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15522710 | Molecular recognition based cadmium removal from human plasma. | Molecularly imprinted polymers (MIPs) are easy to prepare, stable, inexpensive and capable of molecular recognition. MIPs can be considered as affinity separation media. Cadmium is a carcinogenic and mutagenic element. There is no specific treatment available for acute or chronic metal poisoning. Besides supportive the... |
15521776 | Noncovalent anchoring of homogeneous catalysts to silica supports with well-defined binding sites. | The efficient reversible functionalization of silica with catalytic sites using noncovalent interactions is described. We prepared silica materials with well-defined binding sites that selectively bind guest molecules that are equipped with the complementary binding motif, with the interaction between the two component... |
15521768 | Palladium- and copper-catalyzed synthesis of medium- and large-sized ring-fused dihydroazaphenanthrenes and 1,4-benzodiazepine-2,5-diones. control of reaction pathway by metal-switching. | Methods for the synthesis of dihydroazaphenanthrene fused to macrocycles (2) and medium-ring heterocycles (4), as well as 1,4-benzodiazepine-2,5-diones (5), are developed. A distinctly different catalytic property of palladium and copper catalysts was uncovered that leads to the development of a divergent synthesis of ... |
15521765 | Synthesis, self-assembly, and characterization of supramolecular polymers from electroactive dendron rodcoil molecules. | We report here the synthesis and self-assembly of a series of three molecules with dendron rodcoil architecture that contain conjugated segments of oligo(thiophene), oligo(phenylene-vinylene), and oligo(phenylene). Despite their structural differences, all three molecules yield similar self-assembled structures. Electr... |
15521750 | Energy transfer rates and pathways of single donor chromophores in a multichromophoric dendrimer built around a central acceptor core. | An artificial light-harvesting dendrimer showing highly efficient electronic excitation energy transfer from four peripheral donors to one central acceptor has been investigated by single-molecule spectroscopy at low temperatures. Confocal imaging in combination with frequency selective excitation spectroscopy gives di... |
15521726 | Halide-induced supramolecular ligand rearrangement. | A novel reaction involving the halide-induced rearrangement of ligands within supramolecular Rh(I) complexes containing hemilabile ligands is presented. Three analogous bis- and trishemilabile ligands have been synthesized to construct bi- and trimetallic Rh(I) macrocyclic complexes. An intentionally added halide sourc... |
15521724 | Banana-shaped liquid crystals with two oligosiloxane end-groups: field-induced switching of supramolecular chirality. | The first bent core mesogen carrying branched oligosiloxane units at both ends was synthesized and investigated with polarized light microscopy, DSC, X-ray diffraction of well aligned samples, and electrooptical methods. Two different antiferroelectric switching liquid crystalline phases were found. Both can be regarde... |
15521723 | Fluorescence lifetimes and emission patterns probe the 3D orientation of the emitting chromophore in a multichromophoric system. | In this Communication, we report on the fluorescence behavior of an individual first generation multichromophoric dendrimer. The fact that each of the chromophores in time acts as a fluorescent trap is demonstrated by directly probing the dipole orientation of the emitting chromophore by means of defocused wide-field i... |
15521822 | Effects of deletions at the C-terminus of tobacco acetohydroxyacid synthase on the enzyme activity and cofactor binding. | AHAS (acetohydroxyacid synthase) catalyses the first committed step in the biosynthesis of branched-chain amino acids, such as valine, leucine and isoleucine. Owing to the unique presence of these biosynthetic pathways in plants and micro-organisms, AHAS has been widely investigated as an attractive target of several c... |
15270718 | NMR characterization of the interaction between the C-terminal domain of interferon-gamma and heparin-derived oligosaccharides. | Interferons are cytokines that play a complex role in the resistance of mammalian hosts to pathogens. IFNgamma (interferon-gamma) is secreted by activated T-cells and natural killer cells. IFNgamma is involved in a wide range of physiological processes, including antiviral activity, immune response, cell proliferation ... |
15518811 | Conserved residues in the coiled-coil pocket of human immunodeficiency virus type 1 gp41 are essential for viral replication and interhelical interaction. | The human immunodeficiency virus type 1 (HIV-1) gp41 plays an important role in mediating the fusion of HIV with host cells. During the fusion process, three N-terminal helices and three C-terminal helices pack in an anti-parallel direction to form a six-helix bundle. X-ray crystallographic analysis of the gp41 core de... |
15520458 | Cancer siRNA therapy by tumor selective delivery with ligand-targeted sterically stabilized nanoparticle. | Potent sequence selective gene inhibition by siRNA 'targeted' therapeutics promises the ultimate level of specificity, but siRNA therapeutics is hindered by poor intracellular uptake, limited blood stability and non-specific immune stimulation. To address these problems, ligand-targeted, sterically stabilized nanoparti... |
