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14960713 | The diverse superfamily of lysine acetyltransferases and their roles in leukemia and other diseases. | Acetylation of the epsilon-amino group of lysine residues, or N(epsilon)-lysine acetylation, is an important post-translational modification known to occur in histones, transcription factors and other proteins. Since 1995, dozens of proteins have been discovered to possess intrinsic lysine acetyltransferase activity. A... |
15252468 | Aqueous solution chemistry of [Mo3CuSe4]n+ (n = 4, 5) and [W3CuQ4]5+ (Q = S, Se) clusters. | The triangular cluster [Mo3Se4(H2O)9]4+ reacts with Cu turnings to give a new heterometallic cuboidal cluster [Mo3CuSe4(H2O)10]4+(purple; UV/Vis lambda(epsilon): 352(3907), 509(2613)). The reaction of [Mo3Se4(H2O)9]4+ with CuCl afforded the 5+ cube [Mo3CuSe4(H2O)10]5+(red; UV/Vis lambda(epsilon): 356(5406), 500(3477)).... |
15252508 | Molecular and supramolecular features of oxo-peroxovanadium complexes containing O3N, O2N2 and ON3 donor sets. | The complexes [VO(O2)Hbpa]+ (1a), [VO(O2)bpa] (1b, Hbpa = bis(picolyl)-beta-alanine), [VO(O2)heida]- (2, H2heida =N-(2-hydroxyethyl)iminodiacetic acid), [VO(O2)(3OH-pic)2]- (3a), [VO(O2)(3OH-pic)2]-/[V(O2)2(3OH-pic)2]- (3b, 3OH-pic = 3-hydroxypicolinic acid), [VO(O2)(3OH-pa)2] (6, 3OH-pa = 3-hydroxypicolylamide), [VO2(... |
15252506 | Two complexes of Sm(II) with crown ethers-electrochemical synthesis, structure and spectroscopy. | Two complexes of divalent samarium have been synthesized by electrochemical reduction in methanol-tetrahydrofuran solutions: [Sm(18-crown-6)(ClO4)2] and [Sm(15-crown-5)2](ClO4)2. In [Sm(18-crown-6)(ClO4)2] the metal cation is ten-coordinate and its coordination sphere comprises six oxygen atoms of the crown ligand and ... |
15010767 | How is the CH/pi interaction important for molecular recognition? | Ab initio calculations illustrate that CH/pi attractions significantly contribute to host-guest complexation, but are not always a direct factor in molecular recognition. |
15010765 | Anion control of ligand self-recognition in a triple helical array. | Self-assembly of the ligand L(1) with Co(2+) into a dinuclear triple helicate [Co(2)(L(1))(3)](4+) produces an anion binding pocket which encapsulates perchlorate anions. Furthermore we demonstrate how this ability to bind anions can control ligand self-recognition properties. |
15010761 | A helical array of pendant fullerenes on a helical poly(phenylacetylene) induced by non-covalent chiral interactions. | Novel [60]fullerene-based poly(phenylacetylene)s prepared by the copolymerization of achiral phenylacetylenes bearing a C(60) or crown ether pendant form a one-handed helix upon complexation with L- and D-alanine, yielding a helical array of the pendant fullerenes with a predominant screw-sense along the polymer backbo... |
15004358 | Tetra-mu-2-fluorobenzoato-bis[aqua(4,4'-bipyridine)(2-fluorobenzoato)lanthanum(III)]. | Each La3+ ion in the title complex, tetra-micro-2-fluorobenzoato-kappa10 O:O';O:O,O';O:O';O,O':O'-bis[aqua(4,4'-bipyridine-kappaN)(2-fluorobenzoato-kappaO)lanthanum(II)], [La(C7H4FO2)6(C10H8N2)2(H2O)2], is coordinated by six O atoms from the carboxylate groups of five 2-fluorobenzoate ligands, one O atom from a water m... |
15004356 | A quadrupole-quadrupole stacking synthon in (2,3,5,6-tetrafluorobenzenethiolato-kappaS)(triphenylphosphine-kappaP)gold(I). | The title compound, [Au(C6HF4S)(C18H15P)], with both aromatic and fluorinated aromatic rings in its molecular system, shows dimerization through a quadrupole-quadrupole stacking synthon. The dimer further aggregates through intermolecular pi-pi stacking and C-H...pi interactions, giving a supramolecular three-dimension... |
15252503 | Steric control in the oligomerisation of phosphazane dimers; towards new phosphorus-nitrogen macrocycles. | The reaction of [ClP(mu-NtBu)]2 (1) with H2O (1 : 2 equivalents) in the presence of excess Et3N gives the new chain compound [(mu-O)[P(mu-NtBu)2P(H)=O]2] (3), consisting of two P2N2 rings linked by a mu-O atom and terminating in P(V)(H)=O groups. A similar chain species is obtained from the reaction of the lithiate of ... |
14973628 | Well-defined self-assembling supramolecular structures in water containing a small amount of C60. | In this communication, we report for the first time on the spherical bilayer vesicle formation of a dendritic C(60)-amphiphile-surfactant hybrid in aqueous solutions. |
15052366 | Photophysics of calixarenes bearing two or four dansyl fluorophores: charge, proton and energy transfers. | The photophysical properties of calixarenes bearing two and four dansyl derivatives (Calix-DANS2 and Calix-DANS4) were investigated in a CH(3)CN/H(2)O mixture (60 : 40 v/v). The carboxydansyl (DANS1) was used as a reference compound. The pH titration of DANS1 permits determination of two pK(A) values (2.4 and 6.3). The... |
