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15340073 | SRC-mediated phosphorylation of focal adhesion kinase couples actin and adhesion dynamics to survival signaling. | Integrin-associated focal adhesions not only provide adhesive links between cellular actin and extracellular matrix but also are sites of signal transmission into the cell interior. Many cell responses signal through focal adhesion kinase (FAK), often by integrin-induced autophosphorylation of FAK or phosphorylation by... |
15340068 | Sequestosome 1/p62 is a polyubiquitin chain binding protein involved in ubiquitin proteasome degradation. | Herein, we demonstrate that the ubiquitin-associated (UBA) domain of sequestosome 1/p62 displays a preference for binding K63-polyubiquitinated substrates. Furthermore, the UBA domain of p62 was necessary for aggregate sequestration and cell survival. However, the inhibition of proteasome function compromised survival ... |
15340060 | The small nucle(ol)ar RNA cap trimethyltransferase is required for ribosome synthesis and intact nucleolar morphology. | Nucleolar morphogenesis is a poorly defined process. Here we report that the Saccharomyces cerevisiae nucleolar trimethyl guanosine synthase I (Tgs1p), which specifically selects the m(7)G cap structure of snRNAs and snoRNAs for m(2,2,7)G conversion, is required not only for efficient pre-mRNA splicing but also for pre... |
15340051 | A cellular RNA-binding protein enhances internal ribosomal entry site-dependent translation through an interaction downstream of the hepatitis C virus polyprotein initiation codon. | Translational initiation of hepatitis C virus (HCV) mRNA occurs by internal entry of ribosomes into an internal ribosomal entry site (IRES) at the 5' nontranslated region. A region encoding the N-terminal part of the HCV polyprotein has been shown to augment the translation of HCV mRNA. Here we show that a cellular pro... |
15340047 | RhoE inhibits cell cycle progression and Ras-induced transformation. | Rho GTPases are major regulators of cytoskeletal dynamics, but they also affect cell proliferation, transformation, and oncogenesis. RhoE, a member of the Rnd subfamily that does not detectably hydrolyze GTP, inhibits RhoA/ROCK signaling to promote actin stress fiber and focal adhesion disassembly. We have generated fi... |
15339158 | Formation of a hydrogen-bonded receptor assembly in niosomal membranes. | The formation of a hydrogen-bonded receptor in niosomal membranes is reported in this communication. The niosomes prepared from non-ionic surfactants C12EO3 and C14EO3 provide a stable system that allows the self-assembly of hydrogen-bonded receptors to occur in contact with aqueous environments. We demonstrate here by... |
15339143 | Ultrafast aggregate-to-aggregate energy transfer within self-assembled light-harvesting columns of zinc phthalocyanine tetrakis(perylenediimide). | Light harvesting in photosynthetic antenna proteins involves a series of highly efficient ultrafast energy transfers between spectroscopically different populations of chlorophylls. Several strategies have recently been employed to mimic this natural energy transfer process, including polymers, dendrimers, and oligomer... |
15336496 | Tensile mechanical and creep properties of Descemet's membrane and lens capsule. | Descemet's membrane (DM) and the lens capsule (LC) are two ocular basement membrane structures which in comparison with other basement membranes have exceptional thicknesses which increase with age. Both membranes are supposed to contain networks of type IV collagen and laminin linked together with nidogen/entactin and... |
15338050 | Lanthanide-binding peptides and the enzymes that Might Have Been. | The trivalent lanthanide ions are chemically similar to Ca(II) ions, making them useful Ca analogs for a multitude of applications. In addition, Ln(III) ions are efficient catalysts of hydrolysis due to their much stronger Lewis acidity relative to Ca(II) ions. Ln-binding peptides thus offer both the opportunity to stu... |
15338045 | Chromatin modifiers in transcription and DNA repair. | In eukaryotes, the packaging of DNA into nucleosomes and the organization of chromatin fibres generate constraints for all nuclear processes involving DNA, including replication, repair, recombination and transcription. The three major processes that regulate chromatin structure and counterbalance its repressive effect... |
15336572 | Functional evidence for a supramolecular structure for the Streptomyces lividans potassium channel KcsA. | Here we present functional evidence for involvement of poly-(R)-3-hydroxybutyrate (PHB) and inorganic polyphosphate (polyP) in ion conduction and selection at the intracellular side of the Streptomyces lividans potassium channel, KcsA. At < or = 25 degrees C, KcsA forms channels in planar bilayers that display signal c... |
15331716 | Tagging retrovirus vectors with a metal binding peptide and one-step purification by immobilized metal affinity chromatography. | Retroviral vectors produced from packaging cells are invariably contaminated by protein, nucleic acid, and other substances introduced in the manufacturing process. Elimination of these contaminants from retroviral vector preparations is helpful to reduce unwanted side effects, and purified vector preparations are desi... |