15518519 | Interactions of dendrimers with selected amino acids and proteins studied by continuous wave EPR and Fourier transform EPR. | Interactions of polyamidoamine dendrimers, termed Gn, where n indicates the generation (=number of amidoamine layers), at different protonation levels with selected amino acids and proteins have been investigated by means of continuous wave electron paramagnetic resonance (cw-EPR) and pulsed-EPR (electron spin-echo = E... |
15518504 | Surface-dependent transitions during self-assembly of phospholipid membranes on mica, silica, and glass. | Formation of supported membranes by exposure of solid surfaces to phospholipid vesicles is a much-used technique in membrane research. Freshly cleaved mica, because of its superior flatness, is a preferred support, and we used ellipsometry to study membrane formation kinetics on mica. Neutral dioleoyl-phosphatidylcholi... |
15518484 | Modulation with acetonitrile of the dynamics of guest binding to the two distinct binding sites of cholate aggregates. | Bile salt aggregates are supramolecular systems containing two different binding sites. The effect of the addition of acetonitrile on the specificity and dynamics of guest binding to the two binding sites of cholate aggregates was studied. The protection of guests included in the aggregate from interaction with ions in... |
15520247 | The molecular adapter Carma1 controls entry of IkappaB kinase into the central immune synapse. | Carma1 (also known as caspase recruitment domain [CARD]11, Bimp3) is a CARD-containing membrane-associated guanylate kinase family protein that plays an essential role in antigen receptor-induced nuclear factor kappaB activation. We investigated the role of Carma1 in the assembly of signaling molecules at the immune sy... |
15520861 | A viral epitope that mimics a self antigen can accelerate but not initiate autoimmune diabetes. | We document here that infection of prediabetic mice with a virus expressing an H-2Kb-restricted mimic ligand to a self epitope present on beta cells accelerates the development of autoimmune diabetes. Immunization with the mimic ligand expanded autoreactive T cell populations, which was followed by their trafficking to... |
15520805 | Natively unfolded domains in endocytosis: hooks, lines and linkers. | It is commonly assumed that a protein must adopt a tertiary structure to achieve its active native state and that regions of a protein that are devoid of alpha-helix or beta-sheet structures are functionally inert. Although extended proline-rich regions are recognized as presenting binding motifs to, for example, Src h... |
15519306 | Diversity and versatility of lipid-protein interactions revealed by molecular genetic approaches. | The diversity in structures and physical properties of lipids provides a wide variety of possible interactions with proteins that affect their assembly, organization, and function either at the surface of or within membranes. Because lipids have no catalytic activity, it has been challenging to define many of their pre... |
15386623 | Synthetic peptide vaccine development: measurement of polyclonal antibody affinity and cross-reactivity using a new peptide capture and release system for surface plasmon resonance spectroscopy. | A method has been developed for measurement of antibody affinity and cross-reactivity by surface plasmon resonance spectroscopy using the EK-coil heterodimeric coiled-coil peptide capture system. This system allows for reversible capture of synthetic peptide ligands on a biosensor chip surface, with the advantage that ... |
15386621 | Transient complexes of redox proteins: structural and dynamic details from NMR studies. | Redox proteins participate in many metabolic routes, in particular those related to energy conversion. Protein-protein complexes of redox proteins are characterized by a weak affinity and a short lifetime. Two-dimensional NMR spectroscopy has been applied to many redox protein complexes, providing a wealth of informati... |
15386620 | Study on the recognition of templates and their analogues on molecularly imprinted polymer using computational and conformational analysis approaches. | A simplified computational model was proposed to simulate the synthesis of molecularly imprinted polymers (MIP), removal of template and recognition of the template and its analogues by MIP. The MIPs with nicotinamide and iso-nicotinamide as templates were prepared using methacrylic acid as functional monomer. Based on... |
15386619 | DNA condensation by high-affinity interaction with avidin. | Avidin, the basic biotin-binding glycoprotein from chicken egg white, is known to interact with DNA, whereas streptavidin, its neutral non-glycosylated bacterial analog, does not. In the present study we investigated the DNA-binding properties of avidin. Its affinity for DNA in the presence and absence of biotin was co... |
15384176 | A survey of the year 2003 literature on applications of isothermal titration calorimetry. | Over the last decade isothermal titration calorimetry (ITC) has developed from a specialist method which was largely restricted in its use to dedicated experts, to a major, commercially available tool in the arsenal directed at understanding molecular interactions. The number of those proficient in this field has multi... |
15516580 | Purification and characterization of the repressor of the shiga toxin-encoding bacteriophage 933W: DNA binding, gene regulation, and autocleavage. | The genes encoding Shiga toxin (stx), the major virulence factor of Shiga toxin-encoding Escherichia coli (STEC) strains, are carried on lambdoid prophages resident in all known STEC strains. The stx genes are expressed only during lytic growth of these temperate bacteriophages. We cloned the gene encoding the represso... |
