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10649347 | Fluorescence Detection from Single Dendrimers with Multiple Chromophores. | The differences in the fluorescence behavior of a polyphenylene dendrimer with eight peryleneimides chromophores (1) and a single hexaphenylperyleneimide chromophore have been investigated at a single-molecule level through the combination of ultrasensitive fluorescence detection and microscopy. |
10649340 | A Copper(I) Bis-phenanthroline Complex Buried in Fullerene-Functionalized Dendritic Black Boxes. | Virtual inaccessibility to external contact was revealed by electrochemical investigations for a bis(1,10-phenanthroline)copper(I) core embedded in dendrimers with up to 16 peripheral fullerene units (shown schematically). With increasing numbers of fullerene units, less and less light is available to the core, and the... |
10649337 | Synthesis of the First | A "true" allenophane with several rings and allenic bridges was synthesized. The key step in the preparation of 1 was the cyclization to a 28-membered macrocycle (52 % yield) starting from a linear molecule, which already contains three of the four allene units. |
10649336 | Self- and Directed Assembly of Hexaruthenium Macrocycles. | Rigid terpyridine-based building blocks allow easy access to large polymetallomacrocycles (see picture) through a self-assembly process. Such routes are envisioned to provide one-step methods to higher order motifs and facilitate the creation of precisely organized, metal-based networks for new energy storage devices. |
10603466 | Synthesis and applications of novel, highly efficient HPLC chiral stationary phases: a chiral dimension in drug research analysis. | This review provides an overview of the synthesis and application of stable and versatile HPLC chiral stationary phases (CSPs), with emphasis placed on the binding strategies developed to anchor several structurally different chiral selectors to silica-gel microparticles. In addition, selected applications relating to ... |
10602229 | Enantioselective Single-Crystal-to-Single-Crystal Photodimerization of Coumarin and Thiocoumarin in Inclusion Complexes with Chiral Host Compounds. | An intermolecular enantioselective photoreaction by a single-crystal-to-single-crystal transformation has been carried out for the first time, as is evident from X-ray structure analysis and X-ray powder diffractometric studies. This reaction, the dimerization of the title compound to cyclobutane derivative 1 (X=O, S),... |
10602220 | Thermal Conversion of a Helical Coil into a Three-Dimensional Chiral Framework. | Thermal dehydration results in the solid-state supramolecular conversion of the helical coordination polymer [{[Cu(sala)](2)(H(2)O)}(n)] into the chiral three-dimensional covalent open network [{Cu(sala)}(n)] (shown schematically). X-ray crystallography reveals that hydrogen bonding plays a key role in this process. H(... |
10602215 | Self-Assembly of a Radially Functionalized Hexagonal Molecule: Hexakis(4-hydroxyphenyl)benzene. | Two different porous hydrogen-bonded networks are formed by self-assembly of the radially substituted host 1. In the network of type A, formed by 1 small middle dot4 Et(2)O, all OH groups of 1 are involved in hydrogen bonding, and the molecular sheets are stacked without translation to generate extended channels that a... |
10602209 | Into the Next Dimension: Nanometer-Sized, Oligonuclear Coordination Compounds with C(3)-Symmetric Ligands. | Nanometer-sized cavities are present in oligonuclear coordination compounds formed in molecular self-assembly processes from C(3)-symmetric ligands and appropriate metal complex fragments. The structures obtained can be described as basic polyhedra such as tetrahedron, hexahedron, or octahedron (see picture). |
10567935 | Application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to the structure determination of medium and large macrocycles formed by palladium(0)-catalyzed allylation of arenesulfonamides, sulfamide, and cyanamide. | Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry allowed the direct determination of the extent of macrocyclic and linear oligomer formation in the palladium(0)-catalyzed allylation of highly acidic and non-nucleophilic arenesulfonamides, sulfamide, and cyanamide. Palladium-containing 15-mem... |
11671346 | Formation of Separated versus Contact Ion Triplets in Magnesium Thiolates. Synthesis and Characterization of [Mg(15-crown-5)(SCPh(3))(2)] and [Mg(15-crown-5)(THF)(2)][S-2,4,6-tBu(3)C(6)H(2))](2). | The synthesis and structural characterization of two magnesium thiolate complexes are described. Both compounds were prepared by analogous reactions routes, namely, alkane elimination and transamination, but using differently sized ligands. Utilization of the smaller HSCPh(3), resulted in the formation of [Mg(15-crown-... |
11671329 | X-ray Absorption Spectroscopic Studies of the Copper(I) Complexes of Crown Ether Appended Bis{(2-pyridyl)ethyl}amines and Their Dioxygen Adducts. | An X-ray absorption spectroscopic study of the Cu complexes of the bis{(2-pyridyl)ethyl}-appended monoaza crown ether 1, diaza crown ether 2, and diphenylglycoluril diaza basket 3 is reported. Following detailed analysis of the spectra of the crystallographically characterized model compound tetrapyridyl Cu(II) bis(nit... |
11671325 | Super-Charged Porphyrazines: Synthesis and Physical Properties of Octacationic Tetraazaporphyrins. | We report the synthesis of octacationic macrocycles based on the porphyrazine (tetraazaporphyrin) core. The first stage is the synthesis of Mg(II) 2,3,7,8,12,13,17,18-octakis(4-pyridyl)porphyrazine, [Mgpz(pyr)(8)], and the parent [H(2)pz(pyr)(8)]. Both compounds are freely soluble in aqueous acid due to protonation of ... |
