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15291533 | Solvent control of spin-dependent charge recombination mechanisms within donor-conjugated bridge-acceptor molecules. | We have shown recently that the oligomeric p-phenylene bridge within the PTZ-(Ph)n-PDI (PTZ = phenothiazine, Ph = phenyl, and PDI = perylenediimide) donor-bridge-acceptor system acts as a molecular wire in toluene, as shown by a change in the rate of radical ion pair (RP) recombination within PTZ+*-(Ph)n-PDI-* from an ... |
15291523 | Self-assembly of heterobimetallic d-f hybrid complexes: sensitization of lanthanide luminescence by d-block metal-to-ligand charge-transfer excited states. | Carboxylate-bearing d-transition metal bipyridyls form ternary complexes with seven-coordinate lanthanide centers. The neodymium,- ytterbium-, and erbium-containing complexes exhibit lanthanide-centered emissions sensitized by the MLCT states of the d-block components. |
15291473 | Concise preparation of the (3E,5Z)-alkadienyl system. New approach to the synthesis of principal insect sex pheromone constituents. | A new rapid and low-cost preparation of the (3E,5Z)-3,5-alkadienyl system, encountered in several insect pheromone constituents, was developed. Knoevenagel condensation of (E)-2-alkenals with ethyl hydrogen malonate in dimethyl sulfoxide, in the presence of a catalytic amount of piperidinium acetate, led to a mixture o... |
15289552 | The impact of different intensities of green light on the bacteriochlorophyll homologue composition of the Chlorobiaceae Prosthecochloris aestuarii and Chlorobium phaeobacteroides. | Members of the Chlorobiaceae and Chloroflexaceae are unique among the phototrophic micro-organisms in having a remarkably rich chlorophyll pigment diversity. The physiological regulation of this diversity and its ecological implications are still enigmatic. The bacteriochlorophyll composition of the chlorobiaceae Prost... |
15287791 | Efficient proton-templated synthesis of 18- to 38-membered tetraimino(amino)diphenol macrocyclic ligands: structural features and spectroscopic properties. | A whole range of Robson-type tetraiminodiphenol macrocyclic ligands have been prepared as their perchlorate salts [H4L](ClO4)2 in high yield (ca. 90%) by a single-step [2 + 2] condensation reaction between 4-methyl(or tert-butyl)-2,6-diformyl(or diacyl)phenols and alpha,omega-diaminoalkanes (C2-C12) in the presence of ... |
15287779 | A convenient protocol for the synthesis of ligands from a 4-methyl-3,5-diacylaminophenyl platform. | The synthesis of stable and highly organized phenanthroline, terpyridine, and pyridino-oxazoline ligands bearing one or two 4-methyl-3,5-diacylaminophenyl modules equipped with two lateral dialkoxyphenyl groups has been performed using EDC.HCl and DMAP reagents in the final coupling reaction. Evidently, in the final li... |
15287772 | Complexation of metals with piperazine-containing azamacrocyclic fluorophores. | Azamacrocyclic fluorophores containing piperazine units were synthesized using sequential rhodium-catalyzed regioselective hydroformylation-reductive amination. A piperazine unit is introduced into the macrocycles to act simultaneously as electron donor and binding site. The macrocycles chelate divalent cations, either... |
15287766 | Total synthesis of flavocommelin, a component of the blue supramolecular pigment from Commelina communis, on the basis of direct 6-C-glycosylation of flavan. | We succeeded in a first total synthesis of flavocommelin (1), a component of the blue supramolecular pigment, commelinin (2), from Commelina communis, by direct 6-C-glycosylation of the flavan 4 using perbenzylglucosyl fluoride 8 in the presence of MS 5 angstroms in CH2Cl2 and a catalytic amount of BF3 x Et2O. After 6-... |
15287761 | Design and synthesis of a C2-symmetric self-complementary hydrogen-bonding cleft molecule based on the bicyclo[3.3.1]nonane and 4-oxo-5-azaindole framework. formation of channels and inclusion complexes in the solid state. | The synthesis of a C2-symmetric cleft molecule 2 based on the fused framework between bicyclo[3.3.1]nonane and 4-oxo-5-azaindole, incorporating a self-complementary hydrogen-bonding motif, in both racemic and enantiomerically pure forms is reported. This cleft molecule is reminiscent of analogues of Tröger's base thoug... |
15287759 | From branched hydrocarbon propellers to C3-symmetric graphite disks. | Branched hydrocarbon propellers (9 and 12) were prepared by stepwise palladium-catalyzed Hagihara-Sonogashira coupling reactions and Diels-Alder cycloadditions and submitted to oxidative cyclodehydrogenation by FeCl3 to afford two new giant graphite disks 2 and 3 with 3-fold symmetry in high yield. One of the precursor... |
15289504 | Intracellular triggering of Fas aggregation and recruitment of apoptotic molecules into Fas-enriched rafts in selective tumor cell apoptosis. | We have discovered a new and specific cell-killing mechanism mediated by the selective uptake of the antitumor drug 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH(3), Edelfosine) into lipid rafts of tumor cells, followed by its coaggregation with Fas death receptor (also known as APO-1 or CD95) and re... |
15289502 | Limited T cell receptor diversity of HCV-specific T cell responses is associated with CTL escape. | Escape mutations are believed to be important contributors to immune evasion by rapidly evolving viruses such as hepatitis C virus (HCV). We show that the majority of HCV-specific cytotoxic T lymphocyte (CTL) responses directed against viral epitopes that escaped immune recognition in HCV-infected chimpanzees displayed... |
