WorldWideScience

Sample records for acid synthase ii

  1. Salmonella typhimurium mutants defective in acetohydroxy acid synthases I and II.

    Shaw, K J; Berg, C M; Sobol, T J

    1980-01-01

    An analysis of transposon-induced mutants shows that Salmonella typhimurium possesses two major isozymes of acetohydroxy acid synthase, the enzymes which mediate the first common step in isoleucine and valine biosynthesis. A third (minor) acetohydroxy acid synthase is present, but its significance in isoleucine and valine synthesis may be negligible. Mutants defective in acetohydroxy acid synthase II (ilvG::Tn10) require isoleucine, alpha-ketobutyrate, or threonine for growth, a mutant defect...

  2. Cloning and sequence analysis of putative type II fatty acid synthase genes from Arachis hypogaea L.

    Meng-Jun Li; Ai-Qin Li; Han Xia; Chuan-Zhi Zhao; Chang-Sheng Li; Shu-Bo Wan; Yu-Ping Bi; Xing-Jun Wang

    2009-06-01

    The cultivated peanut is a valuable source of dietary oil and ranks fifth among the world oil crops. Plant fatty acid biosynthesis is catalysed by type II fatty acid synthase (FAS) in plastids and mitochondria. By constructing a full-length cDNA library derived from immature peanut seeds and homology-based cloning, candidate genes of acyl carrier protein (ACP), malonyl-CoA:ACP transacylase, -ketoacyl-ACP synthase (I, II, III), -ketoacyl-ACP reductase, -hydroxyacyl-ACP dehydrase and enoyl-ACP reductase were isolated. Sequence alignments revealed that primary structures of type II FAS enzymes were highly conserved in higher plants and the catalytic residues were strictly conserved in Escherichia coli and higher plants. Homologue numbers of each type II FAS gene expressing in developing peanut seeds varied from 1 in KASII, KASIII and HD to 5 in ENR. The number of single-nucleotide polymorphisms (SNPs) was quite different in each gene. Peanut type II FAS genes were predicted to target plastids except ACP2 and ACP3. The results suggested that peanut may contain two type II FAS systems in plastids and mitochondria. The type II FAS enzymes in higher plants may have similar functions as those in E. coli.

  3. Structure of the human beta-ketoacyl [ACP] synthase from the mitochondrial type II fatty acid synthase

    Christensen, Caspar Elo; Kragelund, Birthe Brandt; Von Wettstein-Knowles, Penny; Henriksen, Anette

    2007-01-01

    activities encoded by discrete genes. The beta-ketoacyl [ACP] synthase (KAS) moiety of the mitochondrial FAS (mtKAS) is targeted by the antibiotic cerulenin and possibly by the other antibiotics inhibiting prokaryotic KASes: thiolactomycin, platensimycin, and the alpha-methylene butyrolactone, C75. The high...... hexanoyl complex plus the hexanoyl complex of the plant mtKAS from Arabidopsis thaliana. The structures explain (1) the bimodal (C(6) and C(10)-C(12)) substrate preferences leading to the C(8) lipoic acid precursor and long chains for the membranes, respectively, and (2) the low cerulenin sensitivity of...

  4. Campylobacter jejuni fatty acid synthase II: Structural and functional analysis of [beta]-hydroxyacyl-ACP dehydratase (FabZ)

    Kirkpatrick, Andrew S.; Yokoyama, Takeshi; Choi, Kyoung-Jae; Yeo, Hye-Jeong; (Houston)

    2009-08-14

    Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making FAS II enzymes excellent targets for antibiotics discovery. The {beta}-hydroxyacyl-ACP dehydratase (FabZ) catalyzes an essential step in the FAS II pathway. Here, we report the structure of Campylobacter jejuni FabZ (CjFabZ), showing a hexamer both in crystals and solution, with each protomer adopting the characteristic hot dog fold. Together with biochemical analysis of CjFabZ, we define the first functional FAS II enzyme from this pathogen, and provide a framework for investigation on roles of FAS II in C. jejuni virulence

  5. Functional replacement of the Saccharomyces cerevisiae fatty acid synthase with a bacterial type II system allows flexible product profiles.

    Fernandez-Moya, Ruben; Leber, Christopher; Cardenas, Javier; Da Silva, Nancy A

    2015-12-01

    The native yeast type I fatty acid synthase (FAS) is a complex, rigid enzyme, and challenging to engineer for the production of medium- or short-chain fatty acids. Introduction of a type II FAS is a promising alternative as it allows expression control for each discrete enzyme and the addition of heterologous thioesterases. In this study, the native Saccharomyces cerevisiae FAS was functionally replaced by the Escherichia coli type II FAS (eFAS) system. The E. coli acpS + acpP (together), fabB, fabD, fabG, fabH, fabI, fabZ, and tesA were expressed in individual S. cerevisiae strains, and enzyme activity was confirmed by in vitro activity assays. Eight genes were then integrated into the yeast genome, while tesA or an alternate thioesterase gene, fatB from Ricinus communis or TEII from Rattus novergicus, was expressed from a multi-copy plasmid. Native FAS activity was eliminated by knocking out the yeast FAS2 gene. The strains expressing only the eFAS as de novo fatty acid source grew without fatty acid supplementation demonstrating that this type II FAS is able to functionally replace the native yeast FAS. The engineered strain expressing the R. communis fatB thioesterase increased total fatty acid titer 1.7-fold and shifted the fatty acid profile towards C14 production, increasing it from fatty acids, and reducing C18 production from 39% to 8%. PMID:26084339

  6. Mycocerosic acid synthase exemplifies the architecture of reducing polyketide synthases.

    Herbst, Dominik A; Jakob, Roman P; Zähringer, Franziska; Maier, Timm

    2016-03-24

    Polyketide synthases (PKSs) are biosynthetic factories that produce natural products with important biological and pharmacological activities. Their exceptional product diversity is encoded in a modular architecture. Modular PKSs (modPKSs) catalyse reactions colinear to the order of modules in an assembly line, whereas iterative PKSs (iPKSs) use a single module iteratively as exemplified by fungal iPKSs (fiPKSs). However, in some cases non-colinear iterative action is also observed for modPKSs modules and is controlled by the assembly line environment. PKSs feature a structural and functional separation into a condensing and a modifying region as observed for fatty acid synthases. Despite the outstanding relevance of PKSs, the detailed organization of PKSs with complete fully reducing modifying regions remains elusive. Here we report a hybrid crystal structure of Mycobacterium smegmatis mycocerosic acid synthase based on structures of its condensing and modifying regions. Mycocerosic acid synthase is a fully reducing iPKS, closely related to modPKSs, and the prototype of mycobacterial mycocerosic acid synthase-like PKSs. It is involved in the biosynthesis of C20-C28 branched-chain fatty acids, which are important virulence factors of mycobacteria. Our structural data reveal a dimeric linker-based organization of the modifying region and visualize dynamics and conformational coupling in PKSs. On the basis of comparative small-angle X-ray scattering, the observed modifying region architecture may be common also in modPKSs. The linker-based organization provides a rationale for the characteristic variability of PKS modules as a main contributor to product diversity. The comprehensive architectural model enables functional dissection and re-engineering of PKSs. PMID:26976449

  7. Substrate channeling: alpha-ketobutyrate inhibition of acetohydroxy acid synthase in Salmonella typhimurium.

    Shaw, K J; Berg, C M

    1980-01-01

    Excess alpha-ketobutyrate inhibited the growth of Salmonella typhimurium LT2 by inhibiting the acetohydroxy acid synthase-catalyzed synthesis of alpha-acetolactate (a valine precursor). As a result, cells were starved for valine, and both ilvB (encoding acetohydroxy acid synthase I) and ilvGEDA (ilvG encodes acetohydroxy acid synthase II) were derepressed. The addition of valine reversed the effects of alpha-ketobutyrate.

  8. Folic Acid Reverses Nitric Oxide Synthase Uncoupling and Prevents Cardiac Dysfunction in Insulin Resistance: Role of Ca2+/Calmodulin-Activated Protein Kinase II

    Roe, Nathan D.; He, Emily Y.; Wu, Zhenbiao; Ren, Jun

    2013-01-01

    Nitric oxide synthase (NOS) may be uncoupled to produce superoxide rather than nitric oxide (NO) under pathological conditions such as diabetes mellitus and insulin resistance, leading to cardiac contractile anomalies. Nonetheless, the role of NOS uncoupling in insulin resistance-induced cardiac dysfunction remains elusive. Given that folic acid may produce beneficial effect for cardiac insufficiency partially through its NOS recoupling capacity, this study was designed to evaluate the effect...

  9. Fatty acid synthase inhibitors isolated from Punica granatum L

    Jiang, He-Zhong [School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, (China); Ma, Qing-Yun; Liang, Wen-Juan; Huang, Sheng-Zhuo; Dai, Hao-Fu; Wang, Peng-Cheng; Zhao, You-Xing, E-mail: zhaoyx1011@163.com [Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou (China); Fan, Hui-Jin; Ma, Xiao-Feng, E-mail: maxiaofeng@gucas.ac.cn [College of Life Sciences, Graduate University of Chinese Academy of Sciences, Beijing (China)

    2012-05-15

    The aim of this work is the isolation of fatty acid synthase (FAS) inhibitors from the ethyl acetate extracts of fruit peels of Punica granatum L. Bioassay-guided chemical investigation of the fruit peels resulted in the isolation of seventeen compounds mainly including triterpenoids and phenolic compounds, from which one new oleanane-type triterpene (punicaone) along with fourteen known compounds were isolated for the first time from this plant. Seven isolates were evaluated for inhibitory activities of FAS and two compounds showed to be active. Particularly, flavogallonic acid exhibited strong FAS inhibitory activity with IC{sub 50} value of 10.3 {mu}mol L{sup -1}. (author)

  10. Fatty acid synthase inhibitors isolated from Punica granatum L

    The aim of this work is the isolation of fatty acid synthase (FAS) inhibitors from the ethyl acetate extracts of fruit peels of Punica granatum L. Bioassay-guided chemical investigation of the fruit peels resulted in the isolation of seventeen compounds mainly including triterpenoids and phenolic compounds, from which one new oleanane-type triterpene (punicaone) along with fourteen known compounds were isolated for the first time from this plant. Seven isolates were evaluated for inhibitory activities of FAS and two compounds showed to be active. Particularly, flavogallonic acid exhibited strong FAS inhibitory activity with IC50 value of 10.3 μmol L-1. (author)

  11. Fatty Acid Synthase Inhibitor C75 Ameliorates Experimental Colitis

    Matsuo, Shingo; Yang, Weng-Lang; Aziz, Monowar; Kameoka, Shingo; Wang, Ping

    2013-01-01

    Abnormalities of lipid metabolism through overexpression of fatty acid synthase (FASN), which catalyzes the formation of long-chain fatty acids, are associated with the development of inflammatory bowel disease (IBD). C75 is a synthetic α-methylene-γ-butyrolactone compound that inhibits FASN activity. We hypothesized that C75 treatment could effectively reduce the severity of experimental colitis. Male C57BL/6 mice were fed 4% dextran sodium sulfate (DSS) for 7 d. C75 (5 mg/kg body weight) or...

  12. Feedback-Resistant Acetohydroxy Acid Synthase Increases Valine Production in Corynebacterium glutamicum

    Elišáková, Veronika; Pátek, Miroslav; Holátko, Jiří; Nešvera, Jan; Leyval, Damien; Goergen, Jean-Louis; Delaunay, Stéphane

    2005-01-01

    Acetohydroxy acid synthase (AHAS), which catalyzes the key reactions in the biosynthesis pathways of branched-chain amino acids (valine, isoleucine, and leucine), is regulated by the end products of these pathways. The whole Corynebacterium glutamicum ilvBNC operon, coding for acetohydroxy acid synthase (ilvBN) and aceto hydroxy acid isomeroreductase (ilvC), was cloned in the newly constructed Escherichia coli-C. glutamicum shuttle vector pECKA (5.4 kb, Kmr). By using site-directed mutagenesi...

  13. Expression of fatty acid synthase in nonalcoholic fatty liver disease.

    Dorn, Christoph; Riener, Marc-Oliver; Kirovski, Georgi; Saugspier, Michael; Steib, Kathrin; Weiss, Thomas S; Gäbele, Erwin; Kristiansen, Glen; Hartmann, Arndt; Hellerbrand, Claus

    2010-01-01

    Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic lipid accumulation which starts with simple hepatic steatosis and may progress toward inflammation (nonalcoholic steatohepatitis [NASH]). Fatty acid synthase (FASN) catalyzes the last step in fatty acid biosynthesis, and thus, it is believed to be a major determinant of the maximal hepatic capacity to generate fatty acids by de novo lipogenesis. The aim of this study was to analyze the correlation between hepatic steatosis and inflammation with FASN expression. In vitro incubation of primary human hepatocytes with fatty acids dose-dependently induced cellular lipid-accumulation and FASN expression, while stimulation with TNF did not affect FASN levels. Further, hepatic FASN expression was significantly increased in vivo in a murine model of hepatic steatosis without significant inflammation but not in a murine NASH model as compared to control mice. Also, FASN expression was not increased in mice subjected to bile duct ligation, an experimental model characterized by severe hepatocellular damage and inflammation. Furthermore, FASN expression was analyzed in 102 human control or NAFLD livers applying tissue micro array technology and immunohistochemistry, and correlated significantly with the degree of hepatic steatosis, but not with inflammation or ballooning of hepatocytes. Quantification of FASN mRNA expression in human liver samples confirmed significantly higher FASN levels in hepatic steatosis but not in NASH, and expression of SREBP1, which is the main transcriptional regulator of FASN, paralleled FASN expression levels in human and experimental NAFLD. In conclusion, the transcriptional induction of FASN expression in hepatic steatosis is impaired in NASH, while hepatic inflammation in the absence of steatosis does not affect FASN expression, suggesting that FASN may serve as a new diagnostic marker or therapeutic target for the progression of NAFLD. PMID:20606731

  14. Inhibition of fatty acid synthase prevents preadipocyte differentiation

    Inhibition of fatty acid synthase (FAS) reduces food intake in rodents. As adipose tissue expresses FAS, we sought to investigate the effect of reduced FAS activity on adipocyte differentiation. FAS activity was suppressed either pharmacologically or by siRNA during differentiation of 3T3-L1 cells. Cerulenin (10 μM), triclosan (50 μM), and C75 (50 μM) reduced dramatically visible lipid droplet accumulation, while incorporation of [1-14C]acetate into lipids was reduced by 75%, 70%, and 90%, respectively. Additionally, the substances reduced FAS, CEBPα, and PPARγ mRNA by up to 85% compared to that of control differentiated cells. Transient transfection with FAS siRNA suppressed FAS mRNA and FAS activity, and this was accompanied by reduction of CEBPα and PPARγ mRNA levels, and complete prevention of lipid accumulation. CD36, a late marker of differentiation, was also reduced. Together, these results suggest that FAS generated signals may be essential to support preadipocyte differentiation

  15. p63 promotes cell survival through fatty acid synthase.

    Venkata Sabbisetti

    Full Text Available There is increasing evidence that p63, and specifically DeltaNp63, plays a central role in both development and tumorigenesis by promoting epithelial cell survival. However, few studies have addressed the molecular mechanisms through which such important function is exerted. Fatty acid synthase (FASN, a key enzyme that synthesizes long-chain fatty acids and is involved in both embryogenesis and cancer, has been recently proposed as a direct target of p53 family members, including p63 and p73. Here we show that knockdown of either total or DeltaN-specific p63 isoforms in squamous cell carcinoma (SCC9 or immortalized prostate epithelial (iPrEC cells caused a decrease in cell viability by inducing apoptosis without affecting the cell cycle. p63 silencing significantly reduced both the expression and the activity of FASN. Importantly, stable overexpression of either FASN or myristoylated AKT (myr-AKT was able to partially rescue cells from cell death induced by p63 silencing. FASN induced AKT phosphorylation and a significant reduction in cell viability was observed when FASN-overexpressing SCC9 cells were treated with an AKT inhibitor after p63 knockdown, indicating that AKT plays a major role in FASN-mediated survival. Activated AKT did not cause any alteration in the FASN protein levels but induced its activity, suggesting that the rescue from apoptosis documented in the p63-silenced cells expressing myr-AKT cells may be partially mediated by FASN. Finally, we demonstrated that p63 and FASN expression are positively associated in clinical squamous cell carcinoma samples as well as in the developing prostate. Taken together, our findings demonstrate that FASN is a functionally relevant target of p63 and is required for mediating its pro-survival effects.

  16. Single amino acid substitutions in the enzyme acetolactate synthase confer resistance to the herbicide sulfometuron methyl

    Yadav, Narendra; McDevitt, Raymond E.; Benard, Susan; Falco, S. Carl

    1986-01-01

    Sulfometuron methyl, a sulfonylurea herbicide, blocks growth of bacteria, yeast, and higher plants by inhibition of acetolactate synthase (EC 4.1.3.18), the first common enzyme in the biosynthesis of branched-chain amino acids. Spontaneous mutations that confer increased resistance to the herbicide were obtained in cloned genes for acetolactate synthase from Escherichia coli and Saccharomyces cerevisiae. The DNA sequence of a bacterial mutant gene and a yeast mutant gene revealed single nucle...

  17. Insights from computational analysis of full-length β-ketoacyl-[ACP] synthase-II cDNA isolated from American and African oil palms

    Bhore, Subhash J.; Cha, Thye S.; Amelia, Kassim; Shah, Farida H

    2014-01-01

    Background: Palm oil derived from fruits (mesocarp) of African oil palm (Elaeis guineensis Jacq. Tenera) and American oil palm (E. oleifera) is important for food industry. Due to high yield, Elaeis guineensis (Tenera) is cultivated on commercial scale, though its oil contains high (~54%) level of saturated fatty acids. The rate-limiting activity of beta-ketoacyl-[ACP] synthase-II (KAS-II) is considered mainly responsible for the high (44%) level of palmitic acid (C16:0) in the oil obtained f...

  18. Isolation and partial characterization of the gene for goose fatty acid synthase.

    Kameda, K; Goodridge, A G

    1991-01-01

    Fatty acid synthase is regulated by diet and hormones, with regulation being primarily transcriptional. In chick embryo hepatocytes in culture, triiodothyronine stimulates accumulation of enzyme and transcription of the gene. Since the 5'-flanking region of this gene is likely involved in hormonal regulation of its expression, we have isolated and partially characterized an avian fatty acid synthase gene. A genomic DNA library was constructed in a cosmid vector and screened with cDNA clones that contained sequence complementary to the 3' end of goose fatty acid synthase mRNA. A genomic clone (approximately 35 kilobase pairs (kb] was isolated, and a 6.5-kb EcoRI fragment thereof contained DNA complementary to the 3' noncoding region of fatty acid synthase mRNA. Additional cosmid libraries were screened with 5' fragments of previously isolated genomic clones, resulting in the isolation of five overlapping cosmid DNAs. The entire region of cloned DNA spans approximately 105 kb. Exon-containing fragments were identified by hybridization with end-labeled poly(A)+ RNA and by hybridization of labeled exon-containing genomic DNA fragments to fatty acid synthase mRNA. A new set of cDNA clones spanning approximately 3.2 kb was isolated from a lambda-ZAP goose liver cDNA library using the 5'-most exon-containing fragment of the 5'-most genomic DNA clone. This region of mRNA contains a 5'-untranslated sequence and a continuous open reading frame which includes a region that codes for the essential cysteine of the beta-ketoacyl synthase domain. The entire fatty acid synthase gene spans about 50 kb. The 5' 15 kb of the gene contain 7 exons. S1 nuclease and primer extension analyses were used to identify a single site for initiation of transcription, 174 nucleotides upstream from the putative translation initiation codon. Putative "TATA" and "CCAAT" boxes are located 28 and 60 base pairs (bp), respectively, upstream of the site of initiation of transcription. The 5'-flanking 597

  19. Three-dimensional (3D) structure prediction of the American and African oil-palms β-ketoacyl-[ACP] synthase-II protein by comparative modelling

    Wang, Edina; Chinni, Suresh; Bhore, Subhash Janardhan

    2014-01-01

    Background: The fatty-acid profile of the vegetable oils determines its properties and nutritional value. Palm-oil obtained from the African oil-palm [Elaeis guineensis Jacq. (Tenera)] contains 44% palmitic acid (C16:0), but, palm-oil obtained from the American oilpalm [Elaeis oleifera] contains only 25% C16:0. In part, the b-ketoacyl-[ACP] synthase II (KASII) [EC: 2.3.1.179] protein is responsible for the high level of C16:0 in palm-oil derived from the African oil-palm. To understand more a...

  20. Metabolic engineering of Pseudomonas putida for production of docosahexaenoic acid based on a myxobacterial PUFA synthase.

    Gemperlein, Katja; Zipf, Gregor; Bernauer, Hubert S; Müller, Rolf; Wenzel, Silke C

    2016-01-01

    Long-chain polyunsaturated fatty acids (LC-PUFAs) can be produced de novo via polyketide synthase-like enzymes known as PUFA synthases, which are encoded by pfa biosynthetic gene clusters originally discovered from marine microorganisms. Recently similar gene clusters were detected and characterized in terrestrial myxobacteria revealing several striking differences. As the identified myxobacterial producers are difficult to handle genetically and grow very slowly we aimed to establish heterologous expression platforms for myxobacterial PUFA synthases. Here we report the heterologous expression of the pfa gene cluster from Aetherobacter fasciculatus (SBSr002) in the phylogenetically distant model host bacteria Escherichia coli and Pseudomonas putida. The latter host turned out to be the more promising PUFA producer revealing higher production rates of n-6 docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). After several rounds of genetic engineering of expression plasmids combined with metabolic engineering of P. putida, DHA production yields were eventually increased more than threefold. Additionally, we applied synthetic biology approaches to redesign and construct artificial versions of the A. fasciculatus pfa gene cluster, which to the best of our knowledge represents the first example of a polyketide-like biosynthetic gene cluster modulated and synthesized for P. putida. Combination with the engineering efforts described above led to a further increase in LC-PUFA production yields. The established production platform based on synthetic DNA now sets the stage for flexible engineering of the complex PUFA synthase. PMID:26617065

  1. Mechanistic studies of 3-deoxy-D-manno-octulosonic acid 8-phosphate synthase

    Dotson, G.D.; Woodard, R.W. [Univ. of Michigan, Ann Arbor, MI (United States)

    1994-12-01

    The enzyme 3-deOXY-D-manno-octulosonic acid 8-phosphate synthase (KDO 8-P synthase) catalyses the condensation of arabinose 5-phosphate (A 5-P) with phosphoenolpyruvate (PEP) to give the unique eight-carbon acidic sugar 3-deoxy-D-nianno-octulosonic acid 8-phosphate (KDO 8-P) found only in gram-negative bacteria and required for lipid A maturation and cellular growth. The E. coli gene kdsA that encodes KDO 8-P synthase has been amplified by standard PCR methodologies. The synthetic gene, subcloned into the expression vector pT7-7 was used to infect E. coli BL 21 (DE 3). Purification of crude supernatant from this transformant on Q Sepharose yields >200 mg of near-homogeneous KDO 8-P synthase per liter of cell culture. To explore the mechanism of KDO 8-P synthase, we prepared (E)- and (Z)-(3{sup 2}H)PEP, (2-{sup 13}C)PEP, and (2-{sup 13}C,{sup 18}O)PEP chemically from the appropriately labeled 3-bromopyruvates by reaction with trimethylphosphite under Perkow reaction conditions. Our {sup 1}H-NMR analysis of the stereochemistry at C3 of the KDO 8-Ps, obtained by separate incubation of (E)- and (Z)-(3-{sup 2}H)PEP with A 5-P in the presence of KDO 8-P synthase, demonstrated that the reaction is stereospecific with respect to both the C3 of PEP and the C1 carbonyl of A 5-P. (Z)-(3-{sup 2}H)PEP gave predominantly (3S)-(3{sup 2}H)KDO 8-P and (E)-(3-{sup 2}H)PEP gave predominantly (3R)-(3{sup 2}H)KDO-8P, which indicates condensation of the si face of PEP upon the re face of A 5-P-an orientation analogous to that seen with the similar aldehyde Iyase DAH 7-P synthase. The fate of the enolic oxygen of (2-{sup 13}C, {sup 18}O)PEP, during the course of the KDO 8-P synthase-catalyzed reaction as monitored by both {sup 13}C- and {sup 31}P-NMR spectroscopy demonstrated that the inorganic phosphate (Pi) and not the KDO 8-P contained the {sup 18}O.

  2. Crystallization of Δ{sup 1}-tetrahydrocannabinolic acid (THCA) synthase from Cannabis sativa

    Shoyama, Yoshinari; Takeuchi, Ayako; Taura, Futoshi [Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Tamada, Taro; Adachi, Motoyasu; Kuroki, Ryota [Neutron Science Research Center, Japan Atomic Energy Research Institute, 2-4 Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Shoyama, Yukihiro; Morimoto, Satoshi, E-mail: morimoto@phar.kyushu-u.ac.jp [Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2005-08-01

    Δ{sup 1}-Tetrahydrocannabinolic acid (THCA) synthase from C. sativa was crystallized. The crystal diffracted to 2.7 Å resolution with sufficient quality for further structure determination. Δ{sup 1}-Tetrahydrocannabinolic acid (THCA) synthase is a novel oxidoreductase that catalyzes the biosynthesis of the psychoactive compound THCA in Cannabis sativa (Mexican strain). In order to investigate the structure–function relationship of THCA synthase, this enzyme was overproduced in insect cells, purified and finally crystallized in 0.1 M HEPES buffer pH 7.5 containing 1.4 M sodium citrate. A single crystal suitable for X-ray diffraction measurement was obtained in 0.09 M HEPES buffer pH 7.5 containing 1.26 M sodium citrate. The crystal diffracted to 2.7 Å resolution at beamline BL41XU, SPring-8. The crystal belonged to the primitive cubic space group P432, with unit-cell parameters a = b = c = 178.2 Å. The calculated Matthews coefficient was approximately 4.1 or 2.0 Å{sup 3} Da{sup −1} assuming the presence of one or two molecules of THCA synthase in the asymmetric unit, respectively.

  3. Crystallization of Δ1-tetrahydrocannabinolic acid (THCA) synthase from Cannabis sativa

    Δ1-Tetrahydrocannabinolic acid (THCA) synthase from C. sativa was crystallized. The crystal diffracted to 2.7 Å resolution with sufficient quality for further structure determination. Δ1-Tetrahydrocannabinolic acid (THCA) synthase is a novel oxidoreductase that catalyzes the biosynthesis of the psychoactive compound THCA in Cannabis sativa (Mexican strain). In order to investigate the structure–function relationship of THCA synthase, this enzyme was overproduced in insect cells, purified and finally crystallized in 0.1 M HEPES buffer pH 7.5 containing 1.4 M sodium citrate. A single crystal suitable for X-ray diffraction measurement was obtained in 0.09 M HEPES buffer pH 7.5 containing 1.26 M sodium citrate. The crystal diffracted to 2.7 Å resolution at beamline BL41XU, SPring-8. The crystal belonged to the primitive cubic space group P432, with unit-cell parameters a = b = c = 178.2 Å. The calculated Matthews coefficient was approximately 4.1 or 2.0 Å3 Da−1 assuming the presence of one or two molecules of THCA synthase in the asymmetric unit, respectively

  4. Structure of the ent-Copalyl Diphosphate Synthase PtmT2 from Streptomyces platensis CB00739, a Bacterial Type II Diterpene Synthase.

    Rudolf, Jeffrey D; Dong, Liao-Bin; Cao, Hongnan; Hatzos-Skintges, Catherine; Osipiuk, Jerzy; Endres, Michael; Chang, Chin-Yuan; Ma, Ming; Babnigg, Gyorgy; Joachimiak, Andrzej; Phillips, George N; Shen, Ben

    2016-08-31

    Terpenoids are the largest and most structurally diverse family of natural products found in nature, yet their presence in bacteria is underappreciated. The carbon skeletons of terpenoids are generated through carbocation-dependent cyclization cascades catalyzed by terpene synthases (TSs). Type I and type II TSs initiate cyclization via diphosphate ionization and protonation, respectively, and protein structures of both types are known. Most plant diterpene synthases (DTSs) possess three α-helical domains (αβγ), which are thought to have arisen from the fusion of discrete, ancestral bacterial type I TSs (α) and type II TSs (βγ). Type II DTSs of bacterial origin, of which there are no structurally characterized members, are a missing piece in the structural evolution of TSs. Here, we report the first crystal structure of a type II DTS from bacteria. PtmT2 from Streptomyces platensis CB00739 was verified as an ent-copalyl diphosphate synthase involved in the biosynthesis of platensimycin and platencin. The crystal structure of PtmT2 was solved at a resolution of 1.80 Å, and docking studies suggest the catalytically active conformation of geranylgeranyl diphosphate (GGPP). Site-directed mutagenesis confirmed residues involved in binding the diphosphate moiety of GGPP and identified DxxxxE as a potential Mg(2+)-binding motif for type II DTSs of bacterial origin. Finally, both the shape and physicochemical properties of the active sites are responsible for determining specific catalytic outcomes of TSs. The structure of PtmT2 fundamentally advances the knowledge of bacterial TSs, their mechanisms, and their role in the evolution of TSs. PMID:27490479

  5. Enrichment and identification of Δ9-Tetrahydrocannabinolic acid synthase from Pichia pastoris culture supernatants

    Kerstin Lange; Ansgar Poetsch; Andreas Schmid; Julsing, Mattijs K.

    2015-01-01

    This data article refers to the report Δ9-Tetrahydrocannabinolic acid synthase (THCAS) production in Pichia pastoris enables chemical synthesis of cannabinoids (Lange et. al. 2015) [2]. THCAS was produced on a 2 L lab scale using recombinant P. pastoris KM71 KE1. Enrichment of THCAS as a technically pure enzyme was realized using dialysis and cationic exchange chromatography. nLC-ESI-MS/MS analysis identified THCAS in different fractions obtained by cationic exchange chromatography.

  6. Enrichment and identification of Δ9-Tetrahydrocannabinolic acid synthase from Pichia pastoris culture supernatants

    Kerstin Lange

    2015-09-01

    Full Text Available This data article refers to the report Δ9-Tetrahydrocannabinolic acid synthase (THCAS production in Pichia pastoris enables chemical synthesis of cannabinoids (Lange et. al. 2015 [2]. THCAS was produced on a 2 L lab scale using recombinant P. pastoris KM71 KE1. Enrichment of THCAS as a technically pure enzyme was realized using dialysis and cationic exchange chromatography. nLC-ESI-MS/MS analysis identified THCAS in different fractions obtained by cationic exchange chromatography.

  7. Determination of amino-acidic positions important for Ocimum basilicum geraniol synthase activity

    Fischer, Marc; Meyer, Sophie; Claudel, Patricia; Steyer, Damien; Bergdoll, Marc; Hugueney, Philippe

    2013-01-01

    Terpenes are one of the largest and most diversified families of natural compounds. Although they have found numerous industrial applications, the molecular basis of their synthesis in plants has, until now, not been fully understood. Plant genomes have been shown to contain dozens of terpene synthase (TPS) genes, however knowledge of their amino-acidic protein sequence in not sufficient to predict which terpene(s) will be produced by a particular enzyme. In order to investigate the structura...

  8. The gene controlling marijuana psychoactivity: molecular cloning and heterologous expression of Delta1-tetrahydrocannabinolic acid synthase from Cannabis sativa L.

    Sirikantaramas, Supaart; Morimoto, Satoshi; Shoyama, Yoshinari; Ishikawa, Yu; Wada, Yoshiko; Shoyama, Yukihiro; Taura, Futoshi

    2004-09-17

    Delta(1)-tetrahydrocannabinolic acid (THCA) synthase is the enzyme that catalyzes oxidative cyclization of cannabigerolic acid into THCA, the precursor of Delta(1)-tetrahydrocannabinol. We cloned a novel cDNA (GenBank trade mark accession number AB057805) encoding THCA synthase by reverse transcription and polymerase chain reactions from rapidly expanding leaves of Cannabis sativa. This gene consists of a 1635-nucleotide open reading frame, encoding a 545-amino acid polypeptide of which the first 28 amino acid residues constitute the signal peptide. The predicted molecular weight of the 517-amino acid mature polypeptide is 58,597 Da. Interestingly, the deduced amino acid sequence exhibited high homology to berberine bridge enzyme from Eschscholtzia californica, which is involved in alkaloid biosynthesis. The liquid culture of transgenic tobacco hairy roots harboring the cDNA produced THCA upon feeding of cannabigerolic acid, demonstrating unequivocally that this gene encodes an active THCA synthase. Overexpression of the recombinant THCA synthase was achieved using a baculovirus-insect expression system. The purified recombinant enzyme contained covalently attached FAD cofactor at a molar ratio of FAD to protein of 1:1. The mutant enzyme constructed by changing His-114 of the wild-type enzyme to Ala-114 exhibited neither absorption characteristics of flavoproteins nor THCA synthase activity. Thus, we concluded that the FAD binding residue is His-114 and that the THCA synthase reaction is FAD-dependent. This is the first report on molecular characterization of an enzyme specific to cannabinoid biosynthesis. PMID:15190053

  9. Inhibitor of fatty acid synthase induced apoptosis in human colonic cancer cells

    Pei Lin Huang; Zhen Sheng Dai; Yue Lin Jin; Shi Neng Zhu; Shi Lun Lu

    2000-01-01

    @@INTRODUCTION The treatment of human epithelial malignancies is limited by drug resistance and toxic and side effects,which results in the failure in the treatment of majority of advanced cancer victims. To seek for a new, and specific antineoplastic therapy will provide hope for tumor treatment. Although disordered intermediary metabolism in cancer cells has been known for many years, much of the work focused on abnormal glucose catabolism. At the same time, little attention has been paid to fatty acid synthasis in tumor tissues, dispite of the significance of fatty acid synthase (FAS) in some clinical human ovarian[1], breast[2], colorectal[3],and prostatic cancers[4,5]. Tumor cells which express high levels of fatty acid synthesizing enzymes use endogeneously synthesized fatty acids for membrance biosynthesis and appear to export large amounts of lipid. In contrast, normal cells preferentially utilize diary lipid.

  10. Canola engineered with a microalgal polyketide synthase-like system produces oil enriched in docosahexaenoic acid.

    Walsh, Terence A; Bevan, Scott A; Gachotte, Daniel J; Larsen, Cory M; Moskal, William A; Merlo, P A Owens; Sidorenko, Lyudmila V; Hampton, Ronnie E; Stoltz, Virginia; Pareddy, Dayakar; Anthony, Geny I; Bhaskar, Pudota B; Marri, Pradeep R; Clark, Lauren M; Chen, Wei; Adu-Peasah, Patrick S; Wensing, Steven T; Zirkle, Ross; Metz, James G

    2016-08-01

    Dietary omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs), docosahexaenoic acid (DHA, C22:6) and eicosapentaenoic acid (EPA, C20:5) are usually derived from marine fish. Although production of both EPA and DHA has been engineered into land plants, including Arabidopsis, Camelina sativa and Brassica juncea, neither has been produced in commercially relevant amounts in a widely grown crop. We report expression of a microalgal polyketide synthase-like PUFA synthase system, comprising three multidomain polypeptides and an accessory enzyme, in canola (Brassica napus) seeds. This transgenic enzyme system is expressed in the cytoplasm, and synthesizes DHA and EPA de novo from malonyl-CoA without substantially altering plastidial fatty acid production. Furthermore, there is no significant impact of DHA and EPA production on seed yield in either the greenhouse or the field. Canola oil processed from field-grown grain contains 3.7% DHA and 0.7% EPA, and can provide more than 600 mg of omega-3 LC-PUFAs in a 14 g serving. PMID:27398790

  11. The Mycobacterium Tuberculosis FAS-II Dehydratases and Methyltransferases Define the Specificity of the Mycolic Acid Elongation Complexes

    Sylvain Cantaloube; Romain Veyron-Churlet; Nabila Haddache; Mamadou Daffé; Didier Zerbib

    2011-01-01

    BACKGROUND: The human pathogen Mycobacterium tuberculosis (Mtb) has the originality of possessing a multifunctional mega-enzyme FAS-I (Fatty Acid Synthase-I), together with a multi-protein FAS-II system, to carry out the biosynthesis of common and of specific long chain fatty acids: the mycolic acids (MA). MA are the main constituents of the external mycomembrane that represents a tight permeability barrier involved in the pathogenicity of Mtb. The MA biosynthesis pathway is essential and con...

  12. Fatty Acid Synthase Mediates the Epithelial-Mesenchymal Transition of Breast Cancer Cells

    Li, Junqin; Dong, Lihua; Wei, Dapeng; Wang, Xiaodong; Zhang, Shuo; Li, Hua

    2014-01-01

    This study aimed to investigate the role of fatty acid synthase (FASN) in the epithelial-mesenchymal transition (EMT) of breast cancer cells. MCF-7 cells and MCF-7 cells overexpressing mitogen-activated protein kinase 5 (MCF-7-MEK5) were used in this study. MCF-7-MEK5 cells showed stable EMT characterized by increased vimentin and decreased E-cadherin expression. An In vivo animal model was established using the orthotopic injection of MCF-7 or MCF-7-MEK5 cells. Real-time quantitative PCR and...

  13. Imperfect pseudo-merohedral twinning in crystals of fungal fatty acid synthase

    A case of imperfect pseudo-merohedral twinning in monoclinic crystals of fungal fatty acid synthase is discussed. A space-group transition during crystal dehydration resulted in a Moiré pattern-like interference of the twinned diffraction patterns. The recent high-resolution structures of fungal fatty acid synthase (FAS) have provided new insights into the principles of fatty acid biosynthesis by large multifunctional enzymes. The crystallographic phase problem for the 2.6 MDa fungal FAS was initially solved to 5 Å resolution using two crystal forms from Thermomyces lanuginosus. Monoclinic crystals in space group P21 were obtained from orthorhombic crystals in space group P212121 by dehydration. Here, it is shown how this space-group transition induced imperfect pseudo-merohedral twinning in the monoclinic crystal, giving rise to a Moiré pattern-like interference of the two twin-related reciprocal lattices. The strategy for processing the twinned diffraction images and obtaining a quantitative analysis is presented. The twinning is also related to the packing of the molecules in the two crystal forms, which was derived from self-rotation function analysis and molecular-replacement solutions using a low-resolution electron microscopy map as a search model

  14. Natural fatty acid synthase inhibitors as potent therapeutic agents for cancers: A review.

    Zhang, Jia-Sui; Lei, Jie-Ping; Wei, Guo-Qing; Chen, Hui; Ma, Chao-Ying; Jiang, He-Zhong

    2016-09-01

    Context Fatty acid synthase (FAS) is the only mammalian enzyme to catalyse the synthesis of fatty acid. The expression level of FAS is related to cancer progression, aggressiveness and metastasis. In recent years, research on natural FAS inhibitors with significant bioactivities and low side effects has increasingly become a new trend. Herein, we present recent research progress on natural fatty acid synthase inhibitors as potent therapeutic agents. Objective This paper is a mini overview of the typical natural FAS inhibitors and their possible mechanism of action in the past 10 years (2004-2014). Method The information was collected and compiled through major databases including Web of Science, PubMed, and CNKI. Results Many natural products induce cancer cells apoptosis by inhibiting FAS expression, with fewer side effects than synthetic inhibitors. Conclusion Natural FAS inhibitors are widely distributed in plants (especially in herbs and foods). Some natural products (mainly phenolics) possessing potent biological activities and stable structures are available as lead compounds to synthesise promising FAS inhibitors. PMID:26864638

  15. Functional characterization of amyrin synthase involved in ursolic acid biosynthesis in Catharanthus roseus leaf epidermis.

    Yu, Fang; Thamm, Antje M K; Reed, Darwin; Villa-Ruano, Nemesio; Quesada, Alfonso Lara; Gloria, Edmundo Lozoya; Covello, Patrick; De Luca, Vincenzo

    2013-07-01

    Catharanthus roseus accumulates high levels of the pentacyclic triterpene, ursolic acid, as a component of its wax exudate on the leaf surface. Bioinformatic analyses of transcripts derived from the leaf epidermis provide evidence for the specialized role of this tissue in the biosynthesis of ursolic acid. Cloning and functional expression in yeast of a triterpene synthase derived from this tissue showed it to be predominantly an α-amyrin synthase (CrAS), since the α-amyrin to β-amyrin reaction products accumulated in a 5:1 ratio. Expression analysis of CrAS showed that triterpene biosynthesis occurs predominantly in the youngest leaf tissues and in the earliest stages of seedling development. Further studies using laser capture microdissection to harvest RNA from epidermis, mesophyll, idioblasts, laticifers and vasculature of leaves showed the leaf epidermis to be the preferred sites of CrAS expression and provide conclusive evidence for the involvement of this tissue in the biosynthesis of ursolic acid in C. roseus. PMID:22652241

  16. Quinic acids from Aster caucasicus and from transgenic callus expressing a beta-amyrin synthase.

    Pecchia, Paola; Cammareri, Maria; Malafronte, Nicola; Consiglio, M Federica; Gualtieri, Maria Josefina; Conicella, Clara

    2011-11-01

    Several different classes of secondary metabolites, including flavonoids, triterpenoid saponins and quinic acid derivatives, are found in Aster spp. (Fam. Asteraceae). Several Aster compounds revealed biological as well as pharmacological activities. In this work, a phytochemical investigation of A. caucasicus evidenced the presence of quinic acid derivatives, as well as the absence of triterpene saponins. To combine in one species the production of different phytochemicals, including triterpenes, an Agrobacterium-mediated transformation of A. caucasicus was set up to introduce A. sedifolius beta-amyrin synthase (AsOXA1)-encoding gene under the control of the constitutive promoter CaMV35S. The quali-quantitative analysis of transgenic calli with ectopic expression of AsOXA1 showed, in one sample, a negligible amount of triterpene saponins combined with higher amount of quinic acid derivatives as compared with the wild type callus. PMID:22224284

  17. Crystal Structure and Substrate Specificity of Human Thioesterase 2: INSIGHTS INTO THE MOLECULAR BASIS FOR THE MODULATION OF FATTY ACID SYNTHASE.

    Ritchie, Melissa K; Johnson, Lynnette C; Clodfelter, Jill E; Pemble, Charles W; Fulp, Brian E; Furdui, Cristina M; Kridel, Steven J; Lowther, W Todd

    2016-02-12

    The type I fatty acid synthase (FASN) is responsible for the de novo synthesis of palmitate. Chain length selection and release is performed by the C-terminal thioesterase domain (TE1). FASN expression is up-regulated in cancer, and its activity levels are controlled by gene dosage and transcriptional and post-translational mechanisms. In addition, the chain length of fatty acids produced by FASN is controlled by a type II thioesterase called TE2 (E.C. 3.1.2.14). TE2 has been implicated in breast cancer and generates a broad lipid distribution within milk. The molecular basis for the ability of the TE2 to compete with TE1 for the acyl chain attached to the acyl carrier protein (ACP) domain of FASN is unknown. Herein, we show that human TE1 efficiently hydrolyzes acyl-CoA substrate mimetics. In contrast, TE2 prefers an engineered human acyl-ACP substrate and readily releases short chain fatty acids from full-length FASN during turnover. The 2.8 Å crystal structure of TE2 reveals a novel capping domain insert within the α/β hydrolase core. This domain is reminiscent of capping domains of type II thioesterases involved in polyketide synthesis. The structure also reveals that the capping domain had collapsed onto the active site containing the Ser-101-His-237-Asp-212 catalytic triad. This observation suggests that the capping domain opens to enable the ACP domain to dock and to place the acyl chain and 4'-phosphopantetheinyl-linker arm correctly for catalysis. Thus, the ability of TE2 to prematurely release fatty acids from FASN parallels the role of editing thioesterases involved in polyketide and non-ribosomal peptide synthase synthases. PMID:26663084

  18. 7-deoxyloganetic acid synthase catalyzes a key 3 step oxidation to form 7-deoxyloganetic acid in Catharanthus roseus iridoid biosynthesis.

    Salim, Vonny; Wiens, Brent; Masada-Atsumi, Sayaka; Yu, Fang; De Luca, Vincenzo

    2014-05-01

    Iridoids are key intermediates required for the biosynthesis of monoterpenoid indole alkaloids (MIAs), as well as quinoline alkaloids. Although most iridoid biosynthetic genes have been identified, one remaining three step oxidation required to form the carboxyl group of 7-deoxyloganetic acid has yet to be characterized. Here, it is reported that virus-induced gene silencing of 7-deoxyloganetic acid synthase (7DLS, CYP76A26) in Catharanthus roseus greatly decreased levels of secologanin and the major MIAs, catharanthine and vindoline in silenced leaves. Functional expression of this gene in Saccharomyces cerevisiae confirmed its function as an authentic 7DLS that catalyzes the 3 step oxidation of iridodial-nepetalactol to form 7-deoxyloganetic acid. The identification of CYP76A26 removes a key bottleneck for expression of iridoid and related MIA pathways in various biological backgrounds. PMID:24594312

  19. Para-aminobenzoic acid (PABA synthase enhances thermotolerance of mushroom Agaricus bisporus.

    Zhonglei Lu

    Full Text Available Most mushrooms are thermo-sensitive to temperatures over 23°C, which greatly restricts their agricultural cultivation. Understanding mushroom's innate heat-tolerance mechanisms may facilitate genetic improvements of their thermotolerance. Agaricus bisporus strain 02 is a relatively thermotolerant mushroom strain, while strain 8213 is quite thermo-sensitive. Here, we compared their responses at proteomic level to heat treatment at 33°C. We identified 73 proteins that are differentially expressed between 02 and 8213 or induced upon heat stress in strain 02 itself, 48 of which with a known identity. Among them, 4 proteins are constitutively more highly expressed in 02 than 8213; and they can be further upregulated in response to heat stress in 02, but not in 8213. One protein is encoded by the para-aminobenzoic acid (PABA synthase gene Pabs, which has been shown to scavenge the reactive oxygen species in vitro. Pabs mRNA and its chemical product PABA show similar heat stress induction pattern as PABA synthase protein and are more abundant in 02, indicating transcriptional level upregulation of Pabs upon heat stress. A specific inhibitor of PABA synthesis impaired thermotolerance of 02, while exogenous PABA or transgenic overexpression of 02 derived PABA synthase enhanced thermotolerance of 8213. Furthermore, compared to 8213, 02 accumulated less H2O2 but more defense-related proteins (e.g., HSPs and Chitinase under heat stress. Together, these results demonstrate a role of PABA in enhancing mushroom thermotolerance by removing H2O2 and elevating defense-related proteins.

  20. Green tea catechin inhibits fatty acid synthase without stimulating carnitine Palmitoyltransferase-1 or inducing weight loss in experimental animals

    Puig i Miquel, Teresa; Relat Pardo, Joana; Marrero González, Pedro F.; Haro Bautista, Diego; Brunet, Joan; Colomer Bosch, Ramón

    2008-01-01

    Background: The enzyme fatty acid synthase (FASN) is highly expressed in many human carcinomas and its inhibition is cytotoxic to human cancer cells. The use of FASN inhibitors has been limited until now by anorexia and weight loss, which is associated with the stimulation of fatty acid oxidation. Materials and Methods: The in vitro effect of (-)-epigallocatechin-3-gallate (EGCG) on fatty acid metabolism enzymes, on apoptosis and on cell signalling was evaluated. In vivo, the effect of EGCG o...

  1. Metallophilic HgII...HgII interactions in nucleic acids

    Benda, Ladislav; Tanaka, Y.; Sychrovský, Vladimír; Straka, Michal

    Praha: Matfyzpress, 2011 - (Burda, J.). s. 62-62 ISBN 978-80-7378-180-4. [Modeling Interactions in Biomolecules /5./. 04.09.2011-09.09.2011, Kutná Hora] R&D Projects: GA ČR GA203/09/2037; GA ČR GAP205/10/0228 Grant ostatní: European Reintegration Grant(XE) 230955 Institutional research plan: CEZ:AV0Z40550506 Keywords : metallophilic HgII...HgII interactions * metallophilic interactions * base stacking * nucleic acids Subject RIV: CF - Physical ; Theoretical Chemistry

  2. The effect of porphyrin and radiation on ferrochelatase and 5-aminolevulinic acid synthase in epidermal cells

    The effects of ultraviolet A (UVA) and blue light on ferrochelatase protein, and its mRNA level, in 5-aminolevulinic acid (ALA)-loaded A431 cells was evaluated. Western blot analysis of ferrochelatase protein showed a protein band of 43 kDA. There was a decrease in the protein concentration 24 h and 48 h after irradiation of these cells. In contrast, as judged by Northern blot analysis, there was no change in ferochelatase mRNA level. Measurement of ALA synthase activity showed an ALA dose-dependent but radiation-independent decrease of enzyme activity, suggesting an end-product feedback inhibition. Since reactive oxygen species generated by porphyrin-induced photochemical reaction may be involved in the decrease in ferrochelatase protein, the effect of scavengers of reactive oxygen species was evaluated by measuring porphyrin accumulation in irradiated, ALA-loaded A431 cells. Porphyrin accumulation was significantly decreased in the presence of singlet oxygen scavenger sodium azide (0.05 mM, 40.6% suppression) or hydroxyl radical scavenger mannitol (5.0 mM, 45% suppression). These data suggest that the photochemical reaction induced by porphyrin and irradiation resulted in a decrease in ferrochelatase protein content, but had no effect on ferrochelatase mRNA level nor on ALA synthase activity. The decrease in protein was partly mediated by the reactive oxygen species. (au)

  3. Isolation and Molecular Characterization of 1-Aminocyclopropane-1-carboxylic Acid Synthase Genes in Hevea brasiliensis

    Jia-Hong Zhu

    2015-02-01

    Full Text Available Ethylene is an important factor that stimulates Hevea brasiliensis to produce natural rubber. 1-Aminocyclopropane-1-carboxylic acid synthase (ACS is a rate-limiting enzyme in ethylene biosynthesis. However, knowledge of the ACS gene family of H. brasiliensis is limited. In this study, nine ACS-like genes were identified in H. brasiliensis. Sequence and phylogenetic analysis results confirmed that seven isozymes (HbACS1–7 of these nine ACS-like genes were similar to ACS isozymes with ACS activity in other plants. Expression analysis results showed that seven ACS genes were differentially expressed in roots, barks, flowers, and leaves of H. brasiliensis. However, no or low ACS gene expression was detected in the latex of H. brasiliensis. Moreover, seven genes were differentially up-regulated by ethylene treatment. These results provided relevant information to help determine the functions of the ACS gene in H. brasiliensis, particularly the functions in regulating ethylene stimulation of latex production.

  4. Wild-type phosphoribosylpyrophosphate synthase (PRS from Mycobacterium tuberculosis: a bacterial class II PRS?

    Ardala Breda

    Full Text Available The 5-phospho-α-D-ribose 1-diphosphate (PRPP metabolite plays essential roles in several biosynthetic pathways, including histidine, tryptophan, nucleotides, and, in mycobacteria, cell wall precursors. PRPP is synthesized from α-D-ribose 5-phosphate (R5P and ATP by the Mycobacterium tuberculosis prsA gene product, phosphoribosylpyrophosphate synthase (MtPRS. Here, we report amplification, cloning, expression and purification of wild-type MtPRS. Glutaraldehyde cross-linking results suggest that MtPRS predominates as a hexamer, presenting varied oligomeric states due to distinct ligand binding. MtPRS activity measurements were carried out by a novel coupled continuous spectrophotometric assay. MtPRS enzyme activity could be detected in the absence of P(i. ADP, GDP and UMP inhibit MtPRS activity. Steady-state kinetics results indicate that MtPRS has broad substrate specificity, being able to accept ATP, GTP, CTP, and UTP as diphosphoryl group donors. Fluorescence spectroscopy data suggest that the enzyme mechanism for purine diphosphoryl donors follows a random order of substrate addition, and for pyrimidine diphosphoryl donors follows an ordered mechanism of substrate addition in which R5P binds first to free enzyme. An ordered mechanism for product dissociation is followed by MtPRS, in which PRPP is the first product to be released followed by the nucleoside monophosphate products to yield free enzyme for the next round of catalysis. The broad specificity for diphosphoryl group donors and detection of enzyme activity in the absence of P(i would suggest that MtPRS belongs to Class II PRS proteins. On the other hand, the hexameric quaternary structure and allosteric ADP inhibition would place MtPRS in Class I PRSs. Further data are needed to classify MtPRS as belonging to a particular family of PRS proteins. The data here presented should help augment our understanding of MtPRS mode of action. Current efforts are toward experimental structure

  5. Engineering a Polyketide Synthase for In Vitro Production of Adipic Acid.

    Hagen, Andrew; Poust, Sean; Rond, Tristan de; Fortman, Jeffrey L; Katz, Leonard; Petzold, Christopher J; Keasling, Jay D

    2016-01-15

    Polyketides have enormous structural diversity, yet polyketide synthases (PKSs) have thus far been engineered to produce only drug candidates or derivatives thereof. Thousands of other molecules, including commodity and specialty chemicals, could be synthesized using PKSs if composing hybrid PKSs from well-characterized parts derived from natural PKSs was more efficient. Here, using modern mass spectrometry techniques as an essential part of the design-build-test cycle, we engineered a chimeric PKS to enable production one of the most widely used commodity chemicals, adipic acid. To accomplish this, we introduced heterologous reductive domains from various PKS clusters into the borrelidin PKS' first extension module, which we previously showed produces a 3-hydroxy-adipoyl intermediate when coincubated with the loading module and a succinyl-CoA starter unit. Acyl-ACP intermediate analysis revealed an unexpected bottleneck at the dehydration step, which was overcome by introduction of a carboxyacyl-processing dehydratase domain. Appending a thioesterase to the hybrid PKS enabled the production of free adipic acid. Using acyl-intermediate based techniques to "debug" PKSs as described here, it should one day be possible to engineer chimeric PKSs to produce a variety of existing commodity and specialty chemicals, as well as thousands of chemicals that are difficult to produce from petroleum feedstocks using traditional synthetic chemistry. PMID:26501439

  6. Fatty acid synthase inhibitors from plants: isolation, structure elucidation, and SAR studies.

    Li, Xing-Cong; Joshi, Alpana S; ElSohly, Hala N; Khan, Shabana I; Jacob, Melissa R; Zhang, Zhizheng; Khan, Ikhlas A; Ferreira, Daneel; Walker, Larry A; Broedel, Sheldon E; Raulli, Robert E; Cihlar, Ronald L

    2002-12-01

    Fatty acid synthase (FAS) has been identified as a potential antifungal target. FAS prepared from Saccharomyces cerevisiae was employed for bioactivity-guided fractionation of Chlorophora tinctoria,Paspalum conjugatum, Symphonia globulifera, Buchenavia parviflora, and Miconia pilgeriana. Thirteen compounds (1-13), including three new natural products (1, 4, 12), were isolated and their structures identified by spectroscopic interpretation. They represented five chemotypes, namely, isoflavones, flavones, biflavonoids, hydrolyzable tannin-related derivatives, and triterpenoids. 3'-Formylgenistein (1) and ellagic acid 4-O-alpha-l-rhamnopyranoside (9) were the most potent compounds against FAS, with IC(50) values of 2.3 and 7.5 microg/mL, respectively. Furthermore, 43 (14-56) analogues of the five chemotypes from our natural product repository and commercial sources were tested for their FAS inhibitory activity. Structure-activity relationships for some chemotypes were investigated. All these compounds were further evaluated for antifungal activity against Candida albicans and Cryptococcus neoformans. Although there were several antifungal compounds in the set, correlation between the FAS inhibitory activity and antifungal activity could not be defined. PMID:12502337

  7. Characterization and analysis of the cotton cyclopropane fatty acid synthase family and their contribution to cyclopropane fatty acid synthesis

    Yu X. H.; Shanklin J.; Rawat, R.

    2011-05-01

    Cyclopropane fatty acids (CPA) have been found in certain gymnosperms, Malvales, Litchi and other Sapindales. The presence of their unique strained ring structures confers physical and chemical properties characteristic of unsaturated fatty acids with the oxidative stability displayed by saturated fatty acids making them of considerable industrial interest. While cyclopropenoid fatty acids (CPE) are well-known inhibitors of fatty acid desaturation in animals, CPE can also inhibit the stearoyl-CoA desaturase and interfere with the maturation and reproduction of some insect species suggesting that in addition to their traditional role as storage lipids, CPE can contribute to the protection of plants from herbivory. Three genes encoding cyclopropane synthase homologues GhCPS1, GhCPS2 and GhCPS3 were identified in cotton. Determination of gene transcript abundance revealed differences among the expression of GhCPS1, 2 and 3 showing high, intermediate and low levels, respectively, of transcripts in roots and stems; whereas GhCPS1 and 2 are both expressed at low levels in seeds. Analyses of fatty acid composition in different tissues indicate that the expression patterns of GhCPS1 and 2 correlate with cyclic fatty acid (CFA) distribution. Deletion of the N-terminal oxidase domain lowered GhCPS's ability to produce cyclopropane fatty acid by approximately 70%. GhCPS1 and 2, but not 3 resulted in the production of cyclopropane fatty acids upon heterologous expression in yeast, tobacco BY2 cell and Arabidopsis seed. In cotton GhCPS1 and 2 gene expression correlates with the total CFA content in roots, stems and seeds. That GhCPS1 and 2 are expressed at a similar level in seed suggests both of them can be considered potential targets for gene silencing to reduce undesirable seed CPE accumulation. Because GhCPS1 is more active in yeast than the published Sterculia CPS and shows similar activity when expressed in model plant systems, it represents a strong candidate gene

  8. Aspergillus oryzae type III polyketide synthase CsyA is involved in the biosynthesis of 3,5-dihydroxybenzoic acid.

    Seshime, Yasuyo; Juvvadi, Praveen Rao; Kitamoto, Katsuhiko; Ebizuka, Yutaka; Nonaka, Takamasa; Fujii, Isao

    2010-08-15

    As a novel superfamily of type III polyketide synthases in microbes, four genes csyA, csyB, csyC, and csyD, were found in the genome of Aspergillus oryzae, an industrially important filamentous fungus. In order to analyze their functions, we carried out the overexpression of csyA under the control of alpha-amylase promoter in A. oryzae and identified 3,5-dihydroxybenzoic acid (DHBA) as the major product. Feeding experiments using (13)C-labeled acetates confirmed that the acetate labeling pattern of DHBA coincided with that of orcinol derived from orsellinic acid, a polyketide formed by the condensation and cyclization of four acetate units. Further oxidation of methyl group of orcinol by the host fungus could lead to the production of DHBA. Comparative molecular modeling of CsyA with the crystal structure of Neurospora crassa 2'-oxoalkylresorcylic acid synthase indicated that CsyA cavity size can only accept short-chain acyl starter and tetraketide formation. Thus, CsyA is considered to be a tetraketide alkyl-resorcinol/resorcylic acid synthase. PMID:20630753

  9. Attachment of fatty acid substrate fragments to prostaglandin (PG) H synthase during reaction with arachidonate

    Pure ovine synthase was incubated aerobically with 14C-arachidonate to inactivate the cyclooxygenase. After solvent extraction to remove the bulk of the lipid, the inactive protein was analyzed by polyacrylamide gel electrophoresis. In SDS-PAGE radioactive label was associated with protein that comigrated with the 70 K Da synthase subunit, as well as with protein that accumulated at the upper edge of the resolving gel. In HPLC radioactivity was found in two peaks eluting in the region of unreacted synthase. SDS-PAGE analysis of pooled material from these HPLC peaks gave a distribution of radioactivity similar to that obtained with the unfractionated material. The radioactivity and protein content of inactivated synthase purified by HPLC indicated that 0.3-1.0 mole of substrate fragment were bound per mole of synthase subunit. Incubation of a mixture of the synthase and ovalbumin with arachidonate resulted in 5-fold more labelling of synthase than ovalbumin. Thus, a substrate fragment appears to become selectively attached to the synthase during reaction, and may represent the product of a self-inactivation event

  10. α-Lipoic acid prevents lipotoxic cardiomyopathy in acyl CoA-synthase transgenic mice

    α-Lipoic acid (α-LA) mimics the hypothalamic actions of leptin on food intake, energy expenditure, and activation of AMP-activated protein kinase (AMPK). To determine if, like leptin, α-LA protects against cardiac lipotoxicity, α-LA was fed to transgenic mice with cardiomyocyte-specific overexpression of the acyl CoA synthase (ACS) gene. Untreated ACS-transgenic mice died prematurely with increased triacylglycerol content and dilated cardiomyopathy, impaired systolic function and myofiber disorganization, apoptosis, and interstitial fibrosis on microscopy. In α-LA-treated ACS-transgenic mice heart size, echocardiogram and TG content were normal. Plasma TG fell 50%, hepatic-activated phospho-AMPK rose 6-fold, sterol regulatory element-binding protein-1c declined 50%, and peroxisome proliferator-activated receptor-γ cofactor-1α mRNA rose 4-fold. Since food restriction did not prevent lipotoxicity, we conclude that α-LA treatment, like hyperleptinemia, protects the heart of ACS-transgenic mice from lipotoxicity

  11. Inhibition of Mycobacterium tuberculosis dihydrodipicolinate synthase by alpha-ketopimelic acid and its other structural analogues.

    Shrivastava, Priyanka; Navratna, Vikas; Silla, Yumnam; Dewangan, Rikeshwer P; Pramanik, Atreyi; Chaudhary, Sarika; Rayasam, GeethaVani; Kumar, Anuradha; Gopal, Balasubramanian; Ramachandran, Srinivasan

    2016-01-01

    The Mycobacterium tuberculosis dihydrodipicolinate synthase (Mtb-dapA) is an essential gene. Mtb-DapA catalyzes the aldol condensation between pyruvate and L-aspartate-beta-semialdehyde (ASA) to yield dihydrodipicolinate. In this work we tested the inhibitory effects of structural analogues of pyruvate on recombinant Mtb-DapA (Mtb-rDapA) using a coupled assay with recombinant dihydrodipicolinate reductase (Mtb-rDapB). Alpha-ketopimelic acid (α-KPA) showed maximum inhibition of 88% and IC50 of 21 μM in the presence of pyruvate (500 μM) and ASA (400 μM). Competition experiments with pyruvate and ASA revealed competition of α-KPA with pyruvate. Liquid chromatography-mass spectrometry (LC-MS) data with multiple reaction monitoring (MRM) showed that the relative abundance peak of final product, 2,3,4,5-tetrahydrodipicolinate, was decreased by 50%. Thermal shift assays showed 1 °C Tm shift of Mtb-rDapA upon binding α-KPA. The 2.4 Å crystal structure of Mtb-rDapA-α-KPA complex showed the interaction of critical residues at the active site with α-KPA. Molecular dynamics simulations over 500 ns of pyruvate docked to Mtb-DapA and of α-KPA-bound Mtb-rDapA revealed formation of hydrogen bonds with pyruvate throughout in contrast to α-KPA. Molecular descriptors analysis showed that ligands with polar surface area of 91.7 Å(2) are likely inhibitors. In summary, α-hydroxypimelic acid and other analogues could be explored further as inhibitors of Mtb-DapA. PMID:27501775

  12. Transcripts for genes encoding soluble acid invertase and sucrose synthase accumulate in root tip and cortical cells containing mycorrhizal arbuscules.

    Blee, Kristopher A; Anderson, Anne J

    2002-09-01

    Arbuscule formation by the arbuscular mycorrhizal fungus Glomus intraradices (Schenck & Smith) was limited to cortical cells immediately adjacent to the endodermis. Because these cortical cells are the first to intercept photosynthate exiting the vascular cylinder, transcript levels for sucrose metabolizing-enzymes were compared between mycorrhizal and non-mycorrhizal roots. The probes corresponded to genes encoding a soluble acid invertase with potential vacuolar targeting, which we generated from Phaseolus vulgaris roots, a Rhizobium-responsive sucrose synthase of soybean and a cell wall acid invertase of carrot. Transcripts in non-mycorrhizal roots were developmentally regulated and abundant in the root tips for all three probes but in differentiated roots of P. vulgaris they were predominantly located in phloem tissues for sucrose synthase or the endodermis and phloem for soluble acid invertase. In mycorrhizal roots increased accumulations of transcripts for sucrose synthase and vacuolar invertase were both observed in the same cortical cells bearing arbuscules that fluoresce. There was no effect on the expression of the cell wall invertase gene in fluorescent carrot cells containing arbuscules. Thus, it appears that presence of the fungal hyphae in the fluorescent arbusculated cell stimulates discrete alterations in expression of sucrose metabolizing enzymes to increase the sink potential of the cell. PMID:12175013

  13. Nitro-Arachidonic Acid Prevents Angiotensin II-Induced Mitochondrial Dysfunction in a Cell Line of Kidney Proximal Tubular Cells.

    Beatriz Sánchez-Calvo

    Full Text Available Nitro-arachidonic acid (NO2-AA is a cell signaling nitroalkene that exerts anti-inflammatory activities during macrophage activation. While angiotensin II (ANG II produces an increase in reactive oxygen species (ROS production and mitochondrial dysfunction in renal tubular cells, little is known regarding the potential protective effects of NO2-AA in ANG II-mediated kidney injury. As such, this study examines the impact of NO2-AA on ANG II-induced mitochondrial dysfunction in an immortalized renal proximal tubule cell line (HK-2 cells. Treatment of HK-2 cells with ANG II increases the production of superoxide (O2●-, nitric oxide (●NO, inducible nitric oxide synthase (NOS2 expression, peroxynitrite (ONOO- and mitochondrial dysfunction. Using high-resolution respirometry, it was observed that the presence of NO2-AA prevented ANG II-mediated mitochondrial dysfunction. Attempting to address mechanism, we treated isolated rat kidney mitochondria with ONOO-, a key mediator of ANG II-induced mitochondrial damage, in the presence or absence of NO2-AA. Whereas the activity of succinate dehydrogenase (SDH and ATP synthase (ATPase were diminished upon exposure to ONOO-, they were restored by pre-incubating the mitochondria with NO2-AA. Moreover, NO2-AA prevents oxidation and nitration of mitochondrial proteins. Combined, these data demonstrate that ANG II-mediated oxidative damage and mitochondrial dysfunction is abrogated by NO2-AA, identifying this compound as a promising pharmacological tool to prevent ANG II-induced renal disease.

  14. Ni(II) complexes of dithiophosphonic acids

    Afshin Saadat; Alireza Banaee; Patrick McArdle; Karim Zare; Khodayar Gholivand; Ali Asghar Ebrahimi Valmoozi

    2014-07-01

    The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson reagent) with isobutanol, cyclohexylamine and phenylethylamine produced (4-methoxy-phenyl)-phosphonodithioic acid o-isobutyl ester HS2P(p-C6H4OMe) (OCH2CH(CH3)2) (I), [S2P(C6H11NH)(p-C6H4OMe) H3N+C6H11] (II) and [S2P(phCH2CH2NH) (p-C6H4OMe)H3N+CH2CH2ph] (III), respectively. The reaction of alcohol with Lawesson reagent produced neutral product (I) while that with amines led to an ion pair (II, III). Furthermore, reaction of I, II and III with NiCl2.6H2O in methanol produced novel complexes: IV, V and VI. The compounds were characterized by 1H, 13C and 31P NMR, IR spectroscopy and elemental analysis. The single crystal X-ray structures of IV and V showed that the nickel complexes are square planar. Compound V formed a three-dimensional supramolecular structure via intermolecular P-O…H-N hydrogen bonds. The Xray crystallography of V showed that those three hydrogens of +NH3 cation produced three hydrogen bonds with different distances. The new compounds were additionally tested in view of their anti-bacterial properties. The ligands containing amine substituents exhibited more activity toward tested bacteria than their alcohol substituents, while the Ni(II) complexes including alcohol substituents exhibited high potential.

  15. Wounding stimulates ALLENE OXIDE SYNTHASE gene and increases the level of jasmonic acid in Ipomoea nil cotyledons

    Emilia Wilmowicz

    2016-03-01

    Full Text Available Allene oxide synthase (AOS encodes the first enzyme in the lipoxygenase pathway, which is responsible for jasmonic acid (JA formation. In this study we report the molecular cloning and characterization of InAOS from Ipomoea nil. The full-length gene is composed of 1662 bp and encodes for 519 amino acids. The predicted InAOS contains PLN02648 motif, which is evolutionarily conserved and characteristic for functional enzymatic proteins. We have shown that wounding led to a strong stimulation of the examined gene activity in cotyledons and an increase in JA level, which suggest that this compound may be a modulator of stress responses in I. nil.

  16. Molecular cloning and regulation of murine fatty acid synthase mRNA

    Mouse liver mRNA that was enriched in sequences coding for fatty acid synthase (FAS) by sucrose-density gradient centrifugation was used as a template for cDNA synthesis. Double-stranded cDNA sequences were inserted into pBR322 and λgt10 and cloned. Clones containing putative cDNA sequences for FAS were identified by differential hybridization where 32P-cDNAs, synthesized from sucrose gradient purified liver mRNA from mice starved or starved and refed a fat-free diet, were used as probes. Two of these clones were further studied and found to contain sequences complementary to FAS mRNA by hybrid-selected translation and specific immunoprecipitation. Using these clones as probes, they selected 33 additional clones containing cDNA sequences for FAS. Partial DNA sequence data for these clones were obtained. Northern blot analysis revealed a single mRNA size of 9.3 kb when a cDNA clone with a 3.1 kb insert was used as a probe. This is in contrast to rat liver FAS which showed two mRNAs sizes of 9.2 and 10.0 kb. They also studied FAS mRNA level of 3T3-L1 preadipocytes during differentiation into adipocytes. An approximate 10-fold increase in FAS mRNA content was observed which corresponded with an increased rate of FAS synthesis indicating pretranslational regulation. The FAS cDNA probe was also employed to demonstrate that induction of FAS in the livers of previously starved mice that were fed a fat-free diet was controlled pretranslationally by a parallel modulation of the FAS mRNA concentration

  17. Acid sphingomyelinase gene knockout ameliorates hyperhomocysteinemic glomerular injury in mice lacking cystathionine-β-synthase.

    Krishna M Boini

    Full Text Available Acid sphingomyelinase (ASM has been implicated in the development of hyperhomocysteinemia (hHcys-induced glomerular oxidative stress and injury. However, it remains unknown whether genetically engineering of ASM gene produces beneficial or detrimental action on hHcys-induced glomerular injury. The present study generated and characterized the mice lacking cystathionine β-synthase (Cbs and Asm mouse gene by cross breeding Cbs(+/- and Asm(+/- mice. Given that the homozygotes of Cbs(-/-/Asm(-/- mice could not survive for 3 weeks. Cbs(+/-/Asm(+/+, Cbs(+/-/Asm(+/- and Cbs(+/-/Asm(-/- as well as their Cbs wild type littermates were used to study the role of Asm(-/- under a background of Cbs(+/- with hHcys. HPLC analysis revealed that plasma Hcys level was significantly elevated in Cbs heterozygous (Cbs(+/- mice with different copies of Asm gene compared to Cbs(+/+ mice with different Asm gene copies. Cbs(+/-/Asm(+/+ mice had significantly increased renal Asm activity, ceramide production and O(2.(- level compared to Cbs(+/+/Asm(+/+, while Cbs(+/-/Asm(-/- mice showed significantly reduced renal Asm activity, ceramide production and O(2.(- level due to increased plasma Hcys levels. Confocal microscopy demonstrated that colocalization of podocin with ceramide was much lower in Cbs(+/-/Asm(-/- mice compared to Cbs(+/-/Asm(+/+ mice, which was accompanied by a reduced glomerular damage index, albuminuria and proteinuria in Cbs(+/-/Asm(-/- mice. Immunofluorescent analyses of the podocin, nephrin and desmin expression also illustrated less podocyte damages in the glomeruli from Cbs(+/-/Asm(-/- mice compared to Cbs(+/-/Asm(+/+ mice. In in vitro studies of podocytes, hHcys-enhanced O(2.(- production, desmin expression, and ceramide production as well as decreases in VEGF level and podocin expression in podocytes were substantially attenuated by prior treatment with amitriptyline, an Asm inhibitor. In conclusion, Asm gene knockout or corresponding enzyme

  18. Effect of estrogen on gene expression of fatty acid synthase in periosteum

    ZHENG Rui-min; LIN Shou-qing; LIU Yong; HUANG Man-ting; GONG Wei-yan; WU Zhi-hong

    2009-01-01

    Background Estrogen deficiency contributes to postmenopausal osteoporosis.Periosteum might be a potential target of estrogen,but the underlying mechanism at gene level is far from being elucidated.The objective of this study was to investigate the correlation between estrogen and fatty acid synthase(FAS)expression in periosteum.Methods Human periosteum cells were cultured in vitro.Expressed genes in the substrated cDNA library were verified using semi-quantitative PCR and real-time PCR.The expression of FAS in periosteum of ovarectomized(OVX)SD rats was investigated.Results FAS gene was most significantly expressed in the subtracted cDNA library of periosteal cells screened by semi-quantitative PCR.Low FAS expression was verified by real-time PCR in the estrogen exposed human periosteum rather than in the control.The estradiol levels were(20.81±12.62)pg/ml,(19.64±4.35)pg/ml and(13.47+1.84)pg/ml in the sham group,the control,and the OVX group,respectively.The estradiol levels in the OVX group was significantly lower(P=0.0386).The FAS gene expression in periosteum in the OVX group,sham group,and control group was 3.09±1.97,1.33±0.47 and 1.51±1.32,respectively.The gene expression in the OVX group was significantly higher (P=0.0372).Conclusion Estrogen modulates FAS gene expression in in vitro human perisoteum as well as in in vivo rat periosteum.