14769936 | Molecular cloning and characterization of two Helicobacter pylori genes coding for plasminogen-binding proteins. | Helicobacter pylori binds a number of host cell proteins, including the plasma protein plasminogen, which is the proenzyme of the serine protease plasmin. Two H. pylori plasminogen-binding proteins have been described; however, no genes were identified. Here we report the use of a phage display library to clone two gen... |
14766724 | Stimulation of Xenopus laevis oocyte maturation by methyl-beta-cyclodextrin. | The cholesterol-depleting drug methyl-beta-cyclodextrin (Me-beta-CD) was tested for its effects on amphibian oocyte maturation, cholesterol depletion, and low-density membrane recovery. Progesterone-induced oocyte maturation was accelerated by pretreatment of cells with 5-50 mM Me-beta-CD in a dose-dependent manner. Tr... |
14767081 | Steric restrictions in protein folding: an alpha-helix cannot be followed by a contiguous beta-strand. | Using only hard-sphere repulsion, we investigated short polyalanyl chains for the presence of sterically imposed conformational constraints beyond the dipeptide level. We found that a central residue in a helical peptide cannot adopt dihedral angles from strand regions without encountering a steric collision. Consequen... |
14765128 | The phagocyte NADPH oxidase depends on cholesterol-enriched membrane microdomains for assembly. | The superoxide-producing phagocyte NADPH oxidase consists of a membrane-bound flavocytochrome b558 complex, and cytosolic factors p47phox, p67phox and the small GTPase Rac, which translocate to the membrane to assemble the active complex following cell activation. We here show that insolubility of NADPH oxidase subunit... |
14765124 | DNA topology, not DNA sequence, is a critical determinant for Drosophila ORC-DNA binding. | Drosophila origin recognition complex (ORC) localizes to defined positions on chromosomes, and in follicle cells the chorion gene amplification loci are well-studied examples. However, the mechanism of specific localization is not known. We have studied the DNA binding of DmORC to investigate the cis-requirements for D... |
14765115 | Molecular architecture of photosynthetic membranes in Rhodobacter sphaeroides: the role of PufX. | The effects of the PufX polypeptide on membrane architecture were investigated by comparing the composition and structures of photosynthetic membranes from PufX+ and PufX- strains of Rhodobacter sphaeroides. We show that this single polypeptide profoundly affects membrane morphology, leading to highly elongated cells c... |
14765113 | DIP (mDia interacting protein) is a key molecule regulating Rho and Rac in a Src-dependent manner. | Cell movement is driven by the coordinated regulation of cytoskeletal reorganization through Rho GTPases downstream of integrin and growth-factor receptor signaling. We have reported that mDia, a target protein of Rho, interacts with Src and DIP. Here we show that DIP binds to p190RhoGAP and Vav2, and that DIP is phosp... |
14765118 | Structural basis of HP1/PXVXL motif peptide interactions and HP1 localisation to heterochromatin. | HP1 family proteins are adaptor molecules, containing two related chromo domains that are required for chromatin packaging and gene silencing. Here we present the structure of the chromo shadow domain from mouse HP1beta bound to a peptide containing a consensus PXVXL motif found in many HP1 binding partners. The shadow... |
14973625 | A practical synthesis of amphiphilic cyclodextrins fully substituted with sugar residues on the primary face. | New amphiphilic cyclodextrins fully substituted with sugar residues on the primary face have been synthesised and enzymatically modified. |
14762171 | Cofilin peptide homologs interfere with immunological synapse formation and T cell activation. | The formation of supramolecular activation clusters within the immunological synapse, crucial for sustained signaling and T lymphocyte activation, requires costimulation-dependent reorganization of the actin cytoskeleton. Here we have identified the actin-remodeling protein cofilin as a key player in this process. Cell... |
15005800 | Late gestational lung hypoplasia in a mouse model of the Smith-Lemli-Opitz syndrome. | <h4>Background</h4>Normal post-squalene cholesterol biosynthesis is important for mammalian embryonic development. Neonatal mice lacking functional dehydrocholesterol Delta7-reductase (Dhcr7), a model for the human disease of Smith-Lemli-Opitz syndrome, die within 24 hours of birth. Although they have a number of bioch... |
