id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
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15367990 | Metal-peptide nanoassemblies. | A new class of metal-peptide nanoassemblies has been prepared by combining the principles of supramolecular coordination chemistry with those of de novo protein design. |
15340589 | Crystal engineering of the composition of pharmaceutical phases. Do pharmaceutical co-crystals represent a new path to improved medicines? | The evolution of crystal engineering into a form of supramolecular synthesis is discussed in the context of problems and opportunities in the pharmaceutical industry. Specifically, it has become clear that a wide array of multiple component pharmaceutical phases, so called pharmaceutical co-crystals, can be rationally ... |
15514766 | Formation of heterotopic metallacalix[n]arenes (n=3, 4, 6) containing ethylenediaminepalladium(II) metal fragments and 4,7-phenanthroline and 2-pyrimidinolate bridges. Synthesis, structure and host-guest chemistry. | A multicomponent reaction involving ethylenediaminepalladium(II), 2-pyrimidinol derivatives (L) [L=2-pyrimidinol (a); 4-methyl-2-pyrimidinol (b); 4,6-dimethyl-2-pyrimidinol (c)] and 4,7-phenanthroline (4,7-phen) leads to the formation of heterotopic cyclic metallamacrocycles of the type [Pdn(en)n(mu-N,N'-L)m(mu-N,N'-4,... |
15292453 | Elevated endosomal cholesterol levels in Niemann-Pick cells inhibit rab4 and perturb membrane recycling. | In normal human skin fibroblasts (HSFs), fluorescent glycosphingolipid analogues are endocytosed and sorted into two pools, one that is recycled to the plasma membrane and one that is transported to the Golgi complex. Here, we investigated glycosphingolipid recycling in Niemann-Pick type A and C lipid storage disease f... |
15367999 | Synthesis of hybrid dendrimer-star polymers by the RAFT process. | A first generation phosphorus-containing dendrimer with twelve terminal benzyl dithiobenzoate functions was designed and subsequently used as a multifunctional agent to derive hybrid star copolymers consisting of a dendritic core surrounded by twelve polystyrene branches by reversible addition-fragmentation chain trans... |
15292398 | Sialic acid residues on astrocytes regulate neuritogenesis by controlling the assembly of laminin matrices. | In the developing nervous system migrating neurons and growing axons are guided by diffusible and/or substrate-bound cues, such as extracellular matrix-associated laminin. In a previous work we demonstrated that laminin molecules could self-assemble in two different manners, giving rise to matrices that could favor eit... |
15292507 | De novo design of catalytic proteins. | The de novo design of catalytic proteins provides a stringent test of our understanding of enzyme function, while simultaneously laying the groundwork for the design of novel catalysts. Here we describe the design of an O(2)-dependent phenol oxidase whose structure, sequence, and activity are designed from first princi... |
15514771 | Synthesis, characterization and antioxidant activity of new copper(I) complexes of scorpionate and water soluble phosphane ligands. | New copper(I) complexes have been synthesised from the reaction of CuCl with potassium hydrotris(4-bromo-1H-pyrazol-1-yl)borate, KTp4Br or lithium bis(3,5-dimethylpyrazol-1-yl)acetate, Li[L2CO2] ligands and 4- or 2-(diphenylphosphane)benzoic acid or tris(m-sulfonatophenyl)posphine trisodium salt (TPPTS) coligands. The ... |
15289291 | The evolving role of lipid rafts and caveolae in G protein-coupled receptor signaling: implications for molecular pharmacology. | The many components of G-protein-coupled receptor (GPCR) signal transduction provide cells with numerous combinations with which to customize their responses to hormones, neurotransmitters, and pharmacologic agonists. GPCRs function as guanine nucleotide exchange factors for heterotrimeric (alpha, beta, gamma) G protei... |
15368005 | A nanoscale dendrimer-based Fe24 cluster: synthesis and molecular self-assembly. | We report the synthesis, characterisation and self-assembly of a nanoscopic Fe24 cluster using an organic dendrimer as a molecular substrate for building up well-defined molecular nanostructures. |
15289285 | Aspirin induces nitric oxide release from vascular endothelium: a novel mechanism of action. | 1. The study was designed to test the hypothesis that aspirin may stimulate nitric oxide (NO) release from vascular endothelium, a pivotal factor for maintenance of vascular homeostasis. 2. Clinical evidence suggests that low-dose aspirin may improve vascular endothelial function. Since other cyclooxygenase (COX) inhib... |
15340614 | A charge transfer-type fluorescent molecular sensor that "lights up" in the visible upon hydrogen bond-assisted complexation of anions. | A charge transfer-type fluorescent molecular sensor consisting of a bisamidopyridine receptor and two styryl base chromophores shows H(2)PO(4)(-) and acetate-enhanced fluorescence due to the conversion of weak intramolecular hydrogen bonds into strong ones in the host-guest ensemble. |
15289606 | In different organisms, the mode of interaction between two signaling proteins is not necessarily conserved. | Although interfaces mediating protein-protein interactions are thought to be under strong evolutionary constraints, binding of the chemotaxis histidine kinase CheA to its phosphorylation target CheY suggests otherwise. The structure of Thermotoga maritima CheA domain P2 in complex with CheY reveals a different associat... |
