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12719415 | Covalent and non-covalent interactions of betaig-h3 with collagen VI. Beta ig-h3 is covalently attached to the amino-terminal region of collagen VI in tissue microfibrils. | Transforming growth factor-beta induced gene-h3 (betaig-h3) was found to co-purify with collagen VI microfibrils, extracted from developing fetal ligament, after equilibrium density gradient centrifugation under both nondenaturing and denaturing conditions. Analysis of the collagen VI fraction from the non-denaturing g... |
12716892 | CD98 and intracellular adhesion molecule I regulate the activity of amino acid transporter LAT-2 in polarized intestinal epithelia. | We have previously shown that the heterodimer CD98/LAT-2 (LAT-2: amino acid transporter) is expressed in the basolateral membrane of intestinal epithelia and is associated with beta1 integrin (Merlin, D., Sitaraman, S., Liu, X., Easterburn, K., Sun, J., Kucharzik, T., Lewis, B., and Madara, J. L. (2001) J. Biol. Chem. ... |
12743405 | The host-guest complex between cone-25,26:27,28-bis(methylenedioxy)calix[4]arene and dichloromethane. | The title compound, 25,26:27,28-bis(methylenedioxy)pentacyclo[19.3.1.1(3,7).1(9,13).1(15,19)]octacosa-1(25)3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene dichloromethane solvate, C(30)H(24)O(4).CH(2)Cl(2), possesses crystallographic twofold symmetry in both components. The calixarene shows a pinched cone conformati... |
12704242 | Non-self recognition, transcriptional reprogramming, and secondary metabolite accumulation during plant/pathogen interactions. | Disease resistance of plants involves two distinct forms of chemical communication with the pathogen: recognition and defense. Both are essential components of a highly complex, multifaceted defense response, which begins with non-self recognition through the perception of pathogen-derived signal molecules and results ... |
12732056 | Capillary force on a nanoscale tip in dip-pen nanolithography. | Monte Carlo simulation has been used to characterize the capillary force due to the condensation of a liquid meniscus between a tip with a nanoscale asperity and a flat surface. To consider both hydrophobic and hydrophilic molecules coating the tip as a model of dip-pen nanolithography, tips with various wettabilities ... |
12700355 | The role of side-chain interactions in the early steps of aggregation: Molecular dynamics simulations of an amyloid-forming peptide from the yeast prion Sup35. | Understanding the early steps of aggregation at atomic detail might be crucial for the rational design of therapeutics preventing diseases associated with amyloid deposits. In this paper, aggregation of the heptapeptide GNNQQNY, from the N-terminal prion-determining domain of the yeast protein Sup35, was studied by 20 ... |
12700244 | Design and characterization of a hybrid miniprotein that specifically inhibits porcine pancreatic elastase. | Studying protease/peptide inhibitor interactions is a useful tool for understanding molecular recognition in general and is particularly relevant for the rational design of inhibitors with therapeutic potential. An inhibitory peptide (PMTLEYR) derived from the third domain of turkey ovomucoid inhibitor and optimized fo... |
12700344 | The role of the ABCA1 transporter and cholesterol efflux in familial hypoalphalipoproteinemia. | Defects in the gene encoding for the ATP binding cassette (ABC) transporter A1 (ABCA1) were shown to be one of the genetic causes for familial hypoalphalipoproteinemia (FHA). We investigated the role of ABCA1-mediated cholesterol efflux in Dutch subjects suffering from FHA. Eighty-eight subjects (mean HDL cholesterol l... |
12697905 | Simulating disorder-order transitions in molecular recognition of unstructured proteins: where folding meets binding. | A microscopic study of functional disorder-order folding transitions coupled to binding is performed for the p27 protein, which derives a kinetic advantage from the intrinsically disordered unbound form on binding with the phosphorylated cyclin A-cyclin-dependent kinase 2 (Cdk2) complex. Hierarchy of structural loss du... |
12695858 | Adenocarcinoma cells exposed in vitro to Navelbine or Taxol increase Ep-CAM expression through a novel mechanism. | Ep-CAM antigen expression was shown to vary by phase across the cell cycle. Following pretreatment of various adenocarcinoma cells in culture with clinically relevant concentrations of vinorelbine tartrate (Navelbine) or paclitaxel (Taxol), cell surface expression of Ep-CAM antigen increased by two- to ten-fold compare... |
12692305 | Band 3 is a host receptor binding merozoite surface protein 1 during the Plasmodium falciparum invasion of erythrocytes. | We report the molecular identification of a sialic acid-independent host-parasite interaction in the Plasmodium falciparum malaria parasite invasion of RBCs. Two nonglycosylated exofacial regions of human band 3 in the RBC membrane were identified as a crucial host receptor binding the C-terminal processing products of... |
12682068 | How FMN binds to anabaena apoflavodoxin: a hydrophobic encounter at an open binding site. | Molecular recognition begins when two molecules approach and establish interactions of certain strength. The mechanisms of molecular recognition reactions between biological molecules are not well known, and few systems have been analyzed in detail. We investigate here the reaction between an apoprotein and its physiol... |
