id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
11058848 | New developments of the TWIN algorithm for phase extension and refinement in disordered supramolecular structures. | A new development of the TWIN algorithm is described and used for phase extension/refinement in supramolecular complexes. A small number of phased reflections at low resolution are sufficient for the quasi-automated determination of all atomic coordinates, including disordered atoms. |
11058121 | Enhanced delivery of antisense oligonucleotides with fluorophore-conjugated PAMAM dendrimers. | PAMAM dendrimers are cationic polymers that have been used for the delivery of genes and oligonucleotides to cells. However, little is known about the behavior of dendrimer-nucleic acid complexes once they reach the cell interior. To pursue this issue, we prepared dendrimers conjugated with the fluorescent dye Oregon g... |
11058087 | Differential assembly of alpha- and gamma-filagenins into thick filaments in Caenorhabditis elegans. | Muscle thick filaments are highly organized supramolecular assemblies of myosin and associated proteins with lengths, diameters and flexural rigidities characteristic of their source. The cores of body wall muscle thick filaments of the nematode Caenorhabditis elegans are tubular structures of paramyosin sub-filaments ... |
11056397 | Cholesterol homeostasis in rat astrocytoma cells GA-1. | Astrocytes play a key role in cholesterol metabolism in central nervous system. We have shown that fetal rat astrocytes in primary culture secrete cholesterol-rich HDL with the endogenous apolipoprotein (apo) E and generate cholesterol-poor HDL with exogenous apoE and apoA-I [Ito et al. (1999) J. Neurochem. 72, 2362]. ... |
11054286 | Insights into the molecular recognition of the 5'-GNN-3' family of DNA sequences by zinc finger domains. | In order to construct zinc finger domains that recognize all of the possible 64 DNA triplets, it is necessary to understand the mechanisms of protein/DNA interactions on the molecular level. Previously we reported 16 zinc finger domains which had been characterized in detail to bind specifically to the 5'-GNN-3' family... |
11054834 | Separation and absolute configuration of the enantiomers of a degradation product of the new inhalation anesthetic sevoflurane. | In a rebreathing anesthesia circuit, the inhaled anesthetic sevoflurane degrades into at least two products, termed "compound A" and "compound B." The enantiomer separation of the chiral compound B (1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropane ) by capillary gas chromatography (cGC) using heptakis (2,3-di-O... |
11053856 | Crystallization and preliminary X-ray crystallographic studies of the thermoactive pullulanase type I, hydrolyzing alpha-1,6 glycosidic linkages, from Fervidobacterium pennivorans Ven5. | Crystals of the thermoactive recombinant F. pennivorans type I pullulanase, purified from the supernatant of a Bacillus subtilis culture, have been obtained by the vapour-diffusion method in the presence of the inhibitor beta-cyclodextrin (2 mM) by mixing protein (15 mg ml(-1)) with an equal volume of crystallization s... |
10930414 | Reduction of sphingomyelin level without accumulation of ceramide in Chinese hamster ovary cells affects detergent-resistant membrane domains and enhances cellular cholesterol efflux to methyl-beta -cyclodextrin. | We examined the effects of reduction of sphingomyelin level on cholesterol behavior in cells using 2 types of Chinese hamster ovary cell mutants deficient in sphingomyelin synthesis: LY-A strain defective in intracellular trafficking of ceramide for sphingomyelin synthesis, and LY-B strain defective in the enzyme catal... |
11053404 | Analysis of the role of recA in phenotypic switching of Pseudomonas tolaasii. | Switching between the pathogenic smooth (1116S) and nonpathogenic rough (1116R) forms of Pseudomonas tolaasii occurs due to the reversible duplication of a 661-bp element within the pheN locus. Disruption of the chromosomal recA locus of 1116S and 1116R produced strains 1116SrecA and 1116RrecA, respectively, which show... |
11053380 | Role of the carboxy terminus of Escherichia coli FtsA in self-interaction and cell division. | The role of the carboxy terminus of the Escherichia coli cell division protein FtsA in bacterial division has been studied by making a series of short sequential deletions spanning from residue 394 to 420. Deletions as short as 5 residues destroy the biological function of the protein. Residue W415 is essential for the... |
11053376 | A new thermoactive pullulanase from Desulfurococcus mucosus: cloning, sequencing, purification, and characterization of the recombinant enzyme after expression in Bacillus subtilis. | The gene encoding a thermoactive pullulanase from the hyperthermophilic anaerobic archaeon Desulfurococcus mucosus (apuA) was cloned in Escherichia coli and sequenced. apuA from D. mucosus showed 45.4% pairwise amino acid identity with the pullulanase from Thermococcus aggregans and contained the four regions conserved... |
11053372 | Maltose and maltodextrin transport in the thermoacidophilic gram-positive bacterium Alicyclobacillus acidocaldarius is mediated by a high-affinity transport system that includes a maltose binding protein tolerant to low pH. | We have studied the uptake of maltose in the thermoacidophilic gram-positive bacterium Alicyclobacillus acidocaldarius, which grows best at 57 degrees C and pH 3.5. Under these conditions, accumulation of [(14)C]maltose was observed in cells grown with maltose but not in those grown with glucose. At lower temperatures ... |