14757816 | Freeze-frame inhibitor captures acetylcholinesterase in a unique conformation. | The 1,3-dipolar cycloaddition reaction between unactivated azides and acetylenes proceeds exceedingly slowly at room temperature. However, considerable rate acceleration is observed when this reaction occurs inside the active center gorge of acetylcholinesterase (AChE) between certain azide and acetylene reactants, att... |
18969317 | Study on the new fluorescence enhancement system of Zn-bis-(trimethylolaminomethane)-4-tert-butyl-disalicylicimine in the presence of beta-cyclodextrin and its analytical application. | A new bis-Schiff base ligand, bis-(trimethylolaminomethane)-4-tert-butyl-disalicylicimine (HL), was synthesized. The fluorescence intensity of HL-Zn(2+) complex was increased by about 8-fold upon addition of beta-cyclodextrin (beta-CD). The spectrofluorimetric determination of trace amounts of Zn(2+) based on the pheno... |
18969297 | Global and distribution analysis of fluorescence decays and spectrofluorimetric determination of stoichiometry and association constant of the inclusion complex of 2-amino-5,6-dimethyl-benzimidazole with beta-cyclodextrin. | The steady state and time-resolved fluorescence study of 2-amino-5,6-dimethyl-benzimidazole (ADBI) have been studied in aqueous solution of beta-cyclodextrin (beta-CD). The fluorescence decays were analyzed by global analysis and distribution analysis in order to get insight about the inclusion process. The fluorescenc... |
18516206 | Lipoprotein(a): biology and clinical importance. | Lipoprotein(a) [Lp(a)] is a unique lipoprotein that has emerged as an independent risk factor for developing vascular disease. Plasma Lp(a) levels above the common cut-off level of 300 mg/L place individuals at risk of developing heart disease particularly if combined with other lipid and thrombogenic risk factors. Stu... |
17191842 | Exploratory studies to investigate a linked prebiotic origin of RNA and coded peptides. | An introduction to the premise that RNA and genetically coded proteins should not be viewed as etiologically discrete entities in the origin of life is presented. This premise follows from the mutual interdependence of RNA and coded proteins in biology and the lack of prebiotically plausible constitutional self-assembl... |
15803741 | Nanoscale colloids in a freely adsorbing polymer solution: a Monte Carlo simulation study. | A key issue in nanoscale materials and chemical processing is the need for thermodynamic and kinetic models covering colloid-polymer systems over the mesoscopic length scale (approximately 1-100 nm). We have applied Monte Carlo simulations to attractive nanoscale colloid-polymer mixtures toward developing a molecular b... |
15803716 | Comparative study of electrochemically directed assembly versus conventional self-assembly of thioacetyl-terminated oligo(phenylene ethynylene)s on gold and platinum surfaces. | The assembly of thioacetyl-terminated oligo(phenylene ethynylene)s (OPEs) on Au and Pt surfaces under an electric potential (electrochemical assembly, EA) was compared to assembly at an open circuit (conventional self-assembly, CSA). Cyclic voltammetry and ellipsometry were used to characterize the adsorption kinetics ... |
15803706 | Dynamic in situ characterization of organic monolayer formation via a Novel substrate-mediated mechanism. | Ultrahigh vacuum scanning tunneling microscopy data investigating octylsilane (C8H17SiH3) monolayer pattern formation on Au(111) are presented. The irregular monolayer pattern exhibits a 60 A length scale. Formation of the octylsilane monolayer relaxes the Au(111) 23 x square root3 surface reconstruction and ejects sur... |
15803678 | Structural properties of nonionic cyclodextrin colloids in water. | The amphiphilic character in water of a novel class of chemically modified cyclodextrins has been investigated by means of small-angle X-ray scattering and light scattering. The introduction ofhydrophilic oligo(ethylene glycol) onto the secondary side of heptakis[6-alkylthio-6-deoxy-2-oligo(ethylene glycol)]-beta-cyclo... |
15773132 | Au nanoparticle micropatterns prepared from self-assembled films. | A kind of hybrid multilayer film based on mercaptobenzoic acid-capped Au nanoparticles (MBA-Au-NPs) and photoreactive nitrodiazoresin (NDR) has been fabricated via electrostatic self-assembly. Upon exposure to UV light, the initial ionic bonds between the layers of the film convert into covalent bonds and the film stab... |
