Sample records for alpha-glucan acting enzymes

  1. Aspergillus niger genome-wide analysis reveals a large number of novel alpha-glucan acting enzymes with unexpected expression profiles

    Microsoft Academic Search

    Xiao-Lian Yuan; Rachel M. van der Kaaij; Cees A. M. J. J. van den Hondel; Peter J. Punt; Marc J. E. C. van der Maarel; Lubbert Dijkhuizen; Arthur F. J. Ram

    2008-01-01

    The filamentous ascomycete Aspergillus niger is well known for its ability to produce a large variety of enzymes for the degradation of plant polysaccharide material.\\u000a A major carbon and energy source for this soil fungus is starch, which can be degraded by the concerted action of ?-amylase,\\u000a glucoamylase and ?-glucosidase enzymes, members of the glycoside hydrolase (GH) families 13, 15

  2. Safety evaluation of 1,4-alpha-glucan branching enzymes from Bacillus stearothermophilus and Aquifex aeolicus expressed in Bacillus subtilis.

    PubMed

    Choi, S S H; Danielewska-Nikiel, B; Kojima, I; Takata, H

    2009-08-01

    1,4-alpha-Glucan branching enzyme (BE; EC 2.4.1.18) is a key biocatalyst in the synthesis of polysaccharides, and is therefore useful in the production of food ingredients. The BEs evaluated in this study (BE-01 and BE-02) are obtained by fermentation of Bacillus subtilis expressing the BE gene from either Bacillus stearothermophilus strain TRBE14 or Aquifex aeolicus strain VF5. The safety of BE-01 and BE-02 have not been previously evaluated, and therefore, both were subjected to standard toxicological testing. In a battery of standard Salmonella typhimurium strains (TA98, TA100, TA1535, and TA1537) and in Escherichia coli WP2uvrA, both with and without metabolic activation, neither BE-01 nor BE-02 exhibited mutagenic activity. Similarly, neither was associated with clastogenic properties in Chinese hamster ovary cells in an in vitro chromosomal aberration assay. In rats, oral administration of BE-01 or BE-02 at doses of up to 15 mL/kg body weight/day (approximately 870 and 900 mg/kg body weight/day, respectively) for 13 weeks did not produce compound-related clinical signs or toxicity, changes in body weight gain, food consumption, hematology, clinical chemistry, urinalysis, organ weights, or in any gross and microscopic findings. The results of this study support the safety of BE-01 and BE-02 in food production. PMID:19470400

  3. Safety evaluation of highly-branched cyclic dextrin and a 1,4-alpha-glucan branching enzyme from Bacillus stearothermophilus.

    PubMed

    Choi, Sharon S H; Danielewska-Nikiel, Barbara; Ohdan, Kohji; Kojima, Iwao; Takata, Hiroki; Kuriki, Takashi

    2009-12-01

    Highly-branched cyclic dextrin (HBCD), a dextrin food ingredient presently only used in Japan, was investigated for digestibility and potential toxicity. HBCD was readily hydrolyzed in vitro to maltose and maltotriose by human salivary and porcine pancreatic alpha-amylases. Incubation of HBCD with a rat intestinal homogenate, containing digestive enzymes, resulted in the formation of maltose, maltotriose, and maltotetraose, and with longer incubation times, resulted in the formation of glucose. In an acute toxicity study, Wistar rats orally administered a single-dose of 2000mg/kg body weight of HBCD did not display mortality or any signs or symptoms of toxicity or abnormalities upon necropsy. Transient loose stools were observed, but were resolved within 24h of HBCD administration, and therefore, were not considered as compound-specific adverse effects. In the Ames assay, HBCD was non-mutagenic with or without metabolic activation. Toxicity testing of the branching enzyme (BE) involved in the synthesis of HBCD showed that the BE also was not acutely toxic when orally administered to rats and was non-mutagenic in the mouse lymphoma assay. The results of this study demonstrate that HBCD is digested to normal and safe products of carbohydrate digestion, and therefore, support the safety of HBCD for human consumption. PMID:19651182

  4. Alpha-glucan synthesis on a protein primer. A reconstituted system for the formation of protein-bound alpha-glucan.

    PubMed

    Moreno, S; Cardini, C E; Tandecarz, J S

    1987-02-01

    Reconstitution experiments with the DEAE-cellulose-treated enzymes, engaged in a two-step mechanism of synthesis of alpha-glucan bound to protein, are performed. Urea/sodium dodecyl sulfate/polyacrylamide gel electrophoretic analysis of the radioactive products synthesized by the reconstituted system shows highly glucosylated, labeled bands, whose apparent molecular masses change with the acrylamide concentration in the gels. The long carbohydrate chains synthesized during the second step arise from the sequential addition of glucosyl moieties to the glucoprotein formed during the first step. A deglucosylation experiment confirms that the product of the reconstituted system originates from the 38-kDa glucosylated component of the reaction 1 product by the addition of beta-amylase-sensitive glucosyl moieties. Our data suggest that specific phosphorylases and starch synthetases are found in potato tuber, which are capable of utilizing reaction 1 product as primer for the synthesis of protein-bound glucan. PMID:2951252

  5. Variation in storage alpha-glucans of the Porphyridiales (Rhodophyta).

    PubMed

    Shimonaga, Takahiro; Konishi, Mai; Oyama, Yasunori; Fujiwara, Shoko; Satoh, Aya; Fujita, Naoko; Colleoni, Christophe; Buléon, Alain; Putaux, Jean-Luc; Ball, Steven G; Yokoyama, Akiko; Hara, Yoshiaki; Nakamura, Yasunori; Tsuzuki, Mikio

    2008-01-01

    Storage glucans were analyzed in the Porphyridiales which include the most primitive and phylogenetically diverged species in the Rhodophyta, to understand early evolution of the glucan structure in the Rhodophyta. The storage glucans of both Galdieria sulphuraria and Cyanidium caldarium consisted of glycogen, while those of Rhodosorus marinus, Porphyridium purpureum, P. sordidum and Rhodella violacea could be defined as semi-amylopectin. X-ray diffraction analysis of the glucans demonstrated variation in the crystalline structure: the patterns in P. purpureum and R. violacea were of A- and B-types, respectively, while alpha-glucans of R. marinus and P. sordidum displayed structures with lower crystallinity. Electron microscopic observations indicated that the alpha-glucans of P. sordidum consisted of two kinds of granules; a minor component of more dense granules with crystalline leaflets and a major component of softer ones without crystalline structure. Gel permeation chromatography showed that all the species containing the semi-amylopectin-type glucans also contained amylose, although the relative amounts of this fraction were different depending on the species. Our results are consistent with two distinct evolution scenarios defined either by the independent acquisition of semi-crystalline starch-like structures in the different plant lineages or more probably by the loss of starch and reversion to glycogen synthesis in cyanidian algae growing in hot and acid environments. PMID:18079144

  6. Enzyme

    MedlinePLUS

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  7. Amino acid sequence of fibrolase, a direct-acting fibrinolytic enzyme from Agkistrodon contortrix contortrix venom.

    PubMed Central

    Randolph, A.; Chamberlain, S. H.; Chu, H. L.; Retzios, A. D.; Markland, F. S.; Masiarz, F. R.

    1992-01-01

    The complete amino acid sequence of fibrolase, a fibrinolytic enzyme from southern copperhead (Agkistrodon contortrix contortrix) venom, has been determined. This is the first report of the sequence of a direct-acting, nonhemorrhagic fibrinolytic enzyme found in snake venom. The majority of the sequence was established by automated Edman degradation of overlapping peptides generated by a variety of selective cleavage procedures. The amino-terminus is blocked by a cyclized glutamine (pyroglutamic acid) residue, and the sequence of this region of the molecule was determined by mass spectrometry. Fibrolase is composed of 203 residues in a single polypeptide chain with a molecular weight of 22,891, as determined by the sequence. Its sequence is homologous to the sequence of the hemorrhagic toxin Ht-d of Crotalus atrox venom and with the sequences of two metalloproteinases from Trimeresurus flavoviridis venom. Microheterogeneity in the sequence was found at both the amino-terminus and at residues 189 and 192. All six cysteine residues in fibrolase are involved in disulfide bonds. A disulfide bond between cysteine-118 and cysteine-198 has been established and bonds between cysteines-158/165 and between cysteines-160/192 are inferred from the homology to Ht-d. Secondary structure prediction reveals a very low percentage of alpha-helix (4%), but much greater beta-structure (39.5%). Analysis of the sequence reveals the absence of asparagine-linked glycosylation sites defined by the consensus sequence: asparagine-X-serine/threonine. PMID:1304358

  8. Fumarate Analogs Act as Allosteric Inhibitors of the Human Mitochondrial NAD(P)+-Dependent Malic Enzyme

    PubMed Central

    Yang, Pai-Chun; Lin, Chi-Li; Liu, Guang-Yaw; Hung, Hui-Chih

    2014-01-01

    Human mitochondrial NAD(P)+-dependent malic enzyme (m-NAD(P)-ME) is allosterically activated by the four-carbon trans dicarboxylic acid, fumarate. Previous studies have suggested that the dicarboxylic acid in a trans conformation around the carbon-carbon double bond is required for the allosteric activation of the enzyme. In this paper, the allosteric effects of fumarate analogs on m-NAD(P)-ME are investigated. Two fumarate-insensitive mutants, m-NAD(P)-ME_R67A/R91A and m-NAD(P)-ME_K57S/E59N/K73E/D102S, as well as c-NADP-ME, were used as the negative controls. Among these analogs, mesaconate, trans-aconitate, monomethyl fumarate and monoethyl fumarate were allosteric activators of the enzyme, while oxaloacetate, diethyl oxalacetate, and dimethyl fumarate were found to be allosteric inhibitors of human m-NAD(P)-ME. The IC50 value for diethyl oxalacetate was approximately 2.5 mM. This paper suggests that the allosteric inhibitors may impede the conformational change from open form to closed form and therefore inhibit m-NAD(P)-ME enzyme activity. PMID:24911153

  9. Fumarate analogs act as allosteric inhibitors of the human mitochondrial NAD(P)+-dependent malic enzyme.

    PubMed

    Hsieh, Ju-Yi; Liu, Jyung-Hurng; Yang, Pai-Chun; Lin, Chi-Li; Liu, Guang-Yaw; Hung, Hui-Chih

    2014-01-01

    Human mitochondrial NAD(P)+-dependent malic enzyme (m-NAD(P)-ME) is allosterically activated by the four-carbon trans dicarboxylic acid, fumarate. Previous studies have suggested that the dicarboxylic acid in a trans conformation around the carbon-carbon double bond is required for the allosteric activation of the enzyme. In this paper, the allosteric effects of fumarate analogs on m-NAD(P)-ME are investigated. Two fumarate-insensitive mutants, m-NAD(P)-ME_R67A/R91A and m-NAD(P)-ME_K57S/E59N/K73E/D102S, as well as c-NADP-ME, were used as the negative controls. Among these analogs, mesaconate, trans-aconitate, monomethyl fumarate and monoethyl fumarate were allosteric activators of the enzyme, while oxaloacetate, diethyl oxalacetate, and dimethyl fumarate were found to be allosteric inhibitors of human m-NAD(P)-ME. The IC50 value for diethyl oxalacetate was approximately 2.5 mM. This paper suggests that the allosteric inhibitors may impede the conformational change from open form to closed form and therefore inhibit m-NAD(P)-ME enzyme activity. PMID:24911153

  10. A natural vanishing act: the enzyme-catalyzed degradation of carbon nanomaterials.

    PubMed

    Kotchey, Gregg P; Hasan, Saad A; Kapralov, Alexander A; Ha, Seung Han; Kim, Kang; Shvedova, Anna A; Kagan, Valerian E; Star, Alexander

    2012-10-16

    Over the past three decades, revolutionary research in nanotechnology by the scientific, medical, and engineering communities has yielded a treasure trove of discoveries with diverse applications that promise to benefit humanity. With their unique electronic and mechanical properties, carbon nanomaterials (CNMs) represent a prime example of the promise of nanotechnology with applications in areas that include electronics, fuel cells, composites, and nanomedicine. Because of toxicological issues associated with CNMs, however, their full commercial potential may not be achieved. The ex vitro, in vitro, and in vivo data presented in this Account provide fundamental insights into the biopersistence of CNMs, such as carbon nanotubes and graphene, and their oxidation/biodegradation processes as catalyzed by peroxidase enzymes. We also communicate our current understanding of the mechanism for the enzymatic oxidation and biodegradation. Finally, we outline potential future directions that could enhance our mechanistic understanding of the CNM oxidation and biodegradation and could yield benefits in terms of human health and environmental safety. The conclusions presented in this Account may catalyze a rational rethinking of CNM incorporation in diverse applications. For example, armed with an understanding of how and why CNMs undergo enzyme-catalyzed oxidation and biodegradation, researchers can tailor the structure of CNMs to either promote or inhibit these processes. In nanomedical applications such as drug delivery, the incorporation of carboxylate functional groups could facilitate biodegradation of the nanomaterial after delivery of the cargo. On the other hand, in the construction of aircraft, a CNM composite should be stable to oxidizing conditions in the environment. Therefore, pristine, inert CNMs would be ideal for this application. Finally, the incorporation of CNMs with defect sites in consumer goods could provide a facile mechanism that promotes the degradation of these materials once these products reach landfills. PMID:22824066

  11. Benzoate-Coenzyme A Ligase from Thauera aromatica: an Enzyme Acting in Anaerobic and Aerobic Pathways

    PubMed Central

    Schühle, Karola; Gescher, Johannes; Feil, Ulrich; Paul, Michael; Jahn, Martina; Schägger, Hermann; Fuchs, Georg

    2003-01-01

    In the denitrifying member of the ?-Proteobacteria Thauera aromatica, the anaerobic metabolism of aromatic acids such as benzoate or 2-aminobenzoate is initiated by the formation of the coenzyme A (CoA) thioester, benzoyl-CoA and 2-aminobenzoyl-CoA, respectively. Both aromatic substrates were transformed to the acyl-CoA intermediate by a single CoA ligase (AMP forming) that preferentially acted on benzoate. This benzoate-CoA ligase was purified and characterized as a 57-kDa monomeric protein. Based on Vmax/Km, the specificity constant for 2-aminobenzoate was 15 times lower than that for benzoate; this may be the reason for the slower growth on 2-aminobenzoate. The benzoate-CoA ligase gene was cloned and sequenced and was found not to be part of the gene cluster encoding the general benzoyl-CoA pathway of anaerobic aromatic metabolism. Rather, it was located in a cluster of genes coding for a novel aerobic benzoate oxidation pathway. In line with this finding, the same CoA ligase was induced during aerobic growth with benzoate. A deletion mutant not only was unable to grow anaerobically on benzoate or 2-aminobenzoate, but also aerobic growth on benzoate was affected. This suggests that benzoate induces a single benzoate-CoA ligase. The product of benzoate activation, benzoyl-CoA, then acts as inducer of separate anaerobic or aerobic pathways of benzoyl-CoA, depending on whether oxygen is lacking or present. PMID:12897012

  12. Compartmental and enzyme kinetic modeling to elucidate the biotransformation pathway of a centrally acting antitrypanosomal prodrug.

    PubMed

    Generaux, Claudia N; Ainslie, Garrett R; Bridges, Arlene S; Ismail, Mohamed A; Boykin, David W; Tidwell, Richard R; Thakker, Dhiren R; Paine, Mary F

    2013-02-01

    DB868 [2,5-bis [5-(N-methoxyamidino)-2-pyridyl] furan], a prodrug of the diamidine DB829 [2,5-bis(5-amidino-2-pyridyl) furan], has demonstrated efficacy in murine models of human African trypanosomiasis. A cross-species evaluation of prodrug bioconversion to the active drug is required to predict the disposition of prodrug, metabolites, and active drug in humans. The phase I biotransformation of DB868 was elucidated using liver microsomes and sandwich-cultured hepatocytes from humans and rats. All systems produced four NADPH-dependent metabolites via O-demethylation (M1, M2) and N-dehydroxylation (M3, M4). Compartmental kinetic modeling of the DB868 metabolic pathway suggested an unusual N-demethoxylation reaction that was supported experimentally. A unienzyme Michaelis-Menten model described the kinetics of M1 formation by human liver microsomes (HLMs) (K(m), 11 ?M; V(max), 340 pmol/min/mg), whereas a two-enzyme model described the kinetics of M1 formation by rat liver microsomes (RLMs) (K(m1), 0.5 ?M; V(max1), 12 pmol/min/mg; K(m2), 27 ?M; V(max2), 70 pmol/min/mg). Human recombinant CYP1A2, CYP3A4, and CYP4F2, rat recombinant Cyp1a2 and Cyp2d2, and rat purified Cyp4f1 catalyzed M1 formation. M2 formation by HLMs exhibited allosteric kinetics (S(50), 18 ?M; V(max), 180 pmol/mg), whereas M2 formation by RLMs was negligible. Recombinant CYP1A2/Cyp1a2 catalyzed M2 formation. DB829 was detected in trace amounts in HLMs at the end of the 180-min incubation and was detected readily in sandwich-cultured hepatocytes from both species throughout the 24-h incubation. These studies demonstrated that DB868 biotransformation to DB829 is conserved between humans and rats. An improved understanding of species differences in the kinetics of DB829 formation would facilitate preclinical development of a promising antitrypanosomal prodrug. PMID:23223498

  13. Biosynthesis of the immunosuppressants FK506, FK520, and rapamycin involves a previously undescribed family of enzymes acting on chorismate

    PubMed Central

    Andexer, Jennifer N.; Kendrew, Steven G.; Nur-e-Alam, Mohammad; Lazos, Orestis; Foster, Teresa A.; Zimmermann, Anna-Sophie; Warneck, Tony D.; Suthar, Dipen; Coates, Nigel J.; Koehn, Frank E.; Skotnicki, Jerauld S.; Carter, Guy T.; Gregory, Matthew A.; Martin, Christine J.; Moss, Steven J.; Leadlay, Peter F.; Wilkinson, Barrie

    2011-01-01

    The macrocyclic polyketides FK506, FK520, and rapamycin are potent immunosuppressants that prevent T-cell proliferation through initial binding to the immunophilin FKBP12. Analogs of these molecules are of considerable interest as therapeutics in both metastatic and inflammatory disease. For these polyketides the starter unit for chain assembly is (4R,5R)-4,5-dihydroxycyclohex-1-enecarboxylic acid derived from the shikimate pathway. We show here that the first committed step in its formation is hydrolysis of chorismate to form (4R,5R)-4,5-dihydroxycyclohexa-1,5-dienecarboxylic acid. This chorismatase activity is encoded by fkbO in the FK506 and FK520 biosynthetic gene clusters, and by rapK in the rapamycin gene cluster of Streptomyces hygroscopicus. Purified recombinant FkbO (from FK520) efficiently catalyzed the chorismatase reaction in vitro, as judged by HPLC-MS and NMR analysis. Complementation using fkbO from either the FK506 or the FK520 gene cluster of a strain of S. hygroscopicus specifically deleted in rapK (BIOT-4010) restored rapamycin production, as did supplementation with (4R,5R)-4,5-dihydroxycyclohexa-1,5-dienecarboxylic acid. Although BIOT-4010 produced no rapamycin, it did produce low levels of BC325, a rapamycin analog containing a 3-hydroxybenzoate starter unit. This led us to identify the rapK homolog hyg5 as encoding a chorismatase/3-hydroxybenzoate synthase. Similar enzymes in other bacteria include the product of the bra8 gene from the pathway to the terpenoid natural product brasilicardin. Expression of either hyg5 or bra8 in BIOT-4010 led to increased levels of BC325. Also, purified Hyg5 catalyzed the predicted conversion of chorismate into 3-hydroxybenzoate. FkbO, RapK, Hyg5, and Bra8 are thus founder members of a previously unrecognized family of enzymes acting on chorismate. PMID:21383123

  14. Lipoamide Acts as an Indirect Antioxidant by Simultaneously Stimulating Mitochondrial Biogenesis and Phase II Antioxidant Enzyme Systems in ARPE-19 Cells

    PubMed Central

    Zhao, Lin; Liu, Zhongbo; Jia, Haiqun; Feng, Zhihui; Liu, Jiankang; Li, Xuesen

    2015-01-01

    In our previous study, we found that pretreatment with lipoamide (LM) more effectively than alpha-lipoic acid (LA) protected retinal pigment epithelial (RPE) cells from the acrolein-induced damage. However, the reasons and mechanisms for the greater effect of LM than LA are unclear. We hypothesize that LM, rather than the more direct antioxidant LA, may act more as an indirect antioxidant. In the present study, we treated ARPE-19 cells with LA and LM and compared their effects on activation of mitochondrial biogenesis and induction of phase II enzyme systems. It is found that LM is more effective than LA on increasing mitochondrial biogenesis and inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation to the nucleus, leading to an increase in expression or activity of phase II antioxidant enzymes (NQO-1, GST, GCL, catalase and Cu/Zn SOD). Further study demonstrated that mitochondrial biogenesis and phase II enzyme induction are closely coupled via energy requirements. These results suggest that LM, compared with the direct antioxidant LA, plays its protective effect on oxidative damage more as an indirect antioxidant to simultaneously stimulate mitochondrial biogenesis and induction of phase II antioxidant enzymes. PMID:26030919

  15. Lipoamide Acts as an Indirect Antioxidant by Simultaneously Stimulating Mitochondrial Biogenesis and Phase II Antioxidant Enzyme Systems in ARPE-19 Cells.

    PubMed

    Zhao, Lin; Liu, Zhongbo; Jia, Haiqun; Feng, Zhihui; Liu, Jiankang; Li, Xuesen

    2015-01-01

    In our previous study, we found that pretreatment with lipoamide (LM) more effectively than alpha-lipoic acid (LA) protected retinal pigment epithelial (RPE) cells from the acrolein-induced damage. However, the reasons and mechanisms for the greater effect of LM than LA are unclear. We hypothesize that LM, rather than the more direct antioxidant LA, may act more as an indirect antioxidant. In the present study, we treated ARPE-19 cells with LA and LM and compared their effects on activation of mitochondrial biogenesis and induction of phase II enzyme systems. It is found that LM is more effective than LA on increasing mitochondrial biogenesis and inducing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation to the nucleus, leading to an increase in expression or activity of phase II antioxidant enzymes (NQO-1, GST, GCL, catalase and Cu/Zn SOD). Further study demonstrated that mitochondrial biogenesis and phase II enzyme induction are closely coupled via energy requirements. These results suggest that LM, compared with the direct antioxidant LA, plays its protective effect on oxidative damage more as an indirect antioxidant to simultaneously stimulate mitochondrial biogenesis and induction of phase II antioxidant enzymes. PMID:26030919

  16. The Catalytic Scaffold fo the Haloalkanoic Acid Dehalogenase Enzyme Superfamily Acts as a Mold for the Trigonal Bipyramidal Transition State

    SciTech Connect

    Lu,Z.; Dunaway-Mariano, D.; Allen, K.

    2008-01-01

    The evolution of new catalytic activities and specificities within an enzyme superfamily requires the exploration of sequence space for adaptation to a new substrate with retention of those elements required to stabilize key intermediates/transition states. Here, we propose that core residues in the large enzyme family, the haloalkanoic acid dehalogenase enzyme superfamily (HADSF) form a 'mold' in which the trigonal bipyramidal transition states formed during phosphoryl transfer are stabilized by electrostatic forces. The vanadate complex of the hexose phosphate phosphatase BT4131 from Bacteroides thetaiotaomicron VPI-5482 (HPP) determined at 1.00 Angstroms resolution via X-ray crystallography assumes a trigonal bipyramidal coordination geometry with the nucleophilic Asp-8 and one oxygen ligand at the apical position. Remarkably, the tungstate in the complex determined to 1.03 Angstroms resolution assumes the same coordination geometry. The contribution of the general acid/base residue Asp-10 in the stabilization of the trigonal bipyramidal species via hydrogen-bond formation with the apical oxygen atom is evidenced by the 1.52 Angstroms structure of the D10A mutant bound to vanadate. This structure shows a collapse of the trigonal bipyramidal geometry with displacement of the water molecule formerly occupying the apical position. Furthermore, the 1.07 Angstroms resolution structure of the D10A mutant complexed with tungstate shows the tungstate to be in a typical 'phosphate-like' tetrahedral configuration. The analysis of 12 liganded HADSF structures deposited in the protein data bank (PDB) identified stringently conserved elements that stabilize the trigonal bipyramidal transition states by engaging in favorable electrostatic interactions with the axial and equatorial atoms of the transferring phosphoryl group.

  17. The EAL domain protein YciR acts as a trigger enzyme in a c-di-GMP signalling cascade in E. coli biofilm control

    PubMed Central

    Lindenberg, Sandra; Klauck, Gisela; Pesavento, Christina; Klauck, Eberhard; Hengge, Regine

    2013-01-01

    C-di-GMP—which is produced by diguanylate cyclases (DGC) and degraded by specific phosphodiesterases (PDEs)—is a ubiquitous second messenger in bacterial biofilm formation. In Escherichia coli, several DGCs (YegE, YdaM) and PDEs (YhjH, YciR) and the MerR-like transcription factor MlrA regulate the transcription of csgD, which encodes a biofilm regulator essential for producing amyloid curli fibres of the biofilm matrix. Here, we demonstrate that this system operates as a signalling cascade, in which c-di-GMP controlled by the DGC/PDE pair YegE/YhjH (module I) regulates the activity of the YdaM/YciR pair (module II). Via multiple direct interactions, the two module II proteins form a signalling complex with MlrA. YciR acts as a connector between modules I and II and functions as a trigger enzyme: its direct inhibition of the DGC YdaM is relieved when it binds and degrades c-di-GMP generated by module I. As a consequence, YdaM then generates c-di-GMP and—by direct and specific interaction—activates MlrA to stimulate csgD transcription. Trigger enzymes may represent a general principle in local c-di-GMP signalling. PMID:23708798

  18. The EAL domain protein YciR acts as a trigger enzyme in a c-di-GMP signalling cascade in E. coli biofilm control.

    PubMed

    Lindenberg, Sandra; Klauck, Gisela; Pesavento, Christina; Klauck, Eberhard; Hengge, Regine

    2013-07-17

    C-di-GMP-which is produced by diguanylate cyclases (DGC) and degraded by specific phosphodiesterases (PDEs)-is a ubiquitous second messenger in bacterial biofilm formation. In Escherichia coli, several DGCs (YegE, YdaM) and PDEs (YhjH, YciR) and the MerR-like transcription factor MlrA regulate the transcription of csgD, which encodes a biofilm regulator essential for producing amyloid curli fibres of the biofilm matrix. Here, we demonstrate that this system operates as a signalling cascade, in which c-di-GMP controlled by the DGC/PDE pair YegE/YhjH (module I) regulates the activity of the YdaM/YciR pair (module II). Via multiple direct interactions, the two module II proteins form a signalling complex with MlrA. YciR acts as a connector between modules I and II and functions as a trigger enzyme: its direct inhibition of the DGC YdaM is relieved when it binds and degrades c-di-GMP generated by module I. As a consequence, YdaM then generates c-di-GMP and-by direct and specific interaction-activates MlrA to stimulate csgD transcription. Trigger enzymes may represent a general principle in local c-di-GMP signalling. PMID:23708798

  19. Retrospective longitudinal cohort study comparing the effects of angiotensin-converting enzyme inhibitors and long-acting calcium channel blockers on total and cardiovascular mortality in patients with hypertension

    Microsoft Academic Search

    Jean-Claude Tardif; Anique Ducharme; Holly Yu; Jenifer Wogen; Marie-Claude Guertin

    2004-01-01

    Background: There is controversy regarding the impact that different antihypertensive regimens, including modern combination therapy, have on the incidence of myocardial infarction, other cardiovascular events, and mortality.Objective: The objective of this study was to determine and compare the effects of treatment strategies based on angiotensin-converting enzyme (ACE) inhibitors and long-acting calcium channel blockers (CCBs) on total and cardiovascular mortality in

  20. Identification of bioactivating enzymes involved in the hydrolysis of laninamivir octanoate, a long-acting neuraminidase inhibitor, in human pulmonary tissue.

    PubMed

    Koyama, Kumiko; Ogura, Yuji; Nakai, Daisuke; Watanabe, Mihoko; Munemasa, Toshiko; Oofune, Yuka; Kubota, Kazuishi; Shinagawa, Akira; Izumi, Takashi

    2014-06-01

    Laninamivir octanoate (LO) is an octanoyl ester prodrug of the neuraminidase inhibitor laninamivir. After inhaled administration, LO exhibits clinical efficacy for both treatment and prophylaxis of influenza virus infection, resulting from hydrolytic bioactivation into its pharmacologically active metabolite laninamivir in the pulmonary tissue. In this study, we focused on the identification of LO-hydrolyzing enzymes from human pulmonary tissue extract using proteomic correlation profiling-a technology integration of traditional biochemistry and proteomics. In a single elution step by gel-filtration chromatography, LO-hydrolyzing activity was separated into two distinct peaks, designated as peak I and peak II. By mass spectrometry, 1160 and 1003 proteins were identified and quantitated for peak I and peak II, respectively, and enzyme candidates were ranked based on the correlation coefficient between the enzyme activity and the proteomic profiles. Among proteins with a high correlation value, S-formylglutathione hydrolase (esterase D; ESD) and acyl-protein thioesterase 1 (APT1) were selected as the most likely candidates for peak I and peak II, respectively, which was confirmed by LO-hydrolyzing activity of recombinant proteins. In the case of peak II, LO-hydrolyzing activity was completely inhibited by treatment with a specific APT1 inhibitor, palmostatin B. Moreover, immunohistochemical analysis revealed that both enzymes were mainly localized in the pulmonary epithelia, a primary site of influenza virus infection. These findings demonstrate that ESD and APT1 are key enzymes responsible for the bioactivation of LO in human pulmonary tissue. PMID:24682756

  1. DAX-1 acts as a novel corepressor of orphan nuclear receptor HNF4alpha and negatively regulates gluconeogenic enzyme gene expression.

    PubMed

    Nedumaran, Balachandar; Hong, Sungpyo; Xie, Yuan-Bin; Kim, Yong-Hoon; Seo, Woo-Young; Lee, Min-Woo; Lee, Chul Ho; Koo, Seung-Hoi; Choi, Hueng-Sik

    2009-10-01

    DAX-1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1) is an atypical member of the nuclear receptor family and acts as a corepressor of a number of nuclear receptors. HNF4alpha (hepatocyte nuclear factor 4alpha) is a liver-enriched transcription factor that controls the expression of a variety of genes involved in cholesterol, fatty acid, and glucose metabolism. Here we show that DAX-1 inhibits transcriptional activity of HNF4alpha and modulates hepatic gluconeogenic gene expression. Hepatic DAX-1 expression is increased by insulin and SIK1 (salt-inducible kinase 1), whereas it is decreased in high fat diet-fed and diabetic mice. Coimmunoprecipitation assay from mouse liver samples depicts that endogenous DAX-1 interacts with HNF4alpha in vivo. In vivo chromatin immunoprecipitation assay affirms that the recruitment of DAX-1 on the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter is inversely correlated with the recruitment of PGC-1alpha and HNF4alpha under fasting and refeeding, showing that DAX-1 could compete with the coactivator PGC-1alpha for binding to HNF4alpha. Adenovirus-mediated expression of DAX-1 decreased both HNF4alpha- and forskolin-mediated gluconeogenic gene expressions. In addition, knockdown of DAX-1 partially reverses the insulin-mediated inhibition of gluconeogenic gene expression in primary hepatocytes. Finally, DAX-1 inhibits PEPCK and glucose-6-phosphatase gene expression and significantly lowers fasting blood glucose level in high fat diet-fed mice, suggesting that DAX-1 can modulate hepatic gluconeogenesis in vivo. Overall, this study demonstrates that DAX-1 acts as a corepressor of HNF4alpha to negatively regulate hepatic gluconeogenic gene expression in liver. PMID:19651776

  2. Soil Enzymes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The functionality and resilience of natural and managed ecosystems mainly rely on the metabolic abilities of microbial communities, the main source of enzymes in soils. Enzyme mediated reactions are critical in the decomposition of organic matter, cycling of nutrients, and in the breakdown of herbic...

  3. Enzymes, Industrial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymes serve key roles in numerous biotechnology processes and products that are commonly encountered in the forms of food and beverages, cleaning supplies, clothing, paper products, transportation fuels, pharmaceuticals, and monitoring devices. Enzymes can display regio- and stereo-specificity, p...

  4. Design acts

    E-print Network

    Saslaw, Ellen

    1987-01-01

    What an architect does, designing, is a design act and not the making of an object, a design. A design act is an intentional act about built use. We give reasons for intentional acts and are responsible for knowing that ...

  5. Enzyme Reactions

    NSDL National Science Digital Library

    Maryland Virtual High School

    The enzyme reaction rate activity allows students to simulate the effects of variables such as temperature and pH on the reaction rate of the enzyme catalase. This computer simulation is best used after the students have done a wet lab experiment. The value of the simulation is that it requires the students to interpret and analyze the graphical representation of data and it enables the running of mutiple experiments in a short amount of time.

  6. Molecular mass and antitumor activities of sulfated derivatives of alpha-glucan from Poria cocos mycelia.

    PubMed

    Lin, Yulu; Zhang, Lina; Chen, Li; Jin, Yong; Zeng, Fanbo; Jin, Jing; Wan, Bo; Cheung, Peter C K

    2004-10-01

    Two kinds of water-insoluble (1-->3)-alpha-D-glucan samples, ab-PCM3-I and ac-PCM3-I, isolated from different Poria cocos mycelia were sulfated, to produce two series of water-soluble derivatives ab-PCM3-I-S1-S5 and ac-PCM3-I-S1-S5, respectively. The derivatives having different weight-average molecular mass (Mw) were produced by changing reaction temperature and time as well as molar ratios between chlorosulfonic acid and number of hydroxyl groups in the glucan. The degrees of substitution (DS) of the sulfated derivatives were analyzed by elemental analysis (EA) to be 0.39-0.67 for ab-PCM3-I-S and 0.73-0.96 for ac-PCM3-I-S, respectively. The Mw and the intrinsic viscosity ([eta]) of the samples ab-PCM3-I-S and the ac-PCM3-I-S were measured by size exclusion chromatography combined with laser light scattering (SEC-LLS) and viscometry in phosphate buffer solution (PBS) at 37 degrees C. The results indicated that their Mw ranged from 2.0 to 11.3 x 10(4) for the samples ab-PCM3-I-S, and 4.7 to 40.0 x 10(4) for the samples ac-PCM3-I-S. Moreover, the antitumor activities of the sulfated derivatives ab-PCM3-I-S and ac-PCM3-I-S against Sarcoma 180 tumor cell tested both in vitro and in vivo are significantly higher than those of the native alpha-D-glucans. Therefore, a moderate range of molecular mass from 2.0 x 10(4) to 40.0 x 10(4), relatively high chain stiffness and good water solubility of the sulfated derivatives are beneficial to the enhancement of their antitumor activities. PMID:15556230

  7. Food Enzymes

    ERIC Educational Resources Information Center

    McBroom, Rachel; Oliver-Hoyo, Maria T.

    2007-01-01

    Many students view biology and chemistry as two unrelated, separate sciences; how these courses are generally taught in high schools may do little to change that impression. The study of enzymes provide a great opportunity for both biology and chemistry teachers to share with students the interdisciplinary nature of science. This article describes…

  8. Zinc Enzymes.

    ERIC Educational Resources Information Center

    Bertini, I.; And Others

    1985-01-01

    Discusses the role of zinc in various enzymes concerned with hydration, hydrolysis, and redox reactions. The binding of zinc to protein residues, properties of noncatalytic zinc(II) and catalytic zinc, and the reactions catalyzed by zinc are among the topics considered. (JN)

  9. Pectinolytic Enzymes

    Microsoft Academic Search

    Nicemol Jacob

    Pectic substances are prominent structural constituents of primary cell walls and middle lamella in non-woody plant tissues.\\u000a Pectinases are a group of enzymes that contribute to the degradation of pectin by various mechanisms. In nature, pectinases\\u000a are important for plants as they help in cell wall extension and fruit ripening. They have a significant role in maintaining\\u000a ecological balance by

  10. The NAD(P)H-utilizing glutamate dehydrogenase of Bacteroides thetaiotaomicron belongs to enzyme family I, and its activity is affected by trans-acting gene(s) positioned downstream of gdhA.

    PubMed Central

    Baggio, L; Morrison, M

    1996-01-01

    Previous studies have suggested that regulation of the enzymes of ammonia assimilation in human colonic Bacteroides species is coordinated differently than in other eubacteria. The gene encoding an NAD(P)H-dependent glutamate dehydrogenase (gdhA) in Bacteroides thetaiotaomicron was cloned and expressed in Escherichia coli by mutant complementation from the recombinant plasmid pANS100. Examination of the predicted GdhA amino acid sequence revealed that this enzyme possesses motifs typical of the family I-type hexameric GDH proteins. Northern blot analysis with a gdhA-specific probe indicated that a single transcript with an electrophoretic mobility of approximately 1.6 kb was produced in both B. thetaiotaomicron and E. coli gdhA+ transformants. Although gdhA transcription was unaffected, no GdhA enzyme activity could be detected in E. coli transformants when smaller DNA fragments from pANS100, which contained the entire gdhA gene, were analyzed. Enzyme activity was restored if these E. coli strains were cotransformed with a second plasmid, which contained a 3-kb segment of DNA located downstream of the gdhA coding region. Frameshift mutagenesis within the DNA downstream of gdhA in pANS100 also resulted in the loss of GdhA enzyme activity. Collectively, these results are interpreted as evidence for the role of an additional gene product(s) in modulating the activity of GDH enzyme activity. Insertional mutagenesis experiments which led to disruption of the gdhA gene on the B. thetaiotaomicron chromosome indicated that gdhA mutants were not glutamate auxotrophs, but attempts to isolate similar mutants with insertion mutations in the region downstream of the gdhA gene were unsuccessful. PMID:8955404

  11. PROTEOLYTIC ENZYMES

    PubMed Central

    Grob, David

    1946-01-01

    1. The literature on conditions affecting the activity of proteolytic enzymes has been reviewed. 2. Experimental data on the control of the activity of trypsin, leucoprotease, papain, serum antiprotease, leucopeptidase, and pancreatic peptidase have been presented. These data indicate that: (a) The polymorphonuclearleucocytes of the cat contain abundant proteinase and peptidase active at neutral pH; those of the rabbit lack proteinase active at neutral pH. (b) Reducing agents, including several biologically important thiol-sulfhydryl compounds and ascorbic acid, inhibit the activity of leucoprotease and trypsin. For each reductant the degree of inhibition is proportional to the reducing capacity of the medium. (c) p-Aminobenzoic acid, sulfonamides (especially sulfathiazole), and many diphenyl sulfones inhibit the activity of leucoprotease. (d) Serum, plasma, several heavy metals, ammonium salts, asparagine, thiourea, heparin, glutamic acid, tyrothricin, calcium chloride, and bile salts and bile acids also inhibit the activity of leucoprotease, and in most cases of trypsin too. (e) Preparations of tryptic digests of proteins, and egg white trypsin inhibitor, inhibit trypsin to a much greater degree than leucoprotease. (f) Mild oxidizing agents increase the activity of leucoprotease and trypsin. (g) Oxidizing agents and some inhibitors of sulfhydryl groups inhibit the antiproteolytic activity of the serum. It is suggested that serum antiprotease may consist (chiefly) of reducing agents, including thiol-sulfhydryl peptides which exert their antiproteolytic activity by virtue of the presence of sulfhydryl groups. (h) The antiproteolytic activity of the serum is progressively weakened by exposure to a hydrogen ion concentration below pH 6.5 or above pH 9.7. Because of this the pH optima of leucoprotease and trypsin are shifted in the presence of serum from pH of 7 and 8 to pH of 6 to 6.5, and the range of activity of these enzymes is slightly widened, in both acid and alkaline reactions. (i) Reducing agents increase the activity of leucopeptidase and pancreatic peptidase. Serum, sulfathiazole, and thiourea have little or no effect. 3. The significance of the oxidation-reduction system in the control of the activity of leucoprotease, trypsin, serum antiprotease, leucopeptidase, and pancreatic peptidase has been emphasized. PMID:19873458

  12. BIOCHEMISTRY: Remote Enzyme Microsurgery

    NSDL National Science Digital Library

    J. Martin Bollinger (Pennsylvania State University; Department of Chemistry)

    2010-03-12

    Enzymes enhance the rate of chemical reactions. Useful electrophiles for use in these reactions are few in the standard amino acid building blocks of enzymes. This perspective discusses "enzyme microsurgery" for construction of an electrophile.

  13. ACT Test

    MedlinePLUS

    ... Was this page helpful? Also known as: Activated Coagulation Time Formal name: Activated Clotting Time Related tests: ... and oxygenated. Acquired and inherited conditions such as coagulation factor deficiencies may also affect ACT results. ^ Back ...

  14. Balancing Acts

    MedlinePLUS

    ... Current Issue Past Issues Special Section: Focus on Communication Balancing Acts Past Issues / Fall 2008 Table of ... from the National Institute on Deafness and Other Communication Disorders (NIDCD). It involves simulated trips down the ...

  15. Extracellular Enzymes Lab Biochemistry

    E-print Network

    Vallino, Joseph J.

    Extracellular Enzymes Lab Biochemistry · All organisms convert small organic compounds, of which there are more than 1000, are catalyzed by enzymes. Glucose (C6) Pentose (C5) Triose (C3) Pyruvate Complete Metabolic Network TOP #12;#12;Enzymes · Enzymes are large proteins that all organisms synthesize

  16. Pool & Spa Safety Act

    MedlinePLUS

    ... Safely > The Pool & Spa Safety Act The Pool & Spa Safety Act Download the Act 2008 Pool & Spa ... Act Format: PDF The Virginia Graeme Baker Pool & Spa Safety Act (P&SS Act) was enacted by Congress ...

