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12427545 | Structure and regulation of the murine gamma-casein gene. | The murine casein locus consists of five genes, which are coordinately regulated during mammary development. The levels of casein-specific mRNAs in mammary epithelial cells increase during the second half of pregnancy and remain high during lactation. The murine gamma-casein gene, which corresponds to the alphaS2-casei... |
12426349 | Arginine operator binding by heterologous and chimeric ArgR repressors from Escherichia coli and Bacillus stearothermophilus. | Bacillus stearothermophilus ArgR binds efficiently to the Escherichia coli carAB operator, whereas the E. coli repressor binds very poorly to the argCo operator of B. stearothermophilus. In order to elucidate this contradictory behavior between ArgRs, we constructed chimeric proteins by swapping N-terminal DNA-binding ... |
12417734 | Transport of fragile X mental retardation protein via granules in neurites of PC12 cells. | Lack of fragile X mental retardation protein (FMRP) causes fragile X syndrome, a common form of inherited mental retardation. FMRP is an RNA binding protein thought to be involved in translation efficiency and/or trafficking of certain mRNAs. Recently, a subset of mRNAs to which FMRP binds with high affinity has been i... |
12417413 | Heparan sulfate fine structure and specificity of proteoglycan functions. | Heparan sulfate chains have markedly heterogeneous structures in which distinct patterns of sulfation determine the binding specificity for ligand proteins. These "fine structures" of heparan sulfate are mainly produced by the regulated introduction of sulfate groups at the N-, 2-O-, 6-O-, and 3-O-positions of the suga... |
12414974 | Binding of Norwalk virus-like particles to ABH histo-blood group antigens is blocked by antisera from infected human volunteers or experimentally vaccinated mice. | Attachment of Norwalk (NV), Snow Mountain (SMV), and Hawaii (HV) virus-like particles (VLPs) to specific ABH histo-blood group antigens was investigated by using human saliva and synthetic biotinylated carbohydrates. The three distinct Norwalk-like viruses (NLVs) have various capacities for binding ABH histo-blood grou... |
12414946 | Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) replication and transcription factor activates the K9 (vIRF) gene through two distinct cis elements by a non-DNA-binding mechanism. | The replication and transcription activator (RTA) of Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, a homologue of Epstein-Barr virus BRLF1 or Rta, is a strong transactivator and inducer of lytic replication. RTA acting alone can induce lytic replication of KSHV in infected cell lines that orig... |
12414943 | Distinct poly(rC) binding protein KH domain determinants for poliovirus translation initiation and viral RNA replication. | The limited coding capacity of picornavirus genomic RNAs necessitates utilization of host cell factors in the completion of an infectious cycle. One host protein that plays a role in both translation initiation and viral RNA synthesis is poly(rC) binding protein 2 (PCBP2). For picornavirus RNAs containing type I intern... |
12414940 | An efficient and versatile mammalian viral vector system for major histocompatibility complex class I/peptide complexes. | We report a Sendai virus (SeV) vector system for expression of major histocompatibility complex (MHC) class I/peptide complexes. We cloned the extracellular domain of a human MHC class I heavy chain, HLA-A*2402, and human beta-2 microglobulin (beta2m) fused with HLA-A*2402-restricted human immunodeficiency virus type 1... |
12414927 | Palmitoylation of the murine leukemia virus envelope protein is critical for lipid raft association and surface expression. | To investigate the association of the murine leukemia virus (MuLV) Env protein with lipid rafts, we compared wild-type and palmitoylation-deficient mutant Env proteins by using extraction with the mild detergent Triton X-100 (TX-100) followed by a sucrose gradient flotation assay. We found that the wild-type MuLV Env p... |
12395422 | Macrotricyclic quaternary tetraammonium receptors: halide anion recognition and interfacial activity at an aqueous interface. A molecular dynamics investigation. | We report a molecular dynamics study of the halide inclusion complexes X(-) subset L(4+) of a macrotricyclic tetrahedral receptor L(4+) built from four quaternary ammonium sites connected by six (CH(2))(n) chains. The hydrophilic/hydrophobic character of the complexes is investigated at a water/chloroform interface, re... |
12392946 | Bio-smart hydrogels: co-joined molecular recognition and signal transduction in biosensor fabrication and drug delivery. | Two classes of polymers that are currently receiving widespread attention in biosensor development are hydrogels and conducting electroactive polymers. The present study reports on the integration of these two materials to produce electroactive hydrogel composites that physically entrap enzymes within their matrices fo... |
12389216 | Identification of a "glycine-loop"-like coiled structure in the 34 AA Pro,Gly,Met repeat domain of the biomineral-associated protein, PM27. | Fracture resistance in biomineralized structures has been linked to the presence of proteins, some of which possess sequences that are associated with elastic behavior. One such protein superfamily, the Pro,Gly-rich sea urchin intracrystalline spicule matrix proteins, form protein-protein supramolecular assemblies that... |
