into monosaccharide acceptor 4 by selective removal of the primary acetate protecting group (Scheme 1a). This reaction- uct (4) could be coupled to monosaccharide donor 522,23 in the presence of trimethylsilyl monosaccharide acceptor for the synthesis of 11 was obtained. Acceptor 11 is a sub- strate for GlfT2 (Fig. ...

Imprinted Au nanoparticle (NP) composites are assembled on Au surfaces by the electropolymerization of thioaniline-functionalized Au NPs in the presence of the imprint molecules, picric acid (1), N,N'-dimethyl-4,4'-bipyridinium (2), and N,N'-dimethylbipyridinium-4,4'-ethylene dichloride (3). The existence of pi-donor-acceptor complexes between the ...

The peptidoglycan glycosyltransferases (PGTs) catalyze the processive polymerization of a C55 lipid-linked disaccharide (Lipid II) to form peptidoglycan, the main component of the bacterial cell wall. Our ability to understand this reaction has been limited due to challenges identifying the appropriate substrate analogues to selectively interrogate the ...

The peptidoglycan glycosyltransferases (PGTs) catalyze the processive polymerization of a C55 lipid-linked disaccharide (Lipid II) to form peptidoglycan, the main component of the bacterial cell wall. Our ability to understand this reaction has been limited due to challenges identifying the appropriate substrate analogs to selectively interrogate the donor ...

Structure-guided re-design of the acceptor binding site of D-fructose-6-phosphate aldolase from E. coli leads to the construction of FSA A129S/A165G double mutant with an activity between 5- to >900-fold higher than that of wild-type towards N-Cbz-aminoaldehyde derivatives. PMID:21499643

The hydrolysis of the donor substrate uridine diphosphate galactose (UDP-Gal) by human blood group B galactosyltransferase (GTB) has been followed by nuclear magnetic resonance in the presence and in the absence of an acceptor substrate analog. It is observed that the presence of the acceptor ...

conforming to a sequential mechanism were fit to eq 2. Data for competitive inhibition, noncompetitive inhibition, I-parabolic S-parabolic noncompetitive inhibition, and I-linear S-para- bolic noncompetitive for product quantitation. With UDP as a product inhibitor, a competitive inhibition pattern with respect

With the hope of mimicking the chemical and biological properties of natural 6-O-methyl-D-glucose-containing polysaccharides (MGP), synthetic 6-O-methyl-D-glucose-containing polysaccharides (sMGP) were designed and synthesized from ?-, ?-, and ?-cyclodextrins (CDs). The synthetic route proved to be flexible and general, to furnish a series of sMGPs ranging from 6-mer to 20-mer. A practical and ...

Long term survival of the pathogen Mycobacterium tuberculosis in humans is linked to the immunomodulatory potential of its complex cell wall glycolipids, which include the phosphatidylinositol mannoside (PIM) series as well as the related lipomannan and lipoarabinomannan glycoconjugates. PIM biosynthesis is initiated by a set of cytosolic ?-mannosyltransferases, catalyzing glycosyl transfer from ...

Long term survival of the pathogen Mycobacterium tuberculosis in humans is linked to the immunomodulatory potential of its complex cell wall glycolipids, which include the phosphatidylinositol mannoside (PIM) series as well as the related lipomannan and lipoarabinomannan glycoconjugates. PIM biosynthesis is initiated by a set of cytosolic ?-mannosyltransferases, catalyzing glycosyl transfer from ...

Fluorescently labeled derivatives of a xyloglucan (XG) nonasaccharide Glc(4)Xyl(3)Gal(2) (XLLG) were used as glycosyl acceptors in assays of xyloglucan endotransglycosylase (XET) from germinated nasturtium (Tropaeolum majus) seeds. We have investigated how the type of the oligosaccharide label influences the kinetic parameters of the reaction. The fluorescent probes used to ...

In most natural environments, a multitude of metabolic substrates are resent simultaneously. Organisms that can utilize uranium as a metabolic substrate for respiration also may have the ability to use a variety of other oxidized substrates as electron acceptors. Thus, these substrates are, in ...

With the objective to convert light energy into chemical oxidation energy, a ruthenium-based dyad constituted of the assembly of a photosensitizer and a catalytic fragment was synthesized. Upon irradiation with blue LEDs, and in the presence of an electron acceptor, the complex is able to catalyze selective sulfide oxygenation involving an oxygen atom ...

