculated as the ratio of PPL 20:3/18:2 and 20:4/20:3, respectively. In body mass index (BMI) and waist circumference (WC) adjusted polytomous logistic regression analyses, PPL FAs and FA desaturase EAEs were associated with C-peptide and adiponectin. Individuals with elevated D6D EAEs were less likely (OR 0.33) to have serum adiponectin concentrations > 5.37 μg/mL, compared with adiponectin concentrations ≤ 3.62 μg/mL. Individuals with increased D5D EAEs were less likely (OR 0.8) to have C-peptide concentrations ≥ 3.32 ng/mL, and > 1.80 and ≤ 3.29 ng/mL, compared with those with C-peptide ≤ 1.76 ng/mL. The proinflammatory cytokine tumor necrosis factor-α (TNF- α) was positively associated with C-peptide, but TNF- α was not associated with the D5D EAE. C-peptide and adiponectin concentrations are associated with specific PPL FAs and FA desaturase EAEs. The relationship between C-peptide concentrations and D5D EAEs remained significant after adjusting for BMI, WC, and TNF-α. Thus, future research should investigate whether D5D inhibition may occur through a C-peptide mediated pathway. PMID:27023786

  4. [Desaturases of fatty acids (FADS) and their physiological and clinical implication].

    Science.gov (United States)

    Žák, Aleš; Slabý, Adolf; Tvrzická, Eva; Jáchymová, Marie; Macášek, Jaroslav; Vecka, Marek; Zeman, Miroslav; Staňková, Barbora

    2016-01-01

    States associated with insulin resistance, as overweight/obesity, type 2 diabetes mellitus (DM2), cardiovascular diseases (CVD), some cancers and neuropsychiatric diseases are characterized with a decrease of long-chain polyunsaturated fatty acids (LC-PUFA) levels. Amounts of LC-PUFA depend on the exogenous intake of their precursors [linoleic (LA) and α-linolenic acid (ALA)] and by rate of their metabolism, which is influenced by activities of enzymes, such as Δ6-desaturase (D6D, FADS2), D5D, FADS1, elongases (Elovl2, -5, 6).Altered activities of D5D/D6D were described in plenty of diseases, e.g. neuropsychiatric (depressive disorders, bipolar disorder, dementia), metabolic (obesity, metabolic syndrome, DM2) and cardiovascular diseases (arterial hypertension, coronary heart disease), inflammatory states and allergy (Crohns disease, atopic eczema) or some malignancies. Similar results were obtained in studies dealing with the associations between genotypes/haplotypes of FADS1/FADS2 and above mentioned diseases, or interactions of dietary intake of LA and ALA on one hand and of the polymorphisms of minor allels of FADS1/FADS2, usually characterized by lower activities, on the other hand.The decrease of the desaturases activities leads to decreased concentrations of products with concomitant increased concentrations of substrates. Associations of some SNP FADS with coronary heart disease, concentrations of plasma lipids, oxidative stress, glucose homeostasis, and inflammatory reaction, were described. Experimental studies on animal models and occurrence of rare diseases, associated with missing or with marked fall activities of D5D/D6D emphasized the significance of desaturases for healthy development of organism as well as for pathogenesis of some disease. PMID:27088787

  5. Maternal fatty acid desaturase genotype correlates with infant immune responses at 6 months

    DEFF Research Database (Denmark)

    Muc, Magdalena; Kreiner-Møller, Eskil; Larsen, Jeppe Madura;

    2015-01-01

    Breast milk long-chain PUFA (LCPUFA) have been associated with changes in early life immune responses and may modulate T-cell function in infancy. We studied the effect of maternal fatty acid desaturase (FADS) genotype and breast milk LCPUFA levels on infants' blood T-cell profiles and ex vivo......) and IL-10 (regulatory immune responses), but not with interferon-γ and TNF-α, which could be due to an effect of the maternal FADS variants on the offspring immune response transferred via breast milk LCPUFA. Copyright © The Authors 2015....

  6. StearoylCoA desaturase-5: a novel regulator of neuronal cell proliferation and differentiation.

    Directory of Open Access Journals (Sweden)

    Debora I Sinner

    Full Text Available Recent studies have demonstrated that human stearoylCoA desaturase-1 (SCD1, a Δ9-desaturase that converts saturated fatty acids (SFA into monounsaturated fatty acids, controls the rate of lipogenesis, cell proliferation and tumorigenic capacity in cancer cells. However, the biological function of stearoylCoA desaturase-5 (SCD5, a second isoform of human SCD that is highly expressed in brain, as well as its potential role in human disease, remains unknown. In this study we report that the constitutive overexpression of human SCD5 in mouse Neuro2a cells, a widely used cell model of neuronal growth and differentiation, displayed a greater n-7 MUFA-to-SFA ratio in cell lipids compared to empty-vector transfected cells (controls. De novo synthesis of phosphatidylcholine and cholesterolesters was increased whereas phosphatidylethanolamine and triacylglycerol formation was reduced in SCD5-expressing cells with respect to their controls, suggesting a differential use of SCD5 products for lipogenic reactions. We also observed that SCD5 expression markedly accelerated the rate of cell proliferation and suppressed the induction of neurite outgrowth, a typical marker of neuronal differentiation, by retinoic acid indicating that the desaturase plays a key role in the mechanisms of cell division and differentiation. Critical signal transduction pathways that are known to modulate these processes, such epidermal growth factor receptor (EGFRAkt/ERK and Wnt, were affected by SCD5 expression. Epidermal growth factor-induced phosphorylation of EGFR, Akt and ERK was markedly blunted in SCD5-expressing cells. Furthermore, the activity of canonical Wnt was reduced whereas the non-canonical Wnt was increased by the presence of SCD5 activity. Finally, SCD5 expression increased the secretion of recombinant Wnt5a, a non-canonical Wnt, whereas it reduced the cellular and secreted levels of canonical Wnt7b. Our data suggest that, by a coordinated modulation of key

  7. [Substrate specificity of carotenoid 3',4'-desaturase from Deinococcus radiodurans].

    Science.gov (United States)

    Sun, Zongtao; Tian, Bing; Shen, Shaochuan; Hu, Yuejin

    2010-10-01

    To examine the substrate specificity of carotenoid 3',4'-desaturase (DR2250) from Deinococcus radiodurans, we amplified the dr2250 gene by using PCR methods. The PCR products were digested by Hind III-BamH I and ligated into the vector pUC19, yielding recombinant vector pUC-CRTD. We analyzed the carotenoids of E. coli transformants containing pACCRT-EBI(Eu) and (or) pRK-CRTC and (or) pUC-CRTD. Our results demonstrated that DR2250 had substrate specificity on the carotenoids with hydroxyl group at C1 (1').

  8. A second gene for acyl-(acyl-carrier-protein): glycerol-3-phosphate acyltransferase in squash, Cucurbita moschata cv. Shirogikuza(*), codes for an oleate-selective isozyme: molecular cloning and protein purification studies.

    Science.gov (United States)

    Nishida, I; Sugiura, M; Enju, A; Nakamura, M

    2000-12-01

    A new isogene for acyl-(acyl-carrier-protein):glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15) in squash has been cloned and the gene product was identified as oleate-selective GPAT. Using PCR primers that could hybridise with exons for a previously cloned squash GPAT, we obtained two PCR products of different size: one coded for a previously cloned squash GPAT corresponding to non-selective isoforms AT2 and AT3, and the other for a new isozyme, probably the oleate-selective isoform AT1. Full-length amino acid sequences of respective isozymes were deduced from the nucleotide sequences of genomic genes and cDNAs, which were cloned by a series of PCR-based methods. Thus, we designated the new gene CmATS1;1 and the other one CmATS1;2. Genome blot analysis revealed that the squash genome contained the two isogenes at non-allelic loci. AT1-active fractions were partially purified, and three polypeptide bands were identified as being AT1 polypeptides, which exhibited relative molecular masses of 39.5-40.5 kDa, pI values of 6.75-7.15, and oleate selectivity over palmitate. Partial amino-terminal sequences obtained from two of these bands verified that the new isogene codes for AT1 polypeptides.

  9. Antisense-Mediated Depletion of Tomato Chloroplast Omega-3 Fatty Acid Desaturase Enhances Thermal Tolerance

    Institute of Scientific and Technical Information of China (English)

    Xun-Yan Liu; Jing-Hua Yang; Bin Li; Xiu-Mei Yang; Qing-Wei Meng

    2006-01-01

    A chloroplast-localized tomato (Lycopersicon esculentum Mill.) ω-3 fatty acid desaturase gene (LeFAD7) was isolated and characterized with regard to its sequence, response to various temperatures, and function in antisense transgenic tomato plants. The deduced amino acid sequence had four histidine-rich regions, of which three regions were highly conserved throughout the whole ω-3 fatty acid desaturase gene family.Southern blotting analysis showed that LeFAD7was encoded by a single copy gene and had two homologous genes in the tomato genome. Northern blot showed that LeFAD7was expressed in all organs and was especially abundant in leaf tissue. Meanwhile, expression of LeFAD7was induced by chilling stress (4 ℃),but was inhibited by high temperature (45 ℃), in leaves. Transgenic tomato plants were produced by integration of the antisense LeFAD7 DNA under the control of a CaMV35S promoter into the genome. Antisense transgenic plants with lower 18: 3 content could maintain a higher maximal photochemical efficiency (Fv/Fm)and O2 evolution rate than wild-type plants. These results suggested that silence of the LeFAD7 gene alleviated high-temperature stress. There was also a correlation between the low content of 18: 3 resulting from silence of the LeFAD7 gene and tolerance to high-temperature stress.

  10. Histidine-41 of the cytochrome b5 domain of the borage delta6 fatty acid desaturase is essential for enzyme activity.

    Science.gov (United States)

    Sayanova, O; Shewry, P R; Napier, J A

    1999-10-01

    Unlike most other plant microsomal desaturases, the Delta6-fatty acid desaturase from borage (Borago officinalis) contains an N-terminal extension that shows homology to the small hemoprotein cytochrome (Cyt) b5. To determine if this domain serves as a functional electron donor for the Delta6-fatty acid desaturase, mutagenesis and functional analysis by expression in transgenic Arabidopsis was carried out. Although expression of the wild-type borage Delta6-fatty acid desaturase resulted in the synthesis and accumulation of Delta6-unsaturated fatty acids, this was not observed in plants transformed with N-terminally deleted forms of the desaturase. Site-directed mutagenesis was used to disrupt one of the axial heme-binding residues (histidine-41) of the Cyt b5 domain; expression of this mutant form of the Delta6-desaturase in transgenic plants failed to produce Delta6-unsaturated fatty acids. These data indicate that the Cyt b5 domain of the borage Delta6-fatty acid desaturase is essential for enzymatic activity. PMID:10517856

  11. Polymorphisms in the fatty acid desaturase genes and diet are important determinants of infant docosahexaenoic acid status

    DEFF Research Database (Denmark)

    Lauritzen, L.; Harsløf, L.; Larsen, L.H.;

    2013-01-01

    Tissue docosahexaenoic acid (DHA) accretion in early infancy is supported by DHA in breast-milk and may thus decrease once complementary feeding takes over. Endogenous synthesis of DHA from alphalinolenic acid is low and polymorphisms in the genes that encodes the fatty acid desaturases (FADS) has...

  12. Dietary whole cottonseed depresses lipogenesis but has no effect on stearoyl coenzyme desaturase activity in bovine subcutaneous adipose tissue.

    Science.gov (United States)

    Page, A M; Sturdivant, C A; Lunt, D K; Smith, S B

    1997-09-01

    The primary objective of this study was to determine the effect of long-term feeding of whole cottonseed (WCS) on lipogenesis and stearoyl-coenzyme A desaturase activity in growing steers. Brangus steers were fed either a control, cornbased diet (n = 11) or 30% WCS (n = 12). The 30% WCS contributed an estimated 6.6% additional lipid to the diet. Steers fed the added WCS had greater live weights (P = 0.04) and kidney, pelvic, and heart fat (P = 0.005). Subcutaneous fat thickness was not different (P = 0.20) between treatment groups, although WCS elicited an increase in the proportion of large diameter subcutaneous adipocytes. The rate of [U-14C]acetate incorporation into fatty acids in subcutaneous adipose tissue was reduced by dietary WCS (171.4 vs 122.1 nmol x 100 mg adipose tissue-1 x 2 hr-1, P = 0.03), indicating that the increased dietary fat depressed de novo lipogenesis. Hepatic desaturase activity was much lower than that of subcutaneous adipose tissue, a feature common to cattle. We anticipated that added WCS also would depress stearoyl-coenzyme A desaturase activity in subcutaneous adipose tissue and liver due to its cyclopropene fatty acid content. Instead, desaturase activity was numerically (although not significantly) greater in liver (P = 0.37) and adipose tissue (P = 0.23). PMID:9417995

  13. Thiolation-enhanced substrate recognition by D-alanyl carrier protein ligase DltA from Bacillus cereus [v1; ref status: indexed, http://f1000r.es/3dx

    Directory of Open Access Journals (Sweden)

    Liqin Du

    2014-05-01

    Full Text Available D-alanylation of the lipoteichoic acid on Gram-positive cell wall is dependent on dlt gene-encoded proteins DltA, DltB, DltC and DltD. The D-alanyl carrier protein ligase DltA, as a remote homolog of acyl-(coenzyme A (CoA synthetase, cycles through two active conformations for the catalysis of adenylation and subsequent thiolation of D-alanine (D-Ala. The crystal structure of DltA in the absence of any substrate was observed to have a noticeably more disordered pocket for ATP which would explain why DltA has relatively low affinity for ATP in the absence of any D-alanyl carrier. We have previously enabled the thiolation of D-alanine in the presence of CoA as the mimic of D-alanyl carrier protein DltC which carries a 4’-phosphopantetheine group on a serine residue. Here we show that the resulting Michaelis constants in the presence of saturating CoA for both ATP and D-alanine were reduced more than 10 fold as compared to the values obtained in the absence of CoA. The presence of CoA also made DltA ~100-fold more selective on D-alanine over L-alanine. The CoA-enhanced substrate recognition further implies that the ATP and D-alanine substrates of the adenylation reaction are incorporated when the DltA enzyme cycles through its thiolation conformation.

  14. Desaturase mutants reveal that membrane rigidification acts as a cold perception mechanism upstream of the diacylglycerol kinase pathway in Arabidopsis cells.

    Science.gov (United States)

    Vaultier, Marie-Noëlle; Cantrel, Catherine; Vergnolle, Chantal; Justin, Anne-Marie; Demandre, Chantal; Benhassaine-Kesri, Ghouziel; Ciçek, Dominique; Zachowski, Alain; Ruelland, Eric

    2006-07-24

    Membrane rigidification could be the first step of cold perception in poikilotherms. We have investigated its implication in diacylglycerol kinase (DAGK) activation by cold stress in suspension cells from Arabidopsis mutants altered in desaturase activities. By lateral diffusion assay, we showed that plasma membrane rigidification with temperature decrease was steeper in cells deficient in oleate desaturase than in wild type cells and in cells overexpressing linoleate desaturase. The threshold for the activation of the DAGK pathway in each type of cells correlated with this order of rigidification rate, suggesting that cold induced-membrane rigidification is upstream of DAGK pathway activation. PMID:16839551

  15. Functional assembly of the foreign carotenoid lycopene into the photosynthetic apparatus of Rhodobacter sphaeroides, achieved by replacement of the native 3-step phytoene desaturase with its 4-step counterpart from Erwinia herbicola.

    Science.gov (United States)

    Garcia-Asua, Guillermo; Cogdell, Richard J; Hunter, C Neil

    2002-04-01

    Photosynthetic organisms synthesize a diverse range of carotenoids. These pigments are important for the assembly, function and stability of photosynthetic pigment-protein complexes, and they are used to quench harmful radicals. The photosynthetic bacterium Rhodobacter sphaeroides was used as a model system to explore the origin of carotenoid diversity. Replacing the native 3-step phytoene desaturase (CrtI) with the 4-step enzyme from Erwinia herbicola results in significant flux down the spirilloxanthin pathway for the first time in Rb. sphaeroides. In Rb. sphaeroides, the completion of four desaturations to lycopene by the Erwinia CrtI appears to require the absence of CrtC and, in a crtC background, even the native 3-step enzyme can synthesize a significant amount (13%) of lycopene, in addition to the expected neurosporene. We suggest that the CrtC hydroxylase can intervene in the sequence of reactions catalyzed by phytoene desaturase. We investigated the properties of the lycopene-synthesizing strain of Rb. sphaeroides. In the LH2 light-harvesting complex, lycopene transfers absorbed light energy to the bacteriochlorophylls with an efficiency of 54%, which compares favourably with other LH2 complexes that contain carotenoids with 11 conjugated double bonds. Thus, lycopene can join the assembly pathway for photosynthetic complexes in Rb. sphaeroides, and can perform its role as an energy donor to bacteriochlorophylls. PMID:11967082

  16. Functional assembly of the foreign carotenoid lycopene into the photosynthetic apparatus of Rhodobacter sphaeroides, achieved by replacement of the native 3-step phytoene desaturase with its 4-step counterpart from Erwinia herbicola.

    Science.gov (United States)

    Garcia-Asua, Guillermo; Cogdell, Richard J; Hunter, C Neil

    2002-04-01

    Photosynthetic organisms synthesize a diverse range of carotenoids. These pigments are important for the assembly, function and stability of photosynthetic pigment-protein complexes, and they are used to quench harmful radicals. The photosynthetic bacterium Rhodobacter sphaeroides was used as a model system to explore the origin of carotenoid diversity. Replacing the native 3-step phytoene desaturase (CrtI) with the 4-step enzyme from Erwinia herbicola results in significant flux down the spirilloxanthin pathway for the first time in Rb. sphaeroides. In Rb. sphaeroides, the completion of four desaturations to lycopene by the Erwinia CrtI appears to require the absence of CrtC and, in a crtC background, even the native 3-step enzyme can synthesize a significant amount (13%) of lycopene, in addition to the expected neurosporene. We suggest that the CrtC hydroxylase can intervene in the sequence of reactions catalyzed by phytoene desaturase. We investigated the properties of the lycopene-synthesizing strain of Rb. sphaeroides. In the LH2 light-harvesting complex, lycopene transfers absorbed light energy to the bacteriochlorophylls with an efficiency of 54%, which compares favourably with other LH2 complexes that contain carotenoids with 11 conjugated double bonds. Thus, lycopene can join the assembly pathway for photosynthetic complexes in Rb. sphaeroides, and can perform its role as an energy donor to bacteriochlorophylls.

  17. Characterization and regulation of the bovine stearoyl-CoA desaturase gene promoter

    International Nuclear Information System (INIS)

    The bovine stearoyl-CoA desaturase (Scd) gene plays an important role in the bovine mammary gland where substrates such as stearic and vaccenic acids are converted to oleic acid and conjugated linoleic acid (CLA), respectively. Up to 90% of the CLA in bovine milk is formed due to the action of this enzyme in the mammary gland. The areas of the bovine promoter of importance in regulating this key enzyme were examined and an area of 36 bp in length was identified as having a critical role in transcriptional activation and is designated the Scd transcriptional enhancer element (STE). Electrophoretic mobility shift assay detected three binding complexes on this area in Mac-T cell nuclear extracts. Treatment of cells with CLA caused a significant reduction in transcriptional activity, with this effect being mediated through the STE region. The bovine Scd gene promoter was up-regulated by insulin and down-regulated by oleic acid

  18. Characterization of the two-component, FAD-dependent monooxygenase SgcC that requires carrier protein-tethered substrates for the biosynthesis of the enediyne antitumor antibiotic C-1027.

    Science.gov (United States)

    Lin, Shuangjun; Van Lanen, Steven G; Shen, Ben

    2008-05-21

    C-1027 is a potent antitumor antibiotic composed of an apoprotein (CagA) and a reactive enediyne chromophore. The chromophore has four distinct chemical moieties, including an ( S)-3-chloro-5-hydroxy-beta-tyrosine moiety, the biosynthesis of which from l-alpha-tyrosine requires five proteins: SgcC, SgcC1, SgcC2, SgcC3, and SgcC4; a sixth protein, SgcC5, catalyzes the incorporation of this beta-amino acid moiety into C-1027. Biochemical characterization of SgcC has now revealed that (i) SgcC is a two-component, flavin adenine dinucleotide (FAD)-dependent monooxygenase, (ii) SgcC is only active with SgcC2 (peptidyl carrier protein)-tethered substrates, (iii) SgcC-catalyzed hydroxylation requires O 2 and FADH 2, the latter supplied by the C-1027 pathway-specific flavin reductase SgcE6 or Escherichia coli flavin reductase Fre, and (iv) SgcC efficiently catalyzes regioselective hydroxylation of 3-substituted beta-tyrosyl-S-SgcC2 analogues, including the chloro-, bromo-, iodo-, fluoro-, and methyl-substituted analogues, but does not accept 3-hydroxy-beta-tyrosyl-S-SgcC2 as a substrate. Together with the in vitro data for SgcC4, SgcC1, and SgcC3, the results establish that SgcC catalyzes the hydroxylation of ( S)-3-chloro-beta-tyrosyl-S-SgcC2 as the final step in the biosynthesis of the ( S)-3-chloro-5-hydroxy-beta-tyrosine moiety prior to incorporation into C-1027. SgcC now represents the first biochemically characterized two-component, FAD-dependent monooxygenase that acts on a carrier-protein-tethered aromatic substrate. PMID:18426211

  19. Cloning and transcriptional analysis of Crepis alpina fatty acid desaturases affecting the biosynthesis of crepenynic acid.

    Science.gov (United States)

    Nam, Jeong-Won; Kappock, T Joseph

    2007-01-01

    Crepis alpina acetylenase is a variant FAD2 desaturase that catalyses the insertion of a triple bond at the Delta12 position of linoleic acid, forming crepenynic acid in developing seeds. Seeds contain a high level of crepenynic acid but other tissues contain none. Using reverse transcriptase-coupled PCR (RT-PCR), acetylenase transcripts were identified in non-seed C. alpina tissues, which were highest in flower heads. To understand why functional expression of the acetylenase is limited to seeds, genes that affect acetylenase activity by providing substrate (FAD2) or electrons (cytochrome b5), or that compete for substrate (FAD3), were cloned. RT-PCR analysis indicated that the availability of a preferred cytochrome b5 isoform is not a limiting factor. Developing seeds co-express acetylenase and FAD2 isoform 2 (FAD2-2) at high levels. Flower heads co-express FAD2-3 and FAD3 at high levels, and FAD2-2 and acetylenase at moderate levels. FAD2-3 was not expressed in developing seed. Real-time RT-PCR absolute transcript quantitation showed 10(4)-fold higher acetylenase expression in developing seeds than in flower heads. Collectively, the results show that both the acetylenase expression level and the co-expression of other desaturases may contribute to the tissue specificity of crepenynate production. Helianthus annuus contains a Delta12 acetylenase in a polyacetylene biosynthetic pathway, so does not accumulate crepenynate. Real-time RT-PCR analysis showed relatively strong acetylenase expression in young sunflowers. Acetylenase transcription is observed in both species without accumulation of the enzymatic product, crepenynate. Functional expression of acetylenase appears to be affected by competition and collaboration with other enzymes. PMID:17329262

  20. On the Structure and Function of the Phytoene Desaturase CRTI from Pantoea ananatis, a Membrane-Peripheral and FAD-Dependent Oxidase/Isomerase

    OpenAIRE

    Schaub, Patrick; Yu, Qiuju; Gemmecker, Sandra; Poussin-Courmontagne, Pierre; Mailliot, Justine; McEwen, Alastair G.; Ghisla, Sandro; Al-Babili, Salim; Cavarelli, Jean; Beyer, Peter

    2012-01-01

    CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with t...

  1. Immune interference on conjugate vaccines by carrier proteins or co-administrated vaccines%载体蛋白及多种疫苗同时接种对结合疫苗的免疫干扰

    Institute of Scientific and Technical Information of China (English)

    朱为

    2012-01-01

    多种多糖-蛋白结合疫苗被开发成功,用于预防b型流感嗜血杆菌、脑膜炎球菌和肺炎链球菌感染,为婴幼儿健康提供了保障.常用的载体蛋白是破伤风类毒素、白喉类毒素和白喉类毒素突变体CRM197.在临床研究中观察到,相同载体或不同载体结合疫苗同时接种,或者与DTP/HBV/IPV等疫苗同时接种时,会干扰对某些抗原的免疫应答,其中可能有多种机制在起作用.随着更多的结合疫苗有望进入婴幼儿期基础免疫程序和无细胞百日咳疫苗(aP)逐渐代替全细胞百日咳疫苗(wP),如何选择合适的或者新的载体蛋白和佐剂、谨慎设计临床研究方案和接种程序等问题日益受到关注.%Polysaccharide-protein conjugate vaccines are developed successfully to prevent Haemophilus influenzae type b,Neisseria meningitidis and Streptococus pnuemoniae infections,especially for infants.The most commonly used carrier proteins are tetanus toxoid,diphtheria toxoid,and diphtheria toxin variant CRM197.In clinical trials,immune interference has been observed when conjugate vaccines with the same or different carrier proteins were co-administrated,or the conjugate vaccines were immunized concurrently with DTP/HBV/IPV.Several mechanisms may work together.As more conjugate vaccines are expected to be included into the childhood primary immunization schedule,and whole cell pertussis vaccine (wP) is replaced by acellular pertussis vaccine (aP) gradually,the problemns,including how to choose suitable carrier proteins and adjuvants,carefully designing the clinical trial and immunization schedule,attract more people's attention.

  2. Preparation and application of magnetic microsphere carriers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; XING Jianmin; LIU Huizhou

    2007-01-01

    Magnetic microsphere carriers have received considerable attention,primarily because of their wide applications in the fields of biomedicine and bioengineering.In this paper,preparation methods,surface modification and application of magnetic carriers are reviewed.Emphasis will be placed on recent biological and biomedical developments and trends such as enzyme immobilization,cell isolation,protein purification,target drugs and DNA separation.

  3. A functional variant in the stearoyl-CoA desaturase gene promoter enhances fatty acid desaturation in pork.

    Directory of Open Access Journals (Sweden)

    Joan Estany

    Full Text Available There is growing public concern about reducing saturated fat intake. Stearoyl-CoA desaturase (SCD is the lipogenic enzyme responsible for the biosynthesis of oleic acid (18 ∶ 1 by desaturating stearic acid (18 ∶ 0. Here we describe a total of 18 mutations in the promoter and 3' non-coding region of the pig SCD gene and provide evidence that allele T at AY487830:g.2228T>C in the promoter region enhances fat desaturation (the ratio 18 ∶ 1/18 ∶ 0 in muscle increases from 3.78 to 4.43 in opposite homozygotes without affecting fat content (18 ∶ 0+18 ∶ 1, intramuscular fat content, and backfat thickness. No mutations that could affect the functionality of the protein were found in the coding region. First, we proved in a purebred Duroc line that the C-T-A haplotype of the 3 single nucleotide polymorphisms (SNPs (g.2108C>T; g.2228T>C; g.2281A>G of the promoter region was additively associated to enhanced 18 ∶ 1/18 ∶ 0 both in muscle and subcutaneous fat, but not in liver. We show that this association was consistent over a 10-year period of overlapping generations and, in line with these results, that the C-T-A haplotype displayed greater SCD mRNA expression in muscle. The effect of this haplotype was validated both internally, by comparing opposite homozygote siblings, and externally, by using experimental Duroc-based crossbreds. Second, the g.2281A>G and the g.2108C>T SNPs were excluded as causative mutations using new and previously published data, restricting the causality to g.2228T>C SNP, the last source of genetic variation within the haplotype. This mutation is positioned in the core sequence of several putative transcription factor binding sites, so that there are several plausible mechanisms by which allele T enhances 18 ∶ 1/18 ∶ 0 and, consequently, the proportion of monounsaturated to saturated fat.

  4. Human breast cancer tissues contain abundant phosphatidylcholine(36∶1 with high stearoyl-CoA desaturase-1 expression.

    Directory of Open Access Journals (Sweden)

    Yoshimi Ide

    Full Text Available Breast cancer is the leading cause of cancer and mortality in women worldwide. Recent studies have argued that there is a close relationship between lipid synthesis and cancer progression because some enzymes related to lipid synthesis are overexpressed in breast cancer tissues. However, lipid distribution in breast cancer tissues has not been investigated. We aimed to visualize phosphatidylcholines (PCs and lysoPCs (LPCs in human breast cancer tissues by performing matrix assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS, which is a novel technique that enables the visualization of molecules comprehensively. Twenty-nine breast tissue samples were obtained during surgery and subjected to MALDI-IMS analysis. We evaluated the heterogeneity of the distribution of PCs and LPCs on the tissues. Three species [PC(32∶1, PC(34∶1, and PC(36∶1] of PCs with 1 mono-unsaturated fatty acid chain and 1 saturated fatty acid chain (MUFA-PCs and one [PC(34∶0] of PCs with 2 saturated fatty acid chains (SFA-PC were relatively localized in cancerous areas rather than the rest of the sections (named reference area. In addition, the LPCs did not show any biased distribution. The relative amounts of PC(36∶1 compared to PC(36∶0 and that of PC(36∶1 to LPC(18∶0 were significantly higher in the cancerous areas. The protein expression of stearoyl-CoA desaturase-1 (SCD1, which is a synthetic enzyme of MUFA, showed accumulation in the cancerous areas as observed by the results of immunohistochemical staining. The ratios were further analyzed considering the differences in expressions of the estrogen receptor (ER, human epidermal growth factor receptor 2 (HER2, and Ki67. The ratios of the signal intensity of PC(34:1 to that of PC(34:0 was higher in the lesions with positive ER expression [corrected]. The contribution of SCD1 and other enzymes to the formation of the observed phospholipid composition is discussed.

  5. DHA and EPA reverse cystic fibrosis-related FA abnormalities by suppressing FA desaturase expression and activity

    OpenAIRE

    Njoroge, Sarah W; Laposata, Michael; Katrangi, Waddah; Seegmiller, Adam C.

    2012-01-01

    Patients and models of cystic fibrosis (CF) exhibit consistent abnormalities of polyunsaturated fatty acid composition, including decreased linoleate (LA) and docosahexaenoate (DHA) and variably increased arachidonate (AA), related in part to increased expression and activity of fatty acid desaturases. These abnormalities and the consequent CF-related pathologic manifestations can be reversed in CF mouse models by dietary supplementation with DHA. However, the mechanism is unknown. This study...

  6. Asymmetric Carrier Random PWM

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Lungeanu, Florin; Rasmussen, Peter Omand;

    2010-01-01

    This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on the measurements, it is shown that the spread effect of the discrete components from the motor current spectra is very effective independent of the modulation...

  7. Identification and characterization of Delta12, Delta6, and Delta5 Desaturases from the green microalga Parietochloris incisa.

    Science.gov (United States)

    Iskandarov, Umidjon; Khozin-Goldberg, Inna; Cohen, Zvi

    2010-06-01

    The freshwater microalga Parietochloris incisa accumulates, under nitrogen starvation, large amounts of triacylglycerols containing approximately 60% of the omega6 very long-chain polyunsaturated fatty acid (VLC-PUFA), arachidonic acid. Based on sequence homology, we isolated three cDNA sequences from P. incisa, designated PiDesD12, PiDesD6, PiDesD5. The deduced amino acid sequences of the three genes contained three conserved histidine motifs; the front-end desaturases, PiDes6 and PiDes5, contained a fused N-terminal cytochrome b5 domain. By functional characterization in the yeast Saccharomyces cerevisiae, we confirmed that PiDesD6, PiDesD5 cDNA encode membrane bound desaturases with Delta6, and Delta5 activity, respectively. Both PiDes6 and PiDes5 can indiscriminately desaturate both omega6 and omega3 substrates. A phylogenetic analysis showed that the three genes were homologous to the corresponding desaturases from green microalgae and lower plants that were functionally characterized. Quantitative real-time PCR revealed the concerted expression pattern of all three genes in P. incisa cells subjected to nitrogen starvation, featuring maximum expression level on day 3 of starvation, corresponding to the sharpest increase in the share of arachidonic acid. PMID:20467827

  8. Skin-specific deletion of stearoyl-CoA desaturase-1 alters skin lipid composition and protects mice from high fat diet-induced obesity.

    Science.gov (United States)

    Sampath, Harini; Flowers, Matthew T; Liu, Xueqing; Paton, Chad M; Sullivan, Ruth; Chu, Kiki; Zhao, Minghui; Ntambi, James M

    2009-07-24

    Stearoyl-CoA desaturase-1 (SCD1) catalyzes the synthesis of monounsaturated fatty acids and is an important regulator of whole body energy homeostasis. Severe cutaneous changes in mice globally deficient in SCD1 also indicate a role for SCD1 in maintaining skin lipids. We have generated mice with a skin-specific deletion of SCD1 (SKO) and report here that SKO mice display marked sebaceous gland hypoplasia and depletion of sebaceous lipids. In addition, SKO mice have significantly increased energy expenditure and are protected from high fat diet-induced obesity, thereby recapitulating the hypermetabolic phenotype of global SCD1 deficiency. Genes of fat oxidation, lipolysis, and thermogenesis, including uncoupling proteins and peroxisome proliferator-activated receptor-gamma co-activator-1alpha, are up-regulated in peripheral tissues of SKO mice. However, unlike mice globally deficient in SCD1, SKO mice have an intact hepatic lipogenic response to acute high carbohydrate feeding. Despite increased basal thermogenesis, SKO mice display severe cold intolerance because of rapid depletion of fuel substrates, including hepatic glycogen, to maintain core body temperature. These data collectively indicate that SKO mice have increased cold perception because of loss of insulating factors in the skin. This results in up-regulation of thermogenic processes for temperature maintenance at the expense of fuel economy, illustrating cross-talk between the skin and peripheral tissues in maintaining energy homeostasis.

  9. Photoaffinity analogues of methotrexate as folate antagonist binding probes. 2. Transport studies, photoaffinity labeling, and identification of the membrane carrier protein for methotrexate from murine L1210 cells

    International Nuclear Information System (INIS)

    A membrane-derived component of the methotrexate/one-carbon-reduced folate transport system in murine L1210 cells has been identified by using a photoaffinity analogue of methotrexate. The compound, a radioiodinated 4-azidosalicylyl derivative of the lysine analogue of methotrexate, is transported into murine L1210 cells in a temperature-dependent, sulfhydryl reagent inhibitable manner with a K/sub t/ of 506 +/- 79 nM and a V/sub max/ of 17.9 +/- 4.2 pmol min-1 (mg of total cellular protein)-1. Uptake of the iodinated compound at 200 nM is inhibited by low amounts of methotrexate. The parent compounds of the iodinated photoprobe inhibit [3H]methotrexate uptake, with the uniodinated 4-azidosalicylyl derivative exhibiting a K/sub i/ of 66 +/- 21 nM. UV irradiation, at 4 0C, of a cell suspension that had been incubated with the probe results in the covalent modification of a 46K-48K protein. This can be demonstrated when the plasma membranes from the labeled cells are analyzed via sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Labeling of this protein occurs half-maximally at a reagent concentration that correlates with the K/sub t/ for transport of the iodinated compound. Protection against labeling of this protein by increasing amounts of methotrexate parallels the concentration dependence of inhibition of photoprobe uptake by methotrexate. Evidence that, in the absence of irradiation and at 370C, the iodinated probe is actually internalized is demonstrated by the labeling of two soluble proteins (M/sub r/ 38K and 21K) derived from the cell homogenate supernatant

  10. The role of ß-ketoacyl-acyl carrier protein synthase III in the condensation steps of fatty acid biosynthesis in sunflower

    DEFF Research Database (Denmark)

    González-Mellado, Damián; von Wettstein, Penelope Margaret; Garcés, Rafael;

    2010-01-01

    seeds, a cDNA coding for HaKAS III (EF514400) was isolated, cloned and sequenced. Its protein sequence is as much as 72% identical to other KAS III-like ones such as those from Perilla frutescens, Jatropha curcas, Ricinus communis or Cuphea hookeriana. Phylogenetic study of the HaKAS III homologous...

  11. Identification and heterologous expression of a Δ4-fatty acid desaturase gene from Isochrysis sphaerica.

    Science.gov (United States)

    Guo, Bing; Jiang, Mulan; Wan, Xia; Gong, Yangmin; Liang, Zhuo; Hu, Chuanjiong

    2013-10-28

    The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, C20:5ω-3) and docosahexaenoic acid (DHA, C22:6ω-3) that are important to human health. Here, we report a functional characterization of a Δ4-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.

  12. Fatty Acid Desaturase Gene Polymorphisms and Metabolic Measures in Schizophrenia and Bipolar Patients Taking Antipsychotics

    Directory of Open Access Journals (Sweden)

    Kyle J. Burghardt

    2013-01-01

    Full Text Available Atypical antipsychotics have become a common therapeutic option in both schizophrenia and bipolar disorder. However, these medications come with a high risk of metabolic side effects, particularly dyslipidemia and insulin resistance. Therefore, identification of patients who are at increased risk for metabolic side effects is of great importance. The genetics of fatty acid metabolism is one area of research that may help identify such patients. Therefore, in this present study, we aimed to determine the effect of one commonly studied genetic polymorphism from both fatty acid desaturase 1 (FADS1 and FADS2 gene on a surrogate measure of insulin resistance and lipid levels in a metabolically high-risk population of patients largely exposed to atypical antipsychotics. This study used a cross-sectional design, fasting blood draws, and genetic analysis to investigate associations between polymorphisms, haplotypes, and metabolic measures. A total of 320 subjects with schizophrenia (n=226 or bipolar disorder (n=94 were included in this study. The mean age of the population was 42.5 years and 45% were male. A significant association between FADS1 and FADS2 haplotypes was found with insulin resistance while controlling for confounders. Further investigation is required to replicate this finding.

  13. Elevated stearoyl-CoA desaturase in brains of patients with Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Giuseppe Astarita

    Full Text Available The molecular bases of Alzheimer's disease (AD remain unclear. We used a lipidomic approach to identify lipid abnormalities in the brains of subjects with AD (N = 37 compared to age-matched controls (N = 17. The analyses revealed statistically detectable elevations in levels of non-esterified monounsaturated fatty acids (MUFAs and mead acid (20:3n-9 in mid-frontal cortex, temporal cortex and hippocampus of AD patients. Further studies showed that brain mRNAs encoding for isoforms of the rate-limiting enzyme in MUFAs biosynthesis, stearoyl-CoA desaturase (SCD-1, SCD-5a and SCD-5b, were elevated in subjects with AD. The monounsaturated/saturated fatty acid ratio ('desaturation index'--displayed a strong negative correlation with measures of cognition: the Mini Mental State Examination test (r = -0.80; P = 0.0001 and the Boston Naming test (r = -0.57; P = 0.0071. Our results reveal a previously unrecognized role for the lipogenic enzyme SCD in AD.

