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12506233 | 2-amino-4-(4-chlorophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile. | The supramolecular structure of the title compound, C(18)H(17)ClN(2)O(2), is determined by the intersection of two chains formed by N-H...O and N-H...N hydrogen bonds, forming a two-dimensional sheet. |
12562860 | Effects on apoB-100 secretion and bile acid synthesis by redirecting cholesterol efflux from HepG2 cells. | This study determined the effects of apoA-I, HDL3, or hydroxy-beta-cyclodextrin on apoB-100 secretion and bile acid synthesis by HepG2 cells. The principal observations were that: 1) ApoB-100 secretion into the medium was significantly less after the addition of any of the three agents. 2) Triglyceride mass was not sig... |
12486245 | Bidirectional synaptic plasticity in the cerebellum-like mammalian dorsal cochlear nucleus. | The dorsal cochlear nucleus integrates acoustic with multimodal sensory inputs from widespread areas of the brain. Multimodal inputs are brought to spiny dendrites of fusiform and cartwheel cells in the molecular layer by parallel fibers through synapses that are subject to long-term potentiation and long-term depressi... |
12486108 | The fibronectin-binding integrins alpha5beta1 and alphavbeta3 differentially modulate RhoA-GTP loading, organization of cell matrix adhesions, and fibronectin fibrillogenesis. | We have studied the formation of different types of cell matrix adhesions in cells that bind to fibronectin via either alpha5beta1 or alphavbeta3. In both cases, cell adhesion to fibronectin leads to a rapid decrease in RhoA activity. However, alpha5beta1 but not alphavbeta3 supports high levels of RhoA activity at lat... |
12482939 | Dynamic assembly of MinD into filament bundles modulated by ATP, phospholipids, and MinE. | Accurate positioning of the division septum at the equator of Escherichia coli cells requires a rapid oscillation of MinD ATPase between the polar halves of the cell membrane, together with the division inhibitor MinC, under MinE control. The mechanism underlying MinD oscillation remains poorly understood. Here, we dem... |
12482938 | Three mutations in sterol-sensing domain of SCAP block interaction with insig and render SREBP cleavage insensitive to sterols. | We report the isolation and characterization of a new line of mutant Chinese hamster ovary cells, designated SRD-5, that are resistant to 25HC, a potent suppressor of cleavage of sterol regulatory element-binding proteins (SREBPs) in mammalian cells. In SRD-5 cells, SREBPs are cleaved constitutively, generating transcr... |
12482878 | Essential role of caveolae in interleukin-6- and insulin-like growth factor I-triggered Akt-1-mediated survival of multiple myeloma cells. | Caveolae, specialized flask-shaped lipid rafts on the cell surface, are composed of cholesterol, sphingolipids, and structural proteins termed caveolins; functionally, these plasma membrane microdomains have been implicated in signal transduction and transmembrane transport. In the present study, we examined the role o... |
12481039 | Reduced sodium channel density, altered voltage dependence of inactivation, and increased susceptibility to seizures in mice lacking sodium channel beta 2-subunits. | Sodium channel beta-subunits modulate channel gating, assembly, and cell surface expression in heterologous cell systems. We generated beta2(-/-) mice to investigate the role of beta2 in control of sodium channel density, localization, and function in neurons in vivo. Measurements of [(3)H]saxitoxin (STX) binding showe... |
12481032 | Molecular conformation of a peptide fragment of transthyretin in an amyloid fibril. | The molecular conformation of peptide fragment 105-115 of transthyretin, TTR(105-115), previously shown to form amyloid fibrils in vitro, has been determined by magic-angle spinning solid-state NMR spectroscopy. 13C and 15N linewidth measurements indicate that TTR(105-115) forms a highly ordered structure with each ami... |
12937968 | Formulation and biopharmaceutical issues in the development of drug delivery systems for antiparasitic drugs. | The development of really new antiparasitic drugs to market level is a very rare event. A large number of lead structures have already been screened and discarded, the market is large but poor, and the administrative barriers are increasingly high and costly. Novel antiparasitics must not only be better, they must also... |
12477933 | Spin-dependent mechanism for diatomic ligand binding to heme. | The nature of diatomic ligand recombination in heme proteins is elucidated by using a Landau-Zener model for the electronic coupling in the recombination rate constant. The model is developed by means of explicit potential energy surfaces calculated by using density functional theory (DFT). The interaction of all possi... |
12506231 | (R)-(6,6'-Dihydroxybiphenyl-2,2'-diyl)bis(diphenylphosphine oxide) methanol solvate. | The title compound, C(36)H(28)O(4)P(2).CH(4)O, was synthesized directly from the methoxy analogue. The crystal structure shows that one OH group interacts with an O atom of a phosphine oxide group in an adjacent molecule, while the other OH group complexes with the methanol solvent molecule via intermolecular hydrogen ... |