12682215 | Distinct recognition of substrates by the human and Drosophila serotonin transporters. | The human and Drosophila serotonin transporters (hSERT and dSERT, respectively) were used to explore differences in substrate properties. hSERT and dSERT showed similar Km values for 5-hydroxytryptamine (5-HT; serotonin) transport (1.2 and 0.9 micro M, respectively), suggesting similar recognition of 5-HT by the two sp... |
12682040 | Expression of the molecular chaperone Hsp70 in detergent-resistant microdomains correlates with its membrane delivery and release. | Accumulating evidence suggests that some heat shock proteins (Hsps), in particular the 72-kDa inducible Hsp70, associate to the cell membrane and might be secreted through an unknown mechanism to exert important functions in the immune response and signal transduction. We speculated that specialized structures named li... |
12697055 | Ebola virus infection inversely correlates with the overall expression levels of promyelocytic leukaemia (PML) protein in cultured cells. | <h4>Background</h4>Ebola virus causes severe, often fatal hemorrhagic fever in humans. The mechanism of escape from cellular anti-viral mechanisms is not yet fully understood. The promyelocytic leukaemia (PML) associated nuclear body is part of the interferon inducible cellular defense system. Several RNA viruses have ... |
12857857 | Transcytotic efflux from early endosomes is dependent on cholesterol and glycosphingolipids in polarized hepatic cells. | We examined the role that lipid rafts play in regulating apical protein trafficking in polarized hepatic cells. Rafts are postulated to form in the trans-Golgi network where they recruit newly synthesized apical residents and mediate their direct transport to the apical plasma membrane. In hepatocytes, single transmemb... |
12679333 | Concerted folding and binding of a flexible colicin domain to its periplasmic receptor TolA. | Compared with folded structures, natively unfolded protein domains are over-represented in protein-protein and protein-DNA interactions. Such domains are common features of all colicins and are required for their translocation across the outer membrane of the target Escherichia coli cell. All of these domains bind to a... |
12677339 | Epitope-targeted proteome analysis: towards a large-scale automated protein-protein-interaction mapping utilizing synthetic peptide arrays. | We describe the development of a process for the genome-wide mapping of interactions between protein domains and peptide ligands entirely based on high-throughput biochip technologies. A phage library displaying protein domains from a randomly fragmented and cloned cDNA library will be "panned" on an array of synthetic... |
12672964 | Conducting nanowires built by controlled self-assembly of amyloid fibers and selective metal deposition. | Recent research in the field of nanometer-scale electronics has focused on the operating principles of small-scale devices and schemes to realize useful circuits. In contrast to established "top-down" fabrication techniques, molecular self-assembly is emerging as a "bottom-up" approach for fabricating nanostructured ma... |
35799977 | Engineering of A<sub>3</sub> Adenosine and P2Y Nucleotide Receptors and Their Ligands. | Modification of the ribose moiety of nucleotides and nucleosides has provided new insights into structural and conformational requirements for ligands at P2Y nucleotide receptors and at adenosine receptors (ARs). Methanocarba derivatives (containing a rigid bicyclic ring system in place of ribose) of adenosine, ATP, AD... |
15621863 | Human salivary peptides derived from histatins. | Human saliva from a healthy donor was subjected to fractionation by gel chromatography and six pools were collected and analysed by MALDI-TOF-MS and HPLC-ESI-MS. Three peptides, corresponding to 888.3, 687.3, and 524.1 amu and SNYLYDN, YLYDN, and LYDN sequences (determined by automated Edman sequencing), were isolated ... |
12725864 | Crystal structure and molecular modeling of 17-DMAG in complex with human Hsp90. | Hsp90 is an attractive chemotherapeutic target because it chaperones the folding of proteins found in multiple signal transduction pathways. We describe the 1.75 A resolution crystal structure of human Hsp90 alpha (residues 9-236) complexed with 17-desmethoxy-17-N,N-dimethylaminoethylamino-geldanamycin (17-DMAG). The s... |
12746058 | Minoxidil-containing dosage forms: skin retention and after-rinsing hair-growth promotion. | Three kinds of topical dosage forms of minoxidil (MXD), namely vesicles, double emulsions, and an inclusion complex with hydoxypropyl-beta-cyclodextrin (HP-beta-CD), were prepared. The skin retention of MXD in the preparations was evaluated in vitro using hairless mouse skins. After applying the preparations onto the s... |
12744348 | A new type of three-dimensional framework constructed from dodecanuclear cadmium(II) macrocycles. | A new type of three-dimensional framework based on dodecanuclear Cd(II) macrocycles [[Cd2(dpa)(pya)]6(pya)6(dpe)3]n (1) (H2dpa = diphenic acid; Hpya = isonicotinic acid, dpe = 1,2-di(4-pyridyl)ethylene) was prepared by the hydrothermal reaction and in situ synthesis of pya from dpe precursor. |
12744342 | A substituted triaza crown ether as a binding site in DNA conjugates. | Synthesis of an asymmetrically substituted triaza crown ether, its incorporation into the 3'-end and 5'-end of ninemer oligonucleotides, and the influence of various alkanediamine ligands on duplex thermostabilities are reported. |