  14. Preliminary analysis of Stearoyl Co-A Desaturase gene transcripts in River buffalo

    Directory of Open Access Journals (Sweden)

    L. Ramunno

    2010-02-01

    Full Text Available Stearoyl-CoA desaturase (SCD is a key enzyme in the biosynthesis of monounsaturated fatty acids (MUFAs. In cattle, SCD gene extends over a DNA segment of ~17.0 Kb, and it is organized in 6 exons and 5 introns. The SCD gene has been indicated as the candidate gene to change the saturated/unsaturated FAs ratio and hence it has been suggested as the gene influencing the fat quality. In cattle, eight SNPs have been identified and one of them, (T→C at 231st nt of 5th exon, is responsible for the Val→Ala amino acid change. The C allele has been associated with higher content of MUFAs in carcasses, and it is positively related to a higher index of desaturation (C18:0/C18:1 and C16:0/C16:1 in the milk. In this study, we report on preliminary results of analysis of transcripts of the SCD encoding gene in river buffalo. The electrophoretic analysis of the RT-PCR products and the subsequent sequencing showed at least five different populations of mRNA. The most represented population is correctly assembled (~1300 bp, followed by the one which is deleted of ~750bp, corresponding to the 3rd, 4th and 5th exon and partially to the 2nd and 6th exon.

  15. Small-molecule targeting of a diapophytoene desaturase inhibits S. aureus virulence.

    Science.gov (United States)

    Chen, Feifei; Di, Hongxia; Wang, Youxin; Cao, Qiao; Xu, Bin; Zhang, Xue; Yang, Nana; Liu, Guijie; Yang, Cai-Guang; Xu, Yong; Jiang, Hualiang; Lian, Fulin; Zhang, Naixia; Li, Jian; Lan, Lefu

    2016-03-01

    The surge of antibiotic resistance in Staphylococcus aureus has created a dire need for innovative anti-infective agents that attack new targets, to overcome resistance. In S. aureus, carotenoid pigment is an important virulence factor because it shields the bacterium from host oxidant killing. Here we show that naftifine, a US Food and Drug Administration (FDA)-approved antifungal drug, blocks biosynthesis of carotenoid pigment at nanomolar concentrations. This effect is mediated by competitive inhibition of S. aureus diapophytoene desaturase (CrtN), an essential enzyme for carotenoid pigment synthesis. We found that naftifine attenuated the virulence of a variety of clinical S. aureus isolates, including methicillin-resistant S. aureus (MRSA) strains, in mouse infection models. Specifically, we determined that naftifine is a lead compound for potent CrtN inhibitors. In sum, these findings reveal that naftifine could serve as a chemical probe to manipulate CrtN activity, providing proof of concept that CrtN is a druggable target against S. aureus infections. PMID:26780405

  16. Improved soybean oil quality by targeted mutagenesis of the fatty acid desaturase 2 gene family.

    Science.gov (United States)

    Haun, William; Coffman, Andrew; Clasen, Benjamin M; Demorest, Zachary L; Lowy, Anita; Ray, Erin; Retterath, Adam; Stoddard, Thomas; Juillerat, Alexandre; Cedrone, Frederic; Mathis, Luc; Voytas, Daniel F; Zhang, Feng

    2014-09-01

    Soybean oil is high in polyunsaturated fats and is often partially hydrogenated to increase its shelf life and improve oxidative stability. The trans-fatty acids produced through hydrogenation pose a health threat. Soybean lines that are low in polyunsaturated fats were generated by introducing mutations in two fatty acid desaturase 2 genes (FAD2-1A and FAD2-1B), which in the seed convert the monounsaturated fat, oleic acid, to the polyunsaturated fat, linoleic acid. Transcription activator-like effector nucleases (TALENs) were engineered to recognize and cleave conserved DNA sequences in both genes. In four of 19 transgenic soybean lines expressing the TALENs, mutations in FAD2-1A and FAD2-1B were observed in DNA extracted from leaf tissue; three of the four lines transmitted heritable FAD2-1 mutations to the next generation. The fatty acid profile of the seed was dramatically changed in plants homozygous for mutations in both FAD2-1A and FAD2-1B: oleic acid increased from 20% to 80% and linoleic acid decreased from 50% to under 4%. Further, mutant plants were identified that lacked the TALEN transgene and only carried the targeted mutations. The ability to create a valuable trait in a single generation through targeted modification of a gene family demonstrates the power of TALENs for genome engineering and crop improvement.

  17. The Evolutionary Pattern and the Regulation of Stearoyl-CoA Desaturase Genes

    Directory of Open Access Journals (Sweden)

    Xiaoyun Wu

    2013-01-01

    Full Text Available Stearoyl-CoA desaturase (SCD is a key enzyme that converts saturated fatty acids (SFAs to monounsaturated fatty acids (MUFAs in the biosynthesis of fat. To date, two isoforms of scd gene (scd1 and scd5 have been found widely existent in most of the vertebrate animals. However, the evolutionary patterns of both isofoms and the function of scd5 are poorly understandable. Herein, we aim to characterize the evolutionary pattern of scd genes and further predict the function differentiation of scd genes. The sequences of scd genes were highly conserved among eukaryote. Phylogenetic analysis identified two duplications of scd gene early in vertebrate evolution. The relative rate ratio test, branch-specific dN/dS ratio tests, and branch-site dN/dS ratio tests all suggested that the scd genes were evolved at a similar rate. The evolution of scd genes among eukaryote was under strictly purifying selection though several sites in scd1 and scd5 were undergone a relaxed selection pressure. The variable binding sites by transcriptional factors at the 5′-UTR and by miRNAs at 3′-UTR of scd genes suggested that the regulators of scd5 may be different from that of scd1. This study promotes our understanding of the evolutionary patterns and function of SCD genes in eukaryote.

  18. Photoinduced Transformation between Charge Carrier and Spin Carrier in Polymers

    Institute of Scientific and Technical Information of China (English)

    MEI Yuan; ZHAO Chang; SUN Xin

    2006-01-01

    By dynamical simulations, we show a transforming process between neutral soliton (spin carrier) and charged soliton (charge carrier) in polymers via photo-excitation, taking a polaron as the transitional bridge. It is photoinduced transformation between spin carrier and charge carrier. In this way, we demonstrate an access for polymers to be applied to spintronics.

  19. Hepatocyte Nuclear Factor 4α (HNF4α) Is a Transcription Factor of Vertebrate Fatty Acyl Desaturase Gene as Identified in Marine Teleost Siganus canaliculatus.

    Science.gov (United States)

    Dong, Yewei; Wang, Shuqi; Chen, Junliang; Zhang, Qinghao; Liu, Yang; You, Cuihong; Monroig, Óscar; Tocher, Douglas R; Li, Yuanyou

    2016-01-01

    Rabbitfish Siganus canaliculatus was the first marine teleost demonstrated to have the capability of biosynthesizing long-chain polyunsaturated fatty acids (LC-PUFA) from C18 precursors, and to possess a Δ4 fatty acyl desaturase (Δ4 Fad) which was the first report in vertebrates, and is a good model for studying the regulatory mechanisms of LC-PUFA biosynthesis in teleosts. In order to understand regulatory mechanisms of transcription of Δ4 Fad, the gene promoter was cloned and characterized in the present study. An upstream sequence of 1859 bp from the initiation codon ATG was cloned as the promoter candidate. On the basis of bioinformatic analysis, several binding sites of transcription factors (TF) including GATA binding protein 2 (GATA-2), CCAAT enhancer binding protein (C/EBP), nuclear factor 1 (NF-1), nuclear factor Y (NF-Y), hepatocyte nuclear factor 4α (HNF4α) and sterol regulatory element (SRE), were identified in the promoter by site-directed mutation and functional assays. HNF4α and NF-1 were confirmed to interact with the core promoter of Δ4 Fad by gel shift assay and mass spectrometry. Moreover, over-expression of HNF4α increased promoter activity in HEK 293T cells and mRNA level of Δ4 Fad in rabbitfish primary hepatocytes, respectively. The results indicated that HNF4α is a TF of rabbitfish Δ4 Fad. To our knowledge, this is the first report on promoter structure of a Δ4 Fad, and also the first demonstration of HNF4α as a TF of vertebrate Fad gene involved in transcription regulation of LC-PUFA biosynthesis.

  20. Hepatocyte Nuclear Factor 4α (HNF4α) Is a Transcription Factor of Vertebrate Fatty Acyl Desaturase Gene as Identified in Marine Teleost Siganus canaliculatus

    Science.gov (United States)

    Dong, Yewei; Wang, Shuqi; Chen, Junliang; Zhang, Qinghao; Liu, Yang; You, Cuihong; Monroig, Óscar; Tocher, Douglas R.; Li, Yuanyou

    2016-01-01

    Rabbitfish Siganus canaliculatus was the first marine teleost demonstrated to have the capability of biosynthesizing long-chain polyunsaturated fatty acids (LC-PUFA) from C18 precursors, and to possess a Δ4 fatty acyl desaturase (Δ4 Fad) which was the first report in vertebrates, and is a good model for studying the regulatory mechanisms of LC-PUFA biosynthesis in teleosts. In order to understand regulatory mechanisms of transcription of Δ4 Fad, the gene promoter was cloned and characterized in the present study. An upstream sequence of 1859 bp from the initiation codon ATG was cloned as the promoter candidate. On the basis of bioinformatic analysis, several binding sites of transcription factors (TF) including GATA binding protein 2 (GATA-2), CCAAT enhancer binding protein (C/EBP), nuclear factor 1 (NF-1), nuclear factor Y (NF-Y), hepatocyte nuclear factor 4α (HNF4α) and sterol regulatory element (SRE), were identified in the promoter by site-directed mutation and functional assays. HNF4α and NF-1 were confirmed to interact with the core promoter of Δ4 Fad by gel shift assay and mass spectrometry. Moreover, over-expression of HNF4α increased promoter activity in HEK 293T cells and mRNA level of Δ4 Fad in rabbitfish primary hepatocytes, respectively. The results indicated that HNF4α is a TF of rabbitfish Δ4 Fad. To our knowledge, this is the first report on promoter structure of a Δ4 Fad, and also the first demonstration of HNF4α as a TF of vertebrate Fad gene involved in transcription regulation of LC-PUFA biosynthesis. PMID:27472219

  1. 可食性蛋白质作为营养物质运送载体的研究概况%Overveiw of research on edible protein as delivery carriers for nutrients

    Institute of Scientific and Technical Information of China (English)

    于钰; 刘晨光

    2012-01-01

    Edible proteins are natural and Generally Regarded As Safe(GRAS) materials with high nutritional value and many useful properties of structure and function.These properties make them quite suitable as vehicles for delivering nutrients,and it has an attractive prospect.This overview focuses on several major edible proteins and their physical-chemistry properties.Several forms of carrier and applications in the development of nutraceutical delivery systerms were described.Delivery systems of gel,microsphere and nanoparticle of edible proteins were developed based on their special properties.They were regarded as ideal materials for delivering nutraceutical compounds.%可食性蛋白质具有较高的营养价值和公认的安全性,还有很多可用于营养物质包埋的结构功能特性,用它作为营养物质的运送载体具有诱人的前景。本文介绍了作为载体的几种主要可食性蛋白质及理化性质,载体形式和在营养物质运送发展中的应用。说明利用可食性蛋白质独特的性质开发出的凝胶、微球、纳米粒等运送系统可以对营养物质进行保护,是包埋和运送营养物质的理想材料。

  2. The value of energy carriers

    NARCIS (Netherlands)

    Gool, W. van

    1987-01-01

    The value of energy carriers can be described thermodynamically by the amount of heat (enthalpy method) or work (exergy or availability method) that can be obtained from the carriers. Prices for energy carriers are used in economics to express their values. The prices for energy carriers are often r

  3. Enhanced response of granulosa and theca cells from sheep carriers of the FecB mutation in vitro to gonadotropins and bone morphogenic protein-2, -4, and -6.

    Science.gov (United States)

    Campbell, B K; Souza, C J H; Skinner, A J; Webb, R; Baird, D T

    2006-04-01

    The FecB (Booroola) mutation, which leads to increased ovulation rates and multiple births in sheep, is now known to occur in the signaling domain of the bone morphogenic protein (BMP)-1B receptor. We examined the effect of the mutation on the responsiveness of granulosa (GC) and theca cells (TC) to BMPs and other local regulators using tissue from animals with (Fec(B/B)) and without (Fec(+/+)) the FecB mutation. Experiments examined the effect of BMP-2, -4, and -6 (0.005-50 ng/ml), and their interaction with IGF-I (0.1-10 ng/ml LR3 analog) and gonadotropins, on the proliferation and differentiation of GCs and TCs isolated from small (<2 mm) antral follicles and maintained in serum-free culture for up to 8 d. Dose-finding studies using ovaries from wild-type sheep obtained from the abbattoir showed no difference among the different BMPs in stimulating (P < 0.001) estradiol (E2) production by GCs cultured with FSH (10 ng/ml), but there was a clear interaction (P < 0.001) with IGF-I. BMPs had no effect on GC proliferation or the sensitivity of GCs to FSH. In contrast, higher doses of BMPs (5-50 ng/ml) inhibited LH-stimulated androstenedione production by TCs, whereas lower doses (0.005-0.05 ng/ml) stimulated TC proliferation (P < 0.01). Regardless of dose of IGF-I, at the end of culture (96-192 h) hormone production by GCs (E2, inhibin A) and TCs (androstenedione) was 4- to 5-fold greater (P < 0.001) by cells from Fec(B/B), compared with Fec(+/+) ewes exposed to the same dose of gonadotropin. In the presence of low concentrations of IGF-I (0.1 ng/ml), the maximum increase in the production of E2 and inhibin A by GCs from FF ewes in response to BMPs was observed at doses that were 3- to 10-fold lower (3-10 ng/ml) than ++ (30 ng/ml; P < 0.001). Low doses of BMPs stimulated proliferation of TCs from ++ (P < 0.01) but not FF ewes. Immunohistochemistry confirmed BMP-6 protein expression in the oocyte, granulosa, and thecal layers of antral follicles from both genotypes

  4. Characterization and cloning of a stearoyl/oleoyl specific fatty acyl-acyl carrier protein thioesterase from the seeds of Madhuca longifolia (latifolia).

    Science.gov (United States)

    Ghosh, Santosh K; Bhattacharjee, Ashish; Jha, Jyoti K; Mondal, Ashis K; Maiti, Mrinal K; Basu, Asitava; Ghosh, Dolly; Ghosh, Sudhamoy; Sen, Soumitra K

    2007-12-01

    Deposition of oleate, stearate and palmitate at the later stages of seed development in Mahua (Madhuca longifolia (latifolia)), a tropical non-conventional oil seed plant, has been found to be the characteristic feature of the regulatory mechanism that produces the saturated fatty acid rich Mahua seed fat (commonly known as Mowrah fat). Although, the content of palmitate has been observed to be higher than that of stearate at the initial stages of seed development, it goes down when the stearate and oleate contents consistently rise till maturity. The present study was undertaken in order to identify the kind of acyl-ACP thioesterase(s) that drives the characteristic composition of signature fatty acids (oleate 37%, palmitate 25%, stearate 23%, linoleate 12.5%) in its seed oil at maturity. The relative Fat activities in the crude protein extracts of the matured seeds towards three thioester substrates (oleoyl-, stearoyl- and palmitoyl-ACP) have been found to be present in the following respective ratio 100:31:8. Upon further purification of the crude extract, the search revealed the presence of two partially purified thioesterases: a long-chain oleoyl preferring house-keeping LC-Fat and a novel stearoyl-oleoyl preferring SO-Fat. The characteristic accumulation of oleate and linoleate in the M. latifolia seed fat is believed to be primarily due to the thioesterase activity of the LC-Fat or MlFatA. On the other hand, the SO-Fat showed almost equal substrate specificity towards stearoyl- and oleoyl-ACP, when its activity towards palmitoyl-ACP compared to stearoyl-ACP was only about 12%. An RT-PCR based technique for cloning of a DNA fragment from the mRNA pool of the developing seed followed by nucleotide sequencing resulted in the identification of a FatB type of thioesterase gene (MlFatB). This gene was found to exist as a single copy in the mother plant genome. Ectopic expression of this MlFatB gene product in E. coli strain fadD88 further proved that it induced a

  5. Characterization and cloning of a stearoyl/oleoyl specific fatty acyl-acyl carrier protein thioesterase from the seeds of Madhuca longifolia (latifolia).

    Science.gov (United States)

    Ghosh, Santosh K; Bhattacharjee, Ashish; Jha, Jyoti K; Mondal, Ashis K; Maiti, Mrinal K; Basu, Asitava; Ghosh, Dolly; Ghosh, Sudhamoy; Sen, Soumitra K

    2007-12-01

    Deposition of oleate, stearate and palmitate at the later stages of seed development in Mahua (Madhuca longifolia (latifolia)), a tropical non-conventional oil seed plant, has been found to be the characteristic feature of the regulatory mechanism that produces the saturated fatty acid rich Mahua seed fat (commonly known as Mowrah fat). Although, the content of palmitate has been observed to be higher than that of stearate at the initial stages of seed development, it goes down when the stearate and oleate contents consistently rise till maturity. The present study was undertaken in order to identify the kind of acyl-ACP thioesterase(s) that drives the characteristic composition of signature fatty acids (oleate 37%, palmitate 25%, stearate 23%, linoleate 12.5%) in its seed oil at maturity. The relative Fat activities in the crude protein extracts of the matured seeds towards three thioester substrates (oleoyl-, stearoyl- and palmitoyl-ACP) have been found to be present in the following respective ratio 100:31:8. Upon further purification of the crude extract, the search revealed the presence of two partially purified thioesterases: a long-chain oleoyl preferring house-keeping LC-Fat and a novel stearoyl-oleoyl preferring SO-Fat. The characteristic accumulation of oleate and linoleate in the M. latifolia seed fat is believed to be primarily due to the thioesterase activity of the LC-Fat or MlFatA. On the other hand, the SO-Fat showed almost equal substrate specificity towards stearoyl- and oleoyl-ACP, when its activity towards palmitoyl-ACP compared to stearoyl-ACP was only about 12%. An RT-PCR based technique for cloning of a DNA fragment from the mRNA pool of the developing seed followed by nucleotide sequencing resulted in the identification of a FatB type of thioesterase gene (MlFatB). This gene was found to exist as a single copy in the mother plant genome. Ectopic expression of this MlFatB gene product in E. coli strain fadD88 further proved that it induced a

  6. Evolution of moth sex pheromone composition by a single amino acid substitution in a fatty acid desaturase.

    Science.gov (United States)

    Buček, Aleš; Matoušková, Petra; Vogel, Heiko; Šebesta, Petr; Jahn, Ullrich; Weißflog, Jerrit; Svatoš, Aleš; Pichová, Iva

    2015-10-13

    For sexual communication, moths primarily use blends of fatty acid derivatives containing one or more double bonds in various positions and configurations, called sex pheromones (SPs). To study the molecular basis of novel SP component (SPC) acquisition, we used the tobacco hornworm (Manduca sexta), which uses a blend of mono-, di-, and uncommon triunsaturated fatty acid (3UFA) derivatives as SP. We identified pheromone-biosynthetic fatty acid desaturases (FADs) MsexD3, MsexD5, and MsexD6 abundantly expressed in the M. sexta female pheromone gland. Their functional characterization and in vivo application of FAD substrates indicated that MsexD3 and MsexD5 biosynthesize 3UFAs via E/Z14 desaturation from diunsaturated fatty acids produced by previously characterized Z11-desaturase/conjugase MsexD2. Site-directed mutagenesis of sequentially highly similar MsexD3 and MsexD2 demonstrated that swapping of a single amino acid in the fatty acyl substrate binding tunnel introduces E/Z14-desaturase specificity to mutated MsexD2. Reconstruction of FAD gene phylogeny indicates that MsexD3 was recruited for biosynthesis of 3UFA SPCs in M. sexta lineage via gene duplication and neofunctionalization, whereas MsexD5 representing an alternative 3UFA-producing FAD has been acquired via activation of a presumably inactive ancestral MsexD5. Our results demonstrate that a change as small as a single amino acid substitution in a FAD enzyme might result in the acquisition of new SP compounds. PMID:26417103

  7. Gene transfer of Chlorella vulgaris n-3 fatty acid desaturase optimizes the fatty acid composition of human breast cancer cells

    Directory of Open Access Journals (Sweden)

    Meilan Xue

    2012-12-01

    Full Text Available Chlorella vulgaris has the gene of n-3 fatty acid desaturase (CvFad3, which can synthesize the precursor of n-3 polyunsaturated fatty acids (PUFAs or convert n-6 to n-3 PUFAs. The objective of the present study was to examine whether the CvFad3 gene from C. vulgaris can be functionally and efficiently expressed in human breast cancer cells and whether its expression can exert a significant effect on cell fatty acid composition. We inserted the CvFad3 gene into the plasmid pEGFP-C3 to construct the eukaryotic expression vector pEGFP-C3-n-3 and to express the n-3 Fad gene in human breast cancer cells (MCF-7 cells. Transfection of MCF-7 cells with the recombinant vector resulted in a high expression of n-3 fatty acid desaturase. Lipid analysis indicated that the ratio of n-6/n-3 PUFAs was decreased from 6:1 in the control cells to about 1:1 in the cells expressing the n-3 fatty acid desaturase. Accordingly, the CvFad3 gene significantly decreased the ratio of n-6/n-3 PUFAs of the MCF-7 cell membrane. The expression of the CvFad3 gene can decrease cell proliferation and promote cell apoptosis. This study demonstrates that the CvFad3 gene can dramatically balance the ratio of n-6/n-3 PUFAs and may provide an effective approach to the modification of the fatty acid composition of mammalian cells, also providing a basis for potential applications of its transfer in experimental and clinical settings.

  8. Gene transfer of Chlorella vulgaris n-3 fatty acid desaturase optimizes the fatty acid composition of human breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Meilan; Ge, Yinlin; Zhang, Jinyu [Department of Biochemistry and Molecular Biology, Medical College, Qingdao University, Qingdao Shandong (China); Wang, Qing [Affiliated Hospital of Qingdao University, Qingdao Shandong (China); Hou, Lin [Department of Biochemistry and Molecular Biology, Medical College, Qingdao University, Qingdao Shandong (China)

    2012-09-14

    Chlorella vulgaris has the gene of n-3 fatty acid desaturase (CvFad3), which can synthesize the precursor of n-3 polyunsaturated fatty acids (PUFAs) or convert n-6 to n-3 PUFAs. The objective of the present study was to examine whether the CvFad3 gene from C. vulgaris can be functionally and efficiently expressed in human breast cancer cells and whether its expression can exert a significant effect on cell fatty acid composition. We inserted the CvFad3 gene into the plasmid pEGFP-C3 to construct the eukaryotic expression vector pEGFP-C3-n-3 and to express the n-3 Fad gene in human breast cancer cells (MCF-7 cells). Transfection of MCF-7 cells with the recombinant vector resulted in a high expression of n-3 fatty acid desaturase. Lipid analysis indicated that the ratio of n-6/n-3 PUFAs was decreased from 6:1 in the control cells to about 1:1 in the cells expressing the n-3 fatty acid desaturase. Accordingly, the CvFad3 gene significantly decreased the ratio of n-6/n-3 PUFAs of the MCF-7 cell membrane. The expression of the CvFad3 gene can decrease cell proliferation and promote cell apoptosis. This study demonstrates that the CvFad3 gene can dramatically balance the ratio of n-6/n-3 PUFAs and may provide an effective approach to the modification of the fatty acid composition of mammalian cells, also providing a basis for potential applications of its transfer in experimental and clinical settings.

  9. Intragenic enhancers and suppressors of phytoene desaturase mutations in Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Phoi T Tran

    Full Text Available Photosynthetic organisms synthesize carotenoids for harvesting light energy, photoprotection, and maintaining the structure and function of photosynthetic membranes. A light-sensitive, phytoene-accumulating mutant, pds1-1, was isolated in Chlamydomonas reinhardtii and found to be genetically linked to the phytoene desaturase (PDS gene. PDS catalyzes the second step in carotenoid biosynthesis--the conversion of phytoene to ζ-carotene. Decreased accumulation of downstream colored carotenoids suggested that the pds1-1 mutant is leaky for PDS activity. A screen for enhancers of the pds1-1 mutation yielded the pds1-2 allele, which completely lacks PDS activity. A second independent null mutant (pds1-3 was identified using DNA insertional mutagenesis. Both null mutants accumulate only phytoene and no other carotenoids. All three phytoene-accumulating mutants exhibited slower growth rates and reduced plating efficiency compared to wild-type cells and white phytoene synthase mutants. Insight into amino acid residues important for PDS activity was obtained through the characterization of intragenic suppressors of pds1-2. The suppressor mutants fell into three classes: revertants of the pds1-1 point mutation, mutations that changed PDS amino acid residue Pro64 to Phe, and mutations that converted PDS residue Lys90 to Met. Characterization of pds1-2 intragenic suppressors coupled with computational structure prediction of PDS suggest that amino acids at positions 90 and 143 are in close contact in the active PDS enzyme and have important roles in its structural stability and/or activity.

  10. STEAROYL-CoA DESATURASE-1 DEFICIENCY ATTENUATES OBESITY AND INSULIN RESISTANCE IN LEPTIN-RESISTANT OBESE MICE

    OpenAIRE

    Miyazaki, Makoto; Sampath, Harini; Liu, Xueqing; Flowers, Matthew T.; Chu, Kiki; Dobrzyn, Agnieszka; Ntambi, James M.

    2009-01-01

    Obesity and adiposity greatly increase the risk for secondary conditions such as insulin resistance. Mice deficient in the enzyme stearoyl-CoA desaturase-1 (SCD1) are lean and protected from diet-induced obesity and insulin resistance. In order to determine the effect of SCD1 deficiency on various mouse models of obesity, we introduced a global deletion of the Scd1 gene into leptin-deficient ob/ob mice, leptin-resistant Agouti (Ay/a) mice, and high-fat diet-fed obese (DIO) mice. SCD1 deficien...

  11. Duchenne muscular dystrophy carriers

    International Nuclear Information System (INIS)

    By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated from the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly. (orig.)

  12. The value of energy carriers

    OpenAIRE

    Gool, W. van

    1987-01-01

    The value of energy carriers can be described thermodynamically by the amount of heat (enthalpy method) or work (exergy or availability method) that can be obtained from the carriers. Prices for energy carriers are used in economics to express their values. The prices for energy carriers are often related to their enthalpies when other properties and conditions are equivalent. However, it has been suggested that the exergy of the energy carriers is the proper quantity to establish their value...

  13. The effect of turmeric (Curcuma longa) extract on the functionality of the solute carrier protein 22 A4 (SLC22A4) and interleukin-10 (IL-10) variants associated with inflammatory bowel disease.

    Science.gov (United States)

    McCann, Mark J; Johnston, Sarah; Reilly, Kerri; Men, Xuejing; Burgess, Elaine J; Perry, Nigel B; Roy, Nicole C

    2014-10-13

    Inflammatory bowel disease (IBD) is a chronic relapsing disease. Genetic predisposition to the disease reduces an individual's capacity to respond appropriately to environmental challenges in the intestine leading to inappropriate inflammation. IBD patients often modify their diet to mitigate or reduce the severity of inflammation. Turmeric (Curcuma longa L., Zingiberaceae) has historically been used in Chinese, Hindu, and Ayurvedic medicine over several centuries to treat inflammatory disorders. To understand how turmeric may influence the consequences of a genetic predisposition to inappropriate inflammation, we used HEK293 cells to examine the in vitro capacity of turmeric extract and fractions to affect the functionality of two gene variants, solute carrier protein 22 A4 (SLC22A4, rs1050152) and interleukin-10 (IL-10, rs1800896) associated with IBD. We found that a turmeric extract and several chromatographically separated fractions beneficially affected the variants of SLC22A4 and IL-10 associated with IBD, by reducing inappropriate epithelial cell transport (SLC22A4, 503F) and increasing anti-inflammatory cytokine gene promoter activity (IL-10, -1082A). The effect of turmeric on the IL-10 variant was strongly associated with the curcumin content of the extract and its fractions.

  14. Expression of PIN and AUX1 genes encoding putative carrier proteins for auxin polar transport in etiolated pea epicotyls [correction of epicotyles] under simulated microgravity conditions on a three-dimensional clinostat.

    Science.gov (United States)

    Hoshino, Tomoki; Hitotsubashi, Reiko; Miyamoto, Kensuke; Tanimoto, Eiichi; Ueda, Junichi

    2003-10-01

    Etiolated pea (Pisum sativum L. cv. Alaska) seedlings grown under simulated microgravity conditions on a 3-dimensional clinostat showed automorphosis-like growth and development similar to that observed in true microgravity conditions in space. Application of inhibitors of auxin polar transport phenocopied automorphosis-like growth on 1 g conditions, suggesting that automorophosis is closely related to auxin polar transport. Strenuous efforts to know the relationships between automorphosis and auxin polar transport in pea seedlings at molecular bases resulted in successful identification of PsPIN2 and PsAUX1 encoding putative auxin efflux and influx carrier protein, respectively. Significantly high levels in homology were found on nucleotide and deduced amino acid sequences among PsPIN2, PsPIN1 and AtPINs, and between PsAUX1 and AtAUX1. Expression of PsPIN1 and PsAUX1 genes in etiolated pea seedlings grown on the clinostat were substantially affected, but that of PsPIN2 was not. Roles of these genes in auxin polar transport and automorphosis of etiolated pea seedlings are also described. PMID:14676360

  15. 抗菌肽在大肠杆菌中融合表达的载体蛋白%Carrier proteins for fusion expression of antimicrobial peptides in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    田彩平; 黄冰雪; 袁红霞; 廖世奇

    2011-01-01

    Antimicrobial peptides are an essential component of innate immunity, They can efficiently defence against microbial pathogens, In recently, They have received increasing attention as novel pharmaceutical agents, However, isolation from natural sources and chemical synthesis are high cost, using recombinant DNA technology to produce antimicrobial peptides is very urgent. In this paper discussed the important properties of the most commonly used carrier proteins and SUMO that is as a novel fusion partner (small ubiquitin related modifier).%抗菌肽是天然免疫系统的主要成分,能有效抵御病原微生物的侵害。目前其作为新型药物受到人们很大的关注,由于从天然资源中分离或化学合成成本较高,因此应用基因重组技术生产抗菌肽很迫切。本文主要讨论了抗菌肽在大肠杆菌中的融合表达、融合表达中常用的载体蛋白及新的融合载体SUMO(小泛素修饰因子)的主要性能。

  16. Information and Its Carriers.

    Science.gov (United States)

    Herrmann, F.; And Others

    1985-01-01

    Describes: (1) the structure of a data transmission source, carrier, and receiver; (2) a quantitative measure for the amount of data, followed by some quantitative examples of data transmission processes; (3) the concept of data current; (4) data containers; and (5) how this information can be used to structure physics courses. (JN)

  17. The plant mitochondrial carrier family: functional and evolutionary aspects

    OpenAIRE

    Ilka eHaferkamp; Stephan eSchmitz-Esser

    2012-01-01

    Mitochondria play a key role in respiration and energy production and are involved in multiple eukaryotic but also in several plant specific metabolic pathways. Solute carriers in the inner mitochondrial membrane connect the internal metabolism with that of the surrounding cell. Because of their common basic structure, these transport proteins affiliate to the mitochondrial carrier family (MCF). Generally, MCF proteins consist of six membrane-spanning helices, exhibit typical conserved domain...

  18. 球等鞭金藻中Δ5去饱和酶基因的克隆与功能鉴定%ISOLATION AND FUNCTIONAL ANALYSIS OF A Δ5 DESATURASE GENE FROM ISOCHRYSIS GALBANA

    Institute of Scientific and Technical Information of China (English)

    孙全喜; 李雪滢; 郑德松; 刘江; 李新征; 亓宝秀

    2012-01-01

    . Here, we reported the isolation of the third gene, a A5 desaturase gene that was capable to convert DGLA to AA. That was achieved by the RACE strategy using different degenerate primers based on the conserved motifs of known desaturase sequences to isolate a partial cDNA from an /. galbana cDNA library. The full length cDNA was subsequently assembled and it consisted of 1329 nucleotides, encoding a protein of 442 amino acids with predicted molecular mass of 49.9 kD. Bioinformatics analysis showed that it shared homol-ogy with other functionally known front-end fatty acid desaturases and the highest homology of 56% was found with a A5 desaturase from Pavlova salina. As characterized by this family of desaturases, it contained an N-terminal cytochrome b5 domain, and three histidine rich motifs (his-boxes) related to electron transfer. Functional analysis by expression in Sac-charomyces cerevisiae revealed that it could convert DGLA (20:3△8,11,14 ) to AA (20:4△5,8,11,14 ) by introducing a double bond in the acyl chain at the A5 position, indicating that this newly isolated cDNA sequence encodes a protein that specifically catalyzes for the conversion of C20-△5-polyunsaturated fatty acid, AA, hence it was designated as IgD5.

  19. Plant sterol metabolism. Δ(7-Sterol-C5-desaturase (STE1/DWARF7, Δ(5,7-sterol-Δ(7-reductase (DWARF5 and Δ(24-sterol-Δ(24-reductase (DIMINUTO/DWARF1 show multiple subcellular localizations in Arabidopsis thaliana (Heynh L.

    Directory of Open Access Journals (Sweden)

    Daniele Silvestro

    Full Text Available Sterols are crucial lipid components that regulate membrane permeability and fluidity and are the precursors of bioactive steroids. The plant sterols exist as three major forms, free sterols, steryl glycosides and steryl esters. The storage of steryl esters in lipid droplets has been shown to contribute to cellular sterol homeostasis. To further document cellular aspects of sterol biosynthesis in plants, we addressed the question of the subcellular localization of the enzymes implicated in the final steps of the post-squalene biosynthetic pathway. In order to create a clear localization map of steroidogenic enzymes in cells, the coding regions of Δ(7-sterol-C(5-desaturase (STE1/DWARF7, Δ(24-sterol-Δ(24-reductase (DIMINUTO/DWARF1 and Δ(5,7-sterol-Δ(7-reductase (DWARF5 were fused to the yellow fluorescent protein (YFP and transformed into Arabidopsis thaliana mutant lines deficient in the corresponding enzymes. All fusion proteins were found to localize in the endoplasmic reticulum in functionally complemented plants. The results show that both Δ(5,7-sterol-Δ(7-reductase and Δ(24-sterol-Δ(24-reductase are in addition localized to the plasma membrane, whereas Δ(7-sterol-C(5-desaturase was clearly detected in lipid particles. These findings raise new challenging questions about the spatial and dynamic cellular organization of sterol biosynthesis in plants.

  20. Carrot Juice Administration Decreases Liver Stearoyl-CoA Desaturase 1 and Improves Docosahexaenoic Acid Levels, but Not Steatosis in High Fructose Diet-Fed Weanling Wistar Rats

    Science.gov (United States)

    Mahesh, Malleswarapu; Bharathi, Munugala; Reddy, Mooli Raja Gopal; Kumar, Manchiryala Sravan; Putcha, Uday Kumar; Vajreswari, Ayyalasomayajula; Jeyakumar, Shanmugam M.

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases associated with an altered lifestyle, besides genetic factors. The control and management of NAFLD mostly depend on lifestyle modifications, due to the lack of a specific therapeutic approach. In this context, we assessed the effect of carrot juice on the development of high fructose-induced hepatic steatosis. For this purpose, male weanling Wistar rats were divided into 4 groups, fed either a control (Con) or high fructose (HFr) diet of AIN93G composition, with or without carrot juice (CJ) for 8 weeks. At the end of the experimental period, plasma biochemical markers, such as triglycerides, alanine aminotransferase, and β-hydroxy butyrate levels were comparable among the 4 groups. Although, the liver injury marker, aspartate aminotransferase, levels in plasma showed a reduction, hepatic triglycerides levels were not significantly reduced by carrot juice ingestion in the HFr diet-fed rats (HFr-CJ). On the other hand, the key triglyceride synthesis pathway enzyme, hepatic stearoyl-CoA desaturase 1 (SCD1), expression at mRNA level was augmented by carrot juice ingestion, while their protein levels showed a significant reduction, which corroborated with decreased monounsaturated fatty acids (MUFA), particularly palmitoleic (C16:1) and oleic (C18:1) acids. Notably, it also improved the long chain n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA; C22:6) content of the liver in HFr-CJ. In conclusion, carrot juice ingestion decreased the SCD1-mediated production of MUFA and improved DHA levels in liver, under high fructose diet-fed conditions. However, these changes did not significantly lower the hepatic triglyceride levels. PMID:27752492

  1. Significant associations of stearoyl-CoA desaturase (SCD1 gene with fat deposition and composition in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Zhihua Jiang, Jennifer J. Michal, David J. Tobey, Tyler F. Daniels, Daniel C. Rule, Michael D. MacNeil

    2008-01-01

    Full Text Available Gene expression studies in humans and animals have shown that elevated stearoyl-CoA desaturase (SCD1 activity is associated with increased fat accumulation and monounsaturation of saturated fatty acids in skeletal muscle. However, results of the two reported association studies in humans are inconsistent. In the present study, we annotated the bovine SCD1 gene and identified 3 single nucleotide polymorphisms (SNPs in its 3'untranslated region (UTR. Genotyping these SNPs on a Wagyu x Limousin reference population revealed that the SCD1 gene was significantly associated with six fat deposition and fatty acid composition traits in skeletal muscle, but not with subcutaneous fat depth and percent kidney-pelvic-heart fat. In particular, we confirmed that the high stearoyl-CoA desaturase activities/alleles were positively correlated with beef marbling score, amount of monounsaturated fatty acids and conjugated linoleic acid content, but negatively with amount of saturated fatty acids. The inconsistent associations between human studies might be caused by using different sets of markers because we obeserved that most associated markers are located near the end of 3'UTR. We found that the proximity of the polyadenylation signal site is highly conserved among human, cattle and pig, indicating that the region might contain functional elements involved in posttranscriptional control of SCD1 activity. In conclusion, our cross species study provided solid evidence to support SCD1 gene as a critical player in skeletal muscle fat metabolism.

  2. [Expression of Mortierella isabellina delta6-fatty acid desaturase gene in gamma-linolenic acid production in transgenic tobacco].