12506229 | N6-furfuryladenine (kinetin) hydrochloride. | In the title compound, N(6)-furfuryladenin-3-ium chloride, C(10)H(10)N(5)O(+).Cl(-), the adenine moiety exists as the N3-protonated N7-H tautomer. The orientation of the N6 substituent (furfuryl moiety) is distal to the imidazole ring of the adenine base. The dihedral angle between the adenine plane and the furfuryl ri... |
12475894 | ADAM10-mediated cleavage of L1 adhesion molecule at the cell surface and in released membrane vesicles. | Cells can release membrane components in a soluble form and as membrane vesicles. L1, an important molecule for cell migration of neural and tumor cells, is released by membrane-proximal cleavage, and soluble L1 promotes cell migration. Release of L1 is enhanced by shedding inducers such as phorbol ester and pervanadat... |
12461176 | Consensus-derived structural determinants of the ankyrin repeat motif. | The ankyrin repeat is one of the most common, modular, protein-protein interaction motifs in nature. To understand the structural determinants of this family of proteins and extract the consensus information that defines the architecture of this motif, we have designed a series of idealized ankyrin repeat proteins cont... |
23105165 | Evidence for the Recognition of Non-Nucleotide Antagonists Within the Transmembrane Domains of the Human P2Y(1) Receptor. | Site-directed mutagenesis was used to search for amino acid residues of the human P2Y(1) receptor involved in the binding of the P2 receptor antagonists pyridoxal-5'-phosphate-6-azophenyl-2,4-disulfonate (PPADS), its analogue 6-(2'-chloro-phenylazo)-pyridoxal-α(5)-phosphate (MRS 2210), the suramin analogue 8-8'-[carbon... |
12458494 | Allosteric Binding of an Ag+ Ion to Cerium(IV) Bis-porphyrinates Enhances the Rotational Activity of Porphyrin Ligands. | A series of cerium(IV) bis-porphyrinate double-deckers [Ce(bbpp)(2)] (BBPP=5,15-bis(4-butoxyphenyl)porphyrin dianion), [Ce(tmpp)(2)] (TMPP=5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin dianion), [Ce(tfpp)(2)] (TFPP=5,10,15,20-tetrakis(4-fluorophenyl)porphyrin dianion), [Ce(tmcpp)(2)] (TMCPP=5,10,15,20-tetrakis(4-methox... |
14599352 | Development of a high-throughput scintillation proximity assay for the identification of C-domain translational initiation factor 2 inhibitors. | Translational initiation factor 2 (IF2) is the largest of the 3 factors required for translation initiation in prokaryotes and has been shown to be essential in Escherichia coli. It stimulates the binding of fMet-tRNA(f)(Met) to the 30S ribosomal subunit in the presence of GTP. The selectivity is achieved through speci... |
14550020 | Biotechnological applications of cyclodextrins. | Cyclodextrins (CDs) are a family of cyclic oligosaccharides that are composed of alpha-1,4-linked glucopyranose subunits. Cyclodextrins are produced from starch by enzymatic degradation. These macrocyclic carbohydrates with apolar internal cavities can form complexes with and solubilize many normally water-insoluble co... |
14550019 | Emerging biological materials through molecular self-assembly. | Understanding of new materials at the molecular level has become increasingly critical for a new generation of nanomaterials for nanotechnology, namely, the design, synthesis and fabrication of nanodevices at the molecular scale. New technology through molecular self-assembly as a fabrication tool will become tremendou... |
12908423 | DNA-directed magnetic network formations with ferromagnetic nanoparticles. | We formed a DNA network embedding ferromagnetic cobalt nanoparticles with a 12-nm diameter through a nanoscale self-assembly of DNA molecules on large-scale mica surfaces (12 mm x 12 mm); we then confirmed its structural characteristics with an atomic force microscope. Moreover, noncontact magnetic force microscope mea... |
12693055 | Coordination chemistry in the solid: evidence for coordination modes within hybrid materials different from those in solution. | Two routes of incorporation of europium(III) salts into cyclam-containing hybrid materials have been explored, to elucidate the coordination mode of EuIII in cyclam-containing hybrid materials in a study of the arrangement of cyclam moieties during the solgel process. They were 1) complexation of europium salts by N-te... |
12693037 | Allosteric binding of an Ag+ ion to cerium(IV) bis-porphyrinates enhances the rotational activity of porphyrin ligands. | A series of cerium(IV) bisporphyrinate double-deckers [Ce(bbpp)2] (BBPP = 5,15-bis(4-butoxyphenyl) porphyrin dianion), [Ce(tmpp)2] (TMPP = 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin dianion), [Ce(tfpp)2] (TFPP = 5,10,15,20-tetrakis(4-fluorophenyl)porphyrin dianion), [Ce(tmcpp)2] (TMCPP = 5,10,15,20-tetrakis(4-metho... |
12458492 | The bottom-up approach to molecular-level devices and machines. | The macroscopic concepts of a device and a machine can be extended to the molecular level. Molecular-level devices and machines are constructed by a bottom-up approach. The atom-by-atom bottom-up approach is unrealistic from the chemical viewpoint. The bottom-up approach molecule-by-molecule following the guidelines of... |
12628301 | Occurrence and structural characterization of versican-like proteoglycan in human vitreous. | Human vitreous gel is a special type of extracellular matrix, in which interpenetrating networks of collagen fibrils and hyaluronan are found. In this study, we report that apart from significant amounts of collagen, hyaluronan and sialylated glycoproteins, it was found that the human vitreous gel also contained low am... |
