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12837061 | Self-assembly of chiral molecular polygons. | Treatment of 2,2'-diacetyl-1,1'-binaphthyl-6,6'-bis(ethyne), L-H2, with 1 equiv of trans-Pt(PEt3)2Cl2 led to a mixture of different sizes of chiral metallocycles [trans-(PEt3)2Pt(L)]n (n = 3-8, 1-6). Each of the chiral molecular polygons 1-6 was purified by silica gel column chromatography and characterized by 1H, 13C{... |
12835473 | Ca2+ sparks and embers of mammalian muscle. Properties of the sources. | Ca2+ sparks of membrane-permeabilized rat muscle cells were analyzed to derive properties of their sources. Most events identified in longitudinal confocal line scans looked like sparks, but 23% (1,000 out of 4,300) were followed by long-lasting embers. Some were preceded by embers, and 48 were "lone embers." Average s... |
12834341 | Cholesterol-dependent association of caveolin-1 with the transducin alpha subunit in bovine photoreceptor rod outer segments: disruption by cyclodextrin and guanosine 5'-O-(3-thiotriphosphate). | Evidence suggests that caveolins, 21-24 kDa cholesterol-binding proteins that generally reside in specialized detergent-resistant membrane microdomains, act as signaling scaffolds. Detergent-resistant membranes isolated from rod outer segments (ROS) have been previously shown to contain the photoreceptor G-protein, tra... |
12832469 | Sum1 and Ndt80 proteins compete for binding to middle sporulation element sequences that control meiotic gene expression. | A key transition in meiosis is the exit from prophase and entry into the nuclear divisions, which in the yeast Saccharomyces cerevisiae depends upon induction of the middle sporulation genes. Ndt80 is the primary transcriptional activator of the middle sporulation genes and binds to a DNA sequence element termed the mi... |
12832066 | Energy transfer in a single self-aggregated photosynthetic unit. | The primary events of bacterial photosynthesis rely on the interplay of various specialized protein complexes organized in a supramolecular structure commonly termed the photosynthetic unit (PSU), which consists of the photochemical reaction center and of an associated antenna network. Employing single-molecule spectro... |
12833291 | Cyclodextrin phosphanes as first and second coordination sphere cavitands. | The binding properties of two alpha-cyclodextrins, each containing two C(5)-linked "CH(2)PPh(2)" units, L 1 (A,D-substituted) and L 2 (A,C-substituted), have been investigated. Both ligands readily form transition-metal chelate complexes in which the metal centres are immobilised at the cavity entrance. Although diphos... |
12833282 | N,N'-disubstituted ureas: influence of substituents on the formation of supramolecular polymers. | Symmetrical N,N'-disubstituted ureas have been synthesized and characterized. Among them, the branched dialkylureas prepared are highly soluble in organic media. Moreover, the solutions obtained are very viscous in heptane, if the branched alkyl groups are not too bulky (i.e. a methyl group on the alpha carbon, or an e... |
12833257 | Synthesis and characterization of 2,3-di-O-alkylated amyloses: hydrophobic substitution destabilizes helical conformation. | Amylose was selectively alkylated in the 2,3-O position of each anhydroglucose unit after trityl protection of the 6-OH groups. Alkyl iodides of varying chain length (C(2), C(5), C(8)) were coupled to amylose, and degrees of substitution (DSs) were varied between 0.3 and 1.8, as assessed by NMR analysis. Increasing amo... |
12829818 | Differential inhibition of RNA editing in hepatitis delta virus genotype III by the short and long forms of hepatitis delta antigen. | Hepatitis delta virus (HDV) produces two essential forms of the sole viral protein from the same open reading frame by using host RNA editing activity at the amber/W site in the antigenomic RNA. The roles of these two forms, HDAg-S and HDAg-L, are opposed. HDAg-S is required for viral RNA replication, whereas HDAg-L, w... |
12829509 | Redox-induced structural dynamics of Fe-heme ligand in myoglobin by X-ray absorption spectroscopy. | The Fe(III) --> Fe(II) reduction of the heme iron in aquomet-myoglobin, induced by x-rays at cryogenics temperatures, produces a thermally trapped nonequilibrium state in which a water molecule is still bound to the iron. Water dissociates at T > 160 K, when the protein can relax toward its new equilibrium, deoxy form.... |
12829508 | Concentration effect on the aggregation of a self-assembling oligopeptide. | Concentration is a key parameter in controlling the aggregation of self-assembling oligopeptides. By investigating the concentration effects, an aggregation mechanism of EAK16-II is proposed. Depending on the critical aggregation concentration (CAC) of EAK16-II, the oligopeptide aggregates into protofibrils through see... |
12829507 | Order, disorder, and perturbations in actin-aldolase rafts. | Actin-aldolase rafts provide insights into the use of rafts as models for three-dimensional actin bundles. Although aldolase has three twofold axes, filaments in actin-aldolase rafts were not strictly related by a twofold axis. Interfilament angles were on average +15 degrees off the expected 180 degrees, and most raft... |
12829502 | Conformational polymorphism of the amyloidogenic peptide homologous to residues 113-127 of the prion protein. | Conformational transitions are thought to be the prime mechanism of amyloid formation in prion diseases. The prion proteins are known to exhibit polymorphic behavior that explains their ability of "conformation switching" facilitated by structured "seeds" consisting of transformed proteins. Oligopeptides containing pri... |
