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24944376 | Efficacy and tolerability of conventional nimesulide versus Beta-cyclodextrin nimesulide in patients with pain after surgical dental extraction: a multicenter, prospective, randomized, double-blind, double-dummy study. | <h4>Background</h4>Pain following extraction of an impacted third molar is widely used to assess analgesic efficacy, especially that of a single dose of a drug. The analgesic activity of conventional nimesulide (CN) has been documented in a variety of types of acute and chronic pain. Beta-cyclodextrin nimesulide (BN) i... |
18969011 | Solvent extraction of permanganates (Na, K) by 18-crown-6 ether from water into 1,2-dichloroethane: elucidation of an extraction equilibrium based on component equilibria. | Ion-pair formation constants (K(MLA) mol(-1) dm(3)) of Na(+)- and K(+)-18-crown-6 ether (18C6) complexes with MnO(4)(-) in water (w) were determined potentiometrically at 25 degrees C. Simultaneously, extraction constants (K(ex) mol(-2) dm(6)) of the permanganates with 18C6 from w into 1,2-dichloroethane at 25 degrees ... |
18969006 | Sequential injection analysis with dynamic surface tension detection High throughput analysis of the interfacial properties of surface-active samples. | A sequential injection analysis (SIA) system is coupled with dynamic surface tension detection (DSTD) for the purpose of studying the interfacial properties of surface-active samples. DSTD is a novel analyzer based upon a growing drop method, utilizing a pressure sensor measurement of drop pressure. The pressure signal... |
16256543 | G1 dendrimers-mediated evolution of silver nanostructures from nanoparticles to solid spheres. | With the control of G1 poly(amidoamine) (PAMAM), an evolutionary course of stable colloidal silver from discrete nanoparticles to solid spheres through ultraviolet irradiation reduction of silver nitrate solutions was observed by transmission electron microscopy (TEM). The morphologies of the products depend on the Ag+... |
14569614 | Shotgun Phage Display - Selection for Bacterial Receptins or other Exported Proteins. | Shotgun phage display cloning involves construction of libraries from randomly fragmented bacterial chromosomal DNA, cloned genes, or eukaryotic cDNAs, into a phagemid vector. The library obtained consists of phages expressing polypeptides corresponding to all genes encoded by the organism, or overlapping peptides deri... |
12750515 | Hydrogen storage in microporous metal-organic frameworks. | Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate) with a cubic three-dimensional extended porous structure adsorbed hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. Inel... |
12747778 | Restricted conformation analogues of an anthelmintic cyclodepsipeptide. | Six analogues of the anthelmintic cyclodepsipeptide PF1022A were prepared, each containing a small ring fused to the macrocycle to restrict the number of conformations the larger ring can adopt. It was anticipated that such conformational changes could lead to enhanced biological activity and selectivity. The analogues... |
12745216 | Hydrogen/deuterium exchange on yeast ATPase supramolecular protein complex analyzed at high sensitivity by MALDI mass spectrometry. | To evaluate the ability of hydrogen/deuterium exchange of amide protons followed by mass spectrometry (HXMS) to yield topological information about supramolecular protein complexes, this approach has been tested with the 370 kDa hetero-oligomeric complex of yeast F1-ATPase. The study was focused on the epsilon subunit ... |
12745214 | Dication induced stabilization of gas-phase ternary beta-cyclodextrin inclusion complexes observed by electrospray mass spectrometry. | Electrospray mass spectrometry (ES-MS) is an important tool for characterization of non-covalent binding in the gas phase. In this study, iron (II) has been introduced as a dication to enhance the detection of cyclodextrin (CD) plus aromatic compound complexes in ES-MS. Evidence that a novel ternary complex comprised o... |
12745088 | Subcellular localization of collapsin response mediator proteins to lipid rafts. | Collapsin response mediator proteins (CRMPs) are involved in signal transduction after exposure of neural cells to the axon guidance molecule Semaphorin 3A/collapsin. All five known CRMPs are expressed in the developing cerebral cortex and neocortical neurons are responsive to Semaphorin 3A. Here, we examine the expres... |
12744431 | Complexation of butylbenzenes with 2-hydroxypropyl-cyclodextrins in aqueous solution. | The stability constants for the inclusion of butylbenzenes (BBs) with 2-hydroxypropyl-cyclodextrins (2HP-CDs) in aqueous solution have been determined using the static head-space method. The 1:1 stability constants were obtained by this method. For the complexation of BBs by 2HP-alpha-CD, the order of stability constan... |
12743109 | Neural cell adhesion molecule (NCAM) association with PKCbeta2 via betaI spectrin is implicated in NCAM-mediated neurite outgrowth. | In hippocampal neurons and transfected CHO cells, neural cell adhesion molecule (NCAM) 120, NCAM140, and NCAM180 form Triton X-100-insoluble complexes with betaI spectrin. Heteromeric spectrin (alphaIbetaI) binds to the intracellular domain of NCAM180, and isolated spectrin subunits bind to both NCAM180 and NCAM140, as... |
12741805 | Synthesis and properties of star-shaped polylactide attached to poly(amidoamine) dendrimer. | Star-shaped polylactide was synthesized by bulk polymerization of lactide with poly(amidoamine) (PAMAM) dendrimer as initiator, which was marked as PAMAM-g-PLA for simplicity. The nonlinear architecture of PAMAM-g-PLA was confirmed by gel permeation chromatograph, nuclear magnetic resonance, and differential scanning c... |
