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11306192 | Tecto-isthmo-optic transmission in pigeons is mediated by glutamate and nitric oxide. | The isthmo-optic nucleus of the centrifugal system in birds receives primarily input from the ipsilateral tectum and projects to the contralateral retina. The present study using brain slices and microiontophoresis shows that synaptic transmission from the tectum to the centrifugal nucleus in pigeons is excitatory. Abo... |
11307981 | High-performance chiral separation of fourteen triazole fungicides by sulfated beta-cyclodextrin-mediated capillary electrophoresis. | In this paper, sulfated beta-cyclodextrin-mediated capillary electrophoresis (CE) is evaluated as a new approach for the chiral separation of triazole-type fungicides. The 14 fungicides investigated were bitertanol, cyproconazole, difenoconazole, diniconazole, flutriafol, hexaconazole, myclobutanil, paclobutrazol, penc... |
11307986 | Separation of steroids using temperature-dependent inclusion chromatography. | The influence of temperature on retention and separation of estrogens, progesterone derivatives and beta-cyclodextrin in reversed-phase high-performance liquid chromatography has been studied. Steroids were detected using direct UV detection at 240 and 280 nm. Detection of beta-cyclodextrin was achieved using a post-co... |
11305652 | Plant tissue-based chemiluminescence flow biosensor for glycolic acid. | A novel plant tissue-based chemiluminescence (CL) biosensor for glycolic acid combined with flow injection analysis is proposed in this paper. The spinach tissue acts as the molecular recognition element. Glycolic acid is oxidized by oxygen under the catalysis of glycolate oxidase in the tissue column to produce hydrog... |
11305637 | Statistical analysis of single-molecule colocalization assays. | In chemical assays, specific molecular recognition events result in close physical proximity of two molecular species, e.g., ligands and receptors. Microscopy techniques that are able to image individual molecules allow for achieving a positional accuracy far beyond the resolution limit Therefore, independent position ... |
11305635 | Application of directly coupled HPLC NMR to separation and characterization of lipoproteins from human serum. | Disorders in lipoprotein metabolism are critical in the etiology of several disease states such as coronary heart disease and atherosclerosis. Thus, there is considerable interest in the development of novel methods for the analysis of lipoprotein complexes. We report here a simple chromatographic method for the separa... |
11303870 | Cobaltocenium-functionalized poly(propylene imine) dendrimers: redox and electromicrogravimetric studies and AFM imaging. | The first four generations of cobaltocenium-functionalized, diaminobutane-based poly(propylene imine) dendrimers DAB-dend-Cb,(PFb)x (x = 4, 8, 16, and 32; Cb=[Co(eta5-C5H4CONH)(eta5-C5H5)] (1-4) have been synthesized and characterized. The redox activity of the cobaltocenium centers in 1-4 has been characterized by usi... |
11303861 | Dendromesogens: liquid crystal organizations of poly(amidoamine) dendrimers versus starburst structures. | A new series of liquid crystalline poly(amidoamine) (PAMAM) dendrimers is described. These dendrimers are made by attaching to the 0-, 1-, 2-, 3-, and 4-generation of PAMAM-terminal promesogenic units that carry two decyloxy chains in the 3- and 4-positions of their peripheral aromatic ring. X-ray diffraction studies s... |
11303878 | Dendritic biomimicry: microenvironmental hydrogen-bonding effects on tryptophan fluorescence. | Two series of dendritically modified tryptophan derivatives have been synthesised and their emission spectra measured in a range of different solvents. This paper presents the syntheses of these novel dendritic structures and discusses their emission spectra in terms of both solvent and dendritic effects. In the first ... |
11300843 | Crystal chemistry and physical properties of superconducting and semiconducting charge transfer salts of the type (BEDT-TTF)(4)[A(I)M(III)(C2O4)3]*PhCN (A(I) = H30,NH4,K; M(III) = Cr, Fe, Co, Al; BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene. | Synthesis, structure determination by single-crystal X-ray diffraction, and physical properties are reported and compared for superconducting and semiconducting molecular charge-transfer salts with stoichiometry (BEDT-TTF)(4)[A(I)M(III)(C(2)O(4))(3)].PhCN, where A(I) = H(3)O, NH(4), K; M(III) = Cr, Fe, Co, Al; BEDT-TTF... |
11300824 | The simplest supramolecular complexes containing pairs of Mo(2)(formamidinate)(3) units linked with various dicarboxylates: preparative methods, structures, and electrochemistry. | Twelve compounds containing two quadruply bonded Mo(2)(DAniF)(3) (DAniF = N,N'-di-p-anisylformamidinate) units linked by dicarboxylate anions have been prepared in high purity and good yields. All of these compounds have been characterized by crystallography and NMR. The dinuclear pairs display electrochemical behavior... |
11300806 | Optical, magnetic, and electronic properties of peripherally fused macrocycles: molybdocene porphyrazines. | Metal-free and copper porphyrazines, [H(2)pz] and [Cu pz], have been fused at the periphery with molybdocene dithiolene, [Cp(2)Mo]. The optical, magnetic, and electronic properties of the resulting neutral and cationic complexes are studied, using first-principles density functional theory implemented by the discrete v... |