11671321 | Tetrakis(thiadiazole)porphyrazines. 2. Metal Complexes with Mn(II), Fe(II), Co(II), Ni(II), and Zn(II). | The synthesis and general chemical physical characterization of the following new classes of complexes derived from tetrakis(thiadiazole)porphyrazine (TTDPzH(2)), i.e., [(TTDPz)M(DMSO)(2)] (M = Mn(II), Fe(II)), [(TTDPz)M](H(2)O)(2), and [(TTDPz)M] (M = Mn(II), Fe(II), Co(II), Ni(II), Zn(II)) are reported. The IR spectr... |
11671318 | Electroregulated Metal-Binding with a Crown Ether Tetrathiafulvalene Derivative: Toward Electrochemically Addressed Metal Cation Sponges. | A redox responsive ligand incorporating the tetrathiafulvalene unit has been synthesized. The crystal structure of the free ligand (Z)-1 (C(20)H(30)O(5)S(8), triclinic P&onemacr;, Z = 2, a = 9.087(6) Å, b = 11.637(7) Å, c = 14.370(8) Å, alpha = 65.54(3) degrees, beta = 82.32(5) degrees, gamma = 84.18(6) degrees, V = 13... |
11671307 | Molecular Recognition of Activated and Unactivated Phosphate Diesters. | The molecular recognition of two simple phosphate diesters by a terpyridine-copper (TCu) complex was studied by X-ray crystallography and potentiometry. Molecular recognition of the substrate is the first step in a hydrolysis reaction. The two phosphate diesters bis(p-nitrophenyl) phosphate (BNP) and diphenyl phosphate... |
11671298 | Playing the Keyboard of Fluorine Chemistry(,). | Organometallic fluorides of main group and transition elements are described starting with monocyclopentadienyl derivatives of the group 4 metals and their adducts with AlMe(3). Host-guest type compounds such as [(eta(5)-C(5)Me(4)Et)TiF(3)](4)CaF(2) and supramolecular assemblies such as Ag(S(4)(CN)(2))(2)AsF(6) are als... |
15822325 | [Study on properties of fluorescence and room temperature phosphorescence of 2-bromomethyl naphthalene]. | The properties of fluorescence and room temperature phosphorescense (RTP) of 2-Bromomethyl naphthalene (2-BrMN)were studied. The results show that the wavelength for maximum fluorescence of 2-BrMN is lambda(ex/lambda(em) = 274/334 nm. The fluorescence intersity is proportional to the concentration of 2BrMN in the range... |
11829945 | [Posttraumatic or inflammatory acute respiratory distress syndrome on high altitude area: a retrospective analysis of 94 deaths due to ARDS/MOF]. | <h4>Objective</h4>To determine the characteristic predictors of acute respiratory distress syndrome (ARDS) in the high altitude area of China.<h4>Methods</h4>According to the diagnostic criteria of ARDS, 2 325 cases were screened in the recent 10 years. Except malignant tumors, cardio-cerebrovascular diseases, chronic ... |
11212327 | Signalling via caveolin: involvement in the cross-talk between phosphoinositolglycans and insulin. | In recent years, a number of cross-talk systems have been identified which feed into the insulin signalling cascade at the level of insulin receptor substrate (IRS) tyrosine phosphorylation, e.g., receptor and non-receptor tyrosine kinases and G-protein-coupled receptors. At the molecular level, a number of negative mo... |
11212324 | Cathepsin A/protective protein: an unusual lysosomal multifunctional protein. | Cathepsin A/protective protein [3.4.16.5], carboxypeptidase A, is a lysosomal serine protease with structural homology to yeast (Saccharomyces cerevisiae) carboxypeptidase Y. Cathepsin A is a member of the alpha/beta hydrolase fold family and has been suggested to share a common ancestral relationship with other alpha/... |
10561584 | Supramolecular organization of photosystem II and its light-harvesting antenna in partially solubilized photosystem II membranes. | We present an extended analysis of the organization of green plant photosystem II and its associated light-harvesting antenna using electron microscopy and image analysis. The analysis is based on a large dataset of 16 600 projections of negatively stained PSII-LHCII supercomplexes and megacomplexes prepared by means o... |
10561585 | Localization of cyanobacterial photosystem II donor-side subunits by electron microscopy and the supramolecular organization ofphotosystem II in the thylakoid membrane. | A large set of electron microscopy projections of photosystem II (PSII) dimers isolated from the cyanobacterium Synechococcus elongatus was characterized by single particle image analysis. In addition to previously published maps at lower resolution [Boekema, E.J., Hankamer, B., Bald, D., Kruip, J., Nield, J., Boonstra... |
10561588 | Effects of ligand binding on the internal dynamics of maltose-binding protein. | Ligand binding to proteins often causes large conformational changes. A typical example is maltose-binding protein (MBP), a member of the family of periplasmic binding proteins of Gram-negative bacteria. Upon binding of maltose, MBP undergoes a large structural change that closes the binding cleft, i.e. the distance be... |
10905864 | Selective epimerization of rapamycin via a retroaldol/aldol mechanism mediated by titanium tetraisopropoxide. | We describe the efficient and selective epimerization of the immunosuppressant rapamycin to 28-epirapamycin under mild conditions. The mechanism of epimerization involves an equilibrium of the four C28/C29 diastereomers through a two-step retroaldol/aldol (macrocycle ring-opening/ring-closing) sequence. This retroaldol... |