12741799 | Melting and crystallization behaviors of biodegradable polymers enzymatically coalesced from their cyclodextrin inclusion complexes. | Inclusion complexed (IC) and coalesced biodegradable poly(epsilon-caprolactone) (PCL), poly(L-lactic acid) (PLLA), and their diblock copolymer (PCL-b-PLLA) were achieved by forming ICs between host alpha-cyclodextrin(alpha-CD) and guest PCL, PLLA, and PCL-b-PLLA, followed by removing the alpha-CD host with an amylase e... |
12741767 | Correlation between structure of the lactones and substrate specificity in enzyme-catalyzed polymerization for the synthesis of polyesters. | Small-size (4-membered) and medium-size (5-, 6-, and 7-membered) unsubstituted lactones as well as unsubstituted macrolides (12 and 13 membered) were subjected to the ring-opening polymerization using the extracellular PHB depolymerase from Alcaligenes faecalis T1 (PhaZ(Afa)). The characteristic reactivities of the lac... |
12741824 | In vitro evolution of the binding specificity of neocarzinostatin, an enediyne-binding chromoprotein. | Neocarzinostatin is the most studied member of the enediyne-chromoprotein family, and is clinically used as an antitumoral agent. Neocarzinostatin could be a promising drug delivery vehicle if new binding specificities could be conferred to its protein scaffold. We used in vitro evolution methods to demonstrate that th... |
12739940 | Micro-X-ray fluorescence as a general high-throughput screening method for catalyst discovery and small molecule recognition. | A powerful high-throughput screening technique is described for the rapid screening of bead-based libraries for catalyst discovery and molecular recognition. Micro-X-ray fluorescence (MXRF) screens materials for elemental composition with mesoscale analysis. This method is nondestructive and requires minimal sample pre... |
12739979 | Oxamato-bridged trinuclear NiIICuIINiII complexes: a new (NiIICuIINiII)2 hexanuclear complex and supramolecular structures. Characterization and magnetic properties. | Eight oxamato-bridged heterotrinuclear Ni(II)Cu(II)Ni(II) complexes of formula ([Ni(H(2)O)(dpt)](2)(mu-Cu(H(2)O)(opba)))(ClO(4))2 (1), ([Ni(H(2)O)(dien)](2)(mu-Cu(pba)))(ClO(4))(2).6H(2)O (2), ([Ni(H(2)O)(Medpt)](2)(mu-Cu(OHpba)))(ClO(4))(2).4H(2)O (3), ([Ni(H(2)O)(dien)](2)(mu-Cu(Me(2)pba)))(ClO(4))(2).2.5H(2)O (4), (... |
12739966 | Rh(II) and Rh(I) two-legged piano-stool complexes: structure, reactivity, and electronic properties. | The ligand 1,4-bis[4-(diphenylphosphino)butyl]-2,3,5,6-tetramethylbenzene, 3, was used to synthesize a mononuclear Rh(II) complex [(eta(1):eta(6):eta(1)-1,4-bis[4-(diphenylphosphino)butyl]-2,3,5,6-tetramethylbenzene)Rh][PF(6)](2), 6+, in a two-legged piano-stool geometry. The structural and electronic properties of thi... |
12739954 | A new ligand system based on a bipyridine-functionalized calix[4]arene backbone leading to mono- and bimetallic complexes. | The synthesis of a new ligand system for mono- and bimetallic complexes based on a calixarene is described. Ligand BBPC (3, bis(bipyridine)-calix[4]arene) is obtained in three steps in 40% overall yield by first brominating one of the methyl groups of the 4,4'-dimethyl-2,2'-bipyridine in two steps and subsequently reac... |
12740836 | Rational chemical strategies for carbon nanotube functionalization. | Whereas the chemistry of fullerenes is well-established, the chemistry of single-walled carbon nanotubes (SWNTs) is a relatively unexplored field of research. Investigations into the bonding of moieties onto SWNTs are important because they provide fundamental structural insight into how nanoscale interactions occur. H... |
12737585 | Synthesis and characterization of a metallocycle-based molecular shuttle. | Kinetically stable metallocycle-based molecular shuttles of [2]rotaxanes 4a and 4b, along with [3]rotaxanes 5a and 5b, have been prepared using the rhenium(I)-bridged metallocycle 2 and the dumbbell components containing two stations, 3a and 3b. The rotaxanes were self-assembled by hydrogen bonding interactions upon he... |
12737577 | Molecular recognition of NO/NO+ via multicenter (charge-transfer) binding to bridged diarene donors. Effect of structure on the optical transitions and complexation thermodynamics. | Bridged diarenes form very strong [1:1] complexes with nitrosonium/nitric oxide in which the NO moiety is optimally sandwiched in the cleft between a pair of cofacial aromatic rings which act as a molecular "Venus flytrap". The spectral features of these associates are generally similar to those for [1:1] and [2:1] nit... |
12737569 | Tert-butyl-substituted tripyrranes: insights into the steric and conformational factors that influence porphyrinoid ring formation in the "3 + 1" methodology. | The MacDonald "3 + 1" route for porphyrinoid synthesis involves the acid-catalyzed condensation of tripyrranes with monocyclic dialdehydes, followed by an oxidation step. In the present study, yields were found to be greatly diminished when tert-butyl substituents were introduced on to the tripyrrane unit. Analysis of ... |
12737550 | A suite of novel allenes from Australian melolonthine scarab beetles. Structure, synthesis, and stereochemistry. | A suite of allenic hydrocarbons, previously unknown as a molecular class from insects, has been characterized from several Australian melolonthine scarab beetles. The allenes are represented by the formula CH(3)(CH(2))(n)()CH=*=CH(CH(2))(7)CH(3) with n being 11-15, 17 and 19, and thus, all have Delta(9,10)-unsaturation... |