15289598 | Inhibitor design by wrapping packing defects in HIV-1 proteins. | Two viral proteins, HIV-1 protease and HIV-1 integrase, have been targeted for inhibitor design to prevent assembly and maturation of HIV-1 virions. The enzymatic mechanism of these proteins involves side-chain groups that serve as general acids or bases. Furthermore, catalytic activity requires that water be removed f... |
15289597 | How cholesterol homeostasis is regulated by plasma membrane cholesterol in excess of phospholipids. | How do cells sense and control their cholesterol levels? Whereas most of the cell cholesterol is located in the plasma membrane, the effectors of its abundance are regulated by a small pool of cholesterol in the endoplasmic reticulum (ER). The size of the ER compartment responds rapidly and dramatically to small change... |
15289577 | Integron integrase binds to bulged hairpin DNA. | Gene cassettes are short, monogenic DNA elements that translocate between integrons through site-specific excision and integration. These events require that an integron-coded tyrosine recombinase forms a reactive complex with two sites, at least one of which belongs to the attC class. An attC site can be divided into ... |
32313408 | Discovery of anti-SARS coronavirus drug based on molecular docking and database screening. | The active site of 3CL proteinase (3CL<sup>pro</sup>) for coronavirus was identified by comparing the crystal structures of human and porcine coronavirus. The inhibitor of the main protein of rhinovirus (Ag7088) could bind with 3CL<sup>pro</sup> of human coronavirus, then it was selected as the reference for molecular ... |
29048902 | Self-Assembly of Patchy Particles. | Molecular simulations are performed to study the self-assembly of particles with discrete, attractive interaction sites - "patches" - at prescribed locations on the particle surface. Chains, sheets, rings, icosahedra, square pyramids, tetrahedra, and twisted and staircase structures are obtained through suitable design... |
22640479 | Molecular Dynamics Study of the Effect of the γ-Abu Insert on the Conformational Behavior of the Glycopeptide Dendrimers Based on the Oligolysine Scaffold in N, N'-dimethylformamide. | Abstract Glycodendrimers bearing Tn (α-D-GalNAc-(1→O)-Ser/Thr), an identified tumor-associated carbohydrate antigen, hold promise in the post-surgery treatment of a variety of tumors such as metastatic breast cancer. We used molecular dynamics (MD) techniques to examine structural differences taking place during synt... |
17191902 | The world of beta- and gamma-peptides comprised of homologated proteinogenic amino acids and other components. | The origins of our nearly ten-year research program of chemical and biological investigations into peptides based on homologated proteinogenic amino acids are described. The road from the biopolymer poly[ethyl (R)-3-hydroxybutanoate] to the beta-peptides was primarily a step from organic synthesis methodology (the prep... |
15506281 | [Determination of constant for the inclusion complex of Yinqiao volatile oil with beta-cyclodextrin]. | <h4>Objective</h4>To determine the constant for the inclusion complex of Yinqiao volatile oil with beta-cyclodextrin.<h4>Method</h4>The stability constant for the inclusion complex of Yinqiao the volatile oil with beta-cyclodextrin was detemined under multiwavelength by ultraviolet spectroscopy, and spectroscopy featur... |
15577101 | [Role of magnesium ions on the regulation of NMDA receptor--a pharmacopathology of memantine]. | Magnesium ion blocks the ion channel of the NMDA receptor at a stable condition. The ion channel competes with the binding site of the noncompetitive antagonists phencyclidine (PCP) and MK-801, which prevent a brain impairment due to the ischemia and so on. The binding ability of these antagonists is strong, an exchang... |
15521362 | Dopamine receptor microdomains involved in molecular recognition and the regulation of drug affinity and function. | A cationic protonatable amine moiety on dopaminergic ligands forms a high affinity reinforced ionic bond with an anionic aspartic acid at position 3.32 of dopamine receptors. When present, catechol hydroxyls of the ligands form hydrogen bonds with serines at position 5.42, 5.43, and 5.46, and this network of hydrogen b... |
15513761 | Encapsulation of insulin-cyclodextrin complex in PLGA microspheres: a new approach for prolonged pulmonary insulin delivery. | The insulin administration by pulmonary route has been investigated in the last years with good perspectives as alternative for parenteral administration. However, it has been reported that insulin absorption after pulmonary administration is limited by various factors. Moreover, in the related studies one daily inject... |
15468267 | Release of chlorambucil from poly(N-isopropylacrylamide) hydrogels with beta-cyclodextrin moieties. | The present work is focused on investigating the behavior of controlled drug release poly(N-isopropylacrylamide) (PNIPA) hydrogels in the presence of beta-cyclodextrin (beta-CD). For this purpose, three types of NIPA hydrogels with beta-CD moieties were synthesized with different architectures according to our previous... |
15460451 | Immobilized beta-cyclodextrin as a simple and recyclable method for cholesterol removal in milk. | This study was designed to determine the optimum conditions of three different factors (mixing time, mixing temperature, and tube size) in reduction of cholesterol in milk using immobilized beta-CD beads. Immobilized beta-CD glass beads were prepared at different conditions of silanization and beta-CD immobilization re... |