12744338 | Water-soluble supramolecular bowls formed by intra-clipping of resorcin[4]arene-based ligands with Pd(II) ions. | Bowl-shaped superstructures have been constructed by intra-clipping of resorcin[4]arene derivatives with two equivalents of (en)Pd(NO3)2 in water. The binding phenomena of the aromatic carboxylates were proven to be both enthalpically and entropically favoured. |
12744332 | Water solubilization, determination of the number of different types of single-wall carbon nanotubes and their partial separation with respect to diameters by complexation with eta-cyclodextrin. | Complexation of single-wall carbon nanotubes with 12-membered cyclodextrins enables not only their solubilization in water but also their partial separation with respect to diameters and determination of the number of nanotube types on the basis of NMR spectra. |
12744313 | C-c bond formation through oxidatively induced elimination of platinum complexes--a novel approach towards conjugated macrocycles. | A novel and effective method for the synthesis of conjugated macrocycles is described. By the self-assembly of conveniently accessible building blocks to a metalla-macrocycle, and subsequent C-C bond formation through elimination of transition metal units, the strained cyclodimeric terthiophene-diyne 4 -as a precursor ... |
12740116 | AMPA receptor trafficking and long-term potentiation. | Activity-dependent changes in synaptic function are believed to underlie the formation of memories. A prominent example is long-term potentiation (LTP), whose mechanisms have been the subject of considerable scrutiny over the past few decades. I review studies from our laboratory that support a critical role for AMPA r... |
12740112 | Active dendrites, potassium channels and synaptic plasticity. | The dendrites of CA1 pyramidal neurons in the hippocampus express numerous types of voltage-gated ion channel, but the distributions or densities of many of these channels are very non-uniform. Sodium channels in the dendrites are responsible for action potential (AP) propagation from the axon into the dendrites (back-... |
12739776 | Effective inhibition of mannitol crystallization in frozen solutions by sodium chloride. | <h4>Purpose</h4>The purpose of this work was to study the possibility of preventing mannitol crystallization in frozen solutions by using pharmaceutically acceptable additives.<h4>Methods</h4>Differential scanning calorimetry (DSC) and low-temperature X-ray diffractometry (LTXRD) were used to characterize the effect of... |
12739662 | Self-assembly of a ferrocene-substituted porphyrin capable of electrochemically sensing neutral molecules via a "tail on-tail off" process. | The supramolecular assembly of a ferrocene-porphyrin conjugate allowed ferrocene-based electrochemical sensing of the metalloporphyrin axial coordination via a "tail on-tail off" binding process. |
12739655 | Hydrogen-bonding based multilayer assemblies by self-deposition of dendrimer. | We reported on hydrogen-bonding directed Layer-by-Layer assemblies by self-deposition of a kind of dendrimer bearing carboxyl groups on its periphery that act as hydrogen bonding donor as well as hydrogen bonding acceptor. |
12739654 | Microporous niobium phosphates and catalytic properties prepared by a supramolecular templating mechanism. | Microporous hexagonal niobium phosphate synthesized using neutral surfactants of molecular length, C6 to C10 hydrocarbons, by a supramolecular templating mechanism (S0I0) possesses strong hydrophilic character, which leads to high selectivity for catechol formation (95.3%) in the presence of protic solvent (MeOH) in th... |
12739649 | First example of a Sn-C bond cleaved product in the reaction of Ph3SnOSnPh3 with carboxylic acids. 3D-supramolecular network formation in the X-ray crystal structure of [Ph2Sn(OH)OC(O)(Rf)]2, Rf = 2,4,6-(CF3)3C6H2. | A 1:2 reaction of Ph3SnOSnPh3 1 with RfCOOH 2 leads to the formation of [Ph2Sn(OH)OC(O)(Rf)]2 3, by means of a facile Sn-C bond cleavage process. |
12739631 | The structure of a self-assembled calixarene aqua-channel system. | The crystal structure of the complex 12.calix-[4]-arene dihydroxyphosphonic acid, 12.propane diammonium, 12.ethanol and 40.water molecules is based on dimeric units of the calix, assembled via trigonal units into a hexameric tube of 15 A radius and 16 A depth, further assemby via spanning propane diammonium cations and... |
12739627 | Shape-persistent arylene ethynylene macrocycles: syntheses and supramolecular chemistry. | This article describes recent developments in the synthesis of macrocycles having rigid, monocyclic skeletons composed of arylene and ethynylene units and the studies on their self-assembling behavior. |
12732315 | Plant cell factories and mucosal vaccines. | Many advances continue to be made in the field of plant-derived vaccines. Plants have been shown capable of expressing a multicomponent vaccine that when orally delivered induces a T-helper cell subset 1 response and enables passive immunization. Furthermore, a plant-derived vaccine has been shown to protect against ch... |
12732087 | Clinical effects of percutaneous cardiopulmonary support in severe heart failure: early results and analysis of complications. | Between January 1993 and December 2001, we employed percutaneous cardiopulmonary support (PCPS) in 35 patients. PCPS was used for postcardiotomy in 25 of these patients who could not be weaned from cardiopulmonary bypass (CPB) because of severe cardiogenic shock. In the other 10 patients, PCPS was used for a non-surgic... |