15516566 | Staphylococcus aureus AgrA binding to the RNAIII-agr regulatory region. | The control of virulence gene expression in the human pathogen Staphylococcus aureus is under the partial control of the two-component quorum-sensing system encoded by genes of the agr locus. The product of the agrA gene has been shown by amino acid sequence similarity to be the putative response regulator; however, bi... |
15516561 | Characteristics of zinc transport by two bacterial cation diffusion facilitators from Ralstonia metallidurans CH34 and Escherichia coli. | CzcD from Ralstonia metallidurans and ZitB from Escherichia coli are prototypes of bacterial members of the cation diffusion facilitator (CDF) protein family. Expression of the czcD gene in an E. coli mutant strain devoid of zitB and the gene for the zinc-transporting P-type ATPase zntA rendered this strain more zinc r... |
15516560 | Calcium inhibits bap-dependent multicellular behavior in Staphylococcus aureus. | Bap (biofilm-associated protein) is a 254-kDa staphylococcal surface protein implicated in formation of biofilms by staphylococci isolated from chronic mastitis infections. The presence of potential EF-hand motifs in the amino acid sequence of Bap prompted us to investigate the effect of calcium on the multicellular be... |
15516149 | Selective and sensitive fluorescent sensors for metal ions based on manipulation of side-chain compositions of poly(p-phenyleneethynylene)s. | The syntheses and metal-responsive properties of poly(p-phenyleenethynylene)s with grafted new pseudo-crown-ether groups are reported. These polymers exhibit high sensitivities to alkali ions because of their collective optical properties, which are very sensitive to ion-induced conformational changes. The quenching of... |
15516122 | A low-makeup beveled tip capillary electrophoresis /electrospray ionization mass spectrometry interface for micellar electrokinetic chromatography and nonvolatile buffer capillary electrophoresis. | A robust interface has been developed for interfacing micellar electrokinetic chromatography (MEKC) and nonvolatile buffer capillary electrophoresis (CE) to electrospray ionization mass spectrometry (ESI-MS). The interface consists of two parallel capillaries for separation (50 microm i.d. x 155 microm o.d.) and makeup... |
15511223 | A novel pathway for sequential transformation of 7-dehydrocholesterol and expression of the P450scc system in mammalian skin. | Following up on our previous findings that the skin possesses steroidogenic activity from progesterone, we now show widespread cutaneous expression of the full cytochrome P450 side-chain cleavage (P450scc) system required for the intracellular catalytic production of pregnenolone, i.e. the genes and proteins for P450sc... |
15513555 | Ganglion cells in the posterior cricoarytenoid muscle of the rat following experimental denervation. | <h4>Objective</h4>To investigate morphological changes of the i.m. ganglion cells in the posterior cricoarytenoid (PCA) muscle of the rat following denervation of the recurrent laryngeal nerve.<h4>Material and methods</h4>The recurrent laryngeal nerve on the left side of the rat was resected. Three weeks after transect... |
15509794 | Inactivation of the Mgat1 gene in oocytes impairs oogenesis, but embryos lacking complex and hybrid N-glycans develop and implant. | Complex and hybrid N-glycans contain sugar residues that have been implicated in fertilization, compaction of the embryo, and implantation. Inactivation of the Mgat1 gene responsible for their synthesis is embryonic lethal, but homozygous mutant blastocysts are phenotypically normal due to the presence of maternal Mgat... |
15509172 | Structural selectivity of aromatic diamidines. | Competition dialysis was used to study the interactions of 13 substituted aromatic diamidine compounds with 13 nucleic acid structures and sequences. The results show a striking selectivity of these compounds for the triplex structure poly dA:(poly dT)2, a novel aspect of their interaction with nucleic acids not previo... |
15507613 | Uptake pathway of polyomavirus via ganglioside GD1a. | The pathway of entry of polyomavirus (Py) has been investigated with glycolipid-deficient C6 cells and added ganglioside GD1a as a specific virus receptor. Unsupplemented C6 cells show a low basal level of infection but become highly infectable by Py following preincubation with the sialic acid-containing ganglioside G... |
15507604 | The l2 minor capsid protein of human papillomavirus type 16 interacts with a network of nuclear import receptors. | The L2 minor capsid proteins enter the nucleus twice during viral infection: in the initial phase after virion disassembly and in the productive phase when, together with the L1 major capsid proteins, they assemble the replicated viral DNA into virions. In this study we investigated the interactions between the L2 prot... |
15506790 | Adsorption-induced asymmetric assembly from an achiral adsorbate. | Symmetry breaking in the self-assembled monolayer (SAM) structure of 1-octadecanol on highly ordered pyrolytic graphite (HOPG) is observed. Due to the slight mismatch of the octadecanol molecule with the graphite lattice, the alkane chain undergoes distortion upon adsorption on the surface. The asymmetric distortion of... |
15506789 | Factors controlling the complex architecture of native and modified cyclodextrins with dipeptide (Z-Glu-Tyr) studied by microcalorimetry and NMR spectroscopy: critical effects of peripheral bis-trimethylamination and cavity size. | Complex stability constant (K), standard free energy (DeltaG degrees ), reaction enthalpy (DeltaH degrees ), and entropy change (TDeltaS degrees ) for 1:1 inclusion complexation of the diastereomeric dipeptides Z-d/l-Glu-l-Tyr (Z = benzyloxycarbonyl) and its component amino acids (Z-d/l-Glu and N-Ac-Tyr) with native al... |