12737851 | Humanized docking system for assembly of targeting drug delivery complexes. | Targeted drug delivery requires 'loading' drugs onto targeting proteins. Traditional technologies for loading drugs rely on chemical conjugation of drugs or drug carriers to targeting proteins. An alternative approach might rely on assembly of targeting complexes using a docking system that includes two components: a '... |
12735747 | Synthesis of a novel conformationally locked carbocyclic nucleoside ring system. | [reaction: see text] A fast and efficient synthetic route to novel Northern locked carbocyclic nucleosides (as precursors of carbocyclic locked nucleic acids or cLNAs) is described. The target nucleoside with a oxabicyclo[2.2.1]heptane ring system was prepared from a simple starting material, diethyl malonate. Ring clo... |
12735741 | Molecular recognition of amidines in water. | [structure: see text] Tetraphosphonates of the general structure shown above are biomimetic hosts for bisamidinium cations in drugs such as pentamidine and DAPI. Similar to their insertion into DNA's minor groove, these drugs are often sandwiched by two tetraphosphonate hosts (2:1). The alternative binding mode (1:2) p... |
12735737 | Remarkably enhanced excimer formation of naphthylacetate in cation-charged gamma-cyclodextrin. | [reaction: see text] 6(A),6(D)-Bispyridinio-appended gamma-cyclodextrin effectively enhanced the excimer fluorescence of 2-naphthylacetate. This increase derived from the increase of formation of the 1:2 complex between the cation-charged gamma-cyclodextrin and 2-naphthylacetate by the electrostatic interaction between... |
12736305 | Spectroscopic studies of the multiple binding modes of a trimethine-bridged cyanine dye with DNA. | The interaction between DNA and a benzothiazole-quinoline cyanine dye with a trimethine bridge (TO-PRO-3) results in the formation of three noncovalent complexes. Unbound TO-PRO-3 has an absorption maximum (lambda(max)) of 632 nm, while the bound dyes (with calf thymus DNA) have electronic transitions with lambda(max) ... |
12736688 | Computational design of receptor and sensor proteins with novel functions. | The formation of complexes between proteins and ligands is fundamental to biological processes at the molecular level. Manipulation of molecular recognition between ligands and proteins is therefore important for basic biological studies and has many biotechnological applications, including the construction of enzymes,... |
12736363 | Gating of hippocampal-evoked activity in prefrontal cortical neurons by inputs from the mediodorsal thalamus and ventral tegmental area. | Projections from the hippocampus, the mediodorsal thalamus (MD), and the ventral tegmental area (VTA) form interconnected neural circuits that converge in the prefrontal cortex (PFC) to participate in the regulation of executive functions. The present study assessed the roles that the MD and VTA play in regulating the ... |
12734234 | Detection of Chlamydia pneumoniae-specific antibodies binding to the VD2 and VD3 regions of the major outer membrane protein. | Although Chlamydia pneumoniae is an important human pathogen, the antigens eliciting a specific humoral immune response remain elusive. We scrutinized several recombinant chlamydial surface proteins for species-specific recognition by a panel of human sera previously tested for the presence of anti-C. pneumoniae and an... |
12734812 | Injectable drug-delivery systems based on supramolecular hydrogels formed by poly(ethylene oxide)s and alpha-cyclodextrin. | Polymeric hydrogels long have attracted interest for biomaterials applications because of their generally favorable biocompatibility. High in water content, they are particularly attractive for delivery of delicate bioactive agents, such as proteins. However, because they require covalent crosslinking for gelation, man... |
12733924 | A polyphenylene dendrimer-detergent complex as a highly fluorescent probe for bioassays. | The synthesis of a polyphenylene dendrimer carrying three perylenemonoimide dyes as well as one biotin group is presented. Due to the hydrophobic polyphenylene scaffold, this dendrimer is insoluble in water thus preventing investigations in aqueous media. However, the use of an appropriate detergent results in the form... |
12733922 | Self-activated supramolecular reactions: effects of host-guest recognition on the kinetics of the Diels-Alder reaction of open-chain oligoether quinones with cyclopentadiene. | Diels-Alder reactions of acyclic oligoether-substituted quinones 1b, 1c, 2b, and 2c with cyclopentadiene were accelerated by the addition of alkali and alkaline earth metal perchlorates, and scandium trifluoromethane sulfonate (k(c)/k(f) = 1.2-23 for univalent cations, 11-1160 for divalent cations, and 1700-192 000 for... |
12733920 | Benzoxazine oligomers: evidence for a helical structure from solid-state NMR spectroscopy and DFT-based dynamics and chemical shift calculations. | A combination of molecular modeling, DFT calculations, and advanced solid-state NMR experiments is used to elucidate the supramolecular structure of a series of benzoxazine oligomers. Intramolecular hydrogen bonds are characterized and identified as the driving forces for ring-shape and helical conformations of trimeri... |