12619817 | The improvement of lipase secretion and stability by addition of inert compounds into Acinetobacter calcoaceticus cultures. | Acinetobacter calcoaceticus BD413 produces variable amounts of an exocellular lipase that becomes rapidly inactivated upon secretion. To achieve high yield and protect the enzyme, we assayed the addition of several inert compounds to cell-free supernatants, cell fractions, and whole cultures. Glass beads, poly(ethylene... |
12606811 | Extracellular signals and pancreatic beta-cell development: a brief review. | Cell lineage development is a finely tuned process of proliferation and differentiation, survival and apoptosis, that is regulated by numerous extracellular signals. Here we review some of the extracellular signals--including insoluble cell-cell and extracellular matrix-cell interactions, as well as soluble factors--th... |
12607602 | Appraisal of differentiation markers in urothelial cells. | The expression, subcellular localization, and supramolecular organization of structural and differentiation-related proteins were studied in differentiating superficial cells during regeneration of the rat urothelium. Cytokeratin 17 and epidermal growth factor receptor were expressed in undifferentiated cells, whereas ... |
12585679 | Beta-amyloid production, aggregation, and clearance as targets for therapy in Alzheimer's disease. | 1. Despite major efforts aimed at elucidating the molecular basis and physiopathology of Alzheimer's disease (AD), there is still no effective treatment available for this devastating disorder. The biological mechanisms underlying the development of AD are complex, as multiple factors appear to modulate (either positiv... |
12564799 | Identification of new homoterpene esters from Dufour's gland of the ponerine ant Gnamptogenys striatula. | Extracts of Dufour's gland of the ponerine ant, Gnamptogenys striatula, were analyzed by using the combination of gas chromatography and mass spectrometry. Series of esters of the new homoterpenoids (2E,6)-3,4,7-trimethyl-2,6-octadiene-1-ol (4-methylgeraniol) and (2E,6)-3,4,7-trimethyl-2,6-nonadiene-1-ol (bishomogerani... |
12561322 | Morphological control of helical solid bilayers in high-axial-ratio nanostructures through binary self-assembly. | Mixed molecular species of cardanyl glucoside derived from renewable resources provide nanotubes upon self-assembly in water, while the saturated homologue generated a twisted fibrous morphology. The cardanyl glucoside mixture was fractionated into four individual components in order to study their contribution to the ... |
12561317 | Chemoenzymatic syntheses of linear and branched hemithiomaltodextrins as potential inhibitors for starch-debranching enzymes. | Oligosaccharides embodying the S-maltosyl-6-thiomaltosyl structure have been readily synthesised by using convergent chemoenzymatic approaches. The key steps for the preparation of these molecules involved: 1) transglycosylation reactions of maltosyl fluorides onto suitable acceptors catalysed by the bacterial transgly... |
12561313 | Photoinduced electron transfer between metal-coordinated cyclodextrin assemblies and viologens. | Two novel tris(bipyridine)ruthenium(II) complexes bearing two and six beta-cyclodextrin binding sites on their ligands have been synthesised and characterised. Complex 1, bearing two cyclodextrins, adopts a conformation in aqueous solution where parts of the aromatic ligands are self-included into the cyclodextrin moie... |
12561312 | A direct link between annulene and porphyrin chemistry--21-vacataporphyrin. | A novel molecule, aza-deficient porphyrin 5,10,15,20-tetraaryl-21-vacataporphyrin has been synthesised by a substraction of a tellurium atom from 5,10,15,20-tetraaryl-21-telluraporphyrin under treatment of HCl. The new macrocycle is an annulene-porphyrin hybrid and at the same time is directly related to 21-heteroporph... |
12553424 | Mechanisms of molecular recognition: crystal structure analysis of human and rat transthyretin inhibitor complexes. | Structure-activity data show that many pharmacological agents are strong competitive inhibitors for thyroxine (T4) binding to transthyretin (TTR) and that this competition can interfere with their normal pharmacological actions. TTR is a tetrameric serum protein responsible for the transport of 20% of the circulating T... |
12543515 | Effect of acidity on the enantiomeric resolution of thyroxine and tocainide by HPLC on a (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid column. | Enantiomeric resolution of thyroxine and tocainide was achieved on a (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid column. The mobile phases were methanol/water (4:1, v/v) and methanol/water containing 5 mM sulfuric acid (4:1, v/v) for tocainide and thyroxine respectively. The flow rate was 0.5 ml/min. The effect of ... |
12543508 | Insight into the chiral recognition of warfarin enantiomers by epichlorhydrin/beta-cyclodextrin polymer-based supports: determination of stoichiometry and stability of warfarin/beta-cyclodextrin polymer complexes. | The complexation of warfarin (W) enantiomers by a hydrosoluble high-molecular-weight beta-cyclodextrin/epichlohydrin polymer (EP/beta-CD polymer) was studied using HPLC with a mobile phase of methanol/0.1 M Na acetate/acetic acid (pH 4) at 22 degrees C. It was found that the complexes (W/beta-CD unit) have a 1:1 stoich... |