11300912 | Synthesis and properties of new thiourea-functionalized poly(propylene imine) dendrimers and their role as hosts for urea functionalized guests. | Five generations of poly(propylene imine) dendrimers have been modified by palmityl and adamantyl endgroups via a thiourea linkage. The synthesis of the thiourea dendrimers DAB-dendr-(NHCSNHAd)(n) and DAB-dendr-(NHCSNHC(16)H(33))(n) (n = 4, 8, 16, 32, 64) proceeds smoothly via the amino-terminated DAB dendrimer and the... |
11300896 | Cyclization strategies for the synthesis of macrocyclic bisindolylmaleimides. | Three new approaches to the synthesis of macrocyclic bisindolylmaleimides 1-4 have been identified. Two strategies afford 8, the penultimate intermediate for the synthesis of 1-4, in 73% and 32% yield by intramolecular cyclization of 31 and 40, respectively. The optimum synthesis of 1 was achieved in nine steps and 15%... |
11301482 | Evidence for a DNA triplex in a recombination-like motif: I. Recognition of Watson-Crick base pairs by natural bases in a high-stability triplex. | Data are presented on a triplex type with two parallel homologous strands for which triplex formation is almost as strong as duplex formation at least for some sequences and even at pH 7 and 0.2 M NaCl. The evidence mainly rests upon comparing thermodynamic properties of similar systems. A paperclip oligonucleotide d(A... |
11301481 | Exquisite specificity and peptide epitope recognition promiscuity, properties shared by antibodies from sharks to humans. | This review considers definitions of the specificity of antibodies including the development of recent concepts of recognition polyspecificity and epitope promiscuity. Using sets of homologous and unrelated peptides derived from the sequences of immunoglobulin and T cell receptor chains we offer operational definitions... |
11301480 | Functional characterization of two anti-estradiol antibodies as deduced from modelling and site-directed mutagenesis experiments. | Monoclonal antibodies are now widely used to measure the concentration of steroid hormones in human serum samples. The great development of molecular engineering techniques over the past 10 years has made possible the improvement of specificity and/or sensitivity of selected antibodies. We have obtained two monoclonal ... |
11301479 | Interaction of a designed interleukin-10 epitope mimic with an antibody studied by isothermal titration microcalorimetry. | The mechanism of recognition of proteins and peptides by antibodies and the factors determining binding affinity and specificity are mediated by essentially the same features. However, additional effects of the usually unfolded and flexible solution structure of peptide ligands have to be considered. In an earlier stud... |
11301033 | Role of noncovalent binding of 11-cis-retinal to opsin in dark adaptation of rod and cone photoreceptors. | Regeneration of visual pigments of vertebrate rod and cone photoreceptors occurs by the initial noncovalent binding of 11-cis-retinal to opsin, followed by the formation of a covalent bond between the ligand and the protein. Here, we show that the noncovalent interaction between 11-cis-retinal and opsin affects the rat... |
11302438 | Study of the retention properties of warfarin enantiomers on a beta-cyclodextrin polymeric support. | High-performance liquid chromatography was used to study the retention properties of (R)- and (S)-warfarins on a silica support coated with a beta-cyclodextrin polymer. The influence of the methanol content of the acetate buffer eluent was investigated at pH 4. The measure of the variations of retention time with tempe... |
11302452 | High-performance liquid chromatographic study of the interactions between immobilized beta-cyclodextrin polymers and hydrophobically end-capped polyethylene glycols. | The formation of inclusion complexes between polyethylene glycols (PEGs) bearing hydrophobic ends (naphtyl and phenyladamantyl) and beta-cyclodextrin polymers (poly beta-CD) immobilized onto silica particles was studied by high-performance liquid chromatography (HPLC). It was shown that hydrophobic interactions were in... |
11300555 | EPR of Cu(II)-doped seven-coordinate inclusion compounds, M(stpy)3(NO3)2 x 1/2stpy (M = Cd(II) and Zn(II), stpy = trans-4-styrylpyridine): low symmetry effects in admixture of ground states. | Single crystal EPR of Cu(II)-doped low symmetry pentagonal bipyramidal Werner-type clathrate inclusion complexes of Cd(stpy)3(NO3)2 x 1/2stpy(1) and Zn(stpy)3(NO3)2 x 1/2stpy(2) (stpy = trans-4-styrylpyridine) is reported. The spin Hamiltonian parameters are found to be orthorhombic with g33 = 2.298, g22 = 2.108, g11 =... |
11300514 | Analysis of amphetamine and congeners in illicit samples by liquid chromatography and capillary electrophoresis. | Screening methods based on liquid chromatography (HPLC) and capillary electrophoresis (CE) have been developed for the identification and determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxyethylamphetamine in illicit tablets. Diethylpro... |
11300474 | Human T-cell responses to HLA-A-restricted high binding affinity peptides of human papillomavirus type 18 proteins E6 and E7. | Human Papillomaviruses (HPVs) are sexually transmitted pathogens, which are implicated in the etiology of cervical cancer. The early proteins E6 and E7 of HPV have transforming capacity and interfere with the cell cycle control of infected host cells and are essential for the maintenance of the transformed state. Ident... |
