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11714262 | Ruthenium polypyridine complexes. On the route to biomimetic assemblies as models for the photosynthetic reaction center. | We describe in this Account the preparation of RuL(3) complexes and their significance as biomimetic models for the photosynthetic reation center. Their preparation from simple or more complicated bypyridine ligands L and their photophysical data, especially their stability, are reported. Biomimetic models involving th... |
11714256 | Chirality transfer in ferroelectric liquid crystals. | This Account describes how concepts used in the fields of host-guest chemistry and chiral molecular recognition may be used to explain the unique chiral induction behavior of molecules with atropisomeric biphenyl cores when doped into a two-dimensionally ordered smectic liquid crystal phase formed by rod-shaped molecul... |
11713192 | Prominent mitochondrial DNA recombination intermediates in human heart muscle. | Recombination intermediates containing four-way (Holliday) junctions are generated during DNA repair and replication in many systems, including yeast mitochondrial DNA (mtDNA). In contrast, convincing evidence for recombination in mammalian mtDNA is lacking. We have used two-dimensional agarose-gel electrophoresis to a... |
11713189 | Non-coding RNAs: the architects of eukaryotic complexity. | Around 98% of all transcriptional output in humans is non-coding RNA. RNA-mediated gene regulation is widespread in higher eukaryotes and complex genetic phenomena like RNA interference, co-suppression, transgene silencing, imprinting, methylation, and possibly position-effect variegation and transvection, all involve ... |
11708915 | Neoceptor concept based on molecular complementarity in GPCRs: a mutant adenosine A(3) receptor with selectively enhanced affinity for amine-modified nucleosides. | Adenosine A(3) receptors are of interest in the treatment of cardiac ischemia, inflammation, and neurodegenerative diseases. In an effort to create a unique receptor mutant that would be activated by tailor-made synthetic ligands, we mutated the human A(3) receptor at the site of a critical His residue in TM7, previous... |
11707124 | Supramolecular staircase via self-assembly of disklike molecules at the solid-liquid interface. | A series of soluble hexabenzocoronene (HBC) derivatives with pendant optically active (S)-3,7-dimethyloctanyl and (R,S)-3,7-dimethyloctanyl (mixture of stereoisomers) hydrocarbon side chains with and without a phenylene spacer were assembled into differently ordered arrays at the interface between a solution and the ba... |
11707421 | Topoisomerase II can unlink replicating DNA by precatenane removal. | We have analysed the role of topoisomerase II (topo II) in plasmid DNA replication in Xenopus egg extracts, using specific inhibitors and two-dimensional gel electrophoresis of replication products. Topo II is dispensable for nuclear assembly and complete replication of plasmid DNA but is required for plasmid unlinking... |
11707395 | Strains of [PSI(+)] are distinguished by their efficiencies of prion-mediated conformational conversion. | Yeast prions are protein-based genetic elements that produce phenotypes through self-perpetuating changes in protein conformation. For the prion [PSI(+)] this protein is Sup35, which is comprised of a prion-determining region (NM) fused to a translational termination region. [PSI(+)] strains (variants) with different h... |
11706328 | Multiple organ failure still a major cause of morbidity but not mortality in blunt multiple trauma. | <h4>Background</h4>Multiple organ failure (OF/MOF) was found to be the major complication after blunt multiple trauma during the last 25 years and was correlated with a high mortality rate. Recently, several publications reported a decreased ARDS-related mortality, but there is little information about mortality rates ... |
11705883 | Tumor targeting and imaging of intraperitoneal tumors by use of antisense oligo-DNA complexed with dendrimers and/or avidin in mice. | To establish an effective nonviral gene delivery and a corresponding imaging method for i.p.-disseminated tumors, various oligonucleotide-carrier complexes were synthesized, and their in vitro and in vivo properties were examined. The 20-mer multiamino-linked oligonucleotide (oligo), synthesized as antisense against th... |
11705469 | Isolation and structural analyses of positional isomers of 6(1),6(n)-di-O-(N-acetyl-beta-D-glucosaminyl)cyclomaltoheptaose (n=2, 3, and 4) and 6-O-[6-O-(N-acetyl-beta-D-glucosaminyl)-N-acetyl-beta-D-glucosaminyl]cyclomaltoheptaose. | 6-O-[6-O-(N-acetyl-beta-D-glucosaminyl)-N-acetyl-beta-D-glucosaminyl]cyclomaltoheptaose (beta CD) and three positional isomers of 6(1),6(n)-di-O-(N-acetyl-beta-D-glucosaminyl)cyclomaltoheptaose (n=2, 3, and 4) in a mixture of products from beta CD and N-acetylglucosamine by the reversed reaction of beta-N-acetylhexosam... |
11705373 | Peptide inhibitors of HIV-1 integrase dissociate the enzyme oligomers. | Integration of HIV-1 genome into host cell chromosome is mediated by viral integrase (IN). The IN catalytic core (CC, IN(50-212)) dimerizes through mutual interactions of its alpha1 and alpha5 helices. Peptides INH1 and INH5 reproducing these helix sequences strongly inhibited IN. For instance, an IC(50) of 80 nM was d... |