15289496 | NFkappaB activation by Fas is mediated through FADD, caspase-8, and RIP and is inhibited by FLIP. | Fas (APO-1/CD95) is the prototypic death receptor, and the molecular mechanisms of Fas-induced apoptosis are comparably well understood. Here, we show that Fas activates NFkappaB via a pathway involving RIP, FADD, and caspase-8. Remarkably, the enzymatic activity of the latter was dispensable for Fas-induced NFkappaB s... |
15289931 | Structure-based models of cadherin-mediated cell adhesion: the evolution continues. | Cadherins are glycoproteins that are responsible for homophilic, Ca2+-dependent cell-cell adhesion and play crucial roles in many cellular adhesion processes ranging from embryogenesis to the formation of neuronal circuits in the central nervous system. Many different experimental approaches have been used to unravel t... |
15289927 | Nanoscale science: a big step towards the Holy Grail of single molecule biochemistry and molecular biology. | Light scattering from metal nanoparticles and fluorescence from quantum dots offer distinct advantages over traditional fluorophores when it comes to detection of single molecules in living cells. |
15287747 | Interactions of histone H1 with phospholipids and comparison of its binding to giant liposomes and human leukemic T cells. | Due to its net positive charge histone H1 readily associates with liposomes containing acidic phospholipids, such as phosphatidylserine (PS). Interestingly, circular dichroism reveals that while histone H1 in aqueous solutions appears as a random coil, its binding to liposomes containing PS is associated with a pronoun... |
15285691 | New terpyridine-containing macrocycle for the assembly of dimeric Zn(II) and Cu(II) complexes coupled by bridging hydroxide anions and pi-stacking interactions. | The synthesis of the new terpyridine-containing macrocycle 2,5,8,11,14-pentaaza[15](6,6' ')cyclo(2,2':6',2' ')terpyridinophane (L) is reported. The ligand contains a pentaamine chain linking the 6,6' ' positions of a terpyridine unit. A potentiometric, (1)H NMR, UV-vis spectrophotometric and fluorescence emission study... |
15285652 | Grid-type two-dimensional magnetic multinuclear metal complex: strands of ([CuII(mu-4,4'-bpy)]2+)n cross-linked by octacyanotungstate(V) ions. | Reaction of the preorganized strands of ([Cu(II)(mu-4,4'-bpy)](2+))n (4,4'-bpy = 4,4'-bipyridine) with [W(V)(CN)(8)](3)(-) leads to a novel cyano-bridged Cu(II)(3)W(V)(2) complex [Cu(mu-4,4'-bpy)(DMF)(2)][Cu(mu-4,4'-bpy)(DMF)](2)[W(V)(CN)(8)](2).2DMF. 2H(2)O 1. The structure of 1 consists of the expected 2-dimensional ... |
15281820 | Metal-ion sensing fluorophores with large two-photon absorption cross sections: aza-crown ether substituted donor-acceptor-donor distyrylbenzenes. | Chromophores based on a donor-acceptor-donor structure possessing a large two-photon absorption cross section and one or two mono-aza-15-crown-5 ether moieties, which can bind metal cations, have been synthesized. The influence of Mg(2+) binding on their one- and two-photon spectroscopic properties has been investigate... |
15281818 | Formation of branched calixarene aggregates-a time-resolved static light scattering study. | Mixtures of a calix[4]arene and a naphthyridine derivative dissolved in 1,2-dichlorobenzene form thermoreversible aggregates. The aggregation process was followed by means of time-resolved multiangle light scattering at two different mixing ratios, 1:3 and 1:4, yielding a detailed record of the relative mass, the radiu... |
15281817 | Amplification of chirality from molecules into morphology of crystals through molecular recognition. | We have found a novel type of morphological chiral tuning on inorganic helical crystals through stereochemical recognition of organic molecules. Helical forms consisting of twisted twins emerged from triclinic crystals under diffusion-limited conditions. The proportion of the right- and left-handed helices was precisel... |
15281814 | Synthesis, relaxometric and photophysical properties of a new pH-responsive MRI contrast agent: the effect of other ligating groups on dissociation of a p-nitrophenolic pendant arm. | Two gadolinium(III) chelates, GdNP-DO3A (1-methlyene-(p-NitroPhenol)-1,4,7,10-tetraazacycloDOdecane-4,7,10-triAcetate) and GdNP-DO3AM (1-methlyene(p-NitroPhenol)-1,4,7,10-tetraazacycloDOdecane-4,7,10-triacetAMide), containing a single nitrophenolic pendant arm plus either three acetate or three amide pendant arms were ... |
15281793 | Alkane oxidation via photochemical excitation of a self-assembled molecular cage. | The photoexcitation of a self-assembled M6L4-type coordination cage accommodating photochemically inert alkane guests (e.g., adamantane and cyclooctane) led to the regioselective oxidation of the guest within the cage. Under anaerobic conditions, the guest oxidation was accompanied by the stable radical formation as in... |
15281785 | [60]fullerene-stoppered porphyrinorotaxanes: pronounced elongation of charge-separated-state lifetimes. | A series of Sauvage-type porphyrinorotaxanes containing [60]fullerene stoppers have been synthesized by a convergent route. Photoinduced energy transfer and electron-transfer reactions in these rotaxanes yield long-distance charge-separated radical-pair states, whose lifetimes in solution at ambient temperatures are as... |
15281782 | Thermally and electrochemically controllable self-complexing molecular switches. | Self-complexing molecular systems are obtained when an arm component (a pi-donor) is covalently linked to a preformed macrocycle (a pi-acceptor). The resulting self-complexing compounds are not only attractive in relation to their topology, but also for their potential to undergo reversible movements, i.e., the arm can... |
