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1

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

PubMed Central

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. A major carbon and energy source for this soil fungus is starch, which can be degraded by the concerted action of ?-amylase, glucoamylase and ?-glucosidase enzymes, members of the glycoside hydrolase (GH) families 13, 15 and 31, respectively. In this study we have combined analysis of the genome sequence of A. niger CBS 513.88 with microarray experiments to identify novel enzymes from these families and to predict their physiological functions. We have identified 17 previously unknown family GH13, 15 and 31 enzymes in the A. niger genome, all of which have orthologues in other aspergilli. Only two of the newly identified enzymes, a putative ?-glucosidase (AgdB) and an ?-amylase (AmyC), were predicted to play a role in starch degradation. The expression of the majority of the genes identified was not induced by maltose as carbon source, and not dependent on the presence of AmyR, the transcriptional regulator for starch degrading enzymes. The possible physiological functions of the other predicted family GH13, GH15 and GH31 enzymes, including intracellular enzymes and cell wall associated proteins, in alternative ?-glucan modifying processes are discussed. Electronic supplementary material The online version of this article (doi:10.1007/s00438-008-0332-7) contains supplementary material, which is available to authorized users.

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

2008-01-01

2

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

Microsoft Academic Search

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

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

3

Contribution of AmyA, an extracellular alpha-glucan degrading enzyme, to group A streptococcal host-pathogen interaction.  

PubMed

alpha-Glucans such as starch and glycogen are abundant in the human oropharynx, the main site of group A Streptococcus (GAS) infection. However, the role in pathogenesis of GAS extracellular alpha-glucan binding and degrading enzymes is unknown. The serotype M1 GAS genome encodes two extracellular proteins putatively involved in alpha-glucan binding and degradation; pulA encodes a cell wall anchored pullulanase and amyA encodes a freely secreted putative cyclomaltodextrin alpha-glucanotransferase. Genetic inactivation of amyA, but not pulA, abolished GAS alpha-glucan degradation. The DeltaamyA strain had a slower rate of translocation across human pharyngeal epithelial cells. Consistent with this finding, the DeltaamyA strain was less virulent following mouse mucosal challenge. Recombinant AmyA degraded alpha-glucans into beta-cyclomaltodextrins that reduced pharyngeal cell transepithelial resistance, providing a physiologic explanation for the observed transepithelial migration phenotype. Higher amyA transcript levels were present in serotype M1 GAS strains causing invasive infection compared with strains causing pharyngitis. GAS proliferation in a defined alpha-glucan-containing medium was dependent on the presence of human salivary alpha-amylase. These data delineate the molecular mechanisms by which alpha-glucan degradation contributes to GAS host-pathogen interaction, including how GAS uses human salivary alpha-amylase for its own metabolic benefit. PMID:19735442

Shelburne, Samuel A; Keith, David B; Davenport, Michael T; Beres, Stephen B; Carroll, Ronan K; Musser, James M

2009-09-03

4

Functional characterization of alpha-glucan,water dikinase, the starch phosphorylating enzyme.  

PubMed

GWD (alpha-glucan,water dikinase) is the enzyme that catalyses the phosphorylation of starch by a dikinase-type reaction in which the beta-phosphate of ATP is transferred to either the C-6 or the C-3 position of the glycosyl residue of amylopectin. GWD shows similarity in both sequence and reaction mechanism to bacterial PPS (pyruvate,water dikinase) and PPDK (pyruvate,phosphate dikinase). Amino acid sequence alignments identified a conserved histidine residue located in the putative phosphohistidine domain of potato GWD. Site-directed mutagenesis of this histidine residue resulted in an inactive enzyme and loss of autophosphorylation. Native GWD is a homodimer and shows a strict requirement for the presence of alpha-1,6 branch points in its polyglucan substrate, and exhibits a sharp 20-fold increase in activity when the degree of polymerization is increased from 27.8 to 29.5. In spite of the high variability in the degree of starch phosphorylation, GWD proteins are ubiquitous in plants. The overall reaction mechanism of GWD is similar to that of PPS and PPDK, but the GWD family appears to have arisen after divergence of the plant kingdom. The nucleotide-binding domain of GWD exhibits a closer phylogenetic relationship to prokaryotic PPSs than to PPDKs. PMID:14525539

Mikkelsen, René; Baunsgaard, Lone; Blennow, Andreas

2004-01-15

5

Alpha-glucan, water dikinase (GWD): a plastidic enzyme with redox-regulated and coordinated catalytic activity and binding affinity.  

PubMed

The recently discovered potato tuber (Solanum tuberosum) alpha-glucan, water dikinase (GWD) (formerly known as R1) catalyzes the phosphorylation of starch by a dikinase-type reaction mechanism in which the beta-phosphate of ATP is transferred to either the C-6 or the C-3 position of the glucosyl residue of starch. In the present study, we found that the GWD enzyme is inactive in the oxidized form, which is accompanied by the formation of a specific intramolecular disulfide bond as determined by disulfide-linked peptide mapping. The regulatory properties of this disulfide linkage were confirmed by site-directed mutagenesis studies. Both reduced thioredoxin (Trx) f and Trx m from spinach leaves reduced and activated oxidized GWD at very low concentrations, with Trx f being the more efficient, yielding an S0.5 value of 0.4 microM. Interestingly, GWD displays a reversible and selective binding to starch granules depending on the illumination state of the plant. Here we show that starch granule-bound GWD isolated from dark-adapted plants exists in the inactive, oxidized form, which is capable of reactivation upon treatment with reduced Trx. Furthermore, the soluble form of GWD was found in its fully reduced state, providing evidence of a Trx-controlled regulation mechanism linking enzymatic activity and specific binding affinities of a protein to an intracellular surface. The regulatory site sequence, CFATC, of potato GWD is conserved in chloroplast-targeted GWDs from other species, suggesting an overall redox regulation of the GWD enzyme. PMID:15665090

Mikkelsen, René; Mutenda, Kudzai E; Mant, Alexandra; Schürmann, Peter; Blennow, Andreas

2005-01-21

6

Recombinant production and biochemical characterization of a hyperthermostable alpha-glucan/maltodextrin phosphorylase from Pyrococcus furiosus.  

PubMed

Alpha-glucan phosphorylase catalyzes the reversible cleavage of alpha-1-4-linked glucose polymers into alpha-D-glucose-1-phosphate. We report the recombinant production of an alpha-glucan/maltodextrin phosphorylase (PF1535) from a hyperthermophilic archaeon, Pyrococcus furiosus, and the first detailed biochemical characterization of this enzyme from any archaeal source using a mass-spectrometry-based assay. The apparent 98 kDa recombinant enzyme was active over a broad range of temperatures and pH, with optimal activity at 80 degrees C and pH 6.5-7. This archaeal protein retained its complete activity after 24 h at 80 degrees C in Tris-HCl buffer. Unlike other previously reported phosphorylases, the Ni-affinity column purified enzyme showed broad substrate specificity in both the synthesis and degradation of maltooligosaccharides. In the synthetic direction of the enzymatic reaction, the lowest oligosaccharide required for the chain elongation was maltose. In the degradative direction, the archaeal enzyme can produce glucose-1-phosphate from maltotriose or longer maltooligosaccharides including both glycogen and starch. The specific activity of the enzyme at 80 degrees C in the presence of 10 mM maltoheptaose and at 10 mg ml(-1) glycogen concentration was 52 U mg(-1) and 31 U mg(-1), respectively. The apparent Michaelis constant and maximum velocity for inorganic phosphate were 31 +/- 2 mM and 0.60 +/- 0.02 mM min(-1) microg(-1), respectively. An initial velocity study of the enzymatic reaction indicated a sequential bi-bi catalytic mechanism. Unlike the more widely studied mammalian glycogen phosphorylase, the Pyrococcus enzyme is active in the absence of added AMP. PMID:19054743

Mizanur, Rahman M; Griffin, Amanda K K; Pohl, Nicola L

2008-12-01

7

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

PubMed

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

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

2007-12-13

8

Engineered plant phosphorylase showing extraordinarily high affinity for various alpha-glucan molecules.  

PubMed Central

alpha-Glucan phosphorylases are characterized by considerable difference in substrate specificities, even though the primary structures are well conserved among the enzymes from microorganisms, plants, and animals. The higher plant phosphorylase isozyme designated as type L exhibits low affinity for a large, highly branched glucan (glycogen), presumably due to steric hindrance caused by a unique 78-residue insertion located beside the mouth of the active-site cleft, whereas another isozyme without the insertion (designated as type H) shows very high affinity for both linear and branched glucans. Using the recombinant type L isozyme from potato tuber as a starting framework and aiming at altering its substrate specificity, we have genetically engineered the 78-residue insertion and its flanking regions. Firstly, removal of the insertion and connection of the newly formed C- and N-terminals yielded a totally inactive enzyme, although the protein was produced in Escherichia coli cells in a soluble form. Secondly, a chimeric phosphorylase, in which the 78-residue insertion and its flanking regions are replaced by the corresponding region of the type H isozyme, has been shown to exhibit high affinity for branched glucans (Mori, H., Tanizawa, K., & Fukui, T., 1993, J. Biol. Chem. 268, 5574-5581), but when two and four unconserved residues in the N-terminal flanking region of the chimeric phosphorylase were mutated back to those of the type L isozyme, the resulting mutants showed significantly lowered affinity for substrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Mori, H.; Tanizawa, K.; Fukui, T.

1993-01-01

9

The Structural Basis of Alpha-Glucan Recognition by a Family 41 Carbohydrate-Binding Module from Therotoga Maritima  

SciTech Connect

Starch recognition by carbohydrate-binding modules (CBMs) is important for the activity of starch-degrading enzymes. The N-terminal family 41 CBM, TmCBM41 (from pullulanase PulA secreted by Thermotoga maritima) was shown to have {alpha}-glucan binding activity with specificity for {alpha}-1, 4-glucans but was able to tolerate the {alpha}-1, 6-linkages found roughly every three or four glucose units in pullulan. Using X-ray crystallography, the structures were solved for TmCBM41 in an uncomplexed form and in complex with maltotetraose and 63-{alpha}-d-glucosyl-maltotriose (GM3). Ligand binding was facilitated by stacking interactions between the {alpha}-faces of the glucose residues and two tryptophan side-chains in the two main subsites of the carbohydrate-binding site. Overall, this mode of starch binding is quite well conserved by other starch-binding modules. The structure in complex with GM3 revealed a third binding subsite with the flexibility to accommodate an {alpha}-1, 4- or an {alpha}-1, 6-linked glucose.

van Bueren,A.; Boraston, A.

2006-01-01

10

Functional domain organization of the potato alpha-glucan, water dikinase (GWD): evidence for separate site catalysis as revealed by limited proteolysis and deletion mutants.  

PubMed

The potato tuber (Solanum tuberosum) GWD (alpha-glucan, water dikinase) catalyses the phosphorylation of starch by a dikinase-type reaction mechanism in which the beta-phosphate of ATP is transferred to the glucosyl residue of amylopectin. GWD shows sequence similarity to bacterial pyruvate, water dikinase and PPDK (pyruvate, phosphate dikinase). In the present study, we examine the structure-function relationship of GWD. Analysis of proteolytic fragments of GWD, in conjunction with peptide microsequencing and the generation of deletion mutants, indicates that GWD is comprised of five discrete domains of 37, 24, 21, 36 and 38 kDa. The catalytic histidine, which mediates the phosphoryl group transfer from ATP to starch, is located on the 36 kDa fragment, whereas the 38 kDa C-terminal fragment contains the ATP-binding site. Binding of the glucan molecule appears to be confined to regions containing the three N-terminal domains. Deletion mutants were generated to investigate the functional interdependency of the putative ATP- and glucan-binding domains. A truncated form of GWD expressing the 36 and 38 kDa C-terminal domains was found to catalyse the E+ATP-->E-P+AMP+P(i) (where P(i) stands for orthophosphate) partial reaction, but not the E-P+glucan-->E+glucan-P partial reaction. CD experiments provided evidence for large structural changes on autophosphorylation of GWD, indicating that GWD employs a swivelling-domain mechanism for enzymic phosphotransfer similar to that seen for PPDK. PMID:15361065

Mikkelsen, René; Blennow, Andreas

2005-01-15

11

Schizosaccharomyces pombe rho2p GTPase regulates cell wall alpha-glucan biosynthesis through the protein kinase pck2p.  

PubMed

Schizosaccharomyces pombe rho1(+) and rho2(+) genes are involved in the control of cell morphogenesis, cell integrity, and polarization of the actin cytoskeleton. Although both GTPases interact with each of the two S. pombe protein kinase C homologues, Pck1p and Pck2p, their functions are distinct from each other. It is known that Rho1p regulates (1,3)beta-D-glucan synthesis both directly and through Pck2p. In this paper, we have investigated Rho2p signaling and show that pck2 delta and rho2 delta strains display similar defects with regard to cell wall integrity, indicating that they might be in the same signaling pathway. We also show that Rho2 GTPase regulates the synthesis of alpha-D-glucan, the other main structural polymer of the S. pombe cell wall, primarily through Pck2p. Although overexpression of rho2(+) in wild-type or pck1 delta cells is lethal and causes morphological alterations, actin depolarization, and an increase in alpha-D-glucan biosynthesis, all of these effects are suppressed in a pck2 delta strain. In addition, genetic interactions suggest that Rho2p and Pck2p are important for the regulation of Mok1p, the major (1-3)alpha-D-glucan synthase. Thus, a rho2 delta mutation, like pck2 delta, is synthetically lethal with mok1-664, and the mutant partially fails to localize Mok1p to the growing areas. Moreover, overexpression of mok1(+) in rho2 delta cells causes a lethal phenotype that is completely different from that of mok1(+) overexpression in wild-type cells, and the increase in alpha-glucan is considerably lower. Taken together, all of these results indicate the presence of a signaling pathway regulating alpha-glucan biosynthesis in which the Rho2p GTPase activates Pck2p, and this kinase in turn controls Mok1p. PMID:11102532

Calonge, T M; Nakano, K; Arellano, M; Arai, R; Katayama, S; Toda, T; Mabuchi, I; Perez, P

2000-12-01

12

Molecular cloning of cDNA encoding potato amyloplast alpha-glucan phosphorylase and the structure of its transit peptide.  

PubMed

The type L isozyme of potato tuber alpha-glucan phosphorylase [EC 2.4.1.1], a dimer of 104-kDa subunits, is compartmentalized in the amyloplast. We have cloned a nearly full-length cDNA encoding this isozyme from a cDNA library of immature potato tuber. The sequence was supplemented by a partial genomic clone. The transcription initiation site was identified by a primer extension experiment to be 43 bases upstream from the translation initiation ATG codon. The message encodes a polypeptide of 966 amino acid residues, of which 50 residues constitute an N-terminal extended peptide and 916 residues make up the mature protein. In the mature protein region, the nucleotide sequence is consistent with the chemically determined amino acid sequence (Nakano, K. & Fukui, T. (1986) J. Biol. Chem. 261, 8230-8236). The N-terminal extension bears characteristic features of the transit peptides of nuclear-encoded chloroplastic proteins, and is therefore regarded as a transit peptide for the amyloplast. This peptide is rich in basic amino acids (5 arginines, 3 lysines, and 5 histidines) and hydroxylic amino acids (7 serines and 5 threonines), but lacks acidic amino acids. It is therefore classified as one of the most basic transit peptides so far reported. PMID:2481677

Nakano, K; Mori, H; Fukui, T

1989-10-01

13

High molecular weight glucan of the culinary medicinal mushroom Agaricus bisporus is an alpha-glucan that forms complexes with low molecular weight galactan.  

PubMed

An alpha-glucan was isolated from the culinary medicinal mushroom A. bisporus by hot water extraction, ethanol precipitation and DEAE-cellulose chromatography. The resulting material showed a single HMW peak excluded from a Sephadex G50 column that could completely be degraded by alpha-amylase treatment. After heating in 1% SDS a small additional peak of low MW eluted from the G50 column. The monosaccharide composition of the main peak was evaluated by HPLC, and was found to consist of a majority of glucose (97.6%), and a minor proportion of galactose (2.4%). Methylation analysis and degradation by alpha-amylase indicated the presence of an alpha-glucan with a main chain consisting of (1(R)4)-linked units, substituted at O-6 by alpha-D-glucopyranose single-units in the relation 1:8. Mono- (13C-, 1H-NMR) and bidimensional [1H (obs.),13C-HSQC] spectroscopy analysis confirmed the alpha-configuration of the Glcp residues by low frequency resonances of C-1 at delta 100.6, 100.2, and 98.8 ppm and H-1 high field ones at delta 5.06, 5.11, and 4.74 ppm. The DEPT-13C-NMR allowed assigning the non-substituted and O-substituted -CH(2) signals at delta 60.3/60.8 and 66.2 ppm, respectively. Other assignments were attributed to C-2, C-3, C-4, C-5 and C-6 of the non-reducing ends at delta 71.8; 72.8; 70.0; 71.3 and 60.3/60.8 ppm, respectively. The minor proportion of galactose that was demonstrated was probably derived from a complex between the alpha-glucan and a low molecular weight galactan. PMID:20736909

Smiderle, Fhernanda R; Sassaki, Guilherme L; van Arkel, Jeroen; Iacomini, Marcello; Wichers, Harry J; Van Griensven, Leo J L D

2010-08-25

14

Catalytic activity of the nucleic acid component of the 1,4-alpha-glucan branching enzyme from rabbit muscles.  

PubMed Central

2.5 S RNA, the nucleic acid component of the 1,4-alpha-D-glucan: 1,4-alpha-D-glucan 6-alpha-(1,4-alpha-glucano)-transferase from rabbit muscles, devoid of any protein, catalyses the branching reaction, as does the holoenzyme. The conclusion is drawn that 2.5 S RNA is a ribozyme. To get an insight into the significance of different parts of the molecule for the catalytic activity of 2.5 S RNA, a large fragment isolated from its partial RNAase A digest was investigated. This fragment which proved to be the middle part of polyribonucleotide chain containing all modified nucleotides exerts some catalytic activity, too.

Shvedova, T A; Korneeva, G A; Otroshchenko, V A; Venkstern, T V

1987-01-01

15

An extra-plastidial alpha-glucan, water dikinase from Arabidopsis phosphorylates amylopectin in vitro and is not necessary for transient starch degradation.  

PubMed

Starch phosphorylation catalysed by the alpha-glucan, water dikinases (GWD) has profound effects on starch degradation in plants. The Arabidopsis thaliana genome encodes three isoforms of GWD, two of which are localized in the chloroplast and are involved in the degradation of transient starch. The third isoform, termed AtGWD2 (At4g24450), was heterologously expressed and purified and shown to have a substrate preference similar to potato GWD. Analyses of AtGWD2 null mutants did not reveal any differences in growth or starch and sugar levels, when compared to the wild type. Subcellular localization studies in Arabidopsis leaves and in vitro chloroplast import assays indicated that AtGWD2 was not targeted to the chloroplasts. The AtGWD2 promoter showed a highly restricted pattern of activity, both spatially and temporally. High activity was observed in the companion cells of the phloem, with expression appearing just before the onset of senescence. Taken together, these data indicate that, although AtGWD2 is capable of phosphorylating alpha-glucans in vitro, it is not directly involved in transient starch degradation. PMID:18024995

Glaring, Mikkel A; Zygadlo, Agnieszka; Thorneycroft, David; Schulz, Alexander; Smith, Steven M; Blennow, Andreas; Baunsgaard, Lone

2007-11-17

16

A novel type carbohydrate-binding module identified in alpha-glucan, water dikinases is specific for regulated plastidial starch metabolism.  

PubMed

The phosphorylation of the amylopectin fraction of starch catalyzed by the alpha-glucan, water dikinase (GWD, EC 2.7.9.4) plays a pivotal role in starch metabolism. Limited proteolysis of the potato tuber (Solanum tuberosum) GWD (StGWD, 155 kDa) by trypsin primarily produced stable fragments of 33 and 122 kDa, termed the SBD fragment and N11, respectively, as generated by trypsin cleavage at Arg-286. SBD and N11 were generated using recombinant DNA technology and purified to near homogeneity. Tandem repeat sequences, SBD-1 and SBD-2, of a region that is significantly similar in sequence to N-terminal regions of plastidial alpha-amylases are located in the N-terminus of StGWD. The SBD-1 motif is located within the sequence of the SBD fragment, and our results demonstrate that the fragment composes a new and novel carbohydrate-binding module (CBM), apparently specific for plastidial alpha-glucan degradation. By mutational analyses of conserved Trp residues located within the SBD-1 motif, W62 and W117, we show that these aromatic residues are vital for carbohydrate binding. N11 still possessed starch phosphorylating activity, but with a 2-fold higher specific activity compared to that of wild type (WT) StGWD using potato starch as the glucan substrate, whereas it had double the K(m) value for the same substrate. Furthermore, investigation of the chains phosphorylated by WT StGWD and N11 shows that N11 exhibits a higher preference for phosphorylating shorter chains of the amylopectin molecule as compared to WT. From analyses of the glucan substrate specificity, we found up to 5-fold higher specific activity for N11 using amylose as the substrate. PMID:16584202

Mikkelsen, René; Suszkiewicz, Ken; Blennow, Andreas

2006-04-11

17

Cell wall-associated alpha-glucan is instrumental for Mycobacterium tuberculosis to block CD1 molecule expression and disable the function of dendritic cell derived from infected monocyte.  

PubMed

We previously described an escape mechanism exploited by Mycobacterium tuberculosis (Mtb) to prevent the generation of fully competent dendritic cells (DC). We have now tested the effect of isolated mycobacterial components on human monocyte differentiation into DC and demonstrated that cell wall (CW)-associated alpha-glucan induces monocytes to differentiate into DC (Glu-MoDC) with the same altered phenotype and functional behaviour of DC derived from Mtb-infected monocytes (Mt-MoDC). In fact, Glu-MoDC lack CD1 molecule expression, fail to upregulate CD80 and produce IL-10 but not IL-12. We also showed that Glu-MoDC are not able to prime effector T cells or present lipid antigens to CD1-restricted T-cell clones. Thus, we propose a mechanism of Mtb-monocyte interaction mediated by CW-associated alpha-glucan, which allows the bacterium to evade both innate and acquired immune responses. PMID:17441985

Gagliardi, Maria Cristina; Lemassu, Anne; Teloni, Raffaela; Mariotti, Sabrina; Sargentini, Valeria; Pardini, Manuela; Daffé, Mamadou; Nisini, Roberto

2007-04-17

18

A novel isoform of glucan, water dikinase phosphorylates pre-phosphorylated alpha-glucans and is involved in starch degradation in Arabidopsis.  

PubMed

An Arabidopsis thaliana gene encoding a homologue of the potato alpha-glucan, water dikinase GWD, previously known as R1, was identified by screening the Arabidopsis genome and named AtGWD3. The AtGWD3 cDNA was isolated, heterologously expressed and the protein was purified to apparent homogeneity to determine the enzymatic function. In contrast to the potato GWD protein, the AtGWD3 primarily catalysed phosphorylation at the C-3 position of the glucose unit of preferably pre-phosphorylated amylopectin substrate with long side chains. An Arabidopsis mutant, termed Atgwd3, with downregulated expression of the AtGWD3 gene was analysed. In Atgwd3 the amount of leaf starch was constantly higher than wild type during the diurnal cycle. Compared with wild-type leaf starch, the level of C-3 phosphorylation of the glucosyl moiety of starch in this mutant was reduced. Taken together, these data indicate that the C-3 linked phospho-ester in starch plays a so far unnoticed specific role in the degradation of transitory starch. PMID:15686522

Baunsgaard, Lone; Lütken, Henrik; Mikkelsen, René; Glaring, Mikkel A; Pham, Tam T; Blennow, Andreas

2005-02-01

19

The primitive rhodophyte Cyanidioschyzon merolae contains a semiamylopectin-type, but not an amylose-type, alpha-glucan.  

PubMed

The storage glucans of Cyanidioschyzon merolae [clade L-1 (cyanidian algae), order Porphyridiales, subclass Bangiophycidae], which is considered to be one of the most primitive rhodophytes, were analyzed to understand the early evolution of the glucan structure in the Rhodophyta. Chain-length distribution analysis of the glucans of cyanidian algae demonstrated that while the glucans of Cyanidium caldarium and Galdieria sulphuraria are of the glycogen type, those of C. merolae are of the semiamylopectin type, as in other lineages of the Rhodophyta. Gel permeation chromatography, however, showed that the glucans of C. merolae do not include amylose, being different from those of other Bangiophycidae species. Identification by MALDI-TOF-MS and enzyme assaying of glucan granule-bound proteins indicated that phosphorylase, but not starch synthase, is included. Thus, C. merolae has an unusual glucan and bound-protein composition for the Bangiophycidae, appearing to be a member of the Florideophycidae. The finding that the alga does not contain amylose or the related enzyme, granule-bound starch synthase, is, however, consistent with previously reported results of molecular phylogenetic analysis of starch synthases. Our results support an evolutionary scenario defined by the loss of starch and reversion to glycogen synthesis during the evolution of cyanidian algae, and suggest the possibility that a C. merolae-like primitive rhodophyte might have evolved into the Florideophycidae. PMID:20385610

Hirabaru, Chika; Izumo, Asako; Fujiwara, Shoko; Tadokoro, Yukie; Shimonaga, Takahiro; Konishi, Mai; Yoshida, Mayumi; Fujita, Naoko; Nakamura, Yasunori; Yoshida, Masaki; Kuroiwa, Tsuneyoshi; Tsuzuki, Mikio

2010-04-12

20

Functional Characterization of a Newly Identified Group B Streptococcus Pullulanase Eliciting Antibodies Able to Prevent Alpha-Glucans Degradation  

PubMed Central

Streptococcal pullulanases have been recently proposed as key components of the metabolic machinery involved in bacterial adaptation to host niches. By sequence analysis of the Group B Streptococcus (GBS) genome we found a novel putative surface exposed protein with pullulanase activity. We named such a protein SAP. The sap gene is highly conserved among GBS strains and homologous genes, such as PulA and SpuA, have been described in other pathogenic streptococci. The SAP protein contains two N-terminal carbohydrate-binding motifs, followed by a catalytic domain and a C-terminal LPXTG cell wall-anchoring domain. In vitro analysis revealed that the recombinant form of SAP is able to degrade ?-glucan polysaccharides, such as pullulan, glycogen and starch. Moreover, NMR analysis showed that SAP acts as a type I pullulanase. Studies performed on whole bacteria indicated that the presence of ?-glucan polysaccharides in culture medium up-regulated the expression of SAP on bacterial surface as confirmed by FACS analysis and confocal imaging. Deletion of the sap gene resulted in a reduced capacity of bacteria to grow in medium containing pullulan or glycogen, but not glucose or maltose, confirming the pivotal role of SAP in GBS metabolism of ?-glucans. As reported for other streptococcal pullulanases, we found specific anti-SAP antibodies in human sera from healthy volunteers. Investigation of the functional role of anti-SAP antibodies revealed that incubation of GBS in the presence of sera from animals immunized with SAP reduced the capacity of the bacterium to degrade pullulan. Of interest, anti-SAP sera, although to a lower extent, also inhibited Group A Streptococcus pullulanase activity. These data open new perspectives on the possibility to use SAP as a potential vaccine component inducing functional cross-reacting antibodies interfering with streptococcal infections.

Bosello, Mattia; Berti, Francesco; Mariani, Massimo; Telford, John L.; Grandi, Guido; Soriani, Marco

2008-01-01

21

Klotho: a novel phosphaturic substance acting as an autocrine enzyme in the renal proximal tubule  

PubMed Central

Klotho has profound effects on phosphate metabolism, but the mechanisms of how Klotho affects phosphate homeostasis is unknown. We detected Klotho in the proximal tubule cell, brush border, and urinary lumen, where phosphate homeostasis resides. Increasing Klotho in the kidney and urine chronically by transgenic overexpression or acutely by intravenous infusion caused hypophosphatemia, phosphaturia from decreased proximal phosphate reabsorption, and decreased activity and protein of the principal renal phosphate transporter NaPi-2a. The phosphaturic effect was present in FGF23-null mice, indicating a direct action distinct from Klotho’s known role as a coreceptor for FGF23. Direct inhibition of NaPi-2a by Klotho was confirmed in cultured cells and in cell-free membrane vesicles characterized by acute inhibition of transport activity followed by decreased cell surface protein. Transport inhibition can be mimicked by recombinant ?-glucuronidase and is associated with proteolytic degradation and reduced surface NaPi-2a. The inhibitory effect of Klotho on NaPi-2a was blocked by ?-glucuronidase inhibitor but not by protease inhibitor. Klotho is a novel phosphaturic substance that acts as an enzyme in the proximal tubule urinary lumen by modifying glycans, which cause decreased transporter activity, followed by proteolytic degradation and possibly internalization of NaPi-2a from the apical membrane.—Hu, M. C., Shi, M., Zhang, J., Pastor, J., Nakatani, T., Lanske, B., Shawkat Razzaque, M., Rosenblatt, K. P., Baum, M. G., Kuro-o, M., Moe, O. W. Klotho: a novel phosphaturic substance acting as an autocrine enzyme in the renal proximal tubule.

Hu, Ming Chang; Shi, Mingjun; Zhang, Jianning; Pastor, Johanne; Nakatani, Teruyo; Lanske, Beate; Razzaque, M. Shawkat; Rosenblatt, Kevin P.; Baum, Michel G.; Kuro-o, Makoto; Moe, Orson W.

2010-01-01

22

A new class of enzyme acting on damaged ribosomes: ribosomal RNA apurinic site specific lyase found in wheat germ.  

PubMed

A new enzyme, which we named ribosomal RNA apurinic site specific lyase (RALyase), is described. The protein was found in wheat embryos and has a molecular weight of 50 625 Da. The enzyme specifically cleaves the phosphodiester bond at the 3' side of the apurinic site introduced by ribosome-inactivating proteins into the sarcin/ricin domain of 28S rRNA. The 3' and 5' ends of wheat 28S rRNA at the cleavage site are 5'-GUACG-alpha-hydroxy-alpha, beta-unsaturated aldehyde and pGAGGA-3', demonstrating that the enzyme catalyzes a beta-elimination reaction. The substrate specificity of the enzyme is extremely high: it acts only at the apurinic site in the sarcin/ricin domain of intact ribosomes, not on deproteinized rRNA or DNA containing apurinic sites. The amino acid sequences of five endopeptidase LysC-liberated peptides from the purified enzyme were determined and used to obtain a cDNA sequence. The open reading frame encodes a protein of 456 amino acids, and a homology search revealed a related rice protein. Similar enzyme activities were also found in other plants that express ribosome-inactivating proteins. We believe that RALyase is part of a complex self-defense mechanism. PMID:10562564

Ogasawara, T; Sawasaki, T; Morishita, R; Ozawa, A; Madin, K; Endo, Y

1999-11-15

23

Peculiarities and applications of galactanolytic enzymes that act on type I and II arabinogalactans.  

PubMed

Arabinogalactans (AGs) are branched galactans to which arabinose residues are bound as side chains and are widely distributed in plant cell walls. They can be grouped into two types based on the structures of their backbones. Type I AGs have ?-1,4-galactan backbones and are often covalently linked to the rhamnogalacturonan-I region of pectins. Type II AGs have ?-1,3-galactan backbones and are often covalently linked to proteins. The main enzymes involved in the degradation of AGs are endo-?-galactanases, exo-?-galactanases, and ?-galactosidases, although other enzymes such as ?-L-arabinofuranosidases, ?-L-arabinopyranosidases, and ?-D-glucuronidases are required to remove the side chains for efficient degradation of the polysaccharides. Galactanolytic enzymes have a wide variety of potential uses, including the bioconversion of AGs to fermentable sugars for production of commodity chemicals like ethanol, biobleaching of cellulose pulp, modulation of pectin properties, improving animal feed, and determining the chemical structure of AGs. This review summarizes our current knowledge about the biochemical properties and potential applications of AG-degrading enzymes. PMID:23666442

Sakamoto, Tatsuji; Ishimaru, Megumi

2013-05-11

24

The effect of substrate partitioning on the kinetics of enzymes acting in reverse micelles.  

PubMed Central

A theoretical model for the expression of enzymic activity in reverse micelles previously developed [Bru. Sánchez-Ferrer & García-Carmona (1989) Biochem. J. 259, 355-361] was extended in the present work. The substrate concentration in each reverse-micelle phase (free water, bound water and surfactant apolar tails) and the organic solvent was expressed as a function of the total substrate concentration, taking into account its partition coefficients, that is, partitioning of the substrate in a multiphasic system. In each phase the enzyme expresses a catalytic constant and a Km. Thus the whole reaction rate is the addition of the particular rates expressed in each domain. This model was compared with that developed for a biphasic system [Levashov, Klyachko, Pantin, Khmelnitski & Martinek (1980) Bioorg. Khim. 6, 929-943] by fitting the experimental results obtained with mushroom tyrosinase (working on both 4-t-butylcatechol and 4-methylcatechol) to the two models. The parameters which characterize reverse micelles, omega 0 (water/surfactant molar ratio) and theta (fraction of water) were investigated. The omega 0 profile was shown to be hyperbolic for both substrates. Activity towards 4-t-butylcatechol decreases as theta increases, this observation being attributable to a dilution of the substrate. A Km of 7.8 M for 4-t-butylcatechol could be calculated on the basis of the biphasic model, whereas it was 13.5 mM when calculating on the basis of our model. A new parameter, rho (= [substrate]/theta), was defined to characterize those substrates that mainly solubilize in the reverse micelle ('micellar substrates').

Bru, R; Sanchez-Ferrer, A; Garcia-Carmona, F

1990-01-01

25

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

PubMed

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

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

2012-07-23

26

A Natural Vanishing Act: The Enzyme-Catalyzed Degradation of Carbon Nanomaterials  

PubMed Central

CONSPECTUS 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/biodegradation. Finally, we outline potential future directions that could enhance our mechanistic understanding of the CNM oxidation/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/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 material 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.

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

2012-01-01

27

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

PubMed

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

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

2012-12-06

28

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

PubMed

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

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

2011-03-07

29

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

PubMed Central

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.

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

30

Remote control of DNA-acting enzymes by varying the Brownian dynamics of a distant DNA end  

PubMed Central

Enzyme rates are usually considered to be dependent on local properties of the molecules involved in reactions. However, for large molecules, distant constraints might affect reaction rates by affecting dynamics leading to transition states. In single-molecule experiments we have found that enzymes that relax DNA torsional stress display rates that depend strongly on how the distant ends of the molecule are constrained; experiments with different-sized particles tethered to the end of 10-kb DNAs reveal enzyme rates inversely correlated with particle drag coefficients. This effect can be understood in terms of the coupling between molecule extension and local molecular stresses: The rate of bead thermal motion controls the rate at which transition states are visited in the middle of a long DNA. Importantly, we have also observed this effect for reactions on unsupercoiled DNA; other enzymes show rates unaffected by bead size. Our results reveal a unique mechanism through which enzyme rates can be controlled by constraints on macromolecular or supramolecular substrates.

Bai, Hua; Kath, James E.; Zorgiebel, Felix Manuel; Sun, Mingxuan; Ghosh, Pallavi; Hatfull, Graham F.; Grindley, Nigel D. F.; Marko, John F.

2012-01-01

31

Members 5 and 6 of the Candida albicans BMT family encode enzymes acting specifically on ?-mannosylation of the phospholipomannan cell-wall glycosphingolipid.  

PubMed

A family of nine genes encoding proteins involved in the synthesis of ?-1,2 mannose adhesins of Candida albicans has been identified. Four of these genes, BMT1-4, encode enzymes acting stepwise to add ?-mannoses on to cell-wall phosphopeptidomannan (PPM). None of these acts on phospholipomannan (PLM), a glycosphingolipid member of the mannose-inositol-phosphoceramide family, which contributes with PPM to ?-mannose surface expression. We show that deletion of BMT5 and BMT6 led to a dramatic reduction of PLM glycosylation and accumulation of PLM with a truncated ?-oligomannoside chain, respectively. Disruptions had no effect on sphingolipid biosynthesis and on PPM ?-mannosylation. ?-Mannose surface expression was not affected, confirming that ?-mannosylation is a process based on specificity of acceptor molecules, but liable to global regulation. PMID:22745283

Mille, Céline; Fradin, Chantal; Delplace, Florence; Trinel, Pierre-André; Masset, Annick; François, Nadine; Coddeville, Bernadette; Bobrowicz, Piotr; Jouault, Thierry; Guerardel, Yann; Wildt, Stefan; Janbon, Guilhem; Poulain, Daniel

2012-06-27

32

Regulation of the tissue specificity of an enzyme by a cis-acting genetic element: evidence from interspecific Drosophila hybrids.  

PubMed Central

Homologous genes for alcohol dehydrogenase (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) are expressed in qualitatively different patterns during the development of two closely related species of Hawaiian Drosophila. In interspecific hybrids, each parental structural allele is expressed according to the developmental program characteristic of the species from which it is derived. This provides strong evidence for a cis acting control element. Images

Dickinson, W J; Carson, H L

1979-01-01

33

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

SciTech Connect

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.

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

2008-01-01

34

The catalytic scaffold of the haloalkanoic acid dehalogenase enzyme superfamily acts as a mold for the trigonal bipyramidal transition state  

PubMed Central

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 ? 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 ? 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 ? 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 ? 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.