A method for producing a synthetic CO.sub.2 acceptor by feeding a mixture of finely divided silica and at least one finely divided calcium compound selected from the group consisting of calcium oxide and calcium carbonate to a fluidized bed; operating the fluidized bed at suitable conditions to produce pellets of synthetic CO.sub.2 ...

Sucrose phosphorylase catalyzes the O-glucosylation of a wide range of acceptor substrates. Acceptors presenting a suitable 1,2-diol moiety are glucosylated exclusively at the secondary hydroxyl. Production of the naturally occurring compatible solute, 2-O-alpha-d-glucopyranosyl-sn-glycerol, from sucrose and glycerol is a notable ...

This learning object contains a simulation which is designed to show the effects of various parameters on the resistivity/conductivity of selected semiconductors and an insulator (Diamond). Controls: -The left side of the simulation shows the controls. -The temperature can be varied between 10 and 1000 degrees Kelvin. -There is a choice of three ...

The presence of the C.C mispair in a defined duplex oligodeoxynucleotide enhanced its capacity to serve as a substrate for highly purified human DNA methyltransferase. Analysis of tritiated reaction products showed that the C.C mispair acted as a "methylation acceptor" in that it was itself rapidly methylated. The m5C.G base pair also enhanced the capacity ...

tRNAs, like other RNAs, are subject to quality control steps during and after biosynthesis. We previously described a rapid tRNA degradation (RTD) pathway in which the 5'-3' exonucleases Rat1 and Xrn1 degrade mature tRNA(Val(AAC)) in yeast mutants lacking m(7)G and m(5)C, and mature tRNA(Ser(CGA)) in mutants lacking Um and ac(4)C. To understand how the RTD pathway selects ...

An attractive solution to the problem of the origin of protein synthesis in an evolving `RNA world' involves catalysis by nucleic acid without assistance from proteins,. Indeed, even the modern ribosome has been considered to be fundamentally an RNA machine, and the large ribosomal subunit can carry out peptidyl transfer in the absence of most of its protein subunits. Successive cycles of in vitro ...

Strain TCE1, a strictly anaerobic bacterium that can grow by reductive dechlorination of tetrachloroethene (PCE) and trichloroethane (TCE), was isolated by selective enrichment from a PCE-dechlorinating chemostat mixed culture. Strain TCE1 is a gram-positive, motile, curved rod-shaped organism that is 2 to 4 by 0.6 to 0.8 {micro}m and has approximately six lateral flagella. ...

The StRB and SrRB use a wide spectrum of substrates as electron donors for lithotrophic and heterotrophic type nutrition. The electron acceptors for the ...

... obtain sharp electron profiles, low substrate leakage ... dependence of threshold voltages on acceptor ... Be ion implant energy and dose, and calculate ...

... 4 so that the shock pressure at the end of the spacer was known. ... RDX -" VARIABLE GAP DIA. /, -, PMMA SPACER) ,// BRASS ACCEPTOR ...

We examined the catalytic cycle of transaldolase (TAL) from Thermoplasma acidophilum by cryocrystallography and were able to structurally characterize-for the first time, to our knowledge-different genuine TAL reaction intermediates. These include the Schiff base adducts formed between the catalytic lysine and the donor ketose substrates fructose-6-phosphate and ...

Inhibitors of the enzyme aspartate semialdehyde dehydrogenase, a key biological target for the generation of a new class of antibiotic compounds, have been developed. To investigate improvements to binding within an inhibitor series, the lowering of the entropic barrier to binding through conformational restriction was investigated. A library of linear and cyclic substrate ...

Protein lysine methyltransferases are important regulators of epigenetic signaling. These enzymes catalyze the transfer of donor methyl groups from S-adenosylmethionine to specific acceptor lysines on histones, leading to changes in chromatin structure and transcriptional regulation. These enzymes also methylate nonhistone protein substrates, revealing an ...

The dolichol-linked oligosaccharide Glc₃Man₉GlcNAc₂-PP-Dol is the in vivo donor substrate synthesized by most eukaryotes for asparagine-linked glycosylation. However, many protist organisms assemble dolichol-linked oligosaccharides that lack glucose residues. We have compared donor ...

The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not ...

A process for preparing hydrogenated or partially hydrogenated polynuclear aromatic hydrogen donors from a hydrocarbon feed is described comprising polynuclear aromatic hydrogen acceptors, single ring aromatic hydrogen acceptors and double ring aromatic hydrogen acceptors. The polynuclear aromatics are selectively ...