12733910 | Quantitative formation of [2]catenanes using copper(I) and palladium(II) as templating and assembling centers: the entwining route and the threading approach. | Transition metal-mediated templating and self-assembly have shown powerful potentials for the synthesis of interlocked molecules. These two strategies were combined in designing and preparing a new type of coordination catenanes incorporating Cu(I) and Pd(II) metal centers. The ligand designed here contains a phenanthr... |
12733908 | Side chain assignments of Ile delta 1 methyl groups in high molecular weight proteins: an application to a 46 ns tumbling molecule. | A sensitive 3D NMR pulse scheme, (H)C(CA)NH-COSY, is presented for the assignment of (13)C(delta)(1) Ile chemical shifts in large perdeuterated, methyl-protonated proteins. The nonlinearity of branched amino acids, such as Ile, significantly degrades the quality of TOCSY schemes which transfer magnetization from methyl... |
12733888 | Multielectron transfer in clusters of polar-polarizable chromophores. | We present a model for interacting polar-polarizable molecules. Exotic collective effects are recognized as being due to supramolecular interactions: in attractive lattices, bistable behavior is found, and, for proper molecular orientation, multielectron transfer represents the primary photoexcitation event. |
12732204 | Fabrication and photoelectric response of poly(allylamine hydrochloride)/PM thin films by layer-by-layer deposition technique. | Thin films of poly(allylamine hydrochloride) (PAH) and bacteriorhodopsin (bR) embedded in purple membrane (PM) have been prepared by layer-by-layer (LBL) self-assembly technique. The results obtained by UV-Vis spectroscopy and atomic force microscopy (AFM) analysis showed that the biological activity of bR was preserve... |
12732513 | Characterization of poly-gamma-glutamate hydrolase encoded by a bacteriophage genome: possible role in phage infection of Bacillus subtilis encapsulated with poly-gamma-glutamate. | Some Bacillus subtilis strains, including natto (fermented soybeans) starter strains, produce a capsular polypeptide of glutamate with a gamma-linkage, called poly-gamma-glutamate (gamma-PGA). We identified and purified a monomeric 25-kDa degradation enzyme for gamma-PGA (designated gamma-PGA hydrolase, PghP) from bact... |
12730595 | Supramolecular self-assembly of lipid derivatives on carbon nanotubes. | Images of the assembly of surfactants and synthetic lipids on the surface of carbon nanotubes were obtained by transmission electron microscopy. Above the critical micellar concentration, sodium dodecyl sulfate (SDS) forms supramolecular structures made of rolled-up half-cylinders on the nanotube surface. Depending on ... |
12729728 | A novel member of glycoside hydrolase family 88: overexpression, purification, and characterization of unsaturated beta-glucuronyl hydrolase of Bacillus sp. GL1. | Unsaturated beta-glucuronyl hydrolase of Bacillus sp. GL1 catalyzes the hydrolytic release of unsaturated glucuronic acids from oligosaccharides produced through the reactions of polysaccharide lyases such as gellan, xanthan, hyaluronate, and chondroitin lyases. An overexpression system for the enzyme was constructed i... |
12730167 | The Escherichia coli Fis protein stimulates bacteriophage lambda integrative recombination in vitro. | The Escherichia coli nucleoid-associated protein Fis was previously shown to be involved in bacteriophage lambda site-specific recombination in vivo, enhancing the levels of both integrative recombination and excisive recombination. While purified Fis protein was shown to stimulate in vitro excision, Fis appeared to ha... |
12731028 | Determination of enantiomeric purity of a novel COX-2 anti-inflammatory drug by capillary electrophoresis using single and dual cyclodextrin systems. | E-6087 is the most advanced compound among the cyclooxygenase-2 (COX-2) inhibitor drugs developed in our company. Its activity is mainly associated with the S(-)-enantiomer (E-6232), whereas the R(-)-enantiomer (E-6231) becomes an impurity whose content should be determined. Five main impurities and degradation product... |
12729630 | Antibacterial activity of quinolone-macrocycle conjugates. | Novel quinolone-macrocycle conjugates displayed submicromolar antibacterial activity against Escherichia coli and Staphylococcus aureus bacterial strains. An analogous open-chain structure was not active at 100 microM against the same pathogenic strains. |
12570872 | Different binding motifs in metabotropic glutamate receptor type 7b for filamin A, protein phosphatase 1C, protein interacting with protein kinase C (PICK) 1 and syntenin allow the formation of multimeric protein complexes. | Metabotropic glutamate receptor (mGluR) type 7-mediated neurotransmission depends critically on its regulation by associated molecules, such as kinases, phosphatases and structural proteins. The splice variants mGluR7a and mGluR7b are defined by different intracellular C-termini, and simultaneous or exclusive binding o... |
12727606 | Cradle-to-cradle stewardship of drugs for minimizing their environmental disposition while promoting human health. I. Rationale for and avenues toward a green pharmacy. | Since the 1980s, the occurrence of pharmaceuticals and personal care products (PPCPs) as trace environmental pollutants, originating primarily from consumer use and actions rather than manufacturer effluents, continues to become more firmly established. Although PPCPs typically have been identified in surface and groun... |
12727878 | Cyanobacterial circadian clockwork: roles of KaiA, KaiB and the kaiBC promoter in regulating KaiC. | Using model strains in which we ectopically express the cyanobacterial clock protein KaiC in cells from which the clock genes kaiA, kaiB and/or kaiC are deleted, we found that some features of circadian clocks in eukaryotic organisms are conserved in the clocks of prokaryotic cyanobacteria, but others are not. One unex... |