10844992 | A perspective of biological supramolecular electron transfer. | Electron transfer is an essential activity in biological systems. The migrating electron originates from water-oxygen in photosynthesis and reverts to dioxygen in respiration. In this cycle two metal porphyrin complexes possessing circular conjugated system and macrocyclic pi-clouds, chlorophyll and heme, play a decisi... |
10836052 | Inhibition of phosphatase activity by positively-charged cyclodextrins. | [formula: see text] Aminocyclodextrins are known to bind phosphate esters such as phosphotyrosine and p-nitrophenyl phosphate. This paper describes the inhibition of phosphate ester hydrolysis, as catalyzed by lambda-protein phosphatase and acid phosphatase, that is caused by such binding interactions. ROESY studies pr... |
10836049 | Molecular architecture via coordination: self-assembly of pseudohexagonal A2(3)X2(3)-macrocycles. | [formula: see text] The interaction of two complementary ditopic building blocks, each incorporating 120 degrees angles between the active coordination sites, in methylene chloride at room temperature results in the spontaneous self-assembly of platinum-based assemblies of hexagonal shape. |
10836036 | Synthesis of trisubstituted alkenes via olefin cross-metathesis. | [formula: see text] Trisubstituted alkenes have been prepared for the first time via intermolecular olefin cross-metathesis, using 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ruthenium alkylidene complexes 3a,b in good yields with moderate E selectivity. In addition, protected alcohols near the geminal disubstituted ol... |
10796982 | Two-dimensional crystallization of streptavidin: in pursuit of the molecular origins of structure, morphology, and thermodynamics. | The streptavidin two-dimensional (2D) crystallization model has served as a paradigm for molecular self-assembly at interfaces. We have developed quantitative Brewster angle microscopy for the in situ measurement of spatially resolved relative protein surface densities. This allows investigation of both the thermodynam... |
10746311 | Complexation study of diclofenac with beta-cyclodextrin and spectrofluorimetric determination. | The inclusional complexation between the anti-inflammatory pharmaceutical diclofenac and beta-cyclodextrin (beta-CD) was studied by potentiometry, spectrophotometry and spectrofluorimetry, in both acid and neutral pH. Guest-host 1:1 stoichiometries for the complexes in both media were determined, and their equilibrium ... |
10701078 | Self-assembly of soluble proteins on functionalized lipid layers: a tentative correlation between the fluidity properties of the lipid film and protein ordering. | New series of amphiphilic structures are designed to exhibit various fluidity properties when spread at the air-water interface. The influence of the molecular structure of these lipids on the process of two-dimensional (2D) crystallization of the B subunit of DNA gyrase, a soluble protein, is investigated in terms of ... |
10682344 | Highly purified thermo-stable oxygen-evolving photosystem II core complex from the thermophilic cyanobacterium Synechococcus elongatus having His-tagged CP43. | The carboxyl terminus of the CP43 subunit of photosystem II (PSII) in the thermophilic cyanobacterium, Synechococcus elongatus, was genetically tagged with six consecutive histidine residues to create a metal binding site on the PSII supramolecular complex. The histidine-tagging enabled rapid isolation of an intact cya... |
10678490 | Inclusion complexation of the sunscreen agent 2-ethylhexyl-p-dimethylaminobenzoate with hydroxypropyl-beta-cyclodextrin: effect on photostability. | The interaction between the UV filter, 2-ethylhexyl-p-dimethylaminobenzoate, and unmodified and modified alpha-, beta- or gamma-cyclodextrins was studied in water by phase-solubility analysis. Of the cyclodextrins available, only hydroxypropyl-beta-cyclodextrin caused a marked increase in the aqueous solubility of 2-et... |
10674942 | Enantiomer separation of alpha-ionone using gas chromatography with cyclodextrin derivatives as chiral stationary phases. | The gas chromatographic enantiomer separation of alpha-ionone was studied with three different chiral stationary phases using as chiral selectors: (1) heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin, dissolved in polysiloxane PS-086, (2) octakis(2,6-di-O-pentyl-3-O-trifluoroacetyl)-gamma-cyclodextrin and (3) octakis(2,6... |
10670874 | Age of transfused blood is an independent risk factor for postinjury multiple organ failure. | <h4>Background</h4>Blood transfusion has repeatedly been demonstrated to be an independent risk factor for postinjury multiple organ failure (MOF). Previously believed to represent a surrogate for shock, packed red blood cell (PRBC) transfusion has recently been shown to result in neutrophil priming and pulmonary endot... |
10670873 | Release of anti-inflammatory mediators after major torso trauma correlates with the development of postinjury multiple organ failure. | <h4>Background</h4>Soluble tumor necrosis factor receptor (sTNFr) and interleukin-1 receptor antagonist (IL-1ra) have been identified as endogenous inhibitors of TNF-alpha and IL-1beta. While TNF-alpha and IL-1beta levels are not systematically elevated in postinjury patients who developed multiorgan failure (MOF), the... |
10670850 | The role of the gastrointestinal tract in postinjury multiple organ failure. | Despite intensive investigation, the pathogenesis of postinjury multiple organ failure (MOF) remains elusive. Laboratory and clinical research strongly implicate that the gastrointestinal tract plays a pivotal role. Shock with resulting gut hypoperfusion appears to be one important inciting event. While early studies p... |