12731850 | Resolving the unresolved complex mixture in petroleum-contaminated sediments. | Comprehensive two-dimensional gas chromatography (GC x GC) was used to investigate the chemical composition of the unresolved complex mixture (UCM) of hydrocarbons in petroleum-contaminated marine sediments. The UCM hydrocarbons were extracted and separated with silica and silver-impregnated silica gel chromatography t... |
12727517 | Protein-protein unbinding induced by force: single-molecule studies. | Experiments in which two specifically interacting protein molecules are dissociated by external force have yielded new insights into mechanisms involved in cell adhesion, leukocyte rolling, regulation of integrin activity, antigen-antibody interactions and other protein-mediated reactions contingent upon molecular reco... |
12725411 | Crystal structure of (5,14-methyl-7,12-dimethyl-1,4,8,11-tetraazadiiminecyclotetradecylene-N,N',N'',N''')nickel(II) bis(diisopropyldithiophosphate) complex. | The macrocyclic tetradentate Ni(II) compound was obtained in a reaction and determined by X-ray diffraction. The crystal structure shows that the molecule is centrosymmetric, and Ni atom located in a square planar coordination environment. The two [(iPrO)2PS2]- anions are outside the macrocycle complex to balance. The ... |
12721100 | Extracellular nucleotides induce vasodilatation in human arteries via prostaglandins, nitric oxide and endothelium-derived hyperpolarising factor. | 1. The present study was aimed at examining P2 receptor-mediated vasodilatation in human vessels. The isometric tension was recorded in isolated segments of the human left internal mammary artery branches precontracted with 1 microM noradrenaline. 2. Endothelial denudation abolished the dilator responses. 3. The select... |
12718882 | Structural basis for the molecular recognition between human splicing factors U2AF65 and SF1/mBBP. | The essential splicing factors SF1 and U2AF play an important role in the recognition of the pre-mRNA 3' splice site during early spliceosome assembly. The structure of the C-terminal RRM (RRM3) of human U2AF(65) complexed to an N-terminal peptide of SF1 reveals an extended negatively charged helix A and an additional ... |
12716933 | Lipid rafts in the maintenance of synapses, dendritic spines, and surface AMPA receptor stability. | Cholesterol/sphingolipid microdomains (lipid rafts) in the membrane are involved in protein trafficking, formation of signaling complexes, and regulation of actin cytoskeleton. Here, we show that lipid rafts exist abundantly in dendrites of cultured hippocampal neurons, in which they are associated with several postsyn... |
12716924 | Ligand-dependent recruitment of the ErbB4 signaling complex into neuronal lipid rafts. | Neuregulin (NRG) regulates synapse formation and synaptic plasticity, but little is known about the regulation of NRG signaling at synapses. Here we show that the NRG receptor ErbB4 was localized in anatomically defined postsynaptic densities in the brain. In cultured cortical neurons, ErbB4 was recruited to the neuron... |
12717753 | Multiple lithium exchange under lithium cationization of cyclodextrins. | Multiple lithium exchange is observed during electrospray ionization of alpha-, beta- and gamma-cyclodextrins from aqueous methanolic solution containing LiOH. Apart from [M + Li](+) and [M + nLi - (n - 1)H](+) ions, abundant multiply lithiated doubly charged ions corresponding to [M + nLi - (n - 2)H](2+) ions were obs... |
12714741 | Casting metal nanowires within discrete self-assembled peptide nanotubes. | Tubular nanostructures are suggested to have a wide range of applications in nanotechnology. We report our observation of the self-assembly of a very short peptide, the Alzheimer's beta-amyloid diphenylalanine structural motif, into discrete and stiff nanotubes. Reduction of ionic silver within the nanotubes, followed ... |
12713424 | Sorocein L and sorocein M: two Diels-Alder type adducts from Sorocea ilicifolia. | Two new Diels-Alder type adducts, named sorocein L (1) and sorocein M (2), together with the known kuwanon J and mulberrofuran O, were isolated from the methanolic extract of the roots of Sorocea ilicifolia. Sorocein L shows the same substitution pattern of sorocein M and corresponds to its ketalized derivative. |
12713040 | An equilibrium partitioning model for predicting response to host-guest complexation in electrospray ionization mass spectrometry. | While electrospray ionization mass spectrometry (ESI-MS) has become a powerful technique for analyzing many types of host-guest complexation, questions remain as to just how accurately ion abundances generated by ESI reflect the true distribution of species at equilibrium in solution. To better understand this relation... |
12709666 | The structural abnormality of myeloma immunoglobulins tested by Congo red binding. | <h4>Background</h4>Frequently observed structural deviations of myeloma-derived immunoglobulins affect polypeptide chain packing and domain stability, enhancing their tendency to aggregate, with all the clinical consequences. Congo red complexation with myeloma immunoglobulins is proposed in this work as a general test... |