15773109 | Time-resolved IR studies of monolayer self-assembly on a gold substrate using planar array infrared (PA-IR) spectroscopy. | Time-resolved and spatially resolved infrared spectra (line images) of self-assembled monolayers of octadecylthiol (ODT) on gold substrates were investigated by planar array infrared (PA-IR) spectroscopy, with a grazing incidence reflection attachment. It was observed that PA-IR spectra with a good signal-to-noise rati... |
15773091 | Surface orientation of 3,4,5-tris-substituted benzoic acid amphiphiles. | Regarding the molecular orientation on flat substrates, thin films have been studied of a series of wedge-shaped molecules (3,4,5-tris-substituted benzoate-benzo crown ether compounds) consisting of a hydrophobic outer rim and a polar group at the thin end which form columnar mesomorphic and crystalline structures. For... |
15773086 | Effect of poly(acrylic acid) block length distribution on polystyrene-b-poly(acrylic acid) block copolymer aggregates in solution. 2. A partial phase diagram. | The first paper of the series, which focused on the effect of polydispersity on the self-assembly of block copolymer vesicles, showed that an increase in the width of the poly(acrylic acid) (PAA) block length distribution resulted in a decrease in the size of the vesicles formed. In this paper, the rest of the phase di... |
15773082 | Basic hydrolysis of crystal violet in beta-cyclodextrin/surfactant mixed systems. | The basic hydrolysis of crystal violet (CV) in mixed systems consisting of beta-cyclodextrin (beta-CD) and a micelle-forming surfactant, cetyltrimethylammonium chloride (CTACl), has been studied. beta-CD was found to catalyze the basic hydrolysis of CV through the interaction of its hydroxyl group, in its deprotonated ... |
15769012 | [UV-vis spectroscopic characterization of inclusion compounds of beta-cyclodextrin with lycopene]. | Water-soluble inclusion compounds of beta-cyclodextrin with lycopene were prepared by two methods: (1) complexation in solution and (2) complexation by kneading. It was found that UV-Vis spectra of the inclusion complexes in water are different from those of lycopene in water-miscible organic solvents (tetrahydrofuran)... |
15629041 | Isolation and characterization of 2'-amino-modified RNA aptamers for human TNFalpha. | Human tumor necrosis factor alpha (hTNFalpha), a pleiotropic cytokine with activities ranging from host defense mechanisms in infection and injury to severe toxicity in septic shock or other related diseases, is a promising target for drug screening. Using the SELEX (systematic evolution of ligands by exponential enric... |
15468199 | Supramolecular hydrogel formation based on inclusion complexation between poly(ethylene glycol)-modified chitosan and alpha-cyclodextrin. | Supramolecular hydrogels have been prepared on the basis of polymer inclusion complex (PIC) formation between poly(ethylene glycol) (PEG)-modified chitosans and alpha-cyclodextrin (alpha-CD). A series of PEG-modified chitosans were synthesized by coupling reactions between chitosan and monocarboxylated PEG using water-... |
15468196 | Preparation and characterization of novel physically cross-linked hydrogels composed of poly(vinyl alcohol) and amine-terminated polyamidoamine dendrimer. | Poly(vinyl alcohol) (PVA) and polyamidoamine (PAMAM) dendrimers are water-soluble, biocompatible and biodegradable polymers, which have been widely applied in biomedical fields. In this paper, novel physically cross-linked hydrogels composed of PVA and amine-terminated PAMAM dendrimer G6-NH(2) were prepared by cyclic f... |
15344878 | Thermodynamics of protein-ligand interactions: history, presence, and future aspects. | The understanding of molecular recognition processes of small ligands and biological macromolecules requires a complete characterization of the binding energetics and correlation of thermodynamic data with interacting structures involved. A quantitative description of the forces that govern molecular associations requi... |
15123272 | RNA: primed for packing? | How does RNA's seemingly subtle 2'-hydroxyl group contribute to its diverse biological functions? Using quantitative structure-activity relationship (QSAR) analysis, Piccirilli and colleagues find that the 2'-OH fosters van der Waals and hydrophobic interactions that play underappreciated roles in RNA structure and mol... |
15038280 | Two- and three-dimensional molecular organization of Schiff-base derivatives. | We have designed and synthesized a series of Schiff base derivatives, and studied their structural features in two-dimensional (2D) and three-dimensional (3D) states by combining scanning tunneling microscopy (STM) and X-ray diffraction experiments. The Schiff-base derivatives with short alkyl chains crystallize easily... |