11053291 | In vitro filament-like formation upon interaction between lens alpha-crystallin and betaL-crystallin promoted by stress. | <h4>Purpose</h4>To determine whether alpha-crystallin is capable of forming filament-like structures with other members of the crystallin family.<h4>Methods</h4>Water-soluble crystallins were isolated from calf lenses and fractionated into alpha-, betaH-, betaL-, and gamma-crystallins according to standard procedures. ... |
11053206 | Blockade and reversal of spinal morphine tolerance by peptide and non-peptide calcitonin gene-related peptide receptor antagonists. | This study examined the effects of the peptide CGRP receptor antagonist CGRP(8-37) and the newly-developed non-peptide CGRP receptor antagonist BIBN4096BS for their potential to both inhibit the development and reverse tolerance to the antinociceptive action of morphine. Repeated administration of intrathecal morphine ... |
11053100 | Advances in interleukin 2 receptor targeted treatment. | T cell activation and cellular immune responses are modulated by interleukin 2 (IL2) through binding to its corresponding cell surface receptor. Three forms of the receptor are recognised based on IL2 binding affinity. The high affinity receptor is a heterotrimer composed of alpha, beta, and gamma(c)-polypeptide chains... |
11046051 | Nonopsonic phagocytosis of Mycobacterium kansasii by human neutrophils depends on cholesterol and is mediated by CR3 associated with glycosylphosphatidylinositol-anchored proteins. | Receptors involved in the phagocytosis of microorganisms under nonopsonic conditions have been little studied in neutrophils. Complement receptor type 3 (CR3) is a pattern recognition receptor able to internalize zymosan and C3bi-coated particles. We report that Abs directed against CR3 strongly inhibited nonopsonic ph... |
11046024 | Stimulatory function of gp49A, a murine Ig-like receptor, in rat basophilic leukemia cells. | Murine gp49, a 49-kDa type I transmembrane glycoprotein, is a member of the Ig-like receptors expressed on the surface of cells involved in natural immunity such as mast cells, NK cells, and macrophages. The two major subtypes, gp49A and gp49B, are encoded by two different genes adjacent to each other. gp49B contains a... |
11044104 | Strategy for systematic assembly of large RNA and DNA genomes: transmissible gastroenteritis virus model. | A systematic method was developed to assemble functional full-length genomes of large RNA and DNA viruses. Coronaviruses contain the largest single-stranded positive-polarity RNA genome in nature. The approximately 30-kb genome, coupled with regions of genomic instability, has hindered the development of a full-length ... |
11044089 | Immunization of cats against feline immunodeficiency virus (FIV) infection by using minimalistic immunogenic defined gene expression vector vaccines expressing FIV gp140 alone or with feline interleukin-12 (IL-12), IL-16, or a CpG motif. | Four groups of cats, each containing four animals, were immunized at 0, 3, and 6 weeks with minimalistic immunogenic defined gene expression vector (MIDGE) vaccines containing the gene(s) for feline immunodeficiency virus (FIV) gp140, FIV gp140 and feline interleukin-12 (IL-12), FIV gp140 and feline IL-16, or FIV gp140... |
11042114 | Transmembrane and cytoplasmic domains of syndecan mediate a multi-step endocytic pathway involving detergent-insoluble membrane rafts. | Syndecan heparan sulphate proteoglycans directly mediate a novel endocytic pathway. Using Chinese hamster ovary cells expressing the human syndecan 1 core protein or a chimaeric receptor, FcR-Synd, consisting of the ectodomain of the IgG Fc receptor Ia linked to the transmembrane and cytoplasmic domains of syndecan 1, ... |
11042110 | An examination of how structural changes can affect the rate of electron transfer in a mutated bacterial photoreaction centre. | A series of reaction centres bearing mutations at the (Phe) M197 position were constructed in the photosynthetic bacterium Rhodobacter sphaeroides. This residue is adjacent to the pair of bacteriochlorophyll molecules (P(L) and P(M)) that is the primary donor of electrons (P) in photosynthetic light-energy transduction... |
11040059 | Polyanionic (i.e., polysulfonate) dendrimers can inhibit the replication of human immunodeficiency virus by interfering with both virus adsorption and later steps (reverse transcriptase/integrase) in the virus replicative cycle. | Polyanionic dendrimers were synthesized and evaluated for their antiviral effects. Phenyldicarboxylic acid (BRI6195) and naphthyldisulfonic acid (BRI2923) dendrimers were found to inhibit the replication of human immunodeficiency virus type 1 (HIV-1; strain III(B)) in MT-4 cells at a EC(50) of 0.1 and 0.3 microg/ml, re... |
11036047 | Activities of an intravenous formulation of itraconazole in experimental disseminated Aspergillus, Candida, and Cryptococcus infections. | An intravenous (i.v.) formulation of itraconazole was evaluated in disseminated fungal infection models in guinea pigs. In acute disseminated Candida albicans and Aspergillus fumigatus infections, treatment at 5 mg/kg of body weight twice a day (b.i.d.) significantly prolonged survival. In these models and in animals w... |
11036004 | Anti-human immunodeficiency virus activities of nucleosides and nucleotides: correlation with molecular electrostatic potential data. | Examination of the anti-human immunodeficiency virus (HIV) data of some normal and isomeric dideoxynucleosides (ddNs and isoddNs), their three-dimensional (3-D) electron density patterns, their electrostatic potential surfaces (EPS), and their conformational maps reveals some interesting correlations. For example, the ... |