15280489 | Determinants of virulence of classical swine fever virus strain Brescia. | Two related classical swine fever virus (CSFV) strain Brescia clones were isolated from blood samples from an infected pig. Virus C1.1.1 is a cell-adapted avirulent variant, whereas CoBrB is a virulent variant. Sequence analysis revealed 29 nucleic acid mutations in C1.1.1, resulting in 9 amino acid substitutions compa... |
15280482 | Evidence that rabies virus forms different kinds of fusion machines with different pH thresholds for fusion. | Fusion of rabies virus with membranes is triggered at a low pH and is mediated by a viral glycoprotein (G). Fusion of rabies virus with liposomes was monitored by using a lipid mixing assay based on fluorescence resonance energy transfer. Fusion was detected below pH 6.4, and its extent increased with H(+) concentratio... |
15280478 | Human coronavirus 229E binds to CD13 in rafts and enters the cell through caveolae. | CD13, a receptor for human coronavirus 229E (HCoV-229E), was identified as a major component of the Triton X-100-resistant membrane microdomain in human fibroblasts. The incubation of living fibroblasts with an anti-CD13 antibody on ice gave punctate labeling that was evenly distributed on the cell surface, but raising... |
15280474 | Spirodiketopiperazine-based CCR5 inhibitor which preserves CC-chemokine/CCR5 interactions and exerts potent activity against R5 human immunodeficiency virus type 1 in vitro. | We identified a novel spirodiketopiperazine (SDP) derivative, AK602/ONO4128/GW873140, which specifically blocked the binding of macrophage inflammatory protein 1alpha (MIP-1alpha) to CCR5 with a high affinity (K(d) of approximately 3 nM), potently blocked human immunodeficiency virus type 1 (HIV-1) gp120/CCR5 binding a... |
15279650 | Supramolecular pellicle precursors. | Saliva contacting with solid surfaces in the oral cavity forms a coat termed the pellicle. However, its formation is not fully understood. Although indications for the existence of supramolecular pellicle precursors have been reported, the possible relationship between them and pellicle formation is unclear. This study... |
15276167 | Automated orthogonal control system for electrospray ionization. | Low-flow electrospray ionization is typically a purely electrostatic method, used without supporting sheath-gas nebulization. Complex spray morphology results from a large number of possible spray emission modes. Spray morphology may assume the optimal Taylor cone-jet spray mode under equilibrium conditions. When coupl... |
15273137 | Pharmacokinetics of intravenous itraconazole in stable hemodialysis patients. | The pharmacokinetics of intravenous itraconazole (ITC) was studied in dialysis patients. Dialysis had no effect on the half-life and clearance of ITC or OH-ITC. However, dialysis allowed the clearance of hydroxypropyl-beta-cyclodextrin (HP-beta-CD). The area under the concentration-time curve from time zero to infinity... |
15273119 | Pharmacodynamics of telavancin (TD-6424), a novel bactericidal agent, against gram-positive bacteria. | Telavancin (TD-6424) is a novel lipoglycopeptide that produces rapid and concentration-dependent killing of clinically relevant gram-positive organisms in vitro. The present studies evaluated the in vivo pharmacodynamics of telavancin in the mouse neutropenic thigh (MNT) and mouse subcutaneous infection (MSI) animal mo... |
15273117 | Impact of specific pbp5 mutations on expression of beta-lactam resistance in Enterococcus faecium. | We tested the impact of individual PBP 5 mutations on expression of ampicillin resistance in Enterococcus faecium using a shuttle plasmid designed to facilitate expression of cloned pbp5 in ampicillin-susceptible E. faecium D344SRF. Substitutions that had been implicated in contributing to the resistance of clinical st... |
15271945 | Interaction of Dr adhesin with collagen type IV is a critical step in Escherichia coli renal persistence. | The pathogenic mechanism of recurrent or chronic urinary tract infection is poorly understood. Escherichia coli cells bearing Dr fimbriae display unique tropism to the basement membrane (BM)-renal interstitium that enables the bacteria to cause chronic pyelonephritis in experimental mice. The renal receptors for Dr-fim... |
15271895 | Potential involvement of gelatinases and their inhibitors in Mannheimia haemolytica pneumonia in cattle. | Mannheimia haemolytica infection of the lower respiratory tract of cattle results in a bronchofibrinous pneumonia characterized by massive cellular influx and lung tissue remodeling and scarring. Since altered levels of gelatinases and their inhibitors have been detected in a variety of inflammatory conditions and are ... |
15265920 | B cell lipid rafts regulate both peptide-dependent and peptide-independent APC-T cell interaction. | Formation of an immunological synapse (IS) between APCs and T CD4(+) lymphocytes is a key event in the initiation and the termination of the cognate immune response. We have analyzed the contribution of the APC to IS formation and report the implication of the actin cytoskeleton, the signaling proteins and the lipid ra... |