    Science.gov (United States)

    Li, Ming-Chun; Liu, Li; Hu, Guo-Wu; Xing, Lai-Jun

    2003-03-01

    Gamma-linolenic acid (GLA, C18:3delta6.9.12) is nutritional and important polyunsaturated fatty acid in human and animal diets. GLA play an important role in hormone regulation and fatty acid metabolization. Furthermore it is also the biological precursor of a group of molecules, including prostaglandins, leukotrienes and thromboxanes. Vast majority of oilseed crops do not produce GLA, but linoleic acid (LA, C18:2delta9.12) as its substrate. GLA is only produced by a small number of oilseed plants such as evening promrose ( Oenotheera spp.), borage (Borago officinalis) and etc. delta6-fatty acid desaturase (D6D) is the rate-limiting enzyme in the production of GLA. It can convert from linoleic acid to linolenic acid. To produce GLA in tobacco, plant expression vector was first constructed. To facilitate preparation of plant expression constructs, flanking Xba I and Bgl II restriction enzyme sites were added to the coding region of clone pTMICL6 by PCR amplification. pTMICL6 contains delta6-fatty acid desaturase gene cloned from Mortierella isabellina which is an oil-producing fugus. The PCR product was purified and subcloned into the plant expression vector pGA643 to generate the recombinant vector pGAMICL6 which contains the ORF of the D6D gene of Mortierella isabellina, together with regulatory elements consisting of the cauliflower mosaic virus 35S promoter and the nopaline synthase (nos) termination sequence. The plasmid pGAMICL6 was transformed into Agrobacterium tumefaciens strain LBA4404 by method of freeze thawing of liquid nitrogen. Transformants were selected by plating on YEB medium plates containing kanamycin and streptomycin and grown overnight at 28 degrees C, then transformants were further identified by PCR. The positive transformant containing the plant expression vector pGAMICL6 was transformed into tobacco ( Nicotiana tabacum cv. Xanthi) via Agrobacterium infection. Transgenic plants were selected on 100 microg/mL kanamycin. Plants were

  3. Efficient production of omega-3 fatty acid desaturase (sFat-1)-transgenic pigs by somatic cell nuclear transfer

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Omega-3(ω-3) fatty acid desaturase transgenic pigs may improve carcass fatty acid composition. The use of transgenic pigs is also an excellent large animal model for studying the role of ω-3 fatty acids in the prevention and treatment of coronary heart disease and cancer. Transgenic pigs carrying synthesized fatty acid desaturase-1 gene (sFat-1) from Caenorhabditis briggsae by somatic cell nuclear transfer (SCNT) were produced for the first time in China. Porcine fetal fibroblast cells were transfected with a sFat-1 expression cassette by the liposome-mediated method. Transgenic embryos were reconstructed by nuclear transfer of positive cells into enucleated in vitro matured oocytes. A total of 1889 reconstructed embryos were transferred into 10 naturally cycling gilts. Nine early pregnancies were established, 7 of which went to term. Twenty-one piglets were born. The cloning efficiency was 1.1% (born piglets/transferred embryos). The integration of the sFat-1 gene was confirmed in 15 live cloned piglets by PCR and Southern blot except for 2 piglets. Expression of the sFat-1 gene in 12 of 13 piglets was detected with RT-PCR. The data demonstrates that an efficient system for sFat-1 transgenic cloned pigs was developed, which led to the successful production of piglets expressing the sFat-1 gene.

  4. Fatty acid desaturase 1 polymorphisms are associated with coronary heart disease in a Chinese population

    Institute of Scientific and Technical Information of China (English)

    LIU Si-jun; HU Zhi-bin; WANG Hui; SHEN Hong-bing; ZHI Hong; CHEN Pei-zhan; CHEN Wei; LU Feng; MA Gen-shan; DAI Jun-cheng; SHEN Chong; LIU Nai-feng

    2012-01-01

    Background A recent genome-wide association study in Caucasians revealed that three loci (rs174547 in fatty acid desaturase 1 (FADS1),rs2338104 near mevalonate kinase/methylmalonic aciduria,cobalamin deficiency,cblB type (MVK/MMAB) and rs10468017 near hepatic lipase (LIPC)) influence the plasma concentrations of high-density lipoprotein-cholesterol (HDL-C) and triglycerides (TG).However,there are few reports on the associations between these polymorphisms and plasma lipid concentrations in Chinese individuals.This study aimed to evaluate the associations between these three polymorphisms with HDL-C and TG concentrations,as well as coronary heart disease (CHD) susceptibility in Chinese individuals.Methods We conducted a population-based case-control study in Chinese individuals to evaluate the associations between these three polymorphisms and HDL-C and TG concentrations,and also evaluated their associations with susceptibility to CHD.Genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism assays and TaqMan genotyping assays.Results We found significant differences in TG and HDL-C concentrations among the TT,TC and CC genotypes of FADS1 rs174547 (P=0.017 and 0.003,respectively,multiple linear regression).The CC variant of rs174547 was significantly associated with hyperlipidemia compared with the TT variant (adjusted odds ratio (OR) =1.71,95% confidence intervals (CI):1.16-2.54).The FADS1 rs174547 CC variant was also associated with significantly increased CHD risk compared with the TT and TC variant (adjusted OR=1.53,95% CI:1.01-2.31),and the effect was more evident among nonsmokers and females.The polymorphisms rs2338104 and rs10468017 did not significantly influence HDL-C or TG concentrations in this Chinese population.Conclusion rs174547 in FADS1 may contribute to the susceptibility of CHD by altering HDL-C and TG levels in Chinese individuals.

  5. Partial genetic characterization of Stearoyl Coa-Desaturase´s structural region in Bubalus bubalis

    Directory of Open Access Journals (Sweden)

    R.B. Thomazine

    2010-02-01

    Full Text Available Conjugated Linoleic Acids (CLAs comprise a family of positional and geometric isomers of linoleic acid. The main form of CLA, cis-9, trans-11-C18:2 show positive effects in cancer prevention and treatment. The major dietary sources of these fatty acids are derived from ruminant animals, in particular dairy products. In these animals, the endogenous synthesis mainly occurs in mammary gland by the action of enzyme Stearoyl CoA Desaturase (SCD. Different levels of expression and activity of SCD in mammary gland can explain partially the variation of CLA levels in fat milk. Considering a great fat concentration in bubaline milk and the benefit of a high and positive correlation between fat milk and CLA production, this study was carried on with the intention of sequencing and characterizing part of the gene that codifies SCD in buffaloes. Genomic DNA was extracted from blood samples of lactating bubaline which begins to the breed Murrah. After the (acho que nao precisa desse the extractions, PCR (Polymerase Chain Reaction reactions were made by using primers Z43D1 and E143F1. The fragments obtained in PCR were cloned into “T” vectors and transformed in competent cells DH10B line. After this, three samples of each fragment were sequenced from 5’ and 3’ extremities using a BigDye kit in an automatic sequencer. Sequences were edited in a consensus of each fragment and were submitted to BLAST-n / NCBI for similarity comparisions among other species. The sequence obtained with Z43D1 primers shows 938 bp enclosing exons 1 and 2 and intron 1. The primers E143F1 show 70 bp corresponding to exon 3 of bubaline SCD gene. Similarities were obtained between 85% and 97% among bubaline sequences and sequences of SCD gene described in human, mouse, rat, swine, bovine, caprine and ovine species. This study has permitted the identification and partial characterization of SCD codifing region in Bubalus bubalis specie.

  6. Maternal fatty acid desaturase genotype correlates with infant immune responses at 6 months.

    Science.gov (United States)

    Muc, Magdalena; Kreiner-Møller, Eskil; Larsen, Jeppe M; Birch, Sune; Brix, Susanne; Bisgaard, Hans; Lauritzen, Lotte

    2015-09-28

    Breast milk long-chain PUFA (LCPUFA) have been associated with changes in early life immune responses and may modulate T-cell function in infancy. We studied the effect of maternal fatty acid desaturase (FADS) genotype and breast milk LCPUFA levels on infants' blood T-cell profiles and ex vivo-produced cytokines after anti-CD3/CD28 stimulation of peripheral blood mononuclear cells in 6-month-old infants from the Copenhagen Prospective Study of Asthma in Childhood birth cohort. LCPUFA concentrations of breast milk were assessed at 4 weeks of age, and FADS SNP were determined in both mothers and infants (n 109). In general, breast milk arachidonic acid (AA) levels were inversely correlated with the production of IL-10 (r -0.25; P=0.004), IL-17 (r -0.24; P=0.005), IL-5 (r -0.21; P=0.014) and IL-13 (r -0.17; P=0.047), whereas EPA was positively correlated with the counts of blood regulatory T-cells and cytotoxic T-cells and decreased T-helper cell counts. The minor FADS alleles were associated with lower breast milk AA and EPA, and infants of mothers carrying the minor allele of FADS SNP rs174556 had higher production of IL-10 (r -0.23; P=0.018), IL-17 (r -0.25; P=0.009) and IL-5 (r -0.21; P=0.038) from ex vivo-activated immune cells. We observed no association between T-cell distribution and maternal or infant FADS gene variants. We conclude that increased maternal LCPUFA synthesis and breast milk AA are associated with decreased levels of IL-5, IL-13 (type-2 related), IL-17 (type-17 related) and IL-10 (regulatory immune responses), but not with interferon-γ and TNF-α, which could be due to an effect of the maternal FADS variants on the offspring immune response transferred via breast milk LCPUFA. PMID:26283408

  7. Effects of feeding rapeseed oil, soybean oil, or linseed oil on stearoyl-CoA desaturase expression in the mammary gland of dairy cows

    NARCIS (Netherlands)

    Jacobs, A.A.A.; Baal, van J.; Smits, M.A.; Taweel, H.Z.H.; Hendriks, W.H.; Vuuren, van A.M.; Dijkstra, J.

    2011-01-01

    Stearoyl-CoA desaturase (SCD) is an important enzyme in the bovine mammary gland, and it introduces a double bond at the ¿(9) location of primarily myristoyl-, palmitoyl-, and stearoyl-CoA. The main objective of this study was to compare the effects of various fatty acids (FA) typically present in d

  8. Improvements in glucose tolerance and insulin sensitivity after lifestyle intervention are related to changes in serum fatty acid profile and desaturase activities: the SLIM study

    NARCIS (Netherlands)

    Corpeleijn, E.; Feskens, E.J.M.; Jansen, E.H.J.M.; Mensink, M.R.; Saris, W.H.M.; Bruin, de T.W.A.; Blaak, E.E.

    2006-01-01

    AIMS/HYPOTHESIS: The aim of this study was to investigate whether lifestyle intervention-induced changes in serum fatty acid profile of cholesteryl esters and estimated desaturase activities are related to improvements in insulin sensitivity in subjects at risk of type 2 diabetes. MATERIALS AND METH

  9. Improvements in glucose tolerance and insulin sensitivity after lifestyle intervention are related to changes in serum fatty acid profile and desaturase activities : the SLIM study

    NARCIS (Netherlands)

    Corpeleijn, E.; Feskens, E. J. M.; Jansen, E. H. J. M.; Mensink, M.; Saris, W. H. M.; de Bruin, T. W. A.; Blaak, E. E.

    2006-01-01

    Aims/hypothesis: The aim of this study was to investigate whether lifestyle intervention-induced changes in serum fatty acid profile of cholesteryl esters and estimated desaturase activities are related to improvements in insulin sensitivity in subjects at risk of type 2 diabetes. Materials and meth

  10. Hungarian students’ carrier aspirations

    Directory of Open Access Journals (Sweden)

    A.S. Gubik

    2014-06-01

    Full Text Available The article analyzes the students’ carrier aspiration, right after their graduation and five years after their studies. It examines the differences arising from the students’ family business background and their most important social variables (gender, age. Then the study highlights the effects of study field on the students’ intention. The direct effect of education on starting an enterprise is undiscovered in the literature, the paper deals with the influence of availability and services use, offered by higher institutions.

  11. Carrier transport uphill. I. General

    DEFF Research Database (Denmark)

    Rosenberg, T; Wilbrandt, W

    1963-01-01

    A quantitative treatment of a carrier pump operating with two carrier forms C and Z is presented. Asymmetric metabolic reactions are assumed to transform Z into C on one and C into Z on the other side of the membrane, establishing a carrier cycle. The kinetical consequences of this mechanism...

  12. Targeted mutation of Δ12 and Δ15 desaturase genes in hemp produce major alterations in seed fatty acid composition including a high oleic hemp oil.

    Science.gov (United States)

    Bielecka, Monika; Kaminski, Filip; Adams, Ian; Poulson, Helen; Sloan, Raymond; Li, Yi; Larson, Tony R; Winzer, Thilo; Graham, Ian A

    2014-06-01

    We used expressed sequence tag library and whole genome sequence mining to identify a suite of putative desaturase genes representing the four main activities required for production of polyunsaturated fatty acids in hemp seed oil. Phylogenetic-based classification and developing seed transcriptome analysis informed selection for further analysis of one of seven Δ12 desaturases and one of three Δ15 desaturases that we designate CSFAD2A and CSFAD3A, respectively. Heterologous expression of corresponding cDNAs in Saccharomyces cerevisiae showed CSFAD2A to have Δx+3 activity, while CSFAD3A activity was exclusively at the Δ15 position. TILLING of an ethyl methane sulphonate mutagenized population identified multiple alleles including non-sense mutations in both genes and fatty acid composition of seed oil confirmed these to be the major Δ12 and Δ15 desaturases in developing hemp seed. Following four backcrosses and sibling crosses to achieve homozygosity, csfad2a-1 was grown in the field and found to produce a 70 molar per cent high oleic acid (18:1(Δ9) ) oil at yields similar to wild type. Cold-pressed high oleic oil produced fewer volatiles and had a sevenfold increase in shelf life compared to wild type. Two low abundance octadecadienoic acids, 18:2(Δ6,9) and 18:2(Δ9,15), were identified in the high oleic oil, and their presence suggests remaining endogenous desaturase activities utilize the increased levels of oleic acid as substrate. Consistent with this, CSFAD3A produces 18:2(Δ9,15) from endogenous 18:1(Δ9) when expressed in S. cerevisiae. This work lays the foundation for the development of additional novel oil varieties in this multipurpose low input crop.

  13. Concentrations of long-chain acyl-acyl carrier proteins during fatty acid synthesis by chloroplasts isolated from pea (Pisum sativum), safflower (Carthamus tinctoris), and amaranthus (Amaranthus lividus) leaves

    International Nuclear Information System (INIS)

    Fatty acid synthesis from [1-14C]acetate by chloroplasts isolated from peas and amaranthus was linear for at least 15 min, whereas incorporation of the tracer into long-chain acyl-acyl carrier protein (ACP) did not increase after 2-3 min. When reactions were transferred to the dark after 3-5 min, long-chain acyl-ACPs lost about 90% of their radioactivity and total fatty acids retained all of theirs. Half-lives of the long-chain acyl-ACPs were estimated to be 10-15 s. Concentrations of palmitoyl-, stearoyl-, and oleoyl-ACP as indicated by equilibrium labeling during steady-state fatty acid synthesis, ranged from 0.6-1.1, 0.2-0.7, and 0.4-1.6 microM, respectively, for peas and from 1.6-1.9, 1.3-2.6, and 0.6-1.4 microM, respectively, for amaranthus. These values are based on a chloroplast volume of 47 microliters/mg chlorophyll and varied according to the mode of the incubation. A slow increase in activity of the fatty acid synthetase in safflower chloroplasts resulted in long-chain acyl-ACPs continuing to incorporate labeled acetate for 10 min. Upon re-illumination following a dark break, however, both fatty acid synthetase activity and acyl-ACP concentrations increased very rapidly. Palmitoyl-ACP was present at concentrations up to 2.5 microM in safflower chloroplasts, whereas those of stearoyl- and oleoyl-ACPs were in the lower ranges measured for peas. Acyl-ACPs were routinely separated from extracts of chloroplasts that had been synthesising long-chain fatty acids from labeled acetate by a minor modification of the method of Mancha et al. The results compared favorably with those obtained using alternative analytical methods such as adsorption to filter paper and partition chromatography on silicic acid columns

  14. 骨形态发生蛋白2缓释载体的研究进展%Research Progress of Bone Morphogenetic Protein-2 Controlled-release Carrier

    Institute of Scientific and Technical Information of China (English)

    张以财; 焦力刚

    2012-01-01

    自体骨移植一直是骨修复的"金标准",但仍存在一些问题.异体骨移植同样存在着骨愈合缓慢及排斥反应等问题.随着组织工程学的发展,应用骨组织工程方法来修复骨缺损成为研究热点.骨组织工程主要包括支架材料、种子细胞、生长因子三个方面.骨形态发生蛋白2是目前最强的促骨生长因子,其在体内半衰期很短,必须依靠缓释载体才能发挥其较长效的促骨生长作用.%Autogenous bone graft has long been the " golden standard" of bone repair, while there are some remaining problems. Allograft also have many problems, such as slow bone healing and rejection etc. . With the development of tissue engineering, lots of eyes focus on bone tissue engineering to repair bone defects. There are three key points in bone tissue engineering namely scaffolds, seed cells and growth factor. Bone morphogenetic protein-2 is the most efficient factor to promote bone growth so far,but it has a very short half-time in vivo, which must rely on control-released carrier to fulfill its long-term bone growth-promoting effect.

  15. Maintainable substrate carrier for electroplating

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chen-An; Abas, Emmanuel Chua; Divino, Edmundo Anida; Ermita, Jake Randal G.; Capulong, Jose Francisco S.; Castillo, Arnold Villamor; Ma, Diana Xiaobing

    2016-08-02

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  16. Effects of different carriers on bone-inducing activity of recombinant human osteogenic protein-1%不同载体对重组人成骨蛋白-1骨诱导活性的影响

    Institute of Scientific and Technical Information of China (English)

    王敏; 韩金祥; 宋长征

    2004-01-01

    BACKGROUND: The carriers of recombinant human osteogenic protein-1(rhOP-1) are limited to collagen. The effects of different carriers on its bone inducing activity still have not been proved. OBJECTIVE: To find an optimal carrier material for rhOP-1 through a comparative studies of the effects of different materials on the bone-inducing activity. DESIGN: A completely randomized, auto-control and mutual control study was used. SETTING AND PARTICIPANTS: Ninety-six male mice of Kunming species were recruited in this study and the experiment was completed at the Animal Laboratory of our center. INTERVENTION: The materials included inactive decalcified bone matrix ( DBM), hydroxyapatite ( HA ), polylactic acid ( PLA), polylactic acid-polyethylene glycol copolymers (PLA-PEG) and polylactic glycollc acid (PLGA), and they were compounded with rhOP-1 respectively, and were then implanted into the medial intermuscular septum of the thighs of mice for 3 weeks. Then, samples were taken to evaluate the effects of the five materials on bone-inducing activity of rhOP-1.MAIN OUTCOME MEASURE: New bone maturity and osteogenic rate were assessed by histological studies, determination of alkaline phosphatase (ALP) level and calcium content of the entopic new bone.RESULTS: Three weeks after implantation, groups of DBM/rhOP-1 (A), rhOP-1 (F) and Eukaryon expressed OP-1 (control VI) all showed new bone formation. Group A was found to have massive bone trabeculac, marrow cavity, and lamellar bones as well as rich blood vessels and bone marrow. Group F showed appearance of woven bones. In Group VI, there appeared compact bone tissues of maturity. In the rest of the groups, there was proliferation of mesenchymal cells, and part of the materials were absorbed, and no bone was found. ALP level and calcium content were significantly higher in every compound group than in control group, and they were higher in Group A than in other experimental groups( F =6. 250, P <0.05). No significant

  17. A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer's Disease.

    Science.gov (United States)

    Jiang, Shan; Tang, Ling; Zhao, Na; Yang, Wanling; Qiu, Yu; Chen, Hong-Zhuan

    2016-01-01

    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD) and accounts for 50-65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers' module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson's disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes, whereas AD

  18. Inhibitors of dihydroceramide desaturase 1: Therapeutic agents and pharmacological tools to decipher the role of dihydroceramides in cell biology.

    Science.gov (United States)

    Casasampere, Mireia; Ordoñez, Yadira F; Pou, Ana; Casas, Josefina

    2016-05-01

    Dihydroceramide desaturase (Des1) is the last enzyme in the de novo synthesis of ceramides (Cer). It catalyzes the insertion of a double bond into dihydroceramides (dhCer) to convert them to Cer, both of which are further metabolized to more complex (dihydro) sphingolipids. For many years dhCer have received poor attention, mainly due to their supposed lack of biological activity. It was not until about ten years ago that the concept that dhCer might have regulatory roles in biology emerged for the first time. Since then, multiple publications have established that dhCer are implicated in a wide spectrum of biological processes. Physiological and pathophysiological functions of dhCer have been recently reviewed. In this review we will focus on the biochemical features of Des1 and on its inhibition by different compounds with presumably different modes of action.

  19. Delta-6 desaturase from borage converts linoleic acid to gamma-linolenic acid in HEK293 cells.

    Science.gov (United States)

    Chen, Qing; Nimal, Jonathan; Li, Wanli; Liu, Xia; Cao, Wenguang

    2011-07-01

    Gamma-linolenic acid (GLA, 18:3 n6) is an essential polyunsaturated fatty acid of the omega-6 family and is found to be effective in prevention and/or treatment of various health problems. In this study, we evaluated the possibility of increasing γ-linolenic acid contents in mammalian cells using the delta-6 gene from Borago officinalis. The borage Δ6-desaturase gene (sDelta-6) was codon-optimized and introduced into HEK293 cells by lipofectin transfection. Co-expression of GFP with sDelta-6 and RT-PCR analysis indicated that sDelta-6 could be expressed in mammalian cells. Subsequently, the heterologous expression of borage Δ6-desaturase was evaluated by fatty acid analysis. Total cellular lipid analysis of transformed cells fed with linoleic acid (LA 18:2 n6) as a substrate showed that the expression of sDelta-6 resulted in an 228-483% (p<0.05) increase of GLA when compared with that in the control cells. The highest conversion efficiency of LA into GLA in sDelta-6(+) cells was 6.9 times higher than that in the control group (11.59% vs. 1.69%; p<0.05). Our present work demonstrated that the sDelta-6 gene from borage could be functionally expressed in mammalian cells, and could convert LA into GLA. Furthermore, this study may pave the way to generate transgenic livestock that can synthesise GLA. PMID:21679695

  20. Susceptibility of pancreatic beta cells to fatty acids is regulated by LXR/PPARalpha-dependent stearoyl-coenzyme A desaturase.

    Directory of Open Access Journals (Sweden)

    Karine H Hellemans

    Full Text Available Chronically elevated levels of fatty acids-FA can cause beta cell death in vitro. Beta cells vary in their individual susceptibility to FA-toxicity. Rat beta cells were previously shown to better resist FA-toxicity in conditions that increased triglyceride formation or mitochondrial and peroxisomal FA-oxidation, possibly reducing cytoplasmic levels of toxic FA-moieties. We now show that stearoyl-CoA desaturase-SCD is involved in this cytoprotective mechanism through its ability to transfer saturated FA into monounsaturated FA that are incorporated in lipids. In purified beta cells, SCD expression was induced by LXR- and PPARalpha-agonists, which were found to protect rat, mouse and human beta cells against palmitate toxicity. When their SCD was inhibited or silenced, the agonist-induced protection was also suppressed. A correlation between beta cell-SCD expression and susceptibility to palmitate was also found in beta cell preparations isolated from different rodent models. In mice with LXR-deletion (LXRbeta(-/- and LXRalphabeta(-/-, beta cells presented a reduced SCD-expression as well as an increased susceptibility to palmitate-toxicity, which could not be counteracted by LXR or PPARalpha agonists. In Zucker fatty rats and in rats treated with the LXR-agonist TO1317, beta cells show an increased SCD-expression and lower palmitate-toxicity. In the normal rat beta cell population, the subpopulation with lower metabolic responsiveness to glucose exhibits a lower SCD1 expression and a higher susceptibility to palmitate toxicity. These data demonstrate that the beta cell susceptibility to saturated fatty acids can be reduced by stearoyl-coA desaturase, which upon stimulation by LXR and PPARalpha agonists favors their desaturation and subsequent incorporation in neutral lipids.

  1. Dextran: A promising macromolecular drug carrier

    Directory of Open Access Journals (Sweden)

    Dhaneshwar Suneela

    2006-01-01

    Full Text Available Over the past three decades intensive efforts have been made to design novel systems able to deliver the drug more effectively to the target site. The ongoing intense search for novel and innovative drug delivery systems is predominantly a consequence of the well-established fact that the conventional dosage forms are not sufficiently effective in conveying the drug compound to its site of action and once in the target area, in releasing the active agent over a desired period of time. The potential use of macromolecular prodrugs as a means of achieving targeted drug delivery has attracted considerable interest in recent years. Macromolecules such as antibodies, lipoproteins, lectins, proteins, polypeptides, polysaccharides, natural as well as synthetic polymers offer potential applicabilities as high molecular weight carriers for various therapeutically active compounds. Dextrans serve as one of the most promising macromolecular carrier candidates for a wide variety of therapeutic agents due to their excellent physico-chemical properties and physiological acceptance. The present contribution attempts to review various features of the dextran carrier like its source, structural and physico-chemical characteristics, pharmacokinetic fate and its applications as macromolecular carrier with special emphasis on dextran prodrugs.

  2. A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer’s Disease

    Science.gov (United States)

    Jiang, Shan; Tang, Ling; Zhao, Na; Yang, Wanling; Qiu, Yu; Chen, Hong-Zhuan

    2016-01-01

    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer’s disease (AD) and accounts for 50–65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers’ module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson’s disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes

  3. Mucosal genetic immunization through microsphere–based oral carriers

    OpenAIRE

    Rosli, Rozita; Nograles, Nadine; Hanafi, Aimi; Nor Shamsudin, Mariana; Abdullah, Syahril

    2013-01-01

    Polymeric carriers in the form of cellulose acetate phthalate (CAP) and alginate (ALG) microspheres were used for encapsulation of plasmid DNA for oral mucosal immunization. Access into the intestinal mucosa by pVAX1 eukaryotic expression plasmid vectors carrying gene-coding sequences, either for the cholera enterotoxin B subunit (ctxB) immunostimulatory antigen or the green fluorescent protein (GFP), delivered from both types of microsphere carriers were examined in orally immunized BALB/c m...

  4. Autonomous component carrier selection

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Pedersen, Klaus; Mogensen, Preben

    2009-01-01

    in local areas, basing our study case on LTE-Advanced. We present extensive network simulation results to demonstrate that a simple and robust interference management scheme, called autonomous component carrier selection allows each cell to select the most attractive frequency configuration; improving......Low-power base stations such as e.g. Femto-cells are one of the candidates for high data rate provisioning in local areas, such as residences, apartment complexes, business offices and outdoor hotspot scenarios. Unfortunately, the benefits are not without new challenges in terms of interference...... management and efficient system operation. Due to the expected large number of user-deployed cells, centralized network planning becomes unpractical and new scalable alternatives must be sought. In this article, we propose a fully distributed and scalable solution to the interference management problem...

  5. Development of a high-throughput screening assay for stearoyl-CoA desaturase using rat liver microsomes, deuterium labeled stearoyl-CoA and mass spectrometry

    International Nuclear Information System (INIS)

    Several recent reports suggest that stearoyl-CoA desaturase 1 (SCD1), the rate-limiting enzyme in monounsaturated fatty acid synthesis, plays an important role in regulating lipid homeostasis and lipid oxidation in metabolically active tissues. As several manifestations of type 2 diabetes and related metabolic disorders are associated with alterations in intracellular lipid partitioning, pharmacological manipulation of SCD1 activity might be of benefit in the treatment of these disease states. In an effort to identify small molecule inhibitors of SCD1, we have developed a mass spectrometry based high-throughput screening (HTS) assay using deuterium labeled stearoyl-CoA substrate and induced rat liver microsomes. The methodology developed allows the use of a nonradioactive substrate which avoids interference by the endogenous SCD1 substrate and/or product that exist in the non-purified enzyme source. Throughput of the assay was up to twenty 384-well assay plates per day. The assay was linear with protein concentration and time, and was saturable for stearoyl-CoA substrate (Km = 10.5 μM). The assay was highly reproducible with an average Z' value = 0.6. Conjugated linoleic acid and sterculic acid, known inhibitors of SCD1, exhibited IC50 values of 0.88 and 0.12 μM, respectively. High-throughput mass spectrometry screening of over 1.7 million compounds in compressed format demonstrated that the enzyme target is druggable. A total of 2515 hits were identified (0.1% hit rate), and 346 were confirmed active (>40% inhibition of total SCD activity at 20 μM - 14% conformation rate). Of the confirmed hits 172 had IC50 values of <10 μM, including 111 <1 μM and 48 <100 nM. A large number of potent drug-like (MW < 450) hits representing six different chemical series were identified. The application of mass spectrometry to high-throughput screening permitted the development of a high-quality screening protocol for an otherwise intractable target, SCD1. Further medicinal

  6. Heterogeneity of the Stearoyl-CoA desaturase-1 (SCD1 gene and metabolic risk factors in the EPIC-Potsdam study.

    Directory of Open Access Journals (Sweden)

    Maria Arregui

    Full Text Available BACKGROUND: Stearoyl-CoA desaturase-1 (SCD1 is an enzyme involved in lipid metabolism. In mice and humans its activity has been associated with traits of the metabolic syndrome, but also with the prevention of saturated fatty acids accumulation and subsequent inflammation, whereas for liver fat content inconsistent results have been reported. Thus, variants of the gene encoding SCD1 (SCD1 could potentially modify metabolic risk factors, but few human studies have addressed this question. METHODS: In a sample of 2157 middle-aged men and women randomly drawn from the Potsdam cohort of the European Prospective Investigation into Cancer and Nutrition, we investigated the impact of 7 SCD1 tagging-single nucleotide polymorphisms (rs1502593, rs522951, rs11190480, rs3071, rs3793767, rs10883463 and rs508384 and 5 inferred haplotypes with frequency >5% describing 90.9% of the genotype combinations in our population, on triglycerides, body mass index (BMI, waist circumference (WC, glycated haemoglobin (HbA1c, high-sensitivity C-reactive protein (hs-CRP, gamma-glutamyltransferase (GGT, alanine aminotransferase (ALT and fetuin-A. RESULTS: No significant associations between any of the SNPs or haplotypes and BMI, WC, fetuin-A and hs-CRP were observed. Associations of rs10883463 with triglycerides, GGT and HbA1c as well as of rs11190480 with ALT activity, were weak and became non-significant after multiple-testing correction. Also associations of the haplotype harbouring the minor allele of rs1502593 with HbA1c levels, the haplotype harbouring the minor alleles of rs11190480 and rs508384 with activity of ALT, and the haplotype harbouring the minor alleles of rs522951, rs10883463 and rs508384 with triglyceride and HbA1C levels and GGT activities did not withstand multiple-testing correction. CONCLUSION: These findings suggest that there are no associations between common variants of SCD1 or its inferred haplotypes and the investigated metabolic risk factors

  7. A Candidate Single Nucleotide Polymorphism in the 3′ Untranslated Region of Stearoyl-CoA Desaturase Gene for Fatness Quality and the Gene Expression in Berkshire Pigs

    OpenAIRE

    Lim, Kyu-Sang; Kim, Jun-Mo; Lee, Eun-A; Choe, Jee-Hwan; Hong, Ki-Chang

    2015-01-01

    Fatness qualities in pigs measured by the amount of fat deposition and composition of fatty acids (FAs) in pork have considerable effect on current breeding goals. The stearoyl-CoA desaturase (SCD) gene plays a crucial role in the conversion of saturated FAs into monounsaturated FAs (MUFAs), and hence, is among the candidate genes responsible for pig fatness traits. Here, we identified a single nucleotide polymorphism (SNP, c.*2041T>C) in the 3′ untranslated region by direct sequencing focuse...

  8. Differential Contribution of Endoplasmic Reticulum and Chloroplast ω-3 Fatty Acid Desaturase Genes to the Linolenic Acid Content of Olive (Olea europaea) Fruit.

    Science.gov (United States)

    Hernández, M Luisa; Sicardo, M Dolores; Martínez-Rivas, José M

    2016-01-01

    Linolenic acid is a polyunsaturated fatty acid present in plant lipids, which plays key roles in plant metabolism as a structural component of storage and membrane lipids, and as a precursor of signaling molecules. The synthesis of linolenic acid is catalyzed by two different ω-3 fatty acid desaturases, which correspond to microsomal- (FAD3) and chloroplast- (FAD7 and FAD8) localized enzymes. We have investigated the specific contribution of each enzyme to the linolenic acid content in olive fruit. With that aim, we isolated two different cDNA clones encoding two ω-3 fatty acid desaturases from olive (Olea europaea cv. Picual). Sequence analysis indicates that they code for microsomal (OepFAD3B) and chloroplast (OepFAD7-2) ω-3 fatty acid desaturase enzymes, different from the previously characterized OekFAD3A and OekFAD7-1 genes. Functional expression in yeast of the corresponding OepFAD3A and OepFAD3B cDNAs confirmed that they encode microsomal ω-3 fatty acid desaturases. The linolenic acid content and transcript levels of olive FAD3 and FAD7 genes were measured in different tissues of Picual and Arbequina cultivars, including mesocarp and seed during development and ripening of olive fruit. Gene expression and lipid analysis indicate that FAD3A is the gene mainly responsible for the linolenic acid present in the seed, while FAD7-1 and FAD7-2 contribute mostly to the linolenic acid present in the mesocarp and, therefore, in the olive oil. These results also indicate the relevance of lipid trafficking between the endoplasmic reticulum and chloroplast in determining the linolenic acid content of membrane and storage lipids in oil-accumulating photosynthetic tissues.

  9. Differential Contribution of Endoplasmic Reticulum and Chloroplast ω-3 Fatty Acid Desaturase Genes to the Linolenic Acid Content of Olive (Olea europaea) Fruit.

    Science.gov (United States)

    Hernández, M Luisa; Sicardo, M Dolores; Martínez-Rivas, José M

    2016-01-01

    Linolenic acid is a polyunsaturated fatty acid present in plant lipids, which plays key roles in plant metabolism as a structural component of storage and membrane lipids, and as a precursor of signaling molecules. The synthesis of linolenic acid is catalyzed by two different ω-3 fatty acid desaturases, which correspond to microsomal- (FAD3) and chloroplast- (FAD7 and FAD8) localized enzymes. We have investigated the specific contribution of each enzyme to the linolenic acid content in olive fruit. With that aim, we isolated two different cDNA clones encoding two ω-3 fatty acid desaturases from olive (Olea europaea cv. Picual). Sequence analysis indicates that they code for microsomal (OepFAD3B) and chloroplast (OepFAD7-2) ω-3 fatty acid desaturase enzymes, different from the previously characterized OekFAD3A and OekFAD7-1 genes. Functional expression in yeast of the corresponding OepFAD3A and OepFAD3B cDNAs confirmed that they encode microsomal ω-3 fatty acid desaturases. The linolenic acid content and transcript levels of olive FAD3 and FAD7 genes were measured in different tissues of Picual and Arbequina cultivars, including mesocarp and seed during development and ripening of olive fruit. Gene expression and lipid analysis indicate that FAD3A is the gene mainly responsible for the linolenic acid present in the seed, while FAD7-1 and FAD7-2 contribute mostly to the linolenic acid present in the mesocarp and, therefore, in the olive oil. These results also indicate the relevance of lipid trafficking between the endoplasmic reticulum and chloroplast in determining the linolenic acid content of membrane and storage lipids in oil-accumulating photosynthetic tissues. PMID:26514651

  10. Identification of a Δ12 fatty acid desaturase from oil palm (Elaeis guineensis Jacq.) involved in the biosynthesis of linoleic acid by heterologous expression in Saccharomyces cerevisiae.

    Science.gov (United States)

    Sun, Ruhao; Gao, Lingchao; Yu, Xiaoping; Zheng, Yusheng; Li, Dongdong; Wang, Xinguang

    2016-10-10

    Oil palm (Elaeis guineensis Jacq.) is one of the highest oil-yield crops in the world. A Δ12-desaturases associated with the primary steps of long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis were successfully cloned from oil palm and their functions identified. The open reading frames (ORFs) of egFAD2 (GenBank accession: KT023602) consisted of 1176bp and code for 391 amino acids. Their deduced polypeptides showed 75-93% identity to microsomal Δ12-desaturases from other higher plants, and each contained the three histidine clusters typical of the catalytic domains of such enzymes. RT-PCR experiment indicated that the egFAD2 gene exhibited the highest accumulation in the mesocarp of fruits at 120-140 DAP (i.e. the fourth period of fruit development) and, despite having different expression levels, the other four stages were at significantly lower levels compared with the fourth stage. Plasmid pYES2-egFAD2 was transformed into Saccharomyces cerevisiae strain INVSc1 using lithium acetate method for expression under the induction of galactose. Yeast cells transformed with plasmid constructs containing egFAD12 produced an appreciable amount of linoleic acids (18:2(Δ9,)(12)), not normally present in wild-type yeast cells, indicating that the genes encoded functional Δ12-desaturase enzymes.

  11. Kinetics of Ca2+ carrier in rat liver mitochondria.

    Science.gov (United States)

    Bragadin, M; Pozzan, T; Azzone, G F

    1979-12-25

    The rate of aerobic Ca2+ transport is limited by the rate of the H+ pump rather than by the Ca2+ carrier. The kinetics of the Ca2+ carrier has therefore been studied by using the K+ diffusion potential as the driving force. The apparent Vmax of the Ca2+ carrier is, at 20 degrees C, about 900 nmol (mg of protein)-1 min-1, more than twice the rate of the H+ pump. The apparent Vmax is depressed by Mg2+ and Li+. This supports the view that the electrolytes act as noncompetitive inhibitors of the Ca2+ carrier. The degree of sigmoidicity of the kinetics of Ca2+ transport increases with the lowering of the temperature and proportionally with the concentration of impermeant electrolytes such as Mg2+ and Li+ but not choline. The effects of temperature and of electrolyte do not support the view that the sigmoidicity is due to modifications of the surface potential. Rather, they suggest that Ca2+ transport occurs through a multisubunit carrier, where cooperative phenomena are the result of ligand-induced conformational changes due to the interaction of several allosteric effectors with the carrier subunits. In contrast with La3+ which acts as a competitive inhibitor, Ruthenium Red affects the kinetics by inducing phenomena both of positive and of negative cooperativity. The Ruthenium Red induced kinetics has been reproduced through curve-fitting procedures by applying the Koshland sequential interaction hypothesis to a four-subunit Ca2+ carrier model. PMID:42437

  12. Delta 6- and delta 12-desaturase activities and phosphatidic acid formation in microsomal preparations from the developing cotyledons of common borage (Borago officinalis).