15506788 | Effects of benzyl ether type dendrons as hole-harvesting antennas, and shielding for the neutralization of stilbene core radical cations with chloride ion during two-photon ionization of stilbene dendrimers having stilbene core and benzyl ether type dendrons. | The two-photon ionization (TPI) process (308 and 266 nm) of stilbene dendrimers having a stilbene core and benzyl ether type dendrons has been investigated in an acetonitrile and 1,2-dichloroethane mixture (3:1) in order to elucidate the dendrimer effects. The quantum yield of the formation of stilbene core radical cat... |
15506779 | Five-coordinate Fe(III)NO and Fe(II)CO porphyrinates: where are the electrons and why does it matter? | Recent years have seen dramatic growth in our understanding of the biological roles of nitric oxide (NO). Yet, the fundamental underpinnings of its reactivities with transition metal centers in proteins and enzymes, the stabilities of their structures, and the relationships between structure and reactivity remains, to ... |
15506769 | Structural characterization of modular supramolecular architectures in solution. | Structures of modular supramolecular architectures consisting of a hexameric, diphenylethyne-linked porphyrin macrocyclic array and the corresponding host-guest complex formed by inclusion of a tripyridyl guest molecule were characterized in solution using high-angle X-ray scattering. Scattering measurements made to 6 ... |
15506750 | A new convergent strategy for the synthesis of calixarenes via a triple annulation of Fischer carbene complexes. | A new method for the synthesis of unsymmetrical calix[4]arenes is described which involves the reaction of a diyne with a bis-carbene complex of chromium. This synthesis of calixarenes is unique in that it involves the formation of two of the four benzene rings of the calixarene and the macrocyclic ring of the calixare... |
15506748 | Photodissociation of heme distal methionine in ferrous cytochrome C revealed by subpicosecond time-resolved resonance Raman spectroscopy. | Cytochrome c (cyt c) is an electron-transfer heme protein that also binds nitric oxide (NO). In resting cyt c, two endogenous ligands of the heme iron are histidine-18 (His) and methionine-80 (Met) side chains, and NO binding requires the cleavage of one of the axial bonds. Previous femtosecond transient absorption stu... |
15506744 | DNA triangles and self-assembled hexagonal tilings. | We have designed and constructed DNA complexes in the form of triangles. We have created hexagonal planar tilings from these triangles via self-assembly. Unlike previously reported structures self-assembled from DNA, our structures appear to involve bending of double helices. Bending helices may be a useful design opti... |
15506722 | A high-nuclearity "Celtic-ring" isopolyoxotungstate, [H12W36O120]12-, that captures trace potassium ions. | A high-nuclearity {W36} isopolyoxotungstate cluster, [H12W36O120]12-, with a triangular shape has been isolated by using an encapsulating organic cation, protonated triethanolamine. In analogy to an 18-crown-6 crown ether, the cluster captures a potassium ion, present in trace amounts in the reaction system, within its... |
15507690 | Field-dependent effect of crown ether (18-crown-6) on ionic conductance of alpha-hemolysin channels. | Closing linear poly(ethylene glycol) (PEG) into a circular "crown" dramatically changes its dynamics in the alpha-hemolysin channel. In the electrically neutral crown ether (C2H4O)6, six ethylene oxide monomers are linked into a circle that gives the molecule ion-complexing capacity and increases its rigidity. As with ... |
15495240 | The cytoskeleton in neurodegenerative diseases. | Abundant abnormal aggregates of cytoskeletal proteins are neuropathological signatures of many neurodegenerative diseases that are broadly classified by filamentous aggregates of neuronal intermediate filament (IF) proteins, or by inclusions containing the microtubule-associated protein (MAP) tau. The discovery of muta... |
15504677 | A homodecoupled diffusion experiment for the analysis of complex mixtures by NMR. | Diffusion ordered spectroscopy (DOSY) relies on differences in translation diffusion as a means to separate components in a solution mixture. However, the analysis of spectra of mixtures can be problematic because spectral overlap. It is the aim of this article to propose a pulse sequence and processing method that lea... |
15504874 | Activity of OPT-80, a novel macrocycle, compared with those of eight other agents against selected anaerobic species. | Agar dilution MIC was used to compare activities of OPT-80, linezolid, vancomycin, teicoplanin, quinupristin/dalfopristin, amoxicillin/clavulanate, imipenem, clindamycin, and metronidazole against 350 gram-positive and -negative anaerobes. OPT-80 was active against gram-positive strains only, especially Clostridium spp... |
15504868 | In vitro combination of amdoxovir and the inosine monophosphate dehydrogenase inhibitors mycophenolic acid and ribavirin demonstrates potent activity against wild-type and drug-resistant variants of human immunodeficiency virus type 1. | Amdoxovir [(-)-beta-d-2,6-diaminopurine dioxolane (DAPD)] is a nucleoside analogue reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) replication. DAPD is deaminated by adenosine deaminase to the guanosine analogue dioxolane guanosine (DXG), which is subsequently phosphorylated to the corres... |
