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12944646 | Hydrogen bonding in calcium-trifluoromethanesulfonate-1,3-di-4-pyridylurea-methanol (1/2/2/4). | The structure of the supramolecular complex calcium-trifluoromethanesulfonate-1,3-di-4-pyridylurea-methanol (1/2/2/4), Ca(2+) x 2CF(3)SO(3)(-) x 2C(11)H(10)N(4)O x 4CH(4)O, is presented. The Ca(2+) ion lies on an inversion centre and is octahedrally coordinated by four methanol molecules and two trifluoromethanesulfona... |
12923209 | Elasticity in extracellular matrix 'shape modules' of tendon, cartilage, etc. A sliding proteoglycan-filament model. | Connective tissues (CTs), which define bodily shape, must respond quickly, robustly and reversibly to deformations caused by internal and external stresses. Fibrillar (elastin, collagen) elasticity under tension depends on molecular and supramolecular mechanisms. A second intra-/inter-molecular pair, involving proteogl... |
12923296 | Glutamate-binding affinity of Drosophila metabotropic glutamate receptor is modulated by association with lipid rafts. | Metabotropic glutamate receptors (mGluRs) are responsible for the effects of glutamate in slow synaptic transmission, and are implicated in the regulation of many processes in the CNS. Recently, we have reported the expression and purification of a mGluR from Drosophila melanogaster (DmGluRA), a homologue of mammalian ... |
12920115 | Molecular recognition in dimerization between PB1 domains. | The PB1 (Phox and Bem 1) domain is a recently identified module that mediates formation of a heterodimeric complex with other PB1 domain, e.g. the complexes between the phagocyte oxidase activators p67phox and p40phox and between the yeast polarity proteins Bem1p and Cdc24p. These PB1 domains harbor either a conserved ... |
12912982 | Oligomerization of Ebola virus VP30 is essential for viral transcription and can be inhibited by a synthetic peptide. | Transcription of Ebola virus (EBOV)-specific mRNA is driven by the nucleocapsid proteins NP, VP35, and L. This process is further dependent on VP30, an essential EBOV-specific transcription factor. The present study addresses the self-assembly of VP30 and the functional significance of this process for viral transcript... |
12935030 | Structural polymorphism of DNA-dendrimer complexes. | DNA condensation in vivo relies on electrostatic complexation with small cations or large histones. We report a synchrotron x-ray study of the phase behavior of DNA complexed with synthetic cationic dendrimers of intermediate size and charge. We encounter unexpected structural transitions between columnar mesophases wi... |
12913111 | The tyrosine phosphatase CD148 is excluded from the immunologic synapse and down-regulates prolonged T cell signaling. | CD148 is a receptor-like protein tyrosine phosphatase up-regulated on T cells after T cell receptor (TCR) stimulation. To examine the physiologic role of CD148 in TCR signaling, we used an inducible CD148-expressing Jurkat T cell clone. Expression of CD148 inhibits NFAT (nuclear factor of activated T cells) activation ... |
12944654 | 1-(4-methylamino-1,2,5-thiadiazole-3-carbonyl)thiosemicarbazide. | In the title compound, C(5)H(8)N(6)OS(2), the supramolecular architecture is sustained by two N--H...O and three N--H...S hydrogen bonds, and by N.S electrostatic interactions. The hydrogen-bond network generates a sheet structure, which extends in the a and b directions and is one c-cell dimension thick. These extende... |
12909639 | RecQ helicase stimulates both DNA catenation and changes in DNA topology by topoisomerase III. | Together, RecQ helicase and topoisomerase III (Topo III) of Escherichia coli comprise a potent DNA strand passage activity that can catenate covalently closed DNA (Harmon, F. G., DiGate, R. J., and Kowalczykowski, S. C. (1999) Mol. Cell 3, 611-620). Here we directly assessed the structure of the catenated DNA species f... |
14551251 | Targeted chemical disruption of clathrin function in living cells. | The accurate assignment of molecular roles in membrane traffic is frequently complicated by the lack of specific inhibitors that can work on rapid time scales. Such inhibition schemes would potentially avoid the complications arising from either compensatory gene expression or the complex downstream consequences of inh... |
12904946 | Label-free screening of bio-molecular interactions. | The majority of techniques currently employed to interrogate a biomolecular interaction require some type of radio- or enzymatic- or fluorescent-labelling to report the binding event. However, there is an increasing awareness of novel techniques that do not require labelling of the ligand or the receptor, and that allo... |
12907462 | Cholesterol dependence of vascular ERK1/2 activation and growth in response to stretch: role of endothelin-1. | <h4>Objective</h4>Stretch-induced growth of the vascular wall plays a role in hypertension and neointima formation. Its signal pathways involve integrins, cytoskeleton, membrane receptors, and ion channels, some of which are organized in cholesterol-rich, membrane domains such as lipid rafts or caveolae. This study tes... |
12904297 | Molecular mechanism of host specificity in Plasmodium falciparum infection: role of circumsporozoite protein. | Plasmodium falciparum sporozoites invade liver cells in humans and set the stage for malaria infection. Circumsporozoite protein (CSP), a predominant surface antigen on sporozoite surface, has been associated with the binding and invasion of liver cells by the sporozoites. Although CSP across the Plasmodium genus has h... |