The invention provides isolated MMP-2, MMP-9 and MT1-MMP selective substrate polypeptides or functional peptidomimetics. The selective substrate polypeptides contain the following sequences: MMP-2 selective substrate polypeptides contain SEQ ID NOS:1-27, ...

A sulfurtransferase has been purified to apparent homogeneity from the prokaryote Acinetobacter calcoaceticus lwoffi by conventional protein fractionation techniques. Steady-state kinetic studies of the enzyme revealed that its formal mechanism varies with the acceptor substrate employed. With inorganic thiosulfate as the sulfane sulfur-donor ...

... Accession Number : ADP014402. Title : Selectivity of Polypeptide Binding to Nanoscale Substrates. Descriptive Note : Conference paper. ...

... Title : Materials Selection Parameters for Ceramic Substrates: Property- Processing Relationships. ... Personal Author(s) : Selvaduray, GS. ...

The critical process of charge separation in organic photovoltaic (OPV) devices is determined directly at the organic heterojunction, but these interfaces have been less extensively studied than organic/metal interfaces. We prepare model photovoltaic heterojunctions by deposition of ultrathin films of organic semiconductors on single-crystal metal substrates. The electronic ...

During the period of this research grant, the process of liquid phase electroepitaxy (LPEE) was used to grow ternary and quaternary alloy III-V semiconductor thin films. Selective area growth of InGaAs was performed on InP substrates using a patterned sputtered quartz or spin-on glass layer. The etch back and growth characteristics with respect to ...

During the period of this research grant, the process of liquid phase electroepitaxy (LPEE) was used to grow ternary and quaternary alloy III-V semiconductor thin films. Selective area growth of InGaAs was performed on InP substrates using a patterned sputtered quartz or spin-on glass layer. The etch back and growth characteristics with respect to ...

A series of 4-aryl-1,1-dicyanobutenes (1a-1f) with different substituents were synthesized to control the intramolecular donor-acceptor or charge-transfer (C-T) interactions in the ground state. Photoexcitation of these C-T substrates led to competitive cyclization and rearrangement, the ratio being critically controlled by various environmental factors, ...

Given the significance of carbohydrates in life, medicine, and industry, the development of simple and efficient de novo methods to synthesize carbohydrates are highly desirable. Organocatalytic asymmetric assembly reactions are powerful tools to rapidly construct molecules with stereochemical complexity from simple precursors. Here, we present a simple and robust methodology for the asymmetric ...

Thin films of poly(3-hexylthiophene)-block-polylactide block copolymer exhibiting ordered lamellar morphology have been selectively etched to produce structured films that could be used in fabrication of idealized bulk heterojunctions for organic or hybrid solar energy devices. Etched poly(3-hexylthiophene) films, after being rinsed in water to remove degraded polylactide ...

Multilayers containing a perylene diimide labelled star polymers (FSP) donor adjacent to phosphorus dendrimer layer on a silver substrate were constructed by layer by layer (LBL) approach. Using Surface Plasmon Enhanced Fluorescence Spectroscopy (SPFS) technique, a time-resolved ultrasensitive and selective detection of DNA targets relying on enhanced ...

A method is described for producing a synthetic CO[sub 2] acceptor by feeding a mixture of finely divided silica and at least one finely divided calcium compound selected from the group consisting of calcium oxide and calcium carbonate to a fluidized bed; operating the fluidized bed at suitable conditions to produce pellets of synthetic CO[sub 2] ...

A synthetic CO[sub 2] acceptor is described consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca[sub 5](SiO[sub 4])[sub 2]CO[sub 3]. A method for producing the synthetic CO[sub 2] ...

A synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 acceptor is also ...

a crucial role. To account for this characteristic property, the interface morphology of organic�ubinger and W. Br�utting, "Exciton diffusion and optical interference in organic donor-acceptor photovoltaic Charge Separation at Molecular Donor�Acceptor Interfaces: Correlation Between Morphology and Solar Cell

Strain TCE1, a strictly anaerobic bacterium that can grow by reductive dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE), was isolated by selective enrichment from a PCE-dechlorinating chemostat mixed culture. Strain TCE1 is a gram-positive, motile, curved rod-shaped organism that is 2 to 4 by 0.6 to 0.8 ?m and has approximately six lateral flagella. The pH ...