  19. Homology analyses of the protein sequences of fatty acid synthases from chicken liver, rat mammary gland, and yeast

    Homology analyses of the protein sequences of chicken liver and rat mammary gland fatty acid synthases were carried out. The amino acid sequences of the chicken and rat enzymes are 67% identical. If conservative substitutions are allowed, 78% of the amino acids are matched. A region of low homologies exists between the functional domains, in particular around amino acid residues 1059-1264 of the chicken enzyme. Homologies between the active sites of chicken and rat and of chicken and yeast enzymes have been analyzed by an alignment method. A high degree of homology exists between the active sites of the chicken and rat enzymes. However, the chicken and yeast enzymes show a lower degree of homology. The DADPH-binding dinucleotide folds of the β-ketoacyl reductase and the enoyl reductase sites were identified by comparison with a known consensus sequence for the DADP- and FAD-binding dinucleotide folds. The active sites of all of the enzymes are primarily in hydrophobic regions of the protein. This study suggests that the genes for the functional domains of fatty acid synthase were originally separated, and these genes were connected to each other by using different connecting nucleotide sequences in different species. An alternative explanation for the differences in rat and chicken is a common ancestry and mutations in the joining regions during evolution

  20. Chiral hydroxylation at the mononuclear nonheme Fe(II center of 4-(S hydroxymandelate synthase--a structure-activity relationship analysis.

    Cristiana M L Di Giuro

    Full Text Available (S-Hydroxymandelate synthase (Hms is a nonheme Fe(II dependent dioxygenase that catalyzes the oxidation of 4-hydroxyphenylpyruvate to (S-4-hydroxymandelate by molecular oxygen. In this work, the substrate promiscuity of Hms is characterized in order to assess its potential for the biosynthesis of chiral α-hydroxy acids. Enzyme kinetic analyses, the characterization of product spectra, quantitative structure activity relationship (QSAR analyses and in silico docking studies are used to characterize the impact of substrate properties on particular steps of catalysis. Hms is found to accept a range of α-oxo acids, whereby the presence of an aromatic substituent is crucial for efficient substrate turnover. A hydrophobic substrate binding pocket is identified as the likely determinant of substrate specificity. Upon introduction of a steric barrier, which is suspected to obstruct the accommodation of the aromatic ring in the hydrophobic pocket during the final hydroxylation step, the racemization of product is obtained. A steady state kinetic analysis reveals that the turnover number of Hms strongly correlates with substrate hydrophobicity. The analysis of product spectra demonstrates high regioselectivity of oxygenation and a strong coupling efficiency of C-C bond cleavage and subsequent hydroxylation for the tested substrates. Based on these findings the structural basis of enantioselectivity and enzymatic activity is discussed.

  1. Starvation for ilvB operon leader amino acids other than leucine or valine does not increase acetohydroxy acid synthase activity in Escherichia coli.

    Tsui, P; Freundlich, M

    1985-01-01

    Eleven different amino acids are encoded in the ilvB leader mRNA. Starvation for leucine or valine, but not for any of the other nine amino acids, resulted in high levels of acetohydroxy acid synthase I. These results are discussed in terms of a report (C.A. Hauser and G.W. Hatfield, Proc. Natl. Acad. Sci. U.S.A. 81:76-79, 1984) which suggests that threonine and alanine, in addition to leucine and valine, are involved in the regulation of the ilvB operon.

  2. Fatty acid synthase cooperates with glyoxalase 1 to protect against sugar toxicity.

    Damien Garrido

    2015-02-01

    Full Text Available Fatty acid (FA metabolism is deregulated in several human diseases including metabolic syndrome, type 2 diabetes and cancers. Therefore, FA-metabolic enzymes are potential targets for drug therapy, although the consequence of these treatments must be precisely evaluated at the organismal and cellular levels. In healthy organism, synthesis of triacylglycerols (TAGs-composed of three FA units esterified to a glycerol backbone-is increased in response to dietary sugar. Saturation in the storage and synthesis capacity of TAGs is associated with type 2 diabetes progression. Sugar toxicity likely depends on advanced-glycation-end-products (AGEs that form through covalent bounding between amine groups and carbonyl groups of sugar or their derivatives α-oxoaldehydes. Methylglyoxal (MG is a highly reactive α-oxoaldehyde that is derived from glycolysis through a non-enzymatic reaction. Glyoxalase 1 (Glo1 works to neutralize MG, reducing its deleterious effects. Here, we have used the power of Drosophila genetics to generate Fatty acid synthase (FASN mutants, allowing us to investigate the consequence of this deficiency upon sugar-supplemented diets. We found that FASN mutants are lethal but can be rescued by an appropriate lipid diet. Rescued animals do not exhibit insulin resistance, are dramatically sensitive to dietary sugar and accumulate AGEs. We show that FASN and Glo1 cooperate at systemic and cell-autonomous levels to protect against sugar toxicity. We observed that the size of FASN mutant cells decreases as dietary sucrose increases. Genetic interactions at the cell-autonomous level, where glycolytic enzymes or Glo1 were manipulated in FASN mutant cells, revealed that this sugar-dependent size reduction is a direct consequence of MG-derived-AGE accumulation. In summary, our findings indicate that FASN is dispensable for cell growth if extracellular lipids are available. In contrast, FA-synthesis appears to be required to limit a cell

  3. Cloning and characterization of novel methylsalicylic acid synthase gene involved in the biosynthesis of isoasperlactone and asperlactone in Aspergillus westerdijkiae

    Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298 bp polyketide synthase gene ''aomsas'' has been cloned in Aspergillus westerdijkiae by using gene walking approach and RACE-PCR. The predicted amino acid sequence of aomsas shows an identity of 40-56% with different methylsalicylic acid synthase genes found in Byssochlamys nivea, P. patulum, A. terreus and Streptomyces viridochromogenes. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aomsas expression was found to be associated with the biosynthesis of isoasperlactone and asperlactone. Moreover an aomsas knockout mutant ''aomsas'' of A. westerdijkiae, not only lost the capacity to produce isoasperlactone and asperlactone, but also 6-methylsalicylic acid. The genetically complemented mutant aomsas restored the biosynthesis of all the missing metabolites. Chemical complementation through the addition of 6-methylsalicylic acid, aspyrone and diepoxide to growing culture of aomsas mutant revealed that these compounds play intermediate roles in the biosynthesis of asperlactone and isoasperlactone. (author)

  4. Biochemistry: Acetohydroxyacid Synthase

    Pham Ngoc Chien

    2010-02-01

    Full Text Available Acetohydroxyacid synthase (AHAS, EC 2.2.1.6; formerly known as acetolactate synthase, ALS is a thiamin-and FAD-dependent enzyme which catalyses the first common step in the biosynthesis of the branched-chain amino acids (BCAA isoleucine, leucine and valine. The enzyme is inhibited by several commercial herbicides and has been studied over the last 20 to 30 years. A short introductory note about acetohydroxyacid synthase has been provided.

  5. Biosynthesis of Dictyostelium discoideum differentiation-inducing factor by a hybrid type I fatty acid-type III polyketide synthase.

    Austin, Michael B; Saito, Tamao; Bowman, Marianne E; Haydock, Stephen; Kato, Atsushi; Moore, Bradley S; Kay, Robert R; Noel, Joseph P

    2006-09-01

    Differentiation-inducing factors (DIFs) are well known to modulate formation of distinct communal cell types from identical Dictyostelium discoideum amoebas, but DIF biosynthesis remains obscure. We report complimentary in vivo and in vitro experiments identifying one of two approximately 3,000-residue D. discoideum proteins, termed 'steely', as responsible for biosynthesis of the DIF acylphloroglucinol scaffold. Steely proteins possess six catalytic domains homologous to metazoan type I fatty acid synthases (FASs) but feature an iterative type III polyketide synthase (PKS) in place of the expected FAS C-terminal thioesterase used to off load fatty acid products. This new domain arrangement likely facilitates covalent transfer of steely N-terminal acyl products directly to the C-terminal type III PKS active sites, which catalyze both iterative polyketide extension and cyclization. The crystal structure of a steely C-terminal domain confirms conservation of the homodimeric type III PKS fold. These findings suggest new bioengineering strategies for expanding the scope of fatty acid and polyketide biosynthesis. PMID:16906151

  6. Tobacco streak virus (strain dahlia) suppresses post-transcriptional gene silencing of flavone synthase II in black dahlia cultivars and causes a drastic flower color change.

    Deguchi, Ayumi; Tatsuzawa, Fumi; Hosokawa, Munetaka; Doi, Motoaki; Ohno, Sho

    2015-01-01

    Tobacco streak virus suppressed post-transcriptional gene silencing and caused a flower color change in black dahlias, which supported the role of cyanidin-based anthocyanins for black flower appearance. Black flower color of dahlia (Dahlia variabilis) has been attributed, in part, to the high accumulation of cyanidin-based anthocyanins that occurs when flavone synthesis is reduced because of post-transcriptional gene silencing (PTGS) of flavone synthase II (DvFNS). There are also purple-flow...

  7. Chronic Ultraviolet B Irradiation Causes Loss of Hyaluronic Acid from Mouse Dermis Because of Down-Regulation of Hyaluronic Acid Synthases

    Dai, Guang; Freudenberger, Till; Zipper, Petra; Melchior, Ariane; Grether-Beck, Susanne; Rabausch, Berit; de Groot, Jens; Twarock, Sören; Hanenberg, Helmut; Homey, Bernhard; Krutmann, Jean; Reifenberger, Julia; Fischer, Jens W.

    2007-01-01

    Remodeling of the dermal extracellular matrix occurs during photoaging. Here, the effect of repetitive UVB irradiation on dermal hyaluronic acid (HA) was examined. C57/BL6 mice were chronically (182 days) irradiated with UVB, and consecutive skin biopsies were collected during the irradiation period and afterward (300 and 400 days of age). UVB caused marked loss of HA from the papillary dermis and down-regulation of HA synthase 1 (HAS1), HAS2, and HAS3 mRNA expression. In contrast, hyaluronid...

  8. Trans-chalcone and quercetin down-regulate fatty acid synthase gene expression and reduce ergosterol content in the human pathogenic dermatophyte Trichophyton rubrum

    Bitencourt, Tamires Aparecida; Komoto, Tatiana Takahasi; Massaroto, Bruna Gabriele; Miranda, Carlos Eduardo Saraiva; Beleboni, Rene Oliveira; Marins, Mozart; Fachin, Ana Lúcia

    2013-01-01

    Background Fatty acid synthase (FAS) is a promising antifungal target due to its marked structural differences between fungal and mammalian cells. The aim of this study was to evaluate the antifungal activity of flavonoids described in the scientific literature as FAS inhibitors (quercetin, trans-chalcone, ellagic acid, luteolin, galangin, and genistein) against the dermatophyte Trichophyton rubrum and their effects on fatty acid and ergosterol synthesis. Methods The antifungal activity of th...

  9. Inducible nitric oxide synthase links NF-κB to PGE2 in polyunsaturated fatty acid altered fibroblast in-vitro wound healing

    Turek John J; Jia Yi

    2005-01-01

    Abstract Background This study investigated mechanisms of altered fibroblast collagen production induced by polyunsaturated fatty acids. 3T3-Swiss fibroblasts were grown in medium containing either eicosapentaenoic or arachidonic acid. The effects of nuclear factor-kappaB activation by lipopolysaccharide on inducible nitric oxide synthase, nitric oxide, prostaglandin E2, collagen production, and in-vitro wound healing were studied. Results Eicosapentaenoic acid treated cells produced less pro...

  10. Fatty acid synthase plays a role in cancer metabolism beyond providing fatty acids for phospholipid synthesis or sustaining elevations in glycolytic activity

    Hopperton, Kathryn E., E-mail: kathryn.hopperton@mail.utoronto.ca [Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2 (Canada); Duncan, Robin E., E-mail: robin.duncan@uwaterloo.ca [Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2 (Canada); Bazinet, Richard P., E-mail: richard.bazinet@utoronto.ca [Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2 (Canada); Archer, Michael C., E-mail: m.archer@utoronto.ca [Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2 (Canada); Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 3E2 (Canada)

    2014-01-15

    Fatty acid synthase is over-expressed in many cancers and its activity is required for cancer cell survival, but the role of endogenously synthesized fatty acids in cancer is unknown. It has been suggested that endogenous fatty acid synthesis is either needed to support the growth of rapidly dividing cells, or to maintain elevated glycolysis (the Warburg effect) that is characteristic of cancer cells. Here, we investigate both hypotheses. First, we compared utilization of fatty acids synthesized endogenously from {sup 14}C-labeled acetate to those supplied exogenously as {sup 14}C-labeled palmitate in the culture medium in human breast cancer (MCF-7 and MDA-MB-231) and untransformed breast epithelial cells (MCF-10A). We found that cancer cells do not produce fatty acids that are different from those derived from exogenous palmitate, that these fatty acids are esterified to the same lipid and phospholipid classes in the same proportions, and that their distribution within neutral lipids is not different from untransformed cells. These results suggest that endogenously synthesized fatty acids do not fulfill a specific function in cancer cells. Furthermore, we observed that cancer cells excrete endogenously synthesized fatty acids, suggesting that they are produced in excess of requirements. We next investigated whether lipogenic activity is involved in the maintenance of high glycolytic activity by culturing both cancer and non-transformed cells under anoxic conditions. Although anoxia increased glycolysis 2–3 fold, we observed no concomitant increase in lipogenesis. Our results indicate that breast cancer cells do not have a specific qualitative or quantitative requirement for endogenously synthesized fatty acids and that increased de novo lipogenesis is not required to sustain elevations in glycolytic activity induced by anoxia in these cells. - Highlights: • Fatty acid synthase (FASN) is over-expressed in cancer but its function is unknown. • We compare

  11. Fatty acid synthase plays a role in cancer metabolism beyond providing fatty acids for phospholipid synthesis or sustaining elevations in glycolytic activity

    Fatty acid synthase is over-expressed in many cancers and its activity is required for cancer cell survival, but the role of endogenously synthesized fatty acids in cancer is unknown. It has been suggested that endogenous fatty acid synthesis is either needed to support the growth of rapidly dividing cells, or to maintain elevated glycolysis (the Warburg effect) that is characteristic of cancer cells. Here, we investigate both hypotheses. First, we compared utilization of fatty acids synthesized endogenously from 14C-labeled acetate to those supplied exogenously as 14C-labeled palmitate in the culture medium in human breast cancer (MCF-7 and MDA-MB-231) and untransformed breast epithelial cells (MCF-10A). We found that cancer cells do not produce fatty acids that are different from those derived from exogenous palmitate, that these fatty acids are esterified to the same lipid and phospholipid classes in the same proportions, and that their distribution within neutral lipids is not different from untransformed cells. These results suggest that endogenously synthesized fatty acids do not fulfill a specific function in cancer cells. Furthermore, we observed that cancer cells excrete endogenously synthesized fatty acids, suggesting that they are produced in excess of requirements. We next investigated whether lipogenic activity is involved in the maintenance of high glycolytic activity by culturing both cancer and non-transformed cells under anoxic conditions. Although anoxia increased glycolysis 2–3 fold, we observed no concomitant increase in lipogenesis. Our results indicate that breast cancer cells do not have a specific qualitative or quantitative requirement for endogenously synthesized fatty acids and that increased de novo lipogenesis is not required to sustain elevations in glycolytic activity induced by anoxia in these cells. - Highlights: • Fatty acid synthase (FASN) is over-expressed in cancer but its function is unknown. • We compare utilization of

  12. The Mycobacterium tuberculosis FAS-II dehydratases and methyltransferases define the specificity of the mycolic acid elongation complexes.

    Sylvain Cantaloube

    Full Text Available BACKGROUND: The human pathogen Mycobacterium tuberculosis (Mtb has the originality of possessing a multifunctional mega-enzyme FAS-I (Fatty Acid Synthase-I, together with a multi-protein FAS-II system, to carry out the biosynthesis of common and of specific long chain fatty acids: the mycolic acids (MA. MA are the main constituents of the external mycomembrane that represents a tight permeability barrier involved in the pathogenicity of Mtb. The MA biosynthesis pathway is essential and contains targets for efficient antibiotics. We have demonstrated previously that proteins of FAS-II interact specifically to form specialized and interconnected complexes. This finding suggested that the organization of FAS-II resemble to the architecture of multifunctional mega-enzyme like the mammalian mFAS-I, which is devoted to the fatty acid biosynthesis. PRINCIPAL FINDINGS: Based on conventional and reliable studies using yeast-two hybrid, yeast-three-hybrid and in vitro Co-immunoprecipitation, we completed here the analysis of the composition and architecture of the interactome between the known components of the Mtb FAS-II complexes. We showed that the recently identified dehydratases HadAB and HadBC are part of the FAS-II elongation complexes and may represent a specific link between the core of FAS-II and the condensing enzymes of the system. By testing four additional methyltransferases involved in the biosynthesis of mycolic acids, we demonstrated that they display specific interactions with each type of complexes suggesting their coordinated action during MA elongation. SIGNIFICANCE: These results provide a global update of the architecture and organization of a FAS-II system. The FAS-II system of Mtb is organized in specialized interconnected complexes and the specificity of each elongation complex is given by preferential interactions between condensing enzymes and dehydratase heterodimers. This study will probably allow defining essential and

  13. Role of Plant Fatty acid Elongase (3 keto acyl-CoA Synthase gene in Cuticular Wax Biosynthesis

    Uppala Lokesh

    2013-12-01

    Full Text Available Plant surfaces are ensheathed by cuticular wax, amorphous intra-cuticular embedded in cutin polymer and crystalloid epi-cuticular that imparts a whitish appearance, confers drought resistance by reducing stomatal transpiration and also protects from U.V Radiation, phytophagous insects etc. Very long chain fatty acids acts as precursors for cuticular wax bio-synthesis. Wax bio-synthesis begins with fatty acid synthesis in the plastid (de novo synthesis of C16 and C18 and elongation of fatty acids in endoplasmic reticulum (C20 – C34 by four distinct enzymes 3-ketoacyl-CoA synthase, 3-ketoacyl-CoA reductase, 3-hydroxacyl-CoA dehydratase, trans-2,3-enoyl-CoA reductase (KCS, KCR, HCD, ECR. The KCS, a fatty acid elongase, determines the chain length and substrate specificity of the condensation reaction, a rate limiting step and the subsequent elongated products alkanes, aldehydes, primary alcohols, secondary alcohols, ketones and wax esters. 21 KCS genes were annotated in Arabidopsis thaliana Genome of which some KCSs were identified involved in cuticle formation (CER6 (CUT1, KCS1, KCS2, (DAISY, KCS20 and FDH.The current review will focus on the bio-chemical, genetic and molecular approaches on KCSs genes, predominantly KCS1 in plants particularly useful in identifying and characterizing gene products involved in wax bio-synthesis, secretion and function for developing transgenic crops that combat various stresses. INTRODUCTION

  14. Direct Channeling of Retinoic Acid between Cellular Retinoic Acid-Binding Protein II and Retinoic Acid Receptor Sensitizes Mammary Carcinoma Cells to Retinoic Acid-Induced Growth Arrest

    Budhu, Anuradha S.; Noy, Noa

    2002-01-01

    Cellular retinoic acid-binding protein II (CRABP-II) is an intracellular lipid-binding protein that associates with retinoic acid with a subnanomolar affinity. We previously showed that CRABP-II enhances the transcriptional activity of the nuclear receptor with which it shares a common ligand, namely, the retinoic acid receptor (RAR), and we suggested that it may act by delivering retinoic acid to this receptor. Here, the mechanisms underlying the effects of CRABP-II on the transcriptional ac...

  15. Monoterpene synthases from common sage (Salvia officinalis)

    Croteau, Rodney Bruce (Pullman, WA); Wise, Mitchell Lynn (Pullman, WA); Katahira, Eva Joy (Pullman, WA); Savage, Thomas Jonathan (Christchurch 5, NZ)

    1999-01-01

    cDNAs encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase from common sage (Salvia officinalis) have been isolated and sequenced, and the corresponding amino acid sequences has been determined. Accordingly, isolated DNA sequences (SEQ ID No:1; SEQ ID No:3 and SEQ ID No:5) are provided which code for the expression of (+)-bornyl diphosphate synthase (SEQ ID No:2), 1,8-cineole synthase (SEQ ID No:4) and (+)-sabinene synthase SEQ ID No:6), respectively, from sage (Salvia officinalis). In other aspects, replicable recombinant cloning vehicles are provided which code for (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase, or for a base sequence sufficiently complementary to at least a portion of (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant monoterpene synthases that may be used to facilitate their production, isolation and purification in significant amounts. Recombinant (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase may be used to obtain expression or enhanced expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase in plants in order to enhance the production of monoterpenoids, or may be otherwise employed for the regulation or expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase, or the production of their products.

  16. Effect of amino acids on the interaction between cobalamin(II) and dehydroascorbic acid

    Dereven'kov, I. A.; Thi, Thu Thuy Bui; Salnikov, D. S.; Makarov, S. V.

    2016-03-01

    The kinetics of the reaction between one-electron-reduced cobalamin (cobalamin(II), Cb(II)) and the two-electron-oxidized form of vitamin C (dehydroascorbic acid, DHA) with amino acids in an acidic medium is studied by conventional UV-Vis spectroscopy. It is shown that the oxidation of Cbl(II) by dehydroascorbic acid proceeds only in the presence of sulfur-containing amino acids (cysteine, acetylcysteine). A proposed reaction mechanism includes the step of amino acid coordination on the Co(II)-center through the sulfur atom, along with that of the interaction between this complex and DHA molecules, which results in the formation of ascorbyl radical and the corresponding Co(III) thiolate complex.

  17. Human apolipoprotein C-II: complete nucleic acid sequence of preapolipoprotein C-II.

    Fojo, S S; Law, S W; Brewer, H B

    1984-01-01

    Apolipoprotein (apo) C-II is a cofactor for lipoprotein lipase, the enzyme that catalyzes the hydrolysis of triglycerides on plasma triglyceride-rich lipoproteins. The complete coding sequence of apoC-II mRNA has been determined from an apoC-II clone isolated from a human liver cDNA library. A 17-base-long synthetic oligonucleotide based on amino acid residues 5-10 of apoC-II was utilized as a hybridization probe to select recombinant plasmids containing the apoC-II sequence. Two thousand fou...

  18. Elevated expression of fatty acid synthase and nuclear localization of carnitine palmitoyltransferase 1C are common among human gliomas.

    Wakamiya, Tomihiro; Suzuki, Satoshi O; Hamasaki, Hideomi; Honda, Hiroyuki; Mizoguchi, Masahiro; Yoshimoto, Koji; Iwaki, Toru

    2014-10-01

    Fatty acid synthase (FASN) and carnitine palmitoyltransferase 1C (CPT1C), a brain-specific isoform of the CPT1 family, are upregulated in certain types of cancers, including gliomas. Acetyl-CoA carboxylase (ACC) catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, the rate-limiting step in fatty acid synthesis, and its phosphorylated form inhibits lipid synthesis. We examined the expression and subcellular localization of these fatty acid metabolism-related molecules in human gliomas. We performed immunostaining of two glioma cell lines (U373MG and U87MG) and 41 surgical specimens of diffuse gliomas with various histological grades (21 with the isocitrate dehydrogenase 1(IDH1) R132H mutation and 20 without the mutation). In the cultured glioma cells, CPT1C and phosphorylated ACC (p-ACC) were mainly localized to the nuclei, whereas FASN localized to the cytoplasm. In the surgical specimens, most glioma tissues showed nuclear staining for CPT1C and p-ACC, and cytoplasmic staining for FASN, regardless of the genetic status of IDH1 and the histological grade. Therefore, elevated cytoplasmic expression of FASN and nuclear localization of CPT1C are common among human diffuse gliomas, which may be regulated by the differential phosphorylation status of ACC in the cellular compartment. PMID:24984811

  19. Δ9-Tetrahydrocannabinolic acid synthase: The application of a plant secondary metabolite enzyme in biocatalytic chemical synthesis.

    Lange, Kerstin; Schmid, Andreas; Julsing, Mattijs K

    2016-09-10

    Δ(9)-Tetrahydrocannabinolic acid synthase (THCAS) from the secondary metabolism of Cannabis sativa L. catalyzes the oxidative formation of an intramolecular CC bond in cannabigerolic acid (CBGA) to synthesize Δ(9)-tetrahydrocannabinolic acid (THCA), which is the direct precursor of Δ(9)-tetrahydrocannabinol (Δ(9)-THC). Aiming on a biotechnological production of cannabinoids, we investigated the potential of the heterologously produced plant oxidase in a cell-free system on preparative scale. THCAS was characterized in an aqueous/organic two-liquid phase setup in order to solubilize the hydrophobic substrate and to allow in situ product removal. Compared to the single phase aqueous setup the specific activity decreased by a factor of approximately 2 pointing to a substrate limitation of CBGA in the two-liquid phase system. However, the specific activity remained stable for at least 3h illustrating the benefit of the two-liquid phase setup. In a repeated-batch setup, THCAS showed only a minor loss of specific activity in the third batch pointing to a high intrinsic stability and high solvent tolerance of the enzyme. Maximal space-time-yields of 0.121gL(-1)h(-1) were reached proving the two-liquid phase concept suitable for biotechnological production of cannabinoids. PMID:27369551

  20. Fatty acid synthase as a factor required for exercise-induced cognitive enhancement and dentate gyrus cellular proliferation.

    Nataliya E Chorna

    Full Text Available Voluntary running is a robust inducer of adult hippocampal neurogenesis. Given that fatty acid synthase (FASN, the key enzyme for de novo fatty acid biosynthesis, is critically involved in proliferation of embryonic and adult neural stem cells, we hypothesized that FASN could mediate both exercise-induced cell proliferation in the subgranular zone (SGZ of the dentate gyrus (DG and enhancement of spatial learning and memory. In 20 week-old male mice, voluntary running-induced hippocampal-specific upregulation of FASN was accompanied also by hippocampal-specific accumulation of palmitate and stearate saturated fatty acids. In experiments addressing the functional role of FASN in our experimental model, chronic intracerebroventricular (i.c.v. microinfusions of C75, an irreversible FASN inhibitor, and significantly impaired exercise-mediated improvements in spatial learning and memory in the Barnes maze. Unlike the vehicle-injected mice, the C75 group adopted a non-spatial serial escape strategy and displayed delayed escape latencies during acquisition and memory tests. Furthermore, pharmacologic blockade of FASN function with C75 resulted in a significant reduction, compared to vehicle treated controls, of the number of proliferative cells in the DG of running mice as measured by immunoreactive to Ki-67 in the SGZ. Taken together, our data suggest that FASN plays an important role in exercise-mediated cognitive enhancement, which might be associated to its role in modulating exercise-induced stimulation of neurogenesis.

  1. In Silico Structure Prediction of Human Fatty Acid Synthase-Dehydratase: A Plausible Model for Understanding Active Site Interactions.

    John, Arun; Umashankar, Vetrivel; Samdani, A; Sangeetha, Manoharan; Krishnakumar, Subramanian; Deepa, Perinkulam Ravi

    2016-01-01

    Fatty acid synthase (FASN, UniProt ID: P49327) is a multienzyme dimer complex that plays a critical role in lipogenesis. Consequently, this lipogenic enzyme has gained tremendous biomedical importance. The role of FASN and its inhibition is being extensively researched in several clinical conditions, such as cancers, obesity, and diabetes. X-ray crystallographic structures of some of its domains, such as β-ketoacyl synthase, acetyl transacylase, malonyl transacylase, enoyl reductase, β-ketoacyl reductase, and thioesterase, (TE) are already reported. Here, we have attempted an in silico elucidation of the uncrystallized dehydratase (DH) catalytic domain of human FASN. This theoretical model for DH domain was predicted using comparative modeling methods. Different stand-alone tools and servers were used to validate and check the reliability of the predicted models, which suggested it to be a highly plausible model. The stereochemical analysis showed 92.0% residues in favorable region of Ramachandran plot. The initial physiological substrate β-hydroxybutyryl group was docked into active site of DH domain using Glide. The molecular dynamics simulations carried out for 20 ns in apo and holo states indicated the stability and accuracy of the predicted structure in solvated condition. The predicted model provided useful biochemical insights into the substrate-active site binding mechanisms. This model was then used for identifying potential FASN inhibitors using high-throughput virtual screening of the National Cancer Institute database of chemical ligands. The inhibitory efficacy of the top hit ligands was validated by performing molecular dynamics simulation for 20 ns, where in the ligand NSC71039 exhibited good enzyme inhibition characteristics and exhibited dose-dependent anticancer cytotoxicity in retinoblastoma cancer cells in vitro. PMID:27559295

  2. Geranyl diphosphate synthase from mint

    Croteau, Rodney Bruce; Wildung, Mark Raymond; Burke, Charles Cullen; Gershenzon, Jonathan

    1999-01-01

    A cDNA encoding geranyl diphosphate synthase from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID No:1) is provided which codes for the expression of geranyl diphosphate synthase (SEQ ID No:2) from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase or for a base sequence sufficiently complementary to at least a portion of the geranyl diphosphate synthase DNA or RNA to enable hybridization therewith (e.g., antisense geranyl diphosphate synthase RNA or fragments of complementary geranyl diphosphate synthase DNA which are useful as polymerase chain reaction primers or as probes for geranyl diphosphate synthase or related genes). In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase that may be used to facilitate the production, isolation and purification of significant quantities of recombinant geranyl diphosphate synthase for subsequent use, to obtain expression or enhanced expression of geranyl diphosphate synthase in plants in order to enhance the production of monoterpenoids, to produce geranyl diphosphate in cancerous cells as a precursor to monoterpenoids having anti-cancer properties or may be otherwise employed for the regulation or expression of geranyl diphosphate synthase or the production of geranyl diphosphate.

  3. Geranyl diphosphate synthase from mint

    Croteau, R.B.; Wildung, M.R.; Burke, C.C.; Gershenzon, J.

    1999-03-02

    A cDNA encoding geranyl diphosphate synthase from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID No:1) is provided which codes for the expression of geranyl diphosphate synthase (SEQ ID No:2) from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase or for a base sequence sufficiently complementary to at least a portion of the geranyl diphosphate synthase DNA or RNA to enable hybridization therewith (e.g., antisense geranyl diphosphate synthase RNA or fragments of complementary geranyl diphosphate synthase DNA which are useful as polymerase chain reaction primers or as probes for geranyl diphosphate synthase or related genes). In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase that may be used to facilitate the production, isolation and purification of significant quantities of recombinant geranyl diphosphate synthase for subsequent use, to obtain expression or enhanced expression of geranyl diphosphate synthase in plants in order to enhance the production of monoterpenoids, to produce geranyl diphosphate in cancerous cells as a precursor to monoterpenoids having anti-cancer properties or may be otherwise employed for the regulation or expression of geranyl diphosphate synthase or the production of geranyl diphosphate. 5 figs.

  4. SFH2 regulates fatty acid synthase activity in the yeast Saccharomyces cerevisiae and is critical to prevent saturated fatty acid accumulation in response to haem and oleic acid depletion.

    Desfougères, Thomas; Ferreira, Thierry; Bergès, Thierry; Régnacq, Matthieu

    2008-01-01

    The yeast Saccharomyces cerevisiae is a facultative anaerobic organism. Under anaerobiosis, sustained growth relies on the presence of exogenously supplied unsaturated fatty acids and ergosterol that yeast is unable to synthesize in the absence of oxygen or upon haem depletion. In the absence of exogenous supplementation with unsaturated fatty acid, a net accumulation of SFA (saturated fatty acid) is observed that induces significant modification of phospholipid profile [Ferreira, Régnacq, Alimardani, Moreau-Vauzelle and Bergès (2004) Biochem. J. 378, 899-908]. In the present paper, we focus on the role of SFH2/CSR1, a hypoxic gene related to SEC14 and its involvement in lipid metabolism upon haem depletion in the absence of oleic acid supplementation. We observed that inactivation of SFH2 results in enhanced accumulation of SFA and phospholipid metabolism alterations. It results in premature growth arrest and leads to an exacerbated sensitivity to exogenous SFA. This phenotype is suppressed in the presence of exogenous oleic acid, or by a controlled expression of FAS1, one of the two genes encoding FAS. We present several lines of evidence to suggest that Sfh2p and oleic acid regulate SFA synthase in yeast at different levels: whereas oleic acid acts on FAS2 at the transcriptional level, we show that Sfh2p inhibits fatty acid synthase activity in response to haem depletion. PMID:17803462

  5. Jinggangmycin increases fecundity of the brown planthopper, Nilaparvata lugens (Stål) via fatty acid synthase gene expression.

    Li, Lei; Jiang, Yiping; Liu, Zongyu; You, Linlin; Wu, You; Xu, Bing; Ge, Linquan; Stanley, David; Song, Qisheng; Wu, Jincai

    2016-01-01

    The antibiotic jinggangmycin (JGM) is mainly used in controlling the rice sheath blight, Rhizoctonia solani, in China. JGM also enhances reproduction of the brown planthopper (BPH), Nilaparvata lugens (Stål). To date, however, molecular mechanisms of the enhancement are unclear. Our related report documented the influence of foliar JGM sprays on ovarian protein content. Here, we used isobaric tags for relative and absolute quantitation (iTRAQ) protocols to analyze ovarian proteins of BPH females following JGM spray (JGM-S) and topical application (JGM-T). We recorded changes in expression of 284 proteins (142↑ and 142↓) in JGM-S compared to the JGM-S control group (S-control); 267 proteins were differentially expressed (130↑ and 137↓) in JGM-T compared to the JGM-T control group (T-control), of which, 22 proteins were up-regulated in both groups. Comparing the JGM-S to the JGM-T group, 114 proteins were differentially expressed (62↑ and 52↓). Based on the biological significance of fatty acids, pathway annotation and enrichment analysis, we designed a dsRNA construct to silence a gene encoding fatty acid synthase (FAS). FAS was more highly expressed in JGM-S vs S-control and JGM-S vs JGM-T groups. The dsFAS treatment reduced fecundity by about 46% and reduced ovarian and fat body fatty acid concentrations in JGM-S-treated females relative to controls. We infer FAS provides critically needed fatty acids to support JGM-enhanced fecundity in BPH. PMID:26388431

  6. Increased expression of fatty acid synthase and acetyl-CoA carboxylase in the prefrontal cortex and cerebellum in the valproic acid model of autism

    Chen, Jianling; Wu, Wei; Fu, Yingmei; Yu, Shunying; Cui, Donghong; Zhao, Min; Du, Yasong; Li, Jijun; Li, Xiaohong

    2016-01-01

    The primary aim of the present study was to investigate alterations in enzymes associated with fatty acid synthesis, namely fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC), in the prefrontal cortex and cerebellum of the valproic acid (VPA)-induced animal model of autism. In this model, pregnant rats were given a single intraperitoneal injection of VPA, and prefrontal cortex and cerebellum samples from their pups were analyzed. The results of western blotting and reverse transcription-quantitative polymerase chain reaction analyses demonstrated that the protein and mRNA expression levels of FASN, ACC and phospho-ACC (pACC) were increased in the prefrontal cortex and cerebellum of the VPA model of autism. Furthermore, in the prefrontal cortex and cerebellum of the VPA model of autism, AMPK expression is increased, whereas PI3K and Akt expression are unchanged. This suggests that disorder of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/FASN and/or adenosine 5′-monophosphate-activated protein kinase (AMPK)/ACC pathway may be involved in the pathogenesis of autism. It is hypothesized that fatty acid synthesis participates in autism through PI3K/Akt/FASN and AMPK/ACC pathways. PMID:27602061

  7. Uptake of palmitic acid by rabbit alveolar type II cells

    Alveolar type II cells require a source of palmitic acid for synthesis of dipalmitoyl phosphatidylcholine (DPPC), a major constituent of pulmonary surfactant. Previous studies indicated that maximal rates of DPPC synthesis are achieved only if exogenous palmitate is available to the type II cell. Little is known of the mechanisms by which fatty acids enter type II cells. To determine if uptake is mediated by a membrane carrier system, as described in other cell types, we examined the kinetics of palmitate uptake. Using freshly isolated rabbit type II cells, we demonstrated that radiolabeled palmitate uptake was maximal and linear for 45 s; after 1 min the apparent rate of uptake declined. The initial uptake phase was taken as a measure of cellular fatty acid influx because intracellular radiolabeled palmitate remained 80% nonesterified at this time but was 55% esterified by 2 min. Cellular influx of palmitate showed saturation kinetics with increasing concentration of nonalbumin bound palmitate. Michaelis constant was 52.6 nM, and maximum velocity was 152 pmol.10(6) cells-1.min-1. The hypothesis that saturable cellular influx of palmitate is likely linked to the previously identified membrane fatty acid binding protein (MFABP) was supported by Western-blot analysis of rat lung tissue with an antibody to MFABP that demonstrated the presence of this carrier protein in lung tissue. These data suggest that palmitate uptake by type II cells is saturable and may be mediated by a membrane-associated carrier as described in other cell types

  8. Insulin-like growth factor-II, phosphatidylinositol 3-kinase, nuclear factor-kappaB and inducible nitric-oxide synthase define a common myogenic signaling pathway.

    Kaliman, P; Canicio, J; Testar, X; Palacín, M; Zorzano, A

    1999-06-18

    Insulin-like growth factors (IGFs) are potent inducers of skeletal muscle differentiation and phosphatidylinositol (PI) 3-kinase activity is essential for this process. Here we show that IGF-II induces nuclear factor-kappaB (NF-kappaB) and nitric-oxide synthase (NOS) activities downstream from PI 3-kinase and that these events are critical for myogenesis. Differentiation of rat L6E9 myoblasts with IGF-II transiently induced NF-kappaB DNA binding activity, inducible nitric-oxide synthase (iNOS) expression, and nitric oxide (NO) production. IGF-II-induced iNOS expression and NO production were blocked by NF-kappaB inhibition. Both NF-kappaB and NOS activities were essential for IGF-II-induced terminal differentiation (myotube formation and expression of skeletal muscle proteins: myosin heavy chain, GLUT 4, and caveolin 3), which was totally blocked by NF-kappaB or NOS inhibitors in rat and human myoblasts. Moreover, the NOS substrate L-Arg induced myogenesis in the absence of IGFs in both rat and human myoblasts, and this effect was blocked by NOS inhibition. Regarding the mechanisms involved in IGF-II activation of NF-kappaB, PI 3-kinase inhibition prevented NF-kappaB activation, iNOS expression, and NO production. Moreover, IGF-II induced, through a PI 3-kinase-dependent pathway, a decrease in IkappaB-alpha protein content that correlated with a decrease in the amount of IkappaB-alpha associated with p65 NF-kappaB. PMID:10364173

  9. Inhibition of small G proteins of the Rho family by statins or Clostridium difficile toxin B enhances cytokine-mediated induction of NO synthase II

    Hausding, Michael; Witteck, Andrea; Rodriguez-Pascual, Fernando; von Eichel-Streiber, Christian; Förstermann, Ulrich; Kleinert, Hartmut

    2000-01-01

    In order to investigate the involvement of Ras and/or Rho proteins in the induction of the inducible isoform of nitric oxide synthase (NOS II) we used HMG-CoA reductase inhibitors (statins) and Clostridium difficile toxin B (TcdB) as pharmacological tools. Statins indirectly inhibit small G proteins by preventing their essential farnesylation (Ras) and/or geranylgeranylation (Rho). In contrast, TcdB is a glucosyltransferase and inactivates Rho-proteins directly.Human A549/8- and DLD-1 cells a...

  10. S-2-amino-5-(2-nitroimidazol-1-yl)pentanoic acid: a model for potential bioreductively activated prodrugs for inhibitors of nitric oxide synthase (NOS) activity.

    Ulhaq, S; Naylor, M A; Chinje, E C; Threadgill, M D; Stratford, I J

    1997-01-01

    Treatment of 1,1-dimethylethyl S-(2-1,1-dimethylethoxycarbonylamino)-5-bromopentanoate with 1-potassio-2-nitroimidazole, followed by deprotection, afforded S-2-amino-5-(2-nitroimidazol-1-yl)pentanoic acid, which was reduced to S-2-amino-5-(2-aminoimidazol-1-yl)pentanoic acid. This aminoimadazole inhibited rat brain nitric oxide synthase (NOS) activity 3.2 times more potently than did the nitro analogue. Thus S-2-amino-5-(2-nitroimidazol-1-yl)pentanoic acid is a potent prodrug which may be bioreductively activated to a NOS inhibitor in hypoxic solid tumours. PMID:9051114

  11. EPOXYEICOSATRIENOIC ACID ANALOG ATTENUATES ANGIOTENSIN II HYPERTENSION AND KIDNEY INJURY

    Md. Abdul Hye Khan

    2014-09-01

    Full Text Available Epoxyeicosatrienoic acids (EETs contribute to blood pressure regulation leading to the concept that EETs can be therapeutically targeted for hypertension and the associated end-organ damage. In the present study, we investigated anti-hypertensive and kidney protective actions of an EET analog, EET-B in angiotensin II (ANG II-induced hypertension. EET-B was administered in drinking water for 14 days (10mg/kg/d and resulted in a decreased blood pressure elevation in ANG II hypertension. At the end of the two-week period, blood pressure was 30 mmHg lower in EET analog-treated ANG II hypertensive rats. The vasodilation of mesenteric resistance arteries to acetylcholine was impaired in ANG II hypertension; however, it was improved with EET-B treatment. Further, EET-B protected the kidney in ANG II hypertension as evidenced by a marked 90% decrease in albuminuria and 54% decrease in nephrinuria. Kidney histology demonstrated a decrease in renal tubular cast formation in EET analog-treated hypertensive rats. In ANG II hypertension, EET-B treatment markedly lowered renal inflammation. Urinary monocyte chemoattractant protein-1 excretion was decreased by 55% and kidney macrophage infiltration was reduced by 52% with EET-B treatment. Overall, our results demonstrate that EET-B has anti-hypertensive properties, improves vascular function, and decreases renal inflammation and injury in ANG II hypertension.

  12. Up-regulation of fatty acid synthase induced by EGFR/ERK activation promotes tumor growth in pancreatic cancer

    Bian, Yong, E-mail: drbiany@126.com [Department of Science and Technology, Nanjing University of Chinese Medicine, 210023 (China); Yu, Yun [College of Pharmacy, Nanjing University of Chinese Medicine, 210023 (China); Wang, Shanshan; Li, Lin [Department of Science and Technology, Nanjing University of Chinese Medicine, 210023 (China)

    2015-08-07

    Lipid metabolism is dysregulated in many human diseases including atherosclerosis, type 2 diabetes and cancers. Fatty acid synthase (FASN), a key lipogenic enzyme involved in de novo lipid biosynthesis, is significantly upregulated in multiple types of human cancers and associates with tumor progression. However, limited data is available to understand underlying biological functions and clinical significance of overexpressed FASN in pancreatic ductal adenocarcinoma (PDAC). Here, upregulated FASN was more frequently observed in PDAC tissues compared with normal pancreas in a tissue microarray. Kaplan–Meier survival analysis revealed that high expression level of FASN resulted in a significantly poor prognosis of PDAC patients. Knockdown or inhibition of endogenous FASN decreased cell proliferation and increased cell apoptosis in HPAC and AsPC-1 cells. Furthermore, we demonstrated that EGFR/ERK signaling accounts for elevated FASN expression in PDAC as ascertained by performing siRNA assays and using specific pharmacological inhibitors. Collectively, our results indicate that FASN exhibits important roles in tumor growth and EGFR/ERK pathway is responsible for upregulated expression of FASN in PDAC. - Highlights: • Increased expression of FASN indicates a poor prognosis in PDAC. • Elevated FASN favors tumor growth in PDAC in vitro. • Activation of EGFR signaling contributes to elevated FASN expression.

  13. Curcumin inhibits intracellular fatty acid synthase and induces apoptosis in human breast cancer MDA-MB-231 cells.

    Fan, Huijin; Liang, Yan; Jiang, Bing; Li, Xiabing; Xun, Hang; Sun, Jia; He, Wei; Lau, Hay Tong; Ma, Xiaofeng

    2016-05-01

    High levels of fatty acid synthase (FAS) expression have been found in many tumors, including prostate, breast, and ovarian cancers, and inhibition of FAS has been reported to obstruct tumor growth in vitro and in vivo. Curcumin is one of the major active ingredients of Curcuma longa, which has been proven to inhibit the growth of cancer cells. In the present study, we investigated the potential activity of curcumin as a FAS inhibitor for chemoprevention of breast cancer. As a result, curcumin induced human breast cancer MDA-MB-231 cell apoptosis with the half-inhibitory concentration value of 3.63 ± 0.26 µg/ml, and blocked FAS activity, expression and mRNA level in a dose-dependent manner. Curcumin also regulated B-cell lymphoma 2 (Bcl-2), Bax and p-Akt protein expression in MDA-MB-231 cells. Moreover, FAS knockdown showed similar effect as curcumin. All these results suggested that curcumin may induce cell apoptosis via inhibiting FAS. PMID:26985864

  14. Up-regulation of fatty acid synthase induced by EGFR/ERK activation promotes tumor growth in pancreatic cancer

    Lipid metabolism is dysregulated in many human diseases including atherosclerosis, type 2 diabetes and cancers. Fatty acid synthase (FASN), a key lipogenic enzyme involved in de novo lipid biosynthesis, is significantly upregulated in multiple types of human cancers and associates with tumor progression. However, limited data is available to understand underlying biological functions and clinical significance of overexpressed FASN in pancreatic ductal adenocarcinoma (PDAC). Here, upregulated FASN was more frequently observed in PDAC tissues compared with normal pancreas in a tissue microarray. Kaplan–Meier survival analysis revealed that high expression level of FASN resulted in a significantly poor prognosis of PDAC patients. Knockdown or inhibition of endogenous FASN decreased cell proliferation and increased cell apoptosis in HPAC and AsPC-1 cells. Furthermore, we demonstrated that EGFR/ERK signaling accounts for elevated FASN expression in PDAC as ascertained by performing siRNA assays and using specific pharmacological inhibitors. Collectively, our results indicate that FASN exhibits important roles in tumor growth and EGFR/ERK pathway is responsible for upregulated expression of FASN in PDAC. - Highlights: • Increased expression of FASN indicates a poor prognosis in PDAC. • Elevated FASN favors tumor growth in PDAC in vitro. • Activation of EGFR signaling contributes to elevated FASN expression

  15. Cloning and characterization of the gene encoding β-amyrin synthase in the glycyrrhizic acid biosynthetic pathway in Glycyrrhiza uralensis

    Honghao Chen

    2013-12-01

    Full Text Available Glycyrrhiza uralensis is considered to be one of the most important herbs in traditional Chinese medicine due to its numerous pharmacological effects particularly its ability to relieve cough and act as a mucolytic. Based on previous research, these effects are mediated by a number of active ingredients, especially glycyrrhizic acid (GA. In the present study, a gene encoding β-amyrin synthase (β-AS involved in GA biosynthesis in G. uralensis has been cloned and expressed in Saccharomyces cerevisiae. The cloned enzyme showed similar activity to native enzymes isolated from other Glycyrrhiza species to catalyze the conversion of 2,3-oxidosqualene into β-amyrin. In fact the β-AS gene is particularly important in the GA biosynthetic pathway in G. uralensis. The complete sequence of the enzyme was determined and a phylogenetic tree based on the β-AS gene of G. uralensis and 20 other species was created. This showed that Glycyrrhiza glabra had the closest kinship with G. uralensis. The results of this work will be useful in determining how to improve the efficacy of G. uralensis by improving its GA content and in exploring the biosynthesis of GA in vitro.

  16. Fatty Acid Synthase Cooperates with Glyoxalase 1 to Protect against Sugar Toxicity

    Damien Garrido; Thomas Rubin; Mickael Poidevin; Brigitte Maroni; Arnaud Le Rouzic; Jean-Philippe Parvy; Jacques Montagne

    2015-01-01

    Fatty acid (FA) metabolism is deregulated in several human diseases including metabolic syndrome, type 2 diabetes and cancers. Therefore, FA-metabolic enzymes are potential targets for drug therapy, although the consequence of these treatments must be precisely evaluated at the organismal and cellular levels. In healthy organism, synthesis of triacylglycerols (TAGs)-composed of three FA units esterified to a glycerol backbone-is increased in response to dietary sugar. Saturation in the storag...

  17. Involvement of Salicylic Acid on Antioxidant and Anticancer Properties, Anthocyanin Production and Chalcone Synthase Activity in Ginger (Zingiber officinale Roscoe) Varieties

    Ehsan Karimi; Jaafar, Hawa Z. E.; Ali Ghasemzadeh

    2012-01-01

    The effect of foliar application of salicylic acid (SA) at different concentrations (10−3 M and 10−5 M) was investigated on the production of secondary metabolites (flavonoids), chalcone synthase (CHS) activity, antioxidant activity and anticancer activity (against breast cancer cell lines MCF-7 and MDA-MB-231) in two varieties of Malaysian ginger, namely Halia Bentong and Halia Bara. The results of high performance liquid chromatography (HPLC) analysis showed that application of SA induced t...

  18. Acetohydroxy acid synthase I, a required enzyme for isoleucine and valine biosynthesis in Escherichia coli K-12 during growth on acetate as the sole carbon source.

    Dailey, F E; Cronan, J E

    1986-01-01

    Escherichia coli K-12 has two acetohydroxy acid synthase (AHAS) isozymes (AHAS I and AHAS III). Both of these isozymes catalyze the synthesis of alpha-aceto-alpha-hydroxybutyrate and alpha-acetolactate, which are key intermediates of the isoleucine-valine biosynthetic pathway. Strains lacking either isozyme but not both activities have been previously shown to grow well in minimal media in the absence of isoleucine and valine on any of several commonly used carbon sources (e.g., glucose or su...

  19. Comparison of backbone dynamics of the type III antifreeze protein and antifreeze-like domain of human sialic acid synthase

    Antifreeze proteins (AFPs) are found in a variety of cold-adapted (psychrophilic) organisms to promote survival at subzero temperatures by binding to ice crystals and decreasing the freezing temperature of body fluids. The type III AFPs are small globular proteins that consist of one α-helix, three 310-helices, and two β-strands. Sialic acids play important roles in a variety of biological functions, such as development, recognition, and cell adhesion and are synthesized by conserved enzymatic pathways that include sialic acid synthase (SAS). SAS consists of an N-terminal catalytic domain and a C-terminal antifreeze-like (AFL) domain, which is similar to the type III AFPs. Despite having very similar structures, AFL and the type III AFPs exhibit very different temperature-dependent stability and activity. In this study, we have performed backbone dynamics analyses of a type III AFP (HPLC12 isoform) and the AFL domain of human SAS (hAFL) at various temperatures. We also characterized the structural/dynamic properties of the ice-binding surfaces by analyzing the temperature gradient of the amide proton chemical shift and its correlation with chemical shift deviation from random coil. The dynamic properties of the two proteins were very different from each other. While HPLC12 was mostly rigid with a few residues exhibiting slow motions, hAFL showed fast internal motions at low temperature. Our results provide insight into the molecular basis of thermostability and structural flexibility in homologous psychrophilic HPLC12 and mesophilic hAFL proteins

  20. Comparison of backbone dynamics of the type III antifreeze protein and antifreeze-like domain of human sialic acid synthase

    Choi, Yong-Geun [Gyeongsang National University, Department of Chemistry and Research Institute of Natural Science (Korea, Republic of); Park, Chin-Ju [Gwangju Institute of Science and Technology, Division of Liberal Arts and Sciences and Department of Chemistry (Korea, Republic of); Kim, Hee-Eun; Seo, Yeo-Jin; Lee, Ae-Ree; Choi, Seo-Ree; Lee, Shim Sung; Lee, Joon-Hwa, E-mail: joonhwa@gnu.ac.kr [Gyeongsang National University, Department of Chemistry and Research Institute of Natural Science (Korea, Republic of)

    2015-02-15

    Antifreeze proteins (AFPs) are found in a variety of cold-adapted (psychrophilic) organisms to promote survival at subzero temperatures by binding to ice crystals and decreasing the freezing temperature of body fluids. The type III AFPs are small globular proteins that consist of one α-helix, three 3{sub 10}-helices, and two β-strands. Sialic acids play important roles in a variety of biological functions, such as development, recognition, and cell adhesion and are synthesized by conserved enzymatic pathways that include sialic acid synthase (SAS). SAS consists of an N-terminal catalytic domain and a C-terminal antifreeze-like (AFL) domain, which is similar to the type III AFPs. Despite having very similar structures, AFL and the type III AFPs exhibit very different temperature-dependent stability and activity. In this study, we have performed backbone dynamics analyses of a type III AFP (HPLC12 isoform) and the AFL domain of human SAS (hAFL) at various temperatures. We also characterized the structural/dynamic properties of the ice-binding surfaces by analyzing the temperature gradient of the amide proton chemical shift and its correlation with chemical shift deviation from random coil. The dynamic properties of the two proteins were very different from each other. While HPLC12 was mostly rigid with a few residues exhibiting slow motions, hAFL showed fast internal motions at low temperature. Our results provide insight into the molecular basis of thermostability and structural flexibility in homologous psychrophilic HPLC12 and mesophilic hAFL proteins.

  1. Metal Zn(II), Cu(II), Ni (II) complexes of ursodeoxycholic acid as putative anticancer agents

    Dyakova, Lora; Culita, Daniela-Cristina; Marinescu, Gabriela; Alexandrov, Marin; Kalfin, Reni; Patron, Luminita; Alexandrova, Radostina

    2014-01-01

    The aim of the study was to evaluate the influence of metal [Zn(II), Cu(II), Ni(II)] complexes with ursodeoxycholic acid (UDCA) on the viability and proliferation of tumour and non-tumour cells. Cell lines established from retrovirus-transformed chicken hepatoma (LSCC-SF-Mc29) and rat sarcoma (LSR-SF-SR) as well as from human cancers of the breast (MCF-7), uterine cervix (HeLa), lung (A549) and liver (HepG2) were used as model systems. Non-tumour human embryo (Lep-3) cells were also included ...

  2. Proto-oncogene FBI-1 (Pokemon) and SREBP-1 synergistically activate transcription of fatty-acid synthase gene (FASN).

    Choi, Won-Il; Jeon, Bu-Nam; Park, Hyejin; Yoo, Jung-Yoon; Kim, Yeon-Sook; Koh, Dong-In; Kim, Myung-Hwa; Kim, Yu-Ri; Lee, Choong-Eun; Kim, Kyung-Sup; Osborne, Timothy F; Hur, Man-Wook

    2008-10-24

    FBI-1 (Pokemon/ZBTB7A) is a proto-oncogenic transcription factor of the BTB/POZ (bric-à-brac, tramtrack, and broad complex and pox virus zinc finger) domain family. Recent evidence suggested that FBI-1 might be involved in adipogenic gene expression. Coincidentally, expression of FBI-1 and fatty-acid synthase (FASN) genes are often increased in cancer and immortalized cells. Both FBI-1 and FASN are important in cancer cell proliferation. SREBP-1 is a major regulator of many adipogenic genes, and FBI-1 and SREBP-1 (sterol-responsive element (SRE)-binding protein 1) interact with each other directly via their DNA binding domains. FBI-1 enhanced the transcriptional activation of SREBP-1 on responsive promoters, pGL2-6x(SRE)-Luc and FASN gene. FBI-1 and SREBP-1 synergistically activate transcription of the FASN gene by acting on the proximal GC-box and SRE/E-box. FBI-1, Sp1, and SREBP-1 can bind to all three SRE, GC-box, and SRE/E-box. Binding competition among the three transcription factors on the GC-box and SRE/E-box appears important in the transcription regulation. FBI-1 is apparently changing the binding pattern of Sp1 and SREBP-1 on the two elements in the presence of induced SREBP-1 and drives more Sp1 binding to the proximal promoter with less of an effect on SREBP-1 binding. The changes induced by FBI-1 appear critical in the synergistic transcription activation. The molecular mechanism revealed provides insight into how proto-oncogene FBI-1 may attack the cellular regulatory mechanism of FASN gene expression to provide more phospholipid membrane components needed for rapid cancer cell proliferation. PMID:18682402

  3. Stabilizing Role of Metallophilic HgII ... HgII Interactions in Nucleic Acids

    Benda, Ladislav; Tanaka, Y.; Sychrovský, Vladimír; Straka, Michal

    Praha: -, 2011. s. 35-35. [Quantum Bioinorganic Chemistry Conference /3./. 25.06.2011-28.06.2011, Český Krumlov] R&D Projects: GA ČR GA203/09/2037; GA ČR GAP205/10/0228 Grant ostatní: European Reintegration Grant(XE) 230955 Institutional research plan: CEZ:AV0Z40550506 Keywords : metallophilic HgII ... HgII interactions * mispairing nucleic acids * metallophilic interactions Subject RIV: CF - Physical ; Theoretical Chemistry

  4. Proteomic Upregulation of Fatty Acid Synthase and Fatty Acid Binding Protein 5 and Identification of Cancer- and Race-Specific Pathway Associations in Human Prostate Cancer Tissues

    Myers, Jennifer S.; von Lersner, Ariana K.; Sang, Qing-Xiang Amy

    2016-01-01

    Protein profiling studies of prostate cancer have been widely used to characterize molecular differences between diseased and non-diseased tissues. When combined with pathway analysis, profiling approaches are able to identify molecular mechanisms of prostate cancer, group patients by cancer subtype, and predict prognosis. This strategy can also be implemented to study prostate cancer in very specific populations, such as African Americans who have higher rates of prostate cancer incidence and mortality than other racial groups in the United States. In this study, age-, stage-, and Gleason score-matched prostate tumor specimen from African American and Caucasian American men, along with non-malignant adjacent prostate tissue from these same patients, were compared. Protein expression changes and altered pathway associations were identified in prostate cancer generally and in African American prostate cancer specifically. In comparing tumor to non-malignant samples, 45 proteins were significantly cancer-associated and 3 proteins were significantly downregulated in tumor samples. Notably, fatty acid synthase (FASN) and epidermal fatty acid-binding protein (FABP5) were upregulated in human prostate cancer tissues, consistent with their known functions in prostate cancer progression. Aldehyde dehydrogenase family 1 member A3 (ALDH1A3) was also upregulated in tumor samples. The Metastasis Associated Protein 3 (MTA3) pathway was significantly enriched in tumor samples compared to non-malignant samples. While the current experiment was unable to detect statistically significant differences in protein expression between African American and Caucasian American samples, differences in overrepresentation and pathway enrichment were found. Structural components (Cytoskeletal Proteins and Extracellular Matrix Protein protein classes, and Biological Adhesion Gene Ontology (GO) annotation) were overrepresented in African American but not Caucasian American tumors. Additionally, 5

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

    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

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

    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

  7. Proto-oncogene FBI-1 (Pokemon) and SREBP-1 Synergistically Activate Transcription of Fatty-acid Synthase Gene (FASN)*S⃞

    Choi, Won-Il; Jeon, Bu-Nam; Park, Hyejin; Yoo, Jung-Yoon; Kim, Yeon-Sook; Koh, Dong-In; Kim, Myung-Hwa; Kim, Yu-Ri; Lee, Choong-Eun; Kim, Kyung-Sup; Osborne, Timothy F.; Hur, Man-Wook

    2008-01-01

    FBI-1 (Pokemon/ZBTB7A) is a proto-oncogenic transcription factor of the BTB/POZ (bric-à-brac, tramtrack, and broad complex and pox virus zinc finger) domain family. Recent evidence suggested that FBI-1 might be involved in adipogenic gene expression. Coincidentally, expression of FBI-1 and fatty-acid synthase (FASN) genes are often increased in cancer and immortalized cells. Both FBI-1 and FASN are important in cancer cell proliferation. SREBP-1 is a major regulator of...

  8. Disrupted short chain specific β-oxidation and improved synthase expression increase synthesis of short chain fatty acids in Saccharomyces cerevisiae.

    Leber, Christopher; Choi, Jin Wook; Polson, Brian; Da Silva, Nancy A

    2016-04-01

    Biologically derived fatty acids have gained tremendous interest as an alternative to petroleum-derived fuels and chemical precursors. We previously demonstrated the synthesis of short chain fatty acids in Saccharomyces cerevisiae by introduction of the Homo sapiens fatty acid synthase (hFAS) with heterologous phosphopantetheine transferases and heterologous thioesterases. In this study, short chain fatty acid production was improved by combining a variety of novel enzyme and metabolic engineering strategies. The use of a H. sapiens-derived thioesterase and phosphopantetheine transferase were evaluated. In addition, strains were engineered to disrupt either the full β-oxidation (by deleting FAA2, PXA1, and POX1) or short chain-specific β-oxidation (by deleting FAA2, ANT1, and PEX11) pathways. Prohibiting full β-oxidation increased hexanoic and octanoic acid levels by 8- and 79-fold relative to the parent strain expressing hFAS. However, by targeting only short chain β-oxidation, hexanoic and octanoic acid levels increased further to 31- and 140-fold over the parent. In addition, an optimized hFAS gene increased hexanoic, octanoic, decanoic and total short chain fatty acid levels by 2.9-, 2.0-, 2.3-, and 2.2-fold, respectively, relative to the non-optimized counterpart. By combining these unique enzyme and metabolic engineering strategies, octanoic acid was increased more than 181-fold over the parent strain expressing hFAS. PMID:26388428

  9. Sequence heterogeneity of cannabidiolic- and tetrahydrocannabinolic acid-synthase in Cannabis sativa L. and its relationship with chemical phenotype.

    Onofri, Chiara; de Meijer, Etienne P M; Mandolino, Giuseppe

    2015-08-01

    Sequence variants of THCA- and CBDA-synthases were isolated from different Cannabis sativa L. strains expressing various wild-type and mutant chemical phenotypes (chemotypes). Expressed and complete sequences were obtained from mature inflorescences. Each strain was shown to have a different specificity and/or ability to convert the precursor CBGA into CBDA and/or THCA type products. The comparison of the expressed sequences led to the identification of different mutations, all of them due to SNPs. These SNPs were found to relate to the cannabinoid composition of the inflorescence at maturity and are therefore proposed to have a functional significance. The amount of variation was found to be higher within the CBDAS sequence family than in the THCAS family, suggesting a more recent evolution of THCA-forming enzymes from the CBDAS group. We therefore consider CBDAS as the ancestral type of these synthases. PMID:25865737

  10. Hybrid polyketide synthases

    Fortman, Jeffrey L.; Hagen, Andrew; Katz, Leonard; Keasling, Jay D.; Poust, Sean; Zhang, Jingwei; Zotchev, Sergey

    2016-05-10

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing an even-chain or odd-chain diacid or lactam or diamine. The present invention also provides for a host cell comprising the PKS and when cultured produces the even-chain diacid, odd-chain diacid, or KAPA. The present invention also provides for a host cell comprising the PKS capable of synthesizing a pimelic acid or KAPA, and when cultured produces biotin.

  11. Calcium(II)(3) (3,5-Diisopropylsalicylate)(6)(H(2)O)(6) Activates Nitric Oxide Synthase: An Accounting for its Action in Decreasing Platelet Aggregation.

    Donham, D C; Sorenson, J R

    2000-01-01

    Purposes of these studies were first; to determine whether or not Calcium(II)(3) (3,5- diisopropylsalicylate)(6)(H(2)O)(6) [Ca(II)(3)(3,5-DIPS)(6)], a lipophilic calcium complex, could decrease activated-platelet aggregation, and second; to determine whether or not it is plausible that Ca(II)(3)(3,5-DIPS)(6) decreases activated-platelet aggregation by facilitating the synthesis of Nitric Oxide (NO) by Nitric Oxide Synthase (NOS). The influence of Ca(II)(3)(3,5-DIPS)(6) on the initial rate of activated-platelet aggregation was determined by measuring the decrease in rate of increase in transmission at 550 nm for a suspension of Thrombin-CaCl(2) activated platelets following the addition of 0, 50, 100, 250, or 500 muM Ca(II)(3)(3,5-DIPS)(6). To establish that the Ca(lI)(3)(3,5- DIPS)(6)-mediated decrease in aggregation was due to activation of NOS, the effect of L-NMMA, an inhibitor of NOS, on the inhibition of platelet aggregation by Ca(II)(3)(3,5-DIPS)(6) was determined using a suspension of activated platelets contaimng 0 or 250 muM Ca(II)(3)(3,5-DIPS)(6) without or with 1 mM L-NMMA. An in vitro Bovine Brain NOS reaction mixture, containing CaCl(2) for the activation of Phosphodiesterase-3' ,5'-Cyclic Nucleotide Activator required for the activation of NOS, was used to determine whether or not Ca(II)(3)(3,5-DIPS)(6) could be used as a substitute for the addition of Ca. The decrease in absorbance at 340 nm, lambda maximum for NADPH, was measured to determine NOS activity following the addition of NOS to the complete reaction mixture containing either CaCl(2), Ca(II)(3)(3,5-DIPS)(6), or neither Ca compound. Increasing the concentration of Ca(II)(3)(3,5-DIPS)(6) caused a concentration related decrease in activated platelet aggregation. The addition of L-NMMA to activated platelets, in the absence of Ca(II)(3)(3,5-DIPS)(6), caused a 129% increase in initial rate of platelet aggregation. The initial rate of platelet aggregation decreased 74% with the addition of 250 mu

  12. Folic Acid Promotes Recycling of Tetrahydrobiopterin and Protects Against Hypoxia-Induced Pulmonary Hypertension by Recoupling Endothelial Nitric Oxide Synthase

    Chalupsky, Karel; Kračun, Damir; Kanchev, Ivan; Bertram, Katharina; Görlach, Agnes

    2015-01-01

    Aims: Nitric oxide (NO) derived from endothelial NO synthase (eNOS) has been implicated in the adaptive response to hypoxia. An imbalance between 5,6,7,8-tetrahydrobiopterin (BH4) and 7,8-dihydrobiopterin (BH2) can result in eNOS uncoupling and the generation of superoxide instead of NO. Dihydrofolate reductase (DHFR) can recycle BH2 to BH4, leading to eNOS recoupling. However, the role of DHFR and eNOS recoupling in the response to hypoxia is not well understood. We hypothesized that increas...

  13. Chronic hyperammonemia reduces the activity of neuronal nitric oxide synthase in cerebellum by altering its localization and increasing its phosphorylation by calcium-calmodulin kinase II.

    El-Mlili, Nisrin; Rodrigo, Regina; Naghizadeh, Bahareh; Cauli, Omar; Felipo, Vicente

    2008-08-01

    Impaired function of the glutamate-nitric oxide-cGMP pathway contributes to cognitive impairment in hyperammonemia and hepatic encephalopathy. The mechanisms by which hyperammonemia impairs this pathway remain unclear. Understanding these mechanisms would allow designing clinical treatments for cognitive deficits in hepatic encephalopathy. The aims of this work were: (i) to assess whether chronic hyperammonemia in vivo alters basal activity of neuronal nitric oxide synthase (nNOS) in cerebellum and/or its activation in response to NMDA receptor activation and (ii) to analyse the molecular mechanisms by which hyperammonemia induces these alterations. It is shown that hyperammonemia reduces both basal activity of nNOS and its activation following NMDA receptor activation. Reduced basal activity is because of increased phosphorylation in Ser847 (by 69%) which reduces basal activity of nNOS by about 40%. Increased phosphorylation of nNOS in Ser847 is because of increased activity of calcium-calmodulin-dependent protein kinases (CaMKII) which in turn is because of increased phosphorylation at Thr286. Inhibiting CaMKII with KN-62 normalizes phosphorylation of Ser847 and basal NOS activity in hyperammonemic rats, returning to values similar to controls. Reduced activation of nNOS in response to NMDA receptor activation in hyperammonemia is because of altered subcellular localization of nNOS, with reduced amount in post-synaptic membranes and increased amount in the cytosol. PMID:18498443

  14. Benzalacetone Synthase

    Ikuro eAbe

    2012-03-01

    Full Text Available Benzalacetone synthase, from the medicinal plant Rheum palmatum (Polygonaceae (RpBAS, is a plant-specific chalcone synthase (CHS superfamily of type III polyketide synthase (PKS. RpBAS catalyzes the one-step, decarboxylative condensation of 4-coumaroyl-CoA with malonyl-CoA to produce the C6-C4 benzalacetone scaffold. The X-ray crystal structures of RpBAS confirmed that the diketide-forming activity is attributable to the characteristic substitution of the conserved active-site "gatekeeper" Phe with Leu. Furthermore, the crystal structures suggested that RpBAS employs novel catalytic machinery for the thioester bond cleavage of the enzyme-bound diketide intermediate and the final decarboxylation reaction to produce benzalacetone. Finally, by exploiting the remarkable substrate tolerance and catalytic versatility of RpBAS, precursor-directed biosynthesis efficiently generated chemically and structurally divergent, unnatural novel polyketide scaffolds. These findings provided a structural basis for the functional diversity of the type III PKS enzymes.

  15. Vascular hyporeactivity to angiotensin II induced by Escherichia coli endotoxin is reversed by Nω-Nitro-L-Arginine, an inhibitor of nitric oxide synthase

    L. A. RODRIGUES

    2009-01-01

    Full Text Available

    Septic shock or sepsis is reported to be one of the major causes of death when followed by systemic infectious trauma in humans and other mammals. Its development leads to a large drop in blood pressure and a reduction in vascular responsiveness to physiological vasoconstrictors which, if not contained, can lead to death. It is proposed that this vascular response is due to the action of bacterial cell wall products released into the bloodstream by the vascular endothelium and is considered a normal response of the body`s defenses against infection. A reduction in vascular reactivity to epinephrine and norepinephrine is observed under these conditions. In the present study in rats, the aim was to assess whether those effects of hypotension and hyporeactivity are also related to another endogenous vasoconstrictor, angiotensin II (AII. We evaluated the variation in the power of this vasoconstrictor over the mean arterial pressure in anesthetized rats, before and after the establishment of hypotension by Escherichia coli endotoxin (Etx. Our results show that in this model of septic shock, there is a reduction in vascular reactivity to AII and this reduction can be reversed by the inhibitor of nitric oxide synthase, Nω-Nitro-L-Arginine (NωNLA. Our results also suggest that other endogenous factors (not yet fully known are involved in the protection of rats against septic shock, in addition to the L-arginine NO pathway. Keywords: vascular hyporeactivity; NO; rat; angiotensin II; NωNLA Escherichia coli endotoxin.

  16. Sequence analysis and structure prediction of type II Pseudomonas sp. USM 4–55 PHA synthase and an insight into its catalytic mechanism

    Ahmad Khairudin Nurul

    2006-11-01

    Full Text Available Abstract Background Polyhydroxyalkanoates (PHA, are biodegradable polyesters derived from many microorganisms such as the pseudomonads. These polyesters are in great demand especially in the packaging industries, the medical line as well as the paint industries. The enzyme responsible in catalyzing the formation of PHA is PHA synthase. Due to the limited structural information, its functional properties including catalysis are lacking. Therefore, this study seeks to investigate the structural properties as well as its catalytic mechanism by predicting the three-dimensional (3D model of the Type II Pseudomonas sp. USM 4–55 PHA synthase 1 (PhaC1P.sp USM 4–55. Results Sequence analysis demonstrated that PhaC1P.sp USM 4–55 lacked similarity with all known structures in databases. PSI-BLAST and HMM Superfamily analyses demonstrated that this enzyme belongs to the alpha/beta hydrolase fold family. Threading approach revealed that the most suitable template to use was the human gastric lipase (PDB ID: 1HLG. The superimposition of the predicted PhaC1P.sp USM 4–55 model with 1HLG covering 86.2% of the backbone atoms showed an RMSD of 1.15 Å. The catalytic residues comprising of Cys296, Asp451 and His479 were found to be conserved and located adjacent to each other. In addition to this, an extension to the catalytic mechanism was also proposed whereby two tetrahedral intermediates were believed to form during the PHA biosynthesis. These transition state intermediates were further postulated to be stabilized by the formation of oxyanion holes. Based on the sequence analysis and the deduced model, Ser297 was postulated to contribute to the formation of the oxyanion hole. Conclusion The 3D model of the core region of PhaC1P.sp USM 4–55 from residue 267 to residue 484 was developed using computational techniques and the locations of the catalytic residues were identified. Results from this study for the first time highlighted Ser297 potentially

  17. Modulation of Medium-Chain Fatty Acid Synthesis in Synechococcus sp. PCC 7002 by Replacing FabH with a Chaetoceros Ketoacyl-ACP Synthase

    Gu, Huiya; Jinkerson, Robert E.; Davies, Fiona K.; Sisson, Lyle A.; Schneider, Philip E.; Posewitz, Matthew C.

    2016-01-01

    The isolation or engineering of algal cells synthesizing high levels of medium-chain fatty acids (MCFAs) is attractive to mitigate the high clouding point of longer chain fatty acids in algal based biodiesel. To develop a more informed understanding of MCFA synthesis in photosynthetic microorganisms, we isolated several algae from Great Salt Lake and screened this collection for MCFA accumulation to identify strains naturally accumulating high levels of MCFA. A diatom, Chaetoceros sp. GSL56, accumulated particularly high levels of C14 (up to 40%), with the majority of C14 fatty acids allocated in triacylglycerols. Using whole cell transcriptome sequencing and de novo assembly, putative genes encoding fatty acid synthesis enzymes were identified. Enzymes from this Chaetoceros sp. were expressed in the cyanobacterium Synechococcus sp. PCC 7002 to validate gene function and to determine whether eukaryotic enzymes putatively lacking bacterial evolutionary control mechanisms could be used to improve MCFA production in this promising production strain. Replacement of the Synechococcus 7002 native FabH with a Chaetoceros ketoacyl-ACP synthase III increased MCFA synthesis up to fivefold. The level of increase is dependent on promoter strength and culturing conditions. PMID:27303412

  18. Biosynthesis of Akaeolide and Lorneic Acids and Annotation of Type I Polyketide Synthase Gene Clusters in the Genome of Streptomyces sp. NPS554

    Tao Zhou

    2015-01-01

    Full Text Available The incorporation pattern of biosynthetic precursors into two structurally unique polyketides, akaeolide and lorneic acid A, was elucidated by feeding experiments with 13C-labeled precursors. In addition, the draft genome sequence of the producer, Streptomyces sp. NPS554, was performed and the biosynthetic gene clusters for these polyketides were identified. The putative gene clusters contain all the polyketide synthase (PKS domains necessary for assembly of the carbon skeletons. Combined with the 13C-labeling results, gene function prediction enabled us to propose biosynthetic pathways involving unusual carbon-carbon bond formation reactions. Genome analysis also indicated the presence of at least ten orphan type I PKS gene clusters that might be responsible for the production of new polyketides.