12543506 | Direct calculation and computer simulation of the enantiomerization barrier of oxazepam in dynamic HPLC experiments--a comparative study. | Dynamic chromatographic methods constitute a versatile approach to the rapid and precise determination of enantiomerization barriers of stereolabile drugs. In the present study enantioselective dynamic high-performance liquid chromatography (DHPLC) was employed to determine the enantiomerization barrier of oxazepam. Dy... |
12543505 | Separation of oxazepam, lorazepam, and temazepam enantiomers by HPLC on a derivatized cyclodextrin-bonded phase: application to the determination of oxazepam in plasma. | The enantioselective high-performance liquid chromatography (HPLC) of three racemic 3-hydroxybenzodiazepines, oxazepam (Oxa), lorazepam (Lor), and temazepam (Tem), is a difficult operation because of the spontaneous chiral inversion in polar solvent. To solve this problem, we have developed an HPLC method based on a ch... |
12543501 | Liquid chromatographic separation of the enantiomers of fluoroquinolone antibacterials on a chiral stationary phase based on a chiral crown ether. | A chiral stationary phase (CSP) recently developed by bonding (diphenyl-substituted 1,1'-binaphthyl) crown ether to silica gel for the liquid chromatographic separation of enantiomers was applied to the resolution of investigational fluoroquinolone antibacterial agents including gemifloxacin (formerly LB20304a). All fl... |
12543496 | Strategies for the enantiomeric determination of amphetamine and related compounds by liquid chromatography. | This paper summarizes recent research on the stereospecific analysis of amphetamine, its analogs and metabolites, by liquid chromatography. The different methods proposed have been evaluated and compared in terms of resolution power, time of analysis, sensitivity, or potential for automation. Chiral derivatization, fol... |
12540196 | Transcription in the archaea: basal factors, regulation, and stress-gene expression. | A brief survey is presented of salient findings on transcription in the Archaea, focussing on stress genes of the hsp70(dnaK locus, which code for the molecular chaperones Hsp70(DnaK), Hsp40(DnaJ), and GrpE. Archaeal basal factors and some recently characterized regulators pertinent to non-stress genes are presented fi... |
12536813 | Supramolecular graphyne: a C(sp)-H...N hydrogen-bonded unique network structure of 2,4,6-triethynyl-1,3,5-triazine. | The crystallization of 2,4,6-triethynyl-1,3,5-triazine (2) leads to a pi-stacked layered structure of a C(sp)-H...N hydrogen-bonded unique hexagonal network structure, which may be regarded as a supramolecular analogue of a hitherto unknown graphyne network: in-plane intermolecular interactions are short and linear H..... |
12536806 | Interfacing supramolecular and macromolecular chemistry: metallo-supramolecular triple-helicates incorporated into polymer networks. | Metallo-supramolecular diiron(II) triple-helical cores based on pyridylimine ligands and decorated with acrylate or methacrylate units are copolymerised with methyl methacrylate (MMA) as major comonomer using AIBN. |
12536801 | Spin trapping of superoxide in the presence of beta-cyclodextrins. | The trapping of superoxide anion with DMPO and DEPMPO has been carried out in the presence of a methylated beta-cyclodextrin, Me-beta-CD; inclusion of the spin adducts in the cavity of Me-beta-CD resulted in a seven-fold increase of their half-life (t1/2 = 96 min for DEPMPO-superoxide spin adduct) and in their protecti... |
12536793 | Stable supramolecular dimer of self-complementary benzo-18-crown-6 with a pendant protonated amino arm. | The novel 4'-(ammoniummethylene)benzo-18-crown-6 cation was synthesized as a hexafluorophosphate salt and found to exist as a cyclophane-like dimer in the solid state, gas phase and in acetonitrile solution. |
12536779 | Synthesis and structure of a novel supramolecular Zn3Co8 assembly containing a linear Zn3 core. | Reaction of Zn(OAc)(2).2H2O (OAc = acetate) with LH2 in THF followed by reaction with Co2(CO)8 yields the novel supramolecular assembly Zn3L2(OAc)2[Co2(CO)6](4).0.5CH2Cl2, which was characterized by X-ray diffraction (LH2 = (CH2)3(N=CH-2-OH-5-C identical to CSiMe3C6H3)2 or N,N'-propylenebis(2-hydroxy-5-trimethylsilylet... |
12536777 | Conformational landscape surfing induced by off-on pi-pi stacking in a porphyrin-quinone dyad. | A covalently linked porphyrin-quinone dyad crystallizes with two orientations of the quinone, extended away from (off) and cofacial with the porphyrin macrocycle (on), which induce different conformations of the macrocycle and model the recently proposed structural effect of a nearby residue on the heme prosthetic grou... |
12536763 | Self-assembled oligonucleotide-polyester dendrimers. | A new approach to the controlled synthesis of multicomponent dendrimers is presented, in which three oligonucleotide-dendron conjugates were synthesized using solid phase techniques and hybridized to create a second generation polyester dendrimer with DNA as a core and bearing two types of peripheral functional groups. |
12536761 | Electrochemically controlled interactions between TTF-based dendrimers and an electron-rich oligomer. | Electrochemically controlled interactions have been shown to occur between TTF containing dendrimers 1 and 2 and the electron-rich oligomer 3. |