15031675 | Methyl-beta-cyclodextrin inhibits cell growth and cell cycle arrest via a prostaglandin E(2) independent pathway. | Methyl-beta-cyclodextrin, a cyclic oligosaccharide known for its interaction with the plasma membrane induces several events in cells including cell growth and anti-tumor activity. In this study, we have investigated the possible role of cyclooxygenase 2 (COX-2) in cell growth arrest induced by methyl-beta-cyclodextrin... |
14757499 | Compaction, compression and drug release characteristics of xanthan gum pellets of different compositions. | Compaction and compression of xanthan gum (XG) pellets were evaluated and drug release from tablets made of pellets was characterised. Three formulations were prepared by extrusion-spheronisation and included, among other excipients, diclofenac sodium (Dic Na), at 10% (w/w); xanthan gum, at 16% (w/w); and one of three ... |
14757497 | Influence of hydroxypropyl-beta-cyclodextrin complexation on piroxicam release from buccoadhesive tablets. | Interaction of piroxicam (PX) and hydroxypropyl-beta-cyclodextrin (HPbetaCD) was investigated in solution and in the solid state. Solubility studies demonstrated the formation of the PX-HPbetaCD inclusion complex with 1:1 stoichiometry. Equimolecular PX-HPbetaCD solid systems were prepared and characterized by differen... |
14751255 | Determination of enantiomeric compositions of pharmaceutical products by near-infrared spectrometry. | A new method for the determination of enantiomeric compositions of a variety of drugs including propranolol, atenolol, and ibuprofen has been developed. The method is based on the use of the near-infrared technique to measure diastereomeric interactions between an added carbohydrate compound and both enantiomeric forms... |
14751253 | Cyclodextrin-bound 6-(4-methoxyphenyl)imidazo[1,2-alpha+/-]pyrazin-3(7H)-ones with fluorescein as green chemiluminescent probes for superoxide anions. | In providing chemiluminescent probes that have high chemiluminescence intensity and high specificity to superoxide anions, novel chemiluminescent probes involving cyclodextrins covalently bound to 6-(4-methoxyphenyl)imidazo[1,2-alpha]pyrazin-3(7H)-one with fluorescein were synthesized and characterized. Using the hypox... |
14750829 | Flexible bidentate pyridine and chiral ligands in the self-assembly of supramolecular 3-D cages. | Discrete, nanoscopic 3-D cages are prepared in high yield via coordination-driven self-assembly from a variety of building blocks, including bidentate 3-substituted pyridines, chiral, and silicon-based tripods. All are characterized by NMR ((31)P, (1)H) and electrospray ionization mass spectrometry. |
14750827 | Impact of the solvent on the conformational isomerism of calix[4]arenes: a study based on continuum solvation models. | The influence of solvation on the conformational isomerism of calix[4]arene and p-tert-butylcalix[4]arene has been investigated by using the continuum model reported by Miertus, Scrocco, and Tomasi (MST). The quantum mechanical (QM) and semiclassical (SC) formalisms of the MST model have been considered for two differe... |
14750820 | Recognition through self-assembly. A quadruply-hydrogen-bonded, strapped porphyrin cleft that binds dipyridyl molecules and a [2]rotaxane. | Quadruply-hydrogen-bonded porphyrin homodimer Zn1.Zn1 has been designed, assembled, and evaluated as a supramolecular cleft-featured receptor for its ability to bind dipyridyl guests in chloroform-d. Monomer Zn1 consists of a 2-ureidopyrimidin-4(1H)-one unit, which was initially reported by Meijer et al., and a zinc po... |
14750785 | A high-spin and durable polyradical: poly(4-diphenylaminium-1,2-phenylenevinylene). | A purely organic, high-spin, and durable polyradical molecule was synthesized: It is based on the non-Kekulé- and non-disjoint design of a pi-conjugated poly(1,2-phenylenevinylene) backbone pendantly 4-substituted with multiple robust arylaminium radicals. 4-N,N-Bis(4-methoxy- and -tert-butylphenyl)amino-2-bromostyrene... |
14749181 | The C-terminal domain of measles virus nucleoprotein belongs to the class of intrinsically disordered proteins that fold upon binding to their physiological partner. | The nucleoprotein of measles virus consists of an N-terminal domain, N(CORE) (aa 1-400), resistant to proteolysis, and a C-terminal domain, N(TAIL) (aa 401-525), hypersensitive to proteolysis and not visible by electron microscopy. Using two complementary computational approaches, we predict that N(TAIL) belongs to the... |
14748593 | Preparation of beta-cyclodextrin polyrotaxane: photodimerization of pseudo-polyrotaxane with 2-anthryl and triphenylmethyl groups at the ends of poly(propylene glycol). | [structure: see text] A polyrotaxane containing beta-cyclodextrins has been prepared by photoreactions of a precursor complex between beta-cyclodextrin with poly(propylene glycol) having a triphenylmethyl group at one end and a 2-anthryl group at the other end. |