  19. Influence of humic acid on sorption of Co(II), Sr(II), and Se(IV) on goethite

    Masset, Sonia; Monteil-Rivera, Fanny; Dupont, Laurent; Dumonceau, Jacques; Aplincourt, Michel

    2000-01-01

    International audience This work examined the influence of a leonardite humic acid on the sorption of Co(II), Sr(II), and Se(IV) onto goethite as a function of pH. The sorption of humic acid and ions alone was first studied. The humic acid sorbs appreciably to the goethite surface according to a reversible process, with a maximum sorption of 19 mg of total organic carbon per g of goethite reached at lower pH values ($\\approx$5). Cobalt and selenium are significantly sorbed on goethite whil...

  20. Study on complex formation of cadmium(II) ions, 8. Identification of the precipitates formed in the solutions containing cadmium(II) ion and amino acid

    Matsui, Haruo; Hirabayashi, Yoshihiro (Government Industrial Research Inst., Nagoya (Japan))

    1984-02-01

    In the potentiometric titration of the solution containing a cadmium(II) ion and an amino acid, white precipitates often appear in the test solution, and they disturb the emf measurements. Such precipitates were formed in the solutions, pH ranging 7.5--8.5, during the course of titrations of the test solutions containing cadmium(II) ion and amino acid such as glycine, ..cap alpha..-alanine. 2-aminobutanoic acid, 3-aminobutanoic acid, 4-aminobutanoic acid, 2-aminopentanoic acid, 5-aminopentanoic acid, 2-aminohexanoic acid, 6-aminohexanoic acid, aspartic acid, glutamic acid, asparagine, or glutamine. The identification of the precipitates obtained from the solutions containing cadmium(II) ion and L-aspartic acid, 4-aminobutanoic acid, or 6-aminohexanoic acid were carried out by elemental analysis and infrared spectroscopy. These results indicated that the precipitate obtained from the solution containing cadmium(II) ion and L-aspartic acid was 1:1 cadmium(II)-L-aspartic acid complex and did not contain any cadmium(II) hydroxide, and other two precipitates were mostly cadmium(II) hydroxide and contained a little cadmium(II)-amino acid complexes.

  1. Chlorogenic acid protection of neuronal nitric oxide synthase-positive neurons in the hippocampus of mice with impaired learning and memory

    Qiuyun Tu; Xiangqi Tang; Zhiping Hu

    2008-01-01

    BACKGROUND: Clinical practice and modern pharmacology have confirmed that ehlorogenic acid can ameliorate learning and memory impairments. OBJECTIVE: To observe the effects of chlorogenic acid on neuronal nitric oxide synthase (nNOS)-positive neurons in the mouse hippocampus, and to investigate the mechanisms underlying the beneficial effects of chlorogenic acid on learning and memory. DESIGN, TIME AND SETTING: The present randomized, controlled, neural cell morphological observation was performed at the Institute of Neurobiology, Central South University between January and May 2005.MATERIALS: Forty-eight female, healthy, adult, Kunming mice were included in this study. Learning and memory impairment was induced with an injection of 0.5 μL kainic acid (0.4 mg/mL) into the hippocampus.METHODS: The mice were randomized into three groups (n = 16): model, control, and chlorogenic acid-treated. At 2 days following learning and memory impairment induction, intragastric administration of physiological saline or chlorogenic acid was performed in the model and chlorogenic acid-treated groups, respectively. The control mice were administered 0.5 μ L physiological saline into the hippocampus, and 2 days later, they received an intragastric administration of physiological saline. Each mouse received two intragastric administrations (1 mL solution once) per day, for a total of 35 days. MAIN OUTCOME MEASURES: Detection of changes in hippocampal and cerebral cortical nNOS neurons by immunohistochemistry; determination of spatial learning and memory utilizing the Y-maze device.RESULTS: At day 7 and 35 after intervention, there was no significant difference in the number of nNOS-positive neurons in the cerebral cortex between the model, chlorogenic acid, and control groups (P > 0.05). Compared with the control group, the number of nNOS-positive neurons in the hippocampal CA1-4 region was significantly less in the model group (P 0.05). At day 7 following intervention, the number

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

    González-Mellado, Damián; von Wettstein, Penelope Margaret; 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....... Heterologous expression of HaKAS III in Escherichia coli altered their fatty acid content and composition implying an interaction of HaKAS III with the bacterial FAS complex. Testing purified HaKAS III recombinant protein by adding to a reconstituted E. coli FAS system lacking condensation activity revealed a...

  3. Threonine phosphorylation of rat liver glycogen synthase

    32P-labeled glycogen synthase specifically immunoprecipitated from 32P-phosphate incubated rat hepatocytes contains, in addition to [32P] phosphoserine, significant levels of [32P] phosphothreonine. When the 32P-immunoprecipitate was cleaved with CNBr, the [32P] phosphothreonine was recovered in the large CNBr fragment (CB-2, Mapp 28 Kd). Homogeneous rat liver glycogen synthase was phosphorylated by all the protein kinases able to phosphorylate CB-2 in vitro. After analysis of the immunoprecipitated enzyme for phosphoaminoacids, it was observed that only casein kinase II was able to phosphorylate on threonine and 32P-phosphate was only found in CB-2. These results demonstrate that rat liver glycogen synthase is phosphorylated at threonine site(s) contained in CB-2 and strongly indicate that casein kinase II may play a role in the ''in vivo'' phosphorylation of liver glycogen synthase. This is the first protein kinase reported to phosphorylate threonine residues in liver glycogen synthase

  4. Copper(II) interactions with nonsteroidal antiinflammatory agents. I. Salicylic acid and acetylsalicylic acid.

    Brumas, V; Brumas, B; Berthon, G

    1995-02-15

    Recently a growing body of evidence has accumulated on the beneficial effects of copper compounds toward various models of inflammation, and copper complexes of nonsteroidal antiinflammatory drugs (NSAIDs) have been shown to be more effective in this respect than the parent agents. However, the origin of this activity remains unclear: The ability of NSAIDs to influence copper metabolism is still questionable, and apart from the claimed SOD-like activity of copper salts in vivo, relatively little is known about how copper-NSAID interactions may help regulate the inflammatory process. Before the potential role of copper-NSAID complexes versus inflammation can be elucidated, speciation studies are necessary (i) to analyze the overall influence of these drugs on copper metabolism and (ii) to discriminate the individual complexes likely to represent the active form of the drug in vivo. In this paper, copper(II) complex equilibria with salicylic and acetylsalicylic acids--and benzoic acid used as a reference--as well as the mixed-ligand complex equilibria generated by these binary systems and L-histidine [main low-molar-mass ligand of copper(II) in blood plasma] have been investigated under physiological conditions (37 degrees C; 0.15-M NaCl). Confirming previous observations by others, resulting simulated plasma copper distributions virtually rule out any quantitative influence of salicylate on copper tissue diffusion at therapeutic levels. Even though, as is presently shown, both salicylate and acetylsalicylate may favor the gastrointestinal absorption of copper, it seems unlikely that salicylate can exert its antinflammatory activity predominantly through copper complexation. The assertion that copper-NSAID complexes represent the active forms of NSAIDs therefore seems to be of limited significance for salicylate. PMID:7876837

  5. Producing biofuels using polyketide synthases

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-04-16

    The present invention provides for a non-naturally occurring polyketide synthase (PKS) capable of synthesizing a carboxylic acid or a lactone, and a composition such that a carboxylic acid or lactone is included. The carboxylic acid or lactone, or derivative thereof, is useful as a biofuel. The present invention also provides for a recombinant nucleic acid or vector that encodes such a PKS, and host cells which also have such a recombinant nucleic acid or vector. The present invention also provides for a method of producing such carboxylic acids or lactones using such a PKS.

  6. Cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), dioxouranium(VI) and oxovanadium(IV) complexes with 2-(N-α-benzyl-2-hydroxybenzylidineimino)-ethane sulphonic acid

    The dissociation constants of 2-(N-αbenzyl-2-hydroxbenzylidineimino) ethane sulphonic acid (H2BE) and stability constants of its chelates with CoII, NiII, CuII, ZnII, CdII, UVIO2 and VIVO have been determined in aqueous medium (μ-0.1 M) at 25, 35 and 45deg using Calvin's extension of Bjerrum's method. Values of ΔGo, ΔHo and ΔSo of the chelates have been evaluated. Elemental analysis, molecular weight, electronic and ir spectra, magnetic moments and conductance of the solid complexes indicate an octahedral stereochemistry for these chelates except those of the ZnII and CdII which possesses a tetrahedral geometry. (author)

  7. Equilibrium, thermoanalytical and spectroscopic studies to characterize phytic acid complexes with Mn(II) and Co(II)

    Potentiometric studies were carried out to determine the binding degree of phytic acid with Co(II) and Mn(II) ions, in the absence of dioxygen. Equilibrium constants for all major complexes formed are reported, and the results are presented in the form of distribution diagrams showing the concentrations of individual complexes as a function of pH. The formation constants of the complexes show higher values for the species in which the ligand was more deprotonated. Potentiometric data indicates that the species [MH4L]6-, was totally formed at pH 7.0 and the complexes were synthesized from this data. A solid state complex of Mn(II) and Co(II) with phytic acid was synthesized. Thermogravimetry, differential scanning calorimetry, and infrared spectroscopy were used to investigate and characterize the thermal behavior of these compounds. The results led to information on the composition, dehydration, thermal stability and thermal decomposition of the isolated complexes. (author)

  8. Development of genome-specific primers for homoeologous genes in allopolyploid species: the waxy and starch synthase II genes in allohexaploid wheat (Triticum aestivum L. as examples

    Brûlé-Babel Anita

    2010-05-01

    Full Text Available Abstract Background In allopolypoid crops, homoeologous genes in different genomes exhibit a very high sequence similarity, especially in the coding regions of genes. This makes it difficult to design genome-specific primers to amplify individual genes from different genomes. Development of genome-specific primers for agronomically important genes in allopolypoid crops is very important and useful not only for the study of sequence diversity and association mapping of genes in natural populations, but also for the development of gene-based functional markers for marker-assisted breeding. Here we report on a useful approach for the development of genome-specific primers in allohexaploid wheat. Findings In the present study, three genome-specific primer sets for the waxy (Wx genes and four genome-specific primer sets for the starch synthase II (SSII genes were developed mainly from single nucleotide polymorphisms (SNPs and/or insertions or deletions (Indels in introns and intron-exon junctions. The size of a single PCR product ranged from 750 bp to 1657 bp. The total length of amplified PCR products by these genome-specific primer sets accounted for 72.6%-87.0% of the Wx genes and 59.5%-61.6% of the SSII genes. Five genome-specific primer sets for the Wx genes (one for Wx-7A, three for Wx-4A and one for Wx-7D could distinguish the wild type wheat and partial waxy wheat lines. These genome-specific primer sets for the Wx and SSII genes produced amplifications in hexaploid wheat, cultivated durum wheat, and Aegilops tauschii accessions, but failed to generate amplification in the majority of wild diploid and tetraploid accessions. Conclusions For the first time, we report on the development of genome-specific primers from three homoeologous Wx and SSII genes covering the majority of the genes in allohexaploid wheat. These genome-specific primers are being used for the study of sequence diversity and association mapping of the three homoeologous Wx

  9. The properties of solid Zn(II)-amino acid complexes in the form of suspensions.

    Dolińska, B

    2001-10-01

    An investigation was made into the experimental conditions for the formation of poorly soluble complexes of the divalent Zinc(II) combined with the following selected amino acids: tyrosine, tryptophan, cysteine, histidine, and alanine, in the form of suspensions for parenteral administration. The number of Zn(II)-binding sites in the amino acid (n) as well as the amino acid affinity to Zn(II) (Ka), were determined. Cysteine was found to have the highest number of Zn(II)-binding sites--3, whereas alanine the lowest--1. In the conditions described herein, Zn(II) amino acid complexes of diverse stability (durability) were obtained. The analysis of the kinetics of the binding revealed that the most stable complexes were those formed by Zn(II) in combination with tryptophan (Ka = 405.78 microM(-1) +/- 12.17), and with tyrosine (Ka = 343.88 microM +/- 22.35); whereas the least stable complexes were those formed by Zn(II) in combination with histidine (Ka = 29.90 microM +/- 4.78), and with alanine (Ka = 13.0 microM(-1) +/- 1.04). Cysteine formed complexes of intermediate stability (Ka = 168.53 microM(-1) +/- 12.36). The stability ofthe Zn(II) amino acid complexes obtained was conditioned by both the molecular weight (P = 0.033) of the amino acid and its isoelectric point (P < 0.001). PMID:11718265

  10. The interaction of zinc(II) and hydroxamic acids and a metal-triggered Lossen rearrangement.

    Duchácková, Lucie; Roithová, Jana

    2009-12-14

    The structure and reactivity of a complex of zinc(II), water, acetic acid, and acetohydroxamic acid, in which one of the acids is deprotonated, is investigated by means of mass spectrometry, labeling studies, and density functional calculations to unravel the exceptional binding properties of hydroxamic acids towards zinc-containing enzymes at the molecular level. It is shown that acetohydroxamic acid is deprotonated in the complex, whereas acetic acid is present in its neutral form. The binding energies of the ligands towards zinc increase in the following order: wateracidacid. The structure of the complex and its fragmentation provide experimental evidence for the proposed mode of operation of drugs based on hydroxamic acids. Furthermore, coordinatively unsaturated complexes of zinc and acetohydroxamic acid undergo a zinc-assisted Lossen rearrangement followed by elimination of water if acetohydroxamic acid is present as a neutral ligand, or by loss of methylisocyanate if acetohydroxamic acid is deprotonated. PMID:19937618

  11. Effects of soluble epoxide hydrolase inhibitor on the expression of fatty acid synthase in peripheral blood mononuclear cell in patients with acute coronary syndrome

    Zhao Xuan

    2013-01-01

    Full Text Available Abstract Background Researches have shown that soluble epoxide hydrolase inhibitors (sEHi can protect against the development of atherosclerosis. Simultaneously, emerging evidences have implicated the association between fatty acid synthase (FAS and acute coronary syndrome (ACS. We tested the hypothesis that sEHi could reduce the occurrence of ACS by regulating FAS. Methods Hospitalized ACS patients were selected as the ACS group (n = 65 while healthy normal subjects as the control group (n = 65. The blood levels of lipoproteins, fasting glucose, myocardial enzyme and high-sensitivity C-reactive protein (hs-CRP were measured within 24 hours after admission. The peripheral blood mononuclear cells (PBMCs were isolated and cultured. Trans-4-[4-(3-Adamantan-1-ylureidocyclohexyloxy] benzoic acid (t-AUCB, a kind of sEHi, was then added to cells in various concentrations (0, 10, 50, 100 μmol/L. The expression of FAS, interleukin-6 (IL-6 mRNA and protein was detected by real-time PCR or Western blot, respectively. Results (1 Compared with the control group, the serum concentration of hs-CRP in the ACS group was increased (PPPPP Conclusions sEH inhibition regulated FAS and inhibited inflammation in cultured PBMCs from ACS patients, a mechanism that might prevent rupture of atherosclerotic lesions and protect against development of ACS.

  12. Removal of corper(II) Ions from aqueous solution by a lactic acid bacterium

    M. Yilmaz(Department of Physics, Gazi University, Ankara); T. Tay; M. Kivanc; H. Turk

    2010-01-01

    Enterococcus faecium, a lactic acid bacterium (LAB), was evaluated for its ability to remove copper(II) ions from water. The effects of the pH, contact time, initial concentration of copper(II) ions, and temperature on the biosorption rate and capacity were studied. The initial concentrations of copper(II) ions used to determine the maximum amount of biosorbed copper(II) ions onto lyophilised lactic acid bacterium varied from 25 mg L-1 to 500 mg L-1. Maximum biosorption capacities were attain...

  13. Fatty acid biosynthesis in actinomycetes

    Gago, Gabriela; Diacovich, Lautaro; Arabolaza, Ana; Tsai, Shiou-Chuan; Gramajo, Hugo

    2011-01-01

    All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation fo...

  14. Prolonged Exposure of Primary Human Muscle Cells to Plasma Fatty Acids Associated with Obese Phenotype Induces Persistent Suppression of Muscle Mitochondrial ATP Synthase β Subunit.

    Tran, Lee; Hanavan, Paul D; Campbell, Latoya E; De Filippis, Elena; Lake, Douglas F; Coletta, Dawn K; Roust, Lori R; Mandarino, Lawrence J; Carroll, Chad C; Katsanos, Christos S

    2016-01-01

    Our previous studies show reduced abundance of the β-subunit of mitochondrial H+-ATP synthase (β-F1-ATPase) in skeletal muscle of obese individuals. The β-F1-ATPase forms the catalytic core of the ATP synthase, and it is critical for ATP production in muscle. The mechanism(s) impairing β-F1-ATPase metabolism in obesity, however, are not completely understood. First, we studied total muscle protein synthesis and the translation efficiency of β-F1-ATPase in obese (BMI, 36±1 kg/m2) and lean (BMI, 22±1 kg/m2) subjects. Both total protein synthesis (0.044±0.006 vs 0.066±0.006%·h-1) and translation efficiency of β-F1-ATPase (0.0031±0.0007 vs 0.0073±0.0004) were lower in muscle from the obese subjects when compared to the lean controls (Pculture model, and tested the specific hypothesis that circulating non-esterified fatty acids (NEFA) in obesity play a role in the responses observed in humans. The findings on total protein synthesis and translation efficiency of β-F1-ATPase in primary myotubes cultured from a lean subject, and after exposure to NEFA extracted from serum of an obese subject, were similar to those obtained in humans. Among candidate microRNAs (i.e., non-coding RNAs regulating gene expression), we identified miR-127-5p in preventing the production of β-F1-ATPase. Muscle expression of miR-127-5p negatively correlated with β-F1-ATPase protein translation efficiency in humans (r = - 0.6744; Pobese subject. On the other hand, locked nucleic acid inhibitor synthesized to target miR-127-5p significantly increased β-F1-ATPase translation efficiency in myotubes (0.6±0.1 vs 1.3±0.3, in control vs exposure to 50 nM inhibitor; Pobesity in suppressing muscle protein metabolism, and establish impaired β-F1-ATPase translation as an important consequence of obesity. PMID:27532680

  15. Removal of Cu(II) from acidic electroplating effluent by biochars generated from crop straws.

    Tong, Xuejiao; Xu, Renkou

    2013-04-01

    The removal efficiency of copper (Cu(II)) from an actual acidic electroplating effluent by biochars generated from canola, rice, soybean and peanut straws was investigated. The biochars simultaneously removed Cu(II) from the effluent, mainly through the mechanisms of adsorption and precipitation, and neutralized its acidity. The removal efficiency of Cu(II) by the biochars followed the order: peanut straw char > soybean straw char > canola straw char > rice straw char > a commercial activated carbonaceous material, which is consistent with the alkalinity of the biochars. The pH of the effluent was a key factor determining the removal efficiency of Cu(II) by biochars. Raising the initial pH of the effluent enhanced the removal of Cu(II) from it. The optimum pyrolysis temperature was 400 degrees C for producing biochar from crop straws for acidic wastewater treatment, and the optimum reaction time was 8 hr. PMID:23923773

  16. The Formation of Pyrroline and Tetrahydropyridine Rings in Amino Acids Catalyzed by Pyrrolysine Synthase (PylD)

    Quitterer, Felix

    2014-06-10

    The dehydrogenase PylD catalyzes the ultimate step of the pyrrolysine pathway by converting the isopeptide L-lysine-Nε-3R-methyl-D-ornithine to the 22nd proteinogenic amino acid. In this study, we demonstrate how PylD can be harnessed to oxidize various isopeptides to novel amino acids by combining chemical synthesis with enzyme kinetics and X-ray crystallography. The data enable a detailed description of the PylD reaction trajectory for the biosynthesis of pyrroline and tetrahydropyridine rings as constituents of pyrrolysine analogues. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Deregulation of acetohydroxy-acid synthase: loss of allosteric inhibition conferred by mutations in the catalytic subunit

    Kopecký, Jan; Kyselková, Martina; Šigutová, Lucie; Pospíšil, Stanislav; Felsberg, Jürgen; Spížek, Jaroslav; Janata, Jiří

    2008-01-01

    Roč. 53, č. 6 (2008), s. 467-471. ISSN 0015-5632 R&D Projects: GA ČR GA204/01/1001; GA ČR GA204/05/0616 Institutional research plan: CEZ:AV0Z50200510 Keywords : acetohydroxy acid * ilvb genes * sequencing Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

  18. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II), Cu(II), Ni(II), and Zn(II) Complexes With Amino Acid-Derived Compounds

    Zahid H. Chohan; Arif, M.; Akhtar, Muhammad A.; Supuran, Claudiu T.

    2006-01-01

    A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II), copper(II), nickel(II), and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L1)−(L5) were derived by condensation of β-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc) via the azo...

  19. M-CSF from Cancer Cells Induces Fatty Acid Synthase and PPARβ/δ Activation in Tumor Myeloid Cells, Leading to Tumor Progression

    Jonghanne Park

    2015-03-01

    Full Text Available We investigate crosstalk between cancer cells and stromal myeloid cells. We find that Lewis lung carcinoma cells significantly induce PPARβ/δ activity in myeloid cells in vitro and in vivo. Myeloid cell-specific knockout of PPARβ/δ results in impaired growth of implanted tumors, and this is restored by adoptive transfer of wild-type myeloid cells. We find that IL-10 is a downstream effector of PPARβ/δ and facilitates tumor cell invasion and angiogenesis. This observation is supported by the finding that the CD11blowIL-10+ pro-tumoral myeloid cell is scarcely detected in tumors from myeloid-cell-specific PPARβ/δ knockout mice, where vessel densities are also decreased. Fatty acid synthase (FASN is shown to be an upstream regulator of PPARβ/δ in myeloid cells and is induced by M-CSF secreted from tumor cells. Our study gives insight into how cancer cells influence myeloid stromal cells to get a pro-tumoral phenotype.

  20. Maintained activity of glycogen synthase kinase-3{beta} despite of its phosphorylation at serine-9 in okadaic acid-induced neurodegenerative model

    Lim, Yong-Whan [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Yoon, Seung-Yong, E-mail: ysy@amc.seoul.kr [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Jung-Eun [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Kim, Sang-Min [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Hui-Sun; Choe, Han [Department of Physiology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Seung-Chul [CrystalGenomics, Seoul (Korea, Republic of); Kim, Dong-Hou, E-mail: dhkim@amc.seoul.kr [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2010-04-30

    Glycogen synthase kinase-3{beta} (GSK3{beta}) is recognized as one of major kinases to phosphorylate tau in Alzheimer's disease (AD), thus lots of AD drug discoveries target GSK3{beta}. However, the inactive form of GSK3{beta} which is phosphorylated at serine-9 is increased in AD brains. This is also inconsistent with phosphorylation status of other GSK3{beta} substrates, such as {beta}-catenin and collapsin response mediator protein-2 (CRMP2) since their phosphorylation is all increased in AD brains. Thus, we addressed this paradoxical condition of AD in rat neurons treated with okadaic acid (OA) which inhibits protein phosphatase-2A (PP2A) and induces tau hyperphosphorylation and cell death. Interestingly, OA also induces phosphorylation of GSK3{beta} at serine-9 and other substrates including tau, {beta}-catenin and CRMP2 like in AD brains. In this context, we observed that GSK3{beta} inhibitors such as lithium chloride and 6-bromoindirubin-3'-monoxime (6-BIO) reversed those phosphorylation events and protected neurons. These data suggest that GSK3{beta} may still have its kinase activity despite increase of its phosphorylation at serine-9 in AD brains at least in PP2A-compromised conditions and that GSK3{beta} inhibitors could be a valuable drug candidate in AD.

  1. 4-Methylumbelliferone inhibits hyaluronan synthesis by depletion of cellular UDP-glucuronic acid and downregulation of hyaluronan synthase 2 and 3

    Kultti, Anne, E-mail: anne.kultti@uku.fi [Institute of Biomedicine, Anatomy, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio (Finland); Pasonen-Seppaenen, Sanna [Institute of Biomedicine, Anatomy, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio (Finland); Jauhiainen, Marjo [Department of Pharmaceutical Chemistry, University of Kuopio, FIN-70211 Kuopio (Finland); Rilla, Kirsi J.; Kaernae, Riikka; Pyoeriae, Emma; Tammi, Raija H.; Tammi, Markku I. [Institute of Biomedicine, Anatomy, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio (Finland)

    2009-07-01

    Hyaluronan accumulation on cancer cells and their surrounding stroma predicts an unfavourable disease outcome, suggesting that hyaluronan enhances tumor growth and spreading. 4-Methylumbelliferone (4-MU) inhibits hyaluronan synthesis and retards cancer spreading in experimental animals through mechanisms not fully understood. These mechanisms were studied in A2058 melanoma cells, MCF-7 and MDA-MB-361 breast, SKOV-3 ovarian and UT-SCC118 squamous carcinoma cells by analysing hyaluronan synthesis, UDP-glucuronic acid (UDP-GlcUA) content, and hyaluronan synthase (HAS) mRNA levels. The maximal inhibition in hyaluronan synthesis ranged 22-80% in the cell lines tested. Active glucuronidation of 4-MU produced large quantities of 4-MU-glucuronide, depleting the cellular UDP-GlcUA pool. The maximal reduction varied between 38 and 95%. 4-MU also downregulated HAS mRNA levels: HAS3 was 84-60% lower in MDA-MB-361, A2058 and SKOV-3 cells. HAS2 was the major isoenzyme in MCF-7 cells and lowered by 81%, similar to 88% in A2058 cells. These data indicate that both HAS substrate and HAS2 and/or HAS3 mRNA are targeted by 4-MU. Despite different target point sensitivities, the reduction of hyaluronan caused by 4-MU was associated with a significant inhibition of cell migration, proliferation and invasion, supporting the importance of hyaluronan synthesis in cancer, and the therapeutic potential of hyaluronan synthesis inhibition.

  2. Effects of a subconvulsive dose of kainic acid on the gene expressions of the arginine vasopressin, oxytocin and neuronal nitric oxide synthase in the rat hypothalamus.

    Yoshimura, Mitsuhiro; Ohkubo, Jun-ichi; Hashimoto, Hirofumi; Matsuura, Takanori; Maruyama, Takashi; Onaka, Tatsushi; Suzuki, Hideaki; Ueta, Yoichi

    2015-10-01

    Arginine vasopressin (AVP) synthesis in the hypothalamo-neurohypophysial system (HNS) is up-regulated by kainic acid (KA)-induced seizure in rats. However, it remains unknown whether a subconvulsive dose of KA affects the HNS. Here we examined the effects of subcutaneous (s.c.) administration of a low dose of KA (4 mg/kg) on the gene expressions of the AVP, oxytocin (OXT) and neuronal nitric oxide synthase (nNOS) in the supraoptic (SON) and paraventricular nuclei (PVN) of the rat hypothalamus, using in situ hybridization histochemistry. The expression of the AVP gene in the SON and PVN was judged to be up-regulated in KA-treated rats in comparison with saline-treated rats as controls. Next, the expression of the OXT gene was significantly increased in the SON at 6-24h and in the PVN at 6 and 12h after s.c. administration of KA. Finally, the expression of the nNOS gene was significantly increased in the SON and PVN at 3 and 6h after s.c. administration of KA. These results suggest that up-regulation of the gene expressions of the AVP, OXT and nNOS in the rat hypothalamus may be differentially affected by peripheral administration of a subconvulsive dose of KA. PMID:26003742

  3. Alkyl sulfonic acide hydrazides: Synthesis, characterization, computational studies and anticancer, antibacterial, anticarbonic anhydrase II (hCA II) activities

    O. Ozdemir, Ummuhan; İlbiz, Firdevs; Balaban Gunduzalp, Ayla; Ozbek, Neslihan; Karagoz Genç, Zuhal; Hamurcu, Fatma; Tekin, Suat

    2015-11-01

    Methane sulfonic acide hydrazide, CH3SO2NHNH2 (1), ethane sulfonic acide hydrazide, CH3CH2SO2NHNH2 (2), propane sulfonic acide hydrazide, CH3CH2CH2SO2NHNH2 (3) and butane sulfonic acide hydrazide, CH3CH2CH2CH2SO2NHNH2 (4) have been synthesized as homologous series and characterized by using elemental analysis, spectrophotometric methods (1H-13C NMR, FT-IR, LC-MS). In order to gain insight into the structure of the compounds, we have performed computational studies by using 6-311G(d, p) functional in which B3LYP functional were implemented. The geometry of the sulfonic acide hydrazides were optimized at the DFT method with Gaussian 09 program package. A conformational analysis of compounds were performed by using NMR theoretical calculations with DFT/B3LYP/6-311++G(2d, 2p) level of theory by applying the (GIAO) approach. The anticancer activities of these compounds on MCF-7 human breast cancer cell line investigated by comparing IC50 values. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Gram negative bacteria; Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442, Klebsiella pneumonia ATCC 70063 by using the disc diffusion method. The inhibition activities of these compounds on carbonic anhydrase II enzyme (hCA II) have been investigated by comparing IC50 and Ki values. The biological activity screening shows that butane sulfonic acide hydrazide (4) has more activity than the others against tested breast cancer cell lines MCF-7, Gram negative/Gram positive bacteria and carbonic anhydrase II (hCA II) isoenzyme.

  4. Cyclopropane fatty acid synthase mutants of probiotic human-derived Lactobacillus reuteri are defective in TNF inhibition

    Jones, Sara E.; Whitehead, Kristi; Saulnier, Delphine; Thomas, Carissa M.; Versalovic, James; Britton, Robert A

    2011-01-01

    Although commensal microbes have been shown to modulate host immune responses, many of the bacterial factors that mediate immune regulation remain unidentified. Select strains of human-derived Lactobacillus reuteri synthesize immunomodulins that potently inhibit production of the inflammatory cytokine TNF. In this study, genetic and genomic approaches were used to identify and investigate L. reuteri genes required for human TNF immunomodulatory activity. Analysis of membrane fatty acids from ...

  5. Involvement of Salicylic Acid on Antioxidant and Anticancer Properties, Anthocyanin Production and Chalcone Synthase Activity in Ginger (Zingiber officinale Roscoe Varieties

    Ehsan Karimi

    2012-11-01

    Full Text Available The effect of foliar application of salicylic acid (SA at different concentrations (10−3 M and 10−5 M was investigated on the production of secondary metabolites (flavonoids, chalcone synthase (CHS activity, antioxidant activity and anticancer activity (against breast cancer cell lines MCF-7 and MDA-MB-231 in two varieties of Malaysian ginger, namely Halia Bentong and Halia Bara. The results of high performance liquid chromatography (HPLC analysis showed that application of SA induced the synthesis of anthocyanin and fisetin in both varieties. Anthocyanin and fisetin were not detected in the control plants. Accordingly, the concentrations of some flavonoids (rutin and apigenin decreased significantly in plants treated with different concentrations of SA. The present study showed that SA enhanced the chalcone synthase (CHS enzyme activity (involving flavonoid synthesis and recorded the highest activity value of 5.77 nkat /mg protein in Halia Bara with the 10−5 M SA treatment. As the SA concentration was decreased from 10−3 M to 10−5 M, the free radical scavenging power (FRAP increased about 23% in Halia Bentong and 10.6% in Halia Bara. At a concentration of 350 μg mL−1, the DPPH antioxidant activity recorded the highest value of 58.30%–72.90% with the 10−5 M SA treatment followed by the 10−3 M SA (52.14%–63.66% treatment. The lowest value was recorded in the untreated control plants (42.5%–46.7%. These results indicate that SA can act not only as an inducer but also as an inhibitor of secondary metabolites. Meanwhile, the highest anticancer activity against MCF-7 and MDA-MB-231 cell lines was observed for H. Bara extracts treated with 10−5 M SA with values of 61.53 and 59.88%, respectively. The results suggest that the high anticancer activity in these varieties may be related to the high concentration of potent anticancer components including fisetin and anthocyanin. The results thus indicate that the synthesis of

  6. A Mutant of Hepatitis B Virus X Protein (HBxΔ127 Promotes Cell Growth through A Positive Feedback Loop Involving 5-Lipoxygenase and Fatty Acid Synthase

    Qi Wang

    2010-02-01

    Full Text Available Hepatocellular carcinoma (HCC is one of the most common malignant tumors worldwide. Hepatitis B virus X protein (HBx contributes to the development of HCC, whereas HBx with COOH-terminal deletion is a frequent event in the HCC tissues. Previously, we identified a natural mutant of HBx-truncated 27 amino acids at the COOH-terminal (termed HBxΔ127, which strongly enhanced cell growth. In the present study, we focused on investigating the mechanism. Accordingly, fatty acid synthase (FAS plays a crucial role in cancer cell survival and proliferation; thus, we examined the signaling pathways involving FAS. Our data showed that HBxΔ127 strongly increased the transcriptional activities of FAS in human hepatoma HepG2 and H7402 cells. Moreover, we found that 5-lipoxygenase (5-LOX was responsible for the up-regulation of FAS by using MK886 (an inhibitor of 5-LOX and 5-LOX small interfering RNA. We observed that HBxΔ127 could upregulate 5-LOX through phosphorylated extracellular signal-regulated protein kinases 1/2 and thus resulted in the increase of released leukotriene B4 (LTB4, a metabolite of 5-LOX by ELISA. The additional LTB4 could upregulate the expression of FAS in the cells as well. Interestingly, we found that FAS was able to upregulate the expression of 5-LOX in a feedback manner by using cerulenin (an inhibitor of FAS. Collectively, HBxΔ127 promotes cell growth through a positive feedback loop involving 5-LOX and FAS, in which released LTB4 is involved in the up-regulation of FAS. Thus, our finding provides a new insight into the mechanism involving the promotion of cell growth mediated by HBxΔ127.

  7. Aldosterone synthase C-344T, angiotensin II type 1 receptor A1166C and 11- hydroxysteroid dehydrogenase G534A gene polymorphisms and essential hypertension in the population of Odisha, India

    Manisha Patnaik; Pallabi Pati; Surendra N. Swain; Manoj K. Mohapatra; Bhagirathi Dwibedi; Shantanu K. Kar; Manoranjan Ranjit

    2014-12-01

    Essential hypertension which accounts 90–95% of the total hypertension cases is affected by both genetic and environmental factors. This study was undertaken to investigate the association of aldosterone synthase C-344T, angiotensin II type I receptor A1166C and 11- hydroxysteroid dehydrogenase type 2 G534A polymorphisms with essential hypertension in the population of Odisha, India. A total of 246 hypertensive subjects (males, 159; females, 87) and 274 normal healthy individuals (males, 158; females, 116) were enrolled in this study based on the inclusion and exclusion criteria. Analysis of genetic and biochemical data revealed that in this population the CT and TT genotypes of aldosterone synthase C-344T polymorphism, frequency of alcohol consumption and aldosterone levels were significantly high among the total as well as male hypertensives, while the AC and CC genotypes of angiotensin II type I receptor A1166C polymorphism were significantly high among the total as well as female hypertensives. High density lipoprotein levels were higher in male hypertensives.

  8. Aldosterone synthase C-344T, angiotensin II type 1 receptor A1166C and 11- hydroxysteroid dehydrogenase G534A gene polymorphisms and essential hypertension in the population of Odisha, India

    Manisha Patnaik; Pallabi Pati; Surendra N. Swain; Manoj K. Mohapatra; Bhagirathi Dwibedi; Shantanu K. Kar; Manoranjan Ranjit

    2015-06-01

    Essential hypertension which accounts 90–95% of the total hypertension cases is affected by both genetic and environmental factors. This study was undertaken to investigate the association of aldosterone synthase C-344T, angiotensin II type I receptor A1166C and 11- hydroxysteroid dehydrogenase type 2 G534A polymorphisms with essential hypertension in the population of Odisha, India. A total of 246 hypertensive subjects (males, 159; females, 87) and 274 normal healthy individuals (males, 158; females, 116) were enrolled in this study based on the inclusion and exclusion criteria. Analysis of genetic and biochemical data revealed that in this population the CT and TT genotypes of aldosterone synthase C-344T polymorphism, frequency of alcohol consumption and aldosterone levels were significantly high among the total as well as male hypertensives, while the AC and CC genotypes of angiotensin II type I receptor A1166C polymorphism were significantly high among the total as well as female hypertensives. High density lipoprotein levels were higher in male hypertensives.

  9. Chemodynamics of soft nanoparticulate complexes: Cu(II) and Ni(II) complexes with fulvic acids and aquatic humic acids

    Town, R.M.; Leeuwen, van H.P.; Buffle, J.

    2012-01-01

    The dynamics of metal complexation by small humic substances (fulvic acid and aquatic humic acid, collectively denoted as "fulvic-like substance", FS) are explored within the framework of concepts recently developed for soft nanoparticulate complexants. From a comprehensive collection of published e

  10. Conjugated Linoleic Acid (CLA) inhibits expression of the Spot 14 (THRSP) and fatty acid synthase genes and impairs the growth of human breast cancer and liposarcoma cells

    Donnelly, Christina; Olsen, Arne M.; Lewis, Lionel D; Eisenberg, Burton L.; Eastman, Alan; Kinlaw, William B

    2009-01-01

    Spot 14 (THRSP, S14) is a nuclear protein involved in the regulation of genes required for fatty acid synthesis in normal and malignant mammary epithelial and adipose cells. Havartine and Bauman reported that conjugated linoleic acid (CLA) inhibits S14 gene expression in bovine mammary and mouse adipose tissues, and reduces milk fat production in cows. We hypothesized that CLA inhibits S14 gene expression in human breast cancer and liposarcoma cells, and that this will retard their growth. Ex...

  11. Rapid Photodegradation of Methyl Orange (MO Assisted with Cu(II and Tartaric Acid.

    Jing Guo

    Full Text Available Cu(II and organic carboxylic acids, existing extensively in soil and aquatic environments, can form complexes that may play an important role in the photodegradation of organic contaminants. In this paper, the catalytic role of Cu(II in the removal of methyl orange (MO in the presence of tartaric acid with light was investigated through batch experiments. The results demonstrate that the introduction of Cu(II could markedly enhance the photodegradation of MO. In addition, high initial concentrations of Cu(II and tartaric acid benefited the decomposition of MO. The most rapid removal of MO assisted by Cu(II was achieved at pH 3. The formation of Cu(II-tartaric acid complexes was assumed to be the key factor, generating hydroxyl radicals (•OH and other oxidizing free radicals under irradiation through a ligand-to-metal charge-transfer pathway that was responsible for the efficient degradation of MO. Some intermediates in the reaction system were also detected to support this reaction mechanism.

  12. Radiochemical extraction of mercury(II) from acidic chloride solutions using dialkylsulphides

    The liquid-liquid extraction behavior of Hg(II) from aqueous acidic chloride solutions has been investigated by tracer techniques using dialkylsulphides (R2S) namely, dibutylsulphide (DBS) and dioctylsulphide (DOS) as extractants. These extraction data have been analyzed by both graphical and theoretical methods by taking into account complexation of the metal ion in the aqueous phase with inorganic ligands and all plausible complexes extracted into the organic phase. The results clearly indicate that Hg(II) is extracted into xylene as HgCl2 x nDBS/nDOS (where n = 2 and 3). The equilibrium constants of the extracted complexes have been deduced by non-linear regression analysis. The separation possibilities of Hg(II) from other metal ions viz. Ca(II), Mg(II), Ba(II) and Fe(III), which are present in the industrial wastes of the chlor-alkali industry has also been discussed. (author)

  13. Sequence analysis and structure prediction of type II Pseudomonas sp. USM 4–55 PHA synthase and an insight into its catalytic mechanism

    Ahmad Khairudin Nurul; Wahab Habibah A; Samian Mohd; Najimudin Nazalan

    2006-01-01

    Abstract Background Polyhydroxyalkanoates (PHA), are biodegradable polyesters derived from many microorganisms such as the pseudomonads. These polyesters are in great demand especially in the packaging industries, the medical line as well as the paint industries. The enzyme responsible in catalyzing the formation of PHA is PHA synthase. Due to the limited structural information, its functional properties including catalysis are lacking. Therefore, this study seeks to investigate the structura...

  14. Synthesis and characterization of Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate Schiff base derived from vanillin and DL-α-aminobutyric acid

    Nair, M. Sivasankaran; Joseyphus, R. Selwin

    2008-09-01

    Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base derived from vanillin and DL-α-aminobutyric acid were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, magnetic measurements, powder XRD and biological activity. The analytical data show the composition of the metal complex to be [ML(H 2O)], where L is the Schiff base ligand. The conductance data indicate that all the complexes are non-electrolytes. IR results demonstrate the tridentate binding of the Schiff base ligand involving azomethine nitrogen, phenolic oxygen and carboxylato oxygen atoms. The IR data also indicate the coordination of a water molecule with the metal ion in the complex. The electronic spectral measurements show that Co(II) and Ni(II) complexes have tetrahedral geometry, while Cu(II) complex has square planar geometry. The powder XRD studies indicate that Co(II) and Cu(II) complexes are amorphous, whereas Ni(II) and Zn(II) complexes are crystalline in nature. Magnetic measurements show that Co(II), Ni(II) and Cu(II) complexes have paramagnetic behaviour. Antibacterial results indicated that the metal complexes are more active than the ligand.

  15. Discovery of arjunolic acid as a novel non-zinc binding carbonic anhydrase II inhibitor.

    Kalyanavenkataraman, Subhalakshmi; Nanjan, Pandurangan; Banerji, Asoke; Nair, Bipin G; Kumar, Geetha B

    2016-06-01

    Elevated levels of carbonic anhydrase II (CA II) have been shown to be associated with cardiac hypertrophy and heart failure. Although arjunolic acid (AA) has a diverse range of therapeutic applications including cardio-protection, there have been no reports on the effect of AA on CA II. The present study describes for the first time, the novel zinc independent inhibition of CA II by AA. The molecular docking studies of AA indicated that the hydroxyl group at C2 of the A-ring, which hydrogen bonds with the catalytic site residues (His64, Asn62 and Asn67), along with the gem-dimethyl group at C20 of the E-ring, greatly influences the inhibitory activity, independent of the catalytic zinc, unlike the inhibition observed with most CA II inhibitors. Among the triterpenoids tested viz. arjunolic acid, arjunic acid, asiatic acid, oleanolic acid and ursolic acid, AA was the most potent in inhibiting CA II in vitro with an IC50 of 9μM. It was interesting to note, that in spite of exhibiting very little differences in their structures, these triterpenoids exhibited vast differences in their inhibitory activities, with IC50 values ranging from 9μM to as high as 333μM. Furthermore, AA also inhibited the cytosolic activity of CA in H9c2 cardiomyocytes, as reflected by the decrease in acidification of the intracellular pH (pHi). The decreased acidification reduced the intracellular calcium levels, which further prevented the mitochondrial membrane depolarization. Thus, these studies provide a better understanding for establishing the novel molecular mechanism involved in CA II inhibition by the non-zinc binding inhibitor AA. PMID:27038848

  16. HYDRAZOIC ACID CONTROLS AND RISKS WHEN PROCESSING NEPTUNIUM SOLUTIONS IN HB-LINE PHASE II

    Hydrazine mononitrate will be used in processing neptunium in Phase II of HB-Line to scavenge nitrous acid (a byproduct of nitric acid) in the column feed adjustment tank (JT-71 or JT-72) and also in the precipitation feed adjustment tanks (NT-41/42). Nitrous acid can interfere with valence adjustment chemicals (e.g., ferrous sulfamate and ascorbic acid) and thus interfere with controls that give proper neptunium valence. Hydrazine reacts with nitrous acid to form hydrazoic acid, and the hydrazoic acid also reacts with nitrous acid. The concentration of hydrazoic acid can be controlled below the autocatalytic decomposition limit in both liquid and vapor by controlling the maximum concentration of hydrazine mononitrate in the acid solution. The concentration of nitrous acid available for reaction with hydrazine also limits the amount of hydrazoic acid in solution. The hydrazine concentration will be controlled at or below 0.15M in the neptunium solutions to maintain the hydrazoic acid concentration below autocatalytic decomposition limits. Equipment failures and/or human errors that could cause hydrazine to be present above this limit are evaluated. Satisfying the assumptions stated in this report result in a frequency of Beyond Extremely Unlikely (BEU) for a hydrazoic acid autocatalytic decomposition reaction in either the liquid or vapor phase of the process vessels

  17. Equilibrium, thermoanalytical and spectroscopic studies to characterize phytic acid complexes with Mn(II) and Co(II)

    Carli, Ligia de; Schnitzler, Egon; Rosso, Neiva Deliberali [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Dept. de Quimica], e-mail: ndrosso@uepg.br; Ionashiro, Massao [Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica; Szpoganicz, Bruno [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Quimica

    2009-07-01

    Potentiometric studies were carried out to determine the binding degree of phytic acid with Co(II) and Mn(II) ions, in the absence of dioxygen. Equilibrium constants for all major complexes formed are reported, and the results are presented in the form of distribution diagrams showing the concentrations of individual complexes as a function of pH. The formation constants of the complexes show higher values for the species in which the ligand was more deprotonated. Potentiometric data indicates that the species [MH{sub 4}L]{sup 6-}, was totally formed at pH 7.0 and the complexes were synthesized from this data. A solid state complex of Mn(II) and Co(II) with phytic acid was synthesized. Thermogravimetry, differential scanning calorimetry, and infrared spectroscopy were used to investigate and characterize the thermal behavior of these compounds. The results led to information on the composition, dehydration, thermal stability and thermal decomposition of the isolated complexes. (author)

  18. Engineering of chromosomal wax ester synthase integrated Saccharomyces cerevisiae mutants for improved biosynthesis of fatty acid ethyl esters.

    Shi, Shuobo; Valle-Rodríguez, Juan Octavio; Siewers, Verena; Nielsen, Jens

    2014-09-01

    In recent years, significant advances have been made to engineer robust microbes for overproducing biochemical products from renewable resources. These accomplishments have to a large extend been based on plasmid based methods. However, plasmid maintenance may cause a metabolic burden on the host cell and plasmid-based overexpression of genes can result in genetically unstable strains, which contributes to loss in productivity. Here, a chromosome engineering method based on delta integration was applied in Saccharomyces cerevisiae for the production of fatty acid ethyl esters (FAEEs), which can be directly used as biodiesel and would be a possible substitute for conventional petroleum-based diesel. An integration construct was designed and integrated into chromosomal delta sequences by repetitive transformation, which resulted in 1-6 copies of the integration construct per genome. The corresponding FAEE production increased up to 34 mg/L, which is an about sixfold increase compared to the equivalent plasmid-based producer. The integrated cassette in the yeast genome was stably maintained in nonselective medium after deletion of RAD52 which is essential for efficient homologous recombination. To obtain a further increase of FAEE production, genes encoding endogenous acyl-CoA binding protein (ACB1) and a bacterial NADP(+)-dependent glyceraldehyde-3-phosphate dehydrogenase (gapN) were overexpressed in the final integration strain, which resulted in another 40% percent increase in FAEE production. Our integration strategy enables easy engineering of strains with adjustable gene copy numbers integrated into the genome and this allows for an easy evaluation of the effect of the gene copy number on pathway flux. It therefore represents a valuable tool for introducing and expressing a heterologous pathway in yeast. PMID:24752598

  19. A Ser/Thr protein kinase phosphorylates MA-ACS1 (Musa acuminata 1-aminocyclopropane-1-carboxylic acid synthase 1) during banana fruit ripening.

    Choudhury, Swarup Roy; Roy, Sujit; Sengupta, Dibyendu N

    2012-08-01

    1-Aminocyclopropane-1-carboxylic acid synthase (ACS) catalyzes the rate-limiting step in ethylene biosynthesis during ripening. ACS isozymes are regulated both transcriptionally and post-translationally. However, in banana, an important climacteric fruit, little is known about post-translational regulation of ACS. Here, we report the post-translational modification of MA-ACS1 (Musa acuminata ACS1), a ripening inducible isozyme in the ACS family, which plays a key role in ethylene biosynthesis during banana fruit ripening. Immunoprecipitation analyses of phospholabeled protein extracts from banana fruit using affinity-purified anti-MA-ACS1 antibody have revealed phosphorylation of MA-ACS1, particularly in ripe fruit tissue. We have identified the induction of a 41-kDa protein kinase activity in pulp at the onset of ripening. The 41-kDa protein kinase has been identified as a putative protein kinase by MALDI-TOF/MS analysis. Biochemical analyses using partially purified protein kinase fraction from banana fruit have identified the protein kinase as a Ser/Thr family of protein kinase and its possible involvement in MA-ACS1 phosphorylation during ripening. In vitro phosphorylation analyses using synthetic peptides and site-directed mutagenized recombinant MA-ACS1 have revealed that serine 476 and 479 residues at the C-terminal region of MA-ACS1 are phosphorylated. Overall, this study provides important novel evidence for in vivo phosphorylation of MA-ACS1 at the molecular level as a possible mechanism of post-translational regulation of this key regulatory protein in ethylene signaling pathway in banana fruit during ripening. PMID:22419220

  20. Fetal and neonatal exposure to nicotine leads to augmented hepatic and circulating triglycerides in adult male offspring due to increased expression of fatty acid synthase

    While nicotine replacement therapy is assumed to be a safer alternative to smoking during pregnancy, the long-term consequences for the offspring remain elusive. Animal studies now suggest that maternal nicotine exposure during perinatal life leads to a wide range of adverse outcomes for the offspring including increased adiposity. The focus of this study was to investigate if nicotine exposure during pregnancy and lactation leads to alterations in hepatic triglyceride synthesis. Female Wistar rats were randomly assigned to receive daily subcutaneous injections of saline (vehicle) or nicotine bitartrate (1 mg/kg/day) for two weeks prior to mating until weaning. At postnatal day 180 (PND 180), nicotine exposed offspring exhibited significantly elevated levels of circulating and hepatic triglycerides in the male offspring. This was concomitant with increased expression of fatty acid synthase (FAS), the critical hepatic enzyme in de novo triglyceride synthesis. Given that FAS is regulated by the nuclear receptor Liver X receptor (LXRα), we measured LXRα expression in both control and nicotine-exposed offspring. Nicotine exposure during pregnancy and lactation led to an increase in hepatic LXRα protein expression and enriched binding to the putative LXRE element on the FAS promoter in PND 180 male offspring. This was also associated with significantly enhanced acetylation of histone H3 [K9,14] surrounding the FAS promoter, a hallmark of chromatin activation. Collectively, these findings suggest that nicotine exposure during pregnancy and lactation leads to an increase in circulating and hepatic triglycerides long-term via changes in the transcriptional and epigenetic regulation of the hepatic lipogenic pathway. - Highlights: • Our data reveals the links nicotine exposure in utero and long-term hypertriglyceridemia. • It is due to nicotine-induced augmented expression of hepatic FAS and LXRα activity. • Moreover, this involves nicotine-induced enhanced

  1. Fetal and neonatal exposure to nicotine leads to augmented hepatic and circulating triglycerides in adult male offspring due to increased expression of fatty acid synthase

    Ma, Noelle [Department of Physiology and Pharmacology, The University of Western Ontario (Canada); Department of Obstetrics and Gynecology, The University of Western Ontario (Canada); The Lawson Health Research Institute, The University of Western Ontario (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University (Canada); Wong, Michael [Department of Physiology and Pharmacology, The University of Western Ontario (Canada); Department of Obstetrics and Gynecology, The University of Western Ontario (Canada); The Lawson Health Research Institute, The University of Western Ontario (Canada); Holloway, Alison C. [Department of Obstetrics and Gynecology, McMaster University (Canada); Hardy, Daniel B., E-mail: Daniel.Hardy@schulich.uwo.ca [Department of Physiology and Pharmacology, The University of Western Ontario (Canada); Department of Obstetrics and Gynecology, The University of Western Ontario (Canada); The Children' s Health Research Institute, The University of Western Ontario (Canada); The Lawson Health Research Institute, The University of Western Ontario (Canada)

    2014-02-15

    While nicotine replacement therapy is assumed to be a safer alternative to smoking during pregnancy, the long-term consequences for the offspring remain elusive. Animal studies now suggest that maternal nicotine exposure during perinatal life leads to a wide range of adverse outcomes for the offspring including increased adiposity. The focus of this study was to investigate if nicotine exposure during pregnancy and lactation leads to alterations in hepatic triglyceride synthesis. Female Wistar rats were randomly assigned to receive daily subcutaneous injections of saline (vehicle) or nicotine bitartrate (1 mg/kg/day) for two weeks prior to mating until weaning. At postnatal day 180 (PND 180), nicotine exposed offspring exhibited significantly elevated levels of circulating and hepatic triglycerides in the male offspring. This was concomitant with increased expression of fatty acid synthase (FAS), the critical hepatic enzyme in de novo triglyceride synthesis. Given that FAS is regulated by the nuclear receptor Liver X receptor (LXRα), we measured LXRα expression in both control and nicotine-exposed offspring. Nicotine exposure during pregnancy and lactation led to an increase in hepatic LXRα protein expression and enriched binding to the putative LXRE element on the FAS promoter in PND 180 male offspring. This was also associated with significantly enhanced acetylation of histone H3 [K9,14] surrounding the FAS promoter, a hallmark of chromatin activation. Collectively, these findings suggest that nicotine exposure during pregnancy and lactation leads to an increase in circulating and hepatic triglycerides long-term via changes in the transcriptional and epigenetic regulation of the hepatic lipogenic pathway. - Highlights: • Our data reveals the links nicotine exposure in utero and long-term hypertriglyceridemia. • It is due to nicotine-induced augmented expression of hepatic FAS and LXRα activity. • Moreover, this involves nicotine-induced enhanced

  2. Metformin blocks the stimulative effect of a high-energy diet on colon carcinoma growth in vivo and is associated with reduced expression of fatty acid synthase.

    Algire, Carolyn; Amrein, Lilian; Zakikhani, Mahvash; Panasci, Lawrence; Pollak, Michael

    2010-06-01

    The molecular mechanisms responsible for the association of obesity with adverse colon cancer outcomes are poorly understood. We investigated the effects of a high-energy diet on growth of an in vivo colon cancer model. Seventeen days following the injection of 5x10(5) MC38 colon carcinoma cells, tumors from mice on the high-energy diet were approximately twice the volume of those of mice on the control diet. These findings were correlated with the observation that the high-energy diet led to elevated insulin levels, phosphorylated AKT, and increased expression of fatty acid synthase (FASN) by the tumor cells. Metformin, an antidiabetic drug, leads to the activation of AMPK and is currently under investigation for its antineoplastic activity. We observed that metformin blocked the effect of the high-energy diet on tumor growth, reduced insulin levels, and attenuated the effect of diet on phosphorylation of AKT and expression of FASN. Furthermore, the administration of metformin led to the activation of AMPK, the inhibitory phosphorylation of acetyl-CoA carboxylase, the upregulation of BNIP3 and increased apoptosis as estimated by poly (ADP-ribose) polymerase (PARP) cleavage. Prior work showed that activating mutations of PI3K are associated with increased AKT activation and adverse outcome in colon cancer; our results demonstrate that the aggressive tumor behavior associated with a high-energy diet has similar effects on this signaling pathway. Furthermore, metformin is demonstrated to reverse the effects of the high-energy diet, thus suggesting a potential role for this agent in the management of a metabolically defined subset of colon cancers. PMID:20228137

  3. A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

    A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 μg ml-1. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C

  4. Functionalization of conducting polymer with novel Co(II) complex: Electroanalysis of ascorbic acid

    We report for the first time the functionalization of a conducting polymer with a metal complex in order to develop a new type of catalytic material exhibiting better electronic communication through their delocalized π electrons. The Co(II) complex having hydroxyl group as functional moiety is chemically coupled with carboxyl group of polyanthranilic acid which itself is a self doped conducting polymer. The covalent linkage between Co(II) and -OH group is confirmed using UV-vis, FT-IR and NMR spectroscopic techniques. The Co(II) complex functionalized polymer does exhibit excellent redox behavior and stability with mixed properties of Co(II) complex and π-conjugated polymer. The material possesses potential benefits in sensors/biosensor applications and it is demonstrated for the electroanalysis of ascorbic acid at a level of nano molar concentration.

  5. Determination of stability constants of the Co(II) complexes with weathered coal fulvic acid

    The stability constants of Co(II) complexes with weathered coal fulvic acid are determined by both Schubert method and Stevenson method at pH = 5.3 +- 0.2, I = 0.001-1.0 mol/kg and (30 +- 1) degree C. The modified Schubert method is also used to estimate the stability constants of Co(II) complexes with the fulvic acid. It is shown that the trend of forming poly nuclei complexes of Co(II)-fulvic acid increases with increasing ionic strength in the solution and that 1:1 and 2:1 type complexes, respectively, are formed at different ionic strength. A comparison between the values of lg β obtained by different methods is made

  6. A two-dimensional cadmium(II) polymer based on nicotinic acid and thiocyanate ligands.

    Zhou, Lin; Wang, Hui-Ting

    2015-09-01

    A cadmium-thiocyanate complex, poly[[bis(nicotinic acid-κN)di-μ-thiocyanato-κ(2)N:S;κ(2)S:N-cadmium(II)] monohydrate], {[Cd(NCS)2(C6H5NO2)2]·H2O}n, was synthesized by the reaction of nicotinic acid, cadmium nitrate tetrahydrate and potassium thiocyanide in aqueous solution. In the crystal structure, each Cd(II) cation is in a distorted octahedral coordination environment, coordinated by the N and S atoms of nicotinic acid and thiocyanate ligands. Neighbouring Cd(II) cations are linked together by thiocyanate bridges to form a two-dimensional network. Hydrogen-bond interactions between the uncoordinated solvent water molecules and the organic ligands result in the formation of the three-dimensional supramolecular network. PMID:26322616

  7. Pb(II) leaching from waste CRT funnel glass in nitric acid solutions

    A. Strzałkowska; M. Wojtala; J. Siwka

    2012-01-01

    Purpose: The paper presents experimental results of Pb (II) leaching from waste CRT funnel glass using solution of nitric acid (V) . This work focused on examining the impact of concentration and particle size on the leaching percentage of Pb (II) from funnel glass.Design/methodology/approach: Material for the investigation was crushed and sieved. Leaching was carried out using working solutions pfrom co repared ncentrated HNO3 and mechanical stirrer.Findings: The received results show the po...

  8. Nitric oxide donors prevent while the nitric oxide synthase inhibitor L-NAME increases arachidonic acid plus CYP2E1-dependent toxicity

    Polyunsaturated fatty acids such as arachidonic acid (AA) play an important role in alcohol-induced liver injury. AA promotes toxicity in rat hepatocytes with high levels of cytochrome P4502E1 and in HepG2 E47 cells which express CYP2E1. Nitric oxide (NO) participates in the regulation of various cell activities as well as in cytotoxic events. NO may act as a protectant against cytotoxic stress or may enhance cytotoxicity when produced at elevated concentrations. The goal of the current study was to evaluate the effect of endogenously or exogenously produced NO on AA toxicity in liver cells with high expression of CYP2E1 and assess possible mechanisms for its actions. Pyrazole-induced rat hepatocytes or HepG2 cells expressing CYP2E1 were treated with AA in the presence or absence of an inhibitor of nitric oxide synthase L-N G-Nitroarginine Methylester (L-NAME) or the NO donors S-nitroso-N-acetylpenicillamine (SNAP), and (Z)-1-[-(2-aminoethyl)-N-(2-aminoethyl)]diazen-1-ium-1,2-diolate (DETA-NONO). AA decreased cell viability from 100% to 48 ± 6% after treatment for 48 h. In the presence of L-NAME, viability was further lowered to 23 ± 5%, while, SNAP or DETA-NONO increased viability to 66 ± 8 or 71 ± 6%. The L-NAME potentiated toxicity was primarily necrotic in nature. L-NAME did not affect CYP2E1 activity or CYP2E1 content. SNAP significantly lowered CYP2E1 activity but not protein. AA treatment increased lipid peroxidation and lowered GSH levels. L-NAME potentiated while SNAP prevented these changes. Thus, L-NAME increased, while NO donors decreased AA-induced oxidative stress. Antioxidants prevented the L-NAME potentiation of AA toxicity. Damage to mitochondria by AA was shown by a decline in the mitochondrial membrane potential (MMP). L-NAME potentiated this decline in MMP in association with its increase in AA-induced oxidative stress and toxicity. NO donors decreased this decline in MMP in association with their decrease in AA-induced oxidative stress and

  9. Fatty acid synthase is a key target in multiple essential tumor functions of prostate cancer: uptake of radiolabeled acetate as a predictor of the targeted therapy outcome.

    Yukie Yoshii

    Full Text Available Fatty acid synthase (FASN expression is elevated in several cancers, and this over-expression is associated with poor prognosis. Inhibitors of FASN, such as orlistat, reportedly show antitumor effects against cancers that over-express FASN, making FASN a promising therapeutic target. However, large variations in FASN expression levels in individual tumors have been observed, and methods to predict FASN-targeted therapy outcome before treatment are required to avoid unnecessary treatment. In addition, how FASN inhibition affects tumor progression remains unclear. Here, we showed the method to predict FASN-targeted therapy outcome using radiolabeled acetate uptake and presented mechanisms of FASN inhibition with human prostate cancer cell lines, to provide the treatment strategy of FASN-targeted therapy. We revealed that tumor uptake of radiolabeled acetate reflected the FASN expression levels and sensitivity to FASN-targeted therapy with orlistat in vitro and in vivo. FASN-targeted therapy was noticeably effective against tumors with high FASN expression, which was indicated by high acetate uptake. To examine mechanisms, we established FASN knockdown prostate cancer cells by transduction of short-hairpin RNA against FASN and investigated the characteristics by analyses on morphology and cell behavior and microarray-based gene expression profiling. FASN inhibition not only suppressed cell proliferation but prevented pseudopodia formation and suppressed cell adhesion, migration, and invasion. FASN inhibition also suppressed genes involved in production of intracellular second messenger arachidonic acid and androgen hormones, both of which promote tumor progression. Collectively, our data demonstrated that uptake of radiolabeled acetate is a useful predictor of FASN-targeted therapy outcome. This suggests that [1-(11C]acetate positron emission tomography (PET could be a powerful tool to accomplish personalized FASN-targeted therapy by non

  10. Liquid-Liquid Extraction and Separation of Co (II) and Ni(II) from Chloride Medium by bis (2,4,4-trimethylpentyl) dithio phosphinic acid in Kerosene

    The extraction of Co(II) and Ni(II) from chloride solutions using bis (2,4,4-trimethylpentyl) dithio phosphinic acid (CYANEX 301) in kerosene has been investigated. The various factors affecting the extraction process of Co(II) and Ni(II) by the investigated extractant such as contact time, ph, extractant and metal ion concentration as well as temperature, are separately investigated. The stripping of the extracted metal ions from loaded organic solutions is also carried out using different stripping reagents. The results were used to assess the conditions for maximum Co(II)/Ni(II) separation from chloride medium using CYANEX 301

  11. Manganese(II) catalyzes the bicarbonate-dependent oxidation of amino acids by hydrogen peroxide and the amino acid-facilitated dismutation of hydrogen peroxide.

    Berlett, B S; Chock, P B; Yim, M B; Stadtman, E. R.

    1990-01-01

    In bicarbonate/CO2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H2O2 and the dismutation of H2O2. As the Mn(II)/Fe(II) ratio is increased, the yield of carbonyl compounds per mole of leucine oxidized is essentially constant, but the ratio of alpha-ketoisocaproate to isovaleraldehyde formed increases, and the fraction of H2O2 converted to O2 increases. In the absence of Fe(II), the rate of Mn(II)-catalyzed leucine oxidation is directly proportional to the H2O2, Mn(II), an...

  12. OsJAR1 and OsJAR2 are jasmonyl-L-isoleucine synthases involved in wound- and pathogen-induced jasmonic acid signalling.

    Wakuta, Shinji; Suzuki, Erika; Saburi, Wataru; Matsuura, Hideyuki; Nabeta, Kensuke; Imai, Ryozo; Matsui, Hirokazu

    2011-06-17

    The synthesis of JA-Ile was catalysed by JA-Ile synthase, which is a member of the group I GH3 family of proteins. Here, we showed evidence that OsGH3.5 (OsJAR1) and OsGH3.3 (OsJAR2) are the functional JA-Ile synthases in rice, using recombinant proteins. The expression levels of OsJAR1 and OsJAR2 were induced in response to wounding with the concomitant accumulation of JA-Ile. In contrast, only the expression of OsJAR1 was associated with the accumulation of JA-Ile after blast infection. Our data suggest that these two JA-Ile synthases are differentially involved in the activation of JA signalling in response to wounding and pathogen challenge in rice. PMID:21619871

  13. Fatty acid nitroalkenes induce resistance to ischemic cardiac injury by modulating mitochondrial respiration at complex II

    Koenitzer, Jeffrey R; Gustavo Bonacci; Woodcock, Steven R.; Chen-Shan Chen; Nadiezhda Cantu-Medellin; Kelley, Eric E.; Schopfer, Francisco J.

    2016-01-01

    Nitro-fatty acids (NO2-FA) are metabolic and inflammatory-derived electrophiles that mediate pleiotropic signaling actions. It was hypothesized that NO2-FA would impact mitochondrial redox reactions to induce tissue-protective metabolic shifts in cells. Nitro-oleic acid (OA-NO2) reversibly inhibited complex II-linked respiration in isolated rat heart mitochondria in a pH-dependent manner and suppressed superoxide formation. Nitroalkylation of Fp subunit was determined by BME capture and the s...

  14. Solving nucleic acid structures by molecular replacement: examples from group II intron studies

    Strategies for phasing nucleic acid structures by molecular replacement, using both experimental and de novo designed models, are discussed. Structured RNA molecules are key players in ensuring cellular viability. It is now emerging that, like proteins, the functions of many nucleic acids are dictated by their tertiary folds. At the same time, the number of known crystal structures of nucleic acids is also increasing rapidly. In this context, molecular replacement will become an increasingly useful technique for phasing nucleic acid crystallographic data in the near future. Here, strategies to select, create and refine molecular-replacement search models for nucleic acids are discussed. Using examples taken primarily from research on group II introns, it is shown that nucleic acids are amenable to different and potentially more flexible and sophisticated molecular-replacement searches than proteins. These observations specifically aim to encourage future crystallographic studies on the newly discovered repertoire of noncoding transcripts

  15. Solving nucleic acid structures by molecular replacement: examples from group II intron studies

    Marcia, Marco, E-mail: marco.marcia@yale.edu; Humphris-Narayanan, Elisabeth; Keating, Kevin S.; Somarowthu, Srinivas [Yale University, New Haven, CT 06511 (United States); Rajashankar, Kanagalaghatta [Argonne National Laboratory, Argonne, IL 60439 (United States); Pyle, Anna Marie, E-mail: marco.marcia@yale.edu [Yale University, New Haven, CT 06511 (United States); Yale University, New Haven, CT 06511 (United States); Howard Hughes Medical Institute, Chevy Chase, MD 20815 (United States)

    2013-11-01

    Strategies for phasing nucleic acid structures by molecular replacement, using both experimental and de novo designed models, are discussed. Structured RNA molecules are key players in ensuring cellular viability. It is now emerging that, like proteins, the functions of many nucleic acids are dictated by their tertiary folds. At the same time, the number of known crystal structures of nucleic acids is also increasing rapidly. In this context, molecular replacement will become an increasingly useful technique for phasing nucleic acid crystallographic data in the near future. Here, strategies to select, create and refine molecular-replacement search models for nucleic acids are discussed. Using examples taken primarily from research on group II introns, it is shown that nucleic acids are amenable to different and potentially more flexible and sophisticated molecular-replacement searches than proteins. These observations specifically aim to encourage future crystallographic studies on the newly discovered repertoire of noncoding transcripts.

  16. Prebiotic syntheses of vitamin coenzymes: II. Pantoic acid, pantothenic acid, and the composition of coenzyme A

    Miller, S. L.; Schlesinger, G.

    1993-01-01

    Pantoic acid can by synthesized in good prebiotic yield from isobutyraldehyde or alpha-ketoisovaleric acid + H2CO + HCN. Isobutyraldehyde is the Strecker precursor to valine and alpha-ketoisovaleric acid is the valine transamination product. Mg2+ and Ca2+ as well as several transition metals are catalysts for the alpha-ketoisovaleric acid reaction. Pantothenic acid is produced from pantoyl lactone (easily formed from pantoic acid) and the relatively high concentrations of beta-alanine that would be formed on drying prebiotic amino acid mixtures. There is no selectivity for this reaction over glycine, alanine, or gamma-amino butyric acid. The components of coenzyme A are discussed in terms of ease of prebiotic formation and stability and are shown to be plausible choices, but many other compounds are possible. The gamma-OH of pantoic acid needs to be capped to prevent decomposition of pantothenic acid. These results suggest that coenzyme A function was important in the earliest metabolic pathways and that the coenzyme A precursor contained most of the components of the present coenzyme.

  17. Fatty Acid Synthase and Hormone-sensitive Lipase Expression in Liver Are Involved in Zinc-α2-glycoprotein-induced Body Fat Loss in Obese Mice

    Feng-ying Gong; Jie-ying Deng; Hui-juan Zhu; Hui Pan; Lin-jie Wang; Hong-bo Yang

    2010-01-01

    Objective To explore the effects of zinc-a2-glycoprotein (ZAG) on body weight and body fat in high-fat-diet (HFD)-induced obesity in mice and the possible mechanism.Methods Thirty-six male mice were fed with standard food (SF) (n=9) and HFD (n=27), respec-tively. Five weeks later, 9 mice fed with HFD were subjected to ZAG expression plasmid DNA transfection by liposome transfection method, and another 9 mice to negative control plasmid transfection. Two weeks later, serum ZAG level in the mice was assayed by Western blot, and the effects of ZAG over-expression on body weight, body fat, serum biochemical indexes, and adipose tissue of obese mice were evaluated. The mRNA expressions of fatty acid synthase (FAS) and hormone-sensitive lipase (HSL) in liver tissue were de-termined by reverse transcription-polymerase chain reaction.Results Serum ZAG level significantly lowered in simple HFD-fed mice in comparison to SF-fed mice (0.51±0.10 AU vs. 0.75±0.07 AU, P<0.01). Further statistical analysis demonstrated that ZAG level was negatively correlated with body weight (r =-0.56, P<0.001), epididymal fat mass (r=-0. 67, P<0.001), percentage of epididymal fat (r=-0.65, P<0.001 ), and increased weight (r=-0.57, P<0.001) in simple SF-and HFD-fed mice. ZAG over-expression in obese mice reduced body weight and the percentage of epididy-mal fat. Furthermore, FAS mRNA expression decreased (P<0.01) and HSL mRNA expression increased (P<0.001) in the liver in ZAG over-expressing mice.Conclusions ZAG is closely related to obesity. Serum ZAG level is inversely correlated with body weight and percentage of body fat. The action of ZAG is associated with reduced FAS expression and in-creased HSL expression in the liver of obese mice.

  18. Removal of Ni(II) and Cu(II) ions using native and acid treated Ni-hyperaccumulator plant Alyssum discolor from Turkish serpentine soil.

    Bayramoglu, Gulay; Arica, M Yakup; Adiguzel, Nezaket

    2012-09-01

    Alyssum discolor biomass was collected from serpentine soil and was used for removal of metal ions. The plant species grown on serpentine soils are known to be rich with metals ions and thus have more capability for accumulating heavy metals. Native and acid-treated biomass of A. discolor (A. discolor) were utilized for the removal of Ni(II) and Cu(II) ions from aqueous solutions. The effects of contact time, initial concentration, and pH on the biosorption of Ni(II) and Cu(II) ions were investigated. Biosorption equilibrium was established in about 60 min. The surface properties of the biomass preparations were varied with pH, and the maximum amounts of Ni(II) and Cu(II) ions on both A. discolor biomass preparations were adsorbed at pH 5.0. The maximum biosorption capacities of the native, and acid-treated biomass preparations for Ni(II) were 13.1 and 34.7 mgg(-1) and for Cu(II) 6.15 and 17.8 mgg(-1) dry biomass, respectively. The biosorption of Ni(II) and Cu(II) ions from single and binary component systems can be successfully described by Langmuir and Freundlich isotherms. When the heavy metal ions were in competition, the amounts of biosorbed metal ions on the acid treated plant biomass were found to be 0.542 mmolg(-1) for Ni(II) and 0.162 mmolg(-1) for Cu(II), the A. discolor biomass was significantly selective for Ni(II) ions. The information gained from these studies was expected to indicate whether the native, and acid-treated forms can have the potential to be used for the removal and recovery of Ni(II) ions from wastewaters. PMID:22608134

  19. Association of Cross Linked C-Telopeptide II Collagen and Hyaluronic Acid with Knee Osteoarthritis Severity

    John Butar Butar

    2013-12-01

    Full Text Available BACKGROUND: This study was carried out to investigate the association of Cross Linked C-Telopeptide Type I & II Collagen (CTX-I and II and hyaluronic acid (HA with knee osteoarthritis (OA severity. METHODS: Sixty menopause women with primary knee OA were enrolled in this study during their visits to the Outpatient Department. Patients with knee pain during weight bearing, active or passive range of motion, or tenderness with Kellgren-Lawrence (KL grade of more than I were included. Patients with injury, inflammatory and metabolic diseases were excluded. Patients were put in a 10-hour fasting prior to withdrawal of morning blood samples for examinations of HA, CTX-I, interleukin 1 beta (IL-1β, and high sensitivity C reactive protein (hs-CRP level. Second void morning urine specimens were taken for CTXII assessment. HA, CTX-I and II levels were measured by enzyme-linked immunosorbent assay. RESULTS: Sixty menopausal female patients were included in this study, 35 with KL grade II, 17 grade III, and 8 grade IV. Means of CTX-II were significantly different between subjects KL grade IV and III (p=0.021. Correlation of KL grade was significant with CTX-II (p=0.001, r=0.412 and HA (p=0.0411, r=0.269. KL grades were not significantly associated with CTX-I (p=0.8364, r=-0.0272; IL-1β (p=0.5773, r=0.0853 and hs-CRP (p=0.2625, r=0.1470. CONCLUSIONS: CTX-II and HA were associated with severity of knee OA, suggesting that CTX-II and HA can be used as marker for knee OA severity. KEYWORDS: CTX-II, hyaluronic acid, otestoarthritis, knee.