15504843 | Highly active anti-Pneumocystis carinii compounds in a library of novel piperazine-linked bisbenzamidines and related compounds. | Trimethoprim-sulfamethoxazole and pentamidine isethionate have been used extensively for the prophylaxis and therapy of pneumonia caused by Pneumocystis jirovecii. Problems associated with toxicity and potential emerging resistance for both therapies necessitate the development of safe and effective analogs or new trea... |
15504830 | Chemical diversity of polyene macrolides produced by Streptomyces noursei ATCC 11455 and recombinant strain ERD44 with genetically altered polyketide synthase NysC. | The gram-positive bacterium Streptomyces noursei ATCC 11455 produces a complex mixture of polyene macrolides generally termed nystatins. Although the structures for nystatins A(1) and A(3) have been reported, the identities of other components of the nystatin complex remain obscure. Analyses of the culture extract from... |
15501004 | Applicability of (SBE)7m-beta-CD in controlled-porosity osmotic pump tablets (OPTs). | The purpose of this study was to investigate the general application of a controlled-porosity osmotic pump tablet (OPT) utilizing (SBE)7m-beta-CD as both a solubilizer and an osmotic agent for drugs with varying physical properties. OPTs utilizing (SBE)7m-beta-CD were prepared for five poorly soluble and two highly wat... |
15500358 | Oxidation of mixed-valence Co(III)/Fe(II) complexes reversed at high pH: a kinetico-mechanistic study of water oxidation. | The outer-sphere oxidation of Fe(II) in the mixed-valence complex trans-[L(14S)Co(III)NCFe(II)(CN)(6)](-), being L(14S) an N(3)S(2) macrocylic donor set on the cobalt(III) center, has been studied. The comparison with the known processes of N(5) macrocycle complexes has been carried out in view of the important differe... |
15500345 | Supramolecular copper hydroxide tennis balls: self-assembly, structures, and magnetic properties of octanuclear [Cu(8)L(8)(OH)(4)](4+) clusters (HL = N-(2-pyridylmethyl)acetamide). | The self-assembly of supramolecular copper "tennis balls" that possess unusual magnetic properties using a small pyridyl amide ligand is described. Copper(II) complexes of N-(2-pyridylmethyl)acetamide (HL) were synthesized in methanol. In the absence of base, the mononuclear complex [Cu(HL)(2)](ClO(4))(2) (1) was prepa... |
15500335 | Electrochemical, spectral, and computational studies of metalloporphyrin dimers formed by cation complexation of crown ether cavities. | The effect on the electrochemical oxidation and reduction potentials of 5,10,15,20-tetrakis(benzo-15-crown-5)porphyrin (TCP) and its metal derivatives (MTCP; M = Mg(II), VO(IV), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Ag(II)) upon potassium ion induced dimerization of the porphyrins was systematically performed in benz... |
15500331 | Binding of inorganic oxoanions to macrocyclic ligands: effect of the degree of protonation on supramolecular assemblies formed by phosphate and [18]aneN(6). | Five macrocycle-oxoanion adducts have been isolated from aqueous solutions containing 1,4,7,10,13,16-hexaazacyclooctadecane ([18]aneN(6), L) and phosphoric acid whose pH had been adjusted to selected values in the 1-8 range. Four products, (H(6)L)(H(2)PO(4))(6).2H(3)PO(4) (1), (H(6)L)(H(2)PO(4))(6) (2), (H(4)L)(H(2)PO(... |
15500323 | Structure of a discrete hexadecameric water cluster in a metal-organic framework structure. | Pyrazine-2,3,5,6-tetracarboxylic acid (pytcH(4)) reacts with Cu(NO(3))(2)x6H(2)O in 1:2 molar ratio in the presence of pyridine (py) vapor to form blue crystals of a coordination polymer with the empirical formula [Cu(2.5)(pytc)(py)(8)(NO(3)(-))x10H(2)O](n). Four such polymeric chains gather around a hexadecameric wate... |
15500321 | A three-dimensional, noninterpenetrating metal--organic framework with the moganite topology: a simple (4(2)x6(2)x8(2))(4x6(4)x8)(2) net containing two kinds of topologically nonequivalent points. | Self assembly of Cu(2+) with the multifunctional ligand 2-(4-pyridyl)thiazole-4-carboxylic acid (Pytac) affords the neutral 3D coordination polymer [Cu(3)(Pytac)(6)](H(2)O)(14) (hereafter, SZL-1), which has the rare moganite topology. The mineral moganite has a topology that is closely related to the well-known quartz ... |
15500318 | Interwoven 2-D coordination network prepared from the molecular host tris(isonicotinoyl)cyclotriguaiacylene and silver(I) cobalt(III) bis(dicarbollide). | A new 3-fold symmetric molecular host, tris(isonicotinoyl)cyclotriguaiacylene, has been synthesized from cyclotriguaiacylene and isonicotinoyl chloride hydrochloride in 70% yield. Its crystal structure shows dimerization of the host molecules into a capsule-like arrangement. When reacted with Ag[Co(C(2)B(9)H(11))(2)], ... |
15501760 | Antimycobacterial calixarenes enhance innate defense mechanisms in murine macrophages and induce control of Mycobacterium tuberculosis infection in mice. | Tuberculosis remains the leading cause of death among infectious diseases, accounting for more than two million deaths annually. The incidence of the disease is increasing globally, partially because of the resurgence of drug-resistant strains of Mycobacterium tuberculosis. Calixarenes are macrocyclic oligomers, some o... |
15498942 | Distinct protein interfaces in transmembrane domains suggest an in vivo folding model. | Given the known high-resolution structures of alpha-helical transmembrane domains, we show that there are statistically distinct classes of transmembrane interfaces which relate to the folding and oligomerization of transmembrane domains. Distinct types of interfaces have been categorized and refer to those between: th... |