11703135 | X-ray photoelectron spectroscopy as a probe of intermolecular interactions in porphyrin polymer thin films. | High-resolution X-ray photoelectron spectroscopy (XPS) has been applied to a series of free-base and Zn-porphyrin polymers in which the macrocycles are separated by oligo(phenylene vinylene) units (OPV) of different, controllable lengths. Neat films of all the Zn-porphyrin polymers unexpectedly reveal two peaks in the ... |
11703132 | Magnetic characteristics of new cyano-bridged two-dimensional honeycomb-like bimetallic assemblies containing Ni(II)-N[triple bond]C-Cr(III) or Ni(II)-N[triple bond]C-Cr(I) linkages. | Three cyano-bridged bimetallic assemblies, [NiL(1)](3)[Cr(CN)(6)](2).7H(2)O (1), [NiL(2)](3)[Cr(CN)(6)](2).9H(2)O (2), and [NiL(2)](3)[Cr(CN)(5)(NO)](2).9H(2)O (3) (L(1) = 3,10-dimethyl-1,3,5,8,10,12-hexaazacycloctadecane and L(2) = 3,10-diethyl-1,3,5,8,10,12-hexaazacycloctadecane), have been prepared and characterized... |
11703123 | Self-assembly of polymer and sheet structures from palladium(II) complexes by hydrogen bonding between carboxamide substituents. | The self-assembly of supramolecular structures from either neutral or cationic palladium(II) complexes containing primary or secondary carboxamide groups as substituents on pyridine ligands has been explored. The displacement of PhCN in trans-[PdCl(2)(PhCN)(2)] by L = N-methylnicotinamide (MNA), isonicotinamide (INA), ... |
11703122 | Supramolecular structures of cadmium(II) coordination polymers: a new class of ligands formed by linking tripodal tris(pyrazolyl)methane units. | The new ligands C(6)H(4)[CH(2)OCH(2)C(pz)(3)](2) (pz = pyrazolyl ring), 1 (ortho), 2 (meta), and 3 (para), that can potentially bond two or more metal centers were obtained in a single step from the reaction of the appropriate dibromoxylene, 2 equiv of tris-2,2,2-(1-pyrazolyl)ethanol, and excess NaH. Although the arran... |
11704653 | Effects of cannabinoids on adrenaline release from adrenal medullary cells. | 1. The objective of the present study was to analyse the peripheral effects of cannabinoids on adrenaline release from adrenal chromaffin cells. 2. In pithed rabbits with electrically stimulated sympathetic outflow, intravenous injection of the cannabinoid receptor agonists WIN55212-2 and CP55940 (5, 50 and 500 microg ... |
11704651 | Influence of membrane cholesterol on modulation of the GABA(A) receptor by neuroactive steroids and other potentiators. | 1. The influence of membrane cholesterol on some pharmacological properties of the GABA(A) receptor was investigated in acutely dissociated rat hippocampal neurones with whole cell patch clamp recording. The cholesterol levels were varied between 56% and 235% control using methyl-beta-cyclodextrin as the cholesterol ca... |
11704639 | Characterization of two Bunodosoma granulifera toxins active on cardiac sodium channels. | 1. Two sodium channel toxins, BgII and BgIII, have been isolated and purified from the sea anemone Bunodosoma granulifera. Combining different techniques, we have investigated the electrophysiological properties of these toxins. 2. We examined the effect of BgII and BgIII on rat ventricular strips. These toxins prolong... |
11704638 | Differential effects of serotonin reuptake inhibitors on erectile responses, NO-production, and neuronal NO synthase expression in rat corpus cavernosum tissue. | Increased incidence of impotence is associated with some selective serotonin-reuptake-inhibitors (SSRIs), but the pathophysiological mechanism is unknown. Paroxetine and citalopram are extensively used SSRIs, but only paroxetine has been shown to inhibit nitric oxide synthase (NOS) activity. NO is a key mediator of pen... |
11701037 | Binding affinity properties of dendritic glycosides based on a beta-cyclodextrin core toward guest molecules and concanavalin A. | The inclusion behavior and concanavalin A binding properties of hepta-antennated and newly synthesized tetradeca-antennated C-6-branched mannopyranosyl and glucopyrannosyl cyclomaltoheptaose (beta-cyclodextrin) derivatives have been evaluated by isothermal titration microcalorimetry and enzyme-linked lectin assay (ELLA... |
11701033 | Dendralene-type TTF vinylogs containing a 1,3-diselenole ring. | 2-Diformylmethylene-1,3-diselenole was prepared and condensed with dithiolium phoshonium bromides and dithiolium phosphonates in the presence of base to give dendralene-type vinylogs of TTF bearing a 1,3-diselenole moiety. The electrochemistry of these dendrimers was studied. SEEPR measurements were also carried out. C... |
11700095 | Efficient assembly of the phomactin core via two different macrocyclization protocols. | [reaction--see text] The core structure of phomactins C and D was assembled by an efficient strategy starting from 3,4-dimethylcyclohexen-2-one. Key reactions include (1) a high yielding and highly diastereoselective Michael addition of a mixed cuprate, (2) a carbonylative alkyne-enoltriflate coupling or an intramolecu... |
11700554 | Equilibrating metal-oxide cluster ensembles for oxidation reactions using oxygen in water. | Although many enzymes can readily and selectively use oxygen in water-the most familiar and attractive of all oxidants and solvents, respectively-the design of synthetic catalysts for selective water-based oxidation processes utilizing molecular oxygen remains a daunting task. Particularly problematic is the fact that ... |
11698680 | Cholesterol depletion induces large scale domain segregation in living cell membranes. | Local inhomogeneities in lipid composition play a crucial role in regulation of signal transduction and membrane traffic. Nevertheless, most evidence for microdomains in cells remains indirect, and the nature of membrane inhomogeneities has been difficult to characterize. We used lipid analogs and lipid-anchored protei... |