11297350 | Protein design and folding: template trapping of self-assembled helical bundles. | An experimental system is described, permitting a detailed and systematic analysis of the factors governing self-assembly of amphipathic helices, e.g. to a four-helical bundle, a subject of major relevance for tertiary structure formation, protein folding and design. Following the Template Assembled Synthetic Proteins ... |
11293590 | Capillary electrophoretic determination of the constituents of Artemisiae Capillaris Herba. | Two capillary electrophoretic methods, a micellar electrokinetic electrophoretic (MEKC) one and a capillary zone electrophoretic (CZE) one, were developed for the separation of 12 constituents in Artemisiae Capillaris Herba. Detection at 254 nm with 20 mM sodium dodecyl sulfate and 20 mM sodium borate buffer (pH 9.82) ... |
11293586 | New single-isomer chiral selector for capillary electrophoresis: the highly water-soluble heptakis(2-N,N-dimethylcarbamoyl)-beta-cyclodextrin. | A new single isomer beta-cyclodextrin, the heptakis(2-N,N-dimethylcarbamoyl)-beta-cyclodextrin (HDMC-beta-CD), has been synthesized and spectroscopically characterized. The outstanding feature of the new neutral beta-CD derivatives is their high solubility in water (>100 mM) and methanol. The resolution of chiral drugs... |
11289439 | Intramolecular fluorescence resonance energy transfer system with coumarin donor included in beta-cyclodextrin. | In aqueous solutions, the fluorescence of the intramolecular fluorescence resonance energy-transfer (FRET) system 1 was strongly quenched, because of close contact between the donor and acceptor moieties. FRET occurred, and the acceptor fluorescence was increased, by adding beta-cyclodextrin (beta-CD) to aqueous soluti... |
11281606 | Qualitative comparison between the quantum calculations and electrospray mass spectra of complexes of polyammonium macrotricyclic ligands with dicarboxylic acids. | The host-guest interactions play a very important role in chemical and biological processes. It is therefore important to be able to characterize these complexes. Electrospray mass spectrometry can be used to characterize the complex formation. It provides information on the mass and the charge of these ionic complexes... |
11281603 | Chiral recognition in gas-phase cyclodextrin: amino acid complexes--is the three point interaction still valid in the gas phase? | The validity of the "three-point interaction" model is examined in the guest exchange reaction involving complexes of cyclodextrins and amino acids. The amino acid guest is exchanged in the gas phase in the presence of a gaseous alkyl amine. The net reaction is proton transfer between the protonated amino acid and the ... |
11281600 | Gas-phase reactions of hydrated alkaline earth metal ions, M2+ (H2O)n (M = Mg, Ca, Sr, Ba and n = 4-7), with benzene. | Gas-phase reactions of hydrated divalent alkaline earth metal ions and benzene were investigated by electrospray ionization Fourier-transform mass spectrometry. Rate constants for solvent-exchange reactions were determined as a function of hydration extent for Mg2+, Ca2+, Sr2+, and Ba2+ clusters containing four to seve... |
11281132 | Biosynthesis of the bicycloalternarenes, mixed terpenoids of Alternaria alternata. | By incorporation of [2-13C]-mevalonate, [1-13C]-acetate and [1-13C]-glucose we could reveal that the phytopathogenic fungus Alternaria alternata biosynthesized the mixed terpenoids bicycloalternarenes via the classic mevalonate pathway. The polyketid pathway does not participate in the biosynthesis of bicycloalternaren... |
11274810 | Effect of drug lipophilicity on in vitro release rate from oil vehicles using nicotinic acid esters as model prodrug derivatives. | The rate constants for transfer of a homologous series of nicotinic acid esters from oil vehicles to aqueous buffer phases were determined using a rotating dialysis cell. The chemical stability of butyl nicotinate has been investigated at 60 degrees C over pH range 0.5--10. Maximum stability occurs at pH 4--5 and an in... |
11274436 | Modular organization of the Friend murine leukemia virus envelope protein underlies the mechanism of infection. | Retrovirus infection is initiated by receptor-dependent fusion of the envelope to the cell membrane. The modular organization of the envelope protein of C type retroviruses has been exploited to investigate how binding of the surface subunit (SU) to receptor triggers fusion mediated by the transmembrane (TM) subunit. W... |
11274414 | Visualization of oligonucleotide probes and point mutations in interphase nuclei and DNA fibers using rolling circle DNA amplification. | Rolling circle amplification (RCA) is a surface-anchored DNA replication reaction that can be exploited to visualize single molecular recognition events. Here we report the use of RCA to visualize target DNA sequences as small as 50 nts in peripheral blood lymphocytes or in stretched DNA fibers. Three unique target seq... |
11274383 | Self-assembled monolayers from a designed combinatorial library of de novo beta-sheet proteins. | A variety of naturally occurring biomaterials owe their unusual structural and mechanical properties to layers of beta-sheet proteins laminated between layers of inorganic mineral. To explore the possibility of fabricating novel two-dimensional protein layers, we studied the self-assembly properties of de novo proteins... |
11274059 | Topoisomerase IV, alone, unknots DNA in E. coli. | Knotted DNA has potentially devastating effects on cells. By using two site-specific recombination systems, we tied all biologically significant simple DNA knots in Escherichia coli. When topoisomerase IV activity was blocked, either with a drug or in a temperature-sensitive mutant, the knotted recombination intermedia... |