12829501 | Structurally homologous all beta-barrel proteins adopt different mechanisms of folding. | Acidic fibroblast growth factors from human (hFGF-1) and newt (nFGF-1) (Notopthalamus viridescens) are 16-kDa, all beta-sheet proteins with nearly identical three-dimensional structures. Guanidine hydrochloride (GdnHCl)-induced unfolding of hFGF-1 and nFGF-1 monitored by fluorescence and far-UV circular dichroism (CD) ... |
12829484 | Functional and biochemical analysis of the type 1 inositol (1,4,5)-trisphosphate receptor calcium sensor. | Modulation of the type 1 inositol (1,4,5)-trisphosphate receptors (InsP(3)R1) by cytosolic calcium (Ca(2+)) plays an essential role in their signaling function, but structural determinants and mechanisms responsible for the InsP(3)R1 regulation by Ca(2+) are poorly understood. Using DT40 cell expression system and Ca(2... |
12829472 | Protocol for MM/PBSA molecular dynamics simulations of proteins. | Continuum solvent models have been employed in past years for understanding processes such as protein folding or biomolecular association. In the last decade, several attempts have been made to merge atomic detail molecular dynamics simulations with solvent continuum models. Among continuum models, the Poisson-Boltzman... |
12829467 | Membrane fission: model for intermediate structures. | Membrane budding-fission is a fundamental process generating intracellular carriers of proteins. Earlier works were focused only on formation of coated buds connected to the initial membrane by narrow membrane necks. We present the theoretical analysis of the whole pathway of budding-fission, including the crucial stag... |
12824479 | The role of side chain conformational flexibility in surface recognition by Tenebrio molitor antifreeze protein. | Two-dimensional nuclear magnetic resonance spectroscopy was used to investigate the flexibility of the threonine side chains in the beta-helical Tenebrio molitor antifreeze protein (TmAFP) at low temperatures. From measurement of the (3)J(alphabeta) (1)H-(1)H scalar coupling constants, the chi(1) angles and preferred r... |
12824478 | Crystal structures of fusion proteins with large-affinity tags. | The fusion of a protein of interest to a large-affinity tag, such as the maltose-binding protein (MBP), thioredoxin (TRX), or glutathione-S-transferase (GST), can be advantageous in terms of increased expression, enhanced solubility, protection from proteolysis, improved folding, and protein purification via affinity c... |
12824412 | OligoDesign: Optimal design of LNA (locked nucleic acid) oligonucleotide capture probes for gene expression profiling. | We report the development of new software, OligoDesign, which provides optimal design of LNA (locked nucleic acid) substituted oligonucleotides for functional genomics applications. LNAs constitute a novel class of bicyclic RNA analogs having an exceptionally high affinity and specificity toward their complementary DNA... |
12823980 | Insulin assembly damps conformational fluctuations: Raman analysis of amide I linewidths in native states and fibrils. | The crystal structure of insulin has been investigated in a variety of dimeric and hexameric assemblies. Interest in dynamics has been stimulated by conformational variability among crystal forms and evidence suggesting that the functional monomer undergoes a conformational change on receptor binding. Here, we employ R... |
12823969 | The supramolecular organization of collagen VI microfibrils. | Collagen VI has a ubiquitous distribution throughout connective tissues, and has key roles in linking cells and matrix macromolecules. We have generated three-dimensional reconstructions of collagen VI microfibrils using automated electron tomography (AET) in order to obtain new insights into the organisation of collag... |
12823008 | Hydrogen bonding in redox-modulated molecular recognition. An experimental and theoretical investigation. | Two receptors, a diaminotriazine derivative (DAT) and diamidopyridine (DAP), are complementary to the electroactive naphthalimide (N) through three-point hydrogen bonding. The association constants of the two receptors were evaluated for both the fully oxidized and the radical anion forms of N. In the oxidized state, t... |
12822978 | High quantum yield blue emission from water-soluble Au8 nanodots. | Prepared within biocompatible poly(amidoamine) dendrimer hosts, blue emitting Au8 nanodots were prepared with fluorescence quantum yields more than 100 times larger than any previously prepared. The strong size-dependent blue emission from these from monodisperse Au8 nanodots was measured to be 41% in aqueous solution ... |
12822976 | Synthetic catalytic pores. | Catalytic activity of a synthetic multifunctional pore is studied in large unilamellar vesicles under conditions where substrate and synthetic catalytic pore (SCP) approach the membrane either from the same side (cis catalysis) or from opposite sides (trans catalysis). A synthetic supramolecular rigid-rod beta-barrel w... |
12822971 | Synthesis and characterization of a macrocyclic near-infrared optical scaffold. | Macrocyclization of a bioactive peptide with a bifunctional near-infrared fluorescent optical probe gives a compound that retained the receptor binding affinity of the peptide and the photophysical properties of the optical probe. The robust nature of the new compound provides a structural framework for optimizing the ... |
