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18969956 | Molecular lego for the assembly of biosensing layers. | We propose a procedure to assemble monolayers of redox mediator, coenzyme, enzyme and stabilizing polyelectrolyte on an electrode surface using essentially electrostatic and complexing interactions. In a first step a monolayer of redox mediator, substituted nitrofluorenones, is adsorbed. In a second step, a layer of ca... |
15609011 | Determination of ion-pair formation constants of univalent metal-crown ether complex ions with anions in water using ion-selective electrodes: application of modified determination methods to several salts. | Ion-pair formation constants (mol(-1) dm3 unit), K(MX) for a univalent metal salt (MX) and K(MLX) for its ion-pair complex (ML+X-) with a crown ether (L) in water, were determined at various ionic strengths (I) and 25 degrees C by potentiometry with ion-selective electrodes for MX=NaPic, NaMnO4, NaBPh4, KPic, and KMnO4... |
15640590 | Hydrogen-bonded azopyridine and succinic acid co-crystal. | In the 1:1 supramolecular adduct of azopyridine (AZP) and succinic acid (SA) [systematic name: di-4-pyridyldiazene-succinic acid (1/1)], C10H8N4.C4H6O4 or AZP.SA, both components lie on inversion centers. Alternating AZP and SA molecules are linked by O-H...N hydrogen bonds to form a linear chain extending in the [31-1... |
15606917 | The quantal theory of how the immune system discriminates between "self and non-self" | In the past 50 years, immunologists have accumulated an amazing amount of information as to how the immune system functions. However, one of the most fundamental aspects of immunity, how the immune system discriminates between self vs. non-self, still remains an enigma. Any attempt to explain this most intriguing and f... |
15700073 | Molecular recognition in a uradinyl-functionalized stable radical. | Stable radical 2-(6-uradinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl (1) binds to hydrogen-bonding complement 2,6-di(propylamido)pyridine (DAP) in chloroform with Ka=220 M(-1) at 33 degrees C; ESI-MS shows not only 1:DAP complementary dyad formation, but also 1:(DAP)2 formation at higher concentrations of ... |
15654374 | Efficient relaxivity enhancement in dendritic gadolinium complexes: effective motional coupling in medium molecular weight conjugates. | Enhancement of the relaxivities of Gd-based MRI contrast agents is achieved by placing the metal ion at the barycentre of the molecular complex in order to improve motional coupling. |
15854817 | Analytical applications of aptamers. | So far, several bio-analytical methods have used nucleic acid probes to detect specific sequences in RNA or DNA targets through hybridisation. More recently, specific nucleic acids, aptamers, selected from random sequence pools, have been shown to bind non-nucleic acid targets, such as small molecules or proteins. The ... |
15685327 | Synergistic assembly of hyperbranched polyethylenimine and fatty acids leading to unusual supramolecular nanocapsules. | Self-assembly of hyperbranched polyethylenimine (PEI) and fatty acids leads to supramolecular inverted micellar structures that are able to irreversibly transfer water-soluble guest molecules into organic solvents. |
15616586 | The structure of the TrmE GTP-binding protein and its implications for tRNA modification. | TrmE is a 50 kDa guanine nucleotide-binding protein conserved between bacteria and man. It is involved in the modification of uridine bases (U34) at the first anticodon (wobble) position of tRNAs decoding two-family box triplets. The precise role of TrmE in the modification reaction is hitherto unknown. Here, we report... |
15604099 | Sonic hedgehog controls stem cell behavior in the postnatal and adult brain. | Sonic hedgehog (Shh) signaling controls many aspects of ontogeny, orchestrating congruent growth and patterning. During brain development, Shh regulates early ventral patterning while later on it is critical for the regulation of precursor proliferation in the dorsal brain, namely in the neocortex, tectum and cerebellu... |
15620873 | Effect of penetration enhancers on the release and skin permeation of bupranolol from reservoir-type transdermal delivery systems. | A reservoir-type transdermal delivery system (TDS) of bupranolol (BPL) was designed and evaluated for different formulation variables like gel reservoirs (made with anionic and nonionic polymers), rate controlling membranes and penetration enhancers on the drug release and in vitro skin permeation kinetics of the devic... |
15604456 | Sequence-dependent cytotoxicity of second-generation oligonucleotides. | In this study, we have examined the potential of second-generation antisense chimeric 2'-O-(2-methoxy)ethyl/DNA phosphorothioate oligonucleotides (ONs) to affect cell growth through non-antisense mechanisms. Evaluation of a series of ONs demonstrated that only a small number were cytotoxic at concentrations close to th... |
15742043 | Chiral molecular tapes from novel tetra(thiafulvalene-crown-ether)-substituted phthalocyanine building blocks. | A tetra(thiafulvalene-crown-ether) phthalocyanine self-assembles into helical tapes nanometers wide and micrometers long. Formation of these scrolled molecular architectures is a first for phthalocyanine fibres and shows potential as a novel conducting material. |
