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15571630 | Characterisation of weak magnetic field effects in an aqueous glutamic acid solution by nonlinear dielectric spectroscopy and voltammetry. | BACKGROUND: Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequenci... |
15572450 | Structural basis for peptidoglycan binding by peptidoglycan recognition proteins. | Peptidoglycan (PGN) recognition proteins (PGRPs) are pattern-recognition receptors of the innate immune system that bind and, in some cases, hydrolyze bacterial PGNs. We determined the crystal structure, at 2.30-A resolution, of the C-terminal PGN-binding domain of human PGRP-Ialpha in complex with a muramyl tripeptide... |
15576020 | Effect of acidic ternary compounds on the formation of miconazole/cyclodextrin inclusion complexes by means of supercritical carbon dioxide. | <h4>Purpose</h4>The aim of the study is to evaluate the effect of different acidic compounds on the inclusion of miconazole (MICO) in several cyclodextrins (CDs) using supercritical carbon dioxide (SCCO(2) ) processing.<h4>Methods</h4>Physical mixtures were processed by SCCO(2) at 30 MPa, 125 degrees C during 60 minute... |
15645026 | Encapsulated sulfates: insight to binding propensities. | Two crystal structures of sulfate inclusion complexes in an aza- and amido-cryptand represent the first examples of encapsulated sulfate in synthetic cryptand receptors and indicate penta- and octa-coordination, respectively. |
15605157 | A study of the complexation and extraction of Cu(II) sulfate and Ni(II) sulfate by N3O2-donor macrocycles. | Comparative solvent extraction (water/chloroform) studies of Ni(II) and Cu(II) employing a dinonyl-substituted N3O2-donor macrocycle (L2) as extractant have been undertaken from sulfate, chloride, nitrate and acetate-containing aqueous media. Contrary to expectations, efficient extraction of both metal sulfates was obs... |
15569940 | Identification and modulation of a caveolae-dependent signal pathway that regulates plasminogen activator inhibitor-1 in insulin-resistant adipocytes. | Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathogenesis of obesity-driven type 2 diabetes mellitus and associated cardiovascular complications. Here, we show that perturbation of caveolar microdomains leads to insulin resistance and concomitant up-regulation of PAI-1 in 3T3L1 adipocytes. W... |
15569936 | Structural basis of activity and allosteric control of diguanylate cyclase. | Recent discoveries suggest that a novel second messenger, bis-(3'-->5')-cyclic di-GMP (c-diGMP), is extensively used by bacteria to control multicellular behavior. Condensation of two GTP to the dinucleotide is catalyzed by the widely distributed diguanylate cyclase (DGC or GGDEF) domain that occurs in various combinat... |
15569709 | Kinetochore-driven formation of kinetochore fibers contributes to spindle assembly during animal mitosis. | It is now clear that a centrosome-independent pathway for mitotic spindle assembly exists even in cells that normally possess centrosomes. The question remains, however, whether this pathway only activates when centrosome activity is compromised, or whether it contributes to spindle morphogenesis during a normal mitosi... |
15568031 | Self-assembled polymeric solid films with temperature-induced large and reversible photonic-bandgap switching. | In aqueous solutions the response of polymers and biological matter to external conditions, such as temperature and pH, is typically based on the hydrophobic/hydrophilic balance and its effects on the polymer conformation. In the solid state, related concepts using competing interactions could allow novel functions. In... |
15568029 | Very large electro-optic responses in H-bonded heteroaromatic films grown by physical vapour deposition. | A crucial goal for modern telecommunications systems is development of very high-speed components for broadband (>100 GHz), all-optical signal/information processing. The core component of such technologies is the electro-optic modulator, which encodes electrical signals onto fibre-optic transmissions. A significant ch... |
15566570 | Magnetic techniques for the isolation and purification of proteins and peptides. | Isolation and separation of specific molecules is used in almost all areas of biosciences and biotechnology. Diverse procedures can be used to achieve this goal. Recently, increased attention has been paid to the development and application of magnetic separation techniques, which employ small magnetic particles. The p... |
15614355 | Synthesis and characterization of covalently immobilized bis-crown ether based potassium ionophore. | The synthesis of a novel covalently immobilized crown ether based potassium ionophore is presented. Apart from previously proposed methods for the preparation of PVC linked ionophores based on the chemical modification of functionalized PVC polymers, the hereby proposed procedure involves the direct copolymerization of... |
15614382 | NMR and ion selective electrode studies of hydraphile channels correlate with biological activity in E. coli and B. subtilis. | Previous sodium ion transport results obtained by NMR methods are compared with those obtained by a new ISE technique and are found to correlate well with each other and with the biological activity against E. coli and B. subtilis. |