11274058 | Tn7 recognizes transposition target structures associated with DNA replication using the DNA-binding protein TnsE. | We report that the bacterial transposon Tn7 selects targets by recognizing features associated with DNA replication using the transposon-encoded DNA-binding protein TnsE. We show that Tn7 transposition directed by TnsE occurs in one orientation with respect to chromosomal DNA replication, indicating that a structure or... |
11270220 | A comparison of phosphated and sulfated beta-cyclodextrins as chiral selectors for capillary electrophoresis. | The enantioseparation capabilities of three different functionalized beta-cyclodextrins, two sulfated beta-cyclodextrins with 4 and 15 nominal degrees of substitution and a phosphated beta-cyclodextrin with 8 degrees of substitution, were compared. While anodic detection was used with both sulfated cyclodextrins, the p... |
11266650 | [3H]MRS 1754, a selective antagonist radioligand for A(2B) adenosine receptors. | MRS 1754 [N-(4-cyanophenyl)-2-[4-(2,3,6,7-tetrahydro-2,6-dioxo-1,3-dipropyl-1H-purin-8-yl)-phenoxy]acetamide] is a selective antagonist ligand of A(2B) adenosine receptors. This is the least well-defined adenosine receptor subtype, and A(2B) antagonists have potential as antiasthmatic drugs. For use as a radioligand, M... |
11269595 | Cyclodextrin biospecific-like displacement in dye-affinity chromatography. | Interactions between Cibacron Blue F3GA (CB F3GA), as a model of triazine dye, and 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD), as a model of cyclodextrin, were investigated by monitoring the spectral shift that accompanies the binding phenomena. Matrix analysis of the difference spectral titration of CB F3GA with H... |
11263881 | Molecule-mimetic chemistry and mesoscale self-assembly. | Molecules are structured aggregates of atoms joined by chemical bonds; crystals are aggregates of molecules, interacting covalently or noncovalently. The work described in this Account uses molecules, crystals, and other forms of atomic/molecular matter to suggest principles that can be used in generating structured ag... |
11263876 | Dendrimer-encapsulated metal nanoparticles: synthesis, characterization, and applications to catalysis. | This Account reports the synthesis and characterization of dendrimer-encapsulated metal nanoparticles and their applications to catalysis. These materials are prepared by sequestering metal ions within dendrimers followed by chemical reduction to yield the corresponding zerovalent metal nanoparticle. The size of such p... |
11261972 | Electron/atom transfer in halo-bridged homobimetallic complexes. structure and donor-acceptor properties of face-to-face dicopper complexes with teraazamacrocyclic ligands. | The syntheses and donor-acceptor properties of some novel, halo-bridged dicopper(II) complexes of alpha,alpha'-bis(5,7-dimethyl-1,4,8,11-tetraazacyclotetradecane-6-yl)-o-xylene are reported. These complexes were characterized by their magnetic and electrochemical behavior, X-ray structure analysis, FAB mass spectroscop... |
11261962 | Density functional study of tetraphenolate and calix[4]arene complexes of early transition metals. | Density functional calculations have been performed on some calix[4]arenes complexes of early transition metals. Particular emphasis has been placed on the comparison of the main properties of these metal complexes with the analogous metal complexes based on four monodentate phenolate ligands to study the effect of the... |
11261957 | Synthesis and Structure of [DB24C8)Na][Cd(SCN)3. Formation of a novel linear Cd...Cd...Cd chain with a mer-CdN3S3 coordination confirmation and new coiled [(DB24C8)Na]+ cation. | We report herein a novel coordination solid, [(DB24C8)Na][Cd(SCN)3] (6) (DB24C8 denotes dibenzo-24-crown-8), which exhibits a new type of [Cd(SCN)3-]infinity chain with two unusual stereochemical characteristics: (1) a mer-CdN3S3 coordination and (2) a linear Cd chain with a Cd...Cd...Cd angle of 180 degrees. In additi... |
11261949 | N-monofunctionalized 1,4,7-triazacyclononane macrocycles as building blocks in inorganic crystal engineering. | The syntheses of N-(3-prop-1-ene)-1,4,7-triazacyclononane molybdenum tricarbonyl (2), N-(4-but-1-ene)-1,4,7-triazacyclononane molybdenum tricarbonyl (3), N-(3-prop-1-ene)-1,4,7-triazacyclononane molybdenum trioxide (5), N-(4-but-1-ene)-1,4,7-triazacyclononane molybdenum trioxide (6), N-(hydroxyethyl)-1,4,7-triazacyclon... |
11262110 | Cyclopropane-derived peptidomimetics. design, synthesis, and evaluation of novel Ras farnesyltransferase inhibitors. | Trisubstituted cyclopropanes have previously been established as rigid replacements of dipeptide arrays in several biological systems. Toward further evaluating the utility of these dipeptide mimics in the design of novel CA(1)A(2)X-based inhibitors of Ras farnesyltransferase (FTase), the conformationally constrained, ... |
11262097 | Tetrapyrrole derivatives substituted with ferrocenylethynyl moieties. synthesis and electrochemical studies. | Up to eight redox-active ferrocenyl units have been incorporated, through the unsaturated ethynyl linkers, on the periphery of a series of cyclic tetrapyrrole derivatives including zinc(II) phthalocyanine and 2,3-naphthalocyanine, and nickel(II) meso-diphenylporphyrin. The synthesis of the former two macrocycles 4 and ... |