Sodium was incorporated into high-purity ZnSe single crystals by dipping the crystal into molten Se-base Na alloys. The I1Na line and two types of donor-acceptor pair (DAP) emissions were observed. An acceptor binding energy of 117 meV was obtained for Na by analyzing the selective photoluminescence spectra on the I1Na line and the ...

Peptides patterned on the N-terminal sequence of fibronectin were synthesized and tested for amine acceptor qualities in reactions with dansylcadaverine catalyzed either by coagulation factor XIIIa or intracellular transglutaminase (protein-glutamine:amine gamma-glutamyltransferase, EC 2.3.2.13). On the basis of inverse half-saturations of the enzymes, the order of ...

UDP-GalNAc:polypeptide ?-N-acetylgalactosaminyltransferases (ppGaNTases) initiate the formation of mucin-type, O-linked glycans by catalyzing the transfer of ?-N-acetylgalactosamine from UDP-GalNAc to Ser or Thr residues of core proteins to form the Tn antigen (GalNAc-?-1-O-Ser/Thr). ppGaNTases are unique among glycosyltransferases in containing a C-terminal lectin domain. We present the x-ray ...

Site-specific protein labeling with Escherichia coli biotin ligase (BirA) has been used to introduce fluorophores, quantum dots (QDs), and photocross-linkers onto recombinant proteins fused to a 15-amino acid acceptor peptide (AP) substrate for BirA and expressed on the surface of living mammalian cells. Here, we used phage display to engineer a new and ...

Glycosaminoglycans (GAGs) play a central role in many pathophysiological events, and exogenous xyloside substrates of ?1,4-galactosyltransferase 7 (?4GalT7), a major enzyme of GAG biosynthesis, have interesting biomedical applications. To predict functional peptide regions important for substrate binding and activity of human ?4GalT7, we conducted a ...

Sialic acids play important roles in various biological processes and typically terminate the oligosaccharide chains on the cell surfaces of a wide range of organisms including mammals and bacteria. Their attachment is catalyzed by a set of sialyltransferases with defined specificities both for their acceptor sugars and the position of attachment. However, little is known of ...

To map the preferred cleavage sites of xyloglucan endotransglycosylases (XETs; EC 2.4.1.207) along the donor substrate chain, we incubated the enzymes with tamarind (Tamarindus indica) xyloglucan (donor substrate; approximately 205 kDa; 21 microM) plus the nonasaccharide [(3)H]XLLGol (Gal(2).Xyl(3).Glc(3). [(3)H]glucitol; acceptor ...

Recently, a novel family of methyltransferases was identified in plants. Some members of this newly discovered and recently characterized methyltransferase family catalyze the formation of small-molecule methyl esters using S-adenosyl-L-Met (SAM) as a methyl donor and carboxylic acid-bearing substrates as methyl acceptors. These enzymes include SAMT ...

Recently, a novel family of methyltransferases was identified in plants. Some members of this newly discovered and recently characterized methyltransferase family catalyze the formation of small-molecule methyl esters using S-adenosyl-l-Met (SAM) as a methyl donor and carboxylic acid�bearing substrates as methyl acceptors. These enzymes include SAMT ...

Bacterial dd-peptidases, the targets of beta-lactam antibiotics, are believed to catalyze d-alanyl-d-alanine carboxypeptidase and transpeptidase reactions in vivo. To date, however, there have been few concerted attempts to explore the kinetic and thermodynamic specificities of the active sites of these enzymes. We have shown that the peptidoglycan-mimetic peptide, ...

Ubiquitination involves the attachment of ubiquitin to lysine residues on substrate proteins or itself, which can result in protein monoubiquitination or polyubiquitination. Ubiquitin attachment to different lysine residues can generate diverse substrate-ubiquitin structures, targeting proteins to different fates. The mechanisms of lysine ...

Yi Liu Alternative Donor-Acceptor Design, Synthesis and Assembly of Novel Organic Semiconductors Selected Publications Klivansky, L. M.; Koshkakaryan, G.; Cao, D.; Liu, Y.*...

In the ubiquitin-proteasome system (UPS), E2 enzymes mediate the conjugation of ubiquitin to substrates and thereby control protein stability and interactions. The E2 enzyme hCdc34 catalyzes the ubiquitination of hundreds of proteins in conjunction with the cullin-RING (CRL) superfamily of E3 enzymes. We identified a small molecule termed CC0651 that ...