12708871 | Coordination-driven self-assembly of predesigned supramolecular triangles. | The design and self-assembly of three supramolecular triangles is described. A novel 60 degrees corner unit directs the exclusive formation of triangular assemblies that are not in detectable equilibrium with other macrocycles. The resulting triangles have sides ranging from 2.7 to 3.5 nm in length and molecular masses... |
12708867 | Self-assembly of a tripodal pseudorotaxane on the surface of a titanium dioxide nanoparticle. | This paper describes the self-assembly of a heterosupramolecular system consisting of a tripodal viologen, adsorbed at the surface of a titanium dioxide nanoparticle, that threads a crown ether to form a pseudorotaxane. The viologen, a 1,1'-disubstituted-4,4'-bipyridinium salt with a rigid tripodal anchor group, has be... |
12708859 | Evaluation of multivalent dendrimers based on melamine: kinetics of thiol-disulfide exchange depends on the structure of the dendrimer. | The rate of thiol-disulfide exchange of dansyl groups mediated by dithiothreitol depends on the structure of the dendrimer. In general, the rate of exchange decreases as the size of the dendrimer increases. Dendrimers with disulfides attached near the core undergo exchange more slowly than dendrimers with disulfides ne... |
12708858 | Formation process of cyclodextrin necklace-analysis of hydrogen bonding on a molecular level. | By means of scanning tunneling microscopy (STM), we succeeded for the first time in the quantitative analysis of the intramolecular conformation of a supramolecule, cyclodextrin (CyD) necklace, driven by hydrogen bonding. Contrary to the current model, based on macroscopic analyses, which indicates that all CyDs are ar... |
12708855 | Comparison of nanotube structures constructed from alpha-, beta-, and gamma-cyclodextrins by potential-controlled adsorption. | "Nanotube" structures of the alpha-, beta-, and gamma-cyclodextrins (CyD's), which are similar to that of CyD-polyrotaxane, were constructed by potential-controlled adsorption onto Au(111) surfaces in sodium perchlorate solution without a threaded polymer. CyD molecules adsorbed randomly on bare Au(111) surfaces withou... |
12708832 | Self-assembly of microporous manganese oxide octahedral molecular sieve hexagonal flakes into mesoporous hollow nanospheres. | Manganese oxide hollow nanospheres were prepared using a straightforward, template-free synthesis. The resulting material was mesoporous, crystalline, and of uniform diameter. The nanospheres were characterized by XRD, HR-SEM, and HR-TEM, and pore size distributions were calculated from nitrogen desorption. Unlike prev... |
12707299 | Topological requirements and signaling properties of T cell-activating, anti-CD28 antibody superagonists. | Full activation of naive T cells requires both engagement of the T cell antigen receptor (TCR; signal 1) and costimulatory signaling by CD28 (signal 2). We previously identified two types of rat CD28-specific monoclonal antibodies (mAbs): "conventional," TCR signaling-dependent costimulatory mAbs and "superagonistic" m... |
12706832 | In situ observation of mobility and anchoring of PKCbetaI in plasma membrane. | We employed fluorescence correlation spectroscopy (FCS) to analyze the characteristics of biomolecules in living cells. Protein kinase C (PKC) changes its subcellular localization from cytosol to the plasma membrane by its ligand. Using FCS, we found PKCbetaI labeled with enhanced green fluorescent protein freely diffu... |
12706817 | The fully conserved Asp residue in conserved sequence region I of the alpha-amylase family is crucial for the catalytic site architecture and activity. | The alpha-amylase family is a large group of starch processing enzymes [Svensson, B. (1994) Plant Mol. Biol. 25, 141-157]. It is characterized by four short sequence motifs that contain the seven fully conserved amino acid residues in this family: two catalytic carboxylic acid residues and four substrate binding residu... |
12705605 | Interfacing the orbitrap mass analyzer to an electrospray ion source. | The orbitrap mass analyzer employs the trapping of pulsed ion beams in an electrostatic quadro-logarithmic field. This field is created between an axial central electrode and a coaxial outer electrode. Stable ion trajectories combine rotation around the central electrode with harmonic oscillations along it. The frequen... |
12705597 | Medium effect (transfer activity coefficient) of methanol and acetonitrile on beta-cyclodextrin/benzoate complexation in capillary zone electrophoresis. | Association constants, Kc, were derived from the electrophoretic mobilities of the anionic solutes (seven benzoates with hydroxy or chloro substituents) by capillary zone electrophoresis in different solvent systems, consisting of binary mixtures of water with up to 20% (v/v) methanol or acetonitrile, respectively. The... |
12702869 | On the origins of morphological complexity in block copolymer surfactants. | Amphiphilic compounds such as lipids and surfactants are fundamental building blocks of soft matter. We describe experiments with poly(1,2-butadiene-b-ethylene oxide) (PB-PEO) diblock copolymers, which form Y-junctions and three-dimensional networks in water at weight fractions of PEOintermediate to those associated wi... |