  20. Isolation and characterization of the zSSIIa and zSSIIb starch synthase cDNA clones from maize endosperm.

    Harn, C; Knight, M; Ramakrishnan, A; Guan, H; Keeling, P L; Wasserman, B P

    1998-07-01

    Two starch synthase clones, zSSIIa and zSSIIb, were isolated from a cDNA library constructed from W64A maize endosperm. zSSIIa and zSSIIb are 3124 and 2480 bp in length, and contain open reading frames of 732 and 698 amino acid residues, respectively. The deduced amino acid sequences of the two clones share 58.1% sequence identity. Amino acid sequence identity between the zSSIIa and zSSIIb clones and the starch synthase II clones of potato and pea ranges between 45 to 51%. The predicted amino acid sequence from each SSII cDNA contains the KXGGL consensus motif at the putative ADP-Glc binding site. Both clones also contain putative transit peptides followed by the VRAA(E)A motif, the consensus cleavage site located at the C-terminus of chloroplast transit peptides. The identity of the zSSIIa and zSSIIb clones as starch synthases was confirmed by expression of enzyme activity in Escherichia coli. Genomic DNA blot analysis revealed two copies of zSSIIa and a single copy of zSSIIb. zSSIIa was expressed predominantly in the endosperm, while transcripts for zSSIIb were detected mainly in the leaf at low abundance. These findings establish that the zSSIIa and zSSIIb genes are characteristically distinct from genes encoding granule-bound starch synthase I (Waxy protein) and starch synthase I. PMID:9687068

  1. Effect of oleic acid modified polymeric bilayered nanoparticles on percutaneous delivery of spantide II and ketoprofen

    Shah, Punit; Desai, Pinaki; Singh, Mandip

    2011-01-01

    The objective of present study was to evaluate the effect of oleic acid modified polymeric bilayered nanoparticles (NPS) on combined delivery of two anti-inflammatory drugs, spantide II (SP) and ketoprofen (KP) on the skin permeation. NPS were prepared using poly(lactic-co-glycolic acid) (PLGA) and chitosan. SP and KP were encapsulated in different layers alone or/and in combination (KP-NPS, SP-NPS and SP+KP-NPS). The surface of NPS was modified with oleic acid (OA) (`Nanoease' technology) us...

  2. N-[3,4-dimethoxycinnamoyl]-anthranilic acid (tranilast) suppresses microglial inducible nitric oxide synthase (iNOS) expression and activity induced by interferon-γ (IFN-γ)

    Platten, Michael; Wick, Wolfgang; Wischhusen, Jörg; WELLER, MICHAEL

    2001-01-01

    Microglial cells up-regulate inducible nitric oxide synthase (iNOS) expression in response to various pro-inflammatory stimuli including interferon-γ (IFN-γ), allowing for the release of nitric oxide (NO). Tranilast (N-[3,4-dimethoxycinnamoyl]-anthranilic acid) is an antiallergic compound with suppressive effects on the activation of monocytes.Here, we show that N9 murine microglial cells express iNOS mRNA and protein and release nitric oxide into the culture medium in response to IFN-γ (200 ...

  3. Investigation of Adsorption of Lead(II) onto a Montmorillonite Clay modified by Humic Acid

    This study investigated the adsorption of Pb(II) in aqueous solution onto humic acid (HA) surface. The adsorption of lead(II) ions was studied using montmorillonite clay as adsorbent in the presence of humic acid under fix pH condition. The effect of HA on the adsorption of Pb(II) onto montmorillonite depends on its concentration in the solution, i.e., metal adsorption decreases with increasing concentration of HA in the solution. The HA was found to enhance the metal adsorption capacity of mineral surfaces in ternary system. The adsorption for Pb(II) on HA was high and this may due to its strong affinity for carboxylic and phenolic groups of humic substances. Since Pb(II) is divalent cation so its adsorption may have consumed two carboxylic/phenolic groups of HA. The decrease in adsorption of Pb(II) in the presence of HA in a ternary system is may be due to the blocking of adsorptive surfaces and reduction of cation exchange capacity by the clay in the presence of HA through its polar adsorption on mineral surface. (author)

  4. Nitrosyl induces phosphorous-acid dissociation in ruthenium(II).

    Truzzi, Daniela Ramos; Ferreira, Antonio Gilberto; da Silva, Sebastião Claudino; Castellano, Eduardo Ernesto; Lima, Francisco das Chagas Alves; Franco, Douglas Wagner

    2011-12-28

    The trans-[Ru(NO)(NH(3))(4)(P(OH)(3))]Cl(3) complex was synthesized by reacting [Ru(H(2)O)(NH(3))(5)](2+) with H(3)PO(3) and characterized by spectroscopic ((31)P-NMR, δ = 68 ppm) and spectrophotometric techniques (λ = 525 nm, ε = 20 L mol(-1) cm(-1); λ = 319 nm, ε = 773 L mol(-1) cm(-1); λ = 241 nm, ε = 1385 L mol(-1) cm(-1); ν(NO(+)) = 1879 cm(-1)). A pK(a) of 0.74 was determined from infrared measurements as a function of pH for the reaction: trans-[Ru(NO)(NH(3))(4)(P(OH)(3))](3+) + H(2)O ⇌ trans-[Ru(NO)(NH(3))(4)(P(O(-))(OH)(2))](2+) + H(3)O(+). According to (31)P-NMR, IR, UV-vis, cyclic voltammetry and ab initio calculation data, upon deprotonation, trans-[Ru(NO)(NH(3))(4)(P(OH)(3))](3+) yields the O-bonded linkage isomer trans- [Ru(NO)(NH(3))(4)(OP(OH)(2))](2+), then the trans-[Ru(NO)(NH(3))(4)(OP(H)(OH)(2))](3+) decays to give the final products H(3)PO(3) and trans-[Ru(NO)(NH(3))(4)(H(2)O)](3+). The dissociation of phosphorous acid from the [Ru(NO)(NH(3))(4)](3+) moiety is pH dependent (k(obs) = 2.1 × 10(-4) s(-1) at pH 3.0, 25 °C). PMID:22027926

  5. Polarographic study of mixed-ligand complexes of cadmium(II) with L-amino acid and vitamin B5

    A survey of literature shows that ternary complexes of CdII with L-amino acids and vitamin B5 have not been studied so far. The present communication reports the formation of mixed-ligand complexes of CdII with L-amino acids as primary ligands and vitamin B5 as secondary ligand, studied by polarographic technique. (author)

  6. Purification and H-1 NMR spectroscopic characterization of phase II metabolites of tolfenamic acid

    Sidelmann, U. G.; Christiansen, E.; Krogh, L.;

    1997-01-01

    acid; the study shows the applicability of H-1 NMR for the identification of drug metabolites in biological fluids. In addition to NMR analysis, two metabolites were also identified by mass spectrometry (MS), The glucuronides of the following parent compounds, N-(2-methyl-3-chlorophenyl...... endogenous polar compounds that are present in the urine. The individual metabolites were purified by preparative high performance liquid chromatography (HPLC) and then identified using H-1 NMR, Both one- and two-dimensional NMR experiments were performed to identify the phase II metabolites of tolfenamic......), and N-(2-methyl-4-hydroxyphenyl)-anthranilic acid (11) were identified. The phase II metabolites (5-11) had not previously been identified in urine from humans administered tolfenamic acid. The phase I metabolites of the glucuronides 7, 8, 10, and 11 were identified here for the first time. An HPLC...

  7. Phosphatase activity of Poa pratensis seeds. I. Preliminary studies on acid phosphatase II

    I. Lorenc-Kubis

    2015-05-01

    Full Text Available Acid phosphatase (EC 3.1.3.2 was extracted with 0.1 M sodium acetate buffer pH 5.1 from Poa pratensis seeds, and separated into three fractions by chromatography on DEAE cellulose. The highest activity was found in fraction Il-b (acid phosphatase II. The activity of the enzyme was optimal at pH 4.9. It hydrolyzed p-nitrophenyl phosphate most readily among the various phosphomonoesters examined. Acid phosphatase II showed also a high activity toward β-naphtyl phosphate and phenyl phosphate, very low activity towards β-glycero phosphate, 5'-GMP and no activity with glucose-1 phosphate. The enzyme was inhibited by Ca2+ and fluoride, but activated by Mg2+. EDTA had no influence on the activity of the enzyme.

  8. Salvianolic Acid B Attenuates Rat Hepatic Fibrosis via Downregulating Angiotensin II Signaling

    Shu Li

    2012-01-01

    Full Text Available The renin-angiotensin system (RAS plays an important role in hepatic fibrosis. Salvianolic acid B (Sal B, one of the water-soluble components from Radix Salviae miltiorrhizae, has been used to treat hepatic fibrosis, but it is still not clear whether the effect of Sal B is related to angiotensin II (Ang II signaling pathway. In the present study, we studied Sal B effect on rat liver fibrosis and Ang-II related signaling mediators in dimethylnitrosamine-(DMN- induced rat fibrotic model in vivo and Ang-II stimulated hepatic stellate cells (HSCs in vitro, with perindopril or losartan as control drug, respectively. The results showed that Sal B and perindopril inhibited rat hepatic fibrosis and reduced expression of Ang II receptor type 1 (AT1R and ERK activation in fibrotic liver. Sal B and losartan also inhibited Ang II-stimulated HSC activation including cell proliferation and expression of type I collagen I (Col-I and α-smooth muscle actin (α-SMA production in vitro, reduced the gene expression of transforming growth factor beta (TGF-β, and downregulated AT1R expression and ERK and c-Jun phosphorylation. In conclusion, our results indicate that Sal B may exert an antihepatic fibrosis effect via downregulating Ang II signaling in HSC activation.

  9. Removal of corper(II Ions from aqueous solution by a lactic acid bacterium

    M. Yilmaz

    2010-06-01

    Full Text Available Enterococcus faecium, a lactic acid bacterium (LAB, was evaluated for its ability to remove copper(II ions from water. The effects of the pH, contact time, initial concentration of copper(II ions, and temperature on the biosorption rate and capacity were studied. The initial concentrations of copper(II ions used to determine the maximum amount of biosorbed copper(II ions onto lyophilised lactic acid bacterium varied from 25 mg L-1 to 500 mg L-1. Maximum biosorption capacities were attained at pH 5.0 and 6.0. Temperature variation between 20°C and 40°C did not affect the biosorption capacity of the bacterial biomass. The highest copper(II ion removal capacity was 106.4 mg per g dry biomass. The correlation regression coefficients show that the biosorption process can be well defined by the Freundlich equation. The change in biosorption capacity with time was found to fit a pseudo-second-order equation.

  10. Dissection of the Critical Binding Determinants of Cellular Retinoic Acid Binding Protein II by Mutagenesis and Fluorescence Binding Assay

    Vasileiou, Chrysoula; Lee, Kin Sing Stephen; Crist, Rachael M.; Vaezeslami, Soheila; Goins, Sarah M.; Geiger, James H.; Borhan, Babak

    2009-01-01

    The binding of retinoic acid to mutants of Cellular Retinoic Acid Binding Protein II (CRABPII) was evaluated to better understand the importance of the direct protein/ligand interactions. The important role of Arg111 for the correct structure and function of the protein was verified and other residues that directly affect retinoic acid binding have been identified. Furthermore, retinoic acid binding to CRABPII mutants that lack all previously identified interacting amino acids was rescued by ...

  11. Evolutinoary Consideration on 5-Aminolevulinate Synthase in Nature

    Oh-Hama, Tamiko

    1997-08-01

    5-Aminolevulinic acid (ALA), a universal precursor of tetrapyrrole compounds can be synthesized by two pathways: the C5 (glutamate) pathway and ALA synthase. From the phylogenetic distribution it is shown that distribution of ALA synthase is restricted to the α subclass of purple bacteria in prokaryotes, and further distributed to mitochondria of eukaryotes. The monophyletic origin of bacterial and eukaryotic ALA synthase is shown by sequence analysis of the enzyme. Evolution of ALA synthase in the α subclass of purple bacteria is discussed in relation to the energy-generating and biosynthetic devices in subclasses of this bacteria.

  12. Phosphorylation of N-methyl-D-aspartic acid receptor-associated neuronal nitric oxide synthase depends on estrogens and modulates hypothalamic nitric oxide production during the ovarian cycle.

    Parkash, Jyoti; d'Anglemont de Tassigny, Xavier; Bellefontaine, Nicole; Campagne, Celine; Mazure, Danièle; Buée-Scherrer, Valérie; Prevot, Vincent

    2010-01-01

    Within the preoptic region, nitric oxide (NO) production varies during the ovarian cycle and has the ability to impact hypothalamic reproductive function. One mechanism for the regulation of NO release mediated by estrogens during the estrous cycle includes physical association of the calcium-activated neuronal NO synthase (nNOS) enzyme with the glutamate N-methyl-d-aspartate (NMDA) receptor channels via the postsynaptic density 95 scaffolding protein. Here we demonstrate that endogenous vari...

  13. Antioxidant protective effect of flavonoids on linoleic acid peroxidation induced by copper(II)/ascorbic acid system.

    Beker, Bilge Yıldoğan; Bakır, Temelkan; Sönmezoğlu, Inci; Imer, Filiz; Apak, Reşat

    2011-11-01

    Antioxidants are compounds that can delay or inhibit lipid oxidation. The peroxidation of linoleic acid (LA) in the absence and presence of Cu(II) ion-ascorbate combinations was investigated in aerated and incubated emulsions at 37°C and pH 7. LA peroxidation induced by copper(II)-ascorbic acid system followed first order kinetics with respect to hydroperoxides concentration. The extent of copper-initiated peroxide production in a LA system assayed by ferric thiocyanate method was used to determine possible antioxidant and prooxidant activities of the added flavonoids. The effects of three different flavonoids of similar structure, i.e. quercetin (QR), morin (MR) and catechin (CT), as potential antioxidant protectors were studied in the selected peroxidation system. The inhibitive order of flavonoids in the protection of LA peroxidation was: morin>catechin≥quercetin, i.e. agreeing with that of formal reduction potentials versus NHE at pH 7, i.e. 0.60, 0.57 and 0.33V for MR, CT, and QR, respectively. Morin showed antioxidant effect at all concentrations whereas catechin and quercetin showed both antioxidant and prooxidant effects depending on their concentrations. The structural requirements for antioxidant activity in flavonoids interestingly coincide with those for Cu(II)-induced prooxidant activity, because as the reducing power of a flavonoid increases, Cu(II)-Cu(I) reduction is facilitated that may end up with the production of reactive species. The findings of this study were evaluated in the light of structure-activity relationships of flavonoids, and the results are believed to be useful to better understand the actual conditions where flavonoids may act as prooxidants in the preservation of heterogeneous food samples containing traces of transition metal ions. PMID:21925488

  14. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II, Cu(II, Ni(II, and Zn(II Complexes with Amino Acid-Derived Compounds

    Zahid H. Chohan

    2006-01-01

    Full Text Available A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II, copper(II, nickel(II, and zinc(II metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L1–(L5 were derived by condensation of β-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc via the azomethine-N and deprotonated-O of the respective amino acid. The stoichiometric reaction between the metal(II ion and synthesized ligands in molar ratio of M: L (1: 1 resulted in the formation of the metal complexes of type [M(L(H2O4]Cl (where M = Co(II, Cu(II, and Zn(II and of M: L (1: 2 of type [M(L2(H2O2] (where M = Co(II, Cu(II, Ni(II, and Zn(II. The magnetic moment data suggested for the complexes to have an octahedral geometry around the central metal atom. The electronic spectral data also supported the same octahedral geometry of the complexes. Elemental analyses and NMR spectral data of the ligands and their metal(II complexes agree with their proposed structures. The synthesized ligands, along with their metal(II complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexeneri, Pseudomonas aeruginosa, and Salmonella typhi and two Gram-positive (Bacillus subtilis and Staphylococcus aureus bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glaberata. The results of these studies show the metal(II complexes to be more antibacterial/antifungal against one or more species as compared to the uncomplexed ligands. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties. Five compounds, (3, (7, (10, (11, and (22, displayed potent cytotoxic

  15. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II), Cu(II), Ni(II), and Zn(II) Complexes With Amino Acid-Derived Compounds.

    Chohan, Zahid H; Arif, M; Akhtar, Muhammad A; Supuran, Claudiu T

    2006-01-01

    A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II), copper(II), nickel(II), and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L(1))-(L(5)) were derived by condensation of beta-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc) via the azomethine-N and deprotonated-O of the respective amino acid. The stoichiometric reaction between the metal(II) ion and synthesized ligands in molar ratio of M : L (1 : 1) resulted in the formation of the metal complexes of type [M(L)(H(2)O)(4)]Cl (where M = Co(II), Cu(II), and Zn(II)) and of M : L (1 : 2) of type [M(L)(2)(H(2)O)(2)] (where M = Co(II), Cu(II), Ni(II), and Zn(II)). The magnetic moment data suggested for the complexes to have an octahedral geometry around the central metal atom. The electronic spectral data also supported the same octahedral geometry of the complexes. Elemental analyses and NMR spectral data of the ligands and their metal(II) complexes agree with their proposed structures. The synthesized ligands, along with their metal(II) complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexeneri, Pseudomonas aeruginosa, and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glaberata. The results of these studies show the metal(II) complexes to be more antibacterial/antifungal against one or more species as compared to the uncomplexed ligands. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties. Five compounds, (3), (7), (10), (11), and (22

  16. New copper(II) complexes with dopamine hydrochloride and vanillymandelic acid: Spectroscopic and thermal characterization

    Mohamed, Gehad G.; Nour El-Dien, F. A.; El-Nahas, R. G.

    2011-10-01

    The dopamine derivatives participate in the regulation of wide variety of physiological functions in the human body and in medication life. Increase and/or decrease in the concentration of dopamine in human body reflect an indication for diseases such as Schizophrenia and/or Parkinson diseases. The Cu(II) chelates with coupled products of dopamine hydrochloride (DO.HCl) and vanillymandelic acid (VMA) with 4-aminoantipyrine (4-AAP) are prepared and characterized. Different physico-chemical techniques namely IR, magnetic and UV-vis spectra are used to investigate the structure of these chelates. Cu(II) forms 1:1 (Cu:DO) and 1:2 (Cu:VMA) chelates. DO behave as a uninegative tridentate ligand in binding to the Cu(II) ion while VMA behaves as a uninegative bidentate ligand. IR spectra show that the DO is coordinated to the Cu(II) ion in a tridentate manner with ONO donor sites of the phenolic- OH, -NH and carbonyl- O, while VMA is coordinated with OO donor sites of the phenolic- OH and -NH. Magnetic moment measurements reveal the presence of Cu(II) chelates in octahedral and square planar geometries with DO and VMA, respectively. The thermal decomposition of Cu(II) complexes is studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The activation thermodynamic parameters, such as, energy of activation, enthalpy, entropy and free energy change of the complexes are evaluated and the relative thermal stability of the complexes are discussed.

  17. Polarographic investigations on the cadmium(II)-imidazole-amino acid systems (amino acid L-leucine or DL-serine)

    The stability constants of ternary complexes of cadmium(II) with imidazole (IM) as primary ligand and amino acids L-leucine (LE) or DL-serine (SE) as secondary ligand have been determined polarographically at 35 degC and μ=0.5M (KNO3). In each system, four mixed complexes, viz, Cd(IM)-(AA)+, Cd(IM)2-(AA)+, Cd(IM)(AA)2 and Cd(IM)2(AA)2, were formed. The relative stability of the ternary as compared to that of corresponding binary complexes has been expressed in terms of Δlog K and log X values. (author). 12 refs., 4 figs., 1 tab

  18. Direct Synthesis of 5-Aryl Barbituric Acids by Rhodium(II)-Catalyzed Reactions of Arenes with Diazo Compounds**

    Best, Daniel; Burns, David J.; Lam, Hon Wai

    2015-01-01

    A commercially available rhodium(II) complex catalyzes the direct arylation of 5-diazobarbituric acids with arenes, allowing straightforward access to 5-aryl barbituric acids. Free N—H groups are tolerated on the barbituric acid, with no complications arising from N—H insertion processes. This method was applied to the concise synthesis of a potent matrix metalloproteinase (MMP) inhibitor.

  19. Direct Synthesis of 5-Aryl Barbituric Acids by Rhodium(II)-Catalyzed Reactions of Arenes with Diazo Compounds**

    Best, Daniel; Burns, David J; Lam, Hon Wai

    2015-01-01

    A commercially available rhodium(II) complex catalyzes the direct arylation of 5-diazobarbituric acids with arenes, allowing straightforward access to 5-aryl barbituric acids. Free N—H groups are tolerated on the barbituric acid, with no complications arising from N—H insertion processes. This method was applied to the concise synthesis of a potent matrix metalloproteinase (MMP) inhibitor. PMID:25959544

  20. Direct Synthesis of 5-Aryl Barbituric Acids by Rhodium(II)-Catalyzed Reactions of Arenes with Diazo Compounds.

    Best, Daniel; Burns, David J; Lam, Hon Wai

    2015-06-15

    A commercially available rhodium(II) complex catalyzes the direct arylation of 5-diazobarbituric acids with arenes, allowing straightforward access to 5-aryl barbituric acids. Free N-H groups are tolerated on the barbituric acid, with no complications arising from N-H insertion processes. This method was applied to the concise synthesis of a potent matrix metalloproteinase (MMP) inhibitor. PMID:25959544

  1. Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

    Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L-1, NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.

  2. Heme A synthase in bacteria depends on one pair of cysteinyls for activity.

    Lewin, Anna; Hederstedt, Lars

    2016-02-01

    Heme A is a prosthetic group unique for cytochrome a-type respiratory oxidases in mammals, plants and many microorganisms. The poorly understood integral membrane protein heme A synthase catalyzes the synthesis of heme A from heme O. In bacteria, but not in mitochondria, this enzyme contains one or two pairs of cysteine residues that are present in predicted hydrophilic polypeptide loops on the extracytoplasmic side of the membrane. We used heme A synthase from the eubacterium Bacillus subtilis and the hyperthermophilic archeon Aeropyrum pernix to investigate the functional role of these cysteine residues. Results with B. subtilis amino acid substituted proteins indicated the pair of cysteine residues in the loop connecting transmembrane segments I and II as being essential for catalysis but not required for binding of the enzyme substrate, heme O. Experiments with isolated A. pernix and B. subtilis heme A synthase demonstrated that a disulfide bond can form between the cysteine residues in the same loop and also between loops showing close proximity of the two loops in the folded enzyme protein. Based on the findings, we propose a classification scheme for the four discrete types of heme A synthase found so far in different organisms and propose that essential cysteinyls mediate transfer of reducing equivalents required for the oxygen-dependent catalysis of heme A synthesis from heme O. PMID:26592143

  3. Pb(II leaching from waste CRT funnel glass in nitric acid solutions

    A. Strzałkowska

    2012-12-01

    Full Text Available Purpose: The paper presents experimental results of Pb (II leaching from waste CRT funnel glass using solution of nitric acid (V . This work focused on examining the impact of concentration and particle size on the leaching percentage of Pb (II from funnel glass.Design/methodology/approach: Material for the investigation was crushed and sieved. Leaching was carried out using working solutions pfrom co repared ncentrated HNO3 and mechanical stirrer.Findings: The received results show the possibility of find the parameters of leaching that could remove the whole Pb(II from funnel glass.Practical implications: Results after additional research can be applicate by glass industry.Originality/value: Worked out technologies can be used in glass recycling and production.

  4. Hydrolytic activity of -alkoxide/acetato-bridged binuclear Cu(II) complexes towards carboxylic acid ester

    Weidong Jiang; Bin Xu; Zhen Xiang; Shengtian Huang; Fuan Liu; Ying Wang

    2013-09-01

    Two -alkoxide/acetate-bridged small molecule binuclear copper(II) complexes were synthesized, and used to promote the hydrolysis of a classic carboxylic acid ester, -nitrophenyl picolinate (PNPP). Both binuclear complexes exhibited good hydrolytic reactivity, giving rise to . 15547- and 17462-fold acceleration over background value for PNPP hydrolysis at neutral conditions, respectively. For comparing, activities of the other two mononuclear analogues were evaluated, revealing that binuclear complexes show approximately 150- and 171-fold kinetic advantage over their mononuclear analogues.

  5. An Arabidopsis callose synthase

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole;

    2002-01-01

    unclear whether callose synthases can also produce cellulose and whether plant cellulose synthases may also produce beta-1,3-glucans. We describe here an Arabidopsis gene, AtGsl5, encoding a plasma membrane-localized protein homologous to yeast beta-1,3-glucan synthase whose expression partially......Beta-1,3-glucan polymers are major structural components of fungal cell walls, while cellulosic beta-1,4-glucan is the predominant polysaccharide in plant cell walls. Plant beta-1,3-glucan, called callose, is produced in pollen and in response to pathogen attack and wounding, but it has been...

  6. Loop residues and catalysis in OMP synthase

    Wang, Gary P.; Hansen, Michael Riis; Grubmeyer, Charles

    2012-01-01

    Residue-to-alanine mutations and a two-amino acid deletion have been made in the highly conserved catalytic loop (residues 100?109) of Salmonella typhimurium OMP synthase (orotate phosphoribosyltransferase, EC 2.4.2.10). As described previously, the K103A mutant enzyme exhibited a 104-fold decrease...

  7. Starch phosphorylation in potato tubers is influenced by allelic variation in the genes encoding glucan water dikinase, starch branching enzymes I and II, and starch synthase III

    Margaret Ann Carpenter

    2015-03-01

    Full Text Available Starch phosphorylation is an important aspect of plant metabolism due to its role in starch degradation. Moreover, the degree of phosphorylation of starch determines its physicochemical properties and is therefore relevant for industrial uses of starch. Currently, starch is chemically phosphorylated to increase viscosity and paste stability. Potato cultivars with elevated starch phosphorylation would make this process unnecessary, thereby bestowing economic and environmental benefits. Starch phosphorylation is a complex trait which has been previously shown by antisense gene repression to be influenced by a number of genes including those involved in starch synthesis and degradation. We have used an association mapping approach to discover genetic markers associated with the degree of starch phosphorylation. A diverse collection of 193 potato lines was grown in replicated field trials, and the levels of starch phosphorylation at the C6 and C3 positions of the glucosyl residues were determined by mass spectrometry of hydrolyzed starch from tubers. In addition, the potato lines were genotyped by amplicon sequencing and microsatellite analysis, focusing on candidate genes known to be involved in starch synthesis. As potato is an autotetraploid, genotyping included determination of allele dosage. Significant associations (p<0.001 were found with SNPs in the glucan water dikinase (GWD, starch branching enzyme I (SBEI and the starch synthase III (SSIII genes, and with a SSR allele in the SBEII gene. SNPs in the GWD gene were associated with C6 phosphorylation, whereas polymorphisms in the SBEI and SBEII genes were associated with both C6 and C3 phosphorylation and the SNP in the SSIII gene was associated with C3 phosphorylation. These allelic variants have potential as genetic markers for starch phosphorylation in potato.

  8. Colorimetric detection of lead (II) based on silver nanoparticles capped with iminodiacetic acid

    We report on a colorimetric probe for the determination of Pb(II). It is based on the use of silver nanoparticles that have been functionalized with iminodiacetic acid (IDA-Ag NPs). The absorption spectrum and solution color of IDA-Ag NPs undergo dramatic changes on exposure to Pb(II) with a new absorption peak appearing at 650 nm and a concomitant color change from yellow to green. This is assumed to result from the aggregation of IDA-Ag NPs induced by Pb(II). Under optimum conditions, there is a linear relationship between the ratio of the absorbances at 650 and 396 nm, respectively, and the concentration of Pb(II) in the 0.4 to 8.0 μM concentration range, with a detection limit of 13 nM. The method was applied to the determination of Pb(II) in tap water and urea samples, and recoveries ranged from 93.7 % to 98.6 %. (author)

  9. A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

    Arya, S. P.; Mahajan, M. [Haryana, Kurukshetra Univ. (India). Dept. of Chemistry

    1998-05-01

    A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 {mu}g ml{sup -1}. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C. [Italiano] Si propone un rapido e semplice metodo spettrofotometrico per la determinazione dell`acido ascorbico. L`acido ascorbico riduce il ferro(III) a ferro(II) che forma con la dimetilgliossima, in presenza di piridina, un complesso colorato in rosso. L`assorbanza della soluzione risultante e` misurata a 514 nm e si ottiene una relazione lineare tra assorbanza e concentrazione dell`acido ascorbico fino a 14 {mu}g ml{sup -1}. Si sono condotti studi sugli interferenti usualmente associati all`acido ascorbico ed e` stata valutata l`applicabilita` del metodo all`analisi di preparati farmaceutici di vitamina C.

  10. Cellular fatty acid composition of cyanobacteria assigned to subsection II, order Pleurocapsales.

    Caudales, R; Wells, J M; Butterfield, J E

    2000-05-01

    The cellular fatty acid composition of five of the six genera of unicellular cyanobacteria in subsection II, Pleurocapsales (Dermocarpa, Xenococcus, Dermocarpella, Myxosarcina and the Pleurocapsa assemblage) contained high proportions of saturated straight-chain fatty acids (26-41% of the total) and unsaturated straight chains (40-67%). Isomers of 16:1 were the main monounsaturated acid component (11-59%). Polyunsaturated acids were present at trace levels (0-1% or less) in Xenococcus and Myxosarcina, at concentrations of less than 7% in Dermocarpa, Dermocarpella, Pleurocapsa and CCMP 1489, and at high concentrations (35% or more) in Chroococcidiopsis. Chroococcidiopsis was also different in terms of the percentage of 16:1 isomers (10-12%) compared to other genera (30-59%), and in terms of total 16-carbon and 18-carbon fatty acids. In general, the composition and heterogeneity of fatty acids in the order Pleurocapsales was similar to that reported for the unicellular cyanobacteria of subsection I, order Chroococcales. PMID:10843042

  11. Synthesis, crystal structure and Thermogravimetry of ortho-phthalic acid bridged coordination polymer of Copper(II)

    BABITA SARMA; SAURAV BHARALI; DIGANTA KUMAR DAS

    2016-06-01

    Coordination polymer of Cu(II) bridged by o-phthalic acid alone is not known. The reaction of$CuCl_{2}.2H_{2}O$ with (2-butoxycarbonyl)benzoic acid yielded three dimensional coordination polymer bridged byo-phthalic acid. X-ray crystal structure shows structure with monoclinic P21/c space group. o-Phthalic acidmolecules act as bridge between two Cu(II), one carboxylate binds to one Cu(II) as bidentate while the othercarboxylate binds to another Cu(II) as monodentate. The four planar co-ordination positions of Cu(II) aresatisfied by two chelated carboxylates while fifth and sixth co-ordination positions are satisfied by monodentatecarboxylates. EPR and TGA of the coordination polymer are also reported.

  12. A pentacyclic reaction intermediate of riboflavin synthase

    Illarionov, Boris; Eisenreich, Wolfgang; Bacher, Adelbert

    2001-01-01

    The S41A mutant of riboflavin synthase from Escherichia coli catalyzes the formation of riboflavin from 6,7-dimethyl-8-ribityllumazine at a very low rate. Quenching of presteady-state reaction mixtures with trifluoroacetic acid afforded a compound with an absorption maximum at 412 nm (pH 1.0) that can be converted to a mixture of riboflavin and 6,7-dimethyl-8-ribityllumazine by treatment with wild-type riboflavin synthase. The compound was shown to qualify as a kinetically competent intermedi...

  13. 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

    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

  14. 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

    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.

  15. SFH2 regulates fatty acid synthase activity in the yeast Saccharomyces cerevisiae and is critical to prevent saturated fatty acid accumulation in response to haem and oleic acid depletion

    Desfougères, Thomas; Ferreira, Thierry; Bergès, Thierry; Régnacq, Matthieu

    2007-01-01

    Abstract The yeast Saccharomyces cerevisiae is a facultative anaerobic organism. In anaerobiosis, sustained growth relies on the presence of exogenously supplied unsaturated fatty acids and ergosterol that yeast is unable to synthesize in the absence of oxygen or upon haem depletion. In the absence of exogenous supplementation with unsaturated fatty acid, a net accumulation of saturated fatty acid (SFA) is observed that induces significant modification of phospholipid profile [1]. ...

  16. Highly Efficient Synthesis of Two Hyaluronan Trisaccharide Analogues for Potential Hyaluronic Acid Synthases Inhibitors%透明质酸三糖模拟物的高效合成

    魏国华; 杜宇国; Khushi L. Matta

    2009-01-01

    The syntheses of two hyaluronan trisaccharide analogues, naphthyl 0-(3-methoxy-B-D-glucopy-ranosyluronic acid)-(1,3)-O-(2-acetamido-2-deoxy-B-D-glucopyranosyl)-(1,4)-0-B-D-glucopyranosyluronic acid and naphthyl O-(3-methoxy-2-acetamido-2-deoxy-B-D-glucopyranosyl)-(1,4)-O-(B-D-glucopyranosylu-ronic acid)-(1,3 )-O-2-acetamido-2-deoxy-B-D-glucopyranoside, were described. Construction of the target molecules was achieved through a combination of BF_3·Et_2O/toluene system and trichloroacetimidate glycosyia-tion methodology. This is the first report on the synthesis of the 3-methoxyl derivatives, which represent the smallest fragments that incorporate all the structural features of polymeric hyaluronan and can be used for potential hyaluronic acid synthases inhibitors.%设计合成了2个透明质酸(HA)模拟物1和2, 通过最小基团MeO的引入修饰, 模拟天然HA片段的特性, 用于透明质酸合成酶(HAS)催化机理与抑制剂的研究.

  17. Thiolactomycin-Based Inhibitors of Bacterial β-Ketoacyl-ACP Synthases with in Vivo Activity.

    Bommineni, Gopal R; Kapilashrami, Kanishk; Cummings, Jason E; Lu, Yang; Knudson, Susan E; Gu, Chendi; Walker, Stephen G; Slayden, Richard A; Tonge, Peter J

    2016-06-01

    β-Ketoacyl-ACP synthases (KAS) are key enzymes involved in the type II bacterial fatty acid biosynthesis (FASII) pathway and are putative targets for antibacterial discovery. Several natural product KAS inhibitors have previously been reported, including thiolactomycin (TLM), which is produced by Nocardia spp. Here we describe the synthesis and characterization of optically pure 5R-thiolactomycin (TLM) analogues that show improved whole cell activity against bacterial strains including methicillin-resistant Staphylococcus aureus (MRSA) and priority pathogens such as Francisella tularensis and Burkholderia pseudomallei. In addition, we identify TLM analogues with in vivo efficacy against MRSA and Klebsiella pneumoniae in animal models of infection. PMID:27187871

  18. Acetohydroxyacid Synthase, a Novel Target for Improvement of l-Lysine Production by Corynebacterium glutamicum▿ †

    Blombach, Bastian; Hans, Stephan; Bathe, Brigitte; Eikmanns, Bernhard J.

    2008-01-01

    The influence of acetohydroxy acid synthase (AHAS) on l-lysine production by Corynebacterium glutamicum was investigated. An AHAS with a deleted C-terminal domain in the regulatory subunit IlvN was engineered by truncating the ilvN gene. Compared to the wild-type AHAS, the newly constructed enzyme showed altered kinetic properties, i.e., (i) an about twofold-lower Km for the substrate pyruvate and an about fourfold-lower Vmax; (ii) a slightly increased Km for the substrate α-ketobutyrate with...

  19. Extraction of Pd(II), Pt(IV), Fe(III), Zn(II), Cu(II) and Ag(I) From Hydrochloric Acid Solutions with Selected Cyanamides as a Novel Extractants

    Three of structurally related novel extractants namely; N, Ndihexylcyanamide( DHCY), N,N-di(2-ethylhexyl)cyanamide (DEHCY) and N, N-d-octyl cyanamid (DOCY) were synthesized in our laboratory and characterized by different techniques. The general method for synthesizing the above extractants was to react relevant secondary amines with cyanogen bromide in presence of sodium acetate anhydride. Their extracting ability for Pd(II), Pt(IV), Fe(III), Zn(II), Cu(II) and Ag(I) from hydrochloric acid media in toluene as diluent has been studied. The extraction of hydrochloric acid was studied also. Pd(II) was strongly extracted by the extractants used at low hydrochloric acid concentration and the extraction decreased with increasing hydrochloric concentration while the reverse in extraction behavior was found in is the case of Pt(IV), Fe(III) and Zn(II) extraction. Both Cu(II) and Ag(I) were found to be poor extracted with this synthesized extractants. Hydrochloric acid was extracted only in its high concentration region. A systematic investigation has been carried out on the extraction of Pd(II) by using two synthesized extractants. Pd(II) was extracted as a solvated complex with the composition, metal:chloride ion:extractant = l:2:2 the extracted species was also studied using IR spectra

  20. Sm(II)-Mediated Electron Transfer to Carboxylic Acid Derivatives: Development of Complexity-Generating Cascades.

    Just-Baringo, Xavier; Procter, David J

    2015-05-19

    Reductive electron transfer (ET) to organic compounds is a powerful method for the activation of substrates via the formation of radicals, radical anions, anions, and dianions that can be exploited in bond-cleaving and bond-forming processes. Since its introduction to the synthetic community in 1977 by Kagan, SmI2 has become one of the most important reducing agents available in the laboratory. Despite its widespread application in aldehyde and ketone reduction, it was widely accepted that carboxylic acid derivatives could not be reduced by SmI2; only recently has our work led to this dogma being overturned, and the reduction of carboxylic acid derivatives using SmI2 can now take its place alongside aldehyde/ketone reduction as a powerful activation mode for synthesis. In this Account, we set out our studies of the reduction of carboxylic acid derivatives using SmI2, SmI2-H2O, and SmI2-H2O-NR3 and the exploitation of the unusual radical anions that are now accessible in unprecedented carbon-carbon bond-forming processes. The Account begins with our serendipitous discovery that SmI2 mixed with H2O is able to reduce six-membered lactones to diols, a transformation previously thought to be impossible. After the successful development of selective monoreductions of Meldrum's acid and barbituric acid heterocyclic feedstocks, we then identified the SmI2-H2O-NR3 reagent system for the efficient reduction of a range of acyclic carboxylic acid derivatives that typically present a significant challenge for ET reductants. Mechanistic studies have led us to propose a common mechanism for the reduction of carboxylic acid derivatives using Sm(II), with only subtle changes observed as the carboxylic acid derivative and Sm(II) reagent system are varied. At the center of our postulated mechanism is the proposed reversibility of the first ET to the carbonyl of carboxylic acid derivatives, and this led us to devise several strategies that allow the radical anion intermediates to be

  1. Palladium(II)-Catalyzed Tandem Synthesis of Acenes Using Carboxylic Acids as Traceless Directing Groups.

    Kim, Kiho; Vasu, Dhananjayan; Im, Honggu; Hong, Sungwoo

    2016-07-18

    A straightforward synthetic strategy for generating useful anthracene derivatives was developed involving palladium(II)-catalyzed tandem transformation with carboxylic acids as traceless directing groups. Carboxyl-directed C-H alkenylation, carboxyl-directed secondary C-H activation and rollover, intramolecular C-C bond formation, and decarboxylative aromatization are proposed as the key steps in the tandem reaction pathway. This novel synthetic route utilizes a broad range of substrates and provides a convenient synthetic tool that allows access to acenes. PMID:27244536

  2. Estimation of Stability Constants of Copper(II) Chelates with Amino Acids by Overlapping Spheres Method

    Raos, Nenad

    2005-01-01

    The method of overlapping spheres (OS) was applied to the estimation of stability constants of mono- (log β110) and bis-complexes (log β120) of α-amino acids and their N-alkyl and N,Ndialkyl derivatives with copper(II). The central sphere, with a 0.3 or 0.4 nm radius, was placed at the central (Cu), equatorial (N) or apical (X) position of the coordination polyhedron. The overlapping volume of the central sphere and the van der Waals spheres of neighbouring atoms was calculated and correlated...

  3. Phase II Open Label Study of Valproic Acid in Spinal Muscular Atrophy

    Swoboda, Kathryn J.; Scott, Charles B.; Reyna, Sandra P.; Prior, Thomas W.; LaSalle, Bernard; Sorenson, Susan L.; Wood, Janine; Acsadi, Gyula; Thomas O. Crawford; Kissel, John T.; Krosschell, Kristin J.; D'Anjou, Guy; Bromberg, Mark B.; Schroth, Mary K.; Chan, Gary M.

    2009-01-01

    Preliminary in vitro and in vivo studies with valproic acid (VPA) in cell lines and patients with spinal muscular atrophy (SMA) demonstrate increased expression of SMN, supporting the possibility of therapeutic benefit. We performed an open label trial of VPA in 42 subjects with SMA to assess safety and explore potential outcome measures to help guide design of future controlled clinical trials. Subjects included 2 SMA type I ages 2–3 years, 29 SMA type II ages 2–14 years and 11 type III ages...

  4. Amino acid sequence of the beta subunit of bovine lung casein kinase II.

    Takio, K.; Kuenzel, E A; Walsh, K. A.; Krebs, E G

    1987-01-01

    The amino acid sequence of the 209-residue beta subunit of bovine lung casein kinase II has been determined. Excluding the amino-terminal blocking group, which was not identified, the molecular weight of the polypeptide chain is 24,239. A marked polarity of the beta subunit is indicated by clusters of negative charges in the amino-terminal region and of positive charges in the carboxyl-terminal region. Whereas the beta subunit shows no homology with any known protein, a segment of the sequenc...

  5. Extraction and separation of beryllium (II) and aluminium (III) by di-(2-ethyl-hexyl)-phosphoric acid from sulphate media

    The distribution of Be(II) and Al(III) between aqueous sulphuric acid solutions and organic phases of di-(2-ethyl-hexyl)-phosphoric acid, has been investigated. The dependance of extraction on Psup(H) of aqueous phase, metal and extractant concentration as also on the diluent type, was thoroughly examined. A nuclear grade Be product is finally obtained

  6. STRUCTURAL ANALYSIS AND MOLECULAR DYNAMICS STUDY OF PHB SYNTHASE

    T. Femlin Blessia

    2012-02-01

    Full Text Available Polyhydroxybutyrate (PHB is a polyhydroxyalkanoate (PHA, a polymer belonging to polyesters class and is composed of hydroxy fatty acids. PHB is produced by microorganisms apparently in response to conditions of physiological stress. PHB synthases are the key enzymes of PHB biosynthesis. The PHB synthases obtained from Chromobacterium violaceum, belongs to the class I PHA synthases. Due to the limited structural information of PHB synthase, its functional properties including catalysis are unknown. Therefore, this study seeks to investigate the structural and functional properties of PHB synthase (phaC by predicting its three dimensional structure using bioinformatics methods. Present 15 ns molecular dynamics study provides an overall insight about some of the parameters such as energy, RMSD (Root Mean Square Deviation, SASA (Solvent Accessible Surface Area, hydrogen bonds, etc., Protein-protein docking reveals the binding mode of the protein in the active dimer state.

  7. Kinetics of the oxidative hydroxylation of sodium hypophosphite in the presence of copper (II) chloride modified by humic (fulvo-) acid

    Zhaksyntay Kairbekov; Dina Akbayeva; Zhaniya Eshova; M. Bazhanovа

    2012-01-01

    It was established that in soft conditions (50-70oC, PO2 = 1 atm) sodium hypophosphite effectively is oxidized by oxygen in water solutions of copper(II) chloride  to give mainly a phosphorous acid. Humic (fulvo-) acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, the intermediate and final products, optimal conditions...

  8. Stereoselective analysis of D and L dansyl amino acids as the mixed chelate copper(II) complexes by HPLC.

    Lam, S

    1984-09-01

    This paper reviews the mixed chelation approach to resolution of the optical isomers of D and L dansyl amino acids by high performance liquid chromatography. The use of eluants containing Cu(II) complexes of L-proline, L-arginine, L-histidine, and L-histidine methyl ester effected the separation of many D and L amino acids, including those with aliphatic, polar, and aromatic substituents. The mechanism of separation, which is based on the preferential ternary complex formation of the analyte amino acid and the chiral chelate with Cu(II) in the mobile phase, is discussed. The stereoselectivity depends mainly on the different steric interactions between the alkyl side chains of the amino acid analytes and the chiral ligands coordinating around Cu(II), although such parameters as pH, temperature, organic modifier, and concentration of the chiral additive also affect the chromatographic separation. Among the chiral ligands studied, L-histidine methyl ester is unique in that it possesses both achiral selectivity for the dansyl amino acids and chiral selectivity for the respective D and L enantiomers. With a mobile phase gradient of acetonitrile in a buffer containing Cu(II) L-histidine methyl ester complex, a stereoselective procedure was devised for the analysis of D and L amino acid enantiomers, achieving the separation that the current amino acid analyzer could not perform. Finally, the use of the mixed chelation approach in two biomedical studies is described. In the first application, the histidine methyl ester gradient was adapted for analyzing amino acids in cerebrospinal fluid; in the second, an L-aspartame Cu(II) complex eluant was developed for measuring the urine concentration of D and L pipecolic acid (piperidine-2-carboxylic acid), a metabolite of lysine. PMID:6490790

  9. Mycogenic Mn(II) oxidation promotes remediation of acid mine drainage and other anthropogenically impacted environments

    Santelli, C. M.; Chaput, D.; Hansel, C. M.; Burgos, W. D.

    2014-12-01

    Manganese is a pollutant in worldwide environments contaminated with metals and organics, such as acid mine drainage (AMD), freshwater ponds, and agricultural waste storage sites. Microorganisms contribute to the removal of dissolved Mn compounds in the environment by promoting Mn(II) oxidation reactions. The oxidation of Mn(II) results in the precipitation of sparingly soluble Mn(IV) oxide minerals, effectively removing the metal from the aqueous milieu (e.g., groundwater or wastewater streams). In recent years, our research has identified a diversity of Mn(II)-oxidizing fungi inhabiting these polluted environments, however their overall contribution to the remediation process in situ remains poorly understood. Here we present results of culture-based and Next Generation Sequencing (NGS) studies in AMD treatment systems actively remediating Mn and other metals where we profile the bacterial, fungal, algal and archaeal communities to determine the overall community diversity and to establish the relative abundance of known Mn(II) oxidizers. A variety of treatment systems with varying Mn-removal efficiencies were sampled to understand the relationship between remediation efficiency and microbial community composition and activity. Targeted-amplicon sequencing of DNA and RNA of the 16S rRNA genes (bacteria and archaea), 23S rRNA genes (algae) and ITS region (fungi) was performed using both 454 pyrosequencing and Illumina platforms. Results showed that only the fungal taxonomic profiles significantly differed between sites that removed the majority of influent Mn and those that did not. Specifically, Ascomycota (which include known Mn(II) oxidizers isolated from these treatment systems) dominated greater efficiency systems whereas less efficient systems were dominated by Basidiomycota. Furthermore, known Mn(II) oxidizers accounted for only a minor proportion of bacterial sequences but a far greater proportion of fungal sequences. These culture-independent studies lend

  10. In Vivo Nitric Oxide Synthase Inhibitors Can Be Deprived of This Activity: Unexpected Influence of the Tetrachloroplatinate(II) Counteranion. Crystal Structures of Bis(S-Methyl-Isothiouronium)-N,N'-Bis(3-Guanidinopropyl)Piperazinium and Hexamidinium Tetrachloroplatinates(II) Salts.

    Morgant, G; Viossat, B; Roch-Arveiller, M; Prognon, P; Giroud, J P; Lancelot, J C; Robba, M; Huy, D N

    1998-01-01

    The synthesis and crystal structures of bis(S-methylisothiouronium) (MSTUH)(+), N,N'-bis((3- guanidinopropyl)piperazinium (PipeC3GuaH4)(4+) and hexamidinium (HexaH2)(2+) tetrachloro platinate(ll) salts ( called hereafter PtMSTU, PtPipeC3Gua and PtHexa respectively ) were investigated. These compounds contain the "amidine" function ( - C(=NH)NH(2) ) in which the H atoms supplied by the acid have become attached to the imino group of each terminal amidino function. Moreover, in PtPipeC3Gua, the nitrogen atoms of the chair-piperazine moiety are also protonated. The influence of tetrachloroplatinate(ll) counteranion ( versus sulfate, nitrate and diisethionate ) in the in vivo nitrite inhibition by the (MSTUH)(+), (PipeC3GuaH4)(4+) and (HexaH2)(2+) cations was investigated. The three tetrachloroplatinate(ll) salts, unexpectedly, do not inhibit significantly the in vivo nitrite production in comparison with the other salts (sulfate, nitrate and diisethionate and their corresponding previous countercations) which exhibit NO synthase inhibition, especially bis(S-methylisothiouronium) sulfate, a selective and potent inducible NO synthase (iNOS) inhibitor commonly used as standard. PMID:18475834

  11. Evaluation of mono or mixed cultures of lactic acid bacteria in type II sourdough system.

    Ekinci, Raci; Şimşek, Ömer; Küçükçuban, Ayca; Nas, Sebahattin

    2016-04-01

    The aim of this study was to evaluate the use of mono and mixed lactic acid bacteria (LAB) cultures to determine suitable LAB combinations for a type II sourdough system. In this context, previously isolated sourdough LAB strains with antimicrobial activity, which included Lactobacillus plantarum PFC22, Lactobacillus brevis PFC31, Pediococcus acidilactici PFC38, and Lactobacillus sanfranciscensis PFC80, were used as mono or mixed culture combinations in a fermentation system to produce type II sourdough, and subsequently in bread dough production. Compared to the monoculture fermentation of dough, the use of mixed cultures shortened the adaptation period by half. In addition, the use of mixed cultures ensured higher microbial viability, and enhanced the fruity flavor during bread dough production. It was determined that the combination of L. plantarum PFC22 + P. acidilactici PFC38 + L. sanfranciscensis PFC80 is a promising culture mixture that can be used in the production of type II sourdough systems, and that may also contribute to an increase in metabolic activity during bread production process. PMID:25807196

  12. Caffeine synthase and related methyltransferases in plants.

    Misako, Kato; Kouichi, Mizuno

    2004-05-01

    Caffeine (1,3,7-trimethylxanthine) is a purine alkaloid present in high concentrations in tea and coffee and it is also found in a number of beverages such as coca cola. It is necessary to elucidate the caffeine biosynthetic pathway and to clone the genes related to the production of caffeine not only to determine the metabolism of the purine alkaloid but also to control the content of caffeine in tea and coffee. The available data support the operation of a xanthosine-->7-methylxanthosine-->7-methylxanthine-->theobromine-->caffeine pathway as the major route to caffeine. Since the caffeine biosynthetic pathway contains three S-adenosyl-L-methionine (SAM) dependent methylation steps, N-methyltransferases play important roles. This review focuses on the enzymes and genes involved in the methylation of purine ring. Caffeine synthase, the SAM-dependent methyltransferase involved in the last two steps of caffeine biosynthesis, was originally purified from young tea leaves (Camellia sinensis). The isolated cDNA, termed TCS1, consists of 1,483 base pairs and encodes a protein of 369 amino acids. Subsequently, the homologous genes that encode caffeine biosynthetic enzymes from coffee (Coffea arabica) were isolated. The recombinant proteins are classified into the three types on the basis of their substrate specificity i.e. 7-methylxanthosine synthase, theobromine synthase and caffeine synthase. The predicted amino acid sequences of caffeine biosynthetic enzymes derived from C. arabica exhibit more than 80% homology with those of the clones and but show only 40% homology with TCS1 derived from C. sinensis. In addition, they share 40% homology with the amino acid sequences of salicylic carboxyl methyltransferase, benzoic acid carboxyl methyltransferase and jasmonic acid carboxyl methyltransferase which belong to a family of motif B' methyltransferases which are novel plant methyltransferases with motif B' instead of motif B as the conserved region. PMID:14977590

  13. Influence of medium acidity on the equilibrium sorption of Zn(II) and Cd(II) ions by cellulose base polymers

    Influence of medium acidity in pH range of 1-9 on sorption of Zn(II) and Cd(II) ions by oxyethylcellulose, sodium salt of carboxymethylcellulose, ethylcellulose and triacetatecellulose was considered to study sorption properties of cellulose ester base polymeric materials. It has been ascertained that the change in aqueous phase acidity from acid (pH∼1) to low-alkaline (pH∼7-9) one gives rise to increase in zinc and cadmium ions distribution by a factor of 10-12 and 15-18 respectively. A scheme of sorption equilibrium of zinc and cadmium ions in the system studied, depending on pH and considering the state of the ions in the form of cationic aquocomplexes, is suggested. It is shown that the optimal pH value during cadmium ions sorption equals 8, irrespective of polymer sorbent nature

  14. The defective phosphoribosyl diphosphate synthase in a temperature-sensitive prs-2 mutant of Escherichia coli i>is compensated by increased enzyme synthesis

    Post, David A.; Switzer, Robert L.; Hove-Jensen, Bjarne

    1996-01-01

    this position specified a glycine residue that is conserved among PRPP synthases across a broad phylogenetic range. Cells harbouring the glycine-to-serine alteration specified by a plasmid contained approximately 50% of the PRPP synthase activity of cells harbouring a plasmid-borne wild-type allele......, both grown at 25 degrees C. The mutant enzyme had nearly normal heat stability, as long as it was synthesized at 25 degrees C. In contrast, there was hardly any PRPP synthase activity or anti-PRPP synthase antibody cross-reactive material present in cells harbouring the glycine to serine alteration...... following temperature shift to 42 degrees C. The other mutation was a C -> T transition located 39 bp upstream of the G -> A mutation, i.e. outside the coding sequence and close to the Shine-Dalgarno sequence. Cells harbouring only the C -> T mutation in a plasmid contained approximately three times as much...

  15. Synthesis and characterization of transition metal 2,6-pyridinedicarboxylic acid derivatives, interactions of Cu(II) and Ni(II) complexes with DNA in vitro

    Khan, Sadaf; Nami, Shahab A. A.; Siddiqi, K. S.; Husain, Eram; Naseem, Imrana

    2009-03-01

    Mononuclear complexes M(L)Cl 2 where M = Mn(II), Fe(II), Co(II), Ni(II) and Cu(II) and (L = N,N-diethylpiperazinyl,2,6-pyridinedicarboxylate), have been synthesized and characterized by elemental analysis, FT-IR, 1H NMR spectroscopy, UV-vis, magnetic moment, TGA/DSC, cyclic voltammetry and conductivity measurement data. The spectral data suggests that the dipicolinic acid acts as a bidentate ligand and is coordinated to the metal ion through the carboxylate oxygen. The cyclic voltammogram for Cu(L)Cl 2 complex was found to display two reversible Cu(II)/Cu(I) and Cu(II)/Cu(III) redox couple. The ligand exhibits a two-step thermolytic pattern while the complexes decompose in three stages respectively. An octahedral geometry has been proposed for both the complexes. The investigation of the interaction of the complexes with calf thymus DNA has been performed with absorption spectroscopy and fluorescence quenching experiments, which showed that the complexes are avid binders of calf thymus DNA. Also the interaction of the Cu(II) and Ni(II) complexes with plasmid DNA (pUC 19) was studied using agarose gel electrophoresis. The results revealed that these complexes can act as effective DNA cleaving agents resulting in the nicked form of DNA (pUC 19) under physiological conditions. The gel was run both in the absence and presence of an oxidizing agent (H 2O 2). The ligand and its complexes have also been screened against microbes in order to study their antibacterial action. The results revealed that the Cu(II) complex has activity comparable with the reference drugs gentamycin and flucanzole.

  16. Amino acid residues of heparin cofactor II required for stimulation of thrombin inhibition by sulphated polyanions.

    Colwell, N S; Grupe, M J; Tollefsen, D M

    1999-04-12

    A variety of sulphated polyanions in addition to heparin and dermatan sulphate stimulate the inhibition of thrombin by heparin cofactor II (HCII). Previous investigations indicated that the binding sites on HCII for heparin and dermatan sulphate overlap but are not identical. In this study we determined the concentrations (IC50) of various polyanions required to stimulate thrombin inhibition by native recombinant HCII in comparison with three recombinant HCII variants having decreased affinity for heparin (Lys-173-->Gln), dermatan sulphate (Arg-189-->His), or both heparin and dermatan sulphate (Lys-185-->Asn). Pentosan polysulphate, sulphated bis-lactobionic acid amide, and sulphated bis-maltobionic acid amide resembled dermatan sulphate, since their IC50 values were increased to a much greater degree (>/=8-fold) by the mutations Arg-189-->His and Lys-185-->Asn than by Lys-173-->Gln (Gln and Lys-185-->Asn (>/=6-fold) than by Arg-189-->His (acidic domain. PMID:10209287

  17. Cd(II) Sorption on Montmorillonite-Humic acid-Bacteria Composites

    Du, Huihui; Chen, Wenli; Cai, Peng; Rong, Xingmin; Dai, Ke; Peacock, Caroline L.; Huang, Qiaoyun

    2016-01-01

    Soil components (e.g., clays, bacteria and humic substances) are known to produce mineral-organic composites in natural systems. Herein, batch sorption isotherms, isothermal titration calorimetry (ITC), and Cd K-edge EXAFS spectroscopy were applied to investigate the binding characteristics of Cd on montmorillonite(Mont)-humic acid(HA)-bacteria composites. Additive sorption and non-additive Cd(II) sorption behaviour is observed for the binary Mont-bacteria and ternary Mont-HA-bacteria composite, respectively. Specifically, in the ternary composite, the coexistence of HA and bacteria inhibits Cd adsorption, suggesting a “blocking effect” between humic acid and bacterial cells. Large positive entropies (68.1 ~ 114.4 J/mol/K), and linear combination fitting of the EXAFS spectra for Cd adsorbed onto Mont-bacteria and Mont-HA-bacteria composites, demonstrate that Cd is mostly bound to bacterial surface functional groups by forming inner-sphere complexes. All our results together support the assertion that there is a degree of site masking in the ternary clay mineral-humic acid-bacteria composite. Because of this, in the ternary composite, Cd preferentially binds to the higher affinity components-i.e., the bacteria. PMID:26792640

  18. Synthesis and characterization of binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) ions based on 4-aminotoluene-3-sulfonic acid

    Faheim, Abeer A.; Abdou, Safaa N.; Abd El-Wahab, Zeinab H.

    2013-03-01

    Salicylidene (4-aminotoluene-3-sulfonic acid) Schiff base ligand H2L, and its binary and ternary Co(II), Ni(II), Cu(II) and Zn(II) complexes using 8-hydroxyquinoline (8-HOqu) and 2-aminopyridine (2-Ampy) as secondary ligands have been synthesised and characterized via elemental analysis, spectral data (IR, 1H NMR, mass and solid reflectance), molar conductance, magnetic moment, TG-DSC measurements and XRPD analysis. Correlation of all spectroscopic data suggest that H2L ligand acts as monoanionic terdentate ligand with ONO sites coordinating to the metal ions via deprotonated phenolic-O, azomethine-N and sulfonate-O while 2-Ampy behaves as a neutral monodentate ligand via amino group-N and 8-HOqu behaves as a monoanionic bidentate ligand through the ring-N and deprotonated phenolic-O. The thermal behavior of these complexes shows that the coordinated water molecules were eliminated from the complexes at relatively higher temperatures than the hydrated water and there are two routes in removal of coordinated water molecules. All complexes have mononuclear structure and the tetrahedral, square planar or an octahedral geometry have been proposed. The ligand and its complexes have been screened for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Candida albicans and Aspergillus fumigatus. Among the synthesised compounds, the binary and ternary Ni(II) complexes, (2, 8 and 10) and ternary Zn(II) complex, (12) were found to be very effective against Candida albicans and Bacillus subtilis than all other complexes with MICs of 2 and 8 μg/mL, respectively.

  19. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II) chloride modified by humic (fulvo-) acid

    Zhaksyntay Kairbekov; Dina Akbayeva; Zh. Eshova

    2012-01-01

    It was established that in mild conditions (50-70 oC, РО2= 1 atm) white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II) chloride modified by humic (fulvo-) acid to give mainly phosphoric acid. Humic (fulvo-) acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final ...

  20. Purification and cDNA Cloning of Isochorismate Synthase from Elicited Cell Cultures of Catharanthus roseus

    van Tegelen, Léon J.P.; Moreno, Paolo R.H.; Croes, Anton F.; Verpoorte, Robert; Wullems, George J.

    1999-01-01

    Isochorismate is an important metabolite formed at the end of the shikimate pathway, which is involved in the synthesis of both primary and secondary metabolites. It is synthesized from chorismate in a reaction catalyzed by the enzyme isochorismate synthase (ICS; EC 5.4.99.6). We have purified ICS to homogeneity from elicited Catharanthus roseus cell cultures. Two isoforms with an apparent molecular mass of 64 kD were purified and characterized. The Km values for chorismate were 558 and 319 μm for isoforms I and II, respectively. The isoforms were not inhibited by aromatic amino acids and required Mg2+ for enzyme activity. Polymerase chain reaction on a cDNA library from elicited C. roseus cells with a degenerated primer based on the sequence of an internal peptide from isoform II resulted in an amplification product that was used to screen the cDNA library. This led to the first isolation, to our knowledge, of a plant ICS cDNA. The cDNA encodes a protein of 64 kD with an N-terminal chloroplast-targeting signal. The deduced amino acid sequence shares homology with bacterial ICS and also with anthranilate synthases from plants. Southern analysis indicates the existence of only one ICS gene in C. roseus. PMID:9952467

  1. Effect of fish oils containing different amounts of EPA, DHA, and antioxidants on plasma and brain fatty acids and brain nitric oxide synthase activity in rats

    Engström, Karin; Saldeen, Ann-Sofie; Yang, Baichun; Mehta, Jawahar L.; Saldeen, Tom

    2009-01-01

    Background The interest in n-3 polyunsaturated fatty acids (PUFAs) has expanded significantly in the last few years, due to their many positive effects described. Consequently, the interest in fish oil supplementation has also increased, and many different types of fish oil supplements can be found on the market. Also, it is well known that these types of fatty acids are very easily oxidized, and that stability among supplements varies greatly. Aims of the study In this pilot study we investi...

  2. Synthesis, Biological, and Quantum Chemical Studies of Zn(II) and Ni(II) Mixed-Ligand Complexes Derived from N,N-Disubstituted Dithiocarbamate and Benzoic Acid

    Anthony C. Ekennia; Damian C. Onwudiwe; Aderoju A Osowole; Olasunkanmi, Lukman O.; Eno E. Ebenso

    2016-01-01

    Some mixed-ligand complexes of Zn(II) and Ni(II) derived from the sodium salt of N-alkyl-N-phenyl dithiocarbamate and benzoic acid have been prepared. The complexes are represented as ZnMDBz, ZnEDBz, NiMDBz, and NiEDBz (MD: N-methyl-N-phenyl dithiocarbamate, ED: N-ethyl-N-phenyl dithiocarbamate, and Bz: benzoate); and their coordination behavior was characterized on the basis of elemental analyses, IR, electronic spectra, magnetic and conductivity measurements, and quantum chemical calculatio...

  3. Chromium(III), manganese(III), iron(III), oxovanadium(II), zirconium(IV) and dioxouranium(II) complexes of hydrazone of isonicotinic acid hydrazide

    Coordination complexes of Cr(III), Mn(III), Fe(III), VO(II), Zr(IV) and UO2(II), with Schiff base derived from 2-hydroxy-5-methylacetophenone and isonicotinic acid hydrazide (HMAIH) have been prepared. The ligand acts as monobasic bidentate, monobasic tridentate and dibasic tridentate depending upon the reaction conditions. The thermal data have been analyzed for the activation energies by Broido's method and obey first order kinetics. The ligand and the complexes have been screened for their antimicrobial activity. (author)

  4. Dissolution of plutonium dioxide in nitric acid media by silver(II) electroreduction

    Oxidative dissolution of plutonium dioxide with electrogenerated silver(II) was undertaken first on an analytical scale in order to discover the parameters controlling this dissolution process and to prove the feasibility of the technique for 300 grams of material. The influence on the rate of PuO2 dissolution of the following parameters was studied: mass of PuO2, current density, total concentration of silver ion, nitric acid concentration, temperature, and agitation efficiency. The results demonstrate that: 1. the limiting step of the dissolution process is the electrogeneration of silver(II); 2. the dissolution of PuO2 can be achieved with a good current efficiency; 3. the best temperature range is 30±100C; 4. the optimum [HNO3] is 4 to 6 M; 5. the plutonium(VI) solution up to 500 g l-1 can be prepared. A six litres capacity thermostated glass electrolyser was built which consists of two separated compartments inlcuding: 1. an anodic compartment equipped with a cylindrical platinum grid electrode (area, 1000 cm2) and a tantalum propeller, and 2. a cathodic compartment of 0.2 litre capacity consisting of an aluminium silicate diaphragm with a tantalum rod cathode. Quantitative dissolutions of 300 g of PuO2 in 4 M HNO3 were performed for 2 h at an applied current of 60 A. (orig.)

  5. Synthesis and characterization of tin(II) complexes of fluorinated Schiff bases derived from amino acids

    Singh, Har Lal

    2010-07-01

    New tin(II) complexes of general formula Sn(L) 2 (L = monoanion of 3-methyl-4-fluoro-acetophenone phenylalanine L 1H, 3-methyl-4-fluoro-acetophenone alanine L 2H, 3-methyl-4-fluoro acetophenone tryptophan L 3H, 3-methyl-4-fluoro-acetophenone valine L 4H, 3-methyl-4-fluoro-acetophenone isoleucine L 5H and 3-methyl-4-fluoro-acetophenone glycine L 6H) have been prepared. It is characterized by elemental analyses, molar conductance measurements and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance ( 1H, 13C, 19F and 119Sn NMR) spectral studies. The ligands act as bidentate towards metal ions, via the azomethine nitrogen and deprotonated oxygen of the respective amino acid. Elemental analyses and NMR spectral data of the ligands with their tin(II) complexes agree with their proposed square pyramidal structures. A few representative ligands and their tin complexes have been screened for their antibacterial activities and found to be quite active in this respect.

  6. Mn(II) complexes with bipyridine, phenanthroline and benzoic acid: Biological and catalase-like activity

    Ibrahim Kani; Özlem Atlier; Kiymet Güven

    2016-04-01

    Five mononuclear Mn(II) complexes, [Mn(phen)2(ClO4)2] (1), [Mn(phen)3](ClO4)2(H2CO3)2(2), [Mn(bipy)2(ClO4)2] (3), [Mn(bipy)3](ClO4)2) (4), and Mn(phen)2(ba)(H2O)](ClO4)(CH3OH) (5), where bipy = 2,2’-bipyridine, phen = 1,10-phenanthroline, and ba = benzoic acid were prepared and characterized by Xray, IR and UV-Vis spectroscopies, and their catalase-like and biological activities were studied. The presence of two different types and the number of chelating NN-donor neutral ligands allowed for analysis of their effects on the catalase and biological activities. It was observed that the presence and number of phen ligands improved the activity more than the bipy ligand. Complexes 1 and 2, which contain more basic phen ligands, disproportionate H2O2 faster than complexes 3 and 4, which contain less basic bipy ligands. The in vitro antimicrobial activities of all the complexes were also tested against seven bacterial strains by microdilution tests. All the bacterial isolates demonstrated sensitivity to the complexes and the antifungal (anticandidal) activities of the Mn(II) complexes were remarkably higher than the reference drug ketoconazole.

  7. Fluorescence spectrometry for quantitative characterization of cobalt(II) complexation by Leonardite humic acid.

    Monteil-Rivera, Fanny; Dumonceau, Jacques

    2002-11-01

    Quenching of the fluorescence of a Leonardite humic acid by Co(II) has been studied at different pH. The interaction was monitored by emission fluorescence and by synchronous fluorescence with two different offsets (deltalambda=20 and 80 nm). It was found that synchronous fluorescence performed with the smaller offset resolves the individual components of the heterogeneous material better than emission or synchronous fluorescence performed with the larger offset. Enhancement of the signal induced by Cobalt(II) complexation resulted in more complex behavior for measurements performed by synchronous fluorescence with an offset of 20 nm, however. The quenching profiles obtained for pH 5.0, 6.0, and 7.0 ([KNO(3)]=0.1 mol L(-1); [LHA]=3.3 mg(C) L(-1); [Co(II)]=1.0 x 10(-6)-1.6 x 10 (-3) mol L(-1)) by emission and synchronous (deltalambda=80 nm) fluorescence were analyzed by two methods: 1. a non-linear least-squares procedure that leads to conditional constants; and 2. a pH-dependent discrete logK spectrum model that leads to stability constants. The first method resulted in poor fitting and unreasonable values for maximum capacities. The second procedure resulted in smooth fitting that accounted well for the pH changes when results for pH 6.0 and 5.0 were predicted by use of the four values of logK(Co)(i) (4.31, 3.76, 7.32, and 7.67 corresponding to the four sites (i) of the respective pKa(i) values 4, 6, 8, and 10) calculated at pH 7.0 for the equilibrium PMID:12458428

  8. Comparative biosorption of Mn(II) and Pb(II) ions on raw and oxalic acid modified maize husk: kinetic, thermodynamic and isothermal studies

    Adeogun, Abideen Idowu; Idowu, Mopelola Abidemi; Ofudje, Andrew Edwin; Kareem, Sarafadeen Olateju; Ahmed, Sikiru Akinyeye

    2013-03-01

    Maize husk, an abundant agricultural waste was used to prepare a biosorbent for the biosorption of Mn(II) and Pb(II) ions from aqueous solution in a batch process. Equilibrium and kinetics of biosorption of the metals ions were studied at 25 °C. The adsorbtion data were treated with common kinetic and isotherm models. The equilibrium data fitted well with Langmuir isotherm with maximum capacity of 8.52 and 7.38 mg g-1 for Mn(II) and Pb(II), respectively on raw biomass (UTCS). The capacity of 9.00 and 9.33 mg g-1 was observed for Mn(II) and Pb(II), respectively on acid modified biomass (ATCS). The study also revealed that the sorption process in both cases depend on biomass dosage, temperature, pH and initial metal ion concentration, respectively. The calculated thermodynamic parameters (∆ G o, ∆ H o and ∆ S o) showed that the biosorption of the metal ions onto maize husk is feasible, spontaneous and exothermic in nature.

  9. Structural elucidation of the hormonal inhibition mechanism of the bile acid cholate on human carbonic anhydrase II

    Boone, Christopher D. [University of Florida, PO Box 100267, Gainesville, FL 32610 (United States); Tu, Chingkuang [University of Florida, PO Box 100245, Gainesville, FL 32610 (United States); McKenna, Robert, E-mail: rmckenna@ufl.edu [University of Florida, PO Box 100267, Gainesville, FL 32610 (United States)

    2014-06-01

    The structure of human carbonic anhydrase II in complex with cholate has been determined to 1.54 Å resolution. Elucidation of the novel inhibition mechanism of cholate will aid in the development of a nonsulfur-containing, isoform-specific therapeutic agent. The carbonic anhydrases (CAs) are a family of mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO{sub 2} into bicarbonate and a proton. Human isoform CA II (HCA II) is abundant in the surface epithelial cells of the gastric mucosa, where it serves an important role in cytoprotection through bicarbonate secretion. Physiological inhibition of HCA II via the bile acids contributes to mucosal injury in ulcerogenic conditions. This study details the weak biophysical interactions associated with the binding of a primary bile acid, cholate, to HCA II. The X-ray crystallographic structure determined to 1.54 Å resolution revealed that cholate does not make any direct hydrogen-bond interactions with HCA II, but instead reconfigures the well ordered water network within the active site to promote indirect binding to the enzyme. Structural knowledge of the binding interactions of this nonsulfur-containing inhibitor with HCA II could provide the template design for high-affinity, isoform-specific therapeutic agents for a variety of diseases/pathological states, including cancer, glaucoma, epilepsy and osteoporosis.

  10. Phosphorylation of inhibitor-2 and activation of MgATP-dependent protein phosphatase by rat skeletal muscle glycogen synthase kinase

    Rat skeletal muscle contains a glycogen synthase kinase (GSK-M) which is not stimulated by Ca2+ or cAMP. This kinase has an apparent Mr of 62,000 and uses ATP but not GTP as a phosphoryl donor. GSK-M phosphorylated glycogen synthase at sites 2 and 3. It phosphorylated ATP-citrate lyase and activated MgATP-dependent phosphatase in the presence of ATP but not GTP. As expected, the kinase also phosphorylated phosphatase inhibitor 2 (I-2). Phosphatase incorporation reached approximately 0.3 mol/mol of I-2. Phosphopeptide maps were obtained by digesting 32P-labeled I-2 with trypsin and separating the peptides by reversed phase HPLC. Two partially separated 32P-labeled peaks were obtained when I-2 was phosphorylated with either GSK-M or glycogen synthase kinase 3 (GSK-3) and these peptides were different from those obtained when I-2 was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase (CSU) or casein kinase II (CK-II). When I-2 was phosphorylated with GSK-M or GSK-3 and cleaved by CNBr, a single radioactive peak was obtained. Phosphoamino acid analysis showed that I-2 was phosphorylated by GSK-M or GSK-3 predominately in Thr whereas CSU and CK-II phosphorylated I-2 exclusively in Ser. These results indicate that GSK-M is similar to GSK-3 and to ATP-citrate lyase kinase. However, it appears to differ in Mr from ATP-citrate lyase kinase and it differs from GSK-3 in that it phosphorylates glycogen synthase at site 2 and it does not use GTP as a phosphoryl donor

  11. Phosphorylation of inhibitor-2 and activation of MgATP-dependent protein phosphatase by rat skeletal muscle glycogen synthase kinase

    Hegazy, M.G.; Reimann, E.M.; Thysseril, T.J.; Schlender, K.K.