Lu, Zhibing; Dunaway-Mariano, Debra; Allen, Karen N.

2008-01-01

35

Ni(2+), a double-acting inhibitor of neuronal nitric oxide synthase interfering with L-arginine binding and Ca(2+)/calmodulin-dependent enzyme activation.  

PubMed

Ni(2+), a toxic and carcinogenic pollutant and one of the leading causes of contact dermatitis, is shown to inhibit neuronal nitric oxide synthase (nNOS) in a competitive, reversible manner with respect to the substrate l-arginine (K(i) = 30 +/- 4 microM). The IC(50) values were dependent on calmodulin (CaM) concentration, but proved independent of Ca(2+), tetrahydrobiopterin (BH(4)) and other essential cofactors. Ni(2+) also inhibited CaM-dependent cytochrome c reduction, NADPH oxidation, and H(2)O(2) production by nNOS. Overall, the action profile of Ni(2+) was suggestive of an unusual, double-acting inhibitor of nNOS affecting l-arginine-binding and Ca(2+)/CaM-dependent enzyme activation. PMID:11437384

Palumbo, A; Astarita, G; Picardo, M; d'Ischia, M

2001-07-01

36

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

PubMed Central

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.

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

2013-01-01

37

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

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

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

2004-01-01

38

Peroxisomal multifunctional enzyme type 2 from the fruitfly: dehydrogenase and hydratase act as separate entities, as revealed by structure and kinetics.  

PubMed

All of the peroxisomal ?-oxidation pathways characterized thus far house at least one MFE (multifunctional enzyme) catalysing two out of four reactions of the spiral. MFE type 2 proteins from various species display great variation in domain composition and predicted substrate preference. The gene CG3415 encodes for Drosophila melanogaster MFE-2 (DmMFE-2), complements the Saccharomyces cerevisiae MFE-2 deletion strain, and the recombinant protein displays both MFE-2 enzymatic activities in vitro. The resolved crystal structure is the first one for a full-length MFE-2 revealing the assembly of domains, and the data can also be transferred to structure-function studies for other MFE-2 proteins. The structure explains the necessity of dimerization. The lack of substrate channelling is proposed based on both the structural features, as well as by the fact that hydration and dehydrogenation activities of MFE-2, if produced as separate enzymes, are equally efficient in catalysis as the full-length MFE-2. PMID:21320074

Haataja, Tatu J K; Koski, M Kristian; Hiltunen, J Kalervo; Glumoff, Tuomo

2011-05-01

39

Arabidopsis COP10 is a ubiquitin-conjugating enzyme variant that acts together with COP1 and the COP9 signalosome in repressing photomorphogenesis  

PubMed Central

A group of evolutionarily conserved pleiotropic COP/DET/FUS proteins was initially defined by their ability to repress photomorphogenesis in Arabidopsis. It was proposed that this regulation be mediated by targeting degradation of key cellular regulators that promote photomorphogenesis. Among them, COP1 and the COP9 signalosome have been hypothesized to fulfill the roles as an ubiquitin ligase (E3) and an essential E3 modulator. Here we report that COP10 encodes a protein similar to ubiquitin-conjugating enzyme (E2) variant proteins (UEV). COP10 is part of a nuclear protein complex and capable of directly interacting with both COP1 and the COP9 signalosome. Our data indicates that COP10 defines a possible E2 activity, thus validating the working hypothesis that the pleiotropic COP/DET/FUS group of proteins defined a protein ubiquitination pathway.

Suzuki, Genki; Yanagawa, Yuki; Kwok, Shing F.; Matsui, Minami; Deng, Xing-Wang

2002-01-01

40

A fluorescence high-performance liquid chromatography assay for enzymes acting on the di-N-acetylchitobiosyl part of asparagine-linked glycans.  

PubMed

The glycoasparagine, Man7GlcNAc2Asn ('Man7') was labelled with resorufin and used as a specific substrate for the detection and quantification of endo-beta-N-acetyl glucosaminidases (Endos) acting on the di-N-acetylchitobiosyl part of asparagine-linked glycans. Peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidases (PNGases) cannot transform this substrate but they can be detected by the procedure described earlier using the resorufin-labelled N-glycopeptide [Glycoconjugate J., 9 (1992) 162-167]. These two substrates can be used in a simple, reproducible and very sensitive fluorescence HPLC assay in order to monitor Endo and PNGase activities during isolation and purification processes, or studies of the evolution of such activities during cultivation of the producing cells. PMID:7963249

Bourgerie, S; Berger, S; Strecker, G; Julien, R; Karamanos, Y

1994-06-01

41

Identification of cis-Acting Elements Important for Expression of the Starch-Branching Enzyme I Gene in Maize Endosperm1  

PubMed Central

The genes encoding the starch-branching enzymes (SBE) SBEI, SBEIIa, and SBEIIb in maize (Zea mays) are differentially regulated in tissue specificity and during kernel development. To gain insight into the regulatory mechanisms controlling their expression, we analyzed the 5?-flanking sequences of Sbe1 using a transient gene expression system. Although the 2.2-kb 5?-flanking sequence between ?2,190 and +27 relative to the transcription initiation site was sufficient to promote transcription, the addition of the transcribed region between +28 and +228 containing the first exon and intron resulted in high-level expression in suspension-cultured maize endosperm cells. A series of 5? deletion and linker-substitution mutants identified two critical positive cis elements, ?314 to ?295 and ?284 to ?255. An electrophoretic mobility-shift assay showed that nuclear proteins prepared from maize kernels interact with the 60-bp fragment containing these two elements. Expression of the Sbe1 gene is regulated by sugar concentration in suspension-cultured maize endosperm cells, and the region ?314 to ?145 is essential for this effect. Interestingly, the expression of mEmBP-1, a bZIP transcription activator, in suspension-cultured maize endosperm cells resulted in a 5-fold decrease in Sbe1 promoter activity, suggesting a possible regulatory role of the G-box present in the Sbe1 promoter from ?227 to ?220.

Kim, Kyung-Nam; Guiltinan, Mark J.

1999-01-01

42

Catalyzed enzyme electrodes  

SciTech Connect

An enzyme electrode is prepared with a composite coating on an electrical conductor. The composite coating is formed from a casting solution of a perfluorosulfonic acid polymer, an enzyme, and a carbon supported catalyst. The solution may be cast directly on the conductor surface or may be formed as a membrane and applied to the surface. The perfluorosulfonic acid ionomer formed from the casting solution provides an insoluble biocompatible protective matrix for the enzyme and acts to retain the enzyme for long term availability in the electrode structure. The carbon supported catalyst provides catalytic sites throughout the layer for the oxidation of hydrogen peroxide from the enzyme reactions. The carbon support then provides a conductive path for establishing an electrical signal to the electrical conductor. In one embodiment, the electrical conductor is a carbon cloth that permits oxygen or other gas to be introduced to the perfluorosulfonic polymer to promote the enzyme reaction independent of oxygen in the solution being tested.

Zawodzinski, T.A.; Wilson, M.S.; Rishpon, J.; Gottesfeld, S.

1993-07-13

43

Catalyzed enzyme electrodes  

DOEpatents

An enzyme electrode is prepared with a composite coating on an electrical conductor. The composite coating is formed from a casting solution of a perfluorosulfonic acid polymer, an enzyme, and a carbon supported catalyst. The solution may be cast directly on the conductor surface or may be formed as a membrane and applied to the surface. The perfluorosulfonic acid ionomer formed from the casting solution provides an insoluble biocompatible protective matrix for the enzyme and acts to retain the enzyme for long term availability in the electrode structure. The carbon supported catalyst provides catalytic sites throughout the layer for the oxidation of hydrogen peroxide from the enzyme reactions. The carbon support then provides a conductive path for establishing an electrical signal to the electrical conductor. In one embodiment, the electrical conductor is a carbon cloth that permits oxygen or other gas to be introduced to the perfluorosulfonic polymer to promote the enzyme reaction independent of oxygen in the solution being tested.

Zawodzinski, Thomas A. (Los Alamos, NM); Wilson, Mahlon S. (Los Alamos, NM); Rishpon, Judith (Ramat-Aviv, IL); Gottesfeld, Shimshon (Los Alamos, NM)

1993-01-01

44

Catalyzed enzyme electrodes  

DOEpatents

An enzyme electrode is prepared with a composite coating on an electrical conductor. The composite coating is formed from a casting solution of a perfluorosulfonic acid, polymer, an enzyme, and a carbon supported catalyst. The solution may be cast directly on the conductor surface or may be formed as a membrane and applied to the surface. The perfluorosulfonic acid ionomer formed from the casting solution provides an insoluble biocompatible protective matrix for the enzyme and acts to retain the enzyme for long term availability in the electrode structure. The carbon supported catalyst provides catalytic sites throughout the layer for the oxidation of hydrogen peroxide from the enzyme reactions. The carbon support then provides a conductive path for establishing an electrical signal to the electrical conductor. In one embodiment, the electrical conductor is a carbon cloth that permits oxygen or other gas to be introduced to the perfluorosulfonic polymer to promote the enzyme reaction independent of oxygen in the solution being tested.

Zawodzinski, T.A.; Wilson, M.S.; Rishpon, J.; Gottesfeld, S.

1992-12-31

45

Testing and characterizing enzymes and membrane-bound carrier proteins acting on amphipathic ligands in the presence of bilayer membrane material and soluble binding protein. Application to the uptake of oleate into isolated cells.  

PubMed

1. A multiphasic modelling approach [Heirwegh, Meuwissen, Vermeir & De Smedt (1988) Biochem. J. 254, 101-108] is applied to systems containing poorly water-soluble amphipathic reactants, membrane material, soluble binding protein and acceptor protein (enzyme or membrane-bound carrier protein). 2. The field of application is constrained by the assumptions (i) that the amount of acceptor-bound substrate is small compared with the total amount and (ii) that all preceding chemical reactions and steps of mass transport are rapid compared with the chemical change monitored. 3. Initial-rate formulae for systems in which an acceptor interacts with unbound or protein-bound ligand are given. The saturation curves are near-hyperbolic or sigmoidal, depending both (i) on the form of ligand (unbound or protein-bound) acted upon by the acceptor and (ii) on whether the assays are performed at constant concentration of soluble binding protein Cp or at constant substrate/binding-site molar ratio RS. 4. Several diagnostic features permit unequivocal distinction between acceptor action on unbound or protein-bound substrate. In the former case, saturation curves, run at the same constant concentration of one of several binding proteins of increasing binding affinity, will show progressively increasing inhibition, the shape changing from near-hyperbolic at Km' less than K1' to sigmoidal at Km' greater than K1'.Km' is the effective Michaelis constant of the acceptor and K1' the effective dissociation constant of the binding sites of the soluble protein (for the sites with the higher binding affinity, if several classes of binding site are present on the protein). Alternatively, the maximum velocity obtained at constant RS less than or equal to 1 should increase hyperbolically with RS/(1-RS) for a binding protein with a single class of binding site. The formula that applies when the binding protein contains two classes of independent binding site is also available. When the acceptor acts on protein-bound ligand, the maximum velocity obtained at constant binding-protein concentration, Cp, increases hyperbolically with Cp. 5. Application of these and additional criteria to initial-rate data on the uptake of oleate into isolated cells supports a mechanism of carrier-mediated uptake of the unbound ligand and allows one to clarify some observations that hitherto had been poorly explained. 6. The influence of soluble binding protein on the reaction and substrate specificities of ligand/acceptor interaction is also discussed. 7. In its present state, data treatment for 'double binding-protein systems' generally requires separate determination of the binding parameters of the soluble binding protein.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1599418

Heirwegh, K P; Meuwissen, J A

1992-06-01

46

Juggling Act  

ERIC Educational Resources Information Center

|Two education bills from George W. Bush's first term are long overdue for reauthorization. One, of course, is the No Child Left Behind Act (NCLB), passed in late 2001. The other is the Education Sciences Reform Act (ESRA), which in November 2002 replaced the Office of Educational Research and Improvement (OERI) with a new Institute of Education…

Rudalevige, Andrew

2009-01-01

47

Juggling Act  

ERIC Educational Resources Information Center

Two education bills from George W. Bush's first term are long overdue for reauthorization. One, of course, is the No Child Left Behind Act (NCLB), passed in late 2001. The other is the Education Sciences Reform Act (ESRA), which in November 2002 replaced the Office of Educational Research and Improvement (OERI) with a new Institute of Education…

Rudalevige, Andrew

2009-01-01

48

Acting Atoms.  

ERIC Educational Resources Information Center

|Describes a fun game in which students act as electrons, protons, and neutrons. This activity is designed to help students develop a concrete understanding of the abstract concept of atomic structure. (DKM)|

Farin, Susan Archie

1997-01-01

49

Modernization Act  

Center for Biologics Evaluation and Research (CBER)

... Procedural; Modernization Act, PET Drug Applications - Content and Format for NDAs and ANDAs_2011 (PDF - 429KB), Final Guidance, 08/31/11. ... More results from www.fda.gov/drugs/guidancecomplianceregulatoryinformation/guidances

50

Enzyme Reactors  

Microsoft Academic Search

More than 80% of the commercial value of enzymes is linked to their applications as process catalysts. Hydrolytic reactions\\u000a conducted mainly with the enzyme dissolved in the aqueous medium has been the traditional way of using enzymes, this technology\\u000a still representing a major share of enzyme processes. However, in recent decades the use of enzymes in organic synthesis has\\u000a widened

Andrés Illanes; Claudia Altamirano

51

DNA adenine methyltransferase (Dam) controls the expression of the cytotoxic enterotoxin (act) gene of Aeromonas hydrophila via tRNA modifying enzyme-glucose-inhibited division protein (GidA)  

PubMed Central

Aeromonas hydrophila is both a human and animal pathogen, and the cytotoxic enterotoxin (Act) is a crucial virulence factor of this bacterium because of its associated hemolytic, cytotoxic, and enterotoxic activities. Previously, to define the role of some regulatory genes in modulating Act production, we showed that deletion of a glucose-inhibited division gene (gidA) encoding tRNA methylase reduced Act levels, while overproduction of DNA adenine methyltransferase (Dam) led to a concomitant increase in Act-associated biological activities of a diarrheal isolate SSU of A. hydrophila. Importantly, there are multiple GATC binding sites for Dam within an upstream sequence of the gidA gene and one such target site in the act gene upstream region. We showed the dam gene to be essential for the viability of A. hydrophila SSU, and, therefore, to better understand the interaction of the encoding genes, Dam and GidA, in act gene regulation, we constructed a gidA in-frame deletion mutant of Escherichia coli GM28 (dam+) and GM33 (?dam) strains. We then tested the expressional activity of the act and gidA genes by using a promoterless pGlow-TOPO vector containing a reporter green fluorescent protein (GFP). Our data indicated that in GidA+ strains of E. coli, constitutive methylation of the GATC site(s) by Dam negatively regulated act and gidA gene expression as measured by GFP production. However, in the ?gidA strains, irrespective of the presence or absence of constitutively active Dam, we did not observe any alteration in the expression of the act gene signifying the role of GidA in positively regulating Act production. To determine the exact mechanism of how Dam and GidA influence Act, a real-time quantitative PCR (RT-qPCR) assay was performed. The analysis indicated an increase in gidA and act gene expression in the A. hydrophila Dam-overproducing strain, and these data matched with Act production in the E. coli GM28 strain. Thus, the extent of DNA methylation caused by constitutive versus overproduction of Dam, as well as possible conformation of DNA influence the expression of act and gidA genes in A. hydrophila SSU. Our results indicate that the act gene is under the control of both Dam and GidA modification methylases, and Dam regulates Act production via GidA.

Erova, Tatiana E.; Kosykh, Valeri G.; Sha, Jian; Chopra, Ashok K.

2013-01-01

52

The kinetics of enzyme inactivation  

Microsoft Academic Search

The course of hydrolysis of ?-glycerophosphate catalyzed by a group of different enzyme extracts, both with and without the\\u000a addition of Mg, with and without preincubation of the enzyme, has been studied and the results discussed on the basis of a\\u000a mathematical analysis. In all the extracts, it appears that two distinct and independently acting constituent enzymes—or perhaps\\u000a “principles” of

Alston S. Householder; George Gomori

1943-01-01

53

Enzyme Kinetics  

NSDL National Science Digital Library

This resrouce provides detailed protocols for performing a laboratory exercise in enzyme kinetics. The activity of enzymes are characterized both by reaction rates and the effect of different concentrations of substrates.

Carl Stiefbold (University of Oregon;); Karen Sprague (University of Oregon;); Will Goodwin (University of Oregon;); Sam Donovan (University of Oregon;); Vicki Chandler (University of Oregon;)

1998-01-01

54

Balancing Act  

ERIC Educational Resources Information Center

|For some administrators and planners, designing and building education facilities may sometimes seem like a circus act--trying to project a persona of competence and confidence while juggling dozens of issues. Meanwhile, the audience--students, staff members and taxpayers--watch and wait with anticipation in hopes of getting what they paid for…

Kennedy, Mike

2007-01-01

55

Balancing Act  

ERIC Educational Resources Information Center

For some administrators and planners, designing and building education facilities may sometimes seem like a circus act--trying to project a persona of competence and confidence while juggling dozens of issues. Meanwhile, the audience--students, staff members and taxpayers--watch and wait with anticipation in hopes of getting what they paid for and…

Kennedy, Mike

2007-01-01

56

Enzyme Kinetics.  

ERIC Educational Resources Information Center

|Conveys an appreciation of enzyme kinetic analysis by using a practical and intuitive approach. Discusses enzyme assays, kinetic models and rate laws, the kinetic constants (V, velocity, and Km, Michaels constant), evaluation of V and Km from experimental data, and enzyme inhibition. (CW)|

Moe, Owen; Cornelius, Richard

1988-01-01

57

Acting Out  

NSDL National Science Digital Library

This activity (on pages 21-32 of PDF) has learners act out several classic brain teasers. Instead of moving checkers or pennies around on a table, learners play the role of the different pieces of the puzzle, and have to move themselves around. The lesson plan includes printable pictures of different characters than can be worn by the learners. Answers to the puzzles are provided so the facilitator can guide learners towards the solution.

Omsi

2008-01-01

58

Enzyme Informatics  

PubMed Central

Over the last 50 years, sequencing, structural biology and bioinformatics have completely revolutionised biomolecular science, with millions of sequences and tens of thousands of three dimensional structures becoming available. The bioinformatics of enzymes is well served by, mostly free, online databases. BRENDA describes the chemistry, substrate specificity, kinetics, preparation and biological sources of enzymes, while KEGG is valuable for understanding enzymes and metabolic pathways. EzCatDB, SFLD and MACiE are key repositories for data on the chemical mechanisms by which enzymes operate. At the current rate of genome sequencing and manual annotation, human curation will never finish the functional annotation of the ever-expanding list of known enzymes. Hence there is an increasing need for automated annotation, though it is not yet widespread for enzyme data. In contrast, functional ontologies such as the Gene Ontology already profit from automation. Despite our growing understanding of enzyme structure and dynamics, we are only beginning to be able to design novel enzymes. One can now begin to trace the functional evolution of enzymes using phylogenetics. The ability of enzymes to perform secondary functions, albeit relatively inefficiently, gives clues as to how enzyme function evolves. Substrate promiscuity in enzymes is one example of imperfect specificity in protein-ligand interactions. Similarly, most drugs bind to more than one protein target. This may sometimes result in helpful polypharmacology as a drug modulates plural targets, but also often leads to adverse side-effects. Many cheminformatics approaches can be used to model the interactions between druglike molecules and proteins in silico. We can even use quantum chemical techniques like DFT and QM/MM to compute the structural and energetic course of enzyme catalysed chemical reaction mechanisms, including a full description of bond making and breaking.

Alderson, Rosanna G.; Ferrari, Luna De; Mavridis, Lazaros; McDonagh, James L.; Mitchell, John B. O.; Nath, Neetika

2012-01-01

59

Thermodynamic and extrathermodynamic requirements of enzyme catalysis  

Microsoft Academic Search

An enzyme's affinity for the altered substrate in the transition state (symbolized here as S‡) matches the value of kcat\\/Km divided by the rate constant for the uncatalyzed reaction in water. The validity of this relationship is not affected by the detailed mechanism by which any particular enzyme may act, or on whether changes in enzyme conformation occur on the

Richard Wolfenden

2003-01-01

60

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...

61

Modular enzymes  

Microsoft Academic Search

Although modular macromolecular devices are encountered frequently in a variety of biological situations, their occurrence in biocatalysis has not been widely appreciated. Three general classes of modular biocatalysts can be identified: enzymes in which catalysis and substrate specificity are separable, multisubstrate enzymes in which binding sites for individual substrates are modular, and multienzyme systems that can catalyse programmable metabolic pathways.

Pehr B. Harbury; Chaitan Khosla

2001-01-01

62

Understanding Enzymes.  

ERIC Educational Resources Information Center

|Describes the way enzymes operate through reaction energetics, and explains that most of the catalytic power of enzymes lies in the strong noncovalent forces responsible for initial binding of substrate, which are only manifested at the transition state of the reaction. (Author/GA)|

Sinnott, M. L.

1979-01-01

63

Enzyme Electrode.  

National Technical Information Service (NTIS)

The patent application relates to an electrochemical device, and more particularly to an improved electrode structure for amperometric analysis of substances. Amperometric electrode sensors are known which include enzymes in their structure. Such devices ...

Guilbault

1973-01-01

64

Enzyme Reactions  

NSDL National Science Digital Library

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.

School, Maryland V.

65

Enzyme Action  

NSDL National Science Digital Library

In this activity that can be used as a lab or demonstration, learners use Lactaid® and lactose to demonstrate the concept of enzyme action. Learners test a drop of milk and Lactaid® for the presence of glucose using glucose test paper. Learners also discover the color range of glucose test paper readings. In addition, learners construct paper models to help visualize enzyme action.

Crumlish, Jane

2009-01-01

66

Zinc Enzymes.  

ERIC Educational Resources Information Center

|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)|

Bertini, I.; And Others

1985-01-01

67

Food Enzymes  

ERIC Educational Resources Information Center

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…

McBroom, Rachel; Oliver-Hoyo, Maria T.

2007-01-01

68

Food Enzymes  

ERIC Educational Resources Information Center

|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…

McBroom, Rachel; Oliver-Hoyo, Maria T.

2007-01-01

69

Privacy Act: Privacy Act System Notices.  

National Technical Information Service (NTIS)

A basic premise of the Privacy Act of 1974 is that information about individuals should not be maintained in secret files. Accordingly, the Privacy Act instructs agencies to publish in the Federal Register a notice of each system of records covered by the...

1987-01-01

70

Recovery Act Milestones  

ScienceCinema

Every 100 days, the Department of Energy is held accountable for a progress report on the American Recovery and Reinvestment Act. Update at 200 days, hosted by Matt Rogers, Senior Advisor to Secretary Steven Chu for Recovery Act Implementation.

71

The Computer Misuse Act  

Microsoft Academic Search

The Computer Misuse Act 1990 (CMA) created a number of offences to address the growing incidence of unauthorised access to computer systems. This paper describes the provisions of the Act and examines the experience of the 15 years that it has been in force. The Act was based on a report from the law commission which provides good insight into

Richard Walton

2006-01-01

72

Role of Enzymes in Maintaining Soil Health  

Microsoft Academic Search

\\u000a Soil enzymes are constantly playing vital roles for the maintenance of soil ecology and soil health. These enzymatic activities\\u000a in the soil are mainly of microbial origin, being derived from intracellular, cell-associated or free enzymes. Therefore,\\u000a microorganisms are acting as the indicators of soil health, as they have active effects on nutritional cycling, also affecting\\u000a the physical and chemical properties

Shonkor Kumar Das; Ajit Varma

73

Synthesis and single enzyme activity of a clicked lipase-BSA hetero-dimer.  

PubMed

Click chemistry is used to construct a novel lipase-BSA hetero-dimer, in which the latter protein acts as a foot enabling the anchoring of the enzyme onto the surface for single enzyme studies. PMID:16767259

Hatzakis, Nikos S; Engelkamp, Hans; Velonia, Kelly; Hofkens, Johan; Christianen, Peter C M; Svendsen, Allan; Patkar, Shamkantr A; Vind, Jesper; Maan, Jan C; Rowan, Alan E; Nolte, Roeland J M

2006-02-09

74

Contact Dermatitis in Home Helps Following the Use of Enzyme Detergents  

Microsoft Academic Search

Twelve women in the home help service in Nottingham developed dermatitis after using enzyme detergents. A survey based on a questionary showed an incidence of 5% among those using them. The enzyme appears to act as a primary irritant.

Christina F. J. Ducksbury; V. K. Dave

1970-01-01

75

Network context and selection in the evolution to enzyme specificity  

PubMed Central

Enzymes are thought to have evolved highly specific catalytic activities from promiscuous ancestral proteins. By analyzing a genome-scale model of Escherichia coli metabolism, we found that 37% of its enzymes act on a variety of substrates and catalyze 65% of the known metabolic reactions. However, it is not apparent why these generalist enzymes remain. Here, we show that there are marked differences between generalist enzymes and specialist enzymes, known to catalyze a single chemical reaction on one particular substrate in vivo. Specialist enzymes (i) are frequently essential, (ii) maintain higher metabolic flux, and (iii) require more regulation of enzyme activity to control metabolic flux in dynamic environments than do generalist enzymes. Furthermore, these properties are conserved in Archaea and Eukarya. Thus, the metabolic network context and environmental conditions influence enzyme evolution toward high specificity.

Nam, Hojung; Lewis, Nathan E.; Lerman, Joshua A.; Lee, Dae-Hee; Chang, Roger L.; Kim, Donghyuk; Palsson, Bernhard O.

2012-01-01

76

OPTIMIZATION OF APPLICATIONS OF DEXTRANASES IN SUGARCANE FACTORIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The application of commercial dextranases (1, 6-alpha-glucan hydrolases, EC 3.2.1.11) to breakdown dextran (alpha-(1'6)-alpha-D-glucan) in U.S. sugar manufacture is still not optimized, partly because of misinformation about where to add the enzyme and which enzyme to use. Furthermore, there was no...

77

Recovery Act Funding Awards  

Cancer.gov

NCI has quickly moved to utilize Recovery Act funds for projects. Deserving projects are being funded through new grants and contracts as well as supplements to existing grants. Information on this page will be periodically updated so please check back to see how NCI is spending Recovery Act funds.

78

ACT Reference Catalog.  

National Technical Information Service (NTIS)

The U.S. Naval Observatory has completed the compilation of the ACT Reference Catalog, containing 988,758 stars covering the entire sky. The motivation behind the ACT was to provide accurate proper motions for the majority of the stars in the Tycho Catalo...

S. E. Urban T. E. Corbin G. L. Wycoff

1998-01-01

79

Effect of turmeric on xenobiotic metabolising enzymes  

Microsoft Academic Search

Diet contains several substances capable of inhibiting chemical carcinogenesis. It is known that such inhibitors may either act directly by scavenging the reactive substances or indirectly by promoting mechanisms which enhance detoxification. Turmeric which contains curcumin both in vitro and in vivo is an active antimutagen. Studies were therefore conducted to evaluate the effects of turmeric on xenobiotic metabolising enzymes

V. K. Goud; K. Polasa; K. Krishnaswamy

1993-01-01

80

Enzyme kinetics at high enzyme concentration  

Microsoft Academic Search

We re-visit previous analyses of the classical Michaelis-Menten substrate-enzyme reaction and, with the aid of the reverse\\u000a quasi-steady-state assumption, we challenge the approximation d[C]\\/dt ? 0 for the basic enzyme reaction at high enzyme concentration. For the first time, an approximate solution for the concentrations\\u000a of the reactants uniformly valid in time is reported. Numerical simulations are presented to verify

S. Schnell; P. K. Maini

2000-01-01

81

Draconian dress act repealed.  

PubMed

The Dress Act was put into place in Malawi by the government of President Kamuzu Banda after the long period of direct colonialism. The act made it illegal for women in Malawi to be seen publicly wearing dresses which did not completely cover their knees or wearing pants; men had to wear their hair short. Police officers even scrutinized women's attire at private house parties and in homes. The autocratic political structure established by Banda, however, was voted out in a referendum June 14, 1993. Pressure by opposition forces such as the United Democratic Front forced a repeal of the act on November 16 of the same year. The repeal was vigorously attacked by female Parliament members as a move which would result in moral degradation and an increase in the level of sexual harassment against women. Other citizens and tourists have generally detested the act. The act has most certainly kept many potential visitors from vacationing in Malawi. Some expert observers think that repeals of the Dress Act, the Forfeiture Act, and legislation which allowed the government to detain opposition figures without trial were done to garner support from the Paris Club for the resumption of balance of payments support suspended due to the country's poor human rights record. PMID:12318566

Mhone, C

1994-01-01

82

DNA Gyrase: An Enzyme that Introduces Superhelical Turns into DNA  

Microsoft Academic Search

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

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

1976-01-01

83

Public Health Service Act  

Cancer.gov

The Public Health Service was established by act of July 16, 1798 (ch. 77, 1 Stat. 605), authorizing marine hospitals for the care of American merchant seamen. Subsequent legislation has vastly broadened the scope of its activities.

84

Prevention (Affordable Care Act)  

MedlinePLUS

... Beginning of content Prevention What are my preventive care benefits? Most health plans must cover a set ... private insurance plans. Email How does the Affordable Care Act help people like me? If you need ...

85

Assertive Community Treatment (ACT)  

MedlinePLUS

... community treatment? Assertive community treatment (ACT) is a model of psychiatric care that can be very effective ... it the most. Similar to the “treatment team” model of an inpatient psychiatric unit, which includes nurses, ...

86

“Str8acting  

Microsoft Academic Search

This essay analyses performances of masculinity in the profiles constructed by users of the gay men's dating website Gaydar, as well as normative ideological framings of identity built in to key features of the site. In particular, focus is placed on the self-categorisation “straight-acting”, which participates in reductive typologies of gay masculinity. The apparent heteronormativity of “straight-acting” is complicated by

Robert Payne

2007-01-01

87

Synthesis of Amylose by Potato D-Enzyme  

Microsoft Academic Search

THE synthesis of the chain-forming alpha-1: 4-bonds of potato starch (amylose + amylopectin) has for long been ascribed to phosphorylase acting on glucose-1-phosphate and a preformed starch-like primer1. We now report the synthesis of amylose-like material by another enzyme system from potato. This synthesis makes use of D-enzyme, discovered in 1953 by Peat and co-workers2. D-enzyme catalyses the reversible disproportionation

Gwen J. Walker; W. J. Whelan

1959-01-01

88

Novel enzymes for the degradation of cellulose  

PubMed Central

The bulk terrestrial biomass resource in a future bio-economy will be lignocellulosic biomass, which is recalcitrant and challenging to process. Enzymatic conversion of polysaccharides in the lignocellulosic biomass will be a key technology in future biorefineries and this technology is currently the subject of intensive research. We describe recent developments in enzyme technology for conversion of cellulose, the most abundant, homogeneous and recalcitrant polysaccharide in lignocellulosic biomass. In particular, we focus on a recently discovered new type of enzymes currently classified as CBM33 and GH61 that catalyze oxidative cleavage of polysaccharides. These enzymes promote the efficiency of classical hydrolytic enzymes (cellulases) by acting on the surfaces of the insoluble substrate, where they introduce chain breaks in the polysaccharide chains, without the need of first “extracting” these chains from their crystalline matrix.

2012-01-01

89

Enzyme electrochemical sensor electrode.  

National Technical Information Service (NTIS)

An electrochemical sensor electrode is formed from an electronic conductor coated with a casting solution containing a perfluorosulfonic acid ionomer and a selected enzyme. The selected enzyme catalyzes a reaction between a predetermined substance in a so...

J. Rishpon S. Gottesfeld T. A. Zawodzinski

1989-01-01

90

Enzyme Catalyzed Synthetic Reactions.  

National Technical Information Service (NTIS)

Use of an enzyme attached to a cellulosic carrier in organic synthesis is described. Cellulose matrix-supported enzymes constitute useful biological catalysts with broad potential applications in the food, chemical, and pharmaceutical industries. In the c...

G. J. Bartling

1974-01-01

91

VII D. Enzymes  

Center for Food Safety and Applied Nutrition (CFSAN)

Text Version... In general, enzyme preparations from organisms with a history of safe use do not require the same level of toxicological testing as enzymes from ... More results from www.fda.gov/downloads/food/guidanceregulation

92

Enzymes in detergents  

Microsoft Academic Search

Factors affecting the performance of proteolytic and amylolytic enzymes in an anionic and nonionic detergent formulation have\\u000a been studied using stain removal from EMPA blood-milk-ink and cocoa-milk-sugar soil test cloths as a measure of enzyme activity\\u000a in the detergent solution. Factors considered include enzyme concentration, and temperature and pH of the wash solution. Results\\u000a on stability of these enzymes in

R. L. Liss; R. P. Langguth

1969-01-01

93

Developments in Enzyme Technology.  

ERIC Educational Resources Information Center

Enzyme technology has a well-established industrial base, with applications that have survived competition. The most prominent applications of enzymes in biotechnology are examined with an explanation of some theoretical background. Topics include extending an enzyme's useful life, partition and diffusion, industrial uses, and therapeutic uses.…

Chaplin, M. F.

1984-01-01

94

Enzyme Nomenclature 1998  

NSDL National Science Digital Library

The Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB) has made available this online version of Enzyme Nomenclature 1998. NC-IUBMB is currently accepting recommendations for enzyme nomenclature of Oxidoreductases, Transferases, Hydrolases, Lyases, Isomerases, and Ligases. A list of approved peptidases is available. December 31, 1998 is the deadline for submission of enzyme nomenclature recommendations.

Committee., International U.

1998-01-01

95

Sensitive Enzyme Electrodes  

Microsoft Academic Search

Conventional enzyme electrodes are relatively insensitive devices capable of measuring analytes in the micromolar range. Inhibited enzyme electrodes work by measuring the inhibition of an enzyme turning over undersaturated conditions. This increased turnover gives greater sensitivity. The detection limits are controlled either by the thermodynamic amplitude or by the kinetic discrimination. Software has been developed to analyse the current time

W. John Albery; Martyn G. Boutelle; Sally L. T. Durrant; Marrianne Fillenz; Andrew R. Hopkins; Bernard P. Mangold

1990-01-01

96

[Human drug metabolizing enzymes. II. Conjugation enzymes].  

PubMed

In this review we focus on human conjugation enzymes (UDP-glucuronyltransferases, methyl-trasferases, N-acetyl-transferases, O-acetyl-transferases, Amidases/carboxyesterases, sulfotransferases, Glutation-S-transferases and the enzymes involved in the conjugation with amino acids) that participate in the metabolism of xenobiotics. Although conjugation reactions in most of the cases result in detoxication, more and more publications prove that the reactions catalysed by these enzymes very often lead to activated molecules that may attack macromolecules (proteins, RNAs, DNAs), resulting in toxicity (liver, neuro-, embryotoxicity, allergy, carcinogenecity). We have summarised the data available on these enzymes concerning their catalytic profile and specificity, inhibition, induction properties, their possible role in the generation of toxic compounds, their importance in clinical practice and drug development. PMID:9805814

Vereczkey, L; Jemnitz, K; Gregus, Z

1998-09-01

97

Divergence and Convergence in Enzyme Evolution*  

PubMed Central

Comparative analysis of the sequences of enzymes encoded in a variety of prokaryotic and eukaryotic genomes reveals convergence and divergence at several levels. Functional convergence can be inferred when structurally distinct and hence non-homologous enzymes show the ability to catalyze the same biochemical reaction. In contrast, as a result of functional diversification, many structurally similar enzyme molecules act on substantially distinct substrates and catalyze diverse biochemical reactions. Here, we present updates on the ATP-grasp, alkaline phosphatase, cupin, HD hydrolase, and N-terminal nucleophile (Ntn) hydrolase enzyme superfamilies and discuss the patterns of sequence and structural conservation and diversity within these superfamilies. Typically, enzymes within a superfamily possess common sequence motifs and key active site residues, as well as (predicted) reaction mechanisms. These observations suggest that the strained conformation (the entatic state) of the active site, which is responsible for the substrate binding and formation of the transition complex, tends to be conserved within enzyme superfamilies. The subsequent fate of the transition complex is not necessarily conserved and depends on the details of the structures of the enzyme and the substrate. This variability of reaction outcomes limits the ability of sequence analysis to predict the exact enzymatic activities of newly sequenced gene products. Nevertheless, sequence-based (super)family assignments and generic functional predictions, even if imprecise, provide valuable leads for experimental studies and remain the best approach to the functional annotation of uncharacterized proteins from new genomes.

Galperin, Michael Y.; Koonin, Eugene V.

2012-01-01

98

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".

99

Water and enzyme mobility  

NASA Astrophysics Data System (ADS)

Enzymes are complex structures that have been produced by evolution to function in water. The interrelation between water and proteins is not completely understood. However, data of the last decades have shown that water is indeed an essential component of enzymes. It is central in their formation, often it forms an essential part of their three-dimensional structure, and it is fundamental for supporting enzyme action, at least at rates compatible with life. It is precisely because of the intimate relation that exists between water and enzymes that water may be used to gain deeper insight into how enzymes are formed and function.