    Science.gov (United States)

    Griffiths, G; Stobart, A K; Stymne, S

    1988-06-15

    Microsomal membrane preparations from the maturing cotyledons of common borage (Borago officinalis) exhibit delta 12- and delta 6-desaturase activities, which resulted in the synthesis of linoleate and gamma-linolenate respectively. The desaturase enzymes utilized the complex lipid substrate phosphatidylcholine. The activity of these enzymes was sufficiently high to allow the monitoring of the mass changes in the endogenous oleate, linoleate and gamma-linolenate in the microsomal phosphatidylcholine in the presence of NADH (i.e. under desaturating conditions). The results illustrate that the delta 12-desaturase uses the oleate substrate at both the sn-1 and -2 positions of sn-phosphatidylcholine, whereas the delta 6-desaturase is almost totally restricted to the linoleate at position 2 of the complex lipid. Estimate of the acyl-substrate pool size at position 2 of sn-phosphatidylcholine for both desaturases indicated that some 50% of the oleate and linoleate was available to the enzymes. The microsomes (microsomal fractions) had a somewhat impaired Kennedy [(1961) Fed. Proc. Fed. Am. Soc. Exp. Biol. 20, 934-940] pathway for the formation of triacylglycerols when compared with other oil-rich plant species that have been studied [Stymne & Stobart (1987) The Biochemistry of Plants: a Comprehensive Treatise (Stumpf, P.K., ed.), vol. 10, chapter 8, pp. 175-214, Academic Press, New York]. In the presence of sn-glycerol 3-phosphate and acyl-CoA, large quantities of phosphatidic acid accumulated in the membranes. Acyl-selectivity studies on the glycerol-acylating enzymes showed that gamma-linolenate could be acylated to both the sn-1 and sn-2 positions of sn-glycerol 3-phosphate. However, stereochemical analysis of the acyl components of the sn-triacylglycerol obtained from mature seeds indicated that, whereas no gamma-linolenate was present at the sn-1 position, it accounted for over 50% of the fatty acids at position sn-3. The results indicate that the diacylglycerol

  13. Nanostructured Lipid Carriers: A potential drug carrier for cancer chemotherapy

    Directory of Open Access Journals (Sweden)

    Selvamuthukumar Subramanian

    2012-11-01

    Full Text Available Abstract Nanotechnology having developed exponentially, the aim has been on therapeutic undertaking, particularly for cancerous disease chemotherapy. Nanostructured lipid carriers have attracted expanding scientific and commercial vigilance in the last couple of years as alternate carriers for the pharmaceutical consignment, particularly anticancer pharmaceuticals. Shortcomings often came across with anticancer mixtures, such as poor solubility, normal tissue toxicity, poor specificity and steadiness, as well as the high incidence rate of pharmaceutical resistance and the rapid degradation, need of large-scale output procedures, a fast release of the pharmaceutical from its carrier scheme, steadiness troubles, the residues of the organic solvents utilized in the output method and the toxicity from the polymer with esteem to the carrier scheme are anticipated to be overcome through use of the Nanostructured Lipid Carrier. In this review the benefits, types, drug release modulations, steadiness and output techniques of NLCs are discussed. In supplement, the function of NLC in cancer chemotherapy is presented and hotspots in research are emphasized. It is foreseen that, in the beside future, nanostructured lipid carriers will be further advanced to consign cytotoxic anticancer compounds in a more efficient, exact and protected manner.

  14. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  15. Systemic down-regulation of delta-9 desaturase promotes muscle oxidative metabolism and accelerates muscle function recovery following nerve injury.

    Directory of Open Access Journals (Sweden)

    Ghulam Hussain

    Full Text Available The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS. Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles.

  16. Polymorphism in the fatty acid desaturase genes and diet are important determinants of infant n-3 fatty acid status

    DEFF Research Database (Denmark)

    Harsløf, L.B.S.; Larsen, L.H.; Ritz, C.;

    breastfeeding was obtained by questionnaires and fish intake was assessed by 7-day pre-coded food diaries. Results: FADS-genotype, breastfeeding, and fish intake were found to explain 25% of the variation in infant RBC DHA-status (mean±SD: 6.6±1.9% of the fatty acids (FA%)). Breastfeeding was the most important......Background and objectives: Tissue docosahexaenoic acid (DHA) accretion in early infancy has been shown to be supported by the DHA-content of breast-milk and thus may decrease once complementary feeding takes over. Endogenous synthesis of DHA from alpha-linolenic acid has been shown to be very low...... and polymorphism in the genes that encodes the fatty acid desaturases (FADS) has little effect on DHA-status in adults. It is however unclear to what extent endogenous DHA-synthesis contributes to infant DHA-status. Aim: To investigate the role of diet and FADS polymorphism on DHA-status at 9 months and 3 years...

  17. Carotenogenesis gene cluster and phytoene desaturase catalyzing both three- and four-step desaturations from Rhodobacter azotoformans.

    Science.gov (United States)

    Zhang, Jinhua; Lu, Lili; Yin, Lijie; Xie, Shen; Xiao, Min

    2012-08-01

    A carotenogenesis gene cluster from the purple nonsulfur photosynthetic bacterium Rhodobacter azotoformans CGMCC 6086 was cloned. A total of eight carotenogenesis genes ( crtA , crtI , crtB , tspO , crtC , crtD , crtE , and crtF ) were located in two separate regions within the genome, a 4.9 kb region containing four clustered genes of crtAIB - tspO and a 5.3 kb region containing four clustered genes of crtCDEF . The organization was unusual for a carotenogenesis gene cluster in purple photosynthetic bacteria. A gene encoding phytoene desaturase ( CrtI ) from Rba. azotoformans was expressed in Escherichia coli. The recombinant CrtI could catalyze both three- and four-step desaturations of phytoene to produce neurosporene and lycopene, and the relative contents of neurosporene and lycopene formed by CrtI were approximately 23% and 75%, respectively. Even small amounts of five-step desaturated 3,4-didehydrolycopene could be produced by CrtI . This product pattern was novel because CrtI produced only neurosporene leading to spheroidene pathway in the cells of Rba. azotoformans. In the in vitro reaction, the relative content of lycopene in desaturated products increased from 19.6% to 62.5% when phytoene reduced from 2.6 to 0.13 μM. The results revealed that the product pattern of CrtI might be affected by the kinetics.

  18. A mitochondrial import receptor for the ADP/ATP carrier

    OpenAIRE

    Söllner, Thomas; Griffiths, Gareth; Pfanner, Nikolaus; Neupert, Walter

    1990-01-01

    We have identified a mitochondrial outer membrane protein of 72 kd (MOM72) that exhibits the properties of an import receptor for the ADP/ATP carrier (AAC), the most abundant mitochondrial protein. Monospecific antibodies and Fab fragments against MOM72 selectively inhibit import of AAC at the level of specific binding to the mitochondria. AAC bound to the mitochondrial surface is coprecipitated with antibodies against MOM72 after lysis of mitochondria with detergent. MOM72 thus has a complem...

  19. Straddle carrier radiation portal monitoring

    Science.gov (United States)

    Andersen, Eric S.; Samuel, Todd J.; Mullen, O. Dennis

    2005-05-01

    U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation"s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. The U.S. ports of entry include the following vectors: land border crossings, seaports, airports, rail crossings, and mail and express consignment courier facilities. U.S. Customs and Border Protection (CBP) determined that a screening solution was needed for Seaport cargo containers being transported by Straddle Carriers (straddle carriers). A stationary Radiation Portal Monitor (RPM) for Straddle Carriers (SCRPM) is needed so that cargo containers can be scanned while in transit under a Straddle Carrier. The Straddle Carrier Portal operational impacts were minimized by conducting a time-motion study at the Port, and adaptation of a Remotely Operated RPM (RO-RPM) booth concept that uses logical lighting schemes for traffic control, cameras, Optical Character Recognition, and wireless technology.

  20. M istic融合蛋白促进ω-3脂肪酸去饱和酶 Fat-1在大肠埃希菌中高效表达%Fusion to Mistic improved fatty acid desaturase Fat-1 overexpression in E .coli

    Institute of Scientific and Technical Information of China (English)

    赵艳; 柳欣欣; 王大新; 李湘鸣; 陈平; 王昊

    2016-01-01

    目的:构建真核膜蛋白ω‐3脂肪酸去饱和酶Fat‐1基因在大肠埃希菌中的高效表达质粒。方法利用分子克隆技术构建携带Fat‐1基因的重组原核表达质粒pET32a‐Fat‐1和插入膜蛋白表达分子伴侣Mistic基因的pET32a‐Mistic‐Fat‐1;将两种重组质粒转化大肠埃希菌株BL21(DE3),IPTG诱导表达Fat‐1蛋白和M110‐Fat‐1蛋白,通过十二烷基‐聚丙烯酰胺凝胶电泳(SDS‐PAGE)灰度分析其表达量,蛋白免疫印迹法(Western blot)进一步鉴定蛋白表达。结果经酶切鉴定和测序证实成功构建了pET32a‐Fat‐1和pET32a‐Mistic‐Fat‐1原核表达载体;SDS‐PAGE和Western blot证实ω‐3脂肪酸去饱和酶Fat‐1在原核表达系统中没有明显诱导表达,而M 110‐Fat‐1融合蛋白在大肠埃希菌中获得了高效表达,占全细胞蛋白总量的15%。结论ω‐3脂肪酸去饱和酶Fat‐1基因与Mistic基因融合表达,实现了在原核宿主中高效表达真核膜整合蛋白ω‐3脂肪酸去饱和酶Fat‐1。%Objective To construct a highly efficient expression plasmid of eukaryotic nuclear membrane protein Omega 3 fatty acid desaturase gene Fat‐1 in E .coli .Methods Using molecular cloning technology to construct the recombinant prokaryotic expression plasmid pET32a Fat‐1 and pET32a‐Mistic‐Fat‐1 fused with Membrane proteins expression chaperon mistic ;the two re‐combinant plasmids were transformed into E .coli strain BL21 (DE3) ,the expression of Fat‐1 protein and M110 Fat‐1 protein in‐duced by IPTG were identified by SDS‐PAGE and gray degree analysed the amount of expression ,further identified by Western blot .Results The results of enzyme digestion and sequencing demonstrated that we successfully constructed the prokaryotic ex‐pression vectors pET32a Fat‐1 and pET32a‐Mistic‐Fat‐1;SDS‐PAGE and Western blot showed that Fat‐1 fatty acid desaturase wasn′t significantly

  1. Impact of carriers in oral absorption

    DEFF Research Database (Denmark)

    Gram, Luise Kvisgaard; Rist, Gerda Marie; Lennernäs, Hans;

    2009-01-01

    Carriers may mediate the permeation across enterocytes for drug substances being organic anions. Carrier mediated permeation for the organic anions estrone-3-sulfate (ES) and glipizide across Caco-2 cells were investigated kinetically, and interactions on involved carriers evaluated. Initial......(APP) was not described by carrier kinetics. However, glipizide is affecting exsorption for ES, due to interactions on basolateral carrier. The study confirms that estrone-3-sulfate can be used to characterize anionic carrier kinetics. Furthermore it is suggested that estrone-3-sulfate may be used to identify compounds...... which may interact on anionic carriers....

  2. Determination of Stearoyl-Coenzyme A Desaturase 1 Gene Variants in South Anatolian Red and East Anatolian Red Cattle

    Directory of Open Access Journals (Sweden)

    İjlal İpek PAYA

    2015-07-01

    Full Text Available Fat composition in ruminant’s milk is one of the factors that can affect human health in positive or adverse ways. Optimizing ruminant feed to achieve ideal fatty acid composition in milk has been an ongoing area of research in recent years, without satisfactory results to date. It has been argued that in addition to changes in feed, genetic information can also be utilized to improve milk fatty acid composition. The aim of the study is to investigate the incidence of stearoyl-CoA-desaturase 1 (SCD gene variants, which are claimed to affect fat content and quality of milk in Turkish native cattle breeds. Fifty South Anatolian Red (SAR and 50 East Anatolian Red (EAR cattle were used in the study. The 5th exon of SCD gene was amplified using polymerase chain reaction (PCR and the PCR products were subjected to sequencing analysis. Among the samples sequenced polymorphism at three nucleotide positions have been observed on the 5th exon of the SCD gene, namely A702G, T762C and C878T. Of these three, the polymorphic position C878T was utilized to determine peptide variants of A (293Ala or the V (293 Val of individual samples. Frequency of A variant and AA genotype in SAR and EAR cattle breeds was 0.91 and 0.77 as well as 0.43 and 0.29, respectively. In particular the SAR exhibits a very low frequency of the V allele, believed to have been an ancestral allele. In both samples, 2 individuals were identified to have the VV genotype. The results suggested that high frequency of A allele and AA genotype which confers great advantage on milk composition and meat fatty acid composition was present in SAR and EAR cattle breeds

  3. Enhancement of carotenoid production by disrupting the C22-sterol desaturase gene (CYP61 in Xanthophyllomyces dendrorhous

    Directory of Open Access Journals (Sweden)

    Loto Iris

    2012-10-01

    Full Text Available Abstract Background Xanthophyllomyces dendrorhous is a basidiomycetous yeast that synthesizes astaxanthin, which is a carotenoid with a great biotechnological impact. The ergosterol and carotenoid synthesis pathways are derived from the mevalonate pathway, and in both pathways, cytochrome P450 enzymes are involved. Results In this study, we isolated and described the X. dendrorhous CYP61 gene, which encodes a cytochrome P450 involved in ergosterol biosynthesis. This gene is composed of nine exons and encodes a 526 amino acid polypeptide that shares significant percentages of identity and similitude with the C22-sterol desaturase, CYP61, from other fungi. Mutants derived from different parental strains were obtained by disrupting the CYP61 gene with an antibiotic selection marker. These mutants were not able to produce ergosterol and accumulated ergosta-5,8,22-trien-3-ol and ergosta-5,8-dien-3-ol. Interestingly, all of the mutants had a more intense red color phenotype than their respective parental strains. The carotenoid composition was qualitatively and quantitatively analyzed by RP-HPLC, revealing that the carotenoid content was higher in the mutant strains without major changes in their composition. The expression of the HMGR gene, which encodes an enzyme involved in the mevalonate pathway (3-hydroxy-3-methylglutaryl-CoA reductase, was analyzed by RT-qPCR showing that its transcript levels are higher in the CYP61 mutants. Conclusions These results suggest that in X. dendrorhous, ergosterol regulates HMGR gene expression by a negative feedback mechanism and in this way; it contributes in the regulation of the carotenoid biosynthesis.

  4. Direct in vivo characterization of delta 5 desaturase activity in humans by deuterium labeling: Effect of insulin

    International Nuclear Information System (INIS)

    The conversion of dihomogamma linolenic acid (DHLA) into arachidonic acid (AA) was compared in normal subjects and diabetic patients before and after treatment with insulin. The kinetics of the incorporation of deuterium-labeled DHLA and its conversion product, deuterium-labeled AA, was determined in plasma triglycerides, plasma phospholipids, and platelet lipids of subjects after ingestion of 2 g of the labeled precursor. Analysis was performed by gas liquid chromatography-mass spectrometry using multiple ion detection. In normal subjects, the deuterium-labeled DHLA concentration rose to 24 to 69 mg/L in plasma triglycerides four to nine hours after ingestion and to 20 to 34 mg/L in plasma phospholipids about four hours later. Deuterium-labeled AA appeared at 12 hours, rose to 2.4 to 3.8 mg/L between 48 and 72 hours in plasma phospholipids, but remained at the limit of detection in plasma triglycerides and was undetectable in platelet lipids. In diabetic patients both before and after insulin treatment, the deuterium-labeled DHLA concentration in plasma triglycerides and in plasma phospholipids followed the same pattern as in normal subjects. However, the deuterium-labeled arachidonic acid concentration was below 1 mg/L in plasma phospholipids before insulin. After insulin treatment the patients recovered normal DHLA metabolism because deuterium-labeled AA rose in phospholipids to a mean value of 3.5 mg/L, which is in the same range as that observed in normal subjects (3.2 mg/L). The present data provide direct evidence for the conversion of DHLA into AA in humans. The effect of insulin and the data from the literature of animal studies suggest insulin dependence of delta 5 desaturase in humans

  5. Cloning and Molecular Identification of A Fatty Acid Desaturase 2 Gene in a and C Genome of Brassica Species

    Institute of Scientific and Technical Information of China (English)

    Lei CHEN; Sang SHUANG; Song CHEN; Feng CHEN; Qi PENG

    2016-01-01

    The fatty acid desaturase 2 (fad2) gene was proven to be a major locus for high oleic acid (C18:1). Brassica napus is an amphidiploid species originating from a spontaneous hybridization of Brassica rapa and Brassica oleracea. B. napus contains multiple copies in genome for most of the genes, including fad2 genes. The research cloned nine fad2 genes from 3 varieties of B. rapa and 3 varieties of B. oleracea, respectively. Alignment of the nine fad2 sequences from B. rapa and B. oleracea detect-ed 6 single nucleotide polymorphic sites, which resulted in 6 amino-acid substitutions. The nucleotide substitutions at position 743 bp in the fad2-A gene and position 947 bp in the fad2-C gene were used as 3’ end of al ele-specific primers. In use of the al-lele-specific primers to amplify fad2 gene, we could identify if the fad2 gene originated from A genome or C genome. Besides, the research found that fad2 genes in C genome are more conserved in evolutionary process than those in A genome. The fad2 expression data reported in this study revealed that fad2-A from B. rapa was not only expressed in siliques same as fad2-C from B. oleracea, but also expressed in a high level in stems. Not even the less, fad2 gene from B. napus was expressed higher in roots and flowers. Al these results provided evidences that fad2, though it was expressed differently in B. rapa and B. oleracea, but it was regulated by the same approach in B. napus.

  6. Serum levels of pancreatic stone protein (PSP)/reg1A as an indicator of beta-cell apoptosis suggest an increased apoptosis rate in hepatocyte nuclear factor 1 alpha (HNF1A-MODY) carriers from the third decade of life onward

    LENUS (Irish Health Repository)

    Bacon, Siobhan

    2012-07-18

    AbstractBackgroundMutations in the transcription factor hepatocyte nuclear factor-1-alpha (HNF1A) result in the commonest type of maturity onset diabetes of the young (MODY). HNF1A-MODY carriers have reduced pancreatic beta cell mass, partially due to an increased rate of apoptosis. To date, it has not been possible to determine when apoptosis is occurring in HNF1A-MODY.We have recently demonstrated that beta cell apoptosis stimulates the expression of the pancreatic stone protein\\/regenerating (PSP\\/reg) gene in surviving neighbour cells, and that PSP\\/reg1A protein is subsequently secreted from these cells. The objective of this study was to determine whether serum levels of PSP\\/reg1A are elevated during disease progression in HNF1A-MODY carriers, and whether it may provide information regarding the onset of beta-cell apoptosis.MethodsWe analysed serum PSP\\/reg1A levels and correlated with clinical and biochemical parameters in subjects with HNF1A-MODY, glucokinase (GCK-MODY), and type 1 diabetes mellitus. A control group of normoglycaemic subjects was also analysed.ResultsPSP\\/reg1A serum levels were significantly elevated in HNF1A-MODY (n = 37) subjects compared to controls (n = 60) (median = 12.50 ng\\/ml, IQR = 10.61-17.87 ng\\/ml versus median = 10.72 ng\\/ml, IQR = 8.94-12.54 ng\\/ml, p = 0.0008). PSP\\/reg1A correlated negatively with insulin levels during OGTT, (rho = −0.40, p = 0.02). Interestingly we noted a significant positive correlation of PSP\\/reg1A with age of the HNF1A-MODY carriers (rho = 0.40 p = 0.02) with an age of 25 years separating carriers with low and high PSP\\/reg1A levels. Patients with type 1 diabetes mellitus also had elevated serum levels of PSP\\/reg1A compared to controls, however this was independent of the duration of diabetes.ConclusionOur data suggest that beta cell apoptosis contributes increasingly to the pathophysiology of HNF1A-MODY in patients 25 years and

  7. MGA2 or SPT23 is required for transcription of the delta9 fatty acid desaturase gene, OLE1, and nuclear membrane integrity in Saccharomyces cerevisiae.

    OpenAIRE

    S. Zhang; Skalsky, Y; Garfinkel, D J

    1999-01-01

    MGA2 and SPT23 are functionally and genetically redundant homologs in Saccharomyces cerevisiae. Both genes are implicated in the transcription of a subset of genes, including Ty retrotransposons and Ty-induced mutations. Neither gene is essential for growth, but mga2 spt23 double mutants are inviable. We have isolated a gene-specific activator, SWI5, and the Delta9 fatty acid desaturase of yeast, OLE1, as multicopy suppressors of an mga2Delta spt23 temperature-sensitive mutation (spt23-ts). T...

  8. Skin-specific Deletion of Stearoyl-CoA Desaturase-1 Alters Skin Lipid Composition and Protects Mice from High Fat Diet-induced Obesity*

    OpenAIRE

    Sampath, Harini; Flowers, Matthew T; Liu, Xueqing; Chad M Paton; Sullivan, Ruth; Chu, Kiki; Zhao, Minghui; Ntambi, James M.

    2009-01-01

    Stearoyl-CoA desaturase-1 (SCD1) catalyzes the synthesis of monounsaturated fatty acids and is an important regulator of whole body energy homeostasis. Severe cutaneous changes in mice globally deficient in SCD1 also indicate a role for SCD1 in maintaining skin lipids. We have generated mice with a skin-specific deletion of SCD1 (SKO) and report here that SKO mice display marked sebaceous gland hypoplasia and depletion of sebaceous lipids. In addition, SKO mice have significantly increased en...

  9. STEAROYL-COA DESATURASE GENE TRANSCRIPTION, mRNA, AND ACTIVITY IN RESPONSE TO TRANS-VACCENIC ACID AND CONJUGATED LINOLEIC ACID ISOMERS

    OpenAIRE

    Lin, Xiaobo

    2000-01-01

    Studies were conducted to investigate: 1) desaturation of dietary trans-vaccenic acid (TVA, trans11-18:1) to the cis9,trans11-18:2 isomer of conjugated linoleic acid (9/11CLA), 2) effects of two conjugated linoleic acid isomers [9/11CLA or trans10,cis12-18:2 (10/12CLA)] and TVA on enzyme activities and mRNA abundance for lipogenic enzymes, and 3) regulation of stearoyl-CoA desaturase (SCD) gene transcription. In the first study, lactating mice were fed 3% linoleic acid (LA...

  10. 以重组肺炎球菌表面黏附素A 为载体蛋白的流感嗜血杆菌多糖结合疫苗的实验研究%Evaluation of the immunogenicity and efficacy of a Hib polysaccharide-protein conjugate vaccine by using PsaA as carrier protein

    Institute of Scientific and Technical Information of China (English)

    陈泽宇; 郭蓉; 徐江红; 吴娟; 薛红刚; 范小勇

    2014-01-01

    Objective To prepare a conjugate vaccine by linking Haemophilus influenzae type b (Hib)polysaccharide to PsaA protein carrier and evaluate the immunogenicity and efficacy of the conjugate vaccine. Methods A recombinant protein rPsaA,expressed by using the genetic engineering technology, was used as a protein carrier to prepare conjugate vaccine together with Hib polysaccharide. Ten mice at age of 3 weeks were immunized with the conjugate vaccine,while another 10 age-matched mice were immunized with Hib-tetanus toxoid(Hib-TT)vaccine which was produced formerly as a control. The mice treated with equal volume of PBS were set up as the negative control. The IgG antibodies in serum samples against PsaA and Hib polysaccharide were detected in two weeks after the final immunization. A suspension of Pneumococ-cus was injected into the middle ears of mice from experiment and control group. Histopathological analysis was performed to measure the clearance of bacteria in the middle ears and the severity of infection on days 3 and 7 after bacterial challenge. Results The rPsaA protein was prepared by the genetic engineering tech-nology and purified successfully with anion-exchange column. The Hib polysaccharide-PsaA protein conju-gate vaccine was prepared through a series of amide condensation reactions. The detection of IgG antibodies against PsaA protein and Hib polysaccharide in the immunized mice demonstrated that there was no signifi-cant difference with the titer of IgG against Hib polysaccharide between the mice immunized with the Hib-PsaA conjugate vaccine and those immunized with the Hib-TT vaccine. Less Pneumococcus strains were de-tected in the middle ears of mice immunized with the conjugate vaccine than those mice immunized with the Hib-TT vaccine three days after challenge. The mice from control group showed severe inflammation in the middle ears than those from experiment group. The Hib polysaccharide-PsaA protein conjugate vaccine im-proved protection against

  11. Evaluation of carrier-mediated siRNA delivery

    DEFF Research Database (Denmark)

    Colombo, Stefano; Nielsen, Hanne Mørck; Foged, Camilla

    2013-01-01

    RNA delivered by use of carriers remains an analytical challenge. The purpose of the present study was to optimize and validate an analytical protocol based on stem-loop reverse transcription quantitative polymerase chain reaction (RT qPCR) to quantitatively monitor the carrier-mediated intracellular si......RNA delivery. An in vitro cell culture model system expressing enhanced green fluorescent protein (EGFP) was used to develop the assay, which was based on the intracellular quantification of a full-length double-stranded Dicer substrate siRNA by stem-loop RT qPCR. The result is a well-documented protocol...

  12. Carrier sense data highway system

    Science.gov (United States)

    Frankel, Robert

    1984-02-14

    A data transmission system includes a transmission medium which has a certain propagation delay time over its length. A number of data stations are successively coupled to the transmission medium for communicating with one another. Each of the data stations includes a transmitter for originating signals, each signal beginning with a carrier of a duration which is at least the propagation delay time of the transmission medium. Each data station also includes a receiver which receives other signals from other data stations and inhibits operation of the transmitter at the same data station when a carrier of another signal is received.

  13. Comparison of immune responses against foot-and-mouth disease virus induced by fusion proteins using the swine IgG heavy chain constant region or β-galactosidase as a carrier of immunogenic epitopes

    International Nuclear Information System (INIS)

    Previously, we demonstrated that a fusion protein (Gal-FMDV) consisting of β-galactosidase and an immunogenic peptide, amino acids (141-160)-(21-40)-(141-160), of foot-and-mouth disease virus (FMDV) VP1 protein induced protective immune responses in guinea pigs and swine. We now designed a new potential recombinant protein vaccine against FMDV in swine. The immunogenic peptide, amino acids (141-160)-(21-40)-(141-160) from the VP1 protein of serotype O FMDV, was fused to the carboxy terminus of a swine immunoglobulin G single heavy chain constant region and expressed in Escherichia coli. The expressed fusion protein (IgG-FMDV) was purified and emulsified with oil adjuvant. Vaccination twice at an interval of 3 weeks with the emulsified IgG-FMDV fusion protein induced an FMDV-specific spleen proliferative T-cell response in guinea pigs and elicited high levels of neutralizing antibody in guinea pigs and swine. All of the immunized animals were efficiently protected against FMDV challenge. There was no significant difference between IgG-FMDV and Gal-FMDV in eliciting immunity after vaccination twice in swine. However, when evaluating the efficacy of a single inoculation of the fusion proteins, we found that IgG-FMDV could elicit a protective immune response in swine, while Gal-FMDV only elicited a weak neutralizing activity and could not protect the swine against FMDV challenge. Our results suggest that the IgG-FMDV fusion protein is a promising vaccine candidate for FMD in swine

  14. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  15. On the structure and function of the phytoene desaturase CRTI from Pantoea ananatis, a membrane-peripheral and FAD-dependent oxidase/isomerase.

    Science.gov (United States)

    Schaub, Patrick; Yu, Qiuju; Gemmecker, Sandra; Poussin-Courmontagne, Pierre; Mailliot, Justine; McEwen, Alastair G; Ghisla, Sandro; Al-Babili, Salim; Cavarelli, Jean; Beyer, Peter

    2012-01-01

    CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with the lipophilic substrate phytoene contained in phosphatidyl-choline (PC) liposome membranes. The first crystal structure of apo-CRTI reveals that CRTI belongs to the flavoprotein superfamily comprising protoporphyrinogen IX oxidoreductase and monoamine oxidase. CRTI is a membrane-peripheral oxidoreductase which utilizes FAD as the sole redox-active cofactor. Oxygen, replaceable by quinones in its absence, is needed as the terminal electron acceptor. FAD, besides its catalytic role also displays a structural function by enabling the formation of enzymatically active CRTI membrane associates. Under anaerobic conditions the enzyme can act as a carotene cis-trans isomerase. In silico-docking experiments yielded information on substrate binding sites, potential catalytic residues and is in favor of single half-site recognition of the symmetrical C(40) hydrocarbon substrate. PMID:22745782

  16. Effects of growth phase and nitrogen starvation on expression of fatty acid desaturases and fatty acid composition of Isochrysis aff. galbana (TISO).

    Science.gov (United States)

    Huerlimann, Roger; Steinig, Eike J; Loxton, Heather; Zenger, Kyall R; Jerry, Dean R; Heimann, Kirsten

    2014-07-15

    Very long-chain polyunsaturated fatty acids (VLC-PUFAs) are important dietary requirements for maintaining human health. Many marine microalgae are naturally high in ω-3 VLC-PUFAs, however, the molecular mechanisms underpinning fatty acid (FA) desaturation and elongation in algae are poorly understood. An advanced molecular understanding would facilitate improvements of this nascent industry. We aimed to investigate expression responses of four front-end fatty acid desaturase genes and downstream effects on FA profiles to nitrogen limitation and cultivation growth stage in Isochrysis aff. galbana (TISO). Cultures were grown in nitrogen-replete and -deplete medium; samples were harvested during logarithmic, late logarithmic and stationary growth phases to analyse FA content/composition and gene expression of ∆(6)-, ∆(8)-, ∆(5)- and ∆(4)-desaturases (d6FAD (putative), d8FAD, d5FAD and d4FAD, respectively). d6FAD (putative) exhibited no differential expression, while d8FAD, d5FAD and d4FAD were significantly upregulated during logarithmic growth of nutrient-replete cultures, coinciding with rapid cell division. In conclusion, it is demonstrated that expression of some FADs in I. aff. galbana varies with culture age and nitrogen status which has downstream consequences on FA desaturation levels. This has implications for the commercial production of VLC-PUFAs where a trade-off between total lipid yield and VLC-PUFAs has to be made.

  17. Expression of the genes encoding the CasK/R two-component system and the DesA desaturase during Bacillus cereus cold adaptation.

    Science.gov (United States)

    Diomandé, Sara Esther; Doublet, Bénédicte; Vasaï, Florian; Guinebretière, Marie-Hélène; Broussolle, Véronique; Brillard, Julien

    2016-08-01

    Two-component systems (TCS) allow a cell to elaborate a variety of adaptive responses to environment changes. The recently discovered CasK/R TCS plays a role in the optimal unsaturation of fatty acids necessary for cold adaptation of the foodborne-pathogen Bacillus cereus Here, we showed that the promoter activity of the operon encoding this TCS was repressed during growth at low temperature in the stationary phase in the parental strain when compared to the casK/R mutant, suggesting that CasR negatively regulates the activity of its own promoter in these conditions. The promoter activity of the desA gene encoding the Δ5 fatty acid desaturase, providing unsaturated fatty acids (UFAs) required for low temperature adaptation, was repressed in the casK/R mutant grown at 12°C versus 37°C. This result suggests that CasK/R activates desA expression during B. cereus growth at low temperature, allowing an optimal unsaturation of the fatty acids. In contrast, desA expression was repressed during the lag phase at low temperature in presence of UFAs, in a CasK/R-independent manner. Our findings confirm that the involvement of this major TCS in B. cereus cold adaptation is linked to the upregulation of a fatty acid desaturase. PMID:27435329

  18. On the structure and function of the phytoene desaturase CRTI from Pantoea ananatis, a membrane-peripheral and FAD-dependent oxidase/isomerase.

    Directory of Open Access Journals (Sweden)

    Patrick Schaub

    Full Text Available CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with the lipophilic substrate phytoene contained in phosphatidyl-choline (PC liposome membranes. The first crystal structure of apo-CRTI reveals that CRTI belongs to the flavoprotein superfamily comprising protoporphyrinogen IX oxidoreductase and monoamine oxidase. CRTI is a membrane-peripheral oxidoreductase which utilizes FAD as the sole redox-active cofactor. Oxygen, replaceable by quinones in its absence, is needed as the terminal electron acceptor. FAD, besides its catalytic role also displays a structural function by enabling the formation of enzymatically active CRTI membrane associates. Under anaerobic conditions the enzyme can act as a carotene cis-trans isomerase. In silico-docking experiments yielded information on substrate binding sites, potential catalytic residues and is in favor of single half-site recognition of the symmetrical C(40 hydrocarbon substrate.

  19. Fatty Acid Composition of Tissue Cultured Breast Carcinoma and the Effect of Stearoyl-CoA Desaturase 1 Inhibition

    Science.gov (United States)

    Mohammadzadeh, Fatemeh; Mosayebi, Gholamali; Montazeri, Vahid; Darabi, Maryam; Fayezi, Shabnam; Shaaker, Maghsod; Rahmati, Mohammad; Baradaran, Behzad; Mehdizadeh, Amir

    2014-01-01

    Purpose Stearoyl-CoA desaturase 1 (SCD1) is a novel therapeutic target in various malignancies, including breast cancer. The present study was designed to investigate the effect of the pharmacologic inhibition of SCD1 on fatty acid composition in tissue explant cultures of human breast cancer and to compare these effects with those in adjacent nonneoplastic breast tissue. Methods Paired samples of tumor and adjacent noncancerous tissue were isolated from 12 patients with infiltrating ductal breast cancer. Samples were explant cultured in vitro, exposed to the highly selective SCD1 inhibitor CAY10566, and examined for fatty acid composition by gas liquid chromatography. The cytotoxic and antigrowth effects were evaluated by quantification of lactate dehydrogenase release and by sulforhodamine B (SRB) measurement, respectively. Results Breast cancer tissue samples were found to have higher levels of monounsaturated fatty acids (MUFA) (p<0.001) and arachidonic acid (20:4n-6, p<0.001) and a lower level of linoleic acid (18:2n-6, p=0.02) than the normal-appearing breast tissues. While exhibiting no evident cytotoxicity, treatment with the SCD1 inhibitor, CAY10566 (0.1-1 µM), for 48 hours significantly increased 18:2n-6 levels in both the tumor and adjacent normal-appearing tissue (approximately 1.2 fold, p<0.05). However, the breast cancer tissue samples showed significant increases in the levels of MUFA and 20:4n-6 compared to the normal-appearing breast tissues (p<0.05). The SRB growth assay revealed a higher rate of inhibition with the SCD1 inhibitor in breast cancer tissues than in normal-appearing tissues (p<0.01, 41% vs. 29%). The SCD1 inhibitor also elevated saturated fatty acid (1.46-fold, p=0.001) levels only in the tumor tissue explant. Conclusion The fatty acid composition and response to SCD1 inhibition differed between the explant cultures from breast cancer and the adjacent normal-appearing tissue. Altered fatty acid composition induced by SCD1 inhibition

  20. Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of delta6-desaturated fatty acids in transgenic tobacco.

    Science.gov (United States)

    Sayanova, O; Smith, M A; Lapinskas, P; Stobart, A K; Dobson, G; Christie, W W; Shewry, P R; Napier, J A

    1997-04-15

    gamma-Linolenic acid (GLA; C18:3 delta(6,9,12)) is a component of the seed oils of evening primrose (Oenothera spp.), borage (Borago officinalis L.), and some other plants. It is widely used as a dietary supplement and for treatment of various medical conditions. GLA is synthesized by a delta6-fatty acid desaturase using linoleic acid (C18:2 delta(9,12)) as a substrate. To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants. Analysis of leaf lipids from a transformed plant demonstrated the accumulation of GLA and octadecatetraenoic acid (C18:4 delta(6,9,12,15)) to levels of 13.2% and 9.6% of the total fatty acids, respectively. The borage delta6-fatty acid desaturase differs from other desaturase enzymes, characterized from higher plants previously, by the presence of an N-terminal domain related to cytochrome b5. PMID:9108131

  1. Fatigue reliability for LNG carrier

    Institute of Scientific and Technical Information of China (English)

    Xiao Taoyun; Zhang Qin; Jin Wulei; Xu Shuai

    2011-01-01

    The procedure of reliability-based fatigue analysis of liquefied natural gas (LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave heading angles and wave lengths are evaluated by global ship finite element method (FEM). Based on the probabilistic distribution function of hotspots' short-term stress-range using spectral-based analysis, Weibull distribution is adopted and discussed for fitting the long-term probabilistic distribution of stress-range. Based on linear cumulative damage theory, fatigue damage is characterized by an S-N relationship, and limit state function is established. Structural fatigue damage behavior of several typical hotspots of LNG middle ship section is clarified and reliability analysis is performed. It is believed that the presented results and conclusions can be of use in calibration for practical design and initial fatigue safety evaluation for membrane type LNG carrier.

  2. Gemini surfactants as gene carriers

    Directory of Open Access Journals (Sweden)

    Teresa Piskorska

    2010-03-01

    Full Text Available Gemini surfactants are a new class of amphiphilic compounds built from two classic surfactant moieties bound together by a special spacer group. These compounds appear to be excellent for creating complexes with DNA and are effective in mediating transfection. Thanks to their construction, DNA carrier molecules built from gemini surfactants are able to deliver genes to cells of almost any DNA molecule size, unattainable when using viral gene delivery systems. Moreover, they are much safer for living organisms.

  3. Preventative maintenance of straddle carriers

    Directory of Open Access Journals (Sweden)

    Si Li

    2015-02-01

    Full Text Available Background: Robotic vehicles such as straddle carriers represent a popular form of cargo handling amongst container terminal operators.Objectives: The purpose of this industry-driven study is to model preventative maintenance (PM influences on the operational effectiveness of straddle carriers.Method: The study employs historical data consisting of 21 273 work orders covering a 27-month period. Two models are developed, both of which forecast influences of PM regimes for different types of carrier.Results: The findings of the study suggest that the reliability of the straddle fleet decreases with increased intervals of PM services. The study also finds that three factors – namely resources, number of new straddles, and the number of new lifting work centres – influence the performances of straddles.Conclusion: The authors argue that this collaborative research exercise makes a significant contribution to existing supply chain management literature, particularly in the area of operations efficiency. The study also serves as an avenue to enhance relevant management practice.

  4. Δ-6 Desaturase substrate competition: dietary linoleic acid (18:2n-6) has only trivial effects on α-linolenic acid (18:3n-3) bioconversion in the teleost rainbow trout.

    Science.gov (United States)

    Emery, James A; Hermon, Karen; Hamid, Noor K A; Donald, John A; Turchini, Giovanni M

    2013-01-01

    It is generally accepted that, in vertebrates, omega-3 (n-3) and omega-6 (n-6) poly-unsaturated fatty acids (PUFA) compete for Δ-6 desaturase enzyme in order to be bioconverted into long-chain PUFA (LC-PUFA). However, recent studies into teleost fatty acid metabolism suggest that these metabolic processes may not conform entirely to what has been previously observed in mammals and other animal models. Recent work on rainbow trout has led us to question specifically if linoleic acid (LA, 18∶2n-6) and α-linolenic acid (ALA, 18∶3n-3) (Δ-6 desaturase substrates) are in direct competition for access to Δ-6 desaturase. Two experimental diets were formulated with fixed levels of ALA, while LA levels were varied (high and low) to examine if increased availability of LA would result in decreased bioconversion of ALA to its LC-PUFA products through substrate competition. No significant difference in ALA metabolism towards n-3 LC-PUFA was exhibited between diets while significant differences were observed in LA metabolism towards n-6 LC-PUFA. These results are evidence for minor if any competition between substrates for Δ-6 desaturase, suggesting that, paradoxically, the activity of Δ-6 desaturase on n-3 and n-6 substrates is independent. These results call for a paradigm shift in the way we approach teleost fatty acid metabolism. The findings are also important with regard to diet formulation in the aquaculture industry as they indicate that there should be no concern for possible substrate competition between 18∶3n-3 and 18∶2n-6, when aiming at increased n-3 LC-PUFA bioconversion in vivo. PMID:23460861

  5. Δ-6 Desaturase substrate competition: dietary linoleic acid (18:2n-6 has only trivial effects on α-linolenic acid (18:3n-3 bioconversion in the teleost rainbow trout.