15330857 | Roles of lipid rafts in integrin-dependent adhesion and gp130 signalling pathway in mouse embryonic neural precursor cells. | Neuronal and glial cells organizing the central nervous system are generated from common neural precursor cells present in the neuroepithelium during development. We tried to clarify functions of a cell surface microdomain, lipid raft, in neuroepithelial cells (NECs). NECs are suggested to adhere to fibronectin substra... |
15327323 | Self-assembly of flexible supramolecular metallacyclic ensembles: structures and adsorption properties of their nanoporous crystalline frameworks. | The syntheses, structures, and N2 adsorption properties of six new supramolecular metallacycles are reported. Flexible ditopic linkers, 1-4, with systematically varied lengths and conformational degrees of freedom were synthesized utilizing ester linkages. They were used in combination with (dppp)M(OTf)2, where M = Pt(... |
15327322 | Supramolecular assemblies based on copolymers of PEG600 and functionalized aromatic diesters for drug delivery applications. | A chemoenzymatic approach has been developed to synthesize poly(ethylene glycol)-based amphiphilic copolymers under mild reaction conditions that self-assemble in aqueous media to form polymeric nanomicelles in the range of 20-50 nm. The supramolecular organization of polymeric nanomicelles was studied by 1H NMR longit... |
15327319 | Supramolecular p-n-heterojunctions by co-self-organization of oligo(p-phenylene vinylene) and perylene bisimide dyes. | Comparative studies on hydrogen-bonded versus covalently linked donor-acceptor-donor dye arrays obtained from oligo(p-phenylene vinylene)s (OPVs) as donor and bay-substituted perylene bisimides (PERYs) as acceptor dyes are presented. Both systems form well-ordered J-type aggregates in methylcyclohexane, but only hydrog... |
15327310 | Highly efficient dendrimer-based mimic of glutathione peroxidase. | In this communication, we report the synthesis of the three generations of Fréchet-type poly(aryl ether) dendrimers with a diselenide core that demonstrate generation-dependent glutathione peroxidase (GPx) activity with initial reduction rates as high as 2431.20 muM min-1 for the third-generation product, around 1400 t... |
15327287 | Microcontact printing of colloidal crystals. | Patterned two-dimensional (2D) colloidal crystals have been transferred by a modified mucp technique that was based on the use of polymer film as "glue" to provide an efficient interaction between the microsphere "ink" and substrate. The versatility of this method has been demonstrated by the patterning of colloidal cr... |
15328098 | Human tear lipocalin exhibits antimicrobial activity by scavenging microbial siderophores. | Human tear lipocalin (TL; also known as Lcn1) is a secretory protein present in large amounts in fluids that cover epithelial surfaces such as tears and respiratory secretions. It is supposed to act as a physiological scavenger of hydrophobic, potentially harmful molecules, but there is evidence that it also inhibits b... |
15328096 | De novo design of potent antimicrobial peptides. | Lipopolysaccharide (LPS), shed by gram-negative bacteria during infection and antimicrobial therapy, may lead to lethal endotoxic shock syndrome. A rational design strategy based on the presumed mechanism of antibacterial effect was adopted to design cationic antimicrobial peptides capable of binding to LPS through tan... |
15325274 | Tat-dependent repression of human immunodeficiency virus type 1 long terminal repeat promoter activity by fusion of cellular transcription factors. | Transcription initiation from HIV-1 long terminal repeat (LTR) promoter requires the virally encoded transactivator, Tat, and several cellular co-factors to accomplish the Tat-dependent processive transcription elongation. Individual cellular transcription activators, LBP-1b and Oct-1, on the other hand, have been show... |
15322166 | Strong and durable TCR clustering at the T/dendritic cell immune synapse is not required for NFAT activation and IFN-gamma production in human CD4+ T cells. | The exact function of TCR clustering and organized macromolecular patterns at the immune synapse between APCs and T lymphocytes is unclear. Using human immature or mature dendritic cells (DCs) and autologous CD4(+) effector T cells, we demonstrate that, within a given conjugate, mature DCs induce strong and long-lastin... |
15322154 | Lipid rafts mediate association of LFA-1 and CD3 and formation of the immunological synapse of CTL. | Lipid rafts accumulate in the immunological synapse formed by an organized assembly of the TCR/CD3, LFA-1, and signaling molecules. However, the precise role of lipid rafts in the formation of the immunological synapse is unclear. In this study, we show that LFA-1 on CTL is constitutively active and mediates Ag-indepen... |
15322032 | Involvement of raft-like plasma membrane domains of Entamoeba histolytica in pinocytosis and adhesion. | Lipid rafts are highly ordered, cholesterol-rich, and detergent-resistant microdomains found in the plasma membrane of many eukaryotic cells. These domains play important roles in endocytosis, secretion, and adhesion in a variety of cell types. The parasitic protozoan Entamoeba histolytica, the causative agent of amoeb... |