12822966 | Two ion/ion charge inversion steps to form a doubly protonated peptide from a singly protonated peptide in the gas phase. | An approach is described to increase the degree of protonation of a polypeptide ion in the gas phase. Sequential charge inversion reactions involving the reactions of oppositely charged ions are used to yield a net increase in ion charge. The approach is illustrated here with the conversion of singly protonated bradyki... |
12824260 | Role of hypoxia during normal retinal vessel development and in experimental retinopathy of prematurity. | <h4>Purpose</h4>To test the hypothesis that retinal hypoxia is present during vascular development in normal rat pups and in a newborn rat model of retinopathy of prematurity (ROP).<h4>Methods</h4>Preretinal vitreous PO(2) measurements were made during room air breathing using (19)F magnetic resonance spectroscopy (MRS... |
12821156 | The first intron of the murine beta-casein gene contains a functional promoter. | Caseins are the major milk proteins in most mammals. Together with calcium and phosphate they form the casein micelle. The corresponding casein genes are clustered in mammalian genomes and their expression is coordinately regulated with regard to developmental and tissue specificity. Casein gene promoters are responsiv... |
12821448 | Biosynthetic origin of hygromycin A. | Hygromycin A, an antibiotic produced by Streptomyces hygroscopicus, is an inhibitor of bacterial ribosomal peptidyl transferase. The antibiotic binds to the ribosome in a distinct but overlapping manner with other antibiotics and offers a different template for generation of new agents effective against multidrug-resis... |
12818819 | Conformational stability of a model protein (bovine serum albumin) during primary emulsification process of PLGA microspheres synthesis. | The goal of this study was to investigate the conformational stability of a model protein, bovine serum albumin (BSA), during the primary emulsification process of poly(D,L-lactide-co-glycolide) (PLGA) microspheres preparation. Differential scanning calorimeter (DSC) was utilized to assess the conformational structure ... |
12818815 | Efficacy of clofazimine-modified cyclodextrin against Mycobacterium avium complex in human macrophages. | Clofazimine, a water insoluble substituted iminophenazine derivative with anti-mycobacterial and anti-inflammatory activity, is recommended by the WHO for the treatment of leprosy. It is also active against disseminated Mycobacterium avium complex (MAC) disease in HIV-infected patients. Recently, we achieved a 4000-fol... |
12819075 | Activation of toll-like receptor 2 (TLR2) and TLR4/MD2 by Neisseria is independent of capsule and lipooligosaccharide (LOS) sialylation but varies widely among LOS from different strains. | Lipooligosaccharide (LOS) structure and capsular polysaccharide of Neisseria meningitidis each greatly influence the virulence of the organism and the quality of host innate immune responses. In this study, we found that production of the proinflammatory cytokine tumor necrosis factor (TNF) by a human monocyte-derived ... |
12818946 | The pharmacokinetics and pharmacodynamics of propofol in a modified cyclodextrin formulation (Captisol) versus propofol in a lipid formulation (Diprivan): an electroencephalographic and hemodynamic study in a porcine model. | <h4>Unlabelled</h4>The currently marketed propofol formulation has a number of undesirable properties that are in part a function of the lipid emulsion formulation, including pain on injection, serious allergic reactions, and the support of microbial growth. A modified cyclodextrin-based formulation of propofol (sulfob... |
12814880 | Use of tracer tests to evaluate the impact of enhanced-solubilization flushing on in-situ biodegradation. | Tracer tests were conducted to evaluate the effect of a complexing sugar flush (CSF) on in-situ biodegradation potential at a site contaminated by jet fuel, solvents, and other organic compounds. Technical-grade hydroxypropyl-beta-cyclodextrin was used during the CSF study, which was conducted in a hydraulically isolat... |
12689332 | Deep-apical tubules: dynamic lipid-raft microdomains in the brush-border region of enterocytes. | The brush border of small intestinal enterocytes is highly enriched in cholesterol- and glycosphingolipid-containing membrane microdomains, commonly termed as lipid 'rafts'. Functionally, transcytosis of IgA and exocytosis of newly made brush-border proteins in enterocytes occur through apical lipid raft-containing com... |
12813095 | The ATPase FliI can interact with the type III flagellar protein export apparatus in the absence of its regulator, FliH. | Salmonella FliI is the ATPase that drives flagellar protein export. It normally exists as a complex together with the regulatory protein FliH. A fliH null mutant was slightly motile, with overproduction of FliI resulting in substantial improvement of its motility. Mutations in the cytoplasmic domains of FlhA and FlhB, ... |
12813071 | Common and distinguishing regulatory and expression characteristics of the highly related KorB proteins of streptomycete plasmids pIJ101 and pSB24.2. | The conjugative plasmid pIJ101 of the spore-forming bacterium Streptomyces lividans contains a regulatory gene, korB, whose product is required to repress potentially lethal expression of the pIJ101 kilB gene. The KorB protein also autoregulates korB gene expression and may be involved in control of pIJ101 copy number.... |