    1986-05-01

    Rat skeletal muscle contains a glycogen synthase kinase (GSK-M) which is not stimulated by Ca/sup 2 +/ or cAMP. This kinase has an apparent Mr of 62,000 and uses ATP but not GTP as a phosphoryl donor. GSK-M phosphorylated glycogen synthase at sites 2 and 3. It phosphorylated ATP-citrate lyase and activated MgATP-dependent phosphatase in the presence of ATP but not GTP. As expected, the kinase also phosphorylated phosphatase inhibitor 2 (I-2). Phosphatase incorporation reached approximately 0.3 mol/mol of I-2. Phosphopeptide maps were obtained by digesting /sup 32/P-labeled I-2 with trypsin and separating the peptides by reversed phase HPLC. Two partially separated /sup 32/P-labeled peaks were obtained when I-2 was phosphorylated with either GSK-M or glycogen synthase kinase 3 (GSK-3) and these peptides were different from those obtained when I-2 was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase (CSU) or casein kinase II (CK-II). When I-2 was phosphorylated with GSK-M or GSK-3 and cleaved by CNBr, a single radioactive peak was obtained. Phosphoamino acid analysis showed that I-2 was phosphorylated by GSK-M or GSK-3 predominately in Thr whereas CSU and CK-II phosphorylated I-2 exclusively in Ser. These results indicate that GSK-M is similar to GSK-3 and to ATP-citrate lyase kinase. However, it appears to differ in Mr from ATP-citrate lyase kinase and it differs from GSK-3 in that it phosphorylates glycogen synthase at site 2 and it does not use GTP as a phosphoryl donor.

  12. Electrodialytic separation of Cu(II) and As(V) in acidic electrolytes; Separacion electrodialitica de Cu(II) y As(V) en electrolitos acidos

    Ibanez, J. P.; Ipinza, J.; Cifuentes, L.

    2007-07-01

    The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. the effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II) transport rate was 0.75 mol/m''2/h and the As(V) transport rate was 0.002 mol/m''2/h. An efficient separation between Cu(II) and As(V) was achieved; Generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well. (Author) 23 refs.

  13. Fatty acid nitroalkenes induce resistance to ischemic cardiac injury by modulating mitochondrial respiration at complex II

    Jeffrey R. Koenitzer

    2016-08-01

    Full Text Available Nitro-fatty acids (NO2-FA are metabolic and inflammatory-derived electrophiles that mediate pleiotropic signaling actions. It was hypothesized that NO2-FA would impact mitochondrial redox reactions to induce tissue-protective metabolic shifts in cells. Nitro-oleic acid (OA-NO2 reversibly inhibited complex II-linked respiration in isolated rat heart mitochondria in a pH-dependent manner and suppressed superoxide formation. Nitroalkylation of Fp subunit was determined by BME capture and the site of modification by OA-NO2 defined by mass spectrometric analysis. These effects translated into reduced basal and maximal respiration and favored glycolytic metabolism in H9C2 cardiomyoblasts as assessed by extracellular H+ and O2 flux analysis. The perfusion of NO2-FA induced acute cardioprotection in an isolated perfused heart ischemia/reperfusion (IR model as evidenced by significantly higher rate-pressure products. Together these findings indicate that NO2-FA can promote cardioprotection by inducing a shift from respiration to glycolysis and suppressing reactive species formation in the post-ischemic interval.

  14. Fatty acid nitroalkenes induce resistance to ischemic cardiac injury by modulating mitochondrial respiration at complex II.

    Koenitzer, Jeffrey R; Bonacci, Gustavo; Woodcock, Steven R; Chen, Chen-Shan; Cantu-Medellin, Nadiezhda; Kelley, Eric E; Schopfer, Francisco J

    2016-08-01

    Nitro-fatty acids (NO2-FA) are metabolic and inflammatory-derived electrophiles that mediate pleiotropic signaling actions. It was hypothesized that NO2-FA would impact mitochondrial redox reactions to induce tissue-protective metabolic shifts in cells. Nitro-oleic acid (OA-NO2) reversibly inhibited complex II-linked respiration in isolated rat heart mitochondria in a pH-dependent manner and suppressed superoxide formation. Nitroalkylation of Fp subunit was determined by BME capture and the site of modification by OA-NO2 defined by mass spectrometric analysis. These effects translated into reduced basal and maximal respiration and favored glycolytic metabolism in H9C2 cardiomyoblasts as assessed by extracellular H(+) and O2 flux analysis. The perfusion of NO2-FA induced acute cardioprotection in an isolated perfused heart ischemia/reperfusion (IR) model as evidenced by significantly higher rate-pressure products. Together these findings indicate that NO2-FA can promote cardioprotection by inducing a shift from respiration to glycolysis and suppressing reactive species formation in the post-ischemic interval. PMID:26722838

  15. The mycosubtilin synthetase of Bacillus subtilis ATCC6633 : A multifunctional hybrid between a peptide synthetase, an amino transferase, and a fatty acid synthase

    Duitman, EH; Hamoen, LW; Rembold, M; Venema, G; Seitz, H; Saenger, W; Bernhard, F; Reinhardt, R; Schmidt, M; Ullrich, C; Stein, T; Leenders, F; Vater, J

    1999-01-01

    Bacillus subtilis strain ATCC6633 has been identified as a producer of mycosubtilin, a potent antifungal peptide antibiotic. Mycosubtilin, which belongs to the iturin family of lipopeptide antibiotics, is characterized by a p-amino fatty acid moiety linked to the circular heptapeptide Asn-Tyr-Asn-Cl

  16. Sorption of Ba and Sr on potassium-copper, -nickel, -cobalt, -zinc hexacyanoferrate(II) and DOWEX-50 from hydrochloric and sulfuric acid solutions

    We have determined sorption coefficients of Ba and Sr on nickel-potassium hexacyanoferrate(II) (NiNF), cobalt-potassium hexacyanoferrate(II) (CoNF), cupric-potassium hexacyanoferrate(II) (CuNF) and on the ion exchange resin (Dowex-50) in the sulfuric and hydrochloric acid solutions. The results indicate that Ba is strongly sorbed on the investigated hexacyanoferrates and Dowex-50 from sulfuric acid while it is sorbed from the hydrochloric acid at the low acid concentrations. The sorption mechanism of Sr from H2SO4 and HCl is similar, at all presented acid concentrations the values of the coefficients for Sr are rather low. (author)

  17. Interacting quantum fragments-rooted preorganized-interacting fragments attributed relative molecular stability of the Be(II) complexes of nitrilotriacetic acid and nitrilotri-3-propionic acid.

    Cukrowski, Ignacy; Mangondo, Paidamwoyo

    2016-06-01

    A method designed to investigate, on a fundamental level, the origin of relative stability of molecular systems using Be(II) complexes with nitrilotriacetic acid (NTA) and nitrilotri-3-propionic acid (NTPA) is described. It makes use of the primary and molecular fragment energy terms as defined in the IQA/F (Interacting Quantum Atoms/Fragments) framework. An extensive classical-type investigation, focused on single descriptors (bond length, density at critical point, the size of metal ion or coordination ring, interaction energy between Be(II) and a donor atom, etc.) showed that it is not possible to explain the experimental trend. The proposed methodology is fundamentally different in that it accounts for the total energy contributions coming from all atoms of selected molecular fragments, and monitors changes in defined energy terms (e.g., fragment deformation, inter- and intra-fragment interaction) on complex formation. By decomposing combined energy terms we identified the origin of relative stability of Be(II) (NTA) and Be(II) (NTPA) complexes. We found that the sum of coordination bonds' strength, as measured by interaction energies between Be(II) ion and donor atoms, favours Be(II) (NTA) but the binding energy of Be(II) ion to the entire ligand correlates well with experimental trend. Surprisingly, the origin of Be(II) (NTPA) being more stable is due to less severe repulsive interactions with the backbone of NTPA (C and H-atoms). This general purpose protocol can be employed not only to investigate the origin of relative stability of any molecular system (e.g., metal complexes) but, in principle, can be used as a predictive tool for, e.g., explaining reaction mechanism. © 2016 Wiley Periodicals, Inc. PMID:26993356

  18. The mycosubtilin synthetase of Bacillus subtilis ATCC6633: A multifunctional hybrid between a peptide synthetase, an amino transferase, and a fatty acid synthase

    Duitman, Erwin H.; Hamoen, Leendert W.; Rembold, Martina; Venema, Gerard; Seitz, Harald; Saenger, Wolfram; Bernhard, Frank; Reinhardt, Richard; Schmidt, Manuel; Ullrich, Christian; Stein, Torsten; Leenders, Frank; Vater, Joachim

    1999-01-01

    Bacillus subtilis strain ATCC6633 has been identified as a producer of mycosubtilin, a potent antifungal peptide antibiotic. Mycosubtilin, which belongs to the iturin family of lipopeptide antibiotics, is characterized by a β-amino fatty acid moiety linked to the circular heptapeptide Asn-Tyr-Asn-Gln-Pro-Ser-Asn, with the second, third, and sixth position present in the D-configuration. The gene cluster from B. subtilis ATCC6633 specifying the biosynthesis of mycosubtilin was identified. The ...

  19. Simultaneous extraction of Cr(VI) and Cu(II) from humic acid with new synthesized EDTA derivatives.

    Zhang, Tao; Wu, Ying-Xin; Huang, Xiong-Fei; Liu, Jun-Min; Xia, Bing; Zhang, Wei-Hua; Qiu, Rong-Liang

    2012-07-01

    Soil washing is one of the few permanent treatment alternatives for removing metal contaminants. Ethylenediaminetetraacetic acid and its salts (EDTA) is very effective at removing cationic metals and has been utilized globally. However it is ineffective for anionic metal contaminants or metals bound to soil organic matter. The simultaneous removal of cationic and anionic metal contaminants by soil washing is difficult due to differences in their properties. The present study evaluated the potential of a washing process using two synthesized EDTA-derivatives, C(6)HEDTA (2,2'-((2-((carboxymethyl)(2-(hexanoyloxy)ethyl)amino)ethyl)azanediyl)diacetic acid) and C(12)HEDTA (2,2'-((2-((carboxymethyl) (2-(dodecanoyloxy)ethyl)amino)ethyl)azanediyl)diacetic acid), which consist of a hydrophilic polycarboxylic moiety and a hydrophobic moiety with a monoalkyl ester group. A series of equilibrium batch experiments at room temperature were conducted to investigate the efficacy of C(6)HEDTA and C(12)HEDTA as extractants for both oxyanion Cr(VI) and cationic Cu(II). Results showed that either C(6)HEDTA or C(12)HEDTA can extract both Cr(VI) and Cu(II) from humic acid simultaneously. However, C(6)HEDTA was less effective for Cr(VI) probably because it has no surface activities to increase solubility of humic acid, like C(12)HEDTA. Extraction of Cr(VI) was mainly attributed to the decreased surface tension and enhanced solubility of organic matter. Extraction of Cu(II) was attributed to both the Cu(II) chelation and enhanced solubility of humic acid. It was demonstrated that the hydrophilic polycarboxylic moiety of C(12)HEDTA chelates cations while the monoalkyl ester group produces surface active properties that enhance the solubility of humic acid. PMID:22555067

  20. Characterization of Type I and Type II nNOS-Expressing Interneurons in the Barrel Cortex of Mouse

    Quentin ePerrenoud; Hélène eGeoffroy; Benjamin eGautier; Armelle eRancillac; Fabienne eAlfonsi; Nicoletta eKessaris; Jean eRossier; Tania eVitalis; Thierry eGallopin

    2012-01-01

    In the neocortex, neuronal nitric oxide (NO) synthase (nNOS) is essentially expressed in two classes of GABAergic neurons: type I neurons displaying high levels of expression and type II neurons displaying weaker expression. Using immunocytochemistry in mice expressing GFP under the control of the glutamic acid decarboxylase 67k (GAD67) promoter, we studied the distribution of type I and type II neurons in the barrel cortex and their expression of parvalbumin (PV), somatostatin (SOM), and vas...

  1. 9-CIS-RETINOIC ACID REPRESSES ESTROGEN-INDUCED EXPRESSION OF THE VERY-LOW-DENSITY APOLIPOPROTEIN-II GENE

    SCHIPPERS, IJ; KLOPPENBURG, M; SNIPPE, L; AB, G

    1994-01-01

    The chicken very low density apolipoprotein II (apoVLDLII) gene is estrogen-inducible and specifically expressed in liver. We examined the possible involvement of the retinoid X receptor (RXR) and its ligand 9-cis-retinoic acid (9-cis-RA) in the activation of the apoVLDLII promoter. We first concent

  2. Serum levels of fatty acid synthase in colorectal cancer patients and its clinical significance%结直肠癌患者血清脂肪酸合成酶水平的检测及其临床意义

    闾晨涛; 韩潞; 江勇; 韩东兴

    2014-01-01

    背景与目的:脂肪酸合成酶(fatty acid synthase, FAS)是唯一有能力在细胞内合成长链脂肪酸的蛋白。由于肿瘤组织对脂肪酸的需求旺盛,包括结直肠癌在内的多种恶性肿瘤组织中常见FAS过表达。本实验研究结直肠癌患者血清FAS水平与肿瘤病理特征的关系。方法:选择2013年3月-2014年3月接受根治性手术治疗的60例结直肠癌患者为研究组,另选20名健康志愿者为对照组。采用酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)检测血清FAS水平,分析结直肠癌患者血清FAS水平与其临床病理特征的关系。结果:研究组FAS平均为20.77±10.56 mg/L,对照组FAS水平为10.33±5.65 mg/L,差异有统计学意义(P0.05)。结论:血清FAS水平可能与结直肠癌的发生、发展有一定关系,可以对其作为评估肿瘤进展情况的标志物的可行性作进一步研究。%Background and purpose:Fatty acid synthase (FAS) is the sole protein in the human genome capable of intracellular synthesis of long-chain fatty acids. FAS overexpression is detected in various cancer tissues including colorectal cancer because of the increasing requirement of tumor for long-chain fatty acid. This study was to investigate the association between serum levels of FAS in patients with colorectal cancer and clinicopathological characteristics of colorectal cancer.Methods:A total of 60 patients who underwent radical surgical resection for colorectal cancer from Mar. 2013 to Mar. 2014 were selected as the study group, while 20 healthy volunteers were selected as the control group. The serum levels of FAS were measured by enzyme-linked immunosorbent assay (ELISA) methods. Differences of serum levels of FAS in patients with various clinicopathological characteristics of colorectal cancer were analyzed.Results:The serum levels of FAS in the study group were signiifcantly different with those in the control group. Serum FAS levels of

  3. Influence of methoxy-substituents on the strength of Br … Br type II halogen bonds in bromobenzoic acid

    Raffo, Pablo A.; Marcolongo, Juan P.; Funes, Alejandro V.; Slep, Leonardo D.; Baggio, Ricardo F.; Cukiernik, Fabio D.

    2016-03-01

    4-bromo-3,5-di(methoxy)benzoic acid (I) crystallizes in the monoclinic C2/c space group, a = 22.3405 (6) Å, b = 4.85142 (14) Å, c = 18.1583 (5) Å, β = 93.086 (2)°. The crystal structure shows head-to-head dimeric units linked via type II Br … Br interactions as well as Br … π and weak H-bonding interactions. The whole structure exhibits features similar to those of the parent 4-bromobenzoic acid (II), most notably the overall geometrical features involved in the Br … Br type II interactions. Both structures display comparable C-Br … Br angles (θ1 = 98.3 and 91.6° and θ2 = 163.0 and 163.5° for (I) and (II) respectively), but the Br … Br distance is significantly shorter in (I) (3.58 Å) than in (II) (3.81 Å). QM computations provide the magnitude of the intermolecular interactions present in both (I) and (II), and allow disclosing the individual covalent and electrostatic contributions to the Br⋯Br halogen bond in terms of interaction energies, electrostatic potentials, and a molecular orbital (MO) analysis.

  4. Study on complex formation of cadmium (II) ions, 9. Formation constants on cadmium (II) complexes with dicarboxylic acids

    Matsui, Haruo (Government Industrial Research Inst., Nagoya (Japan))

    1984-03-01

    Formation constants of cadmium (11) complexes with dicarboxylic acids such as oxalic, malonic, methylmalonic, succinic, and glutaric acids were determined in aqueous solutions containing 3 mol.dm/sup -3/ LiClO/sub 4/ as a constant ionic medium at 25/sup 0/C by potentiometric titrations. It was reported in the previous works that cadmium (11)- aspartic acid complexes contained two chelate rings. However, a problem remained whether the second chelate ring could be formed by six membered-ring containing -O-Cd-N- bond or by seven membered-ring containing -O-Cd-O- bond. The results of the present work suggested that it would be formed by a six membered ring. Cadmium (11) ions were coordinated with a carboxylic group of the dicarboxylic acids studied, and formed no chelate ring within the complexes. The white precipitate appeared in the solution containing cadmium (11) ion and oxalic acid, in the pH range below 3.0, therefore, the chelate formation was not ascertained in this case. The formation constants, log ..beta..sub(pr)= log((Cdsub(p)Lsub(r)sup((2p-2r)+))/((Cd/sup 2 +/)sup(p)(L/sup 2 -/)sup(r))), of the complexes were: log ..beta../sub 11/ = 1.98, log ..beta../sub 12/ = 3.05 for cadmium (11)-malonic acid; log ..beta../sub 11/ = 2.28, log ..beta../sub 12/ = 3.06 for cadmium (11)-methylmalonic acid; log ..beta../sub 11/ = 1.78, log ..beta../sub 12/ = 3.08 for cadmium (11)-succinic acid; log ..beta../sub 11/ = 1.85, log ..beta../sub 12/ = 3.28 for cadmium (11)-glutaric acid complexes.

  5. Kinetics of Nitrite Reduction and Peroxynitrite Formation by Ferrous Heme in Human Cystathionine β-Synthase.

    Carballal, Sebastián; Cuevasanta, Ernesto; Yadav, Pramod K; Gherasim, Carmen; Ballou, David P; Alvarez, Beatriz; Banerjee, Ruma

    2016-04-01

    Cystathionine β-synthase (CBS) is a pyridoxal phosphate-dependent enzyme that catalyzes the condensation of homocysteine with serine or with cysteine to form cystathionine and either water or hydrogen sulfide, respectively. Human CBS possesses a noncatalytic heme cofactor with cysteine and histidine as ligands, which in its oxidized state is relatively unreactive. Ferric CBS (Fe(III)-CBS) can be reduced by strong chemical and biochemical reductants to Fe(II)-CBS, which can bind carbon monoxide (CO) or nitric oxide (NO(•)), leading to inactive enzyme. Alternatively, Fe(II)-CBS can be reoxidized by O2to Fe(III)-CBS, forming superoxide radical anion (O2 (̇̄)). In this study, we describe the kinetics of nitrite (NO2 (-)) reduction by Fe(II)-CBS to form Fe(II)NO(•)-CBS. The second order rate constant for the reaction of Fe(II)-CBS with nitrite was obtained at low dithionite concentrations. Reoxidation of Fe(II)NO(•)-CBS by O2showed complex kinetic behavior and led to peroxynitrite (ONOO(-)) formation, which was detected using the fluorescent probe, coumarin boronic acid. Thus, in addition to being a potential source of superoxide radical, CBS constitutes a previously unrecognized source of NO(•)and peroxynitrite. PMID:26867575

  6. Equilibria in aqueous solution between Be(II) and nitrilotriacetic, methyl-C-nitrilotriacetic, nitrilodiaceticpropionic, nitriloaceticdipropionic and nitrilotripropionic acids

    The complex species formed in aqueous solution between Be(II) and nitrilotriacetic acid (NTA),methyl-C-nitrilotriacetic acid (MNTA), nitrilodiaceticpropionic acid (NDAP), nitriloaceticdipropionic acid (NADP) and nitrilotripropionic acid (NTP) were studied at 250C and ionic strength 0.5 M in NaClO4. The application of the calculus program LETAGROP to the experimental potentiometric data, taking into account hydrolysis of the ion Be(II), indicates that, upon varying the ligand-metal relationships, the following complex species are formed (H3C ligands): NTA(BeC:-, log K = 6.84); MNTA (:BeC: -, log K = 7.39: BeHC, log K = 1.79); NDAP (:BeC:-, log K 8.10: BeHC, log K = 1.96; [BeH2C]+, log K = 1.37; NADP ([BeC]-, log K = 9.25; BeHC, log K 2.37); and NTP ([BeC]-, log K = 9.23). The values of the stability constants (:BeC: -, log K) indicate the following order of coordinating capacity: NTA < MNTA < NDAP < NADP approx. NTP. This order is attributed to the increase in propionic groups. It has been confirmed that six-membered ring chelates are the most stable for Be(II), in a similar manner to other elements of the first short period, such as boron and carbon, while Cu(II), Ni(II), lanthanides and other heavier elements prefer five-membered ring chelates. (author)

  7. Equilibria in aqueous solution between Be(II) and nitrilotriacetic, methyl-C-nitrilotriacetic, nitrilodiaceticpropionic, nitriloaceticdipropionic and nitrilotripropionic acids

    Mederos, A.; Dominguez, S.; Medina, A.M.; Brito, F.; Chinea, E.; Bazdikian, K.

    1987-01-01

    The complex species formed in aqueous solution between Be(II) and nitrilotriacetic acid (NTA),methyl-C-nitrilotriacetic acid (MNTA), nitrilodiaceticpropionic acid (NDAP), nitriloaceticdipropionic acid (NADP) and nitrilotripropionic acid (NTP) were studied at 25/sup 0/C and ionic strength 0.5 M in NaClO/sub 4/. The application of the calculus program LETAGROP to the experimental potentiometric data, taking into account hydrolysis of the ion Be(II), indicates that, upon varying the ligand-metal relationships, the following complex species are formed (H/sub 3/C ligands): NTA(BeC:/sup -/, log K = 6.84); MNTA (:BeC: /sup -/, log K = 7.39: BeHC, log K = 1.79); NDAP (:BeC:/sup -/, log K 8.10: BeHC, log K = 1.96; (BeH/sub 2/C)/sup +/, log K = 1.37; NADP ((BeC)/sup -/, log K = 9.25; BeHC, log K 2.37); and NTP ((BeC)/sup -/, log K = 9.23). The values of the stability constants (:BeC: /sup -/, log K) indicate the following order of coordinating capacity: NTA < MNTA < NDAP < NADP approx. NTP. This order is attributed to the increase in propionic groups. It has been confirmed that six-membered ring chelates are the most stable for Be(II), in a similar manner to other elements of the first short period, such as boron and carbon, while Cu(II), Ni(II), lanthanides and other heavier elements prefer five-membered ring chelates.

  8. New manganese (II) structures derived from 2,6-dichlorobenzoic acid: Syntheses, crystal structures and magnetism

    One novel coordination polymer [Mn2(μ-2,6-DCBA)3(μ2-CH3CO2)2(2H2O)]·2H2O (2,6-DCBA = 2,6-dichlorobenzoato) (compound 1) has been synthesized by self-assembly of bridging ligand 2,6-dichlorobenzoic acid and manganese acetate tetrahydrate. Single crystal X-ray diffraction analysis reveals that this compound crystallizes in space group P21/c with a = 10.1547(7), b = 24.5829(2), c = 12.6606(2) Å, β = 93.707(3), V = 3153.9(3) Å3 and Z = 4. The Mn(II) ions are connected by 2,6-DCBA and acetate group in μ-bridging mode to form 1D chains. Two water molecules are in the inter-layer space forming strong hydrogen bonds originating 2D layer structure. The preparation of this compound is very sensitive to the synthesis conditions, mainly to the solution pH and solvent yielding other two compounds 2 and 3. In compound 1 Mn(II) atoms in octahedral coordination are arranged in a zig–zag chain, with a trimeric structure repeated periodically along the chain, giving two exchange parameters: J1 related to a syn–syn bond; and J2 related to a bond of type anti–anti. A theoretical model was developed and then fitted to the magnetic susceptibility data, revealing an antiferromagnetic arrangement along the chain

  9. New manganese (II) structures derived from 2,6-dichlorobenzoic acid: Syntheses, crystal structures and magnetism

    Esteves, D. [CICECO, Departamento de Química Universidade de Aveiro, 3810-193 Aveiro (Portugal); Tedesco, J.C.D.; Pedro, S.S.; Cruz, C.; Reis, M.S. [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, 24210-346 Niterói, RJ (Brazil); Brandão, P., E-mail: pbrandao@ua.pt [CICECO, Departamento de Química Universidade de Aveiro, 3810-193 Aveiro (Portugal)

    2014-10-15

    One novel coordination polymer [Mn{sub 2}(μ-2,6-DCBA){sub 3}(μ{sub 2}-CH{sub 3}CO{sub 2}){sub 2}(2H{sub 2}O)]·2H{sub 2}O (2,6-DCBA = 2,6-dichlorobenzoato) (compound 1) has been synthesized by self-assembly of bridging ligand 2,6-dichlorobenzoic acid and manganese acetate tetrahydrate. Single crystal X-ray diffraction analysis reveals that this compound crystallizes in space group P2{sub 1}/c with a = 10.1547(7), b = 24.5829(2), c = 12.6606(2) Å, β = 93.707(3), V = 3153.9(3) Å{sup 3} and Z = 4. The Mn(II) ions are connected by 2,6-DCBA and acetate group in μ-bridging mode to form 1D chains. Two water molecules are in the inter-layer space forming strong hydrogen bonds originating 2D layer structure. The preparation of this compound is very sensitive to the synthesis conditions, mainly to the solution pH and solvent yielding other two compounds 2 and 3. In compound 1 Mn(II) atoms in octahedral coordination are arranged in a zig–zag chain, with a trimeric structure repeated periodically along the chain, giving two exchange parameters: J{sub 1} related to a syn–syn bond; and J{sub 2} related to a bond of type anti–anti. A theoretical model was developed and then fitted to the magnetic susceptibility data, revealing an antiferromagnetic arrangement along the chain.

  10. Isolation and Characterization of Soybean Genes Involved in Phytic Acid Metabolism: Phytase and 1-L-myo-Inositol-1-Phosphate Synthase

    Hegeman, Carla Elizabeth

    1999-01-01

    The objective of this research was to isolate and characterize soybean genes involved in phytic acid metabolism for use in genetic engineering strategies to improve phosphorus utilization. A soybean phytase from germinated cotyledons was purified 28,000-fold to apparent homogeneity and was determined to be a glycosylated homodimer with 70 kD subunits. Soybean phytase preferred phytate as substrate (Km = 60 mM) and was capable of removing of all six phosphate groups from phytate. The pH and ...

  11. Enhanced seizures and hippocampal neurodegeneration following kainic acid-induced seizures in metallothionein-I + II-deficient mice

    Carrasco, J; Penkowa, M; Hadberg, H;

    2000-01-01

    Metallothioneins (MTs) are major zinc binding proteins in the CNS that could be involved in the control of zinc metabolism as well as in protection against oxidative stress. Mice lacking MT-I and MT-II (MT-I + II deficient) because of targeted gene inactivation were injected with kainic acid (KA...... (ICE) and caspase-3 levels. Histochemically reactive zinc in the hippocampus was increased by KA to a greater extent in MT-I + II-deficient compared with control mice. KA-induced seizures also caused increased oxidative stress, as suggested by the malondialdehyde (MDA) and protein tyrosine nitration......), a potent convulsive agent, to examine the neurobiological importance of these MT isoforms. At 35 mg/kg KA, MT-I + II deficient male mice showed a higher number of convulsions and a longer convulsion time than control mice. Three days later, KA-injected mice showed gliosis and neuronal injury in the...

  12. Ellagic acid and polyhydroxylated urolithins are potent catalytic inhibitors of human topoisomerase II: an in vitro study.

    Furlanetto, Valentina; Zagotto, Giuseppe; Pasquale, Riccardo; Moro, Stefano; Gatto, Barbara

    2012-09-12

    Ellagic acid (EA), a natural polyphenol abundant in fruits and common in our diet, is under intense investigation for its chemopreventive activity resulting from multiple effects. EA inhibits topoisomerase II, but the effects on the human enzyme of urolithins, its monolactone metabolites, are not known. Therefore, the action of several synthetic urolithins toward topoisomerases II was evaluated, showing that polyhydroxylated urolithins, EA, and EA-related compounds are potent inhibitors of the α and β isoforms of human topoisomerase II at submicromolar concentrations. Competition tests demonstrate a dose-dependent relationship between ATP and the inhibition of the enzyme. Docking experiments show that the active compounds bind the ATP pocket of the human enzyme, thus supporting the hypothesis that EA and polyhydroxylated urolithins act as ATP-competitive inhibitors of human topoisomerase II. PMID:22924519

  13. Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

    Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

    2015-12-01

    Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future. PMID:26138876

  14. Interaction between metals and nucleic acids. Part 3. Synthesis and structural studies of copper(II) complexes with Schiff base ligands derived from barbituric acid

    Sasaki, I.; Gaudemer, A.; Chiaroni, A.; Riche, C.

    1986-02-17

    Schiff bases have been prepared from 5-formylbarbituric acid and 5-formyl-1,3-dimethyl-barbituric acid and various di- or tri-amines. The structure of the corresponding copper(II) complexes have been established by elemental analysis and spectroscopic methods. The molecular structure of one of the complexes, Cu(DiMeBardpt), was determined by X-ray diffraction. Electrochemical study shows that these complexes are reduced at slightly more negative potentials than the corresponding complexes obtained from uracil, which suggests that these new ligands are better electron-donors.

  15. Some characteristics of the mechanism of action of copper (II) complexes with alpha-amino acids

    On the basis of the supposed difference in the mechanisms of action of copper (II) complexes with alpha-amino acids and of alkylating agents, the antitumor activity of Cu-2 when given in conjunction with cis-diamminedichloroplatinum (DDP) is studied. The DNA precursor C 14-thymidine was injected into mice 30 min before sacrifice. Doses of the substances appropriate as regards toxicity were used: Cu-2 9 mg/kg, DPP 4 mg/kg. The antitumor effect was assessed as inhibition of tumor growth, calculated relative to the mean volumes of the tumor in the experimental animals, was compared with the controls over a period of time. Toxicity was recorded as the percentage of mice which died and changes in the mean weight of the spleen. The investigations show that Cu-1 does not induce direct inhibition of DNA synthesis in the tumor cell, unlike DDP and sarcolysin. Combined administration of Cu-2 and DDP leads to summation of their antitumor effect without any increase in toxicity

  16. SYNTHESIS, CHARACTERIZATION AND ANTITUMOR ACTIVITY OF A Ca (II COORDINATION POLYMER BASED ON 3-AMINO-2-PYRAZINECARBOXYLIC ACID

    XI-SHI TAI

    2015-10-01

    Full Text Available A new Ca(II coordination polymer has been obtained by reaction of Ca(ClO42·H2O with 3-amino-2-pyrazinecarboxylic acid in CH3CH2OH/H2O. It was characterized by IR, 1HNMR, thermal analysis and X-ray single crystal diffraction analysis. X-ray analysis reveals that each Ca(II center is seven-coordination with a N2O5 distorted pentagonal bipyramidal coordination environment. The Ca(II ions are linked through the O atoms of 3-amino-2-pyrazinecarboxylic acid ligands to form 1D chain structure. And then a 3D network structure is constructed by hydrogen bonds and π-π stacking. The antitumor activity of 3-amino-2-pyrazinecarboxylic acid ligand and its Ca(II coordination polymer against human intestinal adenocarcinoma HCT-8 cells, lung adenocarcinoma HCT-116 cells and human lung adenocarcinoma A549 cells line have been investigated.

  17. The decolorization of Acid Orange II in non-homogeneous Fenton reaction catalyzed by natural vanadium-titanium magnetite

    Liang Xiaoliang; Zhong Yuanhong [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhu Sanyuan; Zhu Jianxi; Yuan Peng [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 (China); He Hongping, E-mail: hehp@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 (China); Zhang Jing [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2010-09-15

    The catalytic activity of natural vanadium-titanium magnetite was investigated in the decolorization of Acid Orange II by non-homogeneous Fenton process. The natural catalysts purified by magnetic separation were characterized using X-ray diffraction (XRD), polarizing microscope, X-ray absorption fine structure (XAFS) analysis and Moessbauer spectroscopy. The obtained results show that the natural samples after magnetic separation mainly contain titanomagnetite, with a small amount of ilmenite and chlorite. Titanomagnetite is doped with vanadium, whose the valency is mainly +3 and occupies the octahedral site. Batch decolorization studies were performed to evaluate the influences of various experimental parameters like initial pH, the amount of catalyst and initial concentration of hydrogen peroxide on the decolorization efficiency of Acid Orange II. The decolorization of the dye mainly relied on degradation. The degradation efficiency was strongly dependent on pH of the medium where it increased as the pH decreased in acid range. The increase of catalyst and hydrogen peroxide could accelerate the degradation. The catalytic property of natural vanadium-titanium magnetite in the degradation of Acid Orange II was stronger than that of synthetic magnetite (Fe{sub 3}O{sub 4}). The catalytic activity of the natural samples was greatly related to the titanomagnetite content. The degradation process was dominated by heterogeneous Fenton reaction, complying with pseudo-first-order rate law. The natural catalyst has a good catalytic stability.

  18. The decolorization of Acid Orange II in non-homogeneous Fenton reaction catalyzed by natural vanadium-titanium magnetite

    The catalytic activity of natural vanadium-titanium magnetite was investigated in the decolorization of Acid Orange II by non-homogeneous Fenton process. The natural catalysts purified by magnetic separation were characterized using X-ray diffraction (XRD), polarizing microscope, X-ray absorption fine structure (XAFS) analysis and Moessbauer spectroscopy. The obtained results show that the natural samples after magnetic separation mainly contain titanomagnetite, with a small amount of ilmenite and chlorite. Titanomagnetite is doped with vanadium, whose the valency is mainly +3 and occupies the octahedral site. Batch decolorization studies were performed to evaluate the influences of various experimental parameters like initial pH, the amount of catalyst and initial concentration of hydrogen peroxide on the decolorization efficiency of Acid Orange II. The decolorization of the dye mainly relied on degradation. The degradation efficiency was strongly dependent on pH of the medium where it increased as the pH decreased in acid range. The increase of catalyst and hydrogen peroxide could accelerate the degradation. The catalytic property of natural vanadium-titanium magnetite in the degradation of Acid Orange II was stronger than that of synthetic magnetite (Fe3O4). The catalytic activity of the natural samples was greatly related to the titanomagnetite content. The degradation process was dominated by heterogeneous Fenton reaction, complying with pseudo-first-order rate law. The natural catalyst has a good catalytic stability.

  19. Fluorescence quenching and bonding properties of some hydroxamic acid derivatives by iron(III) and manganese(II).

    Senthilnithy, R; De Costa, M D P; Gunawardhana, H D

    2009-01-01

    Spectrophotometric investigations of highly fluorescent metal chelating molecules are of relevance due to their potential application in novel, selective fluorescence-based sensors. Benzene and naphthalene chromophores are highly fluorescent while hydroxamic acids are widely used as ligands for complexation of transition metals. In order to develop fluorescence probes, several phenyl derivatives of N-phenylbenzohydroxamic acid and an aminodihydroxamic acid linked with a naphthalene chromophore were synthesized and their selective ionophoric properties towards iron(III) and manganese(II) ions were investigated using fluorescence and absorption spectroscopy. Both methods confirm the formation of 1:1 and 1:2 complexes for iron(III) and a 1:1 complex for manganese(II). The complex that is formed depends on the concentration of the ligand and pH of the medium. The amino dihydroxamic acid exhibits a prominent selectivity towards iron(III) with a two-step 1:1 and 1:2 quenching mechanism at pH 3 and towards manganese(II) with a 1:1 quenching mechanism at a probe concentration of 1 x 10(-5) mol dm(-3) at pH 9.5 The logarithm of overall formation constants of 1:1 and 1:2 complexes of iron(III) were estimated as 3.30 and 9.05, respectively. PMID:18800360

  20. Non-enzymatic modifications of prostaglandin H synthase 1 affect bifunctional enzyme activity - Implications for the sensitivity of blood platelets to acetylsalicylic acid.

    Kassassir, Hassan; Siewiera, Karolina; Talar, Marcin; Stec-Martyna, Emilia; Pawlowska, Zofia; Watala, Cezary

    2016-06-25

    Due to its ability to inhibit the blood platelet PGHS-1, acetylsalicylic acid (ASA, Aspirin(®)) is widely used as a preventive agent in atherothrombotic diseases. However, its beneficial effects seem to be lower in diabetic patients, suggesting that protein glycation may impair effective ASA-mediated acetylation process. On the other hand, it is proposed that ASA can prevent some of the late complications of diabetes by lowering the extent of glycation at protein free amino groups. The aim of this work was to evaluate the extents of non-enzymatic N-glycosylation (glycation) and acetylation of blood platelet PGHS-1 (COX-1) and the competition between glycation and acetylation was investigated in order to demonstrate how these two reactions may compete against platelet PGHS-1. When PGHS-1 was incubated with glycating/acetylating agents (glucose, Glu; 1,6-bisphosphofructose, 1,6-BPF; methylglyoxal, MGO, acetylsalicylic acid, ASA), the enzyme was modified in 13.4 ± 1.6, 5.3 ± 0.5, 10.7 ± 1.2 and 6.4 ± 1.1 mol/mol protein, respectively, and its activity was significantly reduced. The prior glycation/carbonylation of PGHS-1 with Glu, 1,6-BPF or MGO decreased the extent of acetylation from 6.4 ± 1.1 down to 2.5 ± 0.2, 3.6 ± 0.3 and 5.2 ± 0.2 mol/mol protein, respectively, but the enzyme still remained susceptible to the subsequent inhibition of its activity with ASA. When PGHS-1 was first acetylated with ASA and then incubated with glycating/carbonylating agents, we observed the following reductions in the enzyme modifications: from 13.4 ± 1.6 to 8.7 ± 0.6 mol/mol protein for Glu, from 5.3 ± 0.5 to 3.9 ± 0.3 mol/mol protein for 1,6-BPF and from 10.7 ± 1.2 to 7.5 ± 0.5 mol/mol protein for MGO, however subsequent glycation/carbonylation did not significantly affect PGHS-1 function. Overall, our outcomes allow to better understand the structural aspects of the chemical competition between glycation and acetylation of PGHS-1

  1. Artemisia capillaris formula inhibits hepatic steatosis via an miR‑122‑induced decrease in fatty acid synthase expression in vivo and in vitro.

    Liu, Liya; Zhao, Jinyan; Li, Ying; Wan, Yun; Lin, Jiumao; Shen, Aling; Xu, Wei; Li, Huang; Zhang, Yuchen; Xu, Jianfeng; Peng, Jun; Hong, Zhenfeng

    2016-06-01

    treatment decreased the expression levels of fatty acid synthase (FASN) and increased miR‑122 in vivo and in vitro. In conclusion, these results suggested that ACF may inhibit hepatic steatosis via miR‑122‑induced downregulation of FASN in vivo and in vitro. PMID:27081834

  2. Prenyldiphosphate synthases and gibberellin biosynthesis

    C.C.N. van Schie; M.A. Haring; R.C. Schuurink

    2013-01-01

    Gibberellins are derived from the diterpene precursor geranylgeranyl diphophosphate (GGPP). GGPP is converted to ent-kaurene, which contains the basic structure of gibberellins, in the plastids by the combined actions of copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS). Generally, ge

  3. Copper(II) complex formation equilibria involving L-carnosine, the role in the catalysis of amino acid ester hydrolisis

    Shoukry, E.M.; Shoukry, M.M.; Mahgoub, A.E.; Galal, H.M. [Cairo Univ., Cairo (Egypt). Faculty of Science

    2000-10-01

    The binary and ternary complexes of copper(II) involving carnosine (H{sub 3}L), amino acids and DNA constituents were examined. Copper(II) was found to form CuL and CuLH{sub 1} complexes with carnosine. The ternary complexes of Copper(II) with carnosine and DNA constituents are formed in a stepwise mechanism, whereby carnosine binds to copper(II), then followed by ligation of the DNA constituents. The concentration distribution of the various complex species has been evaluated. The hydrolysis of amino acid ester is catalysed by the Cu-carnosine complex. The rate enhancement compared with the fee ester hydrolysis is investigated in terms of the ester coordination mode. [Italian] Sono stati considerati i complessi binari e ternari del rame(II) con la carnosina (H{sub 3}L), amino acidi e constituenti del DNA. Si e' trovato che il rame(II) forma complessi CuL e CuLH{sub 1} con la carnosina. I complessi ternari di rame(II) con carnosina e constitutenti del DNA si formano con un meccanismo a stadi, prima la carnosina lega il rame e successivamente sono legati i constituenti del DNA. E' stata valutata la distribuzione della concentrazione delle varie specie complesse. Il complesso Cu-carnosina catalizza l'idrolisi degli esteri di aminoacidi. L'incremento di velocita', rispetto all'idrolisi dell'estere libero, e' stato studiato in termini di modo di coordinazione dell'estere.

  4. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II chloride modified by humic (fulvo- acid

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available It was established that in mild conditions (50-70 oC, РО2= 1 atm white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II chloride modified by humic (fulvo- acid to give mainly phosphoric acid. Humic (fulvo- acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final products, optimum conditions of new catalytic reaction of P4 oxidation by oxygen in water medium were defined by kinetics, volumometry, redox-potentiometry, 31Р{1Н} NMR spectroscopy and  titration. 

  5. Structure and oxidation state of hemitite surfaces reacted with aqueous Fe(II) at acidic and neutral pH.

    Catalano, J. G.; Fenter, P.; Park, C.; Zhang, Z.; Rosso, K. M.; Washington Univ.; PNNL

    2010-01-01

    Structural changes and surface oxidation state were examined following the reaction of hematite (0 0 1), (0 1 2), and (1 1 0) with aqueous Fe(II). X-ray reflectivity measurements indicated that Fe(II) induces changes in the structure of all three surfaces under both acidic (pH 3) and neutral (pH 7) conditions. The structural changes were generally independent of pH although the extent of surface transformation varied slightly between acidic and neutral conditions; no systematic trends with pH were observed. Induced changes on the (1 1 0) and (0 1 2) surfaces include the addition or removal of partial surface layers consistent with either growth or dissolution. In contrast, a <1 nm thick, discontinuous film formed on the (0 0 1) surface that appears to be epitaxial yet is not a perfect extension of the underlying hematite lattice, being either structurally defective, compositionally distinct, or nanoscale in size and highly relaxed. Resonant anomalous X-ray reflectivity measurements determined that the surface concentration of Fe(II) present after reaction at pH 7 was below the detection limit of approximately 0.5-1 {micro}mol/m{sup 2} on all surfaces. These observations are consistent with Fe(II) oxidative adsorption, whereby adsorbed Fe(II) is oxidized by structural Fe(III) in the hematite lattice, with the extent of this reaction controlled by surface structure at the atomic scale. The observed surface transformations at pH 3 show that Fe(II) oxidatively adsorbs on hematite surfaces at pH values where little net adsorption occurs, based on historical macroscopic Fe(II) adsorption behavior on fine-grained hematite powders. This suggests that Fe(II) plays a catalytic role, in which an electron from an adsorbed Fe(II) migrates to and reduces a lattice Fe(III) cation elsewhere, which subsequently desorbs in a scenario with zero net reduction and zero net adsorption. Given the general pH-independence and substantial mass transfer involved, this electron and atom

  6. Structure and Oxidation State of Hematite Surfaces Reacted with Aqueous Fe(II) at Acidic and Neutral pH

    Catalano, Jeffrey G.; Fenter, Paul; Park, Changyong; Zhang, Zhan; Rosso, Kevin M.

    2010-03-01

    Structural changes and surface oxidation state were examined following the reaction of hematite (001), (012), and (110) with aqueous Fe(II). X-ray reflectivity measurements indicated that Fe(II) induces changes in the structure of all three surfaces under both acidic (pH 3) and neutral (pH 7) conditions. The structural changes were generally independent of pH although the extent of surface transformation varied slightly between acidic and neutral conditions; no systematic trends with pH were observed. Induced changes on the (110) and (012) surfaces include the addition or removal of partial surface layers consistent with either growth or dissolution. In contrast, a <1 nm thick, discontinuous film formed on the (001) surface that appears to be epitaxial yet is not a perfect extension of the underlying hematite lattice, being either structurally defective, compositionally distinct, or nanoscale in size and highly relaxed. Resonant anomalous X-ray reflectivity measurements determined that the surface concentration of Fe(II) present after reaction at pH 7 was below the detection limit of approximately 0.5 to 1 mol/m2 on all surfaces. These observations are consistent with Fe(II) oxidative adsorption, whereby adsorbed Fe(II) is oxidized by structural Fe(III) in the hematite lattice, with the extent of this reaction controlled by surface structure at the atomic scale. The observed surface transformations at pH 3 show that Fe(II) oxidatively adsorbs on hematite surfaces at pH values where little net adsorption occurs, based on historical macroscopic Fe(II) adsorption behavior on fine-grained hematite powders. This suggests that Fe(II) plays a catalytic role, in which an electron from an adsorbed Fe(II) migrates to and reduces a lattice Fe(III) cation elsewhere, which subsequently desorbs in a scenario with zero net reduction and zero net adsorption. Given the general pH-independence and substantial mass transfer involved, this electron and atom exchange processes

  7. Structure and oxidation state of hematite surfaces reacted with aqueous Fe(II) at acidic and neutral pH

    Catalano, Jeffrey G.; Fenter, Paul; Park, Changyong; Zhang, Zhan; Rosso, Kevin M.

    2010-03-01

    Structural changes and surface oxidation state were examined following the reaction of hematite (0 0 1), (0 1 2), and (1 1 0) with aqueous Fe(II). X-ray reflectivity measurements indicated that Fe(II) induces changes in the structure of all three surfaces under both acidic (pH 3) and neutral (pH 7) conditions. The structural changes were generally independent of pH although the extent of surface transformation varied slightly between acidic and neutral conditions; no systematic trends with pH were observed. Induced changes on the (1 1 0) and (0 1 2) surfaces include the addition or removal of partial surface layers consistent with either growth or dissolution. In contrast, a <1 nm thick, discontinuous film formed on the (0 0 1) surface that appears to be epitaxial yet is not a perfect extension of the underlying hematite lattice, being either structurally defective, compositionally distinct, or nanoscale in size and highly relaxed. Resonant anomalous X-ray reflectivity measurements determined that the surface concentration of Fe(II) present after reaction at pH 7 was below the detection limit of approximately 0.5-1 μmol/m 2 on all surfaces. These observations are consistent with Fe(II) oxidative adsorption, whereby adsorbed Fe(II) is oxidized by structural Fe(III) in the hematite lattice, with the extent of this reaction controlled by surface structure at the atomic scale. The observed surface transformations at pH 3 show that Fe(II) oxidatively adsorbs on hematite surfaces at pH values where little net adsorption occurs, based on historical macroscopic Fe(II) adsorption behavior on fine-grained hematite powders. This suggests that Fe(II) plays a catalytic role, in which an electron from an adsorbed Fe(II) migrates to and reduces a lattice Fe(III) cation elsewhere, which subsequently desorbs in a scenario with zero net reduction and zero net adsorption. Given the general pH-independence and substantial mass transfer involved, this electron and atom exchange

  8. Serum Collagen Type II Cleavage Epitope and Serum Hyaluronic Acid as Biomarkers for Treatment Monitoring of Dogs with Hip Osteoarthritis

    Vilar, José M.; Rubio, Mónica; Spinella, Giuseppe; Cuervo, Belén; Sopena, Joaquín; Cugat, Ramón; Garcia-Balletbó, Montserrat; Dominguez, Juan M.; Granados, Maria; Tvarijonaviciute, Asta; Ceron, José J.; Carrillo, José M.

    2016-01-01

    The aim of this study was to evaluate the use of serum type II collagen cleavage epitope and serum hyaluronic acid as biomarkers for treatment monitoring in osteoarthritic dogs. For this purpose, a treatment model based on mesenchymal stem cells derived from adipose tissue combined with plasma rich in growth factors was used. This clinical study included 10 dogs with hip osteoarthritis. Both analytes were measured in serum at baseline, just before applying the treatment, and 1, 3, and 6 months after treatment. These results were compared with those obtained from force plate analysis using the same animals during the same study period. Levels of type II collagen cleavage epitope decreased and those of hyaluronic acid increased with clinical improvement objectively verified via force plate analysis, suggesting these two biomarkers could be effective as indicators of clinical development of joint disease in dogs. PMID:26886592

  9. Electrogeneration of hydrogen peroxide in acidic medium using gas diffusion electrodes modified with cobalt (II) phthalocyanine

    Hydrogen peroxide (H2O2) is a commonly used oxidant with a wide variety of applications in, for example, organic synthesis and wastewater treatment. This paper describes the development of catalysts for the electrogeneration of H2O2 in acidic medium using gas diffusion electrodes (GDE). Initial experiments were performed using rotating ring-disk electrodes modified with microporous layers of Printex 6L carbon containing various amounts of cobalt (II) phthalocyanine (CoPc) in order to evaluate catalytic activities. The results showed that the current efficiency for the formation of H2O2 increased from 69.7% for Printex 6L carbon without catalyst to 81.5% when using Printex 6L carbon with CoPc, and this was accompanied by a decrease in the number of electrons involved in the oxygen reduction reaction from 2.6 to 2.3. Based on these findings, modified GDEs were constructed containing 3.0, 5.0 and 10.0% of CoPc on Printex 6L carbon. The concentration of H2O2 that formed after 90 min electrolysis with the GDE modified with Printex 6L carbon alone was 176 mg L−1, while the GDE with 5.0% CoPc on carbon produced 331 mg L−1 of H2O2, i.e. an increase in yield of 89.1% relative to Printex 6L carbon. Additionally, using GDE s modified with CoPc on carbon, the potential at which H2O2 formation attained its maximum value shifted to less negative values in comparison with electrodes without catalyst. It is concluded that CoPc is an appropriate catalyst for efficient electrogeneration of H2O2

  10. Photocatalytic CO2 reduction to formic acid using a Ru(II)-Re(I) supramolecular complex in an aqueous solution.

    Nakada, Akinobu; Koike, Kazuhide; Nakashima, Takuya; Morimoto, Tatsuki; Ishitani, Osamu

    2015-02-16

    In an aqueous solution, photophysical, photochemical, and photocatalytic abilities of a Ru(II)-Re(I) binuclear complex (RuReCl), of which Ru(II) photosensitizer and Re(I) catalyst units were connected with a bridging ligand, have been investigated in details. RuReCl could photocatalyze CO2 reduction using ascorbate as an electron donor, even in an aqueous solution. The main product of the photocatalytic reaction was formic acid in the aqueous solution; this is very different in product distribution from that in a dimethylformamide (DMF) and triethanolamine (TEOA) mixed solution in which the main product was CO. A (13)CO2 labeling experiment clearly showed that formic acid was produced from CO2. The turnover number and selectivity of the formic acid production were 25 and 83%, respectively. The quantum yield of the formic acid formation was 0.2%, which was much lower, compared to that in the DMF-TEOA mixed solution. Detail studies of the photochemical electron-transfer process showed back-electron transfer from the one-electron-reduced species (OERS) of the photosensitizer unit to an oxidized ascorbate efficiently proceeded, and this should be one of the main reasons why the photocatalytic efficiency was lower in the aqueous solution. In the aqueous solution, ligand substitution of the Ru(II) photosensitizer unit proceeded during the photocatalytic reaction, which was a main deactivation process of the photocatalytic reaction. The product of the ligand substitution was a Ru(II) bisdiimine complex or complexes with ascorbate as a ligand or ligands. PMID:25654586

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

    Nanson, Jeffrey D; 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 fatty acid biosynthesis (FASII) system, to synthesise components of lipoproteins, phospholipids, and lipopolysaccharides essential for bacterial growth and survival. As such, these enzymes are promising targets for the development of novel therapeutic agents. We have determined the crystal structures of the Y. pestis β-ketoacyl-acyl carrier protein synthases FabF and FabH, and compared these with the unpublished, deposited structure of Y. pestis FabB. Comparison of FabB, FabF, and FabH provides insights into the substrate specificities of these enzymes, and investigation of possible interactions with known β-ketoacyl-acyl carrier protein synthase inhibitors suggests FabB, FabF and FabH may be targeted simultaneously to prevent synthesis of the fatty acids necessary for growth and survival. PMID:26469877

  12. Removal of Pb(II) from water by the activated carbon modified by nitric acid under microwave heating.

    Yao, Shuheng; Zhang, Jiajun; Shen, Dekui; Xiao, Rui; Gu, Sai; Zhao, Ming; Liang, Junyu

    2016-02-01

    The rice husk based activated carbon (RH-AC) was treated by nitric acid under microwave heating, in order to improve its capability for the removal of heavy metal ions from water. The optimal conditions for the modification of RH-AC (M-RH-AC) were determined by means of orthogonal array experimental design, giving those as the concentration of nitric acid of 8mol/L, modification time of 15min, modification temperature of 130°C and microwave power of 800W. The characteristics of the M-RH-AC and RH-AC were examined by BET, XRD, Raman spectrum, pH titration, zeta potential, Boehm titration and FTIR analysis. The M-RH-AC has lower pore surface area, smaller crystallite, lower pHIEP and more oxygen-containing functional groups than the RH-AC. Removal capacity of Pb(II) ions by the M-RH-AC and RH-AC from water solution was estimated concerning the influence of contact time, pH value, and initial concentration. The equilibrium time of Pb(II) removal was found to be around 90min after modification process. Two kinetic models are adopted to describe the possible Pb(II) adsorption mechanism, finding that the adsorption rate of Pb(II) ions by the M-RH-AC is larger than that of RH-AC. PMID:26520818

  13. Optical characterization and blu-ray recording properties of metal(II) azo barbituric acid complex films

    Smooth thin films of nickel(II), cobalt(II) and zinc(II) complexes with azo barbituric acid were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrates in 300-700 nm wavelength region were measured. Optical constants (complex refractive index N = n + ik) of the thin films prepared on single-crystal silicon substrates in 275-695 nm wavelength region were investigated on rotating analyzer-polarizer type of scanning ellipsometer, and dielectric constant ε (ε = ε1 + iε2) as well as absorption coefficient α of thin films were calculated at 405 nm. In addition, static optical recording properties of the cobalt(II) complex thin film with an Ag reflective layer was carried out using a 406.7 nm blue-violet laser and a high numerical aperture (NA) of 0.90. Clear recording marks with high reflectivity contrast (>60%) at proper laser power and pulse width were obtained, and the size of recording mark was as small as 250 nm. The results indicate that these metal(II) complexes are promising organic recording medium for the blu-ray optical storage system

  14. Optical characterization and blu-ray recording properties of metal(II) azo barbituric acid complex films

    Li, X.Y. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)], E-mail: xyli@siom.ac.cn; Wu, Y.Q. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Key Lab of Functional Inorganic Material Chemistry (Heilongjiang University), Ministry of Education, Haerbin 150080 (China)], E-mail: yqwu@siom.ac.cn; Gu, D.D.; Gan, F.X. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2009-02-25

    Smooth thin films of nickel(II), cobalt(II) and zinc(II) complexes with azo barbituric acid were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrates in 300-700 nm wavelength region were measured. Optical constants (complex refractive index N = n + ik) of the thin films prepared on single-crystal silicon substrates in 275-695 nm wavelength region were investigated on rotating analyzer-polarizer type of scanning ellipsometer, and dielectric constant {epsilon} ({epsilon} = {epsilon}{sub 1} + i{epsilon}{sub 2}) as well as absorption coefficient {alpha} of thin films were calculated at 405 nm. In addition, static optical recording properties of the cobalt(II) complex thin film with an Ag reflective layer was carried out using a 406.7 nm blue-violet laser and a high numerical aperture (NA) of 0.90. Clear recording marks with high reflectivity contrast (>60%) at proper laser power and pulse width were obtained, and the size of recording mark was as small as 250 nm. The results indicate that these metal(II) complexes are promising organic recording medium for the blu-ray optical storage system.

  15. Cellulose synthase complexes: structure and regulation

    Lei eLei

    2012-04-01

    Full Text Available This review is to update the most recent progress on characterization of the composition, regulation, and trafficking of cellulose synthase complexes. We will highlight proteins that interact with cellulose synthases, e.g. cellulose synthase-interactive protein 1 (CSI1. The potential regulation mechanisms by which cellulose synthase interact with cortical microtubules in primary cell walls will be discussed.

  16. A comprehensive analysis of the geranylgeranylglyceryl phosphate synthase enzyme family identifies novel members and reveals mechanisms of substrate specificity and quaternary structure organization.

    Peterhoff, David; Beer, Barbara; Rajendran, Chitra; Kumpula, Esa-Pekka; Kapetaniou, Evangelia; Guldan, Harald; Wierenga, Rik K; Sterner, Reinhard; Babinger, Patrick

    2014-05-01

    Geranylgeranylglyceryl phosphate synthase (GGGPS) family enzymes catalyse the formation of an ether bond between glycerol-1-phosphate and polyprenyl diphosphates. They are essential for the biosynthesis of archaeal membrane lipids, but also occur in bacterial species, albeit with unknown physiological function. It has been known that there exist two phylogenetic groups (I and II) of GGGPS family enzymes, but a comprehensive study has been missing. We therefore visualized the variability within the family by applying a sequence similarity network, and biochemically characterized 17 representative GGGPS family enzymes regarding their catalytic activities and substrate specificities. Moreover, we present the first crystal structures of group II archaeal and bacterial enzymes. Our analysis revealed that the previously uncharacterized bacterial enzymes from group II have GGGPS activity like the archaeal enzymes and differ from the bacterial group I enzymes that are heptaprenylglyceryl phosphate synthases. The length of the isoprenoid substrate is determined in group II GGGPS enzymes by 'limiter residues' that are different from those in group I enzymes, as shown by site-directed mutagenesis. Most of the group II enzymes form hexamers. We could disrupt these hexamers to stable and catalytically active dimers by mutating a single amino acid that acts as an 'aromatic anchor'. PMID:24684232

  17. Isonicotinic acid-ligated cobalt (II phthalocyanine-modified titania as photocatalyst for benzene degradation via fluorescent lamp

    Joey Andrew A. Valinton

    2016-06-01

    Full Text Available The utilization of bis(isonicotinic acidphthalocyaninatocobalt (II [CoPc(isa2] incorporated on TiO2 has been studied as a photocatalyst to degrade benzene vapor under fluorescent lamp (indoor light conditions. The photocatalytic activity of [CoPc(isa2]-TiO2 compared to TiO2 showed an increase in the extent of degradation. The axial isonicotinic acid ligand attached to CoPc improved the degradation rate of benzene as compared with unligated CoPc-TiO2 which may be attributed to the enhancement of electronic structure in the complex due to the additional isonicotinic acid ligand and its possible attachment to the TiO2 surface through the carboxylic acid moiety. Therefore, covalently-linked CoPc(isa2 to TiO2 can enhance the extent of photodegradation of benzene and other common volatile organic compounds under indoor lighting conditions.

  18. Kinetics of the oxidative hydroxylation of sodium hypophosphite in the presence of copper (II chloride modified by humic (fulvo- acid

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available It was established that in soft conditions (50-70oC, PO2 = 1 atm sodium hypophosphite effectively is oxidized by oxygen in water solutions of copper(II chloride  to give mainly a phosphorous acid. Humic (fulvo- acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, the intermediate and final products, optimal conditions of new catalytic reaction of NaH2PO2 oxidation by oxygen in water solution were defined by kinetics, volumometry, redox-potentiometry and a titration.

  19. Study on complex formation of cadmium (II) ions, 6. Formation constants of cadmium (II) complexes with 2-mercaptoacetic, 2-mercaptopropionic, and 3-mercaptopropionic acids

    Matsui, Haruo (Government Industrial Research Inst., Nagoya (Japan)); Ohtaki, Hitoshi

    1983-10-01

    The formations of cadmium (II) complexes with 2-mercaptoacetic acid (H/sub 2/L). 2-mercaptopropionic acid (H/sub 2/L'), and 3-mercaptopropionic acid were investigated in 3 mol dm/sup -3/ LiCIO/sub 4/ solutions of pH 5.0 to 10.0 at 25/sup 0/C by potentiometric titration. The 1:1 and 1:2 complexes, as well as a protonated complex of the CdHL/sup +/ (or CdHL'/sup +/)-type were found in each solution containing H/sub 2/L or H/sub 2/L' as a ligand. A mixed ligand complex, CdLL'/sup 2 -/, was also formed in a solution containing both ligands. The 1:1 complex was also found in a solution containing 3-mercaptopropionic acid. The formation constants of the complexes were as follows: CdL, log ..beta../sub 1010/ = 4.34; CdL/sub 2//sup 2 -/, log ..beta../sub 1020/ = 6.49; CdHL/sup +/, log ..beta../sub 1110/ = 11.08; CdL', log ..beta../sub 1001/ = 5.66; CdL'/sub 2//sup 2 -/, log ..beta../sub 1002/ = 8.51; CdHL'/sup +/, log ..beta../sub 1101/ = 11.22; CdLL'/sup 2 -/, log ..beta../sub 1011/ = 7.93, and Cd (3-mercaptopropionic acid), log ..beta../sub 1010/ or log ..beta../sub 1001/ = 4.55.

  20. Synthesis, characterization and screening of biological activity of Zn(II), Fe(II) and Mn(II) complexes with trithiocyanuric acid

    Kopel, P.; Doležal, Karel; Machala, L.; Langer, V.

    2007-01-01

    Roč. 26, č. 8 (2007), s. 1583-1589. ISSN 0277-5387 Institutional research plan: CEZ:AV0Z50380511 Keywords : Complexes * Trithiocyanuric acid * Cytotoxicity Subject RIV: CA - Inorganic Chemistry Impact factor: 1.756, year: 2007

  1. The embolization effect of tanshinone II A-polylactic acid/glycolic acid microspheres on the hepatic artery in experimental rabbits

    Objective: To observe the embolization effect of tanshinone II A-polylactic acid/glycolic acid microspheres (PLGA) on the hepatic artery in experimental rabbits. Methods: Under DSA guidance, hepatic catheterization and angiography was performed in 24 New Zealand white rabbits. Via the catheter tanshinone II A-PLGA microspheres was injected into the hepatic arteries. Each time at 10 minutes and on the 1 st, 3 rd, 7 th, 14 th, 21 st, 30 th and 42 nd day after the treatment, every three rabbits were randomly selected for the re-examination with angiography to observe the embolization state of the hepatic arteries, then the animals were sacrificed and the liver, heart, spleen, lung kidney and stomach were removed and sent for pathologic exam. Simultaneously, the functional tests of liver and kidney as well as the routine blood tests were made. The results were evaluated. Results: The peripheral micro-vessels of the hepatic artery vanished away at 10 minutes after embolization, and they remained un-visualized till the 30th day after embolization. On the 42nd day after embolization the peripheral micro-vessels of the hepatic artery could be visualized again. Pathologically,signs of inflammation and necrosis appeared in the occluded areas. Blood biochemical examination showed that there was a transient elevation of white blood cells after the procedure, which fell to normal level on the 7th day (P > 0.05). Both AST and ALT reached their peaks on the 3rd day, then they decreased gradually and returned to normal on the 7th day (P > 0.05). Conclusion: Tanshinone II A-PLGA microspheres have better embolization effect on the hepatic arteries, this effect lasts for 30 to 42 days. Therefore, tanshinone II A-PLGA microsphere is an ideal embolization agent for the treatment of neoplasm. (authors)

  2. Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

    Ballesta-Claver, J.; Rodríguez-Gómez, R. [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain); Capitán-Vallvey, L.F., E-mail: lcapitan@ugr.es [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain)

    2013-04-03

    Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy){sub 3}{sup 2+} in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10{sup −5} to 1.0 × 10{sup −3} M with a limit of detection of 3.1 × 10{sup −6} M and an accuracy of 13.6% (1.0 × 10{sup −4} M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.

  3. Pb(II), Cr(VI) and atrazine sorption behavior on sludge-derived biochar: role of humic acids.

    Zhou, Fengsa; Wang, Hong; Fang, Sheng'en; Zhang, Weihua; Qiu, Rongliang

    2015-10-01

    Pyrolyzing municipal wastewater treatment sludge into biochar can be a promising sludge disposal approach, especially as the produced sludge-derived biochar (SDBC) is found to be an excellent sorbent for heavy metals and atrazine. The aim of this study was to investigate how and why the coexisting humic acids influence the sorption capacity, kinetic, and binding of these contaminants on SDBC surface. Results showed humic acids enhanced Pb(II)/Cr(VI) sorption binding, and increased the corresponding Pb(II) Langmuir sorption capacity at pH 5.0 from 197 to 233 μmol g(-1), and from 688 to 738 μmol g(-1) for Cr(VI) at pH 2.0. It can be mainly attributed to the sorbed humic acids, whose active functional groups can offer the additional sites to form stronger inner-sphere complexes with Pb(2+), and supply more reducing agent to facilitate the transformation of Cr(VI) to Cr(III). However, humic acids reduced the atrazine adsorption Freundlich constant from 1.085 to 0.616 μmol g(-1). The pore blockage, confirmed by the decreased BET-specific surface area, as well as the more hydrophilic surface with more sorbed water molecules may be the main reasons for that suppression. Therefore, the coexisting humic acids may affect heavy metal stabilization or pesticide immobilization during SDBC application to contaminated water or soils, and its role thus should be considered especially when organic residues are also added significantly to increase the humic acid content there. PMID:26062468

  4. Molecular cloning and nucleotide sequence for the complete coding region of human UMP synthase

    The last two steps in the de novo biosynthesis of UMP are catalyzed by orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. In mammals these two activities are found in a single, bifunctional protein called UMP synthase. A human T-lymphoblastic cell cDNA library constructed in λgt10 was screened with a UMP synthase-specific rat cDNA probe. Human UMP synthase cDNAs were isolated and then used to select UMP synthase gene fragments. The complete coding sequence of the mRNA for UMP synthase was determined by analysis of overlapping cDNA and genomic fragments. One of the cDNAs appears to have been synthesized from an incompletely or alternatively processed form of the UMP synthase mRNA. This cDNA lacks a poly(A) tail and has an extended 3'-nontranslated region that hybridizes with larger forms of the UMP synthase mRNA. The UMP synthase protein is composed of 480 amino acids with a molecular weight of 52,199. The two activities of UMP synthase reside in distinct domains encoded by the 3' and 5' halves of the mRNA. The COOH-terminal 258 amino acids of the human UMP synthase protein contain the orotidine-5'-monophosphate decarboxylase catalytic domain. This region is highly homologous to the mouse orotidine-5'-monophosphate decarboxylase sequence. The NH2-terminal 214 amino acids contain the OPRT domain. There is amino acid homology between this protein domain and specific regions of the Escherichia coli OPRT. The human OPRT domain also contains the putative catalytic site common to other human phosphoribosyltransferases

  5. Human Retroviruses and AIDS. A compilation and analysis of nucleic acid and amino acid sequences: I--II; III--V

    Myers, G.; Korber, B. [eds.] [Los Alamos National Lab., NM (United States); Wain-Hobson, S. [ed.] [Laboratory of Molecular Retrovirology, Pasteur Inst.; Smith, R.F. [ed.] [Baylor Coll. of Medicine, Houston, TX (United States). Dept. of Pharmacology; Pavlakis, G.N. [ed.] [National Cancer Inst., Frederick, MD (United States). Cancer Research Facility

    1993-12-31

    This compendium and the accompanying floppy diskettes are the result of an effort to compile and rapidly publish all relevant molecular data concerning the human immunodeficiency viruses (HIV) and related retroviruses. The scope of the compendium and database is best summarized by the five parts that it comprises: (I) HIV and SIV Nucleotide Sequences; (II) Amino Acid Sequences; (III) Analyses; (IV) Related Sequences; and (V) Database Communications. Information within all the parts is updated at least twice in each year, which accounts for the modes of binding and pagination in the compendium.

  6. Chemotaxonomic Evaluation of Species of Turkish Salvia: Fatty Acid Composition of Seed Oils. II

    Turgut Kılıç

    2007-05-01

    Full Text Available Fatty acids composition of seed oil of Salvia viridis, S. hydrangea, S. blepharochleana, S. chianantha, S. staminea, S. hypergeia,, S. cilicica, S. caespitosa, S. sclarea, S. cadmica, S. microstegia, S. pachystachys and S. verticillata were analyzed by GC/MS. The main compound were found to be as linoleic acid (18:2; 12.8 % to 52.2 %, linolenic acid (18:3; 3.2 % to 47.7 %, oleic acid (18:1; 11.3 % to 25.6 %, palmitic acid (16:0; 0.7 % to 16.8 % and stearic acid (18:0; 1.8 % to 4.8 %. A phylogenetic tree of species of Salvia were reported and compared to 18:3/18:2 ratio of the seed oils. Fatty acid composition of Salvia seed oils could be used as a chemotaxonomical marker.

  7. Potential therapeutic target for malignant paragangliomas: ATP synthase on the surface of paraganglioma cells

    Fliedner, Stephanie MJ; Yang, Chunzhang; Thompson, Eli; Abu-Asab, Mones; Hsu, Chang-Mei; Lampert, Gary; Eiden, Lee; Tischler, Arthur S; Wesley, Robert; Zhuang, Zhengping; Lehnert, Hendrik; Pacak, Karel

    2015-01-01

    F1FoATP synthase (ATP synthase) is a ubiquitous enzyme complex in eukaryotes. In general it is localized to the mitochondrial inner membrane and serves as the last step in the mitochondrial oxidative phosphorylation of ADP to ATP, utilizing a proton gradient across the inner mitochondrial membrane built by the complexes of the electron transfer chain. However some cell types, including tumors, carry ATP synthase on the cell surface. It was suggested that cell surface ATP synthase helps tumor cells thriving on glycolysis to survive their high acid generation. Angiostatin, aurovertin, resveratrol, and antibodies against the α and β subunits of ATP synthase were shown to bind and selectively inhibit cell surface ATP synthase, promoting tumor cell death. Here we show that ATP synthase β (ATP5B) is present on the cell surface of mouse pheochromocytoma cells as well as tumor cells of human SDHB-derived paragangliomas (PGLs), while being virtually absent on chromaffin primary cells from bovine adrenal medulla by confocal microscopy. The cell surface location of ATP5B was verified in the tissue of an SDHB-derived PGL by immunoelectron microscopy. Treatment of mouse pheochromocytoma cells with resveratrol as well as ATP5B antibody led to statistically significant proliferation inhibition. Our data suggest that PGLs carry ATP synthase on their surface that promotes cell survival or proliferation. Thus, cell surface ATP synthase may present a novel therapeutic target in treating metastatic or inoperable PGLs. PMID:26101719

  8. Influence of the steric effect of flexible isomeric phenylenediacetic acids on the resultant lead(II) coordination polymers

    To study the steric effect of the flexible dicarboxylate ligands on the resultant formations of coordination polymers (CPs), four new PbII CPs [Pb(1,2-pda)(H2O)]n (1), [Pb(1,3-pda)]n·nH2O (2), [Pb2(1,4-pda)2(H2O)]n·2nH2O (3a and 3b) have been produced by the isomeric phenylenediacetic acids (H2pda). The X-ray crystallography study reveals that CP 1 is a two-dimensional (2D) 4-connected sql (44.62) network via the weak Pb···O interactions built on 1D chain-like structure. CP 2 crystallizes in orthorhombic system with chiral space group P212121, showing a 4-connected sra (42.63.8) framework where a left-handed helical motif is formed by PbII ions and trans-1,3-pda ligands. More interestingly, CPs 3a and 3b are two true 3D polymorphs and have the different morphology. Topologically, the framework of 3a exhibits a 4-connected lon 66 motif, while that of 3b is a (4,6)-connected fsh (43.63)2(46.66.83) net. It is found that the three isomeric pda anions display the various coordination fashions in four CPs. The different structural arrangements show that the steric effect of the isomeric H2pda tectons has a positive role in directing the final products of PbII CPs. Also, the fluorescent properties of the CPs were studied in the solid state at room temperature. - Graphical abstract: Four new PbII-based CPs have been produced by the isomeric phenylenediacetic acids (H2pda). The different structural arrangements show that the steric effect of the isomeric H2pda tectons has a positive role in directing the final products of PbII CPs. Also, the fluorescent properties of the CPs were studied in the solid state at room temperature. - Highlights: • Four PbII-based coordination polymers were produced by phenylenediacetic acids. • The crystal and topological structures of the CPs have been investigated carefully. • Different structures show the steric effect of H2pda has a role in directing CPs. • The fluorescence of the CPs were studied in the solid state at room

  9. Assessing the allelotypic effect of two aminocyclopropane carboxylic acid synthase-encoding genes MdACS1 and MdACS3a on fruit ethylene production and softening in Malus

    Dougherty, Laura; Zhu, Yuandi; Xu, Kenong

    2016-01-01

    Phytohormone ethylene largely determines apple fruit shelf life and storability. Previous studies demonstrated that MdACS1 and MdACS3a, which encode 1-aminocyclopropane-1-carboxylic acid synthases (ACS), are crucial in apple fruit ethylene production. MdACS1 is well-known to be intimately involved in the climacteric ethylene burst in fruit ripening, while MdACS3a has been regarded a main regulator for ethylene production transition from system 1 (during fruit development) to system 2 (during fruit ripening). However, MdACS3a was also shown to have limited roles in initiating the ripening process lately. To better assess their roles, fruit ethylene production and softening were evaluated at five time points during a 20-day post-harvest period in 97 Malus accessions and in 34 progeny from 2 controlled crosses. Allelotyping was accomplished using an existing marker (ACS1) for MdACS1 and two markers (CAPS866 and CAPS870) developed here to specifically detect the two null alleles (ACS3a-G289V and Mdacs3a) of MdACS3a. In total, 952 Malus accessions were allelotyped with the three markers. The major findings included: The effect of MdACS1 was significant on fruit ethylene production and softening while that of MdACS3a was less detectable; allele MdACS1–2 was significantly associated with low ethylene and slow softening; under the same background of the MdACS1 allelotypes, null allele Mdacs3a (not ACS3a-G289V) could confer a significant delay of ethylene peak; alleles MdACS1–2 and Mdacs3a (excluding ACS3a-G289V) were highly enriched in M. domestica and M. hybrid when compared with those in M. sieversii. These findings are of practical implications in developing apples of low and delayed ethylene profiles by utilizing the beneficial alleles MdACS1-2 and Mdacs3a. PMID:27231553

  10. Isolation and expression of the Pneumocystis carinii thymidylate synthase gene

    Edman, U; Edman, J C; Lundgren, B;

    1989-01-01

    The thymidylate synthase (TS) gene from Pneumocystis carinii has been isolated from complementary and genomic DNA libraries and expressed in Escherichia coli. The coding sequence of TS is 891 nucleotides, encoding a 297-amino acid protein of Mr 34,269. The deduced amino acid sequence is similar t...... into plasmid vectors under control of the lac and tac promoters. These constructs direct the synthesis of catalytically active enzyme to the extent of 2% of total soluble protein....