11698618 | Mouse strain differences in opiate reward learning are explained by differences in anxiety, not reward or learning. | Gene-targeting techniques to produce null mutations provide a powerful method for evaluating the contribution of particular candidate genes involved in motivation. The embryonic stem cell lines in which homologous recombination is undertaken are derived from 129 mice, but because of the impoverished performance of 129 ... |
11698583 | Presynaptic R-type calcium channels contribute to fast excitatory synaptic transmission in the rat hippocampus. | The possibility that R-type calcium channels contribute to fast glutamatergic transmission in the hippocampus has been assessed using low concentrations of NiCl(2) and the peptide toxin SNX 482, a selective antagonist of the pore-forming alpha(1E) subunit of R-type calcium channel. EPSPs or EPSCs were recorded in the w... |
11698455 | Association of FcgammaRII with low-density detergent-resistant membranes is important for cross-linking-dependent initiation of the tyrosine phosphorylation pathway and superoxide generation. | IgG immune complexes trigger humoral immune responses by cross-linking of FcRs for IgG (FcgammaRs). In the present study, we investigated role of lipid rafts, glycolipid- and cholesterol-rich membrane microdomains, in the FcgammaR-mediated responses. In retinoic acid-differentiated HL-60 cells, cross-linking of Fcgamma... |
11697957 | Phase transfer of hydrophilic, cyclodextrin-modified gold nanoparticles to chloroform solutions. | The preparation and characterization of gold nanoparticles (approximately 3 nm in diameter) capped with thiolated alpha- and beta-cyclodextrins (alpha and beta-CD) is described. The CD-capped nanoparticles are hydrophilic and bind ferrocene derivatives as evidenced by electrochemical and (1)H NMR spectroscopic measurem... |
11696607 | Prolonged residence time of a noncovalent molecular adapter, beta-cyclodextrin, within the lumen of mutant alpha-hemolysin pores. | Noncovalent molecular adapters, such as cyclodextrins, act as binding sites for channel blockers when lodged in the lumen of the alpha-hemolysin (alphaHL) pore, thereby offering a basis for the detection of a variety of organic molecules with alphaHL as a sensor element. beta-Cyclodextrin (betaCD) resides in the wild-t... |
11696375 | A novel dicyclodextrinyl ditelluride compound with antioxidant activity. | Reactive oxygen species (ROS) primarily arise from products of normal metabolic activities and are thought to be the etiology of many diseases. A novel dicyclodextrinyl ditelluride (2-TeCD) compound was designed to be a functional mimic of the glutathione peroxidase that normally removes ROS. 2-TeCD exhibited highly ca... |
11695898 | In vitro effect of cryptophycin 52 on microtubule assembly and tubulin: molecular modeling of the mechanism of action of a new antimitotic drug. | Cryptophycin 52 (C52) is a new synthetic compound of the cryptophycin family of antitumor agents that is currently undergoing clinical evaluation for cancer chemotherapy. The cryptophycin class of compounds acts on microtubules. This report details the mechanism by which C52 substoichiometrically inhibits tubulin self-... |
11694592 | N-terminal protein acylation confers localization to cholesterol, sphingolipid-enriched membranes but not to lipid rafts/caveolae. | When variably fatty acylated N-terminal amino acid sequences were appended to a green fluorescent reporter protein (GFP), chimeric GFPs were localized to different membranes in a fatty acylation-dependent manner. To explore the mechanism of localization, the properties of acceptor membranes and their interaction with a... |
11694588 | Cytoskeleton-dependent membrane domain segregation during neutrophil polarization. | On treatment with chemoattractant, the neutrophil plasma membrane becomes organized into detergent-resistant membrane domains (DRMs), the distribution of which is intimately correlated with cell polarization. Plasma membrane at the front of polarized cells is susceptible to extraction by cold Triton X-100, whereas memb... |
11694586 | Cell cycle-dependent expression and nucleolar localization of hCAP-H. | Condensin is a conserved 13S heteropentamer composed of two nonidentical structural maintenance of chromosome (SMC) family proteins, in Xenopus XCAP-C and XCAP-E, and three regulatory subunits, XCAP-D2, XCAP-G, and XCAP-H. Both biochemical and genetic analyses have demonstrated an essential role for the 13S condensin c... |
11691917 | On the molecular discrimination between adenine and guanine by proteins. | The molecular recognition and discrimination of adenine and guanine ligand moieties in complexes with proteins have been studied using empirical observations on carefully selected crystal structures. The distribution of protein folds that bind these purines has been found to differ significantly from that across the wh... |
11689423 | X-ray structure of the orphan nuclear receptor RORbeta ligand-binding domain in the active conformation. | The retinoic acid-related orphan receptor beta (RORbeta) exhibits a highly restricted neuronal-specific expression pattern in brain, retina and pineal gland. So far, neither a natural RORbeta target gene nor a functional ligand have been identified, and the physiological role of the receptor is not well understood. We ... |