12727867 | An H-bond between two residues from different loops of the acetylcholine binding site contributes to the activation mechanism of nicotinic receptors. | The molecular mechanisms of nicotinic receptor activation are still largely unknown. The crystallographic structure of the acetylcholine binding protein (AChBP) reveals a single H-bond between two different acetylcholine binding loops. Within these homologous loops we systematically introduced alpha4 residues into the ... |
12727863 | Functional aspects of protein mono-ADP-ribosylation. | Mono-ADP-ribosylation is the enzymatic transfer of ADP-ribose from NAD(+) to acceptor proteins. It is catalysed by cellular ADP-ribosyltransferases and certain bacterial toxins. There are two subclasses of cellular enzymes: the ectoenzymes that modify targets such as integrins, defensin and other cell surface molecules... |
12721390 | Capsaicinoids cause inflammation and epithelial cell death through activation of vanilloid receptors. | Capsaicinoids, found in less-than-lethal self-defense weapons, have been associated with respiratory failure and death in exposed animals and people. The studies described herein provide evidence for acute respiratory inflammation and damage to epithelial cells in experimental animals, and provide precise molecular mec... |
12720454 | Facile access to monodisperse ultralarge rings. | A facile access to monodisperse ultralarge rings counting 126, 174, and 294 ring atoms is described. It follows a reaction sequence that is well suited for the preparation of [2]catenanes but altered just in the sequence of the two steps cyclization and carbonate formation. The carbonate acts as a covalent template tha... |
12720449 | Ruthenium(II) dendrimers containing carbazole-based chromophores as branches. | Three new luminescent and redox-active Ru(II) complexes containing novel dendritic polypyridine ligands have been synthesized, and their absorption spectra, luminescence properties (both at room temperature in fluid solution and at 77 K in rigid matrix), and redox behavior have been investigated. The dendritic ligands ... |
12720440 | Spirastrellolide A, an antimitotic macrolide isolated from the Caribbean marine sponge Spirastrella coccinea. | Sprirastrellolide A, a novel antimitotic macrolide, has been isolated from the Caribbean marine sponge Spirastrella coccinea. It has a 47-carbon linear polyketide backbone incorporated into a highly functionalized 38-membered lactone containing a tetrahydropyran and two spiro bispyran substructures embedded in the macr... |
12720349 | Specific aptamer-protein interaction studied by atomic force microscopy. | Aptamers are a new class of synthetic DNA/RNA oligonucleotides generated from in vitro selection to selectively bind with various molecules. Due to their molecular recognition capability for proteins, aptamers are becoming promising reagents in protein detection and new drug development. In this study, the specific int... |
12719600 | Green fluorescent protein-tagged retroviral envelope protein for analysis of virus-cell interactions. | Fluorescent retroviral envelope (Env) proteins were developed for direct visualization of viral particles. By fusing the enhanced green fluorescent protein (eGFP) to the N terminus of the amphotropic 4070A envelope protein, extracellular presentation of eGFP was achieved. Viruses incorporated the modified Env protein a... |
12719582 | Hyperglycosylated mutants of human immunodeficiency virus (HIV) type 1 monomeric gp120 as novel antigens for HIV vaccine design. | The ability to induce broadly neutralizing antibodies should be a key component of any forthcoming vaccine against human immunodeficiency virus type 1. One potential vaccine candidate, monomeric gp120, has generally failed to elicit such antibodies. We postulated that gp120 might be a better immunogen if it could be en... |
12719264 | Analyzing intracellular binding and diffusion with continuous fluorescence photobleaching. | Transport and binding of molecules to specific sites are necessary for the assembly and function of ordered supramolecular structures in cells. For analyzing these processes in vivo, we have developed a confocal fluorescence fluctuation microscope that allows both imaging of the spatial distribution of fluorescent mole... |
12719262 | Site-specific identification of non-beta-strand conformations in Alzheimer's beta-amyloid fibrils by solid-state NMR. | The most well-established structural feature of amyloid fibrils is the cross-beta motif, an extended beta-sheet structure formed by beta-strands oriented perpendicular to the long fibril axis. Direct experimental identification of non-beta-strand conformations in amyloid fibrils has not been reported previously. Here w... |
12719261 | Energetic and structural considerations for the mechanism of protein sliding along DNA in the nonspecific BamHI-DNA complex. | The molecular mechanism by which DNA-binding proteins find their specific binding sites is still unclear. To gain insights into structural and energetic elements of this mechanism, we used the crystal structure of the nonspecific BamHI-DNA complex as a template to study the dominant electrostatic interaction in the non... |