In this study, we used photoluminescence (PL) measurement for analysis of deep acceptor states in unintentionally doped CdTe films on GaAs substrates. We analyzed PL and time-resolved spectra (TRS) in the vicinity of the 1.42 eV band. By analyzing the peak shift of the 1.42 eV band as a function of time after pulsed excitation, the bound-to-bound reaction ...

azide using a Staudinger ligation with a phosphine conjugate to the FLAG peptide (Figure 4).25 Product-Az by Staudinger ligation. PhBL was used to ligate DTB-Az to p67 acceptor protein. The introduced azide ligation of biotin onto a lysine side chain of a 15-amino acid recognition sequence called the "acceptor

Various abiotic and biotic processes such as sorption, dilution, and degradation are known to affect the fate of organic contaminants, such as petroleum hydrocarbons in saturated porous media. Reactive transport modeling of such plumes indicates that the biodegradation of organic pollutants is, in many cases, controlled by mixing and therefore occurs locally at the plume's fringes, where electron ...

cDNAs and genes encoding a hydroxycinnamoyl-CoA:hydroxyphenyllactate hydroxycinnamoyltransferase (CbRAS; rosmarinic acid synthase) and a hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyltransferase (CbHST) were isolated from Coleus blumei Benth. (syn. Solenostemon scutellarioides (L.) Codd; Lamiaceae). The proteins were expressed in E. coli and the substrate specificity of both ...

A process for efficient modification and metallization of substrates includes the steps of providing a substrate with highly photo-efficient chemical functional groups on at least a portion of this substrate, exposing the substrate to actinic radiation to...

An aqueous extract of oat leaves catalyzes a transamination between cysteine-sulfinic acid and alpha -ketoglutaric acid. Under the conditions utilized pyruvic acid is not an acceptor of the amino group. Neither cysteic nor aspartic acid is a substrate for the transaminase of cysteinesulfinic acid. (auth)

... cell surface (Griffith and Sanders, 1991). These terminal saccharides seem to present differentiation signals to the neighboring ... source and Gal-acceptor (10 mM mono/oligo saccharide or the GP substrat...

A photochemical device for conversion of visible light to electricity comprising one or more monolayers of dye material such as chlorophyll, an electron acceptor monolayer of saturated fatty acid between suitable electrode layers, all formed or mounted on a suitable substrate sheet.

Study of valence isomerization of organic compounds has focused on two mechanisms of photosensitization involving either electron donor-acceptor interaction or energy transfer. The quenching of fluorescent sensitizers by isomerizable substrates results in...

A series of dansyl-labeled glycosides with di-, tetra-, and hexasaccharides carrying the terminal N-acetyllactosamine (LacNAc) sequence were synthesized as acceptor substrates for ?2,6- and ?2,3-sialyltransferases. As an alternative design, dansyl-labeled LacNAc glycoside carrying a long-spacer linked glycan was engineered by replacement of the LacNAc or ...

Several phenomena at the polymer-solid substrate interface has been investigated with the objective of elucidating the mechanism of adhesion. It has been established by IR spectroscopy that adhesion of polymers is largely due to chemical (donor-acceptor) ...

plague by Streptococcus mutans). Depending on their monosaccharide composition and biosynthetic pathways on the acceptor substrate used, sucrases perform oligomerization (transfer of a monosaccharide to another sucrose molecule, or to fructo- or gluco-oligosaccharides) or polymerization (coupling of a monosaccharide

During this reporting period, efforts were begun to incorporate Na and N acceptors in ZnSe. Other efforts underway included studies of the efforts of growth rate on unintentionally-doped ZnSe, studies of the effectiveness of present substrate preparation ...

... Title : Chemical Patterning of Silicon Dioxide Substrates for Selective Deposition of Gold Nanoparticles and Fabrication of Single-Electron ...

Glutamine-dependent amidotransferase (Gn-AT) catalyzes the transfer of the amido nitrogen of glutamine to an acceptor substrate to produce glutamate and an aminated product. Although most Gn-ATs are involved in biosyntheses of primary metabolites, some are important in the synthesis of secondary metabolites. Recently, a Gn-AT (NspN) was discovered in the ...

We report on the determination of the three-dimensional orientation of the donor and acceptor transition dipoles in individual fluorescence resonance energy transfer (FRET) pairs by means of scanning optical microscopy with annular illumination. Knowledge of the mutual orientation of the donor and acceptor dipole is mandatory for reliable distance ...

This patent describes a process for removing sulfur oxides, nitrogen oxides, and hydrogen halides from a gas contaminated with same in which the gas is contacted at a temperature below 250/sup 0/C with particulate solid acceptor comprising a mineral support having a coating containing divalent metal oxide, hydroxide, or both, the support being water-moistened particles ...