15724211 | Formation of helical superstructures from a semi-fluorinated alkoxysilane through a surface and solution self-assembly process. | Helical superstructures were obtained through a surface and solution self-assembly process when a semi-fluorinated alkoxysilane modified silicon wafer was immersed in water of pH values ranging from 5.0 to 7.0 for more than one month. |
15563605 | Fibronectin matrix turnover occurs through a caveolin-1-dependent process. | Extracellular matrix remodeling occurs during development, tissue repair, and in a number of pathologies, including fibrotic disorders, hypertension, and atherosclerosis. Extracellular matrix remodeling involves the complex interplay between extracellular matrix synthesis, deposition, and degradation. Factors that cont... |
15613271 | Effects of steroid hormones on synaptosomal ectonucleotidase activities from hippocampus and cortex of adult female rats. | Over the last few years, the effects of steroid hormones on the brain have been intensively discussed. It has been demonstrated that ATP (acting as a neurotransmitter) is hydrolyzed to adenosine in the synaptic cleft by the conjugated action of ectonucleotidases, which include an enzyme of the E-NTPDase family (NTPDase... |
15605150 | Ditopic hexaazamacrocycles containing pyridine: synthesis, protonation and complexation studies. | Structural studies of metal complexes of five ditopic hexaazamacrocycles containing two pyridine rings ([n]py2N4 n= 18, 20, 22, 24 and 26) have been carried out. The synthesis of macrocycles [22]- to [26]-py2N4 are also reported. The protonation constants of the last three compounds and the stability constants of their... |
15563602 | The high- and low-affinity receptor binding sites of growth hormone are allosterically coupled. | Growth hormone regulates its biological properties via a sequential hormone-induced receptor homodimerization mechanism. Using a mutagenesis-scanning analysis of 81 single and 32 pairwise double mutations, we show that the hormone's two spatially distal receptor binding sites (Site1 and Site2) are allosterically couple... |
15563596 | Coordinated assembly of human translation initiation complexes by the hepatitis C virus internal ribosome entry site RNA. | Protein synthesis in all cells begins with recruitment of the small ribosomal subunit to the initiation codon in a messenger RNA. In some eukaryotic viruses, RNA upstream of the coding region forms an internal ribosome entry site (IRES) that directly binds to the 40S ribosomal subunit and enables translation initiation... |
15862662 | High-resolution method for regulatory control of Echinacea species in Nutraceuticals by CD-MEKC. | One problem in the international regulatory control of Echinacea, a therapeutic Nutraceutical, is recognition of caffeoyl solutes and alkamides in different products. Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) has been applied to Echinacea spp. in combination with pattern recognition of some... |
15561758 | Sex-specific effects of dual ET-1/ANG II receptor (Dear) variants in Dahl salt-sensitive/resistant hypertension rat model. | Essential (polygenic) hypertension is a complex genetic disorder that remains a major risk factor for cardiovascular disease despite clinical advances, reiterating the need to elucidate molecular genetic mechanisms. Elucidation of susceptibility genes remains a challenge, however. Blood pressure (BP) regulatory pathway... |
15600639 | Pretransitional fluctuations in the isotropic phase of a lyotropic chromonic liquid crystal. | We have studied isotropic-to-nematic pretransitional fluctuations in an aqueous solution of disodium cromoglycate (cromolyn) by static and dynamic light scattering. Cromolyn is a representative of lyotropic chromonic liquid crystals with building units being elongated rods formed by aggregates of disk-like molecules. B... |
15562000 | In situ imaging and isolation of proteins using dsDNA oligonucleotides. | As proteomics initiatives mature, the need will arise for the multiple visualization of proteins and supramolecular complexes within their true context, in situ. Single-stranded DNA and RNA aptamers can be used for low resolution imaging of cellular receptors and cytoplasmic proteins by light microscopy (LM). These tec... |
15557339 | Competition of electrons to enter the respiratory chain: a new regulatory mechanism of oxidative metabolism in Saccharomyces cerevisiae. | In the yeast Saccharomyces cerevisiae, the most important systems for conveying excess cytosolic NADH to the mitochondrial respiratory chain are the external NADH dehydrogenases (Nde1p and Nde2p) and the glycerol-3-phosphate dehydrogenase shuttle. In the latter system, NADH is oxidized to NAD+ and dihydroxyacetone phos... |
15605158 | Synthesis and luminescence properties of lanthanide complexes incorporating a hydralazine-derived chromophore. | Reaction of 1-hydrazinophthalazine with chloroacetyl chloride yields 3-chloromethyl-1,2,4-triazolo-phthalazine. Reaction of this product with the tris tert-butyl ester of DO3A yields a triazolophthalazine appended macrocycle. Hydrolysis and complexation with lanthanide ions gives access to a series of lanthanide comple... |
15558035 | Humidity-induced magnetization and magnetic pole inversion in a cyano-bridged metal assembly. | In general, magnetic properties of bulk magnetic materials are independent of the humidity of the environment. To obtain a magnetic material that has humidity-sensitive characteristics, water vapour must penetrate the lattice and act on spin sites. Nanoporous materials composed of metal-assembled complexes may be expec... |