11262096 | Effect of cyclodextrin on the intramolecular catalysis of amide hydrolysis. | The hydrolysis reaction of phthalamic acids (HOOCArCONHR, R = p-NO(2)Ph 1a, Ph 1b, adamantyl 1c) and N-phenyl maleamic acid 2b was studied in the presence of hydroxypropyl-beta-cyclodextrin (HPCD) in acid solution. The reactions of 1a and 1b were studied also in the presence of beta-cyclodextrin (beta-CD). All the comp... |
11262095 | Synthesis, aggregation, and binding behavior of synthetic amphiphilic receptors. | Amphiphilic bowl-shaped receptor molecules have been synthesized starting from diphenylglycoluril. Upon dispersion in water, these molecules self-assemble to form vesicles that bind neutral guests and alkali metal ions. In the case of bis(alkylester)-modified receptor compound 4, electron microscopy reveals that an inc... |
11262094 | Synthesis and photochromism of spirobenzopyran derivatives bearing an oxymethylcrown ether moiety: metal ion-induced switching between positive and negative photochromisms. | Spirobenzopyran derivatives carrying an oxymethylcrown ether moiety were synthesized, and their photochromism was studied in the presence of various metal ions in acetonitrile. The metal ion complexing ability of the crown ether moiety in crowned spirobenzopyrans affects both thermal isomerization and photoisomerizatio... |
11262085 | Thiazole and thiadiazole analogues as a novel class of adenosine receptor antagonists. | Novel classes of heterocyclic compounds as adenosine antagonists were developed based on a template approach. Structure-affinity relationships revealed insights for extended knowledge of the receptor-ligand interaction. We replaced the bicyclic heterocyclic ring system of earlier described isoquinoline and quinazoline ... |
11262084 | Design, synthesis, and evaluation of a novel pyrrolobenzodiazepine DNA-interactive agent with highly efficient cross-linking ability and potent cytotoxicity. | A novel sequence-selective pyrrolobenzodiazepine (PBD) dimer 5 (SJG-136) has been developed that comprises two C2-exo-methylene-substituted DC-81 (3) subunits tethered through their C8 positions via an inert propanedioxy linker. This symmetric molecule is a highly efficient minor groove interstrand DNA cross-linking ag... |
11259060 | Transfer of stereochemical information in a minimal self-replicating system. | [structure: see text]. The rational design, synthesis, and characterization of a minimal self-replicating system based on a 1,3-dipolar cycloaddition between a nitrone and a maleimide is presented. The importance of molecular recognition in this system is demonstrated using a competitive inhibitor. Doping experiments d... |
11259046 | Tandem hetero diels-alder reaction: synthesis of oxygenated macrocycles. | [structure: see text]. C2-symmetric, oxygenated macrocycles have been synthesized from simple acyclic precursors in a single step by a tandem hetero Diels-Alder reaction. Thermolysis and Lewis acid catalysis can effect this novel transformation. The tandem reaction product is formed in preference to the intramolecular ... |
11261777 | Molecular motors involved in T cell receptor clusterings. | Engagement of antigen receptors on T and B cells triggers reorganization of the cytoskeleton and ordered clustering of cell surface receptors. These receptor clusters constitute spatially organized signaling machines and form the immune synapse with antigen-presenting cells. Formation of supramolecular activation clust... |
11261730 | New chiral crown ether stationary phase for the liquid chromatographic resolution of alpha-amino acid enantiomers. | A new chiral stationary phase (CSP) for the liquid chromatographic separation of enantiomers was prepared by bonding a novel enantiopure (diphenyl-substituted 1,1'-binaphthyl) crown ether to 5 microm silica gel. The resulting CSP was applied to the separation of the enantiomers of various natural and unnatural alpha-am... |
11261726 | Study of a novel cationic calix[4]arene used a selectivity modifier in capillary electrophoresis with electrochemical detection. | The use of a novel cationic calixarene, p-(quaternary ammonium) calix[4]arene, as selectivity modifier in capillary electrophoresis coupled with electrochemical detection was reported. The calixarene displayed good selectivity for the positional isomers of benzenediol and aminophenol and their successful separation was... |
11257135 | Pivotal role of signal transducer and activator of transcription (Stat)4 and Stat6 in the innate immune response during sepsis. | Signal transducer and activator of transcription (Stat)4 and Stat6 are transcription factors that provide type 1 and type 2 response, respectively. Here, we explored the role of Stat4 and Stat6 in innate immunity during septic peritonitis. Stat4-/- and Stat6-/- mice were resistant to the lethality compared with wild-ty... |
11257120 | The high mobility group (HMG) boxes of the nuclear protein HMG1 induce chemotaxis and cytoskeleton reorganization in rat smooth muscle cells. | HMG1 (high mobility group 1) is a ubiquitous and abundant chromatin component. However, HMG1 can be secreted by activated macrophages and monocytes, and can act as a mediator of inflammation and endotoxic lethality. Here we document a role of extracellular HMG1 in cell migration. HMG1 (and its individual DNA-binding do... |
11254742 | Lysosomal cholesterol derived from mildly oxidized low density lipoprotein is resistant to efflux. | In atherosclerotic lesions, macrophages store lipid in cytoplasmic inclusions and lysosomes. Regression studies show that lysosomal lipid is not as easily cleared as cytoplasmic inclusion lipid. Macrophages enriched with mildly oxidized low density lipoprotein (oxLDL) accumulate cholesteryl ester (CE) and free choleste... |