We describe a standardized approach for searching potent and selective inhibitors of glycosyltransferases by high throughput quantitative MALDI-TOFMS-based screening of focused compound libraries constructed by 1,3-dipolar cycloaddition of the desired azidosugar nucleotides with various alkynes. An aminooxy-functionalized reagent with a stable isotope was conjugated with ...

Juvenile hormones (JHs) play key roles in regulating metamorphosis and reproduction in insects. The last two steps of JH synthesis diverge depending on the insect order. In Lepidoptera, epoxidation by a P450 monooxygenase precedes esterification by a juvenile hormone acid methyltransferase (JHAMT). In Orthoptera, Dictyoptera, Coleoptera and Diptera epoxidation follows methylation. The aim of our ...

We have analyzed the spectral shape of the selective pair luminescence (SPL) in undoped semi-insulating Czochralski grown GaAs. The shape of the SPL spectra, consisting of sharp peaks and a broadband, depends strongly on the excitation photon energy, the excitation intensity, and the acceptor concentrations. The characteristic spectral variations are ...

We investigated optical properties of Sb-doped p-type ZnO films grown on n-Si (100) substrates by oxygen plasma-assisted pulsed laser deposition. Two acceptor states, with the acceptor levels of 161 and 336 meV, are identified by well-resolved photoluminescence spectra. Under oxygen-rich conditions, the deep ...

The isolation of a xanthine dehydrogenase from Pseudomonas putida 40 which utilizes ferricyanide as an electron acceptor at high efficiency is presented. The new activity is separate from the NAD+ and oxygen-utilizing activities of the same organism but displays a broad pattern for reducing substrates typical of those of previously studied ...

The hyperthermophile Aquifex aeolicus belongs to the deepest branch in the bacterial genealogy. Although it has long been recognized that this unique Gram-negative bacterium carries genes for different steps of lipopolysaccharide (LPS) formation, data on the LPS itself or detailed knowledge of the LPS pathway beyond the first committed steps of lipid A and 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) ...

We report herein a method for the ultra-trace detection of TNT on p-aminothiophenol-functionalized silver nanoparticles coated on silver molybdate nanowires based on surface-enhanced Raman scattering (SERS). The method relies on ?-donor-acceptor interactions between the ?-acceptor TNT and the ?-donor p,p'-dimercaptoazobenzene (DMAB), with the latter ...

Accommodation of donor and acceptor substrates is critical to the catalysis of (thio)phosphoryl group transfer, but there has been no systematic study of donor nucleotide recognition by kinase ribozymes, and there is relatively little known about the structural requirements for phosphorylating internal 2?OH. To address these questions, new ...

Glycoside phosphorylases (GPs) are interesting enzymes for the glycosylation of chemical molecules. They require only a glycosyl phosphate as sugar donor and an acceptor molecule with a free hydroxyl group. Their narrow substrate specificity, however, limits the application of GPs for general glycoside synthesis. Although an enzyme's ...

Previous studies have demonstrated that microorganisms may selectively colonize mineral surfaces in diverse environments. Mineral substrates may serve as an important source of limiting nutrients or provide electron acceptors and donors for dissimilatory reactions. This work presents a new method for characterizing the microbial ...

We report the synthesis of a series of block copolymers consisting of a rod-like semiconducting poly(2,5-di(2'-ethylhexyloxy)-1,4-phenylenevinylene) (DEH-PPV) block and a flexible poly(lactic acid) (PLA) block that can be selectively degraded under mild conditions. Such selectively degradable block copolymers are designed as self-assembling templates for ...

The ability of cyanoxime-based synthons to act as versatile synthetic tools for the construction of co-crystals is demonstrated through the preparation and structural characterization of seven co-crystals. Cyanoximes can bind effectively to both five-membered and six-membered N-heterocyclic hydrogen-bond acceptors, and they also display selectivity towards ...

Wall teichoic acids (WTAs) are anionic polymers that coat the cell walls of Gram-positive bacteria. Because they are essential for survival or virulence in many organisms, the enzymes involved in the biosynthesis of WTAs are attractive antibiotic targets. The first committed step in the WTA biosynthetic pathway in Bacillus subtilis is catalyzed by TagA, which transfers N-acetyl mannosamine ...