15321992 | Mycoplasma fermentans binds to and invades HeLa cells: involvement of plasminogen and urokinase. | Adherence of Mycoplasma fermentans to HeLa cells followed saturation kinetics, required a divalent cation, and was enhanced by preincubation of the organism at 37 degrees C for 1 h in a low-osmolarity solution. Proteolytic digestion, choline phosphate, or anti-choline phosphate antibodies partially inhibited the adhere... |
15317762 | The reaction center H subunit is not required for high levels of light-harvesting complex 1 in Rhodospirillum rubrum mutants. | The gene (puhA) encoding the H subunit of the reaction center (RC) was deleted by site-directed interposon mutagenesis by using a kanamycin resistance cassette lacking transcriptional terminators to eliminate polar effects in both the wild-type strain Rhodospirillum rubrum S1 and the carotenoid-less strain R. rubrum G9... |
15317760 | Transglutaminase-mediated cross-linking of GerQ in the coats of Bacillus subtilis spores. | The spores of Bacillus subtilis show remarkable resistance to many environmental stresses, due in part to the presence of an outer proteinaceous structure known as the spore coat. GerQ is a spore coat protein essential for the presence of CwlJ, an enzyme involved in the hydrolysis of the cortex during spore germination... |
15313630 | A miniprotein scaffold used to assemble the polyproline II binding epitope recognized by SH3 domains. | SH3 domains are molecular-recognition modules that function by interacting with proteins containing sequences in polyproline II (PPII) conformation. The main limitation in designing short-ligand peptides to interact with these domains is the preservation of this helical arrangement, for which a high content of proline ... |
15313627 | Amyloid fibril formation by a partially structured intermediate state of alpha-chymotrypsin. | Here we investigated the effects of 2,2,2-trifluoroethanol (TFE) on the structure of alpha-chymotrypsin. The protein aggregates maximally in 35% (v/v) TFE. Congo red and thioflavin-T binding experiments suggest that the aggregates induced by TFE have amyloid-like properties, and transmission electron microscopy data sh... |
15308751 | Mobility of the human immunodeficiency virus (HIV) receptor CD4 and coreceptor CCR5 in living cells: implications for HIV fusion and entry events. | The sequence of events leading to human immunodeficiency virus fusion and entry likely involves the recruitment of multiple receptor and coreceptor proteins to a specific complex by the viral envelope. Using fluorescence recovery after photobleaching technology, we find that both CD4 and CCR5 are mobile in the cell mem... |
15308747 | Measles virus interacts with and alters signal transduction in T-cell lipid rafts. | By a contact-dependent surface interaction, the measles virus (MV) glycoprotein complex induces a pronounced inhibition of T-cell proliferation. We now show that MV directly interacts with glycosphingolipid-enriched membrane microdomains on human primary T cells and alters recruitment and segregation of membrane proxim... |
15308738 | Kinetic analysis of the interactions between vaccinia virus complement control protein and human complement proteins C3b and C4b. | The vaccinia virus complement control protein (VCP) is an immune evasion protein of vaccinia virus. Previously, VCP has been shown to bind and support inactivation of host complement proteins C3b and C4b and to protect the vaccinia virions from antibody-dependent complement-enhanced neutralization. However, the molecul... |
15304097 | Cholesterol depletion upregulates involucrin expression in epidermal keratinocytes through activation of p38. | Cholesterol has been recently suggested to regulate the early steps of keratinocyte differentiation through lipid rafts. In many cell types, depletion of cholesterol activates signaling proteins like epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), or extracellular signal-regula... |
15300914 | Glutamine supplemented parenteral nutrition prevents intestinal ischemia- reperfusion injury in rats. | <h4>Aim</h4>To examine whether glutamine prevents the injury to the intestinal mucosa after intestinal ischemia-reperfusion (I/R) in rats.<h4>Methods</h4>Thirty male Sprague-Dawley rats were randomly divided into 3 groups: a standard parenteral nutrition (PN) group (n = 10); an I/R-PN group (n = 10); an I/R-glutamine e... |
15224414 | Absolute configuration determination of angular dihydrocoumarins from Peucedanum praeruptorum. | From Peucedanum praeruptorum, one new khellactone ester (3'R)-O-acetyl-(4'S)-O-angeloylkhellactone (3), as well as four known angular dihydropyranocoumarins (1, 2, 4, 5) have been isolated. On the basis of NMR spectra and X-ray crystallography, their structures were determined. We have elucidated their absolute configu... |
18007476 | Synthesis and magnetic properties of the novel dithiadiazolyl radical, p-NCC6F4C6F4CNSSN*. | The dithiadiazolyl radical p-NCC6F4C6F4CNSSN* (4) retains its monomeric nature in the solid state with molecules linked together into chains via supramolecular CN-S interactions. Variable temperature magnetic studies on 4 show that it behaves as a near-ideal Curie paramagnet (|theta| less than 0.1 K), indicating neglig... |