11231291 | Effects of methylcyclodextrin on lysosomes. | The cholesterol complexing agent methyl-cyclodextrin (MCD) provides an efficient mean for the removal of cholesterol from biological membranes. In order to study the effects of this agent on the lysosomal membrane in situ, we treated HepG2 cells with MCD and studied the effects of this treatment on lysosomes in isolate... |
11231268 | Construction, separation and properties of hybrid hexamers of glutamate dehydrogenase in which five of the six subunits are contributed by the catalytically inert D165S. | In vitro subunit hybridization was used to explore the basis of putative allosteric behaviour in clostridial glutamate dehydrogenase. C320S and D165S mutant enzymes were chosen to construct the hybrid proteins. The C320S mutant protein is fully active and shows normal allosteric properties but lacks the reactive cystei... |
11230143 | The small DNA binding domain of lambda integrase is a context-sensitive modulator of recombinase functions. | lambda Integrase (Int) has the distinctive ability to bridge two different and well separated DNA sequences. This heterobivalent DNA binding is facilitated by accessory DNA bending proteins that bring flanking Int sites into proximity. The regulation of lambda recombination has long been perceived as a structural pheno... |
11251077 | An ADP-ribosylation factor GTPase-activating protein Git2-short/KIAA0148 is involved in subcellular localization of paxillin and actin cytoskeletal organization. | Paxillin acts as an adaptor protein in integrin signaling. We have shown that paxillin exists in a relatively large cytoplasmic pool, including perinuclear areas, in addition to focal complexes formed at the cell periphery and focal adhesions formed underneath the cell. Several ADP-ribosylation factor (ARF) GTPase-acti... |
11254196 | Separation of olanzapine, carbamazepine and their main metabolites by capillary electrophoresis with pseudo-stationary phases. | Conditions were worked out for the separation of carbamazepine, olanzapine, and their main metabolites carbamazepine 10,11-epoxide, 10-hydroxycarbamazepine, and desmethylolanzapine. The separation was based on electrokinetically driven methods in the capillary format. The main difficulty in separating these compounds i... |
11253937 | Microencapsulation of ascorbic acid: effect of process variables on product characteristics. | This study deals with a comparative investigation of the characteristics of ascorbic acid microcapsules prepared by different methods, such as thermal phase separation, melt dispersion, solvent evaporation and spray drying. Scanning electron microscopy (SEM), release tests and size distribution were used for the evalua... |
11253930 | Functional analysis of the iron(II) etiocorrphycene incorporated in the myoglobin heme pocket. | The iron(III) complex of 2,7,12,17-tetraethyl-3,6,11,18-tetra-methylcorrphycene, an isomeric heme, was complexed with apomyoglobin to examine the ligand binding ability of the novel macrocycle under physiological conditions. The reconstituted holoprotein was found to be functionally active at pH 7.4 and 20 degrees C an... |
11250111 | Transport of poly amidoamine dendrimers across Madin-Darby canine kidney cells. | The objective of this study was to determine the permeability of a series of poly amidoamine (PAMAM) dendrimers of generations 0-4 (G0-G4) across MDCK (Madin-Darby Canine Kidney) cell line. PAMAM dendrimers with incremental increase in size and molecular weight were labeled by fluorescein isothiocyanate (FITC) and the ... |
11250099 | Complexation with tolbutamide modifies the physicochemical and tableting properties of hydroxypropyl-beta-cyclodextrin. | The physicochemical and tableting properties of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and its tolbutamide (TBM) complex were studied. The kinetics of TBM/HP-beta-CD inclusion complex formation in solution were determined by the phase solubility method. Solid complexes were prepared by freeze-drying and spray-dry... |
11250550 | Starch digestion in tropical fishes: isolation, structural studies and inhibition kinetics of alpha-amylases from two tilapias Oreochromis niloticus and Sarotherodon melanotheron. | alpha-Amylases from the intestinal cavity of two tilapia species, Oreochromis niloticus (ONI-AMY) and Sarotherodon melanotheron (SME-AMY), were purified using ammonium sulfate precipitation, affinity chromatography and chromatofocusing procedures. The purification was approximately 100-fold. The amylolytic activity, sp... |
11250583 | 6,7-Bis(bromomethyl)-2,11,18,21,24-pentaoxatetracyclo. | The 17-crown-5 unit, C(26)H(26)Br(2)O(5), consisting of a 1,2-bis(bromomethyl) group, three benzo groups and diethylene glycol, was prepared from the reaction of 1,2,4,5-tetrakis(bromomethyl)benzene and bis-phenol in the presence of sodium hydride as a base. This molecule seems to offer an internal cavity for the forma... |
11248118 | A method for soluble overexpression of the alpha7 nicotinic acetylcholine receptor extracellular domain. | We describe the construction of a soluble protein carrying the N-terminal extracellular domain (ECD) of the alpha7 subunit of the nicotinic acetylcholine receptor. The approach was to fuse the alpha7 ECD at the C and N termini of several monomeric and pentameric soluble carrier proteins and to investigate the soluble e... |
11248052 | Raft-partitioning of the ubiquitin ligases Cbl and Nedd4 upon IgE-triggered cell signaling. | The high affinity receptor for IgE, FcepsilonRI on mast cells and basophils plays an essential role in immunological defense. Upon multivalent antigen binding, FcepsilonRI becomes phoshorylated by the protein-tyrosine kinase Lyn, as a result of receptor clustering in lipid rafts. FcepsilonRI has been shown to be ubiqui... |