14749392 | Cleavage of poly(A)-binding protein by poliovirus 3C protease inhibits host cell translation: a novel mechanism for host translation shutoff. | Cleavage of eukaryotic translation initiation factor 4GI (eIF4GI) by viral 2A protease (2Apro) has been proposed to cause severe translation inhibition in poliovirus-infected cells. However, infections containing 1 mM guanidine-HCl result in eIF4GI cleavage but only partial translation shutoff, indicating eIF4GI cleava... |
14749389 | p66SHC promotes apoptosis and antagonizes mitogenic signaling in T cells. | Of the three Shc isoforms, p66Shc is responsible for fine-tuning p52/p46Shc signaling to Ras and has been implicated in apoptotic responses to oxidative stress. Here we show that human peripheral blood lymphocytes and mouse thymocytes and splenic T cells acquire the capacity to express p66Shc in response to apoptogenic... |
14749384 | Matrilin-3 is dispensable for mouse skeletal growth and development. | Matrilin-3 belongs to the matrilin family of extracellular matrix (ECM) proteins and is primarily expressed in cartilage. Mutations in the gene encoding human matrilin-3 (MATN-3) lead to autosomal dominant skeletal disorders, such as multiple epiphyseal dysplasia (MED), which is characterized by short stature and early... |
14747100 | Preparation and study on the novel solid inclusion complex of ciprofloxacin with HP-beta-cyclodextrin. | The interaction of ciprofloxacin with HP-beta-cyclodextrin (HP-beta-CD) has been studied by several analytical techniques, including 1H nuclear magnetic resonance (NMR), 13C NMR, fluorescence spectra, infrared spectroscopy, thermal analyzer and scanning electron microscope. In this paper, solid inclusion complex of cip... |
14747569 | Complete genome sequence of Fer-de-Lance virus reveals a novel gene in reptilian paramyxoviruses. | The complete RNA genome sequence of the archetype reptilian paramyxovirus, Fer-de-Lance virus (FDLV), has been determined. The genome is 15,378 nucleotides in length and consists of seven nonoverlapping genes in the order 3' N-U-P-M-F-HN-L 5', coding for the nucleocapsid, unknown, phospho-, matrix, fusion, hemagglutini... |
14747552 | Glycine decarboxylase mediates a postbinding step in duck hepatitis B virus infection. | Envelope protein precursors of many viruses are processed by a basic endopeptidase to generate two molecules, one for receptor binding and the other for membrane fusion. Such a cleavage event has not been demonstrated for the hepatitis B virus family. Two binding partners for duck hepatitis B virus (DHBV) pre-S envelop... |
14747530 | Conservation of a stepwise, energy-sensitive pathway involving HP68 for assembly of primate lentivirus capsids in cells. | Previously we have described a stepwise, energy-dependent pathway for human immunodeficiency virus type 1 (HIV-1) capsid assembly in a cell-free system. In this pathway, Gag polypeptides utilize the cellular factor HP68 and assemble into immature capsids by way of assembly intermediates that have defined biochemical ch... |
14747526 | Recruitment of replication protein A by the papillomavirus E1 protein and modulation by single-stranded DNA. | With the exception of viral proteins E1 and E2, papillomaviruses depend heavily on host replication machinery for replication of their viral genome. E1 and E2 are known to recruit many of the necessary cellular replication factors to the viral origin of replication. Previously, we reported a physical interaction betwee... |
14746474 | Regioselective cis-trans isomerization of arachidonic double bonds by thiyl radicals: the influence of phospholipid supramolecular organization. | Trans unsaturated fatty acids in humans may be originated by two different contributions. The exogenous track is due to dietary supplementation of trans fats and the endogenous path deals with free-radical-catalyzed cis-trans isomerization of fatty acids. Arachidonic acid residue (5c,8c,11c,14c-20:4), which has only tw... |
14746471 | Modular DNA-programmed assembly of linear and branched conjugated nanostructures. | A new strategy for self-assembly and covalent coupling of encoded molecular modules into nanostructures with predetermined connectivity has been developed. The method uses DNA-functionalized oligo(phenylene ethynylene)-derived organic modules for controlling the assembly and covalent coupling of multiple modules. Rigid... |
