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12423952 | Three-dimensional structure of the inclusion complex between phloridzin and beta-cyclodextrin. | The inclusion of phloridzin into beta-cyclodextrin was studied as a model of molecular recognition in membranes. Effects on 1H NMR spectra and NOE correlational peaks between phloridzin and beta-cyclodextrin were observed in the complex. Strong NOEs were observed between hydrogens of a phenol group in phloridzin and be... |
12423967 | Interaction of lead(II) with beta-cyclodextrin in alkaline solutions. | Polarographic and UV-spectrophotometric investigations of Pb(II) complex formation with beta-cyclodextrin have showed that the complexation of Pb(II) ions begins at pH >10. The formation of lead(II) 1:1 complex with the beta-cyclodextrin anion was observed at pH 10-11.5. The logarithm of the stability constant of this ... |
12421119 | Charge transfer fluorescent probes using boronic acids for monosaccharide signaling. | We have developed a new series of glucose sensitive fluorophores that display shifts in emission wavelengths and/or intensity change upon the binding of monosaccharides. Complexation of glucose with the boronic acid moiety changes both its orbital hybridization and its ability to accept and donate electrons. This chang... |
12412115 | A hybrid microdevice for electrophoresis and electrochromatography using UV detection. | We have designed a new class of microdevices composed of a supporting plastic (polyvinyl chloride, PVC) plate integrated with a groove for a piece of fused silica capillary (the separation channel), a slit for on-tube detection, an "islet" for the application of sample, electrode vessels and platinum electrodes. The de... |
12406216 | Domains in the S-layer protein CbsA of Lactobacillus crispatus involved in adherence to collagens, laminin and lipoteichoic acids and in self-assembly. | The protein regions in the S-layer protein CbsA of Lactobacillus crispatus JCM 5810, needed for binding to collagens and laminin, anchoring to bacterial cell wall, as well as self-assembly, were mapped by deletion analysis of His-tagged peptides isolated from Escherichia coli and by heterologous expression on Lactobaci... |
12406591 | Anisotropy decay study on the host-guest interaction of distally dialkylated calix[4]arenes with 1-chloro-4-(trifluoromethyl)benzene. | The 'host' properties of distally dialkylated calix[4]arenes and 4-tert-butylcalix[4]arenes in the presence of 1-chloro-4-(trifluoromethyl)benzene (BFT) were studied in chloroform solvent by intensity-independent spectrofluorometric method. The anisotropy decay experiments were found as suitable method to indicate the ... |
12406583 | Chiral separation of bioactive cyclic Mannich ketones by HPLC and CE using cellulose derivatives and cyclodextrins as chiral selectors. | The chiral separation of cyclic Mannich ketones of potential pharmaceutical interest is investigated using HPLC and CE. These Mannich ketones show a marked antibacterial and antifungal activity. In HPLC, stationary phases containing cellulose derivatives or beta-cyclodextrin were used and in CE different cyclodextrins,... |
12403603 | Comprehensive two-dimensional gas chromatography with fast enantioseparation. | The development of fast chiral analysis for use in comprehensive two-dimensional gas chromatography in which a short second dimension enantioselective capillary column provides a route to precise measurement of chiral ratios of enantiomers is described. Retention times as short as 8 s are reported for (+/-)-limonene, w... |
12403590 | Determination of binding constants of cyclodextrins in room-temperature ionic liquids by near-infrared spectrometry. | Near-infrared spectrometry has been successfully used to determine association binding constants between phenol and alpha-, beta- and gamma-cyclodextrin (CD) in [butylmethylimidazolium][chloride] room-temperature ionic liquid (RTIL). It was found that adding CD into the RTIL solution of phenol resulted in an enhancemen... |
12403463 | A biosensor for theophylline based on fluorescence detection of ligand-induced hammerhead ribozyme cleavage. | Recently, Breaker and coworkers engineered hammerhead ribozymes that rearrange from a catalytically inactive to an active conformation upon allosteric binding of a specific ligand. To monitor cleavage activity in real time, we have coupled a donor-acceptor fluorophore pair to the termini of the substrate RNA of such a ... |
12403461 | tRNomics: analysis of tRNA genes from 50 genomes of Eukarya, Archaea, and Bacteria reveals anticodon-sparing strategies and domain-specific features. | From 50 genomes of the three domains of life (7 eukarya, 13 archaea, and 30 bacteria), we extracted, analyzed, and compared over 4,000 sequences corresponding to cytoplasmic, nonorganellar tRNAs. For each genome, the complete set of tRNAs required to read the 61 sense codons was identified, which permitted revelation o... |
12400160 | [Creation of new supramolecular chemistry based on multiple interaction in aqueous solution]. | Novel supramolecular chemistry of multinuclear zinc(II) complexes in aqueous solution has been created by utilizing multiple interactions with polyanions. We have established reliable and convenient synthetic methods of multidentate macrocyclic polyamines and their zinc(II) complexes and thereby undertook a focused inv... |