15339924 | Galpha13 stimulates cell migration through cortactin-interacting protein Hax-1. | Galpha13, the alpha-subunit of the heterotrimeric G protein G13, has been shown to stimulate cell migration in addition to inducing oncogenic transformation. Cta, a Drosophila ortholog of G13, has been shown to be critical for cell migration leading to the ventral furrow formation in Drosophila embryos. Loss of Galpha1... |
15339935 | Inhibition of HIV-1 envelope glycoprotein-mediated cell fusion by a DL-amino acid-containing fusion peptide: possible recognition of the fusion complex. | The N-terminal fusion peptide (FP) of human immunodeficiency virus-1 (HIV-1) is a potent inhibitor of cell-cell fusion, possibly because of its ability to recognize the corresponding segments inside the fusion complex within the membrane. Here we show that a fusion peptide in which the highly conserved Ile(4), Phe(8), ... |
15339809 | Defining the physical gate of a mechanosensitive channel, MscL, by engineering metal-binding sites. | The mechanosensitive channel of large conductance, MscL, of Escherichia coli is one of the best-studied mechanosensitive proteins. Although the structure of the closed or "nearly-closed" state of the Mycobacterium tuberculosis ortholog has been solved and mechanisms of gating have been proposed, the transition from the... |
15339804 | Calculation of cyclodextrin binding affinities: energy, entropy, and implications for drug design. | The second generation Mining Minima method yields binding affinities accurate to within 0.8 kcal/mol for the associations of alpha-, beta-, and gamma-cyclodextrin with benzene, resorcinol, flurbiprofen, naproxen, and nabumetone. These calculations require hours to a day on a commodity computer. The calculations also in... |
15339801 | Physical detwinning of hemihedrally twinned hexagonal crystals of bacteriorhodopsin. | Hexagonal crystals of the membrane protein bacteriorhodopsin of space group P6 3 grown in lipidic cubic phase are twinned hemihedrally. It was shown that slow changes of salt concentration in the mother liquor lead to a split of crystals so that the split parts preserved high diffraction quality. Analysis of diffractio... |
15339800 | Long-residency hydration, cation binding, and dynamics of loop E/helix IV rRNA-L25 protein complex. | Molecular dynamics simulations of RNA-protein complex between Escherichia coli loop E/helix IV (LE/HeIV) rRNA and L25 protein reveal a qualitative agreement between the experimental and simulated structures. The major groove of LE is a prominent rRNA cation-binding site. Divalent cations rigidify the LE major groove ge... |
15339795 | The protein-tethered lipid bilayer: a novel mimic of the biological membrane. | A new concept of solid-supported tethered bilayer lipid membrane (tBLM) for the functional incorporation of membrane proteins is introduced. The incorporated protein itself acts as the tethering molecule resulting in a versatile system in which the protein determines the characteristics of the submembraneous space. Thi... |
15339857 | 5-HT7 receptor efficacy distribution throughout the canine stomach. | This study aimed to determine, quantify and explain regional differences in the relaxant response to the selective 5-HT(1) and 5-HT(7) receptor agonist 5-carboxamidotryptamine (5-CT) throughout the canine stomach. Longitudinal muscle strips from eight gastric corpus regions and six antrum regions were mounted for isoto... |
15447556 | Criticality in aqueous solutions of 3-methylpyridine and sodium bromide. | We address a controversial issue regarding the nature of critical behavior in ternary electrolyte solutions of water, 3-methylpyridine, and sodium bromide. Earlier light-scattering studies showed an anomalous critical behavior in this system that was attributed to the formation of a microheterogeneous phase associated ... |
15340782 | Characterisation of a thermoalkali-stable cyclodextrin glycosyltransferase from the anaerobic thermoalkaliphilic bacterium Anaerobranca gottschalkii. | The thermoalkaliphilic anaerobic bacterium Anaerobranca gottschalkii produces an extracellular CGTase when grown on starch at 55 degrees C and pH 9.0. The gene encoding this CGTase was cloned and successfully expressed in Escherichia coli. It encodes a protein consisting of 721 amino acids with a signal sequence of 34 ... |
15340169 | Structure and function of the Gondwanian hemoglobin of Pseudaphritis urvillii, a primitive notothenioid fish of temperate latitudes. | The suborder Notothenioidei dominates the Antarctic ichthyofauna. The non-Antarctic monotypic family Pseudaphritidae is one of the most primitive families. The characterization of the oxygen-transport system of euryhaline Pseudaphritis urvillii is herewith reported. Similar to most Antarctic notothenioids, this tempera... |
15349516 | Evaluation of the drug treatment and persistence of onychomycosis. | Onychomycosis is a common nail disease responsible for approximately 50% of diseases of the nail. It occurs more in the elderly, though several cases have been reported among children. Several factors influence, such as climate, geography, and migration. The two dermatophytes most commonly implicated in onychomycosis a... |
15345861 | Diethyl piperazine-1,4-diyldioxalate. | The ethyl oxamate group, N-C(O)-C(O)-OEt, in the title compound, alternatively called diethyl N,N':N,N'-bis(ethylene)dioxamate, C12H18N2O6, can be considered as being composed of two singly bonded amide and ester functionalities. The ethyl oxamate group is not planar. The two carbonyl groups are almost perpendicular, w... |