10670743 | Chromatographic approach to study beta-cyclodextrin as a promoter of the penetration of bifonazole into keratinic tissue. | A high-performance liquid chromatographic method for the determination of bifonazole in dimethyl sulfoxide solvent was developed to study its penetration into sheephoof. The analytical method was linear over the concentration range studied, i.e., from 0.1 mg/ml to 1 mg/ml. The relative standard deviation was less than ... |
10669300 | Nonaqueous capillary electrophoresis equipped with amperometric detection for analysis of chlorinated phenolic compounds. | Nonaqueous capillary electrophoresis (NACE) equipped with amperometric detection has been developed for separation and detection of an 11-member model mixture of chlorinated phenolic compounds. With triacetyl-beta-cyclodextrin (TACD) as a novel selectivity selector, acetonitrile proved to be an excellent solvent for th... |
10669297 | Heats of adsorption of some organic compounds on beta-cyclodextrin determined by gas-solid chromatography. | Isosteric adsorptive enthalpies have been derived from the temperature dependence of retention volumes determined by eluted pulse gas-solid chromatography. The heat data were obtained for systems using more than 20 organic liquids as adsorbates, and beta-cyclodextrin as adsorbent. The experimental results have been dis... |
10658836 | Evolution of the genetic code: the nonsense, antisense, and antinonsense codes make no sense. | According to the molecular recognition theory, the complementarity of the sense and nonsense DNA strands is reflected in a complementarity of polypeptides and the corresponding nonsense polypeptides. A comparison of the sense and nonsense code matrices, and of the antisense and antinonsense code matrices, either by vis... |
10658572 | Molecular recognition by acetylcholinesterase at the peripheral anionic site: structure-activity relationships for inhibitions by aryl carbamates. | Substituted phenyl-N-butyl carbamates (1-9) are potent irreversible inhibitors of Electrophorus electricus acetylcholinesterase. Carbamates 1-9 act as the peripheral anionic site-directed irreversible inhibitors of acetylcholinesterase by the stop-time assay in the presence of a competitive inhibitor, edrophonium. Line... |
10651977 | Microbiological and HPLC analysis of miconazole in skin, serum and phase-solubility studies. | <h4>Objective</h4>To develop stability-indicating assays for miconazole.<h4>Methods</h4>A reversed phase high-performance liquid chromatographic assay and a bioassay were developed.<h4>Results</h4>The HPLC and the bioassay were linear in the range of 0.5-100 and 0.64-1.56 microg/ml, respectively. The sensitivity of HPL... |
10648931 | Selection of a human anti-progesterone antibody fragment from a transgenic mouse library by ARM ribosome display. | In antibody-ribosome-mRNA complex (ARM) ribosome display, stable complexes of nascent protein, mRNA and ribosomes are produced in a eukaryotic in vitro expression system, through coupled transcription and translation of DNA lacking a 3' stop codon. Selection of the protein simultaneously captures the relevant mRNA, whi... |
10651521 | Anion recognition: synthetic receptors for anions and their application in sensors. | Important contributions to the field of anion sensing include electrochemical lipophilic uranyl salophene receptors incorporated into membranes that act as fluoride-selective potentiometric microsensors. A promising optical-based sensor, selective for cyclic AMP, involves a preorganized, molecularly imprinted polymer e... |
10646247 | Analysis of changes in indicators of functional and motor readiness of female basketball players within one-year training cycles. | The basic goal of this work was the evaluation of functional and motor preparedness of 13 top female basketball players during a one-year training cycle. Across of the six time points the preparedness of subjects was measured by means of a twelve-test battery measuring the basic and specific motor and functional abilit... |
10639277 | Molecular recognition of modified adenine nucleotides by the P2Y(1)-receptor. 2. A computational approach. | The molecular recognition of C2- or C8-substituted ATP derivatives by the P2Y(1)-receptor (P2Y(1)-R) is analyzed using ab initio quantum mechanical calculations. Parameters that may determine ligand specificity toward P2Y(1)-R were examined on reduced models and correlated with the biochemical data for the parent compo... |
10639276 | Molecular recognition of modified adenine nucleotides by the P2Y(1)-receptor. 1. A synthetic, biochemical, and NMR approach. | The remarkably high potencies of 2-thioether-adenine nucleotides regarding the activation of the P2Y(1)-receptor (P2Y(1)-R) in turkey erythrocyte membranes represent some of the largest substitution-promoted increases in potencies over that of a natural receptor ligand. This paper describes the investigation regarding ... |
10644075 | Application of supercritical carbon dioxide for the preparation of a piroxicam-beta-cyclodextrin inclusion compound. | <h4>Purpose</h4>Piroxicam is a poorly soluble NSAID, whose solubility is enhanced when included into beta-cyclodextrin. The preparation of a piroxicam-beta-cyclodextrin inclusion compound using supercritical CO2 was investigated.<h4>Methods</h4>The solubility and the stability of piroxicam in supercritical CO2 were det... |