11689184 | An orthorhombic crystal form of cyclohexaicosaose, CA26.32.59 H(2)O: comparison with the triclinic form. | Cycloamylose containing 26 glucose residues (cyclohexaicosaose, CA26) crystallized from water and 30% (v/v) polyethyleneglycol 400 in the orthorhombic space group P2(1)2(1)2(1) in the highly hydrated form CA26.32.59 H(2)O. X-ray analysis of the crystals at 0.85 A resolution shows that the macrocycle of CA26 is folded i... |
11686709 | Effect of solvation on induce-fit molecular recognition in supercritical fluid to organic crystals immobilized on a quartz crystal microbalance. | The inclusion behavior of guest molecules to a solid apohost of an orthogonal anthracene-bis(resorcinol)tetraol (1) was investigated in supercritical carbon dioxide (scCO(2)) by using a 9 MHz quartz-crystal microbalance (QCM). Compound 1 forms crystals composed of molecular-sheet bound together by an extensive hydrogen... |
11686708 | Triplet excitation transfer through the walls of hemicarcerands: dependence of the electronic coupling on the size of the molecular cage. | Triplet excitation transfer from biacetyl trapped inside three hemicarcerands of different size (1, 2, and 3) to acceptors in the surrounding medium was investigated. The largest hemiracerand 1 employs four butyl linkers and the intermediate hemicarcerand 2 four o-xylyl linkers. The smallest hemicarcerand 3 contains on... |
11687519 | Neuronal nitric oxide synthase and the autonomic innervation of the mouse lacrimal gland. | <h4>Purpose</h4>To determine the expression patterns of the vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH) and neuronal nitric oxide synthase (nNOS) in the pterygopalatine ganglion (PPG) and the exorbital lacrimal gland of normal mice.<h4>Methods</h4>Mouse PPG and lacrimal glands were processed ... |
11683884 | Caveolin-1 negatively regulates SR-BI mediated selective uptake of high-density lipoprotein-derived cholesteryl ester. | The class B, type I scavenger receptor (SR-BI) mediates the selective uptake of high density lipoprotein (HDL) cholesteryl esters and the efflux of free cholesterol. SR-BI is predominantly associated with caveolae in Chinese hamster ovary cells. The caveola protein, caveolin-1, binds to cholesterol and is involved in i... |
11681951 | Circular dichroism spectra of the achiral guest N-aryl-N-nitrosamines included in the crystal host matrices of cholic acid. | The crystalline inclusion complexes of cholic acid with three symmetric N-aryl-N-nitrosamines were prepared, and their X-ray structures were solved. As a result of chiral conformations adopted by the enclathrated guest nitrosamines, the solid-state CD spectra were measured in KBr disks. The observed Cotton effect sign,... |
11681947 | Synthesis of meso-substituted chlorins via tetrahydrobilene-a intermediates. | Chlorin building blocks incorporating a geminal dimethyl group in the reduced ring and synthetic handles in specific patterns at the perimeter of the macrocycle are expected to have utility in biomimetic and materials chemistry. A prior route employed condensation of a dihydrodipyrrin (Western half) and a bromodipyrrom... |
11681943 | Thermodynamic aspects of dicarboxylate recognition by simple artificial receptors. | Recognition of dicarboxylates by bis-functional hydrogen-bonding receptors displays divergent thermodynamics in different solvent systems. NMR titration and isothermal titration calorimetry indicated that neutral bis-urea and bis-thiourea receptors form exothermic complexes with dicarboxylates in DMSO, with a near zero... |
11682497 | Validation of a commercially available monoclonal antibody-based competitive-inhibition enzyme-linked immunosorbent assay for detection of serum antibodies to Neospora caninum in cattle. | A previously described monoclonal antibody (MAb)-based competitive-inhibition enzyme-linked immunosorbent assay (cELISA) was modified to optimize performance, and the assay was validated in various defined cattle populations for detection of serum antibody to Neospora caninum, a major cause of bovine abortion. Modifica... |
11682496 | Helicobacter pylori growth and urease detection in the chemically defined medium Ham's F-12 nutrient mixture. | Obstacles continue to hinder in vitro studies of the gastric human pathogen Helicobacter pylori, including difficulty culturing the organism in the absence of serum or blood, rapid loss of viability following exponential growth due to autolysis, and the necessity for using high starting inocula. We demonstrate that H. ... |
11681921 | Gold-gold interactions as crystal engineering design elements in heterobimetallic coordination polymers. | A series of coordination polymers containing Cu(II) and [Au(CN)(2)](-) units has been prepared. Most of their structures incorporate attractive gold-gold interactions, thus illustrating that such "aurophilic" interactions can be powerful tools for increasing structural dimensionality in supramolecular systems. [Cu(tren... |
11681902 | Extended polymorphism in copper(II) imidazolate polymers: a spectroscopic and XRPD structural study. | Copper(II) bisimidazolate affords five different polymorphs; of these, one was structurally characterized 40 years ago by standard single-crystal X-ray diffraction (Jarvis, J. A. J.; Wells, A. F. Acta Crystallogr. 1960, 13, 1027), while the remaining four, selectively prepared as pure polycrystalline phases, have been ... |
11681901 | Tethered pyrazolyl phosphinate: pyrazolyl-N- and phosphoryl-O-metal coordination in Ph(2)P(O)[OCH(2)CH(2)(3,5-Me(2)Pz)]. | Phosphorus pyrazolides, P(O)(3,5-Me(2)Pz)(3) or RP(E)(3,5-Me(2)Pz)(2) [E = S or O, R = Me or Ph], are hydrolytically sensitive particularly upon interaction with transition metal ions. In this paper, we report a new tethered pyrazolyl phosphinate, Ph(2)P(O)[OCH(2)CH(2)(3,5-Me(2)Pz)] DPEP (1), where the pyrazolyl group ... |