11035741 | Staphylococcal fibronectin binding protein interacts with heat shock protein 60 and integrins: role in internalization by epithelial cells. | We reported previously that internalization of Staphylococcus aureus by nonprofessional phagocytes involves an interaction between fibronectin (Fn) binding protein (FnBP) and the host cell, resulting in signal transduction, tyrosine kinase activity, and cytoskeletal rearrangement (K. Dziewanowska, J. M. Patti, C. F. De... |
11029443 | Deletion of the min operon results in increased thermosensitivity of an ftsZ84 mutant and abnormal FtsZ ring assembly, placement, and disassembly. | To investigate the interaction between FtsZ and the Min system during cell division of Escherichia coli, we examined the effects of combining a well-known thermosensitive mutation of ftsZ, ftsZ84, with DeltaminCDE, a deletion of the entire min locus. Because the Min system is thought to down-regulate Z-ring assembly, t... |
11029429 | The mammalian neuroendocrine hormone norepinephrine supplies iron for bacterial growth in the presence of transferrin or lactoferrin. | Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriosta... |
11029414 | Characterization of the distal tail fiber locus and determination of the receptor for phage AR1, which specifically infects Escherichia coli O157:H7. | Phage AR1 is similar to phage T4 in several essential genes but differs in host range. AR1 infects various isolates of Escherichia coli O157:H7 but does not infect K-12 strains that are commonly infected by T4. We report here the determinants that confer this infection specificity. In T-even phages, gp37 and gp38 are c... |
11029577 | Effect of amino-acid substitutions on Alzheimer's amyloid-beta peptide-glycosaminoglycan interactions. | One of the major clinical features of Alzheimer's disease is the presence of extracellular amyloid plaques that are associated with glycosaminoglycan-containing proteoglycans. It has been proposed that proteoglycans and glycosaminoglycans facilitate amyloid fibril formation and/or stabilize these aggregates. Characteri... |
11027475 | Mathematical treatment of transport data of bacterial transport systems to estimate limitation in diffusion through the outer membrane. | Bacterial transport systems are traditionally treated as enzymes exhibiting a saturable binding site giving rise to an apparent K(m)of transport, whereas the maximal rate of transport is regarded equivalent to the V(max)of enzymatic reactions. Thus, the Michaelis-Menten theory is usually applied in the analysis of tran... |
11027294 | Inhibition of p300 histone acetyltransferase by viral interferon regulatory factor. | Kaposi's sarcoma-associated herpesvirus (KSHV) has been consistently identified in Kaposi's sarcomas, body cavity-based lymphomas, and some forms of Castleman's disease. The K9 open reading frame of KSHV encodes a viral interferon regulatory factor (vIRF) which functions as a repressor for cellular interferon-mediated ... |
11024108 | Mutations in the PPPY motif of vesicular stomatitis virus matrix protein reduce virus budding by inhibiting a late step in virion release. | The N terminus of the matrix (M) protein of vesicular stomatitis virus (VSV) and of other rhabdoviruses contains a highly conserved PPPY sequence (or PY motif) similar to the late (L) domains in the Gag proteins of some retroviruses. These L domains in retroviral Gag proteins are required for efficient release of virus... |
11015693 | Release characteristics of a short-chain fatty acid, n-butyric acid, from its beta-cyclodextrin ester conjugate in rat biological media. | 6(A)-O-(n-Butanoyl)-beta-cyclodextrin was prepared and its hydrolysis behavior in aqueous solutions and in rat intestinal fluids was investigated. Furthermore, the enzymatic hydrolyses of the n-butyric acid-beta-cyclodextrin conjugate using alpha-amylase and esterase were studied to gain insight into the release behavi... |
11015689 | Complexation of zolpidem with 2-hydroxypropyl-beta-, methyl-beta-, and 2-hydroxypropyl-gamma-cyclodextrin: effect on aqueous solubility, dissolution rate, and ataxic activity in rat. | The effect of some chemically modified cyclodextrins [namely, 2-hydroxypropyl-beta-, methyl-beta-, and 2-hydroxypropyl-gamma-cyclodextrin (HP-beta-CD, Me-beta-CD, and HP-gamma-CD, respectively)] on the aqueous solubility and dissolution rate of the hypnotic agent Zolpidem (ZP) was investigated. Solid complexes were pre... |
11015684 | Statistical properties of thermodynamic quantities for cyclodextrin complex formation. | Literature values of DeltaG degrees (change in Gibbs free energy), DeltaH degrees (change in enthalpy), and TDeltaS degrees (temperature times change in entropy) for 1:1 complex formation by alpha-, beta-, and gamma-cyclodextrins constitute normally distributed populations with the following statistical parameters (all... |
11000379 | Spatially related amelogenin interactions in developing rat enamel as revealed by molecular cross-linking studies. | A cleavable cross-linker (dithiobis[succinimidyl propionate], DTSP) was used to investigate the subunit structure of the developing enamel matrix. Intact matrix was cross-linked under conditions chosen to simulate those found in vivo. The cross-linked complexes were isolated by preparative sodium dodecyl sulphate-polya... |