12378541 | Trajectorial organisation of cytokeratins within the subapical region of umbrella cells. | The subapical region of umbrella cells in the urinary bladder contains a dense cytokeratin (CK) network. Yet, this network should enable a very intensive traffic of specific fusiform vesicles involved in alterations of the surface area of the apical membrane. Therefore, the cytokeratins should be organised in a way to ... |
12361625 | Coating with genetic engineered hydrophobin promotes growth of fibroblasts on a hydrophobic solid. | Class I Hydrophobins self-assemble at hydrophilic-hydrophobic interfaces into a highly insoluble amphipathic film. Upon self-assembly of these fungal proteins hydrophobic solids turn hydrophilic, while hydrophilic materials can be made hydrophobic. Hydrophobins thus change the nature of a surface. This property makes t... |
12325040 | Effect of acute and chronic administration of the selective 5-HT2C receptor antagonist SB-243213 on midbrain dopamine neurons in the rat: an in vivo extracellular single cell study. | In this study, we examined the effect of the acute and chronic administration of the selective 5-HT2C receptor antagonist SB-243213 (SB) on the activity of spontaneously active dopamine (DA) cells in the substantia nigra pars compacta (SNC) and ventral tegmental area (VTA) in anesthetized, albino, male Sprague-Dawley r... |
12456984 | Crystal structure of the inclusion complex of beta-cyclodextrin with mefenamic acid from high-resolution synchrotron powder-diffraction data in combination with molecular-mechanics calculations. | The crystal structure of the inclusion complex of beta-cyclo-dextrin with mefenamic acid has been determined from a combination of high-resolution synchrotron powder-diffraction data and molecular-mechanics calculations. A grid search indicates two possible solutions, which are corroborated by molecular-mechanics calcu... |
12456983 | A reexamination of the low-temperature crystal structure of the p-tert-butylcalix[4]arene-toluene inclusion compound. Differences in spatial averaging with Cu and Mo Kalpha radiation. | The low-temperature crystal structure of the p-tert-butylcalix[4]arene-toluene inclusion compound, C(44)H(56)O(4) x C(7)H(8), exhibits significant guest-induced distortion of the host calixarene molecule. This distortion persists long enough to establish a correlation in the orientation of guests in adjacent host molec... |
12458210 | Trafficking of cholesterol from cell bodies to distal axons in Niemann Pick C1-deficient neurons. | Niemann Pick type C (NPC) disease is a progressive neurodegenerative disorder. In cells lacking functional NPC1 protein, endocytosed cholesterol accumulates in late endosomes/lysosomes. We utilized primary neuronal cultures in which cell bodies and distal axons reside in separate compartments to investigate the require... |
12456892 | An mRNA structure that controls gene expression by binding FMN. | The RFN element is a highly conserved domain that is found frequently in the 5'-untranslated regions of prokaryotic mRNAs that encode for flavin mononucleotide (FMN) biosynthesis and transport proteins. We report that this domain serves as the receptor for a metabolite-dependent riboswitch that directly binds FMN in th... |
12456886 | De novo designed peptide-based amyloid fibrils. | Identification of therapeutic strategies to prevent or cure diseases associated with amyloid fibril deposition in tissue (Alzheimer's disease, spongiform encephalopathies, etc.) requires a rational understanding of the driving forces involved in the formation of these organized assemblies rich in beta-sheet structure. ... |
12456883 | Murine apolipoprotein serum amyloid A in solution forms a hexamer containing a central channel. | Serum amyloid A (SAA) is a small apolipoprotein that binds to high-density lipoproteins in the serum. Although SAA seems to play a role in host defense and lipid transport and metabolism, its specific functions have not been defined. Despite the growing implications that SAA plays a role in the pathology of various dis... |
12450412 | Structural analysis of hemicatenated DNA loops. | <h4>Background</h4>We have previously isolated a stable alternative DNA structure, which was formed in vitro by reassociation of the strands of DNA fragments containing a 62 bp tract of the CA-microsatellite poly(CA).poly(TG). In the model which was proposed for this structure the double helix is folded into a loop, th... |
12466616 | catena-Poly[[tetraaquairon(II)]-mu-succinato-kappa2O:O']. | The title complex, ([Fe(C(4)H(4)O(4))(H(2)O)(4)])(n), is an infinite polymeric compound bridged by the succinate dianion. Two carboxylate groups coordinate in a monodentate manner to the Fe(II) atom, in a trans fashion, with an O-Fe-O bond angle of 175.72 (6) degrees and Fe-O distances of 2.0886 (14) and 2.1008 (15) A.... |
12446837 | Single pilus motor forces exceed 100 pN. | Force production by type IV pilus retraction is critical for infectivity of Neisseria gonorrhoeae and DNA transfer. We investigated the roles of pilus number and the retraction motor, PilT, in force generation in vivo at the single-molecule level and found that individual retraction events are generated by a single pil... |