11681899 | Macrocyclic metalloenediynes of Cu(II) and Zn(II): a thermal reactivity comparison. | The syntheses of tetradentate enediyne macrocycles with 24 (tact1:1)-, 26 (tact1:2)-, and 28 (tact2:2)-membered rings are described, along with their thermal reactivities and those of the corresponding Cu(II) (Cu(tact1:1), Cu(tact1:2)) and Zn(II) (Zn(tact1:1), Zn(tact1:2)) complexes. These enediyne macrocyclic ligands ... |
11681892 | Optimization of the lariat ether carboxylic acid host structure for ferrioxamine B: demonstration of a second coordination shell chelate effect. | Host-guest supramolecular assembly formation constants involving the second-sphere complexation of the siderophore ferrioxamine B (FeHDFB(+)) by a lariat ether carboxylic acid host (L(n+2)COOH) in wet chloroform were obtained from liquid-liquid extractions at pH values above and below the host pK(a) (approximately 5.3)... |
11681887 | Cyanide complexes of iron corrolates: spin delocalization and autoreduction. | Complex formation of (7,13-dimethyl-2,3,8,12,17,18-hexaethylcorrolato)iron chloride, [(7,13-Me(2)Et(6)C)FeCl], with cyanide ion in dimethylformamide, DMF-d(7), was studied by (1)H NMR spectroscopy. It is found that a bis-cyanide complex is formed initially, in which the electron configuration is a low-spin Fe(III) corr... |
11678697 | Change of connectivity on catenane ring: ring expansion by annulation-ring scission sequence. | [reaction: see text]. Ring expansion of a catenane without destruction of the interlocked structure was attained by Diels-Alder reaction followed by ozonolysis. Annulation by Diels-Alder reaction introduced a C4 fragment onto the ring, and the ozonolysis scissored the resulting double bond to expand the catenane ring. ... |
11678686 | Signal communication between molecular switches. | [structure: see text]. Efficient strategies for the communication of signals between molecules must be identified for the development of molecule-based nanoprocessors. We have demonstrated that photoinduced proton transfer can be exploited to implement intermolecular digital transmission. Light inputs operate a three-s... |
11679320 | Oral toxicity of Photorhabdus luminescens W14 toxin complexes in Escherichia coli. | Previous attempts to express the toxin complex genes of Photorhabdus luminescens W14 in Escherichia coli have failed to reconstitute their oral toxicity to the model insect Manduca sexta. Here we show that the combination of three genes, tcdA, tcdB, and tccC, is essential for oral toxicity to M. sexta when expression i... |
11675025 | Trapping of a covalent enzyme intermediate in the reaction of Bacillus macerans cyclomaltodextrin glucanyltransferase with cyclomaltohexaose. | The mechanism of catalysis of Bacillus macerans cyclomaltodextrin glucanyltransferase (CGTase, EC 2.4.1.19) was studied by trapping and isolating a covalent-enzyme intermediate. CGTase catalyzes an acceptor or coupling reaction between cyclomaltohexaose and a carbohydrate acceptor such as D-glucose. CGTase was incubate... |
11673890 | Radiative decay engineering: biophysical and biomedical applications. | Fluorescence spectroscopy is a widely used research tool in biochemistry and molecular biology. Fluorescence has also become the dominant method enabling the revolution in medical diagnostics, DNA sequencing, and genomics. To date all the fluorescence observables, including spectral shifts, anisotropies, quantum yields... |
11673433 | Escherichia coli division inhibitor MinCD blocks septation by preventing Z-ring formation. | The min system spatially regulates division through the topological regulation of MinCD, an inhibitor of cell division. MinCD was previously shown to inhibit division by preventing assembly of the Z ring (E. Bi and J. Lutkenhaus, J. Bacteriol. 175:1118-1125, 1993); however, this was questioned in a recent report (S. S.... |
11672423 | Identification of the autophosphorylation sites and characterization of their effects in the protein kinase DYRK1A. | Protein kinases of the DYRK ('dual-specificity tyrosine-regulated kinase') family are characterized by a conserved Tyr-Xaa-Tyr motif (Tyr-319-Tyr-321) in a position exactly corresponding to the activation motif of the mitogen-activated protein kinase (MAP kinase) family (Thr-Xaa-Tyr). In a molecular model of the cataly... |
11672422 | LIM-domain protein cysteine- and glycine-rich protein 2 (CRP2) is a novel marker of hepatic stellate cells and binding partner of the protein inhibitor of activated STAT1. | Activation of hepatic stellate cells is considered to be the main step in the development of liver fibrosis, which is characterized by the transition of quiescent vitamin-A-rich cells to proliferative, fibrogenic and contractile myofibroblasts. The identification of regulatory genes during early cell activation and tra... |
11672421 | Structural, signalling and regulatory properties of the group I metabotropic glutamate receptors: prototypic family C G-protein-coupled receptors. | In 1991 a new type of G-protein-coupled receptor (GPCR) was cloned, the type 1a metabotropic glutamate (mGlu) receptor, which, despite possessing the defining seven-transmembrane topology of the GPCR superfamily, bore little resemblance to the growing number of other cloned GPCRs. Subsequent studies have shown that the... |