  11. Studies on the liquid-liquid extraction and ion and precipitate flotation of Co(II) with decanoic acid

    The liquid-liquid extraction, ion and precipitate flotation of Co(II) from chloride media of 1*10-4 M initial Co(II) concentration and μ = 0.1 have been investigated using decanoic acid and the results are compared. Organic solvents used were chloroform in the case of liquid-liquid extraction and ethanol (used as a solvent for the collector and a frother) in the case of flotation. From the results it appears that liquid-liquid extraction takes place through the formation of the complex: (CoR2)2(HR)2 but flotation occurs through the formation of a surface active product which has the empirical formula CoR2. The effects of pH and of decanoic acid concentration on the three separation processes were also investigated and the results discussed. Good agreement was observed between the experimental precipitate flotation curves and the theoretical curve calculated from the data published for Co(II) hydrolysis. (author) 30 refs.; 4 figs.; 1 tab

  12. Spectrophotometric determination of palladium (II) with rubeanic acid (RA) in presence of pyridine, piperidine and 3-picoline

    Unpretentious and exclusive methods for the spectrophotometric determination of trace amount of divalent palladium (II) have been developed with rubeanic acid (dithio-oxamide) in presence of secondary ligands like pyridine, piperidine and 3-picoline. Both direct and extraction spectrophotometry showed that coloured rubeanates are only stable in acidic medium. The violent yellow coloured products are formed below ph 5.0 with an absorption maxima at 416.0 and 422.0 (pyridine), 405.0 and 416.5 (piperidine) and 418.0 and 422.0 (3-picoline) both in direct and isoamyl alcohol (IAA) extracted system, respectively. Results indicate that the highest sensitivity and molar absorptivity of Pd-RA pyridine system in direct spectrophotometry were 0.01497 mu g Pd(II) cm/sup -2/ and 7107.89 L mol sup -1/ cm/sup -1/ respectively. IAA extracted Pd-RA-piperidine system was found to give a sensitivity of 0.01087 mu g(Pd(II) cm /sup -2/ and molar absorptivity of 9788.80 L mol /sup -1/ cm/sup -1/ which were the highest of all the system. The effects due to variation of pH, reagent concentrations, order of addition of reagents, time, temperature and solvent media on the absorption spectra have been investigated and the optimum conditions determined. The effects of diverse ions and their tolerance limit have also been studies. (author)

  13. Complexation of Cu(II) by original tartaric acid-based ligands in nonionic micellar media: thermodynamic study and applications.

    Dupont-Leclercq, Laurence; Giroux, Sébastien; Parant, Stéphane; Khoudour, Leïla; Henry, Bernard; Rubini, Patrice

    2009-04-01

    The complexation of Cu(II) with original alkylamidotartaric acids (C(x)T) is investigated in homogeneous aqueous medium and in the presence of nonionic micelles of Brij 58 (C16EO20), thanks to various analytical techniques such as NMR self-diffusion experiments, CD and UV-vis spectroscopy, ESI mass spectrometry, pHmetry and micellar-enhanced ultrafiltration (MEUF). First, a complete speciation study proves the formation of dimeric complexes in water and provides their formation constants. Second, a similar study is led in the presence of nonionic micelles. It underlines a modification of the apparent equilibrium constants in micellar medium and demonstrates that the structure of the complexes is slightly modified in the presence of micelles. This thermodynamic and structural study is applied to modelize the evolution of the extraction yields of Cu(II) by the micelles as a function of pH and to identify the complexes extracted in the micelles. The effects of the chain length of the ligand (C3T vs C8T) on the solubilization properties are put into relief and discussed. Anionic species are proved to be more incorporated in the nonionic micelles than the cationic species. The extracting system constituted of octylamidotartaric acid (CsT) solubilized in nonionic micelles of Brij 58 is demonstrated to be very efficient for the extraction of Cu(II) by MEUF, this technique being an interesting green alternative to traditional solvent extraction. PMID:19708239

  14. Synthesis and Characterization of a Heteroleptic Ru(II Complex of Phenanthroline Containing Oligo-Anthracenyl Carboxylic Acid Moieties

    Peter A. Ajibade

    2010-09-01

    Full Text Available In an effort to develop new ruthenium(II complexes, this work describes the design, synthesis and characterization of a ruthenium(II functionalized phenanthroline complex with extended π-conjugation. The ligand were L1 (4,7-bis(2,3-dimethylacrylic acid-1,10-phenanthroline, synthesized by a direct aromatic substitution reaction, and L2 (4,7-bis(trianthracenyl-2,3-dimethylacrylic acid-1,10-phenanthroline, which was synthesized by the dehalogenation of halogenated aromatic compounds using a zero-valent palladium cross-catalyzed reaction in the absence of magnesium-diene complexes and/or cyclooctadienyl nickel (0 catalysts to generate a new carbon-carbon bond (C-C bond polymerized hydrocarbon units. The ruthenium complex [RuL1L2(NCS2] showed improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients, luminescence and interesting electrochemical properties. Cyclic and square wave voltammetry revealed five major redox processes. The number of electron(s transferred by the ruthenium complex was determined by chronocoulometry in each case. The results show that processes I, II and III are multi-electron transfer reactions while processes IV and V involved one-electron transfer reaction. The photophysical property of the complex makes it a promising candidate in the design of chemosensors and photosensitizers, while its redox-active nature makes the complex a potential mediator of electron transfer in photochemical processes.

  15. Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays; Improvement of determinations in acid ethanol extracts by the use of truncated IGF-I as radioligand

    Bang, P.; Eriksson, U.; Wivall, I.-L.; Hall, K. (Department of Endocrinology, Karolinska Institute, Stockholm (Sweden)); Sara, V. (Department of Pathology, Karolinska Institute, Stockholm (Sweden))

    1991-01-01

    Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N=42, r=0.91, p<0.001) and in patients with acromegaly (N=10, r=0.85, p<0.01), GH deficiency (N=10, r=0.88, p<0.001) or Type I diabetes mellitus (N=10, r=0.90, p<0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r=0.61, NS) or GH deficiency (r=0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand. (author).

  16. Molecular cloning and functional expression of geranylgeranyl pyrophosphate synthase from Coleus forskohlii Briq

    Kawamukai Makoto

    2004-11-01

    Full Text Available Abstract Background Isopentenyl diphosphate (IPP, a common biosynthetic precursor to the labdane diterpene forskolin, has been biosynthesised via a non-mevalonate pathway. Geranylgeranyl diphosphate (GGPP synthase is an important branch point enzyme in terpenoid biosynthesis. Therefore, GGPP synthase is thought to be a key enzyme in biosynthesis of forskolin. Herein we report the first confirmation of the GGPP synthase gene in Coleus forskohlii Briq. Results The open reading frame for full-length GGPP synthase encodes a protein of 359 amino acids, in which 1,077 nucleotides long with calculated molecular mass of 39.3 kDa. Alignments of C. forskohlii GGPP synthase amino acid sequences revealed high homologies with other plant GGPP synthases. Several highly conserved regions, including two aspartate-rich motifs were identified. Transient expression of the N-terminal region of C. forskohlii GGPP synthase-GFP fusion protein in tobacco cells demonstrated subcellular localization in the chloroplast. Carotenoid production was observed in Escherichia coli harboring pACCAR25ΔcrtE from Erwinia uredovora and plasmid carrying C. forskohlii GGPP synthase. These results suggested that cDNA encoded functional GGPP synthase. Furthermore, C. forskohlii GGPP synthase expression was strong in leaves, decreased in stems and very little expression was observed in roots. Conclusion This investigation proposed that forskolin was synthesised via a non-mevalonate pathway. GGPP synthase is thought to be involved in the biosynthesis of forskolin, which is primarily synthesised in the leaves and subsequently accumulates in the stems and roots.

  17. Cd(II) removal from aqueous solution by adsorption on α-ketoglutaric acid-modified magnetic chitosan

    The present study developed an α-ketoglutaric acid-modified magnetic chitosan (α-KA-Fe3O4/CS) for highly efficient adsorption of Cd(II) from aqueous solution. Several techniques, including transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and vibrating sample magnetometer (VSM), were applied to characterize the adsorbent. Batch tests were conducted to investigate the Cd(II) adsorption performance of α-KA-Fe3O4/CS. The maximum adsorption efficiency of Cd(II) appeared at pH 6.0 with the value of 93%. The adsorption amount was large and even reached 201.2 mg/g with the initial Cd(II) concentration of 1000 mg/L. The adsorption equilibrium was reached within 30 min and commendably described by pseudo-second-order model, and Langmuir model fitted the adsorption isotherm better. Furthermore, thermodynamic parameters, free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) of Cd(II) adsorption were also calculated and showed that the overall adsorption process was endothermic and spontaneous in nature because of positive ΔH values and negative ΔG values, respectively. Moreover, the Cd(II)-loaded α-KA-Fe3O4/CS could be regenerated by 0.02 mol/L NaOH solution, and the cadmium removal capacity could still be kept around 89% in the sixth cycle. All the results indicated that α-KA-Fe3O4/CS was a promising adsorbent in environment pollution cleanup.

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

    Nanson, Jeffrey D.; Zainab Himiari; 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...

  19. A kinetic study of plutonium dioxide dissolution in hydrochloric acid using iron (II) as an electron transfer catalyst

    Effective dissolution of plutonium dioxide has traditionally been accomplished by contact with strong nitric acid containing a small amount of fluoride at temperatures of ∼ 100 C. In spite of these aggressive conditions, PuO2 dissolution is sometimes incomplete requiring additional contact with the solvent. This work focused on an alternative to conventional dissolution in nitric acid where an electron transfer catalyst, Fe(II), was used in hydrochloric acid. Cyclic voltammetry was employed as an in-situ analytical technique for monitoring the dissolution reaction rate. The plutonium oxide selected for this study was decomposed plutonium oxalate with > 95% of the material having a particle diameter (< 70 microm) as determined by a scanning laser microscopy technique. Attempts to dry sieve the oxide into narrow size fractions prior to dissolution in the HCl-Fe(II) solvent system failed, apparently due to significant interparticle attractive forces. Although sieve splits were obtained, subsequent scanning laser microscopy analysis of the sieve fractions indicated that particle segregation was not accomplished and the individual sieve fractions retained a particle size distribution very similar to the original powder assemblage. This phenomena was confirmed through subsequent dissolution experiments on the various screen fractions which illustrated no difference in kinetic behavior between the original oxide assemblage and the sieve fractions

  20. Divergence of multimodular polyketide synthases revealed by a didomain structure.

    Zheng, Jianting; Gay, Darren C; Demeler, Borries; White, Mark A; Keatinge-Clay, Adrian T

    2012-07-01

    The enoylreductase (ER) is the final common enzyme from modular polyketide synthases (PKSs) to be structurally characterized. The 3.0 Å-resolution structure of the didomain comprising the ketoreductase (KR) and ER from the second module of the spinosyn PKS reveals that ER shares an ∼600-Å(2) interface with KR distinct from that of the related mammalian fatty acid synthase (FAS). In contrast to the ER domains of the mammalian FAS, the ER domains of the second module of the spinosyn PKS do not make contact across the two-fold axis of the synthase. This monomeric organization may have been necessary in the evolution of multimodular PKSs to enable acyl carrier proteins to access each of their cognate enzymes. The isolated ER domain showed activity toward a substrate analog, enabling us to determine the contributions of its active site residues. PMID:22634636

  1. Protection of ascorbic acid from copper(II)-catalyzed oxidative degradation in the presence of flavonoids: quercetin, catechin and morin.

    Beker, Bilge Yildoğan; Sönmezoğlu, Inci; Imer, Filiz; Apak, Reşat

    2011-08-01

    Protection of ascorbic acid (AA) (vitamin C) from Cu(II)-catalyzed autoxidation is an important aspect of antioxidant chemistry. The autoxidation of AA in the absence and presence of Cu(II) ions was investigated in aerated solution at room temperature and I = 0.1 ionic strength (KNO(3)); the effects of three different flavonoids of similar structure (quercetin, morin and catechin) and their mixtures on the AA system were studied. The concentration of unoxidized AA remaining in solution was measured with the modified cupric ion reducing antioxidant capacity spectrophotometric method. The Cu(II)-catalyzed oxidation at pH 4.5 followed first-order kinetics with respect to AA concentration. Catalytic autoxidation of AA was inhibited to a greater extent by stable quercetin and morin complexes of Cu(II) than by catechin complex. The inhibitive effectiveness order of mixtures gives information about possible synergistic or antagonistic combinations of flavonoid antioxidants, which should be further confirmed with other antioxidant tests. PMID:21391791

  2. The c-Ring of the F1FO-ATP Synthase: Facts and Perspectives.

    Nesci, Salvatore; Trombetti, Fabiana; Ventrella, Vittoria; Pagliarani, Alessandra

    2016-04-01

    The F1FO-ATP synthase is the only enzyme in nature endowed with bi-functional catalytic mechanism of synthesis and hydrolysis of ATP. The enzyme functions, not only confined to energy transduction, are tied to three intrinsic features of the annular arrangement of c subunits which constitutes the so-called c-ring, the core of the membrane-embedded FO domain: (i) the c-ring constitution is linked to the number of ions (H(+) or Na(+)) channeled across the membrane during the dissipation of the transmembrane electrochemical gradient, which in turn determines the species-specific bioenergetic cost of ATP, the "molecular currency unit" of energy transfer in all living beings; (ii) the c-ring is increasingly involved in the mitochondrial permeability transition, an event linked to cell death and to most mitochondrial dysfunctions; (iii) the c subunit species-specific amino acid sequence and susceptibility to post-translational modifications can address antibacterial drug design according to the model of enzyme inhibitors which target the c subunits. Therefore, the simple c-ring structure not only allows the F1FO-ATP synthase to perform the two opposite tasks of molecular machine of cell life and death, but it also amplifies the enzyme's potential role as a drug target. PMID:26621635

  3. BIOSORPTION OF LEAD (II ON MODIFIED BARKS EXPLAINED BY THE HARD AND SOFT ACIDS AND BASES (HSAB THEORY

    Cedric Astier,

    2012-01-01

    Full Text Available Chemical modification of Douglas fir bark and its subsequent utilization in adsorption of Pb(II from aqueous solutions was investigated. The polysaccharidic moiety of barks was functionalized by periodate oxidation and derivatized after reductive amination in the presence of aminated oligo-carrageenans. Pb(II adsorption isotherms of derivatized barks were then determined and compared to the capabilities of crude barks using the Langmuir adsorption model in terms of affinity (b and maximum binding capacity (qmax. Compared to crude barks, the derivatization of barks by oligo-carrageenans resulted in significant enhancements of qmax and b by up to x8 and x4, respectively. The results obtained from crude barks on chemically grafted carboxylic and sulfated barks are discussed and interpreted through the Hard and Soft Acids and Bases (HSAB theory.

  4. Synthesis, Biological, and Quantum Chemical Studies of Zn(II and Ni(II Mixed-Ligand Complexes Derived from N,N-Disubstituted Dithiocarbamate and Benzoic Acid

    Anthony C. Ekennia

    2016-01-01

    Full Text Available Some mixed-ligand complexes of Zn(II and Ni(II derived from the sodium salt of N-alkyl-N-phenyl dithiocarbamate and benzoic acid have been prepared. The complexes are represented as ZnMDBz, ZnEDBz, NiMDBz, and NiEDBz (MD: N-methyl-N-phenyl dithiocarbamate, ED: N-ethyl-N-phenyl dithiocarbamate, and Bz: benzoate; and their coordination behavior was characterized on the basis of elemental analyses, IR, electronic spectra, magnetic and conductivity measurements, and quantum chemical calculations. The magnetic moment measurement and electronic spectra were in agreement with the four proposed coordinate geometries for nickel and zinc complexes and were corroborated by the theoretical quantum chemical calculations. The quantum chemically derived thermodynamics parameters revealed that the formation of N-methyl-N-phenyl dithiocarbamate complexes is more thermodynamically favourable than that of the N-ethyl-N-phenyl dithiocarbamate complexes. The bioefficacy of the mixed-ligand complexes examined against different microbes showed moderate to high activity against the test microbes. The anti-inflammatory and antioxidant studies of the metal complexes showed that the ethyl substituted dithiocarbamate complexes exhibited better anti-inflammatory and antioxidant properties than the methyl substituted dithiocarbamate complexes.

  5. CYCLIC VOLTAMMETRY STUDIES OF COPPER (II) AND TELLURIUM (IV) IONS IN ACIDIC AQUEOUS SOLUTIONS FOR THIN FILM DEPOSITION

    SARAVANAN NAGALINGAM; GEOK BEE TEH

    2014-01-01

    Cyclic voltammetry studies of copper (II) and tellurium (IV) ions in acidic aqueous solutions were carried out to determine the optimum condition for copper telluride thin film deposition. The voltammetry studies include reversible scans at different solution pH. Based on the voltammogram, suitable deposition conditions was determined to be in the range of -0.35 V to -0.45 V versus Ag/AgCl at pH values between 2.0 to 2.2 under non diffusion-limited conditions.

  6. Precipitation of pertechnetate ion from nitric acid solutions using complexes of copper(II) with heterocyclic N-donor ligands

    The TcO4- precipitation with organic complexes of Cu(II) from nitric acid solutions was studied. Complex Cu(phen)3(NO3)2 was chosen as the optimal precipitant. The conditions for maximum Tc precipitation of 95 ± 3 % were determined. It was shown the possibility to obtain metal-Tc alloys by thermal treatment of the precipitates. As found, the addition of the fusible metal (Sn) to the sediment was required to receive appropriate matrix. Cu-Tc-Sn matrix was tested for Tc leaching. (author)

  7. Modeling of solvent extraction equilibrium of Cu(II) from sulphuric Acid solution with MOC-55TD

    Alguacil, F. J.; Alonso, M

    1999-01-01

    The extraction of Cu(II) from acidic sulphate aqueous solutions using the commercial MOC-55TD extractant is studied. A predictive model, which consists in a set of non-linear mass action and mass balance equations is proposed. The model was solved using a tailor-made equation-solving program. The extraction of copper can be described by the formation of CuR2 species (log Kext= 0.717 ± 0.03) in the organic phase. The copper equil...

  8. Mixed ligand two dimensional Cd(ii)/Ni(ii) metal organic frameworks containing dicarboxylate and tripodal N-donor ligands: Cd(ii) MOF is an efficient luminescent sensor for detection of picric acid in aqueous media.

    Rachuri, Yadagiri; Parmar, Bhavesh; Bisht, Kamal Kumar; Suresh, Eringathodi

    2016-05-01

    Two dimensional metal organic frameworks (MOFs) [Cd(5-BrIP)(TIB)]n () and [Ni2(5-BrIP)2(TIB)2]n (), involving the aromatic polycarboxylate ligand 5-bromo isophthalic acid (H2BrIP), flexible tripodal ligand 1,3,5-tris(imidazol-1-ylmethyl)benzene (TIB) and Cd(ii)/Ni(ii) metal nodes have been synthesized by different methods. These compounds were characterized by various analytical methods, and variable temperature X-ray diffraction data showed thermal stability of both MOFs up to 350 °C. Phase purity as well as water stability of the MOFs were established by powder X-ray diffraction, and the structural diversity of the compounds were investigated by single-crystal X-ray diffraction. Both the MOFs are mixed ligand 2D nets, and the topology of the network can be described as a binodal 3,5-c connected net with 3,5L2 topology having the point symbol {4(2)·6(7)·8}{4(2)·6}. Sensing of picric acid [2,4,6-trinitrophenol, TNP] by luminescence quenching among a large range of nitroanalytes in aqueous phase by the Cd(ii) luminescent MOF (LMOF) were been investigated. Structural studies on 1 : 1 co-crystals () of TIB and TNP were carried out. The selective and sensitive fluorescence quenching response of towards electron-deficient TNP over other nitro analytes in aqueous phase was demonstrated by fluorescence quenching titration. Concomitant occurrence of electron transfer/energy transfer processes and electrostatic interaction favours the selective sensing of TNP. A Cd(ii) LMOF ()-coated paper strip that we developed demonstrated fast and selective response to TNP, by the complete quenching of the blue fluorescence upon excitation of the paper strip at 365 nm radiation in its presence. PMID:27067118

  9. Structure and Function of Fusicoccadiene Synthase, a Hexameric Bifunctional Diterpene Synthase.

    Chen, Mengbin; Chou, Wayne K W; Toyomasu, Tomonobu; Cane, David E; Christianson, David W

    2016-04-15

    Fusicoccin A is a diterpene glucoside phytotoxin generated by the fungal pathogen Phomopsis amygdali that causes the plant disease constriction canker, first discovered in New Jersey peach orchards in the 1930s. Fusicoccin A is also an emerging new lead in cancer chemotherapy. The hydrocarbon precursor of fusicoccin A is the tricyclic diterpene fusicoccadiene, which is generated by a bifunctional terpenoid synthase. Here, we report X-ray crystal structures of the individual catalytic domains of fusicoccadiene synthase: the C-terminal domain is a chain elongation enzyme that generates geranylgeranyl diphosphate, and the N-terminal domain catalyzes the cyclization of geranylgeranyl diphosphate to form fusicoccadiene. Crystal structures of each domain complexed with bisphosphonate substrate analogues suggest that three metal ions and three positively charged amino acid side chains trigger substrate ionization in each active site. While in vitro incubations reveal that the cyclase domain can utilize farnesyl diphosphate and geranyl diphosphate as surrogate substrates, these shorter isoprenoid diphosphates are mainly converted into acyclic alcohol or hydrocarbon products. Gel filtration chromatography and analytical ultracentrifugation experiments indicate that full-length fusicoccadiene synthase adopts hexameric quaternary structure, and small-angle X-ray scattering data yield a well-defined molecular envelope illustrating a plausible model for hexamer assembly. PMID:26734760

  10. Synthesis, Characterization, and Interaction with Biomolecules of Platinum(II Complexes with Shikimic Acid-Based Ligands

    Yan Peng

    2013-01-01

    Full Text Available Starting from the active ingredient shikimic acid (SA of traditional Chinese medicine and NH2(CH2nOH, (n=2–6, we have synthesized a series of new water-soluble Pt(II complexes PtLa–eCl2, where La–e are chelating diamine ligands with carbon chain covalently attached to SA (La–e = SA-NH(CH2nNHCH2CH2NH2; La, n=2; Lb, n=3; Lc, n=4; Ld, n=5; Le, n=6. The results of the elemental analysis, LC-MS, capillary electrophoresis, and 1H, 13C NMR indicated that there was only one product (isomer formed under the present experimental conditions, in which the coordinate mode of PtLa–eCl2 was two-amine bidentate. Their in vitro cytotoxic activities were evaluated by MTT method, where these compounds only exhibited low cytotoxicity towards BEL7404, which should correlate their low lipophilicity. The interactions of the five Pt(II complexes with DNA were investigated by agarose gel electrophoresis, which suggests that the Pt(II complexes could induce DNA alteration. We also studied the interactions of the Pt(II complexes with 5′-GMP with ESI-MS and 1H NMR and found that PtLbCl2, PtLcCl2, and PtLdCl2 could react with 5′-GMP to form mono-GMP and bis-GMP adducts. Furthermore, the cell-cycle analysis revealed that PtLbCl2, PtLcCl2 cause cell G2-phase arrest after incubation for 72 h. Overall, these water-soluble Pt(II complexes interact with DNA mainly through covalent binding, which blocks the DNA synthesis and replication and thus induces cytotoxicity that weakens as the length of carbon chain increases.

  11. Two new Zn(II) coordination polymers based on mixed pipemidic acid and flexible aromatic dicarboxylic acid ligands: Syntheses, crystal structures and luminescent properties

    Jia, Yanxia; Zhou, Pingping

    2016-09-01

    Two new Zn(II) coordination polymers, namely [Zn(4,4‧-sdb) (HPPA)]n (1) and [Zn(2,2‧-bpdc)0.5(PPA)]n (2) (4,4‧-H2sdb = 4,4‧-sulfonyldibenzoate, 2,2‧-H2bpdc = 2,2‧-biphenyldicarboxylic acid, HPPA = pipemidic acid) were successfully obtained under hydrothermal conditions. These two compounds were further characterized by single-crystal X-ray diffraction analyses, elemental analyses, powder X-ray diffraction (PXRD) analyses and IR spectra. Compound 1 features a 1D chain structure, which further extended into a 3D supramolecular framework via intermolecular hydrogen bonds and weak van der Waals interactions, and compound 2 features a 3D framework with 6-connected α-Po-type topology. The structural regulation for these two compounds was successfully achieved by changing the flexible aromatic dicarboxylic acid ligand. Moreover, the thermal stabilities and luminescent properties for these two compounds were also investigated.

  12. Copper(II)-rubeanic acid coprecipitation system for separation-preconcentration of trace metal ions in environmental samples for their flame atomic absorption spectrometric determinations

    A simple and facile preconcentration procedure based on the coprecipitation of trace heavy metal ions with copper(II)-rubeanic acid complex has been developed. The analytical parameters including pH, amounts of rubeanic acid, sample volume, etc. was investigated for the quantitative recoveries of Pb(II), Fe(III), Cd(II), Au(III), Pd(II) and Ni(II). No interferic effects were observed from the concomitant ions. The detection limits for analyte ions by 3 sigma were in the range of 0.14 μg/l for iron-3.4 μg/l for lead. The proposed coprecipitation method was successfully applied to water samples from Palas Lake-Kayseri, soil and sediment samples from Kayseri and Yozgat-Turkey

  13. Effect of substratum, serum and linoleic acid on the lipid synthesis of isolated alveolar type II cells

    The authors examined the effect of cellular substratum (plastic or amnionic basement membrane (ABM)) and serum additive (fetal bovine (FBS), pork, horse, rat or human) on phospholipid synthesis in alveolar type II cells. The cells were isolated from adult rats, cultured for 48 hours under the various substratum and serum conditions, and then incubated for an additional 2 hours with [1-14C] acetate. ABM consistently caused a significant increase in the percent of radiolabel incorporated into phosphatidylcholine (PC) and/or phosphatidylglycerol (PG). Serum also had a significant effect with the highest values of PC and saturated PC being obtained with rat serum and the highest PG values with horse serum. The fatty acid composition of the sera used varied according to species with the largest variations in percent linoleic acid. Supplementing media with linoleic acid resulted in a marked increase in saturated PC values and a fall in PG values. Therefore, they conclude that: 1) ABM improves differentiated function, 2) FBS supplementation may not be optimal, and 3) the different effects of linoleic acid supplementation on PC, saturated PC, and PG values suggests an independent regulation of synthesis for these lipid species in vitro

  14. VAC chemotherapy with valproic acid for refractory/relapsing small cell lung cancer: a phase II study

    Thierry Berghmans

    2015-10-01

    Full Text Available Salvage chemotherapy (CT for relapsing or refractory small cell lung cancer (SCLC remains disappointing. In vitro experiments showed that valproic acid increases apoptosis of SCLC cell lines exposed to doxorubicin, vindesine and bis(2-chloroethylamine. The primary objective of this phase II study was to determine whether epigenetic modulation with valproic acid in addition to a doxorubicin, vindesine and cyclophosphamide (VAC regimen improves 6-month progression-free survival (PFS. Patients with pathologically proven SCLC refractory to prior platinum derivatives and etoposide were eligible. After central registration, patients received VAC plus daily oral valproic acid. 64 patients were registered, of whom six were ineligible. Seven patients did not receive any CT, leaving 51 patients assessable for the primary end-point. The objective response rate was 19.6%. Median PFS was 2.8 months (95% CI 2.5–3.6 months and 6-month PFS was 6%. Median survival time was 5.9 months (95% CI 4.7–7.5 months. Toxicity was mainly haematological, with 88% and 26% grade 3–4 neutropenia and thrombopenia, respectively. Despite an interesting response rate, the addition of valproic acid to VAC did not translate into adequate PFS in relapsing SCLC or SCLC refractory to platinum–etoposide.

  15. Systematic replacement of lysine with glutamine and alanine in Escherichia coli malate synthase G: effect on crystallization

    Alanine and glutamine mutations were made to the same 15 lysine positions on the surface of E. coli malate synthase G and the impact on crystallization observed. The results support lysine replacement for improvement of crystallization and provide insight into site selection and type of amino-acid replacement. Two proposals recommend substitution of surface lysine residues as a means to improve the quality of protein crystals. In proposal I, substitution of lysine by alanine has been suggested to improve crystallization by reducing the entropic cost of ordering flexible side chains at crystal contacts. In proposal II, substitution of lysine by residues more commonly found in crystal contacts, such as glutamine, has been proposed to improve crystallization. 15 lysine residues on the surface of Escherichia coli malate synthase G, distributed over a variety of secondary structures, were individually mutated to both alanine and glutamine. For 28 variants, detailed studies of the effect on enzymatic activity and crystallization were conducted. This has permitted direct comparison of the relative effects of the two types of mutations. While none of the variants produced crystals suitable for X-ray structural determination, small crystals were obtained in a wide variety of conditions, in support of the general approach. Glutamine substitutions were found to be more effective than alanine in producing crystals, in support of proposal II. Secondary structure at the site of mutation does not appear to play a major role in determining the rate of success

  16. Nature’s Starships. II. Simulating the Synthesis of Amino Acids in Meteorite Parent Bodies

    Cobb, Alyssa K.; Pudritz, Ralph E.; Pearce, Ben K. D.

    2015-08-01

    Carbonaceous chondrite meteorites are known for having high water and organic material contents, including amino acids. Here we address the origin of amino acids in the warm interiors of their parent bodies (planetesimals) within a few million years of their formation, and we connect this with the astrochemistry of their natal protostellar disks. We compute both the total amino acid abundance pattern and the relative frequencies of amino acids within the CM2 (e.g., Murchison) and CR2 chondrite subclasses based on Strecker reactions within these bodies. We match the relative frequencies to well within an order of magnitude among both CM2 and CR2 meteorites for parent body temperatures natal protostellar disks.

  17. Acidification of Forest Soils: A Model for Analyzing Impacts of Acidic Deposition in Europe - Version II

    Kauppi, P.; Kaemaeri, J.; Posch, M; Kauppi, L.; Matzner, E.

    1985-01-01

    Acidification is an unfavorable process in forest soils. Timber logging, natural accumulation of biomass in the ecosystem, and acidic deposition are sources of acidification. Acidification causes a risk of damage to plant roots and a subsequent risk of a decline in ecosystem productivity. A dynamic model is introduced for describing the acidification of forest soils. In one-year time steps the model calculates the soil pH as function of acid stress and the buffer mechanisms of the soil. ...

  18. Analytical applications of N-phenyl-n-butyro hydroxamic and N-p-tolyl-n-butyro hydroxamic acids towards chromium (VI), copper (II), iron (III) and uranium (VI)

    Two aliphatic hydroxamic acids were prepared; N-phenyl-n-butyro hydroxamic acid and N-p-tolyl-n-butyro hydroxamic acid, by the reaction of β-phenylhydroxylamine and p-tolyl hydroxylamine with n-butyryl chloride. The acids were identified by: their melting points, characteristic reactions with acidic solutions of vanadium (V) and iron (III), infrared spectroscopy, nitrogen content and molecular weight determination. The extractability of these acids towards Cr (VI), Cu (II), Fe (III) and U (VI) were investigated at different pH values and molar acid concentrations. N-phenyl-n- butyro hydroxamic acid has a maximum extraction (98.80%) for Cr (VI) at 4 M H2SO4, (83.25%) for Cu (II) at pH 6, (99.17%) for Fe (III) at pH 5 and (99.76%) at 4 M HNO3 for U (VI) respectively. N-p-tolyl-n-butyro hydroxamic acid has a maximum extraction (98.40%) for Cr (VI)at 4 M H2 SO4, (81.30%) for Cu (II) at pH 6, (92.80%) for Fe (III) at pH 5 and (99.64%) for U (VI) at 4 M HNO3, respectively. The ratios of the metal to ligands were determined by job method (continuous variation method) and were found to be 1:2 for Cr (VI) and U (VI). (Author)

  19. Synthesis, Structures and Photoluminescent Properties of Two Novel Zinc(II) Compounds Constructed from 5-Sulfoisophthalic Acid

    Hydrothermal reaction of zinc(II) salts with 5-sulfoisophthalic acid monosodium salt (NaO3SC6H3-1,3-(COOH)2, NaH2- SIP) and 1,10-phenanthroline (phen) led to two new compounds, [Zn(phen)3]·2H2SIP·4H2O and [Zn(phen)2(H2O)2]· 2H2SIP·2H2O. They were characterized by element analysis, IR spectroscopy, thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), and single-crystal X-ray diffraction. Both compounds 1-2 represent the first example of Zn/phen/SIP system. The Zn (II) ion in 1 is six-coordinated by six nitrogen atoms from three phen molecules, and the H2SIP- ligands engage in the formation of hydrogen bond. The Zn(II) ion in 2 is coordinated by four nitrogen atoms from two phen molecules and two oxygen atoms from two water molecules. Moreover, both 1 and 2 are assembled into 3D supramolecular architectures by hydrogen bonds (O-H···O) and π-π interactions. Solvent water molecules occupying voids of the compounds serve as receptors or donors of the extensive O-H···O hydrogen bonds

  20. Photoperiodism and Crassulacean acid metabolism : II. Relations between leaf aging and photoperiod in Crassulacean acid metabolism induction.

    Brulfert, J; Guerrier, D; Queiroz, O

    1982-05-01

    Measurements of net CO2 exchange, malate accumulation, properties and capacity of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) in leaves of different ages of two short-day dependent Crassulacean acid metabolism (CAM) plants (Kalanchoe blossfeldiana v. Poelln. Tom thumb and K. velutina Welw.) show that, in both species: a) young leaves from plants grown under long days display a CO2 exchange pattern typical of C3 plants; b) leaf aging promotes CAM under long-day conditions; c) short-day treatment induces CAM in young leaves to a higher degree than aging under long days; d) at least in K. blossfeldiana, the PEPC form developed with leaf aging under long days and the enzyme form synthetized de novo in young leaves grown under short days were shown to have similar properties. Short days also promote CAM in older leaves though at a lesser extent than in young leaves: The result is that this photoperiodic treatment increases the general level of CAM performance by the whole plant. The physiological meaning of the control of PEPC capacity by photoperiodism could be to afford a precisely timed seasonal increase in CAM potentiality, enabling the plant to immediately optimize its response to the onset of drought periods. PMID:24276160

  1. A solid-state sensor based on ruthenium (II) complex immobilized on polytyramine film for the simultaneous determination of dopamine, ascorbic acid and uric acid

    Khudaish, Emad A., E-mail: ejoudi@squ.edu.om [Sultan Qaboos University, College of Science, Chemistry Department, PO Box 36, PC 123 Muscat (Oman); Al-Ajmi, Khawla Y. [Sultan Qaboos University, College of Science, Chemistry Department, PO Box 36, PC 123 Muscat (Oman); Al-Harthi, Salim H. [Sultan Qaboos University, College of Science, Department of Physics, PO Box 36, PC 123 Muscat (Oman)

    2014-08-01

    A solid-state sensor based on a polytyramine (Pty) film deposited on a glassy carbon electrode doped with a tris(2,2′-bipyridyl)Ru(II) complex (Ru/Pty/GCE) was constructed electrochemically. The surface morphology of the film modified electrode was characterized using electrochemical and surface scanning techniques. A redox property represented by a [Ru(bpy){sub 3}]{sup 3+/2+} couple immobilized at the Pty moiety was characterized using typical voltammetric techniques. A distinct Ru 3d peak obtained at 280.9 eV confirms doping of the Ru species onto the Pty moiety characterized by X-ray photoelectron (XPS). Atomic force microscopy (AFM) images demonstrate that incorporation of Ru decreases the surface roughness of the native Pty film modified electrode. The Ru/Pty/GCE exhibits efficient electrochemical sensing toward the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA) in their mixture. Three well-defined peaks were resolved with a large peak to peak separation and the detection limits of AA, DA and UA are brought down to 0.31, 0.08 and 0.58 μM, respectively. Interference studies and application for DA determination in real samples were conducted with satisfactory results. - Highlights: • XPS data confirm doping of ruthenium onto the polytyramine moiety. • The voltammetric signals of ascorbic acid, dopamine and uric acid are well defined. • The sensor is stable and offers a large adsorption facility for all species. • The sensor is highly sensitive to dopamine oxidation. • The sensor is applied to a real sample with a satisfactory recovery percentage.

  2. A solid-state sensor based on ruthenium (II) complex immobilized on polytyramine film for the simultaneous determination of dopamine, ascorbic acid and uric acid

    A solid-state sensor based on a polytyramine (Pty) film deposited on a glassy carbon electrode doped with a tris(2,2′-bipyridyl)Ru(II) complex (Ru/Pty/GCE) was constructed electrochemically. The surface morphology of the film modified electrode was characterized using electrochemical and surface scanning techniques. A redox property represented by a [Ru(bpy)3]3+/2+ couple immobilized at the Pty moiety was characterized using typical voltammetric techniques. A distinct Ru 3d peak obtained at 280.9 eV confirms doping of the Ru species onto the Pty moiety characterized by X-ray photoelectron (XPS). Atomic force microscopy (AFM) images demonstrate that incorporation of Ru decreases the surface roughness of the native Pty film modified electrode. The Ru/Pty/GCE exhibits efficient electrochemical sensing toward the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA) in their mixture. Three well-defined peaks were resolved with a large peak to peak separation and the detection limits of AA, DA and UA are brought down to 0.31, 0.08 and 0.58 μM, respectively. Interference studies and application for DA determination in real samples were conducted with satisfactory results. - Highlights: • XPS data confirm doping of ruthenium onto the polytyramine moiety. • The voltammetric signals of ascorbic acid, dopamine and uric acid are well defined. • The sensor is stable and offers a large adsorption facility for all species. • The sensor is highly sensitive to dopamine oxidation. • The sensor is applied to a real sample with a satisfactory recovery percentage

  3. Structural role of hydrogen bond networks in amino acid-acid systems. (II) The network with weakly polarizable OHO hydrogen bonds in sarcosine-p-toluenesulfonic acid (1:1) crystal

    The sarcosine-p-toluenesulfonic acid (1:1) crystal crystallizes as monoclinic system and belongs to the: (i) P21/c at 293 and 200 K; (ii) P21/n at 100 K space groups. It was selected for examination of two problems: relations between different components of the amino acid-acid hydrogen bond network and a role of medium strong and weakly polarizable OHO hydrogen bond in the main structural units of the crystal: sarcosinium-p-toluenesulfonate complexes. Our observations are based on phase transitions of the crystal monitored by DSC, X-ray diffraction and temperature evolutions of selected modes of IR spectra. The O...O distance of the primary hydrogen bond as well as conformations of sarcosinium and p-toluenesulfonate are very sensitive on state of NHO secondary hydrogen bonds

  4. Down-Regulation of Porcine Heart Diaphorase Reactivity by Trimanganese Hexakis(3,5-Diisopropylsalicylate), Mn(3)(3,5-DIPS)6, and Down-Regulation of Nitric Oxide Synthase Reactivity by Mn(3)(3,5-DIPS)(6) and Cu(II)(2)(3,5-DIPS)(4).

    Booth, B L; Pitters, E; Mayer, B; Sorenson, J R

    1999-01-01

    Purposes of this work were to examine the plausible down-regulation of porcine heart diaphorase (PHD) enzyme reactivity and nitric oxide synthase (NOS) enzyme reactivity by trimanganese hexakis(3,5-diisopropylsalicylate), [Mn(3)(3,5-DIPS)(6)] as well as dicopper tetrakis(3,5- diisopropylsalicylate, [Cu(II)(2)(3,5-DIPS)(4)] as a mechanistic accounting for their pharmacological activities.Porcine heart disease was found to oxidize 114 muM reduced nicotinamide-adenine- dinucleotide-'(3)-phosphate (NADPH) with a corresponding reduction of an equivalent concentration of 2,6-dichlorophenolindophenol (DCPIP). As reported for Cu(II)(2) (3,5-DIPS)(4), addition of Mn(3)(3,5-DIPS)(6) to this reaction mixture decreased the reduction of DCPIP without significantly affecting the oxidation of NADPH. The concentration of Mn(3)(3,5-DIPS)(6) that produced a 50% decrease in DCPIP reduction (IC(50)) was found to be 5muM. Mechanistically, this inhibition of DCPIP reduction with ongoing NADPH oxidation by PHD was found to be due to the ability of Mn(3)(3,5-DIPS)(6) to serve as a catalytic electron acceptor for reduced PHD as had been reported for Cu(II)(2)(3,5-DIPS)(4). This catalytic decrease in reduction of DCPIP by Mn(3)(3,5-DIPS)(6) was enhanced by the presence of a large concentration of DCPIP and decreased by the presence of a large concentration of NADPH, consistent with what had been observed for the activity of Cu(II)(2)(3,5-DIPS)(4)Oxidation of NADPH by PHD in the presence of Mn(3)(3,5-DIPS)(6) and the absence of DCPIP was linearly related to the concentration of added Mn(3)(3,5-DIPS)(6) through the concentration range of 2.4 muM to 38muM with a 50% recovery of NADPH oxidation by PHD at a concentration of 6 muM Mn(3)(3,5-DIPS)(6)Conversion of [(3)H] L-Arginine to [(3)H] L-Citrulline by purified rat brain nitric oxide synthase (NOS) was decreased in a concentrated related fashion with the addition of Mn(3)(3,5-DIPS)(6) as well as Cu(II)(2)(3,5-DIPS)(4) which is an extention of

  5. A method for measuring disease-specific iduronic acid from the non-reducing end of glycosaminoglycan in mucopolysaccharidosis type II mice.

    Shimada, Yohta; Wakabayashi, Taichi; Akiyama, Kazumasa; Hoshina, Hiroo; Higuchi, Takashi; Kobayashi, Hiroshi; Eto, Yoshikatsu; Ida, Hiroyuki; Ohashi, Toya

    2016-02-01

    Mucopolysaccharidosis type II (MPS II) is an X-linked lysosomal storage disorder arising from deficiency of iduronate-2-sulfatase (IDS), which results in progressive accumulation of glycosaminoglycans (GAGs) in multiple tissues. Accumulated GAGs are generally measured as the amount of total GAGs. However, we recently demonstrated that GAG accumulation in the brain of MPS II model mice cannot be reliably detected by conventional dye-binding assay measuring total GAGs. Here we developed a novel quantitative method for measurement of disease-specific GAGs based on the analysis of 2-sulfoiduronic acid levels derived from the non-reducing terminal end of the polysaccharides by using recombinant human IDS (rhIDS) and recombinant human iduronidase (rhIDUA). This method was evaluated on GAGs obtained from the liver and brain of MPS II mice. The GAGs were purified from tissue homogenates and then digested with rhIDS and rhIDUA to generate a desulfated iduronic acid from their non-reducing terminal end. HPLC analysis revealed that the generated iduronic acid levels were markedly increased in the liver and cerebrum of the MPS II mice, whereas the uronic acid was not detected in wild-type mice. These results indicate that this assay clearly detects the disease-specific GAGs in tissues from MPS II mice. PMID:26051019

  6. Synthesis and evaluation of different thio-modified cellulose resins for the removal of mercury (II) ion from highly acidic aqueous solutions.

    Takagai, Yoshitaka; Shibata, Atsushi; Kiyokawa, Shigemi; Takase, Tsugiko

    2011-01-15

    Seven different types of thio- and/or amine-modified cellulose resin materials were synthesized and their mercury (II) ion adsorption properties determined. All seven resins showed good mercury (II) adsorption capability in the more neutral pH regions. However, the o-benzenedithiol- and o-aminothiophenol-modified cellulosic resins were found to be very effective in removing mercury (II) ions from strongly acidic media. For example, 93.5-100% mercury (II) ion recoveries from very acid aqueous solutions (nitric acid concentration ranged from 0.1 to 2.0 mol/L) were obtained using the o-benzenedithiol-modified resin while recoveries ranged from ca. 50% to 60% for the o-aminothiophenol-modified resin. An adsorption capacity of 23 mg (as Hg atoms) per gram of resin was observed for the o-benzenedithiol-modified cellulose in the presence of 1.0 mol/L nitric acid. This same resin shows very good selectivity for mercury (II) as only ruthenium (II) also somewhat adsorbed onto it out of 14 other metal ions studied (Ag(+), Al(3+), As(3+), Co(2+), Cd(2+), Cr(3+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pt(2+), Pb(2+), Ru(2+), and Zn(2+)). PMID:20974469

  7. Topography of prostaglandin H synthase. Antiinflammatory agents and the protease-sensitive arginine 253 region.

    Kulmacz, R J

    1989-08-25

    Prostaglandin H synthase catalyzes two reactions: the bis-dioxygenation of arachidonic acid to form prostaglandin G2 (cyclooxygenase activity), and the reduction of hydroperoxides to the corresponding alcohols (peroxidase activity). The cyclooxygenase activity can be selectively inhibited by many nonsteroidal antiinflammatory agents including indomethacin. In the native synthase, there is a single prominent protease-sensitive region, located near Arg253; binding of the heme prosthetic group makes the synthase resistant to proteases. To investigate the spatial relationship between the area of the synthase which interacts with indomethacin and the protease-sensitive region, the effects of indomethacin and similar agents on the protease sensitivity of the two enzymatic activities and of the synthase polypeptide were examined. Incubation of the synthase apoenzyme with trypsin (3.6% w/w) resulted in the time-dependent coordinate loss (75% at 1 h) of both enzymatic activities and the cleavage (85% at 1 h) of the 70-kDa subunit into 38- and 33-kDa fragments, indicating that proteolytic cleavage of the polypeptide at Arg253, destroyed both activities of the synthase simultaneously. Indomethacin, (S)-flurbiprofen, or meclofenamate (each at 20 microM) rendered both activities and the synthase polypeptide (at 5 microM subunit) resistant to attack by trypsin or proteinase K; these agents also inhibited the cyclooxygenase activity of the intact synthase. Two reversible cyclooxygenase inhibitors, ibuprofen and flufenamate, also made both of the activities and the synthase polypeptide more resistant to trypsin. Titration of the apoenzyme with indomethacin (0-3 mol/mol of synthase dimer) resulted in proportional increases in the inhibition of the cyclooxygenase and in the resistance to attack by trypsin. (R)-Flurbiprofen did not increase the resistance to protease or appreciably inhibit the cyclooxygenase. These results suggest that the same stereospecific interaction of these

  8. Cycloisomerization of Dienes with Carbophilic Lewis Acids: Mimicking Terpene Biosynthesis with Pt(II) Catalysts

    Kerber, William D.; Gagné, Michel R

    2005-01-01

    Dicationic Pt(II) complexes containing triphosphine pincer ligands are excellent catalysts for the cycloisomerization of 1,6- and 1,7-dienes into bicyclopropane carbocycles. In analogy to the biosynthetic route to these monoterpene-like compounds, carbocation intermediates are proposed and supported by trapping experiments. Re-activation of the trapped intermediates indicate that cation generation by C-C bond formation is both rapid and reversible.

  9. Co(II) complexes of amino acids and peptides in aqueous solution studied by 170 NMR

    Structural, dynamic and kinetic 170 NMR investigations of the complexation of metal ions with amino acids and peptides were performed in Glicine, proling cyclo(Ala '1'70-Ala), cyclo-(Gly170-Pro) and cyclo(Pro170-Gly). The 170 carboxyl and carbonylsignals of paramagnetic complexes with amino acids were observed and allowed for the determinatio, in several cases, of the stoichiometry of the ocmplexes formed and the kinetic and thermodynamic parameters characterizing ligand exchange. It was found that the paramagnetic ions bind to the oxygen of the peptide carboxyl group. (H.W.). 25 refs.; 10 figs.; 3 tabs

  10. Manganese(II)/Picolinic Acid Catalyst System for Epoxidation of Olefins.

    Moretti, Ross A; Du Bois, J; Stack, T Daniel P

    2016-06-01

    An in situ generated catalyst system based on Mn(CF3SO3)2, picolinic acid, and peracetic acid converts an extensive scope of olefins to their epoxides at 0 °C in <5 min, with remarkable oxidant efficiency and no evidence of radical behavior. Competition experiments indicate an electrophilic active oxidant, proposed to be a high-valent Mn = O species. Ligand exploration suggests a general ligand sphere motif contributes to effective oxidation. The method is underscored by its simplicity and use of inexpensive reagents to quickly access high value-added products. PMID:27191036

  11. A particular phenotype in a girl with aldosterone synthase deficiency.

    Williams, Tracy A; Mulatero, Paolo; Bosio, Maurizio; Lewicka, Sabina; Palermo, Mario; Veglio, Franco; Armanini, Decio

    2004-07-01

    Aldosterone synthase deficiency (ASD) usually presents in infancy as a life-threatening electrolyte imbalance. A 4-wk-old child of unrelated parents was examined for failure to thrive and salt-wasting. Notable laboratory findings were hyperkalemia, high plasma renin, and low-normal aldosterone levels. Urinary metabolite ratios of corticosterone/18-hydroxycorticosterone and 18-hydroxycorticosterone/aldosterone were intermediate between ASD type I and type II. Sequence analysis of CYP11B2, the gene encoding aldosterone synthase (P450c11AS), revealed that the patient was a compound heterozygote carrying a previously described mutation located in exon 4 causing a premature stop codon (E255X) and a further, novel mutation in exon 5 that also causes a premature stop codon (Q272X). The patient's unaffected father was a heterozygous carrier of the E255X mutation, whereas the unaffected mother was a heterozygous carrier of the Q272X mutation. Therefore, the patient's CYP11B2 encodes two truncated forms of aldosterone synthase predicted to be inactive because they lack critical active site residues as well as the heme-binding site. This case of ASD is of particular interest because despite the apparent lack of aldosterone synthase activity, the patient displays low-normal aldosterone levels, thus raising the question of its source. PMID:15240589

  12. Nature's Starships II: Simulating the Synthesis of Amino Acids in Meteorite Parent Bodies

    Cobb, Alyssa K; Pearce, Ben K D

    2015-01-01

    Carbonaceous chondrite meteorites are known for having high water and organic material contents, including amino acids. Here we address the origin of amino acids in the warm interiors of their parent bodies (planetesimals) within a few million years of their formation, and connect this with the astrochemistry of their natal protostellar disks. We compute both the total amino acid abundance pattern as well as the relative frequencies of amino acids within the CM2 (e.g. Murchison) and CR2 chondrite subclasses based on Strecker reactions within these bodies. We match the relative frequencies to well within an order of magnitude among both CM2 and CR2 meteorites for parent body temperatures $<$ 200$^{\\circ}$C. These temperatures agree with 3D models of young planetesimal interiors. We find theoretical abundances of approximately 7x10$^5$ parts-per-billion (ppb), which is in agreement with the average observed abundance in CR2 meteorites of 4$\\pm$7x10$^5$, but an order of magnitude higher than the average obser...

  13. Influence of the steric effect of flexible isomeric phenylenediacetic acids on the resultant lead(II) coordination polymers

    Wu, Yunlong; Zhao, Yanqing; Yang, Guo-Ping, E-mail: ygp@nwu.edu.cn; Guo, Yanjun; Wang, Yao-Yu, E-mail: wyaoyu@nwu.edu.cn; Shi, Qi-Zhen

    2015-03-15

    To study the steric effect of the flexible dicarboxylate ligands on the resultant formations of coordination polymers (CPs), four new Pb{sup II} CPs [Pb(1,2-pda)(H{sub 2}O)]{sub n} (1), [Pb(1,3-pda)]{sub n}·nH{sub 2}O (2), [Pb{sub 2}(1,4-pda){sub 2}(H{sub 2}O)]{sub n}·2nH{sub 2}O (3a and 3b) have been produced by the isomeric phenylenediacetic acids (H{sub 2}pda). The X-ray crystallography study reveals that CP 1 is a two-dimensional (2D) 4-connected sql (4{sup 4}.6{sup 2}) network via the weak Pb···O interactions built on 1D chain-like structure. CP 2 crystallizes in orthorhombic system with chiral space group P2{sub 1}2{sub 1}2{sub 1}, showing a 4-connected sra (4{sup 2}.6{sup 3}.8) framework where a left-handed helical motif is formed by Pb{sup II} ions and trans-1,3-pda ligands. More interestingly, CPs 3a and 3b are two true 3D polymorphs and have the different morphology. Topologically, the framework of 3a exhibits a 4-connected lon 6{sup 6} motif, while that of 3b is a (4,6)-connected fsh (4{sup 3}.6{sup 3}){sub 2}(4{sup 6}.6{sup 6}.8{sup 3}) net. It is found that the three isomeric pda anions display the various coordination fashions in four CPs. The different structural arrangements show that the steric effect of the isomeric H{sub 2}pda tectons has a positive role in directing the final products of Pb{sup II} CPs. Also, the fluorescent properties of the CPs were studied in the solid state at room temperature. - Graphical abstract: Four new Pb{sup II}-based CPs have been produced by the isomeric phenylenediacetic acids (H{sub 2}pda). The different structural arrangements show that the steric effect of the isomeric H{sub 2}pda tectons has a positive role in directing the final products of Pb{sup II} CPs. Also, the fluorescent properties of the CPs were studied in the solid state at room temperature. - Highlights: • Four Pb{sup II}-based coordination polymers were produced by phenylenediacetic acids. • The crystal and topological structures of the

  14. Chromatographic analysis of the effects of fatty acids and glycation on binding by probes for Sudlow sites I and II to human serum albumin.

    Anguizola, Jeanethe; Debolt, Erin; Suresh, D; Hage, David S

    2016-05-15

    The primary endogenous ligands of human serum albumin (HSA) are non-esterified fatty acids, with 0.1-2mol of fatty acids normally being bound to HSA. In type II diabetes, fatty acid levels in serum are often elevated, and the presence of high glucose results in an increase in the non-enzymatic glycation of HSA. High-performance affinity chromatography (HPAC) was used to examine the combined effects of glycation and the presence of long chain fatty acids on the binding of HSA with R-warfarin and l-tryptophan (i.e., probes for Sudlow sites I and II, the major sites for drugs on this protein). Zonal elution competition studies were used to examine the interactions of myristic acid, palmitic acid and stearic acid with these probes on HSA. It was found that all these fatty acids had direct competition with R-warfarin at Sudlow site I of normal HSA and glycated HSA, with the glycated HSA typically having stronger binding for the fatty acids at this site. At Sudlow site II, direct competition was observed for all the fatty acids with l-tryptophan when using normal HSA, while glycated HSA gave no competition or positive allosteric interactions between these fatty acids and l-tryptophan. These data indicated that glycation can alter the interactions of drugs and fatty acids at specific binding sites on HSA. The results of this study should lead to a better understanding of how these interactions may change during diabetes and demonstrate how HPAC can be used to examine drug/solute-protein interactions in complex systems. PMID:26468085

  15. Rational conversion of substrate and product specificity in a Salvia monoterpene synthase: structural insights into the evolution of terpene synthase function.

    Kampranis, Sotirios C; Ioannidis, Daphne; Purvis, Alan; Mahrez, Walid; Ninga, Ederina; Katerelos, Nikolaos A; Anssour, Samir; Dunwell, Jim M; Degenhardt, Jörg; Makris, Antonios M; Goodenough, Peter W; Johnson, Christopher B

    2007-06-01

    Terpene synthases are responsible for the biosynthesis of the complex chemical defense arsenal of plants and microorganisms. How do these enzymes, which all appear to share a common terpene synthase fold, specify the many different products made almost entirely from one of only three substrates? Elucidation of the structure of 1,8-cineole synthase from Salvia fruticosa (Sf-CinS1) combined with analysis of functional and phylogenetic relationships of enzymes within Salvia species identified active-site residues responsible for product specificity. Thus, Sf-CinS1 was successfully converted to a sabinene synthase with a minimum number of rationally predicted substitutions, while identification of the Asn side chain essential for water activation introduced 1,8-cineole and alpha-terpineol activity to Salvia pomifera sabinene synthase. A major contribution to product specificity in Sf-CinS1 appears to come from a local deformation within one of the helices forming the active site. This deformation is observed in all other mono- or sesquiterpene structures available, pointing to a conserved mechanism. Moreover, a single amino acid substitution enlarged the active-site cavity enough to accommodate the larger farnesyl pyrophosphate substrate and led to the efficient synthesis of sesquiterpenes, while alternate single substitutions of this critical amino acid yielded five additional terpene synthases. PMID:17557809

  16. Inhibition of Escherichia coli ATP synthase by amphibian antimicrobial peptides.

    Laughlin, Thomas F; Ahmad, Zulfiqar

    2010-04-01

    Previously melittin, the alpha-helical basic honey bee venom peptide, was shown to inhibit F(1)-ATPase by binding at the beta-subunit DELSEED motif of F(1)F(o)-ATP synthase. Herein, we present the inhibitory effects of the basic alpha-helical amphibian antimicrobial peptides, ascaphin-8, aurein 2.2, aurein 2.3, carein 1.8, carein 1.9, citropin 1.1, dermaseptin, maculatin 1.1, maganin II, MRP, or XT-7, on purified F(1) and membrane bound F(1)F(0)Escherichia coli ATP synthase. We found that the extent of inhibition by amphibian peptides is variable. Whereas MRP-amide inhibited ATPase essentially completely (approximately 96% inhibition), carein 1.8 did not inhibit at all (0% inhibition). Inhibition by other peptides was partial with a range of approximately 13-70%. MRP-amide was also the most potent inhibitor on molar scale (IC(50) approximately 3.25 microM). Presence of an amide group at the c-terminal of peptides was found to be critical in exerting potent inhibition of ATP synthase ( approximately 20-40% additional inhibition). Inhibition was fully reversible and found to be identical in both F(1)F(0) membrane preparations as well as in isolated purified F(1). Interestingly, growth of E. coli was abrogated in the presence of ascaphin-8, aurein 2.2, aurein 2.3, citropin 1.1, dermaseptin, magainin II-amide, MRP, MRP-amide, melittin, or melittin-amide but was unaffected in the presence of carein 1.8, carein 1.9, maculatin 1.1, magainin II, or XT-7. Hence inhibition of F(1)-ATPase and E. coli cell growth by amphibian antimicrobial peptides suggests that their antimicrobial/anticancer properties are in part linked to their actions on ATP synthase. PMID:20100509

  17. Preparation, characterization and ion-exchange behavior of polyantimonic acid-polyacrylonitrile (PAA-PAN) composite beads for strontium(II)

    An organic-inorganic composite ion exchanger of polyantimonic acid-polyacrylonitrile (PAA-PAN) was synthesized to remove strontium(II) from radioactive waste water. Ion exchange behavior of the composite toward strontium(II) were investigated and the results indicated that the composite presents excellent performance in 0.1 mol L-1 nitric acid. The maximum uptake capacity of strontium(II) can reach up to 49 mg g-1 on composite. Adsorption thermodynamic parameters showed that the ion exchange was endothermic and spontaneous reaction and equilibrium adsorption data fit well with the Langmuir adsorption isotherms. In addition, PAA-PAN beads were found to have chemical and adsorption stability under irradiation and acidic media. (author)

  18. Separation of cobalt from uranium (VI), manganese (II), and lithium on AG50W-X8 resin hydrochloric acid-acetone

    Cobalt can be separated from uranium(VI), manganese(II), and lithium, the most difficult elements to separate from cobalt when using the 8% cross-linked AG50W resin and hydrochloric acid-acetone eluting agents, by eluting uranium(VI) with 0,4M-hydrochloric acid-86% acetone, followed by cobalt with 1M-hydrochloric acid-80% acetone, while manganese(II) and lithium are still retained. Excellent separations are obtained, provided that not more than 10 mg of uranium(VI), 0,5 mmol of manganese(II), and 1 mmol of lithium are present together with 1 mmol of cobalt when a 60 ml resin columm is used. Appropriate elution curves and results for the analysis of synthetic mixtures are presented

  19. Slow Onset Inhibition of Bacterial β-Ketoacyl-acyl Carrier Protein Synthases by Thiolactomycin*

    Machutta, Carl A.; Bommineni, Gopal R.; Luckner, Sylvia R.; Kapilashrami, Kanishk; Ruzsicska, Bela; Simmerling, Carlos; Kisker, Caroline; Tonge, Peter J.

    2009-01-01

    Thiolactomycin (TLM), a natural product thiolactone antibiotic produced by species of Nocardia and Streptomyces, is an inhibitor of the β-ketoacyl-acyl carrier protein synthase (KAS) enzymes in the bacterial fatty acid synthase pathway. Using enzyme kinetics and direct binding studies, TLM has been shown to bind preferentially to the acyl-enzyme intermediates of the KASI and KASII enzymes from Mycobacterium tuberculosis and Escherichia coli. These studies, which utilized acyl-enzyme mimics in...

  20. Photodissociation of organic molecules in star-forming regions II: Acetic acid

    Pilling, S; Boechat-Roberty, H M

    2006-01-01

    Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH$_3$COOH), a glycine (NH$_2$CH$_2$COOH) precursor molecule, by soft X-ray photons. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator (TGM) beamline (100 - 310 eV). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, that only 4-6% of CH$_3$COOH survive the strong ionization field. CH$_3$CO$^+$, COOH$^+$ and CH$_3^+$ ions are the mai...

  1. Nitrated fatty acids suppress angiotensin II-mediated fibrotic remodelling and atrial fibrillation

    Rudolph, T.K.; Ravekes, T.; Klinke, A.; Friedrichs, K.; Mollenhauer, M.; Pekarová, Michaela; Ambrožová, Gabriela; Martíšková, Hana; Kaur, J.J.; Matthes, B.; Schwoerer, A.; Woodcock, S.R.; Kubala, Lukáš; Freeman, B.A.; Baldus, S.; Rudolph, V.

    2016-01-01

    Roč. 109, č. 1 (2016), s. 174-184. ISSN 0008-6363 R&D Projects: GA ČR(CZ) GP13-40824P; GA MŠk(CZ) EE2.3.30.0030 Grant ostatní: GAAV(CZ) M200041208 Institutional support: RVO:68081707 Keywords : Atrial fibrillation * Fibrosis * Nitro-fatty acids Subject RIV: BO - Biophysics Impact factor: 5.940, year: 2014

  2. A dinuclear ruthenium(II) complex as turn-on luminescent probe for hypochlorous acid and its application for in vivo imaging

    Liu, Zonglun; Gao, Kuo; Wang, Beng; Yan, Hui; Xing, Panfei; Zhong, Chongmin; Xu, Yongqian; Li, Hongjuan; Chen, Jianxin; Wang, Wei; Sun, Shiguo

    2016-06-01

    A dinuclear ruthenium(II) complex Ruazo was designed and synthesized, in which oxidative cyclization of the azo and o-amino group was employed for the detection of hypochlorous acid (HClO) in aqueous solution. The non-emissive Ruazo formed highly luminescent triazole-ruthenium(II) complex in presence of HClO and successfully imaged HClO in living cell and living mouse.

  3. A dinuclear ruthenium(II) complex as turn-on luminescent probe for hypochlorous acid and its application for in vivo imaging

    Liu, Zonglun; Gao, Kuo; Wang, Beng; Yan, Hui; Xing, Panfei; Zhong, Chongmin; Xu, Yongqian; Li, Hongjuan; Chen, Jianxin; Wang, Wei; Sun, Shiguo

    2016-01-01

    A dinuclear ruthenium(II) complex Ruazo was designed and synthesized, in which oxidative cyclization of the azo and o-amino group was employed for the detection of hypochlorous acid (HClO) in aqueous solution. The non-emissive Ruazo formed highly luminescent triazole-ruthenium(II) complex in presence of HClO and successfully imaged HClO in living cell and living mouse. PMID:27356618

  4. Molecular cloning of starch synthase I from maize (W64) endosperm and expression in Escherichia coli.

    Knight, M E; Harn, C; Lilley, C E; Guan, H; Singletary, G W; MuForster, C; Wasserman, B P; Keeling, P L

    1998-06-01

    A full length cDNA clone encoding a starch synthase (zSS) from maize endosperm (inbred line W64) was isolated and characterized. The cDNA clone (Ss1) is 2907 bp in length and contains an open reading frame of 1866 bp corresponding to a polypeptide of 622 amino acid residues including a transit peptide of 39 amino acids. The Ss1 cDNA clone was identified as zSSI by its direct alignment with sequences to: (i) the N-terminus obtained from the granule-associated form of the zSSI polypeptide, (ii) four internal peptide fragments obtained from the granule-associated form of the zSSI protein, and (iii) one internal fragment from the soluble form of the zSSI protein. The deduced amino acid sequence of Ss1 shares 75.7% sequence identity with rice soluble Ss and contains the highly conserved KSGGLGDV putative ADP-Glc binding site. Moreover, Ss1 exhibited significant activity when expressed in E. coli and the expressed protein is recognized by the antibody raised against the granule associated zSSI protein. Ss1 transcripts were detected in endosperm beginning at 15 days after pollination, but were not found in embryo, leaf or root. Maize contains a single copy of the Ss1 gene, which maps close to the Waxy locus of chromosome 9. PMID:9675904

  5. Structure and Mechanism of Human UDP-xylose Synthase

    Eixelsberger, Thomas; Sykora, Sabine; Egger, Sigrid; Brunsteiner, Michael; Kavanagh, Kathryn L; Oppermann, Udo; Brecker, Lothar; Nidetzky, Bernd

    2012-01-01

    UDP-xylose synthase (UXS) catalyzes decarboxylation of UDP-d-glucuronic acid to UDP-xylose. In mammals, UDP-xylose serves to initiate glycosaminoglycan synthesis on the protein core of extracellular matrix proteoglycans. Lack of UXS activity leads to a defective extracellular matrix, resulting in strong interference with cell signaling pathways. We present comprehensive structural and mechanistic characterization of the human form of UXS. The 1.26-Å crystal structure of the enzyme bound with ...

  6. Nitric oxide synthase is induced in sporulation of Physarum polycephalum

    Golderer, Georg; Werner, Ernst R.; Leitner, Stefan; Gröbner, Peter; Werner-Felmayer, Gabriele

    2001-01-01

    The myxomycete Physarum polycephalum expresses a calcium-independent nitric oxide (NO) synthase (NOS) resembling the inducible NOS isoenzyme in mammals. We have now cloned and sequenced this, the first nonanimal NOS to be identified, showing that it shares < 39% amino acid identity with known NOSs but contains conserved binding motifs for all NOS cofactors. It lacks the sequence insert responsible for calcium dependence in the calcium-dependent NOS isoenzymes. NOS expression was strongly up-r...

  7. The Domain Responsible for Sphingomyelin Synthase (SMS) Activity

    Yeang, Calvin; Varsheny, Shweta; Wang, Renxiao; ZHANG, YA; Ye, Deyong; Jiang, Xian-Cheng

    2008-01-01

    Sphingomyelin synthase (SMS) sits at the crossroads of sphingomyelin (SM), ceramide, diacylglycerol (DAG) metabolism. It utilizes ceramide and phosphatidylcholine as substrates to produce SM and DAG, thereby regulating lipid messengers which play a role in cell survival and apoptosis. There are two isoforms of the enzyme, SMS1 and SMS2. Both SMS1 and SMS2 contain two histidines and one aspartic acid which are evolutionary conserved within the lipid phosphate phosphatase superfamily. In this s...

  8. In Silico Prediction of Drug Dissolution and Absorption with variation in Intestinal pH for BCS Class II Weak Acid Drugs: Ibuprofen and Ketoprofen§

    Tsume, Yasuhiro; Langguth, Peter; Garcia-Arieta, Alfredo; Amidon, Gordon L.

    2012-01-01

    The FDA Biopharmaceutical Classification System guidance allows waivers for in vivo bioavailability and bioequivalence studies for immediate-release solid oral dosage forms only for BCS class I. Extensions of the in vivo biowaiver for a number of drugs in BCS Class III and BCS class II have been proposed, particularly, BCS class II weak acids. However, a discrepancy between the in vivo- BE results and in vitro- dissolution results for a BCS class II acids was recently observed. The objectives of this study were to determine the oral absorption of BCS class II weak acids via simulation software and to determine if the in vitro dissolution test with various dissolution media could be sufficient for in vitro bioequivalence studies of ibuprofen and ketoprofen as models of carboxylic acid drugs. The oral absorption of these BCS class II acids from the gastrointestinal tract was predicted by GastroPlus™. Ibuprofen did not satisfy the bioequivalence criteria at lower settings of intestinal pH=6.0. Further the experimental dissolution of ibuprofen tablets in the low concentration phosphate buffer at pH 6.0 (the average buffer capacity 2.2 mmol L-1/pH) was dramatically reduced compared to the dissolution in SIF (the average buffer capacity 12.6 mmol L -1/pH). Thus these predictions for oral absorption of BCS class II acids indicate that the absorption patterns largely depend on the intestinal pH and buffer strength and must be carefully considered for a bioequivalence test. Simulation software may be very useful tool to aid the selection of dissolution media that may be useful in setting an in vitro bioequivalence dissolution standard. PMID:22815122

  9. In silico prediction of drug dissolution and absorption with variation in intestinal pH for BCS class II weak acid drugs: ibuprofen and ketoprofen.

    Tsume, Yasuhiro; Langguth, Peter; Garcia-Arieta, Alfredo; Amidon, Gordon L

    2012-10-01

    The FDA Biopharmaceutical Classification System guidance allows waivers for in vivo bioavailability and bioequivalence studies for immediate-release solid oral dosage forms only for BCS class I. Extensions of the in vivo biowaiver for a number of drugs in BCS class III and BCS class II have been proposed, in particular, BCS class II weak acids. However, a discrepancy between the in vivo BE results and in vitro dissolution results for BCS class II acids was recently observed. The objectives of this study were to determine the oral absorption of BCS class II weak acids via simulation software and to determine if the in vitro dissolution test with various dissolution media could be sufficient for in vitro bioequivalence studies of ibuprofen and ketoprofen as models of carboxylic acid drugs. The oral absorption of these BCS class II acids from the gastrointestinal tract was predicted by GastroPlus™. Ibuprofen did not satisfy the bioequivalence criteria at lower settings of intestinal pH of 6.0. Further the experimental dissolution of ibuprofen tablets in a low concentration phosphate buffer at pH 6.0 (the average buffer capacity 2.2 mmol l (-1) /pH) was dramatically reduced compared with the dissolution in SIF (the average buffer capacity 12.6 mmol l (-1) /pH). Thus these predictions for the oral absorption of BCS class II acids indicate that the absorption patterns depend largely on the intestinal pH and buffer strength and must be considered carefully for a bioequivalence test. Simulation software may be a very useful tool to aid the selection of dissolution media that may be useful in setting an in vitro bioequivalence dissolution standard. PMID:22815122

  10. Syntheses and characterization of copper (II), nickel (II), iron (III), zinc (II), cadmium (II), zirconium (IV), molybdenum (V and VI) and uranium (VI) complexes of polystyrene supported resin containing the Schiff base derived from 3-formylsalicylic acid and O-aminophenol

    A new series of polystyrene supported metal complexes of the formulae PS-LCu.DMF, PS-LNi.3DMF, PS-LFeCl.2DMF, PS-LZn.DMF, Ps-Lcd.DMF, PS-LMoOCl.DMF, PS-LMoO2.DMF,PS-LZr(OH)2.2DMF and PS-LUO2.DMF (where Ps-L deprotonated polymer-anchored Schiff base) have been synthesized by the reaction of metal salt/metal complex with the chelating resin containing the Schiff base derived from 3-formylsalicylic acid and o-aminophenol. The polymer supported metal complexes have been characterized by elemental analysis, IR, electronic and ESR spectra and magnetic susceptibility measurements. The geometry of the complexes are comparable with the corresponding metal complexes of non-anchored ligands. The polymer supported Cu(II) complex is square planar, Zn(II) and Cd(II) complexes are tetrahedral, Ni(II), Fe(III), U(VI) and Mo(V and VI) complexes are octahedral and zirconium(IV) complex is pentagonal bipyramidal. The polymer-anchored Ni(II), Cu(II), Fe(III) and Mo(V) complexes are paramagnetic while the Zn(II), Cd(II), Zr(IV), U(VI) and Mo(VI) complexes are diamagnetic. (author). 33 refs

  11. Normal protein content but abnormally inhibited enzyme activity in muscle carnitine palmitoyltransferase II deficiency.