12812987 | Distinct chaperone mechanisms can delay the formation of aggresomes by the myopathy-causing R120G alphaB-crystallin mutant. | A familial form of desmin-related myopathy (DRM) is associated with a missense mutation (R120G) in alphaB-crystallin (alphaB) and is characterized by intracellular desmin aggregation. Because alphaB is a molecular chaperone that participates in the assembly of desmin filaments, it has been suggested that the desmin agg... |
12810913 | Aminoacylation of an unusual tRNA(Cys) from an extreme halophile. | The extreme halophile Halobacterium species NRC-1 overcomes external near-saturating salt concentrations by accumulating intracellular salts comparable to those of the medium. This raises the fundamental question of how halophiles can maintain the specificity of protein-nucleic acid interactions that are particularly s... |
12809719 | Sesquiterpene constituents from the liverwort Bazzania japonica. | The hydrodistillation products of the liverwort Bazzania japonica were separated by preparative gas chromatography (GC) and investigated by spectroscopic methods. Seven unknown compounds were isolated and identified by GC-MS and NMR. Four of them, the norsesquiterpene hydrocarbons 4-epi-11-nor-aristola-1(10),11-diene (... |
12805465 | Mutational analysis of the HLA class II interaction with Epstein-Barr virus glycoprotein 42. | Entry of Epstein-Barr virus (EBV) into B lymphocytes requires the binding of viral glycoprotein 42 (gp42), a C-type lectin family member, to HLA class II. Recently, the structure of the gp42:HLA-DR1 complex was determined. In order to confirm the interaction as determined in the structural study and to identify other p... |
12805454 | Antibody-dependent enhancement of Ebola virus infection. | Most strains of Ebola virus cause a rapidly fatal hemorrhagic disease in humans, yet there are still no biologic explanations that adequately account for the extreme virulence of these emerging pathogens. Here we show that Ebola Zaire virus infection in humans induces antibodies that enhance viral infectivity. Plasma o... |
12805452 | Kinetic analysis of binding interaction between the subgroup A Rous sarcoma virus glycoprotein SU and its cognate receptor Tva: calcium is not required for ligand binding. | Tva is the receptor for subgroup A Rous sarcoma virus, and it contains a single LDL-A module which is the site of virus interaction. In this study, we expressed the entire extracellular region of Tva (referred to as Ecto-Tva) as a GST fusion protein and characterized its refolding properties. We demonstrated that the c... |
12805440 | Activation of tumor antigen-specific cytotoxic T lymphocytes (CTLs) by human dendritic cells infected with an attenuated influenza A virus expressing a CTL epitope derived from the HER-2/neu proto-oncogene. | The development of cancer vaccines requires approaches to induce expansion and functional differentiation of tumor antigen-specific cytotoxic T lymphocyte (CTL) effectors which posses cytolytic capability and produce cytokines. Efficient induction of such cells is hindered by the poor immunogenicity of tumor antigens a... |
12805434 | Second-strand genome conversion of adeno-associated virus type 2 (AAV-2) and AAV-5 is not rate limiting following apical infection of polarized human airway epithelia. | Recombinant adeno-associated virus type 5 (rAAV-5) is known to efficiently transduce airway epithelia via apical infection. In contrast, rAAV-2 has been shown to be inherently ineffective at transducing airway epithelia from the apical surface. However, tripeptide proteasome inhibitors (such as LLnL) can dramatically e... |
12804916 | Binding of poly(amido amine) dendrimer to sodium hyaluronate in aqueous NaCl solution. | Binding of poly(amido amine) dendrimer to sodium hyaluronate (NaHA) in aqueous 0.25 M NaCl solution has been investigated by static light scattering. It was observed that the apparent weight-average molecular weight and the radius of gyration increase with the ratio of NH(2) terminal groups in the dendrimer to the carb... |
12798201 | Pullulan-cyclodextrin microspheres. A chromatographic approach for the evaluation of the drug-cyclodextrin interactions and the determination of the drug release profiles. | Pullulan microspheres containing cyclodextrin (CyD) were obtained by chemical crosslinking with epichlorohydrin of an alkaline solution of pullulan (Pul) and alpha-, beta- or gamma-CyD. The amount of alpha-, beta- and gamma-CyD in microspheres was 120, 156, and 138 micromol/g, respectively, as determined from the perce... |
12798180 | Development and validation of a capillary zone electrophoresis method for the determination of ephedrine and related compounds in urine without extraction. | A capillary zone electrophoresis (CZE) method, with UV detection and in the presence of dimethyl-beta-CD, was optimized by means of an experimental design for the separation and the simultaneous quantitation of ephedrine, pseudoephedrine, norephedrine (phenylpropanolamine) and norpseudoephedrine (cathine) in urine with... |
12788460 | Study on vitamin K3-cyclodextrin inclusion complex and analytical application. | The inclusion interaction of the complexes between Vitamin K(3) (VK(3)) and beta-cyclodextrin (beta-CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and sulfobutylether-beta-cyclodextrin (SBE-beta-CD) were studied by using steady-state fluorescence measurements. The various factors affecting the inclusion process were... |