Lysophosphatidate (LPA) acyltransferase (EC 2.3. 1.51) in the microsomes from the maturing seeds of meadowfoam (Limnanthes alba), nasturtium (Tropaeolum majus), palm (Syagrus cocoides), castor bean (Ricinus communis), soybean (Glycine max), maize (Zea mays), and rapeseed (Brassica napus) were tested for their specificities toward 1-oleoyl-LPA or 1-erucoyl-LPA, and oleoyl coenzyme A (CoA) or ...

Ubiquitin (Ub)-conjugating enzymes (E2s) and ubiquitin ligases (E3s) catalyze the attachment of Ub to lysine residues in substrates and Ub during monoubiquitination and polyubiquitination. Lysine selection is important for the generation of diverse substrate-Ub structures, which provides versatility to this pathway in the targeting of ...

Ferric ion-respiring microorganisms (FRMs) are a group of prokaryotes that use Fe(III) as well as other metals as terminal electron acceptors in the process of anaerobic respiration. Special attention is paid to a biotechnological significance of FRMs because of their potential role in electricity production in microbial fuel cells (MFCs) where the terminal ...

Reduction/oxidation (redox) conditions in 15 principal aquifer (PA) systems of the United States, and their impact on several water quality issues, were assessed from a large data base collected by the National Water-Quality Assessment Program of the USGS. The logic of these assessments was based on the observed ecological succession of electron acceptors such as dissolved ...

Three industrial by-products (fly ash, phosphogypsum and blast furnace slag), were evaluated for their potential re-use as soil amendments to reduce methane (CH(4)) emission resulting from rice cultivation. In laboratory incubations, CH(4) production rates from anoxic soil slurries were significantly reduced at amendment levels of 0.5%, 1%, 2% and 5% (wt wt(-1)), while observed CO(2) production ...

Lysophosphatidate (LPA) acyltransferase (EC 2.3.1.51) in the microsomes from palm endosperm (Syagrus cocoides Martius), maize scutellum (Zea mays L.), and rapeseed cotyledon (Brassica napus L.) of maturing seeds were studied for their specificities toward the acyl moiety of the substrates lysophosphatidate and acyl coenzyme A (CoA). The LPA acceptor ...

Lysophosphatidate (LPA) acyltransferase (EC 2.3.1.51) in the microsomes from palm endosperm (Syagrus cocoides Martius), maize scutellum (Zea mays L.), and rapeseed cotyledon (Brassica napus L.) of maturing seeds were studied for their specificities toward the acyl moiety of the substrates lysophosphatidate and acyl coenzyme A (CoA). The LPA acceptor ...

ZnO is a promising wide bandgap semiconductor. Its renowned and prominent properties as its bandgap of 3.37eV at 4.2K; its very high excitonic binding energy, 60meV; its high melting temperature, 2248K constitute the basis for the recently renewed and sustained scientific interests in the material. In addition to the foregoing, the availability of bulk substrates of ...

A selective extraction technique based on the combination of membrane assisted solvent extraction and molecularly imprinted solid phase extraction for triazine herbicides in food samples was developed. Simazine, atrazine, prometon, terbumeton, terbuthylazine and prometryn were extracted from aqueous food samples into a hydrophobic polypropylene membrane bag containing 1000?L ...

The standard theory of the electron transfer between donor and acceptor molecules was used to describe oscillations in the reduction kinetics of the intermediate electron acceptor BA and the primary electron acceptor HA. The kinetics of the reduction of BA and HA were simulated on the basis of the model in which one and two accepting ...

A gasification process is disclosed using a synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 ...

Plant XETs [XG (xyloglucan) endotransglycosylases] catalyse the transglycosylation from a XG donor to a XG or low-molecular-mass XG fragment as the acceptor, and are thought to be important enzymes in the formation and remodelling of the cellulose-XG three-dimensional network in the primary plant cell wall. Current methods to assay XET activity use the XG polysaccharide as the ...

Experiments with selected organic substrates reveal that the rate-limiting process governing microbial degradation rates changes with substrate concentration, S, in such a manner that substrate removal is enhanced at lower values of S. This enhancement is...

Experiments with selected organic substrates reveal that the rate-limiting process governing microbial degradation rates changes with substrate concentration, S, in such a manner that substrate removal is enhanced at lower values of S. This enhancement is the result of the domina...

Fluorescent-SiC (f-SiC), which contains donor and acceptor impurities with optimum concentrations, has high conversion efficiency from NUV to visible light caused by donor-acceptor-pair (DAP) recombination. This material can be used as a substrate for a near UV light-emitting diode (LED) stack, and leads to monolithic white LED device ...