11248047 | Direct observation of the enhancement of noncooperative protein self-assembly by macromolecular crowding: indefinite linear self-association of bacterial cell division protein FtsZ. | Recent measurements of sedimentation equilibrium and sedimentation velocity have shown that the bacterial cell division protein FtsZ self-associates to form indefinitely long rod-like linear aggregates in the presence of GDP and Mg(2+). In the present study, the newly developed technique of non-ideal tracer sedimentati... |
11248036 | Herpes simplex virus DNA packaging sequences adopt novel structures that are specifically recognized by a component of the cleavage and packaging machinery. | The product of the herpes simplex virus type 1 U(L)28 gene is essential for cleavage of concatemeric viral DNA into genome-length units and packaging of this DNA into viral procapsids. To address the role of U(L)28 in this process, purified U(L)28 protein was assayed for the ability to recognize conserved herpesvirus D... |
11248029 | Mechanism of topology simplification by type II DNA topoisomerases. | Type II DNA topoisomerases actively reduce the fractions of knotted and catenated circular DNA below thermodynamic equilibrium values. To explain this surprising finding, we designed a model in which topoisomerases introduce a sharp bend in DNA. Because the enzymes have a specific orientation relative to the bend, they... |
11248672 | Thermodynamic analysis of binding of p-substituted benzamidines to trypsin. | Understanding the structural basis of inhibitor-enzyme interactions, important for the design of new drugs, requires a complete thermodynamic characterization of the binding process as well as a description of the structure of the complex. In this paper, the binding of p-substituted benzamidinium derivatives to the str... |
11248480 | A preliminary study of beta-cyclodextrin/metoprolol tartrate inclusion complex for potential enantiomeric separation. | The inclusion complex formation between Metoprolol tartarata (MeT) and beta-cyclodextrin (beta-CD) has been investigated using hyperchromic shift at lambda(max) 274.4 nm of MeT. Different parameters such as stirring time, solvent composition (aqueous and aqueous/methanol solutions with methanol content up to 50%), pH v... |
11248479 | Analysis and enantioresolution of donepezil by capillary electrophoresis. | The analysis of donepezil, a centrally acting acetylcholine esterase inhibitor, is described by a CZE method suitable for applications in pharmaceutical field. A rapid migration of the analyte was obtained under acidic conditions (pH 3.0); with detection wavelength of 320 nm a LOD of 0.8 x 10(-3) mg/ml was provided. Ap... |
11248471 | Capillary electrophoretic separation, immunochemical recognition and analysis of the diastereomers quinine and quinidine and two quinidine metabolites in body fluids. | The capillary electrophoretic separation and immunochemical recognition of the two naturally fluorescing, cationic diastereomers quinine (QN) and quinidine (QD), their hydroderivatives and two major QD metabolites (3-hydroxyquinidine and quinidine-N-oxide) was investigated. Plain aqueous phosphate buffers and an alkali... |
11246022 | HMG1 and 2, and related 'architectural' DNA-binding proteins. | The HMG-box proteins, one of the three classes of high mobility group (HMG) chromosomal proteins, bend DNA and bind preferentially to distorted DNA structures. The proteins appear to act primarily as architectural facilitators in the assembly of nucleoprotein complexes; for example, in effecting recombination and in th... |
11230534 | Tracing the origin of the compensasome: evolutionary history of DEAH helicase and MYST acetyltransferase gene families. | Dosage compensation in Drosophila is mediated by a complex of proteins and RNAs called the "compensasome." Two of the genes that encode proteins of the complex, maleless (mle) and males-absent-on-the-first (mof), respectively, belong to the DEAH helicase and MYST acetyltransferase gene families. We performed comprehens... |
11229887 | Protein trans-splicing to produce herbicide-resistant acetolactate synthase. | Protein splicing in trans has been demonstrated both in vivo and in vitro by biochemical and immunological analyses, but in vivo production of a functional protein by trans-splicing has not been reported previously. In this study, we used the DnaE intein from Synechocystis sp. strain PCC6803, which presumably reconstit... |
11243812 | Papillomavirus capsid protein expression in Escherichia coli: purification and assembly of HPV11 and HPV16 L1. | The L1 major capsid proteins of human papillomavirus (HPV) types 11 and 16 were purified and analyzed for structural integrity and in vitro self-assembly. Proteins were expressed in Escherichia coli as glutathione-S-transferase-L1 (GST-L1) fusions and purified to near homogeneity as pentamers (equivalent to viral capso... |
11238988 | Escherichia coli and Salmonella 2000: the view from here. | Five years after the publication of the second edition of the reference book Escherichia coli and Salmonella: Cellular and Molecular Biology, and on the eve of launching a successor venture, the editors and colleagues examine where we stand in our quest for an understanding of these organisms. The main areas selected f... |