15724205 | pH dependent self-assembly of dimetallic lanthanide complexes. | pH dependent self-association has been observed in a series of DO3A-derived lanthanide complexes bearing a carboxylate group that can act as a bridging ligand at high pH, switching on the luminescence from the lanthanide. |
15556983 | Forces during bacteriophage DNA packaging and ejection. | The conjunction of insights from structural biology, solution biochemistry, genetics, and single-molecule biophysics has provided a renewed impetus for the construction of quantitative models of biological processes. One area that has been a beneficiary of these experimental techniques is the study of viruses. In this ... |
15556982 | The transmembrane domain of the acetylcholine receptor: insights from simulations on synthetic peptide models. | We have studied the structure and properties of a bundle of alpha-helical peptides embedded in a 1,2-dimyristoyl-3-phosphatidylcholine phospholipid bilayer by molecular dynamics simulations. The bundle of five transmembrane deltaM2 segments constitutes the model for the pore region of the nicotinic acetylcholine recept... |
15556947 | ADAR1 RNA deaminase limits short interfering RNA efficacy in mammalian cells. | Double-stranded RNA induces the homology-dependent degradation of cognate mRNA in the cytoplasm via RNA interference (RNAi) but also is a target for adenosine-to-inosine (A-to-I) RNA editing by adenosine deaminases acting on RNA (ADARs). An interaction between the RNAi and the RNA editing pathways in Caenorhabditis ele... |
15680235 | The SH2 domain: versatile signaling module and pharmaceutical target. | The Src homology 2 (SH2) domain is the most prevalent protein binding module that recognizes phosphotyrosine. This approximately 100-amino-acid domain is highly conserved structurally despite being found in a wide variety proteins. Depending on the nature of neighboring protein module(s), such as catalytic domains and ... |
15597211 | A DFT investigation of conformational geometries and interconversion equilibria of phenylthiosemicarbazone and its complexation with zinc. | The geometrical structures of phenylthiosemicarbazone (HAPhTSC) conformers have been obtained by geometry optimizations using density functional theory (DFT) calculations at the B3LYP/6-31G(d) and B3LYP/6-311G(d,p) levels of theory. Six thioamino and 24 thioimino tautomers of HAPhTSC have been found. Six tautomerizatio... |
15550177 | CLOE: identification of putative functional relationships among genes by comparison of expression profiles between two species. | <h4>Background</h4>Public repositories of microarray data contain an incredible amount of information that is potentially relevant to explore functional relationships among genes by meta-analysis of expression profiles. However, the widespread use of this resource by the scientific community is at the moment limited by... |
15557006 | Metastability of Helicobacter pylori bab adhesin genes and dynamics in Lewis b antigen binding. | Heterogeneity among Helicobacter pylori strains in gastric epithelial adherence is postulated to contribute to pathogen fitness in the physiologically diverse human population. H. pylori adherence to ABO and Lewis b (Leb) blood group antigens in the human stomach is mediated by the blood group antigen-binding adhesin B... |
15557002 | Synthesis of galmic: a nonpeptide galanin receptor agonist. | Galanin is a neuropeptide with a wide variety of biological functions. Few nonpeptide ligands, capable of activating galanin receptors, are available today. Based on known pharmacophores of galanin and the tripeptidomimetic galnon, a combinatorial library was formulated, synthesized, and screened against the galanin re... |
15557000 | Halogen bonds in biological molecules. | Short oxygen-halogen interactions have been known in organic chemistry since the 1950s and recently have been exploited in the design of supramolecular assemblies. The present survey of protein and nucleic acid structures reveals similar halogen bonds as potentially stabilizing inter- and intramolecular interactions th... |
15556999 | Inhibition of vascular endothelial growth factor with a sequence-specific hypoxia response element antagonist. | Vascular endothelial growth factor (VEGF) and its receptors have been implicated as key factors in tumor angiogenesis that are up-regulated by hypoxia. We evaluated the effects of DNA-binding small molecules on hypoxia-inducible transcription of VEGF. A synthetic pyrrole-imidazole polyamide designed to bind the hypoxia... |
15550396 | Supramolecular amyloid-like assembly of the polypeptide sequence coded by exon 30 of human tropoelastin. | Elastin is known to self-aggregate in twisted-rope filaments. However, an ultrastructural organization different from the fibrils typical of elastin, but rather similar to those shown by amyloid networks, is shown by the polypeptide sequence encoded by exon 30 of human tropoelastin. To better understand the molecular p... |
15605144 | Selective metal promoted hydrolysis of nitrile groups in the side chain of tetraazamacrocyclic Cu2+-complexes. | The metal promoted hydrolysis of nitrile groups in the side chains of tetraazamacrocyclic Cu2+ complexes has been studied by stopped-flow techniques. It is shown that the reaction proceeds by an intramolecular attack of an axially coordinated OH- onto the nitrile group to give the corresponding amide. In alkaline solut... |