    Directory of Open Access Journals (Sweden)

    James A Emery

    Full Text Available It is generally accepted that, in vertebrates, omega-3 (n-3 and omega-6 (n-6 poly-unsaturated fatty acids (PUFA compete for Δ-6 desaturase enzyme in order to be bioconverted into long-chain PUFA (LC-PUFA. However, recent studies into teleost fatty acid metabolism suggest that these metabolic processes may not conform entirely to what has been previously observed in mammals and other animal models. Recent work on rainbow trout has led us to question specifically if linoleic acid (LA, 18∶2n-6 and α-linolenic acid (ALA, 18∶3n-3 (Δ-6 desaturase substrates are in direct competition for access to Δ-6 desaturase. Two experimental diets were formulated with fixed levels of ALA, while LA levels were varied (high and low to examine if increased availability of LA would result in decreased bioconversion of ALA to its LC-PUFA products through substrate competition. No significant difference in ALA metabolism towards n-3 LC-PUFA was exhibited between diets while significant differences were observed in LA metabolism towards n-6 LC-PUFA. These results are evidence for minor if any competition between substrates for Δ-6 desaturase, suggesting that, paradoxically, the activity of Δ-6 desaturase on n-3 and n-6 substrates is independent. These results call for a paradigm shift in the way we approach teleost fatty acid metabolism. The findings are also important with regard to diet formulation in the aquaculture industry as they indicate that there should be no concern for possible substrate competition between 18∶3n-3 and 18∶2n-6, when aiming at increased n-3 LC-PUFA bioconversion in vivo.

  6. Decrease in membrane phospholipid unsaturation induces unfolded protein response.

    Science.gov (United States)

    Ariyama, Hiroyuki; Kono, Nozomu; Matsuda, Shinji; Inoue, Takao; Arai, Hiroyuki

    2010-07-16

    Various kinds of fatty acids are distributed in membrane phospholipids in mammalian cells and tissues. The degree of fatty acid unsaturation in membrane phospholipids affects many membrane-associated functions and can be influenced by diet and by altered activities of lipid-metabolizing enzymes such as fatty acid desaturases. However, little is known about how mammalian cells respond to changes in phospholipid fatty acid composition. In this study we showed that stearoyl-CoA desaturase 1 (SCD1) knockdown increased the amount of saturated fatty acids and decreased that of monounsaturated fatty acids in phospholipids without affecting the amount or the composition of free fatty acid and induced unfolded protein response (UPR), evidenced by increased expression of C/EBP homologous protein (CHOP) and glucose-regulated protein 78 (GRP78) mRNAs and splicing of Xbox-binding protein 1 (XBP1) mRNA. SCD1 knockdown-induced UPR was rescued by various unsaturated fatty acids and was enhanced by saturated fatty acid. Lysophosphatidylcholine acyltransferase 3 (LPCAT3), which incorporates preferentially polyunsaturated fatty acids into phosphatidylcholine, was up-regulated in SCD1 knockdown cells. Knockdown of LPCAT3 synergistically enhanced UPR with SCD1 knockdown. Finally we showed that palmitic acid-induced UPR was significantly enhanced by LPCAT3 knockdown as well as SCD1 knockdown. These results suggest that a decrease in membrane phospholipid unsaturation induces UPR.

  7. Responsible implementation of expanded carrier screening

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-01-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines. PMID:26980105

  8. Spacelab carrier complement thermal design and performance

    Science.gov (United States)

    Bancroft, S.; Key, R.; Kittredge, S.

    1992-01-01

    The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

  9. 7 CFR 33.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Carrier. 33.4 Section 33.4 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.4 Carrier. Carrier means any common...

  10. Effect of different contents of extruded linseed in the sow diet on piglet fatty acid composition and hepatic desaturase expression during the post-natal period.

    Science.gov (United States)

    de Quelen, F; Boudry, G; Mourot, J

    2013-10-01

    n-3 polyunsaturated fatty acids (n-3 PUFA) contribute to the normal growth and development of numerous organs in the piglet. The fatty acid composition of piglet tissues is linked to the fatty acid composition of sow milk and, consequently, to the composition of sow diet during the gestation and lactation period. In this study, we investigated the impact of different contents of extruded linseed in the sow diet on the fatty acid composition and desaturase gene expression of piglets. Sows received a diet containing either sunflower oil (low 18:3n-3 with 18:3n-3 representing 3% of total fatty acids) or a mixture of extruded linseed and sunflower oil (medium 18:3n-3 with 9% of 18:3n-3) or extruded linseed (high 18:3n-3 with 27% of 18:3n-3) during gestation and lactation. Fatty acid composition was evaluated on sow milk and on different piglet tissues at days 0, 7, 14, 21 and 28. The postnatal evolution of delta5 (D5D) and delta6 (D6D) desaturase mRNA expression was also measured in the liver of low 18:3n-3 and high 18:3n-3 piglets. The milk of high 18:3n-3 sows had higher proportions of n-3PUFA than that of low 18:3n-3 and medium 18:3n-3 sows. Piglets suckling the high 18:3n-3 sows had greater proportions of 18:3n-3, 20:5n-3, 22:5n-3 and 22:6n-3 in the liver, and of 22:5n-3 and 22:6n-3 in the brain than low 18:3n-3 and medium 18:3n-3 piglets. D5D and D6D mRNA expressions in piglet liver were not affected by the maternal diet at any age. In conclusion, extruded linseed in the sow diet modifies the n-3PUFA status of piglets during the postnatal period. However, a minimal content of 18:3n-3 in the sow diet is necessary to increase the n-3PUFA level in piglet liver and brain. Moreover, modifications in the n-3PUFA fatty acid composition of piglet tissue seem linked to the availability of 18:3n-3 in maternal milk and not to desaturase enzyme expression.

  11. 49 CFR 376.22 - Exemption for private carrier leasing and leasing between authorized carriers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Exemption for private carrier leasing and leasing... MOTOR CARRIER SAFETY REGULATIONS LEASE AND INTERCHANGE OF VEHICLES Exemptions for the Leasing Regulations § 376.22 Exemption for private carrier leasing and leasing between authorized carriers....

  12. Carrier synchronization for STBC OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Cai Jueping; Song Wentao; Li Zan; Ge Jianhua

    2005-01-01

    All-digital carrier synchronization strategies and algorithms for space-time block coding (STBC) orthogonal frequency division multiplexing (OFDM) are proposed in this paper. In our scheme, the continuous pilots (CP) are saved, and the complexity of carrier synchronization is reduced significantly by dividing the process into three steps. The coarse carrier synchronization and the fine carrier synchronization algorithms are investigated and analyzed in detail. Simulations show that the carrier can be locked into tracking mode quickly, and the residual frequency error satisfies the system requirement in both stationary and mobile environments.

  13. Carrier frequencies, holomorphy and unwinding

    CERN Document Server

    Coifman, Ronald R; Wu, Hau-tieng

    2016-01-01

    We prove that functions of intrinsic-mode type (a classical models for signals) behave essentially like holomorphic functions: adding a pure carrier frequency $e^{int}$ ensures that the anti-holomorphic part is much smaller than the holomorphic part $ \\| P_{-}(f)\\|_{L^2} \\ll \\|P_{+}(f)\\|_{L^2}.$ This enables us to use techniques from complex analysis, in particular the \\textit{unwinding series}. We study its stability and convergence properties and show that the unwinding series can stabilize and show that the unwinding series can provide a high resolution time-frequency representation, which is robust to noise.

  14. Biocheese: A Food Probiotic Carrier

    Directory of Open Access Journals (Sweden)

    J. M. Castro

    2015-01-01

    Full Text Available This review describes some aspects related to the technological barriers encountered in the development and stability of probiotic cheeses. Aspects concerning the viability of probiotic cultures in this matrix are discussed and the potential of cheese as a biofunctional food carrier is analyzed, outlying some points related to health and safety. In general, the manufacture of probiotic cheese should have little change when compared with the elaboration of cheese in the traditional way. The physicochemical and technological parameters influencing the quality of these products have also to be measured so as to obtain a process optimization.

  15. Wuestite - a solar energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Weidenkaff, A.; Nueesch, P.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Reller, A. [Hamburg Univ., Hamburg (Germany)

    1997-06-01

    Hydrogen is produced when Wuestite (Fe{sub 1-y}O) is oxidised by water. This reaction is part of a two-step thermochemical metal oxide cycle for the storage of solar energy in the form of chemical energy carriers, characterised by a high chemical potential. The reaction was studied in a tubular furnace with on-line gas analysis and further characterised in detail by DTA und high-temperature X-ray powder diffraction. The influence of non-stoichiometry, morphology and temperature on the mechanism and kinetics of the water-splitting reaction was determined. (author) 3 figs., tabs., 3 refs.

  16. Carrier detection in xeroderma pigmentosum

    International Nuclear Information System (INIS)

    We were able to detect clinically normal carriers of xeroderma pigmentosum (XP) genes with coded samples of either peripheral blood lymphocytes or skin fibroblasts, using a cytogenetic assay shown previously to detect individuals with cancer-prone genetic disorders. Metaphase cells of phytohemagglutinin-stimulated T-lymphocytes from eight individuals who are obligate heterozygotes for XP were compared with those from nine normal controls at 1.3, 2.3, and 3.3 h after x-irradiation (58 R) during the G2 phase of the cell cycle. Lymphocytes from the XP heterozygotes had twofold higher frequencies of chromatid breaks or chromatid gaps than normal (P less than 10(-5)) when fixed at 2.3 or 3.3 h after irradiation. Lymphocytes from six XP homozygotes had frequencies of breaks and gaps threefold higher than normal. Skin fibroblasts from an additional obligate XP heterozygote, when fixed approximately 2 h after x-irradiation (68 R), had a twofold higher frequency of chromatid breaks and a fourfold higher frequency of gaps than fibroblasts from a normal control. This frequency of aberrations in cells from the XP heterozygote was approximately half that observed in the XP homozygote. The elevated frequencies of chromatid breaks and gaps after G2 phase x-irradiation may provide the basis of a test for identifying carriers of the XP gene(s) within known XP families

  17. Carrier localization in gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, C. [Lawrence Berkeley National Lab., CA (United States)][California Univ., Berkeley, CA (United States); Walukiewicz, W. [Lawrence Berkeley National Lab., CA (United States); Haller, E.E. [Lawrence Berkeley National Lab., CA (United States)][California Univ., Berkeley, CA (United States)] [and others

    1996-09-01

    In wide bandgap GaN, a large number of interesting and important scientific questions remain to be answered. For example, the large free electron concentration reaching 10{sup 19} to 10{sup 20} cm{sup - 3} in nominally undoped material are ascribed to intrinsic defects because no chemical impurity has been found at such high concentrations. According to theoretical models, a nitrogen vacancy acts as a donor but its formation energy is very large in n-type materials, making this suggestion controversial. We have investigated the nature of this yet unidentified donor at large hydrostatic pressure. Results from infrared reflection and Raman scattering indicate strong evidence for localization of free carriers by large pressures. The carrier density is drastically decreased by two orders of magnitude between 20 and 30 GPa. Several techniques provide independent evidence for results in earlier reports and present the first quantitative analysis. A possible interpretation of this effect in terms of the resonant donor level is presented.

  18. Posttranslational modification and trafficking of PIN auxin efflux carriers.

    Science.gov (United States)

    Löfke, Christian; Luschnig, Christian; Kleine-Vehn, Jürgen

    2013-01-01

    Cell-to-cell communication is absolutely essential for multicellular organisms. Both animals and plants use chemicals called hormones for intercellular signaling. However, multicellularity of plants and animals has evolved independently, which led to establishment of distinct strategies in order to cope with variations in an ever-changing environment. The phytohormone auxin is crucial to plant development and patterning. PIN auxin efflux carrier-driven polar auxin transport regulates plant development as it controls asymmetric auxin distribution (auxin gradients), which in turn modulates a wide range of developmental processes. Internal and external cues trigger a number of posttranslational PIN auxin carrier modifications that were demonstrated to decisively influence variations in adaptive growth responses. In this review, we highlight recent advances in the analysis of posttranslational modification of PIN auxin efflux carriers, such as phosphorylation and ubiquitylation, and discuss their eminent role in directional vesicle trafficking, PIN protein de-/stabilization and auxin transport activity. We conclude with updated models, in which we attempt to integrate the mechanistic relevance of posttranslational modifications of PIN auxin carriers for the dynamic nature of plant development.

  19. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  20. Bioinformatics analysis for structure and function of mitochondrial carrier protein superfamily from Spirometra mansoni%曼氏迭宫绦虫线粒体载体蛋白结构和功能的生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    芦亚君; 史大中; 钟赛凤; 甘秀凤; 吕刚

    2013-01-01

    目的 应用生物信息学技术预测曼氏迭宫绦虫线粒体载体蛋白超家族的结构和功能,为进一步研究曼氏迭宫绦虫的蛋白质提供理论依据.方法 将测得的曼氏迭宫绦虫成虫EST序列用ORF finder获取开放读码框,Blast进行分析其结构域.应用分析工具Protparam、InterProScan、protscale、SignalP-3.0、PSORTⅡ、BepiPred、TMHMM、VectorNTI Suite 9软件包、Phyre2分别进行该蛋白质的基本性质、结构域、疏水性、信号肽、亚细胞定位、抗原表位、跨膜区及空间结构的预测及分析.结果 Blast预测该蛋白质为线粒体载体蛋白超家族,保守功能域为线粒体二羧酸载体,含294个氨基酸残基,理论分子量为32 132.2 Da.与曼氏血吸虫进化地位最接近;有1个信号肽位点和6个潜在的抗原表位.结论 曼氏迭宫绦虫线粒体二羧酸载体能够介导苹果酸、琥珀酸等二羧酸的转运,使其跨越线粒体膜参与三羧酸循环,为虫体自身提供能量,可能是潜在的疫苗候选分子及药物作用靶点.%Objective To study the structure and function of mitochondrial carrier protein superfamily from Spirometra mansoni by bioinformatics technology,and to provide a theoretical basis for further study.Methods Open reading frame (ORF) of EST sequence from Spirometra mansoni was obtained by ORF finder and was translated into amino acid by DNAclub.The structure domain was analyzed by Blast.By the method of online analysis tools:Protparam,InterProScan,protscale,SignalP-3.0,PSORT Ⅱ,BepiPred,TMtHMM,VectorNTI Suite 9 packages and Phyre2,the structure and function of the protein were predicted and analyzed.Results The mitochondrial carrier protein superfamily may be Spirometra mansoni mitochondrial dicarboxylate carrier (Sm DIC).The sequence contained 294 amino acid residues and its theoretical molecular weight was 32003.4 Da.It had three full conserved functional domains that was mito-carr superfamily,with the closest to

  1. A mRNA molecule encoding truncated excitatory amino acid carrier 1 (EAAC1) protein (EAAC2) is transcribed from an independent promoter but not an alternative splicing event

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Glutamate transporter EAAC1 removes excitatory neurotransmitter in central nervous system, and alsoabsorbs glutamate in epithelia of intestine, kidney, liver and heart for normal cell growth. When a mousecDNA was screened using EAAC1 cDNA fragment as probe in our lab, a transcript (GenBank U75214)encoding an EAAC1 protein with 148 residues truncated at N-terminal was cloned and named as EAAC2.Sequence analysis shows that EAAC2 has it's own start code and unique 5'UTR that is different from that ofEAAC1. A mouse genomic library was screened and a positive clone including EAAC1 CDS was sequenced(GenBank AF 322393) and indicates that normal EAAC1 transcript (GenBank U73521) is transcribed from10 exons in terms of exon I, II, III, IV, V, VI, VII, VIII, IX, X, and EAAC2 transcript is consisted by exonsfrom IV to IX as same as that of EAAC1 and with its unique exonβ upstream to exon IV and exon δdownstream to IX. EAAC2 transcript has a cluster of transcriptional start sites not overlapping with thetranscriptional start sites of EAAC1. These results indicate that EAAC2 is transcribed from an independentpromoter but not an alternative splicing event.

  2. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schonning, Kristian;

    2016-01-01

    pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium...... microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate...

  3. Contribution of Tumoral and Host Solute Carriers to Clinical Drug Response

    OpenAIRE

    Sprowl, Jason A; Mikkelsen, Torben S.; Giovinazzo, Hugh; Sparreboom, Alex

    2012-01-01

    Members of the solute carrier family of transporters are responsible for the cellular uptake of a broad range of endogenous compounds and xenobiotics in multiple tissues. Several of these solute carriers are known to be expressed in cancer cells or cancer cell lines, and decreased cellular uptake of drugs potentially contributes to the development of resistance. As result, the expression levels of these proteins in humans have important consequences for an individual’s susceptibility to certa...

  4. Carriers of the astronomical 2175 ? extinction feature

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J; Dai, Z; Ernie, R; Browning, N; Graham, G; Weber, P; Smith, J; Hutcheon, I; Ishii, H; Bajt, S; Floss, C; Stadermann, F

    2004-07-20

    The 2175 {angstrom} extinction feature is by far the strongest spectral signature of interstellar dust observed by astronomers. Forty years after its discovery the origin of the feature and the nature of the carrier remain controversial. The feature is enigmatic because although its central wavelength is almost invariant its bandwidth varies strongly from one sightline to another, suggesting multiple carriers or a single carrier with variable properties. Using a monochromated transmission electron microscope and valence electron energy-loss spectroscopy we have detected a 5.7 eV (2175 {angstrom}) feature in submicrometer-sized interstellar grains within interplanetary dust particles (IDPs) collected in the stratosphere. The carriers are organic carbon and amorphous silicates that are abundant and closely associated with one another both in IDPs and in the interstellar medium. Multiple carriers rather than a single carrier may explain the invariant central wavelength and variable bandwidth of the astronomical 2175 {angstrom} feature.

  5. Ultrafast carriers dynamics in filled-skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Liang; Xu, Xianfan, E-mail: xxu@purdue.edu [School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Salvador, James R. [Chemical and Materials Systems Laboratory, GM Global R and D, Warren, Michigan 48090 (United States)

    2015-06-08

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  6. Ultrafast carriers dynamics in filled-skutterudites

    Science.gov (United States)

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-01

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4-0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  7. Global Telecommunications Services: Strategies of Major Carriers

    OpenAIRE

    Jerry Mccreary; William R. Boulton; Chetan Sankar

    1993-01-01

    The globalization of telecommunications markets is of primary concern for today’s large telecommunications carriers. International business telecommunications is growing at a rate twice that of domestic traffic. Multi-national customers with offices around the world are demanding integrated solutions to their telecommunications needs. As telecommunication carriers respond to these customers’ needs, the carriers are beginning to expand outside their national boundaries. This paper identifi...

  8. Secure quantum carriers for quantum state sharing

    OpenAIRE

    Karimipour, Vahid; Marvian, Milad

    2010-01-01

    We develop the concept of quantum carrier and show that messages can be uploaded and downloaded from this carrier and while in transit, these messages are hidden from external agents. We explain in detail the working of the quantum carrier for different communication tasks, including quantum key distribution, classical secret and quantum state sharing among a set of $n$ players according to general threshold schemes. The security of the protocol is discussed and it is shown that only the legi...

  9. Heterozygote advantage in Tay-Sachs carriers?

    OpenAIRE

    Spyropoulos, B; Moens, P B; Davidson, J.; Lowden, J. A.

    1981-01-01

    Chi-square analyses of new data as well as data previously reported by Myrianthopoulos have shown that grandparents of Tay-Sachs carriers die from proportionally the same causes as grandparents of noncarriers. It is unlikely that there is any advantage to being a Tay-Sachs carrier insofar as resistance to tuberculosis is concerned. Our results are further evidence to support Fraikor's claim that the high carrier frequency of the allele in Ashkenazi Jews is probably caused by a combination of ...

  10. Carriers by chemical vapor deposition

    Science.gov (United States)

    Mronga, Norbert; Adel, J.; Czech, Erwin

    1990-07-01

    Printed materials are affecting people's lives in a variety of ways and to a constantly increasing extent, both in the private and in the business spheres. In particular, the predicted reduction of printed materials resulting from electronic data processing - the so-called "paperless electronic office" - has not occured, indeed quite the reverse. In recent years electrophotographic reprography has established itself successfully as a competitor to conventional printing processes. In the office a photocopier is now a part of the standard equipment. Because of BASF's traditional intensive involvement with pigments and colored printing inks its interest in new technologies in these areas is especially great. BASF has therefore been engaged in research on carriers for some years now.

  11. The Kinetics of Carrier Transport Inhibition

    DEFF Research Database (Denmark)

    Rosenberg, T.; Wilbrandt, Robert Walter

    1962-01-01

    The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing with the subst......The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing...

  12. CARRIER/CASK HANDLING SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.F. Loros

    2000-06-23

    The Carrier/Cask Handling System receives casks on railcars and legal-weight trucks (LWTs) (transporters) that transport loaded casks and empty overpacks to the Monitored Geologic Repository (MGR) from the Carrier/Cask Transport System. Casks that come to the MGR on heavy-haul trucks (HHTs) are transferred onto railcars before being brought into the Carrier/Cask Handling System. The system is the interfacing system between the railcars and LWTs and the Assembly Transfer System (ATS) and Canister Transfer System (CTS). The Carrier/Cask Handling System removes loaded casks from the cask transporters and transfers the casks to a transfer cart for either the ATS or CTS, as appropriate, based on cask contents. The Carrier/Cask Handling System receives the returned empty casks from the ATS and CTS and mounts the casks back onto the transporters for reshipment. If necessary, the Carrier/Cask Handling System can also mount loaded casks back onto the transporters and remove empty casks from the transporters. The Carrier/Cask Handling System receives overpacks from the ATS loaded with canisters that have been cut open and emptied and mounts the overpacks back onto the transporters for disposal. If necessary, the Carrier/Cask Handling System can also mount empty overpacks back onto the transporters and remove loaded overpacks from them. The Carrier/Cask Handling System is located within the Carrier Bay of the Waste Handling Building System. The system consists of cranes, hoists, manipulators, and supporting equipment. The Carrier/Cask Handling System is designed with the tooling and fixtures necessary for handling a variety of casks. The Carrier/Cask Handling System performance and reliability are sufficient to support the shipping and emplacement schedules for the MGR. The Carrier/Cask Handling System interfaces with the Carrier/Cask Transport System, ATS, and CTS as noted above. The Carrier/Cask Handling System interfaces with the Waste Handling Building System for building

  13. miR-17 is involved in the regulation of LC-PUFA biosynthesis in vertebrates: effects on liver expression of a fatty acyl desaturase in the marine teleost Siganus canaliculatus.

    Science.gov (United States)

    Zhang, Qinghao; Xie, Dizhi; Wang, Shuqi; You, Cuihong; Monroig, Oscar; Tocher, Douglas R; Li, Yuanyou

    2014-07-01

    Biosynthesis in vertebrates of long-chain polyunsaturated fatty acids (LC-PUFA) such as arachidonic (ARA; 20:4n-6), eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3) acids requires the catalysis by fatty acyl desaturases (Fads). A vertebrate Fad with Δ4 activity catalyzing the direct conversion of 22:5n-3 to DHA was discovered in the marine teleost rabbitfish Siganus canaliculatus. Recent studies in vertebrates have shown that miRNAs may participate in the regulation of lipid metabolism at post-transcription level. However, their roles in LC-PUFA biosynthesis were not known. In the present study, in silico analysis predicts that the rabbitfish Δ4 Fad may be a target of miR-17 and thus we cloned miR-17, which is located at the forepart of the miR-17-92 cluster. Dual luciferase reporter assays demonstrated that miR-17 targeted the 3'UTR of Δ4 Fad directly. Furthermore, the expression level of miR-17 displayed an inverse pattern with that of Δ4 Fad mRNA in gill, liver and eyes, and also the Δ4 Fad protein quantity in rabbitfish liver. Incubation of rabbitfish primary hepatocytes with linoleic acid (LA; 18:2n-6), α-linolenic acid (LNA; 18:3n-3), EPA or DHA showed differential effects on miR-17, Δ4 Fad and Δ6/Δ5 Fad expression. LNA promoted the expression of miR-17 and Δ6/Δ5 Fad, but suppressed the expression of Δ4 Fad. In contrast, LA and EPA decreased the expression of miR-17 and Δ6/Δ5 Fad, but had no effect on Δ4 Fad. However, all the above were down-regulated by DHA. These data indicate that miR-17 was involved in the regulation of LC-PUFA biosynthesis in rabbitfish liver by targeting Δ4 Fad.

  14. Knockdown of delta-5-desaturase promotes the anti-cancer activity of dihomo-γ-linolenic acid and enhances the efficacy of chemotherapy in colon cancer cells expressing COX-2.

    Science.gov (United States)

    Xu, Yi; Yang, Xiaoyu; Zhao, Pinjing; Yang, Zhongyu; Yan, Changhui; Guo, Bin; Qian, Steven Y

    2016-07-01

    Cyclooxygenase (COX), commonly overexpressed in cancer cells, is a major lipid peroxidizing enzyme that metabolizes polyunsaturated fatty acids (ω-3s and ω-6s). The COX-catalyzed free radical peroxidation of arachidonic acid (ω-6) can produce deleterious metabolites (e.g. 2-series prostaglandins) that are implicated in cancer development. Thus, COX inhibition has been intensively investigated as a complementary therapeutic strategy for cancer. However, our previous study has demonstrated that a free radical-derived byproduct (8-hydroxyoctanoic acid) formed from COX-catalyzed peroxidation of dihomo-γ-linolenic acid (DGLA, the precursor of arachidonic acid) can inhibit colon cancer cell growth. We thus hypothesize that the commonly overexpressed COX in cancer (~90% of colon cancer patients) can be taken advantage to suppress cell growth by knocking down delta-5-desaturase (D5D, a key enzyme that converts DGLA to arachidonic acid). In addition, D5D knockdown along with DGLA supplement may enhance the efficacy of chemotherapeutic drugs. After knocking down D5D in HCA-7 colony 29 cells and HT-29 cells (human colon cancer cell lines with high and low COX levels, respectively), the antitumor activity of DGLA was significantly enhanced along with the formation of a threshold range (~0.5-1.0μM) of 8-hydroxyoctanoic acid. In contrast, DGLA treatment did not inhibit cell growth when D5D was not knocked down and only limited amount of 8-hydroxyoctanoic acid was formed. D5D knockdown along with DGLA treatment also enhanced the cytotoxicities of various chemotherapeutic drugs, including 5-fluorouracil, regorafenib, and irinotecan, potentially through the activation of pro-apoptotic proteins, e.g. p53 and caspase 9. For the first time, we have demonstrated that the overexpressed COX in cancer cells can be utilized in suppressing cancer cell growth. This finding may provide a new option besides COX inhibition to optimize cancer therapy. The outcome of this translational

  15. Improving live attenuated bacterial carriers for vaccination and therapy.

    Science.gov (United States)

    Loessner, Holger; Endmann, Anne; Leschner, Sara; Bauer, Heike; Zelmer, Andrea; zur Lage, Susanne; Westphal, Kathrin; Weiss, Siegfried

    2008-01-01

    Live attenuated bacteria are well established as vaccines. Thus, their use as carriers for prophylactic and therapeutic macromolecules is a logical consequence. Here we describe several experimental applications of bacteria to carry heterologous macromolecules into the murine host. First, Listeria monocytogenes are described that are able to transfer eukaryotic expression plasmids into host cells for gene therapy. High multiplicities of infection are still required for efficient gene transfer and we point out some of the bottlenecks that counteract a more efficient transfer and application in vivo. Then, we describe Salmonella enterica serovar Typhimurium (S. typhimurium) as an expression plasmid transfer vehicle for oral DNA vaccination of mice. We demonstrate that the stabilization of the plasmid transformants results in an improved immune response. Stabilization was achieved by replacing the origin of replication of the original high-copy-number plasmid by a low-copy-number origin. Finally, we describe Salmonella carriers for the improved expression of heterologous proteins. We introduce a system in which the plasmid is carried as a single copy during cultivation but is amplified several fold upon infection of the host. Using the same in vivo inducible promoter for both protein expression and plasmid amplification, a substantial increase in antigen expression in vivo can be achieved. A modification of this approach is the introduction of inducible gene expression in vivo with a low-molecular-weight compound. Using P(BAD) promoter and L-arabinose as inducer we were able to deliberately activate genes in the bacterial carrier. No background activity could be observed with P(BAD) such that an inducible suicide gene could be introduced. This is adding an important safety feature to such live attenuated carrier bacteria.

  16. Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

    DEFF Research Database (Denmark)

    Dery, H.; Tromborg, Bjarne; Eisenstein, G.

    2003-01-01

    We describe carrier-carrier scattering dynamics in an inverted quantum well structure including the nonparabolic nature of the valance band. A solution of the semiconductor Bloch equations yields strong evidence to a large change in the temporal evolution of the carrier distributions compared...

  17. Inert carrier drying and coating process

    International Nuclear Information System (INIS)

    An inert carrier process is described for drying radioactive (particularly low level) waste material and for incorporating the dry material into a binder matrix from which the dried material will not be leached. Experimental details, and examples of the carrier and binder materials, are given. (U.K.)

  18. 14 CFR Section 04 - Air Carrier Groupings

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC... upon their level of operations and the nature of these operations. In order to determine the level of... carrier's level of operations passes the upper or lower limit of its currently assigned carrier...

  19. Providing resilience for carrier ethernet multicast traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang;

    2009-01-01

    This paper presents an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we detail how multicast traffic, which is essential for e.g. IPTV can be protected. We present Carrier Ethernet resilience methods for linear and ring networks and show by simulation...

  20. AQUASOMES: A NOVEL CARRIER FOR DRUG DELIVERY

    Directory of Open Access Journals (Sweden)

    Vishal Sutariya

    2012-03-01

    Full Text Available Nanobiopharmaceutics involves delivery of biopharmaceutical product through different biomaterials like multifunctional nanoparticles, quantum dots, aquasomes, superparamagnetic iron oxide crystals, and liposomes dendrimers. Nanotechnology has emerged fields of biomedical research in the last few decades the presents context is an attempt to present the brief information about nanobiotechnological applications. Aquasomes are nanoparticulate carrier system but instead of being simple nanoparticles these arse three layered self assembled structures, comprised of a solid phase nanocrystalline core coated with oligomeric film to which biochemically active molecules are adsorbed with or without modification. Aquasomes are spherical 60–300 nm particles used for drug and antigen delivery. Aquasomes discovery comprises a principle from microbiology, food chemistry, biophysics and many discoveries including solid phase synthesis, supramolecular chemistry, molecular shape change and self assembly. Three types of core materials are mainly used for producing aquasomes: tin oxide, nanocrystalline carbon ceramics (diamonds and brushite (calcium phosphate dihydrate. Calcium phosphate is the core of interest, owing to its natural presence in the body. The brushite is unstable and converts to hydroxyapatite upon prolong storage. Hydroxyapatite seems, therefore, a better core for the preparation of aquasomes. It is widely used for the preparation of implants for drug delivery. The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the biochemically active molecules. This property of maintaining the conformational integrity of bioactive molecules has led to the proposal that aquasomes have potential as a carrier system for delivery of peptide, protein, hormones, antigens and genes to specific sites. Aquasome deliver their content through specific targeting, molecular sheiling and slow

  1. Modeling of Carrier Dynamics in Electroabsorption Modulators

    DEFF Research Database (Denmark)

    Højfeldt, Sune

    2002-01-01

    and a phenomenological model for the carrier sweep-out dynamics, we investigate all-optical wavelength conversion, all-optical signal regeneration, and all-optical demultiplexing. A detailed drift-diffusion type model for the sweerp-out of photo-excited carriers in electroabsorption modulators is presented. We use...... the model to calclulate absorption spectra and steady-state carrier distributions in different modulator structures. This allows us to investigate a number of important properties of electroabsorption modulators, such as the electroabsorption effect and th saturation properties. We also investigate...... the influence that carrier recapture has on the device properties, and we discuss the recapture process on a more fundamental level. The model is also used to investigate in detail the carrier sweep-out process in electroabsorption modulators. We investigate how the intrinsic-region width, the separate...

  2. Selection of Carrier Waveforms for PWM Inverter

    Institute of Scientific and Technical Information of China (English)

    陈国呈; 屈克庆; 许春雨; 孙承波

    2003-01-01

    In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics exist in the neighborhood of the output frequency of the inverter output voltage and current due to the dead time. The triangular carrier waveform used in soft-switching PWM inverter will cause difficulties in controlling resonance-trigger time, higher loss in the resonant circuit, and less utilization of the DC bus voltage. If a sawtooth carrier is used in hard-switching PWM inverter, there will be severe distortion in the current waveform. When sawtooth carriers with alternate positive and negative slopes are used in soft-switching PWM inverters, the resonancetrigger time is easy to control, and distortion in the output voltage and current caused by the dead time will not appear.

  3. Methanol as an energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Biedermann, P.; Grube, T.; Hoehlein, B. (eds.)

    2006-07-01

    For the future, a strongly growing energy demand is expected in the transport sector worldwide. Economically efficient oil production will run through a maximum in the next decade. Higher fuel prices and an environmentally desirable reduction of emissions will increase the pressure for reducing fuel consumption and emissions in road traffic. These criteria show the urgent necessity of structural changes in the fuel market. Due to its advantages concerning industrial-scale production, storage and global availability, methanol has the short- to medium-term potential for gaining increased significance as a substitution product in the energy market. Methanol can be produced both from fossil energy sources and from biomass or waste materials through the process steps of synthesis gas generation with subsequent methanol synthesis. Methanol has the potential to be used in an environmentally friendly manner in gasoline/methanol mixtures for flexible fuel vehicles with internal combustion engines and in diesel engines with pure methanol. Furthermore, it can be used in fuel cell vehicles with on-board hydrogen production in direct methanol fuel cell drives, and in stationary systems for electricity and heat generation as well as for hydrogen production. Finally, in portable applications it serves as an energy carrier for electric power generation. In this book, the processes for the production and use of methanol are presented and evaluated, markets and future options are discussed and issues of safety and environmental impacts are addressed by a team of well-known authors. (orig.)

  4. Optoelectronic characterization of carrier extraction in a hot carrier photovoltaic cell structure

    Science.gov (United States)

    Dimmock, James A. R.; Kauer, Matthias; Smith, Katherine; Liu, Huiyun; Stavrinou, Paul N.; Ekins-Daukes, Nicholas J.

    2016-07-01

    A hot carrier photovoltaic cell requires extraction of electrons on a timescale faster than they can lose energy to the lattice. We optically and optoelectronically characterize two resonant tunneling structures, showing their compatability with hot carrier photovoltaic operation, demonstrating structural and carrier extraction properties necessary for such a device. In particular we use time resolved and temperature dependent photoluminescence to determine extraction timescales and energy levels in the structures and demonstrate fast carrier extraction by tunneling. We also show that such devices are capable of extracting photo-generated electrons at high carrier densities, with an open circuit voltage in excess of 1 V.

  5. Effects of carrier-carrier scattering on population inversion in graphene under pulse photoexcitation

    Science.gov (United States)

    Satou, Akira; Ryzhii, Victor; Otsuji, Taiichi

    2015-01-01

    We study the carrier relaxation dynamics in intrinsic graphene after pulse photoexcitation and reveal effects of intraband carrier-carrier scattering on population inversion in the terahertz region, by conducting simulation based on the quasi-classical Boltzmann equation. It is demonstrated that by changing the dielectric constant of the surrounding materials the rate of carrier-carrier scattering can be controlled and the relaxation dynamics differs for cases with low and high dielectric constants. It is also found that the Pauli blocking of photogeneration in case of the pulse photoexcitation causes decrease in the photocarrier concentration and thus weakening of population inversion with higher dielectric constant.

  6. 肺炎球菌表面蛋白A的原核表达及其作为多糖结合疫苗载体的可行性%Prokaryotic Expression of Pneumococcal Surface Protein A (PspA) and Its Feasibility as a Carrier of Polysaccharide Conjugate Vaccine

    Institute of Scientific and Technical Information of China (English)

    李启明; 唐玉龙; 张学峰; 靳玉琴; 马智静; 张靖

    2011-01-01

    目的 原核表达肺炎球菌表面蛋白A(Pneumococcal surface protein A,PspA),并探讨其作为多糖结合疫苗候选载体的可行性.方法 合成PspA基因,定向克隆至pET-30a(+)载体,构建重组表达质粒pET-30a-rPspA,转化E.coli Star( DE3)菌株,IPTG诱导表达.表达产物经Ni离子亲和层析纯化后,经Western blot鉴定.取破伤风类毒素(Tetanus toxoid,TT)及纯化的rPspA,分别与A群脑膜炎球菌多糖(Group A meningococcal capsular polysaccharide,GAMP)通过溴化氰活化法进行偶联,获得rPspA-GAMP与TT-GAMP多糖蛋白结合物,对其进行纯化及检定.多糖结合物分别以滴鼻和肌肉注射途径免疫BALB/c小鼠,评价其诱发的体液免疫和黏膜免疫水平.结果 重组表达质粒经双酶切及测序鉴定构建正确;表达产物主要以可溶形式存在,表达量约占菌体总蛋白的20%,经纯化后纯度可达90%,可与His单抗特异性结合;肌肉注射途径显示,两种蛋白载体的结合物均能诱发较高水平的体液免疫,不同载体间差异无统计学意义(P>0.05);滴鼻途径显示,载体蛋白rPspA的结合物刺激产生sIgA的能力优于传统载体TT,差异有统计学意义(P<0.05).结论 原核表达并纯化了rPspA,其具有新型多糖蛋白载体的潜力,也可作为黏膜投递型多糖结合疫苗的候选载体.%Objective To express pneumococcal surface protein A (PspA) in prokaryotic cells and investigate its feasibility as a carrier of polysaccharide conjugate vaccine. Methods PspA was synthesized and cloned into vector pET-30a( + ). The constructed recombinant plasmid pET-30a-rPspA was transformed to E. Coli Star (DE3) and induced with IPTG. The expressed product was purified by nickel ion affinity chromatography and identified by Western blot. Tetanus toxoid (TT) and purified recombinant PspA (rPspA) were conjugated with group A meningococcal capsular polysaccharide (GAMP) by activation with cyanogen bromide respectively, and the obtained

  7. Rabies virus glycoprotein as a carrier for anthrax protective antigen

    International Nuclear Information System (INIS)

    Live viral vectors expressing foreign antigens have shown great promise as vaccines against viral diseases. However, safety concerns remain a major problem regarding the use of even highly attenuated viral vectors. Using the rabies virus (RV) envelope protein as a carrier molecule, we show here that inactivated RV particles can be utilized to present Bacillus anthracis protective antigen (PA) domain-4 in the viral membrane. In addition to the RV glycoprotein (G) transmembrane and cytoplasmic domains, a portion of the RV G ectodomain was required to express the chimeric RV G anthrax PA on the cell surface. The novel antigen was also efficiently incorporated into RV virions. Mice immunized with the inactivated recombinant RV virions exhibited seroconversion against both RV G and anthrax PA, and a second inoculation greatly increased these responses. These data demonstrate that a viral envelope protein can carry a bacterial protein and that a viral carrier can display whole polypeptides compared to the limited epitope presentation of previous viral systems

  8. Drug carriers for the delivery of therapeutic peptides.

    Science.gov (United States)

    Du, Alice W; Stenzel, Martina H

    2014-04-14

    Peptides take on an increasingly important role as therapeutics in areas including diabetes, oncology, and metabolic, cardiovascular, and infectious diseases. In addition, many peptides such as insulin have been employed for many years. A challenge in the administration of peptide drugs is their often low hydrolytic stability, as well as other problems that are common to any drug treatment such as systemic distribution. There is a significant attention in the literature of protein drugs and their delivery strategies, but not many overviews are specifically dedicated to peptides. In this review, the different approaches to deliver peptides have been summarized where the focus is only on drug carriers based on organic materials. Initial discussion is on different methods of polymer-peptide conjugation before being followed by physical encapsulation techniques, which is divided into surfactant-based techniques and polymer carriers. Surfactant-based techniques are dominated by liposome, microemulsions and solid-lipid nanoparticles. The field widens further in the polymer field. The delivery of peptides has been enhanced using polymer-decorated liposomes, solid microspheres, polyelectrolyte complex, emulsions, hydrogels, and injectable polymers. The aim of this article is to give the reader an overview over the different types of carriers. PMID:24661025

  9. Aptamers as Both Drugs and Drug-Carriers

    Directory of Open Access Journals (Sweden)

    Md. Ashrafuzzaman

    2014-01-01

    Full Text Available Aptamers are short nucleic acid oligos. They may serve as both drugs and drug-carriers. Their use as diagnostic tools is also evident. They can be generated using various experimental, theoretical, and computational techniques. The systematic evolution of ligands by exponential enrichment which uses iterative screening of nucleic acid libraries is a popular experimental technique. Theory inspired methodology entropy-based seed-and-grow strategy that designs aptamer templates to bind specifically to targets is another one. Aptamers are predicted to be highly useful in producing general drugs and theranostic drugs occasionally for certain diseases like cancer, Alzheimer’s disease, and so on. They bind to various targets like lipids, nucleic acids, proteins, small organic compounds, and even entire organisms. Aptamers may also serve as drug-carriers or nanoparticles helping drugs to get released in specific target regions. Due to better target specific physical binding properties aptamers cause less off-target toxicity effects. Therefore, search for aptamer based drugs, drug-carriers, and even diagnostic tools is expanding fast. The biophysical properties in relation to the target specific binding phenomena of aptamers, energetics behind the aptamer transport of drugs, and the consequent biological implications will be discussed. This review will open up avenues leading to novel drug discovery and drug delivery.