    Lehmann, Diana; Zierz, Stephan

    2014-04-15

    The biochemical consequences of the disease causing mutations of muscle carnitine palmitoyltransferase II (CPT II) deficiency are still enigmatic. Therefore, CPT II was characterized in muscle biopsies of nine patients with genetically proven muscle CPT II deficiency. Total CPT activity (CPT I+CPT II) of patients was not significantly different from that of controls. Remaining activities upon inhibition by malonyl-CoA and Triton X-100 were significantly reduced in patients. Immunohistochemically CPT II protein was predominantly expressed in type-I-fibers with the same intensity in patients as in controls. Western blot showed the same CPT II staining intensity ratio in patients and controls. CPT I and CPT II protein concentrations estimated by ELISA were not significantly different in patients and in controls. Citrate synthase activity in patients was significantly increased. Total CPT activity significantly correlated with both CPT I and CPT II protein concentrations in patients and controls. This implies (i) that normal total CPT activity in patients with muscle CPT II deficiency is not due to compensatory increase of CPT I activity and that (ii) the mutant CPT II is enzymatically active. The data further support the notion that in muscle CPT II deficiency enzyme activity and protein content are not reduced, but rather abnormally inhibited when fatty acid metabolism is stressed. PMID:24602495

  12. Molecular cloning and expression profile of ß-ketoacyl-acp synthase gene from tung tree (Vernicia fordii Hemsl.)

    Tung tree (Vernicia fordii) is an important woody oil tree. Tung tree seeds contain 50-60% oil with approximately 80 mole a-eleostearic acid (9cis, 11trans, 13trans octadecatrienoic acid). Fatty acid synthesis is catalyzed by the concerted action of acetyl-CoA carboxylase and fatty acid synthase, a ...

  13. Palladium(II-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

    Tanveer Mahamadali Shaikh

    2013-08-01

    Full Text Available A series of general and selective Pd(II-catalyzed Heck reactions were investigated under mild reaction conditions. The first protocol has been developed employing an imidazole-based secondary phosphine oxide (SPO ligated palladium complex (6 as a precatalyst. The catalytic coupling of aryl halides and olefins led to the formation of the corresponding coupled products in excellent yields. A variety of substrates, both electron-rich and electron-poor olefins, were converted smoothly to the targeted products in high yields. Compared with the existing approaches employing SPO–Pd complexes in a Heck reaction, the current strategy features mild reaction conditions and broad substrate scope. Furthermore, we described the coupling of arylboronic acids with olefins, which were catalyzed by Pd(OAc2 and employed N-bromosuccinimide as an additive under ambient conditions. The resulted biaryls have been obtained in moderate to good yields.

  14. Synthesis, Crystal Structure, and Luminescence Properties of a New Calcium(II Coordination Polymer Based on L-Malic Acid

    Duraisamy Senthil Raja

    2013-01-01

    Full Text Available A new calcium coordination polymer [Ca(HL-MA]n (H3L-MA = L-malic acid has been solvothermally synthesized. The structure of the newly synthesized complex has been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, reflectance UV-Vis & IR spectra, powder X-ray diffraction (PXRD, and thermogravimetric analysis (TGA. The single crystal structure analysis showed that the complex forms three-dimensional framework. The new Ca(II complex has displayed very high thermal stability which was inferred from TGA and PXRD results. As far as the optical property of the new complex is concerned, the complex emitted its own characteristic sensitized luminescence.

  15. Radiolabeling of a wound-inducible pyridoxal phosphate utilizing protein from tomato: evidence for its identification as ACC synthase

    Aminocyclopropane 1-carboxylic acid (ACC) synthase, a pyridoxal phosphate utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate limiting step in the biosynthesis of the plant hormone, ethylene. Ethylene, besides being involved in normal plant growth processes, is also produced in response to stress, e.g. wounding, pathogen infection, etc. The authors report the partial purification (400 fold) of ACC synthase from wounded pink tomato pericarp by classical techniques including ammonium sulfate precipitation, ion exchange and phenyl sepharose chromatography. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme and the low levels present in plant tissue. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase enriched fraction was achieved. Evidence that this radiolabeled protein is ACC synthase will be presented. Amino acid sequence determination of putative ACC synthase-derived peptides is underway

  16. Cellulose Microfibril Formation by Surface-Tethered Cellulose Synthase Enzymes.

    Basu, Snehasish; Omadjela, Okako; Gaddes, David; Tadigadapa, Srinivas; Zimmer, Jochen; Catchmark, Jeffrey M

    2016-02-23

    Cellulose microfibrils are pseudocrystalline arrays of cellulose chains that are synthesized by cellulose synthases. The enzymes are organized into large membrane-embedded complexes in which each enzyme likely synthesizes and secretes a β-(1→4) glucan. The relationship between the organization of the enzymes in these complexes and cellulose crystallization has not been explored. To better understand this relationship, we used atomic force microscopy to visualize cellulose microfibril formation from nickel-film-immobilized bacterial cellulose synthase enzymes (BcsA-Bs), which in standard solution only form amorphous cellulose from monomeric BcsA-B complexes. Fourier transform infrared spectroscopy and X-ray diffraction techniques show that surface-tethered BcsA-Bs synthesize highly crystalline cellulose II in the presence of UDP-Glc, the allosteric activator cyclic-di-GMP, as well as magnesium. The cellulose II cross section/diameter and the crystal size and crystallinity depend on the surface density of tethered enzymes as well as the overall concentration of substrates. Our results provide the correlation between cellulose microfibril formation and the spatial organization of cellulose synthases. PMID:26799780

  17. Modeling of solvent extraction equilibrium of Cu(II from sulphuric Acid solution with MOC-55TD

    Alguacil, F. J.

    1999-06-01

    Full Text Available The extraction of Cu(II from acidic sulphate aqueous solutions using the commercial MOC-55TD extractant is studied. A predictive model, which consists in a set of non-linear mass action and mass balance equations is proposed. The model was solved using a tailor-made equation-solving program. The extraction of copper can be described by the formation of CuR2 species (log Kext= 0.717 ± 0.03 in the organic phase. The copper equilibrium isotherm was also obtained at 20°C.

    Se estudia la extracción de Cu(II de disoluciones acuosas acidas, en medio sulfato, mediante la oxima comercial MOC-55TD. Se propone un modelo para predecir la extracción del metal; este modelo consiste en una serie de ecuaciones no lineales de acción de masas y balance de masas. El modelo se resolvió empleando un programa de ordenador específicamente definido para este tipo de equilibrios. La extracción de cobre se describe por la formación de la especie CuR2 (log Kext= 0,717 ± 0,03 en la fase orgánica. Se ha obtenido la isoterma de extracción de cobre a 20 °C.

  18. Nucleic acid interaction and antibacterial behaviours of a ternary palladium(II) complexes

    Patel, Mohan N.; Dosi, Promise A.; Bhatt, Bhupesh S.

    2012-02-01

    The bidentate ligands and Pd(II) complexes have been synthesized and characterized using elemental analysis (C, H, N), 1H NMR, 13C NMR, electronic spectra, FT-IR and FAB mass spectroscopy. The binding of palladium complexes with calf thymus DNA (CT DNA) has been explored using absorption titration, DNA melting temperature and viscosity measurements. The cleavage reaction on pUC19 DNA has been monitored by agarose gel electrophoresis. The results suggest that complexes can bind to DNA by intercalative modes and exhibit nuclease activities in which supercoil form is converted to open circular form. The antibacterial activity of ligands and complexes has been performed against three Gram(-ve) and two Gram(+ve) microorganisms and the study indicates that all the complexes show better microbial inhibition activity than ligands and palladium salt.

  19. Hg (II) Catalysed Oxidation of D-Arabinose and D-Mannose by Acidic Solution of Potassium Permanganate: Kinetics and Mechanism

    R. Naz; *R. Azmat; Qamar, N; 3N. I. Siddiqi

    2014-01-01

    The kinetics of Hg (II) catalyzed oxidation of D-Arabinose (Ara) and D-Mannose (Man) by potassium permanganate in acidic medium have been studied spectrophotometrically in the temperature range 30-50oC. The reactions exhibit first order kinetics with respect to [Man] and [MnO4-] while second order with [Ara]. The reaction rates were found to be unaffected by the change in [H+]. It has been observed that Hg (II) catalyzed the reaction but as the [Hg(II)] increases, reaction rate becomes indepe...

  20. Heterologous expression of human carnitine palmitoyltransferase (CPT) II in yeast: A model for the molecular analysis of mitochondrial fatty acid oxidation defects

    Cavadini, P.; Invernizzi, F.; Baratta, S. [Istituto Nazionale Neurologico Carlo Besta, Milano (Italy)] [and others

    1994-09-01

    The CPT enzyme system, which is composed of two distinct mitochondrial membrane-bound proteins (CPT I and CPT II), provides the mechanism whereby long-chain fatty acids are transferred from the cytosol to the mitochondrial matrix to undergo {beta}-oxidation. Here, we report the development of an expression system for investigating genotype/phenotype correlations in CPT II deficiency and, potentially, other mitochondrial fatty acid oxidation defects. To explore yeast as an expression system, we introduced a cDNA encoding the entire human CPT II precursor into Saccharomyces cerevisiae. Expression was programmed by using an inducible galactose operon promoter (GAL1). Following induction, human CPT II was expressed at high levels, with activity 4- to 16-fold greater than in human fibroblasts. Levels of expression paralleled those of respiration, being higher in cells grown on a nonfermentable carbon source than in those grown on glucose. Immunoprecipitation of pulse-labeled transformed cells demonstrated that human CPT II expressed in yeast was targeted to mitochondria with correct proteolytic processing of its 25-residue mitochondrial leader sequence. Preliminary results on the expression of a number of mutant CPT II alleles associated with different clinical phenotypes demonstrated the value of this system for examining the functional consequences of disease-causing mutations and investigating genotype/phenotype correlations in patients with CPT II deficiency.

  1. Homogeneous nucleation rates of nitric acid dihydrate (NAD at simulated stratospheric conditions – Part II: Modelling

    O. Möhler

    2006-01-01

    Full Text Available Activation energies ΔGact for the nucleation of nitric acid dihydrate (NAD in supercooled binary HNO3/H2O solution droplets were calculated from volume-based nucleation rate measurements using the AIDA (Aerosol, Interactions, and Dynamics in the Atmosphere aerosol chamber of Forschungszentrum Karlsruhe. The experimental conditions covered temperatures T between 192 and 197 K, NAD saturation ratios SNAD between 7 and 10, and nitric acid molar fractions of the nucleating sub-micron sized droplets between 0.26 and 0.28. Based on classical nucleation theory, a new parameterisation for ΔGact=A×(T ln SNAD−2+B is fitted to the experimental data with A=2.5×106 kcal K2 mol−1 and B=11.2−0.1(T−192 kcal mol−1. A and B were chosen to also achieve good agreement with literature data of ΔGact. The parameter A implies, for the temperature and composition range of our analysis, a mean interface tension σsl=51 cal mol−1 cm−2 between the growing NAD germ and the supercooled solution. A slight temperature dependence of the diffusion activation energy is represented by the parameter B. Investigations with a detailed microphysical process model showed that literature formulations of volume-based (Salcedo et al., 2001 and surface-based (Tabazadeh et al., 2002 nucleation rates significantly overestimate NAD formation rates when applied to the conditions of our experiments.

  2. LC-MS and GC-MS metabolite profiling of nickel(II) complexes in the latex of the nickel-hyperaccumulating tree Sebertia acuminata and identification of methylated aldaric acid as a new nickel(II) ligand.

    Callahan, Damien L; Roessner, Ute; Dumontet, Vincent; Perrier, Nicolas; Wedd, Anthony G; O'Hair, Richard A J; Baker, Alan J M; Kolev, Spas D

    2008-01-01

    Targeted liquid chromatography-mass spectrometry (LC-MS) technology using size exclusion chromatography and metabolite profiling based on gas chromatography-mass spectrometry (GC-MS) were used to study the nickel-rich latex of the hyperaccumulating tree Sebertia acuminata. More than 120 compounds were detected, 57 of these were subsequently identified. A methylated aldaric acid (2,4,5-trihydroxy-3-methoxy-1,6-hexan-dioic acid) was identified for the first time in biological extracts and its structure was confirmed by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. After citric acid, it appears to be one of the most abundant small organic molecules present in the latex studied. Nickel(II) complexes of stoichiometry NiII:acid=1:2 were detected for these two acids as well as for malic, itaconic, erythronic, galacturonic, tartaric, aconitic and saccharic acids. These results provide further evidence that organic acids may play an important role in the transport and possibly in the storage of metal ions in hyperaccumulating plants. PMID:17765935

  3. Interactions of Zn(II) Ions with Humic Acids Isolated from Various Type of Soils. Effect of pH, Zn Concentrations and Humic Acids Chemical Properties

    Boguta, Patrycja; Sokołowska, Zofia

    2016-01-01

    The main aim of this study was the analysis of the interaction between humic acids (HAs) from different soils and Zn(II) ions at wide concentration ranges and at two different pHs, 5 and 7, by using fluorescence and FTIR spectroscopy, as well as potentiometric measurements. The presence of a few areas of HAs structures responsible for Zn(II) complexing was revealed. Complexation at α-sites (low humified structures of low-molecular weight and aromatic polycondensation) and β-sites (weakly humified structures) was stronger at pH 7 than 5. This trend was not observed for γ-sites (structures with linearly-condensed aromatic rings, unsaturated bonds and large molecular weight). The amount of metal complexed at pH5 and 7 by α and γ-structures increased with a decrease in humification and aromaticity of HAs, contrary to β-areas where complexation increased with increasing content of carboxylic groups. The stability of complexes was higher at pH 7 and was the highest for γ-structures. At pH 5, stability decreased with C/N increase for α-areas and -COOH content increase for β-sites; stability increased with humification decrease for γ-structures. The stability of complexes at α and β-areas at pH 7 decreased with a drop in HAs humification. FTIR spectra at pH 5 revealed that the most-humified HAs tended to cause bidentate bridging coordination, while in the case of the least-humified HAs, Zn caused bidentate bridging coordination at low Zn additions and bidentate chelation at the highest Zn concentrations. Low Zn doses at pH 7 caused formation of unidentate complexes while higher Zn doses caused bidentate bridging. Such processes were noticed for HAs characterized by high oxidation degree and high oxygen functional group content; where these were low, HAs displayed bidentate bridging or even bidentate chelation. To summarize, the above studies have showed significant impact of Zn concentration, pH and some properties of HAs on complexation reactions of humic

  4. Characterization studies and cyclic voltammetry on nickel(II amino acid dithiocarbamates with triphenylphosphine in the coordination sphere

    SUBBIAH THIRUMARAN

    2008-02-01

    Full Text Available Nickel(II amino acid dithiocarbamate complexes of the composition [Ni(AAdtc(PPh3(NCS], [Ni(AAdtc(PPh3(CN] and [Ni(AAdtc(PPh32]ClO4 [(AAdtc = dithiocarbamate derivatives of amino acids, i.e., glycine (glydtc, L-iso-leucine (i-leudtc and L-proline (prodtc] were synthesized. The compounds were characterized by IR and electronic spectroscopy, thermal analysis, cyclic voltammetry and conductivity measurements. In the case of the mixed ligand complexes, the thioureide n(C−N values were shifted to higher wave numbers compared to [Ni(AAdtc2]. This observation shows the increased strength of the thioureide bond due to the presence of the p-accepting phosphine. Electronic spectral studies suggest square planar geometry for the complexes. Thermal analyses of the complexes are in keeping with the proposed formulae. Almost all the complexes showed signs of decay above 170 °C. At around 390 °C, the final mass corresponded to NiS. Cyclic voltammetry showed a decrease of the electron density on the nickel in the mixed ligand complexes compared to [Ni(AAdtc2].

  5. Fluorometric determination of aluminium (III) and cadmium (II) by solvent extraction of the ternary complex composed of metal ion, 8-hydroxy-5-quinolinesulfonic acid, and methyltrioctylammonium ion

    Kondoh, Yukihiro; Kataoka, Masamitsu; Kambara, Tomihito (Hokkaido Univ., Sapporo (Japan). Faculty of Science)

    1982-02-01

    A fluorometric micro determination of aluminium (III) and cadmium (II) using the formation of metal-8-hydroxy-5-quinolinesulfonic acid-capriquat (methyltrioctylammonium) ternary complex is described. These complexes are easily extracted into chloroform phase and the extract emits a strong fluorescence. Spectra of aluminium (III) and cadmium (II) ternary complexes have the excitation maximum at 396 nm and 400 nm, and emission maximum at 501 nm and 524 nm, respectively. Fluorescence intensity of the aluminium (III) and cadmium (II) ternary complexes extracted into chloroform showed the constant and maximum values in the pH range of aqueous phase from 5.3 to 8.5 and 8.1 to 8.5, respectively. The calibration curves for aluminium (III) and cadmium (II) show good proportionality in the concentration range from 0.5 to 5.0 and 1.0 to 50.0 ..mu..g, respectively. The relative standard deviation observed with four measurements was found to be 1.8% for 0.5 ..mu..g of aluminium (III) and 1.1% for 10.0 ..mu..g of cadmium (II). The effect of diverse ions is studied and a 25-fold amount of Cu(II), Ni(II), Fe(II), Fe(III) in weight gave errors, however, the interferences were easily eliminated by the addition of appropriate masking agent. In the determination of cadmium (II), an equal amount of Co(II), Ni(II), Mn(II), Fe(III) and twice amount of Al(III) gave negative errors, however, the interference of Fe(III) and Al(III) were also eliminated as above.

  6. Electrochemiluminescence of Tris(2,2'-bipyridyl)ruthenium(II) with Ascorbic Acid and Dehydroascorbic Acid in Aqueous and Non-aqueous Solutions.

    Takahashi, Fumiki; Hattori, Kaoru; Matsuoka, Masanori; Jin, Jiye

    2016-01-01

    The electrochemiluminescence (ECL) of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+)) is studied in non-aqueous media using dehydroascorbic acid (DHA) as coreactant to validate the evidence for the mechanism of the ascorbic acid (H2A)/Ru(bpy)3(2+) ECL system in an aqueous media. DHA is electrochemically reduced around -1.2 V vs. Ag/Ag(+) in pure acetonitrile to generate the ascorbyl radical anion (A(•-)), which is confirmed by in-situ UV-visible absorption measurements using a thin-layer spectroelectrochemical cell. The ECL of the DHA/Ru(bpy)3(2+) system in non-aqueous media is not observed in the potential range from 0 to +1.4 V in anodic potential sweep mode; however, distinct ECL is detected using double potential step electrolysis from -1.2 to +1.4 V vs. Ag/Ag(+). The ECL may be generated by a homogeneous charge-transfer process between A(•-) produced during the first pulse potential step (-1.2 V) and Ru(bpy)3(3+) generated during the second pulse potential step (+1.4 V). The calculated standard enthalpy (-ΔH°) for the charge-transfer reaction between A(•-) and Ru(bpy)3(3+) is 2.29 eV, which is larger than the lowest excited singlet state energy of Ru(bpy)3(2+) (*Ru(bpy)3(2+); 2.03 eV, 610 nm). It is determined that the generated intermediate A(•-) is crucial in the Ru(bpy)3(2+) ECL reaction. PMID:27063718

  7. Lead-acid batteries in micro-hybrid applications. Part II. Test proposal

    Schaeck, S.; Stoermer, A.O. [BMW Group, 80788 Muenchen (Germany); Albers, J. [Johnson Controls Power Solutions EMEA, 30419 Hannover (Germany); Weirather-Koestner, D. [ZSW Ulm, 89081 Ulm (Germany); Kabza, H. [Universitaet Ulm, Institut fuer Energiewandlung und -speicherung, 89081 Ulm (Germany)

    2011-02-01

    In the first part of this work selected key parameters for applying lead-acid (LA) batteries in micro-hybrid power systems (MHPS) were investigated. Main results are integrated in an accelerated, comprehensive test proposal presented here. The test proposal aims at a realistic representation of the pSoC operation regime, which is described in Refs. The test is designed to be sensitive with respect to dynamic charge acceptance (DCA) at partially discharged state (critical for regenerative braking) and the internal resistance at high-rate discharge (critical for idling stop applications). First results are presented for up-to-date valve-regulated LA batteries with absorbent glass mat (AGM) separators. The batteries are close to the limits of the first proposal of pass/fail-criteria. Also flooded batteries were tested; the first out of ten units failed already. (author)

  8. Electron transfer reactions of osmium(II) complexes with phenols and phenolic acids

    Rajeswari, Angusamy; Ramdass, Arumugam; Muthu Mareeswaran, Paulpandian; Velayudham, Murugesan; Rajagopal, Seenivasan

    2016-07-01

    Three [Os(NN)3]2+ complexes (NN = polypyridine) with ligands of varying hydrophobicity were synthesized and characterized by NMR spectral techniques. The geometry of the molecules are optimized by DFT calculations. The interaction between [Os(NN)3]2+ complexes and phenolate ion in ground state is confirmed by absorption spectral study and the binding constant values are in the range of 3-740 M-1. The photoinduced electron transfer reaction of these [Os(NN)3]2+ complexes with phenols and phenolic acids at pH 12.5 leads to the formation of phenoxyl radical confirmed through transient absorption spectral study. Binding constants and electron transfer rate constants within the [Os(NN)3]2+-phenolate ion adduct account for the change for the overall quenching constant with the change of structure of reactants.

  9. Lead-acid batteries in micro-hybrid applications. Part II. Test proposal

    Schaeck, S.; Stoermer, A. O.; Albers, J.; Weirather-Koestner, D.; Kabza, H.

    In the first part of this work [1] selected key parameters for applying lead-acid (LA) batteries in micro-hybrid power systems (MHPS) were investigated. Main results are integrated in an accelerated, comprehensive test proposal presented here. The test proposal aims at a realistic representation of the pSoC operation regime, which is described in Refs. [1,6]. The test is designed to be sensitive with respect to dynamic charge acceptance (DCA) at partially discharged state (critical for regenerative braking) and the internal resistance at high-rate discharge (critical for idling stop applications). First results are presented for up-to-date valve-regulated LA batteries with absorbent glass mat (AGM) separators. The batteries are close to the limits of the first proposal of pass/fail-criteria. Also flooded batteries were tested; the first out of ten units failed already.

  10. Proton conducting polydimethylsiloxane/metal oxide hybrid membranes added with phosphotungstic acid(II)

    Flexible polymer electrolyte membranes consisting of zirconia (titania) and polydimethylsiloxane (PDMS) with the different molecular mass of 4500 and 600 have been synthesized by sol-gel processes. The polymeric membranes showed thermal stability and flexibility up to 300 deg.C due to the presence of cross-linkable inorganic nano-phase in the hybrid macromolecular matrix. The membrane becomes proton conducting polymer electrolyte by addition of 12-phosphotungstic acid (PWA). The conductivity increased up to 7.7x10-2 S/cm through ultrasonic treatment on the membrane, which is in the application level to polymer electrolyte fuel cells. The hybrid materials can be recognized as new, low cost and environment friendly electrolyte membranes

  11. Ruthenium(II) multi carboxylic acid complexes: chemistry and application in dye sensitized solar cells.

    Shahroosvand, Hashem; Nasouti, Fahimeh; Sousaraei, Ahmad

    2014-04-01

    Novel ruthenium multi carboxylic complexes (RMCCs) have been synthesized by using ruthenium nitrosyl nitrate, 1,2,4,5-benzenetetracarboxylic acid (H4btec) and 4,7-diphenyl-1,10-phenanthroline (BPhen) as photosensitizers for titanium dioxide semiconductor solar cells. The complexes were characterized by (1)H-NMR, FT-IR, UV-Vis, ICP and CHN analyses. The reaction details and features were then described. SEM analysis revealed that the penetration of dyes into the pores of the nanocrystalline TiO2 surface was improved by increasing the number of btec units. The solar energy to electricity conversion efficiency of complexes shows that the number of attached carboxylates on a dye has an influence on the photoelectrochemical properties of the dye-sensitized electrode. An incident photon-to-current conversion efficiency (IPCE) of 13% at 510 nm was obtained for ruthenium complexes with three btec units. PMID:24500312

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

    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.

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

    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 (AcpSSA), Vibrio cholerae (AcpSVC) and Bacillus anthracis (AcpSBA) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpSBA 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 AcpSBA may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP

  14. Use of an o-aminobenzoic acid-functionalized XAD-4 copolymer resin for the separation and preconcentration of heavy metal(II) ions

    XAD copolymer resins may be functionalized with heavy metal ion-selective ligands either by covalent linkage to the polymer backbone or by impregnation. These resins may be tailored to be specific for certain heavy metals by adjusting the adsorption and elution parameters, thereby enabling simple and cost-effective spectrophotometric and flame atomic absorption spectrometry (FAAS) determinations of these metals without requiring the more sophisticated coupled instrumental techniques. For the synthesis of o-aminobenzoic acid (ABA)-immobilized XAD-4 copolymer resin that is expected to preconcentrate a number of transition and heavy metals, the azo-linkage method was chosen. For this purpose the copolymer was nitrated, reduced to the corresponding amine, converted to the diazonium salt with nitrite, and reacted with o-aminobenzoic acid to produce the XAD-ABA sorbent. This sorbent was capable of preconcentrating Pb(II), Cd(II), Ni(II), Co(II) and Zn(II) from weakly acidic or neutral aqueous solution. The retained metals were eluted with 1.0 M HNO3 from the resin column, and were subsequently determinated with by flame atomic absorption spectrometry. The developed resin preconcentration and determination method was successfully applied to the analysis of a synthetic metal mixture solution, a certified reference material (CRM) of coal sample, and brackish lake water

  15. Chemical and spectroscopic characterizations, ESI-QTOF mass spectrometric measurements and DFT studies of new complexes of palladium(II) with tryptamine and mefenamic acid

    Carvalho, Marcos A.; Arruda, Eduardo G. R.; Profirio, Daniel M.; Gomes, Alexandre F.; Gozzo, Fábio C.; Formiga, André L. B.; Corbi, Pedro P.

    2015-11-01

    New palladium(II) complexes with tryptamine (Pd-tra) and mefenamic acid (Pd-mef) were prepared and characterized by chemical and spectroscopic methods. Elemental, ESI-QTOF mass spectrometric and thermogravimetric analyses of the compounds confirm the composition [PdCl2(tra)2] for Pd-tra and [Pd(mef)2(bipy)] for Pd-mef. Infrared data indicate the coordination of tryptamine to Pd(II) by the nitrogen atom of the amino group, while for mefenamic acid coordination occurs by the oxygen atom of carboxylate group in a monodentate form. The 1H, 13C and {15N,1H} NMR spectroscopic data confirm the nitrogen coordination of the NH2 group of trypatmine to Pd(II) in the Pd-tra complex and also the oxygen coordination of the carboxylate group of mefenamic acid to Pd(II) in the Pd-mef complex. Density functional theory (DFT) studies were applied to determine the difference in energy between the geometric isomers (cis/trans) of Pd-tra and to optimize the structure of the Pd-mef complex. Raman spectroscopic measurements reinforce the nitrogen coordination of tryptamine to Pd(II) in the Pd-tra complex and confirms the presence of the cis-[PdCl2(tra)2] isomer in the solid state. The complexes are insoluble in water.

  16. High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study

    Highlights: • Two scenarios of acid gases removal in WTE plants were compared in an LCA study. • A detailed inventory based on primary data has been reported for the production of the new dolomitic sorbent. • Results show that the comparison between the two scenarios does not show systematic differences. • The potential impacts are reduced only if there is an increase in the energy efficiency of the WTE plant. - Abstract: The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO2 emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in

  17. High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study

    Biganzoli, Laura, E-mail: laura.biganzoli@mail.polimi.it [Politecnico di Milano, Department of Civil and Environmental Engineering, Piazza L. da Vinci 32, 20133 Milano (Italy); Racanella, Gaia [Politecnico di Milano, Department of Civil and Environmental Engineering, Piazza L. da Vinci 32, 20133 Milano (Italy); Marras, Roberto [Unicalce S.p.A., R and D Department, Via Tonio da Belledo 30, 23900 Lecco (Italy); Rigamonti, Lucia [Politecnico di Milano, Department of Civil and Environmental Engineering, Piazza L. da Vinci 32, 20133 Milano (Italy)

    2015-01-15

    Highlights: • Two scenarios of acid gases removal in WTE plants were compared in an LCA study. • A detailed inventory based on primary data has been reported for the production of the new dolomitic sorbent. • Results show that the comparison between the two scenarios does not show systematic differences. • The potential impacts are reduced only if there is an increase in the energy efficiency of the WTE plant. - Abstract: The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO{sub 2} emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in

  18. PhTX-II a Basic Myotoxic Phospholipase A2 from Porthidium hyoprora Snake Venom, Pharmacological Characterization and Amino Acid Sequence by Mass Spectrometry

    Salomón Huancahuire-Vega

    2014-10-01

    Full Text Available A monomeric basic PLA2 (PhTX-II of 14149.08 Da molecular weight was purified to homogeneity from Porthidium hyoprora venom. Amino acid sequence by in tandem mass spectrometry revealed that PhTX-II belongs to Asp49 PLA2 enzyme class and displays conserved domains as the catalytic network, Ca2+-binding loop and the hydrophobic channel of access to the catalytic site, reflected in the high catalytic activity displayed by the enzyme. Moreover, PhTX-II PLA2 showed an allosteric behavior and its enzymatic activity was dependent on Ca2+. Examination of PhTX-II PLA2 by CD spectroscopy indicated a high content of alpha-helical structures, similar to the known structure of secreted phospholipase IIA group suggesting a similar folding. PhTX-II PLA2 causes neuromuscular blockade in avian neuromuscular preparations with a significant direct action on skeletal muscle function, as well as, induced local edema and myotoxicity, in mice. The treatment of PhTX-II by BPB resulted in complete loss of their catalytic activity that was accompanied by loss of their edematogenic effect. On the other hand, enzymatic activity of PhTX-II contributes to this neuromuscular blockade and local myotoxicity is dependent not only on enzymatic activity. These results show that PhTX-II is a myotoxic Asp49 PLA2 that contributes with toxic actions caused by P. hyoprora venom.

  19. Synthesis and characterization of mixed ligand complexes of Zn(II) and Co(II) with amino acids: Relevance to zinc binding sites in zinc fingers

    P Rabindra Reddy; M Radhika; P Manjula

    2005-05-01

    Mixed ligand complexes of Zn(II) and Co(II) with cysteine, histidine, cysteinemethylester, and histidinemethylester have been synthesized and characterized by elemental analysis, conductivity, magnetic susceptibility measurements, and infrared, 1H NMR, TGA and FAB mass spectra. In these complexes, histidine, and histidinemethylester act as bidentate ligands involving amino and imidazole nitrogens in metal coordination. Similarly, cysteine, and cysteinemethylester also act as bidentate ligands coordinating through thiol sulphur and amino nitrogen. Tetrahedral geometry has been proposed for Zn(II) and Co(II) complexes based on experimental evidence.

  20. Reaction of nucleic acids with cis-diamminedichloroplatinum(II): interstrand cross-links

    In the reaction of cis-diamminedichloroplatinum(II) (cis-DDP) with double-helical (dC-dG)4-(dC-dG)4 or (dC-dG)5-(dC-dG)5, intrastrand and interstrand cross-links between two guanine residues are formed. This is shown by gel electrophoresis in denaturing conditions of the reaction products and by high-performance liquid chromatography (HPLC) analysis of the products digested with nuclease P1. In the reaction of cis-DDP and poly(dG-dC)-poly(dG-dC), at relatively low levels of platination, it is mainly interstrand cross-links between two guanine residues that are formed. This is shown by HPLC analysis of the nuclease P1 digest and by gel electrophoresis in denaturing and nondenaturing conditions of the platinated polymer after cleavage with the restriction enzyme HhaI. Moreover, the antibodies to platinated poly(dG-dC)-poly(dG-dC) cross-react with the interstrand cross-linked (dC-dG)4 or (dC-dG)5 but not with the intrastrand cross-linked (dG-dC)4 or (dC-dG)5. These antibodies cross-react with platinated natural DNA. The amount of interstrand cross-links deduced from radioimmunoassays (0.5% of the total bound platinum) is lower than that (2%) deduced by gel electrophoresis in denaturing conditions of a platinated DNA restriction fragment. By gel electrophoresis, it is also shown that in vitro the isomer trans-DDP is more efficient in forming interstrand cross-links than cis-DDP

  1. (Eta6-arene) ruthenium(II) complexes and metallo-papain hybrid as Lewis acid catalysts of Diels-Alder reaction in water.

    Talbi, Barisa; Haquette, Pierre; Martel, Annie; Montigny, Frédéric de; Fosse, Céline; Cordier, Stéphane; Roisnel, Thierry; Jaouen, Gérard; Salmain, Michèle

    2010-01-01

    International audience Covalent embedding of a (eta(6)-arene) ruthenium(II) complex into the protein papain gives rise to a metalloenzyme displaying a catalytic efficiency for a Lewis acid-mediated catalysed Diels-Alder reaction enhanced by two orders of magnitude in water.

  2. Rational synthesis of an exceptionally stable Zn(ii) metal-organic framework for the highly selective and sensitive detection of picric acid.

    Hu, Yingli; Ding, Meili; Liu, Xiao-Qin; Sun, Lin-Bing; Jiang, Hai-Long

    2016-04-14

    Based on an organic ligand involving both carboxylate and tetrazole groups, a chemically stable Zn(ii) metal-organic framework has been rationally synthesized and behaves as a fluorescence chemosensor for the highly selective and sensitive detection of picric acid, an extremely hazardous and strong explosive. PMID:27046028

  3. pH dependence of the interaction between immunogenic peptides and MHC class II molecules. Evidence for an acidic intracellular compartment being the organelle of interaction

    Mouritsen, S; Buus, Anette Stryhn; Petersen, B L; Buus, S

    1992-01-01

    most notably in the endosome-lysosome compartment in which Ag processing is thought to occur. Thus, Ag processing and interaction with MHC class II molecules can potentially happen in the very same compartment. This yet undefined acidic compartment would have to contain proteolytic enzymes and MHC...

  4. High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study.

    Biganzoli, Laura; Racanella, Gaia; Marras, Roberto; Rigamonti, Lucia

    2015-01-01

    The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCA was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO2 emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in Biganzoli et al. (2014) and from the dolomitic sorbent production plant. The results of the LCA show minor changes in the potential impacts between the two operational modes of the plants. These differences are for 8 impact categories in favour of the new operational mode based on the addition of the dolomitic sorbent, and for 7 impact categories in favour of the traditional operation. A final evaluation was conducted on the potential

  5. Ozone stress induces the expression of ACC synthase in potato plants

    Schlagnhaufer, C.D.; Arteca, R.N.; Pell, E.J. (Pennsylvania State Univ., University Park (United States))

    1993-05-01

    When potato plants (Solanum tuberosum L. cv Norland) are subjected to oxone stress ethylene is emitted. Increases in ethylene production are often the result of increased expression of the enzyme ACC synthase. We used the polymerase chain reaction (PCR) to clone a cDNA encoding an ozone-induced ACC synthase. After treating potato plants with 300 ppb ozone for 4 h, RNA was extracted using a guanidinium isothiocyanate method. Using degenerate oligonucleotides corresponding to several conserved regions of ACC synthase sequences reported from different plant tissues as primers, we were able to reverse transcribe the RNA and amplify a cDNA for ACC synthase. The clone is 1098 bp in length encoding for 386 amino acids comprising [approximately]80% of the protein. Computer analysis of the deduced amino acid sequence showed that our clone is 50-70% homologous with ACC synthase genes cloned from other plant tissues. Using the cDNA as a probe in northern analysis we found that there is little or no expression in control tissue: however there is a large increase in the expression of the ACC synthase message in response to ozone treatment.

  6. Plasmenylethanolamine is the major storage depot for arachidonic acid in rabbit vascular smooth muscle and is rapidly hydrolyzed after angiotensin II stimulation

    The present study demonstrates that rabbit aortic intimal smooth muscle cells contain the majority of their endogenous arachidonic acid mass in plasmenylethanolamine molecular species. To demonstrate the potential significance of these plasmenylethanolamines as substrates for the smooth muscle cell phospholipases that are activated during agonist stimulation, aortic rings were prelabeled with [3H]arachidonic acid and stimulated with angiotensin II. Although the specific activities of the choline and inositol glycerophospholipid pools were similar after the labeling interval, ethanolamine glycerophospholipids had a specific activity of only 20% of the specific activity of choline and inositol glycerophospholipids. Despite the marked disparity in the specific activities of these three phospholipid classes, angiotensin II stimulation resulted in similar fractional losses (35-41%) of [3H]arachidonic acid from vascular smooth muscle choline, ethanolamine, and inositol glycerophospholipid classes. Reverse-phase HPLC demonstrated that >60% of the [3H]arachidonic acid released from ethanolamine glycerophospholipids after angiotensin II stimulation originated from plasmenylethanolamine molecular species. Taken together, the results demonstrate that the major phospholipid storage depot for arachidonic acid in vascular smooth muscle cells are plasmenylethanolamine molecular species which are important substrates for the phospholipase(s) that are activated during agonist stimulation

  7. Hg (II Catalysed Oxidation of D-Arabinose and D-Mannose by Acidic Solution of Potassium Permanganate: Kinetics and Mechanism

    *1R. Naz

    2014-09-01

    Full Text Available The kinetics of Hg (II catalyzed oxidation of D-Arabinose (Ara and D-Mannose (Man by potassium permanganate in acidic medium have been studied spectrophotometrically in the temperature range 30-50oC. The reactions exhibit first order kinetics with respect to [Man] and [MnO4-] while second order with [Ara]. The reaction rates were found to be unaffected by the change in [H+]. It has been observed that Hg (II catalyzed the reaction but as the [Hg(II] increases, reaction rate becomes independent. Negligible effect of ionic strength (μ on the rate of oxidation has also been noted which supports the presence of at least one neutral specie in the rate determining step. The rate of oxidation was influenced by the change in temperature. Various activation parameters have been calculated. Formic acid and erythronic acid were identified as main oxidation product in case of arabinose while for mannose formic acid and arabinonic acid were identified. A mechanism consistent with the above findings has also been proposed.

  8. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing, E-mail: eqgao@chem.ecnu.edu.cn

    2013-10-15

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H{sub 2}CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn{sub 5}(μ{sub 3}-OH){sub 2}(2,7-CDC){sub 4}(DEF){sub 2}] (1) (DEF=N,N-diethylformamide), [Zn{sub 2}(2,7-CDC){sub 2}(DABCO)(H{sub 2}O)]·5DMF·H{sub 2}O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn{sub 2}(2,7-CDC){sub 2}(bpea)]·3DMA·2 H{sub 2}O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle–wheel [Zn{sub 2}(COO){sub 4}] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle–wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied. - Graphical abstract: A new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid, was used to construct Zn(II) metal-organic frameworks, including a novel self-catenated network with the rare 3D alb-3,6-C2/c net and two pcu-type networks based on an unprecedented pentanuclear clusters and the common paddle–wheel units. The compounds show blue fluorescent properties. Display Omitted - Highlights: • MOFs with a new carbazole-based dicarboxylate ligand. • New pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building unit. • The rare self-catenated 3D alb-3,6-C2/c net.

  9. Zinc(II) complexes with heterocyclic ether, acid and amide. Crystal structure, spectral, thermal and antibacterial activity studies

    Jabłońska-Wawrzycka, Agnieszka; Rogala, Patrycja; Czerwonka, Grzegorz; Hodorowicz, Maciej; Stadnicka, Katarzyna

    2016-02-01

    The reaction of zinc salts with heterocyclic ether (1-ethoxymethyl-2-methylimidazole (1-ExMe-2-MeIm)), acid (pyridine-2,3-dicarboxylic acid (2,3-pydcH2)) and amide (3,5-dimethylpyrazole-1-carboxamide (3,5-DMePzCONH2)) yielded three new zinc complexes formulated as [Zn(1-ExMe-2-MeIm)2Cl2] 1, fac-[Zn(H2O)6][Zn(2,3-pydcH)3]22 and [Zn(3,5-DMePz)2(NCO)2] 3. Complexes of 1 and 3 are four-coordinated with a tetrahedron as coordination polyhedron. However, compound 2 forms an octahedral cation-anion complex. The complex 3 was prepared by eliminating of the carboxamide group from the ligand and then the 3,5-dimethylpyrazole (3,5-DMePz) and isocyanates formed were employed as new ligands. The IR and X-ray studies have confirmed a bidentate fashion of coordination of the 2,3-pydcH and monodentate fashion of coordination of the 1-ExMe-2-MeIm and 3,5-DMePz to the Zn(II) ions. The crystal packing of Zn(II) complexes are stabilized by intermolecular classical hydrogen bonds of O-H⋯O and N-H⋯O types. The most interesting feature of the supramolecular architecture of complexes is the existence of C-H⋯O, C-H⋯Cl and C-H⋯π interactions and π⋯π stacking, which also contributes to structural stabilisation. The correlation between crystal structure and thermal stability of zinc complexes is observed. In all compounds the fragments of ligands donor-atom containing go in the last steps. Additionally, antimicrobial activities of compounds were carried out against certain Gram-positive and Gram-negative bacteria and counts of CFU (colony forming units) were also determined. The achieved results confirmed a significant antibacterial activity of some tested zinc complexes. On the basis of the Δ log CFU values the antibacterial activity of zinc complexes follows the order: 3 > 2 > 1. Influence a number of N-donor atoms in zinc environment on antibacterial activity is also observed.

  10. Estudo da estabilidade do complexo ácido fítico e o íon Ni(II Study of stability of phytic acid with Ni(II complex

    Ligia De Carli

    2006-03-01

    Full Text Available A técnica de titulação potenciométrica foi utilizada para verificar as propriedades ácida-base do ácido fítico [1,2,3,4,5,6-hexaquis(dihidrogenofosfato-mio-inositol] e do complexo ácido fítico e Ni(II, em solução aquosa, em temperatura e força iônica constantes. Para avaliar o comportamento térmico e a complexação do ácido fítico com o íon Ni(II foram realizadas análises de Termogravimetria (TG, Termogravimetria Derivada (DTG, Calorimetria Exploratória Diferencial (DSC e estudos de Espectrofotometria de Infravermelho. Foram obtidas oito constantes de protonação da amostra de ácido fítico na forma de sal de dipotássio e sete constantes de estabilidade do complexo ácido fítico e Ni(II. As reações de protonação e de formação ocorrem na faixa de pH de 2,0 a 11,0. Os dados obtidos mostram que o ácido fítico encontra-se totalmente deprotonado em pH 12,0 no qual a espécie ML (um ligante para um íon metálico encontra-se totalmente formada no mesmo valor de pH. Os resultados obtidos por TG e DSC revelaram tanto para o ácido fítico como para o complexo boa estabilidade até a temperatura próxima a 200ºC. Por TG, DTG e DSC conclui-se também que a estequiometria do complexo estudado foi de um mol de ligante para um mol de íon metálico. A Espectrofotometria de Infravermelho comprovou a estabilidade do ácido fítico e a sua interação com o íon Ni(II.The technique of potenciometric titration was used to verify the acid-basic properties of the phytic acid, [1,2,3,4,5,6-hexakis(dihydrogen phosphate-myo-inositol] and the Phytic Acid-Ni(II complex, in aqueous solution, in constant temperature and ionic strength. To evaluate the thermal behavior end complexation of the isolated phytic acid with the Ni(II were performed analyses of thermogravimetry (TG, calorimetric scanning differential (DSC and studies Spectroscopy Infrared (IR. Eight protonation constants of the phytic acid sample as dipotassium salt were

  11. Humic acid adsorption onto cationic cellulose nanofibers for bioinspired removal of copper( ii ) and a positively charged dye

    Sehaqui, H.

    2015-01-01

    © The Royal Society of Chemistry. Waste pulp residues are herein exploited for the synthesis of a sorbent for humic acid (HA), which is a major water pollutant. Cellulose pulp was etherified with a quaternary ammonium salt in water thereby introducing positive charges onto the surface of the pulp fibers, and subsequently mechanically disintegrated into high surface area cellulose nanofibers (CNF). CNF with three different charge contents were produced and their adsorption capacity towards HA was investigated with UV-spectrophotometry, quartz crystal microbalance with dissipation, and ζ-potential measurements. Substantial coverage of the CNF surface with HA in a wide pH range led to a reversal of the positive ζ-potentials of CNF suspensions. The HA adsorption capacity and the kinetics of HA uptake were found to be promoted by both acidic pH conditions and the surface charge content of CNF. It is suggested that HA adsorption onto CNF depends on electrostatic interactions between the two components, as well as on the conformation of HA. At pH ∼ 6, up to 310 mg g-1 of HA were adsorbed by the functionalized CNF, a substantially higher capacity than that of previously reported HA sorbents in the literature. It is further shown that CNF-HA complexes could be freeze-dried into "soil-mimicking" porous foams having good capacity to capture Cu(ii) ions and positive dyes from contaminated water. Thus, the most abundant natural polymer, i.e., cellulose could effectively bind the most abundant natural organic matter for environmental remediation purpose.

  12. Optimization of ATP synthase function in mitochondria and chloroplasts via the adenylate kinase equilibrium

    Abir U Igamberdiev

    2015-01-01

    Full Text Available The bulk of ATP synthesis in plants is performed by ATP synthase, the main bioenergetics engine of cells, operating both in mitochondria and in chloroplasts. The reaction mechanism of ATP synthase has been studied in detail for over half a century; however, its optimal performance depends also on the steady delivery of ATP synthase substrates and the removal of its products. For mitochondrial ATP synthase, we analyze here the provision of stable conditions for (i the supply of ADP and Mg2+, supported by adenylate kinase (AK equilibrium in the intermembrane space, (ii the supply of phosphate via membrane transporter in symport with H+, and (iii the conditions of outflow of ATP by adenylate transporter carrying out the exchange of free adenylates. We also show that, in chloroplasts, AK equilibrates adenylates and governs Mg2+ contents in the stroma, optimizing ATP synthase and Calvin cycle operation, and affecting the import of inorganic phosphate in exchange with triose phosphates. It is argued that chemiosmosis is not the sole component of ATP synthase performance, which also depends on AK-mediated equilibrium of adenylates and Mg2+, adenylate transport and phosphate release and supply.

  13. 1D iron(II) spin crossover complexes with 1,2,4-triazol-4-yl-propanoic acid

    Railliet, Antoine P.; Naik, Anil D. [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences (Belgium); Rotaru, Aurelian [' Stefan cel Mare' University, Department of Electrical Engineering and Computer Science (Romania); Marchand-Brynaert, Jacqueline; Garcia, Yann, E-mail: yann.garcia@uclouvain.be [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences (Belgium)

    2012-03-15

    A series of 1D coordination polymers [Fe(patrz){sub 3}]X{sub 2}{center_dot}solv, (patrz = 1,2,4-triazol-4-yl-propanoic acid; X = BF{sub 4{sup -}}, ClO{sub 4{sup -}}, Cl{sup - }, NO{sub 3}-bar and solv = MeOH or H{sub 2}O) were precipitated from methanol. Their spin crossover properties were studied by temperature dependent SQUID magnetometry and {sup 57}Fe Moessbauer spectroscopy, both for solvated and desolvated complexes. Compounds show gradual incomplete spin crossover with distinct thermochromism, in particular [Fe(patrz){sub 3}](BF{sub 4}){sub 2}{center_dot}MeOH, for which only 27% of Fe{sup II} ions are switched to the low-spin state at 77 K, as determined by a detailed {sup 57}Fe Moessbauer study. Other prominent features of this work are the interesting self assembly of 1D chain with exclusively triazole coordination from patrz ligand despite its ditopic nature and a hysteretic room temperature spin crossover in [Fe(patrz){sub 3}]Cl{sub 2}.

  14. Synthesis, Characterization, and Biological Activity Studies of Copper(II Mixed Compound with Histamine and Nalidixic Acid

    Egla Yareth Bivián-Castro

    2009-01-01

    Full Text Available A mixed copper complex with deprotonated nalidixic acid (nal and histamine (hsm was synthesized and characterized by FTIR, UV-Vis, elemental analysis, and conductivity. The crystal structure of [Cu(hsm(nalH2O]Cl·3H2O (chn showed a pentacoordinated cooper(II in a square pyramidal geometry surrounded by two N atoms from hsm, two O atoms from the quinolone, and one apical water oxygen. Alteration of bacterial DNA structure and/or associated functions in vivo by [Cu(hsm(nalH2O]Cl·3H2O was demonstrated by the induction of a recA-lacZ fusion integrated at the amyE locus of a recombinant Bacillus subtilis strain. Results from circular dichroism and denaturation of calf thymus DNA (CT-DNA suggested that increased amounts of copper complex were able to stabilize the double helix of DNA in vitro mainly by formation of hydrogen bonds between chn and the sugars of DNA minor groove. In vivo and in vitro biological activities of the chn complex were compared with the chemical nuclease [Cu(phen(nalH2O]NO3·3H2O (cpn where phen is phenanthroline.

  15. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing

    2013-10-01

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H2CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn5(μ3-OH)2(2,7-CDC)4(DEF)2] (1) (DEF=N,N-diethylformamide), [Zn2(2,7-CDC)2(DABCO)(H2O)]·5DMF·H2O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn2(2,7-CDC)2(bpea)]·3DMA·2 H2O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn5(μ3-OH)2(COO)8] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle-wheel [Zn2(COO)4] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle-wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied.

  16. SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A NOVEL Mg(II COMPLEX WITH 1,2-PHENYLENEDIOXYDIACETIC ACID

    XI-SHI TAI

    2014-11-01

    Full Text Available A novel Mg(II complex, [Mg(HL2•(H2O4]•4H2O•HCl (HL = 1,2-phenylenedioxydiacetato, has been synthesized by the reaction of 1,2-phenylenedioxydiacetic acid, NaOH and MgCl2•6H2O in one-pot. The compound was characterized by X-ray single crystal diffraction analysis. The crystal of the title complex belongs to monoclinic, space group Pn with a = 10.772(2 Å, b = 9.7145(19 Å, c = 13.996(3 Å, β = 104.32(3º, V = 1419.1(5 Å3, Z = 2, Dc = 1.498 μg•m-3, μ = 0.245 mm-1, F(000 = 658 and final R1 = 0.0653, ωR2 = 0.1913. The molecules are connected by π-π stacking to form three dimensional network structures.

  17. Radiometric determination of boron with mandelic acid and zinc-65-labelled bis(1,10-phenanthroline)zinc(II)

    The use of solvent extraction methods for the radiometric determination of boron is scarce. This work was undertaken to examine the feasibility of an indirect radiometric method for the determination of trace amounts of boron by solvent extraction. Mandelic acid was used as the complexing agent for boron and the complex anion formed was extracted as an ion associate with zinc-65-labelled bis(1,10-phenanthroline)zinc(II) into isobutyl methyl ketone. The activity of zinc in the organic layer was measured using an NaI-Tl well-type scintillation detector, and was a linear function of the concentration of boron in the aqueous phase over the range 0-10 μg in a final volume of 15 ml. A detection limit of 0.25 μg of boron in a 15 ml aqueous volume could be achieved. The interfering effect of various ions was overcome by selective distillation of boron as methyl borate. The method was applied to the determination of boron in Cr-Mo-B alloy, ointments, talcum powder and eye lotion samples. The reliability of the proposed method was checked by comparing the results obtained for the above samples with those given by ICP-AES. (author)

  18. Light-harvesting complexes in photosystem II regulate glutathione-induced sensitivity of Arabidopsis guard cells to abscisic acid.

    Jahan, Md Sarwar; Nozulaidi, Mohd; Khairi, Mohd; Mat, Nashriyah

    2016-05-20

    Light-harvesting complexes (LHCs) in photosystem II (PSII) regulate glutathione (GSH) functions in plants. To investigate whether LHCs control GSH biosynthesis that modifies guard cell abscisic acid (ABA) sensitivity, we evaluated GSH content, stomatal aperture, reactive oxygen species (ROS), weight loss and plant growth using a ch1-1 mutant that was defective of LHCs and compared this with wild-type (WT) Arabidopsis thaliana plants. Glutathione monoethyl ester (GSHmee) increased but 1-chloro-2,4 dinitrobenzene (CDNB) decreased the GSH content in the guard cells. The guard cells of the ch1-1 mutants accumulated significantly less GSH than the WT plants. The guard cells of the ch1-1 mutants also showed higher sensitivity to ABA than the WT plants. The CDNB treatment increased but the GSHmee treatment decreased the ABA sensitivity of the guard cells without affecting ABA-induced ROS production. Dark and light treatments altered the GSH content and stomatal aperture of the guard cells of ch1-1 and WT plants, irrespective of CDNB and GSHmee. The ch1-1 mutant contained fewer guard cells and displayed poor growth, late flowering and stumpy weight loss compared with the WT plants. This study suggests that defective LHCs reduced the GSH content in the guard cells and increased sensitivity to ABA, resulting in stomatal closure. PMID:26970687

  19. Mathematical modeling of cadmium(II) solvent extraction from neutral and acidic chloride media using Cyanex 923 extractant as a metal carrier

    This paper describes experimental work and the mathematical modeling of solvent extraction of cadmium(II) from neutral and acidic aqueous chloride media with a Cyanex 923 extractant in Exxol D-100. Solvent extraction experiments were carried out to analyze the influence of variations in the composition of the aqueous and organic phases on the efficiency of cadmium(II) extraction. In neutral and acidic chloride conditions, the extraction of cadmium(II) by the organophosphorous extractant Cyanex 923 (L) is based on the solvation mechanism of neutral HnCdCl(2+n) species and the formation of HnCdCl(2+n)Lq complexes in the organic phase, where n = 0, 1, 2 and q = 1, 2. The mathematical model of cadmium(II) extraction was derived from the mass balances and chemical equilibria involved in the separation system. The model was computed with the Matlab software. The equilibrium parameters for metal extraction, i.e. the stability constants of the aqueous Cd-Cl complexes, the formation constants of the acidic Cd-Cl species and the metal equilibrium extraction constants, were proposed. The optimized constants were appropriate, as there was good agreement when the model was fitted to the experimental data for each of the experiments.

  20. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu0.5L]n (1), [Cu(HL)2Cl2]n (2), [Cu(HL)2Cl2(H2O)] (3), [Cu(L)2(H2O)]n (4) and [Cu(L)(phen)(HCO2)]n (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl-, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units –Cu–O–Cu–O– are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated. - Graphical abstract: Copper(II) compounds with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid, were prepared, structurally characterized and investigated for antifungal activity. - Highlights: • The title compounds formed by thermodynamics and thermokinetics. • The five compounds show higher inhibition percentage than reactants. • The structure effect on the antifungal activity

  1. Reduction of Pertechnetate By Acetohydroxamic Acid: Formation of [tc**II(NO)(AHA)(2)(H(2)O)]**+ And Implications for the UREX Process

    Gong, C.-M.S.; Lukens, W.W.; Poineau, F.; Czerwinski, K.R.

    2009-05-18

    Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the X-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry and the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but it may be augmented by some products of the reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex ([Tc{sup II}(NO)(AHA){sub 2}H{sub 2}O]{sup +}, 1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent: potentiometric-spectrophotometric titration studies indicate a single species from pH 4 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The potential formation of 1 during reprocessing may strongly impact the fate of technetium in the nuclear fuel cycle.

  2. Distribution of callose synthase, cellulose synthase, and sucrose synthase in tobacco pollen tube is controlled in dissimilar ways by actin filaments and microtubules

    Cai, G.; Faleri, C.; Casino, C.; Emons, A.M.C.; Cresti, M.

    2011-01-01

    Callose and cellulose are fundamental components of the cell wall of pollen tubes and are probably synthesized by distinct enzymes, callose synthase and cellulose synthase, respectively. We examined the distribution of callose synthase and cellulose synthase in tobacco (Nicotiana tabacum) pollen tub

  3. Effect of gamma-aminobutyric acid B receptor on nitric oxide/nitric oxide synthase system during recurrent febrile seizures%反复热性惊厥过程中γ-氨基丁酸B受体对一氧化氮/一氧化氮合酶体系的调节作用

    韩颖; 秦炯; 卜定方; 杨志仙; 常杏芝; 杜军保

    2006-01-01

    目的:探讨γ-氨基丁酸B受体(γ-aminobutyric acid B receptor,GABABR)对热性惊厥(febrile seizure,FS)大鼠一氧化氮(nitric oxide,NO)/一氧化氮合酶(nitric oxide synthase,NOS)体系表达的影响.方法:将21 d龄SD大鼠随机分为对照组、FS组、FS+巴氯芬(baclofen)组和FS+法克罗芬(phaclofen)组.采用热水浴诱导大鼠FS,隔日诱导1次,共10次.采用分光光度计法测定大鼠血浆中NO含量;用原位杂交方法观察神经元型一氧化氮合酶(neuronal nitric oxide synthase,nNOS)mRNA表达情况;用免疫组化方法观察nNOS蛋白表达情况.结果:FS+baclofen组NO含量低于FS组[(19.02±9.31)μmol/L比(40.03±9.12)μmol/L],同时nNOS蛋白和mRNA表达也较FS组减弱;而FS+phaclofen组NO含量高于FS组[(66.46±8.15)μmol/L比(40.03±9.12)μmol/L],同时nNOS蛋白和mRNA表达也较FS组增强.结论:反复热性惊厥过程中,GABABR的改变可影响NO/NOS体系的表达.

  4. X-ray structure of 1D-coordination polymer of copperII bearing 1,4-pyrazine-2,3-dicarboxylic acid and 2-aminopyrimidine

    Mirzaei Masoud; Eshtiagh-Hosseini Hossein; Hassanpoor Azam; Barba Victor

    2012-01-01

    The new 1D-coordination polymer of CuII ion, {(2- apymH)2[Cu(pyzdc)2] .6H2O}n, (2-apym = 2-aminopyrimidine, pyzdcH2 = 1,4- pyrazine-2,3-dicarboxylic acid), was synthesized based on proton transfer mechanism and characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction. The coordination polymer consists of infinite anionic chains of [Cu(pyzdc)2]2- anion bridged crossing double chain running along a-axis and discrete (2-apymH)+ fragment. The CuII ion...

  5. Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey

    In situ hybridization histochemistry, using cRNA probes, revealed a complementarity in the distributions of cells in the basal ganglia, basal nucleus of Meynert, thalamus, hypothalamus, and rostral part of the midbrain that showed gene expression for glutamic acid decarboxylase (GAD) or the alpha-subunit of type II calcium-calmodulin-dependent protein kinase (CAM II kinase-alpha). Cells in certain nuclei such as the thalamic reticular nucleus, globus pallidus, and pars reticulata of the substantia nigra show GAD gene expression only; others in nuclei such as the basal nucleus of Meynert, medial mamillary nuclei, and ventromedial hypothalamic nuclei show CAM II kinase-alpha gene expression only. A few nuclei, for example, the pars compacta of the substantia nigra and the greater part of the subthalamic nucleus, display gene expression for neither GAD nor CAM II kinase-alpha. In other nuclei, notably those of the dorsal thalamus, and possibly in the striatum, GAD- and CAM II kinase-expressing cells appear to form two separate populations that, in most thalamic nuclei, together account for the total cell population. In situ hybridization reveals large amounts of CAM II kinase-alpha mRNA in the neuropil of most nuclei containing CAM II kinase-alpha-positive cells, suggesting its association with dendritic polyribosomes. The message may thus be translated at those sites, close to the synapses with which the protein is associated. The in situ hybridization results, coupled with those from immunocytochemical staining for CAM II kinase-alpha protein, indicate that CAM II kinase-alpha is commonly found in certain non-GABAergic afferent fiber systems but is not necessarily present in the postsynaptic cells on which they terminate. It appears to be absent from most GABAergic fiber systems but can be present in the cells on which they terminate

  6. 20-Hydroxyeicosatetraenoic acid contributes to the inhibition of K+ channel activity and vasoconstrictor response to angiotensin II in rat renal microvessels.

    Fan Fan

    Full Text Available The present study examined whether 20-hydroxyeicosatetraenoic acid (HETE contributes to the vasoconstrictor effect of angiotensin II (ANG II in renal microvessels by preventing activation of the large conductance Ca(2+-activated K(+ channel (KCa in vascular smooth muscle (VSM cells. ANG II increased the production of 20-HETE in rat renal microvessels. This response was attenuated by the 20-HETE synthesis inhibitors, 17-ODYA and HET0016, a phospholipase A2 inhibitor AACOF3, and the AT1 receptor blocker, Losartan, but not by the AT2 receptor blocker, PD123319. ANG II (10(-11 to 10(-6 M dose-dependently decreased the diameter of renal microvessels by 41 ± 5%. This effect was blocked by 17-ODYA. ANG II (10(-7 M did not alter KCa channel activity recorded from cell-attached patches on renal VSM cells under control conditions. However, it did reduce the NPo of the KCa channel by 93.4 ± 3.1% after the channels were activated by increasing intracellular calcium levels with ionomycin. The inhibitory effect of ANG II on KCa channel activity in the presence of ionomycin was attenuated by 17-ODYA, AACOF3, and the phospholipase C (PLC inhibitor U-73122. ANG II induced a peak followed by a steady-state increase in intracellular calcium concentration in renal VSM cells. 17-ODYA (10(-5 M had no effect on the peak response, but it blocked the steady-state increase. These results indicate that ANG II stimulates the formation of 20-HETE in rat renal microvessels via the AT1 receptor activation and that 20-HETE contributes to the vasoconstrictor response to ANG II by blocking activation of KCa channel and facilitating calcium entry.

  7. Properties of phosphorylated thymidylate synthase

    Frączyk, Tomasz; Ruman, Tomasz; Wilk, Piotr; Palmowski, Pawel; Rogowska-Wrzesinska, Adelina; Cieśla, Joanna; Zieliński, Zbigniew; Nizioł, Joanna; Jarmuła, Adam; Maj, Piotr; Gołos, Barbara; Wińska, Patrycja; Ostafil, Sylwia; Wałajtys-Rode, Elżbieta; Shugar, David; Rode, Wojciech

    2015-01-01

    Thymidylate synthase (TS) may undergo phosphorylation endogenously in mammalian cells, and as a recombinant protein expressed in bacterial cells, as indicated by the reaction of purified enzyme protein with Pro-Q® Diamond Phosphoprotein Gel Stain (PGS). With recombinant human, mouse, rat, Trichin......Thymidylate synthase (TS) may undergo phosphorylation endogenously in mammalian cells, and as a recombinant protein expressed in bacterial cells, as indicated by the reaction of purified enzyme protein with Pro-Q® Diamond Phosphoprotein Gel Stain (PGS). With recombinant human, mouse, rat......, Trichinella spiralis and Caenorhabditis elegans TSs, expressed in Escherichia coli, the phosphorylated, compared to non-phosphorylated recombinant enzyme forms, showed a decrease in Vmax(app), bound their cognate mRNA (only rat enzyme studied), and repressed translation of their own and several heterologous m......RNAs (human, rat and mouse enzymes studied). However, attempts to determine the modification site(s), whether endogenously expressed in mammalian cells, or recombinant proteins, did not lead to unequivocal results. Comparative ESI-MS/analysis of IEF fractions of TS preparations from parental and Fd...

  8. RNAi mediated down regulation of myo-inositol-3-phosphate synthase to generate low phytate rice

    Ali, Nusrat; Paul, Soumitra; Gayen, Dipak; Sarkar, Sailendra Nath; Datta, Swapan K.; Datta, Karabi

    2013-01-01

    Background Phytic acid (InsP6) is considered as the major source of phosphorus and inositol phosphates in cereal grains. Reduction of phytic acid level in cereal grains is desirable in view of its antinutrient properties to maximize mineral bioavailability and minimize the load of phosphorus waste management. We report here RNAi mediated seed-specific silencing of myo-inositol-3-phosphate synthase (MIPS) gene catalyzing the first step of phytic acid biosynthesis in rice. Moreover, we also stu...

  9. Translocation of the potato 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase into isolated spinach chloroplasts

    A cDNA for potato (Solanum tuberosum L.) 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase, the first enzyme of the shikimate pathway, encodes a 56 KD polypeptide whose amino terminus resembles a chloroplast transit sequence. The cDNA was placed downstream of the phage T7 polymerase recognition sequence in plasmid pGEM-3Z. DNA of the resulting plasmid pGEM-DWZ directed T7 polymerase to synthesize potato DAHP synthase mRNA in vitro. The mRNA was used in wheat germ and rabbit reticulocyte lysates for the synthesis of 35S-labeled pro-DAHP synthase. The predominant translation product is a 59 KD polypeptide that can be immunoprecipitated by rabbit polyclonal antibodies raised against the 53 KD DAHP synthase purified from potato tubers. Isolated spinach chloroplasts process the 59 KD pro-DAHP synthase to a 50 KD polypeptide. The processed polypeptide is protected from protease degradation, suggesting uptake of the enzyme into the cell organelle. Fractionation of reisolated chloroplasts after import of pro-DAHP synthase showed mature enzyme in the stroma. The uptake and processing of DAHP synthase is inhibited by antibodies raised against the mature enzyme. Our results are consistent with the assumption that potato contains a nuclear DNA encoded DAHP synthase that is synthesized as a proenzyme and whose mature form resides in the chloroplasts. Our data provide further evidence that green plants synthesize aromatic amino acids in plastids

  10. Translocation of the potato 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase into isolated spinach chloroplasts

    Zhao, Jianmin; Weaver, L.M.; Herrmann, K.M. (Purdue Univ., West Lafayette, IN (USA))

    1990-05-01

    A cDNA for potato (Solanum tuberosum L.) 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase, the first enzyme of the shikimate pathway, encodes a 56 KD polypeptide whose amino terminus resembles a chloroplast transit sequence. The cDNA was placed downstream of the phage T7 polymerase recognition sequence in plasmid pGEM-3Z. DNA of the resulting plasmid pGEM-DWZ directed T7 polymerase to synthesize potato DAHP synthase mRNA in vitro. The mRNA was used in wheat germ and rabbit reticulocyte lysates for the synthesis of {sup 35}S-labeled pro-DAHP synthase. The predominant translation product is a 59 KD polypeptide that can be immunoprecipitated by rabbit polyclonal antibodies raised against the 53 KD DAHP synthase purified from potato tubers. Isolated spinach chloroplasts process the 59 KD pro-DAHP synthase to a 50 KD polypeptide. The processed polypeptide is protected from protease degradation, suggesting uptake of the enzyme into the cell organelle. Fractionation of reisolated chloroplasts after import of pro-DAHP synthase showed mature enzyme in the stroma. The uptake and processing of DAHP synthase is inhibited by antibodies raised against the mature enzyme. Our results are consistent with the assumption that potato contains a nuclear DNA encoded DAHP synthase that is synthesized as a proenzyme and whose mature form resides in the chloroplasts. Our data provide further evidence that green plants synthesize aromatic amino acids in plastids.

  11. Nitric Oxide synthases and atrial fibrillation

    CynthiaAnnCarnes

    2012-04-01

    Full Text Available Oxidative stress has been implicated in the pathogenesis of atrial fibrillation. There are multiple systems in the myocardium which contribute to redox homeostasis, and loss of homeostasis can result in oxidative stress. Potential sources of oxidants include nitric oxide synthases, which normally produce nitric oxide in the heart. Two nitric oxide synthase isoforms (1 and 3 are normally expressed in the heart. During pathologies such as heart failure, there is induction of nitric oxide synthase 2 in multiple cell types in the myocardium. In certain conditions, the NOS enzymes may become uncoupled, shifting from production of nitric oxide to superoxide anion, a potent free radical and oxidant. Multiple lines of evidence suggest a role for nitric oxide synthases in the pathogenesis of atrial fibrillation. Therapeutic approaches to reduce atrial fibrillation by modulation of nitric oxide synthase activity may be beneficial, although further investigation of this strategy is needed.

  12. Mechanism of Germacradien-4-ol Synthase-Controlled Water Capture.

    Grundy, Daniel J; Chen, Mengbin; González, Verónica; Leoni, Stefano; Miller, David J; Christianson, David W; Allemann, Rudolf K

    2016-04-12

    The sesquiterpene synthase germacradiene-4-ol synthase (GdolS) from Streptomyces citricolor is one of only a few known high-fidelity terpene synthases that convert farnesyl diphosphate (FDP) into a single hydroxylated product. Crystals of unliganded GdolS-E248A diffracted to 1.50 Å and revealed a typical class 1 sesquiterpene synthase fold with the active site in an open conformation. The metal binding motifs were identified as D(80)DQFD and N(218)DVRSFAQE. Some bound water molecules were evident in the X-ray crystal structure, but none were obviously positioned to quench a putative final carbocation intermediate. Incubations in H2(18)O generated labeled product, confirming that the alcohol functionality arises from nucleophilic capture of the final carbocation by water originating from solution. Site-directed mutagenesis of amino acid residues from both within the metal binding motifs and without identified by sequence alignment with aristolochene synthase from Aspergillus terreus generated mostly functional germacradien-4-ol synthases. Only GdolS-N218Q generated radically different products (∼50% germacrene A), but no direct evidence of the mechanism of incorporation of water into the active site was obtained. Fluorinated FDP analogues 2F-FDP and 15,15,15-F3-FDP were potent noncompetitive inhibitors of GdolS. 12,13-DiF-FDP generated 12,13-(E)-β-farnesene upon being incubated with GdolS, suggesting stepwise formation of the germacryl cation during the catalytic cycle. Incubation of GdolS with [1-(2)H2]FDP and (R)-[1-(2)H]FDP demonstrated that following germacryl cation formation a [1,3]-hydride shift generates the final carbocation prior to nucleophilic capture. The stereochemistry of this shift is not defined, and the deuteron in the final product was scrambled. Because no clear candidate residue for binding of a nucleophilic water molecule in the active site and no significant perturbation of product distribution from the replacement of active site residues

  13. Synthesis of high molecular weight polylactic acid from aqueous lactic acid co-catalyzed by tin(II)chloride dihydrate and succinic anhydride

    LEI Ziqiang; BAI Yanbin; WANG Shoufeng

    2005-01-01

    Polylactic acid was synthesized from commercial available cheap aqueous lactic acid (85%―90% w/w) using succinic anhydride and SnCl2·2H2O as catalyst in the absence of organic solvents. As a result, polylactic acid with a molecular weight of 60000 was prepared in 10 h. The new procedure is much simple, cheap and outstanding in that the start material is aqueous lactic acid; the catalytic system is environmentally benign.

  14. Plant cell wall imaging by metabolic click-mediated labelling of rhamnogalacturonan II using azido 3-deoxy-d-manno-oct-2-ulosonic acid.

    Dumont, Marie; Lehner, Arnaud; Vauzeilles, Boris; Malassis, Julien; Marchant, Alan; Smyth, Kevin; Linclau, Bruno; Baron, Aurélie; Mas Pons, Jordi; Anderson, Charles T; Schapman, Damien; Galas, Ludovic; Mollet, Jean-Claude; Lerouge, Patrice

    2016-02-01

    In plants, 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) is a monosaccharide that is only found in the cell wall pectin, rhamnogalacturonan-II (RG-II). Incubation of 4-day-old light-grown Arabidopsis seedlings or tobacco BY-2 cells with 8-azido 8-deoxy Kdo (Kdo-N3 ) followed by coupling to an alkyne-containing fluorescent probe resulted in the specific in muro labelling of RG-II through a copper-catalysed azide-alkyne cycloaddition reaction. CMP-Kdo synthetase inhibition and competition assays showing that Kdo and D-Ara, a precursor of Kdo, but not L-Ara, inhibit incorporation of Kdo-N3 demonstrated that incorporation of Kdo-N3 occurs in RG-II through the endogenous biosynthetic machinery of the cell. Co-localisation of Kdo-N3 labelling with the cellulose-binding dye calcofluor white demonstrated that RG-II exists throughout the primary cell wall. Additionally, after incubating plants with Kdo-N3 and an alkynated derivative of L-fucose that incorporates into rhamnogalacturonan I, co-localised fluorescence was observed in the cell wall in the elongation zone of the root. Finally, pulse labelling experiments demonstrated that metabolic click-mediated labelling with Kdo-N3 provides an efficient method to study the synthesis and redistribution of RG-II during root growth. PMID:26676799

  15. Crystal structure of 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase from the ESKAPE pathogen Acinetobacter baumannii.

    Sutton, Kristin A; Breen, Jennifer; Russo, Thomas A; Schultz, L Wayne; Umland, Timothy C

    2016-03-01

    The enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase catalyzes the sixth step of the seven-step shikimate pathway. Chorismate, the product of the pathway, is a precursor for the biosynthesis of aromatic amino acids, siderophores and metabolites such as folate, ubiquinone and vitamin K. The shikimate pathway is present in bacteria, fungi, algae, plants and apicomplexan parasites, but is absent in humans. The EPSP synthase enzyme produces 5-enolpyruvylshikimate 3-phosphate and phosphate from phosphoenolpyruvate and shikimate 3-phosphate via a transferase reaction, and is the target of the herbicide glyphosate. The Acinetobacter baumannii gene encoding EPSP synthase, aroA, has previously been demonstrated to be essential during host infection for the growth and survival of this clinically important drug-resistant ESKAPE pathogen. Prephenate dehydrogenase is also encoded by the bifunctional A. baumannii aroA gene, but its activity is dependent upon EPSP synthase since it operates downstream of the shikimate pathway. As part of an effort to evaluate new antimicrobial targets, recombinant A. baumannii EPSP (AbEPSP) synthase, comprising residues Ala301-Gln756 of the aroA gene product, was overexpressed in Escherichia coli, purified and crystallized. The crystal structure, determined to 2.37 Å resolution, is described in the context of a potential antimicrobial target and in comparison to EPSP synthases that are resistant or sensitive to the herbicide glyphosate. PMID:26919521

  16. Product Variability of the ‘Cineole Cassette'Monoterpene Synthases of Related Nicotiana Species

    Anke F(a)hnrich; Katrin Krause; Birgit Piechulla

    2011-01-01

    Nicotiana species of the section Alatae characteristically emit the floral scent compounds of the ‘cineole cassere' comprising 1,8-cineole,limonene,myrcene,α-pinene,β-pinene,sabinene,and α-terpineol.We successfully isolated genes of Nicotiana alata and Nicotiana langsdorfii that encoded enzymes,which produced the characteristic monoterpenes of this ‘cineole cassette' with α-terpineol being most abundant in the volatile spectra.The amino acid sequences of both terpineol synthases were 99% identical.The enzymes cluster in a monophyletic branch together with the closely related cineole synthase of Nicotiana suaveolens and monoterpene synthase 1 of Solanum lycopersicum.The cyclization reactions (α-terpineol to 1,8-cineole) of the terpineol synthases of N.alata and N.langsdorfii were less efficient compared to the ‘cineole cassette′ monoterpene synthases of Arabidopsis thaliana,N.suaveolens,Salvia fruticosa,Salvia officinalis,and Citrus unshiu.The terpineol synthases of N.alata and N.langsdorfii were localized in pistils and in the adaxial and abaxial epidermis of the petals.The enzyme activities reached their maxima at the second day after anthesis when flowers were fully opened and the enzyme activity in N.alata was highest at the transition from day to night (diurnal rhythm).