10951331 | Model peptide studies of sequence repeats derived from the intracrystalline biomineralization protein, SM50. II. Pro,Asn-rich tandem repeats. | In the biomineralization process, a number of Pro-rich proteins participate in the formation of three-dimensional supramolecular structures. One such protein superfamily, the Pro,Gly-rich sea urchin intracrystalline spicule matrix proteins, form protein-protein supramolecular assemblies that modify the microstructure o... |
11053421 | Syncoilin, a novel member of the intermediate filament superfamily that interacts with alpha-dystrobrevin in skeletal muscle. | Dystrophin coordinates the assembly of a complex of structural and signaling proteins that are required for normal muscle function. A key component of the dystrophin protein complex is alpha-dystrobrevin, a dystrophin-associated protein whose absence results in neuromuscular junction defects and muscular dystrophy. To ... |
11042179 | Growth hormone receptor ubiquitination coincides with recruitment to clathrin-coated membrane domains. | Endocytosis of the growth hormone receptor (GHR) depends on a functional ubiquitin conjugation system. A 10-amino acid residue motif within the GHR cytosolic tail (the ubiquitin-dependent endocytosis motif) is involved in both GHR ubiquitination and endocytosis. As shown previously, ubiquitination of the receptor itsel... |
11041984 | High affinity binding of proteins HMG1 and HMG2 to semicatenated DNA loops. | <h4>Background</h4>Proteins HMG1 and HMG2 are two of the most abundant non histone proteins in the nucleus of mammalian cells, and contain a domain of homology with many proteins implicated in the control of development, such as the sex-determination factor Sry and the Sox family of proteins. In vitro studies of intera... |
11036083 | The yeast NuA4 and Drosophila MSL complexes contain homologous subunits important for transcription regulation. | In Drosophila, the MSL complex is required for the dosage compensation of X-linked genes in males and contains a histone acetyltransferase, MOF. A point mutation in the MOF acetyl-CoA-binding site results in male-specific lethality. Yeast Esa1p, a MOF homolog, is essential for cell cycle progression and is the catalyti... |
21432195 | Community-based analysis of the factorial structures of the recent increase in low birthweight infants. | This study was conducted to determine whether the regional factors were related to the increase in the percentage of low birthweight (LBW: <2,500g) infants in Kumamoto Pref., and to establish a tentative structure model for predicting low birthweight infants. Analyses for frequency of LBW infants between 1974 and 1997,... |
19003377 | Production of podophyllotoxin from Podophyllum hexandrum: a potential natural product for clinically useful anticancer drugs. | Podophyllum hexandrum Royle of family Berberidaceae is an endangered medicinal plant. Rhizome ofP.hexandrum contains several lignans which posses antitumor activity. Podphyllotoxin is the most active cytotoxic natural product. It is used as starting compound for the synthesis of anticancer drug etoposide and teniposide... |
18968098 | Cation complexing of crown ethers using fluorescence spectroscopy, part II. | The complex formations of benzo[12]crown-4, benzo[15]crown-5 and benzo[18]crown-6 with perchlorate salts of Mg(2+), Li(+) and Na(+) were investigated using the steady state fluorescence emission spectroscopy in acetonitrile. The complexation enhanced quenched fluorescence spectra, (CEQFS) exhibited the ion complexation... |
11091368 | Artificial Molecular Machines. | The miniaturization of components used in the construction of working devices is being pursued currently by the large-downward (top-down) fabrication. This approach, however, which obliges solid-state physicists and electronic engineers to manipulate progressively smaller and smaller pieces of matter, has its intrinsic... |
11073252 | Polyphospha | The Eglinton reaction of diethynyl(2,4,6-tri-tert-butylphenyl)phosphane (7a), that is, the oxidative coupling of 3, 4, 5, or 6 of these phosphane units, affords a mixture of the 15-, 20-, 25-, and 30-membered macrocycles 8, 9, 10, and 11. Pure triphosphacyclopentadecahexayne 8 and pentaphosphacyclopentacosadecayne 10 w... |
11073251 | Induced-fit molecular recognition with water-soluble cavitands | Synthesis of novel water-soluble cavitands 1 and 2 and their complexes--the caviplexes--is described. The solubility in water derives from four primary ammonium groups on the lower rim and eight secondary amide groups on the upper rim. Cavitands 1 and 2 exist as D2d velcraplex dimers in aqueous solution but the additio... |
11073250 | Hydrogen-bonding effects in calix | The synthesis and spectroscopic characterization of self-assembling calix[4]arene based capsules 1a.1a and 1b.1b are described. These compounds feature four urea substituents at the upper rims and four secondary amide fragments at the lower rims that can participate in inter- and intramolecular hydrogen bonding in apol... |
11073248 | The use of complexation induced proton NMR chemical shifts for structural analysis of host-guest complexes in solution | Proton shielding variations in supramolecular complexes contain a wealth of information on complex geometries in solution that has been until now mostly neglected. We describe herein ways for such analyses with five cyclophane and two cyclodextrin complexes in water, by using a program SHIFT which is based on and param... |
11073236 | Supramolecular assemblies of quaternary ammonium cations and halide anions in the gas phase: ESMS-FTICR data and computer modelling | Supramolecular aggregates of tetraalkylammonium halides (R4NX) are formed by electrospray out of acetonitrile solution. Mass spectrometry reveals 88 charged aggregates for R= Me, Et, Bu; X= Br, I, ranging up to [(Bu4N)39Br42]3- in size. With the objective of improving calculations of intermolecular energies for supramo... |