15550544 | Human and murine inhibitory natural killer cell receptors transfer from natural killer cells to target cells. | Intercellular transfer of proteins across the immunological synapse is emerging as a common outcome of immune surveillance. We previously reported that target-cell MHC class I protein transfers onto natural killer (NK) cells expressing cognate killer Ig-like receptors (KIRs). We now show that, for both murine and human... |
15550565 | The stability of Seeman JX DNA topoisomers of paranemic crossover (PX) molecules as a function of crossover number. | We use molecular dynamics simulations in explicit water and salt (Na+) to determine the effect of varying the number of crossover points on the structure and stability of the PX65 paranemic crossover DNA molecule and its JXM topoisomers (M denotes the number of missing crossover points), recently synthesized by the See... |
15630515 | Cyclodextrin glucanotransferase: from gene to applications. | Cyclodextrin glucanotransferase (CGTase) is an important industrial enzyme which is used to produce cyclodextrins. CGTase genes from more than 30 bacteria have been isolated and several of the enzymes have been identified and biochemically characterized. For a better understanding of the reaction mechanism and function... |
15548613 | The structure of carbonmonoxy neuroglobin reveals a heme-sliding mechanism for control of ligand affinity. | Neuroglobin (Ngb), a globular heme protein expressed in the brain of vertebrates, binds oxygen reversibly, with an affinity comparable to myoglobin (Mb). Despite low sequence identity, the overall 3D fold of Ngb and Mb is very similar. Unlike in Mb, in Ngb the sixth coordination position of the heme iron is occupied by... |
15548605 | Compound library development guided by protein structure similarity clustering and natural product structure. | To identify biologically relevant and drug-like protein ligands for medicinal chemistry and chemical biology research the grouping of proteins according to evolutionary relationships and conservation of molecular recognition is an established method. We propose to employ structure similarity clustering of the ligand-se... |
15546497 | Spider silks: recombinant synthesis, assembly, spinning, and engineering of synthetic proteins. | Since thousands of years humans have utilized insect silks for their own benefit and comfort. The most famous example is the use of reeled silkworm silk from Bombyx mori to produce textiles. In contrast, despite the more promising properties of their silk, spiders have not been domesticated for large-scale or even indu... |
15547248 | Negatively charged self-assembling DNA/poloxamine nanospheres for in vivo gene transfer. | Over the past decade, numerous nonviral cationic vectors have been synthesized. They share a high density of positive charges and efficiency for gene transfer in vitro. However, their positively charged surface causes instability in body fluids and cytotoxicity, thereby limiting their efficacy in vivo. Therefore, there... |
15545640 | Bonus, a Drosophila TIF1 homolog, is a chromatin-associated protein that acts as a modifier of position-effect variegation. | Bonus, a Drosophila TIF1 homolog, is a nuclear receptor cofactor required for viability, molting, and numerous morphological events. Here we establish a role for Bonus in the modulation of chromatin structure. We show that weak loss-of-function alleles of bonus have a more deleterious effect on males than on females. T... |
15600654 | Self-assembly of polyhedral shells: a molecular dynamics study. | The use of reduced models for investigating the self-assembly dynamics underlying protein shell formation in spherical viruses is described. The spontaneous self-assembly of these polyhedral, supramolecular structures, in which icosahedral symmetry is a conspicuous feature, is a phenomenon whose dynamics remain unexplo... |
15545624 | Identification of a Drosophila Myb-E2F2/RBF transcriptional repressor complex. | The Drosophila Myb complex has roles in both activating and repressing developmentally regulated DNA replication. To further understand biochemically the functions of the Myb complex, we fractionated Drosophila embryo extracts relying upon affinity chromatography. We found that E2F2, DP, RBF1, RBF2, and the Drosophila ... |
15627620 | Construction of antibody mimics from a noncatalytic enzyme-detection of polysialic acid. | We have used a conceptually novel way to construct antibody mimics based on the binding of a noncatalytic enzyme to its substrate. Bacteriophage-derived endosialidase cleaves polysialic acid (polySia), an important oncofetal and bacterial antigen, which is poorly immunogenic. We fused to green fluorescent protein (GFP)... |
15619423 | Cytotoxicity of Clostridium septicum alpha-toxin: its oligomerization in detergent resistant membranes of mammalian cells. | Alpha-toxin is an important agent of the virulence of Clostridium septicum. We examined cytotoxicity for alpha-toxin to various mammalian cells with recombinant toxin fused with a histidine-tag at the amino-terminal. The recombinant toxin retained the activity indistinguishable from the native form. Mammalian nucleated... |