15710507 | Polymeric micellar pH-sensitive drug delivery system for doxorubicin. | A novel polymeric micellar pH-sensitive system for delivery of doxorubicin (DOX) is described. Polymeric micelles were prepared by self-assembly of amphiphilic diblock copolymers in aqueous solutions. The copolymers consist of a biocompatible hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic block containi... |
15685329 | Photoreversible supramolecular polymer formation. | Particle sizes of a supramolecular polymer composed of diarylethene having two quadruple hydrogen bonding moieties were changed photoreversibly. |
15685325 | [3]rotaxane synthesized via covalent bond formation can recognize cations forming a sandwich structure. | A novel [3]rotaxane composed of two 25-membered crownophanes and one axle molecule having two anthryl end groups was successfully synthesized via covalent bond formation followed by aminolysis, and can incorporate caesium ion into the space between the two macrocycles as a 1 : 1 sandwich-type complex, whereas it makes ... |
15601471 | Optimized expression of Plasmodium falciparum erythrocyte membrane protein 1 domains in Escherichia coli. | <h4>Background</h4>The expression of recombinant proteins in Escherichia coli is an important and frequently used tool within malaria research, however, this method remains problematic. High A/T versus C/G content and frequent lysine and arginine repeats in the Plasmodium falciparum genome are thought to be the main re... |
15601771 | Ribavirin suppresses eIF4E-mediated oncogenic transformation by physical mimicry of the 7-methyl guanosine mRNA cap. | The eukaryotic translation initiation factor eIF4E is deregulated in many human cancers, and its overexpression in cells leads to malignant transformation. Oncogenic properties of eIF4E are directly linked to its ability to bind 7-methyl guanosine of the 5' mRNA. Here, we observe that the antiviral guanosine analogue r... |
15601759 | Human myoglobin recognition of oxygen: dynamics of the energy landscape. | Femtosecond to nanosecond dynamics of O(2) rebinding to human WT myoglobin and its mutants, V68F and I107F, have been studied by using transient absorption. The results are compared with NO rebinding. Even though the immediate environment around the heme binding site is changed by the mutations, the picosecond geminate... |
15672172 | Study of the Michael addition of beta-cyclodextrin-thiol complexes to conjugated alkenes in water. | An environmentally benign and highly efficient supramolecular Michael addition of thiols from the secondary side of beta-cyclodextrin to alpha,beta-unsaturated compounds at the primary side in water is described in quantitative yields; products of undesirable side reactions resulting from polymerization are not observe... |
15632973 | Azidocryptands-synthesis, structure, and complexation properties. | Cryptands bearing an intraannular azido substituent have been synthesized and characterized spectroscopically. Their complexation properties were investigated by picrate extraction analysis. The oxygen-containing cryptands were found to be good ligands for alkali cations, with a preference for Li(+) and Na(+). The mole... |
15598740 | Potent inhibition of huntingtin aggregation and cytotoxicity by a disulfide bond-free single-domain intracellular antibody. | Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion in the number of polyglutamine-encoding CAG repeats in the gene that encodes the huntingtin (htt) protein. A property of the mutant protein that is intimately involved in the development of the disease is the propensity of the ... |
15596490 | Molecular modeling of nearly full-length ErbB2 receptor. | Members of the epidermal growth factor receptor family play important roles in various cellular processes, both in physiological and in pathological conditions. Dimerization and autophosphorylation of these receptor tyrosine kinases are key events of signal transduction. Details of the molecular events of the signaling... |
15672163 | A new [2 + 2] photodimerization of 5-chloro- and 5-methyl-2-pyridone in their inclusion complexes with 1,1'-biphenyl-2,2'-dicarboxylic acid as a model for DNA damage by photodimerization of its thymine component. | As a model for DNA damage by photodimerization of its thymine component, a new [2 + 2] photodimerization of 5-chloro and 5-methyl-2-pyridone to the corresponding cis-anti-dimers as their inclusion complexes with 1,1'-biphenyl-2,2'-dicarboxylic acid was found, and the mechanism of this stereoselective solid state reacti... |
15645029 | Selective single crystal complexation of L- or D-leucine by p-sulfonatocalix[6]arene. | p-Sulfonatocalix[6]arene, organised in the 'double cone' conformation, has multi-guest capability binding either L- or D-leucine in a single crystal in a bi-layer type arrangement from a racemic mixture of the amino acid. |