12902541 | Single-molecule study of DNA unlinking by eukaryotic and prokaryotic type-II topoisomerases. | Type-II topoisomerases are responsible for untangling DNA during replication by removing supercoiled and interlinked DNA structures. Using a single-molecule micromanipulation setup, we follow the real-time decatenation of two mechanically braided DNA molecules by Drosophila melanogaster topoisomerase (Topo) II and Esch... |
12900507 | Dissociation of amyloid fibrils of alpha-synuclein and transthyretin by pressure reveals their reversible nature and the formation of water-excluded cavities. | Protein misfolding and aggregation have been linked to several human diseases, including Alzheimer's disease, Parkinson's disease, and systemic amyloidosis, by mechanisms that are not yet completely understood. The hallmark of most of these diseases is the formation of highly ordered and beta-sheet-rich aggregates refe... |
22900313 | N-glycolylneuraminic acid conjugates: implications of their absence in mammalian biochemistry. | N-glycolylneuraminic acid (Neu5Gc) is one of the two most common forms of sialic acids present in glycoproteins and glycolipids of mammalian tissues. It is synthesized from the most ubiquitous sialic acid, N-acetylneuraminic acid (Neu5Ac) in a hydroxylation reaction catalysed by the enzyme Neu5Ac hydroxylase. Though Ne... |
12689600 | Cholesterol deficiency increases the vulnerability of hippocampal glia in primary culture to glutamate-induced excitotoxicity. | Cholesterol, a molecule critical for cellular function, is found in particular high concentration in the brain and has been implicated to synaptic plasticity and neuronal regeneration. This study was undertaken to investigate the mechanism by which cholesterol shortage modulates glutamate (Glu)-induced excitotoxicity i... |
14664191 | [Packing: current concepts of "life-saving" surgery]. | Abdominal packing is a lifesaving technique for temporary control of severe injury and it is used in Damage Control Surgery schedule. Technically bleeding from abdominal cavity can generally be achieved by applying pressure with several large abdominal packs. It's possible too applying packs in organ-specific technique... |
14661838 | Speciation of new tri- and tetra-glucoconjugated tetrapyrrolic macrocycles (porphyrins and chlorins): an electronic molecular spectroscopy study. | In this work, we study the physicochemical properties of some newly developed glycoconjugated photosensitizers that can be used in photodynamic therapy (PDT) of cancers: meso-tri- and tetra-(meta-O-beta-D-glucosyloxyphenyl)porphyrins and meso-, tri-, and tetra-(meta-O-beta-D-glucosyloxyphenyl)chlorins. Their properties... |
14661836 | Two-dimensional infrared spectroscopy and principal component analysis studies on a new azobenzene derivative supramolecular system based on hydrogen bonds. | Infrared (IR) spectra of a supramolecular assembly with an azobenzene derivative and intermolecular hydrogen bonds have been measured in the temperature range from 30 to 200 degrees C to investigate heat-induced structural changes and thermal stability. Principal component analysis (PCA) and two kinds of two-dimensiona... |
14635781 | The insect plasma membrane H+ V-ATPase: intra-, inter-, and supramolecular aspects. | The plasma membrane H+ V-ATPase from the midgut of larval Manduca sexta, commonly called the tobacco hornworm, is the sole energizer of epithelial ion transport in this tissue, being responsible for the alkalinization of the gut lumen up to a pH of more than 11 and for any active ion movement across the epithelium. Thi... |
12897192 | Dynamics of membrane lipid domains in neuronal cells differentiated in culture. | Treatment with methyl-beta-cyclodextrin (MCD) induced a time- and dose-dependent efflux of cholesterol, sphingolipids, and phosphatidylcholine (PC) from cerebellar neurons differentiated in culture. With a "mild" treatment, the loss of cell lipids induced a deep reorganization of the remaining membrane lipids. In fact,... |
14632144 | Effect of polymer concentration on partitioning and molecular recognition in plasticized poly(vinyl chloride). | Mixtures of poly(vinyl chloride) (PVC) with plasticizers have been used in ion-selective electrodes for many years. The same material has proven useful in solid-phase microextraction (SPME), both with and without artificial receptors. We hypothesized that by changing the polymer concentration in plasticized PVC membran... |
14632129 | Oligonucleotide-functionalized gold nanoparticles as probes in a dry-reagent strip biosensor for DNA analysis by hybridization. | The highly specific molecular recognition properties of oligonucleotides are combined with the unique optical properties of gold nanoparticles for the development of a dry-reagent strip-type biosensor that enables visual detection of double stranded DNA within minutes. The assay does not require instrumentation and avo... |
14598906 | Antioxidant activities of natural vitamin E formulations. | The antioxidant activities of natural d-alpha-tocopherol, mixed tocopherols and tocotrienols, and formulations comprising all forms of vitamin E, providing 400 IU, were determined employing an improved oxygen radical absorbance capacity (ORAC) assay using fluorescein (FL) as the fluorescent probe, randomly methylated b... |