11668087 | Signaling pathway for nitric oxide generation with simulated ischemia in flow-adapted endothelial cells. | Ischemia in the intact ventilated lung (oxygenated ischemia) leads to endothelial generation of reactive oxygen species (ROS) and nitric oxide (NO). This study investigated the signaling pathway for NO generation with oxygenated ischemia in bovine pulmonary artery endothelial cells (BPAEC) that were flow adapted in vit... |
11641434 | Allosteric modulation of A(3) adenosine receptors by a series of 3-(2-pyridinyl)isoquinoline derivatives. | Allosteric modulators of A(1) and A(2A) adenosine receptors have been described; however, for the A(3) adenosine receptor, neither an allosteric site nor a compound with allosteric effects has been described. In this study, the allosteric modulation of human A(3) adenosine receptors by a series of 3-(2-pyridinyl)isoqui... |
11606620 | Neuronal glutamate transporters limit activation of NMDA receptors by neurotransmitter spillover on CA1 pyramidal cells. | Glutamate released at synapses in the CA1 region of the hippocampus escapes the synaptic cleft and activates extrasynaptic targets; it also may "spill over" into neighboring synapses and activate receptors there. Glutamate transporters in glial membranes restrict extrasynaptic diffusion, but it is unclear whether neuro... |
11606308 | Comparison of the membrane association of two antimicrobial peptides, magainin 2 and indolicidin. | Interactions of two antimicrobial peptides, magainin 2 and indolicidin, with three different model biomembranes, namely, monolayers, large unilamellar vesicles (LUVs), and giant liposomes, were studied. Insertion of both peptides into lipid monolayers was progressively enhanced when the content of an acidic phospholipi... |
11606298 | A simple model for gene targeting. | Sequence-specific binding to genomic-size DNA sequences by artificial agents is of major interest for the development of gene-targeting strategies, gene-diagnostic applications, and biotechnical tools. The binding of one such agent, peptide nucleic acid (PNA), to a randomized human genome has been modeled with statisti... |
11606286 | Lipid membrane reorganization induced by chemical recognition. | Nanoscale structural reorganization of a lipid bilayer membrane induced by a chemical recognition event has been imaged using in situ atomic force microscopy (AFM). Supported lipid bilayers, composed of distearylphosphatidylcholine (DSPC) and a synthetic lipid functionalized with a Cu(2+) receptor, phase-separate into ... |
11606281 | Mapping the energy surface of transmembrane helix-helix interactions. | Transmembrane helices are no longer believed to be just hydrophobic segments that exist solely to anchor proteins to a lipid bilayer, but rather they appear to have the capacity to specify function and structure. Specific interactions take place between hydrophobic segments within the lipid bilayer whereby subtle mutat... |
11606269 | T-cell activation by soluble MHC oligomers can be described by a two-parameter binding model. | T-cell activation is essential for initiation and control of immune system function. T cells are activated by interaction of cell-surface antigen receptors with major histocompatibility complex (MHC) proteins on the surface of other cells. Studies using soluble oligomers of MHC-peptide complexes and other types of rece... |
11604544 | Distance mapping of protein-binding sites using spin-labeled oligosaccharide ligands. | The binding of a nitroxide spin-labeled analog of N-acetyllactosamine to galectin-3, a mammalian lectin of 26 kD size, is studied to map the binding sites of this small oligosaccharide on the protein surface. Perturbation of intensities of cross-peaks in the (15)N heteronuclear single quantum coherence (HSQC) spectrum ... |
11604535 | Insights into the alkaline transformation of ferricytochrome c from (1)H NMR studies in 30% acetonitrile-water. | Recently, we found that ferricytochrome c (ferricyt c) undergoes significant structural changes in mixed aqueous-nonaqueous media, resulting in the formation of a mixture of alkaline-like species. The equilibrium composition of this mixture of species is dependent on the dielectric constant of the mixed solvent medium.... |
11604523 | Reconstitution of a native-like SH2 domain from disordered peptide fragments examined by multidimensional heteronuclear NMR. | The N-terminal SH2 domain from the p85alpha subunit of phosphatidylinositol 3' kinase is cleaved specifically into 9- and 5-kD fragments by limited proteolytic digestion with trypsin. The noncovalent SH2 domain complex and its constituent tryptic peptides have been investigated using high-resolution heteronuclear magne... |
11604508 | Mitochondrially associated hepatitis B virus X protein constitutively activates transcription factors STAT-3 and NF-kappa B via oxidative stress. | The hepatitis B virus X protein (HBx) plays essential roles in viral replication and the generation of hepatocellular carcinoma. In spite of a large number of suggestive cellular targets and functions, a clear picture of its mechanism(s) of action has remained elusive. In this report, we continue to characterize its re... |
11604499 | Role of an ING1 growth regulator in transcriptional activation and targeted histone acetylation by the NuA4 complex. | The yeast NuA4 complex is a histone H4 and H2A acetyltransferase involved in transcription regulation and essential for cell cycle progression. We identify here a novel subunit of the complex, Yng2p, a plant homeodomain (PHD)-finger protein homologous to human p33/ING1, which has tumor suppressor activity and is essent... |