11073235 | Fullerodendrimers: a new class of compounds for supramolecular chemistry and materials science applications | Encapsulation of a fullerene sphere in the middle of a dendritic structure prevents unfavorable effects of the C60 unit, such as aggregation or steric hindering. Such fullerodendrimers appear to be promising compounds for materials science applications. On the other hand, fullerodendrons with peripheral C60 subunits or... |
11072822 | A photochemically driven molecular-level abacus | A molecular-level abacus-like system driven by light inputs has been designed in the form of a [2]rotaxane, comprising the pi-electron-donating macrocyclic polyether bis-p-phenylene-34-crown-10 (BPP34C10) and a dumbbell-shaped component that contains 1) a Ru(II) polypyridine complex as one of its stoppers in the form o... |
11072819 | Template effects and kinetic selection in the self-assembly of crown ether cyclobis(paraquat-p-phenylene) | The template effects exerted by bis(p-phenylene)[34]crown-10 (3) and by 1,5-dinaphto[38]crown-10 (4) in the ring-closure reaction of the trication 2(3+) to yield the [2]catenanes 7(4+) and 8(4+) have been quantitatively evaluated in acetonitrile at 62 degrees C by UV/visible spectroscopy. The rate of ring closure of th... |
11072814 | A liquid crystalline supramolecular complex of C60 with a cyclotriveratrylene derivative | Cyclotriveratrylene (CTV) derivatives substituted with 9 (1) or 18 (2) long alkyl chains have been prepared. Whereas no liquid crystalline behavior has been observed for 1, the CTV derivative 2 has mesomorphic properties. Indeed, at room temperature compound 2 exhibits a nematic phase characterized by cybotactic groups... |
11072813 | Interactions at the outside faces of calix | Attractive pi-pi interactions between two of the four outside cavity faces of 1,3-bis-pyridylmethylcalix[4]arene (1) and both faces of 1,4-diiodotetrafluorobenzene (2a) form infinite one-dimensional non-covalent ribbons where the two modules alternate. These ribbons are cross-linked by electron donor-acceptor interacti... |
11055734 | MALDI TOF mass spectrometry for the characterization of phosphorus-containing dendrimers. Scope and limitations | Neutral phosphorus-containing dendrimers with aldehyde groups at the periphery have been analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) up to generation four. Although the expected quasi-molecular ion is generally observed, the mass spectral pattern, presence o... |
11052106 | Ester hydrolysis and enol nitrosation reactions of ethyl cyclohexanone-2-carboxylate inhibited by beta-cyclodextrin | Both the ester hydrolysis and the nitrosation reactions of the enol tautomer of ethyl cyclohexanone-2-carboxylate (ECHC) are investigated in the absence and presence of beta-cyclodextrin (beta-CD). The ester hydrolysis reaction is studied in dilute H2O and D2O solutions of hydrochloric acid and in aqueous buffered solu... |
11031035 | Molecular design of crown ethers. 21.(1,2) synthesis of novel double-armed benzo-15-crown-5 lariats and their complexation thermodynamics with light lanthanoid nitrates in acetonitrile | Three new disubstituted benzo-15-crown-5 derivatives (3-5) have been synthesized from 4',5'-bis(bromomethyl)benzo-15-crown-5 (2) and the corresponding alkanols in the presence of Na(2)S(2), and their complexation thermodynamics with light lanthanoid(III) nitrates (La-Gd) have been studied in anhydrous acetonitrile at 2... |
11031018 | Novel ferrocenyl polyene derivatives and their binding to unmodified cyclodextrins | Two new ferrocene derivatives, 7-ferrocenyl-2,4,6-heptatrienal (1) and 7-ferrocenyl-2,4,6-heptatrienol (2), were synthesized and characterized. These two compounds possess a rigid triene chain conjugated to one of the cyclopentadienyl rings of the ferrocene residue, and as a result, they exhibit very stiff structures. ... |
11031005 | Catalysis of ester aminolysis by cyclodextrins. The reaction of alkylamines with p-nitrophenyl alkanoates | The effects of four cyclodextrins (alpha-CD, beta-CD, hydroxypropyl-beta-CD, and gamma-CD) on the aminolysis of p-nitrophenyl alkanoates (acetate to heptanoate) by primary amines (n-propyl to n-octyl, isobutyl, isopentyl, cyclopentyl, cyclohexyl, benzyl) in aqueous solution have been investigated. Rate constants for am... |
11030938 | Soap froths and crystal structures | We propose a physical mechanism to explain the crystal symmetries found in macromolecular and supramolecular micellar materials. We argue that the packing entropy of the hard micellar cores is frustrated by the entropic interaction of their brushlike coronas. The latter interaction is treated as a surface effect betwee... |
11029199 | Increasing the efficiency of the transannular diels-alder strategy via stille macrocyclizations | To increase the potential and flexibility of the transannular Diels-Alder strategy to build tricycles and tetracycles, the synthesis of macrocyclic trienes of defined geometries has been approached via Stille macrocyclization, giving very high yield and purity of the desired macrocycles or tricycles. |
11029188 | Two-dimensional molecular layers: interplay of H-bonding and van der waals interactions in the self-assembly of N,N'-dialkylsulfamides | N,N'-Dialkylsulfamide molecules assemble into solid-state structures consisting of 2D layers. The 2D layers are based on a hydrogen-bonded network of the sulfamide groups and the close-packing of alkyl groups on both sides of the 2D H-bonded network. The thickness of a 2D layer is proportional to the size of the alkyl ... |