12446835 | The membrane protein FeoB contains an intramolecular G protein essential for Fe(II) uptake in bacteria. | G proteins are critical for the regulation of membrane protein function and signal transduction. Nevertheless, coupling between G proteins and membrane proteins with multiple membrane-spanning domains has so far been observed only in higher organisms. Here we show that the polytopic membrane protein FeoB, which is esse... |
12441398 | The 2B domain of the Escherichia coli Rep protein is not required for DNA helicase activity. | The Escherichia coli Rep protein is a 3' to 5' SF1 DNA helicase required for replication of bacteriophage phiX174 in E. coli, and is structurally homologous to the E. coli UvrD helicase and the Bacillus stearothermophilus PcrA helicase. Previous crystallographic studies of Rep protein bound to single-stranded DNA revea... |
12438698 | Control of biochemical reactions through supramolecular RING domain self-assembly. | RING domains act in a variety of unrelated biochemical reactions, with many of these domains forming key parts of supramolecular assemblies in cells. Here, we observe that purified RINGs from a variety of functionally unrelated proteins, including promyelocytic leukemia protein, KAP-1TIF1beta, Z, Mel18, breast cancer s... |
12438683 | Altered host plant volatiles are proxies for sex pheromones in the gall wasp Antistrophus rufus. | We describe a previously uncharacterized function for changes in plant chemistry induced by phytophagous insects: to provide cues for mate location. Larvae of the gall wasp Antistrophus rufus Gillette (Hymenoptera: Cynipidae) feed within inconspicuous galls inside the flowering stems of the prairie perennials Silphium ... |
12438413 | Clustering of neuronal potassium channels is independent of their interaction with PSD-95. | Voltage-dependent potassium channels regulate membrane excitability and cell-cell communication in the mammalian nervous system, and are found highly localized at distinct neuronal subcellular sites. Kv1 (mammalian Shaker family) potassium channels and the neurexin Caspr2, both of which contain COOH-terminal PDZ domain... |
12576514 | pH6 antigen of Yersinia pestis interacts with plasma lipoproteins and cell membranes. | The bacterial pathogen Yersinia pestis expresses a potential adhesin, the pH6 antigen (pH6-Ag), which appears as fimbria-like structures after exposure of the bacteria to low pH. pH6-Ag was previously shown to agglutinate erythrocytes and to bind to certain galactocerebrosides. We demonstrate that purified pH6-Ag selec... |
12432096 | Bornyl diphosphate synthase: structure and strategy for carbocation manipulation by a terpenoid cyclase. | The x-ray crystal structure of dimeric (+)-bornyl diphosphate synthase, a metal-requiring monoterpene cyclase from Salvia officinalis, is reported at 2.0-A resolution. Each monomer contains two alpha-helical domains: the C-terminal domain catalyzes the cyclization of geranyl diphosphate, orienting and stabilizing multi... |
12427870 | Hsc70 is required for endocytosis and clathrin function in Drosophila. | By screening for Drosophila mutants exhibiting aberrant bride of sevenless (Boss) staining patterns on eye imaginal disc epithelia, we have recovered a point mutation in Hsc70-4, the closest homologue to bovine clathrin uncoating ATPase. Although the mutant allele was lethal, analysis of mutant clones generated by FLP/... |
12466599 | An organometallic RhIII complex with a distorted octahedral structure: (acetonitrile-kappaN)dimethyl(1,4,7-trimethyl-1,4,7-triazacyclononane-kappa3N,N',N")rhodium(III) tetraphenylborate. | In the title compound, [Rh(CH(3))(2)(C(2)H(3)N)(C(9)H(21)N(3))](C(24)H(20)B), the geometry around the Rh(III) centre is distorted octahedral, with elongated Rh-N bonds trans to the metal-bonded methyl groups. The metal-containing cations are located in channels formed by an anionic supramolecular mesh, in which aromati... |
12437772 | Small-molecule modulators of Hedgehog signaling: identification and characterization of Smoothened agonists and antagonists. | <h4>Background</h4>The Hedgehog (Hh) signaling pathway is vital to animal development as it mediates the differentiation of multiple cell types during embryogenesis. In adults, Hh signaling can be activated to facilitate tissue maintenance and repair. Moreover, stimulation of the Hh pathway has shown therapeutic effica... |
12520452 | Enantiomeric purity determination of ketoprofen by capillary electrophoresis: development and validation of the method. | A simple, fast capillary electrophoresis method for determining the total ketoprofen content in an oral pharmaceutical formulation is proposed. The addition of 75 mM of heptakis(tri- O-methyl)-beta-cyclodextrin to the background electrolyte allows the quantitation of the enantiomeric impurity of ( R)-(-)-ketoprofen con... |
12419850 | Human CD8+ T cells do not require the polarization of lipid rafts for activation and proliferation. | Lipid rafts are important signaling platforms in T cells. Little is known about their properties in human CD8(+) T cells. We studied polarization of lipid rafts by digital immunofluorescence microscopy in primary human T cells, using beads coated with anti-CD3 and anti-CD28 mAbs (CD3/28 beads). Unlike CD4(+) T cells, C... |