15458232 | Toward the development of an injectable dosage form of propofol: preparation and evaluation of propofol-sulfobutyl ether 7-beta-cyclodextrin complex. | The objectives of the present study were to undertake activities toward the development of an aqueous-based formulation of propofol (2,6-diisopropyl phenol), using sulfobutylether 7-beta-cyclodextrin (SBECD). Preformulation studies, including high performance liquid chromatography (HPLC) method development and phase-so... |
15449706 | Molecular recognition in bone morphogenetic protein (BMP)/receptor interaction. | Bone morphogenetic proteins (BMPs) and other members of the TGF-beta superfamily are secreted signalling proteins determining the development, maintenance and regeneration of tissues and organs. These dimeric proteins bind, via multiple epitopes, two types of signalling receptor chains and numerous extracellular modula... |
15446744 | Self-assembly and characterization of hydrogen-bond-induced nanostructure aggregation. | A supramolecular system of a perylene derivative containing bis(2,6-diacylaminopyridine) units and a perylene bisimide bound through three hydrogen-bonds was synthesized and characterized. 1H NMR spectra confirmed the existence of hydrogen-bonding interactions between the perylene derivative (3) and the perylene bisimi... |
15387196 | Hybrid organic-inorganic monolithic stationary phase for acidic compounds separation by capillary electrochromatography. | A novel type of organic-inorganic hybrid porous silica-based monolithic stationary phase for capillary electrochromatography (CEC) has been developed by sol-gel chemistry combined with supramolecular template-based approach in a simple and rapid manner. Both chromatographic interaction and electrophoretic migration con... |
15378903 | Electrophoretic aggregation of humic acid. | Capillary electrophoresis (CE) has been used to characterize humic acid (HA) aggregation. It was found that when pumping HA solution through the capillary at a constant flow rate with no electric field, the number of spikes could be reduced by filtration of the solution. Applying high voltage (30 kV), the amount of spi... |
15378886 | Chiral counter-current chromatography of gemifloxacin guided by capillary electrophoresis using (+)-(18-crown-6)-tetracarboxylic acid as a chiral selector. | (+)-(18-crown-6)-tetracarboxylic acid (18C6H4) has been known as a highly efficient chiral selector for resolving primary amine enantiomers in capillary electrophoresis (CE). We investigated the chiral separation of gemifloxacin using 18C6H4 in analytical counter-current chromatography (CCC). The separation conditions ... |
15361298 | Expression and self-assembly of HCV structural proteins into virus-like particles and their immunogenicity. | <h4>Background</h4>The synthesis of virus-like particles (VLPs) provides an important tool to determine the structural requirements for viral particle assembly and virus-host interactions. Our purpose was to express simultaneously all three structural proteins of hepatitis C virus (HCV) in insect cells to investigate t... |
15352024 | Direct enantioseparation of catechin and epicatechin in tea drinks by 6-O-alpha-D-glucosyl-beta-cyclodextrin-modified micellar electrokinetic chromatography. | Cyclodextrin-modified micellar electrokinetic chromatography was applied to the enantioseparation of catechin and epicatechin using 6-O-alpha-D-glucosyl-beta-cyclodextrin together with sodium dodecyl sulfate and borate-phosphate buffer. Factors affecting chiral resolution and migration time of catechin and epicatechin ... |
15352023 | Application of stepwise discriminant analysis to classify commercial orange juices using chiral micellar electrokinetic chromatography-laser induced fluorescence data of amino acids. | The use of chiral amino acids content and stepwise discriminant analysis to classify three types of commercial orange juices (i.e., nectars, orange juices reconstituted from concentrates, and pasteurized orange juices not from concentrates) is presented. Micellar electrokinetic chromatography with laser-induced fluores... |
15352022 | Optimization and validation of an enantioselective method for a chiral drug with eight stereo-isomers in capillary electrophoresis. | Highly selective capillary electrophoresis (CE) screening methods were applied to find a satisfactory separation of a chiral drug with eight stereoisomeric compounds. The initial separation conditions were further optimized using response surface modelling by applying a Box-Behnken experimental design. This approach re... |
15352021 | Assessment of the N-oxidation of deprenyl, methamphetamine, and amphetamine enantiomers by chiral capillary electrophoresis: an in vitro metabolism study. | A chiral capillary electrophoresis method using hydroxypropyl-beta-cyclodextrin as chiral selector was developed and validated for the quantification of the N-oxygenated metabolites of deprenyl, methamphetamine, and amphetamine enantiomers, formed in vitro. The influence of various parameters (selector concentration, b... |
15352020 | Evaluation of chiral purity for a substituted imidazole p38 MAP kinase inhibitor and its intermediates using a single chiral capillary electrophoresis method. | The chiral separation of a substituted imidazole p38 MAP kinase inhibitor and its intermediates was investigated using capillary electrophoresis (CE) with various sulfated cyclodextrins. After initial screens, a single CE chiral method with a randomly sulfated beta-CD was selected for the evaluation of chiral purity fo... |