  10. Injectable nanomaterials for drug delivery: carriers, targeting moieties, and therapeutics.

    Science.gov (United States)

    Webster, David M; Sundaram, Padma; Byrne, Mark E

    2013-05-01

    Therapeutics such as nucleic acids, proteins/peptides, vaccines, anti-cancer, and other drugs have disadvantages of low bio-availability, rapid clearance, and high toxicity. Thus, there is a significant need for the development of efficient delivery methods and carriers. Injectable nanocarriers have received much attention due to their vast range of structures and ability to contain multiple functional groups, both within the bulk material and on the surface of the particles. Nanocarriers may be tailored to control drug release and/or increase selective cell targeting, cellular uptake, drug solubility, and circulation time, all of which lead to a more efficacious delivery and action of therapeutics. The focus of this review is injectable, targeted nanoparticle drug delivery carriers highlighting the diversity of nanoparticle materials and structures as well as highlighting current therapeutics and targeting moieties. Structures and materials discussed include liposomes, polymersomes, dendrimers, cyclodextrin-containing polymers (CDPs), carbon nanotubes (CNTs), and gold nanoparticles. Additionally, current clinical trial information and details such as trial phase, treatment, active drug, carrier sponsor, and clinical trial identifier for different materials and structures are presented and discussed.

  11. Carrier scattering in metals and semiconductors

    CERN Document Server

    Gantmakher, VF

    1987-01-01

    The transport properties of solids, as well as the many optical phenomena in them are determined by the scattering of current carriers. ``Carrier Scattering in Metals and Semiconductors'' elucidates the state of the art in the research on the scattering mechanisms for current carriers in metals and semiconductors and describes experiments in which these mechanisms are most dramatically manifested.The selection and organization of the material is in a form to prepare the reader to reason independently and to deal just as independently with available theoretical results and experimental

  12. High capacity carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao;

    2009-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and T-MPLS, it is now possible to use Ethernet as a transport...... OAM functions, survivability and the increased bandwidth requirements of carrier class systems. This article provides an overview of PBB-TE and T-MPLS and demonstrates how IPTV services can be realized in the framework of Carrier Ethernet. In addition we provide a case study on performing bit error...

  13. ISRAEL’S NATIONAL WATER CARRIER

    OpenAIRE

    Nathan Cohen

    2008-01-01

    The National Water Carrier of Israel (Ha Movil Ha' Artzi). It is the main water project of Israel and its main task is to transfer water from the rainy north to the center and to the arid south. The National Water Carrier connects the Sea of Galilee with Israel's water system. The original goal was to provide irrigation water to Negev. Today 80% of the water is utilized for Israel's domestic consumption. Most of the water works in Israel are combined with the National Water Carrier for about...

  14. Effect of Exercise and Calorie Restriction on Tissue Acylcarnitines, Tissue Desaturase Indices, and Fat Accumulation in Diet-Induced Obese Rats.

    Science.gov (United States)

    Gopalan, Venkatesh; Michael, Navin; Ishino, Seigo; Lee, Swee Shean; Yang, Adonsia Yating; Bhanu Prakash, K N; Yaligar, Jadegoud; Sadananthan, Suresh Anand; Kaneko, Manami; Zhou, Zhihong; Satomi, Yoshinori; Hirayama, Megumi; Kamiguchi, Hidenori; Zhu, Bin; Horiguchi, Takashi; Nishimoto, Tomoyuki; Velan, S Sendhil

    2016-01-01

    Both exercise and calorie restriction interventions have been recommended for inducing weight-loss in obese states. However, there is conflicting evidence on their relative benefits for metabolic health and insulin sensitivity. This study seeks to evaluate the differential effects of the two interventions on fat mobilization, fat metabolism, and insulin sensitivity in diet-induced obese animal models. After 4 months of ad libitum high fat diet feeding, 35 male Fischer F344 rats were grouped (n = 7 per cohort) into sedentary control (CON), exercise once a day (EX1), exercise twice a day (EX2), 15% calorie restriction (CR1) and 30% calorie restriction (CR2) cohorts. Interventions were carried out over a 4-week period. We found elevated hepatic and muscle long chain acylcarnitines with both exercise and calorie restriction, and a positive association between hepatic long chain acylcarnitines and insulin sensitivity in the pooled cohort. Our result suggests that long chain acylcarnitines may not indicate incomplete fat oxidation in weight loss interventions. Calorie restriction was found to be more effective than exercise in reducing body weight. Exercise, on the other hand, was more effective in reducing adipose depots and muscle triglycerides, favorably altering muscle/liver desaturase activity and improving insulin sensitivity. PMID:27197769

  15. Expression analysis identifies FAD2-2 as the olive oleate desaturase gene mainly responsible for the linoleic acid content in virgin olive oil.

    Science.gov (United States)

    Hernández, M Luisa; Padilla, María N; Mancha, Manuel; Martínez-Rivas, José M

    2009-07-22

    The effect of ripening stage and water regimen on oleate desaturase gene expression levels in the fruit of different olive ( Olea europaea L.) varieties was investigated to elucidate the contribution of each to the linoleic acid content in virgin olive oil. To this end, fatty acid analysis and quantitative real time PCR were performed using distinct olive tissues and different developmental stages from the Picual and Arbequina cultivars. The results showed that the olive FAD2-1, FAD2-2, and FAD6 genes were spatial and temporally regulated. In addition, the data indicated that FAD2-2 seems to be the main gene responsible for the linoleic acid content in the olive fruit mesocarp tissue. This conclusion was also confirmed when the study was extended to Hojiblanca, Picudo, and Manzanilla varieties. With regard to the water regimen, unlike the Picual cultivar, a small increase of linoleic acid was observed in the Arbequina variety cultivated with irrigation, which correlated well with the increase detected for the FAD2-2 gene expression level. All of these data strongly suggest that FAD2-2 is the main gene that determines the linoleic acid content in the virgin olive oil. PMID:19601663

  16. Subcutaneous ectopic osteogenesis induced by porous calcium phosphate cement and gelatin sponge as the carrier of recombinant bone morphogenetic protein-2 in rats:A comparative study%两种材料复合rhBMP-2诱导大鼠皮下异位成骨的比较研究

    Institute of Scientific and Technical Information of China (English)

    李想; 董纪元; 彭江; 汪爱媛; 睢翔; 赵斌; 刘道宏

    2011-01-01

    Objective To analyze the difference in subcutaneous ectopic osteogenesis induced by porous calcium phosphate cement (CPC) and gelatin sponge as a carrier of recombinant bone morphogenetic protein-2 (rhBMP-2). Methods Thirty Sprague Dawley rats with an average body weight of 200g were divided into groups A-D. CPC+rhBMP-2, CPC, gelatin sponge+rhBMP-2, and gelatin sponge were implanted into the rats after anesthesia. Ten rats were killed 2, 4 and 8 weeks after they were fed under sterile environment. Bone tissue samples were collected from the implantation sites. Tissue mineral density (TMD) and trabecular thickness were detected with micro-CT scanner and analyzed with SPSS 1 OX) statistical software. Bone tissue was fixed in 4% paraformaldehyde for 2 days, embedded in paraffin, and cut into sections. The sections were stained with H&E to observe their histological change. Results The tissue mineral density and trabecular thickness of the samples with rhBMP-2 were higher in two experimental groups 2,4 and 8 weeks after implantation, which increased with the prolongation of time (P<0.05). Conclusion Porous CPC can be used as a carrier of rhBMP-2 for osteogenesis.%目的 分析多孔自固化磷酸钙骨水泥(Calcium Phosphate Cement,CPC)和明胶海绵复合重组人骨形态发生蛋白(Recombinantion Humen Bone Morphogenetic Protein-2,rhBMP-2)诱导大鼠皮下异位成骨的区别.方法 平均质量200g SD大鼠30只,麻醉后分别植入A:多孔CPC复合rhBMP-2(2μg);B:多孔CPC;C:明胶海绵复合rhBMP-2(2μg);D:空白明胶海绵,无菌喂养后分别于2、4、8周各处死10只.对植入部位组织取材,分别进行micro-CT扫描,并使用Micview V2.1三维重建处理软件扫及ABA骨形态分析软件检测,记录组织骨密度(Tissue Mineral Density,TMD)及骨小梁厚度(Trabecular Thickness,Tb.Th).运用SPSS10.0统计软件进行统计学分析.后行甲醛固定2周,石蜡包埋切片,HE染色进行组织学观察.结果 在2、4、8

  17. Antiphospholipid antibodies in Brazilian hepatitis C virus carriers

    Directory of Open Access Journals (Sweden)

    A.M. Atta

    2008-06-01

    Full Text Available Hepatitis C, a worldwide viral infection, is an important health problem in Brazil. The virus causes chronic infection, provoking B lymphocyte dysfunction, as represented by cryoglobulinemia, non-organ-specific autoantibody production, and non-Hodgkin's lymphoma. The aim of this research was to screen for the presence of antiphospholipid autoantibodies in 109 Brazilian hepatitis C virus carriers without clinical history of antiphospholipid syndrome. Forty healthy individuals were used as the control group. IgA, IgG, and IgM antibodies against cardiolipin and β2-glycoprotein I were measured with an enzyme-linked immunosorbent assay, using a cut-off point of either 20 UPL or 20 SBU. While 24 (22.0% hepatitis C carriers had moderate titers of IgM anticardiolipin antibodies (median, 22.5 MPL; 95%CI: 21.5-25.4 MPL, only three carriers (<3% had IgG anticardiolipin antibodies (median, 23 GPL; 95%CI: 20.5-25.5 GPL. Furthermore, IgA anticardiolipin antibodies were not detected in these individuals. Male gender and IgM anticardiolipin seropositivity were associated in the hepatitis C group (P = 0.0004. IgA anti-β2-glycoprotein-I antibodies were detected in 29 of 109 (27.0% hepatitis C carriers (median, 41 SAU; 95%CI: 52.7-103.9 SAU. Twenty patients (18.0% had IgM anti-β2-glycoprotein I antibodies (median, 27.6 SMU; 95%CI: 23.3-70.3 SMU, while two patients had IgG antibodies against this protein (titers, 33 and 78 SGU. Antiphospholipid antibodies were detected in only one healthy individual, who was seropositive for IgM anticardiolipin. We concluded that Brazilian individuals chronically infected with hepatitis C virus present a significant production of antiphospholipid antibodies, mainly IgA anti-β2-glycoprotein I antibodies, which are not associated with clinical manifestations of antiphospholipid syndrome.

  18. Structures of Pseudomonas aeruginosa β-ketoacyl-(acyl-carrier-protein) synthase II (FabF) and a C164Q mutant provide templates for antibacterial drug discovery and identify a buried potassium ion and a ligand-binding site that is an artefact of the crystal form

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Bernhard [Johannes Gutenberg-Universität, Staudinger Weg 5, 55128 Mainz (Germany); Lecker, Laura S. M.; Zoltner, Martin [University of Dundee, Dundee DD1 4EH, Scotland (United Kingdom); Jaenicke, Elmar [Johannes Gutenberg-Universität, Jakob Welder Weg 26, 55128 Mainz (Germany); Schnell, Robert [Karolinska Institutet, 17 177 Stockholm (Sweden); Hunter, William N., E-mail: w.n.hunter@dundee.ac.uk [University of Dundee, Dundee DD1 4EH, Scotland (United Kingdom); Brenk, Ruth, E-mail: w.n.hunter@dundee.ac.uk [Johannes Gutenberg-Universität, Staudinger Weg 5, 55128 Mainz (Germany)

    2015-07-28

    Three crystal structures of recombinant P. aeruginosa FabF are reported: the apoenzyme, an active-site mutant and a complex with a fragment of a natural product inhibitor. The characterization provides reagents and new information to support antibacterial drug discovery. Bacterial infections remain a serious health concern, in particular causing life-threatening infections of hospitalized and immunocompromised patients. The situation is exacerbated by the rise in antibacterial drug resistance, and new treatments are urgently sought. In this endeavour, accurate structures of molecular targets can support early-stage drug discovery. Here, crystal structures, in three distinct forms, of recombinant Pseudomonas aeruginosa β-ketoacyl-(acyl-carrier-protein) synthase II (FabF) are presented. This enzyme, which is involved in fatty-acid biosynthesis, has been validated by genetic and chemical means as an antibiotic target in Gram-positive bacteria and represents a potential target in Gram-negative bacteria. The structures of apo FabF, of a C164Q mutant in which the binding site is altered to resemble the substrate-bound state and of a complex with 3-(benzoylamino)-2-hydroxybenzoic acid are reported. This compound mimics aspects of a known natural product inhibitor, platensimycin, and surprisingly was observed binding outside the active site, interacting with a symmetry-related molecule. An unusual feature is a completely buried potassium-binding site that was identified in all three structures. Comparisons suggest that this may represent a conserved structural feature of FabF relevant to fold stability. The new structures provide templates for structure-based ligand design and, together with the protocols and reagents, may underpin a target-based drug-discovery project for urgently needed antibacterials.

  19. Intraoral radiation carrier for edentulous patients

    International Nuclear Information System (INIS)

    The principles of fabricating an intraoral radioactive carrier have been described to treat malignant diseases of the oral cavity. The prosthesis provides consistent direction and fixation of the radioactive source into the same location

  20. Intraoral radiation carrier for edentulous patients

    Energy Technology Data Exchange (ETDEWEB)

    Sela, M.; Taicher, S.

    1983-12-01

    The principles of fabricating an intraoral radioactive carrier have been described to treat malignant diseases of the oral cavity. The prosthesis provides consistent direction and fixation of the radioactive source into the same location.

  1. Simulation of dual transponder carrier ranging measurements

    Institute of Scientific and Technical Information of China (English)

    Xiang-yu ZHAO; Xiao-jun JIN; Zhong-he JIN

    2009-01-01

    The most dominant error source for microwave ranging is the frequency instability of the oscillator that generates the carrier phase signal. The oscillator noise is very difficult to filter due to its extremely low frequency. A dual transponder carrier ranging method can effectively minimize the oscillator noise by combing the reference phase and the to-and-fro measurement phase from the same single oscillator. This method does not require an accurate time tagging system, since it extracts phases on the same satellite. This paper analyzes the dual transponder carrier ranging system by simulation of the phase measurements with comprehensive error models. Both frequency domain and time domain noise transfer characteristics were simulated to compare them with dual one-way ranging. The simulation results in the two domains conformed to each other and demonstrated that a high level of accuracy can also be achieved by use of the dual transponder carrier ranging system, with relatively simple instruments.

  2. Physician Fee Schedule Carrier Specific Files

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) has condensed all 56 Physician Fee Schedule (PFS) carrier specific pricing files into one zip file. It is...

  3. Evaluating multicast resilience in carrier ethernet

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang;

    2010-01-01

    This paper gives an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we show how multicast traffic, which is essential for IPTV can be protected. We detail the ackground for resilience mechanisms and their control and e present Carrier Ethernet resilie...... resilience methods for linear nd ring networks. By simulation we show that the vailability of a multicast connection can be significantly increased by applying protection methods....

  4. Preparation and activity analysis of hu3D3/core-streptavidin fusion protein as a universal carrier targeting to lung cancer%肺癌靶向通用载体hu3D3/cSA融合蛋白的制备和活性分析

    Institute of Scientific and Technical Information of China (English)

    王勇军; 颜江华; 王阶平; 王臻; 黄志平; 陈彩霞

    2008-01-01

    目的 制备一种新型的肺癌靶向通用载体hu3D3与核心链霉亲和素(core-streptavidin,cSA)的融合蛋白hu3D3/cSA,并鉴定其活性.方法 PCR扩增cSA基因,克隆至质粒hu3D3/pET-22b(+)而获得表达载体hu3D3/cSA/pET-22b(+),并在E. coli BL21(DE3)中表达,镍亲和层析柱纯化hu3D3/cSA融合蛋白,采用TEA缓冲液进行复性.SDS-PAGE和Western blot鉴定融合蛋白四聚体的形成.FITC标记hu3D3/cSA,通过荧光显微镜分析hu3D3组分的抗原反应性和特异性,流式细胞术比较hu3D3/cSA和hu3D3与靶点的结合能力;ELISA和Western blot鉴定cSA组分结合生物素(biotin)的能力.结果 获得序列正确的hu3D3/cSA/pET-22b(+)重组子,融合基因在E.coli BL21(DE3)中主要以包涵体的形式表达.纯化复性后的融合蛋白能够形成四聚体复合物,保留了cSA结合生物素的活性,hu3D3组分能与肺癌细胞表面抗原结合,且结合能力与单体hu3D3相比有明显增强.结论 成功制备了具有结合靶抗原和生物素活性的hu3D3/cSA融合蛋白,同时改善了hu3D3组分结合其靶点的亲合力(avidity).因此,hu3D3/cSA可以作为一个通用的肺癌靶向载体,与多种生物素化的抗肿瘤药物或试剂联用,有望为多药物联合靶向治疗肺癌提供一种可行的方法.%Objective To prepare a novel fusion protein of hu3D3 and core-streptavidin(hu3D3/cSA) as a universal carrier targeting to lung cancer,and analyze its activities. Methods cSA gene was acquired by PCR,and inserted into plasmid hu3D3/pET-22b(+)to construct a recombinant plasmid hu3D3/cSA/pET-22b(+).The fusion gene was expressed in E. Coli BL21(DE3).The fusion protein was purified through nickel-affinity chromatography column and renatured using TEA buffer. The tetrameric hu3D3/cSA complex was analyzed by SDS-PAGE and Western blot.The hu3D3/cSA protein was labeled with FITC,then its antigen-binding activity was analyzed using fluorescence microscopy,and the functional affinity of hu3D3/cSA and

  5. Carrier induced epitopic suppression of antibody responses induced by virus-like particles is a dynamic phenomenon caused by carrier-specific antibodies.

    Science.gov (United States)

    Jegerlehner, Andrea; Wiesel, Melanie; Dietmeier, Klaus; Zabel, Franziska; Gatto, Dominique; Saudan, Philippe; Bachmann, Martin F

    2010-07-26

    Pre-existing immunity against vaccine carrier proteins has been reported to inhibit the immune response against antigens conjugated to the same carrier by a process termed carrier induced epitopic suppression (CIES). Hence understanding the phenomenon of CIES is of major importance for the development of conjugate vaccines. Virus-like particles (VLPs) are a novel class of potent immunological carriers which have been successfully used to enhance the antibody response to virtually any conjugated antigen. In the present study we investigated the impact of a pre-existing VLP-specific immune response on the development of antibody responses against a conjugated model peptide after primary, secondary and tertiary immunization. Although VLP-specific immune responses led to reduced peptide-specific antibody titers, we showed that CIES against peptide-VLP conjugates could be overcome by high coupling densities, repeated injections and/or higher doses of conjugate vaccine. Furthermore we dissected VLP-specific immunity by adoptively transferring VLP-specific antibodies, B-cells or T(helper) cells separately into naïve mice and found that the observed CIES against peptide-VLP conjugates was mainly mediated by carrier-specific antibodies.

  6. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus.

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  7. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  8. The Green Microalga Chlamydomonas reinhardtii Has a Single ω-3 Fatty Acid Desaturase That Localizes to the Chloroplast and Impacts Both Plastidic and Extraplastidic Membrane Lipids1[C][W

    Science.gov (United States)

    Nguyen, Hoa Mai; Cuiné, Stéphan; Beyly-Adriano, Audrey; Légeret, Bertrand; Billon, Emmanuelle; Auroy, Pascaline; Beisson, Fred; Peltier, Gilles; Li-Beisson, Yonghua

    2013-01-01

    The ω-3 polyunsaturated fatty acids account for more than 50% of total fatty acids in the green microalga Chlamydomonas reinhardtii, where they are present in both plastidic and extraplastidic membranes. In an effort to elucidate the lipid desaturation pathways in this model alga, a mutant with more than 65% reduction in total ω-3 fatty acids was isolated by screening an insertional mutant library using gas chromatography-based analysis of total fatty acids of cell pellets. Molecular genetics analyses revealed the insertion of a TOC1 transposon 113 bp upstream of the ATG start codon of a putative ω-3 desaturase (CrFAD7; locus Cre01.g038600). Nuclear genetic complementation of crfad7 using genomic DNA containing CrFAD7 restored the wild-type fatty acid profile. Under standard growth conditions, the mutant is indistinguishable from the wild type except for the fatty acid difference, but when exposed to short-term heat stress, its photosynthesis activity is more thermotolerant than the wild type. A comparative lipidomic analysis of the crfad7 mutant and the wild type revealed reductions in all ω-3 fatty acid-containing plastidic and extraplastidic glycerolipid molecular species. CrFAD7 was localized to the plastid by immunofluorescence in situ hybridization. Transformation of the crfad7 plastidial genome with a codon-optimized CrFAD7 restored the ω-3 fatty acid content of both plastidic and extraplastidic lipids. These results show that CrFAD7 is the only ω-3 fatty acid desaturase expressed in C. reinhardtii, and we discuss possible mechanisms of how a plastid-located desaturase may impact the ω-3 fatty acid content of extraplastidic lipids. PMID:23958863

  9. Solute carriers (SLCs) identified and characterized from kidney transcriptome of golden mahseer (Tor putitora) (Fam: Cyprinidae).

    Science.gov (United States)

    Barat, Ashoktaru; Sahoo, Prabhati Kumari; Kumar, Rohit; Pande, Veena

    2016-10-01

    The solute carriers (SLC) are trans-membrane proteins, those regulate the transport of various substances (sugars, amino acids, nucleotides, inorganic cations/anions, metals, drugs etc.) across the cell membrane. There are more than 338 solute carriers (slc) reported in fishes that play crucial role in cellular influx and efflux. The study of solute carrier families may reveal many answers regarding the function of transporter genes in the species and their effect in the existing environment. Therefore, we performed RNA sequencing of kidney tissue of the golden mahseer (Tor putitora) using Illumina platform to identify the solute carrier families and characterized 24 putative functional genes under 15 solute carrier families. Out of 24 putative functional genes, 11 genes were differentially expressed in different tissues (head kidney, trunk kidney, spleen, liver, gill, muscle, intestine and brain) using qRT-PCR assay. The slc5a1, slc5a12, slc12a3, slc13a3, slc22a13 and slc26a6 were highly expressed in kidney. The slc15a2, slc25a47, slc33a1 and slc38a2 were highly expressed in brain and slc30a5 was over-expressed in gill. The unrooted phylogenetic trees of slc2, slc5, slc13 and slc33 were constructed using amino acid sequences of Homo sapiens, Salmo salar, Danio rerio, Cyprinus carpio and Tor putitora. It appears that all the putative solute carrier families are very much conserved in human and fish species including the present fish, golden mahseer. This study provides the first hand database of solute carrier families particularly transporter encoding proteins in the species.

  10. Increased oxidative damage in carriers of the germline TP53 p.R337H mutation.

    Directory of Open Access Journals (Sweden)

    Gabriel S Macedo

    Full Text Available Germline mutations in TP53 are the underlying defect of Li-Fraumeni Syndrome (LFS and Li-Fraumeni-like (LFL Syndrome, autosomal dominant disorders characterized by predisposition to multiple early onset cancers. In Brazil, a variant form of LFS/LFL is commonly detected because of the high prevalence of a founder mutation at codon 337 in TP53 (p.R337H. The p53 protein exerts multiple roles in the regulation of oxidative metabolism and cellular anti-oxidant defense systems. Herein, we analyzed the redox parameters in blood samples from p.R337H mutation carriers (C, n = 17 and non-carriers (NC, n = 17. We identified a significant increase in erythrocyte GPx activity and in plasma carbonyl content,an indicator of protein oxidative damage, in mutation carriers compared to non-carriers (P = 0.048 and P = 0.035, respectively. Mutation carriers also showed a four-fold increase in plasma malondialdehyde levels, indicating increased lipid peroxidation (NC = 40.20±0.71, C = 160.5±0.88, P<0.0001. Finally, carriers showed increased total antioxidant status but a decrease in plasma ascorbic acid content. The observed imbalance could be associated with deregulated cell bioenergetics and/or with increased inflammatory stress, two effects that may result from loss of wild-type p53 function. These findings provide the first evidence that oxidative damage occurs in carriers of a germline TP53 mutation, and these may have important implications regarding our understanding of the mechanisms responsible for germline TP53 p.R337H mutation-associated carcinogenesis.

  11. Enhanced attached growth of microalgae Scenedesmus. LX1 through ambient bacterial pre-coating of cotton fiber carriers.

    Science.gov (United States)

    Zhuang, Lin-Lan; Azimi, Yaldah; Yu, Dawei; Wang, Wen-Long; Wu, Yin-Hu; Dao, Guo-Hua; Hu, Hong-Ying

    2016-10-01

    The role of bacteria/extracellular polymeric substances (EPS) coated carriers on attached microalgae growth in suspended-solid phase photobioreactor (sspBR) was assessed in this study. The results showed that pre-coating cotton with ambient bacteria and their EPS improved the attached microalgal growth by as much as 230% in terms of attached microalgae density. Additionally, the single cell dry weight, chemical composition and oxygen evolving activity of attached microalgae were significantly affected by the presence of bacteria/EPS coating on the cotton carriers. The protein content of microalgae cells cultivated in the ssPBRs with carriers coated by bacteria and sterilized bacteria were on average 26% and 15% more than uncoated carriers, respectively. Through absorbing and immobilizing nutrients from the bulk medium, the bacteria/EPS coating provided the attached microalgae with nitrogen/phosphorus for protein synthesis, especially during the late stages of batch cultivation. PMID:27416514

  12. 49 CFR 1139.22 - Revenue data for study carriers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Revenue data for study carriers. 1139.22 Section... BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE PROCEDURES IN MOTOR CARRIER REVENUE PROCEEDINGS Intercity Bus Industry § 1139.22 Revenue data for study carriers. The study carriers, as identified...

  13. Charge carrier transport in liquid crystals

    International Nuclear Information System (INIS)

    The materials exhibiting charge carrier mobility ranging from 10−3 to 0.1 cm2/Vs, i.e., between those of amorphous and crystalline materials, had been missing before the 1990s when the electronic conduction in liquid crystals was discovered. Since then, various liquid crystalline materials including discotic and calamitic liquid crystals have been studied in order to clarify their charge carrier transport properties in liquid crystalline mesophases. In this article, the historical background of the discovery of electronic conduction in liquid crystals, intrinsic and extrinsic conductions, unique properties of the charge carrier transport, the effect of molecular alignment on it, and the conduction mechanism in liquid crystalline mesophases are shortly described on the basis of the experimental and theoretical studies accumulated in these two decades, noting that the missing materials were liquid crystals. - Highlights: • Liquid crystals exhibit charge mobility ranging from 10–3 to 0.1 cm2/Vs. • Electronic (intrinsic) and ionic (extrinsic) conductions in liquid crystals • Unique charge carrier transport properties in liquid crystals • Effect of molecular alignment in mesophases on charge carrier transport • Conduction mechanism in smectic liquid crystals

  14. Extracting hot carriers from photoexcited semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  15. Identification of a Δ5-like fatty acyl desaturase from the cephalopod Octopus vulgaris (Cuvier 1797) involved in the biosynthesis of essential fatty acids.

    Science.gov (United States)

    Monroig, Oscar; Navarro, Juan C; Dick, James R; Alemany, Frederic; Tocher, Douglas R

    2012-08-01

    Long-chain polyunsaturated fatty acids (LC-PUFA) have been identified as essential compounds for common octopus (Octopus vulgaris), but precise dietary requirements have not been determined due, in part, to the inherent difficulties of performing feeding trials on paralarvae. Our objective is to establish the essential fatty acid (EFA) requirements for paralarval stages of the common octopus through characterisation of the enzymes of endogenous LC-PUFA biosynthetic pathways. In this study, we isolated a cDNA with high homology to fatty acyl desaturases (Fad). Functional characterisation in recombinant yeast showed that the octopus Fad exhibited Δ5-desaturation activity towards saturated and polyunsaturated fatty acyl substrates. Thus, it efficiently converted the yeast's endogenous 16:0 and 18:0 to 16:1n-11 and 18:1n-13, respectively, and desaturated exogenously added PUFA substrates 20:4n-3 and 20:3n-6 to 20:5n-3 (EPA) and 20:4n-6 (ARA), respectively. Although the Δ5 Fad enables common octopus to produce EPA and ARA, the low availability of its adequate substrates 20:4n-3 and 20:3n-6, either in the diet or by limited endogenous synthesis from C(18) PUFA, might indicate that EPA and ARA are indeed EFA for this species. Interestingly, the octopus Δ5 Fad can also participate in the biosynthesis of non-methylene-interrupted FA, PUFA that are generally uncommon in vertebrates but have been found previously in marine invertebrates, including molluscs, and now also confirmed to be present in specific tissues of common octopus.

  16. A single nucleotide polymorphism in the promoter region of river buffalo stearoyl CoA desaturase gene (SCD) is associated with milk yield.

    Science.gov (United States)

    Pauciullo, Alfredo; Cosenza, Gianfranco; Steri, Roberto; Coletta, Angelo; La Battaglia, Antonio; Di Berardino, Dino; Macciotta, Nicolò P P; Ramunno, Luigi

    2012-11-01

    An association study between the milk yield trait and the stearoyl-CoA desaturase (SCD) polymorphism (g.133A > C) in Italian Mediterranean river buffalo was carried out. A full characterization of the river buffalo SCD promoter region was presented. Genotyping information was provided and a quick method for allelic discrimination was developed. The frequency of the C allele was 0·16. Test-day (TD) records (43 510) of milk production belonging to 226 lactations of 169 buffalo cows were analysed with a mixed linear model in order to estimate the effect of g.133A > C genotype, as well as the effect of parity and calving season. The SCD genotype was significantly associated with milk yield (P = 0·02). The genotype AC showed an over-dominance effect with an average daily milk yield approximately 2 kg/d higher than CC buffaloes. Such a difference represents about 28% more milk/d. The effect of the genotype was constant across lactation stages. The contribution of SCD genotype (r(2)SCD) to the total phenotypic variance in milk yield was equal to 0·12. This report is among the first indications of genetic association between a trait of economic importance in river buffalo. Although such results need to be confirmed with large-scale studies in the same and other buffalo populations, they might offer useful indications for the application of MAS programmes in river buffalo and in the future they might be of great economic interest for the river buffalo dairy industry. PMID:22994977

  17. A polymorphism in the stearoyl-CoA desaturase gene promoter influences monounsaturated fatty acid content of Duroc × Iberian hams

    Directory of Open Access Journals (Sweden)

    Eliana Henriquez-Rodriguez

    2015-12-01

    Full Text Available Data on 74 dry-cured hams from Duroc × Iberian pigs were used to examine whether the tag polymorphism AY487830:g.2228T>C in the promoter region of the stearoyl-CoA desaturase [SCD] gene affect fat desaturation and monounsaturated fatty acid (MUFA as previously described in purebred Duroc hams. Samples were taken from sliced trays of dry-cured hams marketed as Jamón Ibérico de cebo, which were randomly purchased from the same supplier in different stores of the same supermarket chain. Genomic DNA was isolated from each sample to genotype for SCD and gender. Also, a sample of two slices was used to determine fat content and fatty acid (FA composition by gas chromatography. The effect of the genotype (TT and CT and gender (barrows and gilts was estimated under a Bayesian setting. Results showed that the SCD polymorphism was associated to fat composition but not to fat content, with TT hams showing increased C18:1n-7, C18:1n-9, C20:1n-9 and MUFA (probability between 0.92-0.98 and decreased C18:2n-6, C20:4n-6 and polyunsaturated FA (PUFA (probability between 0.91-0.99 as compared to the CT. As a result, the TT hams had more MUFA (0.95% and a higher MUFA/PUFA ratio (0.43 than the CT. Barrows had more saturated FA (SFA and less PUFA than gilts. No differences in MUFA content were found between genders. The SCD polymorphism had a greater impact on MUFA than using hams from barrows instead of gilts. It is concluded that the SCD polymorphism is a good tool to increase MUFA and MUFA/PUFA ratio in Duroc crossbred dry-cured hams.

  18. Stearoyl-CoA Desaturase 1 Is a Key Determinant of Membrane Lipid Composition in 3T3-L1 Adipocytes.

    Science.gov (United States)

    Rodriguez-Cuenca, Sergio; Whyte, Lauren; Hagen, Rachel; Vidal-Puig, Antonio; Fuller, Maria

    2016-01-01

    Stearoyl-CoA desaturase 1 (SCD1) is a lipogenic enzyme important for the regulation of membrane lipid homeostasis; dysregulation likely contributes to obesity associated metabolic disturbances. SCD1 catalyses the Δ9 desaturation of 12-19 carbon saturated fatty acids to monounsaturated fatty acids. To understand its influence in cellular lipid composition we investigated the effect of genetic ablation of SCD1 in 3T3-L1 adipocytes on membrane microdomain lipid composition at the species-specific level. Using liquid chromatography/electrospray ionisation-tandem mass spectrometry, we quantified 70 species of ceramide, mono-, di- and trihexosylceramide, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, bis(monoacylglycero)phosphate, phosphatidylinositol and cholesterol in 3T3-L1 adipocytes in which a 90% reduction in scd1 mRNA expression was achieved with siRNA. Cholesterol content was unchanged although decreases in other lipids resulted in cholesterol accounting for a higher proportion of lipid in the membranes. This was associated with decreased membrane lateral diffusion. An increased ratio of 24:0 to 24:1 in ceramide, mono- and dihexosylceramide, and sphingomyelin likely also contributed to this decrease in lateral diffusion. Of particular interest, we observed a decrease in phospholipids containing arachidonic acid. Given the high degree of structural flexibility of this acyl chain this will influence membrane lateral diffusion, and is likely responsible for the transcriptional activation of Lands' cycle enzymes lpcat3 and mboat7. Of relevance these profound changes in the lipidome were not accompanied by dramatic changes in gene expression in mature differentiated adipocytes, suggesting that adaptive homeostatic mechanisms to ensure partial maintenance of the biophysical properties of membranes likely occur at a post-transcriptional level. PMID:27632198

  19. Omega-3 fatty acid deficiency selectively up-regulates delta6-desaturase expression and activity indices in rat liver: prevention by normalization of omega-3 fatty acid status.

    Science.gov (United States)

    Hofacer, Rylon; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Magrisso, I Jack; Benoit, Stephen C; McNamara, Robert K

    2011-09-01

    This study investigated the effects of perinatal dietary omega-3 (n-3) fatty acid depletion and subsequent repletion on the expression of genes that regulate long-chain (LC) polyunsaturated fatty acid biosynthesis in rat liver and brain. It was hypothesized that chronic n-3 fatty acid deficiency would increase liver Fads1 and Fads2 messenger RNA (mRNA) expression/activity and that n-3 fatty acid repletion would normalize this response. Adult rats fed the n-3-free diet during perinatal development exhibited significantly lower erythrocyte, liver, and frontal cortex LCn-3 fatty acid composition and reciprocal elevations in LC omega-6 (n-6) fatty acid composition compared with controls (CONs) and repleted rats. Liver Fads2, but not Fads1, Elovl2, or Elovl5, mRNA expression was significantly greater in n-3-deficient (DEF) rats compared with CONs and was partially normalized in repleted rats. The liver 18:3n-6/18:2n-6 ratio, an index of delta6-desturase activity, was significantly greater in DEF rats compared with CON and repleted rats and was positively correlated with Fads2 mRNA expression among all rats. The liver 18:3n-6/18:2n-6 ratio, but not Fads2 mRNA expression, was also positively correlated with erythrocyte and frontal cortex LCn-6 fatty acid compositions. Neither Fads1 or Fads2 mRNA expression was altered in brain cortex of DEF rats. These results confirm previous findings that liver, but not brain, delta6-desaturase expression and activity indices are negatively regulated by dietary n-3 fatty acids. PMID:22024496

  20. Functional characterization of flax fatty acid desaturase FAD2 and FAD3 isoforms expressed in yeast reveals a broad diversity in activity.