15339335 | Facilitating arrhythmia simulation: the method of quantitative cellular automata modeling and parallel running. | <h4>Background</h4>Many arrhythmias are triggered by abnormal electrical activity at the ionic channel and cell level, and then evolve spatio-temporally within the heart. To understand arrhythmias better and to diagnose them more precisely by their ECG waveforms, a whole-heart model is required to explore the associati... |
15337847 | Ionic interactions between PRNA and P protein in Bacillus subtilis RNase P characterized using a magnetocapture-based assay. | Ribonuclease P (RNase P) is a ribonucleoprotein complex that catalyzes the cleavage of the 5' end of precursor tRNA. To characterize the interface between the Bacillus subtilis RNA (PRNA) and protein (P protein) components, the intraholoenzyme KD is determined as a function of ionic strength using a magnetocapture-base... |
15338314 | 153Sm and 166Ho complexes with tetraaza macrocycles containing pyridine and methylcarboxylate or methylphosphonate pendant arms. | A set of tetraaza macrocycles containing pyridine and methylcarboxylate (ac(3)py14) or methylphosphonate (MeP(2)py14 and P(3)py14) pendant arms were prepared and their stability constants with La(3+), Sm(3+), Gd(3+) and Ho(3+) determined by potentiometry at 25 degrees C and 0.10 M ionic strength in NMe(4)NO(3). The met... |
15483703 | Silver cages with encapsulated acetylenediide as building blocks for hydrothermal synthesis of supramolecular complexes with n-cyanopyridine and pyridine-n-carboxamide (n=3, 4). | New silver(i) double salts (Ag(2)C(2))(AgCF(3)CO(2))(8)(3-pyCONH(2))(2)(H(2)O)(4) (1), [(Ag(2)C(2))(AgCF(3)CO(2))(4)(4-pyCONH(2))(H(2)O)].H(2)O (2), (Ag(2)C(2))(AgCF(3)CO(2))(6)(3-pyCONH(2))(4) (3), (Ag(2)C(2))(AgCF(3)CO(2))(6)(3-pyCN)(2) (4) and (Ag(2)C(2))(AgCF(3)CO(2))(4)(4-pyCN)(2) (5) (n-pyCONH(2) is pyridine-n-ca... |
15333695 | Rational design of DNA sequences for nanotechnology, microarrays and molecular computers using Eulerian graphs. | Nucleic acids are molecules of choice for both established and emerging nanoscale technologies. These technologies benefit from large functional densities of 'DNA processing elements' that can be readily manufactured. To achieve the desired functionality, polynucleotide sequences are currently designed by a process tha... |
15477675 | Synchrotron charge-density studies in materials chemistry: 16 K X-ray charge density of a new magnetic metal-organic framework material, [Mn2(C8H4O4)2(C3H7NO)2]. | A new magnetic metal-organic framework material, [Mn(2)(C(8)OH(4)(4))(2)(C(3)H(7)NO)(2)], has been synthesized. The structure consists of chains of carboxylate-bridged Mn atoms interconnected with acid linkers, giving much larger interchain than intrachain Mn...Mn distances. Magnetic susceptibility data fitted to a Cur... |
15455140 | Tetracyanoresorcin[4]arene as a pH dependent artificial acetylcholine receptor. | This communication describes the facile synthesis of tetracyanoresorcin[4]arene and its high and pH dependent affinities toward biologically important acetylcholine in the physiological pH region. |
15447147 | Hydrodynamics of nanoscopic tubulin rings in dilute solutions. | We combine fluorescence correlation spectroscopy and sedimentation velocity measurements to probe the hydrodynamic behavior of tubulin dimers and nanoscopic tubulin rings. The rings are rigid, have circular geometry, and are monodisperse in size. We use the high-precision ratio of the sedimentation coefficients and tha... |
15328160 | Acute cholesterol depletion impairs functional expression of tissue factor in fibroblasts: modulation of tissue factor activity by membrane cholesterol. | Cholesterol, in addition to providing rigidity to the fluid membrane, plays a critical role in receptor function, endocytosis, recycling, and signal transduction. In the present study, we examined the effect of membrane cholesterol on functional expression of tissue factor (TF), a cellular receptor for clotting factor ... |
15447094 | Aharonov-Bohm effects in entangled molecules. | Molecules which are magnetic and conducting, if suitably entangled (e.g., catenanes and knots) could exhibit Aharonov-Bohm effects which can be viewed as particular examples of a Berry phase. The corrections to the quantum energy levels reflect the entangled geometry of the molecules and, while small (they are proporti... |
15328368 | Thioredoxin can influence gene expression by affecting gyrase activity. | The expression of many genes of facultatively photosynthetic bacteria of the genus Rhodobacter is controlled by the oxygen tension. Among these are the genes of the puf and puc operons, which encode proteins of the photosynthetic apparatus. Previous results revealed that thioredoxins are involved in the regulated expre... |
15467886 | A supramolecular approach to the selective detection of dopamine in the presence of ascorbate. | Dopamine can be detected selectively in the presence of ascorbate at a gold electrode modified by a beta-cyclodextrin/thioctic acid mixed monolayer. |