15352019 | Development and validation of a capillary electrophoresis method for the enantiomeric purity determination of SLV307, a basic potential antipsychotic compound. | A capillary electrophoresis method for the enantiomeric purity determination of SLV307, a basic potential antipsychotic compound, has been developed and validated. It is shown that the presence of the eutomer in the sample solution may have a significant effect on the peak shape of the distomer, due to electrodispersio... |
15352017 | Influence of methanol on the enantioresolution of antihistamines with carboxymethyl-beta-cyclodextrin in capillary electrophoresis. | According to the model of Wren and Rowe, the separation between two enantiomers in capillary electrophoresis (CE) decreases if an organic modifier is added to the run buffer containing a neutral cyclodextrin (CD) in a concentration below its optimal value in a solvent-free system. In previous work, however, it was obse... |
15352016 | Determination of the chiral and achiral related substances of methotrexate by cyclodextrin-modified micellar electrokinetic chromatography. | A cyclodextrin-modified micellar electrokinetic chromatographic (CD-MEKC) method for the determination of the most important potential impurities of methotrexate (MTX): 2,4-diamino-6-(hydroxymethyl)pteridine, aminopterine hydrate, 4-[N-(2-amino-4-hydroxy-6-pteridinylmethyl)-N-methylamino] benzoic acid, 4-[N-(2,4-diamin... |
15352012 | Chiral capillary electrophoresis: facts and fiction on the reproducibility of resolution with randomly substituted cyclodextrins. | Comparative enantioseparation of the enantiomers of 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate was performed with cyclodextrin (CD)-modified capillary electrophoresis (CE). Two single isomers, beta-CD, heptakis(2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD), and heptakis(2,6-di-O-methyl)-beta-CD (DM-beta-CD) of 98% purity ... |
15352011 | Heptakis(6-amino-6-deoxy)-beta-cyclodextrin as a chiral selector for the separation of anionic analyte enantiomers by capillary electrophoresis. | A hepta-substituted beta-cyclodextrin bearing seven amino groups, heptakis(6-amino-6-deoxy)-beta-cyclodextrin (per-6-NH2-beta-CD) was successfully used as a chiral selector for the enantioseparation of different anionic analytes. The running buffer pH and chiral selector concentration were the studied parameters crucia... |
15352010 | Enantioseparations of hydrobenzoin and structurally related compounds in capillary zone electrophoresis using heptakis(2,3-dihydroxy-6-O-sulfo)-beta-cyclodextrin as chiral selector and enantiomer migration reversal of hydrobenzoin with a dual cyclodextrin system in the presence of borate complexation. | We investigated the enantioseparations of racemic hydrobenzoin, together with benzoin and benzoin methyl ether, in capillary electrophoresis (CE) using the single-isomer heptakis(2,3-dihydroxy-6-O-sulfo)-beta-cyclodextrin (SI-S-beta-CD) as a chiral selector in the presence and absence of borate complexation and enantio... |
15352009 | A screening strategy for the development of enantiomeric separation methods in capillary electrophoresis. | Method development of enantiomeric separations in capillary electrophoresis (CE) is a time-consuming task, since finding the appropriate chiral selector is usually a "trial and error" process. It is impossible to predict the selectivity of a selector towards a certain enantiomer. Therefore, the affinity of all selector... |
15352008 | Ultrashort partial-filling technique in capillary electrophoresis for infinite resolution of tramadol enantiomers and its metabolites with highly sulfated cyclodextrins. | The possibility to enhance resolution to infinite value in chiral capillary electrophoresis is attained as soon as the apparent mobility of one enantiomer becomes opposite to the other. This could be achieved on the basis of the carrier ability of multiple charged chiral selectors such as highly sulfated cyclodextrin (... |
15352007 | Enantioseparation of aromatic amino acids and amino acid esters by capillary electrophoresis with crown ether and prediction of enantiomer migration orders by a three-dimensional quantitative structure-property relationship/comparative field analysis model. | The complete enantioseparations of eight aromatic amino acids and four alkyl esters of 2-phenylglycine were achieved by chiral capillary electrophoresis employing 20 mM Tris-citric acid background electrolyte (pH 2.50) containing 5.0 mM of (+)-18-crown-6-tetracarboxylic acid. The relative migration times (RMTs) to that... |
15352006 | Chiral capillary electrophoresis applied to the determination of phenylglycidol enantiomers obtained from cinnamyl alcohol by asymmetric epoxidation using new titanium(IV) alkoxide compounds as catalysts. | A capillary electrophoresis method for the simultaneous determination of phenylglycidol enantiomers in the presence of an excess of cinnamyl alcohol was developed. The effects of the nature, pH and concentration of the buffer, the nature and concentration of chiral selector, the addition of methanol or acetonitrile, an... |
15352005 | Chiral separation of N-imidazole derivatives, aromatase inhibitors, by cyclodextrin-capillary zone electrophoresis. Mechanism of enantioselective recognition. | Baseline separation of ten new, substituted [1-(imidazo-1-yl)-1-phenylmethyl)] benzothiazolinone and benzoxazolinone derivatives with one chiral center was achieved using cyclodextrin-capillary zone electrophoresis (CD-CZE). A method for the enantiomeric resolution of these compounds was developed using neutral CDs (na... |