12536760 | An hermaphroditic [c2]daisy chain. | A cyclic dimeric daisy chain compound, which has been assembled from a disfunctional [2]rotaxane in a sequence of noncovalent and covalent synthetic steps, the most important of which is a bis-Wittig reaction, has been characterised by X-ray crystallography. |
12536757 | The specific contribution of phosphorus in dendrimer chemistry. | Besides properties commonly found for all types of dendrimers, phosphorus-containing dendrimers possess some specific properties seldom or never found for other types of dendrimers. Emphasis will be put on these specificities. |
12523667 | Formation of fine drug particles by cogrinding with cyclodextrins. I. The use of beta-cyclodextrin anhydrate and hydrate. | <h4>Purpose</h4>To improve the micromeritical properties of pranlukast (PRK) hydrate, a cogrinding process with cyclodextrin was used, and the formation of fine drug particles was investigated.<h4>Methods</h4>PRK crystals were ground with either beta-cyclodextrin (beta-CD) anhydrate or beta-CD hydrate crystals at a mix... |
12516211 | Singlet energy transfer as the main pathway in the sensitization of near-infrared Nd3+ luminescence by dansyl and lissamine dyes. | In general, sensitization of lanthanide(III) ions by organic sensitizers is regarded to take place via the triplet state of the sensitizers. Herein, we show that in dansyl- and lissamine-functionalized Nd3+ complexes energy transfer occurs from the singlet state of the sensitizers to the Nd3+ center. No sensitized emis... |
12516210 | Excitation energy transfer in dendritic host-guest donor-acceptor systems. | We report on a study of a physically formed host-guest system, which was designed to be investigated by fluorescence energy transfer. All donor and acceptor molecules used were cyanine dyes. Investigation was performed at the ensemble level as well as at the single-molecule level. The ensemble measurements revealed a d... |
12510387 | [Supramolecular chemistry of multinuclear zinc(II) complexes in aqueous solution]. | We report novel supramolecular polyhedrons formed by three-dimensional self-assembly of multinuclear zinc(II)-12-membered tetraamine (= cyclen = 1,4,7,10-tetraazacyclododecane) complexes with potentially multidentate ligands such as cyanuric acid (CA) and trithiocyanuric acid (TCA) in aqueous solution. Two new supermol... |
12511088 | Supramolecular interaction between water-soluble calix[4]arene and ATP--the catalysis of calix[4]arene for hydrolysis of ATP. | The catalysis effect of water-soluble calix[4]arene C[4] (calix[4]arene-5,11,17,23-tetrasulfonate) on hydrolysis of ATP in aqueous solution was studied by HPLC. Using laser photolysis and pulse radiolysis, the supramolecular interaction between water-soluble calix[4]arene and ATP was investigated. |
12511039 | Photoisomerization of stilbene dendrimers: the need for a volume-conserving isomerization mechanisms. | Highly branched stilbene dendrimers were synthesized and their photochemical behavior was studied. Even the stilbene dendrimer with molecular weight over 6500 underwent trans-cis isomerization in the excited singlet state within the lifetime of 10 ns. The photoisomerization of C=C double bond of stilbene dendrimers in ... |
12510758 | Electrochemical and Raman studies of the biointeraction between Escherichia coli and mannose in polydiacetylene derivative supported on the self-assembled monolayers of octadecanethiol on a gold electrode. | Here, we describe a new method to study the biointeraction between Escherichia coli and mannose by using supramolecular assemblies composed of polydiacetylene supported on the self-assembled monolayer of octadecanethiol on a gold electrode. These prepared bilayer materials simply are an excellent protosystem to study a... |
12510753 | Effect of signal interference from dosing excipients on pharmacokinetic screening of drug candidates by liquid chromatography/mass spectrometry. | The effect of dosing vehicle excipients such as PEG400, propylene glycol, Tween 80, and hydroxypropyl-beta-cyclodextrin on the accuracy of LC/MS measurements used in pharmacokinetic studies is examined. Using PEG400 as a probe compound, the concentration-time profile of the excipient in plasma from rats dosed both oral... |
12510746 | End-group analysis of blue light-emitting polymers using matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry. | An analytical method based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been applied to provide information on the structure of a copolymer, e.g., repeat unit and end group. Seven conjugated polymers, which have been demonstrated as the active component in blue ligh... |
12502740 | Biological functions of the ISWI chromatin remodeling complex NURF. | The nucleosome remodeling factor (NURF) is one of several ISWI-containing protein complexes that catalyze ATP-dependent nucleosome sliding and facilitate transcription of chromatin in vitro. To establish the physiological requirements of NURF, and to distinguish NURF genetically from other ISWI-containing complexes, we... |
12501001 | Effects of prohormone supplementation in humans: a review. | Despite a relative dearth of information on their effects, supplementation with prohormones has become a popular practice. Unlike synthetic anabolic-androgenic steroids, many of these over-the-counter androgens are produced endogenously by adrenal, gonadal and peripheral steroidogenic pathways as part of the normal sex... |