11602312 | Manipulating redox systems: application to nanotechnology. | Redox proteins and enzymes are attractive targets for nanobiotechnology. The theoretical framework of biological electron transfer is increasingly well-understood, and several properties make redox centres good systems for exploitation: many can be detected both electrochemically and optically; they can perform specifi... |
11602750 | Human T-cell leukemia virus type 1 Tax protein binds to assembled nuclear proteasomes and enhances their proteolytic activity. | The human T-cell leukemia virus type 1 (HTLV-1) Tax protein activates the HTLV-1 long terminal repeat and key regulatory proteins involved in inflammation, activation, and proliferation and may induce cell transformation. Tax is also the immunodominant target antigen for cytotoxic T cells in HTLV-1 infection. We found ... |
11602744 | Structure and assembly of intracellular mature vaccinia virus: isolated-particle analysis. | In a series of papers, we have provided evidence that during its assembly vaccinia virus is enveloped by a membrane cisterna that originates from a specialized, virally modified, smooth-membraned domain of the endoplasmic reticulum (ER). Recently, however, Hollinshead et al. (M. Hollinshead, A. Vanderplasschen, G. I. S... |
11602728 | Caveolae are involved in the trafficking of mouse polyomavirus virions and artificial VP1 pseudocapsids toward cell nuclei. | Electron and confocal microscopy were used to observe the entry and the movement of polyomavirus virions and artificial virus-like particles (VP1 pseudocapsids) in mouse fibroblasts and epithelial cells. No visible differences in adsorption and internalization of virions and VP1 pseudocapsids ("empty" or containing DNA... |
11602723 | C terminus of infectious bursal disease virus major capsid protein VP2 is involved in definition of the T number for capsid assembly. | Infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is a double-stranded RNA virus. The IBDV capsid is formed by two major structural proteins, VP2 and VP3, which assemble to form a T=13 markedly nonspherical capsid. During viral infection, VP2 is initially synthesized as a precursor, called VP... |
11602705 | A short sequence within domain C of duck carboxypeptidase D is critical for duck hepatitis B virus binding and determines host specificity. | Virus-cell surface receptor interactions are of major interest. Hepadnaviruses are a family of partially double-stranded DNA viruses with liver tropism and a narrow host range of susceptibility to infection. At least in the case of duck hepatitis B virus (DHBV), host specificity seems controlled partly at the receptor ... |
11602700 | The replicator of the Epstein-Barr virus latent cycle origin of DNA replication, oriP, is composed of multiple functional elements. | Replication of the Epstein-Barr virus genome initiates at one of several sites in latently infected, dividing cells. One of these replication origins is close to the viral DNA maintenance element, and, together, this replication origin and the maintenance element are referred to as oriP. The replicator of oriP contains... |
11602792 | Chimeric papillomavirus-like particles expressing a foreign epitope on capsid surface loops. | Neutralization capsid epitopes are important determinants for antibody-mediated immune protection against papillomavirus (PV) infection and induced disease. Chimeric L1 major capsid proteins of the human PV type 16 (HPV-16) and the bovine PV type 1 (BPV-1) with a foreign peptide incorporated into several capsid surface... |
11599019 | QSAR: hydropathic analysis of inhibitors of the p53-mdm2 interaction. | To date, a number of p53-derived peptides have been evaluated in vitro for their ability to inhibit the carcinogenic p53-mdm2 interaction. Design of second-generation nonpeptidic compounds requires the reduction of large peptide structures down to small molecules maintaining the proper spatial arrangement of key functi... |
11598074 | A 60-kilodalton immunodominant glycoprotein is essential for cell wall integrity and the maintenance of cell shape in Streptococcus mutans. | We have demonstrated previously by Western blotting that in naturally sensitized humans, the serum or salivary antibody response to Streptococcus mutans was directed predominantly to a protein antigen with a size of approximately 60-kDa. To identify this immunodominant antigen, specific serum antibodies were eluted fro... |
11598055 | Bordetella pertussis autoregulates pertussis toxin production through the metabolism of cysteine. | Pertussis toxin (Ptx) expression and secretion in Bordetella pertussis are regulated by a two-component signal transduction system encoded by the bvg regulatory locus. However, it is not known whether the metabolic pathways and growth state of the bacterium influence synthesis and secretion of Ptx and other virulence f... |
11598027 | Identification of an antigenic epitope in Helicobacter pylori urease that induces neutralizing antibody production. | We previously reported a mouse monoclonal antibody (MAb), termed L2, specific for Helicobacter pylori urease strongly inhibited its enzymatic activity. Here, to gain insight into how this antibody affects urease activity, the epitope that was recognized by the antibody was determined. By screening a panel of overlappin... |