15352004 | Enantiomeric separation of neutral hydrophobic dihydrofuroflavones by cyclodextrin-modified micellar capillary electrophoresis. | The enantiomeric separations of several very hydrophobic dihydrofuroflavones were performed and optimized using cyclodextrin-modified micellar capillary electrophoresis. Overall, the greatest enantiomeric peak-to-peak separations for the greatest number of flavones were obtained with hydroxypropyl-gamma-cyclodextrin. T... |
15352001 | Enantiomeric separation of basic compounds using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin in combination with potassium camphorsulfonate in nonaqueous capillary electrophoresis: optimization by means of an experimental design. | The enantiomeric separation of a series of basic pharmaceuticals (beta-blockers, local anesthetics, sympathomimetics) has been investigated in nonaqueous capillary electrophoresis (NACE) systems using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-beta-CD) in combination with potassium camphorsulfonate (ca... |
15352000 | Effects of partial/asymmetrical filling of micelles and chiral selectors on capillary electrophoresis enantiomeric separation: generation of a gradient. | The effect of several experimental parameters on enantiomeric separations in micellar capillary electrophoresis (MCE) was studied. A model separation system was tested. It was composed of an acidic phosphate buffer with sodium dodecyl sulfate (SDS) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as the chiral selector... |
15351998 | Influence of (hydroxy)alkylamino substituents on enantioseparation ability of single-isomer amino-beta-cyclodextrin derivatives in chiral capillary electrophoresis. | A family of single-isomer amino-beta-cyclodextrin (amino-beta-CD) derivatives containing an amino or (hydroxy)alkylamino group in one of the primary positions has been synthesized. The steric effect and hydrogen bond forming ability of the different substituents on enantioseparation of acidic enantiomers has been studi... |
15351996 | Single-isomer sulfated alpha-cyclodextrins for capillary electrophoresis: hexakis(2,3-di-O-methyl-6-O-sulfo)-alpha-cyclodextrin, synthesis, analytical characterization, and initial screening tests. | The third, concluding member of the family of single-isomer, fully sulfated alpha-cyclodextrins, the sodium salt of hexakis(2,3-di-O-methyl-6-O-sulfo)-alpha-cyclodextrin (HxDMS), has been synthesized on the kilogram scale, completing the nine-member array of the single-isomer, 6-O-sulfo CDs now available. HxDMS was tes... |
15351995 | Enantiomeric resolution of 2-arylpropionic acid nonsteroidal anti-inflammatory drugs by capillary electrophoresis: methods and applications. | The 2-arylpropionic acids (2-APAs) are an important group of nonsteroidal anti-inflammatory drugs. These agents, the majority of which are available as racemates, exhibit stereoselectivity in both their action and disposition. Developments in stereoselective separation science methodology, mainly chromatographic, have ... |
15342500 | The high-mobility group A-type protein CarD of the bacterium Myxococcus xanthus as a transcription factor for several distinct vegetative genes. | CarD is the only reported prokaryotic protein showing structural and functional features typical of eukaryotic high-mobility group A transcription factors. In prokaryotes, proteins similar to CarD appear to be confined primarily to myxobacteria. In Myxococcus xanthus, CarD has been previously shown to act as a positive... |
15338571 | The chemical hunt for the identification of drugable targets. | Chemical biology has emerged as a new scientific discipline to change the way scientists approach and study the interface between chemistry, biology, and physics. By integrating the knowledge base of the human genome with the power of diverse and flexible chemical technology platforms, the ultimate goal is to define th... |
15330664 | Strained aromatic oligoamide macrocycles as new molecular clips. | Can one join both ends of a helix? A helical aromatic oligoamide was macrocyclized into a saddle-shaped bifunctional clip molecule that self-assembles into discrete circular dodecamers in the solid state and shows great potential for binding aromatic acid guests in solution. The cyclization step requires that the helix... |
15330653 | Supramolecular architecture consisting of an enantiopure amine and an achiral carboxylic acid: application to the enantioseparation of racemic alcohols. | Three-dimensionally dissymmetric cavities are created from an enantiopure amine and an achiral carboxylic acid, which can incorporate the third components to realize the formation of closely packed crystals. The combination demonstrates enantioselective inclusion for 20 kinds of racemic alcohols. The inclusion phenomen... |
15330641 | From IHF protein to design and synthesis of a sequence-specific DNA bending peptide. | The design and synthesis of a small peptide that mimics the integration host factor (IHF), a major nucleoid-associated protein, is reported. IHF induces DNA compaction by sequence-specific binding that leads to significant bending of the DNA double strand. In a modular approach a small L-lysine dendrimer responsible fo... |
15323524 | Surface-immobilized self-assembled protein-based quantum dot nanoassemblies. | Luminescent semiconductor quantum dot (QD)-based optical biosensors have the potential to overcome many of the limitations associated with using conventional organic dyes for biodetection. We have previously demonstrated a hybrid QD-protein-based fluorescence resonance energy transfer (FRET) sensor. Although the QD act... |