    Science.gov (United States)

    Radovanovic, Natasa; Thambugala, Dinushika; Duguid, Scott; Loewen, Evelyn; Cloutier, Sylvie

    2014-07-01

    With 45 % or more oil content that contains more than 55 % alpha linolenic (LIN) acid, linseed (Linum usitatissimum L.) is one of the richest plant sources of this essential fatty acid. Fatty acid desaturases 2 (FAD2) and 3 (FAD3) are the main enzymes responsible for the Δ12 and Δ15 desaturation in planta. In linseed, the oilseed morphotype of flax, two paralogous copies, and several alleles exist for each gene. Here, we cloned three alleles of FAD2A, four of FAD2B, six of FAD3A, and seven of FAD3B into a pYES vector and transformed all 20 constructs and an empty construct in yeast. The transformants were induced in the presence of oleic (OLE) acid substrate for FAD2 constructs and linoleic (LIO) acid for FAD3. Conversion rates of OLE acid into LIO acid and LIO acid into LIN acid were measured by gas chromatography. Conversion rate of FAD2 exceeded that of FAD3 enzymes with FAD2B having a conversion rate approximately 10 % higher than FAD2A. All FAD2 isoforms were active, but significant differences existed between isoforms of both FAD2 enzymes. Two FAD3A and three FAD3B isoforms were not functional. Some nonfunctional enzymes resulted from the presence of nonsense mutations causing premature stop codons, but FAD3B-C and FAD3B-F seem to be associated with single amino acid changes. The activity of FAD3A-C was more than fivefold greater than the most common isoform FAD3A-A, while FAD3A-F was fourfold greater. Such isoforms could be incorporated into breeding lines to possibly further increase the proportion of LIN acid in linseed. PMID:24522837

  1. Stearoyl-CoA desaturase-1 (SCD1 augments saturated fatty acid-induced lipid accumulation and inhibits apoptosis in cardiac myocytes.

    Directory of Open Access Journals (Sweden)

    Hiroki Matsui

    Full Text Available Mismatch between the uptake and utilization of long-chain fatty acids in the myocardium leads to abnormally high intracellular fatty acid concentration, which ultimately induces myocardial dysfunction. Stearoyl-Coenzyme A desaturase-1 (SCD1 is a rate-limiting enzyme that converts saturated fatty acids (SFAs to monounsaturated fatty acids. Previous studies have shown that SCD1-deficinent mice are protected from insulin resistance and diet-induced obesity; however, the role of SCD1 in the heart remains to be determined. We examined the expression of SCD1 in obese rat hearts induced by a sucrose-rich diet for 3 months. We also examined the effect of SCD1 on myocardial energy metabolism and apoptotic cell death in neonatal rat cardiac myocytes in the presence of SFAs. Here we showed that the expression of SCD1 increases 3.6-fold without measurable change in the expression of lipogenic genes in the heart of rats fed a high-sucrose diet. Forced SCD1 expression augmented palmitic acid-induced lipid accumulation, but attenuated excess fatty acid oxidation and restored reduced glucose oxidation. Of importance, SCD1 substantially inhibited SFA-induced caspase 3 activation, ceramide synthesis, diacylglycerol synthesis, apoptotic cell death, and mitochondrial reactive oxygen species (ROS generation. Experiments using SCD1 siRNA confirmed these observations. Furthermore, we showed that exposure of cardiac myocytes to glucose and insulin induced SCD1 expression. Our results indicate that SCD1 is highly regulated by a metabolic syndrome component in the heart, and such induction of SCD1 serves to alleviate SFA-induced adverse fatty acid catabolism, and eventually to prevent SFAs-induced apoptosis.

  2. 甘蓝型油菜BnFAD8基因编码序列的克隆和表达谱分析%Cloning and expression characteristics of fatty acid desaturase 8 gene from rape (Brassica napus L.)

    Institute of Scientific and Technical Information of China (English)

    刘绵学; 王茂华; 向俊蓓; 杨毅; 李旭锋

    2011-01-01

    通过比对拟南芥等同源基因,克隆了甘蓝型油菜FAD8基因中的保守序列.以得到的FAD8(Fatty Acid Desaturase 8)保守序列片段为信息探针,在GenBank的EST数据库中检索高度同源的EST,并通过人工拼接及RT-PCR得到油菜该基因的全长为1299 bp的cDNA序列,命名为BnFAD8.序列分析结果中发现该基因符合质体定位的ω3脂肪酸脱饱和酶序列特征.通过比较22℃和8℃处理的甘蓝型油菜的BnFAD8基因表达谱,发现该基因在常温下仅存在痕量表达;而在低温条件下在叶中表达出现较大幅度的升高.推测BnFAD8基因和油菜的低温调控存在联系.%Brassica napus fatty acid desaturase 8 (FAD8) belongs to cold-induced omega 3 fatty acid desaturase.By aligning Arabidopsis FAD8 and other homologous FAD8 genes, one highly conserved sequence of FAD8 from rape was cloned in study.Using the FAD8 conserved sequence as a querying probe, highly homologous EST were obtained from database of GenBank and a putative complete ORF of 1299 bp (named: BnFAD8) was assembled according to the rape clone.Furthermore, the full length cDNA of Brassica napus FAD8 was cloned by RT-PCR with two primers designed based on this assembled cDNA sequence.Features of plasmid-located o3 fatty acid desaturase were found in sequence analysis of cDNA cloned.As shown in expression profile result, BnFAD8 was highly expressed in leaves at 8 ℃, but only trace-level expression in leaves at 22 ℃, which suggested that BnFAD8 involved in the process of rape cold acclimation.

  3. Dedicated Carrier Deployment in Heterogeneous Networks with Inter-site Carrier Aggregation

    DEFF Research Database (Denmark)

    Wang, Hua; Rosa, Claudio; Pedersen, Klaus I.

    2013-01-01

    ) or picos with dedicated carrier deployment. Collaborative inter-site carrier aggregation (CA) is proposed in scenarios with macro+RRH deployment to make an efficient use of the fragmented spectrum from multiple cells. While in scenarios with macro+pico deployment, UEs can only connect to either...

  4. Magnetic Sephadex as a carrier for enzyme immobilization and drug targeting

    Energy Technology Data Exchange (ETDEWEB)

    Torchilin, V.P.; Papisov, M.I.; Smirnov, V.N.

    1985-04-01

    Magnetic materials were suggested as carriers for protein immobilization about 10 years ago. The main advantage of these carriers is their ability to be concentrated near magnetic terminals upon the application of the external magnetic field. This property is used in technological processes for selective catalyst removal from the reaction mixture (3), in immunological studies for the separation of cells to which magnetic particles are specifically bound modified with antibodies against cell surface components, in experiments for the drug targeting in vivo into appropriate tissues under the action of external magnetic field. There exist a number of methods to obtain porous magnetic carriers, containing immobilized matter not only on the surface, but also in the volume of a particle. Normally, these preparations are obtained by the granule formation from the suspension of ferromagnetic particles in the solution or melt of appropriate high-molecular-weight compound. The drawback of the above-mentioned methods is the pronounced aggregation of ferromagnetic particles. The aggregation does not permit to use concentrated enough suspensions of magnetic particles and causes the formation of the product with a variety of sizes and magnetic properties. We made an attempt to synthesize the magnetic carrier for protein immobilization on the basis of commercial Sephadex porous spheres. Sephadex granules were made magnetic by adsorptional fixation of ferromagnetic particles in its pores. The properties of the ''native'' and ''magnetic'' Sephadexes as carriers for protein immobilization were compared by parallel immobilization on both carriers of alpha-chymotrypsin and T I-albumin. In in vivo experiments we studied the ability of magnetic Sephadex to be concentrated in a desired region of the circulation under the action of external magnetic field.

  5. Hiding secret data into a carrier image

    Directory of Open Access Journals (Sweden)

    Ovidiu COSMA

    2012-06-01

    Full Text Available The object of steganography is embedding hidden information in an appropriate multimedia carrier, e.g., image, audio, or video. There are several known methods of solving this problem, which operate either in the space domain or in the frequency domain, and are distinguished by the following characteristics: payload, robustness and strength. The payload is the amount of secret data that can be embedded in the carrier without inducing suspicious artefacts, robustness indicates the degree in which the secret data is affected by the normal processing of the carrier e.g., compression, and the strength indicate how easy the presence of hidden data can be detected by steganalysis techniques. This paper presents a new method of hiding secret data into a digital image compressed by a technique based on the Discrete Wavelet Transform (DWT [2] and the Set Partitioning In Hierarchical Trees (SPIHT subband coding algorithm [6]. The proposed method admits huge payloads and has considerable strength.

  6. Hot Carrier extraction with plasmonic broadband absorbers

    CERN Document Server

    Ng, Charlene; Dligatch, Svetlana; Roberts, Ann; Davis, Timothy J; Mulvaney, Paul; Gomez, Daniel E

    2016-01-01

    Hot charge carrier extraction from metallic nanostructures is a very promising approach for applications in photo-catalysis, photovoltaics and photodetection. One limitation is that many metallic nanostructures support a single plasmon resonance thus restricting the light-to-charge-carrier activity to a spectral band. Here we demonstrate that a monolayer of plasmonic nanoparticles can be assembled on a multi-stack layered configuration to achieve broad-band, near-unit light absorption, which is spatially localised on the nanoparticle layer. We show that this enhanced light absorbance leads to $\\sim$ 40-fold increases in the photon-to-electron conversion efficiency by the plasmonic nanostructures. We developed a model that successfully captures the essential physics of the plasmonic hot-electron charge generation and separation in these structures. This model also allowed us to establish that efficient hot carrier extraction is limited to spectral regions where the photons possessing energies higher than the S...

  7. Carrier lifetimes in thin-film photovoltaics

    Science.gov (United States)

    Baek, Dohyun

    2015-09-01

    The carrier lifetimes in thin-film solar cells are reviewed and discussed. Shockley-Read-Hall recombination is dominant at low carrier density, Auger recombination is dominant under a high injection condition and high carrier density, and surface recombination is dominant under any conditions. Because the surface photovoltage technique is insensitive to the surface condition, it is useful for bulk lifetime measurements. The photoconductance decay technique measures the effective recombination lifetime. The time-resolved photoluminescence technique is very useful for measuring thin-film semiconductor or solar-cell materials lifetime, because the sample is thin, other techniques are not suitable for measuring the lifetime. Many papers have provided time-resolved photoluminescence (TRPL) lifetimes for copper-indium-gallium-selenide (CIGS) and CdTe thin-film solar cell. The TRPL lifetime strongly depends on open-circuit voltage and conversion efficiency; however, the TRPL life time is insensitive to the short-circuit current.

  8. Development of radioisotope labeled polymeric carriers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jin; Jeong, Jea Min; Hwang, Hyun Jeong [Ewha Womans University, Seoul (Korea)

    2000-04-01

    This research was performed with the aim of developing polymeric radioisotope or drug carriers for obtaining efficient diagnostic therapeutic efficacy. As polymers, polyethylene oxides, polylactides, polycaprolactone were chosen to prepare the devices including micelle system, microemulsion, nanospheres. In addition, anticancer drug loaded polylactide microparticulates were fabricated as a regional chemotherapeutics for the treatment of cancer. Technetium or radioactive iodine was labeled to the polymeric carriers via ligands such as DTPA and HPP, respectively. Labeling efficiency was above 90% and stable enough up to 24 hours. Moreover, injected polymer carriers demonstrated higher blood maintenance and bone uptake than Tin colloid, a control. These results suggested that radioisotope carrying polymeric particulate are promising tools for diagnosing blood vessels or bones. Besides, anticancer drug loaded particulates demonstrated appropriate maintenance of therapeutic concentration and localization. Therefore it was proposed that this therapeutic system may be potential as a cancer therapy modality. 20 refs., 24 figs.,5 tabs. (Author)

  9. Hot-carrier effects in MOS devices

    CERN Document Server

    Takeda, Eiji; Miura-Hamada, Akemi

    1995-01-01

    The exploding number of uses for ultrafast, ultrasmall integrated circuits has increased the importance of hot-carrier effects in manufacturing as well as for other technological applications. They are rapidly movingout of the research lab and into the real world.This book is derived from Dr. Takedas book in Japanese, Hot-Carrier Effects, (published in 1987 by Nikkei Business Publishers). However, the new book is much more than a translation. Takedas original work was a starting point for developing this much more complete and fundamental text on this increasingly important topic. The new work

  10. Line broadening caused by Coulomb carrier-carrier correlations and dynamics of carrier capture and emission in quantum dots

    DEFF Research Database (Denmark)

    Uskov, Alexander V; Magnúsdóttir, Ingibjörg; Tromborg, Bjarne;

    2001-01-01

    Mechanisms of pure dephasing in quantum dots due to Coulomb correlations and the dynamics of carrier capture and emission are suggested, and a phenomenological model for the dephasing is developed. It is shown that, if the rates of these capture and emission processes are sufficiently high, signi......, significant homogeneous line broadening of the order of several meV can result....

  11. Advanced two-way satellite frequency transfer by carrier-phase and carrier-frequency measurements

    Science.gov (United States)

    Fujieda, Miho; Gotoh, Tadahiro; Amagai, Jun

    2016-06-01

    Carrier-phase measurement is one of the ways to improve the measurement resolution of two-way satellite frequency transfer. We introduce two possible methods for carrier-phase measurement: direct carrier-phase detection identified by Two-Way Carrier-Phase (TWCP) and the use of carrier-frequency information identified by Two-Way Carrier Frequency (TWCF). We performed the former using an arbitrary waveform generator and an analog-to-digital sampler and the latter using a conventional modem. The TWCF measurement using the modem had a resolution of 10-13 and the result agreed with that obtained by GPS carrier-phase frequency transfer in a 1500 km baseline. The measurement accuracy may have been limited by the poor frequency resolution of the modem; however, the TWCF measurement was able to improve the stability of conventional two-way satellite frequency transfer. Additionally, we show that the TWCP measurement system has the potential to achieve a frequency stability of 10-17.

  12. Nanotechnological carriers for cancer chemotherapy: the state of the art.

    Science.gov (United States)

    Estanqueiro, Marilene; Amaral, Maria Helena; Conceição, Jaime; Sousa Lobo, José Manuel

    2015-02-01

    Cancer is a term used for a heterogeneous group of malignant diseases in which abnormal cells divide without control and are able to invade other tissues, resulting in metastasis. According to the last data of World Health Organization the incidence and mortality rates of cancer are high and tend to increase. Chemotherapy is usually used in cancer treatments, but due to the lack of specificity of drugs, is associated to various and damaging side effects that have a severe impact on patients quality of life. Nanotechnology is actually an important area of interest in science and technology, which has been extensively explored during the last decade, particularly in the development of carriers for cytotoxic drugs. These carriers include vesicular and particulate systems such as liposomes, niosomes, transfersomes, ethosomes, micelles, dendrimers, and polymeric, protein and lipid nanoparticles. Polymer-drug conjugates and antibody-drug conjugates have also been studied. The present review is an attempt to contemplate the studied nanocarriers in the field of anticancer drugs delivery, their advantages and disadvantages and future perspectives. PMID:25591851

  13. Polyester Dendrimers: Smart Carriers for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Jean–d’Amour K. Twibanire

    2014-01-01

    Full Text Available Polyester dendrimers have been shown to be outstanding candidates for biomedical applications. Compared to traditional polymeric drug vehicles, these biodegradable dendrimers show excellent advantages especially as drug delivery systems because they are non-toxic. Here, advances on polyester dendrimers as smart carriers for drug delivery applications have been surveyed. Both covalent and non-covalent incorporation of drugs are discussed.

  14. Towards 100 gigabit carrier ethernet transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Anders; Zhang, Jiang; Yu, Hao;

    2010-01-01

    Ethernet as a transport technology has, up to now, lacked the features such as network layer architecture, customer separation and manageability that carriers require for wide-scale deployment. However, with the advent of PBB-TE and TMPLS, it is now possible to use Ethernet as a transport...

  15. A new lubricant carrier for metal forming

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Bay, Niels; Tang, Peter Torben;

    2009-01-01

    A lubricant carrier for metal forming processes is developed. Surfaces with pores of micrometer size for entrapping lubricant are generated by electrochemical deposition of an alloy, consisting of two immiscible metals, of which one metal subsequently is etched away leaving 5 mu m layers with a s...... extrusion at high reduction and excessive stroke comparing with conventionally lubrication using phosphate coating and soap....

  16. Polyester Dendrimers: Smart Carriers for Drug Delivery

    OpenAIRE

    Jean–d’Amour K. Twibanire; T. Bruce Grindley

    2014-01-01

    Polyester dendrimers have been shown to be outstanding candidates for biomedical applications. Compared to traditional polymeric drug vehicles, these biodegradable dendrimers show excellent advantages especially as drug delivery systems because they are non-toxic. Here, advances on polyester dendrimers as smart carriers for drug delivery applications have been surveyed. Both covalent and non-covalent incorporation of drugs are discussed.

  17. Itaconic acid carrier ampholytes for isoelectric focusing.

    Science.gov (United States)

    Brenna, O

    1977-04-11

    Commercial carrier ampholytes, obtained by coupling polyethylene polyamines to acrylic acid, exhibit a conductivity minimum in the pH range 5.5-6.5 owing to the lack of appropriate pK values of the polyamine in this pH region. By replacing acrylic with itaconic acid, it has been possible to effect substantial improvements in the pH range 5.5-6.5 as itaconic acid has a pK2 value of 5.45. Upon coupling, the pK of the gramma-carboxyl group remains virtually unaltered. With itoconic acid carrier ampholytes it has been possible to improve the conductivity in the pH range 5.5-6.5 by as much as 400% compared with conventional carrier ampholytes. It is suggected that the commercial products should be supplemented with itaconic acid carrier ampholytes in order to obtain a more uniform conductivity and buffering capacity in the pH range 3-10.

  18. 7 CFR 35.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Carrier. 35.4 Section 35.4 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS EXPORT...

  19. Management of asymptomatic gene carriers of transthyretin familial amyloid polyneuropathy.

    Science.gov (United States)

    Schmidt, Hartmut H-J; Barroso, Fabio; González-Duarte, Alejandra; Conceição, Isabel; Obici, Laura; Keohane, Denis; Amass, Leslie

    2016-09-01

    Transthyretin familial amyloid polyneuropathy (TTR-FAP) is a rare, severe, and irreversible, adult-onset, hereditary disorder caused by autosomal-dominant mutations in the TTR gene that increase the intrinsic propensity of transthyretin protein to misfold and deposit systemically as insoluble amyloid fibrils in nerve tissues, the heart, and other organs. TTR-FAP is characterized by relentless, progressively debilitating polyneuropathy, and leads to death, on average, within 10 years of symptom onset without treatment. With increased availability of disease-modifying treatment options for a wider spectrum of patients with TTR-FAP, timely detection of the disease may offer substantial clinical benefits. This review discusses mutation-specific predictive genetic testing in first-degree relatives of index patients diagnosed with TTR-FAP and the structured clinical follow-up of asymptomatic gene carriers for prompt diagnosis and early therapeutic intervention before accumulation of substantial damage. Muscle Nerve 54: 353-360, 2016.

  20. Lower frequency of Gaucher disease carriers among Tay-Sachs disease carriers.

    Science.gov (United States)

    Peleg, L; Frisch, A; Goldman, B; Karpaty, M; Narinsky, R; Bronstein, S; Frydman, M

    1998-01-01

    The heterozygote frequency of Gaucher disease (GD) and Tay-Sachs disease (TSD) is distinctly high among Ashkenazi Jews (1:29 for TSD and 1:16 for GD). Two main theories have been suggested to explain this high occurrence: a founder effect with subsequent genetic drift, and a selective advantage of heterozygotes. We compared the frequency of the GD most common mutation (1226A-->G) among carriers of the common TSD mutation (+1277 TATC) with the frequency of this mutation in the general Ashkenazi population. The frequency of GD carriers among 308 TSD heterozygotes was 1:28 which is about half the expected (P = 0.03). These results indicate that carriers of both diseases do not possess additional evolutionary advantage over single mutation carriers. A reasonable interpretation of these findings is that one or both mutations have arisen relatively recently in different regions of Europe and have not yet reached genetic equilibrium. PMID:9781065

  1. PAPR Reduction in OFDM Systems with Large Number of Sub-Carriers by Carrier Interferometry Approaches

    Institute of Scientific and Technical Information of China (English)

    HE Jian-hui; QUAN Zi-yi; MEN Ai-dong

    2004-01-01

    High Peak-to-Average Power Ratio (PAPR) is one of the major drawbacks of Orthogonal Frequency Division Multiplexing ( OFDM) systems. This paper presents the structures of the particular bit sequences leading to the maximum PAPR (PAPRmax) in Carrier-Interferometry OFDM (CI/OFDM) and Pseudo Orthogonal Carrier-Interferometry OFDM (PO-CI/OFDM) systems for Binary Phase Shift Keying (BPSK) modulation. Furthermore, the simulation and analysis of PAPRmax and PAPR cumulative distribution in CI/OFDM and PO-CI/OFDM systems with 2048 sub-carriers are presented in this paper. The results show that the PAPR of OFDM system with large number of sub-carriers reduced evidently via CI approaches.

  2. Relationships between hepatic stearoyl-CoA desaturase-1 activity and mRNA expression with liver fat content in humans.

    Science.gov (United States)

    Peter, Andreas; Cegan, Alexander; Wagner, Silvia; Elcnerova, Michaela; Königsrainer, Alfred; Königsrainer, Ingmar; Häring, Hans-Ulrich; Schleicher, Erwin D; Stefan, Norbert

    2011-02-01

    Stearoyl-CoA desaturase-1 (SCD1) has gained much interest as a future drug target to treat fatty liver and its consequences. However, there are few and inconsistent human data about expression and activity of this important enzyme. We investigated activity and expression of SCD1 and their relationships with liver fat (LF) content in human liver samples. Fifty subjects undergoing liver surgery were studied. SCD1 activity was estimated from the ratio of oleate (C18:1) to stearate (C18:0) within lipid subfractions. Furthermore, SCD1 mRNA expression and LF content were measured. Similarly to previous studies, we observed a strong positive correlation between LF content and the C18:1/C18:0 ratio in the combined fatty acid (FA) fractions (r = 0.96, P < 0.0001), which could be interpreted as higher SCD1 activity with increasing LF. However, hepatic SCD1 mRNA expression did not correlate with LF (r = 0.16, P = 0.13). To solve these conflicting data, we analyzed the FA composition of hepatic lipid subfractions. With increasing LF content the amount of FAs from the triglyceride (TG) fraction increased (r = 0.96, P < 0.0001), whereas the FAs from the phospholipid (PL) fraction remained unchanged (r = -0.17, P = 0.19). Of these two major lipid fractions, the C18:1/C18:0 ratio in TG was 16-fold higher than in PL. Supporting the SCD1 mRNA expression data, the C18:1/C18:0 ratio of the TG or PL fraction did not correlate with LF (r = 0.26, P = 0.12 and r = 0.08, P = 0.29). We provide novel information that SCD1 activity and mRNA expression appear not to be elevated in subjects with high LF content. We suggest that the FA composition of lipid subclasses, rather than of mixed lipids, should be analyzed to estimate SCD1 activity.

  3. Carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool

    Science.gov (United States)

    Cai, Yu; Sha, Shuang

    2016-09-01

    This paper proposes a new carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool used in a cylindrical borehole environment during oil-based mud drilling processes. The new tool is an orthogonal frequency division multiplexing access-based contactless multi-measurand detection tool. The tool can measure formation resistivity in different azimuthal angles and elevational depths. It can measure many more measurands simultaneously in a specified bandwidth than the legacy frequency division multiplexing multi-measurand tool without a channel-select filter while avoiding inter-carrier interference. The paper also shows that formation resistivity is not sensitive to frequency in certain frequency bands. The average resistivity collected from N subcarriers can increase the measurement of the signal-to-noise ratio (SNR) by N times given no amplitude clipping in the current-injection electrode. If the clipping limit is taken into account, with the phase rotation of each single carrier, the amplitude peak-to-average ratio can be reduced by 3 times, and the SNR can achieve a 9/N times gain over the single-carrier system. The carrier-interleaving technique is also introduced to counter the carrier frequency offset (CFO) effect, where the CFO will cause inter-pad interference. A qualitative analysis and simulations demonstrate that block-interleaving performs better than tone-interleaving when coping with a large CFO. The theoretical analysis also suggests that increasing the subcarrier number can increase the measurement speed or enhance elevational resolution without sacrificing receiver performance. The complex orthogonal multi-pad multi-carrier resistivity logging tool, in which all subcarriers are complex signals, can provide a larger available subcarrier pool than other types of transceivers.

  4. Benchmark and gap analysis of current mask carriers vs future requirements: example of the carrier contamination

    Science.gov (United States)

    Fontaine, H.; Davenet, M.; Cheung, D.; Hoellein, I.; Richsteiger, P.; Dejaune, P.; Torsy, A.

    2007-02-01

    In the frame of the European Medea+ 2T302 MUSCLE project, an extensive mask carriers benchmark was carried out in order to evaluate whether some containers answer to the 65nm technology needs. Ten different containers, currently used or expected in the future all along the mask supply chain (blank, maskhouse and fab carriers) were selected at different steps of their life cycle (new, aged, aged & cleaned). The most critical parameters identified for analysis versus future technologies were: automation, particle contamination, chemical contamination (organic outgassing, ionic contamination), cleanability, ESD, airtightness and purgeability. Furthermore, experimental protocols corresponding to suitable methods were then developed and implemented to test each criterion. The benchmark results are presented giving a "state of the art" of mask carriers currently available and allowing a gap analysis for the tested parameters related to future needs. This approach is detailed through the particular case of carrier contamination measurements. Finally, this benchmark / gap analysis leads to propose advisable mask carrier specifications (and the test protocols associated) on various key parameters which can also be taken as guidelines for a standardization perspective for the 65nm technology. This also indicates that none of tested carriers fulfills all the specifications proposed.

  5. 鲤耐低温候选基因CcSCD全长cDNA的克隆及功能预测%Isolation and Characterization of Full Length cDNA Sequence of A Stearoyl-CoA Desaturase Gene Responding to Low Temperature from Common Carp(Cyprinus carpio)

    Institute of Scientific and Technical Information of China (English)

    常玉梅; 徐丽华; 李世国; 唐然; 梁利群

    2012-01-01

    The gene of stearoyl-CoA Desaturase(SCD) as a rate limiting enzyme involved in desaturation of saturated fatty acids plays vital roles in maintaining membrane fluidity and is considered as a key candidate which helps to improve cold tolerance.A SCD cDNA from common carp(Cyprinus carpio)(CcSCD) brain at cooling temperature was characterized and the transcription expression profiles were examined in the common carp exposed to cold(6℃) and warm(23℃) temperatures using real time RT-PCR.A full-length CcSCD cDNA was shown to be comprised of 2618 bp,including an open reading-frame of 975 bp and deduced 324 amino acid residues.Phylogenetic analysis revealed that the SCD protein sequences of the common carp and grass carp(Ctenopharyngodon idella) were clustered together,sharing the highest level of similarity(88%).The quantified results showed that under cooling temperature,CcSCD transcripts were significantly up-regulated(P〈0.01),in comparison to transcripts of samples from normal temperature.The findings help to establish a transgene construction and to apply genetic manipulation to identify functions of CcSCD gene of fish during cold response in future.%硬酯酰辅酶A脱氢酶(Stearoyl-CoA Desaturase,SCD)是参与脂肪酸脱氢反应的限速酶和关键酶,此酶编码基因SCD对增加膜磷脂的不饱和脂肪酸成分,提高细胞膜在低温下的流动性发挥重要作用,可能是抗寒过程中的关键基因成员。本研究采用cDNA末端快速扩增技术(Rapid Amplifications of cDNAEnds,RACE)克隆了鲤(Cyprinus carpio)脑组织CcSCD基因的全长cDNA序列,采用实时荧光定量PCR技术检测该基因在低温(6℃)和常温(23℃)条件下的转录表达差异,对其蛋白编码序列的结构和功能进行了预测分析。结果显示,CcSCD基因cDNA全长2618bp,包含一个由324个氨基酸残基组成的长度为975bp的阅读框(ORF);蛋白分子进化树显示鲤的SCD和草鱼(Ctenopharyngodon idella)

  6. Isolation and functional analysis of a Brassica juncea gene encoding a component of auxin efflux carrier

    Institute of Scientific and Technical Information of China (English)

    WEI; MIN; NI; XIAO; YA; CHEN; ZHI; HONG; XU; HONG; WEI; XUE

    2002-01-01

    Polar auxin transport plays a divergent role in plant growth and developmental processes including rootand embryo development, vascular pattern formation and cell elongation. Recently isolated Arabidopsispin gene family was believed to encode a component of auxin efflux carrier (Galweiler et al, 1998). Basedon the Arabidopsis pin1 sequence we have isolated a Brassica juncea cDNA (designated Bjpinl), whichencoded a 70-kDa putative auxin efflux carrier. Deduced BjPIN1 shared 65% identities at protein level withAtPIN1 and was highly homologous to other putative PIN proteins of Arabidopsis (with highest homologyto AtPIN3). Hydrophobic analysis showed similar structures between BjPIN1 and AtPIN proteins. Presenceof 6 exons (varying in size between 65 bp and 1229 bp) and 5 introns (sizes between 89 bp and 463 bp)in the genomic fragment was revealed by comparing the genomic and cDNA sequences. Northern blotanalysis indicated that Bjpinl was expressed in most of the tissues tested, with a relatively higher levelof transcript in flowers and a lower level in root tissues. Promoter-reporter gene fusion studies furtherrevealed the expression of Bjpinl in the mature pollen grains, young seeds, root tip, leaf vascular tissue andtrace bundle, stem epidermis, cortex and vascular cells. BjPIN1 was localized on the plasma membraneas demonstrated through fusion expression of green fluorescent protein (GFP). Auxin efflux carrier activitywas elevated in transgenic Arabidopsis expressing BjPIN1.

  7. 48 CFR 1615.470 - Carrier investment of FEHB funds.

    Science.gov (United States)

    2010-10-01

    ... CONTRACTING BY NEGOTIATION Contract Pricing 1615.470 Carrier investment of FEHB funds. (a) Except for contracts based on a combination of cost and price analysis (community-rated), the carrier is required...

  8. Carrier cultures of simian foamy virus.

    Science.gov (United States)

    Clarke, J K; Samuels, J; Dermott, E; Gay, F W

    1970-05-01

    The production of cultures of HEp-2 and BHK-21 cells persistently infected with a type 1 simian foamy virus is described. After infection, HEp-2 cells showed no structural changes, whereas BHK-21 cells lost their normal spindle shape and showed mitochondrial damage, and some cells contained many lysosomes. Thin sections also showed that a few BHK-21 cells contained virus particles in low concentration, and infectious virus could be isolated from both the cells and the supernatant fluid. No virus was seen in thin sections of HEp-2 cells, although infectious virus in low titer could be recovered intermittently from lysed cells. Both carrier cultures were immune to challenge with homologous virus and antigen could be detected in over 90% of the cells even after growth for 9 weeks in the presence of virus-neutralizing serum. The distribution of antigen in carrier cultures of both cell types is described and compared with that seen in cytocidal infections. PMID:4986851

  9. Carrier synchronization and detection of polyphase signals.

    Science.gov (United States)

    Lindsey, W. C.; Simon, M. K.

    1972-01-01

    Digital communication networks used for the distribution of high-speed digital information are currently the subject of design studies for many civil and military applications. This paper presents results that are useful in such studies as well as in network planning. In particular, the paper is concerned with the problems of carrier synchronization and noisy reference detection of polyphase signals. Reconstruction of coherent references for the detection of polyphase signals is considered and analyzed for three carrier reconstruction loops, namely, Nth power (multiply-and-divide) loops, generalized Costas (I-Q) loops, and extensions of data-aided (modulation wipeoff) loops. General expressions for the error probability are developed when the reconstructed reference signals are noisy.

  10. Superconductivity in carrier-doped silicon carbide

    Directory of Open Access Journals (Sweden)

    Takahiro Muranaka, Yoshitake Kikuchi, Taku Yoshizawa, Naoki Shirakawa and Jun Akimitsu

    2008-01-01

    Full Text Available We report growth and characterization of heavily boron-doped 3C-SiC and 6H-SiC and Al-doped 3C-SiC. Both 3C-SiC:B and 6H-SiC:B reveal type-I superconductivity with a critical temperature Tc=1.5 K. On the other hand, Al-doped 3C-SiC (3C-SiC:Al shows type-II superconductivity with Tc=1.4 K. Both SiC:Al and SiC:B exhibit zero resistivity and diamagnetic susceptibility below Tc with effective hole-carrier concentration n higher than 1020 cm−3. We interpret the different superconducting behavior in carrier-doped p-type semiconductors SiC:Al, SiC:B, Si:B and C:B in terms of the different ionization energies of their acceptors.

  11. Terahertz transport dynamics of graphene charge carriers

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due

    The electronic transport dynamics of graphene charge carriers at femtosecond (10-15 s) to picosecond (10-12 s) time scales are investigated using terahertz (1012 Hz) time-domain spectroscopy (THz-TDS). The technique uses sub-picosecond pulses of electromagnetic radiation to gauge the electrodynamic...... response of thin conducting films at up to multi-terahertz frequencies. In this thesis THz-TDS is applied towards two main goals; (1) investigation of the fundamental carrier transport dynamics in graphene at femtosecond to picosecond timescales and (2) application of terahertz time-domain spectroscopy...... to rapid and non-contact electrical characterization of large-area graphene, relevant for industrial integration. We show that THz-TDS is an accurate and reliable probe of graphene sheet conductance, and that the technique provides insight into fundamental aspects of the nanoscopic nature of conduction...

  12. Screening-induced carrier transport in silicene

    International Nuclear Information System (INIS)

    Based on the Boltzmann transport equation in the MRT approximation, we present a theory to investigate low-field carrier transport in dual-gated silicene FETs by taking into account screened charged impurity scattering, which is the most likely scattering mechanism limiting the conductivity. Static RPA dielectric screening is also included in the conductivity calculation to study temperature-dependent silicene transport. It is found that both calculated conductivity and band gap not only depend strongly on carrier sheet density, but also depend strongly on effective offset density. More importantly, screening-induced metal-insulator-transition phenomena in buckled silicene can be observed theoretically, which is similar to that obtained in monolayer graphene. (paper)

  13. Experimental distribution of entanglement with separable carriers.

    Science.gov (United States)

    Fedrizzi, A; Zuppardo, M; Gillett, G G; Broome, M A; Almeida, M P; Paternostro, M; White, A G; Paterek, T

    2013-12-01

    The key requirement for quantum networking is the distribution of entanglement between nodes. Surprisingly, entanglement can be generated across a network without direct transfer-or communication-of entanglement. In contrast to information gain, which cannot exceed the communicated information, the entanglement gain is bounded by the communicated quantum discord, a more general measure of quantum correlation that includes but is not limited to entanglement. Here, we experimentally entangle two communicating parties sharing three initially separable photonic qubits by exchange of a carrier photon that is unentangled with either party at all times. We show that distributing entanglement with separable carriers is resilient to noise and in some cases becomes the only way of distributing entanglement through noisy environments.

  14. Protection switching for carrier ethernet multicast

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Berger, Michael Stübert

    2010-01-01

    This paper addresses network survivability for IPTV multicast transport in Carrier Ethernet networks. The impact of link failures is investigated and suggestions for intelligent multicast resilience schemes are proposed. In particular, functions of the multicast tree are integrated with the Carri...... recovery path length, recovery time, number of branch nodes and operational complexity. The integrated approach therefore shows significant potential to increase the QoE for IPTV users in case of network failures and recovery actions....

  15. Nanogel Carrier Design for Targeted Drug Delivery

    OpenAIRE

    Eckmann, D.M.; Composto, R. J.; Tsourkas, A; Muzykantov, V. R.

    2014-01-01

    Polymer-based nanogel formulations offer features attractive for drug delivery, including ease of synthesis, controllable swelling and viscoelasticity as well as drug loading and release characteristics, passive and active targeting, and the ability to formulate nanogel carriers that can respond to biological stimuli. These unique features and low toxicity make the nanogels a favorable option for vascular drug targeting. In this review, we address key chemical and biological aspects of nanoge...

  16. Software defined networking: meeting carrier grade requirements

    OpenAIRE

    Staessens, Dimitri; Sharma, Sachin; Colle, Didier; Pickavet, Mario; Demeester, Piet

    2011-01-01

    Software Defined Networking is a networking paradigm which allows network operators to manage networking elements using software running on an external server. This is accomplished by a split in the architecture between the forwarding element and the control element. Two technologies which allow this split for packet networks are ForCES and Openflow. We present energy efficiency and resilience aspects of carrier grade networks which can be met by Openflow. We implement flow restoration and ru...

  17. Atlas V Aft Bulkhead Carrier Rideshare System

    OpenAIRE

    Willcox, Maj Travis

    2012-01-01

    This paper gives the background and details of the Atlas V Aft Bulkhead Carrier to be flown on the National Recoinnassance Office Launch 36 with the Operationally Unique Technologies Satellite Auxiliary Payload. The CubeSats included are from a number of labs, universities and government entities for the purpose of technology demonstration, science experimentation and operational proof of concepts. This mission will pave the way for rideshare on NRO missions and other Atlas V launches.

  18. The solute carrier 6 family of transporters

    DEFF Research Database (Denmark)

    Bröer, Stefan; Gether, Ulrik

    2012-01-01

    The solute carrier 6 (SLC6) family of the human genome comprises transporters for neurotransmitters, amino acids, osmolytes and energy metabolites. Members of this family play critical roles in neurotransmission, cellular and whole body homeostasis. Malfunction or altered expression...... of these transporters is associated with a variety of diseases. Pharmacological inhibition of the neurotransmitter transporters in this family is an important strategy in the management of neurological and psychiatric disorders. This review provides an overview of the biochemical and pharmacological properties...

  19. Photoinduced carrier annihilation in silicon pn junction

    Science.gov (United States)

    Sameshima, Toshiyuki; Motoki, Takayuki; Yasuda, Keisuke; Nakamura, Tomohiko; Hasumi, Masahiko; Mizuno, Toshihisa

    2015-08-01

    We report analysis of the photo-induced minority carrier effective lifetime (τeff) in a p+n junction formed on the top surfaces of a n-type silicon substrate by ion implantation of boron and phosphorus atoms at the top and bottom surfaces followed by activation by microwave heating. Bias voltages were applied to the p+ boron-doped surface with n+ phosphorus-doped surface kept at 0 V. The values of τeff were lower than 1 × 10-5 s under the reverse-bias condition. On the other hand, τeff markedly increased to 1.4 × 10-4 s as the forward-bias voltage increased to 0.7 V and then it leveled off when continuous-wave 635 nm light was illuminated at 0.74 mW/cm2 on the p+ surface. The carrier annihilation velocity S\\text{p + } at the p+ surface region was numerically estimated from the experimental τeff. S\\text{p + } ranged from 4000 to 7200 cm/s under the reverse-bias condition when the carrier annihilation velocity S\\text{n + } at the n+ surface region was assumed to be a constant value of 100 cm/s. S\\text{p + } markedly decreased to 265 cm/s as the forward-bias voltage increased to 0.7 V.