10644065 | PAMAM dendrimers as delivery agents for antisense oligonucleotides. | <h4>Purpose</h4>To investigate the potential use of PAMAM dendrimers for the delivery of antisense oligonucleotides into cells under conditions that mimic the in vivo environment.<h4>Methods</h4>We used HeLa cells stably transfected with plasmid pLuc/705 which has a luciferase gene interrupted by a human beta-globin in... |
10641281 | The tert-butylammonium perchlorate complex of 2,3-naphtho-18-crown-6 at 115 K. | In the title complex, tert-butylammonium perchlorate-2,5,8,11,14,17-hexaoxatricyclo[16.8.0.0(20,25]hexac osa- 1(26),18,20(25),21,23-pentaene-ethyl acetate-dichloromethane (4/4/1/1), C4H12N+.C20H26O6.ClO4-.0.25C4-H8O2.0.25CH2Cl2 , the tert-butylammonium cation binds to the macrocyclic host (Chemical Abstracts name: 2,3,... |
10639734 | VIP-, galanin-, and neuropeptide-Y-immunoreactive fibers in the chicken carotid bodies after various types of denervation. | The chicken carotid body receives numerous branches from the vagus nerve, especially distal (nodose) ganglion, and the recurrent laryngeal nerve. Dense networks of peptidergic nerve fibers immunoreactive for substance P, calcitonin gene-related peptide (CGRP), galanin, vasoactive intestinal peptide (VIP) and neuropepti... |
10636087 | Evaluation of single-stranded nucleic acids as carriers in the DNA-directed assembly of macromolecules. | Current developments in nanosciences indicate that the self-assembly of macromolecules, such as proteins or metallic nanoclusters, can be conveniently achieved by means of nucleic acid hybridization. Within this context, we here report on the evaluation of single-stranded nucleic acids to be utilized as carrier backbon... |
10631599 | The Met243 sulfonium ion linkage is responsible for the anomalous magnetic circular dichroism and optical spectral properties of myeloperoxidase. | The heme group of myeloperoxidase shows anomalous optical properties, and the enzyme possesses the unique ability to catalyze the oxidation of chloride. However, the nature of the covalently bound heme macrocycle has been difficult to identify. In this work, the electronic and magnetic properties of the heme groups in ... |
10631997 | Function of the central domain of streptokinase in substrate plasminogen docking and processing revealed by site-directed mutagenesis. | The possible role of the central beta-domain (residues 151-287) of streptokinase (SK) was probed by site-specifically altering two charged residues at a time to alanines in a region (residues 230-290) previously identified by Peptide Walking to play a key role in plasminogen (PG) activation. These mutants were then scr... |
10631977 | Structural determinants of trypsin affinity and specificity for cationic inhibitors. | The binding free energies of four inhibitors to bovine beta-trypsin are calculated. The inhibitors use either ornithine, lysine, or arginine to bind to the S1 specificity site. The electrostatic contribution to binding free energy is calculated by solving the finite difference Poisson-Boltzmann equation, the contributi... |
10631976 | Alpha1-microglobulin chromophores are located to three lysine residues semiburied in the lipocalin pocket and associated with a novel lipophilic compound. | Alpha1-microglobulin (alpha1m) is an electrophoretically heterogeneous plasma protein. It belongs to the lipocalin superfamily, a group of proteins with a three-dimensional (3D) structure that forms an internal hydrophobic ligand-binding pocket. Alpha1m carries a covalently linked unidentified chromophore that gives th... |
10630881 | Chiral resolution of basic drugs by capillary electrophoresis with new glycosaminoglycans. | New glycosaminoglycans, fucose-containing glycosaminoglycan (FGAG) and depolymerized holothurian glycosaminoglycan (DHG), were investigated as chiral additives for the separation of drug enantiomers by capillary electrophoresis. The average molecular masses of FGAG and DHG were estimated to be about 59,000 and 14,000, ... |
10628537 | AFM imaging of surface adsorbed polymeric 3-alkylpyridinium salts from the marine sponge Reniera sarai. | Bioactive 3-alkylpyridinium polymers (poly-APS) have recently been isolated from the marine sponge Reniera sarai. Previous results have shown that these molecules in aqueous solutions form supramolecular aggregates with an average hydrodynamic radius of 23 +/- 2 nm. To obtain additional evidences about the shape and th... |
10624945 | Imaging synaptic activity in intact brain and slices with FM1-43 in C. elegans, lamprey, and rat. | The fluorescent probe FM1-43 has been used extensively for imaging vesicle recycling; however, high nonspecific adsorption resulting in elevated background levels has precluded its use in certain tissues, notably brain slices. We have found that a sulfobutylated derivative of beta-cyclodextrin (ADVASEP-7) has a higher ... |
10617571 | TATA element recognition by the TATA box-binding protein has been conserved throughout evolution. | Cocrystal structures of wild-type TATA box-binding protein (TBP) recognizing 10 naturally occurring TATA elements have been determined at 2.3-1.8 A resolution, and compared with our 1.9 A resolution structure of TBP bound to the Adenovirus major late promoter (AdMLP) TATA box (5'-TATAAAAG-3'). Minor-groove recognition ... |