12400159 | [Analysis of molecular mechanism of cancer cell differentiation and apoptosis induced by vitamin D3 analogs on the basis of molecular recognition of vitamin D receptor ligand binding domain]. | 1 alpha,25-Dihydroxyvitamin D3 [1 alpha,25 (OH)2D3] has antiproliferative, differentiation and apoptosis-inducing effects on many malignant cells. These properties have raised the possibility of its use as a therapeutic agent in cancer. Our recent studies using stereoisomers of the A-ring of monohydroxylated 19-nor or ... |
12388761 | EB1-microtubule interactions in Xenopus egg extracts: role of EB1 in microtubule stabilization and mechanisms of targeting to microtubules. | EB1 targets to polymerizing microtubule ends, where it is favorably positioned to regulate microtubule polymerization and confer molecular recognition of the microtubule end. In this study, we focus on two aspects of the EB1-microtubule interaction: regulation of microtubule dynamics by EB1 and the mechanism of EB1 ass... |
12397995 | Gels with exceptional thermal stability formed by bis(amino acid) oxalamide gelators and solvents of low polarity. | Some bis (amino acid) oxalamide gelators form common thermo-reversible gels with various organic solvents but also gels of exceptional thermal stability with some solvents of medium and low polarity; the latter gels can be heated up to 50 degrees C higher temperatures than the bp of the solvent without apparent gel-to-... |
12397991 | New supramolecular organization for a glycoluril: chiral hydrogen-bonded ribbons. | A series of substituted glycoluril molecules exhibits a substantial twist of the fused five-membered rings and assembles exclusively chiral hydrogen-bonded ribbons in the solid-state. |
12397985 | Capture of di-protonated [2.2.2]cryptand in the cavity of two p-sulfonated calixarenes as part of 2-D bi-layer lanthanide coordination polymers. | Treating p-sulfonatocalix[4]arene with lanthanide ions, Ln3+ (Ln = Ce, Nd, Sm and Eu), in the presence of [2.2.2]cryptand results in a 2-D bi-layer coordination polymer with axially elongated diprotonated cryptand in the cavity of two p-sulfonatocalix[4]arenes. |
12397977 | Novel crystalline supramolecular assemblies of amorphous polypyrrole nanoparticles through surfactant templating. | A lamellar-structured crystalline polypyrrole (PPy) supramolecular assembly was prepared by surfactant templating, and the regularly linked amorphous PPy nanoparticles with tunable window sizes could play the role of crystalline lattices in the supramolecular assembly. |
12397975 | Cyclic molecular materials based on [M2O2S2]2+ cores (M = Mo or W). | The purpose of this article is to illustrate how conventional precursors can serve, when used with a drop of imagination, to the synthesis of sophisticated inorganic rings and wheels. The self-condensation of the [M2O2S2]2+ fragments under acido-basic process produces, in the presence or absence of guest species, linea... |
12396049 | The fluorescence study of the inclusion coordinated compound of beta-cyclodextrin and p-hydroxyphenolacetamide and its analytical applications. | The inclusion coordinated compound fluorescence of p-hydroxyphenolacetamide (PHPA) with beta-cyclodextrin was studied and a high sensitive analytical method to determine the content of PHPA was established based on the increased fluorescence intensity of the coordinated compounds in Britton-Robinson buffer solution (pH... |
12395927 | Crystal structures of alpha-helical cytokine-receptor complexes: we've only scratched the surface. | Crystal structure analysis of alpha-helical cytokine-receptor complexes has provided numerous insights into the molecular recognition events that initiate essential cellular responses. Three-dimensional structure information gleaned from crystallographic studies has been used to understand the signal transduction proce... |
12392429 | Selective interaction of lower rim calix[4]arene derivatives and bivalent cations in solution. Crystallographic evidence of the versatile behavior of acetonitrile in lead(II) and cadmium(II) complexes. | The interaction of lower rim calix(4)arene derivatives containing ester (1) and ketone (2) functional groups and bivalent (alkaline-earth, transition- and heavy-metal) cations has been investigated in various solvents (methanol, N,N-dimethylformamide, acetonitrile, and benzonitrile). Thus, 1H NMR studies in CD3OD, C3D7... |
12392426 | Theoretical study of anion binding to calix[4]pyrrole: the effects of solvent, fluorine substitution, cosolute, and water traces. | The binding of different anions to calix[4]pyrrole has been studied by means of molecular dynamics coupled to thermodynamic integration calculations. The effect of different apolar solvents, octafluoro substitution, and the change in binding free energy derived from the presence of cosolute and water traces (the hydrat... |
12392425 | Photoinduced electron transfer in a triad that can be assembled/disassembled by two different external inputs. Toward molecular-level electrical extension cables. | We have designed, synthesized, and investigated a self-assembling supramolecular system which mimics, at a molecular level, the function performed by a macroscopic electrical extension cable. The system is made up of three components, 12+, 2-H3+, and 3. Component 12+ consists of two moieties: a [Ru(bpy)3]2+ unit, which... |
12392412 | Electrochemically driven formation of a molecular capsule around the ferrocenium ion. | Electrochemical experiments were used to show that the oxidation of ferrocene triggers the self-assembly of six molecules of the resocin[4]arene 2 to form a molecular capsule around the oxidized, ferrocenium (+1) form. The nature of the supporting electrolyte anion is crucial for this process of electrochemically drive... |