15265891 | Lipid raft-associated GTPase signaling controls morphology and CD8+ T cell stimulatory capacity of human dendritic cells. | Their eponymous morphology and unique ability to activate naive T cells are hallmark features of dendritic cells (DCs). Specific properties of the actin cytoskeleton may define both characteristics. In search for regulators that coordinate DC phenotype and function, we observed strongly increased expression of the acti... |
15259070 | HCV NS5A abrogates p53 protein function by interfering with p53-DNA binding. | <h4>Aim</h4>To evaluate the inhibition effect of HCV NS5A on p53 transactivation on p21 promoter and explore its possible mechanism for influencing p53 function.<h4>Methods</h4>p53 function of transactivation on p21 promoter was studied with a luciferase reporter system in which the luciferase gene is driven by p21 pro... |
15254246 | Three separable domains regulate GTP-dependent association of H-ras with the plasma membrane. | The microlocalization of Ras proteins to different microdomains of the plasma membrane is critical for signaling specificity. Here we examine the complex membrane interactions of H-ras with a combination of FRAP on live cells to measure membrane affinity and electron microscopy of intact plasma membrane sheets to spati... |
15254199 | Common E protein determinants for attenuation of glycosaminoglycan-binding variants of Japanese encephalitis and West Nile viruses. | Natural isolates and laboratory strains of West Nile virus (WNV) and Japanese encephalitis virus (JEV) were attenuated for neuroinvasiveness in mouse models for flavivirus encephalitis by serial passage in human adenocarcinoma (SW13) cells. The passage variants displayed a small-plaque phenotype, augmented affinity for... |
15246281 | Use of alternative receptors different than alpha-dystroglycan by selected isolates of lymphocytic choriomeningitis virus. | Long-term infections with viruses permit the generation of variants that evolve specific growth advantages in certain tissues and may show altered disease potentials. The selection of such variants is influenced by the host tissue and often involves virus-receptor interactions. Here we report studies of receptor usage ... |
15246273 | Binding of influenza viruses to sialic acids: reassortant viruses with A/NWS/33 hemagglutinin bind to alpha2,8-linked sialic acid. | We have examined the specificity of binding of A/NWS/33 hemagglutinin (HA), exploring the effects of fucosylation, changing the Gal-GlcNAc linkage between the second and third sugars, and binding affinity for alpha2,8-linked sialic acid. The HA of A/NWS/33(HA)-Tokyo/67(NA) (NWS-Tok, H1N2) virus binds to 3'-linked sialy... |
15246262 | Mapping the phosphoprotein binding site on Sendai virus NP protein assembled into nucleocapsids. | To catalyze RNA synthesis, the Sendai virus P-L RNA polymerase complex first binds the viral nucleocapsid (NC) template through an interaction of the P subunit with NP assembled with the genome RNA. For replication, the polymerase utilizes an NP(0)-P complex as the substrate for the encapsidation of newly synthesized R... |
15247190 | Iron, anaemia, and inflammatory bowel diseases. | Iron deficiency anaemia is one of the most common disorders in the world. Also, one third of inflammatory bowel disease (IBD) patients suffer from recurrent anaemia. Anaemia has significant impact on the quality of life of affected patients. Chronic fatigue, a frequent IBD symptom itself, is commonly caused by anaemia ... |
15233375 | On the molecular basis of the receptor mosaic hypothesis of the engram. | 1. This paper revisits the so-called "receptor mosaic hypothesis" for memory trace formation in the light of recent findings in "functional (or interaction) proteomics." The receptor mosaic hypothesis maintains that receptors may form molecular aggregates at the plasma membrane level representing part of the computatio... |
15211509 | Towards a structural classification of phosphate binding sites in protein-nucleotide complexes: an automated all-against-all structural comparison using geometric matching. | A method is described for the rapid comparison of protein binding sites using geometric matching to detect similar three-dimensional structure. The geometric matching detects common atomic features through identification of the maximum common sub-graph or clique. These features are not necessarily evident from sequence... |
15170821 | Sigma-1 receptors potentiate epidermal growth factor signaling towards neuritogenesis in PC12 cells: potential relation to lipid raft reconstitution. | We previously demonstrated that overexpression of sigma-1 receptors (sigma-1R) potentiated neurite sprouting caused by nerve growth factor in PC12 cells (Takebayashi et al. 2002 J Pharmacol Exp Ther 202:1227-1237). In this study we examined if sigma-1R may be involved in the action of epidermal growth factor (EGF). EGF... |
15020150 | A novel polymeric chlorhexidine delivery device for the treatment of periodontal disease. | An implantable, anti-microbial delivery device for the treatment of periodontal disease has been developed. In this polymer-based delivery system, the encapsulation efficiency, release characteristics, and bioactivity of anti-microbial agent were controlled by the complexation of the drug with cyclodextrins of differin... |
15340611 | Template-assisted self assembly of two lipophilic polyion aggregates derived from sodium tetraphenyl imidodiphosphinate-complexes containing sodium ions in four different coordination environments. | The molecular structures of two lipophilic polyion aggregates derived from tetraphenyl imidodiphosphinate are described: [Na(crown ether)][MNa(2)[Ph(2)P(O)NP(O)Ph(2)](4)] with crown ether = 15-crown-5 for 1and benzo-15-crown-5 for (M = Na(+) for 1 and Na(H(2)O)(+) for 2). |