14572062 | Photonic crystal optrode sensor for detection of Pb2+ in high ionic strength environments. | We developed an optrode sensing device that utilizes a polymerized colloidal array (PCCA) photonic crystal material. This array diffracts light in the visible spectral region due to the periodic spacing of colloidal particles. The PCCA changes diffraction wavelength due to binding of Pb2+ to an 18-crown-6 ether molecul... |
14521219 | Synthesis and isomerization of azobenzene dendrimers. | 3,3',5,5'-Tetramethoxyazobenzene and related meta-substituted azobenzene dendrimers show the first evidence of the dendritic effect on trans-to-cis photoisomerization; the thermodynamic parameters for cis-to-trans isomerization have been determined. |
14513830 | Membrane protein folding on the example of outer membrane protein A of Escherichia coli. | The biophysical principles and mechanisms by which membrane proteins insert and fold into a biomembrane have mostly been studied with bacteriorhodopsin and outer membrane protein A (OmpA). This review de-scribes the assembly process of the monomeric outer membrane proteins of Gram-negative bacteria, for which OmpA has ... |
14513829 | Heterologous expression of G-protein-coupled receptors: comparison of expression systems from the standpoint of large-scale production and purification. | G-protein-coupled receptors (GPCRs) are of prime importance for cell signal transduction mechanisms and are the target of many current and potential drugs. However, structural data on these membrane proteins is still scarce because of their low natural abundance and the low efficiency of most of the expression systems ... |
12898323 | Models of the bis-histidine-coordinated ferricytochromes: Mössbauer and EPR spectroscopic studies of low-spin iron(III) tetrapyrroles of various electronic ground states and axial ligand orientations. | The EPR and magnetic Mössbauer spectra of a series of axial ligand complexes of tetrakis(2,6-dimethoxyphenyl)porphyrinatoiron(III), [(2,6-(OMe)(2))(4)TPPFeL(2)](+), where L= N-methylimidazole, 2-methylimidazole, or 4-(dimethylamino)pyridine, of one axial ligand complex of tetraphenylporphyrin, the bis(4-cyanopyridine) ... |
14504656 | Nucleocytoplasmic transport: taking an inventory. | In eukaryotic cells, the enclosure of the genetic information in the nucleus allows the spatial and temporal separation of DNA replication and transcription from cytoplasmic protein synthesis. This compartmentalization not only permits a high level of regulation of these processes but at the same time necessitates a sy... |
12898108 | Olfactory receptors: molecular basis for recognition and discrimination of odors. | The daunting task of our nose to detect and discriminate among thousands of low-molecular-weight organic compounds with diverse chemical structures and properties requires an enormous molecular recognition capacity. This is based on distinct proteins, capable of recognizing and binding odorous compounds, including odor... |
13678529 | Catalysis of protein folding by protein disulfide isomerase and small-molecule mimics. | Protein disulfide isomerase (PDI) catalyzes the formation of native disulfide pairings in secretory proteins. The ability of PDI to act as a disulfide isomerase makes it an essential enzyme in eukaryotes. PDI also fulfills other important roles. Recent studies have emphasized the importance of PDI as an oxidant in the ... |
13678470 | Lipid rafts and HIV pathogenesis: virion-associated cholesterol is required for fusion and infection of susceptible cells. | We have shown that HIV budding occurs at cholesterol-rich membrane microdomains called lipid rafts (Nguyen and Hildreth, J Virol 2000;74:3264-3272). This observation prompted us to examine the role in HIV entry of cholesterol in the membrane of cells. We recently reported that host cell cholesterol is required for HIV ... |
13129487 | Role of aromatization in anticipatory and consummatory aspects of sexual behavior in male rats. | The present study was designed to test the hypothesis that aromatization is involved in the maintenance by testosterone of the appetitive component of male sexual behavior. We measured appetitive sexual behavior by administering behavioral tests in bilevel chambers and quantifying anticipatory level changes during a 5-... |
13677649 | Next generation of protein microarray support materials: evaluation for protein and antibody microarray applications. | The performance of protein and antibody microarrays is dependent on various factors, one of which is the use of an appropriate microarray surface for the immobilisation of either protein or antibody samples. We have investigated the properties of seven new surfaces in the context of both protein and antibody microarray... |
12974293 | Chiral recognition ability of alpha-cyclodextrin with regard to some monoterpenoids under gas-liquid chromatographic conditions. | Gas-liquid chromatography was applied to investigate the mechanism of alpha-cyclodextrin (alpha-CD) complexation processes with some chiral monoterpenoids differing from each other in chemical properties and structure. They were chosen from hydrocarbons, alcohols, aldehydes and ketones of acyclic, monocyclic and bicycl... |