12499598 | Effect of the hydrophobic nature of triacetyl-beta-cyclodextrin on the complexation with nicardipine hydrochloride: physicochemical and dissolution properties of the kneaded and spray-dried complexes. | The inclusion ability of triacetyl-beta-cyclodextrin (TAbetaCD), a hydrophobic cyclodextrin (CD) derivative was examined, using nicardipine hydrochloride (NC) as model drug. The binary compounds were prepared in a 1 : 1 molar ratio by the kneading and the spray-drying techniques. In order to confirm the complexation be... |
12498274 | Separation and on-line concentration of bisphenol A and alkylphenols by micellar electrokinetic chromatography with cationic surfactant. | The separation and on-line concentration of bisphenol A and three alkylphenols were investigated by micellar electrokinetic chromatography with cationic surfactant. Tetradecyltrimethylammonium bromide was used as surfactant and the separation conditions were optimized by the addition of the organic solvents and cyclode... |
12498271 | Separation and migration behavior of structurally related phenothiazines in cyclodextrin-modified capillary zone electrophoresis. | The influences of buffer pH and the concentration of beta-cyclodextrins (beta-CDs) on the separation and migration behavior of 13 structurally related phenothiazines in CD-modified capillary zone electrophoresis (CD-CZE) using a phosphate background electrolyte at low pH were investigated. We focused on the separation ... |
12498248 | Separation and enantioseparation of derivatized amino acids and biogenic amines by high-performance liquid chromatography with reversed and chiral stationary phases. | This study demonstrates that an amino-beta-cyclodextrin-bonded phase column exhibits enantioselectivity for various amino acid derivatives. Mixtures of methanol, acetonitrile, tetrahydrofuran or dioxan and triethylamine buffers (pH 4.0-7.0) were used as mobile phases. The effect of the mobile phase on the resolution pr... |
12498242 | Simultaneous separation of different enantiomeric pairs in capillary electrophoresis by mixing different hemispherodextrins, a very versatile class of receptors. | Six different racemates of the profen family were used as analytes in order to test the chiral selector properties of three members of a new class of cyclodextrin derivatives, hemispherodextrins (HMs), in capillary electrophoresis. In addition to experiments carried out to separate each enantiomeric pair one by one, ot... |
12498239 | Separation of aromatic aminophosphonic acid enantiomers by capillary electrophoresis with the application of cyclodextrins. | The detailed studies concerning capillary electrophoresis separation of aminophosphonic acid enantiomers with various commercially available cyclodextrins are presented. The obtained results show that the separation of these stereoisomers is dependent on pH of background electrolyte, concentration of cyclodextrin as we... |
12495336 | Intra- and intermolecular second-sphere coordination chemistry: formation of capsules, half-capsules, and extended structures with hexaaquo- and hexaamminemetal ions. | In the design of novel extended solids, particularly those based on weaker interactions, reliable "synthons" are a valuable commodity. This work concerns the hydrogen-bonded assemblies which result from the second-sphere coordination interactions between a highly preorganized trisulfonate ligand and hexaaquo metal ions... |
12495332 | Identification of a near-linear supramolecular water dimer, (H2O)2, in the channel of an inorganic framework material. | Supramolecular water dimer, (H(2)O)(2), is fundamentally important. During the course of our work on polyoxometalates, we have been able to identify the existence of hydrogen-bonded, near-linear water dimers in the "sinuous" channels of an inorganic framework material, Na(3)(n)(H(2)O)(6)(n)[Al(OH)(6)Mo(6)O(18)](n)() x ... |
12495327 | Lead as its own luminescent sensor. | Lead (II) in polar organic solvents such as acetone, acetonitrile, and propylenecarbonate with excess bromide generates the highly luminescent lead-halide cluster Pb(4)Br(11)(3)(-). This in situ sensor does not rely on a host-guest relationship and, thus, is intrinsically selective and sensitive, allowing for the detec... |
12496126 | Imaging the environment of green fluorescent protein. | An emerging theme in cell biology is that cell surface receptors need to be considered as part of supramolecular complexes of proteins and lipids facilitating specific receptor conformations and distinct distributions, e.g., at the immunological synapse. Thus, a new goal is to develop bioimaging that not only locates p... |
12496125 | Stability of bacteriorhodopsin alpha-helices and loops analyzed by single-molecule force spectroscopy. | The combination of high-resolution atomic force microscopy imaging and single-molecule force spectroscopy allows the identification, selection, and mechanical investigation of individual proteins. In a recent paper we had used this technique to unfold and extract single bacteriorhodopsins (BRs) from native purple membr... |
12496121 | Molecular dynamics simulation of the RNA complex of a double-stranded RNA-binding domain reveals dynamic features of the intermolecular interface and its hydration. | The interaction between double-stranded RNA (dsRNA) and the third double-stranded domain (dsRBD) from Drosophila Staufen protein represents a paradigm to understand how the dsRBD protein family, one of the most common RNA-binding protein units, binds dsRNA. The nuclear magnetic resonance (NMR) structure of this complex... |