12392395 | Metal switch for amyloid formation: insight into the structure of the nucleus. | The role of Zn2+ in pre-organizing Abeta(10-21) amyloid formation is shown to preferentially alter the relative rate of fibril nucleation and to have little influence on fibril propagation. Fibril morphology, as determined by small angle neutron scattering (SANS) and transmission electron microscopy (TEM), was unchange... |
12394951 | Coagulation/fibrinolysis abnormality and vascular endothelial damage in the pathogenesis of thrombocytopenic multiple organ failure. | <h4>Objective</h4>Until recently, attention has been directed to disseminated intravascular coagulation as a cause of multiple organ failure (MOF). On the other hand, it has now become clear that humoral mediators play important roles in the pathogenesis of MOF. Therefore, we performed the present study in patients wit... |
12391017 | Localization of the adhesion receptor glycoprotein Ib-IX-V complex to lipid rafts is required for platelet adhesion and activation. | The platelet glycoprotein (GP) Ib-IX-V complex mediates the attachment of platelets to the blood vessel wall by binding von Willebrand factor (VWF), an interaction that also transmits signals for platelet activation and aggregation. Because the complex is extensively palmitoylated, a modification known to target protei... |
12390014 | Detecting protein kinase recognition modes of calmodulin by residual dipolar couplings in solution NMR. | Calmodulin-regulated serine/threonine kinases (CaM kinases) play crucial roles in Ca2+-dependent signaling transduction pathways in eukaryotes. Despite having a similar overall molecular architecture of catalytic and regulatory domains, CaM kinases employ different binding modes for Ca2+/CaM recruitment which is requir... |
12388603 | Synaptic localization of nitric oxide synthase and soluble guanylyl cyclase in the hippocampus. | Functional evidence suggests that nitric oxide released from CA1 pyramidal cells can act as a retrograde messenger to mediate hippocampal long-term potentiation, but the failure to find neuronal nitric oxide synthase (NOS-I) in the dendritic spines of these cells has cast doubt on this suggestion. We hypothesized that ... |
12388596 | Rapsyn escorts the nicotinic acetylcholine receptor along the exocytic pathway via association with lipid rafts. | The 43 kDa receptor-associated protein rapsyn is a myristoylated peripheral protein that plays a central role in nicotinic acetylcholine receptor (AChR) clustering at the neuromuscular junction. In a previous study, we demonstrated that rapsyn is specifically cotransported with AChR via post-Golgi vesicles targeted to ... |
12386330 | Self-assembly of highly phosphorylated silaffins and their function in biosilica morphogenesis. | Silaffins are uniquely modified peptides that have been implicated in the biogenesis of diatom biosilica. A method that avoids the harsh anhydrous hydrogen fluoride treatment commonly used to dissolve biosilica allows the extraction of silaffins in their native state. The native silaffins carry further posttranslationa... |
12385799 | Acute effects of corticosterone on LiCl-induced rapid gustatory conditioning in rats: a microstructural analysis of licking patterns. | Acute administration of corticosterone (Cort) has been shown to potentiate a variety of learning processes. Here, the effects of Cort on rapid gustatory conditioning were examined using a lick monitoring system. Over a 3-day period, animals were given intraperitoneal (ip) injections of either a low dose of lithium chlo... |
12384307 | Self-assembly of block copolymers derived from elastin-mimetic polypeptide sequences. | Protein polymers derived from elastin-mimetic peptide sequences can be synthesized with near-absolute control of macromolecular architecture using genetic engineering techniques. Elastin-mimetic diblock and triblock copolymers have been prepared using this approach in which the individual elastin blocks display differe... |
12381188 | Anion-templated rotaxane formation. | The development of an acyclic chloride anion template in which the chloride anion is coordinatively unsaturated and available for subsequent complexation to various hydrogen bond donating components is described. This template orients a neutral hydrogen bond donating ligand and a pyridinium cation orthogonally to one a... |
12381169 | A new class of hybrid materials via salt inclusion: novel copper(II) arsenates Na(5)ACu(4)(AsO(4))(4)Cl(2) (A = Rb, Cs) composed of alternating covalent and ionic lattices. | Two novel copper(II) arsenates Na5ACu4(AsO4)4Cl2 (A = Rb, Cs) were synthesized by conventional solid-state methods using reactive molten salt media. These compounds are isostructural and crystallize in an orthorhombic lattice (Fmmm, No. 69; Z = 8). The cell constants are a = 14.632(3) A, b = 18.872(2) A, c = 14.445(3) ... |
12381361 | Identification of amino acid residues participating in intermolecular salt bridges between self-associating proteins. | Salt bridges between self-associating hen egg white (HEW) lysozyme and bovine insulin molecules were converted to covalent links by ethanedinitrile (cyanogen) and identified using mass spectrometry. Peptides resulting from cyanogen-mediated intermolecular cross-linking of HEW lysozyme were detected using in-gel digesti... |