Fernández-Velasco, D. Alejandro; de Gómez-Puyou, Marietta Tuena; Gómez-Puyou, Armando

1995-08-01

100

Employer monitoring Act proposed  

Microsoft Academic Search

On 20 July, Senator Charles Schumer of New York and Representatives Bob Barr of Georgia and Charles Canady of Florida introduced the Notice of Electronic Monitoring Act (NEMA). The legislation seeks to end unjustified secret monitoring of employees by their bosses. The Bill does not prohibit electronic monitoring but merely requires that employers give their employees clear notice about what

Wayne Madsen

2000-01-01

101

The USA PATRIOT Act.  

ERIC Educational Resources Information Center

|Explains the USA PATRIOT (Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism) Act, passed after the September 11 terrorist attacks, and its implications for libraries and patron records. Considers past dealings with the FBI; court orders; search warrants; wiretaps; and subpoenas.…

Minow, Mary; Coyle, Karen; Kaufman, Paula

2002-01-01

102

The USA PATRIOT Act.  

ERIC Educational Resources Information Center

Explains the USA PATRIOT (Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism) Act, passed after the September 11 terrorist attacks, and its implications for libraries and patron records. Considers past dealings with the FBI; court orders; search warrants; wiretaps; and subpoenas. Includes:…

Minow, Mary; Coyle, Karen; Kaufman, Paula

2002-01-01

103

Acting like a Pro  

ERIC Educational Resources Information Center

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…

Walker, Marlon A.

2012-01-01

104

Acting like a Pro  

ERIC Educational Resources Information Center

|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…

Walker, Marlon A.

2012-01-01

105

Let's Act Like Professionals  

ERIC Educational Resources Information Center

In this article, the author discusses some of the most serious challenges--intellectual, institutional, and political--that he sees for the future of professional learning in education. He states that one common solution to these challenges would be for educators to begin to act more like professionals. One thing is clear about the early stages of…

Elmore, Richard F.

2007-01-01

106

Fast-Acting Valve.  

National Technical Information Service (NTIS)

A fast-acting valve includes an annular valve seat that defines an annular valve orifice between the edges of the annular valve seat, an annular valve plug sized to cover the valve orifice when the valve is closed, and a valve-plug holder for moving the a...

B. V. Wojciechowski R. J. Pegg

2003-01-01

107

The Kentucky Civil Rights Act: Explanation, the Act, Regulations.  

ERIC Educational Resources Information Center

|The Kentucky Civil Rights Act, introduced on January 4, 1966, enacted January 27, 1966 and effective July 1, 1966 is said to meet the requirements of the Federal Civil Rights Act of 1964. In 1968, the Act was amended to prohibit housing discrimination. In 1972, the coverage of the Act was extended to prohibit employment discrimination because of…

Kentucky State Commission on Human Rights, Frankfort.

108

Activated clotting time (ACT).  

PubMed

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

Horton, Stephen; Augustin, Simon

2013-01-01

109

Primary enzyme quantitation using substrates labeled with a second indicator enzyme. I. Elastase determination using peroxidase-labeled elastin  

SciTech Connect

Quantitation of proteolytic enzyme concentration can be accomplished by measuring the release, due to primary enzyme catalysis, of a second enzyme bound to a particulate substrate. As the primary enzyme acts on the substrate, release of the indicator enzyme into the surrounding medium occurs, which in turn can be quantitated colorimetrically, and under suitable reaction conditions the amount of indicator enzyme released is directly proportional to the amount of primary enzyme present. A specific example of such an assay is that for elastolytic activity using powdered elastin labeled with horseradish peroxidase. The detection sensitivity of the system described is 1 ng/ml of pancreatic elastase, and the dynamic range of the assay is 2 orders of magnitude. The reaction time for optimal elastase detection sensitivity is 3 h. For a fixed, nonsaturating concentration of elastase, the amount of peroxidase released is proportional to the elastase concentration.

Saunders, G.C.; Svitra, Z.; Martinez, A.

1982-01-01

110

Roles of maltodextrin and glycogen phosphorylases in maltose utilization and glycogen metabolism in Corynebacterium glutamicum.  

PubMed

Corynebacterium glutamicum transiently accumulates large amounts of glycogen, when cultivated on glucose and other sugars as a source of carbon and energy. Apart from the debranching enzyme GlgX, which is required for the formation of maltodextrins from glycogen, alpha-glucan phosphorylases were assumed to be involved in glycogen degradation, forming alpha-glucose 1-phosphate from glycogen and from maltodextrins. We show here that C. glutamicum in fact possesses two alpha-glucan phosphorylases, which act as a glycogen phosphorylase (GlgP) and as a maltodextrin phosphorylase (MalP). By chromosomal inactivation and subsequent analysis of the mutant, cg1479 was identified as the malP gene. The deletion mutant C. glutamicum DeltamalP completely lacked MalP activity and showed reduced intracellular glycogen degradation, confirming the proposed pathway for glycogen degradation in C. glutamicum via GlgP, GlgX and MalP. Surprisingly, the DeltamalP mutant showed impaired growth, reduced viability and altered cell morphology on maltose and accumulated much higher concentrations of glycogen and maltodextrins than the wild-type during growth on this substrate, suggesting an additional role of MalP in maltose metabolism of C. glutamicum. Further assessment of enzyme activities revealed the presence of 4-alpha-glucanotransferase (MalQ), glucokinase (Glk) and alpha-phosphoglucomutase (alpha-Pgm), and the absence of maltose hydrolase, maltose phosphorylase and beta-Pgm, all three known to be involved in maltose utilization by Gram-positive bacteria. Based on these findings, we conclude that C. glutamicum metabolizes maltose via a pathway involving maltodextrin and glucose formation by MalQ, glucose phosphorylation by Glk and maltodextrin degradation via the reactions of MalP and alpha-Pgm, a pathway hitherto known to be present in Gram-negative rather than in Gram-positive bacteria. PMID:19202084

Seibold, Gerd M; Wurst, Martin; Eikmanns, Bernhard J

2009-02-01

111

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

ERIC Educational Resources Information Center

|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…

Junker, Matthew

2010-01-01

112

Nanostructures for enzyme stabilization  

SciTech Connect

The last decade has witnessed notable breakthroughs in nanotechnology with development of various nanostructured materials such as mesoporous materials and nanoparticles. These nanostructures have been used as a host for enzyme immobilization via various approaches, such as enzyme adsorption, covalent attachment, enzyme encapsulation, and sophisticated combinations of methods. This review discusses the stabilization mechanisms behind these diverse approaches; such as confinement, pore size and volume, charge interaction, hydrophobic interaction, and multipoint attachment. In addition, we will introduce recent rigorous approaches to improve the enzyme stability in these nanostructures or develop new nanostructures for the enzyme stabilization. Especially, we will introduce our recent invention of a nanostructure, called single enzyme nanoparticles (SENs). In the form of SENs, each enzyme molecule is surrounded with a nanometer scale network, resulting in stabilization of enzyme activity without any serious limitation for the substrate transfer from solution to the active site. SENs can be further immobilized into mesoporous silica with a large surface area, providing a hierarchical approach for stable, immobilized enzyme systems for various applications, such as bioconversion, bioremediation, and biosensors.

Kim, Jungbae; Grate, Jay W.; Wang, Ping

2006-02-02

113

Adenylate-forming enzymes  

PubMed Central

Thioesters, amides and esters are common chemical building blocks in a wide array of natural products. The formation of these bonds can be catalyzed in a variety of ways. For chemists, the use of an activating group is a common strategy and adenylate enzymes are exemplars of this approach. Adenylating enzymes activate the otherwise unreactive carboxylic acid by transforming the normal hydroxyl leaving group into adenosine monophosphate. Recently there have been a number of studies of such enzymes and in this review we suggest a new classification scheme. The review highlights the diversity in enzyme fold, active site architecture and metal coordination that has evolved to catalyze this particular reaction.

Schmelz, Stefan; Naismith, James H.

2012-01-01

114

Microbial amylolytic enzymes.  

PubMed

Starch-degrading, amylolytic enzymes are widely distributed among microbes. Several activities are required to hydrolyze starch to its glucose units. These enzymes include alpha-amylase, beta-amylase, glucoamylase, alpha-glucosidase, pullulan-degrading enzymes, exoacting enzymes yielding alpha-type endproducts, and cyclodextrin glycosyltransferase. Properties of these enzymes vary and are somewhat linked to the environmental circumstances of the producing organisms. Features of the enzymes, their action patterns, physicochemical properties, occurrence, genetics, and results obtained from cloning of the genes are described. Among all the amylolytic enzymes, the genetics of alpha-amylase in Bacillus subtilis are best known. Alpha-Amylase production in B. subtilis is regulated by several genetic elements, many of which have synergistic effects. Genes encoding enzymes from all the amylolytic enzyme groups dealt with here have been cloned, and the sequences have been found to contain some highly conserved regions thought to be essential for their action and/or structure. Glucoamylase appears usually in several forms, which seem to be the results of a variety of mechanisms, including heterogeneous glycosylation, limited proteolysis, multiple modes of mRNA splicing, and the presence of several structural genes. PMID:2548811

Vihinen, M; Mäntsälä, P

1989-01-01

115

Dreams and acting out.  

PubMed

Dreams can be used as containers that free patients from increased tension. This may be the principal function of certain types of dreams, called "evacuative dreams." They are dreams used for getting rid of unbearable affects and unconscious fantasies, or as a safety valve for partial discharge of instinctual drives. These dreams are observed primarily in borderline and psychotic patients, but can also be seen in the regressive states of neurotic patients during weekends and other periods of separation. Such dreams have to be differentiated from "elaborative dreams," which have a working-through function and stand in an inverse relationship to acting out: the greater the production of elaborative dreams, the less the tendency to act out, and vice versa. PMID:3562698

Grinberg, L

1987-01-01

116

Toxic Substances Control Act  

SciTech Connect

This Reference Book contains a current copy of the Toxic Substances Control Act 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. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

Not Available

1992-05-15

117

Mean Lifetime and First-Passage Time of the Enzyme Species Involved in an Enzyme Reaction. Application to Unstable Enzyme Systems  

Microsoft Academic Search

Taking as starting point the complete analysis of mean residence times in linear compartmental systems performed by Garcia-Meseguer\\u000a et al. (Bull. Math. Biol. 65:279–308, 2003) as well as the fact that enzyme systems, in which the interconversions between the different enzyme species involved are\\u000a of first or pseudofirst order, act as linear compartmental systems, we hereby carry out a complete analysis

E. Arribas; A. Muñoz-Lopez; M. J. Garcia-Meseguer; A. Lopez-Najera; L. Avalos; F. Garcia-Molina; M. Garcia-Moreno; R. Varon

2008-01-01

118

Enzymes and Reactor Engineering.  

National Technical Information Service (NTIS)

In the first part of this report, a brief review of the state of the art in the field of immobilized enzymes is presented. Topics covered include: (1) silanization of porous glass; (2) covalent bonding reaction schemes; and (3) some enzymes of current int...

H. O. Hultin J. R. Kittrell R. L. Laurence

1972-01-01

119

Enzyme replacement and beyond  

Microsoft Academic Search

During the last decade, enzyme replacement therapy for lysosomal storage diseases became a reality with the demonstration of its safety and effectiveness in type 1 Gaucher disease. Currently, enzyme replacement and several other potential therapeutic strategies are being developed for selected lysosomal storage diseases, including Fabry disease due to the deficient activity of a-galactosidase A (a-Gal A). The development and

R. J. Desnick

2001-01-01

120

Enzyme catalysis: Sweet flexibility  

NASA Astrophysics Data System (ADS)

An enzyme that is unusually tolerant of a truly broad range of substrates can catalyse aldol-type chemistry on sugars in which the various hydroxyl groups are protected. The new methodology combines some of the most important advantages of enzyme and small-molecule catalysis.

Davis, Benjamin G.

2010-02-01

121

Cytochrome P450 enzymes  

Microsoft Academic Search

Cytochrome P450 enzymes are proving to be the stalwarts of the detoxication system in the human body, and in other biological systems. They are found in every type of cell within the body (except red blood cells and skeletal muscle cells), and they are found in every biological kingdom including bacteria. Cytochrome enzymes appear to defend the body against environmental

Guengerich

2009-01-01

122

Enzyme Database - BRENDA  

NSDL National Science Digital Library

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).

Institute Of Biochemistry And Bioinformatics At The Technical University Of Braunschweig, Germany

123

Understanding Enzyme Inhibition  

Microsoft Academic Search

While enzyme inhibition is a widely taught subject across chemical and biochemical disciplines, it remains poorly understood. A mental image is presented to facilitate the understanding of inhibition types other than competitive. Subsequently, enzyme inhibition is developed using Vmax\\/Km in place of Km. Interpretation of direct (initial velocity vs substrate concentration) plots makes clear the meanings of competitive, noncompetitive, and

Raymond S. Ochs

2000-01-01

124

Enzyme electrochemcial sensor electrode  

DOEpatents

An electrochemical sensor electrode is formed from an electronic conductor coated with a casting solution containing a perfluorosulfonic acid ionomer and a selected enzyme. The selected enzyme catalyzes a reaction between a predetermined substance in a solution and oxygen to form an electrochemically active compound that is detected at the electronic conductor. The resulting perfluorosulfonic acid polymer provides a stable matrix for the enzyme for long lived enzyme activity, wherein only thin coatings are required on the metal conductor. The polymer also advantageously repels interfering substances from contacting the enzyme and contains quantities of oxygen to maintain a sensing capability during conditions of oxygen depletion in the sample. In one particular embodiment, glucose oxidase is mixed with the perfluorosulfonic acid ionomer to form an electrode for glucose detection. 3 figs.

Rishpon, J.; Zawodzinski, T.A.; Gottesfeld, S.

1989-12-11

125

Home Mortgage Disclosure Act  

NSDL National Science Digital Library

Enacted by Congress in 1975, the Home Mortgage Disclosure Act (HMDA) requires US banks, savings associations, credit unions, and other mortgage lending institutions to disclose their home mortgage and home improvement lending activity annually. Access to HMDA data with loan amounts by metropolitan area as well as the demographic make-up of applicants, is available at this Federal Financial Institutions Examination Council (FFIEC) page. Users can also search a database of FFIEC data depository locations with HMDA reports or obtain background information on HMDA history and the financial institutions it affects.

126

Cotton cellulose: enzyme adsorption and enzymic hydrolysis  

SciTech Connect

The adsorption of a crude cellulase complex from Trichoderma viride on variously pretreated cotton cellulose samples was studied in the framework of the Langmuir approach at 2-8 degrees. The saturation amount of adsorbed enzyme was related to the susceptibility of the substrates to hydrolysis. In every case the adsorption process was faster by 2-3 orders of magnitude than the hydrolysis step to give end products. For ZnCl/sub 2/-treated cotton cellulose the Langmuir parameters correlated fairly well with the value of the Michaelis constant, measured for its enzymic hydrolysis, and the adsorptive complex was indistinguishable from the complex of the Michaelis-Menten model for the hydrolysis.

Beltrame, P.L.; Carniti, P.; Focher, B.; Marzetti, A.; Cattaneo, M.

1982-01-01

127

Determination of the starch-phosphorylating enzyme activity in plant extracts.  

PubMed

For quantification of alpha-glucan, water dikinase (GWD) activity in crude extracts of plant tissues a radio-labeling assay was established that uses soluble starch and (33)P-labeled ATP as phosphate acceptor and donor, respectively. A constant rate of starch labeling was observed only if the ATP applied was labeled at the beta position. In wild-type extracts from leaves of Arabidopsis thaliana (L.) Heynh. the maximum rate of starch phosphorylation was approximately 27 pmol min(-1) (mg protein)(-1). Leaf extracts from the GWD-deficient sex1 mutants of Arabidopsis showed no significant incorporation of phosphate whereas extracts from potato (Solanum tuberosum L.) tuber expressing a GWD antisense construct exhibited less activity than the wild-type control. To our knowledge this is the first time that a quantification of the starch-phosphorylating activity has been achieved in plant crude extracts. PMID:12624767

Ritte, Gerhard; Steup, Martin; Kossmann, Jens; Lloyd, James R

2002-11-09

128

Enzyme patterns of dermatophytes.  

PubMed

Exoenzymes produced by common dermatophytes, in addition to their ability to cause cutaneous inflammation, are thought to contribute to fungal spread. To investigate the patterns of enzymes released by common dermatophytes as well as Scopulariopsis brevicaulis, the fungi were grown in liquid media containing either hair, stratum corneum, neopeptone or lipids, or in RPMI medium. Enzymes recovered from the culture supernatants were compared using the Api-zyme test. As a result, the widest range of enzymes was seen in protein-containing media, with a maximum of 13 enzymes stimulated by growth on hair. Dermatophytes in all protein media produced high levels of alkaline phosphatase, esterases and leucine arylamidase. In these media the highest total enzymatic activity was released by Microsporum canis, whereas the lowest was released by Epidermophyton floccosum. Although RPMI broth stimulated luxuriant growth of all species, recovery was limited to a maximum of six enzymes. In lipid medium E. floccosum and M. canis failed to grow. When comparing the various nutrients, Scopulariopsis released fewer enzymes than the dermatophytes and only minor quantities of alkaline phosphatase. We conclude that alkaline phosphatase, esterases and leucine arylamidase may be important for the parasitic growth of dermatophytes. The total enzymatic activity of dermatophytes appears to be correlated with the intensity of cutaneous inflammation. Furthermore, enzyme measurements may be helpful for species identification. PMID:7935585

Brasch, J; Zaldua, M

129

``Plugging into Enzymes'': Nanowiring of Redox Enzymes by a Gold Nanoparticle  

NASA Astrophysics Data System (ADS)

The reconstitution of an apo-flavoenzyme, apo-glucose oxidase, on a 1.4-nanometer gold nanocrystal functionalized with the cofactor flavin adenine dinucleotide and integrated into a conductive film yields a bioelectrocatalytic system with exceptional electrical contact with the electrode support. The electron transfer turnover rate of the reconstituted bioelectrocatalyst is ~5000 per second, compared with the rate at which molecular oxygen, the natural cosubstrate of the enzyme, accepts electrons (~700 per second). The gold nanoparticle acts as an electron relay or ``electrical nanoplug'' for the alignment of the enzyme on the conductive support and for the electrical wiring of its redox-active center.

Xiao, Yi; Patolsky, Fernando; Katz, Eugenii; Hainfeld, James F.; Willner, Itamar

2003-03-01

130

The EBI enzyme portal  

PubMed Central

The availability of comprehensive information about enzymes plays an important role in answering questions relevant to interdisciplinary fields such as biochemistry, enzymology, biofuels, bioengineering and drug discovery. At the EMBL European Bioinformatics Institute, we have developed an enzyme portal (http://www.ebi.ac.uk/enzymeportal) to provide this wealth of information on enzymes from multiple in-house resources addressing particular data classes: protein sequence and structure, reactions, pathways and small molecules. The fact that these data reside in separate databases makes information discovery cumbersome. The main goal of the portal is to simplify this process for end users.

Alcantara, Rafael; Onwubiko, Joseph; Cao, Hong; de Matos, Paula; Cham, Jennifer A.; Jacobsen, Jules; Fischer, Julia D.; Rahman, Syed Asad; Jassal, Bijay; Goujon, Mikael; Rowland, Francis; Velankar, Sameer; Lopez, Rodrigo; Overington, John P.; Kleywegt, Gerard J.; Hermjakob, Henning; O'Donovan, Claire; Martin, Maria Jesus; Thornton, Janet M.; Steinbeck, Christoph

2013-01-01

131

Understanding Enzyme Inhibition  

NASA Astrophysics Data System (ADS)

While enzyme inhibition is a widely taught subject across chemical and biochemical disciplines, it remains poorly understood. A mental image is presented to facilitate the understanding of inhibition types other than competitive. Subsequently, enzyme inhibition is developed using Vmax/Km in place of Km. Interpretation of direct (initial velocity vs substrate concentration) plots makes clear the meanings of competitive, noncompetitive, and mixed inhibition in a manner entirely distinct from current textbook treatments. The effects of inhibitors on enzymes can be seen to be reduced to a simple consideration of actions at zero and infinite substrate concentrations, corresponding to Vmax/Km and Vmax, respectively.

Ochs, Raymond S.

2000-11-01

132

Commercial production of microbial enzymes  

SciTech Connect

The advantages and uses of industrially produced microbial enzymes are described. The processes involved in the production of these enzymes, cultivation techniques, enzyme extraction, enzyme purification and immobilization are outlined. Both the history of enzyme technology and its future development are discussed.

Munro, I.G.

1985-01-01

133

Enzyme and microbial sensors for environmental monitoring  

NASA Astrophysics Data System (ADS)

Biosensors employing the biocatalyst on a different level of integration have been developed for monitoring environmental pollution. These probes range from laboratory specimen to commercial detectors applied to analyzers. This paper presents a selection of recent developments on amperometric enzyme and microbial biosensors. A monoenzymatic bulk type carbon electrode is described for biosensing organic hydroperoxides in aqueous solutions. Here, peroxidase is immobilized within the electrode body and the direct electron transfer between electrode and enzyme is measured. Both, reversible and irreversible inhibitors of acetylcholinesterase have been quantified by using a kinetically controlled acetylcholine enzyme sequence electrode. The inhibitory effect of pesticides such as butoxycarboxime, dimethoate, and trichlorfon could be quantified within 6 min in micrometers olar concentrations. Different multi-enzyme electrodes have been developed for the determination of inorganic phosphate. These sensors represent examples of sequentially acting enzymes in combination with enzymatic analyte recycling. Using this type of amplification nanomolar concentrations could be measured. A very fast responding microbial sensor for biological oxygen demand has been developed by immobilizing Trichosporon cutaneum onto an oxygen electrode. With this whole cell sensor waste water can be assayed with a sample frequency of 20 per hour and a working stability of more than 30 days.

Wollenberger, U.; Neumann, B.; Scheller, Frieder W.

1993-03-01

134

DNA gyrase: an enzyme that introduces superhelical turns into DNA.  

PubMed Central

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 greater than that found in intracellularly supercoiled DNA. Images

Gellert, M; Mizuuchi, K; O'Dea, M H; Nash, H A

1976-01-01

135

Mechanism of Enzyme Action.  

National Technical Information Service (NTIS)

The synthetic polymeric catalysts containing pendent imidazole groups have been studied. Poly-4(5)-vinylimidazole and poly-5(6)-benzimidazole exhibited multifunctional catalyses, similar in mechanism to those of an enzyme in the solvolyses of positively o...

C. G. Overberger J. C. Salamone I. Cho R. Corett P. S. Yuen

1967-01-01

136

RNA as an Enzyme.  

ERIC Educational Resources Information Center

|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)|

Cech, Thomas R.

1986-01-01

137

Federal Employees' Compensation Act.  

PubMed

The Federal Employees' Compensation Act (FECA) program provides wage loss compensation and payments for medical treatment to federal civilian employees. Administered by the Department of Labor (DOL), FECA covers over 2.7 million federal employees in more than 70 different agencies. FECA costs rose from $1.4 billion in 1990 to $2.6 in 2006, while the federal workforce remained essentially unchanged. While federal civilian employees represent only 2.1% of all workers eligible for workers' compensation benefits, federal programs account for 6% of the benefits paid. Disability benefits under FECA are far greater than those in the state workers' compensation programs. The benefit payments often exceed the former salary of the injured employee. The last congressional hearings on the FECA program were held over thirty years ago. It is unlikely that Congressional review will occur any time soon, as the entrenched bureaucracy that benefits from the FECA program defines and protects its future. PMID:19496485

Ladou, Joseph

138

FAST ACTING CURRENT SWITCH  

DOEpatents

A high-current, fast-acting switch is designed for utilization as a crowbar switch in a high-current circuit such as used to generate the magnetic confinement field of a plasma-confining and heat device, e.g., Pyrotron. The device particularly comprises a cylindrical housing containing two stationary, cylindrical contacts between which a movable contact is bridged to close the switch. The movable contact is actuated by a differential-pressure, airdriven piston assembly also within the housing. To absorb the acceleration (and the shock imparted to the device by the rapidly driven, movable contact), an adjustable air buffer assembly is provided, integrally connected to the movable contact and piston assembly. Various safety locks and circuit-synchronizing means are also provided to permit proper cooperation of the invention and the high-current circuit in which it is installed. (AEC)

Batzer, T.H.; Cummings, D.B.; Ryan, J.F.

1962-05-22

139

Triple acting radial seal  

SciTech Connect

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.

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

2012-03-13

140

Energetics of enzyme catalysis.  

PubMed Central

Quantitative studies of the energetics of enzymatic reactions and the corresponding reactions in aqueous solutions indicate that charge stabilization is the most important energy contribution in enzyme catalysis. Low electrostatic stabilization in aqueous solutions is shown to be consistent with surprisingly large electrostatic stabilization effects in active sites of enzymes. This is established quantitatively by comparing the relative stabilization of the transition states of the reaction of lysozyme and the corresponding reaction is aqueous solution.

Warshel, A

1978-01-01

141

Act on early warnings.  

PubMed

Two conditions establish the threshold for protective action in the presence of scientific uncertainty; 1. Credible evidence that a synthetic chemical can cause biological changes that are known to result in unintended harmful outcomes to human health or the environment in some cases; 2. The presence of such a chemical where it does not belong and where it can cause damage to biological systems (such as human bodies). Acting with foresight takes many forms. We must create and strengthen human health and wildlife monitoring programs to detect and predict harm; take steps to prevent, eliminate, and mitigate exposure when credible evidence of harm is found; monitor novel technologies; consider clusters of problems to be early warnings of harm; and open toxic tort records. All action taken must be based on precautionary definitions of "harm" and "credible evidence" and must include public participation. Significant precautionary actions may be taken on the state and local level in advance of a precautionary national chemicals policy. PMID:17959564

Myers, Nancy; Rabe, Anne; Silberman, Katie

2007-01-01

142

Double acting bit holder  

DOEpatents

A double acting bit holder that permits bits held in it to be resharpened during cutting action to increase energy efficiency by reducing the amount of small chips produced. The holder consist of: a stationary base portion capable of being fixed to a cutter head of an excavation machine and having an integral extension therefrom with a bore hole therethrough to accommodate a pin shaft; a movable portion coextensive with the base having a pin shaft integrally extending therefrom that is insertable in the bore hole of the base member to permit the moveable portion to rotate about the axis of the pin shaft; a recess in the movable portion of the holder to accommodate a shank of a bit; and a biased spring disposed in adjoining openings in the base and moveable portions of the holder to permit the moveable portion to pivot around the pin shaft during cutting action of a bit fixed in a turret to allow front, mid and back positions of the bit during cutting to lessen creation of small chip amounts and resharpen the bit during excavation use.

Morrell, Roger J. (Blommington, MN); Larson, David A. (Minneapolis, MN); Ruzzi, Peter L. (Eagan, MN)

1994-01-01

143

Aminoglycoside Modifying Enzymes  

PubMed Central

Aminoglycosides have been an essential component of the armamentarium in the treatment of life-threatening infections. Unfortunately, their efficacy has been reduced by the surge and dissemination of resistance. In some cases the levels of resistance reached the point that rendered them virtually useless. Among many known mechanisms of resistance to aminoglycosides, enzymatic modification is the most prevalent in the clinical setting. Aminoglycoside modifying enzymes catalyze the modification at different ?OH or ?NH2 groups of the 2-deoxystreptamine nucleus or the sugar moieties and can be nucleotidyltranferases, phosphotransferases, or acetyltransferases. The number of aminoglycoside modifying enzymes identified to date as well as the genetic environments where the coding genes are located is impressive and there is virtually no bacteria that is unable to support enzymatic resistance to aminoglycosides. Aside from the development of new aminoglycosides refractory to as many as possible modifying enzymes there are currently two main strategies being pursued to overcome the action of aminoglycoside modifying enzymes. Their successful development would extend the useful life of existing antibiotics that have proven effective in the treatment of infections. These strategies consist of the development of inhibitors of the enzymatic action or of the expression of the modifying enzymes.

Ramirez, Maria S.; Tolmasky, Marcelo E.

2010-01-01

144

Enzyme immobilization on tritylagarose  

SciTech Connect

A method is described for the immobilization on tritylated agarose or Sepharose columns of a wide spectrum of enzymes, including types useful in contemporary biochemistry/molecular biology, many of which have never before been reported as immobilized. The method involves the formation of noncovalent hydrophobic bonds between the enzymes and trityl groups which are attached to the agarose by means of ether bonds. The immobilization of calf intestinal and E. coli alkaline phosphatases to tritylagarose is reported in detail. Their binding strength, binding capacity, and long-term stability (greater than six months) are described as a function of the salt concentration, pH, buffer type, and degree of agarose substitution. Homologies are noted between tritylagarose-bound and membrane-bound phosphatases. This method compares favorably with other methods, covalent or otherwise, reported to date, in terms of the enzyme immobilization yield (ca. 100%), the mildness of conditions, resulting, in most cases, in the retention of a high degree of activity, the ease and speed of the manipulations, and the long-term stability of the immobilized enzyme. Further, it is noted that highly tritylated and crosslinked Sephadex G10 selectively and mildly removes detergents from enzyme solutions. (Refs. 64).

Cashion, P.; Javed, A.; Harrison, D.; Seeley, J.; Lentini, V.; Sathe, G.

1982-02-01

145

Bile acids as modulators of enzyme activity and stability.  

PubMed

Bile acids deactivate certain enzymes, such as prolyl endopeptidases (PEPs), which are investigated as candidates for protease-based therapy for celiac sprue. Deactivation by bile acids presents a problem for therapeutic enzymes targetted to function in the upper intestine. However, enzyme deactivation by bile acids is not a general phenomenon. Trypsin and chymotrypsin are not deactivated by bile acids. In fact, these pancreatic enzymes are more efficient at cleaving large dietary substrates in the presence of bile acids. We targeted the origin of the apparently different effect of bile acids on prolyl endopeptidases and pancreatic enzymes by examining the effect of bile acids on the kinetics of cleavage of small substrates, and by determining the effect of bile acids on the thermodynamic stabilities of these enzymes. Physiological amounts (5 mM) of cholic acid decrease the thermodynamic stability of Flavobacterium meningosepticum PEP from 18.5 ± 2 kcal/mol to 10.5 ± 1 kcal/mol, while thermostability of trypsin and chymotrypsin is unchanged. Trypsin and chymotrypsin activation by bile and PEP deactivation can both be explained in terms of a common mechanism: bile acid-mediated protein destabilization. Bile acids, usually considered non-denaturing surfactants, in this case act as a destabilizing agent on PEP thus deactivating the enzyme. However, this level of global thermodynamic destabilization does not account for a more than 50% decrease in enzyme activity, suggesting that bile acids most likely modulate enzyme activity through specific local interactions. PMID:21965022

Robic, Srebrenka; Linscott, Kristin B; Aseem, Madiha; Humphreys, Ellen A; McCartha, Shannon R

2011-12-01

146

Characterization and in vitro expression patterns of extracellular degradative enzymes from non-pathogenic binucleate Rhizoctonia AG-G  

Microsoft Academic Search

Many filamentous fungi produce an array of extracellular enzymes that acting in cell walls release elicitors of the plant defense response These enzymes may therefore be important in biocontrol applications. The aim of this study was to characterize extracellular degradative enzymes produced by a non-pathogenic binucleate isolate of Rhizoctonia AG-G. The fungus was grown in liquid culture supplemented with pectin,

Milagros F. Machinandiarena; Erika A. Wolski; Viviana Barrera; Gustavo R. Daleo; Adriana B. Andreu

2005-01-01

147

A new function for the RNA-editing enzyme ADAR1  

PubMed Central

ADAR1 catalyzes the deamination of adenosine to inosine in double-stranded RNA. This RNA-editing enzyme is now shown to be involved in hematopoiesis, where it acts to suppress interferon signaling and to block premature apoptosis.

Iizasa, Hisashi; Nishikura, Kazuko

2010-01-01

148

Bacterial enzyme mediated biosynthesis of gold nanoparticles.  

PubMed

Development of synthesis methods for anisotropic metal nanoparticles is of considerable interest due to their remarkable optoelectronic properties. Various shapes ranging from rods to cubes to tetrapods and prisms may be obtained by chemical methods. Here we show that anisotropic gold nanoparticles can be synthesized biologically by the bacterium Actinobacter spp. when challenged with gold chloride in the presence of Bovine serum albumin (BSA). We also observed that synthesis of gold nanoparticles occur with simultaneous induction of the protease enzyme secreted by the bacterium in the presence of BSA. The presence of BSA helps to enhance the rate of gold nanoparticles biosynthesis and may also impart some shape control. Controlling simple experimental conditions like incubation temperature and presence or absence of oxygen have drastic effect on the reaction rate and the morphology of the particles. Various assay experiments show that the presence of enzyme protease can act as a reducing as well as shape directing agent. PMID:18283817

Bharde, Atul; Kulkarni, Aarohi; Rao, Mala; Prabhune, Asmita; Sastry, Murali

2007-12-01

149

Glycogen metabolizing enzymes in brain  

Microsoft Academic Search

Three enzymes, glycogen phosphorylase, glycogen synthase, and phosphoglucomutase were evaluated in subcellular fractions and in brain regions. Also the development of each of these enzymes was evaluated in whole brain homogenates. Each enzyme increased during the first three weeks of post partum in a manner that is similar to the development of glycolytic enzymes during this period. The specific activity

Harvey R. Knull; Ramji L. Khandelwal

1982-01-01

150

Finding and using hyperthermophilic enzymes  

Microsoft Academic Search

Recent developments have enhanced the prospects for the discovery of hyperthermophilic enzymes. This is important because the intrinsic basis underlying the extraordinary thermostability of hyperthermophilic enzymes has yet to be revealed, and so engineering this characteristic into less thermophilic enzymes is not possible at this time. Successful efforts to clone and express the genes encoding hyperthermophilic enzymes in mesophilic hosts

Michael W. W Adams; Robert M Kelly

1998-01-01

151

Elaboration and chemical reactivity of enzyme modified ion exchanging textiles  

Microsoft Academic Search

Ion exchanging textile are used as organic supports for enzyme immobilisation with the aim of developing reactive fibrous materials able to be substituted for membrane systems in bioreactors or acting for instance as reactive bags for waste treatment devices, thus extending the range of their potential applications. The cationic or anionic sites of ion exchanging textiles are used for the

M Amounas; V Magne; C Innocent; E Dejean; P Seta

2002-01-01

152

Lipid deacylating enzymes in plants: Old activities, new genes  

Microsoft Academic Search

Because lipids are major components of cellular membranes, their degradation under stress conditions compromises compartmentalization. However, in addition to having structural roles, membrane lipids are also implicated in signalling processes involving the activity of lipolytic enzymes. Phospholipases D and C, acting on the polar heads of phospholipids, have been relatively well characterized in plants. In contrast, knowledge of lipid deacylating

Ana Rita Matos; Anh-Thu Pham-Thi

2009-01-01

153

Specifity of potato isoinhibitors towards various proteolytic enzymes  

Microsoft Academic Search

Summary The isoinhibitors, isolated from potato juice by isoelectric focusing, inhibit mainly serine proteases of animal and microbial origin. The proteolytic activity of the aleuron fraction from wheat is not abolished. On the basis of specifity a classification into 3 groups is possible: specific trypsin inhibitors, trypsin\\/a-chymotrypsin inhibitors and inhibitors with wide specifity, acting on the former enzymes and on

K-P Kaiser; H-D Bélitz

1973-01-01

154

Dirty air act from Detroit. [Reform of Clean Air Act  

Microsoft Academic Search

Efforts to weaken the Clean Air Act are described. The Dingell-Broyhill Act would eliminate the Prevention of Significant Deterioration (PSD) program, allow extensive delays in deadlines for the State Implementation Plans (SIPs), and would allow auto emissions to double. Requirements for protecting consumers from faulty emission control equipment would also be eliminated. (JMT)

Wentworth

1982-01-01

155

Glycogen metabolizing enzymes in brain.  

PubMed

Three enzymes, glycogen phosphorylase, glycogen synthase, and phosphoglucomutase were evaluated in subcellular fractions and in brain regions. Also the development of each of these enzymes was evaluated in whole brain homogenates. Each enzyme increased during the first three weeks of post partum in a manner that is similar to the development of glycolytic enzymes during this period. The specific activity of each enzyme in various subcellular fractions indicated that the enzymes were primarily soluble. Also unlike the glycolytic enzyme phosphoglycerate kinase, the glycogen metabolizing enzymes had a lower specific activity in synaptosomes than in particle free supernatant fractions of homogenates. Regarding regional distribution small (less than twofold) but significant differences were seen between different brain areas. An inverse relationship between the glycogen metabolizing enzymes and hexokinase was observed, that is, regions highest in glycogen synthase and glycogen phosphorylase were lowest in hexokinase and regions highest in hexokinase were lowest in the glycogen metabolizing enzymes. PMID:6218421

Knull, H R; Khandelwal, R L

1982-10-01

156

Antibodies as defensive enzymes  

Microsoft Academic Search

Antibodies (Abs) and enzymes are structural and functional relatives. Abs with promiscuous peptidase activity are ubiquitous in healthy humans, evidently derived from germline variable domain immunoglobulin genes encoding the serine protease-like nucleophilic function. Exogenous and endogenous electrophilic antigens can bind the nucleophilic sites covalently, and recent evidence suggests that immunization with such antigens can induce proteolytic antibodies. Previously, Ab catalytic

Sudhir Paul; Yasuhiro Nishiyama; Stephanie Planque; Sangeeta Karle; Hiroaki Taguchi; Carl Hanson; Marc E. Weksler

2005-01-01

157

Implantable enzyme amperometric biosensors.  