12419801 | Human type 3 iodothyronine selenodeiodinase is located in the plasma membrane and undergoes rapid internalization to endosomes. | The type 3 iodothyronine selenodeiodinase (D3) is an integral membrane protein that inactivates thyroid hormones. By using immunofluorescence cytochemistry confocal microscopy of live or fixed cells transiently expressing FLAG-tagged human D3 or monkey hepatocarcinoma cells expressing endogenous D3, we identified D3 in... |
12417763 | S-layer-streptavidin fusion proteins as template for nanopatterned molecular arrays. | Biomolecular self-assembly can be used as a powerful tool for nanoscale engineering. In this paper, we describe the development of building blocks for nanobiotechnology, which are based on the fusion of streptavidin to a crystalline bacterial cell surface layer (S-layer) protein with the inherent ability to self-assemb... |
19451990 | Microstructured optical fibers: where's the edge? | We establish that Microstructured Optical Fibers (MOFs) have a fundamental mode cutoff, marking the transition between modal confinement and non-confinement, and give insight into the nature of this transition through two asymptotic models that provide a mapping to conventional fibers. A small parameter space region wh... |
19003101 | A monoclonal antibody to cyclomaltoheptaose (beta-cyclodextrin): Characterization and use for immunoassay of beta-cyclodextrin and its derivatives. | Cyclomaltoheptaose (beta-cyclodextrin, beta-CD) is a promising compound for application in various industrial fields because of its ability to entrap various compounds into its hydrophobic cavity. A monoclonal antibody (A7) to beta-CD was generated by using a conjugate of glucosaminylmaltosyl-beta-CD and bovine serum a... |
18968819 | Liquid-liquid extraction, separation recovery and transport of tantalum by crown-ether. | A solvent extraction, separation, preconcentration method and recovery of tantalum is reported. Tantalum is extracted with dibenzo-18-crown-6 (DB18C6) in dichloromethane in presence of niobium from 4 M hydrochloric acid. The transport of tantalum(V) ions through a supported liquid membrane containing DB18C6 has been st... |
18968814 | Spectrofluorimetric study of the beta-cyclodextrin-rubidate complex and determination of rubidate by beta-CD-enhanced fluorimetry. | The supramolecular interaction of rubidate (chemically 2,3-naphthalenedicarboxylic acid, 1,4-dihydroxy-diethyl ester) and beta-cyclodextrin (beta-CD) has been studied by spectrofluorimetry. The influence of temperature on the supramolecular system has also been investigated and the thermodynamic parameters were calcula... |
18432868 | Isolation and use of rafts. | This unit describes methods for isolating and analyzing rafts by detergent insolubility. To distinguish these rafts from raft-like membranes isolated by other methods, they are referred to here as detergent-resistant membranes (DRMs). DRMs can be isolated by flotation on sucrose density gradients or by pelleting after ... |
12776587 | [Study on the preparation of venenum bufonis beta-cyclodextrin inclusion complexes]. | <h4>Objective</h4>To study the preparation of Venenum Bufonis beta-cyclodextrin inclusion complexes.<h4>Method</h4>An optimal condition was established by the uniform design. Under the optimal conditions the Venenum Bufonis beta-cyclodextrin inclusion complexes were prepared with 5 different methods.<h4>Result</h4>The ... |
12776586 | [Application of beta-cyclodextrin inclusion technique in new dosage form of angelica sinensis essential oil]. | <h4>Objective</h4>To make a solid form of Angelica Sinensis essential oil by preparing its inclusion compound with beta-cyclodextrin and evaluate the inclusion rate, dissolution rate and liberating rate of this complex.<h4>Method</h4>GC-MS, X-ray diffraction and thin-layer chromatography were applied to characterize th... |
12774937 | Supramolecular assemblies of DNA delivery systems. | Gene delivery into cultured cells or in vivo is a promising approach to the treatment of diseases. Several gene delivery systems have been developed to promote gene expression either in vitro or in vivo. Concerns about viral-induced immune responses, the risk associated with replication-competent viruses, and productio... |
12702375 | Thin films of Ag nanoparticles prepared from the reduction of AgI nanoparticles in self-assembled films. | A novel method for the preparation of thin films of Ag nanoparticles is reported. Using mercaptoacetic acid as the stabilizing agent, AgI nanoparticles were prepared in aqueous solution. And based on electrostatic interactions, the thiol-passivated AgI nanoparticles were assembled in a self-assembled film by alternativ... |
12682996 | [Advances in the chiral resolution of organophosphorus compounds by liquid chromatography]. | The developments in the chiral resolution of organophosphorus compounds by liquid chromatography in recent years are reviewed. Two different approaches of separation: indirect resolution (chiral derivatization reagent method) and direct resolution (chiral mobile phase additive and chiral stationary phase), focusing on ... |