12496118 | Solution studies and structural model of the extracellular domain of the human amyloid precursor protein. | The amyloid precursor protein (APP) is the precursor of the beta-amyloid peptide (Abeta), which is centrally related to the genesis of Alzheimer's disease (AD). In addition, APP has been suggested to mediate and/or participate in events that lead to neuronal degeneration in AD. Despite the fact that various aspects of ... |
12496115 | Pressure dependence of the photocycle kinetics of bacteriorhodopsin. | The pressure dependence of the photocycle kinetics of bacteriorhodopsin from Halobacterium salinarium was investigated at pressures up to 4 kbar at 25 degrees C and 40 degrees C. The kinetics can be adequately modeled by nine apparent rate constants, which are assigned to irreversible transitions of a single relaxation... |
12496108 | Bidirectional control of sphingomyelinase activity and surface topography in lipid monolayers. | Lipid lateral organization is increasingly found to modulate membrane-bound enzymes. We followed in real time the reaction course of sphingomyelin (SM) degradation by Bacillus cereus sphingomyelinase (SMase) of lipid monolayers by epifluorescence microscopy. There is evidence that formation of ceramide (Cer), a lipid s... |
12496107 | Determination of membrane cholesterol partition coefficient using a lipid vesicle-cyclodextrin binary system: effect of phospholipid acyl chain unsaturation and headgroup composition. | Lateral domain or raft formation in biological membranes is often discussed in terms of cholesterol-lipid interactions. Preferential interactions of cholesterol with lipids, varying in headgroup and acyl chain unsaturation, were studied by measuring the partition coefficient for cholesterol in unilamellar vesicles. A n... |
12496090 | Modulation of endothelial inward-rectifier K+ current by optical isomers of cholesterol. | Membrane potential of aortic endothelial cells under resting conditions is dominated by inward-rectifier K(+) channels belonging to the Kir 2 family. Regulation of endothelial Kir by membrane cholesterol was studied in bovine aortic endothelial cells by altering the sterol composition of the cell membrane. Our results ... |
12496069 | Differences in electrostatic properties at antibody-antigen binding sites: implications for specificity and cross-reactivity. | Antibodies HyHEL8, HyHEL10, and HyHEL26 (HH8, HH10, and HH26, respectively) recognize highly overlapping epitopes on hen egg-white lysozyme (HEL) with similar affinities, but with different specificities. HH8 binding to HEL is least sensitive toward mutations in the epitope and thus is most cross-reactive, HH26 is most... |
12492317 | An acid-base switchable [2]rotaxane. | A chemically addressable, bistable [2]rotaxane, which incorporates a dumbbell-shaped component containing both secondary dialkylammonium and 1,2-bis(pyridinium)ethane recognition sites for its ring component, dibenzo[24]crown-8 (DB24C8), has been assembled. (1)H NMR spectroscopy has demonstrated that deprotonation (and... |
12492312 | Synthesis of novel phthalocyanine-tetrathiafulvalene hybrids; intramolecular fluorescence quenching related to molecular geometry. | A number of silicon phthalocyanine bis-esters have been synthesized and characterized, with axial ligands containing one or more tetrathiafulvalene groups. Variations in the substitution positions around a central aromatic "hinge" within the ligands lead to different molecular geometries, and the fluorescence of the ma... |
12489948 | Efficient sensitized photooxygenation in water by a porphyrin-cyclodextrin supramolecular complex. | [reaction: see text] The 2:1 inclusion complex between (2,3,6-tri-O-methyl)-beta-cyclodextrin (TMbetaCD) and 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrin (TPPS(4)) behaves as a supramolecular sensitizer in water providing photooxygenation with turnover numbers up to 30,000 with a very minor sensitizer bleaching (<1... |
12489934 | High alpha/beta-anomer selectivity in molecular recognition of carbohydrates by artificial receptors. | [structure: see text] New effective, acyclic, pyridine-based receptors 1-3 show remarkable alpha/beta binding selectivity in the recognition of monosaccharides. They are able to participate in cooperative and bidentate hydrogen bonds with sugar hydroxyls as well as in CH-pi interactions with CH's of sugar molecules. |
12488430 | Pregnancy alters glucose-6-phosphate dehydrogenase trafficking, cell metabolism, and oxidant release of maternal neutrophils. | Pregnancy is associated with changes in host susceptibility to infections and inflammatory disease. We hypothesize that metabolic enzyme trafficking affects maternal neutrophil activation. Specifically, immunofluorescence microscopy has shown that glucose-6-phosphate dehydrogenase (G-6-PDase), the rate-controlling step... |
12487611 | Comparative study of the high-pressure behavior of As, Sb, and Bi. | The high-pressure behavior of the heavier group 15 elements As, Sb, and Bi was investigated by means of ab initio density functional calculations employing pseudopotentials and a plane wave basis set. The high-pressure structural sequence of these elements is distinguished by the occurrence of the Bi-III structure, whi... |