15632979 | Molecular mechanism of dielectrically controlled optical resolution (DCR). | We have recently found the first example of dielectrically controlled optical resolution (DCR). By adjusting the dielectric constant of the solvent used in the resolution process, each optical isomer of (R,S)-alpha-amino-epsilon-caprolactam can be selectively obtained using N-tosyl-(S)-phenylalanine as a chiral selecto... |
15596727 | Xe NMR lineshapes in channels of peptide molecular crystals. | To further an understanding of the nature of information available from Xe chemical shifts in cavities in biological systems, it would be advantageous to start with Xe in regular nanochannels that have well known ordered structures built from amino acid units. In this paper, we report the experimental observation of Xe... |
15596521 | HIV-specific cytotoxic T cells from long-term survivors select a unique T cell receptor. | HIV-specific cytotoxic T lymphocytes (CTL) are important in controlling HIV replication, but the magnitude of the CTL response does not predict clinical outcome. In four donors with delayed disease progression we identified Vbeta13.2 T cell receptors (TCRs) with very similar and unusually long beta-chain complementarit... |
15596547 | Processive capping by formin suggests a force-driven mechanism of actin polymerization. | Regulation of actin polymerization is essential for cell functioning. Here, we predict a novel phenomenon-the force-driven polymerization of actin filaments mediated by proteins of the formin family. Formins localize to the barbed ends of actin filaments, but, in contrast to the standard capping proteins, allow for act... |
15596541 | BDNF-induced recruitment of TrkB receptor into neuronal lipid rafts: roles in synaptic modulation. | Brain-derived neurotrophic factor (BDNF) plays an important role in synaptic plasticity but the underlying signaling mechanisms remain unknown. Here, we show that BDNF rapidly recruits full-length TrkB (TrkB-FL) receptor into cholesterol-rich lipid rafts from nonraft regions of neuronal plasma membranes. Translocation ... |
15640587 | Hydrogen bonding and pi-pi stacking in dimethylgenistein. | The title compound, 5-hydroxy-4',7-dimethoxyisoflavone, C17H14O5, is composed of a benzopyranone moiety, a phenyl moiety and two methoxy groups. The benzopyranone ring is not coplanar with the phenyl ring, the dihedral angle between them being 56.28 (3) degrees. The two methoxy groups are nearly coplanar with their cor... |
15640570 | Two two-dimensional MnII and NaI coordination polymers constructed by the flexible benzene-1,4-dioxyacetate ligand. | Two new two-dimensional coordination polymers, poly[[[aqua(2,2'-bipyridine-kappa2N,N')manganese(II)]-mu3-p-phenylenebis(oxyacetato)-kappa3O:O':O''] dihydrate], {[Mn(C10H8O6)(C10H8N2)(H2O)].2H2O}n, (I), and poly[[di-mu-aqua-bis[aquasodium(I)]]-mu4-p-phenylenebis(oxyacetato)-kappaO:O',O'':O''',O'''':O'''''], [Na2(C10H8O6... |
15640567 | A novel three-dimensional supramolecular coordination polymer: poly[[diaquadicadmium(II)-di-mu2-4,4'-bipyridyl-di-mu2-2-sulfonatobenzoato] dihydrate]. | The hydrothermal reaction of Cd(CH3COO)2.2H2O, 4,4'-bipyridyl and 2-sulfobenzoic acid produced the title compound, {[Cd2(C7H4O5S)2(C10H8N2)2(H2O)2].2H2O}n, which forms a two-dimensional coordination polymer, the sheets of which are linked via hydrogen bonds. Two different types of Cd atoms are present, one lying on a t... |
15864663 | Patients with haematological malignancies requiring invasive mechanical ventilation: differences between survivors and non-survivors in intensive care unit. | <h4>Background</h4>Mortality of patients with haematological malignancies requiring intensive therapy is high. We wanted to establish reasons for intensive care unit (ICU) admission and treatment as well as outcome in subjects who required invasive mechanical ventilation. We were also interested in differences between ... |
15829341 | On the possibility of molecular recognition of taste substances studied by Gábor analysis of oscillations. | A liquid membrane oscillator containing nitromethane as membrane material has been investigated. The influence of substances responsible for taste belonging to four classes (sweetness, saltiness, sourness and bitterness) on oscillation patterns of liquid membrane oscillators with cationic surfactant benzyldimethyltetra... |
15740912 | Simultaneous determination of ingredients in a cold medicine by cyclodextrin-modified microemulsion electrokinetic chromatography. | Cyclodextrin-modified microemulsion electrokinetic chromatography (CD-MEEKC) was used to simultaneously determine 14 active ingredients (thiamine nitrate, anhydrous caffeine, acetaminophen, riboflavin, guaifenesin, pseudoephedrine hydrochloride, ascorbic acid, ethenzamide, DL-methylephedrine hydrochloride, dihydrocodei... |
15740908 | HPLC and solubility study of the interaction between pindolol and cyclodextrins. | The complexation with beta-cyclodextrin (beta-CD) has been investigated using reversed-phase liquid chromatography. The compounds tested have been pindolol and, for comparison purposes, indole and 4-methoxyindole. The retention behaviour has been analysed on a Kromasil 100 C18 column and the mobile phase used was metha... |