15351822 | Rigid versus flexible: how important is ligand "preorganization" for metal ion recognition by lower rim-functionalized calix[4]arenes? | For an assessment of the outcomes from use of an appropriately "preorganized" calixarene-based ionophore versus its conformationally mobile prototype, solvent extraction propensities of flexible calix[4]arene di-[N-(X-sulfonyl)carboxamides] for alkali, alkaline earth metal cations, Pb2+, Ag+ and Hg2+ are compared with ... |
15349167 | One- or two-dimensional 2,3-naphtho crown ether complexes [Na(N15C5)]2[M(SCN)4] and [K(N18C6)]2[M(SCN)4] (M = Pd, Pt) constructed by pi-pi stacking interactions. | Four novel 2,3-naphtho-15-crown-5 (N15C5) and 2,3-naphtho-18-crown-6 (N18C6) complexes [Na(N15C5)]2[Pd(SCN)4] (1), [Na(N15C5)]2[Pt(SCN)4] (2), [K(N18C6)]2[Pd(SCN)4] (3) and [K(N18C6)]2[Pt(SCN)4] (4) were synthesized and characterized by elemental analysis, FT-IR spectra and single-crystal X-ray diffraction. The structu... |
15326297 | Structure of heptameric protective antigen bound to an anthrax toxin receptor: a role for receptor in pH-dependent pore formation. | After binding to cellular receptors and proteolytic activation, the protective antigen component of anthrax toxin forms a heptameric prepore. The prepore later undergoes pH-dependent conversion to a pore, mediating translocation of the edema and lethal factors to the cytosol. We describe structures of the prepore (3.6 ... |
15326312 | Effects of Q/N-rich, polyQ, and non-polyQ amyloids on the de novo formation of the [PSI+] prion in yeast and aggregation of Sup35 in vitro. | Prions are infectious protein conformations that are generally ordered protein aggregates. In the absence of prions, newly synthesized molecules of these same proteins usually maintain a conventional soluble conformation. However, prions occasionally arise even without a homologous prion template. The conformational sw... |
15326301 | Kinetic control of dimer structure formation in amyloid fibrillogenesis. | Amyloid fibril formation involves nonfibrillar oligomeric intermediates, which are important as possible cytotoxic species in neurodegenerative diseases. However, their transient nature and polydispersity have made it difficult to identify their formation mechanism or structure. We have investigated the dimerization pr... |
15345859 | C-H...pi, pi-pi and C-H...Cl interactions in chloro-substituted Schiff bases and 4-chloro-N-[4-(dimethylamino)benzylidene]aniline. | Molecular packing analyses were carried out on 15 crystal data sets of chloro-substituted Schiff bases, including that of the title compound, C15H15ClN2. C-H...pi and pi-pi interactions play a major role in the molecular self-assembly in the crystal. The former interactions favor molecules assembling into a screw, with... |
15322120 | The role of loop 6/7 in folding and functional performance of Na,K-ATPase. | Alanine substitutions were made for 15 amino acids in the cytoplasmic loop between transmembrane helices 6 and 7 (L6/7) of the human alpha(1)-subunit of Na,K-ATPase. Most mutations reduced Na,K-ATPase activity by less than 50%; however, the mutations R834A, R837A, and R848A reduced Na,K-ATPase activity by 75, 89, and 6... |
15467884 | A modular ditopic crown-shielded phosphate ion-pair receptor. | The synthesis of a modular hybrid receptor containing both an aza macrocycle and crown ether is described; a complete thermodynamic characterisation of the binding properties, in water, of the zinc(II) complex of the receptor towards phosphate is presented and the parameters are compared to those of the aza macrocycle ... |
15467881 | Cyclic water pentamer in a tape-like structure. | A novel water tape consisting of fused cyclic water pentamers has been observed in a supramolecular compound. |
15467879 | New crystalline forms of permethylated beta-cyclodextrin. | Two new crystalline forms of permethylated [small beta]-cyclodextrin are reported that contain methylglucose residues exclusively in the (4)C(1) conformation, in contrast to the known monohydrate, in which a single methylglucose residue adopts the (1)C(4) conformation. |
15467877 | Ultrastable complexes for in vivo use: a bifunctional chelator incorporating a cross-bridged macrocycle. | The synthesis, copper(II) complexation and biotin conjugation of a bifunctional chelator incorporating a cross-bridged macrocycle are described. |
15467850 | Assembly of large simple 1D and rare polycatenated 3D molecular ladders from T-shaped building blocks containing a new, long N,N'-bidentate ligand. | Molecular ladders [Co(2)(nbpy4)(3)(NO(3))(4)]*solvents and [Cd(2)(nbpy4)(3)(NO(3))(4)](nbpy4 =N,N'-bis-(4-pyridinylmethylene)-1,5-naphthalenediamine) were synthesized via self-assembly; the former is a large, simple, noninterpenetrated 1D ladder that contains guest solvent molecules between the rungs, while the latter ... |
15467846 | Single-walled carbon nanotubes acquire a specific lectin-affinity through supramolecular wrapping with lactose-appended schizophyllan. | Single-walled carbon nanotubes can be entrapped within a helical superstructure composed of schizophyllan bearing lactoside-appendages to show an excellent water-solubility as well as a specific lectin-affinity. |
15351826 | Supramolecular ion channels from a transmembrane bischolic acid derivative showing two discrete conductances. | Bischolic acid derivative 1 linked by m-xylylene dicarbamate at the 3,3'-position was synthesized and the single ion channel properties were examined. Compound 1 showed two clearly distinct conductances, 9.5 (type A) and 25.3 pS (type B), under 500 mM KCl symmetric salt conditions, whereas various conductances, ranging... |