12788447 | Fourier-transform Raman and infrared spectroscopic analysis of 2-nitro-tetraphenylporphyrin and metallo-2-nitro-tetraphenylporphyrins. | The Fourier-transform Raman (FT-Raman) and infrared (FT-IR) spectra of 2-nitro-tetraphenylporphyrin (2-NO(2)-TPP), nickel-2-nitro-tetraphenylporphyrin (Ni-2-NO(2)-TPP), zinc-2-nitro-tetraphenylporphyrin (Zn-2-NO(2)-TPP) and copper-2-nitro-tetraphenylporphyrin (Cu-2-NO(2)-TPP) were acquired for the first time and carefu... |
12783803 | Laminin alpha subunits and their role in C. elegans development. | Laminins are heterotrimeric (alpha/beta/gamma) glycoproteins that form a major polymer within basement membranes. Different alpha, beta and gamma subunits can assemble into various laminin isoforms that have different, but often overlapping, distributions and functions. In this study, we examine the contributions of th... |
12835418 | Determining the basis of channel-tetramerization specificity by x-ray crystallography and a sequence-comparison algorithm: Family Values (FamVal). | We have developed a semiempirical algorithm called Family Values (FamVal), which identifies residues that encode functional specificity in a protein sequence. Given a multiple sequence alignment (MSA) grouped into functionally distinct subfamilies, FamVal calculates a specificity score for each subfamily at every amino... |
12855869 | The gossypol-cyclododecanone (1/2) inclusion complex. | Gossypol and cyclododecanone crystallize at room temperature as an inclusion complex in a 1:2 molar ratio. This complex, viz. 1,1',6,6',7,7'-hexahydroxy-5,5'-diisopropyl-3,3'-dimethyl-2,2'-binaphthalene-8,8'-dicarboxaldehyde-cyclododecanone (1/2), C(30)H(30)O(8).2C(12)H(22)O, is unusual in that there is limited intermo... |
12855868 | Supramolecular structures of 2-cyano-3-dimethylamino-N-(4-methylphenyl)acrylamide and 2-cyano-3-dimethylamino-N-(2-methoxyphenyl)acrylamide. | In the title compounds, C(13)H(15)N(3)O, (I), and C(13)H(15)N(3)O(2), (II), the dihedral angles between the planes of the phenyl ring and the amide group are 4.1 (1) and 20.7 (1) degrees, respectively. The molecules adopt a fully extended conformation, aided by intramolecular interactions. The molecular structures of (... |
12835480 | Restricted clonal expression of IL-2 by naive T cells reflects differential dynamic interactions with dendritic cells. | Limited frequencies of T cells express IL-2 in primary antigenic responses, despite activation marker expression and proliferation by most clonal members. To define the basis for restricted IL-2 expression, a videomicroscopic system and IL-2 reporter transgenic model were used to characterize dendritic cell (DC)-T cell... |
16241244 | Orientational ordering and chiral symmetry breaking in organic monolayers composed of disklike mesogenic molecules: molecular theory and computer simulations. | Orientational ordering of disklike molecules on a flat surface is investigated using a molecular-statistical theory and Monte-Carlo simulations. The theory is based on the two-dimensional orientational order parameter for molecules with a threefold symmetry axis, and on a simple model interaction potential which has be... |
12869208 | Comparison of Plasmodium falciparum transfection methods. | The development of an electroporation based transfection method for Plasmodium falciparum has been very successful for the study of some genes but its efficiency remains very low. While alternative approaches have been documented, electroporation of infected red blood cells generally remains the method of choice for in... |
12832423 | Cellular cholesterol depletion triggers shedding of the human interleukin-6 receptor by ADAM10 and ADAM17 (TACE). | Interleukin-6 (IL-6) activates cells by binding to the membrane-bound IL-6 receptor (IL-6R) and subsequent formation of a glycoprotein 130 homodimer. Cells that express glycoprotein 130, but not the IL-6R, can be activated by IL-6 and the soluble IL-6R which is generated by shedding from the cell surface or by alternat... |
12832396 | A novel class of secreted hydrophobic proteins is involved in aerial hyphae formation in Streptomyces coelicolor by forming amyloid-like fibrils. | Streptomycetes exhibit a complex morphological differentiation. After a submerged mycelium has been formed, filaments grow into the air to septate into spores. A class of eight hydrophobic secreted proteins, ChpA-H, was shown to be instrumental in the development of Streptomyces coelicolor. Mature forms of ChpD-H are u... |
12832616 | Dynamic, yet structured: The cell membrane three decades after the Singer-Nicolson model. | The fluid mosaic membrane model proved to be a very useful hypothesis in explaining many, but certainly not all, phenomena taking place in biological membranes. New experimental data show that the compartmentalization of membrane components can be as important for effective signal transduction as is the fluidity of the... |
12832615 | Factors modulating conformational equilibria in large modular proteins: a case study with cobalamin-dependent methionine synthase. | In the course of catalysis or signaling, large multimodular proteins often undergo conformational changes that reposition the modules with respect to one another. The mechanisms that direct the reorganization of modules in these proteins are of considerable importance, but distinguishing alternate conformations is a ch... |
12830360 | Quantitative enantiomeric analysis of chlorcyclizine, hydroxyzine, and meclizine by capillary electrophoresis. | A simple capillary zone electrophoresis method was developed for the quantitative enantiomeric analysis of piperazine antihistamines with teratogenic suspicion in animals. Enantioseparation of chlorcyclizine, hydroxyzine, and meclizine was performed in glycine buffer (0.6 mol L(-1); pH 3.00) with sulfated beta-cyclodex... |