15616714 | A chiral [2]catenane self-assembled from meso-macrocycles of palladium(II). | Reaction of trans-[PdX2(SMe2)2](X = Cl or Br) with the chiral ligand LL = 1,1'-binaphthyl-2,2'-(NHC(= O)-3-C5H4N)2 gave the [2]catenane complexes trans-[{(PdX2)2(micro-LL)2}2], which are formed by self-assembly from 4 units each of trans-PdX2 and LL. The catenation is favored by the formation of multiple hydrogen bonds... |
15672157 | Inclusion complexes of trivalent lutetium cations with an acidic derivative of per(3,6-anhydro)-alpha-cyclodextrin. | The cyclodextrin derivative (hexakis (2-O-carboxymethyl-3,6-anhydro)-alpha-cyclodextrin) forms mono- and bimetallic complexes with lutetium(III) in aqueous solution; the X-ray structure of the binuclear complex [Lu2(ACX)(H2O)2] is the first example of a lanthanide-cyclodextrin inclusion complex. |
15645023 | Synthesis and optical properties of metallo-supramolecular polymers. | Metal-ligand interactions between metal ions, such as Zn2+, and ditopic low-molecular weight conjugated monomers, which utilize the 2,6-bis(1'-methylbenzimidazolyl)pyridine ligand, lead to the formation of supramolecular conjugated polymers with interesting optical properties. |
16043068 | Structural and orientational studies of chiral N-[4(1-pyrene)butyroyl]-phenylalanine in cast film. | Cast films of chiral material N-[4(1-pyrene)butyroyl]-l-phenylalanine (Py-l-Phe) and the racemic modification (the 1:1 mixture of Py-l-Phe and Py-d-Phe) have been investigated in the present study. The microscopic structure, molecular orientation and the aggregation in the film have been studied by using ultraviolet-vi... |
15724172 | Catechol imine ligands: from helicates to supramolecular tetrahedra. | Di- and tricatechol imines are easily accessible by condensation of appropriate amines with 2,3-dihydroxybenzaldehyde. Dicatechol imines can be used for the alkali metal template-directed self-assembly of dinuclear triple-stranded helicates or meso-helicates with high diastereoselectivity. Tricatechol imines lead in se... |
15591129 | Agonist-induced endocytosis of CC chemokine receptor 5 is clathrin dependent. | The signaling activity of several chemokine receptors, including CC chemokine receptor 5 (CCR5), is in part controlled by their internalization, recycling, and/or degradation. For CCR5, agonists such as the chemokine CCL5 induce internalization into early endosomes containing the transferrin receptor, a marker for clat... |
15645021 | Polycationic dendrimers interact with RNA molecules: polyamine dendrimers inhibit the catalytic activity of Candida ribozymes. | Various polyamine dendrimers with a triethanolamine core inhibit the activity of the Candida ribozyme by forming RNA-dendrimer complexes via electrostatic interactions. |
15632970 | The chirality of dendrimer-based supramolecular complexes. | Boc-protected L-phenylalanine has been connected to a spacer-armed ureido-acetic acid derivative, which can form multiple supramolecular complexes with urea-adamantyl modified poly(propylene imine) dendrimers in chloroform. Complexes of this guest with several generations of urea-adamantyl dendrimers were prepared. The... |
16043072 | Direct fluorimetric determination of ascorbic acid by the supramolecular system of AA with beta-cyclodextrin derivative. | We established a simple and selective fluorimetric method for the determination of ascorbic acid (AA) with the novel mono-[6-N(4-carboxy-phenyl)]-beta-cyclodextrin (ACD). The method is based on the fluorescence intensity of ACD decreases as the ACD-AA supramolecular complexes form. The fluorescence intensity is measure... |
15588280 | Nanoparticles - known and unknown health risks. | Manmade nanoparticles range from the well-established multi-ton production of carbon black and fumed silica for applications in plastic fillers and car tyres to microgram quantities of fluorescent quantum dots used as markers in biological imaging. As nano-sciences are experiencing massive investment worldwide, there w... |
15590676 | The NK1 receptor localizes to the plasma membrane microdomains, and its activation is dependent on lipid raft integrity. | The spatial targeting of receptors to discrete domains within the plasma membrane allows their preferential coupling to specific effectors, which is essential for rapid and accurate discrimination of signals. Efficiency of signaling is further increased by protein and lipid segregation within the plasma membrane. We ha... |
15672146 | Anion induced modulation of self-assembly and optical properties in urea end-capped oligo(p-phenylenevinylene)s. | The non-emissive supramolecular assembly of urea end-capped oligo(p-phenylenevinylene) flourophores turned strongly emissive in the presence of tetrabutylammonium flouride which has implications in the anion controlled design of supramolecular architectures with tunable emission properties. |
15654396 | Calix[4]bipyrrole--a big, flexible, yet effective chloride-selective anion receptor. | Anion binding studies reveal that, in spite of its big size and flexible structure, calix[4]bipyrrole shows strong anion binding in general and good selectivity towards chloride anion in acetonitrile. |
15654364 | Dendritic incorporation of quinacridone: solubility, aggregation, electrochemistry, and solid-state luminescence. | The first incorporation of quinacridone, a technologically important organic electroluminescent emitter, into dendrimers increases solubility, decreases aggregation, retards heterogeneous electron transfer, and enhances luminescence in condensed phases (powders and thin films). |