15319316 | Multiplexed genetic analysis using an expanded genetic alphabet. | <h4>Background</h4>All states require some kind of testing for newborns, but the policies are far from standardized. In some states, newborn screening may include genetic tests for a wide range of targets, but the costs and complexities of the newer genetic tests inhibit expansion of newborn screening. We describe the ... |
15319448 | The ants go marching two by two: oligomeric structure of G-protein-coupled receptors. | A number of class C G-protein coupled receptors (GPCRs) have been shown to form dimers in the plasma membrane, and mounting evidence supports the hypothesis that many, if not all, class A rhodopsin-like receptors also form dimers or higher-order oligomers. Evidence for this hypothesis has come from SDS-polyacrylamide g... |
15319229 | The effect of stress on genome regulation and structure. | <h4>Background</h4>Stresses exert evolutionary pressures on all organisms, which have developed sophisticated responses to cope and survive. These responses involve cellular physiology, gene regulation and genome remodelling.<h4>Scope</h4>In this review, the effects of stress on genomes and the connected responses are ... |
15319493 | DNA-templated organic synthesis and selection of a library of macrocycles. | The translation of nucleic acid libraries into corresponding synthetic compounds would enable selection and amplification principles to be applied to man-made molecules. We used multistep DNA-templated organic synthesis to translate libraries of DNA sequences, each containing three "codons," into libraries of sequence-... |
15317744 | Antimycobacterial activity of synthetic pamamycins. | <h4>Objectives</h4>Early studies have indicated that pamamycins, a group of macrodiolides first isolated from Streptomyces alboniger, have potent antimicrobial activity against Gram-positive bacteria, fungi and mycobacteria but not against Gram-negative bacteria. The recent availability of highly purified and reasonabl... |
15317938 | Sequential shape-and-solder-directed self-assembly of functional microsystems. | We demonstrate the fabrication of packaged microsystems that contain active semiconductor devices and passive components by using a directed self-assembly technique. The directed self-assembly is accomplished by combining geometrical shape recognition with site-specific binding involving liquid solder. Microfabricated ... |
15317871 | Transcription influences the types of deletion and expansion products in an orientation-dependent manner from GAC*GTC repeats. | The genetic instability of (GAC*GTC)n (where n = 6-74) was investigated in an Escherichia coli-based plasmid system. Prior work implicated the instability of a (GAC*GTC)5 tract in the cartilage oligomeric matrix protein (COMP) gene to the 4, 6 or 7mers in the etiology of pseudoachondroplasia and multiple epiphyseal dys... |
15315952 | Cholesterol and ergosterol influence nystatin surface aggregation: relation to pore formation. | Nystatin interaction with liposomes mimicking fungal and mammalian membranes (ergosterol- and cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) large unilamellar vesicles, respectively) was studied by fluorescence spectroscopy. The activity of this antibiotic was also measured using a pyran... |
15322084 | Association of gamma-secretase with lipid rafts in post-Golgi and endosome membranes. | Alzheimer's disease-associated beta-amyloid peptides (Abeta) are generated by the sequential proteolytic processing of amyloid precursor protein (APP) by beta- and gamma-secretases. There is growing evidence that cholesterol- and sphingolipid-rich membrane microdomains are involved in regulating trafficking and process... |
15314240 | Binding between the Niemann-Pick C1 protein and a photoactivatable cholesterol analog requires a functional sterol-sensing domain. | Niemann-Pick type C (NPC) 1 protein plays important roles in moving cholesterol and other lipids out of late endosomes by means of vesicular trafficking, but it is not known whether NPC1 directly interacts with cholesterol. We performed photoaffinity labeling of intact cells expressing fluorescent protein (FP)-tagged N... |
15314211 | Fabricating complex three-dimensional nanostructures with high-resolution conformable phase masks. | High-resolution, conformable phase masks provide a means to fabricate, in an experimentally simple manner, classes of 3D nanostructures that are technologically important but difficult to generate in other ways. In this approach, light passing through a phase mask that has features of relief comparable in dimension to ... |
15316223 | Elucidation of cell secretion: pancreas led the way. | Secretion is a basic process in all cells and is required for several important functions such as neurotransmission, the secretion of digestive juices from the exocrine pancreas and the release of hormones from endocrine and neuroendocrine cells. Due to these important functions, the mechanism of cell secretion has bee... |
15349165 | The formation of dimeric phosph(III)azane macrocycles [[P(mu-NtBu)]2.LL]2 [LL = organic spacer]. | The dimeric macrocycles [[P(mu-NtBu)]2.LL]2 [LL = OCH2C(Me)2CH2O (1), 2,6-(NH)2C5H3N (2), 1,2-(NH)2C6H4(3)] have been obtained by the reactions of the appropriate diols and diamines (LLH2) with the dimeric phosph(III)azane [ClP(mu-NtBu)]2. Under different conditions the reaction of 1,2-(NH2)2C6H4 with [ClP(mu-NtBu)]2 g... |