12968344 | Thermochemistry of (E)- and (Z)-disubstituted alkene species: a combined experimental and theoretical investigation of isomeric dimethyl fumarate and dimethyl maleate. | The first unequivocal thermochemical/calorimetric determination of the enthalpies of combustion, phase change, and formation of a pair of (E)- and (Z)-disubstituted olefins of the type XCH = CHX, where X is an electron withdrawing group, is reported in this paper for the isomeric species dimethyl fumarate and dimethyl ... |
12968343 | From 1D strands to extended molecular assemblies in the binary compounds of dithiooxamide and dithiobiurea with crown ethers. | The hydrogen-bonding networks for seven new binary compounds of dithiooxamide, (NH2CS)2 (dtox) and dithiobiurea (NH2CSNH)2 (dtur) with crown ethers, 18-crown-6 (18C6), 15-crown-5 (15C5), 12-crown-4 (12C4), cis-syn-cis-(DCHA), and cis-anti-cis-(DCHB) isomers of dicyclohexyl-18 -crown-6 are discussed. (15C5.dtox), (18C6.... |
12952250 | A cyclosporin A/maltosyl-alpha-cyclodextrin complex for inhalation therapy of asthma. | The inhalation of cyclosporin (Cs)A to the lung is limited by its hydrophobic properties. In order to improve the poor solubility of CsA, cyclodextrin (CD) was evaluated for its suitability for dry powder inhaler formation, and the benefit of an inhaled CsA/CD complex in vivo was demonstrated. The solubilising effect o... |
12951026 | Role of the gp120 inner domain beta-sandwich in the interaction between the human immunodeficiency virus envelope glycoprotein subunits. | The inner domain of the human immunodeficiency virus (HIV-1) gp120 glycoprotein has been proposed to mediate the noncovalent interaction with the gp41 transmembrane envelope glycoprotein. We used mutagenesis to investigate the functional importance of a conserved beta-sandwich located within the gp120 inner domain. Cha... |
12948207 | Self-assembly of achiral and chiral macrocyclic ligands: synthesis, protonation constants, conformation and asymmetric catalysis. | New 30-membered achiral and chiral polyaza macrocyclic ligands, L1 and L2 were synthesized directly from [3 + 3] condensation of phthalic dicarboxaldehyde with cis- and (1R,2R)-diaminocyclohexane, respectively. The trimeric macrocyclic structures were confirmed by electrospray ionization mass spectrometry (ESI-MS), 1H ... |
12947192 | Helical conformation of alkanes in a hydrophobic cavitand. | Alkanes adopt extended conformations in solution that minimize steric interactions and maximize surface area. Folding can reduce the amount of hydrophobic surface exposed to solvent, but sterically unfavorable gauche interactions result. However, we found that the alkyl chains of two common surfactants in aqueous solut... |
12944962 | Controlling molecular deposition and layer structure with supramolecular surface assemblies. | Selective non-covalent interactions have been widely exploited in solution-based chemistry to direct the assembly of molecules into nanometre-sized functional structures such as capsules, switches and prototype machines. More recently, the concepts of supramolecular organization have also been applied to two-dimensiona... |
12941266 | Molecular recognition of cargo by the COPII complex: a most accommodating coat. | The molecular mechanism by which diverse cargo proteins are recognized and exported from the ER has been unclear. Two papers in this issue of Cell add clarity by mapping multiple cargo recognition sites in the Sec24 subunit of the COPII coat complex and demonstrating roles for these sites in export of specific protein ... |
12938110 | Probing of arginine residues in peptides and proteins using selective tagging and electrospray ionization mass spectrometry. | A general labelling method is presented which allows the determination of the number of guanidine groups (related to arginine and homoarginine in peptides and proteins) by means of mass spectrometry. It implies a guanidine-selective derivatization step with 2,3-butanedione and an arylboronic acid under aqueous, alkalin... |
12938104 | Study of the fragmentation mechanism of novel functionalized macrocycles by Fourier transform ion cyclotron resonance mass spectrometry. | Liquid secondary ion mass spectrometry (L-SIMS) of six new functionalized macrocycles was investigated. All six compounds yielded abundant fragment ions and protonation molecular ions [M + H](+) under L-SIMS conditions. The proposed fragmentation mechanisms were supported by high-resolution accurate mass data from Four... |
12935894 | Lipid rafts determine efficiency of NADPH oxidase activation in neutrophils. | We have investigated the contribution of lipid rafts to activation of the NADPH oxidase enzyme system in neutrophils. Membrane-bound NADPH oxidase subunits are present in the lipid raft compartment of neutrophils. Cytosolic NADPH oxidase components are mainly absent from but are recruited to rafts upon Fcgamma receptor... |
12935893 | Rapamycin inhibits GM-CSF-induced neutrophil migration. | The molecular mechanisms that govern cell movement are the subject of intense study, as they impact biologically and medically important processes such as leukocyte chemotaxis and angiogenesis, among others. We demonstrate that leukocyte chemotaxis is prevented by the macrolide immunosuppressant rapamycin, a specific i... |