  17. Insolubilization process increases enzyme stability

    NASA Technical Reports Server (NTRS)

    Billingham, J.; Lyn, J.

    1971-01-01

    Enzymes complexed with polymeric matrices contain properties suggesting application to enzyme-controlled reactions. Stability of insolubilized enzyme derivatives is markedly greater than that of soluble enzymes and physical form of insolubilized enzymes is useful in column and batch processes.

  18. DNA Gyrase: An Enzyme that Introduces Superhelical Turns into DNA

    Microsoft Academic Search

    Martin Gellert; Kiyoshi Mizuuchi; Mary H. O'Dea; Howard A. Nash

    1976-01-01

    Relaxed closed-circular DNA is converted to negatively supercoiled DNA by DNA gyrase. This enzyme has been purified from Escherichia coli cells. The reaction requires ATP and Mg++ and is stimulated by spermidine. The enzyme acts equally well on relaxed closed-circular colicin E1, phage lambda , and simian virus 40 DNA. The final superhelix density of the DNA can be considerably

  19. Bioterrorism Act of 2002

    MedlinePLUS

    ... Food, Drug, and Cosmetic Act (FD&C Act) Bioterrorism Act of 2002 Sign up for Bioterrorism Act ... Bush signed into law June 12, 2002. - - The Bioterrorism Act is divided into five titles Title I -- ...

  20. Enzyme responsive acetaminophen hydrogels

    E-print Network

    Vemula, Praveen

    Utilization of enzyme catalysis as a tool to disassemble self-assembled hydrogels to control the release encapsulated drug provides an opportunity to design a wide range of enzyme-specific low-molecular-weight hydrogelators ...

  1. Extracellular Enzymes Lab Biochemistry

    E-print Network

    Vallino, Joseph J.

    Extracellular Enzymes Lab Biochemistry · All organisms convert small organic compounds shown here: All of these reactions, of which there are more than 1000, are catalyzed by enzymes. Glucose Phosphate PathwayEMP Pathway #12;Amino Acids #12;More Complete Metabolic Network TOP #12;#12;Enzymes

  2. Extracellular Enzymes Lab Biochemistry

    E-print Network

    Vallino, Joseph J.

    Extracellular Enzymes Lab Biochemistry · All organisms convert small organic compounds by enzymes. Glucose (C6) Pentose (C5) Triose (C3) Pyruvate (C3) AcetylCoA (C2) Citrate (C6) Oxoglutarate (C5 Cycle Pentose Phosphate PathwayEMP Pathway #12;More Complete Metabolic Network TOP #12;#12;Enzymes

  3. Self-powered enzyme micropumps

    NASA Astrophysics Data System (ADS)

    Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

    2014-05-01

    Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

  4. Act resilient.

    PubMed

    Joseph, Genie; Bice-Stephens, Wynona

    2014-01-01

    Attendees have reported changing from being fearful to serene, from listless to energized, from disengaged to connected, and becoming markedly less anxious in a few weeks. Anecdotally, self-reported stress levels have been reduced by over 50% after just one class. Attendees learn not to be afraid of their feelings by working with emotions in a playful manner. When a person can act angry, but separate himself from his personal story, the emotional energy exists in a separate form that is not attached to specific events, and can be more easily dealt with and neutralized. Attendees are taught to "take out the emotional trash" through expressive comedy. They become less intimated by their own emotional intensity and triggers as they learn how even metaphorical buckets of anger, shame, guilt and hurt can be emotionally emptied. The added benefit is that this is accomplished without the disclosure of personal information of the requirement to reexperience past pain which can trigger its own cascade of stress. PMID:24706248

  5. Direct in Situ Observation of Synergism between Cellulolytic Enzymes during the Biodegradation of Crystalline Cellulose Fibers

    E-print Network

    Dutcher, John

    Direct in Situ Observation of Synergism between Cellulolytic Enzymes during the Biodegradation types of T. reesei cellulolytic enzymes TrCel6A, TrCel7A, and TrCel7Band their mixtures. TrCel6A and Tr. When acting alone on native cellulose fibers, each of the three enzymes is incapable of significant

  6. A Hands-On Classroom Simulation to Demonstrate Concepts in Enzyme Kinetics

    ERIC Educational Resources Information Center

    Junker, Matthew

    2010-01-01

    A classroom exercise is described to introduce enzyme kinetics in an undergraduate biochemistry or chemistry course. The exercise is a simulation in which a student acts as an enzyme that "catalyzes" the unscrewing of a nut from a bolt. With other students assisting, the student enzyme carries out reactions with bolt-nut substrates under different…

  7. Rational enzyme redesign

    SciTech Connect

    Ornstein, R.L.

    1994-05-01

    Protein engineering is first a means of elucidating structure-function relations in an enzyme, and second, a means of changing a protein to make it serve a different, but generally related, purpose. In principle, one may change the functional characteristics of an enzyme by altering its substrate specificity, kinetics, optimum range of activity, and chemical mechanism. Obviously one cannot make all possible combinations of amino acid changes for even the smallest enzyme, so the essential question is which changes to make. The intent of rational protein/enzyme redesign is to alter a protein/enzyme in a timely and premeditated fashion. This article provides an outline of the process of rational enzyme redesign.

  8. Restriction Enzyme Mapping Lab

    NSDL National Science Digital Library

    This laboratory activity, by the Biotechnology Education and Training Sequence Investment (BETSI) project at Southwestern College, walks students and educators through the procedure of restriction enzyme mapping. Restriction enzymes are found in bacteria and "cleave the double helix of DNA at specific places." This activity, which is broken up into two parts, allows students to observe this process by presenting specific procedure steps and illustrations to guide them. There is also a worksheet for students to complete: Analysis of a Restriction Enzyme Digest of a Plasmid. This is a helpful activity for any biotechnology classroom to give students hands-on experiences with enzymes and the reconstruction of recombinant DNA molecules.

  9. Dissipative Dynamics of Enzymes

    NASA Astrophysics Data System (ADS)

    Ariyaratne, Amila; Wu, Chenhao; Tseng, Chiao-Yu; Zocchi, Giovanni; Zocchi Lab for Molecular Biophysics Team

    2015-03-01

    We explore enzyme conformational dynamics at sub - Ĺ resolution, specifically temperature effects. The ensemble averaged mechanical response of the folded enzyme is viscoelastic in the whole temperature range between the warm and cold denaturation transitions. The dissipation parameter ? of the viscoelastic description decreases by a factor 2 as the temperature is raised from 10 C to 45 C; the elastic parameter K shows a similar decrease. Thus when probed dynamically, the enzyme softens for increasing temperature. Equilibrium mechanical experiments with the DNA spring (and a different enzyme) also show, qualitatively, a small softening for increasing temperature.

  10. Dissipative Dynamics of Enzymes

    NASA Astrophysics Data System (ADS)

    Ariyaratne, Amila; Wu, Chenhao; Tseng, Chiao-Yu; Zocchi, Giovanni

    2014-11-01

    We explore enzyme conformational dynamics at sub-Ĺ resolution, specifically, temperature effects. The ensemble-averaged mechanical response of the folded enzyme is viscoelastic in the whole temperature range between the warm and cold denaturation transitions. The dissipation parameter ? of the viscoelastic description decreases by a factor of 2 as the temperature is raised from 10 to 45 °C ; the elastic parameter K shows a similar decrease. Thus, when probed dynamically, the enzyme softens for increasing temperature. Equilibrium mechanical experiments with the DNA spring (and a different enzyme) also show, qualitatively, a small softening for increasing temperature.

  11. Influencing Enzymes: A Lesson on Enzyme Reactions

    NSDL National Science Digital Library

    Camia Steinmann (Clear Creek High School)

    2007-08-01

    This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 2007 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org. Students will investigate the catabolic properties of the enzyme amylase and its role in digestion of breaking down starch molecules. Prior to this activity, students should be able to identify the structural and functional properties of carbohydrates and proteins. Upon completion of this activity, students will be able to predict the effect of different environments on enzyme activity.

  12. Enzyme Database - BRENDA

    NSDL National Science Digital Library

    Institute of Biochemistry and Bioinformatics at the Technical University of Braunschweig, Germany

    BRENDA is the main collection of enzyme functional data available to the scientific community. It is available free of charge for via the internet (www.brenda-enzymes.info) and as an in-house database for commercial users (requests to our distributor Biobase).

  13. Aromatase: a neuroprotective enzyme

    Microsoft Academic Search

    Luis M. Garcia-Segura; Sergio Veiga; Amanda Sierra; Roberto C. Melcangi; Ińigo Azcoitia

    2003-01-01

    Estradiol, in addition to its participation in neuroendocrine regulation and sexual behavior, has neuroprotective properties. Different types of brain injury induce the expression of the enzyme aromatase in reactive astroglia. This enzyme catalyzes the conversion of testosterone and other C19 steroids to estradiol. Genetic or pharmacological inhibition of brain aromatase results in marked neurodegeneration after different forms of mild neurodegenerative

  14. Pectinolytic enzymes of large rumen treponemes.

    PubMed Central

    Wojciechowicz, M; Zio?ecki, A

    1979-01-01

    Large spiral organisms isolated from the rumen of cattle produced and released into the external environment a complex of pectinolytic enzymes, consisting mainly of poly(1,4-alpha-D-galacturonide) lyase (EC 4.2.2.2, formerly EC 4.2.99.3), most active at pH 8.0 to 9.0, and another enzyme acting at pH below 7.0, probably a poly(1,4-alpha-D-galacturonide) glycanohydrolase (EC 3.2.1.15). The mixture of enzymes degraded polygalacturonate to saturated and unsaturated monogalacturonates as the end products. A pectin pectylhydrolase (pectinesterase) (EC 3.1.1.11) was also present in the clarified cultures. PMID:32839

  15. Enzyme-Catalyzed Processes in Organic Solvents

    Microsoft Academic Search

    Aleksey Zaks; Alexander M. Klibanov

    1985-01-01

    Three different lipases (porcine pancreatic, yeast, and mold) can vigorously act as catalysts in a number of nearly anhydrous organic solvents. Various transesterification reactions catalyzed by porcine pancreatic lipase in hexane obey Michaelis-Menten kinetics. The dependence of the catalytic activity of the enzyme in organic media on the pH of the aqueous solution from which it was recovered is bell-shaped,

  16. Mechanisms, biology and inhibitors of deubiquitinating enzymes

    Microsoft Academic Search

    Kerry Routenberg Love; André Catic; Christian Schlieker; Hidde L Ploegh

    2007-01-01

    The addition of ubiquitin (Ub) and ubiquitin-like (Ubl) modifiers to proteins serves to modulate function and is a key step in protein degradation, epigenetic modification and intracellular localization. Deubiquitinating enzymes and Ubl-specific proteases, the proteins responsible for the removal of Ub and Ubls, act as an additional level of control over the ubiquitin-proteasome system. Their conservation and widespread occurrence in

  17. Enzyme engineering 8

    SciTech Connect

    Laskin, A.I.; Mosbach, K.; Thomas, D.; Wingard, L.B.

    1987-01-01

    This book discusses the genetic engineering of enzymes. A review is presented of biotechnology advances, hybridization techniques, DNA recombination and genetic mapping of gene operons. Computer-aided design of protein engineering in also briefly discussed.

  18. RNA as an Enzyme.

    ERIC Educational Resources Information Center

    Cech, Thomas R.

    1986-01-01

    Reviews current findings that explain RNA's function as an enzyme in addition to being an informational molecule. Highlights recent research efforts and notes changes in the information base on RNA activity. Includes models and diagrams of RNA activity. (ML)

  19. Enzymes in Analytical Chemistry.

    ERIC Educational Resources Information Center

    Fishman, Myer M.

    1980-01-01

    Presents tabular information concerning recent research in the field of enzymes in analytic chemistry, with methods, substrate or reaction catalyzed, assay, comments and references listed. The table refers to 128 references. Also listed are 13 general citations. (CS)

  20. Enzymes and Their Functions

    NSDL National Science Digital Library

    CLIMB: Cornell's Learning Initiative in Medicine and Bioengineering

    In this module, developed as part of Cornell's Learning Initiative in Medicine and Bioengineering (CLIMB), students will learn about enzymes and how their activities are affected by different environmental factors. Following an introductory activity, students will conduct an experiment using amylase (enzyme) and starch (substrate) as an example. This module includes a teacher's guide with learning objectives and classroom activities; student activity sheets are included. CLIMB is part of the NSF GK-12 program.

  1. Overproduction of ligninolytic enzymes

    SciTech Connect

    Elisashvili, Vladimir; Kachlishvili, Eva; Torok, Tamas

    2014-06-17

    Methods, compositions, and systems for overproducing ligninolytic enzymes from the basidiomycetous fungus are described herein. As described, the method can include incubating a fungal strain of Cerrena unicolor IBB 303 in a fermentation system having growth medium which includes lignocellulosic material and then cultivating the fungal strain in the fermentation system under conditions wherein the fungus expresses the ligninolytic enzymes. In some cases, the lignocellulosic material is mandarin peel, ethanol production residue, walnut pericarp, wheat bran, wheat straw, or banana peel.

  2. [Enzymes of snake venoms].

    PubMed

    Gornitskaia, O V; Platonova, T N; Volkov, G L

    2003-01-01

    Snakes' venom is a mixture of biologically active substances, containing proteins and peptides. A number of these proteins interact with haemostasis system components. Activators and inhibitors affecting blood coagulation and fibrinolysis systems are of special interest. Venom components can be classified into three main groups, such as procoagulants, anticoagulants and fibrinolytic enzymes according to their action. This review is focused on enzymes from Agkistrodon halys halys venom. They are thrombine-like enzyme, named Ancystron-H, flbrinogenolytic enzyme, protein C activator and platelet aggregation inhibitor. Ancystron-H is used for determination of fibrinogen level in blood plasma of patients undergoing heparin treatment and blood coagulation inhibitors accumulation. The fibrinogenolytic enzyme can be used as the instrument for protein-protein interactions in fibrinogen-fibrin system. The protein C activator is used for protein C level determination in blood plasma with different pathologies. Functions of the platelet aggregation inhibitor, belonging to disintegrins group, can be used for development of antithrombotic preparations. Information about the use of snake venoms in science and medicine is presented. PMID:14577148

  3. Lignin-degrading enzymes.

    PubMed

    Pollegioni, Loredano; Tonin, Fabio; Rosini, Elena

    2015-04-01

    A main goal of green biotechnology is to reduce our dependence on fossil reserves and to increase the use of renewable materials. For this, lignocellulose, which is composed of cellulose, hemicellulose and lignin, represents the most promising feedstock. The latter is a complex aromatic heteropolymer formed by radical polymerization of guaiacyl, syringyl, and p-hydroxyphenyl units linked by ?-aryl ether linkages, biphenyl bonds and heterocyclic linkages. Accordingly, lignin appears to be a potentially valuable renewable aromatic chemical, thus representing a main pillar in future biorefinery. The resistance of lignin to breakdown is the main bottleneck in this process, although a variety of white-rot fungi, as well as bacteria, have been reported to degrade lignin by employing different enzymes and catabolic pathways. Here, recent investigations have expanded the range of natural biocatalysts involved in lignin degradation/modification and significant progress related to enzyme engineering and recombinant expression has been made. The present review is focused primarily on recent trends in ligninolytic green biotechnology to suggest the potential (industrial) application of ligninolytic enzymes. Future perspectives could include synergy between natural enzymes from different sources (as well as those obtained by protein engineering) and other pretreatment methods that may be required for optimal results in enzyme-based, environmentally friendly, technologies. PMID:25649492

  4. Hfq stimulates the activity of the CCA-adding enzyme

    PubMed Central

    Scheibe, Marion; Bonin, Sonja; Hajnsdorf, Eliane; Betat, Heike; Mörl, Mario

    2007-01-01

    Background The bacterial Sm-like protein Hfq is known as an important regulator involved in many reactions of RNA metabolism. A prominent function of Hfq is the stimulation of RNA polyadenylation catalyzed by E. coli poly(A) polymerase I (PAP). As a member of the nucleotidyltransferase superfamily, this enzyme shares a high sequence similarity with an other representative of this family, the tRNA nucleotidyltransferase that synthesizes the 3'-terminal sequence C-C-A to all tRNAs (CCA-adding enzyme). Therefore, it was assumed that Hfq might not only influence the poly(A) polymerase in its specific activity, but also other, similar enzymes like the CCA-adding enzyme. Results Based on the close evolutionary relation of these two nucleotidyltransferases, it was tested whether Hfq is a specific modulator acting exclusively on PAP or whether it also influences the activity of the CCA-adding enzyme. The obtained data indicate that the reaction catalyzed by this enzyme is substantially accelerated in the presence of Hfq. Furthermore, Hfq binds specifically to tRNA transcripts, which seems to be the prerequisite for the observed effect on CCA-addition. Conclusion The increase of the CCA-addition in the presence of Hfq suggests that this protein acts as a stimulating factor not only for PAP, but also for the CCA-adding enzyme. In both cases, Hfq interacts with RNA substrates, while a direct binding to the corresponding enzymes was not demonstrated up to now (although experimental data indicate a possible interaction of PAP and Hfq). So far, the basic principle of these stimulatory effects is not clear yet. In case of the CCA-adding enzyme, however, the presented data indicate that the complex between Hfq and tRNA substrate might enhance the product release from the enzyme. PMID:17949481

  5. The ENZYME database in 2000

    Microsoft Academic Search

    Amos Bairoch

    2000-01-01

    The ENZYME database is a repository of information related to the nomenclature of enzymes. In recent years it has became an indispensable resource for the development of metabolic databases. The current version contains information on 3705 enzymes. It is available through the ExPASy WWW server (http:\\/\\/www. expasy.ch\\/enzyme\\/ ).

  6. Microbial pectinolytic enzymes: A review

    Microsoft Academic Search

    Ranveer Singh Jayani; Shivalika Saxena; Reena Gupta

    2005-01-01

    Pectinases or petinolytic enzymes, hydrolyze pectic substances. They have a share of 25% in the global sales of food enzymes. Pectinases are one of the most widely distributed enzymes in bacteria, fungi and plants. Protopectinases, polygalacturonases, lyases and pectin esterases are among the extensively studied pectinolytic enzymes. Protopectinases catalyze the solubilization of protopectin. Polygalacturonases hydrolyze the polygalacturonic acid chain by

  7. Enzymes for trauma

    PubMed Central

    Miller, Russell R.; De Young, Dirk V.; Paxinos, James

    1970-01-01

    We will discuss the mechanism of action, efficacy and side-effects of the proteolytic enzymes. Their exact mechanism of action remains vague which may be partly responsible for the uncertainty about their therapeutic value. Use of chymotrypsin (Alpha-Chymar) in lens extractions has gained general acceptance and the topical use of trypsin-chymotrypsin (Biozyme), streptokinase-streptodornase (Varidase) and fibrinolysin-desoxyribonuclease (Elase) will also be shown to be of some value. The merits of oral, buccal or intramuscular administration, however, will not be conclusively demonstrated. Studies showing favourable results for non-topically administered enzymes are not completely acceptable, primarily due to the lack of precise techniques of measurement. The effectiveness of systemically administered preparations of proteolytic enzymes as anti-inflammatory agents will remain to be established. PMID:4245442

  8. Fun with Enzymes

    NSDL National Science Digital Library

    Dawn DeMayo (Montclair High School)

    2007-08-01

    In this activity, the high school students will design and carry out a procedure to observe and understand how enzymatic reactions are affected by different pH levels, different temperatures, and various substrate and enzyme concentrations. This lab can fit in nicely with a unit on biochemistry or macromolecules. Upon completion of this activity, students will be able to understand how pH, temperature and concentration affect the rate of a reaction, make solutions of different enzyme and/or substrate concentrations, and understand the importance of physiological pH and enzymes. This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 2007 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org.

  9. The Enzyme Function Initiative.

    PubMed

    Gerlt, John A; Allen, Karen N; Almo, Steven C; Armstrong, Richard N; Babbitt, Patricia C; Cronan, John E; Dunaway-Mariano, Debra; Imker, Heidi J; Jacobson, Matthew P; Minor, Wladek; Poulter, C Dale; Raushel, Frank M; Sali, Andrej; Shoichet, Brian K; Sweedler, Jonathan V

    2011-11-22

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic, we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include (1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation), (2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia, (3) computational and bioinformatic tools for using the strategy, (4) provision of experimental protocols and/or reagents for enzyme production and characterization, and (5) dissemination of data via the EFI's Website, http://enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal, and pharmaceutical efforts. PMID:21999478

  10. Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates

    DOEpatents

    Callstrom, Matthew R. (Columbus, OH); Bednarski, Mark D. (Berkeley, CA); Gruber, Patrick R. (St. Paul, MN)

    1997-01-01

    An improvement in enzyme linked immunoassays is disclosed wherein the enzyme is in the form of a water soluble polymer saccharide conjugate which is stable in hostile environments. The conjugate comprises the enzyme which is linked to the polymer at multiple points through saccharide linker groups.

  11. Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates

    DOEpatents

    Callstrom, M.R.; Bednarski, M.D.; Gruber, P.R.

    1997-11-25

    An improvement in enzyme linked immunoassays is disclosed wherein the enzyme is in the form of a water soluble polymer saccharide conjugate which is stable in hostile environments. The conjugate comprises the enzyme which is linked to the polymer at multiple points through saccharide linker groups. 19 figs.

  12. Robust enzyme-silica composites made from enzyme nanocapsules.

    PubMed

    Li, Jie; Jin, Xin; Liu, Yang; Li, Fan; Zhang, Linlin; Zhu, Xianyuan; Lu, Yunfeng

    2015-05-28

    Novel enzyme composites are synthesized first by in situ polymerization around enzymes and a subsequent sol-gel process. Both the polymer shell and the silica shell with desired functional moieties provide not only great enzyme protection but also a favorable microenvironment, resulting in significantly enhanced activity and stability. PMID:25971337

  13. Forgetting ACT UP

    ERIC Educational Resources Information Center

    Juhasz, Alexandra

    2012-01-01

    When ACT UP is remembered as the pinnacle of postmodern activism, other forms and forums of activism that were taking place during that time--practices that were linked, related, just modern, in dialogue or even opposition to ACT UP's "confrontational activism"--are forgotten. In its time, ACT UP was embedded in New York City, and a larger world,…

  14. Treating Wastewater With Immobilized Enzymes

    NASA Technical Reports Server (NTRS)

    Jolly, Clifford D.

    1991-01-01

    Experiments show enzymes are immobilized on supporting materials to make biocatalyst beds for treatment of wastewater. With suitable combination of enzymes, concentrations of various inorganic and organic contaminants, including ammonia and urea, reduced significantly.

  15. Enzymes for trauma

    Microsoft Academic Search

    Russell R. Miller; Dirk V. De Young; James Paxinos

    1970-01-01

    We will discuss the mechanism of action, efficacy and side-effects of the proteolytic enzymes. Their exact mechanism of action remains vague which may be partly responsible for the uncertainty about their therapeutic value.Use of chymotrypsin (Alpha-Chymar) in lens extractions has gained general acceptance and the topical use of trypsin-chymotrypsin (Biozyme), streptokinase-streptodornase (Varidase) and fibrinolysin-desoxyribonuclease (Elase) will also be shown to

  16. Original article Lipogenic enzyme activities

    E-print Network

    Paris-Sud XI, Université de

    Original article Lipogenic enzyme activities in subcutaneous adipose tissue and skeletal muscle, lipogenic enzyme activities and expression of GLUT4 mRNA were determined in subcutaneous adipose tissue. In adipose tissue, acetyl-CoA-carboxylase (CBX), fatty acid synthase (FAS), malic enzyme (ME), glucose-6

  17. Direct in situ observation of synergism between cellulolytic enzymes during the biodegradation of crystalline cellulose fibers.

    PubMed

    Wang, Jingpeng; Quirk, Amanda; Lipkowski, Jacek; Dutcher, John R; Clarke, Anthony J

    2013-12-01

    High-resolution atomic force microscopy (AFM) was used to image the real-time in situ degradation of crystalline by three types of T. reesei cellulolytic enzymes-TrCel6A, TrCel7A, and TrCel7B-and their mixtures. TrCel6A and TrCel7A are exo-acting cellobiohydrolases processing cellulose fibers from the nonreducing and reducing ends, respectively. TrCel7B is an endoglucanase that hydrolyzes amorphous cellulose within fibers. When acting alone on native cellulose fibers, each of the three enzymes is incapable of significant degradation. However, mixtures of two enzymes exhibited synergistic effects. The degradation effects of this synergism depended on the order in which the enzymes were added. Faster hydrolysis rates were observed when TrCel7A (exo) was added to fibers pretreated first with TrCel7B (endo) than when adding the enzymes in the opposite order. Endo-acting TrCel7B removed amorphous cellulose, softened and swelled the fibers, and exposed single microfibrils, facilitating the attack by the exo-acting enzymes. AFM images revealed that exo-acting enzymes processed the TrCel7B-pretreated fibers preferentially from one specific end (reducing or nonreducing). The most efficient (almost 100%) hydrolysis was observed with the mixture of the three enzymes. In this mixture, TrCel7B softened the fiber and TrCel6A and TrCel7A were directly observed to process it from the two opposing ends. This study provides high-resolution direct visualization of the nature of the synergistic relation between T. reesei exo- and endo-acting enzymes digesting native crystalline cellulose. PMID:24195649

  18. Microbial Enzymes with Special Characteristics for Biotechnological Applications

    PubMed Central

    Nigam, Poonam Singh

    2013-01-01

    This article overviews the enzymes produced by microorganisms, which have been extensively studied worldwide for their isolation, purification and characterization of their specific properties. Researchers have isolated specific microorganisms from extreme sources under extreme culture conditions, with the objective that such isolated microbes would possess the capability to bio-synthesize special enzymes. Various Bio-industries require enzymes possessing special characteristics for their applications in processing of substrates and raw materials. The microbial enzymes act as bio-catalysts to perform reactions in bio-processes in an economical and environmentally-friendly way as opposed to the use of chemical catalysts. The special characteristics of enzymes are exploited for their commercial interest and industrial applications, which include: thermotolerance, thermophilic nature, tolerance to a varied range of pH, stability of enzyme activity over a range of temperature and pH, and other harsh reaction conditions. Such enzymes have proven their utility in bio-industries such as food, leather, textiles, animal feed, and in bio-conversions and bio-remediations. PMID:24970183

  19. Actinobacterial enzyme inhibitors - A review.

    PubMed

    Manivasagan, Panchanathan; Venkatesan, Jayachandran; Sivakumar, Kannan; Kim, Se-Kwon

    2015-06-01

    Actinobacteria have potential as important new sources of enzyme inhibitors. Enzyme inhibitors have great demand in medicine, agriculture and biotechnology. In medicine, enzyme inhibitors can be used as therapeutic agents for bacterial, fungal, viral and parasitic diseases as well as treating cancer, neurodegenerative, immunological and cardiovascular diseases. Enzyme inhibitors are also valuable for the control of carbohydrate-dependent diseases such as diabetes, obesity and hyperlipidemia and melanogenesis in skin. They can be also involved in crop protection against plant pathogens, herbivorous pests and abiotic stresses such as drought. In this review, we discuss about several actinobacterial enzyme inhibitors with various industrial uses and biotechnological applications. PMID:24495095

  20. SupplementtoNaturePublishingGroupjournals Enzyme 1 Enzyme 2 Enzyme 3 Scaffold

    E-print Network

    Khalil, Ahmad S.

    Enzyme 1 Enzyme 2 Enzyme 3 lacI tetR cllacItetR lacItetR RNAi Gene RNAi target lacItetR RNAi Gene RNAi and pathways and to use these constructs to rewire and reprogram organisms. These re-engineered organisms

  1. A sensitive enzyme electrode for phenol monitoring

    SciTech Connect

    Kulys, J.; Schmid, R.D. (GBF-Gesellschaft fuer Biotechnologische Forschung mbH, Braunschweig (West Germany))

    1990-01-01

    Tyrosinase (EC.1.14.18.1) was immobilized onto graphite electrodes, which had been modified with tetracyanoquinodimethane (TCNQ). The response time, 12 or 35 s, was dependent on the enzyme immobilization technique used. The electrodes showed a linear calibration function up to 25 or 65 {mu}M phenol, and a sensitivity of 0.36 or 2.2 A/M was achieved which was also dependent on the enzyme immobilization technique used. The detection limit for phenol was 0.23 {mu}M. The electrodes acted from potentials of {minus}200 to +180 mV (vs. a saturated Ag/AgCl electrode). The electrode signal was independent of pH within the pH range 4.5-6.0. The enzyme electrode responded to phenol (100%), p-cresol (93%) and catechol (330%), but not to o-cresol and L-tyrosine. The electrodes showed a stability for more than one week. The electrodes can be utilized for the sensitive assay of phenol in water.

  2. ENZYMES OF THE LUNG

    PubMed Central

    Vatter, A. E.; Reiss, O. K.; Newman, Joyce K.; Lindquist, Karin; Groeneboer, Elly

    1968-01-01

    The esterases of rabbit lung have been investigated from two viewpoints, the cytochemical and the biochemical. To accomplish this objective, we designed and synthesized a series of ester substrates which provide both a cytochemical indicator of the location of the enzyme and a means of following the enzymatic activity in tissue homogenates and subfractions. The substrates are p-nitrophenylthiol esters which yield, upon hydrolysis, carboxylic acid and p-nitrothiophenol. The latter can react with aurous ions to give an electron-opaque deposit; in addition, the strong absorption of p-nitrothiophenol at 410 mµ permits continuous kinetic measurements. Thus, it is possible to correlate the intracellular site of action and the biochemical behavior of the esterases. The new substrates are the thiol analogues of the p-nitrophenyl esters frequently employed as esterase substrates. The rates of hydrolysis of the two series of esters are compared in vitro. During tissue fractionation, most of the esterase activity sediments with a particulate fraction. The effects of a number of common esterase inhibitors, such as diisopropyl phosphorofluoridate and eserine sulfate, are examined, and the effects of enzyme concentration and heat inactivation are shown with the use of the partially purified preparations. The cytochemical work shows that the esterase activity is most prominent in the lamellar bodies of the giant alveolar (type II, septal, or granular pneumatocyte) cells of the lung and to a lesser extent in squamous (type I, or membranous pneumatocyte) epithelial and endothelial cells. In both the cytochemical and biochemical studies, the enzymes are inhibited by diisopropyl phosphorofluoridate and phenyl methylsulfonyl fluoride but are insensitive to eserine sulfate. PMID:5691980

  3. Protein Crystal Malic Enzyme

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Malic Enzyme is a target protein for drug design because it is a key protein in the life cycle of intestinal parasites. After 2 years of effort on Earth, investigators were unable to produce any crystals that were of high enough quality and for this reason the structure of this important protein could not be determined. Crystals obtained from one STS-50 were of superior quality allowing the structure to be determined. This is just one example why access to space is so vital for these studies. Principal Investigator is Larry DeLucas.

  4. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture ...58.436 Rennet, pepsin, other milk clotting enzymes and flavor enzymes. Enzyme preparations used...

  5. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture ...58.436 Rennet, pepsin, other milk clotting enzymes and flavor enzymes. Enzyme preparations used...

  6. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture ...58.436 Rennet, pepsin, other milk clotting enzymes and flavor enzymes. Enzyme preparations used...

  7. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture ...58.436 Rennet, pepsin, other milk clotting enzymes and flavor enzymes. Enzyme preparations used...

  8. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture ...58.436 Rennet, pepsin, other milk clotting enzymes and flavor enzymes. Enzyme preparations used...

  9. Stabilization of the cellulase enzyme complex as enzyme nanoparticle.

    PubMed

    Hegedüs, Imre; Hancsók, Jen?; Nagy, Endre

    2012-11-01

    The native Celluclast BG cellulase enzyme complex consists of different enzymes which can also degrade great substrate molecules as native celluloses. This enzyme complex has been covered by a very thin, a few nanometers thick, polymer layer, in order to improve its stability. It has been proved that the polymer layer around the enzyme molecules does not hinder the digestion as great substrates as crystalline cellulose polymer. The stability of the prepared enzyme nanoparticles (PE) could significantly be increased comparing to that of the native one what was proved by results of the total cellulose activity measured. The pretreated enzyme complex holds its activity often a few magnitudes of orders longer in time than that of the native enzyme complex (enzyme without pretreatment). It retains its activity at least ten times longer than that of the native one, at a temperature range between 20 and 37 °C. The pretreated enzyme complex can have about 50 % of its original activity during 12 h of incubation at even 80 °C, while the native cellulase one totally lost it during 6 h incubation time. The activity of PE has not been significantly reduced even at extreme pH values, namely in the pH range of 1.5 to 12. PMID:22956300

  10. DGAT enzymes and triacylglycerol biosynthesis

    PubMed Central

    Yen, Chi-Liang Eric; Stone, Scot J.; Koliwad, Suneil; Harris, Charles; Farese, Robert V.

    2008-01-01

    Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, and the use of molecular tools, including mice deficient in either enzyme, has shed light on their functions. Although DGAT enzymes are involved in TG synthesis, they have distinct protein sequences and differ in their biochemical, cellular, and physiological functions. Both enzymes may be useful as therapeutic targets for diseases. Here we review the current knowledge of DGAT enzymes, focusing on new advances since the cloning of their genes, including possible roles in human health and diseases. PMID:18757836

  11. de novo computational enzyme design.

    PubMed

    Zanghellini, Alexandre

    2014-10-01

    Recent advances in systems and synthetic biology as well as metabolic engineering are poised to transform industrial biotechnology by allowing us to design cell factories for the sustainable production of valuable fuels and chemicals. To deliver on their promises, such cell factories, as much as their brick-and-mortar counterparts, will require appropriate catalysts, especially for classes of reactions that are not known to be catalyzed by enzymes in natural organisms. A recently developed methodology, de novo computational enzyme design can be used to create enzymes catalyzing novel reactions. Here we review the different classes of chemical reactions for which active protein catalysts have been designed as well as the results of detailed biochemical and structural characterization studies. We also discuss how combining de novo computational enzyme design with more traditional protein engineering techniques can alleviate the shortcomings of state-of-the-art computational design techniques and create novel enzymes with catalytic proficiencies on par with natural enzymes. PMID:24794534

  12. ACT and College Success

    ERIC Educational Resources Information Center

    Bleyaert, Barbara

    2010-01-01

    What is the relationship between ACT scores and success in college? For decades, admissions policies in colleges and universities across the country have required applicants to submit scores from a college entrance exam, most typically the ACT (American College Testing) or SAT (Scholastic Aptitude Test). This requirement suggests that high school…

  13. Proteolytic enzymes of Phymatotrichum omnivorum

    E-print Network

    Burgum, Alexis August

    1964-01-01

    ~CTERIZATION OF THE CRUDE PROTEOLYTIC SYSTEM METHODS a e o o o a o o o o ~ e e o ~ ~ o 12 EXPERIMENTAL PROCEDURES AND RESULTS ~ e a ~ a e ~ 19 DISCUSSION e e o o e a e e a a a o e e ~ e e a 43 PART I I e PURIFICATION OF A PROTE INASE FROM CULTURE... (intracellular enzymes) or in the medium surrounding the cell (extracellular enzymes). Most of the research on these enzymes has been directed toward proteinases from higher forms of life. For example, the mammalian enzymes trypsin, chymotrypsin, and pepsin...

  14. Making the Rate: Enzyme Dynamics

    ERIC Educational Resources Information Center

    Ragsdale, Frances R.

    2004-01-01

    An enzyme exercise to address the problem of students inability to visualize chemical reaction at the molecular level is described. This exercise is designed as a dry lab exercise but can be modified into a classroom activity then can be augmented by a wet lab procedure, thereby providing students with a practical exposure to enzyme function.

  15. Safety Regulations of Food Enzymes

    Microsoft Academic Search

    Armin Spök

    Summary The majority of industrial enzymes available at present is used in food industry. Safe- ty regulations of food enzymes differ among countries, including fundamental aspects, whether a pre-market approval is needed and on the level of details, e.g. what particular information manufacturers have to provide in the course of safety evaluation. Occupa- tional safety concerns focus on allergenic properties

  16. Recent advances in enzyme assays

    Microsoft Academic Search

    Jean-Philippe Goddard; Jean-Louis Reymond

    2004-01-01

    Enzyme assays for high-throughput screening and enzyme engineering, which are often based on derivatives of coumarin, nitrophenol, fluorescein, nitrobenzofurazane or rhodamine dyes, can be divided into two categories: those that depend on labelled substrates, and those that depend on sensing the reactions of unmodified substrates. Labelled substrates include, for example, fluorogenic and chromogenic substrates that generate a reporter molecule by

  17. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  18. PHYSIOLOGY: Sister Act

    NSDL National Science Digital Library

    David D. Moore (Baylor College of Medicine; Department of Molecular and Cellular Biology)

    2007-06-08

    Access to the article is free, however registration and sign-in are required. Particular fibroblast growth factors function as metabolic hormones and act through a certain signaling cascade design to control specific states of homeostasis.

  19. Disabilities Act in Action.

    ERIC Educational Resources Information Center

    Daynes, Kristine S.

    1990-01-01

    Eight true or false questions explore implications of the Americans with Disabilities Act of 1990. Topics include AIDS, drug abuse, undue hardship, reasonable accommodation, and company size affected by the law. (SK)

  20. Deubiquitinating enzymes as oncotargets.

    PubMed

    McClurg, Urszula L; Robson, Craig N

    2015-04-23

    Carcinogenesis is a complex process tightly regulated at multiple levels by post-translational modifications. Epigenetics plays a major role in cancer development, all stable changes to the gene expression process that are not a result of a direct change in the DNA code are described as epigenetics. Epigenetic processes are regulated by post-translational modifications including ubiquitination which can directly affect either histones or transcription factors or may target their co-factors and interacting partners exerting an indirect effect. Deubiquitination of these target proteins is equally important and alterations in this pathway can also lead to cancer development, progression and metastasis. Only the correct, unaltered balance between ubiquitination and deubiquitination ensures healthy cellular homeostasis. In this review we focus on the role of deubiquitinating (DUB) enzymes in various aspects of epigenetics including the regulation of transcription factors, histone modifications, DNA damage repair pathways and cell cycle regulation. We discuss the impact of those processes on tumourigenesis and potential therapeutic applications of DUBs for cancer treatment. PMID:25962961

  1. Single enzyme studies reveal the existence of discrete functional states for monomeric enzymes and how they are "selected" upon allosteric regulation.

    PubMed

    Hatzakis, Nikos S; Wei, Li; Jorgensen, Sune K; Kunding, Andreas H; Bolinger, Pierre-Yves; Ehrlich, Nicky; Makarov, Ivan; Skjot, Michael; Svendsen, Allan; Hedegĺrd, Per; Stamou, Dimitrios

    2012-06-01

    Allosteric regulation of enzymatic activity forms the basis for controlling a plethora of vital cellular processes. While the mechanism underlying regulation of multimeric enzymes is generally well understood and proposed to primarily operate via conformational selection, the mechanism underlying allosteric regulation of monomeric enzymes is poorly understood. Here we monitored for the first time allosteric regulation of enzymatic activity at the single molecule level. We measured single stochastic catalytic turnovers of a monomeric metabolic enzyme (Thermomyces lanuginosus Lipase) while titrating its proximity to a lipid membrane that acts as an allosteric effector. The single molecule measurements revealed the existence of discrete binary functional states that could not be identified in macroscopic measurements due to ensemble averaging. The discrete functional states correlate with the enzyme's major conformational states and are redistributed in the presence of the regulatory effector. Thus, our data support allosteric regulation of monomeric enzymes to operate via selection of preexisting functional states and not via induction of new ones. PMID:22489643

  2. Mathematical Analysis of Activation Thresholds in Enzyme-Catalyzed Positive Feedbacks: Application to the Feedbacks of Blood Coagulation

    Microsoft Academic Search

    Edward Beltrami; Jolyon Jesty

    1995-01-01

    A hierarchy of enzyme-catalyzed positive feedback loops is examined by mathematical and numerical analysis. Four systems are described, from the simplest, in which an enzyme catalyzes its own formation from an inactive precursor, to the most complex, in which two sequential feedback loops act in a cascade. In the latter we also examine the function of a long-range feedback, in

  3. A Perspective on Enzyme Catalysis

    NASA Astrophysics Data System (ADS)

    Benkovic, Stephen J.; Hammes-Schiffer, Sharon

    2003-08-01

    The seminal hypotheses proposed over the years for enzymatic catalysis are scrutinized. The historical record is explored from both biochemical and theoretical perspectives. Particular attention is given to the impact of molecular motions within the protein on the enzyme's catalytic properties. A case study for the enzyme dihydrofolate reductase provides evidence for coupled networks of predominantly conserved residues that influence the protein structure and motion. Such coupled networks have important implications for the origin and evolution of enzymes, as well as for protein engineering.

  4. 21 CFR 864.4400 - Enzyme preparations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 2013-04-01 false Enzyme preparations. 864.4400 Section 864...Specimen Preparation Reagents § 864.4400 Enzyme preparations. (a) Identification. Enzyme preparations are products that are...

  5. ENZYME TESTING LABS German Linguistic Tester

    E-print Network

    ENZYME TESTING LABS German Linguistic Tester Under supervision of the Project Manager, the Tester as possible Please apply via our website: www.enzyme.org or contact us by email at jobs@enzyme.org #12;

  6. 21 CFR 864.4400 - Enzyme preparations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2010-04-01 false Enzyme preparations. 864.4400 Section 864...Specimen Preparation Reagents § 864.4400 Enzyme preparations. (a) Identification. Enzyme preparations are products that are...