12702675 | Mode of selection and experimental evolution of antifungal drug resistance in Saccharomyces cerevisiae. | We show that mode of selection, degree of dominance of mutations, and ploidy are determining factors in the evolution of resistance to the antifungal drug fluconazole in yeast. In experiment 1, yeast populations were subjected to a stepwise increase in fluconazole concentration over 400 generations. Under this regimen,... |
12702673 | Chromosomal lesion suppression and removal in Escherichia coli via linear DNA degradation. | RecBCD is a DNA helicase/exonuclease implicated in degradation of foreign linear DNA and in RecA-dependent recombinational repair of chromosomal lesions in E. coli. The low viability of recA recBC mutants vs. recA mutants indicates the existence of RecA-independent roles for RecBCD. To distinguish among possible RecA-i... |
12699821 | Nanostructured platinum-lipid bilayer composite as biosensor. | The present work describes the preparation of supported bilayer lipid membrane (s-BLM) doped with metal nanoparticles for the design of biosensors. Platinum (Pt) nanoparticles were deposited through s-BLM to build a hybrid device of nanoscale electrode array by potential cycling in 1 mM K(2)PtCl(6) solution containing ... |
12697743 | Chemokine receptor mutant CX3CR1-M280 has impaired adhesive function and correlates with protection from cardiovascular disease in humans. | The chemokine receptor CX3CR1 is a proinflammatory leukocyte receptor specific for the chemokine fractalkine (FKN or CX3CL1). In two retrospective studies, CX3CR1 has been implicated in the pathogenesis of atherosclerotic cardiovascular disease (CVD) based on statistical association of a common receptor variant named C... |
12696913 | A theoretical study of the large Hg-Hg spin-spin coupling constants in Hg(2)(2+), Hg(3)(2+), and Hg(2)(2+)-crown ether complexes. | Nuclear spin-spin coupling constants (1)J(Hg-Hg) in the systems Hg(2)(2+) and Hg(3)(2+) represent the largest coupling constants so far observed in NMR experiments. We have performed a computational study on these ions, on Hg(2)(2+) complexes with 18-crown-6 and 15-crown-5, and on Hg(3)(2+) with solvent molecules and c... |
12696909 | Electrostatic bubbles and supramolecular assistance of photosensitization by carboxylated Ru(II) complexes. | The paper examines the supramolecular effects at play during photosensitization by carboxylated Ru(II) sensitizers, both by experiment and by modeling. Experimentally, twelve Ru(II) complexes of pyrazolylpyridine and polypyridine ligands, including two benchmark complexes and two new species, were assessed as photosens... |
12696908 | Porphyrin and tetrabenzoporphyrin dendrimers: tunable membrane-impermeable fluorescent pH nanosensors. | The pH dependencies of the UV-vis and fluorescent spectra of new water-soluble dendritic porphyrins and tetrabenzoporphyrins were studied. Because of extended pi-conjugation and nonplanar distortion, the absorption and the emission bands of tetraaryltetrabenzoporphyrins (Ar(4)TBP) are red-shifted and do not overlap wit... |
12696902 | Self-sorting: the exception or the rule? | In this paper, we pose the question of whether self-sorting in designed systems is exceptional behavior or whether it is likely to become a more general phenomenon governing molecular recognition and self-assembly. To address this question we prepared a mixture comprising two of Davis' self-assembled ionophores, Rebek'... |
12696891 | Selective recognition of G-qQuadruplex telomeric DNA by a bis(quinacridine) macrocycle. | The interaction of G-quadruplex DNA with the macrocyclic compound BOQ1, which possesses two dibenzophenanthroline (quinacridine) subunits, has been investigated by a variety of methods. The oligonucleotide 5'-A(GGGT(2)A)(3)G(3), which mimics the human telomeric repeat sequence and forms an intramolecular quadruplex, wa... |
12698446 | Stabilizing bolaform amphiphile interfacial assemblies by introducing mesogenic groups. | We describe the synthesis and characterization of the mesogen-bearing bolaform amphiphile 4,4'-dihydroxybiphenylbis(11-pyridinium-N-yl-undecanoic ester) dibromide (BP-10) and its solid/liquid interfacial self-assembly. Cylindrical micelles are directly observed by atomic force microscopy (AFM) at the interface between ... |
12698437 | Spontaneously organizing metal connectors as supramolecular structure directors of two- and three-dimensional organometallic assemblies. | The supramolecular interplay of Me(3)Sn(+) and [M(CN)(2n)](n-) ions (n=3 and 4) with either 4,4'-bipyridine (bpy), trans-bis(4-pyridyl)ethene (bpe) or 4cyanopyridine (cpy) in the presence of H(2)O has been investigated for the first time. Crystal structures of the six novel assemblies: [(Me(3)Sn)(4)Mo(IV)(CN)(8).2 H(2)... |
12698434 | Modulation of a supramolecular bowl and pot by changing solvent systems and/or metal/ligand ratios. | A resorcin[4]arene-based ligand 2 a with four pyrimidine substituents at the upper rim was synthesized, and the generation of different metal-mediated superstructures from the same ligand and metal ions utilizing the unfavorable incorporation of the third and fourth Pd(II) ions to ligand 2 a was investigated. The supra... |
12698477 | Anion-templated synthesis. | In contrast to the well-studied templating properties of cationic and neutral species there are relatively few examples of anion-templated syntheses. This is attributed to some of the intrinsic properties of anions such as their diffuse nature, pH sensitivity, and their relative high solvation free energies. However, t... |