12618803 | Cyclodextrin-threaded conjugated polyrotaxanes as insulated molecular wires with reduced interstrand interactions. | Control of intermolecular interactions is crucial to the exploitation of molecular semiconductors for both organic electronics and the viable manipulation and incorporation of single molecules into nano-engineered devices. Here we explore the properties of a class of materials that are engineered at a supramolecular le... |
12613044 | Twistophane macrocyles with integrated 6,6'-connected-2,2'-bipyridine units: a new lead class of fluorescence sensors for metal ions. | The new twistophane macrocycles 2 and 3 have been synthesised; these compounds are composed of a cyclically conjugated dehydrobenzoannulene framework that incorporates 6,6'-connected-2,2'-bipyridine moieties for the purpose of coordinating metal ions. The cyclophanes were characterised by spectroscopic techniques, and ... |
12613041 | Polymer rings and chains consisting of doubly silyl-bridged metallocenes. | With the formation of novel organometallic macromolecules in mind, the polycondensation of transition metal ions and bridged cyclopentadienyl ligands was studied. To this end solvated salts MX2 (M = Fe, Ni, and Cr) were treated with a ligand that consisted of two doubly silyl-bridged cyclopentadienyl anions. For M = Fe... |
12613035 | Post-assembly processing of [2]rotaxanes. | The concept of using [2]rotaxanes that carry one or more surrogate stoppers which can subsequently be converted chemically into other structural units, resulting in the formation of new interlocked molecular compounds, is introduced and exemplified. Starting from simple NH2(+)-centered/crown-ether-based [2]rotaxanes, c... |
12412059 | Hydrogen-bonded networks through second-sphere coordination. | The reaction of 4, 7-phenanthroline (1) with aqueous transitionmetal complexes [Mn(H2O)6][NO3]2, [Co(H2O)6][NO3]2, [Ni(H2O)6[NO3]2, [Mn(H2O)6][ClO4]2, and [Co(H2O)6][ClO4]2 does not produce coordination complexes between these metal cations and the N-donor ligand as expected. Instead, supramolecular hydrogenbonded netw... |
12412056 | Chemical approaches untangling sequence-specific DNA binding by proteins. | Structure-based design of novel DNA-binding proteins provides an ultimate test of our understanding of protein-DNA interactions. A combination of synthetic, organic, biochemical and molecular biological approaches has been developed to study the principle of molecular recognition associated with the protein-DNA interac... |
12566920 | Signaling complex organization by PDZ domain proteins. | As one of the most abundant protein domains in the genomes of metazoans, PDZ domains play important roles in the targeting of proteins to specific cell membranes, as well as assembling proteins into supramolecular signaling complexes. The structures of individual PDZ domains, along with their diverse cooccurrence with ... |
12385028 | Lipid rafts and T cell receptor signaling: a critical re-evaluation. | The current model suggesting that raft integrity is required for T cell activation is mostly (but not exclusively) based on the use of drugs, such as methyl-beta-cyclodextrin (M beta CD), that disorganize rafts and inhibit T cell receptor (TCR)-induced Ca2+ influx. Here we show that conditions that disrupt lipid raft i... |
12556033 | Effect of lipophylic salts on ise detection limit: application to calixarene-based highly efficient potassium-selective electrodes. | A new interpretative model for interpolation of potentiometric data from liquid membrane ion selective electrodes has been formulated; the model allows one to achieve information about partitioning equilibria establishing at the membrane-analysed solution interface of hydrophilic cations present in the membrane as coun... |
12530525 | Oligo-1,6-glucosidase and neopullulanase enzyme subfamilies from the alpha-amylase family defined by the fifth conserved sequence region. | The alpha-amylase enzyme family is the largest family of glycoside hydrolases. It contains almost 30 different enzyme specificities covering hydrolases, transferases and isomerases. Some of the enzyme specificities from the family are closely related, others less so. This study, based on the analysis of 79 amino acid s... |
12530519 | Role of hydrogen peroxide and oxidative stress in healing responses. | Oxidative stress is a host defense mechanism whose involvement in maintaining homeostasis and/or inducing disease has been widely investigated over the past decade. Various reactive oxygen species (ROS) have been defined and the enzymes involved in generating and/or eliminating them have been widely studied. In this re... |
12528464 | [Neoglycoconjugates based on dendrimeric poly(aminoamides)]. | Neoglycoconjugates containing 4, 8, 16, 32, and 64 terminal residues of B-disaccharide (BDI) or N-acetylneuraminic acid (Neu5Ac) attached to poly(aminoamide)-type dendrimers (PAMAMs) were synthesized. The ability of BDI conjugates to bind natural xenoantibodies (anti-BDI antibodies) and the ability of Neu5Ac conjugates... |
12515356 | Stationary phases for thin-layer chromatography. | This paper presents a review of the literature concerning development of the stationary phases for thin-layer chromatography (TLC) in the last ten years. The silica gel remains the most important adsorbent for TLC separation. The kinetic properties of the silica-gel thin layer and the new TLC plates have been presented... |