PubMed

The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. PMID:22516142

Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

2012-03-28

158

Engineering enzyme specificity  

Microsoft Academic Search

Protein engineering is the application of knowledge to design and alter protein function and structure. Although powerful methods, from specific to random, have been developed for the redesign of protein architecture, their successful application is dependent on the information known about the protein. This database of information is providing a foundation for establishing rules that govern enzyme—substrate interactions.

Jennifer L Harris; Charles S Craik

1998-01-01

159

Enzyme Concentrations in Tissues  

Microsoft Academic Search

Apparent enzyme concentrations in cells and in mitochondria are calculated from data available in the literature. These values are 10-6 to 10-5 moles per kilogram of tissue. It is pointed out that these concentrations are much higher than those used in enzymatic studies in vitro. Metabolic interpretations of experiments in vitro should consider this additional departure from conditions in vivo.

Paul A. Srere

1967-01-01

160

Enzymes in cancer  

PubMed Central

1. A procedure for partial purification of asparaginase from chicken liver is presented. 2. The bulk of the enzyme is located in the soluble fraction of chicken liver. 3. Molecular weights of chicken-liver asparaginase and of the guinea-pig serum enzyme, estimated by gel filtration, were 306000 and 210000 respectively. The Michaelis constants (Km) at 37° and pH8·5 were 6·0×10?5m and 7·2×10?5m respectively. 4. At 50° the chicken-liver enzyme was moderately stable, some activity being lost by aggregation; in dilute electrolyte solutions the activity rapidly diminished. 5. The anti-lymphoma effect of guinea-pig serum in mice carrying the 6C3HED tumour was confirmed. Chicken-liver asparaginase also showed an effect but in this case the enzyme preparation had to be administered repeatedly. 6. Guinea-pig serum asparaginase was stable for several days in mouse blood, after intraperitoneal injection, whereas chicken-liver asparaginase rapidly disappeared. 7. Aspartic acid ?-hydrazide was shown to be a competitive inhibitor of chicken-liver asparaginase with Ki approx. 5·6×10?4m. In mice it produced an anti-lymphoma effect, as reported previously.

Ohnuma, T.; Bergel, F.; Bray, R. C.

1967-01-01

161

Toying with Enzyme Catalysis.  

ERIC Educational Resources Information Center

Describes a set of manipulatives that are used to establish a secure understanding of the concepts related to the environmental factors that affect the activities of enzymes. Includes a description of the model components and procedures for construction of the model. (DDR)

Richards, Debbie

1998-01-01

162

Brain Drug-Metabolizing Cytochrome P450 Enzymes are Active In Vivo, Demonstrated by Mechanism-Based Enzyme Inhibition  

Microsoft Academic Search

Individuals vary in their response to centrally acting drugs, and this is not always predicted by drug plasma levels. Central metabolism by brain cytochromes P450 (CYPs) may contribute to interindividual variation in response to drugs. Brain CYPs have unique regional and cell-type expression and induction patterns, and they are regulated independently of their hepatic isoforms. In vitro, these enzymes can

Sharon Miksys; Rachel F Tyndale

2009-01-01

163

The Enzyme Function Initiative.  

PubMed

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

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

2011-10-26

164

The Enzyme Function Initiative†  

PubMed Central

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, 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.

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.

2011-01-01

165

War Crimes Act: Current Issues.  

National Technical Information Service (NTIS)

The War Crimes Act of 1996, as amended, makes it a criminal offense to commit certain violations of the laws of war when such offenses are committed by or against U.S. nationals or Armed Service members. Among other things, the Act prohibits certain viola...

M. J. Garcia

2006-01-01

166

Nurse Reinvestment Act. Public Law.  

ERIC Educational Resources Information Center

|This document contains the text of the Nurse Reinvestment Act, which amends the Public Health Service Act to address the increasing shortage of registered nurses by instituting a series of policies to improve nurse recruitment and nurse retention. Title I details two initiatives to boost recruitment of nurses. The first initiative includes the…

Congress of the U.S., Washington, DC.

167

Clean Air Act 1990 Amendments  

SciTech Connect

This book is an analysis of the 1990 Amendments to the Clean Air Act that includes compliance requirements, the new operating permit system, the enhanced enforcement provisions and criminal penalties, potential for citizen enforcement, and the increased reporting requirements. Also analyzed are the new defenses such as permit compliance and protection of employees acting within the direction of employers.

Stensvaag, J.M.

1991-01-01

168

Online Challenge versus Offline ACT  

ERIC Educational Resources Information Center

|This article compares essays written in response to the ACT Essay prompt and a locally developed prompt used for placement. The two writing situations differ by time and genre: the ACT Essay is timed and argumentative; the locally developed is untimed and explanatory. The article analyzes the differences in student performance and predictive…

Peckham, Irvin

2010-01-01

169

Implementing the Amended FOI Act.  

ERIC Educational Resources Information Center

|The Freedom of Information Act amendments, which became effective in February 1975, have so far yielded mixed results. This report provides an account of how different federal agencies are implementing this amended statute. Among the topics discussed are modifications of the original 1966 Freedom of Information Act, which were made in the attempt…

McClain, Wallis

170

Education Leaders Applaud ATTAIN Act  

ERIC Educational Resources Information Center

This article talks about Achievement Through Technology and Innovation (ATTAIN) Act, a bill introduced by Senators Bingaman (D-NM), Burr (R-NC), and Murray (D-WA) and applauded by a coalition of education and industry groups. The proposed ATTAIN Act is similar to its companion in the House (HR 2449), and builds upon the Enhancing Education Through…

Curriculum Review, 2007

2007-01-01

171

An isoelectrically trapped enzyme reactor operating in an electric field.  

PubMed

Membrane enzyme reactors constitute an attempt at integrating catalytic conversion, product separation and/or concentration and catalyst recovery into a single operation. Whereas conventional membrane reactors confine an enzyme, in a free form, to one side of a membrane by size exclusion, electrostatic repulsion, or physical or chemical immobilization onto an intermediate support (gel, liposome), the membrane reactor here described is shown to operate under an entirely new principle: enzyme confinement into an isoelectric trap located in a multicompartment electrolyzer operating in an electric field. Two isoelectric membranes, having pI values encompassing both the enzyme pI and the pH of its optimum of activity, act by continuously titrating the enzyme trapped inside, thus preventing it from escaping the reaction chamber. Charged products generated by the enzyme catalysis are continuously electrophoretically transported away from the reaction chamber and collected into other chambers stacked either towards the cathodic or anodic sides. In a urease reactor, ammonia is continuously harvested towards the cathode, thus allowing >95% substrate consumption with maintenance of enzyme integrity over much longer time periods than in a batch reactor. In a trypsin reactor, casein is digested and biologically active peptides are continuously harvested in a pure form into appropriate isoelectric traps. In a third example, pure D-phenylglycine is produced from a racemate mixture, via an acylation reaction onto a cosubstrate (the ester methyl-4-hydroxyphenyl acetate), brought about by the enzyme penicillin G acylase. PMID:9662167

Righetti, P G; Bossi, A

1998-06-01

172

EzyPred: A top–down approach for predicting enzyme functional classes and subclasses  

Microsoft Academic Search

Given a protein sequence, how can we identify whether it is an enzyme or non-enzyme? If it is, which main functional class it belongs to? What about its sub-functional class? It is important to address these problems because they are closely correlated with the biological function of an uncharacterized protein and its acting object and process. Particularly, with the avalanche

Hong-Bin Shen; Kuo-Chen Chou

2007-01-01

173

Molecular Control of Nitrate Reductase and Other Enzymes Involved in Nitrate Assimilation  

Microsoft Academic Search

Nitrate acts as both a nutrient and a signal in plants. Nitrate induces gene expression of enzymes for its metabolism into amino acids but also has other effects on plant metabolism and development. Familiar nitrate-induced enzymes are nitrate and nitrite reductases, nitrate transporters, glutamine synthetase, glutamate synthase, ferredoxin and ferredoxin NADP+ reductase. Microarray analysis of nitrate-stimulated gene expression has identified

Wilbur H. Campbell

174

A Multiple Alignment Algorithm for Metabolic Pathway Analysis Using Enzyme Hierarchy  

Microsoft Academic Search

In many of the chemical reactions in living cells, enzymes act as catalysts in the conversion of certain compounds (substrates) into other com- pounds (products). Comparative analyses the metabolic pathways formed by such reac- tions give important information on their evolu- tion and on pharmacological targets (Dandekar et al. 1999). Each of the enzymes that consti- tute a pathway is

Yukako Tohsato; Hideo Matsuda; Akihiro Hashimoto

2000-01-01

175

Polyethylene glycol as a spacer for solid-phase enzyme immobilization  

Microsoft Academic Search

With the aim to improve the performance of enzyme bound to hydrophilic solid phases, their immobilization with polyethylene glycol (PEG) tether have been studied. Sweet potato ?-amylase, which hydrolyses the high molecular weight substrate starch and ?-galactosidase, which acts on low molecular weight substrates, were used as model enzymes and beaded thiol–agarose as solid phase. Several two step methods for

C Manta; N Ferraz; L Betancor; G Antunes; F Batista-Viera; J Carlsson; K Caldwell

2003-01-01

176

A hydration study of (1-->4) and (1-->6) linked alpha-glucans by comparative 10 ns molecular dynamics simulations and 500-MHz NMR.  

PubMed

The hydration behavior of two model disaccharides, methyl-alpha-D-maltoside (1) and methyl-alpha-D-isomaltoside (2), has been investigated by a comparative 10 ns molecular dynamics study. The detailed hydration of the two disaccharides was described using three force fields especially developed for modeling of carbohydrates in explicit solvent. To validate the theoretical results the two compounds were synthesized and subjected to 500 MHz NMR spectroscopy, including pulsed field gradient diffusion measurements (1: 4.0. 10(-6) cm(2). s(-1); 2: 4.2. 10(-6) cm(2). s(-1)). In short, the older CHARMM-based force field exhibited a more structured carbohydrate-water interaction leading to better agreement with the diffusional properties of the two compounds, whereas especially the alpha-(1-->6) linkage and the primary hydroxyl groups were inaccurately modeled. In contrast, the new generation of the CHARMM-based force field (CSFF) and the most recent version of the AMBER-based force field (GLYCAM-2000a) exhibited less structured carbohydrate-water interactions with the result that the diffusional properties of the two disaccharides were underestimated, whereas the simulations of the alpha-(1-->6) linkage and the primary hydroxyl groups were significantly improved and in excellent agreement with homo- and heteronuclear coupling constants. The difference between the two classes of force field (more structured and less structured carbohydrate-water interaction) was underlined by calculation of the isotropic hydration as calculated by radial pair distributions. At one extreme, the radial O em leader O pair distribution function yielded a peak density of 2.3 times the bulk density in the first hydration shell when using the older CHARMM force field, whereas the maximum density observed in the GLYCAM force field was calculated to be 1.0, at the other extreme. PMID:14735575

Corzana, Francisco; Motawia, Mohammed S; Du Penhoat, Catherine Hervé; Perez, Serge; Tschampel, Sarah M; Woods, Robert J; Engelsen, Søren B

2004-03-01

177

45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.  

Code of Federal Regulations, 2010 CFR

...Clean Air Act and the Federal Water Pollution Control Act. 2543.86 Section...Clean Air Act and the Federal Water Pollution Control Act. Contracts and...et seq.) and the Federal Water Pollution Control Act as amended (33...

2010-10-01

178

45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.  

Code of Federal Regulations, 2010 CFR

...Clean Air Act and the Federal Water Pollution Control Act. 2543.86 Section...Clean Air Act and the Federal Water Pollution Control Act. Contracts and...et seq.) and the Federal Water Pollution Control Act as amended (33...

2009-10-01

179

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

Code of Federal Regulations, 2013 CFR

...Architectural Barriers Act and the Americans with Disabilities Act. ...Architectural Barriers Act and the Americans with Disabilities Act. ...buildings). (b) The Americans with Disabilities Act...accommodations, State and local government services, and...

2013-04-01

180

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

Code of Federal Regulations, 2010 CFR

...Barriers Act and the Americans with Disabilities Act. 570.614 Section...Barriers Act and the Americans with Disabilities Act. (a) The Architectural...buildings). (b) The Americans with Disabilities Act (42 U.S.C....

2009-04-01

181

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

Code of Federal Regulations, 2010 CFR

...Barriers Act and the Americans with Disabilities Act. 570.614 Section...Barriers Act and the Americans with Disabilities Act. (a) The Architectural...buildings). (b) The Americans with Disabilities Act (42 U.S.C....

2010-04-01

182

Advances in enzyme immobilisation  

Microsoft Academic Search

Improvements in current strategies for carrier-based immobilisation have been developed using hetero-functionalised supports\\u000a that enhance the binding efficacy and stability through multipoint attachment. New commercial resins (Sepabeads) exhibit improved\\u000a protein binding capacity. Novel methods of enzyme self-immobilisation have been developed (CLEC, CLEA, Spherezyme), as well\\u000a as carrier materials (Dendrispheres), encapsulation (PEI Microspheres), and entrapment. Apart from retention, recovery and\\u000a stabilisation,

Dean Brady; Justin Jordaan

2009-01-01

183

Enzymes for trauma  

Microsoft Academic Search

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

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

1970-01-01

184

Bacterial Sulfite-Oxidizing EnzymesEnzymes for Chemolithotrophs Only?  

Microsoft Academic Search

All known sulfite-oxidizing enzymes that have been studied in molecular detail belong to the sulfite oxidase family of molybdoenzymes.\\u000a The first bacterial enzymes in this family were only characterized in 2000, but by now it has become clear that bacterial\\u000a enzymes originating from many different types of bacteria may actually be the most abundant proteins in this enzyme family.\\u000a This

Ulrike Kappler

185

Enzyme Relational Network Reveals Target Enzymes within Metabolic Submodules  

Microsoft Academic Search

Identification of enzyme targets for metabolic engineering requires a global view of the functional relationship among enzymes within metabolic network. In this paper, we propose a method to construct an enzyme relational network based on the significant effect of the rate change of one reaction on the rate of another reaction. We illustrate the method by using a kinetic model

Chalothorn Liamwirat; Supapon Cheevadthanarak; Asawin Meechai; Sakarindr Bhumiratana

2009-01-01

186

Enzyme Molar Fractions: A Powerful Tool for Understanding Enzyme Kinetics.  

ERIC Educational Resources Information Center

|Deduces the relationship between reduced velocity and molar fractions for productive enzyme complexes; obtains the mathematical expression of molar fractions for an enzyme with two specific binding sites per molecule; and proposes a useful plot to follow the dependence of enzyme molar fractions with the concentration of one of its ligands. (JN)|

Serra, Juan L.; And Others

1986-01-01

187

Enzyme exposure and enzyme sensitisation in the baking industry  

Microsoft Academic Search

OBJECTIVES: To assess the exposure to enzymes and prevalence of enzyme sensitisation in the baking industry. METHODS: A cross sectional study was conducted in four bakeries, one flour mill, and one crispbread factory. Sensitisation to enzymes, flours, and storage mites was examined by skin prick and radioallergosorbent (RAST) tests. 365 workers were tested. The workers were interviewed for work related

M Vanhanen; T Tuomi; H Hokkanen; O Tupasela; A Tuomainen; P C Holmberg; M Leisola; H Nordman

1996-01-01

188

Enzyme reactions in a multicompartment electrolyzer with isoelectrically trapped enzymes  

Microsoft Academic Search

The possibility of performing bioconversions under an electric field is here reported. A system is described by which the enzyme is trapped by an isoelectric mechanism between two zwitterionic membranes having pI values encompassing the isoelectric point of the enzyme. The enzyme is loaded into a multicompartment electrolyzer and kept operating under an electric field, which will continuously harvest the

Marcella Chiari; Norma Dell'Orto; Monica Mendozza; Giacomo Carrea; Pier Giorgio Righetti

1996-01-01

189

Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates  

DOEpatents

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.

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

1997-01-01

190

Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates  

DOEpatents

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.

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

1997-11-25

191

Stabilization of Enzymes for Bioreactors.  

National Technical Information Service (NTIS)

The objective of the Phase I project was to develop new stabilization techniques for immobilized enzymes used in bioreactors. The rationale was to provide an environment for optimal stability surrounding the enzyme, then to bind it together by copolymeriz...

M. J. Swanson D. L. Fiedler K. A. Leitch

1989-01-01

192

Liprotamase Capsules Pancreatic Enzyme Replacement ...  

Center for Biologics Evaluation and Research (CBER)

Text Version... that are given orally with each meal or snack.2,3,4 The objective of pancreatic enzyme replacement therapy is to deliver the enzymes with food to ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials

193

Freedom of Information Act Report  

NSF Publications Database

NATIONAL SCIENCE FOUNDATION FREEDOM OF INFORMATION ACT REPORT FOR OCTOBER 1, 1997 THROUGH SEPTEMBER ... The FY1998 FOIA Report for the National Science Foundation will be available as one of the choices ...

194

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...

195

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.

196

Update: the Clean Water Act  

Microsoft Academic Search

The Clean Water Act--officially labeled Public Law 92-500, The Federal Water Pollution Control Act Amendments of 1972--established a national permit discharge elimination system (NPDES) to control the discharge of pollutants into the nation's waters and set strict enforcement deadlines to be complied with by July 1, 1977. The ''best available'' technology (BAT) that is economically achievable must be used by

Meinhold

1977-01-01

197

Supramolecular catalysis beyond enzyme mimics  

Microsoft Academic Search

Supramolecular catalysis - the assembly of catalyst species by harnessing multiple weak intramolecular interactions - has, until recently, been dominated by enzyme-inspired approaches. Such approaches often attempt to create an enzyme-like 'active site' and have concentrated on reactions similar to those catalysed by enzymes themselves. Here, we discuss the application of supramolecular assembly to the more traditional transition metal catalysis

Jurjen Meeuwissen; Joost N. H. Reek

2010-01-01

198

Silica-Immobilized Enzyme Reactors  

Microsoft Academic Search

Recent studies have demonstrated the applicability and versatility of immobilized enzyme reactors (IMERs) for chemical and biochemical synthesis and analysis. The majority of IMER systems rely on enzymes immobilized to packed matrices within flow-through devices. This review focuses primarily on the use of silica as a support for enzyme immobilization and specific applications of the resulting silica-based IMERs. A number

Heather R. Luckarift

2008-01-01

199

Catalase Hybrid Enzymes in Maize  

Microsoft Academic Search

In maize endosperm there are two electrophoretic variants of catalase. The variations are under genetic control, and the heterozygote shows three hybrid enzymes with mobilities intermediate between the parental enzymes. Thus, maize catalase may exist as a tetramer, and the hybrid enzymes may be formed by random association of two different catalase monomers.

Lars Beckman; John G. Scandalios; James L. Brewbaker

1964-01-01

200

The Catalytic Function of Enzymes.  

ERIC Educational Resources Information Center

|Discusses: structure of the enzyme molecule; active site; reaction mechanism; transition state; factors affecting enzyme reaction rates, concentration of enzyme; concentration of substrate; product concentration; temperature effects and pH effects; factors causing a lowering of activation energy; proximity and orientation effects; substrate…

Splittgerber, Allan G.

1985-01-01

201

The Catalytic Function of Enzymes.  

ERIC Educational Resources Information Center

Discusses: structure of the enzyme molecule; active site; reaction mechanism; transition state; factors affecting enzyme reaction rates, concentration of enzyme; concentration of substrate; product concentration; temperature effects and pH effects; factors causing a lowering of activation energy; proximity and orientation effects; substrate strain…

Splittgerber, Allan G.

1985-01-01

202

A sensitive enzyme electrode for phenol monitoring  

SciTech Connect

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.

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

1990-01-01

203

Novel starch-related enzymes and carbohydrates.  

PubMed

In chloroplasts, both biosynthesis and degradation of starch are strictly regulated but the mechanisms involved are still incompletely understood. Recent studies revealed two novel and regulatory relevant aspects in the biochemistry of starch: the phosphorylation of starch and the starch-related metabolism of cytosolic heteroglycans. Starch phosphorylation occurs by a sequential action of two plastidial enzymes, the glucan, water dikinase (GWD; EC 2.7.9.4) and the phosphoglucan, water dikinase (PWD; EC 2.7.9.5). Both enzymes utilize ATP as dual phosphate donor and transfer the terminal phosphate group to water whereas the beta-phosphate is used for esterification of glucosyl moieties. The metabolism of starch-derived degradation products is closely linked to recently discovered cytosolic heteroglycans that possess, as prominent constituents, arabinose, galactose, glucose and fucose. The pattern of glycosidic linkages is highly complex comprising more than 25 different bonds. During the dark period the size distribution or the amount of the cytosolic heteroglycans increases depending on the plant species. As revealed by in vitro 14C labeling assays, the heteroglycans act as both glucosyl acceptors and donors for two cytosolic glucosyl transferases, the phosphorylase (EC 2.4.1.1) and the transglucosidase (EC 2.4.1.25) and, at least in part, both enzymes utilize the same glucosyl acceptor and donor sites. In mutants of Arabidopsis thaliana L. that are deficient in the cytosolic transglucosidase both the structure and (bio)chemical properties of the heteroglycans are altered. PMID:17666166

Fettke, J; Eckermann, N; Kötting, O; Ritte, G; Steup, M

2007-01-21

204

Extracellular enzyme-clay mineral complexes: Enzyme adsorption, alteration of enzyme activity, and protection from photodegradation  

Microsoft Academic Search

Enzymes released extracellularly by micro-organisms have major functions in nutrient acquisition and organic matter degradation. Clay particles, common in many surface waters, can modify enzyme activity. Clay minerals are known to form aggregates with organic molecules, and the formation of enzyme-clay complexes could alter the level of activity. Montmorillonite clay and clay extracted from Elledge Lake (Tuscaloosa, Alabama) basin soil

Todd Tietjen; Robert G. Wetzel

2003-01-01

205

Theoretical Study of the Effect of Enzyme-Enzyme Interactions on Steady-State Enzyme Kinetics  

Microsoft Academic Search

Equilibrium statistical mechanics is much concerned with problems involving intermolecular interactions, either in lattices or in pure fluids or solutions. The possibility of enzyme-enzyme interactions suggests that the same problems might be studied profitably at steady state as well as at equilibrium. In the systems we consider, each of the identical enzyme molecules of the system undergoes steady-state stochastic cycling

Terrell L. Hill

1977-01-01

206

A Novel 3-Sulfinopropionyl Coenzyme A (3SP-CoA) Desulfinase from Advenella mimigardefordensis Strain DPN7T Acting as a Key Enzyme during Catabolism of 3,3?-Dithiodipropionic Acid Is a Member of the Acyl-CoA Dehydrogenase Superfamily  

PubMed Central

3-Sulfinopropionyl coenzyme A (3SP-CoA) desulfinase (AcdDPN7) is a new desulfinase that catalyzes the sulfur abstraction from 3SP-CoA in the betaproteobacterium Advenella mimigardefordensis strain DPN7T. During investigation of a Tn5::mob-induced mutant defective in growth on 3,3?-dithiodipropionate (DTDP) and also 3-sulfinopropionate (3SP), the transposon insertion was mapped to an open reading frame with the highest homology to an acyl-CoA dehydrogenase (Acd) from Burkholderia phenoliruptrix strain BR3459a (83% identical and 91% similar amino acids). An A. mimigardefordensis ?acd mutant was generated and verified the observed phenotype of the Tn5::mob-induced mutant. For enzymatic studies, AcdDPN7 was heterologously expressed in Escherichia coli BL21(DE3)/pLysS by using pET23a::acdDPN7. The purified protein is yellow and contains a noncovalently bound flavin adenine dinucleotide (FAD) cofactor, as verified by high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC-ESI-MS) analyses. Size-exclusion chromatography revealed a native molecular mass of about 173 kDa, indicating a homotetrameric structure (theoretically 179 kDa), which is in accordance with other members of the acyl-CoA dehydrogenase superfamily. In vitro assays unequivocally demonstrated that the purified enzyme converted 3SP-CoA into propionyl-CoA and sulfite (SO32?). Kinetic studies of AcdDPN7 revealed a Vmax of 4.19 ?mol min?1 mg?1, an apparent Km of 0.013 mM, and a kcat/Km of 240.8 s?1 mM?1 for 3SP-CoA. However, AcdDPN7 is unable to perform a dehydrogenation, which is the usual reaction catalyzed by members of the acyl-CoA dehydrogenase superfamily. Comparison to other known desulfinases showed a comparably high catalytic efficiency of AcdDPN7 and indicated a novel reaction mechanism. Hence, AcdDPN7 encodes a new desulfinase based on an acyl-CoA dehydrogenase (EC 1.3.8.x) scaffold. Concomitantly, we identified the gene product that is responsible for the final desulfination step during catabolism of 3,3?-dithiodipropionate (DTDP), a sulfur-containing precursor substrate for biosynthesis of polythioesters.

Schurmann, Marc; Deters, Anika; Wubbeler, Jan Hendrik

2013-01-01

207

Pipeline Safety Act of 1979  

SciTech Connect

Thanks to the close cooperation of the members of Congress with gas-industry representatives, the Pipeline Safety Act of 1979 was signed into law with almost unanimous support among all of the parties involved. A brief overview of the key provisions by the Amerian Gas Association demonstrates that this legislation is fair and equitable, especially ragarding the treatment of existing LNG facilities and the legal liability of their owners and operators. The act contains a grandfathering provision protecting facilities applied for prior to March 1, 1978, from subsequent regulatory standards enacted by the US Department of Transportation. Furthermore, in place of the concept of strict liability for LNG accidents by means of an LNG superfund - as stipulated in earlier versions of legislation - the act directs the Secretary of Transportation to undertake a study to determine reasonable liability requirements. As a result, private insurance companies will continue to provide adequate coverage for LNG operations.

Baly, M. III; Ward, W.T. III

1980-01-01

208

7 CFR 1207.302 - Act.  

Code of Federal Regulations, 2012 CFR

...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE POTATO RESEARCH AND PROMOTION PLAN Potato Research and Promotion Plan Definitions § 1207.302 Act. Act means the Potato Research and Promotion Act, Title III of...

2012-01-01

209

7 CFR 1210.302 - Act.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Act. 1210.302 Section 1210.302 Agriculture Regulations of the Department...Watermelon Research and Promotion Plan Definitions § 1210.302 Act. Act means the Watermelon...

2012-01-01

210

7 CFR 1250.302 - Act.  

Code of Federal Regulations, 2012 CFR

...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE EGG RESEARCH AND PROMOTION Egg Research and Promotion Order Definitions § 1250.302 Act. Act means the Egg Research and Consumer Information Act and as it...

2012-01-01

211

ACTS Quarterly, Issue 90/4.  

National Technical Information Service (NTIS)

Articles in this issue include: A Giant Step: The First Call Is Placed Through ACTS NGSI MCS Via the Engineering Model Payload, The ACTS Mobile Terminal, and Development of ACTS BBP Earth Stations Continues.

1990-01-01

212

7 CFR 63.1 - Act.  

Code of Federal Regulations, 2013 CFR

...THE EGG PRODUCTS INSPECTION ACT (CONTINUED) NATIONAL SHEEP INDUSTRY IMPROVEMENT CENTER General Provisions Definitions § 63...Act, 7 U.S.C. 2008j, as amended by section 11009 of the Food, Conservation, and Energy Act of 2008 (Pub. L....

2013-01-01

213

7 CFR 930.1 - Act.  

Code of Federal Regulations, 2013 CFR

...VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE TART CHERRIES GROWN IN THE STATES OF MICHIGAN, NEW YORK, PENNSYLVANIA, OREGON, UTAH, WASHINGTON, AND WISCONSIN Order Regulating Handling Definitions § 930.1 Act. Act means Public Act No....

2013-01-01

214

7 CFR 1160.101 - Act.  

Code of Federal Regulations, 2012 CFR

...Marketing Agreements and Orders; Milk), DEPARTMENT OF AGRICULTURE FLUID MILK PROMOTION PROGRAM Fluid Milk Promotion Order Definitions § 1160.101 Act. Act means the Fluid Milk Promotion Act of 1990, Subtitle H of Title XIX of the...

2012-01-01

215

7 CFR 1210.302 - Act.  

Code of Federal Regulations, 2013 CFR

...COMMODITIES), DEPARTMENT OF AGRICULTURE WATERMELON RESEARCH AND PROMOTION PLAN Watermelon Research and Promotion Plan Definitions § 1210.302 Act. Act means the Watermelon Research and Promotion Act of 1985...

2013-01-01

216

Trans-acting temporal locus within the beta-glucuronidase gene complex.  

PubMed Central

Mice carrying the [Gus]H haplotype of the beta-glucuronidase gene complex have considerably decreased enzyme levels and a decreased rate of enzyme synthesis. This is now shown to result from the action of two regulatory loci within the gene complex. One is a systemic regulator, Gus-u, that acts cis to cause a uniform reduction in enzyme levels in all tissues. The other is a temporal locus, Gus-t, that acts trans to cause abrupt switches in the rate of enzyme synthesis in only certain tissues and at characteristic stages of development. The distinction between these two loci was made possible by the introduction of a method for quantitating the relative numbers of A and H allozyme subunits in beta-glucuronidase tetramers. The procedure involves purification of the enzyme, cleavage at methionyl residues with CNBr, isoelectric focusing to separate the peptides, and quantitation of the peptide containing the A/H amino acid substitution. The presence of a trans-acting regulatory locus within a gene complex raises evolutionary and functional questions about why it is located there and how it acts. Images

Lusis, A J; Chapman, V M; Wangenstein, R W; Paigen, K

1983-01-01

217

Deubiquitylating enzymes and disease  

PubMed Central

Deubiquitylating enzymes (DUBs) can hydrolyze a peptide, amide, ester or thiolester bond at the C-terminus of UBIQ (ubiquitin), including the post-translationally formed branched peptide bonds in mono- or multi-ubiquitylated conjugates. DUBs thus have the potential to regulate any UBIQ-mediated cellular process, the two best characterized being proteolysis and protein trafficking. Mammals contain some 80–90 DUBs in five different subfamilies, only a handful of which have been characterized with respect to the proteins that they interact with and deubiquitylate. Several other DUBs have been implicated in various disease processes in which they are changed by mutation, have altered expression levels, and/or form part of regulatory complexes. Specific examples of DUB involvement in various diseases are presented. While no specific drugs targeting DUBs have yet been described, sufficient functional and structural information has accumulated in some cases to allow their rapid development. Republished from Current BioData's Targeted Proteins database (TPdb; ).

Singhal, Shweta; Taylor, Matthew C; Baker, Rohan T

2008-01-01

218

Long-acting reversible contraception.  

PubMed

Although short-acting reversible hormonal contraceptives, such as oral contraceptives and the contraceptive patch and vaginal ring, remain the most commonly used contraceptive methods in the United States, they are also associated with the highest failure rates. Long-acting reversible contraception (LARC) methods, such as intrauterine devices and contraceptive implants, offer high continuation rates and very low failure rates, and are safe for use in most women. The provision of LARC methods to adolescent, young adult and nulliparous women is a relatively new concept that offers an innovative option for these populations. PMID:24138662

Peck, Susan A

2013-10-01

219

7 CFR 1218.1 - Act.  

Code of Federal Regulations, 2012 CFR

...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE BLUEBERRY PROMOTION, RESEARCH, AND INFORMATION ORDER Blueberry Promotion, Research, and Information Order Definitions § 1218.1 Act. Act...

2012-01-01

220

7 CFR 1218.1 - Act.  

Code of Federal Regulations, 2013 CFR

...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE BLUEBERRY PROMOTION, RESEARCH, AND INFORMATION ORDER Blueberry Promotion, Research, and Information Order Definitions § 1218.1 Act. Act...

2013-01-01

221

Human Lung Angiotensin Converting Enzyme  

PubMed Central

To enable its immunohistologic localization, angiotensin converting enzyme (EC 3.4.15.1) from human lung was solubilized by trypsinization and purified ?2,660-fold to apparent homogeneity from a washed lung particulate fraction. The specific activity of pure enzyme was estimated to be 117 ?mol/min per mg protein with the substrate hippuryl-l-histidyl-l-leucine. Consistent with previously described lung enzyme studies, catalytic activity was strongly inhibited by EDTA, O-phenanthroline, SQ 20,881, and SQ 14,225 and increased by CoCl2. SQ 20,881 was a somewhat more potent inhibitor than SQ 14,225, unlike rabbit lung enzyme. The Michaelis constant (Km) with hippuryl-l-histidyl-l-leucine was 1.6 mM. The molecular weight was estimated at 150,000 from sucrose density gradient centrifugation. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a single polypeptide chain estimated at 130,000 daltons. Rabbit antibody to human lung enzyme was prepared by parenteral administration of pure angiotensin-converting enzyme in Freund's adjuvant. Rabbit antibody to human lung angiotensin-converting enzyme appeared to crossreact weakly with the rabbit enzyme and strongly inhibited the catalytic activity of the enzymes from human serum, lung, and lymph node. The specificity of the rabbit antibody and purity of the final human lung enzyme preparation was suggested by the single precipitin lines obtained by radial double immunodiffusion, and by the coincidence of enzyme catalytic activity and immunoreactivity on polyacrylamide gel electrophoresis, with both relatively pure and highly impure enzymes. Generally applicable sensitive analysis of acrylamide gels for immunoreactivity (and subsequently for any other activity) by use of intact gel slices in radial double immunodiffusion was devised. Human lung enzyme was very tightly bound to and catalytically active on anti-human enzyme antibody covalently bound to Sepharose 4B, and could not be readily dissociated without inactivation. Antibody to human lung angiotensin converting enzyme has permitted tissue localization of the enzyme, which appears to be clinically useful in diseases associated with abnormal abundance of angiotensin-converting enzyme in tissues, such as sarcoidosis. Images

Friedland, Joan; Silverstein, Emanuel; Drooker, Martin; Setton, Charlotte

1981-01-01

222

The altruistic act of asking  

PubMed Central

There are a number of obstacles to increasing the supply of cadaveric organs for transplantation. These include reluctance on the part of relatives to agree to the so called harvesting of organs from their deceased relative, and the unwillingness of some doctors to approach grieving families and ask consent for this harvesting to take place. In this paper I will focus on the altruistic act of asking that the latter entails, and will argue that failure to acknowledge the personal cost of this act to physicians is having an adverse impact on the supply of organs. I will draw analogies with the almost equally neglected altruistic act of undertaking anatomy dissection and all of the related breaking of societal taboos. I will examine the language used in discussions about increasing organ supply and conclude that the terms cadaveric and harvest are unhelpful in gaining public confidence. A process and vocabulary that openly acknowledges and validates the altruistic acts demanded of all the human beings involved—donors, recipients, their respective relatives, and the health professionals who mediate between them—is needed if the supply of organs is to be increased.

Kirklin, D

2003-01-01

223

Implementing the Reading Excellence Act.  

ERIC Educational Resources Information Center

This slide presentation outlines one state's (Utah) version of implementation of a model for literacy learning under the Reading Excellence Act (REA). According to the presentation, the model is called "The Utah Reads K-3 Literacy Model." The presentation is divided into the following sections: Utah's Vision: What We've Learned So Far; One…

Lacy, Laurie; Dole, Janice; Donaldson, Becky; Donaldson, Brady

224

Implementing the 1981 Education Act  

Microsoft Academic Search

This article examines factors affecting the development and implementation of Education Policy with special reference to the 1981 Education Act for England and Wales. Research is reported about professional practice and administrative behaviour in special education assessment. Six professional and administrative factors are identified which may affect the implementation of the new special education legislation:1.The nature of the professional domain

John Welton

1983-01-01

225

The Indian Child Welfare Act.  

ERIC Educational Resources Information Center

|The Indian Child Welfare Act of 1978 (I.C.W.A.) is federal legislation which preempts state law whenever Indian children may be removed from their families. The I.C.W.A. permits Indian tribal courts to decide the future of Indian children, establishes minimum federal standards for removal of Indian children from their families, requires that…

Steward, Katy Jo

226

The Americans with Disabilities Act  

Microsoft Academic Search

This study explored smaller businesses' understanding of and compliance with the Americans with Disabilities Act, particularly as it relates to the accommodation of people with physical versus mental disabilities. An ADA compliance score was developed for personnel practices regarding employees with physical and mental disabilities and a comparison of scores was made between employers who could recall any of the

R. Paul Maiden; Beverly Younger

1996-01-01

227

The Proposed Environmental Justice Act: \\  

Microsoft Academic Search

This Comment addresses the concept of environmental racism, the tools that have been used to fight it, and the proposed Environmental Justice Act of 1993. Part II begins with an examination of the evidence minority communities have relied on as proof that environmental racism exists. The evidence contained in numerous articles clearly shows inequalities in the amounts of environmental and

Claire L. Hasler

1994-01-01

228

ACT: the Artemis comparison tool  

Microsoft Academic Search

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

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

2005-01-01

229

The Antiquities Act of 1906.  

National Technical Information Service (NTIS)

This history of the Antiquities Act of 1906 has been prepared to help fill a gap in knowledge of one of the foundation stones of the National Park System. Its preparation was stimulated partly by the approach of the centennial of Yellowstone National Park...