15644202 | Structural alignment of protein--DNA interfaces: insights into the determinants of binding specificity. | A new method is introduced to structurally align interfaces observed in protein--DNA complexes. The method is based on a procedure that describes the interfacial geometry in terms of the spatial relationships between individual amino acid--nucleotide pairs. An amino acid--amino acid similarity matrix, S, is defined tha... |
15645022 | Intact transfer of layered, bionanocomposite arrays by microcontact printing. | A novel approach is presented that allows high-quality, 3D patterned bionanocomposite layered films to be constructed on substrates whose surface properties are incompatible with existing self-assembly methods. |
15616727 | Dinuclear zinc(II) dithiocarbamate macrocycles: ditopic receptors for a variety of guest molecules. | The synthesis of a series of dinuclear zinc(II) dithiocarbamate (dtc) macrocyclic receptors containing aryl spacer groups of different sizes is reported. As evidenced from 1H NMR titration investigations, these receptors have the ability to bind various neutral and anionic bidentate guests species, including 1,4-diazab... |
15591017 | Synthesis of unimolecularly circular G-quadruplexes as prospective molecular probes. | Synthesis of unimolecularly circular G-quadruplex has been accomplished for the first time during our investigation on the template basis of G-quadruplex through chemical ligations of guanine-rich linear sequences of oligodeoxyribonucleotides. The uniqueness of this newly designed circularization course is its self-rec... |
15590905 | DNA footprinting and biophysical characterization of the controller protein C.AhdI suggests the basis of a genetic switch. | We have cloned and expressed the ahdIC gene of the AhdI restriction-modification system and have purified the resulting controller (C) protein to homogeneity. The protein sequence shows a HTH motif typical of that found in many transcriptional regulators. C.AhdI is found to form a homodimer of 16.7 kDa; sedimentation e... |
15583961 | Hyperphosphorylation-induced self assembly of murine tau: a comparison with human tau. | Alzheimer's disease-like neurofibrillary pathology is neither seen in rodents nor in transgenic animals expressing the disease causing mutant human APP or mutant human presenilins. Whether the absence of this pathology is due to inability of the murine tau to self assemble into filaments or due to some other factors is... |
15958175 | Whole-cell-reporter-gene-based biosensing systems on a compact disk microfluidics platform. | Biosensing systems such as reporter-gene-based whole-cell assays are increasingly finding applications in biological and environmental screening. A whole-cell approach to such analyses can provide valuable information about the bioavailable level of a compound of interest. These biosensing systems rely on the molecular... |
15665968 | Raman spectroscopy of endoliths from Antarctic cold desert environments. | Six endolithic communities from Antarctic cold desert environments have been analysed by Raman spectroscopy. The extreme conditions that the organisms have to withstand in cold environments leads to the adoption of different survival strategies and adaptation of the geological environment. Production of radiation- and ... |
15583715 | Algorithmic self-assembly of DNA Sierpinski triangles. | Algorithms and information, fundamental to technological and biological organization, are also an essential aspect of many elementary physical phenomena, such as molecular self-assembly. Here we report the molecular realization, using two-dimensional self-assembly of DNA tiles, of a cellular automaton whose update rule... |
15654373 | Self-assembled monolayers of optically active Co(III) complexes: a new promoter electrode recognizing the electron transfer site in cytochrome c. | A new-class of promoter electrode bearing a molecular recognition ability has been constructed; the chirality and/or orientation of promoter on the Au electrode surface have affected the electron transfer rate of cytochrome c. |
15643486 | Nucleobases as supramolecular motifs. | The five main natural nucleobases adenine, cytosine, guanine, thymine and uracil are involved in the self-assembly of one of nature's most interesting and intriguing class of biopolymers, namely the nucleic acids DNA and RNA. As such, these nucleobases have held a fascination to researchers in a diverse range of fields... |
15616723 | Synthesis of a novel dinucleating aminocarboxylate macrocycle and structures of its dinuclear complexes with di- and trivalent transition and lanthanide metal ions. | The synthesis of the new ligand L1(H4L1= 3,8,16,21-tetrakis(carboxylmethyl)-3,8,16,21,27,28-hexaazatricyclo[21.3.1.1(10,14)]octacosa-1(27),10,12,14(28),23,25-hexaen-5,18-diine) is reported. The solid-state structures of the four homodinuclear chelate complexes, [Zn2(L1)(H2O)2] x 6H2O, [Fe2(L1)(mu-O)] x 4H2O, [La2(L1)(N... |