12829796 | Male-specific lethal complex of Drosophila targets activated regions of the X chromosome for chromatin remodeling. | The male-specific lethal (MSL) complex of Drosophila is responsible for the presence of a monoacetylated isoform of histone H4 (H4Ac16), found exclusively on the X chromosome of males. This particular covalent modification of histone H4 is correlated with a 2-fold enhancement of the transcription of most X-linked genes... |
12826615 | Asymmetric localization of flotillins/reggies in preassembled platforms confers inherent polarity to hematopoietic cells. | Hematopoietic cells have long been defined as round, nonpolar cells that show uniform distribution of cell surface-associated molecules. However, recent analyses of the immunological synapse and the importance of lipid microdomains in signaling have shed new light on the aspect of lymphocyte polarization during the act... |
12821776 | Directed nucleation assembly of DNA tile complexes for barcode-patterned lattices. | The programmed self-assembly of patterned aperiodic molecular structures is a major challenge in nanotechnology and has numerous potential applications for nanofabrication of complex structures and useful devices. Here we report the construction of an aperiodic patterned DNA lattice (barcode lattice) by a self-assembly... |
12847304 | Molecular packing in network-forming collagens. | Collagen is the most abundant protein among vertebrates and occurs in virtually all multicellular animals. Collagen molecules are classified into 21 different types and differ in their sequence, weight, structure, and function, but they can be broadly subdivided into families. Type IV, VI, VIII, X, and dogfish egg case... |
12827235 | Usefulness of procalcitonin for diagnosing complicating sepsis in patients with cardiogenic shock. | <h4>Objective</h4>Patients in cardiogenic shock (CS) often present with signs of systemic inflammation that mimic infection, especially in the setting of multiple organ failure (MOF). To clarify the usefulness of procalcitonin (PCT) for diagnosing complicating sepsis in patients with CS, especially in the presence of M... |
16241191 | Molecular simulations of mesoscopic bilayer phases. | Dissipative particle dynamics simulations are used to study the self-assembly of lipids into bilayers. With a simple mesoscopic lipid-water model, we observe the formation of the liquid crystalline phase L(alpha) and gel phases in which the tails are interdigitated L(betaI) or noninterdigitated L(beta). For double-tail... |
12819853 | Voltammetric response of diclofenac-molecularly imprinted film modified carbon electrodes. | A voltammetric sensor for the determination of diclofenac was developed, based on the molecular recognition of the analyte by molecularly imprinted methacrylate-ethyleneglycol dimethacrylate co-polymers. Pre-polymerisation solutions were deposited onto the surface of a glassy carbon electrode and a polymer film was obt... |
12815102 | Glycation of the amyloid beta-protein by a nicotine metabolite: a fortuitous chemical dynamic between smoking and Alzheimer's disease. | The origin of Alzheimer's disease (AD) has been subjected to an intense amount of examination; however, a clear conclusion as to the nature of this crippling disease has yet to be identified. What is readily accepted is that a definitive marker of this disease is the aggregation of the amyloid beta-peptide (A beta) int... |
12815073 | Drosophila FACT contributes to Hox gene expression through physical and functional interactions with GAGA factor. | Chromatin structure plays a critical role in the regulation of transcription. Drosophila GAGA factor directs chromatin remodeling to its binding sites. We show here that Drosophila FACT (facilitates chromatin transcription), a heterodimer of dSPT16 and dSSRP1, is associated with GAGA factor through its dSSRP1 subunit, ... |
12930556 | Resolution and outcome of acute circulatory failure does not correlate with hemodynamics. | <h4>Introduction</h4>Hemodynamic goals in the treatment of acute circulatory failure (ACF) are controversial. In critical care, organ failures can be assessed using Sequential Organ Failure Assessment and its refinement, total maximal Sequential Organ Failure Assessment (TMS). We studied the associations between resolu... |
12811457 | Current research activity in biosensors. | Biosensors consist of a molecular recognition element and a transducer. Since the first biosensor was developed by Updike and Hicks many biosensors and their associated techniques have been studied and developed. In this review current research activity on the fundamentals and applications of biosensors is summarized. ... |
12805563 | The interplay of glycosylation and disulfide formation influences fibrillization in a prion protein fragment. | It is now accepted that the structural transition from cellular prion protein (PrPC) to proteinase K-resistant prion protein scrapie (PrPSc) is the major event leading to transmissible spongiform encephalopathies. Although the mechanism of this transition remains elusive, glycosylation has been proposed to impede the P... |
12855857 | The molecular and supramolecular structures of the isomeric compounds 5,7-dimethoxyimidazo[1,2-c]pyrimidine and 7-methoxy-1-methylimidazo[1,2-a]pyrimidin-5(1H)-one. | The supramolecular structures of the isomeric compounds 5,7-dimethoxyimidazo[1,2-c]pyrimidine, C(8)H(9)N(3)O(2), (I), and 7-methoxy-1-methylimidazo[1,2-a]pyrimidin-5(1H)-one, C(8)H(9)N(3)O(2), (II), are determined by weak C-H.N and C-H.O hydrogen bonds in (I), which generate alternating linked centrosymmetric R(2)(2)(8... |