12934910 | Crystallization of two forms of a cyclodextrin inclusion complex containing a common organic guest. | The isolation and structural elucidation by single crystal X-ray diffraction of triclinic and monoclinic modifications of an inclusion complex of beta-cyclodextrin with the same guest, methylparaben, are reported. |
12934882 | Synergetic activation of "silent receptor" sites leading to a new type of inclusion complex: integration of a 64-membered ring comprising K+ and SO4(2-) ions into a molybdenum oxide-based nanoobject. | The new type of inclusion species [Mo(VI)114Mo(V)32O429(H2O)50(KSO4)16]30- comprising 16 encapsulated K+ and SO4(2-) ions shows an unusual 64-membered [K(SO4)]16 ring integrated into a wheel-shaped type nanocluster host; it is formed by a synergetically induced functional complementarity and represents a text-book exam... |
12932086 | Gates and oscillators: a network model of the brain clock. | The suprachiasmatic nuclei (SCN) control circadian oscillations of physiology and behavior. Measurements of electrical activity and of gene expression indicate that these heterogeneous structures are composed of both rhythmic and nonrhythmic cells. A fundamental question with regard to the organization of the circadian... |
12932039 | Lamellar architecture and crystalline transformation in supramolecular complexes of highly-branched polyethyleneimine-octadecanoic acid. | Supramolecular complexes of PEI(OA)x show a lamellar structure, and reversible crystal phase transition of the side alkyl chains in the complex can be observed by temperature-variable FT-IR spectroscopy. |
12932035 | Surface effects in the esterification of 9-pyrenebutyric acid within a glass micro reactor. | Surface phenomena are an important contribution to the "chip effect", leading to higher yields and shorter reaction times, as demonstrated for the acid-catalysed esterification of 9-pyrenebutyric acid within a glass fabricated micro reactor. |
12932017 | n-Alkane hydroconversion on Zeogrid and colloidal ZSM-5 assembled from aluminosilicate nanoslabs of MFI framework type. | n-Alkane hydroisomerisation and hydrocracking experiments reveal that ZSM-5 materials synthesized by self-assembly of nanoslabs show different molecular shape selectivity than ZSM-5 synthesized by hydrothermal methods. |
12931983 | Interdependence of redox state, hydrogen bonding, anion recognition and charge partition in crystals of (EDT-TTF-CONHMe)6 [Re6Se8(CN)6] (CH3CN)2(CH2Cl2)2. | Neutral pi-conjugated molecules and their radical cations co-exist in [(EDT-TTF-CONHMe+*)4(EDT-TTF-CONHMe0)2] [Re6Se8(CN)6]4- (CH3CN)2(CH2Cl2)2 whose crystal structure reveals that, upon one-electron oxidation, an activation of the N-H and C-H hydrogen bond donor ability is coupled to a deactivation of the hydrogen bon... |
12931979 | A two-channel molecular dosimeter for the optical detection of copper(II). | A cyclam-like macrocycle with an integrated push-pull chromophore selectively detects Cu2+ inclusion through both orange-to-yellow colour change and quenching of the green fluorescence. |
12931978 | Pentapyrrolic calix[4]pyrrole. | A new calix[4]pyrrole has been synthesised that contains a 3,4,5-trisbromopyrrole appended to a meso-position which shows enhanced anion affinity as compared to the parent meso-octamethylcalix[4]pyrrole macrocycle. |
12931181 | Epoxidation of polybutadiene by a topologically linked catalyst. | Nature has evolved complex enzyme architectures that facilitate the synthesis and manipulation of the biopolymers DNA and RNA, including enzymes capable of attaching to the biopolymer substrate and performing several rounds of catalysis before dissociating. Many of these 'processive' enzymes have a toroidal shape and c... |
12930797 | The glycine transporter type 1 inhibitor N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)propyl]sarcosine potentiates NMDA receptor-mediated responses in vivo and produces an antipsychotic profile in rodent behavior. | Glycine acts as a necessary coagonist for glutamate at the NMDA receptor (NMDAR) complex by binding to the strychnine-insensitive glycine-B binding site on the NR1 subunit. The fact that glycine is normally found in the brain and spinal cord at concentrations that exceed those required to saturate this site has led to ... |
12930138 | N6-substituted D-4'-thioadenosine-5'-methyluronamides: potent and selective agonists at the human A3 adenosine receptor. | 4'-Thio analogues 3-5 of Cl-IB-MECA (2) (K(i) = 1.0 +/- 0.2 nM at the human A(3) adenosine receptor) were synthesized from d-gulono-gamma-lactone via 4-thioribosyl acetate 14 as the key intermediate. All synthesized 4'-thionucleosides exhibited higher binding affinity to the human A(3) adenosine receptor than Cl-IB-MEC... |
12930137 | Structure-based design of a macrocyclic inhibitor for peptide deformylase. | A macrocyclic, peptidomimetic inhibitor of peptide deformylase was designed by covalently cross-linking the P1' and P3' side chains. The macrocycle, which contains an N-formylhydroxylamine side chain as the metal-chelating group, was synthesized from a diene precursor via olefin metathesis using Grubbs's catalyst. The ... |
12930751 | Scribble is essential for olfactory behavior in Drosophila melanogaster. | The ability to discriminate and respond to chemical signals from the environment is an almost universal prerequisite for survival. Here, we report that the scaffold protein Scribble is essential for odor-guided behavior in Drosophila. Previously, we identified a P-element insert line with generalized sexually dimorphic... |