15323519 | Expression of molecular chirality and two-dimensional supramolecular self-assembly of chiral, racemic, and achiral monodendrons at the liquid-solid interface. | We have investigated the two-dimensional ordering of chiral and achiral monodendrons at the liquid-solid interface. The chiral molecules self-assemble into extended arrays of dimers. As expected, the R enantiomer forms the mirror image type pattern of the chiral two-dimensional structure formed by the S enantiomer. A r... |
15323500 | Probing the reaction pathways of DL-proline on TiO2 (001) single crystal surfaces. | The reaction of DL-Proline on O2-annealed (stoichiometric) and O-defected (sub-stoichiometric) TiO2 (001) single-crystal surfaces has been investigated. This is of significance in trying to understand the concept of how biomolecules interact with the surfaces of biomedical implants (molecular recognition). On an O2-ann... |
15323497 | Specific ion and ph effects on supramolecular assembly of mesostructured V-Mg oxides. | Mesostructured V-Mg oxides were synthesized using the surfactant cetyltrimethylammonium bromide (CTAB) as template, V2O5, V(acac)3 (vanadium acetylacetonate), or NH4VO3 as vanadium source, and Mg(NO3)2, MgCl2, MgSO4, (MgCO3)4.Mg(OH)2, Mg(CH3CO2)2, or Mg(C2H5O)2 as magnesium source. The factors that influence the format... |
15323490 | Charging and aggregation of latex particles by oppositely charged dendrimers. | Poly(amidoamine) (PAMAM) dendrimers were shown to adsorb strongly on negatively charged latex particles, and their effect on the particle charge and aggregation behavior was investigated by light scattering and electrophoretic mobility measurements. Time-resolved simultaneous static and dynamic light scattering was use... |
15323476 | Phase structures of a hydrated anionic phospholipid composition containing cationic dendrimers and pegylated lipids. | The effect of 4th generation poly(amidoamine) dendrimer (4G PAMAM) present in an anionic phospholipid composition, consisting of hydrogenated soyphosphatidylcholine (HSPC), cholesterol (CH), dicetyl phosphate (DCP), and poly(ethylene glycol) (Mw approximately 2000) derivatized phosphatidylethanolamine (PEG2000-PE), on ... |
15323471 | Aqueous solubilization of highly fluorinated molecules by semifluorinated surfactants. | The physical and chemical properties of organic compounds are deeply affected by the introduction of fluorinated substituents. Perfluorinated and highly fluorinated organic molecules are both hydrophobic and lipophobic. This makes the recognition and the binding of fluorinated molecules extremely difficult to achieve t... |
15324813 | Crystal structure of a continuous three-dimensional DNA lattice. | DNA has proved to be a versatile material for the rational design and assembly of nanometer scale objects. Here we report the crystal structure of a continuous three-dimensional DNA lattice formed by the self-assembly of a DNA 13-mer. The structure consists of stacked layers of parallel helices with adjacent layers lin... |
15324802 | Aptamers meet allostery. | Engineered RNAs have demonstrated remarkable properties of molecular recognition and allosteric function. Liu and colleagues now report the isolation and in vivo function of a ligand-dependent RNA-based transcription factor that opens wide the door for allosterically controllable aptamers. |
15317062 | Copper-free monomeric and dendritic palladium catalysts for the Sonogashira reaction: substituent effects, synthetic applications, and the recovery and re-use of the catalysts. | A series of bis(tert-butylphosphine)- and bis(cyclohexylphosphine)-functionalized Pd(II) monomers and polyamino (DAB) dendritic catalysts were synthesized and investigated for Sonogashira carbon-carbon coupling reactions in a copper-free procedure. The influence of phosphine substituents (tBu versus Cy) on the reaction... |
15316992 | Two 3D supramolecular polymers constructed from an amino acid and a high-nuclear Ln6Cu24 cluster node. | The first successful attempt to construct 3D supramolecular frameworks with high-nuclear 3d-4f heterometallic clusters as a node is reported. The self-assembly of Ln3+, Cu2+ and amino acid in solution leads to the formation of two polymers, 35-nuclear complex [Sm6Cu29] 1 with a primitive cubic net-like structure and 36... |
15316991 | Self-assembly of small peptidomimetic cyclophanes. | The self-assembly of a series of small peptidomimetic cyclophanes in organic solvents was studied. X-ray diffraction, NMR spectroscopy, and molecular modelling were used to understand the structural features of these self-assembling compounds both at the molecular and supramolecular level. The factors that could influe... |
15313243 | Self-assembling peptides and proteins for nanotechnological applications. | Photolithography enables the precise construction of nanodevices in two-dimensional formats. However, self-assembly of designed molecules serves as an alternative for the construction of three-dimensional nanoscale systems and is particularly appealing in that material properties can potentially be engineered at the mo... |
15308578 | Efficacy in CB1 receptor-mediated signal transduction. | CB(1) receptor cellular signal transduction is dependent on the expression of G proteins to which the receptor couples, the potential for precoupling of particular G proteins to the receptors either by scaffolding mechanisms or colocalization in lipid raft domains, and the effector mechanisms that these transducer mole... |
15303953 | Structure of star-burst dendrimers: a comparison between small angle x-ray scattering and computer simulation results. | We investigated the generation dependent shape and internal structure of star-burst dendrimers under good solvent conditions using small angle x-ray scattering and molecular modeling. Measurements have been performed on poly(amidoamine) dendrimers with generations ranging from g=0 up to g=8 at low concentrations in met... |