12802014 | Carbohydrate-dependent signaling from the phosphatidylglucoside-based microdomain induces granulocytic differentiation of HL60 cells. | Glycosphingolipids form glycosphingolipid signaling microdomains. Here, we report an unrecognized type of phosphatidylglucoside (PhGlc)-based lipid microdomain in HL60 cells. Treatment of cells with rGL-7, which preferentially reacts with PhGlc, induced differentiation of HL60 cells. This was manifested by the appearan... |
12802011 | Efficient biotinylation and single-step purification of tagged transcription factors in mammalian cells and transgenic mice. | Proteomic approaches require simple and efficient protein purification methodologies that are amenable to high throughput. Biotinylation is an attractive approach for protein complex purification due to the very high affinity of avidin/streptavidin for biotinylated templates. Here, we describe an approach for the singl... |
16241193 | Is the binary hard-sphere mixture a good reference system for sterically stabilized colloids? | The relevance of the hard-sphere mixture model as a starting point for the study of sterically stabilized colloids is discussed. Two physical situations are distinguished: true molecular solvent-colloid mixtures, and pseudobinary mixtures of two supramolecular objects. For the former, the limitation of the hard-sphere ... |
12791688 | Constitutive localization of the gonadotropin-releasing hormone (GnRH) receptor to low density membrane microdomains is necessary for GnRH signaling to ERK. | Specialized membrane microdomains known as lipid rafts are thought to contribute to G-protein coupled receptor (GPCR) signaling by organizing receptors and their cognate signaling molecules into discrete membrane domains. To determine if the GnRHR, an unusual member of the GPCR superfamily, partitions into lipid rafts,... |
12788917 | Type XIX collagen purified from human umbilical cord is characterized by multiple sharp kinks delineating collagenous subdomains and by intermolecular aggregates via globular, disulfide-linked, and heparin-binding amino termini. | Type XIX collagen was discovered from the sequence of rhabdomyosarcoma cDNA clones. The chain is composed of a 268-residue amino terminus, an 832-residue discontinuous collagenous region, and a 19-residue carboxyl peptide. Light microscopy immunohistochemistry of adult human tissues demonstrated that type XIX is locali... |
12782682 | Dominant cataracts result from incongruous mixing of wild-type lens connexins. | Gap junctions are composed of proteins called connexins (Cx) and facilitate both ionic and biochemical modes of intercellular communication. In the lens, Cx46 and Cx50 provide the gap junctional coupling needed for homeostasis and growth. In mice, deletion of Cx46 produced severe cataracts, whereas knockout of Cx50 res... |
24944384 | Effects of trapidil on intestinal mucosal barrier function and bacterial translocation after intestinal ischemia and reperfusion in an experimental rat model. | <h4>Background</h4>Intestinal ischemia and reperfusion may be the primary triggers of mucosal barrier impairment, cytokine expression, and bacterial translocation (BT). Trapidil is a phosphodiesterase and platelet-derived growth factor inhibitor that reduces lipid peroxidation and inhibits the production of cytokines.<... |
19265995 | Pasteuria spp.: Systematics and Phylogeny of These Bacterial Parasites of Phytopathogenic Nematodes. | Pasteuria spp. include endospore-forming bacterial pathogens of cladoceran crustaceans and plant-parasitic nematodes. Propagation of these nematode pathogens requires attachment of soilborne endospores to nematode hosts, infection, growth, sporulation, and release of endospores to repeat the cycle of infection and prop... |
18969071 | Spectrofluorimetric determination of stoichiometry and association constants of the complexes of harmane and harmine with beta-cyclodextrin and chemically modified beta-cyclodextrins. | The association characteristics of the inclusion complexes of the beta-carboline alkaloids harmane and harmine with beta-cyclodextrin (beta-CD) and chemically modified beta-cyclodextrins such as hydroxypropyl-beta-cyclodextrin (HPbeta-CD), 2,3-di-O-methyl-beta-cyclodextrin (DMbeta-CD) and 2,3,6-tri-O-methyl-beta-cyclod... |
18969069 | A fluorimetric study of pindolol and its complexes with cyclodextrins. | Spectrofluorimetric characteristics of pindolol have been investigated with the aim of using this technique for analytical determinations. Other monosubstituted indole derivatives, 4-methoxy and 5-methoxyindole, have been also studied for comparative purposes. Corrected excitation and emission wavelengths in different ... |
18969059 | Determination of tyrosine through a FIA-direct chemiluminescence procedure. | A new FI-direct chemiluminescence method is proposed for the determination of tyrosine, based on the oxidation of the amino acid by K(3)Fe(CN)(6) in potassium hydroxide medium, at room temperature and enhanced by the presence of beta-cyclodextrin and formic acid. The dynamic range was linear over the range 1.0-10.0 mgl... |
18969077 | Anti-oxygen-quenching room temperature phosphorescence stabilized by deoxycholate aggregate. | Oxygen is the most effective dynamic quencher in liquid room temperature phosphorimetry (LRTP). Using oxygen scavenger to achieve significant or more sensitive RTP signals may bring about kinds of trouble in many cases and is apparently not very convenient in procedures. To date a few examples on LRTP without deoxygena... |