15498939 | Position dependence of the 13C chemical shifts of alpha-helical model peptides. Fingerprint of the 20 naturally occurring amino acids. | The position dependence of the (13)C chemical shifts was investigated at the density functional level for alpha-helical model peptides represented by the sequence Ac-(Ala)(i)-X-(Ala)(j)-NH(2), where X represents any of the 20 naturally occurring amino acids, with 0 < or = i < or = 8 and i + j = 8. Adoption of the local... |
15498935 | Folding of a designed simple ankyrin repeat protein. | Ankyrin repeats (AR) are 33-residue motifs containing a beta-turn, followed by two alpha-helices connected by a loop. AR occur in tandem arrangements and stack side-by-side to form elongated domains involved in very different cellular tasks. Recently, consensus libraries of AR repeats were constructed. Protein E1_5 rep... |
15498653 | Inclusion complexes of paclitaxel and oligo(ethylenediamino) bridged bis(beta-cyclodextrin)s: solubilization and antitumor activity. | The inclusion complexation behavior of paclitaxel with a series of oligo(ethylenediamino) bridged bis(beta-cyclodextrin)s possessing bridge chains in different length (1-4) has been investigated in order to improve the water solubility of paclitaxel. It is found that only the long-tethered bis(beta-cyclodextrin)s 1 and... |
15496523 | The crystal structure of a high affinity RNA stem-loop complexed with the bacteriophage MS2 capsid: further challenges in the modeling of ligand-RNA interactions. | We have determined the structure to 2.8 A of an RNA aptamer (F5), containing 2'-deoxy-2-aminopurine (2AP) at the -10 position, complexed with MS2 coat protein by soaking the RNA into precrystallised MS2 capsids. The -10 position of the RNA is an important determinant of binding affinity for coat protein. Adenine at thi... |
15491403 | The Bohr effect of haemoglobin in vertebrates: an example of molecular adaptation to different physiological requirements. | The Bohr effect, i.e. the pH dependence of the oxygen affinity of haemoglobins (Hbs) from a variety of vertebrates, and its modulation by temperature and other heterotropic effectors has been reviewed. Haemoglobins from vertebrates were not reviewed following the usual classification (i.e. mammals, birds, etc.); instea... |
15489447 | TouR-mediated effector-independent growth phase-dependent activation of the sigma54 Ptou promoter of Pseudomonas stutzeri OX1. | Transcription of the catabolic touABCDEF operon, encoding the toluene-o-xylene monooxygenase of Pseudomonas stutzeri OX1, is driven by the sigma(54)-dependent Ptou promoter, whose activity is controlled by the phenol-responsive NtrC-like activator TouR. In this paper we describe for the first time a peculiar characteri... |
15489442 | The BfeR regulator mediates enterobactin-inducible expression of Bordetella enterobactin utilization genes. | Utilization of the enterobactin siderophore by the respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica is dependent on the BfeA outer membrane receptor. This study determined that production of BfeA was increased significantly in iron-starved bacteria upon supplementation of cultures with enterobac... |
15488682 | Preparation and characterisation of poly(vinyl alcohol)/cyclodextrin microspheres as matrix for inclusion and separation of drugs. | Poly(vinyl alcohol) (PVA) microspheres containing cyclodextrin (CD) were obtained by chemical cross-linking with glutaraldehyde of an acidified mixture solution of PVA and alpha-, beta- or gamma-CD. The amount of linked CD in microspheres, estimated by tetrazolium blue method, decreases in the order beta- > gamma- > al... |
15488589 | Considerations about the enantioselective transformation of polycyclic musks in wastewater, treated wastewater and sewage sludge and analysis of their fate in a sequencing batch reactor plant. | The present work consists of two distinct parts: in the first part enantioselective GC was used to separate the different enantiomeric/diastereomeric polycyclic musks, PCMs (HHCB, AHTN, AHDI, ATII and DPMI) including the main transformation product of HHCB, HHCB-lactone, in wastewater and sewage sludge. After optimizat... |
15486121 | Increased high sensitivity C reactive protein concentrations and increased arterial stiffness in children with a history of Kawasaki disease. | <h4>Objectives</h4>To test the hypothesis that low grade inflammation persists after the acute phase and affects arterial stiffness in children with a history of Kawasaki disease.<h4>Design and patients</h4>A cohort of 106 children was studied, which comprised 43 patients with Kawasaki disease with coronary aneurysms (... |
15485682 | Cholesterol- and caveolin-rich membrane domains are essential for phospholipase A2-dependent EDHF formation. | <h4>Objective</h4>Cholesterol-rich membrane domains, which contain the scaffold protein caveolin-1 (Cav-1) (caveolae), represent an important structural element involved in endothelial signal transduction. The present study was designed to investigate the role of these signaling platforms in the generation of endotheli... |
15476600 | Insect-inspired estimation of egomotion. | Tangential neurons in the fly brain are sensitive to the typical optic flow patterns generated during egomotion. In this study, we examine whether a simplified linear model based on the organization principles in tangential neurons can be used to estimate egomotion from the optic flow. We present a theory for the const... |
15476678 | Shift in purine/pyrimidine base recognition upon exchanging extracellular domains in P2Y 1/6 chimeric receptors. | P2Y receptors are G protein-coupled receptors stimulated by extracellular nucleotides. Both the P2Y(1) and the P2Y(6) receptors are preferentially activated by nucleoside 5'-diphosphates, but favor different base moieties. In the case of the P2Y(1) receptor the preferred base is adenine, while the P2Y(6) receptor is ac... |