12510323 | A dithienylethene-tethered beta-cyclodextrin dimer as a photoswitchable host. | The binding of TSPP by a dithienylethene-tethered beta-cyclodextrin dimer can be altered reversibly by irradiation with light. |
12510316 | Highly efficient synthesis of [3]- and [5]-rotaxanes consisting of crown ether and a sec-ammonium salt. | [3]- and [5]-rotaxanes consisting of crown ether and ammonium salts were synthesized in high yields by a tributylphosphine-catalyzed end-capping method which provides a simple and practical means of obtaining higher-order rotaxanes. |
12510282 | A two-dimensional molecular network structure of trimesic acid prepared by adsorption-induced self-organization. | A two-dimensional molecular network of trimesic acid on Au(111) was visualized by in situ scanning tunneling microscopy with submolecular resolution. The supramolecular structures including an 'order to order' phase transition were constructed by precise potential-controlled adsorption based on adsorption-induced self-... |
12510270 | Novel template effect for the preparation of [2]rotaxanes with functionalised centre pieces. | A novel anion-templated synthesis permits the preparation of [2]rotaxanes with a tetralactam wheel through which axles are threaded that are functionalised at their center pieces; the wheel protects these groups efficiently against modifications. |
12510262 | Resorcin[6]arene as a building block for tubular crystalline state architectures. | A resorcin[6]arene with an r-trans-cis-trans-cis-trans configuration of the pendant ethyl groups forms tubular crystal structures. |
12510259 | Cascade energy transfer in a conformationally mobile multichromophoric dendrimer. | A conformationally flexible, generation-2,3 poly(aryl ether) dendrimer favors quantitative cascade fluorescence resonance energy transfer without the appearance of undesired chromophore self-quenching interactions such as excimer formation. |
12510258 | Porous materials via nanocasting procedures: innovative materials and learning about soft-matter organization. | Nanocasting, the 3D-transformation of self-assembled organic nanostructures into hollow inorganic replicas under preservation of fine structural details has recently turned out to be a versatile tool, both for the synthesis of porous media with new pore topology as well as for the characterization of the assembled stru... |
12505093 | Physicochemical properties of quaternized poly(amidoamine) dendrimers with four octyl chains. | A cationic dendrimer-type tetrameric surfactant (C(8)qbG0) with four octyl chains and four ammonium groups was synthesized by the reaction of poly(amidoamine) dendrimers with generation of zero and glycidyldimethyloctylammonium bromide. The physicochemical properties of C(8)qbG0 and of their mixtures with sodium dodecy... |
12505089 | Interactions between a nonionic gemini surfactant and cyclodextrins investigated by small-angle neutron scattering. | The microstructure of complexes between hydroxypropyl-cyclodextrins (HPCDs) (alpha, beta, and gamma) and a novel gemini surfactant has been investigated by small-angle neutron scattering (SANS). This nonionic hetero-gemini surfactant (denoted NIHG750) contains two hydrophobic groups and two hydrophilic groups. One is a... |
12505079 | Effects of various thiol molecules added on morphology of dendrimer-gold nanocomposites. | Interactions between poly(amidoamine) dendrimer (PAMAM)-gold nanocomposites and alkanethiols and between the former nanocomposites and thiol-modified poly(amidoamine) dendrons in ethyl acetate were investigated by adding alkanethiols, such as 1-propanethiol and 1,3-propanedithiol, and thiol-modified poly(amidoamine) de... |
12505077 | Spontaneous formation of Ag nanoparticles in dimethylacetamide solution of poly(ethylene glycol). | The spontaneous formation of Ag nanoparticles in a dimethylacetamide (DMAC) solution of poly(ethylene glycol) (PEG) was studied. FTIR analysis showed the formation of carbonyl groups, revealing that PEG acted as not only a protective agent but also a reducing agent in the formation of Ag nanoparticles. Since no signifi... |
12503132 | Distance measurements in the nanometer range by pulse EPR. | Distances of 1.5 to 8 nm in macromolecules and supramolecular assemblies can be measured by pulse electron paramagnetic resonance (EPR) experiments. In conjunction with site-directed spin labeling or the use of paramagnetic tracers this opens up a new method for the structure determination of complex systems such as bi... |
12502561 | The cardiac sodium-calcium exchanger associates with caveolin-3. | The cardiac Na/Ca exchanger's (NCX1) role in calcium homeostasis during myocardial contractility makes it a possible target of signaling factors regulating inotropy. Caveolae, structured invaginations of the plasmalemma, are known to concentrate a wide variety of signaling factors. The predominant coat proteins of cave... |
12501161 | Brownian dynamics of interactions between aldolase mutants and F-actin. | Previous Brownian dynamics (BD) simulations (Ouporov IG, Knull HR and Thomasson KA 1999. Biophys. J. 76: 17-27) of complex formation between rabbit aldolase and F-actin have identified three lysine residues (K288, K293 and K341) on aldolase and acidic residues (DEDE) at the N-terminus of actin as important to binding. ... |