15654387 | Fluorescence enhancement of a signaling system in the simultaneous presence of transition and alkali metal ions: a potential AND logic gate. | Attachment of a laterally non-symmetric cryptand and a macrocycle at the 9- and 10-positions of anthracene leads to a fluorescent signaling system L1 which gives fluorescence enhancement in the simultaneous presence of alkali and transition metal ions. |
15616709 | Formation of a [2 + 2]-heterotetranuclear macrocycle from reaction of a platina-homoditopic ligand with iron(II). | Reaction of 4'-(2-propyn-1-oxy)-2,2':6',2''-terpyridine (HC triple bond CCH2Oterpy) with trans-[PtI2(PEt3)2] regioselectively metallates the alkyne to give trans-[Pt(C triple bond CCH2Oterpy)2(PEt3)2] which, when treated with Fe(II), gives a [2 + 2]-metallocycle. |
16508098 | Crystallization and preliminary X-ray studies on the reaction center-light-harvesting 1 core complex from Rhodopseudomonas viridis. | The reaction center-light-harvesting 1 (RC-LH1) core complex is the photosynthetic apparatus in the membrane of the purple photosynthetic bacterium Rhodopseudomonas viridis. The RC is surrounded by an LH1 complex that is constituted of oligomers of three types of apoproteins (alpha, beta and gamma chains) with associat... |
15576374 | Inhibition of IkappaB kinase activity by acetyl-boswellic acids promotes apoptosis in androgen-independent PC-3 prostate cancer cells in vitro and in vivo. | Signaling through NF-kappaB has been implicated in the malignant phenotype as well as the chemoresistance of various cancers. Here we show that the natural compounds acetyl-beta-boswellic acid and acetyl-11-keto-beta-boswellic acid (AKbetaBA) inhibit proliferation and elicit cell death in chemoresistant androgen-indepe... |
15654399 | A dynamic supramolecular system exhibiting substrate selectivity in the catalytic epoxidation of olefins. | A dynamic supramolecular system involving hydrogen bonding between a Mn(III) salen catalyst and a Zn(II) porphyrin receptor exhibits selectivity for pyridine appended cis-beta-substituted styrene derivatives over phenyl appended derivatives in a catalytic epoxidation reaction. |
15654384 | Synthesis of anthracene ethers from anthracene methyl ethers via an acid-catalyzed exchange reaction. | Selective synthesis of anthracene ethers was achieved under mild conditions via an acid-catalyzed ether-ether exchange reaction and its scope and limitations, as well as its potential in synthesizing anthracene-based crown ethers, tested. |
15576559 | A novel method reveals that solvent water favors polyproline II over beta-strand conformation in peptides and unfolded proteins: conditional hydrophobic accessible surface area (CHASA). | In aqueous solution, the ensemble of conformations sampled by peptides and unfolded proteins is largely determined by their interaction with water. It has been a long-standing goal to capture these solute-water energetics accurately and efficiently in calculations. Historically, accessible surface area (ASA) has been u... |
15576566 | Computational analysis of the transient movement of helices in sensory rhodopsin II. | MD simulation of sensory rhodopsin II was executed for three intermediates (ground-state, K-state, M-state) appearing in its photocycle. We observed a large displacement of the cytoplasmic side of helixF only in M-state among the three intermediates. This displacement was transmitted to TM2, and the cytoplasmic side of... |
15576561 | Amyloid accomplices and enforcers. | Amyloid-related diseases are often ascribed to protein "misfolding." Yet in the absence of high-resolution structures for mature fibrils or intermediates, the connection between the mechanism of amyloid formation and protein folding remains tenuous. The simplistic view of amyloid fibrillogenesis as a homogeneous self-a... |
15576552 | Contribution of the intrinsic disulfide to the assembly mechanism of islet amyloid. | Amyloidogenesis from soluble protein requires conformational and oligomeric assembly steps. In systems where the precursor protein is natively unfolded, such as islet amyloid polypeptide (IAPP), forces and structural changes relevant to protein unfolding are not thought to participate in the assembly mechanism. Thus, f... |
15576679 | Identification of genes with fast-evolving regions in microbial genomes. | Complete sequences of multiple strains of the same microbial species provide an invaluable source for studying the evolutionary dynamics between orthologous genes over a relatively short time scale. Usually the intensity of the selection pressure is inferred from a comparison between the nonsynonymous substitution rate... |
20704949 | Dendrimer drugs prevent scar tissue formation. | Extract: Dendrimers are hyperbranched synthetic macromolecules that can be made with structural precision. So far, their biomedical applications have been limited to drug delivery. Dendrimers with cationic (i.e., amine or NH3+) end groups are toxic after repeated intravenous use or topical ocular application. In contra... |
20686642 | Toward the Design of MR Agents for Imaging β-Cell Function. | The chemistry of Gd(3+)-based MRI agents has advanced considerably during the past decade toward agents with higher relaxivity and agents that respond to physiology and/or metabolism. This review describes various approaches that have been taken toward the development of responsive contrast agents and discusses the imp... |