12380841 | Quenched phosphorescence detection in cyclodextrin-based electrokinetic chromatography. | Quenched phosphorescence detection is a sensitive detection method recently introduced in capillary zone electrophoresis. It is based on the dynamic quenching interaction of the analytes (quenchers) with a phosphorophore, 1-bromo-4-naphthalenesulfonate (BrNS), present in the separation buffer. In this study, it is show... |
12380652 | AFM structural study of the molecular chaperone GroEL and its two-dimensional crystals: an ideal "living" calibration sample. | Supramolecular complexes, such as chaperonins, are suitable samples for atomic force microscope structural studies because they have a very well defined shape. High-resolution images can be made using tapping mode in liquid under native conditions. Details about the two-dimensional structures formed onto the surface up... |
12379107 | Evidence for a plasma membrane-mediated permeability barrier to Tat basic domain in well-differentiated epithelial cells: lack of correlation with heparan sulfate. | Membrane permeation peptides, such as Tat basic domain, have emerged as useful membrane transduction agents with potential utility in therapeutic delivery and diagnostic imaging. While generally thought to universally permeate all cells by a nonselective process, the mechanism of membrane transduction remains poorly ch... |
12379102 | Insights into channel architecture and substrate specificity from crystal structures of two macrocycle-forming thioesterases of modular polyketide synthases. | Modular polyketide synthases (PKSs) synthesize the polyketide cores of pharmacologically important natural products such as erythromycin and picromycin. Understanding PKSs at high resolution could present new opportunities for chemoenzymatic synthesis of complex molecules. The crystal structures of macrocycle-forming t... |
12378646 | A ten-year study on non-surgical treatment of postoperative bile leakage. | <h4>Aim</h4>To summarize systematically our ten-year experience in non-surgical treatment of postoperative bile leakage, and explore its methods and indications.<h4>Methods</h4>The clinical data of 57 patients with postoperative bile leakage treated non-surgically from January 1991 to December 2000 were reviewed retros... |
12378641 | Synthesis of an enzyme-dependent prodrug and evaluation of its potential for colon targeting. | <h4>Aim</h4>To synthesize dexamethasone-succinate-dextran (DSD) conjugate and to evaluate the potentiality of DSD for the treatment of inflammatory bowel diseases.<h4>Methods</h4>Dexamethasone was attached to dextran (average molecular weight=70,400 Dalton) using succinate anhydride in an anhydrous environment catalyze... |
12377030 | New oxamato-bridged trinuclear Cu(II)-Cu(II)-Cu(II) complexes with hydrogen-bond supramolecular structures: synthesis and magneto-structural studies. | Three oxamato-bridged copper(II) complexes of formula [(Cu(H(2)O)(tmen)Cu(tmen))(mu-Cu(H(2)O)(Me(2)pba))](n)((PF(6))(2))(n).2nH(2)O (1), [(Cu(H(2)O)(tmen)Cu(NCS)(tmen))(mu-Cu(H(2)O)(Me(2)pba))](2)(ClO(4))(2).4H(2)O (2), and [(Cu(H(2)O)(tmen)Cu(NCS)(tmen))(mu-Cu(H(2)O)(Me(2)pba))](2)(PF(6))(2).4H(2)O (3), where Me(2)pba... |
12377024 | Luminescence enhancement induced by aggregation of alkoxy-bridged rhenium(I) molecular rectangles. | Self-assembly of rhenium(I)-based molecular rectangles containing long alkyl chains has been achieved in one-pot synthesis by solvothermal methods. An enormous enhancement in the emission intensity, quantum yield, and lifetime of the rectangles has been observed when the solvent medium is changed from organic to aqueou... |
12377363 | Differential effects of cholesterol on acyl chain order in erythrocyte membranes as a function of depth from the surface. An electron paramagnetic resonance (EPR) spin label study. | The purpose of this work is to analyze the effects of cholesterol modulation on acyl chain ordering in the membrane of human erythrocytes as a function of depth from the surface. Partial cholesterol depletion was achieved by incubation of erythrocytes with liposomes containing saturated phospholipids, or with methyl-be... |
12375935 | Functional group diversity in dendrimers. | [structure: see text] A methodology for synthesizing dendrons with different peripheral functionalities is described. The benzyl ether-based dendrons reported here were synthesized using allyl and methoxymethyl ether-based protection-deprotection strategies. |
12375898 | New insight into the synthesis of a novel azo-based optically active polyamidoamine side chain dendritic polyester architectural photoswitch. | [reaction: see text] A novel chiral polyamidoamine side chain dendritic polyester 4 has been synthesized and found to be a photoresponsive system undergoing reversible E/Z photochemical/thermal isomerization of azo units. Thorough characterization (IR,UV-vis, NMR, FAB-MS, elemental analysis, optical rotation, etc.) wer... |
12375888 | Self-assembly of dendrimers by slippage. | [reaction: see text] A dendrimer with rotaxane-like characteristics has been assembled under thermodynamic control from complementary wedge-shaped precursors by slippage in CH(2)Cl(2). The driving force for the self-assembly process is the molecular recognition that exists as a result of [N(+)-H.O] and [C-H.O] hydrogen... |
12375887 | Translational isomerism in a [3]catenane and a [3]rotaxane. | [structure: see text] Post-assembly covalent modification using Wittig chemistry of [2]rotaxane ylides, wherein NH(2)(+) centers in the dumbbell-shaped components are recognized by dibenzo[24]crown-8 (DB24C8) rings, has afforded a [3]catenane and a [3]rotaxane with a precise and synthetically prescribed shortage of DB2... |