R. F. Lee

1970-01-01

230

Energy Policy Act of 2005  

Microsoft Academic Search

This article provides a comprehensive review and describes the impact of the bill on distributed generation, the electricity market, the national electrical grid, and the future of how electricity will be delivered in the United States. The energy policy act of 2005 removes the requirement that utilities purchase power under the condition that the qualifying facility has access to alternative

Keith Malmedal; Benjamin Kroposki; PANKAJ K. SEN

2007-01-01

231

Debating the Controlled Substances Act  

Microsoft Academic Search

In the United States, the basis of modern drug regulation is the Controlled Substances Act (CSA) of 1970. The CSA laid out the authority of the federal government and provided a framework within which all existing and new substances could be regulated on their abuse potential, safety, and medical utility. The debates over the CSA centered on several critical issues:

Joseph F. Spillane

2004-01-01

232

36 CFR 51.101 - Did the 1998 Act repeal the 1965 Act?  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Did the 1998 Act repeal the 1965 Act? 51.101 Section... CONCESSION CONTRACTS The Effect of the 1998 Act's Repeal of the 1965 Act § 51.101 Did the 1998 Act repeal the 1965 Act? Section 415...

2009-07-01

233

36 CFR 51.101 - Did the 1998 Act repeal the 1965 Act?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Did the 1998 Act repeal the 1965 Act? 51.101 Section... CONCESSION CONTRACTS The Effect of the 1998 Act's Repeal of the 1965 Act § 51.101 Did the 1998 Act repeal the 1965 Act? Section 415...

2010-07-01

234

Ethanologenic enzymes of Zymomonas mobilis  

SciTech Connect

In this study, we have proposed to investigate the mechanisms which permit the high level expression of the ethanologenic enzymes from Zymomonas mobilis (PDC, ADHI, ADHII). This research is continuing essentially as proposed in the original grant except that the scope has been expanded to include additional glycolytic enzymes from the lower portion of the Entner-Doudoroff pathway which are also highly expressed. Several enzymes which are expressed only at moderate levels are being examined for comparison (tryptophan biosynthesis, acid phosphatase).

Ingram, L.O.

1990-02-13

235

A Conserved Family of Enzymes That Phosphorylate Inositol Hexakisphosphate  

Microsoft Academic Search

Inositol pyrophosphates are a diverse group of high-energy signaling molecules whose cellular roles remain an active area of study. We report a previously uncharacterized class of inositol pyrophosphate synthase and find it is identical to yeast Vip1 and Asp1 proteins, regulators of actin-related protein-2\\/3 (ARP 2\\/3) complexes. Vip1 and Asp1 acted as enzymes that encode inositol hexakisphosphate (IP6) and inositol

Sashidhar Mulugu; Wenli Bai; Peter C. Fridy; Robert J. Bastidas; James C. Otto; D. Eric Dollins; Timothy A. Haystead; Anthony A. Ribeiro; John D. York

2007-01-01

236

?-Crystallin Assisted Refolding of Enzyme Substrates: Optimization of External Parameters  

Microsoft Academic Search

?-Crystallin is known to act as a molecular chaperone by preventing the aggregation of partially unfolded substrate proteins.\\u000a It is also known to assist the refolding of a number of denatured enzymes, but the activity yield is often less than 20%.\\u000a In this paper, we have tried to tune the refolding ability of ?-crystallin in vitro by optimizing various external

A. Biswas; K. P. Das

2007-01-01

237

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

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

238

Enzyme actuated bioresponsive hydrogels  

NASA Astrophysics Data System (ADS)

Bioresponsive hydrogels are emerging with technological significance in targeted drug delivery, biosensors and regenerative medicine. Conferred with the ability to respond to specific biologically derived stimuli, the design challenge is in effectively linking the conferred biospecificity with an engineered response tailored to the needs of a particular application. Moreover, the fundamental phenomena governing the response must support an appropriate dynamic range and limit of detection. The design of these systems is inherently complicated due to the high interdependency of the governing phenomena that guide the sensing, transduction, and the actuation response of hydrogels. To investigate the dynamics of these materials, model systems may be used which seek to interrogate the system dynamics by uni-variable experimentation and limit confounding phenomena such as: polymer-solute interactions, polymer swelling dynamics and biomolecular reaction-diffusion concerns. To this end, a model system, alpha-chymotrypsin (Cht) (a protease) and a cleavable peptide-chromogen (pro-drug) covalently incorporated into a hydrogel, was investigated to understand the mechanisms of covalent loading and release by enzymatic cleavage in bio-responsive delivery systems. Using EDC and Sulfo-NHS, terminal carboxyl groups of N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide, a cleavable chromogen, were conjugated to primary amines of a hydrated poly(HEMA)-based hydrogel. Hydrogel discs were incubated in buffered Cht causing enzyme-mediated cleavage of the peptide and concomitant release of the chromophore for monitoring. To investigate substrate loading and the effects of hydrogel morphology on the system, the concentration of the amino groups (5, 10, 20, and 30 mol%) and the cross-linked density (1, 5, 7, 9 and 12 mol%) were independently varied. Loading-Release Efficiency of the chromogen was shown to exhibit a positive relation to increasing amino groups (AEMA). The release rates demonstrated a negative relation to increasing cross-linked density attributed to decreasing void fractions and increasing tortuosities. The diffusion coefficient of Cht, D0, Cht, was determined to be 6.9 +/- 0.5 x 10-7 cm2 s -1, and the range of Deff of Cht for 1 to 12 mol% TEGDA was determined to 6.9 x10-8 to 0.1 x 10 -8cm2 s-1. We show how these parameters may be optimized and used to achieve programmed release rates in engineered bio-responsive systems. The field of bioresponsive hydrogels is continuing to expand as the need for such materials persists. Future work will enable more control over the loading and release of therapeutic and diagnostic moieties. Continued research regarding in enzymatically actuated hydrogels will involve pre-polymerization loading methodologies; in silico diffusion-reaction multiphysics modeling; enzyme actuated degradation of the polymer; and substation of various mediating enzyme, cleavable peptides, and release molecules.

Wilson, Andrew Nolan

239

STUDIES ON ENZYME ACTION  

PubMed Central

The ester-hydrolyzing or lipase actions of extracts of whole rats whose ages ranged from 3 days before birth to 3 years 15 days were tested on ten simple esters by the method described in previous papers. The results are presented in the form of curves, both as absolute actions and as relative actions on the different substrates. The "pictures" of the relative actions changed progressively with increasing age of the rat. For the embryo and the youngest rats, the curves approached those given by the Flexner-Jobling rat carcinoma and by a number of tumors of human origin, changing to a type characteristic of the adult rat, and appearing to revert again to some extent to the embryonic type for the oldest rats. The changes in the actions on individual esters and the relative changes in the actions on different esters are discussed in detail. The greatest increases in actions as the rats became older were found with methyl and ethyl butyrates; at the same time that the actions on some of the other esters were also found to change in characteristic ways. Similar experiments with the protease actions of the extracts of whole rats of different ages on three protein preparations did not give differences similar to those found for the lipase actions. The probable reasons for these observed differences in the two sets of enzyme actions are discussed.

Falk, K. George; Noyes, Helen Miller; Sugiura, Kanematsu

1925-01-01

240

Flow-cell fibre-optic enzyme sensor for phenols  

SciTech Connect

A solid-state fibre-optic luminescent oxygen sensor was used for flow-through measurements. It acts as a transducer in a new flow-cell enzyme sensor arrangement. This arrangement comprises a flow path, sample injector, microcolumn with the immobilized enzyme, oxygen membrane and fibre-optic connector joined together to form an integral unit. Laccase enzyme was used as a recognition system which provided specific oxidation of the substrates with the dissolved oxygen being monitored. The assay procedure was optimized and performance of the new system studied. The sensor was applied to the determination polyphenol content in tea, brandy, etc. (quality control test). The sensitivity to some important phenolic compounds was tested with the view of industrial wastewater control applications. 5 refs., 6 figs., 1 tab.

Papkovsky, D.B.; Ghindilis, A.L.; Kurochkin, I.N. (Research Center of Molecular Diagnostics and Therapy, Moscow (Russian Federation))

1993-07-01

241

7 CFR 1160.101 - Act.  

Code of Federal Regulations, 2013 CFR

...1160.101 Act. Act means the Fluid Milk Promotion Act of 1990, Subtitle H of Title XIX of the Food, Agriculture, Conservation, and Trade Act of 1990, Public Law 101-624, 7 U.S.C. 6401-6417, and any amendments...

2013-01-01

242

Targeting Inactive Enzyme Conformation  

PubMed Central

There has been considerable interest in protein tyrosine phosphatase 1B (PTP1B) as a therapeutic target for diabetes, obesity, as well as cancer. Identifying inhibitory compounds with good bioavailability is a major challenge of drug discovery programs targeted toward PTPs. Most current PTP active site-directed pharmacophores are negatively charged pTyr mimetics which cannot readily enter the cell. This lack of cell permeability limits the utility of such compounds in signaling studies and further therapeutic development. We identify aryl diketoacids as novel pTyr surrogates and show that neutral amide-linked aryl diketoacid dimers also exhibit excellent PTP inhibitory activity. Kinetic studies establish that these aryl diketoacid derivatives act as noncompetitive inhibitors of PTP1B. Crystal structures of ligand-bound PTP1B reveal that both the aryl diketoacid and its dimeric derivative bind PTP1B at the active site, albeit with distinct modes of interaction, in the catalytically inactive, WPD loop open conformation. Furthermore, dimeric aryl diketoacids are cell permeable and enhance insulin signaling in hepatoma cells, suggesting that targeting the inactive conformation may provide a unique opportunity for creating active site-directed PTP1B inhibitors with improved pharmacological properties.

Liu, Sijiu; Zeng, Li-Fan; Wu, Li; Yu, Xiao; Xue, Ting; Gunawan, Andrea M.; Ya-Qiu, Long; Zhang, Zhong-Yin

2009-01-01

243

Enzyme immobilization on graft copolymers  

Microsoft Academic Search

Immobilised enzymes can be reused, easily separated from the reaction medium, and are more stable in most of the cases. Despite of these advantages, there are still some problems facing the usage of the immobilised enzyme in industry. One of those problems is diffusion-limitation of both the reactants and the products. This problem becomes even more serious when the products

M. S. Mohy Eldin

1999-01-01

244

Salivary enzymes and periodontal disease  

Microsoft Academic Search

Background: Host responses to periodontal disease include the production of different enzymes that are released by stromal, epithelial or inflammatory cells. There are important enzymes associated with cell injury and cell death like: aspartate and alanine aminotransferase (AST, ALT), lactate dehydrogenase (LDH), creatine cinase (CK), alkaline and acidic phosphatase (ALP, ACP), gama glutamil transferase (GGT). Changes in enzymatic activity reflect

Tatjana Todorovic; Ivan Dozic; Mario Vicente Barrero; Besir Ljuskovic; Janko Pejovic; Marjan Marjanovic

245

Structural Determinants of Enzymic Processivity  

Microsoft Academic Search

A processive enzyme binds a polymeric substrate and catalyzes a series of similar chcmical reactions along that polymer before releasing the fully modified polymer to solvent. Bovine pancreatic ribonuclease A (RNase A) is a nonprocessive endoribonuclease that binds the bases of adjacent RNA residues in three enzymic subsites: B1, B2, and B3. The B1 subsite binds only to residues having

Stephen B. delCardayre; Ronald T. Raines

1994-01-01

246

Spectroscopy of an Enzyme Reaction  

Microsoft Academic Search

IF a suitable amount of monoethyl-hydrogen peroxide is added to an active preparation of liver catalase at pH 7, the enzyme spectrum disappears instantly, and two new absorption bands in the green range of the spectrum appear. In the course of a few minutes, at room temperature, the new absorption bands decrease in intensity, and simultaneously the original enzyme spectrum

Kurt G. Stern

1935-01-01

247

Immobilized enzyme reactors in proteomics  

Microsoft Academic Search

Fast, efficient characterization of proteins is becoming one of the hottest topics in the bioanalytical community, especially for large-scale proteomic studies. As an attractive approach, protein digestion by enzymes supported on various matrices (referred to as immobilized enzyme reactors, IMERs) has recently attracted much attention.In this article, we present a critical overview of some highly efficient IMERs and related analytical

Junfeng Ma; Lihua Zhang; Zhen Liang; Yichu Shan; Yukui Zhang

2011-01-01

248

Making the Rate: Enzyme Dynamics  

ERIC Educational Resources Information Center

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.

Ragsdale, Frances R.

2004-01-01

249

Making the Rate: Enzyme Dynamics  

ERIC Educational Resources Information Center

|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.|

Ragsdale, Frances R.

2004-01-01

250

Enzyme Investigations for Introductory Courses  

NSDL National Science Digital Library

This resource is a detailed manual for instructing a laboratory exercise in cellular physiology and enzyme kinetic. For example, students will ascertain how various factors (temperature, pH, substrate and enzyme concentration) affect the rate of reaction. This exercise is suitable for introductory courses in cellular biology, physiology, or courses requiring a moderate understanding of biochemistry.

Ruthanne B. Pitkin (Shippensburg University;)

1992-01-01

251

False memories for aggressive acts.  

PubMed

Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed. PMID:23639921

Laney, Cara; Takarangi, Melanie K T

2013-04-29

252

Revising the Clean Air Act  

SciTech Connect

Rewriting the Clean Air Act (CAA) amendments has posed a problem for Congress since the expiration of the 1977 act in 1982; the provisions have been simply extended year to year. With mandatory CAA sanctions threatening many areas of the country this December 31, Congress is once more struggling with issues of acid rain, toxic air pollutants, and the nonattainment of health-related standards in many areas of the United States. The chief legislative focus in the Senate is the bill introduced by Senator George Mitchell; counterpart bills exist in the House of Representatives but have not been subject to the same degree of analysis. Even if the Senate bill is not enacted in its present version, its primary elements will certainly form the basis of a final bill. Some of these provisions are briefly outlined.

Dowd, R.M.

1987-12-01

253

Acting White: A Critical Review  

Microsoft Academic Search

The hypothesis of acting White has been heatedly debated and influential over the last 20 years or so in explaining the Black–White\\u000a test score gap. Recently, economists have joined the debate and started providing new theoretical and empirical analyses of\\u000a the phenomenon. This paper critically reviews the arguments that have been advanced to support and refute the hypothesis.\\u000a This review particularly

Kitae Sohn

2011-01-01

254

The new Clean Air Act  

SciTech Connect

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.

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

1991-05-01

255

Clery Act: Road to Compliance  

Microsoft Academic Search

The purpose of this study was to explore what factors served as impediments to institutional efforts to comply with Clery\\u000a Act guidelines through the perceptions of campus law administrators. Statistical analyses were performed on data collected\\u000a from an online survey, which was distributed to members of the International Association of Campus Law Administrators currently\\u000a working at colleges and universities in

Laura R. McNeal

2007-01-01

256

Layered acting for character animation  

Microsoft Academic Search

We introduce an acting-based animation system for creating and editing character animation at interactive speeds. Our system requires minimal training, typically under an hour, and is well suited for rapidly prototyping and creating expressive motion. A real-time motion-capture framework records the user's motions for simultaneous analysis and playback on a large screen. The animator's real-world, expressive motions are mapped into

Mira Dontcheva; Gary D. Yngve; Zoran Popovic

2003-01-01

257

Moonlighting enzymes in parasitic protozoa.  

PubMed

Enzymes moonlight in a non-enzymatic capacity in a diverse variety of cellular processes. The discovery of these non-enzymatic functions is generally unexpected, and moonlighting enzymes are known in both prokaryotes and eukaryotes. Importantly, this unexpected multi-functionality indicates that caution might be needed on some occasions in interpreting phenotypes that result from the deletion or gene-silencing of some enzymes, including some of the best known enzymes from classic intermediary metabolism. Here, we provide an overview of enzyme moonlighting in parasitic protists. Unequivocal and putative examples of moonlighting are discussed, together with the possibility that the unusual biological characteristics of some parasites either limit opportunities for moonlighting to arise or perhaps contribute to the evolution of novel proteins with clear metabolic ancestry. PMID:20233494

Collingridge, Peter W; Brown, Robert W B; Ginger, Michael L

2010-03-17

258

Enzyme reactions in a multicompartment electrolyzer with isoelectrically trapped enzymes.  

PubMed

The possibility of performing bioconversions under an electric field is here reported. A system is described by which the enzyme is trapped by an isoelectric mechanism between two zwitterionic membranes having pI values encompassing the isoelectric point of the enzyme. The enzyme is loaded into a multicompartment electrolyzer and kept operating under an electric field, which will continuously harvest the reaction product. Since, under focusing conditions, all buffering ions will vacate the reaction chamber at steady state, the buffering ion is trapped into the enzyme chamber by using amphoteric buffers co-isoelectric with the enzyme. As an example of such "isoelectrically immobilized' reactor, the enzyme beta-hydroxysteroid dehydrogenase is blocked into an isoelectric trap delimited by a pI 8.0 and a pI 6.5 membranes. 100 mM histidine (pI 7.47) is co-immobilized by the same isoelectric mechanism into the enzyme chamber. The dehydrocholic acid substrate (3,7,12-trioxo-5 beta-cholanoic acid) and reduced co-factor (NADH) are continuously infused into the enzyme chamber and the product (3 beta-hydroxy-7,12-dioxo- 5 beta-cholanoic acid, a compound of pharmaceutical interest) and the oxidized co-factor (NAD+) collected, separately, into the two neighbouring chambers at the anodic side. Advantages: in a soluble form, the enzyme maintains the reaction kinetics of the free soluble form. Additionally, the reaction product and exhausted co-factor can be recovered by electrophoretic transport. PMID:8675964

Chiari, M; Dell'Orto, N; Mendozza, M; Carrea, G; Righetti, P G

1996-02-01

259

19 CFR 113.68 - Wool and fur products labeling acts and fiber products identification act bond conditions.  

Code of Federal Regulations, 2013 CFR

...Wool and fur products labeling acts and fiber products identification act bond conditions...Wool and fur products labeling acts and fiber products identification act bond conditions...wool and fur products labeling acts and fiber products identification act shall...

2013-04-01

260

Glycolytic enzyme levels in synaptosomes.  

PubMed

The specific activities of glucosephosphate isomerase, aldolase, triosephosphate isomerase, glyceraldehydephosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate mutase, pyruvate kinase and lactate dehydrogenase were all higher in the synaptoplasmic fraction from rat brain than in 100,000 g supernatant fraction of rat brain homogenates when the supernatants were prepared in high ionic strength solutions. Four enzymes in synaptosomes and two enzymes in homogenates were associated with particulate fractions as indicated by the large increase in specific activity of the enzymes when samples were treated with 0.3 M KCl before centrifugation. Glucosephosphate isomerase, aldolase, pyruvate kinase and lactate dehydrogenase were the enzymes that showed a large increase in specific activity following salt treatment of isolated, synaptosomal membrane while aldolase and pyruvate kinase were the two enzymes which showed a large increase in specific activity in the high speed supernatant fractions. Because the specific activities of many enzymes are found to be elevated not only in synaptosomes but in synaptosomal membrane fractions it is suggested that these enzymes may provide the potential for significantly enhanced glycolysis at these locations. PMID:2990810

Knull, H R; Fillmore, S J

1985-01-01

261

12 CFR 212.9 - Effect of Interlocks Act on Clayton Act.  

Code of Federal Regulations, 2010 CFR

... false Effect of Interlocks Act on Clayton Act. 212.9 Section 212.9 Banks...212.9 Effect of Interlocks Act on Clayton Act. The Board regards the provisions...first three paragraphs of section 8 of the Clayton Act (15 U.S.C. 19) to have...

2009-01-01

262

12 CFR 212.9 - Effect of Interlocks Act on Clayton Act.  

Code of Federal Regulations, 2010 CFR

... false Effect of Interlocks Act on Clayton Act. 212.9 Section 212.9 Banks...212.9 Effect of Interlocks Act on Clayton Act. The Board regards the provisions...first three paragraphs of section 8 of the Clayton Act (15 U.S.C. 19) to have...

2010-01-01

263

The Mental Health Act and the Mental Capacity Act: untangling the relationship  

Microsoft Academic Search

The Mental Health Act (1983) and the Mental Capacity Act (2005) (both amended by the Mental Health Act (2007)) together provide a comprehensive framework for the care and treatment of people with a mental disorder in England and Wales. The Mental Health Act relates solely to the treatment of mental disorders whilst the Mental Capacity Act has much wider applicability

Daniel P. Herlihy; Frank Holloway

2009-01-01

264

Fast-acting valve actuator  

DOEpatents

A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response to pressure differentials created by energizing and de-energizing a solenoid which controls the pneumatic input to the actuator as well as selectively providing a venting action to one side of the selector diaphragm.

Cho, Nakwon (Knoxville, TN)

1980-01-01

265

The America Invents Act implementation.  

PubMed

The Leahy-Smith America Invents Act (AIA) is by far the most comprehensive change to the patent law in at least half a century. Implementation of the AIA has been ongoing, but the final and most critical provisions went into effect on March 16, 2013. Although, it will take several years before we fully understand the law's impact, the new law is likely to fundamentally change the way innovation is protected within the United States. Researchers will need to become increasingly vigilant as to publication dates as well as communications coming from their labs. PMID:23560953

Hollinger, Susanne

2013-04-06

266

Novel cyanide-hydrolyzing enzyme from Alcaligenes xylosoxidans subsp. denitrificans.  

PubMed Central

A cyanide-metabolizing bacterium, strain DF3, isolated from soil was identified as Alcaligenes xylosoxidans subsp. denitrificans. Whole cells and cell extracts of strain DF3 catalyzed hydrolysis of cyanide to formate and ammonia (HCN + 2H2O----HCOOH + NH3) without forming formamide as a free intermediate. The cyanide-hydrolyzing activity was inducibly produced in cells during growth in cyanide-containing media. Cyanate (OCN-) and a wide range of aliphatic and aromatic nitriles were not hydrolyzed by intact cells of A. xylosoxidans subsp. denitrificans DF3. Strain DF3 hydrolyzed cyanide with great efficacy. Thus, by using resting induced cells at a concentration of 11.3 mg (dry weight) per ml, the cyanide concentration could be reduced from 0.97 M (approximately 25,220 ppm) to less than 77 nM (approximately 0.002 ppm) in 55 h. Enzyme purification established that cyanide hydrolysis by A. xylosoxidans subsp. denitrificans DF3 was due to a single intracellular enzyme. The soluble enzyme was purified approximately 160-fold, and the first 25 NH2-terminal amino acids were determined by automated Edman degradation. The molecular mass of the active enzyme (purity, greater than 97% as determined by amino acid sequencing) was estimated to be greater than 300,000 Da. The cyanide-hydrolyzing enzyme of A. xylosoxidans subsp. denitrificans DF3 was tentatively named cyanidase to distinguish it from known nitrilases (EC 3.5.5.1) which act on organic nitriles. Images

Ingvorsen, K; H?jer-Pedersen, B; Godtfredsen, S E

1991-01-01

267

Microtubule-severing enzymes at the cutting edge  

PubMed Central

ATP-dependent severing of microtubules was first reported in Xenopus laevis egg extracts in 1991. Two years later this observation led to the purification of the first known microtubule-severing enzyme, katanin. Katanin homologs have now been identified throughout the animal kingdom and in plants. Moreover, members of two closely related enzyme subfamilies, spastin and fidgetin, have been found to sever microtubules and might act alongside katanins in some contexts (Roll-Mecak and McNally, 2010; Yu et al., 2008; Zhang et al., 2007). Over the past few years, it has become clear that microtubule-severing enzymes contribute to a wide range of cellular activities including mitosis and meiosis, morphogenesis, cilia biogenesis and disassembly, and migration. Thus, this group of enzymes is revealing itself to be among the most important of the microtubule regulators. This Commentary focuses on our growing understanding of how microtubule-severing enzymes contribute to the organization and dynamics of diverse microtubule arrays, as well as the structural and biophysical characteristics that afford them the unique capacity to catalyze the removal of tubulin from the interior microtubule lattice. Our goal is to provide a broader perspective, focusing on a limited number of particularly informative, representative and/or timely findings.

Sharp, David J.; Ross, Jennifer L.

2012-01-01

268

Characterization of Angiotensin Converting Enzyme2 (ACE2) in Human Urine  

Microsoft Academic Search

Angiotensin converting enzyme-2 (ACE2) is a recently described membrane-bound carboxypeptidase identified by its homology to ACE, the enzyme responsible for the formation of the potent vasoconstrictor angiotensin II (Ang II). ACE2 inactivates Ang II and is thus thought to act in a counter-regulatory fashion to ACE. ACE2 is highly expressed in epithelial cells of distal renal tubules, and recent evidence

Rebecca A. Lew; Fiona J. Warner; Iresha Hanchapola; A. Ian Smith

2006-01-01

269

QM\\/MM Analysis of Cellulase Active Sites and Actions of the Enzymes on Substrates  

Microsoft Academic Search

Biodegradation of cellulosic biomass requires the actions of three types of secreted enzymes; endoglucanase (EC 3.2.1.4), cellobiohydrolase or exoglucanase (EC 3.2.1.91), and -glucosidase (EC 4.2.1.21). These enzymes act synergistically to hydrolyse the -1,4 bonds of cellulose and converts it into simple sugar. Hydrolysis of the glycosidic bond can occur either by net retention or by inversion of anomeric configuration at

Moumita Saharay; Hao-Bo Guo; Jeremy C Smith; Hong Guo

2010-01-01

270

Regulatory Protein for Nox Enzymes.  

National Technical Information Service (NTIS)

The present invention relates to nucleotides encoding for the production of novel regulatory proteins for Nox enzymes involved in generation of reactive oxygen intermediates that affect cell division. The present invention also provides vectors containing...

J. D. Lambeth G. Cheng

2005-01-01

271

Immobilized Enzymes for Automated Analyses.  

National Technical Information Service (NTIS)

Methods were developed for analyzing enzyme immobilization processes applicable to carrier materials suitable for automated clinical chemistry analyzers. Immobilization was analyzed in terms of (a) amount of bound protein, (b) surface activity, (c) quanti...

G. Herzlinger J. Thompson

1979-01-01

272

Heat Stable Enzymes from Thermophiles.  

National Technical Information Service (NTIS)

Alkaline phosphatase is widely used in the military and civilian sectors. Commercially available enzyme from calf intestine is the weak link in many applications, breaking down when exposed to elevated temperatures or after being stored for prolonged peri...

M. Williamson J. Combia F. Albert K. Runnion K. Budwill

1998-01-01

273

Enzyme Modification, Electrophoresis and Applications.  

National Technical Information Service (NTIS)

As part of research designed to develop novel but practical processes for the industrial application of enzymes in areas where immediate technical, economic, and social advantages might be realized, this third and final phase of the project attempts to br...

W. R. Vieth S. G. Gilbert A. Constantinides F. R. Bernath

1976-01-01

274

78 FR 28532 - Freedom of Information, Privacy Act, and Government in the Sunshine Act Procedures  

Federal Register 2010, 2011, 2012, 2013

...Implementing Recommendations of the 9/11 Commission Act of 2007, Public Law...Implementing Recommendations of the 9/11 Commission Act of 2007, Public Law...Implementing Recommendations of the 9/11 Commission Act of 2007, Public...

2013-05-15

275

Macromolecular juggling by ubiquitylation enzymes  

PubMed Central

The posttranslational modification of target proteins with ubiquitin and ubiquitin-like proteins is accomplished by the sequential action of E1, E2, and E3 enzymes. Members of the E1 and E3 enzyme families can undergo particularly large conformational changes during their catalytic cycles, involving the remodeling of domain interfaces. This enables the efficient, directed and regulated handover of ubiquitin from one carrier to the next one. We review some of these conformational transformations, as revealed by crystallographic studies.

2013-01-01

276

Selective neutrality and enzyme kinetics  

Microsoft Academic Search

This article appeals to a recent theory of enzyme evolution to show that the properties, neutral or adaptive, which characterize\\u000a the observed allelic variation in natural populations can be inferred from the functional parameters, substrate specificity,\\u000a and reaction rate. This study delineates the following relations between activity variables, and the forces—adaptive or neutral—determining\\u000a allelic variation: (1) Enzymes with broad substrate

Lloyd Demetrius

1997-01-01

277

Analysing Lichen Enzymes by Isoelectricfocussing  

Microsoft Academic Search

\\u000a Lichen proteins that most readily lend themselves to analysis by electrophoretic separation are enzymes, particularly those\\u000a that produce substances capable of reacting with specific staining reagents to form visible products. Presumably due to the\\u000a nature of cell walls and intercellular matrices, extraction of enzymes from lichens is more difficult than from many other\\u000a organisms and, thus, some rigorous means of

Dianne Fahselt

278

Enzyme inactivation by peroxyacetyl nitrate  

Microsoft Academic Search

Isocitric dehydrogenase (NADP linked), G-6-P dehydrogenase, and malic dehydrogenase were inactivated by peroxyacetyl nitrate. The enzymes could be protected in some cases; isocitric dehydrogenase by isocitrate and NAPD, the former being more effective, and G-6-P dehydrogenase by NADP but not by G-6-P. Malic dehydrogenase was not significantly protected either by substrate or coenzyme. Inhibition of these three enzymes by cadmium

J MUDD

1963-01-01

279

Homogeneous enzyme immunoassay for netilmicin.  

PubMed Central

A newly developed homogeneous enzyme immunoassay for the determination of netilmicin in serum was evaluated and compared with a radioenzymatic assay. A total of 102 serum samples from patients treated with netilmicin were measured by both methods. This comparison showed an excellent correlation (r = 0.993). The enzyme immunoassay has proved to be precise, accurate, and specific. Because of its rapidity and the ease of performance, this method is a useful alternative to current assays for monitoring serum netilmicin concentrations.

Wenk, M; Hemmann, R; Follath, F

1982-01-01

280

Fair Labor Standards Act: Selected Enforcement Activities.  

National Technical Information Service (NTIS)

The Department of Labor administers the Fair Labor Standards Act (FLSA), enacted in 1938 and amended several times, for workers of firms engaged in interstate and foreign commerce. The act sets standards for minimum wage and overtime pay and requirements ...

1987-01-01

281

7 CFR 1206.1 - Act.  

Code of Federal Regulations, 2013 CFR

...SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MANGO PROMOTION, RESEARCH, AND INFORMATION Mango Promotion, Research, and Information Order Definitions § 1206.1 Act. Act means...

2013-01-01

282

7 CFR 1206.1 - Act.  

Code of Federal Regulations, 2012 CFR

...SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MANGO PROMOTION, RESEARCH, AND INFORMATION Mango Promotion, Research, and Information Order Definitions § 1206.1 Act. Act means...

2012-01-01

283

7 CFR 1216.1 - Act.  

Code of Federal Regulations, 2012 CFR

...SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions § 1216.1 Act. Act...

2012-01-01

284

7 CFR 1214.1 - Act.  

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

285

29 CFR 1614.203 - Rehabilitation Act.  

Code of Federal Regulations, 2013 CFR

...of qualified individuals with disabilities. (b) ADA standards. ...section 501 of the Rehabilitation Act of 1973, as amended (29...through 504 and 510) of the Americans with Disabilities Act of 1990, as amended...

2013-07-01

286

12 CFR 268.203 - Rehabilitation Act.  

Code of Federal Regulations, 2013 CFR

...of qualified individuals with disabilities. (b) ADA standards. ...section 501 of the Rehabilitation Act of 1973, as amended (29...through 504 and 510) of the Americans with Disabilities Act of 1990, as amended (42...

2013-01-01

287

7 CFR 1215.1 - Act.  

Code of Federal Regulations, 2012 CFR

...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...

2012-01-01

288

7 CFR 1215.1 - Act.  

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

289

7 CFR 1220.600 - Act.  

Code of Federal Regulations, 2013 CFR

...Soybean, Promotion, Research, and Consumer Information Act set forth in title XIX, subtitle E, of the Food, Agriculture, Conservation, and Trade Act of 1990 (Pub. L. 101-624), and any amendments...

2013-01-01

290

7 CFR 1220.101 - Act.  

Code of Federal Regulations, 2013 CFR

...means the Soybean Promotion, Research, and Consumer Information Act, subtitle E of title XIX, of the Food, Agriculture, Conservation and Trade Act of 1990, Public Law No. 101-624, and any amendments...

2013-01-01

291

7 CFR 1209.1 - Act.  

Code of Federal Regulations, 2012 CFR

...COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND CONSUMER INFORMATION ORDER Mushroom Promotion, Research, and Consumer Information... § 1209.1 Act. Act means the Mushroom Promotion, Research, and Consumer...

2012-01-01

292

7 CFR 1209.1 - Act.  

Code of Federal Regulations, 2013 CFR

...COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND CONSUMER INFORMATION ORDER Mushroom Promotion, Research, and Consumer Information... § 1209.1 Act. Act means the Mushroom Promotion, Research, and Consumer...

2013-01-01

293

7 CFR 1219.1 - Act.  

Code of Federal Regulations, 2012 CFR

...COMMODITIES), DEPARTMENT OF AGRICULTURE HASS AVOCADO PROMOTION, RESEARCH, AND INFORMATION Hass Avocado Promotion, Research, and Information Order...1219.1 Act. Act means the Hass Avocado Promotion, Research, and Information...

2012-01-01

294

7 CFR 1219.1 - Act.  

Code of Federal Regulations, 2013 CFR

...COMMODITIES), DEPARTMENT OF AGRICULTURE HASS AVOCADO PROMOTION, RESEARCH, AND INFORMATION Hass Avocado Promotion, Research, and Information Order...1219.1 Act. Act means the Hass Avocado Promotion, Research, and Information...

2013-01-01

295

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.

296

Equal Employment Opportunity Act of 1972  

Microsoft Academic Search

The Equal Employment Opportunity Act of 1972 amended and strengthened Title VII of the Civil Rights Act of 1964, which had made it illegal for employers to discriminate against any individual because of race, color, religion, sex, or national origin.

John W. Dietrich

2004-01-01

297

7 CFR 65.100 - Act.  

Code of Federal Regulations, 2013 CFR

...MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) COUNTRY OF ORIGIN LABELING OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions...

2013-01-01

298

21 CFR 864.4400 - Enzyme preparations.  

Code of Federal Regulations, 2013 CFR

... 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...

2013-04-01

299

Telomerase caught in the act  

PubMed Central

The stable linearity of eukaryotic chromosomes depends on special characteristics of their ends, the telomeres. Accurate telomere function in turn requires a sustained presence of repeated DNA elements, which are maintained by the enzyme telomerase. The telomerase holoenzyme is composed of both protein and RNA, and its functions rely on proper expression, maturation, trafficking and assembly of these components. Conflicting models for the recruitment of telomerase at telomeres have been proposed; one suggests a local activation of telomerase at short telomeres, while the other proposes that telomerase is recruited only at short telomeres. To discriminate between these models and investigate the cell cycle-dependent regulation of telomerase in living cells, a GFP reporter system to visualize the yeast telomerase RNA has been recently developed. This assay shed new light on the mechanism of recruitment of telomerase to telomeres, and it uncovered a hitherto unrecognized mechanism for restricting telomerase access to telomeres.

Gallardo, Franck; Laterreur, Nancy; Wellinger, Raymund J.; Chartrand, Pascal

2012-01-01

300

76 FR 4378 - Sunshine Act Meetings; Notice  

Federal Register 2010, 2011, 2012, 2013

...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...

2011-01-25

301

The Indian Child Welfare Act: A Review.  

ERIC Educational Resources Information Center

|Provides historical background on federal policies related to Indian family rights and child welfare and on legislation leading up to the Indian Child Welfare Act. Interprets the act with regard to jurisdiction and standards for child placement for foster care and adoption. Discusses federal funding of the act and monitoring of state compliance.…

Garner, Suzanne

1993-01-01

302

Gender Stereotypes Associated with Altruistic Acts  

Microsoft Academic Search

Possible gender stereotypes associated with altruistic acts presented in two types of vignettes were investigated. A sample of 72 General Psychology students were recruited to participate. The researchers had three main hypotheses: Females would more likely be perceived as the performers of an altruistic act, females would more likely be perceived as the receivers of an altruistic act, and the

Lacey D. Seefeldt

303

Lexical Structure for Dialogue Act Recognition  

Microsoft Academic Search

This paper deals with automatic dialogue acts (DAs) recognition in Czech. Dialogue acts are sentence-level labels that represent different states of a dialogue, such as questions, hesitations, ... In our application, a multimodal reservation system, four dialogue acts are considered: state- ments, orders, yes\\/no questions and other questions. The main contribution of this work is to propose and compare several

Pavel Král; Christophe Cerisara; Jana Klecková

2007-01-01

304

Current and future centrally acting antitussives  

Microsoft Academic Search

The purpose of this review is to highlight some important issues regarding current centrally acting antitussive drugs as well as discuss the implications of these matters on the development of future cough suppressants. Drugs that act in the central nervous system to inhibit cough are termed centrally acting and this designation is based exclusively on evidence obtained from animal models.

Donald C. Bolser

2006-01-01

305

7 CFR 1150.101 - Act.  

Code of Federal Regulations, 2012 CFR

...Dairy Promotion and Research Order Definitions § 1150.101 Act. Act means Title I, Subtitle B, of the Dairy and Tobacco Adjustment Act of 1983, Pub. L. 98-180, 97 Stat. 1128, as approved November 29, 1983, and any amendments...