18969717 | Analytical applications of organized assemblies for on-line spectrometric determinations: present and future. | An amphiphile (surfactant) spread on water can lead to the formation of different aggregates: vesicles, miscelles, emulsions or microemulsions; depending on its concentration; its molecular structure and/or the experimental conditions. Such aggregates, (a) may concentrate products, reactants or analytes and so improve ... |
18404401 | Coronary artery reperfusion: The ADP receptor P2Y(1) mediates early reactive hyperemia in vivo in pigs. | The physiological mechanisms that regulate reactive hyperemia are not fully understood. We postulated that the endothelial P2Y(1) receptor that release vasodilatory factors in response to ADP might play a vital role in the regulation of coronary flow. Intracoronary flow was measured with a Doppler flow-wire in a porcin... |
17330146 | Semi-artificial Fluorescent Molecular Machine for DNA Damage Detection. | The design of artificial molecular machines is complicated because the mechanics used in macromachines is not readily adaptable for nano environments. We constructed a semi-artificial molecular device, which contains a naturally occurring molecular machine-a vaccinia virus encoded protein-linked with an artificial part... |
17191834 | New macrocyclic musk compounds. | The syntheses and olfactory evaluations of eight new macrocyclic musks with a 1,6-dioxa structure (1a-d and 1'a-d) as well as of twelve optically active 3-methyl macrolides (5a-c and 5'a-c) are reported. These macrocycles were synthesized via intramolecular metathesis mediated by the Grubbs catalyst. Despite the absenc... |
17191832 | 'Brain aided' musk design. | This brief review, including new experimental results, is the summary of a talk at the RSC/SCI conference flavours & fragrances 2004 in Manchester, United Kingdom, 12-14 May, 2004. Musk odorants have been a classical domain for computer aided structure-odor relationship (SOR) studies, but, contrary to sandalwood or amb... |
15578182 | Cancer and aging: symposium of the 27th annual meeting of the Japanese society for biomedical gerontology, Tokyo. | Although many hypotheses have been proposed to explain the strong link between aging and cancer, the exact mechanisms responsible for the increased frequency of occurrence of cancer with advancing age have not been fully defined. Recent evidence indicates that malregulation of the apoptotic process may be involved in s... |
15830603 | Evaluation of hydroxypropyl-beta-cyclodextrin in the treatment of aldicarb poisoning in rats. | Cyclodextrins are ring-shaped oligosaccharides with a hydrophilic exterior and a hydrophobic interior. The interior cavity is capable of complexing fat-soluble molecules small enough to fit inside. Sprague-Dawley rats were used to evaluate the efficacy of hydroxypropyl-beta-cyclodextrin as treatment of aldicarb poisoni... |
15807250 | [Study on preparation of the inclusion compound of curcumin with beta-cyclodextrin]. | <h4>Objective</h4>The inclusion compound of curcumin with, beta-CD was preparated to increase the solubility and bioavaliability of curcumin.<h4>Methods</h4>Prepare inclusion compound was studied with orthogonal design. The inclusion compound was verified with fluorometry, TLC, and phase solubility.<h4>Result</h4>The b... |
15649580 | Structure and function of amyloid in Alzheimer's disease. | This review is focused on the structure and function of Alzheimer's amyloid deposits. Amyloid formation is a process in which normal well-folded cellular proteins undergo a self-assembly process that leads to the formation of large and ordered protein structures. Amyloid deposition, oligomerization, and higher order po... |
15574704 | Amyloidogenic self-assembly of insulin aggregates probed by high resolution atomic force microscopy. | As the application of high-resolution atomic force microscopy (AFM) has led us recently to the discovery of a unique pressure-induced circular amyloid, we used the same approach to examine morphological events accompanying insulin aggregation under ambient conditions. This study presents the multistage, hierarchical ch... |
15707832 | Respiratory chain supercomplexes in plant mitochondria. | Supercomplexes are defined associations of protein complexes, which are important for several cellular functions. This "quintenary" organization level of protein structure recently was also described for the respiratory chain of plant mitochondria. Except succinate dehydrogenase (complex II), all complexes of the oxida... |
15692732 | Decrease of P-glycoprotein activity in K562/ADR cells by MbetaCD and filipin and lack of effect induced by cholesterol oxidase indicate that this transporter is not located in rafts. | The effect of low-density membrane domains on function of the plasma membrane transporter P-glycoprotéine (P-gp), involved in multidrug resistance (MDR) phenotype, has been investigated in K562/ADR cells. To this end we reversibly altered the cholesterol content of K562/ADR cells by using methyl-beta-cyclodextrin as a ... |