12719260 | Three-dimensional imaging of lipid gene-carriers: membrane charge density controls universal transfection behavior in lamellar cationic liposome-DNA complexes. | Cationic liposomes (CLs) are used worldwide as gene vectors (carriers) in nonviral clinical applications of gene delivery, albeit with unacceptably low transfection efficiencies (TE). We present three-dimensional laser scanning confocal microscopy studies revealing distinct interactions between CL-DNA complexes, for bo... |
12719258 | Heme structural perturbation of PEG-modified horseradish peroxidase C in aromatic organic solvents probed by optical absorption and resonance Raman dispersion spectroscopy. | The heme structure perturbation of poly(ethylene glycol)-modified horseradish peroxidase (HRP-PEG) dissolved in benzene and toluene has been probed by resonance Raman dispersion spectroscopy. Analysis of the depolarization ratio dispersion of several Raman bands revealed an increase of rhombic B(1g) distortion with res... |
12719240 | Cholesterol in bilayers of sphingomyelin or dihydrosphingomyelin at concentrations found in ocular lens membranes. | Membranes of the lens of the eye of mammals have two particular characteristics, high concentrations of sphingomyelin, and dihydrosphingomyelin and cholesterol. We have studied the miscibility of cholesterol with both egg sphingomyelin and with dihydrosphingomyelin made by hydrogenation of egg sphingomyelin. At a chole... |
12719237 | Cooperative partition model of nystatin interaction with phospholipid vesicles. | Nystatin is a membrane-active polyene antibiotic that is thought to kill fungal cells by forming ion-permeable channels. In this report we have investigated nystatin interaction with phosphatidylcholine liposomes of different sizes (large and small unilamellar vesicles) by time-resolved fluorescence measurements. Our d... |
12719234 | Mechanism of membrane binding by the bovine seminal plasma protein, PDC-109: a surface plasmon resonance study. | PDC-109, the major protein of bovine seminal plasma, binds to sperm plasma membranes upon ejaculation and plays a crucial role in the subsequent events leading to fertilization. The binding process is mediated primarily by the specific interaction of PDC-109 with choline-containing phospholipids. In the present study t... |
12719221 | Profiling charge complementarity and selectivity for binding at the protein surface. | A novel analysis and representation of the protein surface in terms of electrostatic binding complementarity and selectivity is presented. The charge optimization methodology is applied in a probe-based approach that simulates the binding process to the target protein. The molecular surface is color coded according to ... |
12718523 | Role of charges on cytochrome f from the cyanobacterium Phormidium laminosum in its interaction with plastocyanin. | The role of charge on the surface of cytochrome f from the cyanobacterium Phormidium laminosum in the reaction with plastocyanin was investigated in vitro using site-directed mutagenesis. Charge was neutralized at five acidic residues individually and introduced at a residue close to the interface between the two prote... |
12718518 | Binding of NAP-22, a calmodulin-binding neuronal protein, to raft-like domains in model membranes. | The cholesterol-binding protein NAP-22 is a major component of the detergent-insoluble low-density fraction of rat brain. In this study, we found, using fluorescence microscopy, that native NAP-22, but not a demyristoylated form, binds to cholesterol-rich raft-like domains in planar-supported monolayers and remains bou... |
12717023 | Reliable prediction of T-cell epitopes using neural networks with novel sequence representations. | In this paper we describe an improved neural network method to predict T-cell class I epitopes. A novel input representation has been developed consisting of a combination of sparse encoding, Blosum encoding, and input derived from hidden Markov models. We demonstrate that the combination of several neural networks der... |
12717021 | Ligand-induced changes in dynamics in the RT loop of the C-terminal SH3 domain of Sem-5 indicate cooperative conformational coupling. | We report the effects of peptide binding on the (15)N relaxation rates and chemical shifts of the C-SH3 of Sem-5. (15)N spin-lattice relaxation time (T(1)), spin-spin relaxation time (T(2)), and ((1)H)-(15)N NOE were obtained from heteronuclear 2D NMR experiments. These parameters were then analyzed using the Lipari-Sz... |
12716202 | Tetrakis(imidazolyl)borate-based coordination polymers: group II network solids, M[B(Im)4]2(H2O)2 (M = Mg, Ca, Sr). | We are using the coordinating anion tetrakis(imidazolyl)borate to construct new metal-organic framework structures. In this report, we present three alkaline earth metal network solids incorporating this anion. All three compounds have the same formula, M[B(Im)(4)](2)(H(2)O)(2) (M = Mg, Ca, Sr), and the same coordinati... |
12716190 | Self-assembly between silver(I) and di- and tri-2-pyridines with flexible spacer: formation of discrete metallocycle versus coordination polymer. | The self-assembly of metallosupramolecules from reactions of flexible 2-pyridyl ligands and silver salts is described. When 1,3-bis(2-pyridyl)propane (L1), tris[(2-pyridyl)methyl]methane (L2), and 1,3-bis(2-pyridyl)-2-tolylpropane (L3) are used in combination with silver ions, novel discrete metallocyclic complexes are... |
12716174 | Rational design of molecular sheets composed of interconnecting eight- and twenty-four-membered rings: use of lithiated aggregates to control network assembly. | The lithiated (organo)sulfonylacetonitrile complex [MeSO(2)CHCNLi.THF] (3) has been prepared and structurally characterized in order to demonstrate that well-known molecular aggregates of s-block metals may be used as building blocks in the controlled assembly of complex supramolecular architectures. The solid state st... |