15549486 | TNFalpha-stimulated gene product (TSG-6) and its binding protein, IalphaI, in the human intervertebral disc: new molecules for the disc. | Inflammation and irritation of the nerve roots has been indicated as an important factor in the pain associated with symptomatic disc herniations. Tumour necrosis factor alpha (TNFalpha) is now believed to be involved in this pathway. TNFalpha causes connective tissue cells in culture to synthesise a glycoprotein, TNFa... |
15542564 | Dynamic properties of an oriented lipid/DNA complex studied by neutron scattering. | The formation of lipid-DNA (CL-DNA) complexes called lipoplexes, proposed as DNA vectors in gene therapy, is obtained by adding DNA to a solution containing liposomes composed of cationic and neutral lipids. The structural and dynamic properties of such lipoplexes are determined by a coupling between the electrostatic ... |
15542559 | Protein structural perturbation and aggregation on homogeneous surfaces. | We have demonstrated that globular proteins, such as hen egg lysozyme in phosphate buffered saline at room temperature, lose native structural stability and activity when adsorbed onto well-defined homogeneous solid surfaces. This structural loss is evident by alpha-helix to turns/random during the first 30 min and fol... |
15542552 | Understanding the shape of sickled red cells. | To understand the physical basis of the wide variety of shapes of deoxygenated red cells from patients with sickle cell anemia, we have measured the formation rate and volume distribution of the birefringent domains of hemoglobin S fibers. We find that the domain formation rate depends on the approximately 80th power o... |
15542548 | DNA ejection from bacteriophage T5: analysis of the kinetics and energetics. | DNA ejection from bacteriophage T5 can be passively driven in vitro by the interaction with its specific host receptor. Light scattering was used to determine the physical parameters associated with this process. By studying the ejection kinetics at different temperatures, we demonstrate that an activation energy of th... |
15542606 | Structure-activity relationships of diastereomeric lysine ring size analogs of the antimicrobial peptide gramicidin S: mechanism of action and discrimination between bacterial and animal cell membranes. | Structure-activity relationships were examined in seven gramicidin S analogs in which the ring-expanded analog GS14 [cyclo-(VKLKVdYPLKVKLdYP)] is modified by enantiomeric inversions of its lysine residues. The conformation, amphiphilicity, and self-association propensity of these peptides were investigated by circular ... |
15549492 | The HPLC resolution of N-2,4-dinitrophenylated amino acids and peptides stereoisomers on naphthylethylcarbamate-beta-cyclodextrin bonded phase using the acetonitrile-based mobile phase: evidence for the chiral recognition pattern. | A facile method of enantioresolving a variety of alpha-amino acids and peptides on naphthylethylcarbamate-beta-cyclodextrin bonded phases (i.e., SN- and RN-beta-CDs) under the elution of acetonitrile-based mobile phase makes use of 2,4-dinitrofluorobenzene (DNFB) as the tagging reagent, which undergoes nucleophilic sub... |
15539413 | CARD15 gene polymorphisms in patients with spondyloarthropathies identify a specific phenotype previously related to Crohn's disease. | <h4>Background</h4>The association between spondyloarthropathy and Crohn's disease is well known. A risk for evolution to Crohn's disease has already been shown in the subgroup of patients with spondyloarthropathy associated with chronic gut inflammation.<h4>Objective</h4>To investigate whether the reported polymorphis... |
15748985 | T-RFLP analysis of bacterial communities in cyclodextrin-amended bioreactors developed for biodegradation of polychlorinated biphenyls. | In this study, T-RFLP analysis was used to determine the structure and spatial distribution of the indigenous bacterial community of an actual-site PCB-contaminated soil treated in aerobic packed-bed loop reactors (PBLRs) in the absence or in the presence of a mixture of randomly methylated beta-cyclodextrins (RAMEB) a... |
15610971 | Nuclear ferritin in corneal epithelial cells: tissue-specific nuclear transport and protection from UV-damage. | We have identified the heavy chain of ferritin as a developmentally regulated nuclear protein of embryonic chicken corneal epithelial cells. The nuclear ferritin is assembled into a supramolecular form that is indistinguishable from the cytoplasmic form of ferritin found in other cell types. Thus it most likely has iro... |
15538948 | Bi-directional modulation of AMPA receptor unitary conductance by synaptic activity. | <h4>Background</h4>Knowledge of how synapses alter their efficiency of communication is central to the understanding of learning and memory. The most extensively studied forms of synaptic plasticity are long-term potentiation (LTP) and its counterpart long-term depression (LTD) of AMPA receptor-mediated synaptic transm... |
15579966 | Self-inclusion in 5,11,17,23-tetra-tert-butyl-26,27,28-trihydroxy-25-(methoxycarbonylmethoxy)calix[4]arene chloroform trisolvate. | The title compound, C(47)H(60)O(6).3CHCl(3), is the first example of a lower-rim mono-ester calixarene derivative to be crystallographically characterized. The cone conformation adopted by the macrocycle is stabilized by three intramolecular hydrogen bonds. Self-inclusion of the methyl ester chain in the cavity of an a... |