14746449 | Synthesis of amphidinolide T1 via catalytic, stereoselective macrocyclization. | Two nickel-catalyzed reductive coupling reactions of alkynes were instrumental in a modular, stereoselective synthesis of amphidinolide T1 (1). The C13-C21 fragment was prepared from two simple starting materials that were joined in a catalytic alkyne-epoxide fragment coupling operation, whereas an intramolecular aldeh... |
14747352 | Force spectroscopy with a small dithering of AFM tip: a method of direct and continuous measurement of the spring constant of single molecules and molecular complexes. | A new method of direct and continuous measurement of the spring constant of single molecule or molecular complex is elaborated. To that end the standard force spectroscopy technique with functionalized tips and samples is combined with a small dithering of the tip. The change of the dithering amplitude as a function of... |
14747351 | Sensitivity of second harmonic generation from styryl dyes to transmembrane potential. | In this article we present results from the simultaneous nonlinear (second harmonic generation and two-photon excitation fluorescence) imaging and voltage clamping of living cells. Specifically, we determine the sensitivity to transmembrane potential of second harmonic generation by ANEP-chromophore styryl dyes as a fu... |
14747350 | Surface functionalized cationic lipid-DNA complexes for gene delivery: PEGylated lamellar complexes exhibit distinct DNA-DNA interaction regimes. | Cationic lipid-DNA (CL-DNA) complexes are abundantly used in nonviral gene therapy clinical applications. Surface functionality is the next step in developing these complexes as competent, target-specific gene carriers. Poly(ethylene glycol) (PEG) is the natural choice to serve as a protective coat or act as a tether f... |
14747321 | Use of cyclodextrin for AFM monitoring of model raft formation. | The lipid rafts membrane microdomains, enriched in sphingolipids and cholesterol, are implicated in numerous functions of biological membranes. Using atomic force microscopy, we have examined the effects of cholesterol-loaded methyl-beta-cyclodextrin (MbetaCD-Chl) addition to liquid disordered (l(d))-gel phase separate... |
14747311 | Polyproline II helix conformation in a proline-rich environment: a theoretical study. | Interest centers here on whether a polyproline II helix can propagate through adjacent non-proline residues, and on shedding light on recent experimental observations suggesting the presence of significant PP(II) structure in a short alanine-based peptide with no proline in the sequence. For this purpose, we explored t... |
14744486 | Modulating drug release with cyclodextrins in hydroxypropyl methylcellulose gels and tablets. | This paper reports on the effect of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the diffusion and the release behavior of diclofenac sodium and sulphamethizole from HPMC K4M gels and matrix tablets. The gels were prepared with 0.5-2.0% polymer and different drug/CD mole ratios, and t... |
14744478 | Liposomes and disaccharides as carriers in spray-dried powder formulations of superoxide dismutase. | In this study, we aim to investigate the effects of disaccharides and liposome carriers on the activity, solid state characteristics, structural preservation, and aerosol powder performance of spray-dried superoxide dismutase (SOD) formulations. Sucrose, trehalose, and lactose were selected as stabilizing adjuvants in ... |
14744139 | Discrimination between different methylation states of chemotaxis receptor Tar by receptor methyltransferase CheR. | Bacterial chemotaxis receptors are posttranslationally modified by carboxyl methylation of specific glutamate residues within their cytoplasmic domains. This highly regulated, reversible modification counterbalances the signaling effects of ligand binding and contributes to adaptation. On the basis of the crystal struc... |
14742519 | Acid-responsive gene induction of ammonia-producing enzymes in Helicobacter pylori is mediated via a metal-responsive repressor cascade. | Although the adaptive mechanisms allowing the gastric pathogen Helicobacter pylori to survive acid shocks have been well documented, the mechanisms allowing growth at mildly acidic conditions (pH approximately 5.5) are still poorly understood. Here we demonstrate that H. pylori strain 26695 increases the transcription ... |
14741276 | Enantioselective ester hydrolysis catalyzed by beta-cyclodextrin conjugated with beta-hairpin peptides. | Designed cyclodextrin-peptide conjugates, which have one or two beta-hairpin peptides, have been synthesized as catalysts for ester hydrolysis. One or two beta-hairpin peptides were located at the primary hydroxyl group side of beta-cyclodextrin so as to arrange two histidine residues that act as a general acid and a g... |