The human holocarboxylase synthetase (HCS) catalyzes transfer of biotin to biotin-dependent carboxylases, and the enzyme is therefore of fundamental importance for many physiological processes, including fatty acid synthesis, gluconeogenesis, and amino acid catabolism. In addition, the enzyme functions in regulating transcription initiation at several genes that code for proteins involved in ...

... Title : SELECTIVE DOPING OF PIEZOELECTRIC CRYSTALS BY ... and CdS have been doped by ion ... layer in a piezoelectric crystal substrate with ...

Plant phospholipases D (PLDs) occur in a large variety of isoenzymes, which differ in Ca(2+) ion requirement, phosphatidylinositol-4,5-bisphosphate (PIP(2)) activation and substrate selectivity. In the present study a membrane-bound PLD has been identified in the microsomal fractions of poppy seedlings (Papaver somniferum). The maximum PLD activity is ...

This paper compares the photocatalytic activity of eleven porphyrins with variation of the pH of the electrolyte from 1 to 13 and stabilization of the remaining parameters of the system. Etioporphyrin II (EP), octaethylporphyrin (OEP), and tetra phenylporphyrin (TPP) were synthesized according to methods previously described. Pigment films were applied on platinum (Pt 99.99) polished ...

Discoidal-reconstructed high density lipoproteins (rHDL) were used to study the effect of HDL substrates on phosphatidylcholine (PC) transfer by human plasma phospholipid transfer protein (PLTP) by changing the composition and size of rHDL. Sonicated egg-PC:cholesterol vesicles containing radiolabeled dipalmitoyl-PC ({sup 14}C-DPPC) were used as donors and varied rHDL, ...

By photosynthesis 200 billion tons of glucose are formed per annum most of which remains in the sugar state. Thus, the well-known properties of saccharides as the basis for structural materials and energy stores is well established. Increasingly, focus is being addressed to their functions as recognition molecule. Therefore, carbohydrate chemistry became en vogue again as documented by classical ...

Both laboratory and field investigations were conducted to understand the basic biochemical processes involved in the anaerobic transformation of trace metals and selected organic compounds. Controlled laboratory experiments consist of dissolution of trace metals such as As, Cd, Cr, Hg, Mn, Ni, and Pb from model substrate. The effects of the environmental ...

Tissue transglutaminase (TGM2; also known as TG2 or tTG) localizes to the syncytial microvillous membrane (MVM) of the human placenta, the primary interface between maternal and fetal tissue. To identify TGM2 substrates in the MVM, membrane vesicles were prepared and labeled with biotinylated acyl donor or acceptor probes. Biotinylated species were ...

A quantitative histochemical assay for NADPH-ferrihemoprotein (P450) reductase had been developed. For optimal activity, it is necessary to use a relatively electropositive tetrazolium salt such as neotetrazolium chloride as the final acceptor. The apparent Km of the reaction is 0.83 mM. Its specificity has been proven in two ways: (i) activity is increased ...

A novel fluorescent probe (C(60)-FL) was designed and synthesized for the direct determination of trypsin, based on photo-induced electron transfer (PET). The probe consists of two functional moieties: fluorescein which performs as a fluorophore and an electron donor, and fullerene (C(60)) which acts as an electron acceptor and trypsin substrate analogue. ...

A multi-biosensor for detection of herbicides and pollutants was constructed using various photosynthetic preparations as biosensing elements. The photosynthetic thylakoid from Spinacia oleracea L., Senecio vulgaris and its mutant resistant to atrazine were immobilized with (BSA-GA) on the surface of screen-printed sensors composed of a graphite-working electrode and Ag/AgCl reference electrode ...

Biological microscopy would benefit from smaller alternatives to green fluorescent protein for imaging specific proteins in living cells. Here we introduce PRIME (PRobe Incorporation Mediated by Enzymes), a method for fluorescent labeling of peptide-fused recombinant proteins in living cells with high specificity. PRIME uses an engineered fluorophore ligase, which is derived from the natural ...

omega-Aminotransferase (omegaAT) is an interesting biocatalyst for the preparation of chiral amines, which are widely used as building blocks for pharmaceuticals, agrochemicals and fine chemicals. With the assumption that substrate and sequence spaces are in the process of co-evolution, we explored sequences space to screen the enzymes showing activity to new target compounds. ...