15476670 | Antiaggregatory activity in human platelets of potent antagonists of the P2Y 1 receptor. | Activation of the P2Y(1) nucleotide receptor in platelets by ADP causes changes in shape and aggregation, mediated by activation of phospholipase C (PLC). Recently, MRS2500(2-iodo-N(6)-methyl-(N)-methanocarba-2'-deoxyadenosine-3',5'-bisphosphate) was introduced as a highly potent and selective antagonist for this recep... |
15476669 | 2-Substituted adenosine derivatives: affinity and efficacy at four subtypes of human adenosine receptors. | The affinity and efficacy at four subtypes (A(1), A(2A), A(2B) and A(3)) of human adenosine receptors (ARs) of a wide range of 2-substituted adenosine derivatives were evaluated using radioligand binding assays and a cyclic AMP functional assay in intact CHO cells stably expressing these receptors. Similar to previous ... |
15372483 | Host-guest complexation of oxicam NSAIDs with beta-cyclodextrin. | Spectroscopic and molecular modeling techniques have been employed to study the interaction of the oxicam group of nonsteroidal antiinflammatory drugs (NSAIDs) with a polysaccharide such as beta-cyclodextrin (beta-cd). beta-cd is a good drug delivery system and is known to reduce harmful side effects of these drugs in ... |
15474505 | Direct detection of caspase-3 activation in single live cells by cross-correlation analysis. | Dual color fluorescence cross-correlation spectroscopy (FCCS) provides information about the coincidence of spectrally well-defined two fluorescent molecules in a small observation area at the single-molecule level. To evaluate the activity of caspase-3 in vivo directly, FCCS was applied to single live cells. We constr... |
15474472 | R(+)-methanandamide-induced cyclooxygenase-2 expression in H4 human neuroglioma cells: possible involvement of membrane lipid rafts. | Cannabinoids induce the expression of the cyclooxygenase-2 (COX-2) isoenzyme in H4 human neuroglioma cells via a pathway independent of cannabinoid- or vanilloid receptor activation. The underlying mechanism was recently shown to involve increased synthesis of ceramide, which in turn leads to activation of p38 and p42/... |
15474457 | Hsp70 release from peripheral blood mononuclear cells. | There are an increasing number of studies reporting the presence of Hsps in human serum. We have investigated the release of Hsp70 into blood and culture medium from peripheral blood mononuclear cells (PBMCs), and whether this release is due to cell damage or active secretion from the cells. Intact Hsp70 was released f... |
15457503 | Time course of embryonic midbrain and thalamic auditory connection development in mice as revealed by carbocyanine dye tracing. | Central auditory connections develop in mice before the onset of hearing, around postnatal day 7. Two previous studies have investigated the development of auditory nuclei projections and lateral lemniscal nuclear projections in embryonic rats, respectively. Here, we provide detail for the first time of the initiation ... |
15464807 | Fishing of beta-amylase with a SAM of alpha-cyclodextrin-poly- (ethylene glycol) conjugate. | Alpha-cyclodextrin (alpha-CD) with an amino group was conjugated to an alpha, omega-dicarboxylated poly(ethylene glycol) (PEG). The inhibition constant (Ki) of the alpha-CD-PEG conjugate for the catalysis by beta-amylase was larger than that of alpha-CD, due to a steric obstruction of the PEG moiety to the binding of a... |
15464802 | Temperature and concentration effects on supramolecular aggregation and phase behavior for poly(propylene oxide)-b-poly(ethylene oxide)- b-poly(propylene oxide) copolymers of different composition in aqueous mixtures, 1. | The phase behavior (temperature vs composition) and microstructure for the two binary systems Pluronic 25R4 [(PO)19(EO)33(PO)19]-water and Pluronic 25R2 [(PO)21(EO)14(PO)21]-water have been studied by a combined experimental approach in the whole concentration range and from 5 to 80 degrees C. The general phase behavio... |
15465209 | In vivo determination of tumor oxygenation during growth and in response to carbogen breathing using 15C5-loaded alginate capsules as fluorine-19 magnetic resonance imaging oxygen sensors. | <h4>Purpose</h4>The objective was to present a method for the repeated noninvasive measurement of tumor oxygenation (Po(2)) over the whole period of tumor growth.<h4>Methods and materials</h4>A mixture of tumor homogenate (GH3 prolactinoma) and alginate capsules loaded with perfluoro-15-crown-5-ether (15C5) was injecte... |
15390089 | Preparation and enantioseparation characteristics of two chiral stationary phases based on mono(6(A)-azido-6(A)-deoxy)-perphenylcarbamoylated alpha- and gamma-cyclodextrin. | Two chiral stationary phases, ph-alpha-CD and ph-gamma-CD, were prepared from mono(6(A)-azido-6(A)-deoxy)perphenylcarbamoylated alpha- and gamma-cyclodextrin immobilized onto silica gel via the Staudinger reaction. The chromatographic characteristics of these two chiral stationary phases were evaluated. The influence o... |
15465340 | Nucleotide analogues containing 2-oxa-bicyclo[2.2.1]heptane and l-alpha-threofuranosyl ring systems: interactions with P2Y receptors. | The ribose moiety of adenine nucleotide 3',5'-bisphosphate antagonists of the P2Y(1) receptor has been successfully substituted with a rigid methanocarba ring system, leading to the conclusion that the North (N) ring conformation is preferred in receptor binding. Similarly, at P2Y(2) and P2Y(4) receptors, nucleotides c... |