15390260 | Molecular recognition of aldehydes by aldehyde dehydrogenase and mechanism of nucleophile activation. | Experimental structural data on the state of substrates bound to class 3 Aldehyde Dehydrogenases (ALDH3A1) is currently unknown. We have utilized molecular mechanics (MM) simulations, in conjunction with new force field parameters for aldehydes, to study the atomic details of benzaldehyde binding to ALDH3A1. Our result... |
15675006 | Towards a unifying basis of auditory thresholds: the effects of hearing loss on temporal integration reconsidered. | For signal detection and identification, the auditory system needs to integrate sound over time. It is frequently assumed that the quantity ultimately integrated is sound intensity and that the integrator is located centrally. However, we have recently shown that absolute thresholds are much better specified as the tem... |
15672215 | Solid-phase artificial chaperone-assisted refolding using insoluble beta-cyclodextrin-acrylamide copolymer beads. | Solid-phase refolding methods are advantageous since they facilitate both separation of solid additives from the refolded protein and recycling of the additives. Beta-cyclodextrin-acrylamide copolymer hydrogel beads were used as a matrix for detergents in solid-phase artificial chaperone-assisted refolding and improved... |
15574881 | Beta1-integrin orients epithelial polarity via Rac1 and laminin. | Epithelial cells polarize and orient polarity in response to cell-cell and cell-matrix adhesion. Although there has been much recent progress in understanding the general polarizing machinery of epithelia, it is largely unclear how this machinery is controlled by the extracellular environment. To explore the signals fr... |
15606286 | First-principles study of the rotational transitions of H2 physisorbed over benzene. | In the ongoing search for promising compounds for hydrogen storage, novel porous metal-organic frameworks (MOFs) have been discovered recently [M. Eddadoudi, J. Kim, N. L. Rosi, D. Vodak, J. Wachter, M. O'Keeffe, and O. M. Yaghi, Science 295, 469 (2002); N. L. Rosi, J. Eckert, M. Eddadoudi, D. Vodak, J. Kim, M. O'Keeff... |
15606275 | Computational study of hydrogen binding by metal-organic framework-5. | We report the results of quantum chemistry calculations on H(2) binding by the metal-organic framework-5 (MOF)-5. Density functional theory calculations were used to calculate the atomic positions, lattice constant, and effective atomic charges from the electrostatic potential for the MOF-5 crystal structure. Second-or... |
15656510 | Evaluation of pressure distribution under an English saddle at walk, trot and canter. | <h4>Reasons for performing study</h4>Basic information about the influence of a rider on the equine back is currently lacking.<h4>Hypothesis</h4>That pressure distribution under a saddle is different between the walk, trot and canter.<h4>Methods</h4>Twelve horses without clinical signs of back pain were ridden. At leas... |
15611330 | Critical role of PIP5KI{gamma}87 in InsP3-mediated Ca(2+) signaling. | Phosphatidylinositol 4,5-bisphosphate (PIP(2)) is the obligatory precursor of inositol 1,4,5-trisphosphate (InsP(3) or IP(3)) and is therefore critical to intracellular Ca(2+) signaling. Using RNA interference (RNAi), we identified the short splice variant of type I phosphatidylinositol 4-phosphate 5-kinase gamma (PIP5... |
15650689 | Expression of the promoter for the maltogenic amylase gene in Bacillus subtilis 168. | An additional amylase, besides the typical alpha-amylase, was detected for the first time in the cytoplasm of B. subtilis SUH4-2, an isolate from Korean soil. The corresponding gene (bbmA) encoded a maltogenic amylase (MAase) and its sequence was almost identical to the yvdF gene of B. subtilis 168, whose function was ... |
15648271 | Effects of hydrophilic cyclodextrins on aggregation of recombinant human growth hormone. | <h4>Purpose</h4>To evaluate the effect of hydrophilic cyclodextrins (CyDs) on the aggregation induced by different stresses and on the oxidation and deamidation of recombinant human growth hormone (rhGH).<h4>Methods</h4>The aggregation of rhGH was induced by three denaturing techniques including chemical (4.5 M guanidi... |
15646805 | Determination of stability constants of the inclusion complexes of beta-blockers in heptakis (2,3-dimethyl-6-sulfato)-beta-cyclodextrin. | The beta-blockers possess at least one chiral center and the S(-)-enantiomer shows higher affinity for binding to the beta-adrenergic receptors than antipode. The stability constants of acebutolol, celiprolol, propranolol and terbutaline in the inclusion complexes with single-isomer heptakis (2,3-dimethyl-6-sulfato)-be... |
15551322 | The versatile, efficient, and stereoselective self-assembly of transition-metal helicates by using hydrogen-bonds. | A diverse range of dinuclear double-stranded helicates in which the ligand strand is built up by using hydrogen-bonding has been synthesized. The helicates, formulated as [Co(2)(L)(2)(L-H)(2)X(2)], readily self-assemble from a mixture of a suitable pyridine-alcohol compound (L; for example, 6-methylpyridine-2-methanol,... |
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