12501160 | Protein-protein interactions: mechanisms and modification by drugs. | Protein-protein interactions form the proteinaceous network, which plays a central role in numerous processes in the cell. This review highlights the main structures, properties of contact surfaces, and forces involved in protein-protein interactions. The properties of protein contact surfaces depend on their functions... |
12501159 | Essential motions in a fungal lipase with bound substrate, covalently attached inhibitor and product. | As an aid to understanding the influence of dynamic fluctuations during esterolytic catalysis, we follow protein flexibility at three different steps along the catalytic pathway from substrate binding to product clearance via a covalently attached inhibitor, which represents a transition-state mimic. We have applied a ... |
12501158 | The Poisson-Boltzmann equation for biomolecular electrostatics: a tool for structural biology. | Electrostatics plays a fundamental role in virtually all processes involving biomolecules in solution. The Poisson-Boltzmann equation constitutes one of the most fundamental approaches to treat electrostatic effects in solution. The theoretical basis of the Poisson-Boltzmann equation is reviewed and a wide range of app... |
12501157 | Survey of the year 2001 commercial optical biosensor literature. | We have assembled references of 700 articles published in 2001 that describe work performed using commercially available optical biosensors. To illustrate the technology's diversity, the citation list is divided into reviews, methods and specific applications, as well as instrument type. We noted marked improvements in... |
12495559 | Influence of hydroxypropyl-beta-cyclodextrin on photo-induced free radical production by the sunscreen agent, butyl-methoxydibenzoylmethane. | The aim of the study was to investigate the effect of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the photo-induced production of free radicals by the sunscreen agent, butyl-methoxydibenzoylmethane (BMDBM). Spin-trapping/electron paramagnetic resonance spectroscopy was used to evaluate the formation of radicals and... |
12495546 | Solubilization of the lichen metabolite (+)-usnic acid for testing in tissue culture. | The pharmacological testing of natural products can often be hampered by the poor solubility of such compounds in non-toxic solvents. There is thus a need for a suitable agent for solubilization of natural substances to allow testing on a variety of cell lines in-vitro. Such an agent should ideally have no direct effec... |
12495191 | Orientation of Onchocerca lienalis stiles (Filarioidea: Onchocercidae) microfilariae to black fly saliva. | Black flies (Simulium spp.) are intermediate hosts and vectors of parasitic nematodes belonging to the genus Onchocerca (Filarioidea Onchocercidae). Infection and subsequent transmission of infective third-stage larvae occur at the vertebrate host-skin interface. Experimental evidence presented here demonstrates that O... |
12493236 | Inclusion of carvone enantiomers in cyclomaltoheptaose (beta-cyclodextrin): thermal behaviour and H-->D and D-->H exchange. | The inclusion compounds of carvone enantiomers in cylcomaltoheptaose (beta-cyclodextrin, betaCD) are studied at defined temperatures above room temperature and in relation to H-->D and D-->H exchanges. Loss of water molecules and release of carvone molecules from the betaCD cavity are caused by increase of temperature ... |
12493234 | Crystal structure of beta-cyclodextrin-dimethylsulfoxide inclusion complex. | beta-Cyclodextrin (beta-CD) crystallizes from 27% DMSO-water as beta-CD.0.5DMSO.7.35H(2)O in the monoclinic space group P2(1) with unit cell constants: a=15.155(1), b=10.285(1), c=20.906(1) A, beta=109.86(1) degrees. Anisotropic refinement of 888 atomic parameters against 9,127 X-ray diffraction data converged at an R-... |
12493223 | Facile preparation of mono-2-O-modified eicosa-O-methylcyclomaltoheptaoses (-beta-cyclodextrins). | Mono-2-O-benzylated eicosa-O-methylcyclomaltoheptaose (-beta-cyclodextrin) was prepared in one pot from cyclomaltoheptaose (beta-cyclodextrin) in 33% isolated yield and quantitatively converted to mono-2-OH-free eicosa-O-methylcyclomaltoheptaose, which is the key compound for further modification. Transformation of thi... |
12491749 | Spontaneous resolution under supramolecular control. | The spontaneous resolution of enantiomers is an intriguing and important phenomenon in a number of research areas. Non-covalent interactions can play a key role in the process which can now be observed not only in crystals, but in liquid crystals, self-assembled monolayers, self-assembled fibres, and supramolecules sel... |
12490011 | Changes in nitric oxide and expression of nitric oxide synthase in spinal cord after acute traumatic injury in rats. | The aim of this study was to observe the time course of NO production and NOS expression in the spinal cord following acute traumatic injury. Rat spinal cord was injured by extradural static weight-compression, which resulted in an incomplete transverse spinal cord lesion with paralysis of the lower extremities. Using ... |
12489533 | Bond angle versus torsional deformation in an overcrowded alkene: 9-(2,2,2-triphenylethylidene)fluorene. | Competition between bond angle and torsional strain in sterically crowded alkenes generally causes twisting in tetrasubstituted alkenes, while most structurally characterized trisubstituted alkenes are planar. To investigate structural effects of steric repulsion between a planar aromatic ring and a vicinal triphenylme... |