15237189 | (5,11,17,23-Tetra-tert-butyl-26,28-dihydroxycalix[4]arene-25,27-dioxy)diacetic acid N,N-dimethylformamide trisolvate. | The title compound, C48H60O8.3C3H7NO, is a derivative of calix[4]arene in the cone conformation, modified with distal carboxylic acid functional groups at the lower rim. A clathrate dimethylformamide (DMF) molecule is located within the calix[4]arene cone, and two DMF solvate molecules participate in hydrogen bonding w... |
15514764 | Synthesis of new poly(propylenimine) dendrimers DAB-dendr-[NH(O)COCH2CH2OC(O)C5H4Rh(NBD)](n) [n=4, 8, 16, 32, 64] functionalized with alkoxycarbonylcyclopentadienyl complexes of rhodium(I). | The reaction between [Rh[C5H4CO2(CH)2OH](NBD)] (1) and 1,1'-carbonyldiimidazole (CDI) leads to the new CO2-imidazole functionalized alkoxycarbonylcyclopentadienyl complex [Rh[C5H4CO2(CH2)2O2C-Im](NBD)] (2) (Im=imidazole). The latter was treated with five generations of poly(propylenimine) dendrimers DAB-dendr-(NH2)(n) ... |
15322860 | The hypolipidemic compound cetaben induces changes in Golgi morphology and vesicle movement. | The human hepatoma cell line HepG2 was used to study the effect of cetaben, a non-fibrate hypolipidemic drug, on cell morphology and vesicle distribution. Cetaben treatment correlated with a fragmentation and/or condensation of Golgi cisternae and the appearance of large electron-lucent vesicles. The Golgi apparatus, d... |
15760056 | Tablet formulation containing meloxicam and beta-cyclodextrin: mechanical characterization and bioavailability evaluation. | The purpose of this research was to evaluate beta-cyclodextrin (beta-CD) as a vehicle, either singly or in blends with lactose (spray-dried or monohydrate), for preparing a meloxicam tablet. Aqueous solubility of meloxicam in presence of beta-CD was investigated. The tablets were prepared by direct compression and wet ... |
15280439 | Effects of gamma- and hydroxypropyl-gamma-cyclodextrins on the transport of doxorubicin across an in vitro model of blood-brain barrier. | Association between doxorubicin (DOX) and gamma-cyclodextrin (gamma-CD) or hydroxypropyl-gamma-CD (HP-gamma-CD) has been examined to increase the delivery of this antitumoral agent to the brain. The stoichiometry and the stability constant of gamma-CD or HP-gamma-CD and DOX complexes were determined in physiological me... |
15280388 | Metabolic biotinylation as a probe of supramolecular structure of the triad junction in skeletal muscle. | Excitation-contraction coupling in skeletal muscle involves conformational coupling between dihydropyridine receptors (DHPRs) in the plasma membrane and ryanodine receptors (RyRs) in the sarcoplasmic reticulum. However, it remains uncertain what regions, if any, of the two proteins interact with one another. Toward thi... |
15305219 | Cooperative self-assembly and molecular binding behavior of cyclodextrin-crown ether conjugates mediated by alkali metal ions. | In order to quantitatively investigate their molecular binding ability, a series of cyclodextrin-crown ether conjugates containing beta-cyclodextrin (beta-CyD) and crown ether units, i.e.N-(benzoaza-15-crown-5)acylaminomethylene tethered 6-diethylenetriamino-6-deoxy-beta-CyD, N-(benzoaza-15-crown-5)acylaminomethylene t... |
15280544 | Efficient construction of the securine A carbon skeleton. | Securamine A is a structurally intriguing alkaloid possessing a pyrroloindole core joined via a modified isoprene subunit to a functionalized imidazole ring. Recent synthetic efforts in this laboratory have resulted in the efficient construction of key lactone 36, which undergoes tandem azide reduction/ring expansion t... |
15280548 | Pauling and Corey's alpha-pleated sheet structure may define the prefibrillar amyloidogenic intermediate in amyloid disease. | Transthyretin, beta(2)-microglobulin, lysozyme, and the prion protein are four of the best-characterized proteins implicated in amyloid disease. Upon partial acid denaturation, these proteins undergo conformational change into an amyloidogenic intermediate that can self-assemble into amyloid fibrils. Many experiments h... |
15280532 | Total chemical synthesis of N-myristoylated HIV-1 matrix protein p17: structural and mechanistic implications of p17 myristoylation. | The HIV-1 matrix protein p17, excised proteolytically from the N terminus of the Gag polyprotein, forms a protective shell attached to the inner surface of the plasma membrane of the virus. During the late stages of the HIV-1 replication cycle, the N-terminally myristoylated p17 domain targets the Gag polyprotein to th... |
15280547 | Twisting macromolecular chains: self-assembly of a chiral supermolecule from nonchiral polythiophene polyanions and random-coil synthetic peptides. | The self-assembly of a negatively charged conjugated polythiophene derivative and a positively charged synthetic peptide will create a chiral, well ordered supermolecule. This supermolecule has the three-dimensional ordered structure of a biomolecule and the electronic properties of a conjugated polymer. The molecular ... |
15280538 | Translocation of CD28 to lipid rafts and costimulation of IL-2. | Stimulation of the CD28 costimulatory receptor can lead to an increased surface lipid raft expression in T lymphocytes. Here, we demonstrate that CD28 itself is recruited to lipid rafts in both Jurkat and peripheral blood T lymphocytes. This recruitment of CD28 is triggered by engagement with either anti-CD28 mAbs or a... |