10616909 | Establishment of the circumferential actin filament network is a prerequisite for localization of the cadherin-catenin complex in epithelial cells. | With the adhesion molecules, the actin cytoskeleton controls cell-cell and cell-substrate interactions and participates in transmembrane signaling. The relationships between actin and adhesion complexes at the sites of adhesion have been well documented. Here we investigate by a series of studies whether a relationship... |
10613913 | Cingulin contains globular and coiled-coil domains and interacts with ZO-1, ZO-2, ZO-3, and myosin. | We characterized the sequence and protein interactions of cingulin, an M(r) 140-160-kD phosphoprotein localized on the cytoplasmic surface of epithelial tight junctions (TJ). The derived amino acid sequence of a full-length Xenopus laevis cingulin cDNA shows globular head (residues 1-439) and tail (1,326-1,368) domains... |
10613909 | Cofilin phosphorylation and actin cytoskeletal dynamics regulated by rho- and Cdc42-activated LIM-kinase 2. | The rapid turnover of actin filaments and the tertiary meshwork formation are regulated by a variety of actin-binding proteins. Protein phosphorylation of cofilin, an actin-binding protein that depolymerizes actin filaments, suppresses its function. Thus, cofilin is a terminal effector of signaling cascades that evokes... |
10611389 | Cloning of chlorophyllase, the key enzyme in chlorophyll degradation: finding of a lipase motif and the induction by methyl jasmonate. | Chlorophyllase (Chlase) is the first enzyme involved in chlorophyll (Chl) degradation and catalyzes the hydrolysis of ester bond to yield chlorophyllide and phytol. In the present study, we isolated the Chlase cDNA. We synthesized degenerate oligo DNA probes based on the internal amino acid sequences of purified Chlase... |
10611338 | The human natural killer cell immune synapse. | Inhibitory killer Ig-like receptors (KIR) at the surface of natural killer (NK) cells induced clustering of HLA-C at the contacting surface of target cells. In this manner, inhibitory immune synapses were formed as human NK cells surveyed target cells. At target/NK cell synapses, HLA-C/KIR distributed into rings around... |
10611315 | The 65-kDa carrot microtubule-associated protein forms regularly arranged filamentous cross-bridges between microtubules. | In plants, cortical microtubules (MTs) occur in characteristically parallel groups maintained up to one microtubule diameter apart by fine filamentous cross-bridges. However, none of the plant microtubule-associated proteins (MAPs) so far purified accounts for the observed separation between MTs in cells. We previously... |
10611303 | Patterned library analysis: a method for the quantitative assessment of hypotheses concerning the determinants of protein structure. | Site-directed mutagenesis and combinatorial libraries are powerful tools for providing information about the relationship between protein sequence and structure. Here we report two extensions that expand the utility of combinatorial mutagenesis for the quantitative assessment of hypotheses about the determinants of pro... |
10611282 | Synthetic genes for glycoprotein design and the elucidation of hydroxyproline-O-glycosylation codes. | Design of hydroxyproline (Hyp)-rich glycoproteins (HRGPs) offers an approach for the structural and functional analysis of these wall components, which are broadly implicated in plant growth and development. HRGPs consist of multiple small repetitive "glycomodules" extensively O-glycosylated through the Hyp residues. T... |
10611274 | A cyclodextrin dimer with a photocleavable linker as a possible carrier for the photosensitizer in photodynamic tumor therapy. | A cyclodextrin dimer has been synthesized with two beta-cyclodextrins linked by a flexible chain containing a carbon-carbon double bond. This dimer binds and solubilizes a phthalocyanine-based photosensitizer that generates singlet oxygen on irradiation. When the complex is irradiated, the singlet oxygen cleaves the ca... |
10612019 | Preparation and characterization of albendazole beta-cyclodextrin complexes. | Albendazole (ABZ), mebendazole (MBZ), and ricobendazole (RBZ) are low-soluble anthelmintic benzimidazole carbamate drugs. To increase their aqueous solubility, three different types of beta-cyclodextrins (CyDs): beta-cyclodextrin (CD), hydroxypropyl-beta-cyclodextrin (HPCD), and methyl-beta-cyclodextrin (MCD) were used... |
10606594 | Encapsulation of lemon oil by paste method using beta-cyclodextrin: encapsulation efficiency and profile of oil volatiles. | Microencapsulation of lemon oil was undertaken by kneading with beta-cyclodextrin, at a beta-cyclodextrin to lemon oil ratio of 88:12 (w/w). The resulting paste samples of the complex were vacuum- or spray-dried. Ten selected lemon oil flavor volatiles (alpha-pinene, sabinene, beta-pinene, beta-myrcene, limonene, gamma... |
10603246 | Method for determining protein kinase substrate specificities by the phosphorylation of peptide libraries on beads, phosphate-specific staining, automated sorting, and sequencing. | A method is described for the elucidation of the peptide substrate phosphorylation specificity of a protein kinase. Peptide libraries with two to six degenerate positions and a length of seven or nine amino acids were generated directly on Sepharose beads by solid-phase peptide synthesis according to the split-and-mix ... |
10605939 | Cholesterol does not affect the toxicity of amyloid beta fragment but mimics its effect on MTT formazan exocytosis in cultured rat hippocampal neurons. | It has recently been reported that methyl-beta-cyclodextrin-solubilized cholesterol protects PC12 cells from amyloid beta protein (Abeta) toxicity. To ask if this is the case in brain neurons, we investigated its effect in primary cultured rat hippocampal neurons. In basal culture conditions with no addition of Abeta, ... |