15843033 | The molecular mechanism of protecting cells against oxidative stress by 2-selenium-bridged beta-cyclodextrin with glutathione peroxidase activity. | Ultraviolet B (UVB) induces apoptosis and lipid peroxidation of NIH3T3 cells by producing reactive oxygen species (ROS). Glutathione peroxidase (GPX) is one of the most important antioxidant enzymes in organism and it can scavenge ROS. 2-selenium-bridged beta-cyclodextrin (2-SeCD) is a GPX mimic generated in our lab. I... |
15549398 | Cholesterol depletion by methyl-beta-cyclodextrin enhances myoblast fusion and induces the formation of myotubes with disorganized nuclei. | The formation of a skeletal muscle fiber begins with the withdrawal of committed mononucleated precursors from the cell cycle. These myoblasts elongate while aligning with each other, guided by recognition between their membranes. This step is followed by cell fusion and the formation of long striated multinucleated my... |
15565236 | Preparation of macrocyclic 15N-labelled oligoaminodeoxysaccharides as probes for RNA-binding. | Two macrocyclic aminoglycosides were prepared from a 1,4-butanediol linked 2-deoxy-L-rhamnal which was O-allylated at the 4- and 4'-positions via the precursor allyl 3,4-di-O-acetyl-2,6-dideoxy-alpha-L-arabino-hexoside employing olefin metathesis and ring closing metathesis in a sequential manner. The macrocycles were ... |
15537756 | Analysis of side chain mobility among protein G B1 domain mutants with widely varying stabilities. | "Host-guest" studies of the B1 domain from Streptococcal protein G have been used previously to establish a thermodynamic scale for the beta-sheet-forming propensities of the 20 common amino acids. To investigate the contribution of side chain conformational entropy to the relative stabilities of B1 domain mutants, we ... |
15537837 | X-ray photoelectron spectroscopy and infrared spectroscopy study of maleimide-activated supports for immobilization of oligodeoxyribonucleotides. | Surface-tethered nucleic acids are widely applied in solid-phase assays in which complementary strands must be detected against a complex mixture of other sequences. In response to such needs, numerous methods have been developed for immobilizing nucleic acids on solid supports. Often, detailed analysis of associated c... |
15535886 | Role of tyrosine phosphorylation in sperm capacitation / acrosome reaction. | Capacitation is an important physiological pre-requisite before the sperm cell can acrosome react and fertilize the oocyte. Recent reports from several laboratories have amply documented that the protein phosphorylation especially at tyrosine residues is one of the most important events that occur during capacitation. ... |
15536129 | Human cytomegalovirus encodes a highly specific RANTES decoy receptor. | The human cytomegalovirus pUL21.5 protein is a small, secreted glycoprotein whose mRNA is packaged into virions. We demonstrate that pUL21.5 protein is a soluble CC chemokine receptor that functions as a decoy to modulate the host immune response to infection. In contrast to other viral chemokine-binding proteins, whic... |
15533940 | Huntingtin-interacting protein 1 (Hip1) and Hip1-related protein (Hip1R) bind the conserved sequence of clathrin light chains and thereby influence clathrin assembly in vitro and actin distribution in vivo. | Clathrin heavy and light chains form triskelia, which assemble into polyhedral coats of membrane vesicles that mediate transport for endocytosis and organelle biogenesis. Light chain subunits regulate clathrin assembly in vitro by suppressing spontaneous self-assembly of the heavy chains. The residues that play this re... |
15533924 | Molecular dynamics simulations of discoidal bilayers assembled from truncated human lipoproteins. | Human apolipoprotein A-1 (apo A-1) is the major protein component of high-density lipoproteins. The apo A-1 lipid-binding domain was used as a template for the synthesis of amphipathic helical proteins termed membrane scaffold proteins, employed to self-assemble soluble monodisperse discoidal particles called Nanodiscs... |
15533920 | Nanoscale features of fibronectin fibrillogenesis depend on protein-substrate interaction and cytoskeleton structure. | Cell-reorganized fibronectin layers on polymer films providing a gradation of the binding strength between protein and substrate were analyzed by combined fluorescence and scanning force microscopy. The nanoscale fibronectin patterns exhibited paired parallel fibrils with characteristic spacings of 156, 233, 304, and 3... |
15592613 | NMR conformational analysis of biosynthetic precursor-type lipid A: monomolecular state and supramolecular assembly. | The detailed conformational analysis of a single molecule of the tetraacyl biosynthetic precursor-type lipid A and its characteristic supramolecular assembly in aqueous SDS-micelles are described. Regular molecular arrangements were observed by detailed analysis of the NMR spectra of synthetically pure specimens, inclu... |
15533878 | Co-ordinated gene expression of photosynthetic glyceraldehyde-3-phosphate dehydrogenase, phosphoribulokinase, and CP12 in Arabidopsis thaliana. | Photosynthetic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK) interact in the chloroplast stroma through the action of the small peptide CP12. This supramolecular complex concurs with the light-dependent modulation in vivo of GAPDH and PRK activities. The expression patterns of several g... |