15565229 | A general chemiluminescence method for the determination of surfactants based on its quenching effect on the luminol-NaIO4-cyclodextrin reaction. | Here we report that all types of surfactant could be simply and sensitively determined, by directly quenching the chemiluminescence (CL) between luminol and NaIO4 in a basic solution containing one polyhydroxyl compound such as cyclodextrin (CD), glucose or glycerol. This specific quenching effect was attributed to the... |
15277662 | Studies of stereocontrolled allylation reactions for the total synthesis of phorboxazole A. | A highly convergent total synthesis of the potent anticancer agent (+)-phorboxazole A (1) is accomplished. Four components (3-6) are assembled with considerations for control of absolute and relative stereochemistry. Iterative asymmetric allylation methodology addresses key stereochemical features in the preparation of... |
15277670 | The SapB morphogen is a lantibiotic-like peptide derived from the product of the developmental gene ramS in Streptomyces coelicolor. | SapB is a morphogenetic peptide that is important for aerial mycelium formation by the filamentous bacterium Streptomyces coelicolor. Production of SapB commences during aerial mycelium formation and depends on most of the genes known to be required for the morphogenesis of aerial hyphae. Furthermore, the application o... |
15278333 | Chromatographic molecular recognition for catechol-related compounds using thiacalix[4]arene as an effective selector. | Thiacalix[4]arene (5,11,17,23-tetra- tert-butyl-25,26,27,28-tetrahydroxy-2,8,14,20-tetrathiacalix[4]arene) is an amphiphilic molecule comprising four p-tert-butylphenol-like groups ortho-linked by single sulfur atoms. This molecule has a high electron density area owing to the close proximity of the hydroxyl groups and... |
15514759 | Hydrogen-bond mediation of supramolecular aggregation in neutral bis-(C6F5)Pt complexes with aromatic H-bond donating ligands. A synthetic and structural study. | Six pentafluorophenylplatinum(II) complexes containing proton acceptor atoms (F) and pyridine-like aromatic ligands able to act as proton donors have been synthesized and characterized, with emphasis on the factors that mediate their supramolecular aggregation in the solid state--hydrogen bonds and pi-pi interactions. ... |
15273325 | Chemical synthesis and binding activity of the trypanosomatid cap-4 structure. | Leishmania and other trypanosomatids are early eukaryotes that possess unusual molecular features, including polycistronic transcription and trans-splicing of pre-mRNAs. The spliced leader RNA (SL RNA) is joined to the 5' end of all mRNAs, thus donating a 5' cap that is characterized by complex modifications. In additi... |
15273321 | High-affinity binding site for a group II intron-encoded reverse transcriptase/maturase within a stem-loop structure in the intron RNA. | Mobile group II introns encode proteins that have reverse transcriptase and maturase activities and bind specifically to the intron RNA to promote both RNA splicing and intron mobility. Previous studies with the Lactococcus lactis Ll.LtrB intron showed that the intron-encoded protein (LtrA) has a high-affinity binding ... |
15272935 | Accuracy of cDNA microarray methods to detect small gene expression changes induced by neuregulin on breast epithelial cells. | <h4>Background</h4>cDNA microarrays are a powerful means to screen for biologically relevant gene expression changes, but are often limited by their ability to detect small changes accurately due to "noise" from random and systematic errors. While experimental designs and statistical analysis methods have been proposed... |
15273292 | Staphylococcal toxin induced preferential and prolonged in vivo deletion of innate-like B lymphocytes. | Contributing to host defenses from the adaptive immune system, splenic marginal zone (MZ) B cells, with their preactivated state and special topographical location, serve essential roles as primary defenders from blood-borne microbes. From studies designed to define the immunologic impact of protein A of Staphylococcus... |
15271790 | C-reactive protein genotypes affect baseline, but not exercise training-induced changes, in C-reactive protein levels. | <h4>Objective</h4>The goal of this study is to determine whether C-reactive protein (CRP) gene variants affect baseline and training-induced changes in plasma CRP levels.<h4>Methods and results</h4>Sixty-three sedentary men and women aged 50 to 75 years old underwent baseline testing (Vomax, body composition, CRP level... |
15303167 | Heavier alkali metal complexes of 2-phenylamidopyridine: an X-ray crystallographic and theoretical study of a structurally diverse series of crown ether adducts. | Complexes of the anion of the secondary amine 2-phenylaminopyridine (LH) with the heavier alkali metals Na-Cs have been prepared in the presence of various macrocyclic polyether crowns [12-crown-4 (12C4), 15-crown-5 (15C5), and 18-crown-6 (18C6)], which coordinate to the metal ions in all cases. Depending on the combin... |
15272021 | Identification of placenta growth factor determinants for binding and activation of Flt-1 receptor. | Placenta growth factor (PlGF) belongs to the vascular endothelial growth factor (VEGF) family and represents a key regulator of angiogenic events in pathological conditions. PlGF exerts its biological function through the binding and activation of the seven immunoglobulin-like domain receptor Flt-1, also known as VEGFR... |