15465012 | Human ABCA3, a product of a responsible gene for abca3 for fatal surfactant deficiency in newborns, exhibits unique ATP hydrolysis activity and generates intracellular multilamellar vesicles. | ABCA3 is highly expressed at the membrane of lamellar bodies in alveolar type II cells, in which pulmonary surfactant is stored. ABCA3 gene mutations cause fatal surfactant deficiency in newborns. We established HEK293 cells stably expressing human ABCA3 and analyzed the function. Exogenously expressed ABCA3 is glycosy... |
15454218 | Fluorescent sodium ion indicators based on the 1,7-diaza-15-crown-5 system. | A series of novel sodium ion-sensitive fluorescent reagents suitable for biological applications is described. The chelator nitrogen atom substituents affect the selectivity and affinity of cation binding, while the nature of the fluorophore determines the type of fluorescent response to metal ion chelation. |
15451545 | Delivery of all trans-retinoic acid (RA) to hepatocyte cell line from RA/galactosyl alpha-cyclodextrin inclusion complex. | All trans-retinoic acid (RA) plays a role in regulation of P450RAI gene expression. In this study, hepatocyte cell line (HepG2) was used to study an effect of RA released from RA/galactosyl alpha-cyclodextrin (GCD) inclusion complex on regulation of P450RAI gene expression. A delivery system composed of RA/GCD inclusio... |
15451543 | Evaluation of the bioavailability of flurbiprofen and its beta-cyclodextrin inclusion complex in four different doses upon oral administration to rats. | The dissolution profiles of flurbiprofen (Flu) and its beta-cyclodextrin inclusion complex (Flu/beta-CD) in buffer solutions at various pH values were examined. The percent dissolved at 15 min for Flu and Flu/beta-CD was almost 100% at pH 6.8 and 8.0 but the dissolution rate of Flu was extremely reduced at pH 1.2 and 4... |
15451539 | Characterisation of nimesulide-betacyclodextrins systems prepared by supercritical fluid impregnation. | The purpose of this study was to apply the supercritical CO(2) impregnation process for preparing solvent-free nimesulide (NMS)-betacyclodextrins (BCD) association systems with enhanced drug dissolution rate. Several drug-to-carrier molar ratios were tested (1:1; 1:2.5; 1:3.5) at different conditions of temperatures (4... |
15451538 | The solubilization of the poorly water soluble drug nifedipine by water soluble 4-sulphonic calix[n]arenes. | In this study, the solubilizing effect of 4-sulphonic calix[n]arenes on the poorly water soluble drug nifedipine was investigated. 4-Sulphonic calix[n]arenes are water-soluble phenolic cyclooligomers that form complexes with neutral molecules such as nifedipine. Solubility experiments were performed at 30 degrees C usi... |
15388308 | Stretching type II collagen with optical tweezers. | Collagens are the most abundant proteins of vertebrates and they provide mechanical and supportive functions in a wide range of connective tissues. Knowledge of the mechanical properties of single collagen molecules is essential in studying the self-assembly of collagen, the interaction between cells and extracellular ... |
15380411 | Sorption of dibenzofuran derivatives from aqueous solutions by beta-cyclodextrin polymers: an isosteric heat approach. | Crosslinked polymers containing beta-cyclodextrin units have been used to remove dibenzofuran and three of its derivatives from aqueous solutions close to their saturation concentrations. The temperature dependence behavior for the compounds analyzed shows significant differences, attributable both to the influence of ... |
15340914 | Structure of an anti-DNA fab complexed with a non-DNA ligand provides insights into cross-reactivity and molecular mimicry. | Antibodies that recognize DNA (anti-DNA) are part of the autoimmune response underlying systemic lupus erythematosus. To better understand molecular recognition by anti-DNA antibodies, crystallographic studies have been performed using an anti-ssDNA antigen-binding fragment (Fab) known as DNA-1. The previously determin... |
15340912 | Modeling correlated main-chain motions in proteins for flexible molecular recognition. | We describe a new method for modeling protein and ligand main-chain flexibility, and show its ability to model flexible molecular recognition. The goal is to sample the full conformational space, including large-scale motions that typically cannot be reached in molecular dynamics simulations due to the computational in... |
15308179 | Boronated epidermal growth factor as a delivery agent for neutron capture therapy of EGF receptor positive gliomas. | The purpose of the present study was to further evaluate a boronated dendrimer (BD)-epidermal growth factor bioconjugate (BD-EGF), administered by means of convection enhanced delivery (CED), as a molecular targeting agent for boron neutron capture therapy (BNCT) of the F98(EGFR) glioma. Twenty-four hours following CED... |
15308165 | Neutron capture therapy of epidermal growth factor (+) gliomas using boronated cetuximab (IMC-C225) as a delivery agent. | Cetuximab (IMC-C225) is a monoclonal antibody directed against both the wild-type and mutant vIII isoform of the epidermal growth factor receptor (EGFR). The purpose of the present study was to evaluate the monoclonal antibody (MoAb), cetuximab, as a boron delivery agent for neutron capture therapy (NCT) of brain tumor... |
15147818 | Monitoring the self-assembly of chitosan/glutaraldehyde/cysteamine/Au-colloid and the binding of human serum albumin with hesperidin. | A new method for monitoring, in real-time, the self-assembly of chitosan/glutaraldehyde/cysteamine (CGC) on the gold surface and the immobilization of Au-colloid on CGC membrane with piezoelectric quartz crystal impedance (PQCI) are firstly proposed. Cyclic voltammogram and electrochemical impedance spectroscopy were a... |
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