12926967 | Cross-correlated relaxation enhanced 1H[bond]13C NMR spectroscopy of methyl groups in very high molecular weight proteins and protein complexes. | A comparison of HSQC and HMQC pulse schemes for recording (1)H[bond](13)C correlation maps of protonated methyl groups in highly deuterated proteins is presented. It is shown that HMQC correlation maps can be as much as a factor of 3 more sensitive than their HSQC counterparts and that the sensitivity gains result from... |
12926959 | In situ quantum dot growth on multiwalled carbon nanotubes. | The generation of nanoscale interconnects and supramolecular, hierarchical assemblies enables the development of a number of novel nanoscale applications. A rational approach toward engineering a robust system is through chemical recognition. Here, we show the in situ mineralization of crystalline CdTe quantum dots on ... |
12926957 | Molecular squares with paramagnetic diruthenium corners: synthetic and crystallographic challenges. | The reaction of Ru(2)(mu-O(2)CMe)(4)Cl with approximately 2.5 equiv of HDAniF (HDAniF = N,N'-di(p-anisyl)formamidine) in refluxing THF resulted in the synthesis of cis-Ru(2)(mu-DAniF)(2)(mu-O(2)CMe)(2)Cl (1). This Ru(2)(5+)complex, which has two labile acetate groups occupying two equatorial cisoid positions, was used ... |
12926949 | Self-assembly, structure, and dynamic interconversion of metallosupramolecular architectures generated by Pb(II) binding-induced unfolding of a helical ligand. | The binding of lead(II) cations to the terpyridine-type subunits of the helical ligand 1 leads to the self-assembly of different polynuclear metallosupramolecular architectures of nanometric size. Three different entities are generated and may be interconverted as a function of metal/ligand stoichiometry: a [4 x 4]Pb(1... |
12926947 | Rigid macrocyclic triamides as anion receptors: anion-dependent binding stoichiometries and 1H chemical shift changes. | The cyclic triamide of 3'-amino-3-biphenylcarboxlic acid is readily synthesized in a stepwise manner and represents a novel class of anion receptors with a large central cavity. This macrocycle binds more strongly to tetrahedral anions than spherical or planar anions in organic solvents. The binding stoichiometries for... |
12926940 | Viral-induced self-assembly of magnetic nanoparticles allows the detection of viral particles in biological media. | Monodisperse magnetic nanoparticles conjugated with virus-surface-specific antibodies self-assemble in the presence of specific viral particles to create supramolecular structures with enhanced magnetic properties, as detected by magnetic resonance methods (NMR/MRI). The observed magnetic relaxation changes that occur ... |
12926937 | Facile synthesis of cucurbit[n]uril derivatives via direct functionalization: expanding utilization of cucurbit[n]uril. | A long-standing problem in cucurbituril chemistry is answered through the first direct functionalization of cucurbit[n]uril (CB[n]; n = 5-8)) leading to perhydroxyCB[n] which can be further modified to provide tailored CB[n] derivatives with desired functional groups and good solubility. Anchoring a CB[6] derivative on... |
12926936 | Cross-linking strategy for molecular recognition and fluorescent sensing of a multi-phosphorylated peptide in aqueous solution. | In the research field of molecular recognition, selective recognition and sensing of phosphorylated protein surfaces is strongly desirable both for elucidation of protein-protein recognition at the molecular level and for regulation of signal transduction through protein surfaces. Here we describe a new strategy for mo... |
12927392 | The effects of organic salts on the cyclodextrin solubilization of drugs. | Previous studies have indicated that conventional description of drug/cyclodextrin complexes in aqueous solutions as inclusion complexes are not as unambiguous as one might think. It has been shown that in some cases drug/cyclodextrin complexes consist of a mixture of inclusion and non-inclusion complexes. Furthermore ... |
12929168 | A simple polyacrylamide gel electrophoresis procedure for separation of polyamidoamine dendrimers. | A simple, inexpensive, and rapid electrophoresis technique was developed for use as a routine tool for evaluating purity of polyamidoamine (PAMAM) dendrimers. A variety of factors influencing migration of generations 0-7 dendrimers on nongradient polyacrylamide gels were evaluated. The low generation dendrimers were fo... |
12925676 | Arf6 and phosphoinositol-4-phosphate-5-kinase activities permit bypass of the Rac1 requirement for beta1 integrin-mediated bacterial uptake. | Efficient entry of the bacterium Yersinia pseudotuberculosis into mammalian cells requires the binding of the bacterial invasin protein to beta1 integrin receptors and the activation of the small GTPase Rac1. We report here that this Rac1-dependent pathway involves recruitment of phosphoinositol-4-phosphate-5-kinase (P... |
12924884 | Nature of the reactants and influence of water on the supramolecular assembly. | The influences of the nature of reactants and water on the self-assembly of cationic Cu(II) complex structures containing N-(2-pyridylmethyl)glycine (Hpgly) and N-(2-pyridylmethyl)-l-alanine (Hpala) ligands have been investigated. A metallamacrocycle [Cu(6)(pgly)(3)(spgly)(3)] (ClO(4))(6).9H(2)O has been formed by the ... |