10600723 | Synthesis and catalysis by molecularly imprinted materials. | Molecularly imprinted materials have been demonstrated to possess a very high degree of selectivity towards targeted substrates. In addition to such tailor-made molecular recognition, progress has been made in introducing reactive groups into the recognition sites. Putting teeth into imprinted matrices is one method of... |
10600717 | Novel approaches to molecular recognition using porphyrins. | Studies of molecular recognition using designed and synthesised molecules provide valuable information on the principle and possible applications of artificial functional molecules. Porphyrin-based receptors have been used to elucidate haem-protein interactions and the basic mechanism of multi-point recognition. |
10600724 | Bioinspired polymeric materials: in-between proteins and plastics. | Chemical and biological researchers are making rapid progress in the design and synthesis of non-natural oligomers and polymers that emulate the properties of natural proteins. Whereas molecular biologists are exploring biosynthetic routes to non-natural proteins with controlled material properties, synthetic polymer c... |
10601366 | Dynamic interactions of macrophages with T cells during antigen presentation. | We have established a method for real-time video analysis of the interaction of antigen-presenting cells (APCs) with T cells. Green fluorescent protein expression controlled by a nuclear factor of activated T cells (NFAT)-responsive promoter permits the visualization of productive antigen presentation in single T cells... |
10601228 | Structural and functional analyses of the secondary cell wall polymer of Bacillus sphaericus CCM 2177 that serves as an S-layer-specific anchor. | Sacculi of Bacillus sphaericus CCM 2177 contain a secondary cell wall polymer which was completely extracted with 48% hydrofluoric acid. Nuclear magnetic resonance analysis showed that the polymer is composed of repeating units, as follows: -->3)-[4, 6-O-(1-carboxyethylidene)]( approximately 0. 5)-beta-D-ManpNAc-(1-->4... |
10601214 | Regulation of sigma 54-dependent transcription by core promoter sequences: role of -12 region nucleotides. | The tetranucleotide core recognition sequence (TTGC) of the sigma 54 promoter -12 recognition element was altered by random substitution. The resulting promoter mutants were characterized in vivo and in vitro. Deregulated promoters were identified, implying that this core element can mediate the response to enhancer-bi... |
10601196 | Localization of synthesis of beta1,6-glucan in Saccharomyces cerevisiae. | Beta1,6-Glucan is a key component of the yeast cell wall, interconnecting cell wall proteins, beta1,3-glucan, and chitin. It has been postulated that the synthesis of beta1,6-glucan begins in the endoplasmic reticulum with the formation of protein-bound primer structures and that these primer structures are extended in... |
10601028 | The Escherichia coli trmE (mnmE) gene, involved in tRNA modification, codes for an evolutionarily conserved GTPase with unusual biochemical properties. | The evolutionarily conserved 50K protein of Escherichia coli, encoded by o454, contains a consensus GTP-binding motif. Here we show that 50K is a GTPase that differs extensively from regulatory GTPases such as p21. Thus, 50K exhibits a very high intrinsic GTPase hydrolysis rate, rather low affinity for GTP, and extreme... |
10595938 | The deletion of transforming growth factor-beta-induced myofibroblasts depends on growth conditions and actin organization. | Myofibroblasts are important but transient mediators of normal wound contraction and are characterized phenotypically by their high levels of alpha-smooth-muscle actin (SMA). During wound maturation, these cells disappear. We have examined the mechanisms that lead to myofibroblast deletion in a fibroblast culture model... |
10585219 | Effect of cyclodextrins and polymers on triclosan availability and substantivity in toothpastes in vivo. | The aqueous solubility of triclosan is only about 10 microg/mL. This very low solubility can hamper its biological activity in the oral cavity, which could explain the mixed clinical results obtained from triclosan toothpaste trials. Triclosan availability in a silica-based toothpaste was improved through cyclodextrin ... |
10593890 | Does the triple helical domain of type I collagen encode molecular recognition and fiber assembly while telopeptides serve as catalytic domains? Effect of proteolytic cleavage on fibrillogenesis and on collagen-collagen interaction in fibers. | Over the last several decades, it has been established that proteolytic removal of short, non-helical terminal peptides (telopeptides) from type I collagen significantly alters the kinetics of in vitro fibrillogenesis. However, it has also been observed that the protein is still capable of forming fibers even after com... |
10591646 | Three-dimensional structure of the human TFIID-IIA-IIB complex. | The multisubunit transcription factor IID (TFIID) is an essential component of the eukaryotic RNA polymerase II machinery that works in concert with TFIIA (IIA) and TFIIB (IIB) to assemble initiation complexes at core eukaryotic promoters. Here the structures of human TFIID and the TFIID-IIA-IIB complex that were obtai... |