12487133 | Light-emitting molecular machines: pH-induced intramolecular motions in a fluorescent nickel(II) scorpionate complex. | A cyclam-like macrocycle has been synthesized with a pendant arm containing a dansylamide group. In the corresponding nickel(II) complex, binding of the pendant arm to the metal is pH controlled. In particular, at pH 4.3, the sulfonamide group deprotonates and coordinates the NiII center, giving rise to a complex of tr... |
12487132 | Helical (isotactic) and syndiotactic silver(I) metallo-supramolecular coordination polymers assembled from a readily prepared bis-pyridylimine ligand containing a 1,5-naphthalene spacer. | A ligand in which two pyridylimine binding units are linked by a 1,5-naphthalene spacer is prepared and its silver(I) coordination chemistry investigated. In the solid state, a pair of C-H triplebond N interactions between pyridylimine units link the free ligands into chain structures, with further C-H triplebond N and... |
12481292 | Chiral capillary electrophoresis-mass spectrometry: modes and applications. | A review is presented to highlight several approaches for coupling capillary electrophoresis (CE) and electrospray ionization-mass spectrometry (ESI-MS) for analysis of chiral compounds. A short discussion of commercially available CE-MS instruments and interface design is followed by a detail review on various modes o... |
12481291 | Enantiomer migration order in chiral capillary electrophoresis. | Enantiomer migration order (EMO) in chiral capillary electrophoresis (CE) represents a challenging issue, referred to in less than 20% of the articles on CE enantioseparations. This review article will (i) illustrate the actuality of the topic, (ii) discuss some technical problems related to EMO in CE enantioseparation... |
12481287 | Recent progress in adsorbed stationary phases for capillary electrochromatography. | This review surveys the recent progress in the adsorbed stationary phases for capillary electrochromatography (CEC). Adsorption-based methods for preparation of stationary phase are novel approaches in CEC, which allow rapid and facile preparing stationary phases with desirable selectivity onto an open-tubular fused-si... |
12478727 | Heterogeneously functionalized dendrimers. | Significant timely advances have been made in the synthesis of heterogeneously functionalized dendrimers. Convergent, divergent and other functionalization techniques have been used to create a variety of complex dendrimer motifs with more than one type of surface group. Synthetic advances, as well as pertinent applica... |
12476876 | Interaction of iodine with 2-hydroxypropyl-alpha-cyclodextrin and its bactericidal activity. | To obtain an effective iodine solution, the use of 2-hydroxypropyl-alpha-cyclodextrin (2-HP-alpha-CD) as solubilizer was examined in comparison with alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD), potassium iodide (KI), and polyvinylpyrrolidone (PVP). The stability constants for inclusion of iodine with cyc... |
12476870 | Lonidamine solid dispersions: in vitro and in vivo evaluation. | Solid dispersions of lonidamine in PEG 4000 and PVP K 29/32 were prepared by the spray-drying method. Then, the binary systems were studied and characterized using differential scanning calorimetry, hot stage microscopy, and x-ray diffractometry. In vitro dissolution studies of the solid dispersed powders were performe... |
12477043 | Interactions of cyclodextrins with aromatic compounds studied by vibrational circular dichroism spectroscopy. | The host/guest complexation between cyclodextrins (CDs) and aromatic compounds was studied by vibrational circular dichroism (VCD) spectroscopy in mid-IR region. Benzoic acid, 4-aminobenzoic acid, and 2,6-naphthalene-dicarboxylic acid acting as the guests with aromatic skeleton, cause the significant changes in VCD pat... |
12477036 | Calculation of IR spectra of the elementoorganic dendrimers. | Various approximations to the analysis of the dendrimer vibrational spectra are introduced. The merits and demerits of the fragment method, calculation of the first generation and linear chains containing different number of the repeated units are discussed. The experimental spectra of two series of the phosphorus-cont... |
12477034 | Spectroscopic behavior on the formation complex of three double-armed calix[4]arene derivatives with lanthanoid nitrates in acetonitrile. | The complexation spectroscopic behavior of three p-tert-butylcalix[4]arene Schiff bases i.e. 5,11,17,23-tetra-tert-butyl-25,27-bis[2-[N-(3-nitrobenzylidene)amino]ethoxy]-26,28-dihydroxycalix[4]arene (1), 5,11,17,23-tetra-tert-butyl-25,27-bis[2-[N-(2-hydroxybenzylidene)amino]ethoxy]-26,28-dihydroxycalix[4]arene (2), and... |
12477032 | Structural and vibrational study of the Ci(1) conformation of 18-crown-6. | Optimized geometry, vibrational frequencies and IR absorption intensities were calculated for the Ci(1) conformation of 18c6. Optimized geometry was compared with the experimental geometry and that of the Ci(2) conformation of 18c6. The Ci(1) conformation is more planer than the Ci(2) conformation of 18c6, which provid... |
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