2012-01-01

306

29 CFR 4.103 - The Act.  

Code of Federal Regulations, 2010 CFR

...LABOR STANDARDS FOR FEDERAL SERVICE CONTRACTS Application of the McNamara-O'Hara Service Contract Act Introductory § 4.103 The Act. The McNamara-O'Hara Service Contract Act of 1965 (Pub. L. 89-286, 79 Stat. 1034, 41...

2009-07-01

307

29 CFR 4.103 - The Act.  

Code of Federal Regulations, 2010 CFR

...LABOR STANDARDS FOR FEDERAL SERVICE CONTRACTS Application of the McNamara-O'Hara Service Contract Act Introductory § 4.103 The Act. The McNamara-O'Hara Service Contract Act of 1965 (Pub. L. 89-286, 79 Stat. 1034, 41...

2010-07-01

308

New developments concerning the Equal Pay Act  

Microsoft Academic Search

Considers why a wage gap still exists between men and women, despite the introduction in the USA of the Equal Pay Act (EPA) in 1963 and the Civil Rights Act (Title VII) in 1964. Details the Equal Employment Opportunity Commission’s (EEOC’s) interpretations of the two Acts’ provisions relating to employment discrimination on the basis of gender, looking in particular at

Li Yun Chen; Brian H. Kleiner

1998-01-01

309

Helms-Burton Act: A Strategic Critique.  

National Technical Information Service (NTIS)

The 1996 Helms-Burton Act (the Act) codifies and expands U.S. economic sanctions, including a comprehensive embargo, against Cuba. The primary strategic objective behind the Act is the overthrow of Fidel Castro and the establishment of a democratic transi...

J. R. Scharfen

1998-01-01

310

7 CFR 33.1 - Act.  

Code of Federal Regulations, 2013 CFR

... § 33.1 Act. Act and Export Apple Act are synonymous and mean âAn...foreign trade of the United States in apples to protect the reputation of American-grown apples in foreign markets, to prevent deception or...

2013-01-01

311

7 CFR 33.1 - Act.  

Code of Federal Regulations, 2010 CFR

... § 33.1 Act. Act and Export Apple Act are synonymous and mean âAn...foreign trade of the United States in apples to protect the reputation of American-grown apples in foreign markets, to prevent deception or...

2009-01-01

312

7 CFR 33.1 - Act.  

Code of Federal Regulations, 2010 CFR

... § 33.1 Act. Act and Export Apple Act are synonymous and mean âAn...foreign trade of the United States in apples to protect the reputation of American-grown apples in foreign markets, to prevent deception or...

2010-01-01

313

ACT National Curriculum Survey[R], 2009  

ERIC Educational Resources Information Center

|The ACT National Curriculum Survey is a one-of-a-kind nationwide survey of educational practices and expectations conducted by ACT every 3 to 5 years. ACT surveys thousands of middle school/junior high school, secondary, and postsecondary teachers in English/writing, reading (including English language arts and social studies teachers),…

ACT, Inc., 2009

2009-01-01

314

Stratospheric Ozone: A Balancing Act  

NSDL National Science Digital Library

This activity demonstrates the concept of equilibrium as applied to a model system and to stratospheric ozone. Although the materials are easy to come by, this model set-up does require a fair amount of preparation. This can be done as a laboratory activity or as a classroom demonstration. A feature of this site is an animation that shows the depletion of ozone and the regeneration that causes the chlorine atom to act as a catalyst in the destruction of the ozone layer. The teacher's guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

315

Long-acting hormonal contraception.  

PubMed

For 30 years, the combined oral contraceptive pill has been an almost automatic choice for effective contraception in sexually active adolescent women. Nevertheless, consideration of the criteria of a hypothetical "ideal" contraceptive suggests that long-acting progestogen-only methods may have considerable advantages for some adolescents. These would include greater efficacy, easier compliance, avoidance of estrogenic side effects, and potentially greater privacy. The disadvantages of menstrual irregularity, progestogenic side effects including weight gain, and the initial greater medicalization of the method, particularly implants, must be weighed against the wishes and preferences of the adolescent. A number of studies of the uptake and utilization of these methods in adolescence have arisen, particularly from the United States. These are reviewed together with experience from programs in the United Kingdom. PMID:9238299

Bromham, D R

1997-06-17

316

Enzyme exposure and enzyme sensitisation in the baking industry.  

PubMed Central

OBJECTIVES: To assess the exposure to enzymes and prevalence of enzyme sensitisation in the baking industry. METHODS: A cross sectional study was conducted in four bakeries, one flour mill, and one crispbread factory. Sensitisation to enzymes, flours, and storage mites was examined by skin prick and radioallergosorbent (RAST) tests. 365 workers were tested. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method, and the concentration of alpha-amylase in air was measured by a catalytic method. An immunochemical method was used for measuring cellulase and xylanase in air. RESULTS: Total measured dust concentrations were from 0.1 to 18 mg/m3, with highest values in dough making areas of bakeries. The alpha-amylase concentrations generally followed the total dust concentrations and reached the highest values < 6.6 micrograms/m3 in the same areas. Cellulase and xylanase varied with concentrations < 180 ng/m3 and < 40 ng/m3, respectively, in the flour mill and the crispbread factory. No cellulase, but concentrations of 1-200 ng/m3 xylanase, were found in the bakeries, probably indicating the natural xylanase activity of wheat. 12 workers (8%) in the bakeries, three (5%) in the flour mill, and four (3%) in the crispbread factory were skin prick positive to enzymes. The corresponding percentages of positive reactions to flours were 12%, 5%, and 8%. CONCLUSIONS: The study confirmed that industrial enzymes in baking used as additives in a powdered form pose a risk of sensitisation. The no effect air concentrations for industrial enzymes are not known. Based on present knowledge, however, lowering exposures and eliminating short and high peaks by technical measures would lower the risk of sensitisation. This would be most effectively accomplished by shifting to non-dusty products.

Vanhanen, M; Tuomi, T; Hokkanen, H; Tupasela, O; Tuomainen, A; Holmberg, P C; Leisola, M; Nordman, H

1996-01-01

317

The Bayh-Dole Act turns 30.  

PubMed

On 12 December 1980, in the waning days of the lame duck session of the 96th Congress, the U.S. Senate passed the University and Small Business Patent Procedures Act, now known as the Bayh-Dole Act, a seemingly obscure act that allowed universities to claim title to inventions that had been made with federal funding. It is unlikely that many present that day realized what a dramatic impact that act would have. Data clearly show that it played a critical role in rejuvenating the entire U.S. economic system, transforming it from a manufacturing base to an innovation base. Yet ironically, the act has passionate critics. PMID:20926832

Loise, Vicki; Stevens, Ashley J

2010-10-01

318

48 CFR 52.222-44 - Fair Labor Standards Act and Service Contract Act-Price Adjustment.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Fair Labor Standards Act and Service Contract Act-Price...Clauses 52.222-44 Fair Labor Standards Act and Service Contract Act...the following clause: Fair Labor Standards Act and Service Contract...

2010-10-01

319

48 CFR 52.222-44 - Fair Labor Standards Act and Service Contract Act-Price Adjustment.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 false Fair Labor Standards Act and Service Contract Act-Price...Clauses 52.222-44 Fair Labor Standards Act and Service Contract Act...the following clause: Fair Labor Standards Act and Service Contract...

2009-10-01

320

48 CFR 52.222-44 - Fair Labor Standards Act and Service Contract Act-Price Adjustment.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Fair Labor Standards Act and Service Contract Act-Price...Clauses 52.222-44 Fair Labor Standards Act and Service Contract Act...the following clause: Fair Labor Standards Act and Service Contract...

2012-10-01

321

National Energy Act statutes and solar energy  

SciTech Connect

The National Energy Act of 1978 contains many provisions that will significantly affect solar technology commercialization and solar energy users. Four of the five statutes that comprise the National Energy Act deserve close attention. The National Energy Conservation Policy Act will promote residential solar installations. The Energy Tax Act will accelerate both residential and commercial solar system applications. The Public Utilities Regulatory Policies Act promotes efficient use of utility resources as well as decentralized power production. And, the Power Plan and Industrial Fuel Use Act places severe restrictions on future burning of petroleum and natural gas, which should lead some operators to build or convert to solar energy systems. Each of the preceding acts are considered in separate sections of this report. Federal regulations issued pursuant to the various provisions are also identified and discussed, and some of the problems with the provisions and regulations are noted.

Howard, J.

1980-02-01

322

Enzyme-linked enzyme binding assay for Pin1 WW domain ligands  

PubMed Central

Peptidyl prolyl cis-trans isomerase (PPIase) interacting with NIMA-1 (Pin1) catalyzes the cis-trans isomerization of pSer/pThr–Pro amide bonds. Pin1 is a two-domain protein that represents a promising target for the treatment of cancer. Both domains of Pin1 bind the pSer/pThr–Pro motif; PPIase enzymatic activity occurs in the catalytic domain, and the WW domain acts as a recognition module for the pSer/pThr–Pro motif. An assay we call an Enzyme-Linked Enzyme Binding Assay (ELEBA), was developed to measure the Kd of ligands that bind selectively to the WW domain. A ligand specific for the WW domain of Pin1 was covalently immobilized in a 96-well plate. Commercially available Pin1 conjugated to horseradish peroxidase was used for chemiluminescent detection of ligands that block the association of the WW domain with immobilized ligand. The peptide ligands were derived from the cell cycle regulatory phosphatase, Cdc25c, residues 45-50. The Kd values for Fmoc–VPRpTPVGGGK–NH2 and Ac–VPRpTPV–NH2 were determined to be 36 ± 4 ?M and 110 ± 30 ?M respectively. The ELEBA offers a selective approach to detect ligands that bind to the Pin1 WW domain, even in the presence of the catalytic domain. This method may be applied to any dual specificity, multi-domain protein.

Mercedes-Camacho, Ana Y.; Etzkorn, Felicia A.

2010-01-01

323

Enzyme-Based Listericidal Nanocomposites  

PubMed Central

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 105?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.

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

324

Antioxidant enzymes in phytoparasitic nematodes.  

PubMed

Presence of different antioxidant enzymes, such as superoxide dismutase (SOD), catalase, and ascorbate, p-phenilendiamine-pyrocathecol (PPD-PC), o-dianisidine, and guaiacol isoperoxidases, was shown in the phytoparasific nematode species Meloidogyne incognita, M. hapla, Globodera rostochiensis, G. pallida, Heterodera schachtii, H. carotae, and Xiphinema index. The activity of the enzymes tested differed among the life stages examined. SOD was present in cysts but was not detected in Meloidogyne egg masses. Catalase activity of Meloidogyne females was higher than that of preparasitic stages and cyst-nematode females. For the first time, ascorbate peroxidase was found to occur commonly in phytoparasitic nematodes, with the highest activity in the invading life-stages. In all the life stages examined, the antioxidant enzyme activities of M. hapla were markedly higher than those of M. incognita. Glutathione peroxidase was not found in the species examined. PMID:19274144

Molinari, S; Miacola, C

1997-06-01

325

Asymptotic Expansion in Enzyme Reactions with High Enzyme Concentrations  

Microsoft Academic Search

In this paper we find a new asymptotic expansion valid in enzymatic reactions where the total amount of enzyme exceeds greatly the total amount of substrate. In such case it is well known that the Michelis-Menten approximation is no longer valid; therefore our asymptotic expansion is a new tool to approximate in a closed form the concentrations of the reactants

Alberto Maria Bersani; Guido Dell'Acqua

2010-01-01

326

Lithuanian biochemist builds enzyme empire  

SciTech Connect

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.

Dickman, S.

1992-09-11

327

[Faecal enzyme diagnostic (author's transl)].  

PubMed

The hitherto existing results of determinations of enzymatic activities in stool are presented in this review. The chymotrypsin activity is diminished in advanced exocrine pancreatic insufficiency. The faecal alpha-amylase activity has up to now no significance in the diagnosis of pancreatic diseases. Up to five amylolytic enzyme activities are detectable. The alkaline phosphatase is mostly of intestinal origin. Up to 4 enzyme bands can be exhibited with the disc electrophoresis in polyacrylamide gel. Lysozyme and N-Acetyl-beta-D-glycosaminidase can also be detected in stool. PMID:94852

Müller, G

1979-01-01

328

Enzyme-enabled responsive surfaces for anti-contamination materials.  

PubMed

Many real-life stains have origins from biological matters including proteins, lipids, and carbohydrates that act as gluing agents binding along with other particulates or microbes to exposed surfaces of automobiles, furniture, and fabrics. Mimicking naturally occurring self-defensive processes, we demonstrate in this work that a solid surface carrying partially exposed enzyme granules protected the surface in situ from contamination by biological stains and fingerprints. Attributed to the activities of enzymes which can be made compatible with a wide range of materials, such anti-contamination and self-cleaning functionalities are highly selective and efficient toward sticky chemicals. This observation promises a new mechanism in developing smart materials with desired anti-microbial, self-reporting, self-cleaning, or self-healing functions. PMID:23335427

Wu, Songtao; Buthe, Andreas; Jia, Hongfei; Zhang, Minjuan; Ishii, Masahiko; Wang, Ping

2013-02-09

329

A first prototype of PyACTS  

SciTech Connect

The ACTS Collection is a set of software tools that help developers or programmers write high performance parallel codes for their scientific applications. PyACTS is a Python-based interface to some of the tools in the ACTS Collection. The main purpose of developing PyACTS is to provide a uniform easy-to-use external interface to existing ACTS tools,and support ACTS users to rapidly prototype their codes with the tools. In particular, for users who are new to ACTS, they will find PyACTS helpful to test and try the functionality available in the collection. Further, this training will allow users to acquire the necessary experience to develop their own applications. In the current development phase of PyACTS, part of the ScaLAPACK subroutines are being made available. This report illustrates how we develop the idea of wrapping the ACTS Collection with a high level scripting language, like Python, and a status of the development of the Python front-end interface and future plans.

Kang, Ning; Drummond, Leroy A.

2003-08-31

330

Taking the Mystery Out of Enzymes.  

ERIC Educational Resources Information Center

|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)|

DeYoung, H. Garrett

1984-01-01

331

Enzyme specific activity in functionalized nanoporous supports  

Microsoft Academic Search

Here we reveal that enzyme specific activity can be increased substantially by changing the protein loading density (PLD) in functionalized nanoporous supports so that the enzyme immobilization efficiency (Ie, defined as the ratio of the specific activity of the immobilized enzyme to the specific activity of the free enzyme in solution) can be much higher than 100%. A net negatively

Chenghong Lei; Thereza A. Soares; Yongsoon Shin; Jun Liu; Eric J. Ackerman

2008-01-01

332

Cryptic functions of enzymes in chemical catalysis  

Microsoft Academic Search

Using a number of examples, this article demonstrates how the functional groups responsible for the catalytic activity of an enzyme must be studied within the context of the enzyme-substrate complex. Very often a substrate will actively cooperate with the enzyme to bring about its own transformation. The so-called cryptic functions of enzymes are considered in the case of seryl proteases

A. Previero; M. A. Coletti-Previero; L. Galzigna

1983-01-01

333

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...

334

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

Microsoft Academic Search

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

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

2011-01-01

335

A GENETIC ANALYSIS OF THE PTERIDINE BIOSYNTHETIC ENZYME, GUANOSINE TRIPHOSPHATE CYCLOHYDROLASE, IN DROSOPHILA MELANOGASTER  

Microsoft Academic Search

Strains with mutant eye color were surveyed for levels of GTP cyclohydro- lase (GTP CH), the first enzyme acting in the biosynthesis of pteridines, the pigments causing red eye color in Drosophila. Six strains were found to have reduced GTP CH activity. In five of the six strains, the reduction of activity is apparent only in the adult head of

WILLIAM J. MACKAY; JANIS M. O'DONNELL

336

Nitrate reductase, a nitric oxide-producing enzyme: induction by pathogen signals  

Microsoft Academic Search

Nitric oxide (NO) is believed to act as an effector for defense signaling in plant cells. Nitrate reductase (NR) is one of the NO-producing enzymes in plants. Here, we report that infection of Phytophthora infestans, the fungal pathogen of potato late blight, into potato tubers caused a transient increase in the NR transcript in an incompatible, but not a compatible,

Ayako Yamamoto; Shinpei Katou; Hirofumi Yoshioka; Noriyuki Doke; Kazuhito Kawakita

2003-01-01

337

Quantitative Comparison of Catalytic Mechanisms and Overall Reactions in Convergently Evolved Enzymes: Implications for Classification of Enzyme Function  

PubMed Central

Functionally analogous enzymes are those that catalyze similar reactions on similar substrates but do not share common ancestry, providing a window on the different structural strategies nature has used to evolve required catalysts. Identification and use of this information to improve reaction classification and computational annotation of enzymes newly discovered in the genome projects would benefit from systematic determination of reaction similarities. Here, we quantified similarity in bond changes for overall reactions and catalytic mechanisms for 95 pairs of functionally analogous enzymes (non-homologous enzymes with identical first three numbers of their EC codes) from the MACiE database. Similarity of overall reactions was computed by comparing the sets of bond changes in the transformations from substrates to products. For similarity of mechanisms, sets of bond changes occurring in each mechanistic step were compared; these similarities were then used to guide global and local alignments of mechanistic steps. Using this metric, only 44% of pairs of functionally analogous enzymes in the dataset had significantly similar overall reactions. For these enzymes, convergence to the same mechanism occurred in 33% of cases, with most pairs having at least one identical mechanistic step. Using our metric, overall reaction similarity serves as an upper bound for mechanistic similarity in functional analogs. For example, the four carbon-oxygen lyases acting on phosphates (EC 4.2.3) show neither significant overall reaction similarity nor significant mechanistic similarity. By contrast, the three carboxylic-ester hydrolases (EC 3.1.1) catalyze overall reactions with identical bond changes and have converged to almost identical mechanisms. The large proportion of enzyme pairs that do not show significant overall reaction similarity (56%) suggests that at least for the functionally analogous enzymes studied here, more stringent criteria could be used to refine definitions of EC sub-subclasses for improved discrimination in their classification of enzyme reactions. The results also indicate that mechanistic convergence of reaction steps is widespread, suggesting that quantitative measurement of mechanistic similarity can inform approaches for functional annotation.

Almonacid, Daniel E.; Yera, Emmanuel R.; Mitchell, John B. O.; Babbitt, Patricia C.

2010-01-01

338

Rational engineering of enzyme stability  

Microsoft Academic Search

During the past 15 years there has been a continuous flow of reports describing proteins stabilized by the introduction of mutations. These reports span a period from pioneering rational design work on small enzymes such as T4 lysozyme and barnase to protein design, and directed evolution. Concomitantly, the purification and characterization of naturally occurring hyperstable proteins has added to our

Vincent G. H. Eijsink; Alexandra Bjørk; Sigrid Gåseidnes; Reidun Sirevåg; Bjørnar Synstad; Bertus van den Burg; Gert Vriend

2004-01-01

339

Lithuanian Biochemist Builds Enzyme Empire  

Microsoft Academic Search

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

Steven Dickman

1992-01-01

340

Mitochondrial enzymes in hereditary ataxias  

Microsoft Academic Search

As a test of the hypothesis that mitochondrial abnormalities are common in patients with hereditary ataxias, the activities of two mitochondrial enzymes were studied in platelets from an unselected series of patients. For the group of ataxies, the activity of the pyruvate dehydrogenase complex (PDHC) was 68% of the control (P P 2 SD below the control mean. Immunoblots of

Kwan-Fu Rex Sheu; John P. Blass; Jesse M. Cedarbaum; Young-Tai Kim; Bradford J. Harding; Joseph DeCicco

1988-01-01

341

The Angiotensin I Converting Enzyme.  

National Technical Information Service (NTIS)

The angiotensin I converting enzyme (kininase II; peptidyl dipeptidase; EC 3.4. 15.1) has a dual function: it converts angiotensin I to angiotensin II and it inactivates bradykinin. Lung, kidney, guinea pig plasma and testicles are among the richest sourc...

E. G. Erdos

1977-01-01

342

Rennin--a Neglected Enzyme?  

ERIC Educational Resources Information Center

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)

Gill, John; Saunders, Terry

1987-01-01

343

Rennin--a Neglected Enzyme?  

ERIC Educational Resources Information Center

|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)|

Gill, John; Saunders, Terry

1987-01-01

344

Rapid-Equilibrium Enzyme Kinetics  

ERIC Educational Resources Information Center

Rapid-equilibrium rate equations for enzyme-catalyzed reactions are especially useful because if experimental data can be fit by these simpler rate equations, the Michaelis constants can be interpreted as equilibrium constants. However, for some reactions it is necessary to use the more complicated steady-state rate equations. Thermodynamics is…

Alberty, Robert A.

2008-01-01

345

Organoclay-enzyme film electrodes  

Microsoft Academic Search

This paper aims at showing the interest of organoclays (clay minerals containing organic groups covalently attached to the inorganic particles) as suitable host matrices likely to immobilize enzymes onto electrode surfaces for biosensing applications. The organoclays used in this work were natural Cameroonian smectites grafted with either aminopropyl (AP) or trimethylpropylammonium (TMPA) groups. The first ones were exploited for their

Justin Kemmegne Mbouguen; Emmanuel Ngameni; Alain Walcarius

2006-01-01

346

Rapid-Equilibrium Enzyme Kinetics  

ERIC Educational Resources Information Center

|Rapid-equilibrium rate equations for enzyme-catalyzed reactions are especially useful because if experimental data can be fit by these simpler rate equations, the Michaelis constants can be interpreted as equilibrium constants. However, for some reactions it is necessary to use the more complicated steady-state rate equations. Thermodynamics is…

Alberty, Robert A.

2008-01-01

347

Enzymes of respiratory iron oxidation  

Microsoft Academic Search

This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies

Blake; R. II

1991-01-01

348

A Perspective on Enzyme Catalysis  

NSDL National Science Digital Library

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.

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

2003-08-29

349

Angiotensin converting enzyme 2 in the brain  

PubMed Central

Angiotensin (Ang) converting enzyme (ACE) 2 cleaves Ang-II into the vasodilator peptide Ang-(1-7), thus acting as a pivotal element in balancing the local effects of these peptides. ACE2 has been identified in various tissues and is supposed to be a modulator of cardiovascular function. Decreases in ACE2 expression and activity have been reported in models of hypertension, heart failure, atherosclerosis, diabetic nephropathy and others. In addition, the expression level and/or activity are affected by other renin-angiotensin system components (e.g. ACE and AT1 receptors). Local inhibition or global deletion of brain ACE2 induces a reduction in baroreflex sensitivity. Moreover, ACE2-null mice have been shown to exhibit either blood pressure (BP) or cardiac dysfunction phenotypes. On the other hand, over-expression of ACE2 exerts protective effects in local tissues, including the brain. In this review, we will first summarize the major findings linking ACE2 to cardiovascular function in the periphery then focus on recent discoveries related to ACE2 in the central nervous system. Finally, we will unveil new tools designed to address the importance of central ACE2 in various diseases, and discuss the potential for this carboxypeptidase as a new target in the treatment of hypertension and other cardiovascular diseases.

Xia, Huijing; Lazartigues, Eric

2009-01-01

350

Theoretical problems in modeling of enzyme sequences  

SciTech Connect

A model of the elementary catalytic system (ECS), derived from the notions of the general theory of systems, which is capable of performing a single elementary catalytic act (ECA) is as simple as possible functional model of a system with the catalysis function only. The term catalytic system was first used by Rudenko in his analysis of coupled catalysis and transport functions. To modeling of the optimum cooperation between many ECS's and its environment the general models of multicatalytic system (MCS) were used. The MCS's were shown to contain finite numbers n of ECS. An effectiveness of an ECS action inside the MCS, described by a maximum classical probability (MPr(ECA)) of successive ECA occurrence, increases non-linearly with increasing of n in comparison with a system of n ECS non-organized into MCS. For analysis of the catalysis function of enzyme systems the MCS models look to be very useful. It is just the purpose of the present paper to show that optimum value of n for simple MCS is about 15. In term of ECS and MCS a discussion of some modern biophysics and biotechnology problems is presented.

Borowiak, M.A.

1988-01-01

351

Activity of bacteriolytic enzymes adsorbed to clays  

Microsoft Academic Search

Myxococcus virescens is able to produce extracellular bacteriolytic enzymes that are rapidly adsorbed on montmorillonite. These adsorbed enzymes\\u000a are active and can be assayed by measuring the release of UV-absorbing materials in mixtures containingMicrococcus luteus cells. The activity of the clay-adsorbed enzymes is, however, considerably lower than that of the unadsorbed enzymes. Both\\u000a unadsorbed and adsorbed enzymes have their maximum

Guno Haskfi

1981-01-01

352

38 CFR 21.3024 - Nonduplication; Federal Employees' Compensation Act.  

Code of Federal Regulations, 2013 CFR

...Nonduplication; Federal Employees' Compensation Act. 21.3024 Section...Nonduplication; Federal Employees' Compensation Act. (a) Civilian...Programs, under the Federal Employees' Compensation Act (FECA) based...

2013-07-01

353

77 FR 48970 - Sunshine Act Notice  

Federal Register 2010, 2011, 2012, 2013

...DEFENSE NUCLEAR FACILITIES SAFETY BOARD Sunshine Act Notice AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Notice...hereby given of the Defense Nuclear Facilities Safety Board's (Board)...

2012-08-15

354

75 FR 21605 - Sunshine Act Notice  

Federal Register 2010, 2011, 2012, 2013

...DEFENSE NUCLEAR FACILITIES SAFETY BOARD Sunshine Act Notice AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Notice...hereby given of the Defense Nuclear Facilities Safety Board's (Board)...

2010-04-26

355

76 FR 11764 - Sunshine Act Notice  

Federal Register 2010, 2011, 2012, 2013

...DEFENSE NUCLEAR FACILITIES SAFETY BOARD Sunshine Act Notice AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Notice...hereby given of the Defense Nuclear Facilities Safety Board's public...

2011-03-03

356

From Rehearsed Monologue to Spontaneous Acting  

ERIC Educational Resources Information Center

|Suggests that the effective prerequisites for teaching methods courses are cheerleading, modern dance, and dramatics. Follows acting methods and mental attitudes of Polish director, Jerzy Grotowski. (DS)|

Niedzielski, Henri

1972-01-01

357

Improving America's Schools Act of 1993: The Reauthorization of the Elementary and Secondary Education Act and Amendments to Other Acts.  

ERIC Educational Resources Information Center

|Established in 1965, the Elementary and Secondary Education act (ESEA) offered federal support to schools in low-income communities. Over the years, Congress amended and expanded the Act seven times. Evaluations of ESEA indicate that funds are spread thinly, instead of being targeted where the needs are greatest. The traditional add-on programs…

Department of Education, Washington, DC.

358

A new class of synthetic antibacterials acting on lipopolysaccharide biosynthesis.  

PubMed

Although there is a need for antibacterial agents that act only on Gram-negative bacteria, there are at present few such compounds. The 2-deoxy analogue of beta-KDO (3-deoxy-beta-D-manno-2-octulopyranosonic acid) is a potent inhibitor of a key enzyme (CMP-KDO synthetase) in lipopolysaccharide biosynthesis of Gram-negative bacteria, but it fails to penetrate intact bacteria. Coupling an L-L-dipeptide to the 8-amino-2,8-dideoxy analogue of beta-KDO enabled it to be recognized and actively accumulated by certain peptide permeases of the cytoplasmic membrane. The dipeptide was hydrolysed in the cell and the inhibitor released. Subsequent inhibition of CMP-KDO synthetase led to the accumulation of large amounts of lipid A precursor and bacterial death. These compounds represent a new class of synthetic antimicrobials with a novel mechanism of action and considerable potential as chemotherapeutic agents. PMID:3037377

Hammond, S M; Claesson, A; Jansson, A M; Larsson, L G; Pring, B G; Town, C M; Ekström, B

359

Anaplerotic Role for Cytosolic Malic Enzyme in Engineered Saccharomyces cerevisiae Strains?  

PubMed Central

Malic enzyme catalyzes the reversible oxidative decarboxylation of malate to pyruvate and CO2. The Saccharomyces cerevisiae MAE1 gene encodes a mitochondrial malic enzyme whose proposed physiological roles are related to the oxidative, malate-decarboxylating reaction. Hitherto, the inability of pyruvate carboxylase-negative (Pyc?) S. cerevisiae strains to grow on glucose suggested that Mae1p cannot act as a pyruvate-carboxylating, anaplerotic enzyme. In this study, relocation of malic enzyme to the cytosol and creation of thermodynamically favorable conditions for pyruvate carboxylation by metabolic engineering, process design, and adaptive evolution, enabled malic enzyme to act as the sole anaplerotic enzyme in S. cerevisiae. The Escherichia coli NADH-dependent sfcA malic enzyme was expressed in a Pyc? S. cerevisiae background. When PDC2, a transcriptional regulator of pyruvate decarboxylase genes, was deleted to increase intracellular pyruvate levels and cells were grown under a CO2 atmosphere to favor carboxylation, adaptive evolution yielded a strain that grew on glucose (specific growth rate, 0.06 ± 0.01 h?1). Growth of the evolved strain was enabled by a single point mutation (Asp336Gly) that switched the cofactor preference of E. coli malic enzyme from NADH to NADPH. Consistently, cytosolic relocalization of the native Mae1p, which can use both NADH and NADPH, in a pyc1,2? pdc2? strain grown under a CO2 atmosphere, also enabled slow-growth on glucose. Although growth rates of these strains are still low, the higher ATP efficiency of carboxylation via malic enzyme, compared to the pyruvate carboxylase pathway, may contribute to metabolic engineering of S. cerevisiae for anaerobic, high-yield C4-dicarboxylic acid production.

Zelle, Rintze M.; Harrison, Jacob C.; Pronk, Jack T.; van Maris, Antonius J. A.

2011-01-01

360

Anaplerotic role for cytosolic malic enzyme in engineered Saccharomyces cerevisiae strains.  

PubMed

Malic enzyme catalyzes the reversible oxidative decarboxylation of malate to pyruvate and CO(2). The Saccharomyces cerevisiae MAE1 gene encodes a mitochondrial malic enzyme whose proposed physiological roles are related to the oxidative, malate-decarboxylating reaction. Hitherto, the inability of pyruvate carboxylase-negative (Pyc(-)) S. cerevisiae strains to grow on glucose suggested that Mae1p cannot act as a pyruvate-carboxylating, anaplerotic enzyme. In this study, relocation of malic enzyme to the cytosol and creation of thermodynamically favorable conditions for pyruvate carboxylation by metabolic engineering, process design, and adaptive evolution, enabled malic enzyme to act as the sole anaplerotic enzyme in S. cerevisiae. The Escherichia coli NADH-dependent sfcA malic enzyme was expressed in a Pyc(-) S. cerevisiae background. When PDC2, a transcriptional regulator of pyruvate decarboxylase genes, was deleted to increase intracellular pyruvate levels and cells were grown under a CO(2) atmosphere to favor carboxylation, adaptive evolution yielded a strain that grew on glucose (specific growth rate, 0.06 ± 0.01 h(-1)). Growth of the evolved strain was enabled by a single point mutation (Asp336Gly) that switched the cofactor preference of E. coli malic enzyme from NADH to NADPH. Consistently, cytosolic relocalization of the native Mae1p, which can use both NADH and NADPH, in a pyc1,2? pdc2? strain grown under a CO(2) atmosphere, also enabled slow-growth on glucose. Although growth rates of these strains are still low, the higher ATP efficiency of carboxylation via malic enzyme, compared to the pyruvate carboxylase pathway, may contribute to metabolic engineering of S. cerevisiae for anaerobic, high-yield C(4)-dicarboxylic acid production. PMID:21131518

Zelle, Rintze M; Harrison, Jacob C; Pronk, Jack T; van Maris, Antonius J A

2010-12-03

361

Theoretical study of the effect of enzyme-enzyme interactions on steady-state enzyme kinetics.  

PubMed Central

Equilibrium statistical mechanics is much concerned with problems involving intermolecularinteractions, either in lattices or in pure fluids or solutions. The possibility of enzyme-enzyme interactions suggests that the same problems might be studied profitably at steady state as well as at equilibrium. In the systems we consider, each of the identical enzyme molecules of the system undergoes steady-state stochastic cycling among states i equal 1,....,n. But the molecules do not cycle independently. Two neghboring molecules, in states i and j, interact with a free energy wij (a function of the distance r in the solution case).The instantaneous transition probabilities between states for a given molecule will depend on the instantaneous interactions between the molecule in question and its neighbors. The primary question of interest is how the enzyme flux is influenced by the interactions. The general problem is outlined here and some simple special cases are treated. The discussion will be continued in a following paper [Hill, T. L. (1977) Proc. Natl. Acad. Sci. USA 74, in press

Hill, T L

1977-01-01

362

Short-acting versus Long-acting Medications for the Treatment of ADHD  

PubMed Central

Primary care physicians, pediatricians, and psychiatrists account for approximately 80 percent of attention deficit hyperactivity disorder (ADHD) treatments prescribed in the United States. Selection of short-acting versus long-acting ADHD treatment varies by specialty with long-acting agents representing 56 percent of primary care prescriptions, 64 percent of psychiatrist prescriptions, and 79 percent of pediatric prescriptions. There appears to be a correlation between short-acting versus long-acting treatment selection and age, with long-acting agents accounting for 78 percent of prescriptions for pediatric patients (age 0–17) but only 49 percent of prescriptions for adults (patients aged 18+). A discussion of data is included.

Cascade, Elisa; Kalali, Amir H.; Weisler, Richard H.

2008-01-01

363

Metrological aspects of enzyme production  

NASA Astrophysics Data System (ADS)

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.

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

2010-05-01

364

BIOCHEMISTRY: An Enzyme Assembly Line  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Fatty acid synthases and related megaenzymes are highly adaptable to new functions as a result of their modular architecture. The fundamental polymers of biology--proteins, DNA, and RNA--are products of repetitive condensation of simple amino acid or nucleotide building blocks and are comparatively easy to assemble. However, other biomolecules require additional reactions beyond condensation of building blocks. Examples are the fatty acids and the polyketide and nonribosomal peptide secondary metabolites. These molecules are produced by complex enzyme assembly lines that include multiple catalytic domains. Two new crystal structures--one reported recently (1), the other by Maier et al. on page 1315 of this issue (2)--enrich our understanding of how these mega-enzymes function as efficient factories to produce a remarkable range of metabolic products.

Janet L. Smith (University of Michigan;Life Sciences Institute; Department of Biological Chemistry); David H. Sherman (University of Michigan;Life Sciences Institute; Departments of Medicinal Chemistry, Chemistry, and Microbiology and Immunology)

2008-09-05

365

17 CFR 229.801 - Securities Act industry guides.  

Code of Federal Regulations, 2013 CFR

...STANDARD INSTRUCTIONS FOR FILING FORMS UNDER SECURITIES ACT OF 1933, SECURITIES EXCHANGE ACT OF 1934 AND ENERGY POLICY AND CONSERVATION ACT OF 1975-REGULATION...List of Industry Guides § 229.801 Securities Act industry guides....

2013-04-01

366

32 CFR 806b.4 - Privacy Act complaints.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false Privacy Act complaints. 806b.4 Section 806b...DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.4 Privacy Act...

2013-07-01

367

Faces of the Recovery Act: Sun Catalytix  

ScienceCinema

BOSTON- At the Massachusetts Institute of Technology, Dan Nocera talks about Sun Catalytix, the next generation of solar energy, and ARPA-E funding through the Recovery Act. To learn about more ARPA-E projects through the Recovery Act: http://arpa-e.energy.gov/FundedProjects.aspx

368

The Great Acting Teachers and Their Methods.  

ERIC Educational Resources Information Center

|This book explores the acting theories and teaching methods of great teachers of acting--among them, the Europeans Stanislavski, Meyerhold, Brecht, and Grotowski; the Japanese Suzuki (who trained in Europe); and the contemporary Americans, Stella Adler, Lee Strasberg, and Sanford Meisner. Each chapter of the book includes a sample class, which…

Brestoff, Richard

369

Self-Acting Seals for Helicopter Engines.  

National Technical Information Service (NTIS)

An experimental evaluation was conducted with NASA-designed self-acting face and circumferential seals for use in the main shaft positions of advanced gas turbine engines. The seals featured Rayleigh step pads (self-acting geometry) for lift augmentation....

P. Lynwander

1975-01-01

370

78 FR 28895 - Sunshine Act Meetings  

Federal Register 2010, 2011, 2012, 2013

...for her service on the Pro Bono Task Force (Resolution 2013-XXX) 4. Consider and act on whether to authorize an executive session...General Counsel, and Corporate Secretary (Resolution 2013-XXX) 7. Public comment 8. Consider and act on other business...

2013-05-16

371

77 FR 52066 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...request for FY 2014 (Resolution 2012-XXX) 4. Consider and act on the Strategic...for Grants Management (Resolution 2012-XXX) 6. Consider and act on whether to authorize...for Grants Management (Resolution 2012-XXX) 9. Public comment 10. Consider and...