15534220 | Higher-order assembly of microtubules by counterions: from hexagonal bundles to living necklaces. | Cellular factors tightly regulate the architecture of bundles of filamentous cytoskeletal proteins, giving rise to assemblies with distinct morphologies and physical properties, and a similar control of the supramolecular organization of nanotubes and nanorods in synthetic materials is highly desirable. However, it is ... |
15534208 | Integrated regulatory responses of fimB to N-acetylneuraminic (sialic) acid and GlcNAc in Escherichia coli K-12. | Bacterial-host attachment by means of bacterial adhesins is a key step in host colonization. Phase variation (reversible on-off switching) of the type 1 fimbrial adhesin of Escherichia coli involves a DNA inversion catalyzed by FimB (switching in either direction) or FimE (mainly on-to-off switching). fimB is separated... |
15531892 | Escherichia coli Hfq has distinct interaction surfaces for DsrA, rpoS and poly(A) RNAs. | The bacterial Sm-like protein Hfq facilitates RNA-RNA interactions involved in post-transcriptional regulation of the stress response. Specifically, Hfq helps pair noncoding RNAs (ncRNAs) with complementary regions of target mRNAs. To probe the mechanism of this pairing, we generated a series of Hfq mutants and measure... |
15565230 | Multivalency in supramolecular chemistry and nanofabrication. | Multivalency is a powerful and versatile self-assembly pathway that confers unique thermodynamic and kinetic behavior onto supramolecular complexes. The diversity of the examples of supramolecular multivalent systems discussed in this perspective shows that the concept of multivalency is a general phenomenon, and that ... |
15568050 | Dendrimers and gold nanoparticles as exo-receptors sensing biologically important anions. | Dendrimers, alkylthiol-gold nanoparticles and gold-nanoparticle-cored dendrimers containing tethers terminated by a redox group (typically an iron sandwich) attached to a hydrogen-bonding group (amido, amino, silyl) are selective and efficient exo-receptors for the recognition, sensing and titration of oxo-anions, incl... |
15528279 | Hydrophobic interactions drive ligand-receptor recognition for activation and inhibition of staphylococcal quorum sensing. | Two-component systems represent the most widely used signaling paradigm in living organisms. Encoding the prototypical two-component system in Gram-positive bacteria, the staphylococcal agr (accessory gene regulator) operon uses a polytopic receptor, AgrC, activated by an autoinducing peptide (AIP), to coordinate quoru... |
15525699 | Positive selection in the carbohydrate recognition domains of sea urchin sperm receptor for egg jelly (suREJ) proteins. | A wealth of evidence shows that protein-carbohydrate recognition mediates the steps of gamete interaction during fertilization. Carbohydrate-recognition domains (CRDs) comprise a large family of ancient protein modules of approximately 120 amino acids, having the same protein fold, that bind terminal sugar residues on ... |
15525677 | Mitotic regulation of protein 4.1R involves phosphorylation by cdc2 kinase. | The nonerythrocyte isoform of the cytoskeletal protein 4.1R (4.1R) is associated with morphologically dynamic structures during cell division and has been implicated in mitotic spindle function. In this study, we define important 4.1R isoforms expressed in interphase and mitotic cells by RT-PCR and mini-cDNA library co... |
15525704 | Formation of tabular single-domain magnetite induced by Geobacter metallireducens GS-15. | Distinct morphological characteristics of magnetite formed intracellularly by magnetic bacteria (magnetosome) are invoked as compelling evidence for biological activity on Earth and possibly on Mars. Crystals of magnetite produced extracellularly by a variety of bacteria including Geobacter metallireducens GS-15, therm... |
15522962 | C1 inhibitor prevents Gram-negative bacterial lipopolysaccharide-induced vascular permeability. | Gram-negative bacterial endotoxemia may lead to the pathological increase of vascular permeability with systemic vascular collapse, a vascular leak syndrome, multiple organ failure (MOF), and/or shock. Previous studies demonstrated that C1 inhibitor (C1INH) protects mice from lipopolysaccharide (LPS)-induced lethal sep... |
15592624 | Supramolecular optical chemosensors for organic analytes. | Supramolecular optical chemosensors are abiotic molecular devices that bind analytes by noncovalent interactions, producing a change in light absorption or fluorescence. This review summarizes recent progress in the development of such chemosensors for organic analytes based on artificial receptors. Important design co... |
15570390 | Refractive index effects on the oscillator strength and radiative decay rate of 2,3-diazabicyclo[2.2.2]oct-2-ene. | The photophysical properties of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) were determined in 15 solvents, two supramolecular hosts (cucurbit[7]uril and beta-cyclodextrin) as well as in the gas phase. The oscillator strength and radiative decay rate of DBO as a function of refractive index i.e. polarizability have been ana... |
18969682 | The association constants of Na(+) with dibenzo[3n]crown-n in THF/water using ISE. | The Na(+) association constants, K(11) and beta(12), of 1/1 and 1/2 stoichiometry of macrocycles of (1,2)dibenzo[15]crown-5, (1,3)dibenzo[18]crown-6, (1,4)dibenzo[21]crown-7, (2,3)dibenzo[21]crown-7, (2,4)dibenzo[24]-crown-8 and dicyclohexano[24]crown-8 were determined in THF/water, (50/50), mixtures. We used a Methrom... |