11598024 | Enteropathogenic Escherichia coli virulence factor bundle-forming pilus has a binding specificity for phosphatidylethanolamine. | The bundle-forming pilus (BFP) of enteropathogenic Escherichia coli (EPEC), an established virulence factor encoded on the EPEC adherence factor (EAF) plasmid, has been implicated in the formation of bacterial autoaggregates and in the localized adherence of EPEC to cultured epithelial cells. While understanding of the... |
11598879 | Heat-induced formation of a specific binding site for self-assembled Congo Red in the V domain of immunoglobulin L chain lambda. | Moderate heating (40-50 degrees C) of immunoglobulins makes them accessible for binding with Congo Red and some related highly associated dyes. The binding is specific and involves supramolecular dye ligands presenting ribbon-like micellar bodies. The L chain lambda dimer, which upon heating disclosed the same binding ... |
11598874 | Site-specific examination of secondary structure and orientation determination in membrane proteins: the peptidic (13)C=(18)O group as a novel infrared probe. | Detailed site-specific information can be exceptionally useful in structural studies of macromolecules in general and proteins in particular. Such information is usually obtained from spectroscopic studies using a label/probe that can reflect on particular properties of the protein. A suitable probe must not modify the... |
11597461 | Synthesis, DNA cleavage, and cytotoxicity of a series of bis(propargylic) sulfone crown ethers. | Compounds that couple molecular recognition of specific alkali metal ions with DNA damage may display selective cleavage of DNA under conditions of elevated alkali metal ion levels reported to exist in certain cancer cells. We have prepared a homologous series of compounds in which a DNA reactive moiety, a bis(propargy... |
11587837 | Evaluation of beta-cyclodextrin against natural infections of cryptosporidiosis in calves. | The effectiveness of beta-cyclodextrin, excipient used in pharmaceutical industry, in the treatment of natural infection by Cryptosporidium parvum in suckling calves, was evaluated. Administration of the drug at a dose of 500 mg/kg body weight for 3 consecutive days from birth (prophylactically) or following confirmati... |
11585930 | The HOX homeodomain proteins block CBP histone acetyltransferase activity. | Despite the identification of PBC proteins as cofactors that provide DNA affinity and binding specificity for the HOX homeodomain proteins, HOX proteins do not demonstrate robust activity in transient-transcription assays and few authentic downstream targets have been identified for these putative transcription factors... |
11581375 | A novel CD8-independent high-avidity cytotoxic T-lymphocyte response directed against an epitope in the phosphoprotein of the paramyxovirus simian virus 5. | Adoptive transfer studies have shown that cytotoxic T lymphocytes (CTL) of high avidity, capable of recognizing low levels of peptide-MHC I molecules, are more efficient at reducing viral titers than are low-avidity CTL, thus establishing CTL avidity as a critical parameter for the ability of a CTL to clear virus in vi... |
11562281 | Peptide-binding G protein-coupled receptors: new opportunities for drug design. | Over the last decades distinct members of the G Protein-Coupled Receptor (GPCR) family emerged as prominent drug targets within pharmaceutical research, since approximately 60 % of marketed prescription drugs act by selectively addressing representatives of that class of transmembrane signal transduction systems. It is... |
11689561 | CD38 is associated with lipid rafts and upon receptor stimulation leads to Akt/protein kinase B and Erk activation in the absence of the CD3-zeta immune receptor tyrosine-based activation motifs. | T lymphocytes can be activated via the T cell receptor (TCR) or by triggering through a number of other cell surface structures, including the CD38 co-receptor molecule. Here, we show that in TCR+ T cells that express a CD3-zeta lacking the cytoplasmic domain, cross-linking with CD38- or CD3-specific monoclonal antibod... |
11687650 | Enzyme interactions in heparan sulfate biosynthesis: uronosyl 5-epimerase and 2-O-sulfotransferase interact in vivo. | The formation of heparan sulfate occurs within the lumen of the endoplasmic reticulum-Golgi complex-trans-Golgi network by the concerted action of several glycosyltransferases, an epimerase, and multiple sulfotransferases. In this report, we have examined the location and interaction of tagged forms of five of the bios... |
11687628 | Surface molecular recognition. | The spatial display of cellular ligands and receptors is important for cell adhesion and communication. Two approaches that emphasize developing selective methods to dissect, modify, and control receptor-ligand interactions at the cellular interface are discussed. |
11687622 | The plant oncogene rolD encodes a functional ornithine cyclodeaminase. | The plant oncogene rolD stimulates the reproductive phase transition in plants. We define here the function of its gene product. We show that the RolD protein bears sequence homology with ornithine cyclodeaminase, an uncommon enzyme of specialized-niche eubacteria and archaea that catalyzes the unusual NAD(+)-dependent... |
11684706 | MyoD-positive myoblasts are present in mature fetal organs lacking skeletal muscle. | The epiblast of the chick embryo gives rise to the ectoderm, mesoderm, and endoderm during gastrulation. Previous studies revealed that MyoD-positive cells were present throughout the epiblast, suggesting that skeletal muscle precursors would become incorporated into all three germ layers. The focus of the present stud... |
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