2012-08-28

372

The Anabolic Steroid Control Act of 2004  

Microsoft Academic Search

This article examines the processes by which the Anabolic Steroid Control Act of 2004, an act that added steroid precursors such as androstenedione to the list of Schedule III Controlled Substances in the United States, came to pass in both the House of Representatives and the Senate. Grounded theoretically in political economy, the article addresses, in the abstract, how the

Bryan E. Denham

2006-01-01

373

Does the Communications Decency Act Foster Indecency?  

Microsoft Academic Search

A convergence of forces and judicial decisions is narrowing the broad safe harbor of immunity that Section 230 of the Communications Decency Act has provided during the Internet's growth. This immunity protected online computer services from almost all liability for content posted by third parties. But some influential federal judges argue that such broad immunity turns the Communications Decency Act

William H. Freivogel

2011-01-01

374

The Compensation Act 2006 and School Trips  

ERIC Educational Resources Information Center

The Compensation Act 2006 received its Royal Assent on 25 July 2006. The Act allows the courts to have regard to the social utility of "desirable activities", including school trips, in considering negligence claims. The article reviews the law of negligence as it affects teachers of the very young and considers the possible impact of the…

Hunter-Jones, John

2006-01-01

375

Telecommunications Act of 1996: Goals and Impacts.  

ERIC Educational Resources Information Center

|Discusses the effects the Telecommunications Act of 1996 will have on telephone services, telephone and cable mergers and buyouts, cable television rates, alarm monitoring services, satellite services, broadcasting and media ownership, electronic publishing, the television industry, and the Internet. Describes the impacts the act may have on…

Machovec, George S.

1996-01-01

376

Update on the Americans with Disabilities Act  

ERIC Educational Resources Information Center

|In 1990, Congress enacted the Americans with Disabilities Act as a comprehensive mandate to eliminate discrimination against individuals with disabilities. The ADA's primary intent was to extend the protection of Section 504 of the Rehabilitation Act of 1973. The major difference between the two laws is that Section 504 applies to programs that…

Russo, Charles J.; Osborne, Allan G.

2009-01-01

377

The homicide, the pervert act and paternity  

Microsoft Academic Search

Proposition to articulate perverse subjectivity and the pervert act was established, wherein, the dynamics of criminal acts, as means of lust, and convicts' positioning within social bonds configure the outlines. For this purpose, imprisoned were registered in unit of Rio de Janeiro Penal System was interviewed. The concept of perversion was a starting point and means for interpretation of the

Francisco Ramos de Farias

2009-01-01

378

Acts of Reading: Teachers, Text and Childhood  

ERIC Educational Resources Information Center

|"Acts of Reading" is an enchanting and scholarly review of the history of reading and texts for children, from the 18th century to the digital age and beyond. They are examined through the eyes of their various audiences: the children, writers, teachers and parents, so as to explore the act of reading itself, whether oral, silent or performative,…

Styles, Morag, Ed.; Arizpe, Evelyn, Ed.

2009-01-01

379

The Newspaper Preservation Act: A Retrospective Analysis.  

ERIC Educational Resources Information Center

|The Newspaper Preservation Act, passed by the United States Congress in 1970, granted special antitrust exemptions to certain newspapers as a means of maintaining the editorial and reportorial independence and competitive nature of the press. However, an analysis of specific cases that have involved the act reveals that, while purportedly…

Barwis, Gail Lund

380

The USA PATRIOT Act: Archival Implications  

ERIC Educational Resources Information Center

|In October 2001, Congress passed the USA PATRIOT Act to strengthen the ability of the U.S. government to combat terrorism. Unfortunately, some sections of the Act strike at core values and practices of libraries and archives, especially in the areas of record keeping, privacy, confidentiality, security, and access to the collections. This article…

Trinkaus-Randall, Gregor

2005-01-01

381

Private enforcement of the Clean Water Act  

Microsoft Academic Search

The level of citizen enforcement activity has increased most dramatically under the Clean Water Act (CWA), for violations arising under the Act's National Pollutant Discharge Elimination System (NPDES) program. Congress has fashioned a distinct role for private enforcement under the CWA, and national environmental groups, among others, have seized the opportunity. Experience to date suggests that private enforcement can be

2009-01-01

382

Medicare and the Affordable Care Act  

Microsoft Academic Search

The recently enacted Patient Protection and Affordable Care Act made modest changes to improve Medicare and obtained a substantial share of funding for the Act's broader reforms from future spending reductions in the program. Drug benefits and preventive services were improved. While painful, the spending reductions will have only moderate impacts on beneficiaries and should help achieve the goals of

Marilyn Moon

2012-01-01

383

Bill 83: Alberta Mental Health Act1972  

Microsoft Academic Search

On May 12, 1972 a new Mental Health Act was tabled as Bill 83 in the Legislative Assembly of the Province of Alberta which may become the pace setter for North America. The proposed Act was prepared by a committee composed of representatives of the professions of psychology, social work and medicine, along with hospital administrative personnel, legal consultants and

A. G. Scott

1972-01-01

384

Clean Air Act: Promises and Priorities  

Microsoft Academic Search

Many of the nation's heavily polluted areas are substantially cleaner due the cooperative efforts of private industry, government and environmental group in fulfilling the goals of the Clean Air Act. However, too many communities missed the 1982 Clean Air Act deadline, neither reducing pollution to healthy levels nor developing plans to do so. Now as the final 1987 deadline approaches,

Jay D. Hair

1986-01-01

385

Understanding the Family and Medical Leave Act.  

PubMed

In April 1995 final regulations for the Family and Medical Leave Act (FMLA) of 1993 were issued. The act is very detailed, complicated, and difficult to implement for home care agencies. Agencies need to gain a good working understanding of the FMLA to avoid inadvertent violations. PMID:10166264

Zink-Pearson, E A

1997-03-01

386

ACT UP as a Structure of Feeling  

ERIC Educational Resources Information Center

|Revisiting AIDS Coalition to Unleash Power (ACT UP) restarts the "panic of loss" characterizing the author's youth. The author argues that the 25th anniversary of ACT UP marks the failure to consider Raymond Williams's "structure of feeling". Williams counterposes this structure against falsely viewing the past as formalized into something…

Gingrich-Philbrook, Craig

2012-01-01

387

Nursing Training Act of 1975. Fact Sheets.  

ERIC Educational Resources Information Center

|The Nursing training Act of 1975 revises and extends the nursing training authorities provided under Title VIII of the Public Health Service Act for a three-year period, thus providing aid to nursing training through September 30, 1978. It provides two new, separate authorities for the support of Advanced Nursing Training and Nursing Practitioner…

Health Resources Administration (DHEW/PHS), Bethesda, MD. Div. of Nursing.

388

Single-molecule enzyme kinetics in the presence of inhibitors  

NASA Astrophysics Data System (ADS)

Recent studies in single-molecule enzyme kinetics reveal that the turnover statistics of a single enzyme is governed by the waiting time distribution that decays as mono-exponential at low substrate concentration and multi-exponential at high substrate concentration. The multi-exponentiality arises due to protein conformational fluctuations, which act on the time scale longer than or comparable to the catalytic reaction step, thereby inducing temporal fluctuations in the catalytic rate resulting in dynamic disorder. In this work, we study the turnover statistics of a single enzyme in the presence of inhibitors to show that the multi-exponentiality in the waiting time distribution can arise even when protein conformational fluctuations do not influence the catalytic rate. From the Michaelis-Menten mechanism of inhibited enzymes, we derive exact expressions for the waiting time distribution for competitive, uncompetitive, and mixed inhibitions to quantitatively show that the presence of inhibitors can induce dynamic disorder in all three modes of inhibitions resulting in temporal fluctuations in the reaction rate. In the presence of inhibitors, dynamic disorder arises due to transitions between active and inhibited states of enzymes, which occur on time scale longer than or comparable to the catalytic step. In this limit, the randomness parameter (dimensionless variance) is greater than unity indicating the presence of dynamic disorder in all three modes of inhibitions. In the opposite limit, when the time scale of the catalytic step is longer than the time scale of transitions between active and inhibited enzymatic states, the randomness parameter is unity, implying no dynamic disorder in the reaction pathway.

Saha, Soma; Sinha, Antara; Dua, Arti

2012-07-01

389

Enzyme Flexibility in Drosophila melanogaster  

Microsoft Academic Search

POLYMORPHISMS for genetically determined enzyme variants have been reported in humans1, Drosophila2 and several other groups of organisms, but there is no adequate explanation for their occurrence. Genetic polymorphisms can be maintained in numerous ways3, but Haldane4 and Mayr5 have emphasized that geographical or temporal changes in the environment could place a premium on metabolic flexibility and that selection for

John Gibson

1970-01-01

390

Enzymes of respiratory iron oxidation  

SciTech Connect

This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies on whole cells using the oxygen electrode; and to identify, separate, purify, and characterize the individual cellular components.

Blake, R. II.

1991-01-01

391

Weak lignin-binding enzymes  

Microsoft Academic Search

Economic barriers preventing commercialization of lignocellulose-to-ethanol bioconversion processes include the high cost\\u000a of hydrolytic enzymes. One strategy for cost reduction is to improve the specific activities of cellulases by genetic engineering.\\u000a However, screening for improved activity typically uses “ideal” cellulosic substrates, and results are not necessarily applicable\\u000a to more realistic substrates such as pretreated hardwoods and softwoods. For lignocellulosic substrates,

Alex Berlin; Neil Gilkes; Arwa Kurabi; Renata Bura; Maobing Tu; Douglas Kilburn; John Saddler

2005-01-01

392

Weak Lignin-Binding Enzymes  

Microsoft Academic Search

Economic barriers preventing commercialization of lignocellulose-toethanol bioconversion processes include the high cost of\\u000a hydrolytic enzymes. One strategy for cost reduction is to improve the specific activities of cellulases by genetic engineering.\\u000a However, screening for improved activity typically uses “ideal” cellulosic substrates, and results are not necessarily applicable\\u000a to more realistic substrates such as pretreated hardwoods and softwoods. For lignocellulosic substrates,

ALEX BERLINp; Neil Gilkes; Arwa Kurabi; Renata Bura; Maobing Tu; Douglas Kilburn; John Saddler

393

Malolactic enzyme from Oenococcus oeni  

PubMed Central

Malolactic enzymes (MLE) are known to directly convert L-malic acid into L-lactic acid with a catalytical requirement of nicotinamide adenine dinucleotide (NAD+) and Mn2+; however, the reaction mechanism is still unclear. To study a MLE, the structural gene from Oenococcus oeni strain DSM 20255 was heterologously expressed in Escherichia coli, yielding 22.9 kU l?1 fermentation broth. After affinity chromatography and removal of apparently inactive protein by precipitation, purified recombinant MLE had a specific activity of 280 U mg?1 protein with a recovery of approximately 61%. The enzyme appears to be a homodimer with a molecular mass of 128 kDa consisting of two 64 kDa subunits. Characterization of the recombinant enzyme showed optimum activity at pH 6.0 and 45°C, and Km, Vmax and kcat values of 4.9 mM, 427 U mg?1 and 456 sec?1 for L-malic acid, 91.4 µM, 295 U mg?1 and 315 sec?1 for NAD+ and 4.6 µM, 229 U mg?1 and 244 sec?1 for Mn2+, respectively. The recombinant MLE retained 95% of its activity after 3 mo at room temperature and 7 mo at 4°C. When using pyruvic acid as substrate, the enzyme showed the conversion of pyruvic acid with detectable L-lactate dehydrogenase (L-LDH) activity and oxidation of NADH. This interesting observation might explain that MLE catalyzes a redox reaction and hence, the requirements for NAD+ and Mn2+ during the conversion of L-malic to L-lactic acid.

Schumann, Christina; Michlmayr, Herbert; del Hierro, Andres M.; Kulbe, Klaus D.; Jiranek, Vladimir; Eder, Reinhard; Nguyen, Thu-Ha

2013-01-01

394

BpiB05, a novel metagenome-derived hydrolase acting on N-acylhomoserine lactones  

Microsoft Academic Search

The N-acyl-homoserine lactones (N-AHLs) play an important role in bacterial cell–cell signaling. Up to date, however, only a few different experimentally proven classes of N-AHL ring-cleaving enzymes are known. Here we report on the isolation and biochemical characterization of a novel hydrolase derived from the soil metagenome and acting on N-AHLs. The identified protein designated BpiB05 is weakly similar to

P. Bijtenhoorn; C. Schipper; C. Hornung; M. Quitschau; S. Grond; N. Weiland; W. R. Streit

2011-01-01

395

Immobilised enzymes in biorenewables production.  

PubMed

Oils, fats, carbohydrates, lignin, and amino acids are all important raw materials for the production of biorenewables. These compounds already play an important role in everyday life in the form of wood, fabrics, starch, paper and rubber. Enzymatic reactions do, in principle, allow the transformation of these raw materials into biorenewables under mild and sustainable conditions. There are a few examples of processes using immobilised enzymes that are already applied on an industrial scale, such as the production of High-Fructose Corn Syrup, but these are still rather rare. Fortunately, there is a rapid expansion in the research efforts that try to improve this, driven by a combination of economic and ecological reasons. This review focusses on those efforts, by looking at attempts to use fatty acids, carbohydrates, proteins and lignin (and their building blocks), as substrates in the synthesis of biorenewables using immobilised enzymes. Therefore, many examples (390 references) from the recent literature are discussed, in which we look both at the specific reactions as well as to the methods of immobilisation of the enzymes, as the latter are shown to be a crucial factor with respect to stability and reuse. The applications of the renewables produced in this way range from building blocks for the pharmaceutical and polymer industry, transport fuels, to additives for the food industry. A critical evaluation of the relevant factors that need to be improved for large-scale use of these examples is presented in the outlook of this review. PMID:23519171

Franssen, Maurice C R; Steunenberg, Peter; Scott, Elinor L; Zuilhof, Han; Sanders, Johan P M

2013-08-01

396

Inhibitory zinc sites in enzymes.  

PubMed

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

Maret, Wolfgang

2013-03-01

397

77 FR 15555 - Freedom of Information Act and Privacy Act Procedures  

Federal Register 2010, 2011, 2012, 2013

This interim final rule establishes procedures for the public to obtain information from the Special Inspector General for Afghanistan Reconstruction under the Freedom of Information Act (FOIA) and the Privacy Act of 1974. These procedures will facilitate public interaction with...

2012-03-16

398

A method for selective conjugation of an analyte to enzymes without unwanted enzyme–enzyme cross-linking  

Microsoft Academic Search

The conjugation of a ligand to an enzyme is often a necessary step in the development of enzyme-linked immunoassays. Such conjugation is typically accomplished by reacting an amine with a carboxyl functional group in the presence of an activator such as a carbodiimide. However, one enzyme’s free carboxyl groups often react with another’s free amino groups and a large amount

Vincent C Lombardi; David A Schooley

2004-01-01

399

The Roles and Acting Mechanism of Caenorhabditis elegans DNase II Genes in Apoptotic DNA Degradation and Development  

Microsoft Academic Search

DNase II enzymes are acidic endonucleases that have been implicated in mediating apoptotic DNA degradation, a critical cell death execution event. C. elegans genome contains three DNase II homologues, NUC-1, CRN-6, and CRN-7, but their expression patterns, acting sites, and roles in apoptotic DNA degradation and development are unclear. We have conducted a comprehensive analysis of three C. elegans DNase

Huey-Jen Lai; Szecheng J. Lo; Eriko Kage-Nakadai; Shohei Mitani; Ding Xue

2009-01-01

400

Actinomycetes: Sources for Soil Enzymes  

Microsoft Academic Search

\\u000a Soil is the most complicated biomaterial on the planet.It is a natural source for microorganisms and is a natural laboratory\\u000a to do experiments. Soil, which arises from the weathering of parent rock materials, is by definition capable of acting as\\u000a a habitat for microorganisms. Microbially, the most active soil is the upper 16- to 17.2-cm–thick plow layer. As with any

V. Suneetha; Zaved Ahmed Khan

401

78 FR 25685 - Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation Act of 2010  

Federal Register 2010, 2011, 2012, 2013

...Act Provisions; Implementation of the Shark Conservation Act of 2010 AGENCY: National...rule to implement the provisions of the Shark Conservation Act of 2010 (SCA) and prohibit...person from removing any of the fins of a shark at sea, possessing shark fins on...

2013-05-02

402

The Americans with Disabilities Act: Should the Amendments to the Act Help Individuals with Mental Illness?  

Microsoft Academic Search

On July 26, 1990, President George H.W. Bush signed into law the Americans with Disabilities Act of 1990 (ADA). The ADA was intended to eliminate discrimination against individuals with disabilities by expanding the Rehabilitation Act (Rehab Act) to cover people with disabilities in need of coverage from a non-federal employer or entity. Unfortunately, due to a number of Supreme Court

Abigail J. Schopick

2012-01-01

403

From ‘acting on’ to ‘acting with’: the functional anatomy of object-oriented action schemata  

Microsoft Academic Search

In this chapter it is proposed that object-based actions can be broadly classified into types. In the first, objects are ‘acted on’ without a specific purpose. In the second, objects are ‘acted with’. In the latter case the grasp reflects the subsequent goal of the subject. Recent evidence from human functional imaging suggests different neural substrates for acting on an

Scott H. Johnson; Scott T. Grafton

2003-01-01

404

The California Resale Royalty Act and the Fifth Amendment: Why the Act Survives Takings Challenges  

Microsoft Academic Search

The California Resale Royalty Act, which provides fine artists with a 5% inalienable royalty on future sales of their work, has been challenged on several legal grounds, including due process, freedom of contract and preemption. While these challenges have failed, it has also been suggested that the act amounts to a physical taking under the Fifth Amendment. While the act

Forrest Prull

2012-01-01

405

75 FR 36535 - Freedom of Information Act, Privacy Act of 1974; Implementation  

Federal Register 2010, 2011, 2012, 2013

On January 6, 2010, the Department of the Treasury published a document in the Federal Register, amending the Department of the Treasury's regulations on the disclosure of records under the Freedom of Information Act (FOIA) and its regulations concerning the Privacy Act of 1974 (Privacy Act). It also amended the appendices to these subparts setting forth the administrative procedures by which the......

2010-06-28

406

Polymeric Catalysts With Enzyme-Like Properties.  

National Technical Information Service (NTIS)

Enzymes are acknowledged to represent the highest expression of chemical catalysis. Duplication of enzymic catalysis in synthetic materials has been pursued by many investigators for several decades. The high levels of substrate selectivity and catalytic ...

M. Zeldin S. Rubinsztajn W. K. Fife

1990-01-01

407

Immobilized Enzymes and the Food Processing Industry.  

National Technical Information Service (NTIS)

Enzymes have long been recognized as the most efficient catalysts known to man. Unlike most industrial catalysts which operate under extreme conditions of temperature and/or pressure, enzymes work most efficiently at room temperature. The mechanism of enz...

P. F. Greenfield R. L. Lawrence

1974-01-01

408

Isocitrate Dehydrogenase Parameters of Enzyme Activity  

NSDL National Science Digital Library

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.

John H. Williamson (Davidson College;); A. Malcolm Campbell (Davidson College;)

1999-01-01

409

Chemistry and Flatulence: An Introductory Enzyme Experiment  

NASA Astrophysics Data System (ADS)

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.

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

2000-04-01

410

Enzymes toughen up for chemical processing  

SciTech Connect

While enzymes have been making tremendous inroads into detergent formulation and food processing, the penetration of these protein-based catalysts into other chemical-process manufacture and hazardous waste treatment--where they are slated to replace heavy metal catalysts and other processing aids--has been relatively slow. Recently, however, enhancements in the enzyme`s properties are opening the door wider for such broadened usage. Some of these non-traditional uses of enzymes are described.

Hairston, D.

1995-05-01

411

19 CFR 147.23 - Compliance with Plant Quarantine Act and Federal Food, Drug, and Cosmetic Act.  

Code of Federal Regulations, 2013 CFR

...Quarantine Act and Federal Food, Drug, and Cosmetic Act. 147.23 Section 147.23...Quarantine Act and Federal Food, Drug, and Cosmetic Act. (a) Plant Quarantine Act...regulations. (b) Federal Food, Drug, and Cosmetic Act. The entry of food products...

2013-04-01

412

23 CFR 633.211 - Implementation of the Clean Air Act and the Federal Water Pollution Control Act.  

Code of Federal Regulations, 2013 CFR

...Clean Air Act and the Federal Water Pollution Control Act. 633.211 Section...Clean Air Act and the Federal Water Pollution Control Act. Pursuant to...Clean Air Act and the Federal Water Pollution Control Act are included in...

2013-04-01

413

Qualitative yeast enzyme analysis by electrophoresis  

Microsoft Academic Search

Baker's yeast (Saccharomyces cerevisiae) was cultivated under different intensities of aeration on glucose and on ethanol. Seventeen enzymes of the Embden-Meyerhof pathway and the TCA cycle or related reactions were then assayed by starch gel electrophoresis. There were both qualitative and quantitative differences in many enzymes, most notably in glyceraldehyde-3-phosphate dehydrogenase, alcohol dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase, and fumarase. Enzyme

Anssi Saura; Juhani Lokki; Erkki Oura; Heikki Suomalainen

1979-01-01

414

Designing artificial enzymes by intuition and computation  

Microsoft Academic Search

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

Vikas Nanda; Ronald L. Koder

2010-01-01

415

Tailoring new enzyme functions by rational redesign  

Microsoft Academic Search

Site-directed mutagenesis is still a very efficient strategy to elaborate improved enzymes. Recently, advances have been made in developing rational strategies aimed at reshaping enzyme specificities and mechanisms, and at engineering biocatalysts through molecular assembling. These knowledge-based studies greatly benefit from the most recent computational analyses of enzyme structures and functions. The combination of rational and combinatorial methods opens up

Frédéric Cedrone; André Ménez; Eric Quéméneur

2000-01-01

416

Optimising enzyme function by directed evolution  

Microsoft Academic Search

The past decade has seen a revolution in our ability to engineer designer enzymes using genetic tools that mimic evolution on a laboratory timescale. Many excellent examples of directed evolution applied to a wide range of enzymes have clearly demonstrated its future role in adapting enzymes for use in the chemical industry. Recent advances in ‘smart’ library design and computational

Paul A Dalby

2003-01-01

417

Enzyme Replacement Therapy in Feline Mucopolysaccharidosis I  

Microsoft Academic Search

Enzyme replacement therapy (ERT) has long been considered an approach to treating lysosomal storage disorders caused by deficiency of lysosomal enzymes. ERT is currently used to treat Gaucher disease and is being developed for several lysosomal storage disorders now that recombinant sources of the enzymes have become available. We have continued development of ERT for mucopolysaccharidosis I (MPS I) using

E. D. Kakkis; E. Schuchman; X. He; Q. Wan; S. Kania; S. Wiemelt; C. W. Hasson; T. O'Malley; M. A. Weil; G. A. Aguirre; D. E. Brown; M. E. Haskins

2001-01-01

418

Enzyme Inhibition Based Biosensors: A Review  

Microsoft Academic Search

This article reviewed the recent advances in the development of biosensors based on enzyme inhibition. They are an important alternative as compared to conventional analytical techniques due to their high selectivity and sensitivity. Since the most potent inhibitors of enzymes are heavy metals and pesticides, these enzyme inhibition based biosensors have a wide application in the field of environmental safety,

Lata Sheo Bachan Upadhyay; Nishant Verma

2012-01-01

419

Hydrolytic enzyme activity in landfilled refuse  

Microsoft Academic Search

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

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

1993-01-01

420

Molybdenum enzymes in bacteria and their maturation  

Microsoft Academic Search

Molybdenum pterin cofactor-containing enzymes exist in all domains of life and their importance is exemplified by their ubiquity, their roles in metabolic diversity and global geochemical cycles. In the prokaryotic enzymes the pterin cofactor coordinating the molybdenum\\/tungsten center exhibits a diversity of structure that facilitates a range of redox chemistry and reactivity. These enzymes fall into four families based on

Axel Magalon; Justin G. Fedor; Anne Walburger; Joel H. Weiner

2011-01-01

421

Immobilization of Enzymes in Polymer Supports.  

ERIC Educational Resources Information Center

|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)|

Conlon, Hugh D.; Walt, David R.

1986-01-01

422

Enzyme variation between syngens in Paramecium aurelia  

Microsoft Academic Search

Five enzymes (succinic dehydrogenase isocitrate dehydrogenase, glutamate dehydrogenase, ß-hydroxybutyrate dehydrogenase, and fumarase) in the ciliate Paramecium aurelia have been examined by starch gel electrophoresis. Relatively few variants were found among stocks belonging to a given syngen and only in two out of the five enzymes studied. Comparison of stocks belonging to different syngens, however, revealed many enzyme differences, which did

A. Tait

1970-01-01

423

Association of glycolytic enzymes with the cytoskeleton.  

PubMed

The diverse physical associations of the glycolytic enzymes with structural components of the cell suggest that the glycolytic enzymes are not entirely soluble in the cell. The relatively low affinities of the associations are likely responsible for the apparently transient interactions. The binding phenomenon is suggested to regulate metabolism through changes in enzymatic activity and facilitates localized enrichment of the enzymes. PMID:1499331

Knull, H R; Walsh, J L

1992-01-01

424

Immunochemical assays of enzymes in foodstuffs  

Microsoft Academic Search

The paper reviews immunochemical methods used in the field of food enzymology. The advantages of immunochemical identification and assessment of enzymes include high specificity and sensitivity, and the possibility of detecting inactivated enzymes. Immunochemical methods have been applied mainly to the investigation of cereal and malt enzymes, the determination of chill?proofing proteinases and amyloglucosidase in beer, the analysis of combined

Ladislav Fukal; Jan Káš; Pavel Rauch

1988-01-01

425

Angiotensin-converting enzyme in epithelial and neuroepithelial cells.  

PubMed

Angiotensin-converting enzyme (CE) occurs in three types of cell: endothelial, epithelial, and neuroepithelial. In all three, it appears to be bound to plasma membrane. With antisera to the human enzyme, CE is demonstrated in paraffin sections on the apical surface of epithelial cells in the proximal tubule of the kidney, the mucosa of the small intestine, the syncytial trophoblast of the placenta, and the choroid plexus. Epithelial CE is characteristically found on microvillous surfaces in contact with an effluent, well placed to act on substrate in flux. In the brain, CE occurs in nerve fibers and terminals, mainly mesiobasally and in basal ganglia. Mesiobasal CE coincides with other components of the renin-angiotensin system (RAS) in the choroid/ventricular fluid, the subfornical organ, and the magnocellular neurosecretory system of the hypothalamus. Extrapyramidal CE, however, may not be related to the RAS. In the substantia nigra and the globus pallidus, the enzyme has the same cellular distribution as two putative neuromodulators, substance P and enkephalin, the latter a known substrate of CE. PMID:6310427

Defendini, R; Zimmerman, E A; Weare, J A; Alhenc-Gelas, F; Erdös, E G

1983-07-01

426

Potent enzyme inhibitors derived from dromedary heavy-chain antibodies.  

PubMed Central

Evidence is provided that dromedary heavy-chain antibodies, in vivo-matured in the absence of light chains, are a unique source of inhibitory antibodies. After immunization of a dromedary with bovine erythrocyte carbonic anhydrase and porcine pancreatic alpha-amylase, it was demonstrated that a considerable amount of heavy-chain antibodies, acting as true competitive inhibitors, circulate in the bloodstream. In contrast, the conventional antibodies apparently do not interact with the enzyme's active site. Next we illustrated that peripheral blood lymphocytes are suitable for one-step cloning of the variable domain fragments in a phage-display vector. By bio-panning, several antigen-specific single-domain fragments are readily isolated for both enzymes. In addition we show that among those isolated fragments active site binders are well represented. When produced as recombinant protein in Escherichia coli, these active site binders appear to be potent enzyme inhibitors when tested in chromogenic assays. The low complexity of the antigen-binding site of these single-domain antibodies composed of only three loops could be valuable for designing smaller synthetic inhibitors.

Lauwereys, M; Arbabi Ghahroudi, M; Desmyter, A; Kinne, J; Holzer, W; De Genst, E; Wyns, L; Muyldermans, S

1998-01-01

427

Regulation of telomere length and homeostasis by telomerase enzyme processivity.  

PubMed

Telomerase is a ribonucleoprotein consisting of a catalytic subunit, the telomerase reverse transcriptase (TERT), and an integrally associated RNA that contains a template for the synthesis of short repetitive G-rich DNA sequences at the ends of telomeres. Telomerase can repetitively reverse transcribe its short RNA template, acting processively to add multiple telomeric repeats onto the same DNA substrate. The contribution of enzyme processivity to telomere length regulation in human cells is not well characterized. In cancer cells, under homeostatic telomere length-maintenance conditions, telomerase acts processively, whereas under nonequilibrium conditions, telomerase acts distributively on the shortest telomeres. To investigate the role of increased telomerase processivity on telomere length regulation in human cells with limited lifespan that are dependent on human TERT for lifespan extension and immortalization, we mutated the leucine at position 866 in the reverse transcriptase C motif of human TERT to a tyrosine (L866Y), which is the amino acid found at the equivalent position in HIV-1 reverse transcriptase. We report that, similar to the previously reported gain-of-function Tetrahymena telomerase mutant (L813Y), the human telomerase variant displays increased processivity. Human TERT-L866Y, like wild-type human TERT, can immortalize and extend the lifespan of limited-lifespan cells. Moreover, cells expressing human TERT-L866Y display heterogenous telomere lengths, telomere elongation, multiple telomeric signals indicative of fragile sites and replicative stress, and an increase in short telomeres, which is accompanied by telomere trimming events. Our results suggest that telomere length and homeostasis in human cells may be regulated by telomerase enzyme processivity. PMID:23178942

D'Souza, Yasmin; Lauzon, Catherine; Chu, Tsz Wai; Autexier, Chantal

2012-11-23

428

FACT: a Dutch version of ACT.  

PubMed

Assertive Community Treatment (ACT) is a well-defined service delivery model for the care and treatment of the most severely mentally ill in the community. We have opted for a Dutch version named 'Function' ACT or FACT. In a FACT team, ACT is one of the functions that the team can perform. For more stable long-term patients FACT provides coordinated multidisciplinary treatment and care by individual case management. Unstable patients at risk of relapse are followed with assertive outreach care by the same team, working with a shared caseload for this subgroup. This article describes the service model and everyday practice in FACT. PMID:17514502

van Veldhuizen, J Remmers

2007-05-21

429

The Genetic Privacy Act and commentary  

SciTech Connect

The Genetic Privacy Act is a proposal for federal legislation. The Act is based on the premise that genetic information is different from other types of personal information in ways that require special protection. Therefore, to effectively protect genetic privacy unauthorized collection and analysis of individually identifiable DNA must be prohibited. As a result, the premise of the Act is that no stranger should have or control identifiable DNA samples or genetic information about an individual unless that individual specifically authorizes the collection of DNA samples for the purpose of genetic analysis, authorized the creation of that private information, and has access to and control over the dissemination of that information.

Annas, G.J.; Glantz, L.H.; Roche, P.A.

1995-02-28

430

A new group of exo-acting family 28 glycoside hydrolases of Aspergillus niger that are involved in pectin degradation  

PubMed Central

The fungus Aspergillus niger is an industrial producer of pectin-degrading enzymes. The recent solving of the genomic sequence of A. niger allowed an inventory of the entire genome of the fungus for potential carbohydrate-degrading enzymes. By applying bioinformatics tools, 12 new genes, putatively encoding family 28 glycoside hydrolases, were identified. Seven of the newly discovered genes form a new gene group, which we show to encode exoacting pectinolytic glycoside hydrolases. This group includes four exo-polygalacturonan hydrolases (PGAX, PGXA, PGXB and PGXC) and three putative exo-rhamnogalacturonan hydrolases (RGXA, RGXB and RGXC). Biochemical identification using polygalacturonic acid and xylogalacturonan as substrates demonstrated that indeed PGXB and PGXC act as exo-polygalacturonases, whereas PGXA acts as an exo-xylogalacturonan hydrolase. The expression levels of all 21 genes were assessed by microarray analysis. The results from the present study demonstrate that exo-acting glycoside hydrolases play a prominent role in pectin degradation.

Martens-Uzunova, Elena S.; Zandleven, Joris S.; Benen, Jaques A. E.; Awad, Hanem; Kools, Harrie J.; Beldman, Gerrit; Voragen, Alphons G. J.; Van Den Berg, Johan A.; Schaap, Peter J.

2006-01-01

431

ENZYME ACTIVITY AND BACTERIOPHAGE INFECTION  

PubMed Central

Experiments have been performed on the apyrase activity of E. coli, strain B. Although the dependence on pH and substrate is similar to that of rat tissue, the bacterial extracts are inhibited by Ca++ and stimulated by Mg++. In bacterial extracts the rate of phosphate release decreases in the course of the reaction, possibly owing to product inhibition. With multiple bacteriophage infection, the apyrase activity of the intact cells increased several fold, and the activity of extracts increased about 30 per cent. It is suggested that the changes could be attributed to an increase in the amount of enzyme although other alternatives cannot be precluded at present.

Pardee, Arthur B.

1951-01-01

432

Two distinct chondroitin sulfate ABC lyases. An endoeliminase yielding tetrasaccharides and an exoeliminase preferentially acting on oligosaccharides.  

PubMed

Crude enzyme obtained from chondroitin sulfate-induced Proteus vulgaris NCTC 4636 has been fractionated into 1) an endoeliminase capable of depolymerizing chondroitin sulfate and related polysaccharides to produce, as end products, a mixture of Delta4-unsaturated tetra- and disaccharides and 2) an exoeliminase preferentially acting on chondroitin sulfate tetra- and hexasaccharides to yield the respective disaccharides. Isolation of the two enzymes was achieved by a simple two-step procedure: extracting the enzymes from intact P. vulgaris cells with a buffer solution of nonionic surfactant and then treating the extract by cation-exchange chromatography. Each of the enzymes thus prepared was apparently homogeneous as assessed by SDS-polyacrylamide gel electrophoresis and readily crystallized from polyethylene glycol solutions. Both enzymes acted on various substrates such as chondroitin sulfate, chondroitin sulfate proteoglycan, and dermatan sulfate at high, but significantly different, initial rates. They also attacked hyaluronan but at far lower rates and were inactive to keratan sulfate, heparan sulfate, and heparin. Our results show that the known ability of the conventional enzyme called "chondroitinase ABC" to catalyze the complete depolymerization of chondroitin sulfates to unsaturated disaccharides may actually result from the combination reactions by endoeliminase (chondroitin sulfate ABC endolyase) and exoeliminase (chondroitin sulfate ABC exolyase). PMID:9083041

Hamai, A; Hashimoto, N; Mochizuki, H; Kato, F; Makiguchi, Y; Horie, K; Suzuki, S

1997-04-01

433

Structure-Function Relationships of Glucansucrase and Fructansucrase Enzymes from Lactic Acid Bacteria  

PubMed Central

Lactic acid bacteria (LAB) employ sucrase-type enzymes to convert sucrose into homopolysaccharides consisting of either glucosyl units (glucans) or fructosyl units (fructans). The enzymes involved are labeled glucansucrases (GS) and fructansucrases (FS), respectively. The available molecular, biochemical, and structural information on sucrase genes and enzymes from various LAB and their fructan and ?-glucan products is reviewed. The GS?and FS enzymes are both glycoside hydrolase enzymes that act on the same substrate (sucrose) and catalyze (retaining) transglycosylation reactions that result in polysaccharide formation, but they possess completely different protein structures. GS enzymes (family GH70) are large multidomain proteins that occur exclusively in LAB. Their catalytic domain displays clear secondary-structure similarity with ?-amylase enzymes (family GH13), with a predicted permuted (?/?)8 barrel structure for which detailed structural and mechanistic information is available. Emphasis now is on identification of residues and regions important for GS enzyme activity and product specificity (synthesis of ?-glucans differing in glycosidic linkage type, degree and type of branching, glucan molecular mass, and solubility). FS enzymes (family GH68) occur in both gram-negative and gram-positive bacteria and synthesize ?-fructan polymers with either ?-(2?6) (inulin) or ?-(2?1) (levan) glycosidic bonds. Recently, the first high-resolution three-dimensional structures have become available for FS (levansucrase) proteins, revealing a rare five-bladed ?-propeller structure with a deep, negatively charged central pocket. Although these structures have provided detailed mechanistic insights, the structural features in FS enzymes dictating the synthesis of either ?-(2?6) or ?-(2?1) linkages, degree and type of branching, and fructan molecular mass remain to be identified.

van Hijum, Sacha A. F. T.; Kralj, Slavko; Ozimek, Lukasz K.; Dijkhuizen, Lubbert; van Geel-Schutten, Ineke G. H.

2006-01-01

434

Properties of yeast debranching enzyme and its specificity toward branched cyclodextrins.  