  20. 两种主流载体蛋白在大肠杆菌表面展示抗体应用中的系统分析%Comparison of Autotransporter and Ice Nucleation Protein as Carrier Proteins for Antibody Display on The Cell Surface of Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    杨晓; 孙爽; 王海凤; 杭海英

    2013-01-01

    抗体表面展示技术对于新抗体的筛选和抗体亲和力的成熟是非常重要的工具.目前,较为广泛应用的表面展示技术是噬菌体的表面展示和酵母的表面展示.大肠杆菌,以其培养简单和基因改造便捷,有望成为非常好的一种表面展示的宿主.但是,目前为止,大肠杆菌还没有被广泛地应用于抗体的表面展示技术中.主要的原因之一是在大肠杆菌外膜展示抗体的效率还不够高.作为外膜展示的载体,许多蛋白都被研究过,其中自转运蛋白(autotransporter,AT)和冰核蛋白(ice nucleation protein,INP)是人们研究最多的两种载体蛋白.还有一个原因是大肠杆菌作为宿主,在表达异源基因和展示异源蛋白过程中的存活率问题.在本研究中,系统地研究了Ag43β(一种自转运蛋白Antigen43的β结构域)和INPNC(去掉中间冗余序列的冰核蛋白的N端和C端)两种载体蛋白在强弱不同的三种启动子(T7、araBAD和lac)诱导表达的情况下,表达量、展示率、抗原亲和力以及宿主菌存活率的差异.我们发现,Ag43β展示的抗体在抗原亲和力上优于INPNC展示的抗体.在存活率方面,T7启动子诱导表达的存活率很低:用INPNC作为载体蛋白时只有0.0033%,用Ag43β作为载体蛋白时只有0.02%存活率.lac启动子诱导表达的存活率:用INPNC作为载体蛋白时为2.04%,用Ag43β作为载体蛋白时为13.27%.araBAD启动子诱导表达的存活率很高:用INPNC作为载体蛋白时为37.80%,用Ag43β作为载体蛋白时高达90.23%.但是araBAD诱导表达量和展示率都很低,所以其表现出的宿主高存活率意义有限.综合看来,由lac启动子驱动的、以Ag43β为载体蛋白的抗体表面展示系统是最好的选择.

  1. 14 CFR 252.3 - Smoking ban: air carriers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Smoking ban: air carriers. 252.3 Section... PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.3 Smoking ban: air carriers. Air carriers shall prohibit smoking on all scheduled passenger flights....

  2. 14 CFR 252.5 - Smoking ban: foreign air carriers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Smoking ban: foreign air carriers. 252.5... PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.5 Smoking ban: foreign air carriers. (a) Foreign air carriers shall prohibit smoking on all scheduled passenger flight segments: (1) Between...

  3. Terahertz carrier dynamics in graphene and graphene nanostructures

    DEFF Research Database (Denmark)

    Jensen, Søren A.; Turchinovich, Dmitry; Tielrooij, Klaas Jan;

    2014-01-01

    Photoexcited charge carriers in 2D graphene and in 1D graphene nanostructures were studied with optical pump-THz probe spectroscopy. We find efficient hot-carrier multiplication in 2D graphene, and predominantly free carrier early time response in 1D nanostructures. © 2014 OSA....

  4. Joint Iterative Carrier Synchronization and Signal Detection for Dual Carrier 448 Gb/s PDM 16-QAM

    DEFF Research Database (Denmark)

    Zibar, Darko; Carvalho, Luis; Estaran Tolosa, Jose Manuel;

    2013-01-01

    Soft decision driven joint carrier synchronization and signal detection, employing expectation maximization, is experimentally demonstrated. Employing soft decisions offers an improvement of 0.5 dB compared to hard decision digital PLL based carrier synchronization and demodulation....

  5. Literature review of the passenger airline business models: Full service carrier, low-cost carrier and charter airlines

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijks, G.

    2008-01-01

    The deregulation and liberalization of the air transportation industry have developed three main passenger business models: full service carriers, low-cost carriers, and charter airlines. Deregulation removed regulated fares and routes increasing competition and yields. Airlines business models main

  6. Dynamics of intracellular clathrin/AP1 and clathrin/AP3 containing carriers

    OpenAIRE

    2012-01-01

    Clathrin/AP1 and clathrin/AP3 coated vesicular carriers originate from endosomes and the TGN. We report here the real-time visualization of these structures in living cells reliably tracked by using rapid, three-dimensional imaging with a spinning-disk confocal microscope. We imaged relatively sparse, diffraction-limited, fluorescent objects containing chimeric fluorescent protein (clathrin light chain, σ adaptor subunits or dynamin2) with a spatial precision of up to ~ 30 nm and a temporal r...

  7. Evolution and Structural Diversification of PILS Putative Auxin Carriers in Plants

    OpenAIRE

    Feraru, Elena; Vosolsobě, Stanislav; Feraru, Mugurel I.; Petrášek, Jan; Kleine-Vehn, Jürgen

    2012-01-01

    The phytohormone auxin contributes to virtually every aspect of the plant development. The spatiotemporal distribution of auxin depends on a complex interplay between auxin metabolism and intercellular auxin transport. Intracellular auxin compartmentalization provides another link between auxin transport processes and auxin metabolism. The PIN-LIKES (PILS) putative auxin carriers localize to the endoplasmic reticulum (ER) and contribute to cellular auxin homeostasis. PILS proteins regulate in...

  8. Use of the pre-pro part of Staphylococcus hyicus lipase as a carrier for secretion of Escherichia coli outer membrane protein A (OmpA) prevents proteolytic degradation of OmpA by cell-associated protease(s) in two different gram-positive bacteria.

    OpenAIRE

    Meens, J.; Herbort, M. (Mirco); Klein, M.; Freudl, R

    1997-01-01

    Heterologous protein secretion was studied in the gram-positive bacteria Bacillus subtilis and Staphylococcus carnosus by using the Escherichia coli outer membrane protein OmpA as a model protein. The OmpA protein was found to be translocated across the plasma membrane of both microorganisms. However, the majority of the translocated OmpA was similarly degraded in B. subtilis and S. carnosus despite the fact that the latter organism does not secrete soluble exoproteases into the culture mediu...

  9. Carrier Transport Mechanism in Single Crystalline Organic Semiconductor Thin Film Elucidated by Visualized Carrier Motion.

    Science.gov (United States)

    Matsubara, Kohei; Abe, Kentaro; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-04-01

    Time-resolved microscopic second harmonic generation (TRM-SHG) measurement was conducted to evaluate temperature dependence of the anisotropic carrier transport process in 6,13-Bis(triisopropylsilylethynyl) (TIPS) pentacene single crystalline domains for two orthogonal directions. Enhancement of the electric field induced SHG (EFI-SHG) signal at the electrode edge at low temperature suggests the presence of potential drop in the injection process. We directly evaluated temperature dependence of the carrier mobility by taking into account the potential drop, and concluded that the Marcus theory is appropriate to interpret the carrier transport in anisotropic TIPS pentacene thin film. TRM-SHG method is a facile and effective way to directly visualize transport process in anisotropic materials and to evaluate injection and transport processes simultaneously. PMID:27451638

  10. From Sphingosine Kinase to Dihydroceramide Desaturase: A Structure-Activity Relationship (SAR) Study of the Enzyme Inhibitory and Anticancer Activity of 4-((4-(4-Chlorophenyl)thiazol-2-yl)amino)phenol (SKI-II).

    Science.gov (United States)

    Aurelio, Luigi; Scullino, Carmen V; Pitman, Melissa R; Sexton, Anna; Oliver, Victoria; Davies, Lorena; Rebello, Richard J; Furic, Luc; Creek, Darren J; Pitson, Stuart M; Flynn, Bernard L

    2016-02-11

    The sphingosine kinase (SK) inhibitor, SKI-II, has been employed extensively in biological investigations of the role of SK1 and SK2 in disease and has demonstrated impressive anticancer activity in vitro and in vivo. However, interpretations of results using this pharmacological agent are complicated by several factors: poor SK1/2 selectivity, additional activity as an inducer of SK1-degradation, and off-target effects, including its recently identified capacity to inhibit dihydroceramide desaturase-1 (Des1). In this study, we have delineated the structure-activity relationship (SAR) for these different targets and correlated them to that required for anticancer activity and determined that Des1 inhibition is primarily responsible for the antiproliferative effects of SKI-II and its analogues. In the course of these efforts, a series of novel SK1, SK2, and Des1 inhibitors have been generated, including compounds with significantly greater anticancer activity.

  11. The capacity for long-chain polyunsaturated fatty acid synthesis in a carnivorous vertebrate: Functional characterisation and nutritional regulation of a Fads2 fatty acyl desaturase with Δ4 activity and an Elovl5 elongase in striped snakehead (Channa striata).

    Science.gov (United States)

    Kuah, Meng-Kiat; Jaya-Ram, Annette; Shu-Chien, Alexander Chong

    2015-03-01

    The endogenous production of long-chain polyunsaturated fatty acids (LC-PUFA) in carnivorous teleost species inhabiting freshwater environments is poorly understood. Although a predatory lifestyle could potentially supply sufficient LC-PUFA to satisfy the requirements of these species, the nutrient-poor characteristics of the freshwater food web could impede this advantage. In this study, we report the cloning and functional characterisation of an elongase enzyme in the LC-PUFA biosynthesis pathway from striped snakehead (Channa striata), which is a strict freshwater piscivore that shows high deposition of LC-PUFA in its flesh. We also functionally characterised a previously isolated fatty acyl desaturase cDNA from this species. Results showed that the striped snakehead desaturase is capable of Δ4 and Δ5 desaturation activities, while the elongase showed the characteristics of Elovl5 elongases. Collectively, these findings reveal that striped snakehead exhibits the genetic resources to synthesise docosahexaenoic acid (DHA; 22:6n-3) from eicosapentaenoic acid (EPA; 20:5n-3). Both genes are expressed at considerable levels in the brain and the liver. In liver, both genes were up-regulated by dietary C18 PUFA, although this increase did not correspond to a significant rise in the deposition of muscle LC-PUFA. Brain tissue of fish fed with plant oil diets showed higher expression of fads2 gene compared to fish fed with fish oil-based diet, which could ensure DHA levels remain constant under limited dietary DHA intake. This suggests the importance of DHA production from EPA via the ∆4 desaturation step in order to maintain an optimal reserve of DHA in the neuronal tissues of carnivores.

  12. The capacity for long-chain polyunsaturated fatty acid synthesis in a carnivorous vertebrate: Functional characterisation and nutritional regulation of a Fads2 fatty acyl desaturase with Δ4 activity and an Elovl5 elongase in striped snakehead (Channa striata).

    Science.gov (United States)

    Kuah, Meng-Kiat; Jaya-Ram, Annette; Shu-Chien, Alexander Chong

    2015-03-01

    The endogenous production of long-chain polyunsaturated fatty acids (LC-PUFA) in carnivorous teleost species inhabiting freshwater environments is poorly understood. Although a predatory lifestyle could potentially supply sufficient LC-PUFA to satisfy the requirements of these species, the nutrient-poor characteristics of the freshwater food web could impede this advantage. In this study, we report the cloning and functional characterisation of an elongase enzyme in the LC-PUFA biosynthesis pathway from striped snakehead (Channa striata), which is a strict freshwater piscivore that shows high deposition of LC-PUFA in its flesh. We also functionally characterised a previously isolated fatty acyl desaturase cDNA from this species. Results showed that the striped snakehead desaturase is capable of Δ4 and Δ5 desaturation activities, while the elongase showed the characteristics of Elovl5 elongases. Collectively, these findings reveal that striped snakehead exhibits the genetic resources to synthesise docosahexaenoic acid (DHA; 22:6n-3) from eicosapentaenoic acid (EPA; 20:5n-3). Both genes are expressed at considerable levels in the brain and the liver. In liver, both genes were up-regulated by dietary C18 PUFA, although this increase did not correspond to a significant rise in the deposition of muscle LC-PUFA. Brain tissue of fish fed with plant oil diets showed higher expression of fads2 gene compared to fish fed with fish oil-based diet, which could ensure DHA levels remain constant under limited dietary DHA intake. This suggests the importance of DHA production from EPA via the ∆4 desaturation step in order to maintain an optimal reserve of DHA in the neuronal tissues of carnivores. PMID:25542509

  13. Carbon-neutral fuels and energy carriers

    CERN Document Server

    Muradov, Nazim Z

    2011-01-01

    Concerns over an unstable energy supply and the adverse environmental impact of carbonaceous fuels have triggered considerable efforts worldwide to find carbon-free or low-carbon alternatives to conventional fossil fuels. Carbon-Neutral Fuels and Energy Carriers emphasizes the vital role of carbon-neutral energy sources, transportation fuels, and associated technologies for establishing a sustainable energy future. Each chapter draws on the insight of world-renowned experts in such diverse fields as photochemistry and electrochemistry, solar and nuclear energy, biofuels and synthetic fuels, ca

  14. Car Carrier 5.800 TPM

    OpenAIRE

    López de Rojas, Carmen

    2012-01-01

    Tipo de Buque: Car Carrier. Capacidad de carga: carga 1: 3000 coches sin trailers. Carga 2: Carga combinada para 1500 ml de trailers y coches en el resto de las cubiertas del buque no ocupadas por los trailers. Peso muerto 5800 TPM. Capacidad de conductores: 100 personas en camarotes dobles. Sociedad de clasificación: Det Norske Veritas. Reglamentos: Solas, Marpol, Convenio de líneas de carga. Velocidad: 19 nudos al 85% MCR en pruebas. Autonomía: 4500 millas al 80% MCR y 15% al margen de mar....

  15. 76 FR 5424 - Motor Carrier Safety Advisory Committee; Request for Nominations

    Science.gov (United States)

    2011-01-31

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee; Request for Nominations AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Request for Nominations to the Motor Carrier Safety Advisory Committee (MCSAC). SUMMARY: The FMCSA solicits nominations...

  16. A divergent ADP/ATP carrier in the hydrogenosomes of Trichomonas gallinae argues for an independent origin of these organelles.

    NARCIS (Netherlands)

    Tjaden, J.; Haferkamp, I.; Boxma, B.; Tielens, A.G.; Huynen, M.A.; Hackstein, J.H.P.

    2004-01-01

    The evolution of mitochondrial ADP and ATP exchanging proteins (AACs) highlights a key event in the evolution of the eukaryotic cell, as ATP exporting carriers were indispensable in establishing the role of mitochondria as ATP-generating cellular organelles. Hydrogenosomes, i.e. ATP- and hydrogen-ge

  17. Theory of Carrier Phase Ambiguity Resolution

    Institute of Scientific and Technical Information of China (English)

    P. J. G. Teunissen

    2003-01-01

    Carrier phase ambiguity resolution is the key to high precision Global Navigation Satellite System(GNSS) positioning and navigation. It applies to a great variety of current and future models of GPS, modernized GPS and Galileo. A proper handling of carrier phase ambiguity resolution requires a proper understanding of the underlying theory of integer inference. In this contribution a brief review is given of the probabilistic theory of integer ambiguity estimation. We describe the concept of ambiguity pull-in regions, introduce the class of admissible integer estimators, determine their probability mass functions and show how their variability solution. The theory is worked out in more detail for integer least-squares and integer bootstrapping. It is shown that the integer least-squares principle maximizes the probability of correct integer estimation. Sharp and easy-to-compute bounds are given for both the ambiguity success rate and the baseline's probability of concentration. Finally the probability density function of the ambiguity residuals is determined. This allows one for the first time to formulate rigorous tests for the integerness of the parameters.

  18. Localized charge carriers in graphene nanodevices

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, D., E-mail: dominikb@phys.ethz.ch; Varlet, A.; Simonet, P.; Eich, M.; Overweg, H. C.; Ihn, T.; Ensslin, K. [Solid State Physics Laboratory, ETH Zurich, 8093 Zurich (Switzerland)

    2015-09-15

    Graphene—two-dimensional carbon—is a material with unique mechanical, optical, chemical, and electronic properties. Its use in a wide range of applications was therefore suggested. From an electronic point of view, nanostructured graphene is of great interest due to the potential opening of a band gap, applications in quantum devices, and investigations of physical phenomena. Narrow graphene stripes called “nanoribbons” show clearly different electronical transport properties than micron-sized graphene devices. The conductivity is generally reduced and around the charge neutrality point, the conductance is nearly completely suppressed. While various mechanisms can lead to this observed suppression of conductance, disordered edges resulting in localized charge carriers are likely the main cause in a large number of experiments. Localized charge carriers manifest themselves in transport experiments by the appearance of Coulomb blockade diamonds. This review focuses on the mechanisms responsible for this charge localization, on interpreting the transport details, and on discussing the consequences for physics and applications. Effects such as multiple coupled sites of localized charge, cotunneling processes, and excited states are discussed. Also, different geometries of quantum devices are compared. Finally, an outlook is provided, where open questions are addressed.

  19. The Effect of Polymeric Nanoparticles on Biocompatibility of Carrier Red Blood Cells.

    Science.gov (United States)

    Pan, Daniel; Vargas-Morales, Omayra; Zern, Blaine; Anselmo, Aaron C; Gupta, Vivek; Zakrewsky, Michael; Mitragotri, Samir; Muzykantov, Vladimir

    2016-01-01

    Red blood cells (RBCs) can be used for vascular delivery of encapsulated or surface-bound drugs and carriers. Coupling to RBC prolongs circulation of nanoparticles (NP, 200 nm spheres, a conventional model of polymeric drug delivery carrier) enabling their transfer to the pulmonary vasculature without provoking overt RBC elimination. However, little is known about more subtle and potentially harmful effects of drugs and drug carriers on RBCs. Here we devised high-throughput in vitro assays to determine the sensitivity of loaded RBCs to osmotic stress and other damaging insults that they may encounter in vivo (e.g. mechanical, oxidative and complement insults). Sensitivity of these tests is inversely proportional to RBC concentration in suspension and our results suggest that mouse RBCs are more sensitive to damaging factors than human RBCs. Loading RBCs by NP at 1:50 ratio did not affect RBCs, while 10-50 fold higher NP load accentuated RBC damage by mechanical, osmotic and oxidative stress. This extensive loading of RBC by NP also leads to RBCs agglutination in buffer; however, addition of albumin diminished this effect. These results provide a template for analyses of the effects of diverse cargoes loaded on carrier RBCs and indicate that: i) RBCs can tolerate carriage of NP at doses providing loading of millions of nanoparticles per microliter of blood; ii) tests using protein-free buffers and mouse RBCs may overestimate adversity that may be encountered in humans. PMID:27003833

  20. The Metabolome in Finnish Carriers of the MYBPC3-Q1061X Mutation for Hypertrophic Cardiomyopathy

    Science.gov (United States)

    Heliö, Tiina; Jääskeläinen, Pertti; Laine, Mika; Hilvo, Mika; Nieminen, Markku S.; Laakso, Markku; Hyötyläinen, Tuulia; Orešič, Matej; Kuusisto, Johanna

    2015-01-01

    Aims Mutations in the cardiac myosin-binding protein C gene (MYBPC3) are the most common genetic cause of hypertrophic cardiomyopathy (HCM) worldwide. The molecular mechanisms leading to HCM are poorly understood. We investigated the metabolic profiles of mutation carriers with the HCM-causing MYBPC3-Q1061X mutation with and without left ventricular hypertrophy (LVH) and non-affected relatives, and the association of the metabolome to the echocardiographic parameters. Methods and Results 34 hypertrophic subjects carrying the MYBPC3-Q1061X mutation, 19 non-hypertrophic mutation carriers and 20 relatives with neither mutation nor hypertrophy were examined using comprehensive echocardiography. Plasma was analyzed for molecular lipids and polar metabolites using two metabolomics platforms. Concentrations of branched chain amino acids, triglycerides and ether phospholipids were increased in mutation carriers with hypertrophy as compared to controls and non-hypertrophic mutation carriers, and correlated with echocardiographic LVH and signs of diastolic and systolic dysfunction in subjects with the MYBPC3-Q1061X mutation. Conclusions Our study implicates the potential role of branched chain amino acids, triglycerides and ether phospholipids in HCM, as well as suggests an association of these metabolites with remodeling and dysfunction of the left ventricle. PMID:26267065

  1. The Effect of Polymeric Nanoparticles on Biocompatibility of Carrier Red Blood Cells.

    Directory of Open Access Journals (Sweden)

    Daniel Pan

    Full Text Available Red blood cells (RBCs can be used for vascular delivery of encapsulated or surface-bound drugs and carriers. Coupling to RBC prolongs circulation of nanoparticles (NP, 200 nm spheres, a conventional model of polymeric drug delivery carrier enabling their transfer to the pulmonary vasculature without provoking overt RBC elimination. However, little is known about more subtle and potentially harmful effects of drugs and drug carriers on RBCs. Here we devised high-throughput in vitro assays to determine the sensitivity of loaded RBCs to osmotic stress and other damaging insults that they may encounter in vivo (e.g. mechanical, oxidative and complement insults. Sensitivity of these tests is inversely proportional to RBC concentration in suspension and our results suggest that mouse RBCs are more sensitive to damaging factors than human RBCs. Loading RBCs by NP at 1:50 ratio did not affect RBCs, while 10-50 fold higher NP load accentuated RBC damage by mechanical, osmotic and oxidative stress. This extensive loading of RBC by NP also leads to RBCs agglutination in buffer; however, addition of albumin diminished this effect. These results provide a template for analyses of the effects of diverse cargoes loaded on carrier RBCs and indicate that: i RBCs can tolerate carriage of NP at doses providing loading of millions of nanoparticles per microliter of blood; ii tests using protein-free buffers and mouse RBCs may overestimate adversity that may be encountered in humans.

  2. Influence of carrier on the performance of dry powder inhalers.

    Science.gov (United States)

    Saint-Lorant, G; Leterme, P; Gayot, A; Flament, M P

    2007-04-01

    The aim of this work is to study carriers which can become alternatives to monohydrate lactose in dry powder inhalers and to consider particle parameters that influence adhesion between drug and carrier in dry powder inhalers. Different forms of mannitol, lactose and maltitol were mixed with either terbutaline sulphate or formoterol fumarate. The blends were submitted to different adhesion tests where drug detachment from the carrier was obtained either through mechanical vibration or by aspiration. Parameters like particle shape, roughness, amorphous content and cristalline form may affect interactions between drug and carrier. In our case, crystallized forms of the carrier offered lower adhesion but better release of the active ingredient than spray-dried forms. The crystallized mannitol produced maximal fine particle dose. The blends of the mannitols and the two active ingredients gave different results. The two techniques used to assess the adhesion of drugs to carrier particles provide complementary information about drug/carrier interactions and detachment. The mechanical sieving allows to assess blend stability and the air-jet sieving makes it possible to determine how easily the drug separates from carrier. For the drugs tested, the results of fine particle doses are in agreement with the Alpine air-jet sieve results. The tests used are helpful for the choice of a new carrier in the field of the development of new carriers for dry powder inhalers. PMID:17113733

  3. Preparative divergent flow IEF without carrier ampholytes for separation of complex biological samples.

    Science.gov (United States)

    Stastna, Miroslava; Slais, Karel

    2010-01-01

    Efficient separation method is a crucial part of the process in which components of highly complex biological sample are identified and characterized. Based on the principles of recently newly established electrophoretic method called divergent flow IEF (DF IEF), we have tested the DF IEF instrument which is able to operate without the use of background carrier ampholytes. We have verified that during separation and focusing of sample consisting of high numbers of proteins (yeast lysate and wheat flour extract), the pH gradient of preparative DF IEF can be created by autofocusing of the sample components themselves without any addition of carrier ampholytes. In DF IEF, the proteins are separated, desalted and concentrated in one step. The fractions of yeast lysate sample, collected at the DF IEF output and subjected to gel IEF, contained the zones of proteins gradually covering the pI values from 3.7 to 8.5. In our experimental arrangement, the highest number of proteins has been found in fractions with pI values around 5.3 as detected by polyacrylamide gel IEF with CBB staining. During DF IEF, the selected protein bands have been concentrated up to 16.8-fold.

  4. 47 CFR 69.105 - Carrier common line for non-price cap local exchange carriers.

    Science.gov (United States)

    2010-10-01

    ... residential and single-line business lines multiplied by the difference between the residential and single-line business End User Common Line rate cap and the lesser of $6.50 or the non-price cap local exchange... 47 Telecommunication 3 2010-10-01 2010-10-01 false Carrier common line for non-price cap...

  5. Graphene, a material for high temperature devices; intrinsic carrier density, carrier drift velocity, and lattice energy

    CERN Document Server

    Yin, Yan; Wang, Li; Jin, Kuijuan; Wang, Wenzhong

    2016-01-01

    Heat has always been a killing matter for traditional semiconductor machines. The underlining physical reason is that the intrinsic carrier density of a device made from a traditional semiconductor material increases very fast with a rising temperature. Once reaching a temperature, the density surpasses the chemical doping or gating effect, any p-n junction or transistor made from the semiconductor will fail to function. Here, we measure the intrinsic Fermi level (|E_F|=2.93k_B*T) or intrinsic carrier density (n_in=3.87*10^6 cm^-2 K^-2*T^2), carrier drift velocity, and G mode phonon energy of graphene devices and their temperature dependencies up to 2400 K. Our results show intrinsic carrier density of graphene is an order of magnitude less sensitive to temperature than those of Si or Ge, and reveal the great potentials of graphene as a material for high temperature devices. We also observe a linear decline of saturation drift velocity with increasing temperature, and identify the temperature coefficients of ...

  6. Charge-carrier relaxation dynamics in highly ordered poly( p -phenylene vinylene): Effects of carrier bimolecular recombination and trapping

    Science.gov (United States)

    Soci, Cesare; Moses, Daniel; Xu, Qing-Hua; Heeger, Alan J.

    2005-12-01

    We have studied the charge-carrier relaxation dynamics in highly ordered poly( p -phenylene vinylene) over a broad time range using fast (t>100ps) transient photoconductivity measurements. The carrier density was also monitored (t>100fs) by means of photoinduced absorption probed at the infrared active vibrational modes. We find that promptly upon charge-carrier photogeneration, the initial polaron dynamics is governed by bimolecular recombination, while later in the subnanosecond time regime carrier trapping gives rise to an exponential decay of the photocurrent. The more sensitive transient photocurrent measurements indicate that in the low excitation regime, when the density of photocarriers is comparable to that of the trapping states (˜1016cm-3) , carrier hopping between traps along with transport via extended states determines the carrier relaxation, a mechanism that is manifested by a long-lived photocurrent “tail.” This photocurrent tail is reduced by lowering the temperature and/or by increasing the excitation density. Based on these data, we develop a comprehensive kinetic model that takes into account the bipolar charge transport, the free-carrier bimolecular recombination, the carrier trapping, and the carrier recombination involving free and trapped carriers.

  7. DYNAMIC RESPONSE ANALYSIS OF CARRIER-BASED AIRCRAFT DURING LANDING

    Institute of Scientific and Technical Information of China (English)

    段萍萍; 聂宏; 魏小辉

    2013-01-01

    In view of the complexity of landing on the deck of aircraft carrier ,a systematic model ,composed of six-degree-of-freedom mathematic model of carrier-based aircraft ,four-degree-of-freedom model of landing gears and six-degree-of-freedom mathematic model of carrier , is established in the Matlab-Simulink environment , with damping function of landing gears and dynamic characteristics of tires being considered .The model ,where the car-rier movement is introduced ,is applicable for any abnormal landing condition .Moreover ,the equations of motion and relevant parameter are also derived .The dynamic response of aircraft is calculated via the variable step-size Runge-Kuta algorithm .The effect of attitude angles of aircraft and carrier movement during the process of landing is illustrated in details .The analytical results can provide some reference for carrier-based aircraft design and main-tenance .

  8. Characteristics of participants in a gestational carrier program.

    Science.gov (United States)

    Braverman, A M; Corson, S L

    1992-08-01

    Genetic parents and gestational carriers in our gestational carrier program were evaluated by psychodiagnostic interview and by the Minnesota Multiphasic Personality Interview-2 (MMPI-2), a widely used objective psychological test, to identify psychopathology and describe personality characteristics. Overall, participants exhibited no overt psychopathology. Personality differences were found between gestational carriers and genetic mothers and genetic fathers and mothers. Clinical interviews revealed that gestational carriers tended to be the dominant partner in the relationship, were motivated by a wish to help an infertile couple, enjoyed being pregnant, showed narcissistic needs, and expressed a wish for secondary financial gain. The majority of gestational carriers stated that they had considered becoming a traditional surrogate but felt they could not surrender a child that was genetically theirs. These results indicate that there is not any predisposing psychopathology which attracts participants to the gestational carrier program.

  9. Identification of immunogenic Salmonella enterica serotype Typhi antigens expressed in chronic biliary carriers of S. Typhi in Kathmandu, Nepal.

    Directory of Open Access Journals (Sweden)

    Richelle C Charles

    Full Text Available BACKGROUND: Salmonella enterica serotype Typhi can colonize and persist in the biliary tract of infected individuals, resulting in a state of asymptomatic chronic carriage. Chronic carriers may act as persistent reservoirs of infection within a community and may introduce infection to susceptible individuals and new communities. Little is known about the interaction between the host and pathogen in the biliary tract of chronic carriers, and there is currently no reliable diagnostic assay to identify asymptomatic S. Typhi carriage. METHODOLOGY/PRINCIPAL FINDINGS: To study host-pathogen interactions in the biliary tract during S. Typhi carriage, we applied an immunoscreening technique called in vivo-induced antigen technology (IVIAT, to identify potential biomarkers unique to carriers. IVIAT identifies humorally immunogenic bacterial antigens expressed uniquely in the in vivo environment, and we hypothesized that S. Typhi surviving in the biliary tract of humans may express a distinct antigenic profile. Thirteen S. Typhi antigens that were immunoreactive in carriers, but not in healthy individuals from a typhoid endemic area, were identified. The identified antigens included a number of putative membrane proteins, lipoproteins, and hemolysin-related proteins. YncE (STY1479, an uncharacterized protein with an ATP-binding motif, gave prominent responses in our screen. The response to YncE in patients whose biliary tract contained S. Typhi was compared to responses in patients whose biliary tract did not contain S. Typhi, patients with acute typhoid fever, and healthy controls residing in a typhoid endemic area. Seven of 10 (70% chronic carriers, 0 of 8 bile culture-negative controls (0%, 0 of 8 healthy Bangladeshis (0%, and 1 of 8 (12.5% Bangladeshis with acute typhoid fever had detectable anti-YncE IgG in blood. IgA responses were also present. CONCLUSIONS/SIGNIFICANCE: Further evaluation of YncE and other antigens identified by IVIAT could lead to

  10. A Silicon Micromachined Gyroscope Driven by the Rotating Carrier Self

    Institute of Scientific and Technical Information of China (English)

    Fuxue Zhang; Xu Mao; Yu Liu; Nan Zhang; Wei Zhang

    2006-01-01

    This paper reported a silicon micromachined gyroscope which is driven by the rotating carrier's angular velocity, the silicon was manufactured by anisotropy etching. The design, fabrication and packing of the sensing element were introduced in the paper. The imitation experimentation and performance test have certificated that the principle of the gyroscope is correct and the gyroscope can be used to sense yawing or pitching angular velocity of the rotating carrier, and the angular velocity of the rotating carrier itself.

  11. Carrier Statistics and Quantum Capacitance Models of Graphene Nanoscroll

    Directory of Open Access Journals (Sweden)

    M. Khaledian

    2014-01-01

    schematic perfect scroll-like Archimedes spiral. The DOS model was derived at first, while it was later applied to compute the carrier concentration and quantum capacitance model. Furthermore, the carrier concentration and quantum capacitance were modeled for both degenerate and nondegenerate regimes, along with examining the effect of structural parameters and chirality number on the density of state and carrier concentration. Latterly, the temperature effect on the quantum capacitance was studied too.

  12. Exploring Quaternized Hydroxyethylcellulose as Potential Gene Carriers

    Institute of Scientific and Technical Information of China (English)

    丁菲; 尤俊; 翁小成; 周金平; 章晓联; 周翔; 张俐娜

    2012-01-01

    Cationic polysaccharides have been receiving more attentions and used as nonviral gene delivery vectors. In this paper, quaternized hydroxyethylcellulose (QHEC) derivatives were studied as gene carriers for their efficient DNA binding abilities. All QHECs could form stable QHEC/DNA complexes and resist the degradation of DNase I. And the dynamic light scatter (DLS) results showed that all QHEC/DNA complexes could form compact particles. These QHEC/DNA complexes exhibited effective transfeetion abilities in comparison to the naked DNA. The cytotox- icities of QHEC and QHEC/DNA complexes were also evaluated in four cell lines which were relatively low com- pared with 25 kDa bPEI. All results indicated that these quaternized hydroxyethylcelluloses could be used as poten- tial gene delivery vectors.

  13. Carbon phosphide monolayers with superior carrier mobility

    Science.gov (United States)

    Wang, Gaoxue; Pandey, Ravindra; Karna, Shashi P.

    2016-04-01

    Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great promise for applications in high-performance electronics and optoelectronics.Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great

  14. Microemulsions as carriers for therapeutic molecules.

    Science.gov (United States)

    Mehta, Surinder K; Kaur, Gurpreet

    2010-01-01

    The thrust for finding newer drug delivery systems for exiting therapeutic molecules has opened a wide window for colloidal systems. Due to the presence of different domains of variable polarity in the microemulsion systems, they show a huge potential to be used as drug delivery vehicles for a variety of drugs. The use of microemulsion as drug delivery vehicles through a number of routes has engaged a large number of research groups in this area. Microemulsion media finds several applications ranging from drug delivery to drug nanoparticle templating due to its ability to enhance solubility, stability and bioavailability. This review on patent articles recounts the patent literature dealing with different kind of microemulsion carriers used via different routes, solubility and permeability enhancement and its use as a template for nanoparticle synthesis. PMID:19807681

  15. Hot carrier injection degradation under dynamic stress

    Institute of Scientific and Technical Information of China (English)

    Ma Xiao-Hua; Cao Yan-Rong; Hao Yue; Zhang Yue

    2011-01-01

    In this paper, we have studied hot carrier injection (HCI) under alternant stress. Under different stress modes, different degradations are obtained from the experiment results. The different alternate stresses can reduce or enhance the HC effect, which mainly depends on the latter condition of the stress cycle. In the stress mode A (DC stress with electron injection), the degradation keeps increasing. In the stress modes B (DC stress and then stress with the smallest gate injection) and C (DC stress and then stress with hole injection under Vg=0V and Vd = 1.8 V), recovery appears in the second stress period. And in the stress mode D (DC stress and then stress with hole injection under Vg = -1.8 V and Vd = 1.8 V), as the traps filled in by holes can be smaller or greater than the generated interface states, the continued degradation or recovery in different stress periods can be obtained.

  16. Blind Estimation of Multiple Carrier Frequency Offsets

    CERN Document Server

    Yu, Yuanning; Poor, H Vincent; Koivunen, Visa

    2007-01-01

    Multiple carrier-frequency offsets (CFO) arise in a distributed antenna system, where data are transmitted simultaneously from multiple antennas. In such systems the received signal contains multiple CFOs due to mismatch between the local oscillators of transmitters and receiver. This results in a time-varying rotation of the data constellation, which needs to be compensated for at the receiver before symbol recovery. This paper proposes a new approach for blind CFO estimation and symbol recovery. The received base-band signal is over-sampled, and its polyphase components are used to formulate a virtual Multiple-Input Multiple-Output (MIMO) problem. By applying blind MIMO system estimation techniques, the system response is estimated and used to subsequently transform the multiple CFOs estimation problem into many independent single CFO estimation problems. Furthermore, an initial estimate of the CFO is obtained from the phase of the MIMO system response. The Cramer-Rao Lower bound is also derived, and the la...

  17. Take advantage of your insurance carrier

    Energy Technology Data Exchange (ETDEWEB)

    Carlow, S.M.

    1990-02-01

    The primary objective of the developer of an independent energy facility is to make a profit through the sale of electricity and steam. The most effective way to achieve this objective is to design, build and operate a facility in a way that maximizes its availability and efficiency without increasing expenses. A property carrier has a range of insurance products and engineering services designed not only to transfer risk but to increase availability and efficiency and reduce the cost of operating and maintaining a facility. The independent energy producer can benefit by taking full advantage of traditional and specialty insurance products as well as engineering services that are available today. There is a whole range of insurance products that apply during the various stages of pre-construction, construction, testing and commercial operation, and these are described.

  18. Carrier Aggregation for LTE-Advanced

    DEFF Research Database (Denmark)

    Pedersen, Klaus Ingemann; Frederiksen, Frank; Rosa, Claudio;

    2011-01-01

    aggregated. This paper presents a summary of the supported CA scenarios as well as an overview of the CA functionality for LTE-Advanced with special emphasis on the basic concept, control mechanisms, and performance aspects. The discussion includes definitions of the new terms primary cell (PCell) and......Carrier aggregation (CA) is one of the key features for LTE-Advanced. By means of CA, users gain access to a total bandwidth of up to 100 MHz in order to meet the IMT-Advanced requirements. The system bandwidth may be contiguous, or composed of several non-contiguous bandwidth chunks, which are...... secondary cell (SCell), mechanisms for activation and deactivation of CCs, and the new cross-CC scheduling functionality for improved control channel optimizations. We also demonstrate how CA can be used as an enabler for simple yet effective frequency domain interference management schemes. In particular...

  19. Fertility preservation in BRCA mutation carriers.

    Science.gov (United States)

    Revelli, Alberto; Salvagno, Francesca; Delle Piane, Luisa; Casano, Simona; Evangelista, Francesca; Pittatore, Giulia; Razzano, Alessandra; Marchino, Gian L; Gennarelli, Gianluca; Benedetto, Chiara

    2016-10-01

    According to enhanced long-term survival rates of these patients, interest in fertility preservation for young women facing gonadotoxic therapies is increasing. Women who carry a mutation in the BRCA1 or BRCA2 gene have a specifically increased lifetime risk of developing breast and tubo-ovarian cancer. Moreover, they are at high risk of undergoing premature infertility due to the medical interventions that are often performed in order to reduce cancer risk or treat an already existing malignancy. Fertility issues are relevant for healthy BRCA mutation carriers, whose family-planning decisions are often influenced by the need of prophylactic bilateral salpingo-oophorectomy at young age. In BRCA mutation carriers who have a breast cancer at young age, the oncostatic treatment is associated with a significant ovarian toxicity linked to chemotherapy as well as to the long lasting hormonotherapy and to the need of delaying pregnancy for several years. Prompt counselling about different fertility preservation options should be offered to all young girls and women at high risk of ovarian insufficiency and infertility. Validated techniques to preserve fertility include oocyte and embryo cryopreservation, while experimental techniques include ovarian suppression with GnRH-analogs during chemotherapy and ovarian tissue cryopreservation. The choice of the best strategy depends on age, type of chemotherapy, partner status, cancer type, time available for fertility preservation intervention and the risk of ovarian metastasis. All available options should be offered and can be performed alone or in combination. A crucial point is to avoid a significant delay to cancer treatment. PMID:26997146

  20. Carrier-Density-Dependent Lattice Stability in InSb

    International Nuclear Information System (INIS)

    The ultrafast decay of the x-ray diffraction intensity following laser excitation of an InSb crystal has been utilized to observe carrier dependent changes in the potential energy surface. For the first time, an abrupt carrier dependent onset for potential energy surface softening and the appearance of accelerated atomic disordering for a very high average carrier density have been observed. Inertial dynamics dominate the early stages of crystal disordering for a wide range of carrier densities between the onset of crystal softening and the appearance of accelerated atomic disordering