12376001 | Calix[4]- and calix[5]arene-based multicavity macrocycles. | Synthesis and single-crystal X-ray structures of mixed triple and double calixarenes 6 and 7, obtained from the base-catalyzed condensation of calix[5]arene 1 with cone pertosylated calix[4]arene 2, are reported. VT-NMR studies on 7 are consistent with a molecular motion arising from the anti-gauche conformational inte... |
12375987 | Syntheses of chiral homoazacalix[4]arenes incorporating amino acid residues: molecular recognition for racemic quaternary ammonium ions. | Chiral calixarene analogues incorporating amino acid residues into the macrocyclic rings were prepared from the cyclization reactions of bis(chloromethyl)phenol-formaldehyde tetramer with amino acid methyl ester in moderate yields. The macrocycles form a chiral concavity, which is induced by the chiral transmission fro... |
12375963 | Solid-state molecular folding and supramolecular structures of triptycene-derived secondary dicarboxamides. | The synthesis and X-ray crystal structures of triptycene-derived secondary dicarboxamides 1 and 4-7 and reference compounds 2, 3, and 8 are reported. For comparison, molecular conformations of 1-8 in the gas phase and those of 1 and 3-6 in CD2Cl2 investigated by AM1 modeling and 1H NMR spectroscopy, respectively, are a... |
12375962 | Synthesis and electronic properties of regioisomerically pure oxochlorins. | We describe a two-step conversion of C-alkylated zinc chlorins to zinc oxochlorins wherein the keto group is located in the reduced ring (17-position) of the macrocycle. The transformation proceeds by hydroxylation upon exposure to alumina followed by dehydrogenation with DDQ. The reactions are compatible with ethyne, ... |
12374775 | Plasma membrane cholesterol controls the cytotoxicity of Alzheimer's disease AbetaP (1-40) and (1-42) peptides. | Cell degeneration in Alzheimer's disease is mediated by a toxic mechanism that involves interaction of the AbetaP peptide with the plasma membrane of the target cell. We report here that PC12 cells become resistant to the cytotoxic action of AbetaP when incubated in a medium that enriches cholesterol levels of the surf... |
12371880 | Solvent and guest isotope effects on complexation thermodynamics of alpha-, beta-, and 6-amino-6-deoxy-beta-cyclodextrins. | The stability constant (K), standard free energy (DeltaG degrees ), enthalpy (DeltaH degrees ), and entropy changes (TDeltaS degrees ) for the complexation of native alpha- and beta-cyclodextrins (CDs) and 6-amino-6-deoxy-beta-CD with more than 30 neutral, positively, and negatively charged guests, including seven full... |
12371873 | Mesostructured gamma-Al(2)O(3) with a lathlike framework morphology. | A novel three-step assembly pathway is reported for the formation of a mesostructured alumina with framework pore walls made of crystalline, lathlike gamma-Al(2)O(3) nanoparticles. In the initial supramolecular assembly step of the pathway a mesostructured alumina with a wormhole framework morphology and amorphous pore... |
12371854 | Solution NMR techniques for large molecular and supramolecular structures. | Transverse relaxation-optimized spectroscopy (TROSY) or generation of heteronuclear multiple quantum coherences during the frequency labeling period and TROSY during the acquisition period have been combined either with cross-correlated relaxation-induced polarization transfer (CRIPT) or cross-correlated relaxation-enh... |
12371835 | A supramolecular oscillator composed of carbon nanocluster C(120) and a rhodium(III) porphyrin cyclic dimer. | A rhodium(III) porphyrin cyclic dimer (1) included carbon nanocluster C120 (2) to form a pi-electronic supramolecular complex (1 superset2), in which 2 oscillated back and forth within its cavity. Spectroscopic titration of 1 with 2 and line shape analysis on variable-temperature 1H NMR spectral profiles of 1 superset2... |
12372346 | Caveolin-1 phosphorylation in human squamous and epidermoid carcinoma cells: dependence on ErbB1 expression and Src activation. | Previous studies have shown that EGF can induce the tyrosine phosphorylation of caveolin-1 in murine fibroblasts following ErbB1 (EGF receptor) mutation or overexpression, but the cell signaling events linking EGF action with caveolin phosphorylation are not fully established. In this regard, we examined multiple human... |
12372294 | Structures of SET domain proteins: protein lysine methyltransferases make their mark. | Proteins bearing the widely distributed SET domain have been shown to methylate lysine residues in histones and other proteins. In this issue, three-dimensional structures are reported for three very different SET domain-containing proteins. The structures reveal novel folds for several new domains, including SET, and ... |
12370024 | Protein structure to function via dynamics. | Protein folding, binding, catalytic activity and molecular recognition all involve molecular movements, with varying extents. The molecular movements are brought upon via flexible regions. Stemming from sequence, a fine tuning of electrostatic and hydrophobic properties of the protein fold determine flexible and rigid ... |
12370048 | SRC homology-2 inhibitors: peptidomimetic and nonpeptide. | The structural and functional characterization of Src homology-2 (SH2) domains and their relationship to catalytic proteins (e.g., kinases, phosphatases, and lipases) or non-catalytic proteins (e.g., upstream adapters, and downstream transcription factors) has significantly impacted our understanding of signal transduc... |