  7. Freedom of Information Act

    NSDL National Science Digital Library

    The Freedom of Information Act (FOIA) website, part of the National Archives and Record Administration (NARA) has been making it easy for journalists, scholars, activists, or any interested party with the statutory right, to get U.S. government information in executive branch agency records. Visitors interested in getting some information, should first read the "FOIA Reference Guide", which can be accessed via the link in the menu on the top left side of any page. The "FOIA Reference Guide" provides the proper way to make a FOIA request. Users can learn more about "Other FOIA Resources" via the link in the menu on the left side, in the bottom corner. There are a couple of links to other government agencies' information on FOIA, as well as a link to a pamphlet called "Your Right To Federal Records" and a link to "A Citizen's Guide to Using the Freedom of Information Act and Privacy Act of 1974 to Request Government Records".

  8. ORGANOPHOSPHATE DEGRADING ENZYMES - PHASE I

    EPA Science Inventory

    Agave BioSystems in collaboration with Carl A. Batt proposes to develop decon-nanoparticles, which will leverage ongoing opportunities in enzyme engineering and the fabrication of functionalized magnetic nanoparticles. Enhanced performance will be engineered into the system t...

  9. PIXE analysis of Zn enzymes

    NASA Astrophysics Data System (ADS)

    Solís, C.; Oliver, A.; Andrade, E.; Ruvalcaba-Sil, J. L.; Romero, I.; Celis, H.

    1999-04-01

    Zinc is a necessary component in the action and structural stability of many enzymes. Some of them are well characterized, but in others, Zn stoichiometry and its association is not known. PIXE has been proven to be a suitable technique for analyzing metallic proteins embedded in electrophoresis gels. In this study, PIXE has been used to investigate the Zn content of enzymes that are known to carry Zn atoms. These include the carbonic anhydrase, an enzyme well characterized by other methods and the cytoplasmic pyrophosphatase of Rhodospirillumrubrum that is known to require Zn to be stable but not how many metal ions are involved or how they are bound to the enzyme. Native proteins have been purified by polyacrylamide gel electrophoresis and direct identification and quantification of Zn in the gel bands was performed with an external proton beam of 3.7 MeV energy.

  10. Regulation of proteolysis by human deubiquitinating enzymes.

    PubMed

    Eletr, Ziad M; Wilkinson, Keith D

    2014-01-01

    The post-translational attachment of one or several ubiquitin molecules to a protein generates a variety of targeting signals that are used in many different ways in the cell. Ubiquitination can alter the activity, localization, protein-protein interactions or stability of the targeted protein. Further, a very large number of proteins are subject to regulation by ubiquitin-dependent processes, meaning that virtually all cellular functions are impacted by these pathways. Nearly a hundred enzymes from five different gene families (the deubiquitinating enzymes or DUBs), reverse this modification by hydrolyzing the (iso)peptide bond tethering ubiquitin to itself or the target protein. Four of these families are thiol proteases and one is a metalloprotease. DUBs of the Ubiquitin C-terminal Hydrolase (UCH) family act on small molecule adducts of ubiquitin, process the ubiquitin proprotein, and trim ubiquitin from the distal end of a polyubiquitin chain. Ubiquitin Specific Proteases (USPs) tend to recognize and encounter their substrates by interaction of the variable regions of their sequence with the substrate protein directly, or with scaffolds or substrate adapters in multiprotein complexes. Ovarian Tumor (OTU) domain DUBs show remarkable specificity for different Ub chain linkages and may have evolved to recognize substrates on the basis of those linkages. The Josephin family of DUBs may specialize in distinguishing between polyubiquitin chains of different lengths. Finally, the JAB1/MPN+/MOV34 (JAMM) domain metalloproteases cleave the isopeptide bond near the attachment point of polyubiquitin and substrate, as well as being highly specific for the K63 poly-Ub linkage. These DUBs regulate proteolysis by: directly interacting with and co-regulating E3 ligases; altering the level of substrate ubiquitination; hydrolyzing or remodeling ubiquitinated and poly-ubiquitinated substrates; acting in specific locations in the cell and altering the localization of the target protein; and acting on proteasome bound substrates to facilitate or inhibit proteolysis. Thus, the scope and regulation of the ubiquitin pathway is very similar to that of phosphorylation, with the DUBs serving the same functions as the phosphatase. This article is part of a Special Issue entitled: Ubiquitin-Proteasome System. Guest Editors: Thomas Sommer and Dieter H. Wolf. PMID:23845989

  11. 21 CFR 864.4400 - Enzyme preparations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Specimen Preparation Reagents § 864.4400 Enzyme preparations. (a) Identification. Enzyme...

  12. 21 CFR 864.4400 - Enzyme preparations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Specimen Preparation Reagents § 864.4400 Enzyme preparations. (a) Identification. Enzyme...

  13. 21 CFR 864.4400 - Enzyme preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Specimen Preparation Reagents § 864.4400 Enzyme preparations. (a) Identification. Enzyme...

  14. Good Samaritan acts.

    PubMed

    Daniels, S

    1999-05-01

    Good Samaritan Acts are those in which aid is rendered to a needy victim of injury or sudden illness. No antecedent relationship exists with the good samaritan, and no remuneration is anticipated. Emergency physicians have an ethical obligation beyond that of other citizens to provide aid in such situations of medical need; professional and legal standards support that obligation. PMID:10429643

  15. The Balancing Act.

    ERIC Educational Resources Information Center

    Weber, Joseph A.; And Others

    1986-01-01

    Elements of the "Balancing Act--Home and Work" program, developed by the Oklahoma State University Cooperative Extension Service and designed to help employees develop skills and insights for balancing home and work responsibilities, are presented. Discusses needs assessment, pilot testing, program marketing, and program effectiveness. (CT)

  16. The coast: Act II

    Microsoft Academic Search

    1977-01-01

    The major thrust of the Coastal Zone Management Act Amendments of 1976 is to facilitate offshore oil and gas development and to assist coastal governments in handling the economic and environmental impacts of offshore energy-producing activities. Refineries, tank farms, pipelines, public facilities, roads, schools, and an increased water supply will be needed. A rapid increase in population could affect natural

  17. Acting like a Pro

    ERIC Educational Resources Information Center

    Walker, Marlon A.

    2012-01-01

    The Saturday morning acting class in the Pearson Hall auditorium at Miles College boasts the school's highest attendance all year. The teacher, actress Robin Givens, was a lure few students--and others from surrounding areas--could resist. Some came to learn about their prospective field from a professional. Others were there for pointers to…

  18. Improving America's Schools Act

    NASA Technical Reports Server (NTRS)

    Cradler, John; Bridgforth, Elizabeth

    1995-01-01

    The Improving America's Schools ACT (IASA) emphasizes coherent systemic education reform, with Goals 2000 setting common standards for IASA and the recently authorized School-to-Work Program. IASA addresses the need to raise academic achievement, increase opportunities to learn, improve professional development, increase community involvement, utilize instructional applications of technology, and improve assessment, and allow more local flexibility in the use of funds.

  19. Derwent's Doors: Creative Acts

    Microsoft Academic Search

    Julia Gillen

    2007-01-01

    Children's early word learning is not usually considered creative in the same sense as artistic productions of later life. Yet early word learning is a creative response to the intrinsic instability of word meaning. As the child acts to participate in her community, she strives for intersubjectivity, manifest in neologisms and under- and overextensions, commonly characterized as errors. Young children's

  20. Activated clotting time (ACT).

    PubMed

    Horton, Stephen; Augustin, Simon

    2013-01-01

    The standard assay for monitoring anticoagulation during extracorporeal life support (ECLS) is the activated clotting time (ACT) test, with celite, kaolin, and glass beads being the most commonly used activators to initiate contact activation. The point-of-care ACT test has been the preferred test in catheterization labs and cardiac theatres because it has a number of advantages over laboratory tests (Spinler et al., Ann Pharmacother 39(7-8):1275-1285, 2005): Shorter time between sampling and results. Smaller blood sample size. Availability to have test performed by non-lab personnel. Reduced errors associated with sample mislabeling/mishandling. Decreased risk of sample degradation with time. There are other coagulation monitoring tests available; however these are usually specific and do not take into account the global picture of the entire clotting system. The standard coagulation tests (prothrombin time (PT), activated partial thromboplastin time, thrombin time (TT), and fibrinogen level) are plasma tests measuring plasma haemostasis and not patient haemostasis. The ACT measurement uses whole blood, thereby incorporating the importance of platelets and phospholipids in the role of coagulation. Many of the problems with the haemostatic system during ECLS are caused by the activation of platelets, which are not detected by standard tests. Because an ACT test is nonspecific there are many variables such as hypothermia, platelets, aprotinin, GP IIb/IIIa antagonists, haemodilution, etc. that can alter its results. For this reason it is important to gain an understanding as to how these variables interact for meaningful interpretation of the ACT test result. PMID:23546712

  1. Call for an enzyme genomics initiative

    PubMed Central

    Karp, Peter D

    2004-01-01

    I propose an Enzyme Genomics Initiative, the goal of which is to obtain at least one protein sequence for each enzyme that has previously been characterized biochemically. There are 1,437 enzyme activities for which Enzyme Commission (EC) numbers have been assigned but no sequence can be found in public protein-sequence databases. PMID:15287973

  2. Molecular Biology Basics Planning Restriction Enzyme Digests

    E-print Network

    Aris, John P.

    Molecular Biology Basics Planning Restriction Enzyme Digests A. Checklist: Buffer type Addition of BSA Optimum temperature Number of units of enzyme B. Plan to digest DNA with an "excess" of enzyme activity. Plan for the "excess" to be divided between time of digestion and number of units of enzyme

  3. Investigation of Lasso Peptides Maturation Enzymes

    E-print Network

    Petta, Jason

    Investigation of Lasso Peptides Maturation Enzymes Ángel L. Placeres PCCM/PRISM 2012 REU. · Unable to make Astexin-1 in vitro. · Strong possibility that Astexin-1 enzymes are better behaved than the MccJ25 enzymes. #12;Astic C · Maturation Enzyme. · Part of the gene cluster that helps make the lasso

  4. Taking the Mystery Out of Enzymes.

    ERIC Educational Resources Information Center

    DeYoung, H. Garrett

    1984-01-01

    Discusses structure and function of enzymes, design of new enzymes and enzyme substitutes, and enzyme uses in industry, medicine, and wastewater treatment. The latter is a low-cost method which can remove as much as 99 percent of toxic substances found in many industrial wastewater streams. (JN)

  5. The Wilderness Act Handbook

    NSDL National Science Digital Library

    From the Wilderness Society, this 40th anniversary edition of _The Wilderness Act Handbook_ was released in May of 2004. The Handbook "sets forth the relevant laws, regulations, and policies that govern the creation, expansion, and management of the National Wilderness Preservation System. The Wilderness Act is printed out in its entirety, along with interpretation and excerpts from and analysis of subsequent legislation that has influenced the designation or management of wilderness." The 90-page pdf document contains sections on Designating New Wilderness Areas, Wilderness Management and Stewardship, National Wildlife Refuge Wilderness, National Forest Wilderness, Wilderness Myths, and more. The Handbook includes a Wilderness Reading List as well. A text-only version of the Handbook is also available for download.

  6. Freedom of Information Act

    USGS Publications Warehouse

    Newman, D.J.

    2012-01-01

    The Freedom of Information Act( FOIA), 5 U.S.C.§ 552, as amended, generally provides that any person has a right to request access to Federal agency records. The USGS proactively promotes information disclosure as inherent to its mission of providing objective science to inform decisionmakers and the general public. USGS scientists disseminate up-to-date and historical scientific data that are critical to addressing national and global priorities.

  7. Modeling enzyme immobilization in porous solid supports.

    PubMed

    Do, D D; Clark, D S; Bailey, J E

    1982-07-01

    Enzymes are often immobilized on the internal surfaces of porous solid by immersing enzyme-free particles in a well mixed solution of enzyme. The ensuing impregnation process involves coupled transient mass transfer and surface attachment of enzyme. A mathematical model is employed to explore the influences of process parameters on the amount of enzyme loaded and the distribution of immobilized enzyme within the support particles. Nonuniform loading of the support occurs under some conditions. This is significant since the distribution of enzyme within the support particle influences the overall activity and stability of the immobilized enzyme catalyst. The model developed here may also be used to describe removal of reversibly immobilized enzyme during washing or utilization of the immobilized enzyme catalyst. PMID:18546454

  8. Subcellular localization of pituitary enzymes

    NASA Technical Reports Server (NTRS)

    Smith, R. E.

    1970-01-01

    A cytochemical procedure is reported for identifying subcellular sites of enzymes hydrolyzing beta-naphthylamine substrates, and to study the sites of reaction product localization in cells of various tissues. Investigations using the substrate Leu 4-methoxy-8-naphthylamine, a capture with hexonium pararosaniline, and the final chelation of osmium have identified the hydrolyzing enzyme of rat liver cells; this enzyme localized on cell membranes with intense deposition in the areas of the parcanaliculi. The study of cells in the anterior pituitary of the rat showed the deposition of reaction product on cell membrane; and on the membranes of secretion granules contained within the cell. The deposition of reaction product on the cell membrane however showed no increase or decrease with changes in the physiological state of the gland and release of secretion granules from specific cells.

  9. Enzyme-based listericidal nanocomposites.

    PubMed

    Solanki, Kusum; Grover, Navdeep; Downs, Patrick; Paskaleva, Elena E; Mehta, Krunal K; Lee, Lillian; Schadler, Linda S; Kane, Ravi S; Dordick, Jonathan S

    2013-01-01

    Cell lytic enzymes represent an alternative to chemical decontamination or use of antibiotics to kill pathogenic bacteria, such as listeria. A number of phage cell lytic enzymes against listeria have been isolated and possess listericidal activity; however, there has been no attempt to incorporate these enzymes onto surfaces. We report three facile routes for the surface incorporation of the listeria bacteriophage endolysin Ply500: covalent attachment onto FDA approved silica nanoparticles (SNPs), incorporation of SNP-Ply500 conjugates into a thin poly(hydroxyethyl methacrylate) film; and affinity binding to edible crosslinked starch nanoparticles via construction of a maltose binding protein fusion. These Ply500 formulations were effective in killing L. innocua (a reduced pathogenic surrogate) at challenges up to 10(5)?CFU/ml both in non-growth sustaining PBS as well as under growth conditions on lettuce. This strategy represents a new route toward achieving highly selective and efficient pathogen decontamination and prevention in public infrastructure. PMID:23545700

  10. [Carboxylation enzymes of coryneform bacteria].

    PubMed

    Baryshnikova, L M; Loginova, N V

    1979-01-01

    The enzymes of carbon dioxide heterotrophic fixation were studied in six strains of coryneform bacteria belonging to the genera Arthrobacter, Brevibacterium, Corynebacterium and Nocardia. All of the strains were found to contain PEP (phosphoenolpyruvate) carboxylase (EC 4.1.1.31), NADP or NAD dependent malic enzymes (EC 1.1.1.38--40). Pyruvate carboxylase (EC 6.4.1.1) was found only in three strains of coryneforms: Brevibacterium ammoniagenes, Corynebacterium aquaticum and Nocardia erythropolis. PEP carboxykinase (EC 4.1.1.32) was detected in Brevibacterium ammoniagenes and Nocardia erythropolis. PEP carboxytransphosphorylase (EC 4.1.1.38) was found only in Brevibacterium ammoniagenes. These data suggest that carboxylation of C3-acids is one of the essential pathways in some coryneforms supplying the citric acid cycle with the products of glycolysis. The composition and the level of carboxylation enzymes reflect the ecological characteristics of the organisms rather than their taxonomical relations. PMID:119147

  11. The Role of ACT-Like Subdomain in Bacterial Threonine Dehydratases

    PubMed Central

    Yu, Xuefei; Li, Yanyan; Wang, Xiaoyuan

    2014-01-01

    In bacteria, threonine dehydratases could convert L-threonine to 2-ketobutyrate. Some threonine dehydratases contain only a catalytic domain, while others contain an N-terminal catalytic domain and a C-terminal regulatory domain composed of one or two ACT-like subdomains. However, the role of the ACT-like subdomain in threonine dehydratases is not clear. Here, nine different bacterial threonine dehydratases were studied. Three of the nine contain no ACT-like subdomain, four of them contain a single ACT-like subdomain, and two of them contain two ACT-like subdomains. The nine genes encoding these threonine dehydratases were individually overexpressed in E. coli BL21(DE3), and the enzymes were purified to homogeneity. Activities of the purified enzymes were analyzed after incubation at different temperatures and different pHs. The results showed that threonine dehydratases with a single ACT-like subdomain are more stable at higher temperatures and a broad range of pH than those without ACT-like subdomain or with two ACT-like subdomains. Furthermore, the specific activity of threonine dehydratases increases with the increase of the number of ACT-like subdomains they contain. The results suggest that the ACT-like subdomain plays an important role in bacterial threonine dehydratases. PMID:24475306

  12. Thermodynamics of Enzyme-Catalyzed Reactions Database

    National Institute of Standards and Technology Data Gateway

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  13. Lithuanian biochemist builds enzyme empire

    SciTech Connect

    Dickman, S.

    1992-09-11

    Vidas Janulaitis is professor of biochemistry at the University of Vilnius, head of the Institute of Applied Enzymology - and creator of one of the world's largest collections of restriction enzymes, with more than 100 on offer. He also appears to be the first successful biotechnology entrepreneur to emerge from the former Soviet Union. This paper shows how Janulaitis managed to rise above the chaos that has accompanied the dismantlement of the Soviet Union to become one of the world's top suppliers of new restriction enzymes - especially given that the venture capitalists who rushed off to make deals with Moscow labs in the early days of perestroika mostly came back disappointed.

  14. ENZYME PATTERNS OF THE ORGANS OF THE GOOSE EFFECTS OF FATTENING ON LIVER ENZYMES

    E-print Network

    Paris-Sud XI, Université de

    ENZYME PATTERNS OF THE ORGANS OF THE GOOSE EFFECTS OF FATTENING ON LIVER ENZYMES J.P. BRAUN1 A Marsan, France. Résumé DISTRIBUTION DES ENZYMES DANS LES ORGANES DE L'OIE. EFFETS DE L'ENGRAISSEMENT SUR LES ENZYMES HÉPATIQUES. ― La distribution de quelques enzymes dans les organes de l'oie a été

  15. Inhibitors of testosterone biosynthetic and metabolic activation enzymes.

    PubMed

    Ye, Leping; Su, Zhi-Jian; Ge, Ren-Shan

    2011-01-01

    The Leydig cells of the testis have the capacity to biosynthesize testosterone from cholesterol. Testosterone and its metabolically activated product dihydrotestosterone are critical for the development of male reproductive system and spermatogenesis. At least four steroidogenic enzymes are involved in testosterone biosynthesis: Cholesterol side chain cleavage enzyme (CYP11A1) for the conversion of cholesterol into pregnenolone within the mitochondria, 3?-hydroxysteroid dehydrogenase (HSD3B), for the conversion of pregnenolone into progesterone, 17?-hydroxylase/17,20-lyase (CYP17A1) for the conversion of progesterone into androstenedione and 17?-hydroxysteroid dehydrogenase (HSD17B3) for the formation of testosterone from androstenedione. Testosterone is also metabolically activated into more potent androgen dihydrotestosterone by two isoforms 5?-reductase 1 (SRD5A1) and 2 (SRD5A2) in Leydig cells and peripheral tissues. Many endocrine disruptors act as antiandrogens via directly inhibiting one or more enzymes for testosterone biosynthesis and metabolic activation. These chemicals include industrial materials (perfluoroalkyl compounds, phthalates, bisphenol A and benzophenone) and pesticides/biocides (methoxychlor, organotins, 1,2-dibromo-3-chloropropane and prochloraz) and plant constituents (genistein and gossypol). This paper reviews these endocrine disruptors targeting steroidogenic enzymes. PMID:22138857

  16. EzCatDB: the enzyme reaction database, 2015 update

    PubMed Central

    Nagano, Nozomi; Nakayama, Naoko; Ikeda, Kazuyoshi; Fukuie, Masaru; Yokota, Kiyonobu; Doi, Takuo; Kato, Tsuyoshi; Tomii, Kentaro

    2015-01-01

    The EzCatDB database (http://ezcatdb.cbrc.jp/EzCatDB/) has emphasized manual classification of enzyme reactions from the viewpoints of enzyme active-site structures and their catalytic mechanisms based on literature information, amino acid sequences of enzymes (UniProtKB) and the corresponding tertiary structures from the Protein Data Bank (PDB). Reaction types such as hydrolysis, transfer, addition, elimination, isomerization, hydride transfer and electron transfer have been included in the reaction classification, RLCP. This database includes information related to ligand molecules on the enzyme structures in the PDB data, classified in terms of cofactors, substrates, products and intermediates, which are also necessary to elucidate the catalytic mechanisms. Recently, the database system was updated. The 3D structures of active sites for each PDB entry can be viewed using Jmol or Rasmol software. Moreover, sequence search systems of two types were developed for the EzCatDB database: EzCat-BLAST and EzCat-FORTE. EzCat-BLAST is suitable for quick searches, adopting the BLAST algorithm, whereas EzCat-FORTE is more suitable for detecting remote homologues, adopting the algorithm for FORTE protein structure prediction software. Another system, EzMetAct, is also available to searching for major active-site structures in EzCatDB, for which PDB-formatted queries can be searched. PMID:25324316

  17. EzCatDB: the enzyme reaction database, 2015 update.

    PubMed

    Nagano, Nozomi; Nakayama, Naoko; Ikeda, Kazuyoshi; Fukuie, Masaru; Yokota, Kiyonobu; Doi, Takuo; Kato, Tsuyoshi; Tomii, Kentaro

    2015-01-01

    The EzCatDB database (http://ezcatdb.cbrc.jp/EzCatDB/) has emphasized manual classification of enzyme reactions from the viewpoints of enzyme active-site structures and their catalytic mechanisms based on literature information, amino acid sequences of enzymes (UniProtKB) and the corresponding tertiary structures from the Protein Data Bank (PDB). Reaction types such as hydrolysis, transfer, addition, elimination, isomerization, hydride transfer and electron transfer have been included in the reaction classification, RLCP. This database includes information related to ligand molecules on the enzyme structures in the PDB data, classified in terms of cofactors, substrates, products and intermediates, which are also necessary to elucidate the catalytic mechanisms. Recently, the database system was updated. The 3D structures of active sites for each PDB entry can be viewed using Jmol or Rasmol software. Moreover, sequence search systems of two types were developed for the EzCatDB database: EzCat-BLAST and EzCat-FORTE. EzCat-BLAST is suitable for quick searches, adopting the BLAST algorithm, whereas EzCat-FORTE is more suitable for detecting remote homologues, adopting the algorithm for FORTE protein structure prediction software. Another system, EzMetAct, is also available to searching for major active-site structures in EzCatDB, for which PDB-formatted queries can be searched. PMID:25324316

  18. Nutrition and Pancreatic Enzyme Replacement in People with Cystic Fibrosis

    MedlinePLUS

    ... CF digest and absorb their food. What Are Enzymes And How Do They Work? Pancreatic enzyme replacements ... have CF take pancreatic enzyme replacements. How Are Enzymes Given? Enzymes should be taken just before meals ...

  19. 7 CFR 33.1 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.1 Act. Act and Export Apple Act are synonymous and mean “An act...the foreign trade of the United States in apples to protect the reputation of...

  20. 7 CFR 33.1 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.1 Act. Act and Export Apple Act are synonymous and mean “An act...the foreign trade of the United States in apples to protect the reputation of...

  1. 7 CFR 33.1 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.1 Act. Act and Export Apple Act are synonymous and mean “An act...the foreign trade of the United States in apples to protect the reputation of...

  2. 7 CFR 33.1 - Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.1 Act. Act and Export Apple Act are synonymous and mean “An act...the foreign trade of the United States in apples to protect the reputation of...

  3. 7 CFR 33.1 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...REGULATIONS ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.1 Act. Act and Export Apple Act are synonymous and mean “An act...the foreign trade of the United States in apples to protect the reputation of...

  4. A Perspective on Enzyme Catalysis

    NSDL National Science Digital Library

    Stephen J. Benkovic (Pensylvania State University; Department of Chemistry)

    2003-08-29

    The seminal hypotheses proposed over the years for enzymatic catalysis are scrutinized. The historical record is explored from both biochemical and theoretical perspectives. Particular attention is given to the impact of molecular motions within the protein on the enzyme's catalytic properties.

  5. Biochemical remediation using plant enzymes

    SciTech Connect

    Wolfe, N.L.

    1994-06-01

    The transformation of trinitrotoluene (TNT) to environmentally acceptable compounds is achieved through a lab-developed process that uses common aquatic weeds containing a nitroreductase enzyme. This research breakthrough provides an efficient and inexpensive technology for the cleanup of soils contaminated with munitions waste at military installations and other sites.

  6. The enzymes associated with denitrification

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1988-01-01

    The enzymes involved in the reduction of nitrogenous oxides are thought to be intermediates in denitrification processes. This review examines the roles of nitrate reductase, nitrite reductases, nitric oxide reductase, mechanisms of N-N bond formation, and nitrous oxide reductases.

  7. Effects of Environment on Enzymes

    NSDL National Science Digital Library

    Ms. Georgia Everett (Tri-Central Community Schools)

    2011-04-01

    The purpose of this lesson is to help students understand the cellular environment needed for enzymes to work and how it relates to cell activity. This level 4 inquiry activity was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 2010 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org.

  8. Insolubilized enzymes for food synthesis

    NASA Technical Reports Server (NTRS)

    Marshall, D. L.

    1972-01-01

    Cellulose matrix with numerous enzyme-coated silica particles of colloidal size permanently bound at various sites within matrix was produced that has high activity and possesses requisite physical characteristics for filtration or column operations. Product also allows coupling step in synthesis of edible food to proceed under mild conditions.

  9. Rennin--a Neglected Enzyme?

    ERIC Educational Resources Information Center

    Gill, John; Saunders, Terry

    1987-01-01

    Presents investigations to explore the substrate specificity, pH, concentration, and temperature relations of an enzyme with only inexpensive commercial rennet and basic laboratory equipment. Describes how the activities were carried out with a group of 15-year-old students. (CW)

  10. Changes in the enzyme activities of Saccharomyces cerevisiae during aerobic growth on different carbon sources

    PubMed Central

    Polakis, E. S.; Bartley, W.

    1965-01-01

    1. The activities of the enzymes of the citric acid cycle, the glyoxylate by-pass and some other enzymes acting on the substrates of these cycles have been measured at the pH of the yeast cell during the aerobic growth of yeast on different carbon sources and in different growth media. 2. Sugars induced an anaerobic type of metabolism as measured by ethanol production. Glucose was much more effective in inducing the anaerobic pathways than was galactose. The production of ethanol by cells grown on pyruvate was very small. 3. Glucose was also a more effective repressor than was galactose of the citric acid-cycle enzymes but both were equally effective in repressing almost completely the enzymes of the glyoxylate by-pass. 4. Disappearance of the sugars from the growth medium resulted in an increase in the activities of the enzymes of the citric acid cycle and in the appearance of substantial activities of the enzymes of the glyoxylate cycle. By contrast, the activities of purely biosynthetic enzymes (glutamate–oxaloacetate transaminase, NADP+-linked glutamate dehydrogenase) and of pyruvate decarboxylase were decreased. 5. The 2-oxoglutarate-oxidase system was found to be the least active enzyme of the citric acid cycle. 6. The regulatory control at the levels of pyruvate and acetaldehyde and the control of the citric acid cycle are discussed. PMID:16749116

  11. Purification and biochemical characterization of a novel fibrinolytic enzyme from culture supernatant of Cordyceps militaris.

    PubMed

    Liu, Xiaolan; Kopparapu, Narasimha-kumar; Shi, Xi; Deng, Yongping; Zheng, Xiqun; Wu, Jianping

    2015-03-01

    A novel fibrinolytic enzyme from Cordyceps militaris was produced by submerged culture fermentation, purified, and biochemically characterized. The enzyme was purified to homogeneity, with an overall yield of 4.0% and a specific activity of 1682 U/mg. The molecular weight and pI of the enzyme were 32 kDa and 9.3 ± 0.2, respectively. The optimal pH and temperature of the enzyme were 7.4 and 37 °C, respectively. The enzyme activity was inhibited by Fe(2+), phenylmethane sulfonyl fluoride (PMSF), aprotinin, and pepstatin but not by N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and ethylenediamine tetracetic acid (EDTA). Three internal peptides of the enzyme, APQALTVAAVGATWAR, EKNVGSTVNLLSYDGNK, and TDATSVLLDGYNVSAVNDLVAK, were obtained. The enzyme could hydrolyze fibrin(ogen) directly and cleave the ?-chains more efficiently than ?- and ?-chains, suggesting that it is a plasmin like protein. It degraded thrombin, which indicated that it can act as an anticoagulant and prevent thrombosis. Intravascular thrombosis is one of the major reasons of cardiovascular diseases. On the basis of these results, the purified enzyme can be developed as a natural agent for oral fibrinolytic therapy or prevention of thrombosis. PMID:25664761

  12. Characterization of fish-skin gelatin gels and films containing the antomicrobial enzyme lysozyme

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fish skins are rich in collagen and can be used to produce food-grade gelatin. Films cast from fish-skin gelatins are stable at room temperature and can act as a barrier when applied to foods. Lysozyme is a food-safe, antimicrobial enzyme that can also produce gels and films. When cold-water, fish-s...

  13. GENETIC POLYMORPHISM OF BLOOD GROUPS AND ERYTHROCYTES ENZYMES IN POPULATION GROUPS OF THE REPUBLIC OF MACEDONIA

    Microsoft Academic Search

    Abst r act : This study presents the results of an examination of 3 blood-group systems (ABO, Rhesus, and P1) and erythrocyte enzymes (ADA, AK, ALADH, PGD, SAHH, PGM1, PGM3, GPT, GOT, ACP, UMPK, ESD and GLO) in populations that reside in R. Macedonia. Four population samples from the Republic of Macedonia (129 Macedonians from Skopje, 98 Albanians from Skopje,

  14. Relationship between soil enzyme activities, nutrient cycling and soil fungal communities in a northern hardwood forest

    Microsoft Academic Search

    David J. Burke; Michael N. Weintraub; Charlotte R. Hewins; Susan Kalisz

    2011-01-01

    Soil fungi are highly diverse and act as the primary agents of nutrient cycling in forests. These fungal communities are often dominated by mycorrhizal fungi that form mutually beneficial relationships with plant roots and some mycorrhizal fungi produce extracellular and cell-bound enzymes that catalyze the hydrolysis of nitrogen (N)- and phosphorus (P)- containing compounds in soil organic matter. Here we

  15. Using amphiphilic pseudo amino acid composition to predict enzyme subfamily classes

    Microsoft Academic Search

    Kuo-chen Chou

    2005-01-01

    Abstract Motivation: With the protein sequences entering into databanks at an explosive pace, it is important to timely determine the family or subfamily class for a newly-found enzyme molecule because this is directly related to the detailed information about what specific target it acts on, as well as to its catalytic process and biological function. Unfortunately, it is both time-consuming

  16. PROHIBITED ACTSPROHIBITED ACTS (a) GENERAL.-

    E-print Network

    ) and 10 of this Act, with respect to any endangered species of fish or wildlife listed pursuant to section) Except as provided in sections 6(g)(2) and 10 of this Act, with respect to any endangered species or in a controlled environment on the effective date of the Endangered Species Act Amendments of 1978; or #12;(ii

  17. Speech Acts and Conversational Interaction.

    ERIC Educational Resources Information Center

    Geis, Michael L.

    This book unites speech act theory and conversation analysis to advance a theory of conversational competence, called the Dynamic Speech Act Theory (DSAT). In contrast to traditional speech act theory that focuses almost exclusively on intuitive assessments of isolated, constructed examples, this theory is predicated on the assumption that speech…

  18. and Practices HEALTH INFORMATION ACT

    E-print Network

    MacMillan, Andrew

    Guidelines and Practices Manual HEALTH INFORMATION ACT March 2011 #12;This publication is a practical reference tool for the application of Alberta's Health Information Act (HIA). It is designed-2011 Government of Alberta 1Health and Wellness Health Information Act GUIDELINES AND PRACTICES MANUAL TABLE

  19. Angiotensin II-producing enzyme III from acidified serum of nephrectomized dogs.

    PubMed

    Haas, E; Lewis, L; Koshy, T J; Varde, A U; Renerts, L; Bagai, R C

    1989-09-01

    A highly active angiotensin-producing enzyme (enzyme III) was obtained from the serum of bilaterally nephrectomized dogs by acid treatment and ammonium sulfate fractionation. An inactive precursor (proenzyme III) was converted to enzyme III during prolonged storage (or by treatment with acid or with cathepsin G or by incubation at 38 degrees C as described in the following paper). Enzyme III reacted maximally at pH 7.7 and it produced up to 400 ng of angiotensin II/mL serum/h (i.e., amounts 4000 times higher than that generated by the endogenous renin present in serum after bilateral nephrectomy). Enzyme III produced angiotensin II at identical rates when either dog angiotensinogen or angiotensin I was used as substrate, but the rate was 710 times higher with synthetic tetradecapeptide renin substrate. Enzyme III is not identical to renin, cathepsin G, tonin, enzyme I, enzyme II, the calcium-dependent angiotensin I-converting enzyme, or the calcium-independent carboxy peptidase, which acts by sequential cleavage of angiotensin I. Enzyme III was inhibited by alpha-1-antitrypsin, diisopropyl fluorophosphate, and lima bean trypsin inhibitor (hence it is a serine proteinase). It was not inhibited by Captopril, Teprotide, or Enalapril. It had been reported previously that cathepsin G released from neutrophil granulocytes, by producing high local concentrations of angiotensin II, may provide a mobile means for modulating blood flow in tissue microvasculature during the inflammatory response. The present study offers a new, additional pathway, by enzyme III, for a similar rapid formation of angiotensin II from serum protein substrate or angiotensin I. PMID:2572242

  20. Simulating feedback and reversibility in substrate-enzyme reactions

    NASA Astrophysics Data System (ADS)

    van Zwieten, D. A. J.; Rooda, J. E.; Armbruster, D.; Nagy, J. D.

    2011-12-01

    We extend discrete event models (DEM) of substrate-enzyme reactions to include regulatory feedback and reversible reactions. Steady state as well as transient systems are modeled and validated against ordinary differential equation (ODE) models. The approach is exemplified in a model of the first steps of glycolysis with the most common regulatory mechanisms. We find that in glycolysis, feedback and reversibility together act as a significant damper on the stochastic variations of the intermediate products as well as for the stochastic variation of the transit times. This suggests that these feedbacks have evolved to control both the overall rate of, as well as stochastic fluctuations in, glycolysis.

  1. Enzymes and other agents that enhance cell wall extensibility

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1999-01-01

    Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

  2. Kinetic properties of a sex pheromone-degrading enzyme: the sensillar esterase of Antheraea polyphemus.

    PubMed

    Vogt, R G; Riddiford, L M; Prestwich, G D

    1985-12-01

    Behavioral and electrophysiological evidence has suggested that sex pheromone is rapidly inactivated within the sensory hairs soon after initiation of the action-potential spike. We report the isolation and characterization of a sex-pheromone-degrading enzyme from the sensory hairs of the silkmoth Antheraea polyphemus. In the presence of this enzyme at physiological concentration, the pheromone [(6E,11Z)-hexadecadienyl acetate] has an estimated half-life of 15 msec. Our findings suggest a molecular model for pheromone reception in which a previously reported pheromone-binding protein acts as a pheromone carrier, and an enzyme acts as a rapid pheromone inactivator, maintaining a low stimulus noise level within the sensory hairs. PMID:3001718

  3. Androgen-activating enzymes in the central nervous systemProceedings of Xth International Congress on Hormonal Steroids, Quebec, Canada, 17–21 June 1998

    Microsoft Academic Search

    Angelo Poletti; Luciano Martini

    1999-01-01

    In the rat brain, several steroids can be converted by specific enzymes to either more potent compounds or to derivatives showing new biological effects. One of the most studied enzyme is the 5?-reductase (5?-R), which acts on 3keto-?4 steroids. In males, testosterone is the main substrate and gives rise to the most potent natural androgen dihydrotestosterone. In females, progesterone is

  4. Enzymes involved in the biodegradation of hexachlorocyclohexane: a mini review.

    PubMed

    Camacho-Pérez, Beni; Ríos-Leal, Elvira; Rinderknecht-Seijas, Noemí; Poggi-Varaldo, Héctor M

    2012-03-01

    The scope of this paper encompasses the following subjects: (i) aerobic and anaerobic degradation pathways of ?-hexachlorocyclohexane (HCH); (ii) important genes and enzymes involved in the metabolic pathways of ?-HCH degradation; (iii) the instrumental methods for identifying and quantifying intermediate metabolites, such as gas chromatography coupled to mass spectrometry (GC-MS) and other techniques. It can be concluded that typical anaerobic and aerobic pathways of ?-HCH are well known for a few selected microbial strains, although less is known for anaerobic consortia where the possibility of synergism, antagonism, and mutualism can lead to more particular routes and more effective degradation of ?-HCH. Conversion and removals in the range 39%-100% and 47%-100% have been reported for aerobic and anaerobic cultures, respectively. Most common metabolites reported for aerobic degradation of lindane are ?-pentachlorocyclohexene (?-PCCH), 2,5-dichlorobenzoquinone (DCBQ), Chlorohydroquinone (CHQ), chlorophenol, and phenol, whereas PCCH, isomers of trichlorobenzene (TCB), chlorobenzene, and benzene are the most typical metabolites found in anaerobic pathways. Enzyme and genetic characterization of the involved molecular mechanisms are in their early infancy; more work is needed to elucidate them in the future. Advances have been made on identification of enzymes of Sphingomonas paucimobilis where the gene LinB codifies for the enzyme haloalkane dehalogenase that acts on 1,3,4,6-tetrachloro 1,4-cyclohexadiene, thus debottlenecking the pathway. Other more common enzymes such as phenol hydroxylase, catechol 1,2-dioxygenase, catechol 2,3-dioxygenase are also involved since they attack intermediate metabolites of lindane such as catechol and less substituted chlorophenols. Chromatography coupled to mass spectrometric detector, especially GC-MS, is the most used technique for resolving for ?-HCH metabolites, although there is an increased participation of HPLC-MS methods. Scintillation methods are very useful to assess final degradation of ?-HCH. PMID:21992990

  5. Triple acting radial seal

    DOEpatents

    Ebert, Todd A (West Palm Beach, FL); Carella, John A (Jupiter, FL)

    2012-03-13

    A triple acting radial seal used as an interstage seal assembly in a gas turbine engine, where the seal assembly includes an interstage seal support extending from a stationary inner shroud of a vane ring, the interstage seal support includes a larger annular radial inward facing groove in which an outer annular floating seal assembly is secured for radial displacement, and the outer annular floating seal assembly includes a smaller annular radial inward facing groove in which an inner annular floating seal assembly is secured also for radial displacement. A compliant seal is secured to the inner annular floating seal assembly. The outer annular floating seal assembly encapsulates the inner annular floating seal assembly which is made from a very low alpha material in order to reduce thermal stress.

  6. Improvements of biomass deconstruction enzymes

    SciTech Connect

    Sale, K. L.

    2012-03-01

    Sandia National Laboratories and DSM Innovation, Inc. collaborated on the investigation of the structure and function of cellulases from thermophilic fungi. Sandia's role was to use its expertise in protein structure determination and X-ray crystallography to solve the structure of these enzymes in their native state and in their substrate and product bound states. Sandia was also tasked to work with DSM to use the newly solved structure to, using computational approaches, analyze enzyme interactions with both bound substrate and bound product; the goal being to develop approaches for rationally designing improved cellulases for biomass deconstruction. We solved the structures of five cellulases from thermophilic fungi. Several of these were also solved with bound substrate/product, which allowed us to predict mutations that might enhance activity and stability.

  7. Metrological aspects of enzyme production

    NASA Astrophysics Data System (ADS)

    Kerber, T. M.; Dellamora-Ortiz, G. M.; Pereira-Meirelles, F. V.

    2010-05-01

    Enzymes are frequently used in biotechnology to carry out specific biological reactions, either in industrial processes or for the production of bioproducts and drugs. Microbial lipases are an important group of biotechnologically valuable enzymes that present widely diversified applications. Lipase production by microorganisms is described in several published papers; however, none of them refer to metrological evaluation and the estimation of the uncertainty in measurement. Moreover, few of them refer to process optimization through experimental design. The objectives of this work were to enhance lipase production in shaken-flasks with Yarrowia lipolytica cells employing experimental design and to evaluate the uncertainty in measurement of lipase activity. The highest lipolytic activity obtained was about three- and fivefold higher than the reported activities of CRMs BCR-693 and BCR-694, respectively. Lipase production by Y. lipolytica cells aiming the classification as certified reference material is recommended after further purification and stability studies.

  8. Isocitrate Dehydrogenase Parameters of Enzyme Activity

    NSDL National Science Digital Library

    John H. Williamson (Davidson College; )

    1999-01-01

    One of four biology laboratories where students research the properties of a model enzyme, isocitrate dehydrogenase, by using scientifitic method, molecular biology enzyme assay techniques and data analysis using a computer graphing program.

  9. Crystallization studies of 5'-deoxyadenosyl radical enzymes

    E-print Network

    Phillips, Laura (Laura Anne)

    2007-01-01

    Both adenosylcobalamin- and S-adenosylmethionine-dependent radical enzymes use a 5'-deoxyadenosyl radical intermediate to abstract a hydrogen atom from their substrates. In the case of adenosylcobalamin-dependent enzymes, ...