15308605 | Glycodendritic structures: promising new antiviral drugs. | DC-SIGN, a C-type lectin expressed by dendritic cells, is able to recognize high mannosylated glycoproteins at the surface of a broad range of pathogens including viruses, bacteria, fungi and parasites. For at least some of these agents this interaction appears to be an important part of the infection process. Therefor... |
15345843 | Diethyl 3,8-dimethyl-4,7-diazadeca-2,8-dienedioate. | The title compound, C14H24N2O4, consists of two symmetric moieties related through a twofold axis. The whole molecule has a cis conformation. Both the ionic enol form and the non-ionic keto form make comparable contributions to the structure. In the crystal structure, infinite supramolecular chains are formed through N... |
15306681 | Synthetic antibodies from a four-amino-acid code: a dominant role for tyrosine in antigen recognition. | Antigen-binding fragments (Fabs) with synthetic antigen-binding sites were isolated from phage-displayed libraries with restricted complementarity-determining region (CDR) diversity. Libraries were constructed such that solvent-accessible CDR positions were randomized with a degenerate codon that encoded for only four ... |
15514745 | Preparation and structural characterisation of terpy-cored dendrimers and dendriplexes. | 2,2':6',2''-Terpyridine (terpy) ligands and their iron(II) and cobalt(II) complexes bearing first and second generation Frechet-type dendritic wedges have been prepared and structurally characterised. The rotational freedom within the dendritic wedge results in a great diversity in conformational space. Structural stud... |
15302925 | The essence of total synthesis. | For the past century, the total synthesis of natural products has served as the flagship of chemical synthesis and the principal driving force for discovering new chemical reactivity, evaluating physical organic theories, testing the power of existing synthetic methods, and enabling biology and medicine. This perspecti... |
15302855 | Esophageal muscle physiology and morphogenesis require assembly of a collagen XIX-rich basement membrane zone. | Collagen XIX is an extremely rare extracellular matrix component that localizes to basement membrane zones and is transiently expressed by differentiating muscle cells. Characterization of mice harboring null and structural mutations of the collagen XIX (Col19a1) gene has revealed the critical contribution of this matr... |
15302852 | Junctate is a key element in calcium entry induced by activation of InsP3 receptors and/or calcium store depletion. | In many cell types agonist-receptor activation leads to a rapid and transient release of Ca(2+) from intracellular stores via activation of inositol 1,4,5 trisphosphate (InsP(3)) receptors (InsP(3)Rs). Stimulated cells activate store- or receptor-operated calcium channels localized in the plasma membrane, allowing entr... |
15302916 | DNA communications by Type III restriction endonucleases--confirmation of 1D translocation over 3D looping. | DNA cleavage by Type III restriction enzymes is governed strictly by the relative arrangement of recognition sites on a DNA substrate--endonuclease activity is usually only triggered by sequences in head-to-head orientation. Tens to thousands of base pairs can separate these sites. Long distance communication over such... |
15302912 | Interaction of DNA with clusters of amino acids in proteins. | Protein-DNA interactions facilitate the fundamental functions of living cells and are universal in all living organisms. Several investigations have been carried out, essentially identifying pairs of interactions between the amino acid residues in proteins and the bases in DNA. In the present study, we have detected th... |
15300242 | Self-assembly and properties of diblock copolymers by coarse-grain molecular dynamics. | Block-copolymer amphiphiles have been observed to assemble into vesicles and other morphologies long known for lipids but with remarkably different properties. Coarse-grain molecular dynamics (CG-MD) is used herein to elaborate the structures and properties of diblock copolymer assemblies in water. By varying the hydro... |
15514765 | A new pyridine-based 12-membered macrocycle functionalised with different fluorescent subunits; coordination chemistry towards Cu(II), Zn(II), Cd(II), Hg(II), and Pb(II). | The coordination chemistry of the new pyridine-based, N2S2-donating 12-membered macrocycle 2,8-dithia-5-aza-2,6-pyridinophane (L1) towards Cu(II), Zn(II), Cd(II), Hg(II), and Pb(II) has been investigated both in aqueous solution and in the solid state. The protonation constants for L1 and stability constants with the a... |
15298874 | Thermal and sodium dodecylsulfate induced transitions of streptavidin. | The strong specific binding of streptavidin (SA) to biotin is utilized in numerous biotechnological applications. The SA tetramer is also known to exhibit significant stability, even in the presence of sodium dodecylsulfate (SDS). Despite its importance, relatively little is known about the nature of the thermal denatu... |
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