12924873 | Elite new anion ligands: polythioamide macrocycles. | Prototypes for a new class of polythioamide-based macrocycles have been synthesized and anion-binding capabilities assessed. Results indicate higher anion binding for H(2)PO(4)(-), HSO(4)(-), and F(-) for monocycles, but somewhat lessened binding capabilities for bicycles compared with amide corollaries. |
12924960 | Physicochemical aspects of host-guest compounds. | The macro properties of crystalline inclusion compounds depend on their structures. Their thermal stabilities are a function of the strength and the directionality of the various nonbonded interactions occurring in the host-guest assembly. Their lattice energies, as measured by the method of atom-atom potentials, corre... |
12924959 | Cucurbituril homologues and derivatives: new opportunities in supramolecular chemistry. | The supramolecular chemistry of cucurbituril, a synthetic receptor, is fascinating because of the remarkable guest binding behavior of the host. Studies in the field, however, have met with limitations, since the only species known was the hexameric macrocyclic compound, cucurbit[6]uril. Recently we synthesized its hom... |
12923836 | Host-guest antenna materials. | The focus of this review is on host-guest composites with photonic antenna properties. The material generally consists of cylindrical zeolite L crystals the channels of which are filled with dye molecules. The synthesis is based on the fact that molecules can diffuse into individual channels. This means that, under the... |
12919744 | The glycosylation status of the murine hepatitis coronavirus M protein affects the interferogenic capacity of the virus in vitro and its ability to replicate in the liver but not the brain. | The coronavirus M protein, the most abundant coronaviral envelope component, is invariably glycosylated, which provides the virion with a diffuse, hydrophilic cover on its outer surface. Remarkably, while the group 1 and group 3 coronaviruses all have M proteins with N-linked sugars, the M proteins of the group 2 coron... |
12919027 | Synthesis and structure of lower rim C-linked N-tosyl peptidocalix[4]arenes. | Chiral p-tert-butylcalix[4]arenes functionalized at the lower rim with amino acid residues have been prepared. The (1)H and (13)C NMR spectra indicate that the macrocycles preferably adopt a cone conformation. Calix[4]arenes bearing amino acid moieties were prepared as a class of receptors selective for anions that are... |
12919018 | A cyclodextrin-modified ketoester for stereoselective epoxidation of alkenes. | A beta-cyclodextrin-modified ketoester 2 was prepared by covalent attachment of a reactive ketone moiety to beta-cyclodextrin. Treatment of 2 with Oxone as terminal oxidant would produce CD-substituted dioxirane, which can effect stereoselective alkene epoxidation. The 2-mediated (S)-alpha-terpineol epoxidations procee... |
12918145 | Single-dose daclizumab induction therapy in patients with liver transplantation. | <h4>Aim</h4>To investigate the efficacy and safety of a single-dose daclizumab induction therapy in orthotopic liver transplantation (OLTx).<h4>Methods</h4>A retrospective study was made for 54 cases of OLTx in recent three years. The daclizumab group consisted of 23 cases of OLTx who received single-dose of 2 mg/kg in... |
12916998 | Kinetics and thermodynamics of amine and diamine signaling by a trifluoroacetyl azobenzene reporter group. | [reaction: see text] (Trifluoroacetyl)azobenzene dyes were previously employed as amine reporter groups (chemosensors) in a dendrimer-based monomolecular imprinting system. Kinetic and binding studies with a range of amines and diamines show that the highly selective signaling observed for alkane diamines by these impr... |
12914536 | Hormonal control of IGF-binding protein (IGFBP)-5 and IGFBP-2 secretion during differentiation of the HC11 mouse mammary epithelial cell line. | The mouse mammary epithelial cell line HC11 upregulates the synthesis of beta-casein (a differentiation marker) following treatment with the lactogenic hormone mix dexamethasone, insulin and prolactin (DIP). We demonstrate that the basal levels of IGF-binding protein (IGFBP)-5 secreted by undifferentiated HC11 cells ar... |
12914462 | Control of stepwise radial complexation in dendritic polyphenylazomethines. | The fourth generation of a dendritic polyphenylazomethine (DPA G4) has 2, 4, 8, and 16 imine groups in the first, second, third, and fourth shells, respectively (total, 30 imine groups). DPA G4 can trap 30 equiv of SnCl(2) molecules, because the imine group is complexed with SnCl(2) at a ratio of 1:1. During addition o... |
12914457 | Guest encapsulation in a water-soluble molecular capsule based on ionic interactions. | We report on the synthesis and characterization of a water-soluble molecular capsule based on multiple ionic interactions. The assembly has been studied by means of 1H NMR, ESI-MS spectroscopy, and isothermal titration calorimetry (ITC), showing an association constant in water, Ka, of 3.3 x 104 M-1. The achieved water... |
12914450 | Duplex foldamers from assembly induced folding. | Oligoamide strands 1, 2, and 3, consisting of 4-H-bond units, were originally designed to form noncovalent polymers based on the expectation that they would adopt an extended conformation. Instead of assembling into the expected supramolecular polymer through their 4-H-bond units, the 1:1 mixture of 1 and 2 was found t... |