  10. Extracellular enzyme kinetics scale with resource availability

    EPA Science Inventory

    Microbial community metabolism relies on external digestion, mediated by extracellular enzymes that break down complex organic matter into molecules small enough for cells to assimilate. We analyzed the kinetics of 40 extracellular enzymes that mediate the degradation and assimi...

  11. Purification and characterization of carbon-phosphorus bond-cleavage enzyme from glyphosate degrading Pseudomonas putida T5.

    PubMed

    Selvi, A Arul; Manonmani, H K

    2015-01-01

    An inducible, carbon-phosphorus bond-cleavage enzyme was purified from cells of Pseudomonas putida T5 grown on N-phosphonomethyl glycine. The native enzyme had a molecular mass of approximately 70 kD and upon sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), yielded a homogeneous protein band with an apparent molecular mass of about 70 kD. Activity of purified enzyme was increased by 627-fold compared to the crude extract and showed pH and temperature optima of approximately 7 and 30°C, respectively. The purified enzyme had an apparent Km and Vmax of 3.7 mM and 6.8 mM/min, respectively, for its sole substrate N-phosphonomethyl glycine. The enzyme was inhibited by phenylmethylsulfonyl fluoride (PMSF), indicating the presence of serine at the active site. The enzyme was not inhibited by SDS, suggesting the absence of disulfide linkage in the enzyme. The enzyme was found to be inhibited by most of the metals studied except Mg(2+). Detergents studied also inhibited glyphosate acting as a carbon-phosphorus bond-cleavage enzyme. Thus initial characterization of the purified enzyme suggested that it could be used as a potential candidate for glyphosate bioremediation. PMID:24840030

  12. Inhibitory zinc sites in enzymes.

    PubMed

    Maret, Wolfgang

    2013-04-01

    Several pathways increase the concentrations of cellular free zinc(II) ions. Such fluctuations suggest that zinc(II) ions are signalling ions used for the regulation of proteins. One function is the inhibition of enzymes. It is quite common that enzymes bind zinc(II) ions with micro- or nanomolar affinities in their active sites that contain catalytic dyads or triads with a combination of glutamate (aspartate), histidine and cysteine residues, which are all typical zinc-binding ligands. However, for such binding to be physiologically significant, the binding constants must be compatible with the cellular availability of zinc(II) ions. The affinity of inhibitory zinc(II) ions for receptor protein tyrosine phosphatase ? is particularly high (K i = 21 pM, pH 7.4), indicating that some enzymes bind zinc almost as strongly as zinc metalloenzymes. The competitive pattern of zinc inhibition for this phosphatase implicates its active site cysteine and nearby residues in the coordination of zinc. Quantitative biophysical data on both affinities of proteins for zinc and cellular zinc(II) ion concentrations provide the basis for examining the physiological significance of inhibitory zinc-binding sites in proteins and the role of zinc(II) ions in cellular signalling. Regulatory functions of zinc(II) ions add a significant level of complexity to biological control of metabolism and signal transduction and embody a new paradigm for the role of transition metal ions in cell biology. PMID:23456096

  13. Chemistry and Flatulence: An Introductory Enzyme Experiment

    NASA Astrophysics Data System (ADS)

    Hardee, John R.; Montgomery, Tina M.; Jones, Wray H.

    2000-04-01

    An inexpensive introductory-level enzyme experiment was developed using raffinose family sugars extracted from green split peas as a substrate and the enzymes alpha-galactosidase and sucrase found in Beano. The reaction studied was the hydrolysis of raffinose family sugars to galactose, glucose, and fructose, and the reaction rate was determined using a retail glucometer to measure the concentration of glucose. Results are given on the effect of substrate concentration, enzyme concentration, temperature, and heavy metals on enzyme activity.

  14. E2 enzyme inhibition by stabilization of a low affinity interface with ubiquitin

    PubMed Central

    St-Cyr, Daniel J.; Ziemba, Amy; Garg, Pankaj; Plamondon, Serge; Auer, Manfred; Sidhu, Sachdev; Marinier, Anne; Kleiger, Gary; Tyers, Mike; Sicheri, Frank

    2014-01-01

    Weak protein interactions between ubiquitin and the ubiquitin-proteasome system (UPS) enzymes that mediate its covalent attachment to substrates serve to position ubiquitin for optimal catalytic transfer. We show that a small molecule inhibitor of the E2 ubiquitin conjugating enzyme Cdc34A, called CC0651, acts by trapping a weak interaction between ubiquitin and the E2 donor ubiquitin binding site. A structure of the ternary CC0651-Cdc34A-ubiquitin complex reveals that the inhibitor engages a composite binding pocket formed from Cdc34A and ubiquitin. CC0651 also suppresses the spontaneous hydrolysis rate of the Cdc34A-ubiquitin thioester, without overtly affecting the interaction between Cdc34A and the RING domain subunit of the E3 enzyme. Stabilization of the numerous other weak interactions between ubiquitin and UPS enzymes by small molecules may be a feasible strategy to selectively inhibit different UPS activities. PMID:24316736

  15. Regeneration of Cofactors for Enzyme Biocatalysis

    E-print Network

    Zhao, Huimin

    Regeneration of Cofactors for Enzyme Biocatalysis Ryan D. Woodyer, Tyler W. Johannes and Huimin with the need for more selective, safer, and cleaner reactions. Enzymes as catalysts meet many of the needs-independent enzymes such as hydrolases, which perform relatively simple chemistry (Faber 2000). In contrast, cofactor

  16. Determining Enzyme Activity by Radial Diffusion

    ERIC Educational Resources Information Center

    Davis, Bill D.

    1977-01-01

    Discusses advantages of radial diffusion assay in determining presence of enzyme and/or rough approximation of amount of enzyme activities. Procedures are included for the preparation of starch-agar plates, and the application and determination of enzyme. Techniques using plant materials (homogenates, tissues, ungerminated embryos, and seedlings)…

  17. Hydrolytic enzyme activity in landfilled refuse

    Microsoft Academic Search

    A. C. Palmisano; B. S. Schwab; D. A. Maruscik

    1993-01-01

    Extracellular hydrolytic enzyme activity was assayed in 28 refuse samples excavated from 14 bore holes in Fresh Kills Landfill, Staten Island, N. Y. Esterases, proteases and amylases were present in all of the samples. Enzyme screening assays utilizing the API-ZYM test system showed the incidence of enzymes in the order: specific phosphatases > esterases > glycosyl hydrolases. Measurement of cellulase

  18. Probing Product Binding in Cellulase Enzymes

    E-print Network

    Probing Product Binding in Cellulase Enzymes Simulations uncover potential new strategies for increasing the desired effects of enzymes for biofuels. Large-scale computer simulations offer a new interpretation for the discrepancy in experimentally measured product inhibition constants in cellulase enzymes

  19. Better Enzymes for Biofuels and Green Chemistry

    E-print Network

    Better Enzymes for Biofuels and Green Chemistry: Solving the Cofactor Imbalance Problem Imbalances-engineered the cofactor specificity of individual enzymes, this process has historically been arduous and prone to failure. Testing this procedure on a structurally and functionally diverse set of industrially relevant enzymes has

  20. Enzymes with Molecular Tunnels FRANK M. RAUSHEL,*,

    E-print Network

    Holden, Hazel

    Enzymes with Molecular Tunnels FRANK M. RAUSHEL,*, JAMES B. THODEN, AND HAZEL M. HOLDEN become feasible to examine complicated protein structures at high resolution. For those enzymes understanding of molecular tunnels ob- served in various enzyme systems. Introduction A revolution in biological

  1. A Structural Perspective on Enzymes Activated by

    E-print Network

    Di Cera, Enrico

    A Structural Perspective on Enzymes Activated by Monovalent Cations* Published, JBC Papers in Press and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110 Enzymes activated and catalysis. Recent progress in the structural biology of such enzymes has answered long standing questions

  2. Designing artificial enzymes by intuition and computation

    Microsoft Academic Search

    Vikas Nanda; Ronald L. Koder

    2010-01-01

    The rational design of artificial enzymes, either by applying physico-chemical intuition of protein structure and function or with the aid of computational methods, is a promising area of research with the potential to tremendously impact medicine, industrial chemistry and energy production. Designed proteins also provide a powerful platform for dissecting enzyme mechanisms of natural systems. Artificial enzymes have come a

  3. Microorganisms detected by enzyme-catalyzed reaction

    NASA Technical Reports Server (NTRS)

    Vango, S. P.; Weetall, H. H.; Weliky, N.

    1966-01-01

    Enzymes detect the presence of microorganisms in soils. The enzyme lysozymi is used to release the enzyme catalase from the microorganisms in a soil sample. The catalase catalyzes the decomposition of added hydrogen peroxide to produce oxygen which is detected manometrically. The partial pressure of the oxygen serves as an index of the samples bacteria content.

  4. Immobilization of Enzymes in Polymer Supports.

    ERIC Educational Resources Information Center

    Conlon, Hugh D.; Walt, David R.

    1986-01-01

    Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

  5. Enzyme Mimic to Develop Antioxidant Nanoreactors: From Synthesis to Application

    E-print Network

    Amrhein, Valentin

    Enzyme Mimic to Develop Antioxidant Nanoreactors: From Synthesis to Application.................................................................................................................20 1.10.1. Administration of antioxidant enzymes................................................................................20 1.10. 2. Administration of enzyme mimics

  6. Enzyme Mediated Synthesis of a Semiconducting Metal Oxide

    E-print Network

    Johnson, John Michael

    2012-01-01

    specific enzymes thermal denaturation temperature. Urease isof the enzyme increases with increasing temperature. Theand temperature conditions compared with the normal operating conditions of the enzyme

  7. DIGESTIVE ENZYMES IN POIKILOTHERMAL VERTEBRATES. AN INVESTIGATION OF ENZYMES IN FISHES, WITH COM-

    E-print Network

    DIGESTIVE ENZYMES IN POIKILOTHERMAL VERTEBRATES. AN INVESTIGATION OF ENZYMES IN FISHES, WITH COM Tryptic digestion uu u_ 182 Ereptic digestion u n _ 186 Carbohydrate-splitting enzymes _ 184 Amylase _ 184 enzymes in representatives throughout the vertebrate series. It would be of value to know if differences

  8. Enzyme catalysis Enzyme catalysis is the catalysis of chemical reactions by

    E-print Network

    Cavanagh, John

    Enzyme catalysis Enzyme catalysis is the catalysis of chemical reactions by specialized proteins known as enzymes. Catalysis of biochemical reactions in the cell is vital due to the very low reaction rates of the uncatalysed reactions. The mechanism of enzyme catalysis is similar in principle to other

  9. Finding Sequences for over 270 Orphan Enzymes

    PubMed Central

    Shearer, Alexander G.; Altman, Tomer; Rhee, Christine D.

    2014-01-01

    Despite advances in sequencing technology, there are still significant numbers of well-characterized enzymatic activities for which there are no known associated sequences. These ‘orphan enzymes’ represent glaring holes in our biological understanding, and it is a top priority to reunite them with their coding sequences. Here we report a methodology for resolving orphan enzymes through a combination of database search and literature review. Using this method we were able to reconnect over 270 orphan enzymes with their corresponding sequence. This success points toward how we can systematically eliminate the remaining orphan enzymes and prevent the introduction of future orphan enzymes. PMID:24826896

  10. BRENDA: The Comprehensive Enzyme Information System

    NSDL National Science Digital Library

    BRENDA is a comprehensive database of enzymes maintained by the Institute of Biochemistry at the University of Cologne. Scientists collect and evaluate enzyme function data from primary literature sources. The site has recently been updated with new enzymes and an entirely new search engine. Various searches can be performed, including enzyme name, organism, or EC number. Links to literature citations, two dimensional images, and other databases are included for many of the enzymes. Academic and nonprofit use is free; commercial users must acquire a license.

  11. Enzyme Analysis to Determine Glucose Content

    NASA Astrophysics Data System (ADS)

    Carpenter, Charles; Ward, Robert E.

    Enzyme analysis is used for many purposes in food science and technology. Enzyme activity is used to indicate adequate processing, to assess enzyme preparations, and to measure constituents of foods that are enzyme substrates. In this experiment, the glucose content of corn syrup solids is determined using the enzymes, glucose oxidase and peroxidase. Glucose oxidase catalyzes the oxidation of glucose to form hydrogen peroxide (H2O2), which then reacts with a dye in the presence of peroxidase to give a stable colored product.

  12. Application of Enzymes in Food Analysis

    NASA Astrophysics Data System (ADS)

    Powers, Joseph R.

    Enzymes are protein catalysts that are capable of very great specificity and reactivity under physiological conditions. Enzymatic analysis is the measurement of compoundswith the aid of added enzymes or themeasurement of endogenous enzyme activity to give an indication of the state of a biological system including foods. The fact that enzyme catalysis can take place under relatively mild conditions allows for measurement of relatively unstable compounds not amenable to some other techniques. In addition, the specificity of enzyme reactions can allow for measurement of components of complex mixtures without the time and expense of complicated chromatographic separation techniques.

  13. Acting to gain information

    NASA Technical Reports Server (NTRS)

    Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

    1993-01-01

    This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

  14. Peptidoglycan Remodeling by the Coordinated Action of Multispecific Enzymes

    PubMed Central

    Alvarez, Laura; Espaillat, Akbar; Hermoso, Juan A.; de Pedro, Miguel A.

    2014-01-01

    The peptidoglycan (PG) cell wall constitutes the main defense barrier of bacteria against environmental insults and acts as communication interface. The biochemistry of this macromolecule has been well characterized throughout the years but recent discoveries have unveiled its chemical plasticity under environmental stresses. Non-canonical D-amino acids (NCDAA) are produced and released to the extracellular media by diverse bacteria. Such molecules govern cell wall adaptation to challenging environments through their incorporation into the polymer, a widespread capability among bacteria that reveals the inherent catalytic plasticity of the enzymes involved in the cell wall metabolism. Here, we analyze the recent structural and biochemical characterization of Bsr, a new family of broad spectrum racemases able to generate a wide range of NCDAA. We also discuss the necessity of a coordinated action of PG multispecific enzymes to generate adequate levels of modification in the murein sacculus. Finally, we also highlight how this catalytic plasticity of NCDAA-incorporating enzymes has allowed the development of new revolutionary methodologies for the study of PG modes of growth and in vivo dynamics. PMID:24799190

  15. Role of Sphingolipids and Metabolizing Enzymes in Hematological Malignancies

    PubMed Central

    Kitatani, Kazuyuki; Taniguchi, Makoto; Okazaki, Toshiro

    2015-01-01

    Sphingolipids such as ceramide, sphingosine-1-phosphate and sphingomyelin have been emerging as bioactive lipids since ceramide was reported to play a role in human leukemia HL-60 cell differentiation and death. Recently, it is well-known that ceramide acts as an inducer of cell death, that sphingomyelin works as a regulator for microdomain function of the cell membrane, and that sphingosine-1-phosphate plays a role in cell survival/proliferation. The lipids are metabolized by the specific enzymes, and each metabolite could be again returned to the original form by the reverse action of the different enzyme or after a long journey of many metabolizing/synthesizing pathways. In addition, the metabolites may serve as reciprocal bio-modulators like the rheostat between ceramide and sphingosine-1-phosphate. Therefore, the change of lipid amount in the cells, the subcellular localization and the downstream signal in a specific subcellular organelle should be clarified to understand the pathobiological significance of sphingolipids when extracellular stimulation induces a diverse of cell functions such as cell death, proliferation and migration. In this review, we focus on how sphingolipids and their metabolizing enzymes cooperatively exert their function in proliferation, migration, autophagy and death of hematopoetic cells, and discuss the way developing a novel therapeutic device through the regulation of sphingolipids for effectively inhibiting cell proliferation and inducing cell death in hematological malignancies such as leukemia, malignant lymphoma and multiple myeloma. PMID:25997737

  16. 7 CFR 35.1 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...STANDARD CONTAINER REGULATIONS EXPORT GRAPES AND PLUMS Definitions § 35.1 Act. Act or Export Grape and Plum Act means “An Act to promote the foreign trade of the United States in grapes and plums, to protect the...

  17. 7 CFR 35.1 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...STANDARD CONTAINER REGULATIONS EXPORT GRAPES AND PLUMS Definitions § 35.1 Act. Act or Export Grape and Plum Act means “An Act to promote the foreign trade of the United States in grapes and plums, to protect the...

  18. 7 CFR 35.1 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...STANDARD CONTAINER REGULATIONS EXPORT GRAPES AND PLUMS Definitions § 35.1 Act. Act or Export Grape and Plum Act means “An Act to promote the foreign trade of the United States in grapes and plums, to protect the...

  19. University College London: Enzyme Structures Database

    NSDL National Science Digital Library

    Laskowski, Roman

    This website features the Enzyme Structures Database, created by researchers Roman Laskowski and Andrew Wallace of the University College London. The database "contains the known enzyme structures that have been deposited in the Brookhaven Protein Data Bank (the PDB)." As of March 2003 the Brookhaven Protein Data Bank contained 10208 PDB-enzyme entries "involving 9873 separate PDB files - some files having more than one E.C. number associated with them. The enzyme structures are classified by their E.C. number (using the Mar 2003 v.30.0 release of the ENZYME Data Bank)." There are six classified groups of enzyme structures including Oxidoreductases, Transferases, and Hydrolases. This site also links to the PDBsum database which provides users an alternate means of accessing enzyme structures.

  20. Microbial community composition shapes enzyme patterns in topsoil and subsoil horizons along a latitudinal transect in Western Siberia

    PubMed Central

    Schnecker, Jörg; Wild, Birgit; Takriti, Mounir; Eloy Alves, Ricardo J.; Gentsch, Norman; Gittel, Antje; Hofer, Angelika; Klaus, Karoline; Knoltsch, Anna; Lashchinskiy, Nikolay; Mikutta, Robert; Richter, Andreas

    2015-01-01

    Soil horizons below 30 cm depth contain about 60% of the organic carbon stored in soils. Although insight into the physical and chemical stabilization of soil organic matter (SOM) and into microbial community composition in these horizons is being gained, information on microbial functions of subsoil microbial communities and on associated microbially-mediated processes remains sparse. To identify possible controls on enzyme patterns, we correlated enzyme patterns with biotic and abiotic soil parameters, as well as with microbial community composition, estimated using phospholipid fatty acid profiles. Enzyme patterns (i.e. distance-matrixes calculated from these enzyme activities) were calculated from the activities of six extracellular enzymes (cellobiohydrolase, leucine-amino-peptidase, N-acetylglucosaminidase, chitotriosidase, phosphatase and phenoloxidase), which had been measured in soil samples from organic topsoil horizons, mineral topsoil horizons, and mineral subsoil horizons from seven ecosystems along a 1500 km latitudinal transect in Western Siberia. We found that hydrolytic enzyme activities decreased rapidly with depth, whereas oxidative enzyme activities in mineral horizons were as high as, or higher than in organic topsoil horizons. Enzyme patterns varied more strongly between ecosystems in mineral subsoil horizons than in organic topsoils. The enzyme patterns in topsoil horizons were correlated with SOM content (i.e., C and N content) and microbial community composition. In contrast, the enzyme patterns in mineral subsoil horizons were related to water content, soil pH and microbial community composition. The lack of correlation between enzyme patterns and SOM quantity in the mineral subsoils suggests that SOM chemistry, spatial separation or physical stabilization of SOM rather than SOM content might determine substrate availability for enzymatic breakdown. The correlation of microbial community composition and enzyme patterns in all horizons, suggests that microbial community composition shapes enzyme patterns and might act as a modifier for the usual dependency of decomposition rates on SOM content or C/N ratios. PMID:25859057

  1. Inhibitory Analogs of Ubiquinol Act Anti-cooperatively on the Yeast Cytochrome bc1 Complex

    E-print Network

    Trumpower, Bernard L.

    Inhibitory Analogs of Ubiquinol Act Anti-cooperatively on the Yeast Cytochrome bc1 Complex EVIDENCE FOR AN ALTERNATING, HALF-OF-THE-SITES MECHANISM OF UBIQUINOL OXIDATION* Received for publication, September 20, 2001 ubiqui- nol is oxidized at one center in the enzyme, referred to as center P, and ubiquinone is re

  2. Rennin Enzyme of Endothia parasitica

    PubMed Central

    Sardinas, Joseph L.

    1968-01-01

    A microbiological screening program was instituted to search for an animal rennet substitute. Among 381 bacteria and 540 fungi tested, only one organism, Endothia parasitica, yielded a suitable enzyme substitute. The fungal rennin enzyme was crystallized and some of its properties were studied. It was found to be water-soluble, nondialyzable, precipitable with (NH4)2SO4 and organic solvents (e.g., acetone and isopropanol), and destroyed by heating for 5 min at 60 C. It was determined to be most stable in water at pH 4.5 and to have an isoelectric point of pH 5.5. On acid hydrolysis, it yielded: alanine, ammonia, arginine, aspartic acid, cysteic acid, cystine, glutamic acid, glycine, histidine, isoleucine, leucine, phenylalanine, proline, serine, threonine, tyrosine, and valine. No tryptophan was detected after alkaline hydrolysis. Its molecular weight was estimated to be in the range of 34,000 to 39,000. The milk-clotting activities of the fungal and animal rennins proved to be essentially identical in milk containing various concentrations of CaCl2. Both rennins manifested comparable clotting activities in milk at pH 6.0 to 7.0. Images Fig. 1 PMID:4868859

  3. Advanced Communications Technology Satellite (ACTS)

    Microsoft Academic Search

    R. T. Gedney; R. J. Schertler

    1989-01-01

    The authors provide an overview of the NASA Advanced Communications Technology Satellite (ACTS) and discuss the value of the technology for future communication systems. The high-risk technologies selected for ACTS were those having the potential to dramatically enhance the capabilities of the satellite communications industry. This experimental satellite, which is scheduled to be launched in 1992, will furnish very small

  4. The Privacy Act of 1974.

    ERIC Educational Resources Information Center

    O'Reilly, James T.

    This report describes the possible impact of the comprehensive Privacy Act of 1974, which went into effect on 27 September 1975. Specifically, the implications of the act for limitation of disclosure, federal information collection, individual access, private suits; criminal provisions; and exceptions to the provisions of the law are detailed. In…

  5. Nuclear Shield: A Multi-Enzyme Task-Force for Nucleus Protection

    PubMed Central

    Pallottini, Valentina; Canuti, Lorena; De Canio, Michele; Urbani, Andrea; Marzano, Valeria; Cornetta, Tommaso; Stano, Pasquale; Giovanetti, Anna; Stella, Lorenzo; Canini, Antonella; Federici, Giorgio; Ricci, Giorgio

    2010-01-01

    Background In eukaryotic cells the nuclear envelope isolates and protects DNA from molecules that could damage its structure or interfere with its processing. Moreover, selected protection enzymes and vitamins act as efficient guardians against toxic compounds both in the nucleoplasm and in the cytosol. The observation that a cytosolic detoxifying and antioxidant enzyme i.e. glutathione transferase is accumulated in the perinuclear region of the rat hepatocytes suggests that other unrecognized modalities of nuclear protection may exist. Here we show evidence for the existence of a safeguard enzyme machinery formed by an hyper-crowding of cationic enzymes and proteins encompassing the nuclear membrane and promoted by electrostatic interactions. Methodology/Principal Findings Electron spectroscopic imaging, zeta potential measurements, isoelectrofocusing, comet assay and mass spectrometry have been used to characterize this surprising structure that is present in the cells of all rat tissues examined (liver, kidney, heart, lung and brain), and that behaves as a “nuclear shield”. In hepatocytes, this hyper-crowding structure is about 300 nm thick, it is mainly formed by cationic enzymes and the local concentration of key protection enzymes, such as glutathione transferase, catalase and glutathione peroxidase is up to seven times higher than in the cytosol. The catalytic activity of these enzymes, when packed in the shield, is not modified and their relative concentrations vary remarkably in different tissues. Removal of this protective shield renders chromosomes more sensitive to damage by oxidative stress. Specific nuclear proteins anchored to the outer nuclear envelope are likely involved in the shield formation and stabilization. Conclusions/Significance The characterization of this previously unrecognized nuclear shield in different tissues opens a new interesting scenario for physiological and protection processes in eukaryotic cells. Selection and accumulation of protection enzymes near sensitive targets represents a new safeguard modality which deeply differs from the adaptive response which is based on expression of specific enzymes. PMID:21170318

  6. Activation of the Neuroprotective Angiotensin-Converting Enzyme 2 in Rat Ischemic Stroke.

    PubMed

    Bennion, Douglas M; Haltigan, Emily A; Irwin, Alexander J; Donnangelo, Lauren L; Regenhardt, Robert W; Pioquinto, David J; Purich, Daniel L; Sumners, Colin

    2015-07-01

    The angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas axis represents a promising target for inducing stroke neuroprotection. Here, we explored stroke-induced changes in expression and activity of endogenous angiotensin-converting enzyme 2 and other system components in Sprague-Dawley rats. To evaluate the clinical feasibility of treatments that target this axis and that may act in synergy with stroke-induced changes, we also tested the neuroprotective effects of diminazene aceturate, an angiotensin-converting enzyme 2 activator, administered systemically post stroke. Among rats that underwent experimental endothelin-1-induced ischemic stroke, angiotensin-converting enzyme 2 activity in the cerebral cortex and striatum increased in the 24 hours after stroke. Serum angiotensin-converting enzyme 2 activity was decreased within 4 hours post stroke, but rebounded to reach higher than baseline levels 3 days post stroke. Treatment after stroke with systemically applied diminazene resulted in decreased infarct volume and improved neurological function without apparent increases in cerebral blood flow. Central infusion of A-779, a Mas receptor antagonist, resulted in larger infarct volumes in diminazene-treated rats, and central infusion of the angiotensin-converting enzyme 2 inhibitor MLN-4760 alone worsened neurological function. The dynamic alterations of the protective angiotensin-converting enzyme 2 pathway after stroke suggest that it may be a favorable therapeutic target. Indeed, significant neuroprotection resulted from poststroke angiotensin-converting enzyme 2 activation, likely via Mas signaling in a blood flow-independent manner. Our findings suggest that stroke therapeutics that target the angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas axis may interact cooperatively with endogenous stroke-induced changes, lending promise to their further study as neuroprotective agents. PMID:25941346

  7. Engineering Enzymes in Energy Crops: Conditionally Activated Enzymes Expressed in Cellulosic Energy Crops

    SciTech Connect

    None

    2010-01-15

    Broad Funding Opportunity Announcement Project: Enzymes are required to break plant biomass down into the fermentable sugars that are used to create biofuel. Currently, costly enzymes must be added to the biofuel production process. Engineering crops to already contain these enzymes will reduce costs and produce biomass that is more easily digested. In fact, enzyme costs alone account for $0.50-$0.75/gallon of the cost of a biomass-derived biofuel like ethanol. Agrivida is genetically engineering plants to contain high concentrations of enzymes that break down cell walls. These enzymes can be “switched on” after harvest so they won’t damage the plant while it’s growing.

  8. Industrial Fungal Enzymes: An Occupational Allergen Perspective

    PubMed Central

    Green, Brett J.; Beezhold, Donald H.

    2011-01-01

    Occupational exposure to high-molecular-weight allergens is a risk factor for the development and pathogenesis of IgE-mediated respiratory disease. In some occupational environments, workers are at an increased risk of exposure to fungal enzymes used in industrial production. Fungal enzymes have been associated with adverse health effects in the work place, in particular in baking occupations. Exposure-response relationships have been demonstrated, and atopic workers directly handling fungal enzymes are at an increased risk for IgE-mediated disease and occupational asthma. The utilization of new and emerging fungal enzymes in industrial production will present new occupational exposures. The production of antibody-based immunoassays is necessary for the assessment of occupational exposure and the development of threshold limit values. Allergen avoidance strategies including personal protective equipment, engineering controls, protein encapsulation, and reduction of airborne enzyme concentrations are required to mitigate occupational exposure to fungal enzymes. PMID:21747869

  9. Glibenclamide Acts as an Inhibitor of Acyl-CoA:Cholesterol Acyltransferase Enzyme

    Microsoft Academic Search

    Nobutaka Ohgami; Akihiko Kuniyasu; Kohichiro Furukawa; Akira Miyazaki; Hideki Hakamata; Seikoh Horiuchi; Hitoshi Nakayama

    2000-01-01

    Sulfonylureas are used in the treatment of non-insulin-dependent diabetes mellitus. Little is known, however, about their effects on cholesterol metabolism. We tested in the present study the effects of glibenclamide (GB) on cholesterol esterification (CE) in macrophage-derived cells. GB inhibited intracellular accumulation of CE induced by acetylated LDL or oxidized LDL in J774 cells, but no such effect on total

  10. Advanced development of immobilized enzyme reactors

    NASA Technical Reports Server (NTRS)

    Jolly, Clifford D.; Schussel, Leonard J.; Carter, Layne

    1991-01-01

    Fixed-bed reactors have been used at NASA-Marshall to purify wastewater generated by an end-use equipment facility, on the basis of a combination of multifiltration unibeds and enzyme unibeds. The enzyme beds were found to effectively remove such targeted organics as urea, alcohols, and aldehydes, down to levels lying below detection limits. The enzyme beds were also found to remove organic contaminants not specifically targeted.

  11. Carrier-free immobilized enzymes for biocatalysis

    Microsoft Academic Search

    Ulrich Roessl; Jozef Nahálka; Bernd Nidetzky

    2010-01-01

    Methods for the preparation of carrier-free insoluble enzymes are reviewed. The technology of cross-linked enzyme aggregates\\u000a has now been applied to a range of synthetically useful activities. Fusion proteins are also gaining momentum because they\\u000a allow a relatively selective aggregation or even a specific self-assembly of the desired enzyme activity into insoluble particles\\u000a in the absence of potentially denaturing chemicals

  12. Modified enzymes for reactions in organic solvents

    Microsoft Academic Search

    A. B. Salleh; M. Basri; M. Taib; H. Jasmani; R. N. Z. A. Rahman; M. B. A. Rahman; C. N. A. Razak

    2002-01-01

    Recent studies on biocatalysis in water—organic solvent biphasic systems have shown that many enzymes retain their catalytic\\u000a activities in the presence of high concentrations of organic solvents. However, not all enzymes are organic solvent tolerant,\\u000a and most have limited and selective tolerance to particular organic solvents. Protein modification or protein tailoring is\\u000a an approach to alter the characteristics of enzymes,

  13. Functional dynamics of hydrolytic enzymes

    NASA Astrophysics Data System (ADS)

    Kargovsky, Alexey V.; Khodjer, Olga P.; Romanovsky, Yury M.

    2003-10-01

    One of important stages of the substrate bond breaking in the active site (AS) of ?-chymotrypsin (ACT) is considered. Three tasks are solved by methods of quantum mechanics and stochastic molecular dynamics: the loosening of peptide bond of a substrate attacked by O- ion of Ser195 of catalytic group; the opportunity of increase of a peptide bond (PB) breaking probability; the increase of this probability related to nonlinear interacting modes (or Fermi resonance (FR)) of oscillations of group N-H in PB. It is shown also that the splitting of vibrational levels Amide A and Amide B in a spectrum of an amide group pays off due to FR.

  14. ACTS and OLYMPUS propagation experiments

    NASA Technical Reports Server (NTRS)

    Bostian, Charles W.; Baker, Kenneth R.

    1988-01-01

    The OLYMPUS and ACTS satellites both provide opportunities for 10 to 30 GHz propagation measurements. The spacecraft are sufficiently alike that OLYMPUS can be used to test some prototype ACTS equipment and experiments. Data are particularly needed on short term signal behavior and in support of uplink power control and adaptive forward error correction (FEC) techniques. The Virginia Tech Satellite Communications Group has proposed a set of OLYMPUS experiments including attenuation and fade rate measurements, data communications, uplink power control, rain scatter interference, and small-scale site diversity operation. A digital signal processing receiver for the OLYMPUS and ACTS beacon signals is being developed.

  15. The ACT programmable transversal filter

    NASA Astrophysics Data System (ADS)

    Fleisch, Daniel A.; Pieters, Glenn C.

    1991-05-01

    The use of an acoustic charge transfer (ACT) programmable transversal filter (PTF) as a wideband analog filter with a user-programmable amplitude and phase response is considered. The fundamentals of the ACT technology making it possible to implement a wideband tapped delay line with programmable tap weights are described, and it is shown how the ACT tapped delay line can be used to implement a complete transversal filter through the addition of on-chip tap-weighting and memory circuits. Some of the applications that may utilize this approach, including receiver IF filtering, interference cancellation, and signal generation are reviewed.

  16. Deep Seabed Mineral Resources Act

    SciTech Connect

    Johnston, C.H.

    1980-01-01

    The Deep Seabed Mineral Resources Act, approved by the Senate Energy Committee in 1979, would permit U.S. mining interests to begin commercial recovery of hard minerals from the ocean floor. Under the proposed act, NOAA will regulate mining activities by issuing exploration licenses. The act demonstrates the U.S.'s dual commitment to a new and comprehensive internatonal law of the sea treaty and to a national interim regulatory framework for the fast-paced development of necessary deep-seabed mining. (37 references)

  17. Designing Artificial Enzymes by Intuition and Computation

    PubMed Central

    Nanda, Vikas; Koder, Ronald L.

    2012-01-01

    The rational design of artificial enzymes either by applying physio-chemical intuition of protein structure and function or with the aid of computation methods is a promising area of research with the potential to tremendously impact medicine, industrial chemistry and energy production. Designed proteins also provide a powerful platform for dissecting enzyme mechanisms of natural systems. Artificial enzymes have come a long way, from simple ?-helical peptide catalysts to proteins that facilitate multi-step chemical reactions designed by state-of-the-art computational methods. Looking forward, we examine strategies employed by natural enzymes which could be used to improve the speed and selectivity of artificial catalysts. PMID:21124375

  18. Biomedical applications of immobilized enzymes: an update.

    PubMed

    Pastor, Marta; Esquisabel, Amaia; Pedraz, José Luis

    2013-01-01

    Immobilized enzymes have been widely studied during the last few decades. Biocatalyst systems may work as biosensors or may be used for the treatment of different diseases. This chapter presents different attempts to immobilize enzymes in the biomedical field, particularly the use of prolidase and superoxide dismutase as two examples of this approach. Although this chapter focuses on liposomes and nanoparticles for the entrapment of these enzymes, the methods detailed here could be adapted for the immobilization of other enzymes with therapeutic purposes. PMID:23934812

  19. Nocardiopsis species as potential sources of diverse and novel extracellular enzymes.

    PubMed

    Bennur, Tahsin; Kumar, Ameeta Ravi; Zinjarde, Smita; Javdekar, Vaishali

    2014-11-01

    Members of the genus Nocardiopsis are generally encountered in locations that are inherently extreme. They are present in frozen soils, desert sand, compost, saline or hypersaline habitats (marine systems, salterns and soils) and alkaline places (slag dumps, lake soils and sediments). In order to survive under these severe conditions, they produce novel and diverse enzymes that allow them to utilize the available nutrients and to thrive. The members of this genus are multifaceted and release an assortment of extracellular hydrolytic enzymes. They produce enzymes that are cold-adapted (?-amylases), thermotolerant (?-amylases and xylanases), thermoalkalotolerant (cellulases, ?-1,3-glucanases), alkali-tolerant thermostable (inulinases), acid-stable (keratinase) and alkalophilic (serine proteases). Some of the enzymes derived from Nocardiopsis species act on insoluble polymers such as glucans (pachyman and curdlan), keratin (feathers and prion proteins) and polyhydroxyalkanoates. Extreme tolerance exhibited by proteases has been attributed to the presence of some amino acids (Asn and Pro) in loop structures, relocation of multiple salt bridges to outer regions of the protein or the presence of a distinct polyproline II helix. The range of novel enzymes is projected to increase in the forthcoming years, as new isolates are being continually reported, and the development of processes involving such enzymes is envisaged in the future. PMID:25269602

  20. Fast and easy enzyme immobilization by photoinitiated polymerization for efficient bioelectrochemical devices.

    PubMed

    Suraniti, Emmanuel; Studer, Vincent; Sojic, Neso; Mano, Nicolas

    2011-04-01

    Immobilization and electrical wiring of enzymes is of particular importance for the elaboration of efficient biosensors and can be cumbersome. Here, we report a fast and easy protocol for enzyme immobilization, and as a proof of concept, we applied it to the immobilization of bilirubin oxidase, a labile enzyme. In the first step, bilirubin oxidase is mixed with a redox hydrogel "wiring" the enzyme reaction centers to electrodes. Then, this adduct is covered by an outer layer of PEGDA made by photoinitiated polymerization of poly(ethylene-glycol) diacrylate (PEGDA) and a photoclivable precursor, DAROCUR. This two-step protocol is 18 times faster than the current state-of-the-art protocol and leads to currents 25% higher. In addition, the outer layer of PEGDA acts as a protective layer increasing the lifetime of the electrode by 100% when operating continuously for 2000 s and by 60% when kept in dry state for 24 h. This new protocol is particularly appropriate for labile enzymes that quickly denaturate. In addition, by tuning the ratio PEGDA/DAROCUR, it is possible to make the enzyme electrodes even more active or more stable. PMID:21405108

  1. Modelling as a tool of enzyme reaction engineering for enzyme reactor development

    Microsoft Academic Search

    Durda Vasi?-Ra?ki; Zvjezdana Findrik; Ana Vrsalovi? Prese?ki

    2011-01-01

    Strategy of the development of model for enzyme reactor at laboratory scale with respect to the modelling of kinetics is presented.\\u000a The recent literature on the mathematic modelling on enzyme reaction rate is emphasized.

  2. GOALS 2000: Educate America Act

    NSDL National Science Digital Library

    GOALS 2000 Educate America Act was signed into law on March 31, 1994. Related documents are available at the Education Department online library including the full text, related fact sheets, and additional information.

  3. Food Quality Protection Act (FQPA)

    NSDL National Science Digital Library

    Brief summary of the Food Quality Protection Act concerning EPA regulation of pesticides. Links to FQPA Background, Tolerance Reassessment, Endocrine Disruptors, Science Policies, Implementation Status and Other Information Resources for FQPA.

  4. SUPERFUND: GETTING INTO THE ACT

    EPA Science Inventory

    This publication is intended to assist those interest in providing contractual services to the Superfund program. Superfund: Getting Into The Act" describes current Superfund contracts and provides contact points, addresses, and telephone numbers for firms with Superfund contract...

  5. [Preventing dangerous psychotic acting out].

    PubMed

    Bouchard, Jean-Pierre

    2015-01-01

    Delusions of having been wronged, of persecution, of having a mission or order to execute, are frequently the causes of dangerous psychotic acting out. The regular clinical assessment of these patients and their treatment is essential for preventing this acting out, which can have dramatic consequences on the potential victims. If there is a treatment indication but refusal on the part of the patient to cooperate, it is necessary to resort to treatment without the patient's consent. PMID:25751909

  6. ACT-R 6 Proposals Dan Bothell

    E-print Network

    ACT-R 6 Proposals Dan Bothell db30@andrew.cmu.edu July 9, 2004 #12;Overview · General components #12;ACT-R 5 Architecture #12;ACT-R 6 · The picture for ACT-R 6 is similar · Make explicit some additions to be made easily #12;ACT-R 6 Buffers · Unify the operation/implementation ­ Procedural module

  7. [Short-acting insulin analogs].

    PubMed

    Wolffenbuttel, B H; Heine, R J

    1998-02-21

    Patients with diabetes mellitus type I usually are treated with a multiple injection regimen comprising rapid-acting insulin before meals and intermediate-acting insulin at bedtime. Recently, the rapid-acting insulin analogue insulin LISPRO was introduced on the Dutch market. This form of insulin is very rapidly taken up into the bloodstream from the subcutaneous tissue. The advantages of the use of insulin LISPRO are the comfort of injecting the insulin just before a meal, the more rapid correction of incidental hyperglycaemia and the slightly lower incidence of (nocturnal) hypoglycaemia in comparison with conventional rapid-acting insulin. There is no argument in favour of switching diabetics to insulin LISPRO if they are well-controlled with normal rapid-acting insulin and have few episodes of hypoglycaemia. In some persons the duration of action of insulin LISPRO may be too short, leading to preprandial hyperglycaemia. This can be avoided by using a second injection of intermediate-acting insulin, either before breakfast or before lunch. PMID:9562773

  8. Bipolar DNA Translocation Contributes to Highly Processive DNA Unwinding by RecBCD Enzyme*S

    E-print Network

    Kowalczykowski, Stephen C.

    Bipolar DNA Translocation Contributes to Highly Processive DNA Unwinding by RecBCD Enzyme*SBCD enzyme is a bipolar DNA helicase that employs two single-stranded DNA motors of opposite polarity the exceptionally high rate and processivity of DNA unwinding cata- lyzed by the RecBCD enzyme. Using a stopped

  9. Formation of oxylipins by CYP74 enzymes

    Microsoft Academic Search

    Michael Stumpe; Ivo Feussner

    2006-01-01

    Lipid peroxidation is common to all biological systems, both appearing in developmentally and environmentally regulated processes. Products are hydroperoxy polyunsaturated fatty acids and metabolites derived there from collectively named oxylipins. They may either originate from chemical oxidation or are synthesized by the action of various enzymes, such as lipoxygenases. Cloning of many lipoxygenases and other key enzymes metabolizing oxylipins revealed

  10. Enzyme adsorption at solid-liquid interfaces

    Microsoft Academic Search

    S. Duinhoven

    1992-01-01

    Enzymes are proteins with the capacity of catalysing various reactions. Nowadays two types of enzymes, proteases and lipases, are available for use in detergent formulations for household and industrial laundry washing. Proteases are capable of catalysing the hydrolysis of proteins while lipases enable the hydrolysis of glycerol esters, the main component in fats and non-mineral oils. In this study, two

  11. Enzyme Catalysis and the Gibbs Energy

    ERIC Educational Resources Information Center

    Ault, Addison

    2009-01-01

    Gibbs-energy profiles are often introduced during the first semester of organic chemistry, but are less often presented in connection with enzyme-catalyzed reactions. In this article I show how the Gibbs-energy profile corresponds to the characteristic kinetics of a simple enzyme-catalyzed reaction. (Contains 1 figure and 1 note.)