PubMed

Debranching enzyme was purified from Saccharomyces cerevisiae by DEAE-cellulose, omega-aminobutyl agarose and hydroxyapatite column chromatography. The activity of the eluent was monitored by the iodine-staining method which detects both the direct and indirect debranching enzymes. The elution profiles at every step showed a single peak with no shoulder. The crude and the purified enzyme preparations gave a single activity band with the same mobility on PAGE. The crude product produced 80% glucose compared to reducing sugar from glycogen-phosphorylase-limited dextrin while the partially purified and purified preparations produced 100% glucose. The activity of the purified enzyme was characterized and compared with that of the rabbit muscle enzyme by using various branched cyclodextrins as substrates. Both enzymes hydrolyzed 6-O-alpha-D-glucosyl cyclodextrins to glucose and cyclodextrins, but did not act on 6-O-alpha-maltosyl cyclomaltoheptaose. The yeast enzyme gave rise to glucose as a sole reducing sugar from 6-O-alpha-maltotriosyl cyclomaltoheptaose and 6-O-alpha-maltotetraosyl cyclomaltoheptaose, indicating that maltosyl and maltotriosyl transfers, respectively, had occurred, prior to the action of amylo-1,6-glucosidase. 6-O-alpha-D-Glucosyl cyclomaltoheptaose and 6-O-alpha-D-glucosyl cyclomalto-octaose, respectively, were better substrates than glycogen-phosphorylase-limited dextrin for the yeast and muscle enzymes. The yeast enzyme released glucose at a similar rate from 6-O-alpha-maltotriosyl cyclomaltoheptaose as from 6-O-alpha-maltotetraosyl cyclomaltoheptaose, but considerably lower rates than that from limit dextrin. The yeast debranching enzyme appears to be exclusively oligo-1,4----1,4-glucantransferase-amylo-1,6-glucosidase and does not have isoamylase. PMID:1597178

Tabata, S; Hizukuri, S

1992-06-01

435

Production and optimization of L-glutaminase enzyme from Hypocrea jecorina pure culture.  

PubMed

L-Glutaminase (L-glutamine amidohydrolase, EC 3.5.1.2) is the important enzyme that catalyzes the deamination of L-glutamine to L-glutamic acid and ammonium ions. Recently, L-glutaminase has received much attention with respect to its therapeutic and industrial applications. It acts as a potent antileukemic agent and shows flavor-enhancing capacity in the production of fermented foods. Glutaminase activity is widely distributed in plants, animal tissues, and microorganisms, including bacteria, yeasts, and fungi. This study presents microbial production of glutaminase enzyme from Hypocrea jecorina pure culture and determination of optimum conditions and calculation of kinetic parameters of the produced enzyme. The optimum values were determined by using sa Nesslerization reaction for our produced glutaminase enzyme. The optimum pH value was determined as 8.0 and optimum temperature as 50°C for the glutaminase enzyme. The Km and Vmax values, the kinetic parameters, of enzyme produced from Hypocrea jecorina, pure culture were determined as 0.491 mM for Km and 13.86 U/L for Vmax by plotted Lineweaver-Burk graphing, respectively. The glutaminase enzyme from H. jecorina microorganism has very high thermal and storage stability. PMID:23464921

Bülbül, Dilara; Karaku?, Emine

2013-01-01

436

On the mechanism of amylose branching by potato Q-enzyme.  

PubMed

1. When potato Q-enzyme converts amylose into an amylopectin-like molecule, the action is by a random, endo-type transglycosylation of the substrate chains. 2. Inter-chain transfer takes place during the formation of the amylopectin branch linkage. This is seen in experiments in which radioactive label was transferred between substrates of disparate molecular weight. Intra-chain transfer, leading to the formation of a branch linkage, is not excluded by these experiments. 3. The minimum length of amylose chain that can act as an acceptor in the transglycosylation reaction, under the experimental conditions described, is greater than 40 glucose units. 4. The requirement of Q-enzyme for substrate chains at least 40 glucose units in length is interpreted as meaning that a stabilized secondary and tertiary structure must be established in the substrate before it can be utilized by Q-enzyme, and that the forces that provide such conformation are sufficiently strong only when the chains are longer than the minimum. Inter-chain transfer is seen as taking place by one of two mechanisms. The first involved the reaction of the enzyme with a chain that has a stabilized (helical?) conformation. An enzyme-donor chain intermediate is formed, that then reacts with an acceptor chain to complete the transglycosylation. The second mechanism envisages the substrate for the enzyme as being a complex formed between two chains (a double helix?). The enzyme encounters the complex and carries out an inter-chain transglycosylation reactions. PMID:1253793

Borovsky, D; Smith, E E; Whelan, W J

1976-02-16

437

Enzyme/indicator optrodes for detection of heavy metal ions and pesticides  

NASA Astrophysics Data System (ADS)

Composite films containing enzyme and indicator molecules were produced by means of polyelectrolyte self-assembly. These membranes provide two functions: (i) molecular recognition of the substratum by respective enzyme, and (ii) optrode transducing, when the products o the substratum decomposition affect optical spectra of indicator molecules. Apart from direct registration of enzyme reactions, inhibition reactions can also be monitored with this method. Particularly, heavy metal salts and phosphor organic pesticides acting as inhibitors for Urease and Cholinesterase, respectively, were registered. Composite PESA films were deposited onto glass slides and consisted of several layers of poly(alylamine) hydrochloride (PAA) alternated with indicator molecules, either Cyclo-tetra- chromotropylene or Thymol Blue, both containing SO3- Na+ groups. Then a few layers of PAA/enzyme were deposited on top. A typical structure of the samples was (PAA/Indicator)n/(PAA/Enzyme)m/PAA with n equals 1-5. The obtained films were characterized with UV-visible absorption spectroscopy. The effect of the substrate decomposition on the UV-vis spectra of respective indicator molecules was studied. The inhibition of enzymes Urease and Cholinesterase by heavy metal ions and phosphor organic pesticide, respectively was found. The results obtained show the prospects towards development of optical enzyme sensor arrays.

Nabok, Alexei V.; Ray, Asim K.; Starodub, Nickolaj F.; Dowker, Kenneth P.

2000-12-01

438

Activity of native hydrolytic enzymes and their association with the cell wall of three ectomycorrhizal fungi.  

PubMed

The ecological and biogeochemical relevance of hydrolytic enzymes associated with the fungal cell wall has been poorly studied in ectomycorrhizal (ECM) fungi. We used a modified sequential extraction procedure to investigate the activity of various hydrolytic enzymes (?-glucosidase, acid-phosphatase, leucine-aminopeptidase, chitinase, xylanase and glucuronidase) and their association with the cell wall of three ECM fungi (Rhizopogon roseolus, Paxillus involutus and Piloderma croceum). Fungi were grown on C-rich solid medium under three different P concentrations (3.7, 0.37 and 0.037 mM). The sequential extraction procedure classifies enzymes as: (a) cytosolic, (b) loosely bound, (c) hydrophobically bound, (d) ionically bound and (e) covalently bound. Results showed that for the same fungus absolute enzymatic activity was affected by P concentration, whilst enzymatic compartmentalization among the cytosol and the cell wall fractions was not. The association of enzymes with the cell wall was fungus- and enzyme-specific. Our data indicate also that enzymes best known for being either extracellular or cytosolic or both, do act in muro as well. The ecological implications of cell wall-bound enzymes and the potential applications and limitations of sequential extractions are further discussed. PMID:23053575

Pérez-de-Mora, Alfredo; Reuter, Bianca; Lucio, Marianna; Ahne, Alfred; Schloter, Michael; Pritsch, Karin

2012-10-03

439

78 FR 59009 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...COMMODITY FUTURES TRADING COMMISSION Sunshine Act Meeting TIME AND DATE: 10:00 a.m., Friday, October 4, 2013...BE CONSIDERED: Surveillance, Enforcement Matters, and Examinations. In the event that the times, dates...

2013-09-25

440

75 FR 33374 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...rule 34b-1 under the Investment Company Act of 1940 to address concerns that have been raised about target date retirement fund names and marketing materials. At times, changes in Commission priorities require alterations in the scheduling of...

2010-06-11

441

16 CFR 307.4 - Prohibited acts.  

Code of Federal Regulations, 2010 CFR

...LOSS WARNING: THIS PRODUCT IS NOT A SAFE ALTERNATIVE TO CIGARETTES Each smokeless tobacco product shall upon being...event of the distribution of labels or the publication of advertisements that do not conform with the Act and these...

2009-01-01

442

16 CFR 307.4 - Prohibited acts.  

Code of Federal Regulations, 2010 CFR

...LOSS WARNING: THIS PRODUCT IS NOT A SAFE ALTERNATIVE TO CIGARETTES Each smokeless tobacco product shall upon being...event of the distribution of labels or the publication of advertisements that do not conform with the Act and these...

2010-01-01

443

76 FR 63333 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...Protection Act, which relates to reporting requirements regarding conflict minerals originating in the Democratic Republic of the Congo and adjoining countries. For further information, please contact the Office of the Secretary at (202) 551-5400....

2011-10-12

444

78 FR 21419 - Sunshine Act Meetings  

Federal Register 2010, 2011, 2012, 2013

...Operating Budget for FY 2013 and recommend Resolution 2013-XXX to the full Board David Richardson, Treasurer/Comptroller...Advancement Committee 14. Consider and act on Resolution 2013-XXX in recognition of distinguished service by Victor M....

2013-04-10

445

10 CFR 490.603 - Prohibited acts.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Prohibited acts. 490.603 Section 490.603 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Investigations and Enforcement § 490.603 Prohibited...

2013-01-01

446

76 FR 28425 - Sunshine Act Notice  

Federal Register 2010, 2011, 2012, 2013

...DEFENSE NUCLEAR FACILITIES SAFETY BOARD Sunshine Act Notice AGENCY: Defense Nuclear Facilities Safety Board. ACTION: Notice...to be held by the Defense Nuclear Facilities Safety Board in Augusta,...

2011-05-17

447

77 FR 1095 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...Oversight Board and will consider the related annual accounting support fee for the Board under Section 109 of the Sarbanes-Oxley Act of 2002. Commissioner Paredes, as duty officer, determined that no earlier notice thereof was possible. At...

2012-01-09

448

2004 Federal Activities Inventory Reform (FAIR) Act  

NSF Publications Database

... Johnson III Deputy Director for Management Office of Management and Budget Executive Office of the ... Inventory Reform (FAIR) Act (P.L. 105-270), the FY 2004 Commercial Activities Inventory for the ...

449

FDAAA (Food and Drug Administration Amendments Act)  

Center for Drug Evaluation (CDER)

... To Accompany Drug, Biological Product, and Device Applications/Submissions: Compliance with Section 4020) of The Public Health Service Act ... More results from www.fda.gov/drugs/guidancecomplianceregulatoryinformation/guidances

450

Family and Medical Leave Act (FMLA)  

MedlinePLUS

... FMLA Wage and Hour Division (WHD) Family and Medical Leave Act Overview The FMLA entitles eligible employees ... unpaid, job-protected leave for specified family and medical reasons with continuation of group health insurance coverage ...

451

Odor and the Clean Air Act  

SciTech Connect

The case described in this paper involves the interpretation of language contained in the Texas Clean Air Act Texas Health and Safety Code Ann. Sections 382.001-382.141. The State of Texas, on behalf of the Texas Air Control Board, brought suit in the District Court of Erath County, Texas against the F/R Cattle Company, Inc., alleging that, because of odors emanating from the company's cattle feeding facility, the company was violating the Clean Air Act. The Board is granted the power and duty to administer the Clean Air Act and is directed to accomplish the purposes of the Act through the control of air contaminants by all practical and economically feasible methods. Described here is the evidence presented at and proceedings of the trial.

Morse, H.N.

1993-01-01

452

College ACT Data Information Storage and Retrieval  

ERIC Educational Resources Information Center

|Indicates how a college, with an IBM 1130 computer, can facilitate information storage and retrieval by using magnetic disc storage in conjunction with ACT Program, 80-column Hollerith-type card format especially designed for the college. (JF)|

Kimball, Jack E.; Tolman, Hubert

1970-01-01

453

43 CFR 9212.1 - Prohibited acts.  

Code of Federal Regulations, 2012 CFR

... BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR TECHNICAL SERVICES (9000) FIRE MANAGEMENT Wildfire Prevention § 9212.1 Prohibited acts. Unless permitted in writing by the authorized officer, it is prohibited on the...

2012-10-01

454

45 CFR 670.4 - Prohibited acts.  

Code of Federal Regulations, 2011 CFR

...FOUNDATION CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Prohibited Acts, Exceptions...e) Introduction of non-indigenous animals and plants into Antarctica. It is unlawful...person to introduce into Antarctica any animal or plant which is not indigenous to...

2011-10-01

455

45 CFR 670.4 - Prohibited acts.  

Code of Federal Regulations, 2012 CFR

...FOUNDATION CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Prohibited Acts, Exceptions...e) Introduction of non-indigenous animals and plants into Antarctica. It is unlawful...person to introduce into Antarctica any animal or plant which is not indigenous to...

2012-10-01

456

Affordable Care Act: Implications for Behavioral Health  

MedlinePLUS

... 32 million Americans who are now uninsured. It reforms insurance markets to make them more competitive and ... residency training. Find out more information about health reform and the Patient Protection and Affordable Care Act ...

457

77 FR 21100 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...Open. MATTERS TO BE CONSIDERED: The Commission will consider and act upon the following in open session: William Metz v. Carmeuse Lime, Inc., Docket No. PENN 2009-541-DM. (Issues include whether the operator terminated the miner's...

2012-04-09

458

The EEOC's New Equal Pay Act Guidelines.  

ERIC Educational Resources Information Center

Analyzes the new guidelines for enforcement of the Equal Pay Act and their implications for personnel management. Argues that there are key problem areas in the new regulations arising from considerable ambiguity and uncertainty about their interpretation. (SK)

Greenlaw, Paul S.; Kohl, John P.

1982-01-01

459

Regulations for the Egg Products Inspection Act.  

National Technical Information Service (NTIS)

The 'Egg Products Inspection Act' provides for the mandatory inspection of egg products in intrastate, interstate, and foreign commerce; controls the disposition of certain 'restricted eggs' such as dirties, leakers, loss, checks, inedible and incubator r...

1971-01-01

460

78 FR 40690 - Sunshine Act Meetings  

Federal Register 2010, 2011, 2012, 2013

...Gender-Based Violation of Civil Rights Report Status Update on the Federal Civil Rights Engagement with Arab and Muslim American Communities Post 9/11 Report III. Management and Operations Staff Director's report Acting Chief of...

2013-07-08

461

Public Meeting: FDA Food Safety Modernization Act:  

Center for Food Safety and Applied Nutrition (CFSAN)

Text VersionPage 1. Public Meeting: FDA Food Safety Modernization Act: Focus on Inspections and Compliance Breakout Session: Discussion Questions ... More results from www.fda.gov/downloads/food/guidanceregulation

462

Asbestos Hazard and Emergency Response Act Terms  

EPA Pesticide Factsheets

Vibration:  The periodic motion of friable ACBM which may result in the release of asbestos.   From Asbestos Hazard and Emergency Response Act Terms  -  Search all glossaries for terms containing vibration

2012-05-22

463

The family and medical leave act  

Microsoft Academic Search

The complexities of the federal Family and Medical Leave Act can pose administrative headaches and legal liability for managers unaware of its provisions. Worse, managers have no legal precedents to guide their FMLA decisions.

David C. Wyld

1995-01-01

464

78 FR 62357 - Sunshine Act Meeting  

Federal Register 2010, 2011, 2012, 2013

...BROADCASTING BOARD OF GOVERNORS Sunshine Act Meeting DATE AND TIME...EDT. PLACE: Broadcasting Board of Governors, Cohen Building, Room 3321, 330 Independence...Meeting of the Broadcasting Board of Governors. SUMMARY: The members of the...

2013-10-21

465

76 FR 72000 - Patent, Trademark & Copyright Acts  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF THE INTERIOR Geological Survey Patent, Trademark & Copyright Acts AGENCY: U.S. Geological Survey, Interior...application to be filed shortly at the Patent and Trademark Office, both entitled ``Anaerobic Microbial...

2011-11-21

466

Self-Acting and Hydrodynamic Shaft Seals.  

National Technical Information Service (NTIS)

Self-acting and hydrodynamic seals are described. The analytical procedures are outlined for obtaining a seal force balance and the operating film thickness. Particular attention is given to primary ring response (seal vibration) to rotating seat face run...

L. P. Ludwig

1973-01-01

467

Preventive Care for Children (Affordable Care Act)  

MedlinePLUS

... Myspace Close Text Size: A A A Preventive Care for Children Many insurers are now required to ... Services Task Force Recommendations . Fact Sheet: The Affordable Care Act and Immunization Fact Sheet: The Affordable Care ...

468

78 FR 8538 - Privacy Act of 1974  

Federal Register 2010, 2011, 2012, 2013

...veteran; (9) limited health status information (pregnancy...program implements recent health care reform provisions of the Patient Protection and Affordable Care Act (PPACA) (Pub...148) as amended by the Health Care and Education...

2013-02-06

469

Functional dynamics of hydrolytic enzymes  

NASA Astrophysics Data System (ADS)

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.

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

2003-10-01

470

Application of Enzymes in Food Analysis  

NASA Astrophysics Data System (ADS)

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.

Powers, Joseph R.

471

Thymidyl biosynthesis enzymes as antibiotic targets.  

PubMed

The two long-known "classical" enzymes of uridyl-5-methylation, thymidylate synthase and ribothymidyl synthase, have been joined by two alternative methylation enzymes, flavin-dependent thymidylate synthase and folate-dependent ribothymidyl synthase. These two newly discovered enzymes have much in common: both contain flavin cofactors, utilize methylenetetrahydrofolate as a source of methyl group, and perform thymidylate synthesis via chemical pathways distinct from those of their classic counterparts. Several severe human pathogens (e.g., typhus, anthrax, tuberculosis, and more) depend on these "alternative" enzymes for reproduction. These and other distinctive properties make the alternative enzymes and their corresponding genes appealing targets for new antibiotics. PMID:17216455

Chernyshev, Anatoly; Fleischmann, Todd; Kohen, Amnon

2007-01-11

472

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.

2007-07-20

473

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.

2002-01-01

474

Electromagnetic design considerations for fast acting controllers  

SciTech Connect

Electromagnetic design considerations for fast acting controllers in a power system is introduced and defined. A distinction is made in relation to the more commonly understood system control design necessary for damping electromechanical oscillations using stability programs and eigenanalysis. Electromagnetic eigenanalysis tools have limited availability and are consequently rarely used. Electromagnetic transients programs (emtp) on the other hand are widely used and a procedure for undertaking electromagnetic control design of fast acting controllers in a power system using emtp is presented.

Woodford, D.A. [Manitoba HVDC Research Centre, Winnipeg, Manitoba (Canada)

1996-07-01

475

A social network analysis of acting white  

Microsoft Academic Search

Using social network and interview data, this case study illuminates why acting White did not apply to students at a predominantly Somali African American school in the U.S. Specifically, this case study shows that high-achieving Somali working-class students were not isolated from their peer networks in their school. Furthermore, this study suggests that Acting White may be not applicable to

Na’im Madyun; MooSung Lee; Mustafa Jumale

2010-01-01

476

Porous silicon as the carrier matrix in microstructured enzyme reactors yielding high enzyme activities  

Microsoft Academic Search

Miniaturization and silicon integration of micro enzyme reactors for applications in micro total analysis systems (TASs) require new methods to achieve structures with a large surface area onto which the enzyme can be coupled. This paper describes a method to accomplish a highly efficient silicon microstructured enzyme reactor utilizing porous silicon as the carrier matrix. The enzyme activity of microreactors

J Drottyx; K. Lindström; L. Rosengren; T. Laurell

1997-01-01

477

Smart mud and sensitive enzymes  

SciTech Connect

Environmental legislation is increasingly preventing use of oil base mud. Most recently, Marathon Oil U.K. Ltd. won a U.K. production license that specified oil base mud cannot be used on the license blocks. The goal is to protect sea-birds. Unfortunately, water base mud, the green' alternative, does not have a performance to match oil base mud. But an Aberdeen chemist thinks he has found the answer with Smart Mud, an emulsion drilling mud that becomes water soluble as soon as it hits the sea. Smart Mud passed the laboratory test stage and is ready for field trials this year. Another researcher is using enzymes and organisms to detect gases that are hard to monitor and cause problems for the oil and gas industry: phenol vapors, methane, and sulfur and nitrous oxides. The methane sensor, for example, uses methanotrophic organisms. They metabolize methane, producing chemicals that can be detected by electrochemical sensors, which relay signals to instruments. Enzymes perform a similar task for phenol and oxide detection. The main problem is to keep the biosensors alive and detect their by-products, while maintaining contact with the toxic gases. To do this, the team invented a polymer matrix in which the biosensors can live.

Knott, D.

1993-04-19

478

Redox Enzymes in Tethered Membranes  

PubMed Central

An electrode surface is presented that enables the characterisation of redox-active membrane enzymes in a native-like environment. An ubiquinol oxidase from Escherichia coli, cytochrome bo3 (cbo3), has been co-immobilised into tethered bilayer lipid membranes (tBLMs). The tBLM is formed on gold surfaces functionalised with cholesterol tethers which insert into the lower leaflet of the membrane. The planar membrane architecture is formed by self assembly of proteoliposomes and its structure is characterised by surface plasmon resonance (SPR), electrochemical impedance spectroscopy (EIS) and tapping-mode atomic force microscopy (TM-AFM). The functionality of cbo3 is investigated by cyclic voltammetry (CV) and is confirmed by the catalytic reduction of oxygen. Interfacial electron transfer to cbo3 is mediated by the membrane-localised ubiquinol-8, the physiological electron donor of cbo3. Enzyme coverages observed with TM-AFM and CV coincide (2–8.5 fmol·cm?2) indicating that most - if not all - cbo3 on the surface is catalytically active and thus retains its integrity during immobilisation.

Jeuken, Lars J.C.; Connell, Simon D.; Henderson, Peter J.F.; Gennis, Robert B.; Evans, Stephen D.; Bushby, Richard J.

2013-01-01

479

[Study of betacyanin-discolorating enzyme].  

PubMed

An enzyme catalyzing the discoloration and breakdown of betacyanins was isolated from beet roots Beta vulgaris by centrifugation in sucrose density gradient (2.5 M, 2.0 M, 1.5 M, 1.0 M, tris-HCl buffer, 0.05 M, pH 7.2), and purified 100-fold. The enzyme activity induced the discoloration of betanin, betanidin. It was found that the beet root enzyme exists in an insoluble state and is firmly bound with subcellular structures, which were isolated by centrifugation in sucrose gradient. The optimal activity of the enzyme was observed at pH 3.4, +40 degrees C. The dependence of the enzymatic reaction on the enzyme concentration showed a linearity. Studies of the enzyme inhibition by sodium azide, sodium diethyldithiocarbamate, thiourea, demonstrated that the active site of the enzyme contains a metal. The enzymatic discoloration of betanin is followed by the oxygen uptake. PMID:17435

Soboleva, G A; Ul'ianova, M S; Zakharova, N S; Bokuchava, M A

1976-07-01

480

University College London: Enzyme Structures Database  

NSDL National Science Digital Library

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.

Laskowski, Roman; Wallace, Andrew

481

Modifying enzyme activity and selectivity by immobilization.  

PubMed

Immobilization of enzymes may produce alterations in their observed activity, specificity or selectivity. Although in many cases an impoverishment of the enzyme properties is observed upon immobilization (caused by the distortion of the enzyme due to the interaction with the support) in some instances such properties may be enhanced by this immobilization. These alterations in enzyme properties are sometimes associated with changes in the enzyme structure. Occasionally, these variations will be positive. For example, they may be related to the stabilization of a hyperactivated form of the enzyme, like in the case of lipases immobilized on hydrophobic supports via interfacial activation. In some other instances, these improvements will be just a consequence of random modifications in the enzyme properties that in some reactions will be positive while in others may be negative. For this reason, the preparation of a library of biocatalysts as broad as possible may be a key turning point to find an immobilized biocatalyst with improved properties when compared to the free enzyme. Immobilized enzymes will be dispersed on the support surface and aggregation will no longer be possible, while the free enzyme may suffer aggregation, which greatly decreases enzyme activity. Moreover, enzyme rigidification may lead to preservation of the enzyme properties under drastic conditions in which the enzyme tends to become distorted thus decreasing its activity. Furthermore, immobilization of enzymes on a support, mainly on a porous support, may in many cases also have a positive impact on the observed enzyme behavior, not really related to structural changes. For example, the promotion of diffusional problems (e.g., pH gradients, substrate or product gradients), partition (towards or away from the enzyme environment, for substrate or products), or the blocking of some areas (e.g., reducing inhibitions) may greatly improve enzyme performance. Thus, in this tutorial review, we will try to list and explain some of the main reasons that may produce an improvement in enzyme activity, specificity or selectivity, either real or apparent, due to immobilization. PMID:23059445

Rodrigues, Rafael C; Ortiz, Claudia; Berenguer-Murcia, Ángel; Torres, Rodrigo; Fernández-Lafuente, Roberto

2013-08-01

482

Interaction of Non-Phosphorylated Liver Pyruvate Kinase with Fructose 1,6-Bisphosphate and Peptides that Mimic the Phosphorylatable N-terminus of the Enzyme.  

PubMed

The interaction of non-phosphorylated L-type pyruvate kinase (L-PK) with fructose 1,6-bisphosphate (FBP), which is an allosteric activator of the phosphorylated enzyme, and peptides that mimic the phosphorylatable N-terminal regulatory domain of the enzyme, was studied. It was found that the catalytic activity of the enzyme was not enhanced in the presence of FBP, and this ligand acted as a relatively weak reversible inhibitor of the enzyme activity in the micromolar concentration range. The phosphorylation site analogue peptides RRASVA and RRAAVA had no effect on the activity of the enzyme, while the phosphorylated peptide RRAS(Pi)VA reversibly inhibited the enzyme and this process was characterised by the Ki value 47 ?M. As the phosphorylated form of L-PK is a subject of significant allosteric regulation by FBP, it was concluded that phosphorylation should function as a molecular switch of the allosteric properties of this enzyme. PMID:23713905

Faustova, Ilona; Järv, Jaak

2013-11-01

483

Children's Internet Protection Act Deemed Unconstitutional  

NSDL National Science Digital Library

This morning, three federal judges overturned the Children's Internet Protection Act and ruled that public libraries cannot be forced to use Internet filters designed to block pornography. In the 195-page decision, judges asserted that the Act went too far because the filters could also block access to other legitimate sites, which is a violation of the First Amendment. The Act, which was signed by President Clinton in 2000 and widely criticized by First Amendment advocates, would have required public libraries to install the Internet filters, or risk losing federal funding. This recent decision has been applauded by the American Library Association (ALA) and the American Civil Liberties Union (ACLU), which contends that the law is "unenforceable, unconstitutional, vague and overbroad." Furthermore, they argue that it denies "poor people without home computers the same access to information as their wealthier neighbors because the software could mistakenly block Web sites on issues such as breast cancer and homosexuality."Prior to the Children's Internet Protection Act, two other anti-Internet pornography laws were brought before federal judges for constitutional challenges, and overturned. In 1996, the Communications Decency Act (which made it a crime to put adult-oriented material online where children can find it), was declared unconstitutional by the Supreme Court; and in 1998, the 3rd US Circuit Court of Appeals overturned the Child Online Protection Act (which required Web sites to collect a credit card number or other proof of age before allowing Internet users to view material deemed "harmful to minors"), stating it was too broad and vague. For more information on the recent court decision regarding the Children's Internet Protection Act, viewers can access the first link above. The second link provides access to a full copy of the court's decision on the case. Links three and four lead to home pages of the American Library Association and the American Civil Liberties Union, respectively. Lastly, links five, six, and seven provide access to copies of the Children's Internet Protection Act; the 1998 House of Representatives report on the Child Online Protection Act; and the 1996 Communications Decency Act, respectively.

Green, Marcia.

2002-01-01

484

29 CFR 790.2 - Interrelationship of the two acts.  

Code of Federal Regulations, 2013 CFR

...PORTAL-TO-PORTAL ACT OF 1947 ON THE FAIR LABOR STANDARDS ACT OF 1938 General § 790... (a) The effect on the Fair Labor Standards Act of the various provisions...otherwise be subject under the Fair Labor Standards Act. 8 But the act...

2013-07-01

485

How to comply with the Americans with disabilities act  

Microsoft Academic Search

The legal and political roots of the Americans with Disabilities Act (ADA) owe themselves to the civil rights era of the 1960s, which passed the Civil Rights Act in 1964, the Voting Rights Act in 1965 and the Architectural Barriers Act of 1968, and to the Rehabilitation Act of 1973. From the 1970s to the 1990s, activism among the disabled

Ryan Bangerter; Brian H. Kleiner

2005-01-01

486

Highlights of the Clean Water Act of 1977  

Microsoft Academic Search

Amendments to the Federal Water Pollution Control Act Amendments of 1972 (hereinafter 1972 Act), passed by Congress on December 15, 1977, were signed by President Carter on December 28, 1977 (hereinafter 1977 Act). The amendments, which change the popular name of the Federal Water Pollution Control Act to the Clean Water Act, represent a compromise between environmentalists and industry and

Kerner

2009-01-01

487

Encapsulation of Enzymes and Peptides  

NASA Astrophysics Data System (ADS)

A large part of formulated peptides and proteins, e.g., enzymes used as food ingredients, are formulated in a liquid form. Often, they are dissolved in water to which glycerol or sorbitol is added to reduce the water activity of the liquid, thus reducing the change of microbial growth. Still, there are reasons to formulate them in a solid form. Often, these reasons are stability, since a dry formulation is often much better than liquid formulations, and less transportation cost, since less mass is transported if one gets rid of the liquid; however, most of the times, the reason is that the product is mixed with a solid powder. Here, a liquid addition would lead to lump formation.

Meesters, Gabrie M. H.

488

Enzyme analysis of Schistosoma haematobium*  

PubMed Central

Results are reported of enzyme analyses, by isoelectric focusing in polyacrylamide gels, of adult Schistosoma haematobium worms derived from 22 isolates originating from 13 countries. Polymorphisms have been identified in the glucose-6-phosphate dehydrogenase (G6PD) and phosphoglucomutase (PGM) systems. Certain forms appear to be restricted in their geographical distribution and their occurrence outside their usual areas suggests human population movements resulting in mixing of parasite strains. The possible implications of minor variations in some PGM patterns and the apparent absence of heteropolymer fractions in presumed G6PD heterozygotes are discussed. The use of the technique to detect natural multiple miracidial infections in snails is reported and discussed. ImagesFig. 1

Wright, C. A.; Ross, G. C.

1983-01-01

489

Intestinal Phospholipase, a Novel Enzyme  

PubMed Central

We evaluated phospholipase activity in the intestine of rats and other species. Phospholipase activity was assayed by a surface barostat technique or an egg yolk titration system. Mucosal activity was found only by the surface barostat technique with phosphatidylglycerol as substrate; it was not found with phosphatidylcholine as substrate in assays by either technique. In gut luminal fluid activity was found when both phosphatidylcholine and phosphatidylglycerol were used as substrate in assays by the surface barostat technique, and phosphatidylcholine as substrate yielded activity in egg yolk titration. In rats in which pancreatic juice had been diverted, mucosal and gut luminal phospholipase activity was greater than in controls, thus demonstrating that enzyme activity was not due to pancreatic phospholipase. Bacterial origin of phospholipase activity was excluded in that phospholipase activity was found in germ-free rats; gastric and salivary gland origins were excluded in that continued phospholipase activity was found in rats with gastric fistula. The physiological importance of the enzyme was established by the finding that rats with pancreatic fistula absorbed 111 ?mol of phosphatidylcholine and that controls absorbed 119 ?mol of a 135-?mol load. Activity was found to be three times greater in the distal than in the proximal intestine; in cryptal cells it was 10 times greater than in villus tip cells. 65% of the activity in the gut lumen was tightly bound to particulate matter. We propose that intestinal phospholipase may be important in gut bacterial control, in the digestion of vegetable matter (phosphatidylglycerol is a major phospholipid in both plants and bacteria), and in the digestion of phospholipids in the gut lumen.

Mansbach, Charles M.; Pieroni, Gerard; Verger, Robert

1982-01-01

490

Enzyme nanoarchitectonics: organization and device application.  

PubMed

Fabrication of ultrasmall functional machines and their integration within ultrasmall areas or volumes can be useful for creation of novel technologies. The ultimate goal of the development of ultrasmall machines and device systems is to construct functional structures where independent molecules operate as independent device components. To realize exotic functions, use of enzymes in device structures is an attractive solution because enzymes can be regarded as efficient machines possessing high reaction efficiencies and specificities and can operate even under ambient conditions. In this review, recent developments in enzyme immobilization for advanced functions including device applications are summarized from the viewpoint of micro/nano-level structural control, or nanoarchitectonics. Examples are roughly classified as organic soft matter, inorganic soft materials or integrated/organized media. Soft matter such as polymers and their hybrids provide a medium appropriate for entrapment and encapsulation of enzymes. In addition, self-immobilization based on self-assembly and array formation results in enzyme nanoarchitectures with soft functions. For the confinement of enzymes in nanospaces, hard inorganic mesoporous materials containing well-defined channels play an important role. Enzymes that are confined exhibit improved stability and controllable arrangement, which are useful for formation of functional relays and for their integration into artificial devices. Layer-by-layer assemblies as well as organized lipid assemblies such as Langmuir-Blodgett films are some of the best media for architecting controllable enzyme arrangements. The ultrathin forms of these films facilitate their connection with external devices such as electrodes and transistors. Artificial enzymes and enzyme-mimicking catalysts are finally briefly described as examples of enzyme functions involving non-biological materials. These systems may compensate for the drawbacks of natural enzymes, such as their instabilities under harsh conditions. We believe that enzymes and their mimics will be freely coupled, organized and integrated upon demand in near future technologies. PMID:23348617

Ariga, Katsuhiko; Ji, Qingmin; Mori, Taizo; Naito, Masanobu; Yamauchi, Yusuke; Abe, Hideki; Hill, Jonathan P

2013-08-01

491

Fisheries management under the Fishery Conservation and Management Act, the Marine Mammal Protection Act, and the Endangered Species Act. Final report  

Microsoft Academic Search

The purpose of this report is to determine what steps might be taken to ensure that fishery management plans (FMPs) developed under the Fishery Conservation and Management Act (FCMA) are ecologically sound and fully consistent with the FCMA and with the Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA). The relevant provisions of the three Acts were

Hammond; K. A. G

1980-01-01

492

75 FR 10503 - Notice of Lodging of Consent Decree Under the Clean Air Act, the Clean Water Act, the Emergency...  

Federal Register 2010, 2011, 2012, 2013

...Clean Air Act, the Clean Water Act, the Emergency Planning and Community Right-To-Know Act, and the...7401-7671q, the Clean Water Act, 33 U.S.C. 1251-1387...Emergency Planning and Community Right-to-Know Act, 42...

2010-03-08

493

75 FR 42130 - Notice of Lodging of Consent Decree Under the Clean Air Act; Clean Water Act; Resource...  

Federal Register 2010, 2011, 2012, 2013

...Resource Conservation and Recovery Act; Safe Drinking Water Act; Toxic Substances Control Act; and the Reporting Requirements of the...Water Act (``SDWA''), 42 U.S.C. 300f to 300j-26; Toxic Substances Control Act (``TSCA''), 15 U.S.C....

2010-07-20

494

Industrial Fungal Enzymes: An Occupational Allergen Perspective  

PubMed Central

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.

Green, Brett J.; Beezhold, Donald H.

2011-01-01

495

Mammography Quality Standards Act and Program  

NSDL National Science Digital Library

Created and maintained by the FDA, this site is a clearinghouse of information for mammography facility personnel, educators and others about the implementation of MQSA or the Mammography Quality Standards Act of 1992. The purpose of MQSA was to \\"ensure that all women have access to quality mammography for the detection of breast cancer in its earliest, most treatable stages.\\" Congress reauthorized MQSA in the fall of 2004 extending the program to 2007 -- so users may also see references to MQSRA which refer to the Mammography Quality Standards Reauthorization Acts of 1998 and 2004. The full text of the act is accessible at the site as well as a good deal of information and guidance for those in mammography facilities - including information about inspections and certification. Scorecard information and articles which provide an overview about facilities\\' adherence to MQSA are available along with reports related to the MQSA program and accreditation.

2007-02-04

496

29 CFR 779.1 - General scope of the Act.  

Code of Federal Regulations, 2013 CFR

...INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES...779.1 General scope of the Act. The Fair Labor Standards Act of 1938, as amended, is a Federal...

2013-07-01

497

29 CFR 780.1 - General scope of the Act.  

Code of Federal Regulations, 2013 CFR

...AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT Introductory § 780.1 General scope of the Act. The Fair Labor Standards Act is a Federal statute of general application...

2013-07-01

498

7 CFR 400.457 - Program Fraud Civil Remedies Act.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Program Fraud Civil Remedies Act. 400...Continued) FEDERAL CROP INSURANCE CORPORATION, DEPARTMENT OF...Sanctions § 400.457 Program Fraud Civil Remedies Act. Link...in accordance with the Program Fraud Civil Remedies Act...

2009-01-01

499

75 FR 25856 - Privacy Act of 1974; System of Records  

Federal Register 2010, 2011, 2012, 2013

...an individual to the Privacy Act Officer, Federal...correct a record to the Privacy Act Officer, Federal...for a record to the Privacy Act Appeals Officer...representatives, supervisors, employers, other employees, other Federal,...

2010-05-10

500

29 CFR 1625.2 - Discrimination prohibited by the Act.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Discrimination prohibited by the Act. 1625...EMPLOYMENT OPPORTUNITY COMMISSION AGE DISCRIMINATION IN EMPLOYMENT ACT Interpretations § 1625.2 Discrimination prohibited by the Act....

2013-07-01