15304990 | Enhancement of water solubility of fullerene by cogrinding with mixture of cycloamyloses, novel cyclic alpha-1,4-glucans, via solid-solid mechanochemical reaction. | Improvement of solubility for fullerene (C60) was studied by cogrinding with cycloamyloses using a ball mill in the solid state. Cycloamylose is a novel cyclic alpha-1,4-glucan produced from synthetic amylose by enzymatic reaction. Although sample solutions showed a pale yellow for the initial period of cogrinding with... |
15304981 | Design and evaluation of cyclodextrin-based drug formulation. | The pharmaceutically useful cyclodextrins (CyDs) are classified into hydrophilic, hydrophobic, and ionic derivatives. Because of the multi-functional characteristics and bioadaptability, these CyDs are capable of alleviating the undesirable properties of drug molecules through the formation of inclusion complexes or th... |
15301507 | Layer-by-layer self-assembly of multilayer films containing DNA and Eu3+: their characteristics and interactions with small molecules. | Thin films of alternating DNA and rare earth ion Eu3+ layers from dilute aqueous solutions were fabricated onto quartz substrates and silicon wafers through the layer-by-layer (LbL) self-assembly technique. UV-visible spectroscopy shows that a uniform layer of DNA can be fully adsorbed onto each alternate Eu3+ layer. M... |
15301502 | Supramolecular assembly of strongly chemisorbed size- and shape-defined chiral clusters: S- and R-alanine on Cu(110). | The bonding and self-assembly of a chirally organized monolayer of alanine on the Cu(110) surface has been investigated using reflection-absorption infrared spectroscopy, low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM). This multitechnique approach has enabled an in-depth understanding o... |
15301489 | Two-component dendritic gel: effect of spacer chain length on the supramolecular chiral assembly. | The present study investigates in detail the physical gelation of toluene induced by the addition of simple aliphatic diamines to a dendritic L-lysine-based peptide. The gel-phase material obtained was characterized using differential scanning calorimetry, scanning electron microscopy, small-angle X-ray scattering, cir... |
15301487 | Spontaneous vesicle formation and phase behavior in mixtures of an anionic surfactant with imidazoline compounds. | Unexpected colloidal assemblies form in aqueous mixtures of sodium dodecylbenzenesulfonate (SDBS) with the following imidazoline compounds: 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (V-44, which is a commonly used free-radical initiator), 2,2'-tetramethylenedi-2-imidazoline (TMI), and the main recombina... |
15302442 | Enhanced solubilization and removal of naphthalene and phenanthrene by cyclodextrins from two contaminated soils. | The development of innovative methods for cleaning contaminated soils has emerged as a significant environmental priority. Herein, are investigated the effectiveness of cyclodextrin (CD) to solubilize and to extract organic pollutants from soils. The interactions in the cyclodextrin/pollutant/soil system have been stud... |
15303139 | [Influence of seven absorption enhancers on nasal mucosa--assessment of toxicity]. | <h4>Objective</h4>To study the influence of seven different absorption enhancers on nasal mucosa.<h4>Methods</h4>By testing last time of ciliary movement, velocity of ciliary movement, ciliary structural and specific cellular changes of nasal mucosa the influence of seven different absorption enhancers on nasal mucosa... |
15300831 | Dendritic polyamines: simple access to new materials with defined treelike structures for application in nonviral gene delivery. | Polycationic dendrimers are interesting nonviral vectors for in vitro DNA delivery. We describe a simple approach to the synthesis of dendritic polyamines with different molecular weights and adjustable flexibility (degrees of branching; DB). Both parameters influence the transfection efficiency and the cell toxicity o... |
15298927 | Self-assembly of the ionic peptide EAK16: the effect of charge distributions on self-assembly. | Amphiphilic peptides suspended in aqueous solution display a rich set of aggregation behavior. Molecular-level studies of relatively simple amphiphilic molecules under controlled conditions are an essential step toward a better understanding of self-assembly phenomena of naturally occurring peptides/proteins. Here, we ... |
15298919 | Lamellar organization of pigments in chlorosomes, the light harvesting complexes of green photosynthetic bacteria. | Chlorosomes of green photosynthetic bacteria constitute the most efficient light harvesting complexes found in nature. In addition, the chlorosome is the only known photosynthetic system where the majority of pigments (BChl) is not organized in pigment-protein complexes but instead is assembled into aggregates. Because... |
15298911 | Effect of nanomolar concentrations of sodium dodecyl sulfate, a catalytic inductor of alpha-helices, on human calcitonin incorporation and channel formation in planar lipid membranes. | Human Calcitonin (hCt) is a peptide hormone which has a regulatory action in calcium-phosphorus metabolism. It is currently used as a therapeutic tool in bone pathologies such as osteoporosis and Paget's disease. However, due to its amphiphilic property tends to form a gelatinous solution in water which consists of fib... |