12370255 | Interleukin 15 controls both proliferation and survival of a subset of memory-phenotype CD8(+) T cells. | Previous work has shown that memory-phenotype CD44(hi) CD8(+) cells are controlled by a cytokine, interleukin (IL)-15. However, the dependency of CD44(hi) CD8(+) cells on IL-15 is partial rather than complete. Here, evidence is presented that CD44(hi) CD8(+) cells comprise a mixed population of IL-15-dependent and IL-1... |
12369883 | Mechanistic studies of the process of amyloid fibrils formation by the use of peptide fragments and analogues: implications for the design of fibrillization inhibitors. | The process of amyloid fibrils formation is a common mechanism of a large number of unrelated infectious, genetic and spontaneous diseases. A partial list includes the bovine spongiform encephalopathy (BSE), Alzheimer's diseases, Type II diabetes, Creutzfeldt-Jakob disease, and various unrelated amyloidosis diseases. I... |
12367668 | Enantioseparation of vesamicol in human serum by capillary electrophoresis with solid phase extraction and sulfated-beta-cyclodextrin. | An enantioseparation of racemic vesamicol in human serum by capillary electrophoresis with solid phase extraction and sulfated B-cyclodextrin (S-B-CD) is presented The separation was achieved on an uncoated 72 cm x 50 microm id fused silica capillary maintained at 30 degrees C and + 15 kV applied voltage using a run bu... |
12367525 | Identification and characterization of a novel molecular-recognition and self-assembly domain within the islet amyloid polypeptide. | The islet amyloid polypeptide (hIAPP) is a 37 amino acid residue polypeptide that was found to accumulate as amyloid fibrils in the pancreas of individuals with type II diabetes. Previous studies identified various fragments of hIAPP that can form amyloid fibrils in vitro (e.g. hIAPP(8-20), hIAPP(23-27), and hIAPP(30-3... |
12368265 | A widely conserved bacterial cell division protein that promotes assembly of the tubulin-like protein FtsZ. | Cell division in bacteria is mediated by the tubulin-like protein FtsZ, which assembles into a structure known as the Z ring at the future site of cytokinesis. We report the discovery of a Z-ring-associated protein in Bacillus subtilis called ZapA. ZapA was found to colocalize with the Z ring in vivo and was capable of... |
12364614 | MagiProbe: a novel fluorescence quenching-based oligonucleotide probe carrying a fluorophore and an intercalator. | Fluorescence is the favored signaling technology for molecular diagnoses. Fluorescence energy transfer-based methods are powerful homogeneous assay tools. A novel oligonucleotide probe, named MagiProbe, which is simple to use, is described, and information given about the duplex formed with a target. The probe internal... |
12102655 | Binding of C-reactive protein to modified low-density-lipoprotein particles: identification of cholesterol as a novel ligand for C-reactive protein. | C-reactive protein (CRP), an acute-phase reactant, is present in atherosclerotic human arterial intima in association with lipids. In the present work we studied interactions between CRP and LDL on microtitre wells, where either CRP or LDL was immobilized. LDL was modified by vortex-mixing, oxidation, or by lipolysis w... |
12360290 | Activation of the repulsive receptor Roundabout inhibits N-cadherin-mediated cell adhesion. | The formation of axon trajectories requires integration of local adhesive interactions with directional information from attractive and repulsive cues. Here, we show that these two types of information are functionally integrated; activation of the transmembrane receptor Roundabout (Robo) by its ligand, the secreted re... |
12358541 | Porphyrin self-assembly at electrochemical interfaces: role of potential modulated surface mobility. | The self-assembly of 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (TPyP) on Au(111) electrodes was investigated. The adlayer structure was found to depend on the electrode potential. At positive potentials (>0.5V(SCE)), a disordered layer of TPyP is formed on the Au(111) electrode. STM images showed that the disordered... |
12358518 | A FRET-based ultraviolet to near-infrared frequency converter. | The synthesis and photophysical characterization of a generation 1 dendrimer containing four coumarin 2 laser dyes at the periphery and a perylenebis(dicarboximide) derivative at the core are described. It was found that 99% of the UV light absorbed by the peripheral coumarin 2 donor chromophores is transferred through... |
12359625 | Inhibition by acharan sulphate of angiogenesis in experimental inflammation models. | 1. The effects of acharan sulphate, a glycosaminoglycan isolated from the giant African snail Achatina fulica, on angiogenesis in the granulation tissue were analysed using an air pouch-type carrageenin-induced inflammation model in rats and a cotton thread-induced inflammation model in mice. 2. In the carrageenin-indu... |
12359256 | NMR and CD studies on the interaction of Alzheimer beta-amyloid peptide (12-28) with beta-cyclodextrin. | Polymerization of the amyloid beta-peptide (Abeta) has been identified as a major feature of the pathogenesis of Alzheimer's disease (AD). Inhibition of the formation of these toxic polymers of Abeta has emerged as an approach for developing therapeutics for AD. NMR and CD spectra were used to investigate the interacti... |