18969046 | Spectrofluorimetric study of the beta-cyclodextrin-ibuprofen complex and determination of ibuprofen in pharmaceutical preparations and serum. | The inclusion complexation of ibuprofen in beta-cyclodextrin (beta-CD) has been examined by means of spectrofluorimetry at both acid and alkaline pH. The results suggest that stable 1:1 complexes are formed in both media. The analysis of the pK(a) values for ibuprofen in both the absence and presence of beta-CD (4.12 a... |
16256574 | Electrochemical catalysis with redox polymer and polyion-protein films. | Supramolecular redox-active assemblies on electrodes are of fundamental interest and can be used to create functioning devices such as sensors, biosensors, and bioreactors. The ability of redox-active films to mediate electron transfer reactions in 3-D dramatically increases the sensitivity with which target molecules ... |
14768950 | Models for natural killer cell repertoire formation. | Natural killer (NK) cells lyse only cells that do not express sufficient levels of self class I MHC molecules. Inhibition of lysis is mediated by inhibitory receptors expressed by NK cells, such as the murine Ly49 receptors, that bind to MHC class I molecules. Since inhibitory receptor genes and MHC class I genes are l... |
12749895 | Tetrahydroquinoline-based selective estrogen receptor modulators (SERMs). | A new series of estrogen receptor ligands based on a 6-hydroxy-tetrahydroquinoline scaffold is described, in addition to their binding affinity and functional activity in MCF-7 cells. Several 1,2-disubstituted tetrahydroquinolines bearing a basic side chain were shown to be high affinity ligands and antagonists in the ... |
12748345 | A retrospective 5-year study in Moldova of acute renal failure due to leptospirosis: 58 cases and a review of the literature. | <h4>Background</h4>Renal involvement [as acute renal failure (ARF)] is a prominent feature of both mild and severe leptospirosis-a re-emerging infectious disease. Few large series describe in detail clinical and laboratory features of cases with ARF and their outcome.<h4>Methods</h4>We performed a retrospective analysi... |
12746305 | Lipoprotein enhancement of ovarian theca-interstitial cell steroidogenesis: relative contribution of scavenger receptor class B (type I) and adenosine 5'-triphosphate- binding cassette (type A1) transporter in high-density lipoprotein-cholesterol transport and androgen synthesis. | The theca-interstitial cells take up plasma high-density lipoprotein (HDL)- and low-density-lipoprotein-derived cholesterol to convert into steroid hormones. The uptake of HDL-derived cholesterol is mediated by the scavenger receptor, class B, type I (SR-BI). In nonsteroidogenic cells, HDL-stimulated efflux of choleste... |
12743284 | Hepatitis B virus X protein and simian virus 5 V protein exhibit similar UV-DDB1 binding properties to mediate distinct activities. | The UV-damaged DNA-binding activity protein (UV-DDB) consists of two subunits, DDB1 and DDB2, and functions in DNA repair and cell cycle regulation. The DDB1 subunit is a target for the hepatitis B virus X protein (HBx). Binding of HBx to DDB1 interferes with cell growth and viability in culture and has been implicated... |
12743282 | Binding of CCAAT displacement protein CDP to adenovirus packaging sequences. | Adenovirus (Ad) type 5 DNA packaging is initiated in a polar fashion from the left end of the genome. The packaging process is dependent upon the cis-acting packaging domain located between nucleotides 194 and 380. Seven A/T-rich repeats have been identified within this domain that direct packaging. A1, A2, A5, and A6 ... |
12743278 | Formation of disulfide-linked complexes between the three minor envelope glycoproteins (GP2b, GP3, and GP4) of equine arteritis virus. | Equine arteritis virus (EAV) is an enveloped, positive-stranded RNA virus belonging to the family Arteriviridae of the order NIDOVIRALES: Six transmembrane proteins have been identified in EAV particles: the nonglycosylated membrane protein M and the glycoprotein GP(5) (previously named G(L)), which occur as disulfide-... |
12706042 | Development of a method for direct visual determination of aflatoxin production by colonies of the Aspergillus flavus group. | This report describes a simple, rapid and reliable method for screening the aflatoxin production by moulds of the Aspergillus flavus group. Strains were cultivated on yeast extract agar to which methylated beta-cyclodextrin derivative plus sodium desoxycholate was added. Production of aflatoxins was readily detectable ... |
12704680 | Efficacy of dendrimer-mediated angiostatin and TIMP-2 gene delivery on inhibition of tumor growth and angiogenesis: in vitro and in vivo studies. | Gene transfer is an attractive approach to fight cancer by targeting cancer cells or their vasculature. Our study reports the inhibition of tumor growth and angiogenesis by a nonviral method using dendrimers associated with 36-mer anionic oligomers (ON36) for delivering angiostatin (Kringle 1-3) and tissue inhibitor of... |
12676235 | Prediction of the multimeric assembly of staphylococcal enterotoxin A with cell-surface protein receptors. | Staphylococcal enterotoxin A (SEA) cross-links two class II major histocompatibility complex (MHC) molecules and forms a multimeric assembly with T-cell receptors (TcRs). The X-ray crystal structure of SEA has been solved, yet details describing molecular recognition and association remain unclear. We present a structu... |
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