  12. Illustrating Enzyme Inhibition Using Gibbs Energy Profiles

    ERIC Educational Resources Information Center

    Bearne, Stephen L.

    2012-01-01

    Gibbs energy profiles have great utility as teaching and learning tools because they present students with a visual representation of the energy changes that occur during enzyme catalysis. Unfortunately, most textbooks divorce discussions of traditional kinetic topics, such as enzyme inhibition, from discussions of these same topics in terms of…

  13. Restriction Enzyme Mapping: A Simple Student Practical.

    ERIC Educational Resources Information Center

    Higgins, Stephen J.; And Others

    1990-01-01

    An experiment that uses the recombinant plasmid pX1108 to illustrate restriction mapping is described. The experiment involves three restriction enzymes and employs single and double restriction enzyme digestions. A list of needed materials, procedures, safety precautions, results, and discussion are included. (KR)

  14. Enzymes: A Workshop for Secondary School Students.

    ERIC Educational Resources Information Center

    Bering, C. Larry

    1994-01-01

    Describes the weekend science workshop on enzymes and includes several projects that involve students directly, parts of which can be incorporated into a traditional chemistry, biology, or physical science course at the secondary level. Subjects include catalysts and catalytic converters in cars, enzymes as consumer products and in industrial…

  15. Biocatalytic material comprising multilayer enzyme coated fiber

    DOEpatents

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  16. A survey of orphan enzyme activities

    Microsoft Academic Search

    Yannick Pouliot; Peter D. Karp

    2007-01-01

    BACKGROUND: Using computational database searches, we have demonstrated previously that no gene sequences could be found for at least 36% of enzyme activities that have been assigned an Enzyme Commission number. Here we present a follow-up literature-based survey involving a statistically significant sample of such \\

  17. Introduction Pancreatic cholesterol esterase (CEase), an enzyme,

    E-print Network

    Lee, Keun Woo

    535 Introduction Pancreatic cholesterol esterase (CEase), an enzyme, which is also known as bile salt-activated lipase, is responsible for the hydrolysis of various substrates including dietary) and oxyanion hole (Gly107­Ala108­Ala195) resi- dues.10 CEase, serine protease, and serine lipase enzymes share

  18. Introduction Pancreatic cholesterol esterase (CEase), an enzyme,

    E-print Network

    Lee, Keun Woo

    1 Introduction Pancreatic cholesterol esterase (CEase), an enzyme, which is also known as bile salt-activated lipase, is responsible for the hydrolysis of various substrates including dietary cholesterol esters, fat195) resi- dues.10 CEase, serine protease, and serine lipase enzymes share the same catalytic

  19. Enzyme Activity Experiments Using a Simple Spectrophotometer

    ERIC Educational Resources Information Center

    Hurlbut, Jeffrey A.; And Others

    1977-01-01

    Experimental procedures for studying enzyme activity using a Spectronic 20 spectrophotometer are described. The experiments demonstrate the effect of pH, temperature, and inhibitors on enzyme activity and allow the determination of Km, Vmax, and Kcat. These procedures are designed for teaching large lower-level biochemistry classes. (MR)

  20. FIELD MANAGEMENT EFFECTS ON SOIL ENZYME ACTIVITIES

    Microsoft Academic Search

    Alina Dora Samuel; Cornel Domua; Cornelia Ciobanu

    Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for preluvosoil. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can provide information on how soil management affects the soil potential to perform processes, such as decomposi- tion and nutrient cycling. Soil enzyme activities

  1. Potential applications of oxidative enzymes and phenoloxidase-like compounds in wastewater and soil treatment: a review

    Microsoft Academic Search

    Nelson Durán; Elisa Esposito

    2000-01-01

    A number of oxidative enzymes from bacteria, fungi and plants have been reported to play an important role in numerous waste treatment applications. Peroxidases and\\/or phenoloxidases can act on specific recalcitrant pollutants by precipitation or transforming to other products and permitting a better final treatment of the waste. Improvement in the useful life and thereby a reduction in treatment cost

  2. Lipid bilayer nanodisc platform for investigating polyprenol-dependent enzyme interactions and activities

    PubMed Central

    Hartley, Meredith D.; Schneggenburger, Philipp E.; Imperiali, Barbara

    2013-01-01

    Membrane-bound polyprenol-dependent pathways are important for the assembly of essential glycoconjugates in all domains of life. However, despite their prevalence, the functional significance of the extended linear polyprenyl groups in the interactions of the glycan substrates, the biosynthetic enzymes that act upon them, and the membrane bilayer in which they are embedded remains a mystery. These interactions are investigated simultaneously and uniquely through application of the nanodisc membrane technology. The Campylobacter jejuni N-linked glycosylation pathway has been chosen as a model pathway in which all of the enzymes and substrates are biochemically accessible. We present the functional reconstitution of two enzymes responsible for the early membrane-committed steps in glycan assembly. Protein stoichiometry analysis, fluorescence-based approaches, and biochemical activity assays are used to demonstrate the colocalization of the two enzymes in nanodiscs. Isotopic labeling of the substrates reveals that undecaprenyl-phosphate is coincorporated into discs with the two enzymes, and furthermore, that both enzymes are functionally reconstituted and can sequentially convert the coembedded undecaprenyl-phosphate into undecaprenyl-diphosphate-linked disaccharide. These studies provide a proof-of-concept demonstrating that the nanodisc model membrane system represents a promising experimental platform for analyzing the multifaceted interactions among the enzymes involved in polyprenol-dependent glycan assembly pathways, the membrane-associated substrates, and the lipid bilayer. The stage is now set for exploration of the roles of the conserved polyprenols in promoting protein–protein interactions among pathway enzymes and processing of substrates through sequential steps in membrane-associated glycan assembly. PMID:24302767

  3. Effect of additives on enzyme-catalyzed polymerization of phenols and aromatic amines.

    PubMed

    D'Annibale, Alessandro; Stazi, Silvia Rita; Petruccioli, Maurizio

    2012-01-01

    Among biological approaches to the removal of aromatic amines and phenols from wastewater, the so-called enzyme-catalyzed polymerization and precipitation (ECPP) process relies on the use of oxidoreductases acting via radical mechanisms and characterized by a rather relaxed substrate specificity, such as laccase, tyrosinase and peroxidases. The main technical constraints of ECPP processes are due to a variety of enzyme deactivation phenomena occurring during catalysis and to the incomplete removal of oxidation products from solution. In order to put ECPP into practice, these drawbacks have to be either counteracted or minimized. Although several approaches, such as enzyme immobilization and reaction engineering, have been proposed to limit these constraints, this review is intended to provide a wide survey on some chemical additives with either protective or coagulating effects that have been so far employed for these purposes. PMID:22652869

  4. Structure-based repurposing of FDA-approved drugs as inhibitors of NEDD8-activating enzyme.

    PubMed

    Zhong, Hai-Jing; Liu, Li-Juan; Chan, Daniel Shiu-Hin; Wang, Hui-Min; Chan, Philip Wai Hong; Ma, Dik-Lung; Leung, Chung-Hang

    2014-07-01

    We report the discovery of an inhibitor of NEDD8-activating enzyme (NAE) by an integrated virtual screening approach. Piperacillin 1 inhibited NAE activity in cell-free and cell-based systems with high selectivity. Furthermore, piperacillin 1 was able to inhibit the degradation of the NAE downstream protein substrate p27(kip1). Our molecular modeling and kinetic studies suggested that this compound may act as a non-covalent ATP-competitive inhibitor of NAE. PMID:24657219

  5. Tissue-specific enhancement of xenobiotic detoxification enzymes in mice by dietary rosemary extract

    Microsoft Academic Search

    Keith W. Singletary; Joan T. Rokusek

    1997-01-01

    Plant foods contain nutritive and minor, nonnutritive components capable of inhibiting experimental carcinogenesis. Many of\\u000a these cancer-protective extracts act by enhancing the activities of enzymes that can detoxify reactive substances. In the\\u000a present study an extract of the spice plant rosemary was fed at concentrations of 0.3% and 0.6% (by weight) for 4 weeks to\\u000a female A\\/J mice prior to

  6. Enzyme enhancement activity of N-octyl-?-valienamine on ?-glucosidase mutants associated with Gaucher disease

    Microsoft Academic Search

    Ke Lei; Haruaki Ninomiya; Michitaka Suzuki; Takehiko Inoue; Miwa Sawa; Masami Iida; Hiroyuki Ida; Yoshikatsu Eto; Seiichiro Ogawa; Kousaku Ohno; Yoshiyuki Suzuki

    2007-01-01

    Gaucher disease (GD), caused by a defect of ?-glucosidase (?-Glu), is the most common form of sphingolipidosis. We have previously shown that a carbohydrate mimic N-octyl-?-valienamine (NOV), an inhibitor of ?-Glu, could increase the protein level and enzyme activity of F213I mutant ?-Glu in cultured GD fibroblasts, suggesting that NOV acted as a pharmacological chaperone to accelerate transport and maturation

  7. Reaction specificity in pyridoxal phosphate enzymes.

    PubMed

    Toney, Michael D

    2005-01-01

    Pyridoxal phosphate enzymes catalyze a wide variety of reaction types on amines and amino acids, generally by stabilizing carbanionic intermediates. This makes them very useful in cellular metabolism, but it also creates problems in controlling the reaction pathway that a given enzyme follows, i.e., in controlling reaction specificity. Stereoelectronic effects have been proposed to play a major role in determining the bond to Calpha that gets broken in the external aldimine intermediate that is common to all PLP enzymes. Here, we discuss our work on dialkylglycine decarboxylase aimed at providing direct evidence for stereoelectronic control of external aldimine reactivity. Once a bond to Calpha has been broken to form the carbanionic intermediate, enzymes must also carefully control the fate of this reactive species. Our studies with alanine racemase suggest that the enzyme selectively destabilizes the carbanionic quinonoid intermediate to promote higher racemization specificity by avoiding transamination side reactions. PMID:15581583

  8. Nedd8 processing enzymes in Schizosaccharomyces pombe

    PubMed Central

    2013-01-01

    Background Conjugation of the ubiquitin-like modifier Nedd8 to cullins is critical for the function of SCF-type ubiquitin ligases and thus facilitates ubiquitin conjugation and ultimately degradation of SCF substrates, including several cell cycle regulators. Like ubiquitin, Nedd8 is produced as a precursor that must first be processed before it becomes active. In Saccharomyces cerevisiae this is carried out exclusively by the enzyme Yuh1. Results Here we show that in the fission yeast, Schizosaccharomyces pombe, the Yuh1 orthologue, Uch1, is not the sole Nedd8 processing enzyme. Instead it appears that deubiquitylating enzymes can efficiently process the Nedd8 precursor in vivo. Conclusions Several enzymes contribute to Nedd8 precursor processing including a number of deubiquitylating enzymes. PMID:23496905

  9. Highly efficient self-replicating RNA enzymes.

    PubMed

    Robertson, Michael P; Joyce, Gerald F

    2014-02-20

    An RNA enzyme has been developed that catalyzes the joining of oligonucleotide substrates to form additional copies of itself, undergoing self-replication with exponential growth. The enzyme also can cross-replicate with a partner enzyme, resulting in their mutual exponential growth and enabling self-sustained Darwinian evolution. The opportunity for inventive evolution within this synthetic genetic system depends on the diversity of the evolving population, which is limited by the catalytic efficiency of the enzyme. Directed evolution was used to improve the efficiency of the enzyme and increase its exponential growth rate to 0.14 min(-1), corresponding to a doubling time of 5 min. This is close to the limit of 0.21 min(-1) imposed by the rate of product release, but sufficient to enable more than 80 logs of growth per day. PMID:24388759

  10. Substrate analogues for isoprenoid enzymes

    SciTech Connect

    Stremler, K.E.

    1987-01-01

    Diphosphonate analogues of geranyl diphosphate, resistant to degradation by phosphatases, were found to be alternate substrates for the reaction with farnesyl diphosphate synthetase isolated from avian liver. The difluoromethane analogue was shown to be the better alternate substrate, in agreement with solvolysis results which indicate that the electronegativity of the difluoromethylene unit more closely approximates that of the normal bridging oxygen. The usefulness of the C/sub 10/ difluoro analogue, for detecting low levels of isoprenoid enzymes in the presence of high levels of phosphatase activity, was demonstrated with a cell-free preparation from lemon peel. A series of C/sub 5/ through C/sub 15/ homoallylic and allylic diphosphonates, as well as two 5'-nucleotide diphosphonates, was prepared in high overall yield using the activation-displacement sequence. Radiolabeled samples of several of the allylic diphosphonates were prepared with tritium located at C1. A series of geraniols, stereospecifically deuterated at C1, was prepared. The enantiomeric purities and absolute configurations were determined by derivatization as the mandelate esters for analysis by /sup 1/H NMR. The stereochemistry of the activation-displacement sequence was examined using C1-deuterated substrates.

  11. Arbeidslivets lover Act relating to working environment,

    E-print Network

    Johansen, Tom Henning

    Arbeidslivets lover Act relating to working environment, working hours and employment protection, etc. (Working Environment Act). as subsequently amended, last by the Act of 14. December 2012 No. 80.notification................................................................... 6 Chapter 3. Working environment measures..................................... 6 Section.3

  12. 7 CFR 1205.302 - Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.302 Act. Act means the Cotton Research and Promotion Act, as amended (7 U.S.C....

  13. 7 CFR 1205.302 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.302 Act. Act means the Cotton Research and Promotion Act, as amended (7 U.S.C....

  14. 7 CFR 1205.302 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.302 Act. Act means the Cotton Research and Promotion Act, as amended (7 U.S.C....

  15. 7 CFR 1205.302 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.302 Act. Act means the Cotton Research and Promotion Act, as amended (7 U.S.C....

  16. 7 CFR 1205.302 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.302 Act. Act means the Cotton Research and Promotion Act, as amended (7 U.S.C....

  17. 7 CFR 989.2 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE RAISINS PRODUCED FROM GRAPES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 989.2 Act. Act means Public Act No. 10,...

  18. 7 CFR 917.2 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.2 Act. Act means Public Act No. 10,...

  19. 7 CFR 917.2 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.2 Act. Act means Public Act No. 10,...

  20. 7 CFR 917.2 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.2 Act. Act means Public Act No. 10,...

  1. 7 CFR 917.2 - Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.2 Act. Act means Public Act No. 10, 73d...

  2. 7 CFR 982.2 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON AND WASHINGTON Order Regulating Handling Definitions § 982.2 Act. Act means Public Act...

  3. 7 CFR 917.2 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Definitions § 917.2 Act. Act means Public Act No. 10, 73d Congress (May 12,...

  4. 7 CFR 924.2 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PRUNES GROWN IN DESIGNATED COUNTIES IN WASHINGTON AND IN UMATILLA COUNTY, OREGON Order Regulating Handling Definitions § 924.2 Act. Act means Public Act No. 10,...

  5. 40 CFR 791.105 - Prohibited acts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    40 Protection of Environment 31 2010-07-01 2010-07-01 true Prohibited acts. 791.105 Section 791.105 Protection...CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) DATA REIMBURSEMENT Prohibited Acts §...

  6. 7 CFR 1205.10 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.10 Act. The term Act means the Cotton Research and Promotion Act, as...

  7. 7 CFR 1205.10 - Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.10 Act. The term Act means the Cotton Research and Promotion Act, as...

  8. 7 CFR 1205.10 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.10 Act. The term Act means the Cotton Research and Promotion Act, as...

  9. 7 CFR 1205.10 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.10 Act. The term Act means the Cotton Research and Promotion Act, as...

  10. 7 CFR 1205.10 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.10 Act. The term Act means the Cotton Research and Promotion Act, as...

  11. 77 FR 2723 - Sunshine Act Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-19

    ...seconded by Ms. Julie L. Williams, acting in the place and stead of Director John G. Walsh (Acting Comptroller of the Currency), concurred in by Director Richard Cordray (Director, Consumer Financial Protection Bureau), and Acting...

  12. 24 CFR 570.614 - Architectural Barriers Act and the Americans with Disabilities Act.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Architectural Barriers Act and the Americans...Requirements § 570.614 Architectural Barriers Act and the Americans with Disabilities Act. (a) The Architectural Barriers Act of 1968...

  13. 24 CFR 570.614 - Architectural Barriers Act and the Americans with Disabilities Act.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2010-04-01 true Architectural Barriers Act and the Americans...Requirements § 570.614 Architectural Barriers Act and the Americans with Disabilities Act. (a) The Architectural Barriers Act of 1968...

  14. Preparation of some immobilized linked enzyme systems and their use in the automated determination of disaccharides.

    PubMed

    Inman, D J; Hornby, W E

    1974-01-01

    1. Glucose oxidase (EC 1.1.3.4), amyloglucosidase (EC 3.2.1.3), invertase (EC 3.2.1.26) and beta-galactosidase (EC 3.2.1.23) were covalently attached via glutaraldehyde to the inside surface of nylon tube. 2. The linked enzyme system, comprising invertase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of sucrose. 3. The linked enzyme system, comprising beta-galactosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of lactose. 4. The linked enzyme system, comprising amyloglucosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of maltose. 5. Mixtures of glucose oxidase and amyloglucosidase were immobilized within the same piece of nylon tube and used for the automated determination of maltose. 6. Mixtures of glucose oxidase and invertase were immobilized within the same piece of nylon tube and used for the automated determination of sucrose. PMID:4206908

  15. Process for preparing multilayer enzyme coating on a fiber

    DOEpatents

    Kim, Jungbae (Richland, WA); Kwak, Ja Hun (Richland, WA); Grate, Jay W. (West Richland, WA)

    2009-11-03

    A process for preparing high stability, high activity biocatalytic materials is disclosed and processes for using the same. The process involves coating of a material or fiber with enzymes and enzyme aggregate providing a material or fiber with high biocatalytic activity and stability useful in heterogeneous environments. In one illustrative approach, enzyme "seeds" are covalently attached to polymer nanofibers followed by treatment with a reagent that crosslinks additional enzyme molecules to the seed enzymes forming enzyme aggregates thereby improving biocatalytic activity due to increased enzyme loading and enzyme stability. This approach creates a useful new biocatalytic immobilized enzyme system with potential applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  16. An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

    PubMed Central

    Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

    2015-01-01

    The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

  17. Expanding the Halohydrin Dehalogenase Enzyme Family: Identification of Novel Enzymes by Database Mining

    PubMed Central

    Schallmey, Marcus; Koopmeiners, Julia; Wells, Elizabeth; Wardenga, Rainer

    2014-01-01

    Halohydrin dehalogenases are very rare enzymes that are naturally involved in the mineralization of halogenated xenobiotics. Due to their catalytic potential and promiscuity, many biocatalytic reactions have been described that have led to several interesting and industrially important applications. Nevertheless, only a few of these enzymes have been made available through recombinant techniques; hence, it is of general interest to expand the repertoire of these enzymes so as to enable novel biocatalytic applications. After the identification of specific sequence motifs, 37 novel enzyme sequences were readily identified in public sequence databases. All enzymes that could be heterologously expressed also catalyzed typical halohydrin dehalogenase reactions. Phylogenetic inference for enzymes of the halohydrin dehalogenase enzyme family confirmed that all enzymes form a distinct monophyletic clade within the short-chain dehydrogenase/reductase superfamily. In addition, the majority of novel enzymes are substantially different from previously known phylogenetic subtypes. Consequently, four additional phylogenetic subtypes were defined, greatly expanding the halohydrin dehalogenase enzyme family. We show that the enormous wealth of environmental and genome sequences present in public databases can be tapped for in silico identification of very rare but biotechnologically important biocatalysts. Our findings help to readily identify halohydrin dehalogenases in ever-growing sequence databases and, as a consequence, make even more members of this interesting enzyme family available to the scientific and industrial community. PMID:25239895

  18. 62 FR 53803 - Correction; Sunshine Act Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    1997-10-16

    ...NATIONAL COMMISSION ON LIBRARIES AND INFORMATION SCIENCE Correction; Sunshine Act Meeting ``Federal Register...discussed: (1) NCLIS studies and programs, (2) Library Services and Technology Act, (3)...

  19. 7 CFR 1215.1 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...COMMODITIES), DEPARTMENT OF AGRICULTURE POPCORN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Popcorn Promotion, Research, and Consumer Information... § 1215.1 Act. Act means the Popcorn Promotion, Research, and Consumer...

  20. 7 CFR 1215.1 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...COMMODITIES), DEPARTMENT OF AGRICULTURE POPCORN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Popcorn Promotion, Research, and Consumer Information... § 1215.1 Act. Act means the Popcorn Promotion, Research, and Consumer...

  1. 7 CFR 1215.1 - Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...COMMODITIES), DEPARTMENT OF AGRICULTURE POPCORN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Popcorn Promotion, Research, and Consumer Information... § 1215.1 Act. Act means the Popcorn Promotion, Research, and Consumer...

  2. 7 CFR 1215.1 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...COMMODITIES), DEPARTMENT OF AGRICULTURE POPCORN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Popcorn Promotion, Research, and Consumer Information... § 1215.1 Act. Act means the Popcorn Promotion, Research, and Consumer...

  3. 7 CFR 1215.1 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...COMMODITIES), DEPARTMENT OF AGRICULTURE POPCORN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Popcorn Promotion, Research, and Consumer Information... § 1215.1 Act. Act means the Popcorn Promotion, Research, and Consumer...

  4. 7 CFR 1214.1 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions § 1214.1 Act. Act...

  5. 7 CFR 1214.1 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions § 1214.1 Act. Act...

  6. 7 CFR 1214.1 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions § 1214.1 Act. Act...

  7. Potato Peroxidase for the Study of Enzyme Properties.

    ERIC Educational Resources Information Center

    Shamaefsky, Brian R.

    1993-01-01

    Explains how the surface of a freshly sliced potato can be used for a variety of enzyme action experiments including the influence of pH on enzyme action, the enzyme denaturation potential of boiling water, the inhibition of enzymes by heavy metals, and the effects of salt concentration on enzyme effectiveness. (PR)

  8. Angiotensin I converting enzyme inhibitory peptide extracted from freshwater zooplankton.

    PubMed

    Lee, Jung Kwon; Lee, Min-Su; Park, Heum Gi; Kim, Se-Kwon; Byun, Hee-Guk

    2010-04-01

    In this study, hydrolysates obtained from the freshwater rotifer Brachionus calyciflonus were investigated for angiotensin I converting enzyme (ACE) inhibitory peptides. Freshwater rotifer protein was hydrolyzed using six separate enzymes in a batch reactor. The peptic hydrolysate had the highest ACE inhibitory activity compared to the other hydrolysates. The highest ACE inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. The 50% inhibitory concentration (IC(50)) value of purified ACE inhibitory peptide was 40.01 microg/mL. ACE inhibitory peptide was identified as being seven amino acid residues of Ala-Gln-Gly-Glu-Arg-His-Arg by N-terminal amino acid sequence analysis. The IC(50) value of purified ACE inhibitory peptide was 47.1 microM, and Lineweaver-Burk plots suggested that the peptide purified from rotifer protein acts as a competitive inhibitor against ACE. The results of this study suggest that peptides derived from freshwater rotifers may be beneficial as antihypertension compounds in functional foods or as pharmaceuticals. PMID:20170338

  9. Tissue angiotensin-converting enzyme inhibitors: are they more effective than serum angiotensin-converting enzyme inhibitors?

    PubMed

    Shah, Apurva D; Arora, Rohit R

    2005-12-01

    Since their discovery in the 1980s, angiotensin-converting enzyme (ACE) inhibitors have been shown to decrease angiotensin formation, prevent breakdown of bradykinin, and may also act on peptides of the renin-angiotensin system. They are effective in reducing the risk of heart failure, myocardial infarction, and death from cardiovascular causes in patients with left ventricular systolic dysfunction or heart failure, and have been shown to reduce atherosclerotic complications in patients who have vascular disease without heart failure. They may preserve endothelial function and counteract initiation and progression of atherosclerosis. Broadly, ACE inhibitors can be divided into tissue specific or serum ACE inhibitors. Tissue-specific ACE inhibitors as a group are not superior to serum ACE inhibitors in the treatment of coronary artery disease. Pending direct comparator clinical trials between a tissue ACE inhibitor and a plasma ACE inhibitor, both ramipril and perindopril can be recommended for secondary risk prevention, based on the evidence. PMID:16405197

  10. Regulation of enzyme levels in the blood. Influence of environmental and genetic factors on enzyme clearance.

    PubMed Central

    Hayashi, T.; Salata, K.; Kingman, A.; Notkins, A. L.

    1988-01-01

    Since its discovery, lactic dehydrogenase virus (LDV) has remained unique as a model of long-term enzyme elevation due to impairment of enzyme clearance. The present study shows that mice inoculated with silica develop an increase in plasma lactate dehydrogenase (LDH) lasting for at least 6 months and that the enzyme elevation is due, at least in part, to impairment of clearance. The extent of the enzyme elevation is dependent on both the dose and route of silica administration and mice that had received both silica and LDV showed a more profound impairment of LDH clearance than mice that had received silica or LDV alone. Examination of the factors that regulate circulating enzyme levels in normal mice revealed that whereas there was no difference in resting enzyme levels among several inbred strains of mice (BALB/cAnN, NZBWF1/J,B10.D2/nSnN, and A/J mice), when mice were stressed by the administration of an enzyme load, certain inbred strains (BALB/cAnN) cleared the enzyme rapidly and others (B10.D2/nSnN) cleared the enzyme slowly. Moreover, in B10.D2/nSnN mice, enzyme clearance was age-related. When different strains of mice were infected with LDV, LDH levels were substantially higher in the circulation of slow enzyme clearers as compared to rapid enzyme clearers. It is concluded that both environmental and genetic factors influence the clearance of LDH and that impairment of enzyme clearance may be a more important factor than previously suspected in regulating enzyme levels in disease states. PMID:2843049

  11. [Sidelined under the Participation Act].

    PubMed

    Wind, H

    2015-01-01

    In January this year, a new law was introduced in the Netherlands aimed at improving opportunities for people who cannot find work, among them young people with impairments who still have - limited - ability to work. This law, the Participation Act, is executed by municipalities. All young people with the ability to work despite their impairments are entitled to support from the municipalities in finding a job. At present, only a small percentage of these young people are in paid employment. Bureaucracy threatens the proper implementation of the Participation Act and young people with impairments are particularly affected. Integrated action by municipalities and employers, and patience, are important for the promotion of work participation by young workers. The only way to accomplish the objective of the Participation Act is to make the participation in work of the youngster with impairments a central issue. PMID:26058773

  12. [Production of ligninolytic enzymes in bioreactor].

    PubMed

    Gao, Da-wen; Wen, Xiang-hua; Qian, Yi

    2006-02-01

    Production of ligninolytic enzymes under nitrogen limited conditions(C/N = 56/2.2) was studied in a 5-L stirred tank bioreactor with a working volume of 2 L for obtaining higher production of ligninolytic enzymes by white rot fungus Phanerochaete chrysosporium BKM-F-1767 and its control strategy. Results show that the manganese peroxidase (MnP) and laccase (Lac) reached peak at the sixth day and the seventh day, respectively, and the variation of them with time in a batch cultivation are similar to the results by agitated Erlenmeyer flasks; however higher enzyme activity was not achieved by applying a fed-batch strategy, in which nitrogen limited medium was fed to the reactor. In addition, variation of pH during cultivation was related to the growth of P. chrysosporium and enzymes production during both batch and fed-batch cultivation. The pH value of liquid medium began to decline when the enzyme activity occurred in the system, and the decline became more and more slow along with the decrease of enzyme activity at the end of fermentation. So, pH would be as a control parameter to find out the growth of P. chrysosporium and enzymes production during incubating P. chrysosporium. However, fed-batch strategy still need further study. PMID:16686200

  13. ACTS OF VIOLENCE ANNEX V ACTS OF VIOLENCE

    E-print Network

    . CONSIDERATIONS FOR SECONDARY EXPLOSIVE DEVICES...................13 R. MEDICAL TRIAGE AND MASS CASUALTY Operations Plan (EOP) and shall be considered an interactive support document to the EOP. APPROVAL an interactive support document to the EOP. The threat associated with acts of violence and most notably

  14. 75 FR 63703 - Privacy Act of 1974; Privacy Act Regulation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ...primary changes concern the waiver of copying fees charged to current and former Board...proposed amendments: (1) Waived all copying fees in connection with any Privacy Act...information available for inspection and copying during regular business hours at the...

  15. Self-acting shaft seals

    NASA Technical Reports Server (NTRS)

    Ludwig, L. P.

    1978-01-01

    Self-acting seals are described in detail. The mathematical models for obtaining a seal force balance and the equilibrium operating film thickness are outlined. Particular attention is given to primary ring response (seal vibration) to rotating seat face runout. This response analysis reveals three different vibration models with secondary seal friction being an important parameter. Leakage flow inlet pressure drop and affects of axisymmetric sealing face deformations are discussed. Experimental data on self-acting face seals operating under simulated gas turbine conditions are given. Also a spiral groove seal design operated to 244 m/sec (800 ft/sec) is described.

  16. Reforming the Human Tissue Acts.

    PubMed

    McKelvie, Helen

    2006-11-01

    The Human Tissue Acts of the various States and Territories that were enacted following the 1977 Report of the Australian Law Reform Commission on Human Tissue Transplants are in need of an overhaul as a result of rapid advances in medical science and biotechnology, as well as growing public expectations regarding the ethical use of tissues and organs obtained from autopsies and other sources. The author argues that the time is ripe for a comprehensive review and revision of the Acts throughout the country in order to maintain a consistent approach. PMID:17153521

  17. Advanced Communications Technology Satellite (ACTS)

    NASA Technical Reports Server (NTRS)

    Gedney, Richard T.; Schertler, Ronald J.

    1989-01-01

    The NASA Advanced Communications Technology Satellite (ACTS) was conceived to help maintain U.S. leadership in the world's communications-satellite market. This experimental satellite is expected to be launched by NASA in 1992 and to furnish the technology necessary for establishing very small aperture terminal digital networks which provide on-demand full-mesh connectivity, and 1.544-MBPS services with only a single hop. Utilizing on-board switching and processing, each individual voice or data circuit can be separately routed to any location in the network. This paper provides an overview of the ACTS and discusses the value of the technology for future communications systems.

  18. Data mining of enzymes using specific peptides

    PubMed Central

    2009-01-01

    Background Predicting the function of a protein from its sequence is a long-standing challenge of bioinformatic research, typically addressed using either sequence-similarity or sequence-motifs. We employ the novel motif method that consists of Specific Peptides (SPs) that are unique to specific branches of the Enzyme Commission (EC) functional classification. We devise the Data Mining of Enzymes (DME) methodology that allows for searching SPs on arbitrary proteins, determining from its sequence whether a protein is an enzyme and what the enzyme's EC classification is. Results We extract novel SP sets from Swiss-Prot enzyme data. Using a training set of July 2006, and test sets of July 2008, we find that the predictive power of SPs, both for true-positives (enzymes) and true-negatives (non-enzymes), depends on the coverage length of all SP matches (the number of amino-acids matched on the protein sequence). DME is quite different from BLAST. Comparing the two on an enzyme test set of July 2008, we find that DME has lower recall. On the other hand, DME can provide predictions for proteins regarded by BLAST as having low homologies with known enzymes, thus supplying complementary information. We test our method on a set of proteins belonging to 10 bacteria, dated July 2008, establishing the usefulness of the coverage-length cutoff to determine true-negatives. Moreover, sifting through our predictions we find that some of them have been substantiated by Swiss-Prot annotations by July 2009. Finally we extract, for production purposes, a novel SP set trained on all Swiss-Prot enzymes as of July 2009. This new set increases considerably the recall of DME. The new SP set is being applied to three metagenomes: Sargasso Sea with over 1,000,000 proteins, producing predictions of over 220,000 enzymes, and two human gut metagenomes. The outcome of these analyses can be characterized by the enzymatic profile of the metagenomes, describing the relative numbers of enzymes observed for different EC categories. Conclusions Employing SPs for predicting enzymatic activity of proteins works well once one utilizes coverage-length criteria. In our analysis, L ? 7 has led to highly accurate results. PMID:20034383

  19. BIOCHEMISTRY: Enzyme Motions Inside and Out

    NSDL National Science Digital Library

    Stephen J. Benkovic (Pennsylvania State University; Department of Chemistry)

    2006-04-14

    Access to the article is free, however registration and sign-in are required. How does an enzyme reduce the free-energy barrier for a chemical transformation? The authors have reviewed the progression of hypothetical answers to this question and identified a common feature of the various rationales--namely, the requirement for conformational flexibility within the enzyme and substrates. They also discuss how Masgrau et al. examined the importance of dynamics for catalysis by the enzyme aromatic amine dehydrogenase in the oxidation of tryptamine.

  20. Immobilized Enzymes and Cells as Practical Catalysts

    NASA Astrophysics Data System (ADS)

    Klibanov, Alexander M.

    1983-02-01

    Performance of enzymes and whole cells in commercial applications can often be dramatically improved by immobilization of the biocatalysts, for instance, by their covalent attachment to or adsorption on solid supports, entrapment in polymeric gels, encapsulation, and cross-linking. The effect of immobilization on enzymatic properties and stability of biocatalysts is considered. Applications of immobilized enzymes and cells in the chemical, pharmaceutical, and food industries, in clinical and chemical analyses, and in medicine, as well as probable future trends in enzyme technology are discussed.

  1. Steroid promiscuity: Diversity of enzyme action.

    PubMed

    Lathe, Richard; Kotelevtsev, Yuri; Mason, J Ian

    2015-07-01

    This Special Issue on the topic of Steroid and Sterol Signaling: Promiscuity and Diversity, dwells on the growing realization that the 'one ligand, one binding site' and 'one enzyme, one reaction' concepts are out of date. Focusing on cytochromes P450 (CYP), hydroxysteroid dehydrogenases (HSDs), and related enzymes, the Special Issue highlights that a single enzyme can bind to diverse substrates, and in different conformations, and can catalyze multiple different conversions (and in different directions), thereby, generating an unexpectedly wide spectrum of ligands that can have subtly different biological actions. This article is part of a Special Issue entitled 'Steroid/Sterol Signaling' . PMID:25596328

  2. LIGAND: chemical database of enzyme reactions

    PubMed Central

    Goto, Susumu; Nishioka, Takaaki; Kanehisa, Minoru

    2000-01-01

    LIGAND is a composite database comprising three sections: ENZYME for the information of enzyme molecules and enzymatic reactions, COMPOUND for the information of metabolites and other chemical compounds, and REACTION for the collection of substrate–product relations. The current release includes 3390 enzymes, 5645 compounds and 5207 reactions. The database is indispensable for the reconstruction of metabolic pathways in the completely sequenced organisms. The LIGAND database can be accessed through the WWW (http://www.genome.ad.jp/dbget/ligand.html ) or may be downloaded by anonymous FTP (ftp://kegg.genome.ad.jp/molecules/ligand/ ). PMID:10592281

  3. 75 FR 36642 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-28

    ...Central Security Service, Freedom...Information Act and Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  4. 76 FR 3098 - Privacy Act of 1974; Systems of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ...Central Security Service, Freedom...Information Act and Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  5. 75 FR 74019 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  6. 77 FR 56628 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  7. 75 FR 21250 - Privacy Act of 1974; Systems of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-23

    ...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  8. 75 FR 2514 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-15

    ...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  9. 77 FR 26254 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-03

    ...Central Security Service, Freedom...Information Act and Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  10. 75 FR 65457 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  11. 75 FR 56079 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act Office...Central Security Service, Freedom...Information Act/Privacy Act...

  12. Impact of enzyme loading on the efficacy and recovery of cellulolytic enzymes immobilized on enzymogel nanoparticles.

    PubMed

    Samaratunga, Ashani; Kudina, Olena; Nahar, Nurun; Zakharchenko, Andrey; Minko, Sergiy; Voronov, Andriy; Pryor, Scott W

    2015-03-01

    Cellulase and ?-glucosidase were adsorbed on a polyacrylic acid polymer brush grafted on silica nanoparticles to produce enzymogels as a form of enzyme immobilization. Enzyme loading on the enzymogels was increased to a saturation level of approximately 110 ?g (protein) mg(-1) (particle) for each enzyme. Enzymogels with varied enzyme loadings were then used to determine the impact on hydrolysis rate and enzyme recovery. Soluble sugar concentrations during the hydrolysis of filter paper and Solka-Floc with the enzymogels were 45 and 53%, respectively, of concentrations when using free cellulase. ?-Glucosidase enzymogels showed lower performance; hydrolyzate glucose concentrations were just 38% of those using free enzymes. Increasing enzyme loading on the enzymogels did not reduce net efficacy for cellulase and improved efficacy for ?-glucosidase. The use of free cellulases and cellulase enzymogels resulted in hydrolyzates with different proportions of cellobiose and glucose, suggesting differential attachment or efficacy of endoglucanases, exoglucanases, and ?-glucosidases present in cellulase mixtures. When loading ?-glucosidase individually, higher enzyme loadings on the enzymogels produced higher hydrolyzate glucose concentrations. Approximately 96% of cellulase and 66 % of ?-glucosidase were recovered on the enzymogels, while enzyme loading level did not impact recovery for either enzyme. PMID:25564204

  13. BLEACHABILITY OF RECYCLED FIBERS DEINKED WITH ENZYME PREPARATIONS

    E-print Network

    Abubakr, Said

    BLEACHABILITY OF RECYCLED FIBERS DEINKED WITH ENZYME PREPARATIONS Marguerite Sykes John Klungness the recycling emphasis from ink removal to color removal. Our research indicates that enzymes can available enzyme preparations used for deinking office wastepaper on pulp brightness and bleachability

  14. 21 CFR 864.9400 - Stabilized enzyme solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Stabilized enzyme solution. 864.9400 Section 864...Blood Products § 864.9400 Stabilized enzyme solution. (a) Identification. A stabilized enzyme solution is a reagent intended for...

  15. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Insoluble glucose isomerase enzyme preparations. 184.1372 Section 184...184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the...

  16. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Insoluble glucose isomerase enzyme preparations. 184.1372 Section 184...184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the...

  17. 21 CFR 864.9400 - Stabilized enzyme solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Stabilized enzyme solution. 864.9400 Section 864...Blood Products § 864.9400 Stabilized enzyme solution. (a) Identification. A stabilized enzyme solution is a reagent intended for...

  18. 21 CFR 862.3360 - Drug metabolizing enzyme genotyping system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Drug metabolizing enzyme genotyping system. 862.3360 Section...Systems § 862.3360 Drug metabolizing enzyme genotyping system. (a) Identification . A drug metabolizing enzyme genotyping system is a device...

  19. 21 CFR 862.3360 - Drug metabolizing enzyme genotyping system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Drug metabolizing enzyme genotyping system. 862.3360 Section...Systems § 862.3360 Drug metabolizing enzyme genotyping system. (a) Identification. A drug metabolizing enzyme genotyping system is a device...

  20. 21 CFR 862.2500 - Enzyme analyzer for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Enzyme analyzer for clinical use. 862.2500...Laboratory Instruments § 862.2500 Enzyme analyzer for clinical use. (a) Identification. An enzyme analyzer for clinical use is a...

  1. 21 CFR 862.2500 - Enzyme analyzer for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Enzyme analyzer for clinical use. 862.2500...Laboratory Instruments § 862.2500 Enzyme analyzer for clinical use. (a) Identification. An enzyme analyzer for clinical use is a...

  2. 21 CFR 862.2500 - Enzyme analyzer for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Enzyme analyzer for clinical use. 862.2500...Laboratory Instruments § 862.2500 Enzyme analyzer for clinical use. (a) Identification. An enzyme analyzer for clinical use is a...

  3. 21 CFR 862.3360 - Drug metabolizing enzyme genotyping system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Drug metabolizing enzyme genotyping system. 862.3360 Section...Systems § 862.3360 Drug metabolizing enzyme genotyping system. (a) Identification . A drug metabolizing enzyme genotyping system is a device...

  4. 21 CFR 862.2500 - Enzyme analyzer for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Enzyme analyzer for clinical use. 862.2500...Laboratory Instruments § 862.2500 Enzyme analyzer for clinical use. (a) Identification. An enzyme analyzer for clinical use is a...

  5. 21 CFR 862.2500 - Enzyme analyzer for clinical use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Enzyme analyzer for clinical use. 862.2500...Laboratory Instruments § 862.2500 Enzyme analyzer for clinical use. (a) Identification. An enzyme analyzer for clinical use is a...

  6. Real-time monitoring of enzyme activity in a mesoporous silicon double layer

    PubMed Central

    Orosco, Manuel M.; Pacholski, Claudia; Sailor, Michael J.