12359234 | The death-inducing signalling complex is recruited to lipid rafts in Fas-induced apoptosis. | Membrane microdomains known as lipid rafts have been shown recently to be involved in Fas signalling and apoptosis in T and B cell lines. Here, we have investigated further the role of lipid rafts in Fas-induced apoptosis in non-transformed human CD4 T cells. We show that Fas-induced apoptosis in CD4 T cells was inhibi... |
12356827 | Comparison of the enzymatic stability and intraocular pressure effects of 2-arachidonylglycerol and noladin ether, a novel putative endocannabinoid. | <h4>Purpose</h4>The endogenous cannabinoids N-arachidonylethanolamide (AEA) and 2-arachidonylglycerol (2-AG) are known to decrease intraocular pressure (IOP). Recently, a novel putative endogenous cannabinoid, noladin ether, was isolated in porcine and rat brains. In the present study, both the degradation of endogenou... |
12356742 | EcoRII: a restriction enzyme evolving recombination functions? | The restriction endonuclease EcoRII requires the cooperative interaction with two copies of the sequence 5'CCWGG for DNA cleavage. We found by limited proteolysis that EcoRII has a two-domain structure that enables this particular mode of protein-DNA interaction. The C-terminal domain is a new restriction endonuclease,... |
12356725 | Quantitative proteomic analysis of Myc oncoprotein function. | This study applies a new quantitative proteomics technology to the analysis of the function of the Myc oncoprotein in mammalian cells. Employing isotope-coded affinity tag (ICAT) reagent labeling and tandem mass spectrometry, the global pattern of protein expression in rat myc-null cells was compared with that of myc-p... |
12356718 | The human scavenger receptor class B type I is a novel candidate receptor for the hepatitis C virus. | We discovered that the hepatitis C virus (HCV) envelope glycoprotein E2 binds to human hepatoma cell lines independently of the previously proposed HCV receptor CD81. Comparative binding studies using recombinant E2 from the most prevalent 1a and 1b genotypes revealed that E2 recognition by hepatoma cells is independen... |
12354004 | Dimeric self-assembling capsules derived from the highly flexible tribenzylamine skeleton. | Tris(m-ureidobenzyl)amines dimerize both in solid state and in solution to give molecular capsules which are able to encapsulate small molecules. The self-assembly was confirmed by crystal X-ray analysis and NMR spectroscopy. The X-ray structure showed the encapsulation of one molecule of CH(2)Cl(2). This new type of c... |
12353978 | Cyclitol-based metal-complexing agents. Effect of the relative orientation of oxygen atoms in the ionophoric ring on the cation-binding ability of myo-inositol-based crown ethers. | myo-Inositol-derived crown ethers having varying relative orientations (1,3-diaxial, 1,2-diequatorial, and 1,2-axial-equatorial) of the oxygen atoms in the ionophoric ring were synthesized and the extent of their binding with picrates of alkali metals, ammonia, and silver were estimated. These crown ethers bind very we... |
12354075 | A spectroscopic and surface plasmon resonance study of oleic acid/DNA complexes. | The interaction of synthetic polynucleotide double strands with a natural lipid, oleic acid, was examined in diluted aqueous solutions by circular dichroism spectra, UV-absorption measurements, and surface plasmon resonance biosensor investigations. The investigations were performed with defined double and triple stran... |
12354074 | Supramolecular DNA-streptavidin nanocircles with a covalently attached oligonucleotide moiety. | Covalent hybrid conjugates consisting of streptavidin (STV) and a 24-mer single-stranded DNA oligonucleotide have been used as a starting material for the synthesis of supramolecular nanocircles. For this, the covalent hybrid conjugates were oligomerized by cross-linking with 5 ,5 -bis-biotinylated double-stranded DNA ... |
12354065 | X-ray diffraction and (1)H NMR in solution: structural determination of lanthanide complexes of a Py(2)N(6)Ac(4) ligand. | Complexes between the Py(2)N(6)Ac(4) (H(4)L) ligand containing four carboxylate pendant arms and trivalent lanthanide ions have been synthesized, and structural studies have been made both in the solid state and aqueous solution. The crystal structures of the La, Ce, Sm, Tb, Dy, Ho, Er, Tm, and Lu complexes, with chemi... |
12354608 | Actin's propensity for dynamic filament patterning. | Actin, through its various forms of assembly, provides the basic framework for cell motility, cell shape and intracellular organization in all eukaryotic cells. Many other cellular processes, for example endocytosis and cytokinesis, are also associated with dynamic changes of the actin cytoskeleton. Important prerequis... |
12354120 | Properties of the Na+/H+ exchanger protein. Detergent-resistant aggregation and membrane microdistribution. | The Na+/H+ exchanger is a ubiquitous membrane protein of bacteria, plants and mammals. The first isoform discovered (NHE1) is present on the mammalian plasma membrane and transports one H+ out of cells in exchange for one extracellular Na+. With solubilization in standard SDS/PAGE buffer, this protein had a high tenden... |
12355531 | Dendronized molecular knots: selective synthesis of various generations, enantiomer separation, circular dichroism. | For the first time, knot molecules (of the amide type) are synthesized, which bear one to three dendritic units of various generations at their periphery. They were obtained through two different routes: i) attachment of dendritic wedges to new mono-, di- and trihydroxy functionalized dodecaamide knots that have been o... |