11028631 | Thiazole-containing benzo-crown ethers: a new class of ammonium-selective ionophores | A new class of crown ethers containing heterocyclic units has been designed to develop synthetic NH4+-selective ionophores whose resulting potentiometric properties in solvent polymeric membranes are superior or at least comparable to those of nonactin. It was found that the derivatives of thiazole containing dibenzo-1... |
11027324 | Novel polymers: molecular to nanoscale order in three dimensions. | The assembly of polymer chains in solution is a powerful method that is leading to the preparation of interesting and unique macromolecular-based synthetic nanostructures. Specific control over the intramolecular and intermolecular physical interactions dictates either the folding of single chains or the aggregation an... |
11014450 | Evaluation of alkali metal binding selectivities of caged aza-crown ether ligands by microelectrospray ionization/quadrupole ion trap mass spectrometry | Microelectrospray ionization mass spectrometry (MESI-MS) is used to evaluate alkali metal binding selectivities of a variety of macrocyclic compounds. Well-studied crown ethers are used to validate the MESI-MS method. A quantitative correlation between MESI mass spectral ion intensities and solution equilibrium distrib... |
11009356 | Novel synthesis of hybrid calixphyrin macrocycles | The reaction of benzaldehyde with excess pyrrole at room temperature in the absence of solvent affords a mixture of meso-substituted polypyrranes species. After separation by column chromatography, these may be used to prepare a range of calix[4]phyrin macrocycles by condensation with acetone under conditions of acid c... |
11009350 | Novel phenylazomethine dendrimers: synthesis and structural properties | The novel dendrimers consisting of a pi-conjugated backbone, the dendritic polyphenylazomethines (DPAs), were synthesized by the convergent method via the dehydration of aromatic ketones with aromatic amines in the presence of titanium(IV) tetrachloride. The obtained DPAs have a high solubility unlike the conventional ... |
11009343 | A linear multiporphyrinic | A linear multiporphyrinic [2]-rotaxane has been synthesized using the transition metal-templating method for threading a gold(III)-incorporating macrocycle onto a rodlike, phenanthroline-derived chelate bearing carboxylate end groups. Stoppering has been performed by reacting the resulting prerotaxane with the amino de... |
15597685 | Recent trends in antifungal therapy: focus on systemic mycoses. | Amphotericin B (AmB) remains the 'gold standard' for systemic antifungal therapy and newer drug delivery systems have been effectively developed for this drug. The newer azoles e.g. itraconazole, voriconazole and their derivatives are viable alternatives to AmB, and are suitable for oral administration. Combination ant... |
11832163 | [Changes of leukocyte rheologic characteristics and cell adhesion molecules in patients with multiple organ failure after severe trauma]. | <h4>Objective</h4>To explore the changes of leukocyte rheologic characteristics and of cell adhesion molecule in patients with multiple organ failure (MOF) after severe trauma.<h4>Methods</h4>By using the erythrocyte deformability apparatus, platelet and thrombus adhesion dual-purpose apparatus and enzyme-linked immuno... |
12945437 | [The UV-Vis spectrographic and electrochemical study on the beta-cyclodextrin inclusion compound of 3,3',5,5'-tetramethylbenzidine]. | This paper reports the results of UV-Vis spectrographic and electrochemical studying on the beta-cyclodextrin inclusion compound of 3,3',5,5'-tetramethylbenzidine (TMB). The molecules of TMB show better redox performance after they were included in the cavities of beta-cyclodextrin, especially while there were the redo... |
12945436 | [Heat-induced dynamics studies of azobenzene containing long-chain fatty acid by two-dimensional correlational Raman spectroscopy]. | Temperature-dependent Fourier transform Raman (FT-Raman) spectra were measured in the temperature range between 30 to 120 degrees C for the azobenzene-containing long chain fatty acid 8A5H in the solid state. Generalized two-dimensional (2D) correlation was applied to calculate temperature-dependent synchronous and asy... |
12945388 | [The dynamics of electric-field-induced molecular reorientation and segmental mobility in the antiferroelectric LCs studied by time-resolved FTIR spectroscopy]. | We employed dynamic and polarized infrared spectroscopy to monitor the response of different molecular segments to external electric fields. Measurements of absorbance changes of the representative IR bands as a function of the polarization rotation angle at 109 degrees C under DC electric fields of 0.15 and -15 V dete... |
11372447 | [Separation and determination of effective components in silymarin and preparations of silymarin by MECC]. | <h4>Aim</h4>To develop a micellar electrokinetic capillary chromatographic (MECC) method for the separation and determination of silybin, isosilybin, silydianin and silycristin in Legalon capsules, Yiganling tablets and silymarin.<h4>Methods</h4>A buffer solution containing 30 mmol.L-1 disodium tetraborate, 50 mmol.L-1... |
11354309 | Role of crown-like side chains in the biological activity of substituted-phenoxazone drugs. | The antitumour activity of a number of synthetic crown-ether analogues of actinomycin D (AMD) was investigated in order to test the role of side chains that can complex metal cations. The AMD analogues consisted of two series of phenoxazone derivatives substituted with either benzo-15-crown-5 or benzo-18-crown-6 and wi... |