12713318 | Calix[4]arenes containing ferrocene amide as carboxylate anion receptors and sensors. | Calix[4]arene derivatives containing amide ferrocene units at the wide rim and ethyl ester groups at the narrow rim, L1-L3, were synthesized and their anion binding and sensing properties were investigated. It was found from (1)H NMR titrations that L1-L3 were able to bind selectively with carboxylate anions. Moreover,... |
12713379 | Selective binding of steroids by 2,2'-biquinoline-4,4'-dicarboxamide-bridged bis(beta-cyclodextrin): fluorescence enhancement by guest inclusion. | A novel bis(beta-cyclodextrin) was synthesized, and its binding behavior with steroids was investigated to demonstrate that the cooperative co-inclusion of guest and tether by two cyclodextrin moieties is operative to afford the highest molecular selectivity of up to 3.6 for deoxycholate over taurocholate. |
12713374 | Synthesis of phosphoryl-tethered beta-cyclodextrins and their molecular and chiral recognition thermodynamics. | Two novel phosphoryl-bridged bis- and tris(beta-cyclodextrin)s of different tether lengths, i.e., bis[m-(N-(6-cyclodextryl)-2-aminoethylaminosulfonyl)phenyl]-m-(chlorosulfonyl)phenylphosphine oxide (5) and tris[m-(N-(6-cyclodextryl)-8-amino-3,6-diazaoctylaminosulfonyl)phenyl]phosphine oxide (6), have been synthesized b... |
12713372 | Synthesis of p-tert-butylcalix[4]arene derivatives with trans-alkyl substituents on opposite methylene bridges. | Reaction of the bis(spirodiene) calixarene derivative 9 possessing exocyclic double bonds with tetraethylammonium fluoride or chloride afforded bis(spirodienone) calixarene derivatives substituted by the corresponding halogen atoms (11 and 12). Reaction of 9 with alkyl cuprates yielded in one step p-tert-butylcalix[4]a... |
12713349 | Formation and structures of mercury complexes of 18-membered unsaturated and saturated thiacrown ethers. | The complexation of 18-membered unsaturated thiacrown ether, 18-UT-6, with 1 equiv of HgCl(2) in acetone afforded mercury complex Hg(II)(18-UT-6)Cl(2). The complexations of 18-membered saturated thiacrown ether, 18S6, with 1 equiv each of HgCl(2) and CdCl(2) in acetone afforded Hg(II)(18S6)Cl(2) and Cd(II)(18S6)Cl(2), ... |
12713340 | First C3v-symmetrical calix[6](aza)crown. | The first C(3v)-symmetrical calix[6](aza)crown 8 has been obtained in five steps from X(6)H(3)Me(3) 3. The key-step introduction of the triple bridge at the small rim has been achieved through reaction of a tris-arylsulfonamide derivative of tren 1 and tris-tosylcalix[6]arene 6. A (1)H NMR study has shown that the trip... |
12713491 | Host cell caveolae act as an entry-port for group A streptococci. | This study identified caveolae as an entry port for group A streptococci into epithelial and endothelial cells. Scanning electron microscopy as well as ultrathin sections of infected cells demonstrated accumulation of small omega-shaped cavities in the host cell membrane close to adherent streptococci. During invasion,... |
12711436 | Enhanced Fenton degradation of hydrophobic organics by simultaneous iron and pollutant complexation with cyclodextrins. | The effectiveness and selectivity of Fenton degradation of hydrophobic organic compounds (HOCs) can be improved by simultaneous complexation of Fe(2+) and the organic compound with a cyclodextrin or derivatized cyclodextrin. Such selective complexation of a target substrate and a catalytic metal is a crude mimic of enz... |
12711683 | RNA structure-dependent uncoupling of substrate recognition and cleavage by Escherichia coli ribonuclease III. | Members of the ribonuclease III superfamily of double-strand-specific endoribonucleases participate in diverse RNA maturation and decay pathways. Ribonuclease III of the gram-negative bacterium Escherichia coli processes rRNA and mRNA precursors, and its catalytic action can regulate gene expression by controlling mRNA... |
12711676 | The DNA-bending protein HMGB1 is a cellular cofactor of Sleeping Beauty transposition. | Sleeping Beauty (SB) is the most active Tc1/ mariner-type transposon in vertebrates. SB contains two transposase-binding sites (DRs) at the end of each terminal inverted repeat (IR), a feature termed the IR/DR structure. We investigated the involvement of cellular proteins in the regulation of SB transposition. Here, w... |
12711669 | RNA helicase A interacts with dsDNA and topoisomerase IIalpha. | RNA helicase A (RHA) is a multifunctional protein involved in various nuclear processes such as transcription and RNA export. It is believed that the interacting factors play important roles in determining the functional specificity of RHA. Here we show that RHA directly interacts with double-stranded (ds) nucleic acid... |
12712411 | When can cyclodextrins be considered for solubilization purposes? | This communication is intended to address the question: How can one determine, with minimum experimentation, if cyclodextrins (CDs) might be the right choice as solubilization enhancers for a given poorly water-soluble drug? The cyclodextrin utility number, U(CD), a dimensionless number, is introduced to assess the fea... |
12711167 | A PEGylated dendritic nanoparticulate carrier of fluorouracil. | The present study was aimed at developing and exploring the use of uncoated and PEGylated newer PAMAM dendrimers for delivery of anti-cancer drug 5-fluorouracil. For this study, successive Michael addition and exhaustive amidation reactions were used to synthesize 4.0 G PAMAM dendrimers, using ethylenediamine as core a... |