12487600 | Specific interactions of complementary mono- and multivalent guests with recognition-induced polymersomes. | We have explored the interactions of mono- and multivalent guests with Recognition-Induced Polymersomes (RIPs) formed from complementary random copolymers featuring diamidopyridine and thymine functionality. Addition of monovalent guests featuring imide functionality to these RIPs induced a temporary swelling of the ve... |
12487584 | Self-assembly of biphenylene-bridged hybrid mesoporous solid with molecular-scale periodicity in the pore walls. | A synthesis of ordered biphenylene-bridged mesoporous material with a crystal-like periodic pore wall structure is reported. |
12487583 | Aromatic oligomers that form hetero duplexes in aqueous solution. | The electron-deficient 1,4,5,8-naphthalenetetracarboxylic diimide (Ndi) and electron-rich 1,5-dialkoxynaphthalene (Dan) have been shown to complex strongly with each other in water due to the hydrophobic effect as modulated through the electrostatic complementarity of the stacked dimer. Previously, oligomers of alterna... |
12487577 | Collagen mimetic dendrimers. | The synthesis of single-chain, scaffold (TRIS)- and dendrimer-assembled collagen mimetics (both Gly-Pro-Nleu and Gly-Nleu-Pro sequences) is reported. From the CD spectra and the thermal denaturation studies it can be readily seen that mimetics prepared from the Gly-Nleu-Pro sequence form more thermally stable triple he... |
12487575 | Chain-growth polycondensation for well-defined aramide. Synthesis of unprecedented block copolymer containing aramide with low polydispersity. | Poly(p-benzamide) with a defined molecular weight and a low polydispersity and a block copolymer containing this well-defined aramide was synthesized. Phenyl 4-aminobenzoate, which would yield poly(p-benzamide), did not polymerize under the conditions of chain-growth polycondensation. However, phenyl 4-(4-octyloxybenzy... |
12487571 | Dynamics and fluidity of amyloid fibrils: a model of fibrous protein aggregates. | A previous experimentally defined model for the fibril formed from the core residues of the beta-amyloid (Abeta) peptides of Alzheimer's disease, 10YEVHHQKLVFFAEDVGSNKGAIIGLM, Abeta(10-35) using spectroscopic and scattering analyses reports on the average structure, benefiting immensely from the homogeneous assembly of... |
12487570 | Spontaneous formation of hexameric resorcinarene capsule in chloroform solution as detected by diffusion NMR. | NMR diffusion measurements provide unequivocal proof that the resorcinarene 1b self-assembles spontaneously into a stable hexamer capsule in chloroform solution by encapsulating several chloroform molecules, which occupy different chemical positions. Although the affinity of tetrahexylammonium bromide (2a) toward the c... |
12487569 | Controlled interparticle spacing through self-assembly of Au nanoparticles and poly(amidoamine) dendrimers. | Control of particle-particle spacing is a key determinant of optical, electronic, and magnetic properties of nanocomposite materials. We have used poly(amidoamine) (PAMAM) dendrimers to assemble carboxylic acid-functionalized mixed monolayer protected clusters (MMPCs) through acid/base chemistry between the particle an... |
12488010 | Molecular recognition--viewed through the eyes of the solvent. | The binding of a ligand L to a specific site on an adsorbent molecule P is usually studied within the lock-and-key model. In this article we argue that the presence of an aqueous solvent may change dramatically the means by which a ligand recognizes its binding site. The main factor, originating from the specific prope... |
12488050 | Differential localization of glucose transporter isoforms in non-polarized mammalian cells: distribution of GLUT1 but not GLUT3 to detergent-resistant membrane domains. | The hexose transporter family, which mediates a facilitated uptake in mammalian cells, consists of more than 10 members containing 12 membrane-spanning segments with a single N-glycosylation site. However, it remains unknown how these isoforms are functionally organized in the membrane domains. In this report, we descr... |
12485166 | A comparative cDNA microarray analysis reveals a spectrum of genes regulated by Pax6 in mouse lens. | <h4>Background</h4>Pax6 is a transcription factor that is required for induction, growth, and maintenance of the lens; however, few direct target genes of Pax6 are known.<h4>Results</h4>In this report, we describe the results of a cDNA microarray analysis of lens transcripts from transgenic mice over-expressing Pax6 in... |
12484785 | Supramolecular structural constraints on Alzheimer's beta-amyloid fibrils from electron microscopy and solid-state nuclear magnetic resonance. | We describe electron microscopy (EM), scanning transmission electron microscopy (STEM), and solid-state nuclear magnetic resonance (NMR) measurements on amyloid fibrils formed by the 42-residue beta-amyloid peptide associated with Alzheimer's disease (Abeta(1)(-)(42)) and by residues 10-35 of the full-length peptide (A... |
12484791 | Carbon nanotubes: synthesis, integration, and properties. | Synthesis of carbon nanotubes by chemical vapor deposition over patterned catalyst arrays leads to nanotubes grown from specific sites on surfaces. The growth directions of the nanotubes can be controlled by van der Waals self-assembly forces and applied electric fields. The patterned growth approach is feasible with d... |
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