15298908 | Fluorescence correlation spectroscopy relates rafts in model and native membranes. | The lipid raft model has evoked a new perspective on membrane biology. Understanding the structure and dynamics of lipid domains could be a key to many crucial membrane-associated processes in cells. However, one shortcoming in the field is the lack of routinely applicable techniques to measure raft association without... |
15298905 | A kinetic study of the growth of fatty acid vesicles. | Membrane vesicles composed of fatty acids can be made to grow and divide under laboratory conditions, and thus provide a model system relevant to the emergence of cellular life. Fatty acid vesicles grow spontaneously when alkaline micelles are added to buffered vesicles. To investigate the mechanism of this process, we... |
15298889 | Exploring the counterion atmosphere around DNA: what can be learned from molecular dynamics simulations? | The counterion distribution around a DNA dodecamer (5'-CGCGAATTCGCG-3') is analyzed using both standard and novel techniques based on state of the art molecular dynamics simulations. Specifically, we have explored the population of Na(+) in the minor groove of DNA duplex, and whether or not a string of Na(+) can replac... |
15300686 | Reactions between or within molecular crystals. | Reactions that occur within or between molecular crystals, in particular those reactions that are activated by mechanical methods, are reviewed. The focus is on processes (whether intrasolid or intersolid) that are controlled primarily by supramolecular bonding, such as template cycloadditions, formation of inclusion c... |
15296742 | Snapshot of protein structure evolution reveals conservation of functional dimerization through intertwined folding. | Protein-protein interactions govern a wide range of cellular processes. Molecular recognition responsible for homodimerization and heterodimerization in the rel/NF-kappaB family of eukaryotic transcription factors relies on a small cluster of hydrophobic residues. We have carried out a structural analysis of six NF-kap... |
15170387 | Dual regulation of AP-2alpha transcriptional activation by poly(ADP-ribose) polymerase-1. | Poly(ADP-ribose) polymerase-1 (PARP-1) is a co-activator for AP-2alpha (activator protein 2alpha)-mediated transcriptional activation. In the present study, we find that the role of PARP-1 in AP-2alpha transcription is distinctly dualistic with opposing effects. Separate regions of PARP-1 interact with AP-2alpha and in... |
15147240 | Topology of the substrate-binding site of a Lys49-phospholipase A2 influences Ca2+-independent membrane-damaging activity. | BthTx-I (bothropstoxin-I) is a myotoxic Lys49-PLA2 (phospholipase A2 with Lys49) isolated from Bothrops jararacussu venom, which damages liposome membranes by a Ca2+-independent mechanism. The highly conserved Phe5/Ala102/Phe106 motif in the hydrophobic substrate-binding site of the Asp49-PLA2s is substituted by Leu5/V... |
15295038 | Surface targeting of the dopamine transporter involves discrete epitopes in the distal C terminus but does not require canonical PDZ domain interactions. | The human dopamine transporter (hDAT) contains a C-terminal type 2 PDZ (postsynaptic density 95/Discs large/zona occludens 1) domain-binding motif (LKV) known to interact with PDZ domain proteins such as PICK1 (protein interacting with C-kinase 1). As reported previously, we found that, after deletion of this motif, hD... |
15291753 | A quantitative RT-PCR study of the mRNA expression profile of the IGF axis during mammary gland development. | We have used quantitative RT-PCR to analyse the mRNA expression profile of the major components of the IGF axis in different stages of murine mammary gland development, including late pregnancy, lactation and involution. We have shown that all the genes studied, IGF-I, IGF-II, IGF receptor (IGFR) and IGF-binding protei... |
15288949 | Large-scale homogeneous molecular templates for femtosecond time-resolved studies of the guest-host interaction. | Self-assembled monolayer films based on iodobenzoyloxy-functionalized resorc[4]arenes were prepared on gold substrates to serve as model systems for future time-resolved studies of molecular recognition, a mechanism of outstanding importance in bioorganic systems. The film properties were tested using X-ray photoelectr... |
15288350 | In vitro and in vivo evaluation of a melamine dendrimer as a vehicle for drug delivery. | Cell-based and acute and subchronic in vivo toxicity profiles of a dendrimer based on melamine reveal that this class of molecules warrants additional study as vehicles for drug delivery. In cell culture, a substantial decrease in viability was observed at 0.1 mg/mL. For the acute studies, mice were administered 2.5, 1... |
15288339 | Nasal insulin delivery in the chitosan solution: in vitro and in vivo studies. | The effects of chitosan concentrations, osmolarity, medium and absorption enhancers in the chitosan solution on nasal insulin delivery were studied in vitro and in vivo. The penetration of insulin through the mucosa of rabbit nasal septum was investigated by measuring the transmucosal flux in vitro, while the nasal abs... |
15290714 | Multiplexed, particle-based detection of DNA using flow cytometry with 3DNA dendrimers for signal amplification. | <h4>Background</h4>Complex mixtures of DNA may be found in environmental and medical samples. There is a need for techniques that can measure low concentrations of target DNAs. For a multiplexed, flow cytometric assay, we show that the signal-to-noise ratio for fluorescence detection may be increased with the use of 3D... |
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