12355529 | An efficient approach towards the convergent synthesis of "fully-carbohydrate" mannodendrimers. | Glycosylation of sugar trityl ethers with sugar 1,2-O-(1-cyano)ethylidene derivatives (the trityl-cyanoethylidene condensation) has been applied to the synthesis of highly branched (dendritic) mannooligosaccharides incorporating a Manalpha1-->3(Manalpha1-->6)Man structural motif. The convergent synthetic strategy used ... |
12323029 | Modified gamma-cyclodextrins and their rocuronium complexes. | A series of per-6-substituted cyclodextrin derivatives was synthesized as synthetic host molecules for rocuronium, a steroidal muscle relaxant. By forming host-guest complexes with rocuronium, these cyclodextrin derivatives reverse the muscle relaxation induced by rocuronium in vitro and in vivo. The isothermal microca... |
12323020 | Regioselective synthesis of antiparallel loops on a macrocyclic scaffold constrained by oxazoles and thiazoles. | The regioselective syntheses and structures are reported for two tris-macrocylic compounds, each possessing two antiparallel loops on a macrocyclic scaffold constrained by two oxazoles and two thiazoles. NMR solution structures show the loops projecting from the same face of the macrocycle. Such molecules are shown to ... |
12324441 | Aggregation and self-assembly of hydrophobins from Trichoderma reesei: low-resolution structural models. | Hydrophobins are secreted fungal proteins, which have diverse roles in fungal growth and development. They lower the surface tension of water, work as adhesive agents and coatings, and function through self-assembly. One of the characteristic properties of hydrophobins is their tendency to form fibrillar or rod-like ag... |
12324429 | Probing red cell membrane cholesterol movement with cyclodextrin. | We probed the kinetics with which cholesterol moves across the human red cell bilayer and exits the membrane using methyl-beta-cyclodextrin as an acceptor. The fractional rate of cholesterol transfer (% s(-1)) was unprecedented, the half-time at 37 degrees C being ~1 s. The kinetics observed under typical conditions we... |
12324422 | A thermodynamic model for extended complexes of cholesterol and phospholipid. | Studies of monolayer mixtures of certain phospholipids with cholesterol by epifluorescence microscopy and measurement of cholesterol desorption show evidence for the formation of "condensed complexes." A thermodynamic model of these complexes has been developed and has been shown to be generally consistent with observe... |
12324411 | A Monte Carlo study of the self-assembly of bacteriorhodopsin. | Bacteriorhodopsin (BR) and specific lipid molecules self-assemble into a quasi two-dimensional lattice structure known as the purple membrane (PM). In the PM, BR molecules exist in a trimeric form with lipid molecules present in the space enclosed by each trimeric unit and in the inter-trimer space. These trimeric unit... |
12324400 | A procedure for refining a coiled coil protein structure using x-ray fiber diffraction and modeling. | We describe a combined use of experimental and simulation techniques to configure side chains in a coiled coil structure. As already demonstrated in a previous work, x-ray diffraction patterns from hard alpha-keratin fibers in the 5.15 A meridian zone reflect the global configuration of the chi(1) dihedral angle of the... |
12270828 | YfcX enables medium-chain-length poly(3-hydroxyalkanoate) formation from fatty acids in recombinant Escherichia coli fadB strains. | Expression of Escherichia coli open reading frame yfcX is shown to be required for medium-chain-length polyhydroxyalkanoate (PHA(MCL)) formation from fatty acids in an E. coli fadB mutant. The open reading frame encodes a protein, YfcX, with significant similarity to the large subunit of multifunctional beta-oxidation ... |
12270819 | Overexpression of the MtrC-MtrD-MtrE efflux pump due to an mtrR mutation is required for chromosomally mediated penicillin resistance in Neisseria gonorrhoeae. | The importance of the mtrCDE-encoded efflux pump in conferring chromosomally mediated penicillin resistance on certain strains of Neisseria gonorrhoeae was determined by using genetic derivatives of penicillin-sensitive strain FA19 bearing defined mutations (mtrR, penA, and penB) donated by a clinical isolate (FA6140) ... |
12270814 | A novel cytology-based, two-hybrid screen for bacteria applied to protein-protein interaction studies of a type IV secretion system. | DivIVA of Bacillus subtilis and FtsZ of Escherichia coli were used to target heterologous protein complexes to cell division sites of E. coli and Agrobacterium tumefaciens. DivIVA and FtsZ that were fused to the dimerizing leucine zipper (LZ) domain of the yeast transcription activator GCN4 directed the green fluoresce... |
12270618 | Physical properties of chitosan pellets produced by extrusion-spheronisation: influence of formulation variables. | Pellets comprising chitosan, cellulose microcrystalline, povidone, filler excipient and diclofenac sodium as model drug were prepared by extrusion-spheronisation. The effects of chitosan load (zero, 0%, low, 4% and high, 16% levels), type of filler (lactose, tribasic calcium phosphate and beta-cyclodextrin) and composi... |
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