  17. Molecular Cloning and Bacterial Expression of Germacrene A Synthase cDNA from Crepidiastrum sonchifolium

    2006-01-01

    Germacrene A synthase(GAS) catalyzes the biosynthesis of germacrene A, which is a key precursor for sesquiterpene lactones. Cloning of a novel full-length cDNA encoding GAS from the medicinal plant Crepidiastrum sonchifolium(designated CsGAS) is reported in this study. The cDNA is 1837 bp long and contains a 1680-bp open reading frame encoding a 559 amino-acid protein. The functional expression of the cDNA in Escherichia coli, as an N-terminal thioredoxin fusion protein, with the pET32a vector yielding a recombinant enzyme. Sequence analysis was used to compare this enzyme with the mechanistically related epi-aristolochene synthase from tobacco, and the effect of possible involvement of a number of amino acids in sesquiterpene synthase on product specificity was also discussed.

  18. Modified cellulose synthase gene from Arabidopsis thaliana confers herbicide resistance to plants

    Somerville, Chris R.; Scheible, Wolf

    2007-07-10

    Cellulose synthase ("CS"), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl)phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  19. SORPTION OF Cu(II) BY POLY(HYDROXAMIC ACID) CHELATING EXCHANGER PREPARED FROM POL(YMETHYL ACRYLATE) GRAFTED OIL PALM EMPTY FRUIT BUNCH (OPEFB)

    Md Jelas Haron; Mariati Tiansih; Nor Azowa Ibrahim; Anuar Kassim; W. M. Z. Wan Yunus

    2009-01-01

    This paper describes the preparation of chemically modified oil palm empty fruit bunch (OPEFB) with hydroxamic acid functional group and its use for the sorption of Cu(II) from aqueous solution. OPEFB was grafted with poly(methylacrylate) (PMA), using H2O2/Fe2+ as initiator. The PMA grafted OPEFB (PMA-OPEFB) was treated with hydroxylammonium chloride in alkaline medium to produce hydroxamic acid grafted fiber (PHA-OPEFB). The FTIR spectrum of OPEFB grafted with PMA showed an intense absorpt...

  20. O/sub 2/-binding abilities and catalytic oxidation performance of cobalt (II) complexes with dihydroxamic acid functionalized n-pivot lariat ethers

    The oxygenation constants (InKO/sub 2/) and thermodynamic parameter (∇H degree, ∇S degree) of Novel Co (II) complexes with dihydroxamic acids functionalized N-pivot lariat ether CoL/sup 1/∼CoL/sup 4/ and the uncrowned analogue CoL/sup 5/ were measured. Their catalytic performance in oxidation of ρ-xylene to p-toluic acid (PTA) was investigated. The enhancement of O/sub 2/-binding and catalytic oxidation activities by the oxa aza crown ether ring of the cobalt complexes as well as the complexed alkali metal and alkaline-earth metal ions were discussed. (author)

  1. Structural analysis of site-directed mutants of cellular retinoic acid-binding protein II addresses the relationship between structural integrity and ligand binding

    Vaezeslami, Soheila [Rigaku Americas Corporation, 9009 New Trails Drive, The Woodlands, TX 77381 (United States); Jia, Xiaofei; Vasileiou, Chrysoula; Borhan, Babak; Geiger, James H., E-mail: geiger@chemistry.msu.edu [Chemistry Department, Michigan State University, East Lansing, MI 48824-1322 (United States); Rigaku Americas Corporation, 9009 New Trails Drive, The Woodlands, TX 77381 (United States)

    2008-12-01

    A water network stabilizes the structure of cellular retionic acid binding protein II. The structural integrity of cellular retinoic acid-binding protein II (CRABPII) has been investigated using the crystal structures of CRABPII mutants. The overall fold was well maintained by these CRABPII mutants, each of which carried multiple different mutations. A water-mediated network is found to be present across the large binding cavity, extending from Arg111 deep inside the cavity to the α2 helix at its entrance. This chain of interactions acts as a ‘pillar’ that maintains the integrity of the protein. The disruption of the water network upon loss of Arg111 leads to decreased structural integrity of the protein. A water-mediated network can be re-established by introducing the hydrophilic Glu121 inside the cavity, which results in a rigid protein with the α2 helix adopting an altered conformation compared with wild-type CRABPII.

  2. X-ray structure of 1D-coordination polymer of copperII bearing 1,4-pyrazine-2,3-dicarboxylic acid and 2-aminopyrimidine

    Mirzaei Masoud

    2012-01-01

    Full Text Available The new 1D-coordination polymer of CuII ion, {(2- apymH2[Cu(pyzdc2] .6H2O}n, (2-apym = 2-aminopyrimidine, pyzdcH2 = 1,4- pyrazine-2,3-dicarboxylic acid, was synthesized based on proton transfer mechanism and characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction. The coordination polymer consists of infinite anionic chains of [Cu(pyzdc2]2- anion bridged crossing double chain running along a-axis and discrete (2-apymH+ fragment. The CuII ion is located on inversion centre in the basal plane of an elongated octahedron and two oxygen atoms from adjacent (pyzdc2-ligands occupy axial position. The interaction between oxygen atoms of water molecules along with the dicarboxylic acid play an important role in the overall supramolecular assembly.

  3. Chiral Zn(II-Bisamidine Complex as a Lewis-Brønsted Combined Acid Catalyst: Application to Asymmetric Mukaiyama Aldol Reactions of α-Ketoesters

    Ryo Gotoh

    2012-07-01

    Full Text Available Focusing on the steric and electronic properties of the resonance-stabilized amidine framework, a cationic metal-bisamidine complex was designed as a conjugated combined Lewis-Brønsted acid catalyst. The chiral Zn(II-bisamidine catalyst prepared from the 2,2'-bipyridyl derived bisamidine ligand, ZnCl2, and AgSbF6 promoted asymmetric Mukaiyama aldol reaction of α-ketoester and α,α-disubstituted silyl enol ether to afford the α-hydroxyester having sequential quarternary carbons in good yield, albeit with low enantioselectivity. Addition of 1.0 equivalent of the fluoroalcohol having suitable acidity and bulkiness dramatically increased the enantioselectivity (up to 68% ee. DFT calculations suggested that this additive effect would be caused by self-assembly of the fluoroalcohol on the Zn(II-bisamidine catalyst.

  4. Corn oil or corn grain supplementation to steers grazing endophyte-free tall fescue. II. Effects on subcutaneous fatty acid content and lipogenic gene expression.

    Duckett, S K; Pratt, S L; Pavan, E

    2009-03-01

    Twenty-eight Angus steers (289 kg) were finished on a high-concentrate diet (85% concentrate: 15% roughage; CONC), or endophyte-free tall fescue pastures with corn grain supplement (0.52% of BW; PC), corn oil plus soybean hull supplement (0.10% of BW corn oil plus 0.45% of BW soybean hulls; PO), or no supplement (pasture only; PA). Subcutaneous adipose tissues were processed for total cellular RNA extraction and fatty acid composition by GLC. Relative expression of genes involved in lipogenesis [fatty acid synthase (FASN), acetyl-CoA carboxylase, lipoprotein lipase, stearoyl-CoA desaturase (SCD)] and activators of transcription [(peroxisome proliferator-activated receptor-gamma), C/EBPalpha, sterol regulatory binding protein-1, signal transducer and activator of transcription-5, and Spot-14] was determined by real-time quantitative PCR. Housekeeping gene (glyceraldehyde 3-phosphate dehydrogenase and beta-actin) expression was used in analysis to normalize expression data. Total fatty acid content was greatest (P Corn grain supplementation increased (P 0.05) between PO and PA. Corn oil supplementation increased (P Corn grain supplementation to grazing steers did not alter (P > 0.05) the cis-9, trans-11 CLA isomer compared with PA. Oil supplementation increased (P < 0.001) linoleic acid (C18:2) content by 56, 98 and 262% compared with CONC, PC, and PA, respectively. Relative mRNA expression of SCD was upregulated (P < 0.001) by 46-, 18- and 7-fold, respectively, for CONC, PC, and PO compared with PA. Relative FASN mRNA expression was also upregulated (P = 0.004) by 9- and 5-fold, respectively, for CONC and PC compared with PA. Grain feeding, either on CONC or supplemented on pasture, upregulated FASN and SCD mRNA to increase MUFA and de novo fatty acids in subcutaneous adipose tissue. Upregulation of SCD with grain feeding and reduced tissue CLA concentrations suggest that the decreased CLA concentrations were the result of limited substrate (trans-11 vaccenic acid

  5. Structures and spectroscopic properties of Ni(II) and Mn(II) complexes based on 5-(3‧, 5‧-dicarboxylphenyl) picolinic acid ligand

    Ma, Qi; Song, Jin-Ping; Su, Feng; Guo, Jun-Mei; Guo, Yong; Dong, Chuan

    2016-05-01

    Two novel complexes including [Ni(Hdcppa)(H2O)4] (1) and {[Mn3(dcppa)2(H2O)6]·2H2O}n (2) have been synthesized and characterized by single crystal X-ray structure analysis and elemental analysis. Results show that 1 is a mononuclear nickel(II) compound with octahedron coordination geometry, while 2 is a stairs-like 2D layer structure consisting of the trinuclear MnII units linked through dcppa3-. Spectroscopic and electrochemical properties of the complexes 1-2 have also been studied in dimethyl sulfoxide solution at room temperature.

  6. [Effect of Zn(II) on microbial activity in anaerobic acid mine drainage treatment system with biomass as carbon source].

    Li, Shao-Jie; Chen, Tian-Hu; Zhou, Yue-Fei; Yue, Zheng-Bo; Jin, Jiez; Liu, Chang

    2012-01-01

    In this study, with rape straw as carbon source, anaerobic batch experiments were executed to investigate the effect of Zn (II) on the activity of sulphate reducing bacteria (SRB) in the microbial treatment of simulative acid mine drainage (AMD). The results showed that during the 60 experimental days, when initial Zn2+ concentrations were in the range of 73.7 to 196.8 mg x L(-1), SRB had high culturalbility. At the end of these experiments, pH values rose from initial 5.0 to neutral, about 96% of sulphate was reduced and the concentrations of Zn2+ reduced to 0.05 mg x L(-1). The results of Tessier sequential extraction, field emission scanning electron microscope (FE-SEM) and X-ray diffraction(XRD) showed that Zn was found to be fixed through forming organic and sulphide (mainly sphalerite) compounds. For the experiment with high Zn2+ concentration (262.97 mg x L(-1)), at the end of experiments, pH values dropped from initial 5.0 to 4.0, only 27% of sulphate was only reduced and the concentrations of Zn2+ kept in high range (25 mg x L(-1)), the activity of SRB significantly inhibited. This study indicated that: (1) Rape straw can be used as slow-release carbon source for long-term anaerobic AMD treatment; (2) Rape straw can decrease the toxicity of Zn2+ to SRB through adsorption; (3) In anaerobic AMD treatment system, Zn can be fixed by sulphide minerals with mediation of SRB. PMID:22452225

  7. N,N-Diethylamine appended binuclear Zn(ii) complexes: highly selective and sensitive fluorescent chemosensors for picric acid.

    Kumar, Amit; Kumar, Ashish; Pandey, Daya Shankar

    2016-05-28

    Novel binuclear Zn(ii) complexes (1-2) derived from bis-chelating salen type ligands (H2L(1) and H2L(2)) possessing N,N-diethylamine moieties on the periphery of the molecules have been synthesized and thoroughly characterized by satisfactory elemental analyses and spectral (FT-IR, (1)H, (13)C NMR, UV-vis, fluorescence and ESI-MS) studies. The structures of H2L(1) and 1 have been authenticated by single crystal X-ray diffraction analyses. Complexes 1 and 2 strongly fluoresce and act as highly selective and sensitive chemosensors for picric acid in different organic as well as aqueous media. Both 1 and 2 showed strong potential to detect traces of PA in vapour/solid phase through contact mode analysis. Spectral and theoretical (DFT) studies suggested that the observed fluorescence quenching may be associated with ground state (GS) charge transfer as well as electrostatic interactions between 1/2 and PA. The fluorescence lifetime for the representative complex 1 displayed a double exponential curve and unaltered lifetime (τav, 0.63 nm) in the absence and presence of PA and strongly suggested that quenching follows a static mechanism. Further, DFT calculations on 1 and 2 strongly supported the static mechanism through GS charge transfer between complexes and PA. In addition, (1)H NMR spectral studies on 1-2 in the presence of PA firmly advocated strong hydrogen bonding and π-π stacking between the phenolic rings of 1-2 and the aromatic ring of PA. These complexes are capable of detecting PA either individually or in a competitive environment of other nitro- explosives. Florescence spectral studies on the model complex M lacking N,N-diethylamine groups revealed moderate selectivity and sensitivity towards PA and supported the key role of N,N-diethylamine moieties in the selectivity and sensitivity of complexes. PMID:27114325

  8. Sorption of Ni(II) on GMZ bentonite: Effects of pH, ionic strength, foreign ions, humic acid and temperature

    Bentonite has been widely studied in nuclear waste management because of its special physicochemical properties. In this work, the sorption of Ni(II) from aqueous solution onto GMZ bentonite as a function of contact time, pH, ionic strength, foreign ions, humic acid (HA) and temperature was investigated under ambient conditions. The results indicated that the pseudo-second-order rate equation simulated the kinetic sorption process well. The sorption of Ni(II) on GMZ bentonite was strongly dependent on pH and on ionic strength. At low pH, the sorption of Ni(II) was dominated by outer-sphere surface complexation and ion exchange with Na+/H+ on GMZ bentonite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. A positive effect of HA on Ni(II) sorption was found at pH8. The Langmuir, Freundlich, and D-R models were used to simulate the sorption isotherms of Ni(II) at three different temperatures: 303.15, 318.15 and 333.15 K. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) of Ni(II) sorption on GMZ bentonite at the three different temperatures were calculated from the temperature-dependent sorption isotherms. The results indicated that the sorption process of Ni(II) on GMZ bentonite was endothermic and spontaneous. Experimental results indicate that GMZ bentonite is a suitable sorbent for pre-concentration and solidification of Ni(II) from large volume solutions.

  9. Palladium(II)-catalyzed oxidation of L-tryptophan by hexacyanoferrate(III) in perchloric acid medium: a kinetic and mechanistic approach

    Ahmed Fawzy

    2016-02-01

    The catalytic effect of palladium(II) on the oxidation of L-tryptophan by potassium hexacyanoferrate( III) has been investigated spectrophotometrically in aqueous perchloric acid medium. A first order dependence in [hexacyanoferrate(III)] and fractional-first order dependences in both [L-tryptophan] and [palladium(II)] were obtained. The reaction exhibits fractional-second order kinetics with respect to [H+]. Reaction rate increased with increase in ionic strength and dielectric constant of the medium. The effect of temperature on the reaction rate has also been studied and activation parameters have been evaluated and discussed. Initial addition of the reaction product, hexacyanoferrate(II), does not affect the rate significantly. A plausible mechanistic scheme explaining all the observed kinetic results has been proposed. The final oxidation products are identified as indole-3-acetaldehyde, ammonium ion and carbon dioxide. The rate law associated with the reaction mechanism is derived.

  10. Construction of two Cd(II) complexes by flexible adipic acid plus 2-((benzoimidazol-yl)methyl)-1H-tetrazole ligand

    Duan, Wanlu; Zhang, Yuhong; Wang, Xiuxiu; Meng, Xiangru

    2015-10-01

    Two new complexes with the formulas [Cd(bimt)(adi)]n (1) and {[Cd(bimt)(adi)0.5Br]·H2O}n (2) were synthesized through reactions of 2-((benzoimidazol-yl)methyl)-1H-tetrazole (bimt) with Cd(II) salts in the presence of adipic acid (H2adi). Single crystal X-ray analysis reveals that complex 1 shows a 1D chain structure in which adipate ligand coordinates to Cd(II) ions with μ3-bridging mode. Complex 2 displays a 2D layer structure with 4-connected (44·62) topology in which adipate ligand coordinates to Cd(II) ions with μ2-bridging mode. These results reveal that the versatile coordination modes of adipate ligands play an important role in controlling the structures of the complexes. In addition, their IR spectra, element analyses, PXRD patterns and luminescent properties are investigated.

  11. A nano-structured Ni(II)–chelidamic acid modified gold nanoparticle self-assembled electrode for electrocatalytic oxidation and determination of methanol

    A nano-structured Ni(II)–chelidamic acid (2,6-dicarboxy-4-hydroxypyridine) film was electrodeposited on a gold nanoparticle–cysteine–gold electrode. The morphology of Ni(II)–chelidamic acid gold nanoparticle self‐assembled electrode was investigated by scanning electron microscopy (SEM). Electrocatalytic oxidation of methanol on the surface of modified electrode was studied by cyclic voltammetry and chronoamperometry methods. The hydrodynamic amperometry at a rotating modified electrode at constant potential versus reference electrode was used for detection of methanol. Under optimized conditions the calibration plots are linear in the concentration range 0–50 mM with a detection limit of 15 μM. The formed matrix in our work possessed a 3D porous network structure with a large effective surface area, high catalytic activity and behaved like microelectrode ensembles. The modified electrode indicated reproducible behavior and a high level stability during the experiments, making it particularly suitable for analytical purposes. - Highlights: ► The Au electrode modified with thin Ni(II)/CHE-AuNP film shows stable and reproducible behavior. ► Long stability and excellent electrochemical reversibility were observed. ► This modified electrode shows excellent catalytic activity for methanol oxidation. ► Combination of unique properties of AuNP and Ni(II)/CHE resulted in improvement of current responses.

  12. Syntheses, structures, and properties of Co(II)/Zn(II) mixed-ligand coordination polymers based on 4-[(3,5-dinitrobenzoyl)amino]benzoic acid and 1,4-bis(1-imidazolyl) benzene

    Two coordination polymers [Co(dnbab)2(bimb)](H2O)4 (1) and [Zn(dnbab)2(bimb)](H2O)5 (2) (Hdnbab=4-[(3,5-dinitrobenzoyl)amino]benzoic acid, bimb=1,4-bis(1-imidazolyl) benzene) have been solvothermally synthesized. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complexes 1 and 2 are isostructures and each displays an one-dimensional (1D) zigzag chain, which further forms a 3D supramolecular architecture with 1-D channels via inter-chain π–π interactions and hydrogen bonds. Moreover, the magnetic properties of 1 and fluorescent properties of 2 have been investigated. - Graphical abstract: Two coordination supramolecular frameworks [Co(dnbab)2(bimb)](H2O)4(1) and [Zn(dnbab)2(bimb)](H2O)5(2) (Hdnbab=4-[(3,5-dinitrobenzoyl)amino]benzoic acid, bimb=1,4-bis(1-imidazolyl) benzene) have been synthesized and characterized by X-ray single-crystal diffraction. Their thermal, magnetic and fluorescent properties have also been studied. - Highlights: • Two isomorphic Co(II)/Zn(II) complexes with the mixed-ligands have been synthesized. • Hydrogen bonds and π–π stacking interactions directed the final 3-D architecture assembly. • Both Co(II) and Zn(II) complexes show good thermal stability. • Co complex exhibits antiferromagnetic interaction. • The fluorescent property of Zn(II) complex has been investigated in the solid state

  13. Syntheses, structures, and properties of Co(II)/Zn(II) mixed-ligand coordination polymers based on 4-[(3,5-dinitrobenzoyl)amino]benzoic acid and 1,4-bis(1-imidazolyl) benzene

    Yin, Fei; Chen, Jing; Liang, Yongfeng [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018 (China); Zou, Yang, E-mail: zouyang@zstu.edu.cn [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018 (China); Yinzhi, Jiang [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018 (China); Xie, Jingli, E-mail: jlxie@mail.zjxu.edu.cn [College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing, Zhejiang 314001 (China)

    2015-05-15

    Two coordination polymers [Co(dnbab){sub 2}(bimb)](H{sub 2}O){sub 4} (1) and [Zn(dnbab){sub 2}(bimb)](H{sub 2}O){sub 5} (2) (Hdnbab=4-[(3,5-dinitrobenzoyl)amino]benzoic acid, bimb=1,4-bis(1-imidazolyl) benzene) have been solvothermally synthesized. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complexes 1 and 2 are isostructures and each displays an one-dimensional (1D) zigzag chain, which further forms a 3D supramolecular architecture with 1-D channels via inter-chain π–π interactions and hydrogen bonds. Moreover, the magnetic properties of 1 and fluorescent properties of 2 have been investigated. - Graphical abstract: Two coordination supramolecular frameworks [Co(dnbab){sub 2}(bimb)](H{sub 2}O){sub 4}(1) and [Zn(dnbab){sub 2}(bimb)](H{sub 2}O){sub 5}(2) (Hdnbab=4-[(3,5-dinitrobenzoyl)amino]benzoic acid, bimb=1,4-bis(1-imidazolyl) benzene) have been synthesized and characterized by X-ray single-crystal diffraction. Their thermal, magnetic and fluorescent properties have also been studied. - Highlights: • Two isomorphic Co(II)/Zn(II) complexes with the mixed-ligands have been synthesized. • Hydrogen bonds and π–π stacking interactions directed the final 3-D architecture assembly. • Both Co(II) and Zn(II) complexes show good thermal stability. • Co complex exhibits antiferromagnetic interaction. • The fluorescent property of Zn(II) complex has been investigated in the solid state.

  14. SORPTION OF Cu(II BY POLY(HYDROXAMIC ACID CHELATING EXCHANGER PREPARED FROM POL(YMETHYL ACRYLATE GRAFTED OIL PALM EMPTY FRUIT BUNCH (OPEFB

    Md Jelas Haron

    2009-11-01

    Full Text Available This paper describes the preparation of chemically modified oil palm empty fruit bunch (OPEFB with hydroxamic acid functional group and its use for the sorption of Cu(II from aqueous solution. OPEFB was grafted with poly(methylacrylate (PMA, using H2O2/Fe2+ as initiator. The PMA grafted OPEFB (PMA-OPEFB was treated with hydroxylammonium chloride in alkaline medium to produce hydroxamic acid grafted fiber (PHA-OPEFB. The FTIR spectrum of OPEFB grafted with PMA showed an intense absorption band at 1734 cm-1 which is attributed to C=O vibration in the grafted ester. After hydroxylamine treatment, the intensity of absorption band at 1734 cm-1 decreased and new bands appeared at the 1640 cm-1 related to C=O vibration in hydroxamic acid and at the 1568 cm-1 related to the N-H amide. Sorption of Cu(II by PHA-OPEFB was effective over a pH range of 4 to 6. The sorption followed the Langmuir model with maximum capacities of 74.1 mg g-1 at 25 °C. The sorption process was exothermic, as shown by the negative value of enthalpy change, H. The free energy change (G for the sorption was negative, showing that the sorption process was spontaneous. A kinetic study showed that the Cu(II sorption followed a second order kinetic model.

  15. Auxiliary aromatic-acid effect on the structures of a series of ZnII coordination polymers: Syntheses, crystal structures, and photoluminescence properties

    Five novel ZnII-(pyridyl)imidazole derivative coordination polymers, [Zn(L)2] (1), [Zn2(μ3-OH)L(m-BDC)] (2), [Zn2(μ3-OH)L(p-BDC)].H2O (3), [Zn2L(BTC)(H2O)].2.5H2O (4) and [Zn3.5(μ3-OH)L2(BTEC)(H2O)].H2O (5) (L=4-((2-(pyridine-2-yl)-1H-imidazol-1-yl)methyl)benzoic acid, p-H2BDC=1,4-benzenedicarboxylic acid, m-H2BDC=1,3-benzenedicarboxylic acid, H3BTC=1,3,5-benzenetricarboxylic acid, H4BTEC=1,2,4,5-benzenetetracarboxylic acid), were successfully synthesized under hydrothermal conditions through varying auxiliary aromatic-acid ligands and structurally characterized by X-ray crystallography. Compound 1 exhibits a 1D chain linked via double L bridges. Compound 2 features a well-known pcu topology with bent dicarboxylate ligand (m-H2BDC) as an auxiliary ligand, while 3 displays a bcu network with linear dicarboxylate ligand (p-H2BDC) as an auxiliary ligand. The structure of compound 4 is a novel 3D (3,5)-connected network with (4.62)(4.64.82.10.122) topology. It is interesting that compound 5 shows an intricate (3,4,8)-connected framework with (4.62)(42.63.8)(42.64)(42.618.7.86.10) topology. In addition, their infrared spectra (IR), X-ray powder diffraction (XPRD) and photoluminescent properties were also investigated in detail. - Graphical abstract: Five novel ZnII-organic architectures have been hydrothermally synthesized through varying auxiliary aromatic-acid ligands and characterized by X-ray diffraction, the photoluminescence properties of compounds 1-5 were studied.

  16. Crystal structure of riboflavin synthase

    Liao, D.-I.; Wawrzak, Z.; Calabrese, J.C.; Viitanen, P.V.; Jordan, D.B. (DuPont); (NWU)

    2010-03-05

    Riboflavin synthase catalyzes the dismutation of two molecules of 6,7-dimethyl-8-(1'-D-ribityl)-lumazine to yield riboflavin and 4-ribitylamino-5-amino-2,6-dihydroxypyrimidine. The homotrimer of 23 kDa subunits has no cofactor requirements for catalysis. The enzyme is nonexistent in humans and is an attractive target for antimicrobial agents of organisms whose pathogenicity depends on their ability to biosynthesize riboflavin. The first three-dimensional structure of the enzyme was determined at 2.0 {angstrom} resolution using the multiwavelength anomalous diffraction (MAD) method on the Escherichia coli protein containing selenomethionine residues. The homotrimer consists of an asymmetric assembly of monomers, each of which comprises two similar {beta} barrels and a C-terminal {alpha} helix. The similar {beta} barrels within the monomer confirm a prediction of pseudo two-fold symmetry that is inferred from the sequence similarity between the two halves of the protein. The {beta} barrels closely resemble folds found in phthalate dioxygenase reductase and other flavoproteins. The three active sites of the trimer are proposed to lie between pairs of monomers in which residues conserved among species reside, including two Asp-His-Ser triads and dyads of Cys-Ser and His-Thr. The proposed active sites are located where FMN (an analog of riboflavin) is modeled from an overlay of the {beta} barrels of phthalate dioxygenase reductase and riboflavin synthase. In the trimer, one active site is formed, and the other two active sites are wide open and exposed to solvent. The nature of the trimer configuration suggests that only one active site can be formed and be catalytically competent at a time.

  17. Analysis of free amino acids in green coffee beans. II. Changes of the amino acid content in arabica coffees in connection with post-harvest model treatment.

    Arnold, U; Ludwig, E

    1996-10-01

    To investigate amino acid changes in green coffee beans in the post-harvest period, amino acid concentrations were determined in green beans and after modelled drying, fermentation and storage. After the drying at alternating temperatures up to maximally 40 degrees C, considerable changes in the concentrations of individual amino acids were identified. At the beginning of the storage period, significant changes in concentration were found to a minor extent. Under the condition of drying, it was mainly the concentration of glutamic acid that changed considerably. There was an increase in all the samples by 500 mg/kg dry matter on average, which corresponds to an increase of about 50% of the original value. In contrast, the concentration of aspartic acid in most of the samples decreased clearly due to drying. For the predominant part of the coffee samples, there was a significant increase in the hydrophobic amino acids Val, Phe, Ile and Leu. Changes of the quantities of other amino acids were non-uniform and only insignificant. Constant drying at 80 degrees C for most of the amino acids brought about only minor concentration changes compared to those values obtained at 40 degrees C. Modelled fermentation had no significant effect on the concentrations of the individual amino acids. After a 4-week storage of dried beans, amino acid concentrations did not change further. It is very possible that different post-harvest treatment parameters may influence the amount of aroma precursor compounds in the coffee beans. PMID:9123976

  18. Metal based pharmacologically active agents: Synthesis, structural characterization, molecular modeling, CT-DNA binding studies and in vitro antimicrobial screening of iron(II) bromosalicylidene amino acid chelates

    Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Ismael, Mohamed; Seleem, Amin Abdou

    2014-01-01

    In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses, infrared, ultraviolet-visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral geometry according to the general formula [Fe(bs:aa)2]ṡnH2O. The conductivity values between 37 and 64 ohm-1 mol-1 cm2 in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination. In addition, the interaction of these complexes with (CT-DNA) was investigated at pH = 7.2, by using UV-vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari > bshi > bsali > bsasi > bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus

  19. De Novo Lipogenesis Maintains Vascular Homeostasis through Endothelial Nitric-oxide Synthase (eNOS) Palmitoylation*♦

    Wei, Xiaochao; Schneider, Jochen G; Shenouda, Sherene M.; Lee, Ada; Towler, Dwight A.; Chakravarthy, Manu V.; Vita, Joseph A.; Semenkovich, Clay F.

    2010-01-01

    Endothelial dysfunction leads to lethal vascular complications in diabetes and related metabolic disorders. Here, we demonstrate that de novo lipogenesis, an insulin-dependent process driven by the multifunctional enzyme fatty-acid synthase (FAS), maintains endothelial function by targeting endothelial nitric-oxide synthase (eNOS) to the plasma membrane. In mice with endothelial inactivation of FAS (FASTie mice), eNOS membrane content and activity were decreased. eNOS and FAS were physically ...

  20. Insulin-like growth factor II messenger ribonucleic acids are synthesized in the choroid plexus of the rat brain

    Previous studies demonstrating the presence of immunoreactive insulin-like growth factors (IGFs) and their receptors in the brain suggest a role of the IGFs in the central nervous system. IGF-II has been implicated as the predominant IGF in brain of mature animals based on studies of immunoreactive peptide and of IGF-II mRNAs. To obtain information about the sites of synthesis of IGF-II in adult rat brain, a 32P-labeled 31 base long synthetic oligodeoxyribonucleotide complementary in sequence to trailer peptide coding sequences in rat IGF-II mRNA (IGF-II 31 mer) was hybridized with coronal sections of fixed rat brain. The IGF-II 31 mer showed specific hybridization with the choroid plexus throughout rat brain, whereas in other brain regions, structures or cells, hybridization was not discernibly above background. These findings suggest that the choroid plexus is a primary site of synthesis of IGF-II, a probable source of IGF-II in cerebrospinal fluid, and a potential source of IGF-II for actions on target cells within the adult rat brain

  1. Cloning and Expression of Poly(hydroxyalkanoate) Synthase Genes from Photosynthetic bacterium Allochromatium vinosum ATCC 35206

    Poly(hydroxyalkanoate) (PHA) synthases catalyze the polymerization of beta-hydroxy fatty acids to form PHA biopolyesters. These enzymes are grouped into four classes (classes I to IV) based on their subunit composition and substrate specificity. Since PHA biopolymers are naturally synthesized by b...

  2. 3-Bromopyruvic acid, a hexokinase II inhibitor, is an effective antitumor agent on the hepatoma cells : in vitro and in vivo findings.

    Gong, Lei; Wei, Yuhua; Yu, Xin; Peng, Jirun; Leng, Xisheng

    2014-06-01

    Over-expressed in cancer cells, hexokinase II (HK II) forms a mitochondrial complex, which promotes cancer survival. 3- Bromopyruvic acid (3-BrPA) dissociates HK II from this complex, causing cell death, and thus, having an anti-tumor effect. The design of this study was to first analyze the expression of HK II in the hepatoma cell line, BEL-7402, then investigate the effects of 3-Br-PA on these cells, and finally, discuss its potential for clinical usage. HK II expression was detected in BEL-7402 cells by immunocytochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). In vitro treatment of cells with 3-BrPA significantly inhibited their growth, as evaluated by MTT assay and adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA). To analyze the in vivo function and safety of this drug, a tumor model was established by subcutaneously implanting hepatic cancer cells into nude mice. 3-BrPA treatment (50 mg/kg ip. daily, 6 days/week for three weeks) was effective in the animal model by attenuating tumor growth and causing tumor necrosis. Toxic signs were not observed. The acute toxicity study provided an LD50 of 191.7 mg/kg for 3-BrPA. Taken together, our in vitro and in vivo analyses suggest that 3-BrPA exerts anti-hepatoma effects, and may be an effective pharmacological agent for the treatment of hepatocellular carcinoma. PMID:24738957

  3. An investigation of Cu(II) adsorption by raw and acid-activated bentonite: A combined potentiometric, thermodynamic, XRD, IR, DTA study

    Eren, E. [Department of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayis University, 55139 Kurupelit-Samsun (Turkey)], E-mail: erdalern@omu.edu.tr; Afsin, B. [Department of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayis University, 55139 Kurupelit-Samsun (Turkey)

    2008-03-01

    Adsorption of Cu(II) by raw bentonite (RB) and acid-activated bentonite (AAB) samples was investigated as a function of the initial Cu(II) concentration, solution pH, ionic strenght, temperature, the competitive and complexation effects of ligands (Cl{sup -}, SO{sub 4}{sup 2-}, PO{sub 4}{sup 3-}). Langmuir monolayer adsorption capacity of the RB (42.41 mg g{sup -1}) was found greater than that of the AAB (32.17 mg g{sup -1}). The effect of structural charges on the reactivity of the edge groups was evidenced by the particular proton adsorption behaviour of the bentonite samples. The spontaneity of the adsorption process is established by decrease in {delta}G which varied from -0.34 to -0.71 kJ mol{sup -1} (RB), -1.13 to -1.49 kJ mol{sup -1} (AAB) in temperature range 303-313 K. Infrared (IR) spectra of the bentonite samples showed that the positions and shapes of the fundamental vibrations of the OH and Si-O groups were influenced by the adsorbed Cu(II) cations. Differential thermal analysis (DTA) results showed that adsorbed Cu(II) cations have a great effect on the thermal behaviour of the bentonite samples. The X-ray diffraction (XRD) spectra indicated that the Cu(II) adsorption onto the bentonite samples led to changes in unit cell dimensions and symmetry of the parent bentonites.

  4. Novel polyhydroxyalkanoate copolymers produced in Pseudomonas putida by metagenomic polyhydroxyalkanoate synthases.

    Cheng, Jiujun; Charles, Trevor C

    2016-09-01

    Bacterially produced biodegradable polyhydroxyalkanoates (PHAs) with versatile properties can be achieved using different PHA synthases (PhaCs). This work aims to expand the diversity of known PhaCs via functional metagenomics and demonstrates the use of these novel enzymes in PHA production. Complementation of a PHA synthesis-deficient Pseudomonas putida strain with a soil metagenomic cosmid library retrieved 27 clones expressing either class I, class II, or unclassified PHA synthases, and many did not have close sequence matches to known PhaCs. The composition of PHA produced by these clones was dependent on both the supplied growth substrates and the nature of the PHA synthase, with various combinations of short-chain-length (SCL) and medium-chain-length (MCL) PHA. These data demonstrate the ability to isolate diverse genes for PHA synthesis by functional metagenomics and their use for the production of a variety of PHA polymer and copolymer mixtures. PMID:27333909

  5. (Benzoato-κ2O,O′(quinoline-2-carboxylato-κ2N,O(quinoline-2-carboxylic acid-κ2N,Omanganese(II

    Nuno D. Martins

    2008-01-01

    Full Text Available The crystal structure of the title compound, [Mn(C7H5O2(C10H6NO2(C10H7NO2], contains manganese(II ions six-coordinated in a distorted octahedral environment. The equatorial plane is occupied by four O atoms, two from the carboxylate group of the benzoate ion, the other two from carboxylate/carboxyl groups of the quinaldate/quinaldic acid molecules. The axial positions are occupied by the N atoms of the quinoline ring systems. The metal ion lies on a twofold rotation axis that bisects the benzoate ligand; the quinaldate and quinaldic acid ligands are therefore equivalent by symmetry, and the carboxylate/carboxyl groups are disordered. The complexes are joined together by hydrogen bonds between the carboxylate/carboxyl groups of adjacent quinaldate/quinaldic acid molecules, forming zigzag chains that run along the c axis.

  6. The cellulose synthase companion proteins act non-redundantly with CELLULOSE SYNTHASE INTERACTING1/POM2 and CELLULOSE SYNTHASE 6

    Endler, Anne; Schneider, Rene; Kesten, Christopher; Edwin R Lampugnani; Persson, Staffan

    2016-01-01

    ABSTRACT Cellulose is a cell wall constituent that is essential for plant growth and development, and an important raw material for a range of industrial applications. Cellulose is synthesized at the plasma membrane by massive cellulose synthase (CesA) complexes that track along cortical microtubules in elongating cells of Arabidopsis through the activity of the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1). In a recent study we identified another family of proteins that also are associated ...

  7. 1D coordination polymers formed by tetranuclear lead(II) building blocks with carboxylate ligands: In situ isomerization of itaconic acid

    The synthesis of two new lead(II) coordination polymers, [Pb2(mpic)4(H2O)]·0.5H2O (1) and [Pb2(phen)2(cit)(mes)]·2H2O (2) has been reported, where mpic=3-methyl picolinate, phen=o-phenanthroline, H2cit=citraconic acid, H2mes mesaconic acid. X-ray single crystal diffraction analyses showed that the complexes comprise topologically different 1D polymeric chains stabilized by weak interactions and both containing tetranuclear Pb4 units connected by carboxylate groups. In compound 1 3-methylpicolinic acid is formed in situ from 3-methyl piconitrile, and mesaconate and citraconate anions were surprisingly formed from itaconic acid during the synthesis of 2. The photoluminescence and thermal properties of the complexes have been studied. - Graphical abstract: Two new topologically different 1D coordination polymers formed by Pb4 clusters have been synthesized and characterized by X-ray analysis. The luminescence and thermal properties have been studied. Display Omitted - Highlights: • Both the complexes, made up of different ligands, forms topologycally different 1D polymeric chains containing Pb4 clusters. • The final structures are stabilized by weak interactions (H-bond, π∙∙∙π stacking). • In complex 1, the 3-methylpicolinic acid is generated in situ from 3-methyl piconitrile. • Mesaconate and citraconate anions are surprisingly formed in situ from itaconic acid during the synthesis of complex 2, indicating an exceptional transformation

  8. Identification of cofactor and herbicide binding domains in acetolactate synthase by bromopyruvate modification

    Van Dyk, D.E.; Schloss, J.V.

    1987-05-01

    Bromopyruvate is an affinity label for acetolactate synthase isozyme II from Salmonella typhimurium (ALSII). The concentration of bromopyruvate giving half-maximal inactivation is 0.1 mM, and the maximal rate of inactivation is 0.56 hr/sup -1/. Inactivation with (/sup 14/C)bromopyruvate is associated with the incorporation of 4 molecules of reagent per active site lost. Two cysteinyl residues are modified extremely rapidly, with no loss of enzymatic activity, as judged by quenching the reaction with thiol after its initial phase. Inactivation is a consequence of the additional two moles of reagent incorporated per mole of protomer. The additional incorporation is divided between one major and two minor sites of modification. Substantial protection against inactivation is afforded by FAD, with virtually complete protection provided by a mixture of FAD and thiamine pyrophosphate (TPP). The major site of modification, protected by FAD, is cysteinyl residue number67, based upon amino acid sequence analysis of the purified tryptic peptide that encompasses this site. The remaining site of modification, protected by TPP, is associated with cysteinyl residue number44. Both sites of modification are afforded protection by the sulfonylurea herbicide sulfometuron methyl (SM). Although inactivation by bromopyruvate exhibits rate saturation, indicating binding as a prerequisite to inactivation, neither pyruvate nor ..cap alpha..-ketobutyrate prevent modification of the enzyme by bromopyruvate. Thus, it would appear that the bromopyruvate binding site is not the site normally occupied by substrate.

  9. Characterization of Chlamydomonas reinhardtii phosphatidylglycerophosphate synthase in Synechocystis sp. PCC 6803

    Chun-Hsien eHung

    2015-08-01

    Full Text Available Phosphatidylglycerol (PG is an indispensable phospholipid class with photosynthetic function in plants and cyanobacteria. However, its biosynthesis in eukaryotic green microalgae is poorly studied. Here, we report the isolation and characterization of two homologs (CrPGP1 and CrPGP2 of phosphatidylglycerophosphate synthase (PGPS, the rate-limiting enzyme in PG biosynthesis, in Chlamydomonas reinhardtii. Heterologous complementation of Synechocystis sp. PCC 6803 pgsA mutant by CrPGP1 and CrPGP2 rescued the PG-dependent growth phenotype, but the PG level and its fatty acid composition were not fully rescued in the complemented strains. As well, oxygen evolution activity was not fully recovered, although electron transport activity of photosystem II was restored to the wild-type level. Gene expression study of CrPGP1 and CrPGP2 in nutrient-starved C. reinhardtii showed differential response to phosphorus and nitrogen deficiency. Taken together, these results highlight the distinct and overlapping function of PGPS in cyanobacteria and eukaryotic algae.

  10. Synthesis, structure elucidation, biological screening, molecular modeling and DNA binding of some Cu(II) chelates incorporating imines derived from amino acids

    Abdel-Rahman, Laila H.; Abu-Dief, Ahmed M.; Ismael, Mohammed; Mohamed, Mounir A. A.; Hashem, Nahla Ali

    2016-01-01

    Three tridentate Schiff bases amino acids were prepared by direct condensation of 3-methoxysalicylaldehyde (MS) or 4-diethylaminosalicylaldehyde (DS) with α-amino acid ligands [L-phenylalanine (P), L-histidine (H) and DL-tryptophan (T)]. The prepared Schiff bases amino acids were investigated by melting points, elemental analysis, 1HNMR and 13CNMR, IR, UV-Vis spectra, conductivity and magnetic measurements analyses. Subsequently, copper was introduced and Cu(II) complexes formed. These complexes were analyzed by thermal and elemental analyses and further investigated by FT-IR and UV/Vis spectroscopies. The experimental results indicating that all Cu(II) complexes contain hydrated water molecules (except DSPCu complex) and don't contain coordinated water molecules. The kinetic and thermal parameters were extracted from the thermal data using Coast and Redfern method. The molar conductance values of the Schiff base amino acid ligands and their Cu(II) complexes were relatively low, showing that these compounds have non-electrolytic nature. Magnetic susceptibility measurements showed the diamagnetic nature of the Schiff base amino acid ligands and paramagnetic nature of their complexes. Additionally, a spectrophotometric method was determined to extract their stability constants. It was found that the complexes possess 1:2 (M:L) stoichiometry. The results suggested that 3-methoxysalicylaldehyde and 4-diethylaminosalicylaldehyde amino acid Schiff bases behave as monobasic tridentate ONO ligands and coordinate Cu(II) ions in octahedral geometry according to the general formula [Cu(HL)2]·nH2O. To further understanding the structural and electronic properties of these complexes, Density Functional Theory (DFT) calculations were employed and provided a satisfactory description. The optimized structures of MST Schiff base ligand and its complex were calculated using DFT. The antimicrobial activity of the Schiff base ligands and their complexes were screened against some

  11. Trichinella pseudospiralis vs. T. spiralis thymidylate synthase gene structure and T. pseudospiralis thymidylate synthase retrogene sequence

    Jagielska, Elżbieta; Płucienniczak, Andrzej; Dąbrowska, Magdalena; Dowierciał, Anna; Rode, Wojciech

    2014-01-01

    Background Thymidylate synthase is a housekeeping gene, designated ancient due to its role in DNA synthesis and ubiquitous phyletic distribution. The genomic sequences were characterized coding for thymidylate synthase in two species of the genus Trichinella, an encapsulating T. spiralis and a non-encapsulating T. pseudospiralis. Methods Based on the sequence of parasitic nematode Trichinella spiralis thymidylate synthase cDNA, PCR techniques were employed. Results Each of the respective gene...

  12. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Xiong, Pingping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Li, Jie [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Bu, Huaiyu, E-mail: 7213792@qq.com [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Wei, Qing [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Zhang, Ruolin [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Chen, Sanping, E-mail: sanpingchen@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China)

    2014-07-01

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu{sub 0.5}L]{sub n} (1), [Cu(HL){sub 2}Cl{sub 2}]{sub n} (2), [Cu(HL){sub 2}Cl{sub 2}(H{sub 2}O)] (3), [Cu(L){sub 2}(H{sub 2}O)]{sub n} (4) and [Cu(L)(phen)(HCO{sub 2})]{sub n} (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl{sup -}, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units –Cu–O–Cu–O– are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated. - Graphical abstract: Copper(II) compounds with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid, were prepared, structurally characterized and investigated for antifungal activity. - Highlights: • The title compounds formed by thermodynamics and thermokinetics. • The five compounds show higher inhibition percentage than reactants. • The structure effect on the antifungal activity.

  13. Studies on the structure of peat humic acid (II). Study on the determination of the aromatic skeletons in peat humic acid by zinc-dust distillation

    Oka, H.; Sasaki, M.

    1979-01-01

    In order to determine aromatic skeletons in the chemical structure of peat humic acid, zinc-dust distillation was carried out at 500 C for 2 hours in a stream of hydrogen, and the results compared to those from other substances such as phtholic acid, cumarin, naphthoquinone and ..cap alpha..-lactone. Subsequently, methods for the identification and semi-quantitative determination of polycyclic aromatic hydrocarbons were applied. The total yield of polycyclic hydrocarbon having anthracene, pyrene and perylene rings was 1.9% of the original peat humic acid. However, the yield of aromatic hydrocarbons containing 3 to 5 rings from peat humic acid was approximately equal to those from the other substances. From the results, it is assumed that peat humic acid has no polycyclic ring systems as the aromatic structure, and that the polycyclic aromatic hydrocarbons produced by zinc-dust distillation were formed by a rearrangement and condensation of oxygen containing structures during the reaction.

  14. Synthèse bibliographique: la divinyl éther synthase de plantes

    Fauconnier M.L.

    2001-01-01

    Full Text Available Divinyl ether synthase in plants: a review. Divinyl ether synthase, an enzyme of the lipoxygenase pathway transforms, in potato tubers, 9-hydroperoxides of fatty acids into colneleic and colnelenic acid, two divinyl ethers of fatty acids. The enzyme has been described in a limited number of quite different plants. The enzyme has also been detected in tomato roots, garlic bulbs, tobacco plants and in marine algae. The enzyme is bound to membranes and is located in the microsomal fraction. The molecular weight of the enzyme exceeds 100,000 Da, its optimal pH is around 9 and its high specificity for 9-hydroperoxides as substrate is described. The reactional mechanism has been elucidated using radio-labelled molecules. Colneleic and colnelenic acid can be degraded enzymatically or not into aldehydes and oxo-acids. Those last compounds are also formed by the action of hydroperoxide lyase on 9-hydroperoxides of fatty acids. As other enzymes of the lipoxygenase pathway, reaction products of divinyl ether synthase are involved in pathogenic resistance. Colneleic and colnelenic acid content in potato plants has been corelated with resistance to Phytophthora infestans.

  15. Inducible nitric oxide synthase and inflammation.

    Salvemini, D; Marino, M H

    1998-01-01

    Nitric oxide (NO), derived from L-arginine (L-Arg) by the enzyme nitric oxide synthase (NOS), is involved in acute and chronic inflammatory events. In view of the complexity associated with the inflammatory response, the dissection of possible mechanisms by which NO modulates this response will be profitable in designing novel and more efficacious NOS inhibitors. In this review we describe the consequences associated with the induction of inducible nitric oxide synthase (iNOS) and its therapeutic implications. PMID:15991919

  16. Nitric Oxide Synthases and Atrial Fibrillation

    CynthiaAnnCarnes; ArunSridhar; SandorGyorke

    2012-01-01

    Oxidative stress has been implicated in the pathogenesis of atrial fibrillation. There are multiple systems in the myocardium which contribute to redox homeostasis, and loss of homeostasis can result in oxidative stress. Potential sources of oxidants include nitric oxide synthases, which normally produce nitric oxide in the heart. Two nitric oxide synthase isoforms (1 and 3) are normally expressed in the heart. During pathologies such as heart failure, there is induction of nitric oxide syn...

  17. Effects of lipids and oleic acid on biomass development in anaerobic fixed-bed reactors. Part II : oleic acid toxicity and biodegradability

    Alves, M.M.; Vieira, J. A. Mota; Pereira, R. M. Álvares; M. A. PEREIRA; Mota, M.

    2001-01-01

    Oleic acid toxicity and biodegradability were followed during long-term operation of two similar anaerobic fixed-bed units. When treating an oleate based effluent, the sludge from the bioreactor that was acclimated with lipids during the first operation period, showed a higher tolerance to oleic acid toxicity (IC50=137 mg/l) compared with the sludge fed with a non-fat substrate (IC50=80 mg/l). This sludge showed also the highest biodegradation capacity of oleic acid, achieving max...

  18. Dissecting the chemical interactions and substrate structural signatures governing RNA polymerase II trigger loop closure by synthetic nucleic acid analogues

    Xu, Liang; Butler, Kyle Vincent; Chong, Jenny; Wengel, Jesper; Kool, Eric T; Wang, Dong

    2014-01-01

    The trigger loop (TL) of RNA polymerase II (Pol II) is a conserved structural motif that is crucial for Pol II catalytic activity and transcriptional fidelity. The TL remains in an inactive open conformation when the mismatched substrate is bound. In contrast, TL switches from an inactive open...... remains elusive. Here we employed synthetic nucleotide analogues as 'chemical mutation' tools coupling with α-amanitin transcription inhibition assay to systematically dissect the key chemical interactions and structural signatures governing the substrate-coupled TL closure in Saccharomyces cerevisiae Pol...

  19. Effect of gamma irradiation on the properties of various kinds of milk fat. II. Fatty acids composition of milk fat

    Fresh cow's, buffalo's and goat's milk fat were subjected to ascendent doses of 8-rays of 250, 500 and 750 K.rad as compared to raw milk samples (control). The methyl esters of fats separated from these samples were analyzed using gas liquid chromatographic technique. Total saturated fatty acids (T.S.F.A.) were 70.46%, 67.44% and 72.85%, while total unsaturated fatty acid (T.U.F.A.) were 29.51%, 32.54% and 27.15% for cow's buffalo's and goat's raw milk fats, respectively. Water insoluble volatile fatty acids (W.I.V.F.A.) were much higher in goat's raw milk fat (23.24%) than in cows (6.34%) and buffaloes (5.25%) ones. Palmitic acid represents the predominant saturated fatty acid, while oleic acid represents the major unsaturated fatty acids in the three kinds of milk fat. Linoleic acid was present only in buffalo's and goat's raw milk fat. The exposure of buffalo's and goat's milk to 8-rays doses increased TSFA and decreased TUFA of their fats. Meanwhile the same doses induced a minor change in both TSFA and TUFA of cow's milk one. Also, 8-irradiation increased the relative percentage of Palmitic acid in the three types of milk fat, while linoleic acid decreased in buffalo's and goat's milk fat. Besides, W.I.V.F.A. showed a gradual decrease, when the three types of milk were exposed to ascendent doses of 8-rays

  20. Characterization of α-humulene synthases responsible for the production of sesquiterpenes induced by methyl jasmonate in Aquilaria cell culture.

    Kumeta, Yukie; Ito, Michiho

    2016-07-01

    The resinous portions of Aquilaria and Gyrinops plants are known as 'agarwood' and have a distinctive fragrance. To examine the biosynthesis of these fragrant compounds, we previously established cell cultures of Aquilaria crassna in which the production of three sesquiterpenes (α-guaiene, α-humulene, and δ-guaiene) could be induced by methyl jasmonate (MJ), and showed that cloned δ-guaiene synthase from MJ-treated cells is involved in the synthesis of these three compounds, although only very small amounts of α-humulene are produced. In the present study, cDNAs encoding α-humulene synthases were also isolated. Three putative sesquiterpene synthase clones (AcHS1-3) isolated from the MJ-treated cells had very similar amino acid sequences and shared 52 % identity with δ-guaiene synthases. The recombinant enzymes catalyzed the formation of α-humulene as a major product. Expression of transcripts of the α-humulene synthase and δ-guaiene synthase genes in cultured cells increased after treatment with MJ. These results revealed that these α-humulene and δ-guaiene synthases are involved in the synthesis of three sesquiterpenes induced by MJ treatment. PMID:27180085

  1. Identification and characterization of two bisabolene synthases from linear glandular trichomes of sunflower (Helianthus annuus L., Asteraceae).

    Aschenbrenner, Anna-Katharina; Kwon, Moonhyuk; Conrad, Jürgen; Ro, Dae-Kyun; Spring, Otmar

    2016-04-01

    Sunflower is known to produce a variety of bisabolene-type sesquiterpenes and accumulates these substances in trichomes of leaves, stems and flowering parts. A bioinformatics approach was used to identify the enzyme responsible for the initial step in the biosynthesis of these compounds from its precursor farnesyl pyrophosphate. Based on sequence similarity with a known bisabolene synthases from Arabidopsis thaliana AtTPS12, candidate genes of Helianthus were searched in EST-database and used to design specific primers. PCR experiments identified two candidates in the RNA pool of linear glandular trichomes of sunflower. Their sequences contained the typical motifs of sesquiterpene synthases and their expression in yeast functionally characterized them as bisabolene synthases. Spectroscopic analysis identified the stereochemistry of the product of both enzymes as (Z)-γ-bisabolene. The origin of the two sunflower bisabolene synthase genes from the transcripts of linear trichomes indicates that they may be involved in the synthesis of sesquiterpenes produced in these trichomes. Comparison of the amino acid sequences of the sunflower bisabolene synthases showed high similarity with sesquiterpene synthases from other Asteracean species and indicated putative evolutionary origin from a β-farnesene synthase. PMID:26880289

  2. Unique animal prenyltransferase with monoterpene synthase activity

    Gilg, Anna B.; Tittiger, Claus; Blomquist, Gary J.

    2009-06-01

    Monoterpenes are structurally diverse natural compounds that play an essential role in the chemical ecology of a wide array of organisms. A key enzyme in monoterpene biosynthesis is geranyl diphosphate synthase (GPPS). GPPS is an isoprenyl diphosphate synthase that catalyzes a single electrophilic condensation reaction between dimethylallyl diphosphate (C5) and isopentenyl diphosphate (C5) to produce geranyl diphosphate (GDP; C10). GDP is the universal precursor to all monoterpenes. Subsequently, monoterpene synthases are responsible for the transformation of GDP to a variety of acyclic, monocyclic, and bicyclic monoterpene products. In pheromone-producing male Ips pini bark beetles (Coleoptera: Scolytidae), the acyclic monoterpene myrcene is required for the production of the major aggregation pheromone component, ipsdienol. Here, we report monoterpene synthase activity associated with GPPS of I. pini. Enzyme assays were performed on recombinant GPPS to determine the presence of monoterpene synthase activity, and the reaction products were analyzed by coupled gas chromatography-mass spectrometry. The functionally expressed recombinant enzyme produced both GDP and myrcene, making GPPS of I. pini a bifunctional enzyme. This unique insect isoprenyl diphosphate synthase possesses the functional plasticity that is characteristic of terpene biosynthetic enzymes of plants, contributing toward the current understanding of product specificity of the isoprenoid pathway.

  3. Changes in amino acid concentration in plasma and type I and type II fibres during resistance exercise and recovery in human subjects.

    Blomstrand, Eva; Essén-Gustavsson, Birgitta

    2009-10-01

    Eight male subjects performed leg press exercise, 4 x 10 repetitions at 80% of their maximum. Venous blood samples were taken before, during exercise and repeatedly during 2 h of recovery. From four subjects, biopsies were taken from the vastus lateralis muscle prior to, immediately after and following one and 2 h of recovery. Samples were freeze-dried, individual muscle fibres were dissected out and identified as type I or type II. Resistance exercise led to pronounced reductions in the glutamate concentration in both type I (32%) and type II fibres (70%). Alanine concentration was elevated 60-75% in both fibre types and 29% in plasma. Glutamine concentration remained unchanged after exercise; although 2 h later the concentrations in both types of fibres were reduced 30-35%. Two hours after exercise, the plasma levels of glutamate and six of the essential amino acids, including the branched-chain amino acids were reduced 5-30%. The data suggest that glutamate acts as an important intermediate in muscle energy metabolism during resistance exercise, especially in type II fibres. PMID:18931969

  4. Synthesis and characterization of aspartic acid-capped CdS/ZnS quantum dots in reverse micelles and its application to Hg(II) determination

    In this work, CdS/ZnS quantum dots (QDs) coated with aspartic acid (AsA) were synthesized in reverse micelles. The synthesized QDs were characterized by XRD, TEM, IR and photoluminescence (PL) spectroscopy. It was found that the intensity of CdS/ZnS QDs coated with AsA is much greater than CdS, and CdS/ZnS QDs. The interaction of some heavy metal ions with CdS/ZnS/AsA QDs was investigated at different buffering pH media. Based on the PL quenching of the QDs in the presence of each one of the metal ions, the feasibility of their determinations was examined according to the Stern–Volmer equation. The investigations showed that Hg(II) ions can be easily determined in contaminated atmospheric environments with the detection limit of 0.05 mg m−3. The results were satisfactorily confirmed by cold vapor atomic absorption spectrometric method. - Highlights: • A new CdS/ZnS quantum dot capped with aspartic acid (DDBA) was prepared. • The prepared QDs benefit from a favorable fluorescence. • Interaction of some metal ions with the QDs was examined according to the Stern–Volmer equation. • The determination of Hg(II) is feasible in the present of many co-existence metal ions. • The method benefits from a high-speed and considerable simplicity for Hg(II) determination

  5. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Xiong, Pingping; Li, Jie; Bu, Huaiyu; Wei, Qing; Zhang, Ruolin; Chen, Sanping

    2014-07-01

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu0.5L]n (1), [Cu(HL)2Cl2]n (2), [Cu(HL)2Cl2(H2O)] (3), [Cu(L)2(H2O)]n (4) and [Cu(L)(phen)(HCO2)]n (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl-, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units -Cu-O-Cu-O- are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated.

  6. Synthesis and characterization of aspartic acid-capped CdS/ZnS quantum dots in reverse micelles and its application to Hg(II) determination

    Hosseini, Mohammad Saeid, E-mail: mshosseini1336@yahoo.com; Kamali, Mohsen

    2015-11-15

    In this work, CdS/ZnS quantum dots (QDs) coated with aspartic acid (AsA) were synthesized in reverse micelles. The synthesized QDs were characterized by XRD, TEM, IR and photoluminescence (PL) spectroscopy. It was found that the intensity of CdS/ZnS QDs coated with AsA is much greater than CdS, and CdS/ZnS QDs. The interaction of some heavy metal ions with CdS/ZnS/AsA QDs was investigated at different buffering pH media. Based on the PL quenching of the QDs in the presence of each one of the metal ions, the feasibility of their determinations was examined according to the Stern–Volmer equation. The investigations showed that Hg(II) ions can be easily determined in contaminated atmospheric environments with the detection limit of 0.05 mg m{sup −3}. The results were satisfactorily confirmed by cold vapor atomic absorption spectrometric method. - Highlights: • A new CdS/ZnS quantum dot capped with aspartic acid (DDBA) was prepared. • The prepared QDs benefit from a favorable fluorescence. • Interaction of some metal ions with the QDs was examined according to the Stern–Volmer equation. • The determination of Hg(II) is feasible in the present of many co-existence metal ions. • The method benefits from a high-speed and considerable simplicity for Hg(II) determination.

  7. Isolation and bacterial expression of a sesquiterpene synthase CDNA clone from peppermint(mentha .chi. piperita, L.) that produces the aphid alarm pheromone (E)-.beta.-farnesene

    Croteau, Rodney Bruce (Pullman, WA); Wildung, Mark Raymond (Colfax, WA); Crock, John E. (Moscow, ID)

    1999-01-01

    A cDNA encoding (E)-.beta.-farnesene synthase from peppermint (Mentha piperita) has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID NO:1) is provided which codes for the expression of (E)-.beta.-farnesene synthase (SEQ ID NO:2), from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for (E)-.beta.-farnesene synthase, or for a base sequence sufficiently complementary to at least a portion of (E)-.beta.-farnesene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (E)-.beta.-farnesene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant (E)-.beta.-farnesene synthase that may be used to facilitate its production, isolation and purification in significant amounts. Recombinant (E)-.beta.-farnesene synthase may be used to obtain expression or enhanced expression of (E)-.beta.-farnesene synthase in plants in order to enhance the production of (E)-.beta.-farnesene, or may be otherwise employed for the regulation or expression of (E)-.beta.-farnesene synthase, or the production of its product.

  8. Isolation and bacterial expression of a sesquiterpene synthase cDNA clone from peppermint (Mentha x piperita, L.) that produces the aphid alarm pheromone (E)-.beta.-farnesene

    Croteau, Rodney Bruce; Crock, John E.

    2005-01-25

    A cDNA encoding (E)-.beta.-farnesene synthase from peppermint (Mentha piperita) has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID NO:1) is provided which codes for the expression of (E)-.beta.-farnesene synthase (SEQ ID NO:2), from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for (E)-.beta.-farnesene synthase, or for a base sequence sufficiently complementary to at least a portion of (E)-.beta.-farnesene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (E)-.beta.-farnesene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant (E)-.beta.-famesene synthase that may be used to facilitate its production, isolation and purification in significant amounts. Recombinant (E)-.beta.-farnesene synthase may be used to obtain expression or enhanced expression of (E)-.beta.-famesene synthase in plants in order to enhance the production of (E)-.beta.-farnesene, or may be otherwise employed for the regulation or expression of (E)-.beta.-farnesene synthase, or the production of its product.

  9. Kinetic characterization of 4-amino 4-deoxychorismate synthase from Escherichia coli.

    Viswanathan, V K; Green, J M; Nichols, B P

    1995-01-01

    The metabolic fate of p-aminobenzoic acid (PABA) in Escherichia coli is its incorporation into the vitamin folic acid. PABA is derived from the aromatic branch point precursor chorismate in two steps. Aminodeoxychorismate (ADC) synthase converts chorismate and glutamine to ADC and glutamate and is composed of two subunits, PabA and PabB. ADC lyase removes pyruvate from ADC, aromatizes the ring, and generates PABA. While there is much interest in the mechanism of chorismate aminations, there h...

  10. Synthesis and crystal structure of Cu(II and Co(II complexes with 1,3-dimethyl-pyrazole-5-carboxylic acid ligand

    Jaćimović Željko K.

    2015-01-01

    Full Text Available In the reaction of 1,3-dimethyl-pyrazole-5-carboxylic acid (HL with M(OAc2•4H2O, (M = Cu, Co two novel complexes have been prepared, square-planar [CuL2(H2O2] and octahedral [CoL2(MeOH4]. The crystal structures have been determined by single-crystal X-ray diffraction. In both complexes the deprotonated acid displays monodentate coordination to the metal ions. According to the results of CSD survey this is the first structural report on the metal complexes with N1-substituted pyrazole-5-carboxylic ligand. [Projekat Ministarstva nauke Republike Srbije, br. 172014 i br. 172035

  11. Copper(II) and cadmium(II) sorption onto ferrihydrite in the presence of phthalic acid: some properties of the ternary complex.

    Song, Yantao; Swedlund, Peter J; Singhal, Naresh

    2008-06-01

    Copper, cadmium, and phthalic acid (H2Lp) adsorption by ferrihydrite was examined for binary and ternary systems. In binary systems adsorption was well reproduced using the diffuse layer model (DLM), and H2Lp adsorption was analogous to that of inorganic diprotic acids in terms of the relationship between the adsorption constants and acidity constants. In ternary systems H2Lp caused both the enhancement (due to ternary complexformation) and inhibition (due to solution complex formation) of Cu2+ and Cd2+ sorption depending on the conditions. The DLM could only describe the effect of H2Lp on metal ion sorption by including ternary complexes of the form [triple bond]FeOHMLp (0), where [triple bond]FeOH is a surface site and M is Cu or Cd. The relationship between binary metal adsorption constants and the ternary complex adsorption constants from this and previous studies suggest several properties of ternary complexes. First, ternary complex structures on both ferrihydrite and goethite are either the same or similar. Second, those cations having large adsorption constants also have large equilibrium constants for ternary complex formation. Third, ligands forming stronger solution complexes with cations will also form stronger surface ternary complexes though, because of the strong solution complex, they will not necessarily enhance cation adsorption. PMID:18589959

  12. Discovery of Orally Available Prodrugs of the Glutamate Carboxypeptidase II (GCPII) Inhibitor 2-Phosphonomethylpentanedioic Acid (2-PMPA)

    Majer, Pavel; Jančařík, Andrej; Krečmerová, Marcela; Tichý, Tomáš; Tenora, Lukáš; Wozniak, K.; Wu, Y.; Pommier, E.; Ferraris, D.; Rais, R.; Slusher, B. S.

    2016-01-01

    Roč. 59, č. 6 (2016), s. 2810-2819. ISSN 0022-2623 Institutional support: RVO:61388963 Keywords : glutamate carboxypeptidase II * glutamate * 2-PMPA * prodrug Subject RIV: CC - Organic Chemistry Impact factor: 5.447, year: 2014

  13. Establishment of a yeast platform strain for production of p-coumaric acid through metabolic engineering of aromatic amino acid biosynthesis.

    Rodriguez, Angelica; Kildegaard, Kanchana R; Li, Mingji; Borodina, Irina; Nielsen, Jens

    2015-09-01

    Aromatic amino acids are precursors of numerous plant secondary metabolites with diverse biological functions. Many of these secondary metabolites are already being used as active pharmaceutical or nutraceutical ingredients, and there are numerous exploratory studies of other compounds with promising applications. p-Coumaric acid is derived from aromatic amino acids and, besides being a valuable chemical building block, it serves as precursor for biosynthesis of many secondary metabolites, such as polyphenols, flavonoids, and some polyketides. Here we developed a p-coumaric acid-overproducing Saccharomyces cerevisiae platform strain. First, we reduced by-product formation by knocking out phenylpyruvate decarboxylase ARO10 and pyruvate decarboxylase PDC5. Second, different versions of feedback-resistant DAHP synthase and chorismate mutase were overexpressed. Finally, we identified shikimate kinase as another important flux-controlling step in the aromatic amino acid pathway by overexpressing enzymes from Escherichia coli, homologous to the pentafunctional enzyme Aro1p and to the bifunctional chorismate synthase-flavin reductase Aro2p. The highest titer of p-coumaric acid of 1.93 ± 0.26 g L(-1) was obtained, when overexpressing tyrosine ammonia-lyase TAL from Flavobacterium johnsoniaeu, DAHP synthase ARO4(K229L), chorismate mutase ARO7(G141S) and E. coli shikimate kinase II (aroL) in Δpdc5Δaro10 strain background. To our knowledge this is the highest reported titer of an aromatic compound produced by yeast. The developed S. cerevisiae strain represents an attractive platform host for production of p-coumaric-acid derived secondary metabolites, such as flavonoids, polyphenols, and polyketides. PMID:26292030

  14. trans-Fatty Acid Consumption and its Association with Distal Colorectal Cancer in the North Carolina Colon Cancer Study II

    Vinikoor, Lisa C.; Millikan, Robert C.; Satia, Jessie A.; Schroeder, Jane C.; Martin, Christopher F.; Ibrahim, Joseph G.; Sandler, Robert S.

    2009-01-01

    Recently, the potential health effects of trans-fatty acid consumption have raised concerns. A few studies have examined the risk of colorectal cancer with increasing consumption of trans-fatty acids, but none investigated the risk of rectal cancer, which may have different risk factors than colon cancer. Our objective was to explore the relationship between trans-fatty acid consumption and distal colorectal (sigmoid, rectosigmoid, and rectal) cancer using a case-control study of Whites (n=15...

  15. BIOSORPTION OF LEAD (II) ON MODIFIED BARKS EXPLAINED BY THE HARD AND SOFT ACIDS AND BASES (HSAB) THEORY

    Cedric Astier,; Vincent Chaleix,; Celine Faugeron,; David Ropartz,; Pierre Krausz; Vincent Gloaguen

    2012-01-01

    Chemical modification of Douglas fir bark and its subsequent utilization in adsorption of Pb(II) from aqueous solutions was investigated. The polysaccharidic moiety of barks was functionalized by periodate oxidation and derivatized after reductive amination in the presence of aminated oligo-carrageenans. Pb(II) adsorption isotherms of derivatized barks were then determined and compared to the capabilities of crude barks using the Langmuir adsorption model in terms of affinity (b) and maximum ...

  16. Interaction between uranium and humic acid (II): complexation, precipitation and migration behavior of U(VI) in the presence of humic substances

    The complexation, precipitation, and migration behavior of uranium in the presence of humic acid (HA) or fulvic acid (FA) were investigated by cation exchange, ultrafiltration and dynamic experiment, respectively. The results showed that (i) complex equilibrium between the uranium and humic substances was achieved at approximately 72 h, (ii) the coordination number varied from 1:1 to 1:2 (U(VI): humic acid) as pH increased from 3 to 6; and (iii), while the complex stability constant decreased when temperature increased, but increased with pH value. We found that the precipitation of uranyl could only be observed in presence of HA, and the precipitation was influenced by conditions, such as pH, uranium concentration, temperature, and the HA concentration. The maximum precipitation proportion up to 60% could be achieved in the condition of 40 mg/L HA solution at pH 6. We further observed that the migration behavior of uranium in soil in the presence of humic acid (HA) or fulvic acid (FA) was different from that in the presence of inorganic colloid, and the effect of humic substances (HS) was limited. (authors)

  17. The chsA gene, encoding a class-I chitin synthase from Ampelomyces quisqualis.

    Weiss, N; Sztejnberg, A; Yarden, O

    1996-02-01

    Degenerate oligodeoxyribonucleotide primers, designed on the basis of conserved regions of the chitin synthase gene family, were used to amplify a fragment of the Ampelomyces quisqualis (Aq) chsA gene. Subsequently, the PCR product was used as a probe in order to identify and isolate genomic clones harboring the entire chsA gene. Aq chsA is 2786-nt long, has one intron and encodes a 910-amino-acid polypeptide belonging to the class-I chitin synthases. Low-stringency Southern hybridizations to Aq genomic DNA provided evidence for the presence of additional DNA fragments resembling chsA in the fungal genome, suggesting the presence of a multigene family of chitin synthases in Aq. PMID:8626074

  18. Insights into Diterpene Cyclization from Structure of Bifunctional Abietadiene Synthase from Abies grandis

    Zhou, Ke; Gao, Yang; Hoy, Julie A.; Mann, Francis M.; Honzatko, Richard B.; Peters, Reuben J. (Iowa State)

    2013-09-24

    Abietadiene synthase from Abies grandis (AgAS) is a model system for diterpene synthase activity, catalyzing class I (ionization-initiated) and class II (protonation-initiated) cyclization reactions. Reported here is the crystal structure of AgAS at 2.3 {angstrom} resolution and molecular dynamics simulations of that structure with and without active site ligands. AgAS has three domains ({alpha}, {beta}, and {gamma}). The class I active site is within the C-terminal {alpha} domain, and the class II active site is between the N-terminal {gamma} and {beta} domains. The domain organization resembles that of monofunctional diterpene synthases and is consistent with proposed evolutionary origins of terpene synthases. Molecular dynamics simulations were carried out to determine the effect of substrate binding on enzymatic structure. Although such studies of the class I active site do lead to an enclosed substrate-Mg{sup 2+} complex similar to that observed in crystal structures of related plant enzymes, it does not enforce a single substrate conformation consistent with the known product stereochemistry. Simulations of the class II active site were more informative, with observation of a well ordered external loop migration. This 'loop-in' conformation not only limits solvent access but also greatly increases the number of conformational states accessible to the substrate while destabilizing the nonproductive substrate conformation present in the 'loop-out' conformation. Moreover, these conformational changes at the class II active site drive the substrate toward the proposed transition state. Docked substrate complexes were further assessed with regard to the effects of site-directed mutations on class I and II activities.

  19. Coordination assisted molecular assemblies of perylene-3,4,9,10-tetracarboxylic acid with copper (II) ion at the air/water interface

    Perylene-3,4,9,10-tetracarboxylic acid (PTCA) was found to form stable Langmuir films at the air/water interface through the coordination with Cu(II) ion in the subphase although the compound itself could not form monolayer on a plain water surface. The Langmuir films can be transferred onto solid substrates by a Langmuir-Schaefer (LS) method. Surface pressure-area isotherm and measurement of the UV-Vis and FT-IR spectra of the transferred LS films confirmed the coordination between the carboxylic group and Cu(II) ion in the Langmuir films. Atomic force microscopy (AFM) measurements indicated that the Langmuir film was composed of small nanoparticles with a diameter of several tens of nanometers. X-ray diffraction (XRD) measurement on the transferred LS films revealed that the film formed a clear layer structure with a distance of 3.9 nm, which was in agreement with the height measurement from the AFM

  20. Crystal structure and temperature-dependent fluorescent property of a 2D cadmium (II) complex based on 3,6-dibromobenzene-1,2,4,5-tetracarboxylic acid

    Zhang, Liang-Liang; Guo, Yu; Wei, Yan-Hui; Guo, Jie; Wang, Xing-Po; Sun, Dao-Feng

    2013-04-01

    A new cadmium (II) organic coordination polymers [Cd(dbtec)0.5(H2O)3]·H2O (1), has been constructed based on 3,6-dibromobenzene-1,2,4,5-tetracarboxylic acid (H4dbtec), and characterized by elemental analysis (EA), infrared spectroscopy (IR), powder X-ray diffraction (PXRD), and single crystal X-ray diffraction. In 1, μ2-η1:η1 and μ4-η2:η2 dbtec ligands link four hepta-coordinated CdII ions to form a 2D 44 topological layer structure, which is further connected into an interesting 3D network by hydrogen bond and Br⋯O halogen bond. Moreover, the thermal stabilities, solid ultraviolet spectroscopy and temperature-dependent fluorescent properties of 1 were investigated.