    2009-01-01

    A double layer mesoporous silicon with different pore sizes functions as a nano-reactor that can isolate, filter and quantify the kinetics of enzyme reactions in real-time by optical reflectivity. This tiny reactor may be used to rapidly characterize a variety of isolated enzymes in a label-free manner. Activity of certain protease enzymes is often an indicator of disease states such as cancer1,2, stroke2, and neurodegeneracy3, and thus, there is a need for rapid assays that can characterize the kinetics and substrate specificity of enzymatic reactions. Nanostructured membranes can efficiently separate biomolecules4 but coupling a sensitive detection method remains difficult. Here we report a single mesoporous nano-reactor that can isolate and quantify in real-time the reaction products of proteases. The reactor consists of two layers of porous films electrochemically prepared from crystalline silicon. The upper layer with large pore sizes traps the protease enzymes and acts as the reactor while the lower layer with smaller pore sizes excludes the large proteins and captures the reaction products. Infiltration of the digested fragments into the lower layer produces a measurable change in optical reflectivity and this allows label-free quantification of enzyme kinetics in real-time within a volume of approximately 5 nanoliters. PMID:19350037

  7. Heterologous expression of a bioactive ?-hexosyltransferase, an enzyme producer of prebiotics, from Sporobolomyces singularis.

    PubMed

    Dagher, Suzanne F; Azcarate-Peril, M Andrea; Bruno-Bárcena, José M

    2013-02-01

    Galacto-oligosaccharides (GOS) are indigestible dietary fibers that are able to reach the lower gastrointestinal tract to be selectively fermented by health-promoting bacteria. In this report, we describe the heterologous expression of an optimized synthetically produced version of the ?-hexosyltransferase gene (Bht) from Sporobolomyces singularis. The Bht gene encodes a glycosyl hydrolase (EC 3.2.1.21) that acts as galactosyltransferase, able to catalyze a one-step conversion of lactose to GOS. Expression of the enzyme in Escherichia coli yielded an inactive insoluble protein, while the methylotrophic yeast Pichia pastoris GS115 produced a bioactive ?-hexosyltransferase (rBHT). The enzyme exhibited faster kinetics at pHs between 3.5 and 6 and at temperatures between 40 and 50°C. Enzyme stability improved at temperatures lower than 40°C, and glucose was found to be a competitive inhibitor of enzymatic activity. P. pastoris secreted a fraction of the bioactive rBHT into the fermentation broth, while the majority of the enzyme remained associated with the outer membrane. Both the secreted and the membrane-associated forms were able to efficiently convert lactose to GOS. Additionally, resting cells with membrane-bound enzyme converted 90% of the initial lactose into GOS at 68% yield (g/g) (the maximum theoretical is 75%) with no secondary residual (glucose or galactose) products. This is the first report of a bioactive BHT from S. singularis that has been heterologously expressed. PMID:23241974

  8. Lrp1/LDL Receptor Play Critical Roles in Mannose 6-Phosphate-Independent Lysosomal Enzyme Targeting.

    PubMed

    Markmann, Sandra; Thelen, Melanie; Cornils, Kerstin; Schweizer, Michaela; Brocke-Ahmadinejad, Nahal; Willnow, Thomas; Heeren, Joerg; Gieselmann, Volkmar; Braulke, Thomas; Kollmann, Katrin

    2015-07-01

    Most lysosomal enzymes require mannose 6-phosphate (M6P) residues for efficient receptor-mediated lysosomal targeting. Although the lack of M6P residues results in missorting and hypersecretion, selected lysosomal enzymes reach normal levels in lysosomes of various cell types, suggesting the existence of M6P-independent transport routes. Here, we quantify the lysosomal proteome in M6P-deficient mouse fibroblasts (PT(ki) ) using Stable Isotope Labeling by Amino acids in Cell culture (SILAC)-based comparative mass spectrometry, and find unchanged amounts of 20% of lysosomal enzymes, including cathepsins D and B (Ctsd and Ctsb). Examination of fibroblasts from a new mouse line lacking both M6P and sortilin, a candidate for M6P-independent transport of lysosomal enzymes, revealed that sortilin does not act as cargo receptor for Ctsb and Ctsd. Using fibroblast lines deficient for endocytic lipoprotein receptors, we could demonstrate that both LDL receptor and Lrp1 mediate the internalization of non-phosphorylated Ctsb and Ctsd. Furthermore, the presence of Lrp1 inhibitor increased the secretion of Ctsd from PT(ki) cells. These findings establish Lrp1 and LDL receptors in M6P-independent secretion-recapture targeting mechanism for lysosomal enzymes. PMID:25786328

  9. Production of keratinolytic enzyme by an indigenous feather-degrading strain Bacillus cereus Wu2.

    PubMed

    Lo, Wei-Hsun; Too, Jui-Rze; Wu, Jane-Yii

    2012-12-01

    A novel feather-degrading microorganism was isolated from a poultry farm in Taiwan, and was identified Bacillus cereus Wu2 according to 16S rRNA sequencing. The isolated strain produces keratinolytic enzyme using chicken feather as the sole carbon and nitrogen source. The experimental results indicated that the extra carbon sources (glucose, fructose, starch, sucrose, or lactose) could act as a catabolite repressor to the enzyme secretion or keratinolytic activity when keratinous substrates were employed as protein sources. However, addition of 2 g/L of NH(4)Cl to the feather medium increased the enzyme production. The optimum temperature and initial pH for enzyme production were 30°C and 7.0, respectively. The maximum yield of the enzyme was 1.75 kU/mL in the optimal chicken feather medium; this value was about 17-fold higher than the yield in the basal hair medium. The B. cereus Wu2 possessed disulfide reductase activity along with keratinolytic activity. The amino acid contents of feathers degradated by B. cereus Wu2 were higher, especially for lysine, methionine and threonine which were nutritionally essential amino acids and usually deficient in the feather meal. Thus, B. cereus Wu2 could be not only used to enhance the nutritional value of feather meal but is also a potential bioinoculant in agricultural environments. PMID:22999356

  10. NAVE and the Perkins Act.

    ERIC Educational Resources Information Center

    Vocational Education Journal, 1994

    1994-01-01

    Includes "A National Report Card for Vo-Tech. Excerpts from NAVE--the Federal Government's National Assessment of Vocational Education"; "The Path to a New Perkins Act" (Plawin); and "Good Intentions Gone Bad? NAVE Didn't Mean for Skill Training to Be Removed from High Schools. Doing So Would Be a Terrible Mistake" (Denby). (JOW)

  11. ACT: the Artemis comparison tool

    Microsoft Academic Search

    Tim J. Carver; Kim Rutherford; Matthew Berriman; Marie-adčle Rajandream; Bart Barrell; Julian Parkhill

    2005-01-01

    The Artemis Comparison Tool (ACT) allows an interactive visualisation of comparisons between complete genome sequences and associated annotations. The comparison data can be generated with several different programs; BLASTN, TBLASTX or Mummer comparisons between genomic DNA sequences, or orthologue tables generated by reciprocal FASTA comparison between protein sets. It is possible to identify regions of similarity, insertions and rearrangements at

  12. The Indian Mineral Development Act.

    ERIC Educational Resources Information Center

    Houle, Antoinette

    1986-01-01

    Discusses the objectives of the Indian Mineral Development Act of 1982 (IMDA) and the possible effects it may have on Indian mineral development. Explains how the provisions of IMDA work to provide Indian tribes with greater flexibility for the development and sale of their mineral resources. (ML)

  13. Glycosylated linkers in multimodular lignocellulose-degrading enzymes dynamically bind to cellulose.

    PubMed

    Payne, Christina M; Resch, Michael G; Chen, Liqun; Crowley, Michael F; Himmel, Michael E; Taylor, Larry E; Sandgren, Mats; Stĺhlberg, Jerry; Stals, Ingeborg; Tan, Zhongping; Beckham, Gregg T

    2013-09-01

    Plant cell-wall polysaccharides represent a vast source of food in nature. To depolymerize polysaccharides to soluble sugars, many organisms use multifunctional enzyme mixtures consisting of glycoside hydrolases, lytic polysaccharide mono-oxygenases, polysaccharide lyases, and carbohydrate esterases, as well as accessory, redox-active enzymes for lignin depolymerization. Many of these enzymes that degrade lignocellulose are multimodular with carbohydrate-binding modules (CBMs) and catalytic domains connected by flexible, glycosylated linkers. These linkers have long been thought to simply serve as a tether between structured domains or to act in an inchworm-like fashion during catalytic action. To examine linker function, we performed molecular dynamics (MD) simulations of the Trichoderma reesei Family 6 and Family 7 cellobiohydrolases (TrCel6A and TrCel7A, respectively) bound to cellulose. During these simulations, the glycosylated linkers bind directly to cellulose, suggesting a previously unknown role in enzyme action. The prediction from the MD simulations was examined experimentally by measuring the binding affinity of the Cel7A CBM and the natively glycosylated Cel7A CBM-linker. On crystalline cellulose, the glycosylated linker enhances the binding affinity over the CBM alone by an order of magnitude. The MD simulations before and after binding of the linker also suggest that the bound linker may affect enzyme action due to significant damping in the enzyme fluctuations. Together, these results suggest that glycosylated linkers in carbohydrate-active enzymes, which are intrinsically disordered proteins in solution, aid in dynamic binding during the enzymatic deconstruction of plant cell walls. PMID:23959893

  14. Biotechnological relevance of starch-degrading enzymes

    SciTech Connect

    Stewart, G.G.

    1987-01-01

    Traditional enzymes, such as the amylases and the proteases, have been improved, novel applications have been found and new and valuable products have been marketed. The enzymatic hydrolysis of starch is described in some detail. (Refs. 8).

  15. An enzyme immunoassay for plasma betamethasone

    SciTech Connect

    Kominami, G.; Yamauchi, A.; Ishihara, S.; Kono, M.

    1981-03-01

    A sensitive enzyme immunoassay for plasma betamethasone was developed using betamethasone-3-(O-carboxymethyl)oxime-beta-D-galactosidase conjugate as a labelled antigen and 4-methylumbelliferyl-beta-D-galactoside as a fluorescence substrate. The performances of the enzyme immunoassay were compared with that of a radioimmunoassay using /sup 3/H-betamethasone and the same antiserum. The minimal detectable level for the enzyme immunoassay was 0.15 pg/tube or 0.15 ng/ml of plasma, which was remarkably more sensitive than the radioimmunoassay level of 10 pg/tube or 2 ng/ml of plasma. The specificity was sufficient, in particular, the cross reactivity of cortisol as 0.008%. However, the precision of the enzyme immunoassay was inferior to that of the radioimmunoassay.

  16. Enzyme Reactions in Nanoporous, Picoliter Volume Containers

    SciTech Connect

    Siuti, Piro [ORNL; Retterer, Scott T [ORNL; Choi, Chang Kyoung [Michigan Technological University; Doktycz, Mitchel John [ORNL

    2012-01-01

    Advancements in nanoscale fabrication allow creation of small volume reaction containers that can facilitate the screening and characterization of enzymes. A porous, ~19 pL volume vessel has been used in this work to carry out enzyme reactions under varying substrate concentrations. Glucose oxidase and horseradish peroxidase can be contained in these structures and diffusively fed with a solution containing glucose and the fluorogenic substrate Amplex Red through the engineered nanoscale pore structure. Fluorescent microscopy was used to monitor the reaction, which was carried out under microfluidic control. Kinetic characteristics of the enzyme were evaluated and compared with results from conventional scale reactions. These picoliter, nanoporous containers can facilitate quick determination of enzyme kinetics in microfluidic systems without the requirement of surface tethering and can be used for applications in drug discovery, clinical diagnostics and high-throughput screening.

  17. Enzyme mimics: Halogen and chalcogen team up

    NASA Astrophysics Data System (ADS)

    Metrangolo, Pierangelo; Resnati, Giuseppe

    2012-06-01

    The behaviour of di-selenol enzyme mimics indicates that a halogen bond between selenium and iodine, and a chalcogen interaction between the two selenium atoms, play an important role in the activation of thyroid hormones.

  18. A Quantitative Enzyme Study Using Simple Equipment

    NSDL National Science Digital Library

    Linda B. Cholewiak (Princeton University; )

    1991-01-01

    This resource consists of a simple laboratory exercise examining the effects different variables on enzyme-catalysed reactions rates. Background information, instructor notes, and suggested questions and laboratory report exercises are provided.

  19. Enzyme mechanisms: Flexibility leads to function

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhua; Rubinstein, John L.

    2014-03-01

    ATP synthase is an important enzyme for the storage and release of energy in cells. Ion-mobility mass spectrometry has now been used to study its structure, revealing important mechanistic details about its operation and regulation.

  20. Pancreatic enzyme synthesis in pancreatic disease.

    PubMed

    Boyd, E J; Clark, G; Dunbar, J; Wormsley, K G

    1985-08-01

    In a prospective evaluation of patients suspected of having chronic pancreatitis, synthesis of pancreatic enzymes was measured by means of the incorporation of selenium-75-labelled methionine into the proteins of duodenal aspirate during stimulation of pancreatic secretion with secretin (1 CU X kg-1 X h-1) plus cholecystokinin (CCK) (1 IDU X kg-1 X h-1). The rate of pancreatic enzyme synthesis was increased in patients with chronic pancreatitis. Measurement of pancreatic enzyme synthesis was more sensitive in the detection of chronic pancreatitis than either the bicarbonate or the trypsin secretory response to secretin plus CCK. A combination of the bicarbonate secretory response with measurement of the rate of enzyme synthesis provided a positive predictive power of 100% when both tests were abnormal and a negative predictive power of 100% when both tests were normal, so that the combined test can be recommended both for excluding and confirming the presence of chronic pancreatitis. PMID:4035292

  1. Attachment A Clery Act Reportable Crimes / Definitions

    E-print Network

    Shahriar, Selim

    Attachment A Clery Act Reportable Crimes / Definitions Clery Act Crimes (Section 1) Murder. ______________________________________________________________ Clery Act Hate Crimes (Section 3) Hate Crimes A criminal act involving one/more of the crimes listed in Section 1, the crimes of Theft, Simple Assault, Intimidation or Vandalism, or any other crime involving

  2. Tissue enzyme studies in Macaca nemestrina monkeys.

    NASA Technical Reports Server (NTRS)

    Hubbard, R. W.; Hoffman, R. A.; Jenkins, D.

    1971-01-01

    Total enzyme activities in fresh tissue specimens from major organs of Macaca nemestrina were analyzed for lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and aldolase. The concentration of these enzymes varied among the different tissue with skeletal muscle, heart, and brain having the highest activities. LDH isozymes determinations for the various tissues were also made. The spectrum of LDH isozyme distribution appears to be quite specific and characteristic for at least some of the tissues analyzed.

  3. Extracellular enzyme kinetics scale with resource availability

    USGS Publications Warehouse

    Sinsabaugh, Robert L.; Belnap, Jayne; Findlay, Stuart G.; Follstad Shah, Jennifer J.; Hill, Brian H.; Kuehn, Kevin A.; Kuske, Cheryl; Litvak, Marcy E.; Martinez, Noelle G.; Moorhead, Daryl L.; Warnock, Daniel D.

    2014-01-01

    Microbial community metabolism relies on external digestion, mediated by extracellular enzymes that break down complex organic matter into molecules small enough for cells to assimilate. We analyzed the kinetics of 40 extracellular enzymes that mediate the degradation and assimilation of carbon, nitrogen and phosphorus by diverse aquatic and terrestrial microbial communities (1160 cases). Regression analyses were conducted by habitat (aquatic and terrestrial), enzyme class (hydrolases and oxidoreductases) and assay methodology (low affinity and high affinity substrates) to relate potential reaction rates to substrate availability. Across enzyme classes and habitats, the scaling relationships between apparent Vmax and apparent Km followed similar power laws with exponents of 0.44 to 0.67. These exponents, called elasticities, were not statistically distinct from a central value of 0.50, which occurs when the Km of an enzyme equals substrate concentration, a condition optimal for maintenance of steady state. We also conducted an ecosystem scale analysis of ten extracellular hydrolase activities in relation to soil and sediment organic carbon (2,000–5,000 cases/enzyme) that yielded elasticities near 1.0 (0.9 ± 0.2, n = 36). At the metabolomic scale, the elasticity of extracellular enzymatic reactions is the proportionality constant that connects the C:N:P stoichiometries of organic matter and ecoenzymatic activities. At the ecosystem scale, the elasticity of extracellular enzymatic reactions shows that organic matter ultimately limits effective enzyme binding sites. Our findings suggest that one mechanism by which microbial communities maintain homeostasis is regulating extracellular enzyme expression to optimize the short-term responsiveness of substrate acquisition. The analyses also show that, like elemental stoichiometry, the fundamental attributes of enzymatic reactions can be extrapolated from biochemical to community and ecosystem scales.

  4. Dry-Enzyme Test For Gaseous Chemicals

    NASA Technical Reports Server (NTRS)

    Barzana, Eduardo; Karel, Marcus; Klibanov, Alexander

    1990-01-01

    Simple, dry-chemical test detects ethanol in human breath. Method of test also adapted to detection of such toxic chemicals as formaldehyde in airstreams. Used qualitatively to detect chemical compounds above present level; for example, ethanol above legal level for driving. Also used to indicate quantitatively concentrations of compounds. Involves dry enzyme and color indicator. Adapted to detect any gaseous compound transformed by enzymes to produce change evident to human eye or to instrument.

  5. The role of enzymes in modern detergency

    Microsoft Academic Search

    Hans Sejr Olsen; Per Falholt

    1998-01-01

    Enzymes have effectively assisted the development and improvement of modern household and industrial detergents. The major\\u000a classes of detergent enzymes—proteases, lipases, amylases, and cellulases—each provide specific benefits for application in\\u000a laundry and automatic dishwashing. Historically, proteases were first to be used extensively in laundry detergents. In addition\\u000a to raising the level of cleaning, they have also provided environmental benefits by

  6. A dynamic view of enzyme catalysis

    Microsoft Academic Search

    Aurora Jiménez; Pere Clapés; Ramon Crehuet

    2008-01-01

    Recent experimental advances have shown that enzymes are flexible molecules, and point to a direct link between dynamics and\\u000a catalysis. Movements span a wide time range, from nano- to milli-seconds. In this paper we introduce two aspects of enzyme\\u000a flexibility that are treated with two appropriate techniques. First, transition path sampling is used to obtain an unbiased\\u000a picture of the

  7. BIOCHEMISTRY: De Novo Design of an Enzyme

    NSDL National Science Digital Library

    Reinhard Sterner (Universität Regensburg, Institut für Biophysik und Physikalische Biochemie; )

    2004-06-25

    Access to the article is free, however registration and sign-in are required. Enzymes catalyze biological reactions with amazing efficiency, and years of biochemical research have been directed at understanding how they work. In their Perspective, Sterner and Schmid describe recent work (Dwyer et al.) that brings us closer to the ultimate goal of designing enzymes with tailored activities by using computer design to build catalytic activity onto an inert protein scaffold.

  8. Enzyme Biosensor for Tomatine Detection in Tomatoes

    Microsoft Academic Search

    Sergei V. Dzyadevych; Valentyna N. Arkhypova; Alexey P. Soldatkin; Anna V. Elskaya; Claude Martelet

    2004-01-01

    A biosensor for detection of tomatine in tomatoes has been developed using pH?sensitive field effect transistor as transducer and immobilised enzyme butyryl cholinesterase (BuChE) as a biorecognition element. The main analytical characteristics of the biosensor developed were studied for different conditions. The possibility to optimise these working parameters was investigated. By using this biosensor and enzyme inhibition effect, the tomatine

  9. Possible pathways for lysosomal enzyme delivery

    Microsoft Academic Search

    HANS J. GEUZE; JAN W. SLOT; GER J. A. M. STROUS; ANDREJ HASILIK; KURT VON FIGURA

    1985-01-01

    Immunogold double-labeling and ultrathin cryosections were used to compare the subcellular distribution of albumin, mannose 6-phosphate receptor (MPR), galactosyltransfer- ase, and the lysosomal enzymes cathepsin D, beta-hexosaminidase, and alpha-glucosidase in Hep Gz cells. MPR and lysosomal enzymes were found throughout the stack of Golgi cisternae and in a trans-Golgi reticulum (TGR) of smooth-surfaced tubules with coated buds and vesicles. The

  10. Kinetic analysis of the RNAi enzyme complex

    Microsoft Academic Search

    Benjamin Haley; Phillip D Zamore

    2004-01-01

    The siRNA-directed ribonucleoprotein complex, RISC, catalyzes target RNA cleavage in the RNA interference pathway. Here, we show that siRNA-programmed RISC is a classical Michaelis-Menten enzyme in the presence of ATP. In the absence of ATP, the rate of multiple rounds of catalysis is limited by release of the cleaved products from the enzyme. Kinetic analysis suggests that different regions of

  11. Hydrolysis of organophosphorus compounds by microbial enzymes

    Microsoft Academic Search

    Casey M. Theriot; Amy M. Grunden

    2011-01-01

    There are classes of microbial enzymes that have the ability to degrade harmful organophosphorus (OP) compounds that are present\\u000a in some pesticides and nerve agents. To date, the most studied and potentially important OP-degrading enzymes are organophosphorus\\u000a hydrolase (OPH) and organophosphorus acid anhydrolase (OPAA), which have both been characterized from a number of organisms.\\u000a Here we provide an update of

  12. PDEPT: polymer-directed enzyme prodrug therapy

    Microsoft Academic Search

    R Satchi; T A Connors; R Duncan

    2001-01-01

    Polymer-directed enzyme prodrug therapy (PDEPT) is a novel two-step antitumour approach using a combination of a polymeric prodrug and polymer-enzyme conjugate to generate cytotoxic drug selectively at the tumour site. In this study the polymeric prodrug N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-Gly-Phe-Leu-Gly-doxorubicin conjugate PK1 (currently under Phase II clinical evaluation) was selected as the model prodrug, and HPMA copolymer-cathepsin B as a

  13. Antioxidative enzyme activities in human erythrocytes

    Microsoft Academic Search

    Helle Raun Andersen; Jesper B. Nielsen; Flemming Nielsen; Philippe Grandjean

    Reliable and standardized methods are necessary to determine the expression of antioxidative enzymes and their role in maintaining health. In addition, the vari- ability of the enzyme activities within the general pop- ulation caused by age, gender, and life-style factors must be described. This study describes methodological conditions that are suitable for analyzing copper-zinc superoxide dismutase (CuZn-SOD), glutathione peroxi- dase

  14. Crystal structure of methane oxidation enzyme determined

    SciTech Connect

    Baum, R.

    1994-01-10

    A team of chemists has determined to 2.2-[angstrom] resolution the crystal structure of the hydroxylase protein of methane monooxygenase, the enzyme system responsible for the biological oxidation of methane. The hydroxylase, at a molecular weight of 251,000 daltons, if by far the largest component of methane monooxygenase. Although the crystal structure of the hydroxylase did not reveal any startling surprises about the enzyme-many features of the hydroxylase had been inferred previously from modeling and spectroscopic studies -- obtaining it is a significant achievement. For one thing, the crystal structure unambiguously confirms aspects of the enzyme structure that been at least somewhat speculative. The three-dimensional structure of the enzyme, the chemist say, also provides important insight into biological methane oxidation, including how methane, a relatively inert gas, might diffuse to and bind near the active site of the enzyme. The structure points to particular amino acid residues that are likely to participate in catalysis, and clarifies the structure of the dinuclear iron core of the enzyme.

  15. [Enzymes of intermediary metabolism in coryneform bacteria].

    PubMed

    Baryshnikova, L M; Reznik, G I; Golovlev, E L

    1979-01-01

    Enzymes of the intermediate metabolism were studied in ten strains of Corynebacterium-like organisms belonging to the genera Arthrobacter, Brevibacterium, Corynebacterium and Nocardia. All of these were found to contain enzymes of the glycolytic pathway, and nine strains among ten had dehydrogenases of the pentose phosphate shunt. The activity of enzymes of the citric acid cycle was low: alpha-ketoglutarate dehydrogenase was not found in Arthrobacter, Corynebacterium, Brevibacterium linens and Nocardia minima. Eight strains possessed the activity of the key enzyme of the gamma-aminobutyrate shunt, i.e. gamma-aminobutyrate aminotransferase. The activity of enzymes of the glyoxylate shunt was found in nine strains, and their level was rather high even during growth on glucose. Therefore, it is possible to study the taxonomic structure of this group of microorganisms by analyzing the composition and the level of enzymes involved in the intermediate metabolism. The competence of the Brevibacterium genus is corroborated by the typical species Brevibact. linens, as well as the reality of saprophytic representatives of the Corynebacterium genus, and a special taxonomic position of the group Brevibact. ammoniagenes--Brevibact. stationis. PMID:108525

  16. Visualization of enzyme activities inside earthworm pores

    NASA Astrophysics Data System (ADS)

    Hoang, Duyen; Razavi, Bahar S.

    2015-04-01

    In extremely dynamic microhabitats as bio-pores made by earthworm, the in situ enzyme activities are assumed as a footprint of complex biotic interactions. Our study focused on the effect of earthworm on the enzyme activities inside bio-pores and visualizing the differences between bio-pores and earthworm-free soil by zymography technique (Spohn and Kuzyakov, 2013). For the first time, we aimed at quantitative imaging of enzyme activities in bio-pores. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). After two weeks when bio-pore systems were formed by earthworms, we visualized in situ enzyme activities of five hydrolytic enzymes (?-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine-aminopeptidase, and phosphatase. Zymography showed higher activity of ?-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. However, the differences in activity of cellobiohydrolase and leucine aminopeptidase between bio-pore and bulk soil were less pronounced. This demonstrated an applicability of zymography approach to monitor and to distinguish the in situ activity of hydrolytic enzymes in soil biopores.

  17. ACT-R Environment Manual Dan Bothell

    E-print Network

    ACT-R Environment Manual Dan Bothell db30@andrew.cmu.edu #12;2 Introduction This is the current ACT-R will be a more useful tool for a wider audience of old and new ACT-R users alike. Installation First, the two the ACT-R web site at http://act-r.psy.cmu.edu/software/. The one thing to make sure of is that the Lisp

  18. Dietary modulation of thymic enzymes.

    PubMed

    Susana, Feliu María; Paula, Perris; Slobodianik, Nora

    2014-01-01

    Malnutrition is a complex syndrome caused by an inadequate intake of energy, protein, minerals and vitamins which affects the immune system. Nutritional imbalances, present in children with energy-protein malnutrition and infections, make defining the specific effects of each of them on the thymus difficult. For this reason, it is necessary to design an experimental model in animals that could define a single variable. As the thymus atrophy described in humans is similar to that observed in murines, a rat experimental model makes the extrapolation to man possible. Some authors suggest that the activity of Adenosine Deaminase (ADA) and Purine Nucleoside Phosphorylase (PNP)--involved in purine metabolism--have an influence on T lymphocyte development and the immune system, due to intracellular accumulation of toxic levels of deoxynucleotides. Studies in our group, performed in an experimental model on Wistar growing rats, have demonstrated that protein deficiency or imbalance in the profile of essential amino acids in the diet, produce loss of thymus weight, reduction in the number of thymocytes, a diminished proportion of T cells presenting the W3/13 antigenic determinant and DNA content with concomitant increase in cell size, and the proportion of immature T cells and activity of ADA and PNP, without modifying the activity of 5´Nucleotidase in the thymus. It is important to point out that there were neither differences in energy intake between experimental groups and their controls, nor clinical symptoms of deficiency of other nutrients. The increase in these thymic enzyme activities was an alternative mechanism to avoid the accumulation of high levels of deoxynucleotides, which would be toxic for T lymphocytes. On the other hand, the administration of a recovery diet, with a high amount of high quality protein, was able to reverse the mentioned effects. The quick reply of Adenosine Deaminase to nutritional disorders and the following nutritional recovery, points out to this determination as a potential functional marker of nutritional status. Some authors have demonstrated an increase in ADA activity, in serum and other biological fluids in patients with various diseases involving defense mechanisms. According to these findings, it could be inferred that ADA activity in serum would follow the same behavior as observed in a rat thymus. So, we have analyzed if its determination could be considered a functional biochemical parameter in populations at nutritional risk. We analyzed the serum ADA activity in groups of individuals with altered nutritional status evaluated through different markers--young adult patients with Nervous Anorexia, overweight or obese school children, children suffering cystic fibrosis. The results show a statistically significant increase in the ADA activity in all groups, with respect to their healthy controls--same age range and socio economic status. The results obtained to date suggest the importance of including the determination of serum Adenosine Deaminase activity in the biochemical evaluation of the nutritional status, as a functional marker related to defense mechanisms. PMID:25229687

  19. The anti-convulsant stiripentol acts directly on the GABA A receptor as a positive allosteric modulator

    Microsoft Academic Search

    Janet L. Fisher

    2009-01-01

    Stiripentol (STP) has been used as co-therapy for treatment of epilepsy for many years. Its mechanism of action has long been considered to be indirect, as it inhibits the enzymes responsible for metabolism of other anti-convulsant agents. However, a recent report suggested that STP might also act at the neuronal level, increasing inhibitory GABAergic neurotransmission. We examined the effect of

  20. Non-neuronal acetylcholine, a locally acting molecule, widely distributed in biological systems: Expression and function in humans

    Microsoft Academic Search

    Ignaz Wessler; Charles James Kirkpatrick; Kurt Racké

    1998-01-01

    Acetylcholine acts as a neurotransmitter in the central and peripheral nervous systems in humans. However, recent experiments demonstrate a widespread expression of the cholinergic system in non-neuronal cells in humans. The synthesizing enzyme choline acetyltransferase, the signalling molecule acetylcholine, and the respective receptors (nicotinic or muscarinic) are expressed in epithelial cells (human airways, alimentary tract, epidermis). Acetylcholine is also found

  1. The "Death Squad Protection" Act

    NSDL National Science Digital Library

    This very important new electronic briefing book from the National Security Archive (last mentioned in the January 28, 2000 Scout Report) offers analysis and background materials regarding a recently passed (July 13) measure in the FY 2001 Defense Authorization Act that -- if approved by the full Congress -- would severely reduce the amount of information released by the Defense Intelligence Agency (DIA) under the Freedom of Information Act (FOIA). These materials, especially the documents produced by the Defense HUMINT Service and routinely declassified in the past, have been central in many investigations of human rights violations committed by US-supported foreign military and intelligence units. At the site, users will find a summary of how the legislation will impact this research, sample documents that would have been withheld, the full text of the proposed exemption, background on the HUMINT Service, and HUMINT reports.

  2. Advanced Communications Technology Satellite (ACTS)

    NASA Technical Reports Server (NTRS)

    Plecity, Mark S.; Nall, Mark E.

    1991-01-01

    The NASA Advanced Communications Technology Satellite (ACTS) provides high risk technologies having the potential to dramatically enhance the capabilities of the satellite communications industry. This experimental satellite, which will be launched by NASA in 1993, will furnish the technology necessary for providing a range of services. Utilizing the ACTS very-high-gain-hopping spot-beam antennas with on-board routing and processing, Very Small Aperture Terminal (VSAT) digital networks which provide on-demand, full-mesh-convectivity 1.544-MBPS services with only a single hop can be established. The high-gain spot-beam antenna at Ka-band permits wide area, flexible networks providing high data rate services between modest-size earth terminals.

  3. National Park Service: Antiquities Act

    NSDL National Science Digital Library

    Established in 1906, The Antiquities Act was the first law to establish that archaeological sites on public lands are important public resources. This website was designed to commemorate the 100th anniversary of the Act, and should be considered rather essential for any persons interested in such matters. After browsing a basic overview of the Actâ??s primary provisions, visitors should consider the â??Monument Profilesâ?ť section. Within this well-thought out section, visitors can learn about such important sites as Devils Tower National Monument, Chaco Canyon, as well as a number of other locations. Another nice way to learn about these sites is to peruse the interactive maps offered in the â??Maps, Facts & Figuresâ?ť area. Finally, the site also contains complete details on the various events that will take place at these different sites over the coming year.

  4. Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000

    E-print Network

    US Army Corps of Engineers

    Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000 Public Law 106 of the Estuary Restoration Act, Title I of P.L. 106-457 (Act). The contents reflect the views of the Estuary). Background: The purposes of the Act are to promote the restoration of estuary habitat; develop a national

  5. Functional Representation of Enzymes by Specific Peptides

    PubMed Central

    Kunik, Vered; Meroz, Yasmine; Solan, Zach; Sandbank, Ben; Weingart, Uri; Ruppin, Eytan; Horn, David

    2007-01-01

    Predicting the function of a protein from its sequence is a long-standing goal of bioinformatic research. While sequence similarity is the most popular tool used for this purpose, sequence motifs may also subserve this goal. Here we develop a motif-based method consisting of applying an unsupervised motif extraction algorithm (MEX) to all enzyme sequences, and filtering the results by the four-level classification hierarchy of the Enzyme Commission (EC). The resulting motifs serve as specific peptides (SPs), appearing on single branches of the EC. In contrast to previous motif-based methods, the new method does not require any preprocessing by multiple sequence alignment, nor does it rely on over-representation of motifs within EC branches. The SPs obtained comprise on average 8.4 ± 4.5 amino acids, and specify the functions of 93% of all enzymes, which is much higher than the coverage of 63% provided by ProSite motifs. The SP classification thus compares favorably with previous function annotation methods and successfully demonstrates an added value in extreme cases where sequence similarity fails. Interestingly, SPs cover most of the annotated active and binding site amino acids, and occur in active-site neighboring 3-D pockets in a highly statistically significant manner. The latter are assumed to have strong biological relevance to the activity of the enzyme. Further filtering of SPs by biological functional annotations results in reduced small subsets of SPs that possess very large enzyme coverage. Overall, SPs both form a very useful tool for enzyme functional classification and bear responsibility for the catalytic biological function carried out by enzymes. PMID:17722976

  6. Tracing metabolic pathways from enzyme data.

    PubMed

    McDonald, Andrew G; Tipton, Keith F; Boyce, Sinéad

    2009-09-01

    The IUBMB Enzyme List is widely used by other databases as a source for avoiding ambiguity in the recognition of enzymes as catalytic entities. However, it was never designed for activities such as pathway tracing, which have become increasingly important in systems biology. This is because it often relies on generic or representative reactions to show the reactions catalysed by enzymes of wide specificity. It is necessary to go to databases such as BRENDA to find further, more detailed, information on what is known about the range of substrates for any particular enzyme. In order to provide a framework for tracing pathways involving any specific enzyme or metabolite, we have created a Reactions Database from the material in the Enzyme List. This allows reactions to be searched by substrate/product and pathways to be traced from any selected starting/seed substrate. An extensive synonym glossary allows searches by many of the alternative names, including accepted abbreviations, by which a chemical compound may be known. This database was necessary for the development of the application Reaction Explorer (http://www.reaction-explorer.org), which was written in REALbasic to search the Reactions Database and draw metabolic pathways from reactions selected by the user. Having input the name of the starting compound (the "seed"), the user is presented with a list of all reactions containing that compound and then selects the product of interest as the next point on the ensuing graph. The pathway diagram is then generated as the process iterates. A contextual menu is provided, which allows the user to (i) remove a compound from the graph, along with all associated links; (ii) search the reactions database again for additional reactions involving the compound and (iii) search for the compound within the Enzyme List. PMID:19563919

  7. The new Clean Air Act

    SciTech Connect

    Padmanabha, A.P. (Blue Plains Wastewater Treatment Plant, Washington, DC (United States)); Olem, H. (Olem Associates, Washington, DC (United States))

    1991-05-01

    This article is a title by title review of the new Clean Air Act and how it affects water quality and wastewater treatment. The bill provides for restoring and protecting lakes and rivers by reducing acid-rain-causing emissions and toxics from nonpoint-source runoff. Topics covered include urban smog, mobile sources, air toxics, acid rain, permits, ozone-depleting chemicals, enforcement, and the law's socio-economic impacts.

  8. Clean Air Act. Revision 5

    SciTech Connect

    Not Available

    1994-02-15

    This Reference Book contains a current copy of the Clean Air Act, as amended, and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. This Reference Book has been completely revised and is current through February 15, 1994.

  9. Na-taurodeoxycholate acts as a specific intestinal stimulus of exocrine pancreatic secretion in man.

    PubMed

    Lehnert, P; Hempen, I; Fiedler, F; Hotz, E; Danzl, C; Mitra, H; Riepl, R

    1987-01-01

    The effect of intraduodenally administered cattle bile, Na-taurodeoxycholate, and Na-taurocholate on secretin-stimulated exocrine pancreatic secretion was investigated on 40 fasting young healthy volunteers. Intraduodenal bile stimulated significantly and dose-dependently hydrokinetic and ecbolic pancreatic secretion. Only bile, but not secretin intravenously, both applied in a dosage equivalent with respect to their hydrokinetic action, caused a significant increase of enzyme output and enzyme concentration as well. Intraduodenal Na-taurodeoxycholate enhanced also dose-dependently secretin-stimulated volume, bicarbonate, and enzyme secretion. The effect was related to the load, not to the concentration of this bile salt. On the other side, Na-taurocholate had only a weak and not dose-dependent hydrokinetic and no ecbolic effect. It is concluded that not bile salts in general, but only certain of them--like Na-taurodeoxycholate--are the effective constituents of bile, acting as specific intraduodenal stimulants of hydrokinetic and ecbolic pancreatic secretion. PMID:2448866

  10. Occurrence of enzymes involved in biosynthesis of indole-3-acetic acid from indole-3-acetonitrile in plant-associated bacteria, Agrobacterium and Rhizobium.

    PubMed Central

    Kobayashi, M; Suzuki, T; Fujita, T; Masuda, M; Shimizu, S

    1995-01-01

    The occurrence of a hitherto unknown pathway involving the action of two enzymes, a nitrile hydratase and an amidase for the biosynthesis of indole-3-acetic acid was discovered in phytopathogenic bacteria Agrobacterium tumefaciens and in leguminous bacteria Rhizobium. The nitrile hydratase acting on indole-3-acetonitrile was purified to homogeneity through only two steps from the cell-free extract of A. tumefaciens. The molecular mass of the purified enzyme estimated by HPLC was about 102 kDa, and the enzyme consisted of four subunits identical in molecular mass. The enzyme exhibited a broad absorption spectrum in the visible range with absorption maxima at 408 nm and 705 nm, and it contained cobalt and iron. The enzyme stoichiometrically catalyzed the hydration of indole-3-acetonitrile into indole-3-acetamide with a specific activity of 13.7 mol per min per mg and a Km of 7.9 microM. Images Fig. 1 PMID:11607511

  11. Superstable groups acting on trees

    E-print Network

    Houcine, Abderezak Ould

    2008-01-01

    We study superstable groups acting on trees. We prove that an action of an $\\omega$-stable group on a simplicial tree is trivial. This shows that an HNN-extension or a nontrivial free product with amalgamation is not $\\omega$-stable. It is also shown that if $G$ is a superstable group acting nontrivially on a $\\Lambda$-tree, where $\\Lambda=\\mathbb Z$ or $\\Lambda=\\mathbb R$, and if $G$ is either $\\alpha$-connected and $\\Lambda=\\mathbb Z$, or if the action is irreducible, then $G$ interprets a simple group having a nontrivial action on a $\\Lambda$-tree. In particular if $G$ is superstable and splits as $G=G_1*_AG_2$, with the index of $A$ in $G_1$ different from 2, then $G$ interprets a simple superstable non $\\omega$-stable group. We will deal with "minimal" superstable groups of finite Lascar rank acting nontrivially on $\\Lambda$-trees, where $\\Lambda=\\mathbb Z$ or $\\Lambda=\\mathbb R$. We show that such groups $G$ have definable subgroups $H_1 \\lhd H_2 \\lhd G$, $H_2$ is of finite index in $G$, such that if $H...

  12. Acts related to solid waste management in Illinois. Annual report

    SciTech Connect

    Not Available

    1994-04-01

    ;Contents: Degradable Plastic Act; Energy Assistance Act of 1989; Hazardous and Solid Waste Recycling and Treatment Act; Illinois Emergency Planning and Community Right to Know Act; Illinois Environmental Facilities Financing Act; Illinois Purchasing Act; Illinois Solid Waste Management Act; Intergovernmental Cooperation Act; Junkyard Act; Litter Control Act; Local Hazardous Waste Collection Program Act; Local Solid Waste Disposal Act; Metro East Solid Waste Disposal and Energy Producing Service Act; Recycled Newsprint Use Act; Responsible Property Transfer Act of 1988; Solid Waste Disposal District Act; Solid Waste Planning and Recycling Act; Solid Waste Site Operator Certification Law; Township Refuse, Collection and Disposal Act; Toxic Pollution Prevention Act; Used Motor Oil Recycling Act; Waste Oil Recovery Act; and Water Supply, Drainage and Flood Control.

  13. Enzymes Are Enriched in Bacterial Essential Genes

    PubMed Central

    Gao, Feng; Zhang, Randy Ren

    2011-01-01

    Essential genes, those indispensable for the survival of an organism, play a key role in the emerging field, synthetic biology. Characterization of functions encoded by essential genes not only has important practical implications, such as in identifying antibiotic drug targets, but can also enhance our understanding of basic biology, such as functions needed to support cellular life. Enzymes are critical for almost all cellular activities. However, essential genes have not been systematically examined from the aspect of enzymes and the chemical reactions that they catalyze. Here, by comprehensively analyzing essential genes in 14 bacterial genomes in which large-scale gene essentiality screens have been performed, we found that enzymes are enriched in essential genes. Essential enzymes have overrepresented ligases (especially those forming carbon-oxygen bonds and carbon-nitrogen bonds), nucleotidyltransferases and phosphotransferases, while have underrepresented oxidoreductases. Furthermore, essential enzymes tend to associate with more gene ontology domains. These results, from the aspect of chemical reactions, provide further insights into the understanding of functions needed to support natural cellular life, as well as synthetic cells, and provide additional parameters that can be integrated into gene essentiality prediction algorithms. PMID:21738765

  14. Salivary enzymes in peptic ulcer disease

    PubMed Central

    Motamedi, Mojdeh; Mansour-Ghanaei, Fariborz; Sariri, Reyhaneh; Vesal, Mahmoud

    2013-01-01

    Aim Peptic ulcer, the common disease of the upper gastro-intestinal tract, occurs in about 5–10% of the world's population. Therefore, diagnosis of trace disease progression with a noninvasive method is of prime importance in the field of healthcare research. The aim of this study was to evaluate the validity of salivary enzymes as noninvasive biomarkers for peptic ulcer. Materials and methods In practice, 34 peptic ulcer patients and 30 healthy subjects donated their un-stimulated saliva samples after 8 h of fasting. The activity of some selected enzymes was measured using appropriate enzymatic assay methods. Results The results indicated an overall alternation in enzymatic activity of saliva in patients suffering from peptic ulcer. Biological activity of a-amylase, peroxidase and lactate dehydrogenase, showed significantly higher values in almost all patients as compared to control subjects. Conclusions Based on the results of salivary enzyme activity, it was concluded that besides the influence of their peptic ulcer on enzyme activity of saliva, the considerably higher activity of a-amylase could also be related to the major role of the enzyme on physiological oxidative stress. PMID:25737890

  15. The RecD subunit of the Escherichia coli RecBCD enzyme inhibits RecA loading, homologous recombination, and DNA repair.