12695024 | Action of pyrethrum-based formulations against grain weevils. | Pyrethrum extract, containing six insecticidal esters, has a long history of successful application in the control of stored products. Its low environmental hazard makes it an ideal pesticide for outdoor pre-harvest treatment. However the disadvantage of its low light stability then becomes apparent. This drawback can ... |
12695014 | Solubility enhancement of low soluble biologically active compounds--temperature and cosolvent dependent inclusion complexation. | The solubility enhancement of biologically active compounds was analysed in dependence on temperature, amount of cosolvents and on beta-cyclodextrin as complexing agent. The analysis was performed for the systemic fungicide triflumizole (TF), a poorly water soluble compound. All parameters lead to an improvement of the... |
12695009 | Molecular dynamics simulations of beta-cyclodextrin in aqueous solution. | Molecular dynamics (MD) simulations of beta-cyclodextrin (beta-CD) have been carried out in aqueous solution at 300 K over a period of about 200 ps using Tripos force field. The atomic trajectories obtained by these simulations have been analysed by means of the occurrence of hydrogen bonds. The MD simulations lead to ... |
12694880 | Multimodal molecular encapsulation of nicardipine hydrochloride by beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin and triacetyl-beta-cyclodextrin in solution. Structural studies by 1H NMR and ROESY experiments. | Proton nuclear magnetic resonance spectroscopy (1H NMR), which has become an important tool for in vitro study of cyclodextrin (CD) complexes, was used to study and structurally characterize the inclusion compounds formed in solution between nicardipine hydrochloride (NC) and beta-cyclodextrin (betaCD), hydroxypropyl-b... |
12694201 | The GxxxG motif of the transmembrane domain of subunit e is involved in the dimerization/oligomerization of the yeast ATP synthase complex in the mitochondrial membrane. | A conserved putative dimerization GxxxG motif located in the unique membrane-spanning segment of the ATP synthase subunit e was altered in yeast both by insertion of an alanine residue and by replacement of glycine by leucine residues. These alterations led to the loss of subunit g and the loss of dimeric and oligomeri... |
12693957 | Assembly of retinal rod or cone Na(+)/Ca(2+)-K(+) exchanger oligomers with cGMP-gated channel subunits as probed with heterologously expressed cDNAs. | Proper control of intracellular free Ca(2+) is thought to involve subsets of proteins that co-localize to mediate coordinated Ca(2+) entry and Ca(2+) extrusion. The outer segments of vertebrate rod and cone photoreceptors present one example: Ca(2+) influx is exclusively mediated via cGMP-gated channels (CNG), whereas ... |
12693922 | Peptido- and glycocalixarenes: playing with hydrogen bonds around hydrophobic cavities. | This Account reviews the synthesis, conformations, and supramolecular properties of calixarenes endowed with alpha-amino acids or peptides (Peptidocalixarenes) and carbohydrate units (Glycocalixarenes), with a major emphasis on calix[4]arenes functionalized on the aromatic nuclei (upper or wide rim). Most properties of... |
12691582 | New high-dimensional networks based on polyoxometalate and crown ether building blocks. | Three novel supramolecular assemblies constructed from polyoxometalate and crown ether building blocks, [(DB18C6)Na(H(2)O)(1.5)](2)Mo(6)O(19).CH(3)CN, 1, and [(Na(DB18C6)(H(2)O)(2))(3)(H(2)O)(2)]XMo(12)O(40).6DMF.CH(3)CN (X = P, 2, and As, 3; DB18C6 = dibenzo-18-crown-6; DMF = N,N-dimethylfomamide), have been synthesiz... |
12691580 | A new type of anionic metal dicyanamide extended networks through [Cu(N4-macrocycle)]2+ cation templation. Structure and magnetic properties. | Two isomorphous anionic metal dicyanamide extended systems [Cu(pCTH)][M(dca)(4)] (M = Mn(II), Co(II); dca = dicyanamide; pCTH = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetrazacyclotetradecane-4,11-diene) have been prepared through [Cu(pCTH)](2+) templation and characterized by X-ray crystallography and magnetic measurements... |
12691576 | Synthesis and characterization of (octaaryltetraazaporphyrinato)indium(III) complexes for optical limiting. | The preparation of (octaaryltetraazaporphyrinato)indium(III) chlorides [aryl = phenyl (5a), p-tert-butylphenyl (6a), p-(trifluoromethyl)phenyl (7a), m-(trifluoromethyl)phenyl (8a)] and their reactions with aryl Grignard reagents XMgBr to give 5b-8b [X = p-(trifluoromethyl)phenyl] and 5c (R = 3,5-difluorophenyl) are des... |
12691575 | Li, Ti(III), and Ti(IV) trisamidotriazacyclononane complexes. Syntheses, reactivity, and structures. | The preparations of 1,4,7-(NHPhSiMe(2))(3)-1,4,7-triazacyclononane (H(3)N(3)-tacn) and its lithium and sodium derivatives are described. The X-ray structure of the THF adduct of the lithium derivative, Li(3)N(3)-tacn(THF)(2), shows that one of the macrocycle pendant arms is bent to allow the coordination of the its lit... |
12691557 | Heterodimetallic compounds assembled from ferrocenedicarboxylato and ferrocenecarboxylato ligands. | Heteropolynuclear organometallic compounds have been constructed by using two kinds of ferrocene-based ligands, 1,1'-ferrocenedicarboxylic acid (H(2)L(1)) and ferrocenecarboxylic acid (HL(2)). Reactions the ligand H(2)L(1) with copper(II) and nickel(II) salts, in the presence of pyridine, give a tetranuclear Cu(2)Fe(2)... |