11196976 | Copper(II) and nickel(II) complexes of binucleating macrocyclic bis(disulfide)tetramine ligands. | Novel macrocyclic bis(disulfide)tetramine ligands and several Cu(II) and Ni(II) complexes of them with additional ligands have been synthesized by the oxidative coupling of linear tetradentate N2S2 tetramines with iodine. Facile demetalation of the Ni(II) oxidation products affords the free 20-membered macrocycles meso... |
11196963 | Formation of mono-, bi-, tri-, and tetranuclear Ag(I) complexes of C3-symmetric tripodal benzimidazole ligands. | The C3-symmetric tripodal ligand tris(2-benzimidazolylmethyl)amine (ntb) and its alkyl-substituted derivatives tris(N-R-benzimidazol-2-ylmethyl)amine (R = methyl, Mentb; R = ethyl, Etntb; R = propyl, Prntb) react with various silver(I) salts to afford mononuclear [Ag(Prntb)(CF3SO3)].0.25H2O, 1, binuclear [Ag2(Mentb)2](... |
11196944 | Yttrium calix[4]arene complexes. Silylation and silylamine elimination reactions on model oxo surfaces. | The synthesis and the spectroscopic and structural characterization of lower-rim-silylated and rare-earth-metalated calix[4]arenes are presented. Hexamethyldisilazane, HN(SiMe3)2, reacted in a selective manner with [p-tert-buttylcalix[4]arene]H4 (1) in refluxing mesitylene to give the 1,3-silylated product [p-tert-buty... |
11196940 | Calixarenes as scaffolds: introduction of tridentate rare earth metal binding units into calix[4]arene. | The reactions of various derivatives of chelidamic acid (4-hydroxypyridine-2,6-dicarboxylic acid) with p-tert-butylcalix[4]arene have produced several new mono- and difunctionalized derivatives of the calixarene in which tridentate functional groups suitable for the binding of rare earth metal cations have been incorpo... |
11121616 | Formation of micelles and liposomes from carnitine amphiphiles. | Esterification of the carboxy and/or the hydroxy groups of (R)-carnitine (3-hydroxy-4-trimethylammonium butanoate) produces interesting classes of (cationic or zwitterionic) surfactants whose CMC values are in general predictable from their molecular structure. In fact similar relationships between CMC and the number o... |
11127988 | Supermolecular structure of photosystem II and location of the PsbS protein. | This paper addresses the question of whether the PsbS protein of photosystem two (PS II) is located within the LHC II PS II supercomplex for which a three-dimensional structure has been obtained by cryoelectron microscopy and single particle analysis. The PsbS protein has recently been implicated as the site for non-ph... |
11129641 | Identification of novel residues involved in nuclear localization of a baculovirus polyhedrin protein. | A baculovirus polyhedrin protein has proven to possess a nuclear localization signal (NLS) sequence and a domain required for supramolecular assembly. Here we investigated five Bombyx mori nucleopolyhedrovirus (BmNPV) mutants that did not produce polyhedra. Two of five mutants were generated during routine baculoviral ... |
11128490 | Unexpected activity of beta-cyclodextrin against experimental infection by Cryptosporidium parvum. | An unexpected activity of beta-cyclodextrin, an excipient used in pharmaceutical technology, was observed against Cryptosporidium parvum. The viability and infectivity of purified oocysts, exposed for 24 hr to beta-cyclodextrin (2.5% suspension), were evaluated by inclusion/exclusion of 2 fluorogenic vital dyes and a s... |
11090629 | Structural basis of SNT PTB domain interactions with distinct neurotrophic receptors. | SNT adaptor proteins transduce activation of fibroblast growth factor receptors (FGFRs) and neurotrophin receptors (TRKs) to common signaling targets. The SNT-1 phosphotyrosine binding (PTB) domain recognizes activated TRKs at a canonical NPXpY motif and, atypically, binds to nonphosphorylated FGFRs in a region lacking... |
11070165 | Cbl-b is a negative regulator of receptor clustering and raft aggregation in T cells. | Stimulation of T cells via the antigen and costimulatory receptors leads to the organization of a supramolecular activation cluster called the immune synapse. We report that loss of the molecular adaptor Cbl-b in T cells frees antigen receptor-triggered receptor clustering, lipid raft aggregation, and sustained tyrosin... |
11106177 | Dimer formation by a "monomeric" protein. | Dimeric proteins can arise by the swapping of structural domains between monomers. The prevalence of this occurrence is unknown. Ribonuclease A (RNase A) is assumed to be a monomer near physiological conditions. Here, this hypothesis is tested and found to be imprecise. The two histidine residues (His12 and His119) in ... |
11106174 | Protein renaturation by the liquid organic salt ethylammonium nitrate. | The room-temperature liquid salt, ethylammonium nitrate (EAN), has been used to enhance the recovery of denatured-reduced hen egg white lysozyme (HEWL). Our results show that EAN has the ability to prevent aggregation of the denatured protein. The use of EAN as a refolding additive is advantageous because the renaturat... |
11106169 | Formation of insulin amyloid fibrils followed by FTIR simultaneously with CD and electron microscopy. | Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), and electron microscopy (EM) have been used simultaneously to follow the temperature-induced formation of amyloid fibrils by bovine insulin at acidic pH. The FTIR and CD data confirm that, before heating, insulin molecules in solution at pH 2.3 ha... |