    PubMed

    Amundsen, S K; Taylor, A F; Smith, G R

    2000-06-20

    The RecBCD enzyme is required for homologous recombination and DNA repair in Escherichia coli. The structure and function of RecBCD enzyme is altered on its interaction with the recombination hotspot Chi (5'-GCTGGTGG-3'). It has been hypothesized that the RecD subunit plays a role in Chi-dependent regulation of enzyme activity [Thaler, D. S., Sampson, E., Siddiqi, I., Rosenberg, S. M., Stahl, F. W. & Stahl, M. (1988) in Mechanisms and Consequences of DNA Damage Processing, eds. Friedberg, E. & Hanawalt, P. (Liss, New York), pp. 413-422; Churchill, J. J., Anderson, D. G. & Kowalczykowski, S. C. (1999) Genes Dev. 13, 901-911]. We tested the hypothesis that the RecD subunit inhibits recombination by deleting recD from the nuclease- and recombination-deficient mutant recB(D1080A)CD. We report here that the resulting strain, recB(D1080A)C, was proficient for recombination and DNA repair. Recombination proficiency was accompanied by a change in enzyme activity: RecB(D1080A)C enzyme loaded RecA protein onto DNA during DNA unwinding whereas RecB(D1080A)CD enzyme did not. Together, these genetic and biochemical results demonstrate that RecA loading by RecBCD enzyme is required for recombination in E. coli cells and suggest that RecD interferes with the enzyme domain required for its loading. A nuclease-dependent signal appears to be required for a change in RecD that allows RecA loading. Because RecA loading is not observed with wild-type RecBCD enzyme until it acts at a Chi site, our observations support the view that RecD inhibits recombination until the enzyme acts at Chi. PMID:10840065

  16. Stochastic Simulation of Enzyme-Catalyzed Reactions with Disparate Timescales

    E-print Network

    Paul, Mark

    Stochastic Simulation of Enzyme-Catalyzed Reactions with Disparate Timescales Debashis Barik-steady-state approximation'' for enzyme-catalyzed reactions provides a useful framework for efficient and accurate stochastic simulations. The method is applied to three examples: a simple enzyme-catalyzed reaction where enzyme

  17. PURIFICATION AND ISOLATION OF THE PHOSPHOGLYCERATE KINASE ENZYME

    E-print Network

    Collins, Gary S.

    PURIFICATION AND ISOLATION OF THE PHOSPHOGLYCERATE KINASE ENZYME IN RICE PLANTS Cynthia Bach (NADH). The enzyme, phosphoglycerate kinase (PGKase), catalyzes the reaction that results to purify the enzyme from developing rice seeds. Isolation of the enzyme was obtained by obtaining a crude

  18. Directed Enzyme Evolution and High-Throughput Screening

    E-print Network

    Zhao, Huimin

    3 Directed Enzyme Evolution and High-Throughput Screening Michael J. McLachlan,1 Ryan P. Sullivan2, and Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA 3.1 Introduction Early enzyme of a complex mixture of secreted enzymes produced at low yields. Now, over 90% of industrial enzymes

  19. Enzymes: An integrated view of structure, dynamics and function

    Microsoft Academic Search

    Pratul K Agarwal

    2006-01-01

    Microbes utilize enzymes to perform a variety of functions. Enzymes are biocatalysts working as highly efficient machines at the molecular level. In the past, enzymes have been viewed as static entities and their function has been explained on the basis of direct structural interactions between the enzyme and the substrate. A variety of experimental and computational techniques, however, continue to

  20. Evolution of extracellular enzyme activities during manure composting

    E-print Network

    Tiquia-Arashiro, Sonia M.

    Evolution of extracellular enzyme activities during manure composting S.M. Tiquia Environmental to determine the extracellular enzyme pro®les during composting, relate the activities of these enzymes manure composting. Results showed an overall increase in diversity and relative abundance of enzymes

  1. Seeing & Feeling How Enzymes Work Using Tangible Models

    ERIC Educational Resources Information Center

    Lau, Kwok-chi

    2013-01-01

    This article presents a tangible model used to help students tackle some misconceptions about enzyme actions, particularly the induced-fit model, enzyme-substrate complementarity, and enzyme inhibition. The model can simulate how substrates induce a change in the shape of the active site and the role of attraction force during enzyme-substrate…

  2. Original article The effect of feed enzymes on nutrient

    E-print Network

    Paris-Sud XI, Université de

    Original article The effect of feed enzymes on nutrient and energy retention in young racing. No difference in body weight was observed between groups. Despite feed restriction, intake was higher for enzyme-sup- plemented diet. When related to feed intake, excreta were lower by 11% for enzyme-supplemented diet. Enzyme

  3. Enzymic Approach to Eurythermalism of Alvinella pompejana and Its Episymbionts

    Microsoft Academic Search

    Charles K. Lee; S. Craig Cary; Alison E. Murray; Roy M. Daniel

    2008-01-01

    The equilibrium model, which describes the influence of temperature on enzyme activity, has been estab- lished as a valid and useful tool for characterizing enzyme eurythermalism and thermophily. By introducing Keq, a temperature-dependent equilibrium constant for the interconversion between Eact, the active form of enzyme, and Einact, a reversibly inactive form of enzyme, the equilibrium model currently provides the most

  4. An amperometric enzyme biosensor for real-time measurements of cellobiohydrolase activity on insoluble cellulose.

    PubMed

    Cruys-Bagger, Nicolaj; Ren, Guilin; Tatsumi, Hirosuke; Baumann, Martin J; Spodsberg, Nikolaj; Andersen, Heidi Delcomyn; Gorton, Lo; Borch, Kim; Westh, Peter

    2012-12-01

    An amperometric enzyme biosensor for continuous detection of cellobiose has been implemented as an enzyme assay for cellulases. We show that the initial kinetics for cellobiohydrolase I, Cel7A from Trichoderma reesei, acting on different types of cellulose substrates, semi-crystalline and amorphous, can be monitored directly and in real-time by an enzyme-modified electrode based on cellobiose dehydrogenase (CDH) from Phanerochaete chrysosporium (Pc). PcCDH was cross-linked and immobilized on the surface of a carbon paste electrode which contained a mediator, benzoquinone. An oxidation current of the reduced mediator, hydroquinone, produced by the CDH-catalyzed reaction with cellobiose, was recorded under constant-potential amperometry at +0.5 V (vs. Ag/AgCl). The CDH-biosensors showed high sensitivity (87.7 µA mM(-1) cm(-2)), low detection limit (25 nM), and fast response time (t(95%) ? 3 s) and this provided experimental access to the transient kinetics of cellobiohydrolases acting on insoluble cellulose. The response from the CDH-biosensor during enzymatic hydrolysis was corrected for the specificity of PcCDH for the ?-anomer of cello-oligosaccharides and the approach were validated against HPLC. It is suggested that quantitative, real-time data on pure insoluble cellulose substrates will be useful in attempts to probe the molecular mechanism underlying enzymatic hydrolysis of cellulose. PMID:22767376

  5. Paradoxical control properties of enzymes within pathways: can activation cause an enzyme to have increased control?

    PubMed Central

    Kholodenko, B N; Brown, G C

    1996-01-01

    It is widely assumed that within a metabolic pathway inhibition of an enzyme causes the control exerted by that enzyme over the flux through its own reaction to increase, whereas activation causes its control to decrease. This assumption forms the basis of a number of experimental methods. For a pathway conceptually divided into two enzyme groups connected via a single metabolite we have derived a general condition under which this assumption is false, and thus the pathway shows paradoxical control behaviour, i.e. increased control with activation and decreased control with inhibition of an enzyme or group of enzymes. Paradoxical control behaviour occurs widely when enzyme activity is altered by changing Km (if an enzyme is already close to saturation by its substrate), but may also occur with changes in Vmax. when the elasticity to the linking metabolite increases with its concentration (as in some cases of sigmoidal and exponential kinetics or for reactions catalysed by isoenzymes). These findings suggest that enzymes with sigmoidal kinetics may have low control in the absence of activation, but may gain control with activation, and thus have beneficial regulatory properties. PMID:8615766

  6. Development of enzymes and enzyme systems by genetic engineering to convert biomass to sugars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TITLE Development of Enzymes and Enzyme Systems by Genetic Engineering to Convert Biomass to Sugars ABSTRACT Plant cellulosic material is one of the most viable renewable resources for the world’s fuel and chemical feedstock needs. Currently ethanol derived from corn starch is the most common li...

  7. One-Dimensional Crosslinked Enzyme Aggregates in SBA-15: Superior Catalytic Behavior to Conventional Enzyme Immobilization

    SciTech Connect

    Kim, Moon Il; Kim, Jungbae; Lee, Jinwoo; Shin, Su Jeong; Na, Hyon Bin; Hyeon, Taeghwan; Park, Hyun-gyu; Chang, Ho Nam

    2007-07-14

    The following work was acknowledged at EMSL: ?-Chymotrypsin (CT) and lipase (LP) were immobilized in SBA-15 mesoporous silica by crosslinking adsorbed enzymes. This simple approach resulted in one-dimensional crosslinked enzyme aggregates (CLEAs) in the linear pore channels of SBA-15, which was very effective in preventing the enzyme leaching and consequently improving the enzyme stability. Both CLEAs of CT and LP showed negligible activity decrease under harsh shaking condition for one week while the conventional approaches including adsorption and covalent attachment resulted in more than 50–90% enzyme inactivation under the same condition. This effective stabilization results from the bent pore structure of SBA-15 with a high aspect ratio, which prevents the leaching of one-dimensional CLEAs and thereby achieves the higher enzyme loading capacity. Along with the higher specific activity than that of adsorbed enzymes, this CLEA approach is much simpler than that of covalent attachment by obviating the tedious processes for silica functionalization and enzyme attachment.

  8. Arabinogalactan proteins: focus on carbohydrate active enzymes

    PubMed Central

    Knoch, Eva; Dilokpimol, Adiphol; Geshi, Naomi

    2014-01-01

    Arabinogalactan proteins (AGPs) are a highly diverse class of cell surface proteoglycans that are commonly found in most plant species. AGPs play important roles in many cellular processes during plant development, such as reproduction, cell proliferation, pattern formation and growth, and in plant-microbe interaction. However, little is known about the molecular mechanisms of their function. Numerous studies using monoclonal antibodies that recognize different AGP glycan epitopes have shown the appearance of a slightly altered AGP glycan in a specific stage of development in plant cells. Therefore, it is anticipated that the biosynthesis and degradation of AGP glycan is tightly regulated during development. Until recently, however, little was known about the enzymes involved in the metabolism of AGP glycans. In this review, we summarize recent discoveries of carbohydrate active enzymes (CAZy; http://www.cazy.org/) involved in the biosynthesis and degradation of AGP glycans, and we discuss the biological role of these enzymes in plant development. PMID:24966860

  9. Discovery of protein-palmitoylating enzymes.

    PubMed

    Tsutsumi, Ryouhei; Fukata, Yuko; Fukata, Masaki

    2008-09-01

    Posttranslational modification provides proteins with additional function and regulatory control beyond genomic information, allowing cells to maintain homeostasis and respond to extracellular signals. Protein palmitoylation, the common posttranslational modification with the lipid palmitate, plays a pivotal role in protein trafficking and function. Palmitoylation is unique in that it is reversible and dynamically regulated by specific extracellular signals. The reversible nature of protein palmitoylation enables proteins to shuttle between intracellular compartments upon extracellular signals. However, the molecular mechanisms of protein palmitoylation have long been elusive, mostly because the enzymes responsible for protein palmitoylation were unknown. Recently, genetically conserved DHHC family proteins have emerged as palmitoyl-acyl transferases. With the identification of specific enzymes for palmitoylated proteins, including H-Ras, PSD-95, and eNOS, the specificity and regulatory mechanism of DHHC enzymes are beginning to be clarified. PMID:18231805

  10. Controlling reaction specificity in pyridoxal phosphate enzymes.

    PubMed

    Toney, Michael D

    2011-11-01

    Pyridoxal 5'-phosphate enzymes are ubiquitous in the nitrogen metabolism of all organisms. They catalyze a wide variety of reactions including racemization, transamination, decarboxylation, elimination, retro-aldol cleavage, Claisen condensation, and others on substrates containing an amino group, most commonly ?-amino acids. The wide variety of reactions catalyzed by PLP enzymes is enabled by the ability of the covalent aldimine intermediate formed between substrate and PLP to stabilize carbanionic intermediates at C? of the substrate. This review attempts to summarize the mechanisms by which reaction specificity can be achieved in PLP enzymes by focusing on three aspects of these reactions: stereoelectronic effects, protonation state of the external aldimine intermediate, and interaction of the carbanionic intermediate with the protein side chains present in the active site. This article is part of a Special Issue entitled: Pyridoxal Phosphate Enzymology. PMID:21664990

  11. Controlling reaction specificity in pyridoxal phosphate enzymes

    PubMed Central

    Toney, Michael D.

    2012-01-01

    Pyridoxal 5'-phosphate enzymes are ubiquitous in the nitrogen metabolism of all organisms. They catalyze a wide variety of reactions including racemization, transamination, decarboxylation, elimination, retro-aldol cleavage, Claisen condensation, and others on substrates containing an amino group, most commonly ?-amino acids. The wide variety of reactions catalyzed by PLP enzymes is enabled by the ability of the covalent aldimine intermediate formed between substrate and PLP to stabilize carbanionic intermediates at C? of the substrate. This review attempts to summarize the mechanisms by which reaction specificity can be achieved in PLP enzymes by focusing on three aspects of these reactions: stereoelectronic effects, protonation state of the external aldimine intermediate, and interaction of the carbanionic intermediate with the protein side chains present in the active site. PMID:21664990

  12. Introduction to Enzyme Kinetics: Assay of beta-Galactosidase

    NSDL National Science Digital Library

    Joanne Kivela Tillotson (State University of New York; Purchase College REV)

    2007-07-10

    This tutorial describes a colorometric enzyme assay to determine simple enzyme kinetics. It is designed as an introduction for beginning laboratory students in a biology or biochemistry course, and requires no previous understanding of chemistry. It may be used as an assignment to prepare students for a laboratory exercise in enzyme kinetics Through this tutorial, students will gain an understanding of the procedures for measuring enzyme activity, using the specific example of an assay for the bacterial enzyme, ?-galactosidase.

  13. Enzymes in bast fibrous plant processing.

    PubMed

    Kozlowski, Ryszard; Batog, Jolanta; Konczewicz, Wanda; Mackiewicz-Talarczyk, Maria; Muzyczek, Malgorzata; Sedelnik, Natalia; Tanska, Bogumila

    2006-05-01

    The program COST Action 847 Textile Quality and Biotechnology (2000-2005) has given an excellent chance to review the possibilities of the research, aiming at development of the industrial application of enzymes for bast fibrous plant degumming and primary processing. The recent advancements in enzymatic processing of bast fibrous plants (flax, hemp, jute, ramie and alike plants) and related textiles are given. The performance of enzymes in degumming, modification of bast fibres, roving, yarn, related fabrics as well as enzymatic bonding of lignocellulosic composites is provided. PMID:16791732

  14. NetLogo Models Library: Enzyme Kinetics

    NSDL National Science Digital Library

    Uri Wilensky

    Model page from the NetLogo Models Library. The page provides a description and screenshots of a mode of Enzme Kinetics produced using the NetLogo software. The page provides a link to a javascript version of the model that can be run in the browser, as well as a download link for the model file that can be opened, run and edited in NetLogo. This model demonstrates the kinetics of single-substrate enzyme-catalysis. The interactions between enzymes and substrates are often difficult to understand and the model allows users to visualize the complex reaction.

  15. EPR of Cobalt-Substituted Zinc Enzymes

    Microsoft Academic Search

    Brian Bennett

    \\u000a Co(II) is sometimes utilized as a spectroscopically active substitute for Zn(II) in enzymes. Metal binding sites in enzymes\\u000a that contain catalytically active Zn(II) generally yield high-spin S = 3\\/2 Co(II) ions when substituted with cobalt, and these provide EPR spectra rich in information. Extracting this information\\u000a involves an appreciation of the extent to which the properties of Co(II) mirror those

  16. Artificial Enzyme Construction with Temperature Sensitivity

    Microsoft Academic Search

    Tingting Lin; Jun Lin; Xin Huang; Junqiu Liu

    \\u000a Poly (N-isopropylacrylamide) (PNIPAAm) is one of the most popular thermoresponsive polymers, which shows dramatic and reversible\\u000a phase transition behavior in water. Therefore two strategies for the design of temperature-sensitive enzyme model based on\\u000a PNIPAAm derivatives are presented: 1) A temperature-sensitive block copolymer (PAAm-b-PNIPAAm-Te) with a glutathione peroxidase-like\\u000a active site was synthesized via ATRP. 2) An artificial bifunctional enzyme with both

  17. Identification of mouse selenomethionine ?, ?-elimination enzyme

    Microsoft Academic Search

    Tomofumi Okuno; Shinji Motobayashi; Hitoshi Ueno; Katsuhiko Nakamuro

    2005-01-01

    The purpose of this study was to identify the seleno-l-methionine (l-SeMet) ?,?-elimination enzyme that catalyzes l-SeMet to generate methylselenol (CH3SeH), a notable intermediate for the metabolism of selenium compounds, in mammalian tissues. The enzyme purified from ICR\\u000a mouse liver was separated by one-dimensional gel electrophoresis, and the specific band was subjected to in-gel trypsin digestion\\u000a followed by matrix-assisted laser desorption\\/ionization-time-of-flight

  18. Stochastic dynamics of enzymes: molecular scissors

    NASA Astrophysics Data System (ADS)

    Chichigina, Olga A.; Ebeling, Werner O.; Makarov, V. G.; Netrebko, Alexei V.; Romanovsky, Yury M.; Schimansky-Geier, Lutz

    2003-05-01

    The problems studied here are relevant for an understanding of the functioning of hydrolytic enzyme molecules. These enzymes work like molecular machines breaking off the valence peptid bonds of substrates. In particular the role of Fermi resonance which is evident from a spectral lines of valence oscillations is studied. The influence of this resonance on valence splitting is discussed. It is shown that the breaking of these bonds has a higher probability, if the stochastic oscillations of atoms in catalytic groups at the active site have a large quality coefficient. We show that the corresponding low damping is essential for the Fermi resonance modes of these oscillations.

  19. Engineered calcium-precipitable restriction enzyme.

    PubMed

    Hendrix, Josephina; Read, Timothy; Lalonde, Jean-Francois; Jensen, Phillip K; Heymann, William; Lovelace, Elijah; Zimmermann, Sarah A; Brasino, Michael; Rokicki, Joseph; Dowell, Robin D

    2014-12-19

    We have developed a simple system for tagging and purifying proteins. Recent experiments have demonstrated that RTX (Repeat in Toxin) motifs from the adenylate cyclase toxin gene (CyaA) of B. pertussis undergo a conformational change upon binding calcium, resulting in precipitation of fused proteins and making this method a viable alternative for bioseparation. We have designed an iGEM Biobrick comprised of an RTX tag that can be easily fused to any protein of interest. In this paper, we detail the process of creating an RTX tagged version of the restriction enzyme EcoRI and describe a method for expression and purification of the functional enzyme. PMID:25524101

  20. 7 CFR 65.100 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...COUNTRY OF ORIGIN LABELING OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.100 Act. Act means the Agricultural Marketing...

  1. 7 CFR 65.100 - Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...COUNTRY OF ORIGIN LABELING OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.100 Act. Act means the Agricultural Marketing...

  2. 7 CFR 65.100 - Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...COUNTRY OF ORIGIN LABELING OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.100 Act. Act means the Agricultural Marketing...

  3. Estuaries and Clean Water Act of 2000

    NSDL National Science Digital Library

    The Office of Water at the Environmental Protection Agency has posted online this document on the new Estuaries and Clean Water Act of 2000. Available in .pdf format, the document summarizes the Act, which emphasizes restoration of estuary habitat.

  4. Endangered Species Act Biennial Report to Congress

    E-print Network

    jurisdiction, species proposed for listing, as depleted under the Marine Mammal Protection Act. Sincerely, 1, and spec es listed as depleted under the Marine Mammal Protection Act. 1 Sincerely, 1 Rolland A. ~chmjkten

  5. 50 CFR 300.156 - Prohibited acts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Prohibited acts. 300.156 Section 300.156 Wildlife and Fisheries INTERNATIONAL...Fishing in Russian Fisheries § 300.156 Prohibited acts. In addition... (p) To falsify, or fail to report to NMFS, any change in the...

  6. 50 CFR 300.156 - Prohibited acts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Prohibited acts. 300.156 Section 300.156 Wildlife and Fisheries INTERNATIONAL...Fishing in Russian Fisheries § 300.156 Prohibited acts. In addition... (p) To falsify, or fail to report to NMFS, any change in the...

  7. Clean Air Act Amendments of 1990 

    E-print Network

    Hanneschlager, R. E.

    1990-01-01

    Congress is currently debating amendments to the Clean Air Act which would strengthen and enhance the current Clean Air Act. The bill would guarantee a reduction of 10 million tons of sulfur dioxide from 1980 levels; would sharply reduce pollutants...

  8. 77 FR 16837 - Sunshine Act Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-22

    ...motion of Director Thomas J. Curry (Appointive), seconded by Director John G. Walsh (Acting Comptroller of the Currency), concurred in by Director Richard Cordray (Director, Consumer Financial Protection Bureau) and Acting Chairman...

  9. 77 FR 9656 - Sunshine Act Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ...motion of Director Thomas J. Curry (Appointive), seconded by Director John G. Walsh (Acting Comptroller of the Currency), concurred in by Director Richard Cordray (Director, Consumer Financial Protection Bureau) and Acting Chairman...

  10. 47 CFR 32.4 - Communications Act.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Communications Act. 32.4 Section 32.4 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON...COMPANIES Preface § 32.4 Communications Act. Attention is...

  11. Mental Health Parity and Addiction Equity Act

    MedlinePLUS

    ... Regulations and Guidance Stakeholder Engagement Training Resources The Mental Health Parity and Addiction Equity Act Contents Introduction Summary ... Regulation Introduction The Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008 (MHPAEA) ...

  12. 7 CFR 922.2 - Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE APRICOTS GROWN IN DESIGNATED COUNTIES IN WASHINGTON Order Regulating Handling Definitions § 922.2 Act. Act means...

  13. 7 CFR 922.2 - Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE APRICOTS GROWN IN DESIGNATED COUNTIES IN WASHINGTON Order Regulating Handling Definitions § 922.2 Act. Act means...

  14. Extending ACT-R's Memory Capabilities

    Microsoft Academic Search

    Holger Schultheis

    To resolve several problems of ACT-R's declarative memory (DM), Schultheis, Barkowsky, and Bertel (2006) developed a new long-term memory (LTM) component, called LTMC . In this paper we present two ACT-R interfaces which integrate LTMC into ACT-R. Such integrating LTMC makes it easily ac- cessible to ACT-R modelers and allows more thoroughly eval- uating it in its interplay with other

  15. Sexual Offences Act 1993 [20 July 1993].

    PubMed

    1993-01-01

    This Act provides as follows: "1) The presumption of criminal law is that a boy under the age of 14 is incapable of sexual intercourse (whether natural or unnatural) is hereby abolished." The Act comes into force on 20 September 1993. It applies to England and Wales, but not the rest of the United Kingdom, and does not cover acts carried out before the Act comes into force. PMID:12179567

  16. Isolation and characterization of unhydrolyzed oligosaccharides from switchgrass (Panicum virgatum, L.) xylan after exhaustive enzymatic treatment with commercial enzyme preparations.

    PubMed

    Bowman, Michael J; Dien, Bruce S; Vermillion, Karl E; Mertens, Jeffrey A

    2015-04-30

    Switchgrass (Panicum virgatum, L.) is a potential renewable source of carbohydrates for use in microbial conversion to biofuels. Xylan comprises approximately 30% of the switchgrass cell wall. To understand the limitations of commercial enzyme mixtures, alkali-extracted, isolated switchgrass xylan was hydrolyzed by the action of two commercial enzyme cocktails, in the presence and absence of an additional ?-arabinofuranosidase enzyme. The two most abundant enzymatic digestion products from each commercial enzyme treatment were separated and characterized by LC-MS(n), linkage analysis, and NMR. The most abundant oligosaccharide from each commercial cocktail was susceptible to hydrolysis when supplemented with a GH62 ?-arabinofuranosidase enzyme; further characterization confirmed the presence of (1?3)-?-arabinose linkages. These results demonstrate the lack of the required selectivity for arabinose-containing substrates in the commercial enzyme preparations tested. One product from each condition remained intact and was found to contain (1?2)-?-xylose-(1?3)-?-arabinose side chains; this linkage acts as a source of oligosaccharide recalcitrance. PMID:25704197

  17. Increased enzyme binding to substrate is not necessary for more efficient cellulose hydrolysis

    PubMed Central

    Gao, Dahai; Chundawat, Shishir P. S.; Sethi, Anurag; Balan, Venkatesh; Gnanakaran, S.; Dale, Bruce E.

    2013-01-01

    Substrate binding is typically one of the rate-limiting steps preceding enzyme catalytic action during homogeneous reactions. However, interfacial-based enzyme catalysis on insoluble crystalline substrates, like cellulose, has additional bottlenecks of individual biopolymer chain decrystallization from the substrate interface followed by its processive depolymerization to soluble sugars. This additional decrystallization step has ramifications on the role of enzyme–substrate binding and its relationship to overall catalytic efficiency. We found that altering the crystalline structure of cellulose from its native allomorph I? to IIII results in 40–50% lower binding partition coefficient for fungal cellulases, but surprisingly, it enhanced hydrolytic activity on the latter allomorph. We developed a comprehensive kinetic model for processive cellulases acting on insoluble substrates to explain this anomalous finding. Our model predicts that a reduction in the effective binding affinity to the substrate coupled with an increase in the decrystallization procession rate of individual cellulose chains from the substrate surface into the enzyme active site can reproduce our anomalous experimental findings. PMID:23784776

  18. Structural analyses of the chromatin remodelling enzymes INO80-C and SWR-C.

    PubMed

    Watanabe, Shinya; Tan, Dongyan; Lakshminarasimhan, Mahadevan; Washburn, Michael P; Erica Hong, Eun-Jin; Walz, Thomas; Peterson, Craig L

    2015-01-01

    INO80-C and SWR-C are conserved members of a subfamily of ATP-dependent chromatin remodelling enzymes that function in transcription and genome-maintenance pathways. A crucial role for these enzymes is to control chromosomal distribution of the H2A.Z histone variant. Here we use electron microscopy (EM) and two-dimensional class averaging to demonstrate that these remodelling enzymes have similar overall architectures. Each enzyme is characterized by a dynamic 'tail' domain and a compact 'head' that contains Rvb1/Rvb2 subunits organized as hexameric rings. EM class averages and mass spectrometry support the existence of single heterohexameric rings in both SWR-C and INO80-C. EM studies define the position of the Arp8/Arp4/Act1 module within INO80-C, and we find that this module enhances nucleosome-binding affinity but is largely dispensable for remodelling activities. In contrast, the Ies6/Arp5 module is essential for INO80-C remodelling, and furthermore this module controls conformational changes that may couple nucleosome binding to remodelling. PMID:25964121

  19. Investigation at the atomic level of homologous enzymes reveals distinct reaction paths

    NASA Astrophysics Data System (ADS)

    Zoi, Ioanna; Schwartz, Steven D.

    2015-03-01

    Bacterial enzymes Escherichia coli and Vibrio cholerae 5' -Methylthioadenosine nucleosidases (MTANs) have different binding affinities for the same transition state analogue. This was surprising as these enzymes share 60% sequence identity, have almost identical active sites and act under the same mechanism. We performed Transition Path Sampling simulations of both enzymes to reveal the atomic details of the catalytic chemical step, to explain the inhibitor affinity differences. Unlike EcMTAN, VcMTAN has multiple distinct transition states, which is an indication that multiple sets of coordinated protein motions can reach a transition state. We also identified the important residues that participate in each enzyme's reaction coordinate and explained their contribution. Subtle dynamic differences manifest in difference of reaction coordinate and transition state structure and also suggest that MTANs differ from most ribosyl transferases. As experimental approaches report averages regarding reaction coordinate information, this study offers, previously unavailable, detailed knowledge to the explanation of bacterial MTANs catalytic mechanism, and could have a significant impact on pharmaceutical design. We acknowledge the support of the National Institutes of Health through Grant GM068036.

  20. Increased enzyme binding to substrate is not necessary for more efficient cellulose hydrolysis.

    PubMed

    Gao, Dahai; Chundawat, Shishir P S; Sethi, Anurag; Balan, Venkatesh; Gnanakaran, S; Dale, Bruce E

    2013-07-01

    Substrate binding is typically one of the rate-limiting steps preceding enzyme catalytic action during homogeneous reactions. However, interfacial-based enzyme catalysis on insoluble crystalline substrates, like cellulose, has additional bottlenecks of individual biopolymer chain decrystallization from the substrate interface followed by its processive depolymerization to soluble sugars. This additional decrystallization step has ramifications on the role of enzyme-substrate binding and its relationship to overall catalytic efficiency. We found that altering the crystalline structure of cellulose from its native allomorph I(?) to III(I) results in 40-50% lower binding partition coefficient for fungal cellulases, but surprisingly, it enhanced hydrolytic activity on the latter allomorph. We developed a comprehensive kinetic model for processive cellulases acting on insoluble substrates to explain this anomalous finding. Our model predicts that a reduction in the effective binding affinity to the substrate coupled with an increase in the decrystallization procession rate of individual cellulose chains from the substrate surface into the enzyme active site can reproduce our anomalous experimental findings. PMID:23784776

  1. Functional Diversity of Carbohydrate-Active Enzymes Enabling a Bacterium to Ferment Plant Biomass

    PubMed Central

    Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves; Alberti, Adriana; Weissenbach, Jean; Salanoubat, Marcel; Tolonen, Andrew C.

    2014-01-01

    Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme) assays, RNA sequencing (RNA-seq), and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass. PMID:25393313

  2. One-week administration of hydroxytyrosol to humans does not activate Phase II enzymes.

    PubMed

    Crespo, Maria Carmen; Tomé-Carneiro, Joao; Burgos-Ramos, Emma; Loria Kohen, Viviana; Espinosa, Maria Isabel; Herranz, Jesus; Visioli, Francesco

    2015-01-01

    The notion that (poly)phenols act as direct free radical scavengers is being challenged by mere chemical and biochemical considerations such as bioavailability and intracellular concentrations. An alternative hypothesis that is gaining considerable traction is that (poly)phenols are processed by the body as xenobiotics via the Keap1/Nrf2/ARE signaling axis, leading to the induction of Phase II enzymes. However, there are no solid human data to confirm this interesting supposition. In this study, we tested the activities of hydroxytyrosol (HT) on Phase II enzymes' expression in a double-blind, randomized, placebo-controlled study. We tested two HT doses, i.e. 5 and 25mg/d, vs. placebo following a Latin square design. We report that HT is well tolerated but does not significantly modify Phase II enzyme expression in peripheral blood mononuclear cells. Moreover, we were unable to record significant effects on a variety of surrogate markers of cardiovascular disease such as lipid profile and inflammation and oxidation markers. Available evidence indicates that the "hormesis hypothesis" that (poly)phenols activate Phase II enzymes requires solid human confirmation that might be provided by future trials. This study is registered at ClinicalTrials.gov (identifier: NCT02273622). PMID:25836918

  3. Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass.

    PubMed

    Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves; Alberti, Adriana; Weissenbach, Jean; Salanoubat, Marcel; Tolonen, Andrew C

    2014-11-01

    Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme) assays, RNA sequencing (RNA-seq), and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass. PMID:25393313

  4. 76 FR 4378 - Sunshine Act Meetings; Notice

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ...Consider and act on Resolution 2011-XXX thanking Victor M. Fortuno for his service...Consider and act on Resolution 2011-XXX dissolving the 2010 Search Committee for...Consider and act on Resolution 2011-XXX Commemorating the 100 Year Anniversary...

  5. 12 CFR 541.2 - Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    12 ? Banks and Banking ? 6 ? 2014-01-01 ? 2012-01-01 ? true ? Act. ? 541.2 ? Section 541.2 ? Banks and Banking ? OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY ? DEFINITIONS FOR REGULATIONS AFFECTING FEDERAL SAVINGS ASSOCIATIONS ? § 541.2 ? Act. ? The term Act ? means the Home...

  6. Women's Health and Cancer Rights Act

    MedlinePLUS

    Women’s Health and Cancer Rights Act The Federal law The Women’s Health and Cancer Rights Act (WHCRA) helps protect many ... Services. Centers for Medicare and Medicaid Services. The Women’s Health & Cancer Rights Act. Accessed at www.cms.hhs. ...

  7. Speech Act Pluralism So far we have

    E-print Network

    Pylyshyn, Zenon

    the nature of speech acts, we start by outlining, in general terms, how we think speech acts should an investigation to uncover.1 Intuitions and nontheoretic assumptions about speech act content can, of course this is sort of a comedy of errors, bizarre, without getting into it, `the president believes that it is going

  8. 40 CFR 89.1003 - Prohibited acts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...are not considered prohibited acts under § 89.1003(a) if...as defined in Title II of the Act) are not considered prohibited acts under § 89.1003(a) if...a permanent label with your corporate name and trademark and...

  9. 40 CFR 94.1103 - Prohibited acts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...coverage of a warranty under the Act is conditioned upon use of...are not considered prohibited acts under paragraph (a)(3...are not considered prohibited acts under paragraph (a)(3...a permanent label with your corporate name and trademark and the...

  10. Malic Enzyme and Malolactic Enzyme Pathways Are Functionally Linked but Independently Regulated in Lactobacillus casei BL23

    PubMed Central

    Landete, José María; Ferrer, Sergi; Monedero, Vicente

    2013-01-01

    Lactobacillus casei is the only lactic acid bacterium in which two pathways for l-malate degradation have been described: the malolactic enzyme (MLE) and the malic enzyme (ME) pathways. Whereas the ME pathway enables L. casei to grow on l-malate, MLE does not support growth. The mle gene cluster consists of three genes encoding MLE (mleS), the putative l-malate transporter MleT, and the putative regulator MleR. The mae gene cluster consists of four genes encoding ME (maeE), the putative transporter MaeP, and the two-component system MaeKR. Since both pathways compete for the same substrate, we sought to determine whether they are coordinately regulated and their role in l-malate utilization as a carbon source. Transcriptional analyses revealed that the mle and mae genes are independently regulated and showed that MleR acts as an activator and requires internalization of l-malate to induce the expression of mle genes. Notwithstanding, both l-malate transporters were required for maximal l-malate uptake, although only an mleT mutation caused a growth defect on l-malate, indicating its crucial role in l-malate metabolism. However, inactivation of MLE resulted in higher growth rates and higher final optical densities on l-malate. The limited growth on l-malate of the wild-type strain was correlated to a rapid degradation of the available l-malate to l-lactate, which cannot be further metabolized. Taken together, our results indicate that L. casei l-malate metabolism is not optimized for utilization of l-malate as a carbon source but for deacidification of the medium by conversion of l-malate into l-lactate via MLE. PMID:23835171

  11. Dual function of MIPS1 as a metabolic enzyme and transcriptional regulator.

    PubMed

    Latrasse, David; Jégu, Teddy; Meng, Pin-Hong; Mazubert, Christelle; Hudik, Elodie; Delarue, Marianne; Charon, Céline; Crespi, Martin; Hirt, Heribert; Raynaud, Cécile; Bergounioux, Catherine; Benhamed, Moussa

    2013-03-01

    Because regulation of its activity is instrumental either to support cell proliferation and growth or to promote cell death, the universal myo-inositol phosphate synthase (MIPS), responsible for myo-inositol biosynthesis, is a critical enzyme of primary metabolism. Surprisingly, we found this enzyme to be imported in the nucleus and to interact with the histone methyltransferases ATXR5 and ATXR6, raising the question of whether MIPS1 has a function in transcriptional regulation. Here, we demonstrate that MIPS1 binds directly to its promoter to stimulate its own expression by locally inhibiting the spreading of ATXR5/6-dependent heterochromatin marks coming from a transposable element. Furthermore, on activation of pathogen response, MIPS1 expression is reduced epigenetically, providing evidence for a complex regulatory mechanism acting at the transcriptional level. Thus, in plants, MIPS1 appears to have evolved as a protein that connects cellular metabolism, pathogen response and chromatin remodeling. PMID:23341037

  12. Inside the trap: gland morphologies, digestive enzymes, and the evolution of plant carnivory in the Caryophyllales?

    PubMed Central

    Renner, Tanya; Specht, Chelsea D

    2013-01-01

    The digestion of prey by carnivorous plants is determined in part by suites of enzymes that are associated with morphologically and anatomically diverse trapping mechanisms. Chitinases represent a group of enzymes known to be integral to effective plant carnivory. In non-carnivorous plants, chitinases commonly act as pathogenesis-related proteins, which are either induced in response to insect herbivory and fungal elicitors, or constitutively expressed in tissues vulnerable to attack. In the Caryophyllales carnivorous plant lineage, multiple classes of chitinases are likely involved in both pathogenic response and digestion of prey items. We review what is currently known about trap morphologies, provide an examination of the diversity, roles, and evolution of chitinases, and examine how herbivore and pathogen defense mechanisms may have been coopted for plant carnivory in the Caryophyllales. PMID:23830995

  13. Dual function of MIPS1 as a metabolic enzyme and transcriptional regulator

    PubMed Central

    Latrasse, David; Jégu, Teddy; Meng, Pin-Hong; Mazubert, Christelle; Hudik, Elodie; Delarue, Marianne; Charon, Céline; Crespi, Martin; Hirt, Heribert; Raynaud, Cécile; Bergounioux, Catherine; Benhamed, Moussa

    2013-01-01

    Because regulation of its activity is instrumental either to support cell proliferation and growth or to promote cell death, the universal myo-inositol phosphate synthase (MIPS), responsible for myo-inositol biosynthesis, is a critical enzyme of primary metabolism. Surprisingly, we found this enzyme to be imported in the nucleus and to interact with the histone methyltransferases ATXR5 and ATXR6, raising the question of whether MIPS1 has a function in transcriptional regulation. Here, we demonstrate that MIPS1 binds directly to its promoter to stimulate its own expression by locally inhibiting the spreading of ATXR5/6-dependent heterochromatin marks coming from a transposable element. Furthermore, on activation of pathogen response, MIPS1 expression is reduced epigenetically, providing evidence for a complex regulatory mechanism acting at the transcriptional level. Thus, in plants, MIPS1 appears to have evolved as a protein that connects cellular metabolism, pathogen response and chromatin remodeling. PMID:23341037

  14. The Penal Code (Amendment) Act 1989 (Act A727), 1989.

    PubMed

    1989-01-01

    In 1989, Malaysia amended its penal code to provide that inducing an abortion is not an offense if the procedure is performed by a registered medical practitioner who has determined that continuation of the pregnancy would risk the life of the woman or damage her mental or physical health. Additional amendments include a legal description of the conditions which constitute the act of rape. Among these conditions is intercourse with or without consent with a woman under the age of 16. Malaysia fails to recognize rape within a marriage unless the woman is protected from her husband by judicial decree or is living separately from her husband according to Muslim custom. Rape is punishable by imprisonment for a term of 5-20 years and by whipping. PMID:12344384

  15. Quantitative enzyme histochemistry in the brain

    Microsoft Academic Search

    P. Kugler; Accepted March

    1988-01-01

    Summary Two main groups of quantitative methods are used in the brain to relate enzymatic processes to cellular structures, i.e. the methods of microchemistry and microscopic histochemistry. Microchemistry tries to quantify enzyme activities in very small brain regions by miniaturizing biochemical methods, whereas microscopic histochemistry applies staining procedures to tissue sections, preserving the structural relationship that is present in situ

  16. Easily available enzymes as natural retting agents.

    PubMed

    Antonov, Viktor; Marek, Jan; Bjelkova, Marie; Smirous, Prokop; Fischer, Holger

    2007-03-01

    Easily available commercial enzymes currently have great potential in bast fibre processing and can be modified for different end uses. There are several new technologies using enzymes that are able to modify fibre parameters, achieve requested properties, improve processing results and are more beneficial to the ecology in the area of bast fibre processing and fabrics finishing. Enzymatic methods for retting of flax, "cottonisation" of bast fibres, hemp separation, and processing of flax rovings before wet spinning, etc., fall into this group of new technologies. Such enzymatic biotechnologies can provide benefits in textile, composite, reinforced plastic and other technical applications. Laboratory, pilot and industrial scale results and experiences have demonstrated the ability of selected enzymes to decompose interfibre-bonding layers based on pectin, lignin and hemicelluloses. Texazym SER spray is able to increase flax long fibre yields by more than 40%. Other enzymes in combination with mild mechanical treatment can replace aggressive and energy-intensive processing like Laroche "cottonisation". Texazym SCW and DLG pretreatments of flax rovings are presented. PMID:17309044

  17. Peptide-Modified Surfaces for Enzyme Immobilization

    Microsoft Academic Search

    Jinglin Fu; Jeremy Reinhold; Neal W. Woodbury; Jörg D. Hoheisel

    2011-01-01

    BackgroundChemistry and particularly enzymology at surfaces is a topic of rapidly growing interest, both in terms of its role in biological systems and its application in biocatalysis. Existing protein immobilization approaches, including noncovalent or covalent attachments to solid supports, have difficulties in controlling protein orientation, reducing nonspecific absorption and preventing protein denaturation. New strategies for enzyme immobilization are needed that

  18. Sacchariiication of Straw by Actinomycete Enzymes

    Microsoft Academic Search

    ANDREW S. BALL; ALAN J. McCARTHY

    1988-01-01

    Over 200 strains of actinomycetes, representing nine distinct genera, were screened directly for the ability to release reducing sugar from ball-milled wheat straw, using a microtitre plate assay system. Xylanase activity was detected in nearly all of the strains examined while activities against purified cellulosic substrates were less widespread and relatively low. Straw saccharification resulted from cooperative enzyme action and

  19. Original article Enzyme-linked immunosorbent assay

    E-print Network

    Paris-Sud XI, Université de

    enteritidis is recognised as a frequent and important pathogen for poultry and has been isolated from broilerOriginal article Enzyme-linked immunosorbent assay with a Salmonella enteritidis antigen obtained from a clinical isolate of Salmonella enteritidis, were compared with those obtained with the gm

  20. Enzyme Kinetics: The Use of Amylose Azure.

    ERIC Educational Resources Information Center

    Cusimano, Vincent J.