12711162 | Interactions of amphiphilic calix[4]arene-based Solid Lipid Nanoparticles with bovine serum albumin. | The interaction of Solid Lipid Nanoparticles (SLN) based on amphiphilic calix[4]arene with one of the major circulatory protein, serum albumin, has been investigated by Photon Correlation Spectroscopy (PCS) and Atomic Force Microscopy (AFM). The carrier systems have shown the ability to interact with bovine serum album... |
12711157 | Enhancing effect of chitosan on nasal absorption of salmon calcitonin in rats: comparison with hydroxypropyl- and dimethyl-beta-cyclodextrins. | Two types of chitosan, i.e. the free amine (CS J) and the glutamate salt (CS G), were evaluated for their enhancing effect on in vivo nasal absorption of salmon calcitonin (sCT) in rats. The results were subsequently compared with beta-cyclodextrins, one of the most commonly studied enhancers. Solutions containing sCT ... |
12709062 | Identification of amino acids in antiplasmin involved in its noncovalent 'lysine-binding-site'-dependent interaction with plasmin. | The lysine-binding-site-mediated interaction between plasmin and antiplasmin is of great importance for the fast rate of this reaction. It also plays an important part in regulating the fibrinolytic enzyme system. To identify structures important for its noncovalent interaction with plasmin, we constructed seven single... |
12709320 | Functional similarities and differences between Candida albicans Cdr1p and Cdr2p transporters. | The Candida albicans CDR1 and CDR2 genes code for highly homologous ATP-binding cassette (ABC) transporters which are overexpressed in azole-resistant clinical isolates and which confer resistance to multiple drugs by actively transporting their substrates out of the cells. These transporters are formed by two homologo... |
12709314 | Prevention of human rhinovirus infection by multivalent fab molecules directed against ICAM-1. | We have developed a technology for improving avidity by making bivalent, trivalent, or tetravalent recombinant polypeptides. We designed tripartite proteins consisting of the Fab fragment of an antibody fused with a hinge derived from human immunoglobulin D that was further linked to polymerization domains derived from... |
12707346 | The paradox of immune molecular recognition of alpha-galactosylceramide: low affinity, low specificity for CD1d, high affinity for alpha beta TCRs. | CD1 resembles both class I and class II MHC but differs by the important aspect of presenting lipid/glycolipids, instead of peptides, to T cells. Biophysical studies of lipid/CD1 interactions have been limited, and kinetics of binding are in contradiction with functional studies. We have revisited this issue by designi... |
12706976 | A conformational model of per-O-acetyl-cyclomaltoheptaose (-beta-cyclodextrin) in solution: detection of partial inversion of glucopyranose units by NMR spectroscopy. | The stereochemical features of per-O-acetyl-cyclomaltoheptaose (-beta-cyclodextrin) have been investigated in solution by NMR spectroscopy, and the deviation of functionalised glucopyranose rings from 4C(1) chairs to skew-type conformations has been detected. |
12704139 | Gene expression profiling of Helicobacter pylori reveals a growth-phase-dependent switch in virulence gene expression. | The global pattern of growth-phase-dependent gene expression of Helicobacter pylori during in vitro culture was analyzed by using a high-density DNA microarray. To detect consistent coordinated gene expression in this bacterium, temporal changes in transcription were assessed in two independent time courses. Cluster an... |
12570875 | Selective interaction of LAT (linker of activated T cells) with the open-active form of Lck in lipid rafts reveals a new mechanism for the regulation of Lck in T cells. | In T cells, the lipid raft-associated Lck is strongly tyrosine phosphorylated and has reduced enzymic activity in contrast with the detergent-soluble pool, which has substantial activity. Lck tagged at the C-terminus (Lck/V5-His) was efficiently captured by epitope-specific reagents from the detergent-soluble fraction ... |
12556224 | Detection of 3-hydroxykynurenine in a plant pathogenic fungus. | A redox-active compound has been purified from the barley powdery mildew fungus Blumeria ( Erysiphe ) graminis f. sp. hordei. A combination of spectrophotometry, MS and NMR has identified it as 3-hydroxykynurenine (3OHKyn). This compound, never previously detected in any fungus or pathogen, is best known for its role i... |
12701087 | Determination of procaine hydrochloride using flow injection inhibitory chemiluminescence. | A new flow injection chemiluminescent method has been developed for the determination of procaine hydrochloride, based on the inhibition of the chemiluminescence reaction of luminol-hydrogen peroxide by procaine hydrochloride. The influence of several surfactants and beta-cyclodextrin on the chemiluminescence intensity... |
12700266 | Agrobacterium tumefaciens VirB6 protein participates in formation of VirB7 and VirB9 complexes required for type IV secretion. | This study characterized the contribution of Agrobacterium tumefaciens VirB6, a polytopic inner membrane protein, to the formation of outer membrane VirB7 lipoprotein and VirB9 protein multimers required for type IV secretion. VirB7 assembles as a disulfide cross-linked homodimer that associates with the T pilus and a ... |
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