11106163 | The binding of myristoylated N-terminal nonapeptide from neuro-specific protein CAP-23/NAP-22 to calmodulin does not induce the globular structure observed for the calmodulin-nonmyristylated peptide complex. | CAP-23/NAP-22, a neuron-specific protein kinase C substrate, is Nalpha-myristoylated and interacts with calmodulin (CaM) in the presence of Ca2+ ions. Takasaki et al. (1999, J Biol Chem 274:11848-11853) have recently found that the myristoylated N-terminal nonapeptide of CAP-23/NAP-22 (mC/N9) binds to Ca2+ -bound CaM (... |
11105880 | Highly reproducible capillary zone electrophoresis of humic acids in cyclodextrin- or oligosaccharide-modified background electrolytes. | Capillary zone electrophoresis has been used for the characterization and separation of humic acids. It was found that addition of saccharides like alpha-, beta-, gamma-cyclodextrins, maltose, hydroxyethylcellulose or dextran sulfate in the background electrolyte (50 mM Na2 B4 O7, pH 9.6) yields better separation patte... |
11105875 | Determination of optical purity of phosphonic acid analogues of aromatic amino acids by capillary electrophoresis with alpha-cyclodextrin. | A simple and efficient method for the determination of enantiomeric purity of structurally diverse phosphonic and phosphinic acid analogues of phenylalanine and phenylglycine using capillary electrophoresis is presented. These preliminary studies indicated that the enantiomer separation is strongly dependent on the str... |
11105868 | Capillary electrophoretic separation of the enantiomers of organophosphates with a phosphorus stereogenic center using the sodium salt of octakis(2,3-diacetyl-6-sulfo)-gamma-cyclodextrin as resolving agent. | The sodium salt of the single-isomer, chiral resolving agent, octakis(2,3-diacetyl-6-sulfo)-gamma-cyclodextrin (ODAS-gammaCD) has been used for the capillary electrophoretic separation of the enantiomers of alkylarylphosphates which carry a phosphorus-based stereogenic center. The effective mobilities and separation se... |
11105864 | Separation of bisphenol A and three alkylphenols by micellar electrokinetic chromatography. | Analytical conditions of pH, surfactants, and additives were investigated for the simultaneous separation of bisphenol A and alkylphenols by micellar electrokinetic chromatography. Reproducibility of migration time was improved at higher pH (pH 8.0). When five surfactants having linear alkyl chains or four bile salts w... |
11105849 | Capillary electrophoresis analysis of gentamicin sulphate with UV detection after pre-capillary derivatization with 1,2-phthalic dicarboxaldehyde and mercaptoacetic acid. | A selective, sensitive, and rapid pre-capillary derivatization method for determination of the multicomponent aminoglycoside antibiotic gentamicin is described. The derivatization reagents 1,2-phthalic dicarboxaldehyde and mercaptoacetic acid were used and the thioisoindole derivative was UV detected at 330 nm. A centr... |
11105848 | Chiral capillary electrophoresis as predictor for separation of drug enantiomers in continuous flow zone electrophoresis. | Separation of the enantiomers of chlorpheniramine and methadone in acidic buffers containing carboxymethyl-betacyclodextrin (CMCD) as chiral selector was investigated by capillary zone electrophoresis. For a range of pH and CMCD concentrations, the mobility difference and resolution of the enantiomers were determined. ... |
11105847 | Analysis of doxycycline by capillary electrophoresis. Method development and validation. | An optimized capillary electrophoresis method for the analysis of doxycycline is described. The influence of methanol as organic modifier, buffer pH, buffer concentration, capillary length, column temperature, Triton X-100 and methyl-beta-cyclodextrin was systematically investigated. A central composite design was perf... |
11100878 | The impact of buffers and surfactants from micellar electrokinetic chromatography on matrix-assisted laser desorption ionization (MALDI) mass spectrometry of peptides. Effect of buffer type and concentration on mass determination by MALDI-time-of-flight mass spectrometry. | This paper describes the effect of various buffers, surfactants, and organic additives commonly encountered in capillary zone electrophoresis and micellar electrokinetic chromatography on the molecular weight determination of peptides by matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectromet... |
11100869 | Influence of the structure of cyclodextrins and amino acid sequence of dipeptides and tripeptides on the pH-dependent reversal of the migration order in capillary electrophoresis. | The pH-dependent reversal of the migration order in cyclodextrin (CD)-mediated capillary electrophoresis (CE) enantioseparations of dipeptides and tripeptides has been studied between pH 2.5 and 3.5 using beta-CD and several of its neutral derivatives. The occurrence of the phenomenon depended on both the structure of ... |
11100855 | Methyl-beta-cyclodextrin modified micellar electrokinetic capillary chromatography with laser-induced fluorescence for separation and detection of phospholipids. | Micellar electrokinetic capillary chromatography (MECC) with laser-induced fluorescence detection was applied to the separation of amino group-containing phospholipids including phosphatidylethanolamine (PE), phosphatidylserine (PS), lysophosphatidylethanolamine (LysoPE), and lysophosphatidylserine (LysoPS). A fluoroge... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.