15269205 | The crystal structure of Escherichia coli MoaB suggests a probable role in molybdenum cofactor synthesis. | The crystal structure of Escherichia coli MoaB was determined by multiwavelength anomalous diffraction phasing and refined at 1.6-A resolution. The molecule displayed a modified Rossman fold. MoaB is assembled into a hexamer composed of two trimers. The monomers have high structural similarity with two proteins, MogA a... |
15269345 | Anchor residues in protein-protein interactions. | We show that the mechanism for molecular recognition requires one of the interacting proteins, usually the smaller of the two, to anchor a specific side chain in a structurally constrained binding groove of the other protein, providing a steric constraint that helps to stabilize a native-like bound intermediate. We ide... |
15265808 | Increased wakefulness, motor activity and decreased theta activity after blockade of the 5-HT2B receptor by the subtype-selective antagonist SB-215505. | Serotonin-2 receptor antagonists, like ritanserin, greatly enhance deep slow wave sleep (SWS-2) and low-frequency EEG power in humans and rodents. 5-HT(2A) and 5-HT(2C) receptors may be involved in these effects, but the role of the 5-HT(2B) receptor is still unclear. To investigate the role of the 5-HT(2B) receptor in... |
15306898 | Giant dendrimer-like particles from nanolatexes. | A straightforward grafting of a polycationic phosphorus-containing dendritic shell onto polystyrene nanoparticles leads to dendronized nanoparticles showing unique behavior. |
15303153 | Triangles and tetrahedra: metal directed self-assembly of metallo-supramolecular structures incorporating bis-beta-diketonato ligands. | The interaction of six aryl-linked bis-beta-diketones, including a new naphthylene linked species, with copper(II), iron(III) and, in one instance gallium(III), has been investigated with the aim of obtaining metallo-supramolecular assemblies exhibiting different geometries. New examples of two assembly types incorpora... |
15263094 | VLA-4 integrin concentrates at the peripheral supramolecular activation complex of the immune synapse and drives T helper 1 responses. | The integrin alpha 4 beta 1 (VLA-4) not only mediates the adhesion and transendothelial migration of leukocytes, but also provides costimulatory signals that contribute to the activation of T lymphocytes. However, the behavior of alpha 4 beta 1 during the formation of the immune synapse is currently unknown. Here, we s... |
15263076 | IL-2 and IL-15 receptor alpha-subunits are coexpressed in a supramolecular receptor cluster in lipid rafts of T cells. | The private alpha-chains of IL-2 and IL-15 receptors (IL-2R and IL-15R) share the signaling beta- and gamma(c)-subunits, resulting in both common and contrasting roles of IL-2 and IL-15 in T cell function. Knowledge of the cytokine-dependent subunit assembly is indispensable for understanding the paradox of distinct si... |
15258406 | Isomeric iodo-N-(nitrobenzyl)anilines: interplay of hard and soft hydrogen bonds, iodo...nitro interactions and aromatic pi...pi stacking interactions. | Molecules of 2-iodo-N-(4-nitrobenzyl)aniline, 4-O2NC6H4CH2NHC6H4I-2' (1) are linked into chains by C-H...O hydrogen bonds. In the isomeric compound 3-iodo-N-(4-nitrobenzyl)aniline (2) a combination of N-H...O and C-H...O hydrogen bonds and iodo...nitro and aromatic pi...pi stacking interactions links the molecules into... |
15258405 | Supramolecular structures of substituted alpha,alpha'-trehalose derivatives. | The structures of five substituted alpha,alpha'-trehalose trehalose derivatives have been determined, and these are compared with those of four previously published analogues. In 2,2',3,3',4,4'-hexaacetato-6,6'-bis-O-methylsulfonyl-alpha,alpha'-trehalose, C26H38O21S2, where the molecules lie across twofold rotation axe... |
15258595 | Polyvalent dendrimer glucosamine conjugates prevent scar tissue formation. | Dendrimers are hyperbranched macromolecules that can be chemically synthesized to have precise structural characteristics. We used anionic, polyamidoamine, generation 3.5 dendrimers to make novel water-soluble conjugates of D(+)-glucosamine and D(+)-glucosamine 6-sulfate with immuno-modulatory and antiangiogenic proper... |
15272365 | Visualizing the Needle in the Haystack: In Situ Hybridization With Fluorescent Dendrimers. | In situ hybridization with 3DNA trade mark dendrimers is a novel tool for detecting low levels of mRNA in tissue sections and whole embryos. Fluorescently labeled dendrimers were used to identify cells that express mRNA for the skeletal muscle transcription factor MyoD in the early chick embryo. A small population of M... |
15257429 | Ferrocene-containing polyelectrolyte multilayer film-covered electrodes: electrocatalytic determination of ascorbic acid and use of inner blocking layers to improve the upper detection limit of the electrodes. | A multilayer film composed of ferrocene(Fc)-appended poly(allylamine hydrochloride) (Fc-PAH) and poly(potassium vinylsulfate) (PVS) has been prepared on the surface of a gold(Au) electrode by using a layer-by-layer self-assembly technique. Fc-containing polyelectrolyte multilayer (PEM) film-modified electrodes can elec... |
15262977 | The modulation in subunits e and g amounts of yeast ATP synthase modifies mitochondrial cristae morphology. | Subunits e and g of Saccharomyces cerevisiae ATP synthase are required to maintain ATP synthase dimeric forms. Mutants devoid of these subunits display anomalous mitochondrial morphologies. An expression system regulated by doxycycline was used to modulate the expression of the genes encoding the subunits e and g. A de... |