12916124 | N.Br halogen bonding: one-dimensional infinite chains through the self-assembly of dibromotetrafluorobenzenes with dipyridyl derivatives. | The N.Br halogen bonding drives the self-assembly of 1,4-dibromotetrafluorobenzene (1 a) and its 1,3 or 1,2 analogues (1 b,c, respectively) with dipyridyl derivatives 2 a,b. The isomeric supramolecular architectures 3 a-f are obtained as cocrystals that are stable in the air at room temperature. The solid-state feature... |
12916116 | Clays as a host matrix in the synthesis of organic macrocycles. | A new approach for the synthesis of amide macrocycles, based on the use of organo-clay derivatives as controlling template, is proposed as an alternative to the rotaxane method. Dications of p-xylylene diamine inserted in the clay interlayer space act as molding pillars around which neutral diamine molecules are erecte... |
12916111 | Electrostatic complexation and photoinduced electron transfer between Zn-cytochrome c and [olyanionic fullerene dendrimers. | Two dendritic fullerene (DF) monoadducts, 2 and 3, which can carry up to 9 and 18 negative charges, respectively, were examined with respect to electrostatic complexation with Cytochrome c (Cytc). To facilitate comprehensive photophysical investigations, the zinc analogue of Cytc (ZnCytc) was prepared according to a no... |
12916100 | Copper-metallomesogen structures obtained by ionic self-assembly (ISA): molecular electromechanical switching driven by cooperativity. | In a stepwise noncovalent multiple-interaction strategy, copper(II) salts were complexed with the sodium salts of bathophenanthrolinedisulfonic acid (BPS) and bathocuproinedisulfonic acid (BCS), and organized into nanostructured materials by the addition of ammonium surfactants by means of the ionic self-assembly (ISA)... |
12916097 | Supramolecular [6]chochin and "Big Mac" made from chiral Piedfort assemblies. | Facile chemical synthesis of the natural chiral-pool-derived host 1 and its subsequent crystallization ("supramolecular synthesis") from different solvents yielded crystalline assemblies. Crystal structure determinations of five of the so formed solvent-inclusion compounds (1 a-1 e) reveal hexagonal symmetries in four ... |
12916096 | Chemical and biochemical sensing with modified single walled carbon nanotubes. | The nano dimensions, graphitic surface chemistry and electronic properties of single walled carbon nanotubes make such a material an ideal candidate for chemical or biochemical sensing. Carbon nanotubes can be nondestructively oxidized along their sidewalls or ends and subsequently covalently functionalized with colloi... |
12916030 | Endo- and exotemplating to create high-surface-area inorganic materials. | Porous and high-surface-area materials are of interest to many scientific communities. Templating pathways can be used to synthesize such materials with a high degree of control over their structural and textural properties. As templates molecular or supramolecular units are added to the synthesis mixture. They are occ... |
12913639 | Lung injury severity scoring in the era of lung protective mechanical ventilation: the PaO2/FIO2 ratio. | <h4>Background</h4>Lung protective ventilatory strategies using low tidal volume and high positive end-expiratory pressure (PEEP) have become standard practice. Such strategies, however, may invalidate measurement of lung injury severity by traditional methods that are based on plain chest radiograph findings, oxygenat... |
12912921 | Distinct requirements for the naturally occurring splice forms Stat4alpha and Stat4beta in IL-12 responses. | Signal transducer and activator of transcription (Stat)4 is a signaling molecule required for normal responses to interleukin-12 (IL-12) and is critically involved in inflammatory responses. We have isolated an alternatively spliced isoform of Stat4, termed Stat4beta, which lacks 44 amino acids at the C-terminus, encom... |
12912916 | Insulin induces phosphatidylinositol-3-phosphate formation through TC10 activation. | Phosphatidylinositol-3-phosphate (PtdIns-3-P) is considered as a lipid constitutively present on endosomes; it does not seem to have a dynamic role in signalling. In contrast, phosphatidylinositol-3,4,5-trisphosphate (PtdIns-3,4,5-P(3)) plays a crucial role in different signalling pathways including translocation of th... |
12912908 | Contrasting effects of VEGF gene disruption in embryonic stem cell-derived versus oncogene-induced tumors. | Previous gene targeting studies have implicated an indispensable role of vascular endothelial growth factor (VEGF) in tumor angiogenesis, particularly in tumors of embryonal or endocrine origin. In contrast, we report here that transformation of VEGF-deficient adult fibroblasts (MDF528) with ras or neu oncogenes gives ... |
12912944 | Recombinant fowlpox viruses encoding the anchor-modified gp100 melanoma antigen can generate antitumor immune responses in patients with metastatic melanoma. | <h4>Purpose</h4>The purpose of this study was to evaluate the immunological responses and therapeutic effectiveness of immunization with fowlpox vaccines encoding the gp100 melanoma antigen in patients with metastatic melanoma.<h4>Experimental design</h4>In three consecutive clinical trials, patients were immunized wit... |
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