    1978-01-01

    Amylose azure can be used as a chromogenic substrate for alpha-amylase in studying the effects of temperature and pH enzyme action. This is a model system which students can use to measure the energy of activation using the Arrhenius plot. (Author/BB)

  1. Glubodies: randomized libraries of glutathione transferase enzymes

    Microsoft Academic Search

    Eugene W. Napolitano; Hugo O. Villar; Lawrence M. Kauvar; Deborah L. Higgins; Doug Roberts; Janis Mandac; Sandra K. Lee; Robert Bukar; Brenda L. Calio; John A. Tainer

    1996-01-01

    Background: The immunoglobulin framework has been mutagenized to engineer recombinant libraries of proteins as potential diagnostics and novel catalysts, although the often shallow binding cleft may limit the utility of this framework for binding diverse small organic molecules. By contrast, the glutathione S-transferase (GST) family of enzymes contains a deep binding cleft, which has evolved to accommodate a broad range

  2. Computationally designed libraries for rapid enzyme stabilization

    PubMed Central

    Wijma, Hein J.; Floor, Robert J.; Jekel, Peter A.; Baker, David; Marrink, Siewert J.; Janssen, Dick B.

    2014-01-01

    The ability to engineer enzymes and other proteins to any desired stability would have wide-ranging applications. Here, we demonstrate that computational design of a library with chemically diverse stabilizing mutations allows the engineering of drastically stabilized and fully functional variants of the mesostable enzyme limonene epoxide hydrolase. First, point mutations were selected if they significantly improved the predicted free energy of protein folding. Disulfide bonds were designed using sampling of backbone conformational space, which tripled the number of experimentally stabilizing disulfide bridges. Next, orthogonal in silico screening steps were used to remove chemically unreasonable mutations and mutations that are predicted to increase protein flexibility. The resulting library of 64 variants was experimentally screened, which revealed 21 (pairs of) stabilizing mutations located both in relatively rigid and in flexible areas of the enzyme. Finally, combining 10–12 of these confirmed mutations resulted in multi-site mutants with an increase in apparent melting temperature from 50 to 85°C, enhanced catalytic activity, preserved regioselectivity and a >250-fold longer half-life. The developed Framework for Rapid Enzyme Stabilization by Computational libraries (FRESCO) requires far less screening than conventional directed evolution. PMID:24402331

  3. A Qualitative Approach to Enzyme Inhibition

    ERIC Educational Resources Information Center

    Waldrop, Grover L.

    2009-01-01

    Most general biochemistry textbooks present enzyme inhibition by showing how the basic Michaelis-Menten parameters K[subscript m] and V[subscript max] are affected mathematically by a particular type of inhibitor. This approach, while mathematically rigorous, does not lend itself to understanding how inhibition patterns are used to determine the…

  4. Rapid purification of fluorescent enzymes by ultrafiltration

    NASA Technical Reports Server (NTRS)

    Benjaminson, M. A.; Satyanarayana, T.

    1983-01-01

    In order to expedite the preparation of fluorescently tagged enzymes for histo-cyctochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

  5. The bioscouring performance of four polygalacturonase enzymes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) analyses of greige cotton fabrics bioscoured with a combination of ultrasound and endo- and exo-polygalacturonase enzymes obtained from Rhizopus sp. fungi were used in a fractional factorial design experiment to examine their perform...

  6. A Comprehensive Enzyme Kinetic Exercise for Biochemistry

    ERIC Educational Resources Information Center

    Barton, Janice S.

    2011-01-01

    This article describes a comprehensive treatment of experimental enzyme kinetics strongly coupled to electronic data acquisition and use of spreadsheets to organize data and perform linear and nonlinear least-squares analyses, all in a manner that promotes development of important reasoning skills. Kinetic parameters are obtained for the stable…

  7. Rapid purification of fluorescent enzymes by ultrafiltration

    NASA Technical Reports Server (NTRS)

    Benjaminson, M. A.; Satyanarayana, T.

    1983-01-01

    In order to expedite the preparation of fluorescently tagged enzymes for histo/cytochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

  8. Field management effects on soil enzyme activities

    Microsoft Academic Search

    Anna K. Bandick; Richard P. Dick

    1999-01-01

    There is growing recognition for the need to develop sensitive indicators of soil quality that reflect the effects of land management on soil and assist land managers in promoting long-term sustainability of terrestrial ecosystems. Eleven soil enzymes assays were investigated relative to soil management and soil quality at two study sites. Soils were sampled from the Vegetable Crop Rotation Plots

  9. Stabilization of Enzymes in Silk Films

    PubMed Central

    Lu, Shenzhou; Wang, Xiaoqin; Lv, Qiang; Hu, Xiao; Uppal, Neha; Omenetto, Fiorenzo

    2009-01-01

    Material systems are needed that promote stabilization of entrained molecules, such as enzymes or therapeutic proteins, without destroying their activity. We demonstrate that the unique structure of silk fibroin protein, when assembled into the solid state, establishes an environment that is conducive to the stabilization of entrained proteins. Enzymes (glucose oxidase, lipase and horseradish peroxidase) entrapped in these films over ten months retained significant activity, even when stored at 37°C, and in the case of glucose oxidase did not lose any activity. Further, the mode of processing of the silk protein into the films could be correlated to the stability of the enzymes. The relationship between processing and stability offers a large suite of conditions within which to optimize such stabilization processes. Overall, the techniques reported here result in materials that stabilize enzymes to a remarkable extent, without the need for cryoprotectants, emulsifiers, covalent immobilization or other treatments. Further, these systems are amenable to optical characterization, environmental distribution without refrigeration, are ingestible, and offer potential use in vivo, since silk materials are biocompatible and FDA approved, degradable with proteases and currently used in biomedical devices. PMID:19323497

  10. Investigating a Bio-Engineered Enzyme.

    ERIC Educational Resources Information Center

    Bullerwell, Lornie; And Others

    1994-01-01

    Describes science experiments with the enzyme lactose, which is available commercially as Lactaid and Dairy Ease. Experiments show how the rate of reaction of lactose converted to glucose and galactose is influenced by temperature, pH, and substrate concentration. (PR)

  11. Effect of oxidized oil on lipogenic enzymes.

    PubMed

    Iritani, N; Fukuda, E; Kitamura, Y

    1980-05-01

    Male Wistar rats were fed for 4 wk on diets containing 2% oxidized corn oil. Liver tissue was then studied to determine the effect of feeding peroxidized oil on lipogenic enzymes. Although substances which reacted with thiobarbituric acid increased in liver microsomes and mitochondria with increasing peroxide values of the dietary corn oil fed, the activities of glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase in liver were unchanged. However, when rats were fed for 2 wk on diets containing 10% fat, of which 0.5, 5 or 10% was unoxidized corn oil and the remainder was hydrogenated beef tallow filler, the lipogenic enzyme activities and also the liver triglyceride levels were observed to decrease with increasing amounts of dietary corn oil. Therefore, although a synthetic diet containing corn oil was easy to oxidize spontaneously, the reductions of lipogenic enzymes in rats fed the diet would not have been caused by lipid peroxides but by unsaturated fatty acids themselves. PMID:6104772

  12. ENZYME-BASED DETECTION OF CHLORINATED HYDROCARBONS

    EPA Science Inventory

    Recent advances in immobilized enzyme-based analytical methods, e.g., the cholinesterase-based water monitor 'CAM' (cholinesterase antagonsist monitor), have proved useful in the detection of organophosphate and carbamate pesticides. This work has now been extended to the detecti...

  13. Immobilization of enzymes for Klebsiella BOD sensor

    Microsoft Academic Search

    Mal-Nam Kim; Kyoung-Hwa Park

    2004-01-01

    Klebsiella sp. was isolated from the activated sludge of a wastewater disposal facility treating wastewater contaminated with highly concentrated lactose. A BOD probe loaded with Klebsiella sp. showed an improved performance for lactose detection, however, the sensitivity of the microbial BOD sensor toward glucose or fructose was still higher than that corresponding to lactose. Accordingly, an enzyme capable of hydrolyzing

  14. INDUCTION OF THE ALLANTOIN-DEGRADING ENZYMES

    Microsoft Academic Search

    VANESSA TUROSCY; GEORGE CHISHOLM; TERRANCE G. COOPER

    In an effort to understand the regulation of allantoin degradation in Sac- charomyces cerevisiae, we isolated two classes of mutants, each defective in the induction process associated with production of the pathway enzymes. Mutation at one locus (DAL80) results in constitutive expression of the genes involved in allantoin catabolism. Mutation at the second locus (DAL-81) results in the loss of

  15. Enzyme toolbox: novel enantiocomplementary imine reductases.

    PubMed

    Scheller, Philipp N; Fademrecht, Silvia; Hofelzer, Sebastian; Pleiss, Jürgen; Leipold, Friedemann; Turner, Nicholas J; Nestl, Bettina M; Hauer, Bernhard

    2014-10-13

    Reducing reactions are among the most useful transformations for the generation of chiral compounds in the fine-chemical industry. Because of their exquisite selectivities, enzymatic approaches have emerged as the method of choice for the reduction of C=O and activated C=C bonds. However, stereoselective enzymatic reduction of C=N bonds is still in its infancy-it was only recently described after the discovery of enzymes capable of imine reduction. In our work, we increased the spectrum of imine-reducing enzymes by database analysis. By combining the currently available knowledge about the function of imine reductases with the experimentally uncharacterized diversity stored in protein sequence databases, three novel imine reductases with complementary enantiopreference were identified along with amino acids important for catalysis. Furthermore, their reducing capability was demonstrated by the reduction of the pharmaceutically relevant prochiral imine 2-methylpyrroline. These novel enzymes exhibited comparable to higher catalytic efficiencies than previously described enzymes, and their biosynthetic potential is highlighted by the full conversion of 2-methylpyrroline in whole cells with excellent selectivities. PMID:25163890

  16. Dynamics of Radical-Mediated Enzyme Catalyses

    NASA Astrophysics Data System (ADS)

    Warncke, Kurt

    1997-11-01

    An emergent class of enzymes harnesses the extreme reactivity of electron-deficient free radical species to perform some of the most difficult reactions in biology. The regio- and stereo-selectivity achieved by these enzymes defies long-held ideas that radical reactions are non-specific. The common primary step in these catalyses is metal- or metallocenter-assisted generation of an electron-deficient organic "initiator radical". The initiator radical abstracts a hydrogen atom from the substrate, opening a new reaction channel for rearrangement to the product. Our aim is to elucidate the detailed molecular mechanisms of the radical pair separation and radical rearrangement steps. Radical pair separation and substrate radical rearrangement are tracked by using time-resolved (10-7 to 10-3 s) techniques of pulsed-electron paramagnetic resonance spectroscopy (FT-EPR, ESEEM). Synchronous time-evolution of the reactions is attained by triggering with a visible laser pulse. Transient non-Boltzmann population of the states of the spin-coupled systems, and resultant electron spin polarization, facilitates study at or near room temperature under conditions where the enzymes are operative. The systems examined include ethanolamine deaminase, a vitamin B12 coenzyme-dependent enzyme, ribonucleotide reductase and photosynthetic reaction centers. The electronic and nuclear structural and kinetic information obtained from the pulsed-EPR studies is used to address how the initiator radicals are stabilized against deleterious recombination with the metal, and to distinguish the participation of concerted versus sequential rearrangement pathways.

  17. Comparison of Soluble and Immobilised Enzymes

    ERIC Educational Resources Information Center

    Wiseman, Alan

    2003-01-01

    This short article was written in response to a proposed practical featured in the Spring 2002 issue of the "Journal of Biological Education." Beaumont, Cotterill and Williams described a system representing a useful way by which the deleterious effects of free radical attack on enzymes can be demonstrated to undergraduate bioscience students,…

  18. Sugarcane bagasse hydrolysis using yeast cellulolytic enzymes.

    PubMed

    Souza, Angelica Cristina de; Carvalho, Fernanda Paula; Silva e Batista, Cristina Ferreira; Schwan, Rosane Freitas; Dias, Disney Ribeiro

    2013-10-28

    Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with H2SO4. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ?- glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% H2SO4 for 30 min at 150oC. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ?-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production. PMID:23851270

  19. Hyaluronidases--a group of neglected enzymes.

    PubMed Central

    Kreil, G.

    1995-01-01

    Hyaluronan is an important constituent of the extracellular matrix. This polysaccharide can be hydrolyzed by various hyaluronidases that are widely distributed in nature. The structure of some bacterial and animal enzymes of this type has recently been elucidated. It could be shown that the hyaluronidases from bee and hornet venom and the PH-20 hyaluronidase present on mammalian spermatozoa are homologous proteins. PMID:8528065

  20. Divergence and Convergence in Enzyme Evolution: Parallel

    E-print Network

    Tawfik, Dan S.

    Descent Darwin's theory of evolution is associated mostly with the idea of natural selectionDivergence and Convergence in Enzyme Evolution: Parallel Evolution of Paraoxonases from Quorum 76100, Israel We discuss the basic features of divergent versus convergent evolution and of the common

  1. An NMR Study of Enzyme Activity.

    ERIC Educational Resources Information Center

    Peterman, Keith E.; And Others

    1989-01-01

    A laboratory experiment designed as a model for studying enzyme activity with a basic spectrometer is presented. Included are background information, experimental procedures, and a discussion of probable results. Stressed is the value of the use of Nuclear Magnetic Resonance in biochemistry. (CW)

  2. Influence of chlorothalonil on soil enzyme activity

    Microsoft Academic Search

    Lei Yan; Li-yuan Hou; Yu Bai; Bi-ying Li; Xiu-yan Zhou; Zhi-wei Qin

    2011-01-01

    In this paper, we studied the influence of different concentrations of chlorothalonil which was commonly used in North China, on the activities of soil invertase, catalase and urease. The results showed that the influence trend of chlorothalonil at different doses on soil enzyme activity was almost the same. For soil catalase, it showed significant activation. For soil urease, it showed

  3. Cellulases and related enzymes in biotechnology

    Microsoft Academic Search

    M. K. Bhat

    2000-01-01

    Basic and applied research on microbial cellulases, hemicellulases and pectinases has not only generated significant scientific knowledge but has also revealed their enormous potential in biotechnology. At present, cellulases and related enzymes are used in food, brewery and wine, animal feed, textile and laundry, pulp and paper industries, as well as in agriculture and for research purposes. Indeed, the demand

  4. Probing enzyme location in water-in-oil microemulsion using enzyme-carbon dot conjugates.

    PubMed

    Das, Krishnendu; Maiti, Subhabrata; Das, Prasanta Kumar

    2014-03-11

    This article delineates the formation and characterization of different enzyme-carbon dot conjugates in aqueous medium (pH = 7.0). We used soybean peroxidase (SBP), Chromobacterium viscosum (CV) lipase, trypsin, and cytochrome c (cyt c) for the formation of conjugate either with cationic carbon dot (CCD) or anionic carbon dot (ACD) depending on the overall charge of the protein at pH 7.0. These nanobioconjugates were used to probe the location of enzymes in water-in-oil (w/o) microemulsion. The size of the synthesized water-soluble carbon dots were of 2-3 nm with distinctive emission property. The formation of enzyme/protein-carbon dot conjugates in aqueous buffer was confirmed via fluorescence spectroscopy and zeta potential measurement, and the structural alteration of enzyme/protein was monitored by circular dichroism spectroscopy. Biocatalytic activities of protein/enzymes in conjugation with carbon dots were found to be decreased in aqueous phosphate buffer (pH 7.0, 25 mM). Interestingly, the catalytic activity of the nanobioconjugates of SBP, CV lipase, and cyt c did not reduce in cetyltrimethylammonium bromide (CTAB)-based reverse micelle. It indicates different localization of carbon dots and the enzymes inside the reverse micelle. The hydrophilic carbon dots always preferred to be located in the water pool of reverse micelle, and thus, enzyme must be located away from the water pool, which is the interface. However, in case of trypsin-carbon dot conjugate, the enzyme activity notably decreased in reverse micelle in the presence of carbon dot in a similar way that was observed in water. This implies that trypsin and carbon dots both must be located at the same place, which is the water pool of reverse micelle. Carbon dot induced deactivation was not observed for those enzymes which stay away from the water pool and localized at the interfacial domain while deactivation is observed for those enzymes which reside at the water pool. Thus, the location of enzymes in the microdomain of w/o microemulsion can be predicted by comparing the activity profile of enzyme-carbon dot conjugate in water and w/o microemulsion. PMID:24528191

  5. Identification and characterization of an enzyme involved in the elongation of n-6 and n-3 polyunsaturated fatty acids

    PubMed Central

    Parker-Barnes, Jennifer M.; Das, Tapas; Bobik, Emil; Leonard, Amanda E.; Thurmond, Jennifer M.; Chaung, Lu-Te; Huang, Yung-Sheng; Mukerji, Pradip

    2000-01-01

    The enzymes that are involved in the elongation of fatty acids differ in terms of the substrates on which they act. To date, the enzymes specifically involved in the biosynthesis of polyunsaturated fatty acids have not yet been identified. In an attempt to identify a gene(s) encoding an enzyme(s) specific for the elongation of ?-linolenic acid (GLA) (18:3n-6), a cDNA expression library was made from the fungus Mortierella alpina. The cDNA library constructed in a yeast expression vector was screened by measuring the expressed elongase activity [conversion of GLA to dihomo-GLA (20:3n-6)] from an individual yeast clone. In this report, we demonstrate the isolation of a cDNA (GLELO) whose encoded protein (GLELOp) was involved in the conversion of GLA to dihomo-GLA in an efficient manner (60% conversion). This cDNA contains a 957-nucleotide ORF that encodes a protein of 318 amino acids. Substrate specificity analysis revealed that this fungal enzyme acted also on stearidonic acid (18:4n-3). This report identifies and characterizes an elongase subunit that acts specifically on the two ?6-desaturation products, 18:3n-6 and 18:4n-3. When this GLELO cDNA was coexpressed with M. alpina ?5-desaturase cDNA in yeast, it resulted in the conversion of GLA to arachidonic acid (20:4n-6) as well as the conversion of stearidonic acid to eicosopentaenoic acid (20:5n-3). Thus, this GLELO gene may play an critical role in the bio-production of both n-6 and n-3 polyunsaturated fatty acids. PMID:10899997

  6. 73-20-1. Short title. This act may be cited as the "Watershed District Act".

    E-print Network

    Johnson, Eric E.

    73-20-1. Short title. This act may be cited as the "Watershed District Act". History: 1953 Comp of the Watershed District Act. ANNOTATIONS Scope of provisions. -- A careful reading of the Watershed District Act does not clearly indicate that the creation of watersheds is for the exclusive use of agricultural

  7. Child Welfare Act and Child Custody and Right of Access Act. Finland.

    ERIC Educational Resources Information Center

    Utriainen, Sirpa, Ed.

    The two major articles of child welfare legislation in Finland are the Child Welfare Act of 1983 and the Child Custody and Right of Access Act of 1983. These new acts are part of a reform of social legislation and services providing increased flexibility and effectiveness in protecting Finnish children's health and happiness. The Acts attach…

  8. Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000

    E-print Network

    US Army Corps of Engineers

    Estuary Restoration Act of 2000 Title I of Estuaries and Clean Waters Act of 2000 Public Law 106 of Section 108 of the Estuary Restoration Act, Title I of P.L. 106-457 (Act). This report covers the fiscal years 2004 through 2006 and reflects the views of the Estuary Habitat Restoration Council (Council

  9. Quantitation of apolipoprotein B48 in triacylglycerol-rich lipoproteins by a specific enzyme-linked immunosorbent assay

    Microsoft Academic Search

    Julie A. Lovegrove; S. Gail Isherwood; Kim G. Jackson; Christine M. Williams; Barry J. Gould

    1996-01-01

    This paper describes the use of an antiserum, specific for apolipoprotein (apo) B-48, in a competitive, enzyme-linked immunosorbent assay (ELISA) for apo B-48 in triacylglycerol-rich lipoprotein (TRL) fractions prepared from fasting and post-prandial plasma samples. Previously we showed the antiserum to act as an effective immunoblotting agent following sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its use in this ELISA

  10. Cell wall and enzyme changes during the graviresponse of the leaf-sheath pulvinus of oat (Avena sativa)

    NASA Technical Reports Server (NTRS)

    Gibeaut, David M.; Karuppiah, Nadarajah; Chang, S.-R.; Brock, Thomas G.; Vadlamudi, Babu; Kim, Donghern; Ghosheh, Najati S.; Rayle, David L.; Carpita, Nicholas C.; Kaufman, Peter B.

    1990-01-01

    The graviresponse of the leaf-sheath pulvinus of oat (Avena sativa) involves an asymmetric growth response and asymmetric processes involving degradation of starch and cell wall synthesis. Cellular and biochemical events were studied by investigation of the activities of related enzymes and changes in cell walls and their constituents. It is suggested that an osmotic potential gradient acts as the driving factor for growth, while wall extensibility is a limiting factor in pulvinus growth.

  11. ACTS: Technology Description and Results

    NASA Technical Reports Server (NTRS)

    Gedney, Richard T.; Schertler, Ronald; Gargione, Frank

    2000-01-01

    The ACTS Project was originated at NASA Glenn Research Center in the early 1980's to sponsor the development and application of technology that was intended to be used by the private sector. The program was formulated with the underlying philosophy of maintaining US leadership in satellite communications while focusing technology development for efficient use of the frequency spectrum. This report chronicles the execution and results of the program from the perspective of its technology managers, from inception through hardware and system development to on-orbit experiments and demonstrations of the technology. The first eight sections of the report discuss programmatic background, the specific satellite and ground terminal technology and the results generated by the program including industry relevance. A federally funded program of this type attracted strong advocates and adversaries and the resulting impact on the project schedule is also discussed. The last two sections are a list of useful acronyms and extensive references.

  12. Working with Enzymes - Where Is Lactose Digested? An Enzyme Assay for Nutritional Biochemistry Laboratories

    NASA Astrophysics Data System (ADS)

    Pope, Sandi R.; Tolleson, Tonya D.; Williams, R. Jill; Underhill, Russell D.; Deal, S. Todd

    1998-06-01

    At Georgia Southern University, we offer a sophomore-level introductory biochemistry course that is aimed at nutrition and chemistry education majors. The laboratory portion of this course has long lacked an experimental introduction to enzymes. We have developed a simple enzyme assay utilizing lactase enzyme from crushed LactAid tablets and a 5% lactose solution ("synthetic milk"). In the experiment, the students assay the activity of the enzyme on the "synthetic milk" at pHs of approximately 1, 6, and 8 with the stated goal of determining where lactose functions in the digestive tract. The activity of the lactase may be followed chromatographically or spectrophotometrically. The experiment, which is actually a simple pH assay, is easily implemented in allied health chemistry laboratory courses and readily lends itself to adaptation for more complex kinetic assays in upper-level biochemistry laboratory courses. The experimental details, including a list of required supplies and hints for implementation, are provided.

  13. Heterologous Expression of Xylanase Enzymes in Lipogenic Yeast Yarrowia lipolytica

    PubMed Central

    Alahuhta, Markus; Chen, Xiaowen; Hyman, Deborah; Johnson, David K.; Zhang, Min; Himmel, Michael E.

    2014-01-01

    To develop a direct microbial sugar conversion platform for the production of lipids, drop-in fuels and chemicals from cellulosic biomass substrate, we chose Yarrowia lipolytica as a viable demonstration strain. Y. lipolytica is known to accumulate lipids intracellularly and is capable of metabolizing sugars to produce lipids; however, it lacks the lignocellulose-degrading enzymes needed to break down biomass directly. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of several xylanases in Y. lipolytica. The XynII and XlnD expressing Yarrowia strains exhibited an ability to grow on xylan mineral plates. This was shown by Congo Red staining of halo zones on xylan mineral plates. Enzymatic activity tests further demonstrated active expression of XynII and XlnD in Y. lipolytica. Furthermore, synergistic action in converting xylan to xylose was observed when XlnD acted in concert with XynII. The successful expression of these xylanases in Yarrowia further advances us toward our goal to develop a direct microbial conversion process using this organism. PMID:25462572

  14. Rational design of a split-Cas9 enzyme complex.

    PubMed

    Wright, Addison V; Sternberg, Samuel H; Taylor, David W; Staahl, Brett T; Bardales, Jorge A; Kornfeld, Jack E; Doudna, Jennifer A

    2015-03-10

    Cas9, an RNA-guided DNA endonuclease found in clustered regularly interspaced short palindromic repeats (CRISPR) bacterial immune systems, is a versatile tool for genome editing, transcriptional regulation, and cellular imaging applications. Structures of Streptococcus pyogenes Cas9 alone or bound to single-guide RNA (sgRNA) and target DNA revealed a bilobed protein architecture that undergoes major conformational changes upon guide RNA and DNA binding. To investigate the molecular determinants and relevance of the interlobe rearrangement for target recognition and cleavage, we designed a split-Cas9 enzyme in which the nuclease lobe and ?-helical lobe are expressed as separate polypeptides. Although the lobes do not interact on their own, the sgRNA recruits them into a ternary complex that recapitulates the activity of full-length Cas9 and catalyzes site-specific DNA cleavage. The use of a modified sgRNA abrogates split-Cas9 activity by preventing dimerization, allowing for the development of an inducible dimerization system. We propose that split-Cas9 can act as a highly regulatable platform for genome-engineering applications. PMID:25713377

  15. Enzyme recovery during gas/liquid two-phase flow microfiltration of enzyme/yeast mixtures.

    PubMed

    Mercier-Bonin, Muriel; Fonade, Christian

    2002-12-20

    The effect of a gas/liquid two-phase flow on the recovery of an enzyme was evaluated and compared with standard crossflow operation when confronted with the microfiltration of a high-fouling yeast suspension. Ceramic tubular and flat sheet membranes were used. At constant feed concentration (permeate recycling) and transmembrane pressure, the results obtained with the tubular membrane were dependent on the two-phase flow pattern. In comparison with single-phase flow performances at the same liquid velocity, the enzyme transmission was maintained at a high level with a bubble flow pattern but it decreased by 70% with a slug flow, whatever the flow rate ratio. Identical results were obtained with flat sheet membranes: for the highest flow rate ratio, the enzyme transmission was reduced by 70% even though the permeate flux was improved by 240%. During diafiltration experiments with the tubular membrane, it was found that a bubble flow pattern led to a 13% higher enzyme recovery compared to single-phase flow conditions, whereas with a slug flow the enzyme recovery was strongly reduced. With bubble flow conditions, energy consumption was minimal, confirming that this flow pattern was the most suitable for enzyme recovery. PMID:12378602

  16. Inactivation of pyridoxal phosphate enzymes by gabaculine. Correlation with enzymic exchange of beta-protons.

    PubMed

    Soper, T S; Manning, J M

    1982-12-10

    Gabaculine, 5-amino-1,3-cyclohexadienylcarboxylate, is a very efficient enzyme-activated inhibitor of gamma-aminobutyrate transaminase (Rando, R. R. (1977) Biochemistry 16, 4604-4610). However, enzymes for which gamma-aminobutyrate is not a substrate are also inactivated by gabaculine. Thus, purified D-amino acid transaminase, L-alanine transaminase, and L-aspartate transaminase are also inactivated (Ki values of 0.1 mM, 1 mM, and 55 mM, respectively). The effects of this inhibitor on such a diverse group of enzymes appear to be related to the enzymic exchange of beta-protons of their normal substrates. L-Alanine transaminase and L-aspartate transaminase are known to catalyze such an exchange (Walter, U., Luthe, H., Gerhart, F., and Söling, H.-D. (1975) Eur. J. Biochem. 59, 395-403). D-Amino acid transaminase and gamma-aminobutyrate transaminase, which are inactivated by gabaculine, also catalyze exchange of the beta-protons of their substrates. Alanine racemase and tryptophanase, which are known not to catalyze an analogous exchange, were found to be insensitive to gabaculine. We postulate that aromatization of gabaculine, in which the beta-proton is removed, is an enzyme-catalyzed event for those pyridoxal phosphate enzymes that have a nucleophilic group at the active site to catalyze this process. PMID:7142186

  17. PDEPT: polymer-directed enzyme prodrug therapy

    PubMed Central

    Satchi, R; Connors, T A; Duncan, R

    2001-01-01

    Polymer-directed enzyme prodrug therapy (PDEPT) is a novel two-step antitumour approach using a combination of a polymeric prodrug and polymer-enzyme conjugate to generate cytotoxic drug selectively at the tumour site. In this study the polymeric prodrug N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-Gly-Phe-Leu-Gly-doxorubicin conjugate PK1 (currently under Phase II clinical evaluation) was selected as the model prodrug, and HPMA copolymer-cathepsin B as a model for the activating enzyme conjugate. Following polymer conjugation (yield of 30–35%) HPMA copolymer-cathepsin B retained ~20–25% enzymatic activity in vitro. To investigate pharmacokinetics in vivo,125I-labelled HPMA copolymer-cathepsin B was administered intravenously (i.v.) to B16F10 tumour-bearing mice. HPMA copolymer-cathespin B exhibited a longer plasma half-life (free cathepsin B t1/2?= 2.8?h; bound cathepsin B t1/2?= 3.2?h) and a 4.2-fold increase in tumour accumulation compared to the free enzyme. When PK1 (10?mg kg?1dox-equiv.) was injected i.v. into C57 mice bearing subcutaneously (s.c.) palpable B16F10 tumours followed after 5?h by HPMA copolymer-cathepsin B there was a rapid increase in the rate of dox release within the tumour (3.6-fold increase in the AUC compared to that seen for PK1 alone). When PK1 and the PDEPT combination were used to treat established B16F10 melanoma tumour (single dose; 10?mg kg?1dox-equiv.), the antitumour activity (T/C%) seen for the combination PDEPT was 168% compared to 152% seen for PK1 alone, and 144% for free dox. Also, the PDEPT combination showed activity against a COR-L23 xenograft whereas PK1 did not. PDEPT has certain advantages compared to ADEPT and GDEPT. The relatively short plasma residence time of the polymeric prodrug allows subsequent administration of polymer-enzyme without fear of prodrug activation in the circulation and polymer-enzyme conjugates have reduced immunogenicity. This study proves the concept of PDEPT and further optimisation is warranted. © 2001 Cancer Research Campaign?? http://www.bjcancer.com PMID:11592781

  18. 77 FR 69444 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-19

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  19. 78 FR 14281 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-05

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  20. 78 FR 14280 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-05

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  1. 78 FR 41919 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  2. 78 FR 31905 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-28

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  3. 78 FR 41918 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  4. 78 FR 5784 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  5. 78 FR 14286 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-05

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  6. 78 FR 52518 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  7. 78 FR 37799 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate...

  8. 78 FR 41917 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications, DFAS-ZCF...Information/Privacy Act Program Manager, Corporate Communications,...

  9. 77 FR 58106 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-19

    ...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications, DFAS-HKC...Information/Privacy Act Program Manager, Corporate Communications,...

  10. Metal enzymes in "impossible" microorganisms catalyzing the anaerobic oxidation of ammonium and methane.

    PubMed

    Reimann, Joachim; Jetten, Mike S M; Keltjens, Jan T

    2015-01-01

    Ammonium and methane are inert molecules and dedicated enzymes are required to break up the N-H and C-H bonds. Until recently, only aerobic microorganisms were known to grow by the oxidation of ammonium or methane. Apart from respiration, oxygen was specifically utilized to activate the inert substrates. The presumed obligatory need for oxygen may have resisted the search for microorganisms that are capable of the anaerobic oxidation of ammonium and of methane. However extremely slowly growing, these "impossible" organisms exist and they found other means to tackle ammonium and methane. Anaerobic ammonium-oxidizing (anammox) bacteria use the oxidative power of nitric oxide (NO) by forging this molecule to ammonium, thereby making hydrazine (N2H4). Nitrite-dependent anaerobic methane oxidizers (N-DAMO) again take advantage of NO, but now apparently disproportionating the compound into dinitrogen and dioxygen gas. This intracellularly produced dioxygen enables N-DAMO bacteria to adopt an aerobic mechanism for methane oxidation.Although our understanding is only emerging how hydrazine synthase and the NO dismutase act, it seems clear that reactions fully rely on metal-based catalyses known from other enzymes. Metal-dependent conversions not only hold for these key enzymes, but for most other reactions in the central catabolic pathways, again supported by well-studied enzymes from model organisms, but adapted to own specific needs. Remarkably, those accessory catabolic enzymes are not unique for anammox bacteria and N-DAMO. Close homologs are found in protein databases where those homologs derive from (partly) known, but in most cases unknown species that together comprise an only poorly comprehended microbial world. PMID:25707470

  11. Progress in the development of enzyme-based nerve agent bioscavengers.

    PubMed

    Nachon, Florian; Brazzolotto, Xavier; Trovaslet, Marie; Masson, Patrick

    2013-12-01

    Acetylcholinesterase is the physiological target for acute toxicity of nerve agents. Attempts to protect acetylcholinesterase from phosphylation by nerve agents, is currently achieved by reversible inhibitors that transiently mask the enzyme active site. This approach either protects only peripheral acetylcholinesterase or may cause side effects. Thus, an alternative strategy consists in scavenging nerve agents in the bloodstream before they can reach acetylcholinesterase. Pre- or post-exposure administration of bioscavengers, enzymes that neutralize and detoxify organophosphorus molecules, is one of the major developments of new medical counter-measures. These enzymes act either as stoichiometric or catalytic bioscavengers. Human butyrylcholinesterase is the leading stoichiometric bioscavenger. Current efforts are devoted to its mass production with care to pharmacokinetic properties of the final product for extended lifetime. Development of specific reactivators of phosphylated butyrylcholinesterase, or variants with spontaneous reactivation activity is also envisioned for rapid in situ regeneration of the scavenger. Human paraoxonase 1 is the leading catalytic bioscavenger under development. Research efforts focus on improving its catalytic efficiency toward the most toxic isomers of nerve agents, by means of directed evolution-based strategies. Human prolidase appears to be another promising human enzyme. Other non-human efficient enzymes like bacterial phosphotriesterases or squid diisopropylfluorophosphatase are also considered though their intrinsic immunogenic properties remain challenging for use in humans. Encapsulation, PEGylation and other modifications are possible solutions to address this problem as well as that of their limited lifetime. Finally, gene therapy for in situ generation and delivery of bioscavengers is for the far future, but its proof of concept has been established. PMID:23811386

  12. Purification and enzyme activity of ACK1.

    PubMed

    Yokoyama, Noriko; Miller, W Todd

    2006-01-01

    The activated Cdc42 associated kinases (ACKs) are nonreceptor tyrosine kinases that are specific targets of Cdc42. To study the biochemical properties of ACK1, we expressed and purified the enzyme using the baculovirus/Sf9 cell system. This ACK1 construct contains (from N- to C-terminus) the kinase catalytic domain, SH3 domain, and Cdc42-binding CRIB domain. We describe enzyme activity assays based on synthetic peptide substrates. The best such substrate is a peptide derived from the site of ACK1-catalyzed phosphorylation of the Wiskott-Aldrich syndrome protein (WASP). Although the SH3 and CRIB domains of purified ACK1 are able to bind ligands (a polyproline peptide and Cdc42, respectively), the ligands did not stimulate in vitro tyrosine kinase activity. Purified ACK1 undergoes autophosphorylation at Tyr284, and autophosphorylation increases kinase activity. PMID:16472662

  13. Alpha complementation in the Cre recombinase enzyme.

    PubMed

    Casanova, Emilio; Lemberger, Thomas; Fehsenfeld, Sandra; Mantamadiotis, Theo; Schütz, Günther

    2003-09-01

    The Cre-loxP system is increasingly exploited for spatial and temporal gene inactivation. Here we present a novel approach to achieve this goal of selective gene inactivation. Following the model of alpha complementation in the beta-galactosidase enzyme, where the enzyme is split into independent polypeptides which are able to associate and maintain the enzymatic activity, we divided the Cre recombinase into two independent polypeptides (one containing the NH(2) terminus (alpha) and a second one containing the COOH-terminus (beta)). Individually, the two polypeptides have no detectable activity. However, when coexpressed the polypeptides are able to associate, giving rise to Cre enzymatic activity, which optimally is as high as 30% of that seen with wildtype Cre recombinase in vitro. We present this strategy as a modification of the traditional Cre-loxP system, which could be used to obtain a highly specific recombination pattern by expressing the two halves under the control of separate promoters. PMID:14502574

  14. Enzyme replacement therapy for Pompe disease.

    PubMed

    Angelini, Corrado; Semplicini, Claudio

    2012-02-01

    Late-onset glycogenosis type II (glycogen storage disease type II [GSDII]) is a rare autosomal disorder caused by deficiency of acid maltase, a lysosomal enzyme that hydrolyzes glycogen to glucose. Recently, both infantile and adult GSDII patients have been treated with enzyme replacement therapy (ERT), and a number of studies including large cohorts of GSDII patients have recently demonstrated that ERT is effective in modifying the natural course of the disease. The opportunity of this new treatment gave new hope to patients, but also an important impulse to the research on every feature of the disease, leading to a deeper knowledge on the response to treatment, on clinical manifestations, and on pathophysiologic aspects such as the role of autophagy and immune status. PMID:22002767

  15. (Enzyme use in the Jute Industry)

    SciTech Connect

    Niyogi, S.K.

    1991-03-15

    This report covers my official visit to the Indian Jute Industries' Research Association (IJIRA), Calcutta, India. The visit lasted a little over two weeks, including two trips to three jute mills outside Calcutta and a one-day visit to the library of the Indian Institute of Chemical Biology, Calcutta. The report describes the applications of enzymes (derived from a moldy wheat bran extract) in upgrading the jute fiber and in enhancing the quality of tamarind kernel powder used for sizing of jute. The various methodological developments in these processes are discussed in detail along with suggestions for possible improvements. The report also describes the visits to the jute mills where enzyme applications are being made. Interactions with the IJIRA research staff are described in detail. My contributions to the Project are described along with specific recommendations for future research.

  16. Quantitative Interpretation of the Randomness in Single Enzyme Turnover Times

    E-print Network

    Yang, Seongeun

    Fluctuating turnover times of a single enzyme become observable with the advent of modern cutting-edge, single enzyme experimental techniques. Although the conventional chemical kinetics and its modern generalizations could ...

  17. ENZYME-BASED DETECTION OF CHLORINATED HYDROCARBONS IN WATER

    EPA Science Inventory

    An enzyme-based approach for detecting hazardous levels of high molecular weight chlorinated hydrocarbons in natural waters has been explored. An extensive review of the literature indicated that the enzymes, lactate dehydrogenase, carbonic anhydrase, hexokinase, phosphorylase an...

  18. Purification and characterization of two fully deuterated enzymes

    NASA Technical Reports Server (NTRS)

    Crespi, H. L.; Katz, J. J.; Parmerter, S.; Rokop, S.

    1969-01-01

    Comparative data reveal little difference between kinetic and thermal stabilities of pure preparations of two ordinary enzymes and their fully deuterated counterparts. The effects of temperature on the enzymes proved to be consistent with earlier results.

  19. School, Enzymes, and Sports for the Child with Cystic Fibrosis

    MedlinePLUS

    ... or how long they can do it. School, Enzymes, and Sports For the Child with Cystic Fibrosis utrition N • Schools, Enzymes, and Sports ——————————————————————— For children with CF, exercise: • builds ...

  20. Structural analysis of hydroxypropylphosphonic acid epoxidase : a fosfomycin biosynthetic enzyme

    E-print Network

    Higgins, Luke J. (Luke James)

    2006-01-01

    An X-ray crystallographic study of the fosfomycin biosynthetic enzyme hydroxypropylphosphonic acid epoxidase (HppE) from Streptomyces wedmorensis is presented. Structural analysis of this cupin mononuclear iron enzyme in ...