12691550 | Crystal structure and magnetic properties of Gd2([18]crown-6)2(OH)2(CH3CN)2[Ni(dmit)2]4 complex having f- and pi-spins. | Crystal structure and magnetic properties of Gd(2)([18]crown-6)(2)(OH)(2)(CH(3)CN)(2)[Ni(dmit)(2)](2) (dmit(2)(-) = 2-thioxo-1,3-dithiole-4,5-dithiolate) are reported. Gd(3+) ions (S = (7)/(2)) were introduced into the pi-spin network of [Ni(dmit)(2)](-) (S = (1)/(2)) complex as a binuclear supramolecular cation, Gd(2)... |
12692627 | Recombinant tissue plasminogen activator for treatment of hepatic veno-occlusive disease following bone marrow transplantation in children: effectiveness and a scoring system for initiating treatment. | Hepatic veno-occlusive disease (HVOD) following bone marrow transplantation is potentially fatal. Criteria for diagnosis and starting treatment are mainly based on adult studies. Recombinant tissue plasminogen activator (rtPA) has been used with variable success. rtPA and heparin were given to 12 children (nine with im... |
12688730 | Thiol-disulfide exchange yields multivalent dendrimers of melamine. | [reaction: see text] Thiol-disulfide exchange can be used to prepare multivalent conjugates of a small molecule or octapeptide displayed on dendrimers based on melamine. Exchange of four or eight thiopyridyl groups by captopril occurs at room temperature in methanol almost quantitatively. Exchange using the peptide req... |
12690403 | Molecular nanosprings in spider capture-silk threads. | Spider capture silk is a natural material that outperforms almost any synthetic material in its combination of strength and elasticity. The structure of this remarkable material is still largely unknown, because spider-silk proteins have not been crystallized. Capture silk is the sticky spiral in the webs of orb-weavin... |
12690397 | Electrostatic self-assembly of macroscopic crystals using contact electrification. | Self-assembly of components larger than molecules into ordered arrays is an efficient way of preparing microstructured materials with interesting mechanical and optical properties. Although crystallization of identical particles or particles of different sizes or shapes can be readily achieved, the repertoire of method... |
12688788 | Synthesis and photoluminescent properties of 1,1'-binaphthyl-based chiral phenylenevinylene dendrimers. | New chiral, soluble binaphthyl derivatives that incorporate stilbenoid dendrons at the 6,6'-positions have been prepared. The synthesis of the new enantiopure dendrimers was performed in a convergent manner by Horner-Wadsworth-Emmons (HWE) reaction of the appropriately functionalized 1,1'-binaphthyl derivative (R)-1 an... |
12688787 | Enantiomerization study of some alpha-nitroketones by dynamic high-resolution gas chromatography. | The kinetics of the reversible enantiomer interconversion of 3-nitrobutan-2-one (1), 3-nitropentan-2-one (2), and 2-nitropentan-3-one (3) have been studied by dynamic high-resolution gas chromatography (DHRGC) by using a beta-cyclodextrin derivative chiral stationary phase; the process occurs via enolization of the ket... |
12686476 | Determination of carbon isotope ratios in amino acids, proteins, and oligosaccharides by inductively coupled plasma-mass spectrometry. | Carbon isotope ratios ((12)C/(13)C) are measured for aqueous solutions of tryptophan, myoglobin, and beta-cyclodextrin using C(+) ions from an inductively coupled plasma (ICP) and a prototype twin quadrupole mass spectrometer (MS). (13)C/(12)C ratios can be determined with a relative standard deviation (RSD) of approxi... |
12683827 | Single complexation force of 18-crown-6 with ammonium ion evaluated by atomic force microscopy. | The cation complexation force of 18-crown-6 has been measured in ethanol by means of atomic force microscopy using probe tips and mica substrates modified chemically with 18-crown-6 and ammonium ion, respectively. The specific complexation force was suppressed by free potassium ion in the measurement solution, indicati... |
12683824 | Using bifunctional polymers presenting vancomycin and fluorescein groups to direct anti-fluorescein antibodies to self-assembled monolayers presenting d-alanine-d-alanine groups. | This paper describes the synthesis of bifunctional polyacrylamides containing pendant vancomycin (Van) and fluorescein groups, and the use of these polymers to direct antibodies against fluorescein to self-assembled monolayers (SAMs) presenting d-alanine-d-alanine (dAdA) groups. These polymers bind biospecifically to t... |
12683823 | Supramolecular helical stacking of metallomesogens derived from enantiopure and racemic polycatenar oxazolines. | The present report undertakes a challenge of general interest in supramolecular chemistry: the achievement of helical organizations with controlled structure. To achieve this target we considered the possibility of inducing supramolecular chirality using molecules that were designed to organize into columnar mesophases... |
12683819 | Electron transfer between two silyl-substituted phenylene rings: EPR/ENDOR spectra, DFT calculations, and crystal structure of the one-electron reduction compound of a di(m-silylphenylenedisiloxane). | Reduction of a solution of octamethylcyclo-di(m-silylphenylenedisiloxane) 4 in THF on a potassium mirror leads to EPR/ENDOR spectra characterized by a large coupling (approximately 20 MHz) with two protons, similar to the spectra obtained after reduction of the m-disilylbenzene derivative 5, consistent with a localizat... |
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