15262974 | Lipid rafts regulate lipopolysaccharide-induced activation of Cdc42 and inflammatory functions of the human neutrophil. | Lipid rafts are cholesterol-rich membrane microdomains that are thought to act as coordinated signaling platforms by regulating dynamic, agonist-induced translocation of signaling proteins. They have been described to play a role in multiple prototypical cascades, among them the lipopolysaccharide pathway, and to host ... |
15280970 | Recent developments in the supramolecular chemistry of terpyridine-metal complexes. | This critical review describes recent developments in the field of supramolecular chemistry of terpyridine-metal complexes. The synthesis and characteristics of single as well as multiple homo- and heterometallic complexes is discussed. Furthermore, complexes containing fullerenes, biological building blocks, extended ... |
15254266 | Enhanced membrane fusion in sterol-enriched vacuoles bypasses the Vrp1p requirement. | Organization of lipids into membrane microdomains is a vital mechanism of protein processing. Here we show that overexpression of ERG6, a gene involved in ergosterol synthesis, elevates sterol levels 1.5-fold on the vacuole membrane and enhances their homotypic fusion. The mechanism of sterol-enhanced fusion is not via... |
15254265 | NrCAM coupling to the cytoskeleton depends on multiple protein domains and partitioning into lipid rafts. | NrCAM is a cell adhesion molecule of the L1 family that is implicated in the control of axonal growth. Adhesive contacts may promote advance of the growth cone by triggering the coupling of membrane receptors with the F-actin retrograde flow. We sought to understand the mechanisms leading to clutching the F-actin at th... |
15280957 | Photochemical and photophysical properties of a poly(propylene amine) dendrimer functionalized with E-stilbene units. | A second generation poly(propylene amine) dendrimer functionalized at the periphery with eight E-stilbene and eight 4-tert-butylbenzenesulfonyl units has been prepared. The absorption spectrum, fluorescence spectrum and decay, E<==>Z photoisomerization, and photocyclization of the Z-isomer of the stilbene units have be... |
15252027 | Effect of insulin on caveolin-enriched membrane domains in rat liver. | Compartmentalization of signaling molecules may explain, at least in part, how insulin or growth factors achieve specificity. Caveolae/rafts are specialized lipid compartments that have been implicated in insulin signaling. In the present study, we investigated the role of caveolin-enriched membrane domains (CMD) in me... |
15323871 | Molecular dynamics simulations of electrostatic layer-by-layer self-assembly. | Electrostatic assembly of multilayered thin films through sequential adsorption of polyions in layer-by-layer fashion utilizes the strong electrostatic attraction between oppositely charged molecules. We perform molecular dynamics simulations of multilayers of flexible polyelectrolytes around a charged spherical partic... |
15252057 | Dimer dissociation is essential for interleukin-8 (IL-8) binding to CXCR1 receptor. | Chemokines play a fundamental role in trafficking of immune cells and in host defense against infection. The role of chemokines in the recruitment process is highly regulated spatially and temporally and involves interactions with G protein-coupled receptors and cell surface glycosaminoglycans. The dynamic equilibrium ... |
15249672 | Magnetic circular dichroism of peralkylated tetrasilane conformers. | Magnetic circular dichroism (MCD) of five peralkylated tetrasilanes (1-5) conformationally constrained to angles ranging from nearly 0 degrees to 180 degrees and of the open chain tetrasilane Si(4)Me(10) (6) shows a clear conformational dependence and permits the detection of previously hidden transitions. In the tetra... |
15249670 | Heterodimeric complexes of Hop2 and Mnd1 function with Dmc1 to promote meiotic homolog juxtaposition and strand assimilation. | Saccharomyces cerevisiae Hop2 and Mnd1 are abundant meiosisspecific chromosomal proteins, and mutations in the corresponding genes lead to defects in meiotic recombination and in homologous chromosome interactions during mid-prophase. Analysis of various double mutants suggests that HOP2, MND1, and DMC1 act in the same... |
15249666 | A methionine aminopeptidase-2 inhibitor, PPI-2458, for the treatment of rheumatoid arthritis. | The hallmark of rheumatoid arthritis (RA) is the progressive destruction of articular joints, characterized by invasive synovial hyperplasia and pathological neovascularization. Here we report that PPI-2458, a member of the fumagillin class of irreversible methionine aminopeptidase-2 (MetAP-2) inhibitors, potently inhi... |
15249597 | Measuring specific interaction of transcription factor ZmDREB1A with its DNA responsive element at the molecular level. | Specific interactions between transcription factors and DNA responsive elements are of fundamental importance in understanding how genetic regulatory proteins control gene transcription. Here we have developed a new method of using atomic force microscopy (AFM) to quantitatively study the single molecular specific inte... |
15136766 | Targeted delivery of RNA-cleaving DNA enzyme (DNAzyme) to tumor tissue by transferrin-modified, cyclodextrin-based particles. | Short nucleic acid sequences specific to oncogene targets such as bcl-2, bcr-abl, and c-myc have been shown to exhibit specific anti-cancer activity in vitro through antigene or antisense activity. Efficient in vivo delivery of oligonucleotides remains a major limitation for the therapeutic application of these molecul... |
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