10588952 | Regulation of endoplasmic reticulum cholesterol by plasma membrane cholesterol. | The abundance of cell cholesterol is governed by multiple regulatory proteins in the endoplasmic reticulum (ER) which, in turn, are under the control of the cholesterol in that organelle. But how does ER cholesterol reflect cell (mostly plasma membrane) cholesterol? We have systematically quantitated this relationship ... |
10588933 | Regional haemodynamic responses to infusion of lipopolysaccharide in conscious rats: effects of pre- or post-treatment with glibenclamide. | 1. To determine the putative contribution of K(ATP)-channels to the haemodynamic sequelae of endotoxaemia, three experiments were carried out in different groups of conscious, chronically-instrumented, unrestrained, male Long Evans rats. 2. In the first experiment, pretreatment with the K(ATP)-channel antagonist, glibe... |
10587640 | Pleiotropic cell-division defects and apoptosis induced by interference with survivin function. | Here we investigate the role of the control of apoptosis in normal cell division. We show that interference with the expression or function of the apoptosis inhibitor survivin causes caspase-dependent cell death in the G2/M phase of the cell cycle, and a cell-division defect characterized by centrosome dysregulation, m... |
10588749 | Reduced facilitation and vesicular uptake in crustacean and mammalian neuromuscular junction by T-588, a neuroprotective compound. | Bath application of compound T-588, a neuroprotective agent, reduced paired-pulse and repetitive-pulse facilitation at mammalian and crustacean neuromuscular junctions. In addition, it reduced voltage-gated sodium and potassium currents in a use-dependent fashion, but had only a small effect on the presynaptic Ca(2+) c... |
10588739 | Elimination of prions by branched polyamines and implications for therapeutics. | We report that branched polyamines, including polyamidoamide dendimers, polypropyleneimine, and polyethyleneimine, are able to purge PrP(Sc), the protease-resistant isoform of the prion protein, from scrapie-infected neuroblastoma (ScN2a) cells in culture. The removal of PrP(Sc) by these compounds depends on both the c... |
10588706 | Correlation of the structural and functional domains in the membrane protein Vpu from HIV-1. | Vpu is an 81-residue membrane protein encoded by the HIV-1 genome. NMR experiments show that the protein folds into two distinct domains, a transmembrane hydrophobic helix and a cytoplasmic domain with two in-plane amphipathic alpha-helices separated by a linker region. Resonances in one-dimensional solid-state NMR spe... |
10588705 | Molecular dynamics and free-energy calculations applied to affinity maturation in antibody 48G7. | We investigated the relative free energies of hapten binding to the germ line and mature forms of the 48G7 antibody Fab fragments by applying a continuum model to structures sampled from molecular dynamics simulations in explicit solvent. Reasonable absolute and very good relative free energies were obtained. As a resu... |
10588698 | Photoassembly of the manganese cluster and oxygen evolution from monomeric and dimeric CP47 reaction center photosystem II complexes. | Isolated subcomplexes of photosystem II from spinach (CP47RC), composed of D1, D2, cytochrome b(559), CP47, and a number of hydrophobic small subunits but devoid of CP43 and the extrinsic proteins of the oxygen-evolving complex, were shown to reconstitute the Mn(4)Ca(1)Cl(x) cluster of the water-splitting system and to... |
10588693 | A physical basis for protein secondary structure. | A physical theory of protein secondary structure is proposed and tested by performing exceedingly simple Monte Carlo simulations. In essence, secondary structure propensities are predominantly a consequence of two competing local effects, one favoring hydrogen bond formation in helices and turns, the other opposing the... |
10588644 | Two components of actin-based retrograde flow in sea urchin coelomocytes. | Sea urchin coelomocytes represent an excellent experimental model system for studying retrograde flow. Their extreme flatness allows for excellent microscopic visualization. Their discoid shape provides a radially symmetric geometry, which simplifies analysis of the flow pattern. Finally, the nonmotile nature of the ce... |
10585969 | Adding the third dimension to virus life cycles: three-dimensional reconstruction of icosahedral viruses from cryo-electron micrographs. | Viruses are cellular parasites. The linkage between viral and host functions makes the study of a viral life cycle an important key to cellular functions. A deeper understanding of many aspects of viral life cycles has emerged from coordinated molecular and structural studies carried out with a wide range of viral path... |
10585967 | Retroviral DNA integration. | DNA integration is a unique enzymatic process shared by all retroviruses and retrotransposons. During integration, double-stranded linear viral DNA is inserted into the host genome in a process catalyzed by the virus-encoded integrase (IN). The mechanism involves a series of nucleophilic attacks, the first of which rem... |
10585965 | Recombinational repair of DNA damage in Escherichia coli and bacteriophage lambda. | Although homologous recombination and DNA repair phenomena in bacteria were initially extensively studied without regard to any relationship between the two, it is now appreciated that DNA repair and homologous recombination are related through DNA replication. In Escherichia coli, two-strand DNA damage, generated most... |
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