11238986 | P(II) signal transduction proteins, pivotal players in microbial nitrogen control. | The P(II) family of signal transduction proteins are among the most widely distributed signal proteins in the bacterial world. First identified in 1969 as a component of the glutamine synthetase regulatory apparatus, P(II) proteins have since been recognized as playing a pivotal role in control of prokaryotic nitrogen ... |
11238984 | Hyperthermophilic enzymes: sources, uses, and molecular mechanisms for thermostability. | Enzymes synthesized by hyperthermophiles (bacteria and archaea with optimal growth temperatures of > 80 degrees C), also called hyperthermophilic enzymes, are typically thermostable (i.e., resistant to irreversible inactivation at high temperatures) and are optimally active at high temperatures. These enzymes share the... |
11241704 | 3D-micro-MR angiography of mice using macromolecular MR contrast agents with polyamidoamine dendrimer core with reference to their pharmacokinetic properties. | Four novel macromolecular MRI contrast agents, all of which had the same chemical composition but different molecular weights, were prepared using generation-3, -4, -5, and -6 polyamidoamine (PAMAM) dendrimers conjugated with a bifunctional diethylenetriaminepentaacetic acid derivative to change the blood retention, ti... |
11237621 | Crystal structures of the maltodextrin/maltose-binding protein complexed with reduced oligosaccharides: flexibility of tertiary structure and ligand binding. | The structure of the maltodextrin or maltose-binding protein, an initial receptor for bacterial ABC-type active transport and chemotaxis, consists of two globular domains that are separated by a groove wherein the ligand is bound and enclosed by an inter-domain rotation. Here, we report the determination of the crystal... |
11238459 | The supramolecular organization of fibrillin-rich microfibrils. | We propose a new model for the alignment of fibrillin molecules within fibrillin microfibrils. Automated electron tomography was used to generate three-dimensional microfibril reconstructions to 18.6-A resolution, which revealed many new organizational details of untensioned microfibrils, including heart-shaped beads f... |
11238446 | A novel interaction of the Golgi complex with the vimentin intermediate filament cytoskeleton. | The integration of the vimentin intermediate filament (IF) cytoskeleton and cellular organelles in vivo is an incompletely understood process, and the identities of proteins participating in such events are largely unknown. Here, we show that the Golgi complex interacts with the vimentin IF cytoskeleton, and that the G... |
11237872 | Delivery of oligonucleotides into mammalian cells by anionic peptides: comparison between monomeric and dimeric peptides. | The use of antisense oligonucleotides as putative therapeutic agents is limited by their poor delivery into the cytosol and/or the nucleus because they are not able to efficiently cross lipid bilayers. To circumvent this pitfall, anionic amphipathic peptides derived from the influenza virus fusogenic peptide have been ... |
11237854 | Human ornithine transcarbamylase: crystallographic insights into substrate recognition and conformational changes. | Two crystal structures of human ornithine transcarbamylase (OTCase) complexed with the substrate carbamoyl phosphate (CP) have been solved. One structure, whose crystals were prepared by substituting N-phosphonacetyl-L-ornithine (PALO) liganded crystals with CP, has been refined at 2.4 A (1 A=0.1 nm) resolution to a cr... |
11238051 | A putative role for cathepsin K in degradation of AA and AL amyloidosis. | The aims of this study were to investigate the role of cathepsin K in the pathology of amyloidosis by demonstrating its presence in multinucleated giant cells (MGCs) adjacent to amyloid deposits, and determining its ability to degrade amyloid fibril proteins in vitro. The study was performed using autopsy and biopsy sp... |
11222763 | A nicked duplex decamer DNA with a PEG(6) tether. | A dumbbell double-stranded DNA decamer tethered with a hexaethylene glycol linker moiety (DDSDPEG), with a nick in the centre of one strand, has been synthesised. The standard NMR methods, E.COSY, TOCSY, NOESY and HMQC, were used to measure (1)H, (31)P and T:(1) spectral parameters. Molecular modelling using rMD-simula... |
11222698 | Characterization of Rous sarcoma virus Gag particles assembled in vitro. | Purified retrovirus Gag proteins or Gag protein fragments are able to assemble into virus-like particles (VLPs) in vitro in the presence of RNA. We have examined the role of nucleic acid and of the NC domain in assembly of VLPs from a Rous sarcoma virus (RSV) Gag protein and have characterized these VLPs using transmis... |
11222692 | Inhibition of hepatitis B virus replication by the interferon-inducible MxA protein. | Human MxA is an alpha/beta interferon-inducible intracytoplasmic protein that mediates antiviral activity against several RNA viruses. We had previously shown that overexpression of the hepatitis B virus (HBV) capsid led to selective downregulation of MxA gene expression, suggesting a mechanism by which the virus escap... |
11222675 | Type D retrovirus Gag polyprotein interacts with the cytosolic chaperonin TRiC. | The carboxy terminus-encoding portion of the gag gene of Mason-Pfizer monkey virus (M-PMV), the prototype immunosuppressive primate type D retrovirus, encodes a 36-amino-acid, proline-rich protein domain that, in the mature virion, becomes the p4 capsid protein. The p4 domain has no known role in M-PMV replication. We ... |
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