18969699 | Cesium ion-selective electrodes based on 1,3-alternate thiacalix[4]biscrown-6,6. | Four thiacalix[4]biscrown ethers with 1,3-alternate conformation were examined for the potentiometric responses in poly(vinyl chloride) membrane electrodes. Their potentiometric selectivities toward potassium and cesium ions over other alkali, alkaline earth, and transition metal ions were measured by the fixed interfe... |
18969678 | Thermodynamic approach for studying both the retention and complexation mechanisms with hydroxy-propyl-beta-cyclodextrin of a phenoxy-propionic acid herbicide series. | The retention and complexation mechanisms of a herbicide series were studied from a chromatographic approach using a novel column called "Nautilus((R))". The effects of water fraction and the hydroxy-propyl-beta-cyclodextrin (HP-beta-CD) concentration in the mobile phase were analysed in relation to the column temperat... |
18429271 | Preparation and extraction of insoluble (inclusion-body) proteins from Escherichia coli. | High-level expression of many recombinant proteins in Escherichia coli leads to the formation of highly aggregated protein commonly referred to as inclusion bodies. Inclusion bodies are normally formed in the cytoplasm; alternatively, if a secretion vector is used, they can form in the periplasmic space. Inclusion bodi... |
16296729 | The second annual symposium on nanomedicine and drug delivery: exploring recent developments and assessing major advances. 19-20 August 2004, Polytechnic University, Brooklyn, NY, USA. | The meeting was dedicated to novel aspects of nanomedicine, including polymer drug delivery systems (DDS) and biomaterials. Self-assembled micellar DDS have been evaluated in terms of morphology, biological properties, and results of clinical trials. Important advances in the design of nanoparticles as DDS have been hi... |
15810601 | [Study on preparation of beta-cyclodextrin inclusion volatile oil from Rhizoma Curcumae]. | <h4>Objective</h4>To study optimum inclusion process conditions for volatile oil from Rhizoma Curcumae.<h4>Method</h4>The study was carried out with orthogonal design. The process conditions were studied by determining the utilazision ratio of volatile oil from Rhizoma Curcumae, the oil-bearing rate and extract ratio o... |
15807118 | [Preparation and evaluation of 2,6-di-O-pentyl-beta-cyclodextrin bonded silica stationary phase for high performance liquid chromatography]. | In order to improve the chiral separation capability of the conventional beta-cyclodextrin bonded-silica gel stationary phase, 2,6-di-O-pentyl-beta-cyclodextrin bonded stationary phase (PCDS) was prepared via a long spacer. The resulted bonded-silica stationary phase was characterized by three methods, namely Fourier t... |
15807117 | [Enantioseparation of tropicamide by capillary electrophoresis with square wave amperometric detection]. | An enantioseparation method for tropicamide by high performance capillary electrophoresis with square wave amperometric detection (SWAD) was developed. The enantiomers of tropicamide were baseline separated in 16 min with an uncoated fused-silica capillary (75 microm i.d. x 50 cm) under the optimum conditions: 7 mmol/L... |
15807109 | [Study on chiral selective inclusion and retention characteristics of cis-trans isomers and enantiomers of sertraline with HP-beta-CD as a mobile phase modifier]. | The effect of the inclusion complex formation of cis-trans isomers and enantiomers of sertraline with added hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in the reversed-phase high performance liquid chromatographic (RP-HPLC) mobile phase on the retention and selectivity has been investigated. Graphs of 1/k vs [HP-beta-... |
15764373 | The supramolecular structure of the GPCR rhodopsin in solution and native disc membranes. | Rhodopsin, the prototypical G-protein-coupled receptor, which is densely packed in the disc membranes of rod outer segments, was proposed to function as a monomer. However, a growing body of evidence indicates dimerization and oligomerization of numerous G-protein-coupled receptors, and atomic force microscopy images r... |
15762456 | [Synthesis and spectroscopy of Dawson molybdovanadophosphoric acid charge-transfer complexes]. | A series of organic-inorganic charge-transfer complexes formed by (E)-N-butyl-4-(2-(4-dimethylaminophenyl)ethenyl)pyridinium bromide with Dawson molybdovanadophosphorate have been synthesized and characterized by elemental analyses, thermogravimetric analyses, UV-Vis, IR and X ray photoelectron spectroscopy. IR spectru... |
15503131 | Quantitative analysis of granule cell axons and climbing fiber afferents in the turtle cerebellar cortex. | The turtle cerebellar cortex is a single flat sheet of gray matter that greatly facilitates quantitative analysis of biotylinated dextran amine labeled granule cell and olivocerebellar axons and Nissl-stained granule and Purkinje neurons. On average, ascending granule cell axons are relatively thicker than their parall... |
15675441 | Selective potentiometric determination of zolpidem hemitartrate in tablets and biological fluids by using polymeric membrane electrodes. | The construction and electrochemical response characteristics of 4 polymeric membrane sensors were investigated for potentiometric determination of zolpidem hemitartrate. The construction of the 4 sensors was based on the formation of ion-pair complexes between the drug cation and ionic sites in the ratio of 1:2, respe... |
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