14743406 | Emerging supramolecular chemistry of gases. | Molecular recognition of gases is an emerging area of chemistry. Supramolecular chemistry helps us to understand how gases interact with biological molecules and offers delicate insights into the mechanisms of their physiological activity. Principles of molecular recognition have been used for gas sensing, and have pro... |
14742262 | Effect of osteopontin alleles on beta-glucan-induced granuloma formation in the mouse liver. | The granuloma formation is a host defense response against persistent irritants. Osteopontin is centrally involved in the formation of granulomas. Three osteopontin alleles, designated a, b, and c, have been found in mice. Here we used a murine model of zymosan (beta-glucan)-induced granuloma formation in the liver to ... |
14742248 | Differential distribution of the JC virus receptor-type sialic acid in normal human tissues. | JC virus (JCV), a member of the polyomavirus family, causes a demyelinating disease of the central nervous system (CNS) in humans known as progressive multifocal leukoencephalopathy. Although glial cells are the principal target of JCV productive infection in progressive multifocal leukoencephalopathy patients, little ... |
14739334 | The interface of a membrane-spanning leucine zipper mapped by asparagine-scanning mutagenesis. | An oligo-leucine sequence has previously been shown to function as an artificial transmembrane segment that efficiently self-assembles in membranes and in detergent solution. Here, a novel technique, asparagine-scanning mutagenesis, was applied to probe the interface of the self-assembled oligo-leucine domain. This nov... |
14739329 | Role of Phe283 in enzymatic reaction of cyclodextrin glycosyltransferase from alkalophilic Bacillus sp.1011: Substrate binding and arrangement of the catalytic site. | Cyclodextrin glycosyltransferase (CGTase) belonging to the alpha-amylase family mainly catalyzes transglycosylation and produces cyclodextrins from starch and related alpha-1,4-glucans. The catalytic site of CGTase specifically conserves four aromatic residues, Phe183, Tyr195, Phe259, and Phe283, which are not found in... |
14739324 | Accurate and efficient loop selections by the DFIRE-based all-atom statistical potential. | The conformations of loops are determined by the water-mediated interactions between amino acid residues. Energy functions that describe the interactions can be derived either from physical principles (physical-based energy function) or statistical analysis of known protein structures (knowledge-based statistical poten... |
14739323 | An automated in vitro protein folding screen applied to a human dynactin subunit. | The preparation of proteins for structural and functional analysis using the Escherichia coli expression system is often hampered by the formation of insoluble intracellular protein aggregates (inclusion bodies). Transferring those proteins into their native states by in vitro protein folding requires screening for the... |
14738961 | The interaction of glycine, aspartic acid, and lysine by the protonated macrocyclic ligand 6,19-bis(2-hydroxypropyl)-3,6,9,16,19,22-hexaaza-tricyclo-[22.2.2.2(11,14)]triaconta-11,13,24,26,27,29-hexaene. | A new hexaaza macrocyclic ligand (L) bearing two 2-hydroxypropyl pendants, 6,19-bis(2-hydroxypropyl)-3,6,9,16,19,22-hexaaza-tricyclo-[22.2.2.2(11,14)]triaconta-11,13,24,26,27,29-hexaene has been synthesized and characterized. The macrocyclic ligand was isolated as a colorless crystal, monoclinic, P2(1)/n, with a=10.757... |
14563209 | Engineering peroxidase activity in myoglobin: the haem cavity structure and peroxide activation in the T67R/S92D mutant and its derivative reconstituted with protohaemin-l-histidine. | Atomic co-ordinates and structure factors for the T67R/S92D metMbCN mutant have been deposited with the Protein Data Bank, under accession codes 1h1x and r1h1xsf, respectively. Protein engineering and cofactor replacement have been employed as tools to introduce/modulate peroxidase activity in sperm whale Mb (myoglobin... |
14556651 | Development of a novel fluorogenic proteolytic beacon for in vivo detection and imaging of tumour-associated matrix metalloproteinase-7 activity. | The present study describes the in vivo detection and imaging of tumour-associated MMP-7 (matrix metalloproteinase-7 or matrilysin) activity using a novel polymer-based fluorogenic substrate PB-M7VIS, which serves as a selective 'proteolytic beacon' (PB) for this metalloproteinase. PB-M7VIS is built on a PAMAM (polyami... |
14734621 | Microvilli structures on B lymphocytes: inducible functional domains? | Interactive contact between B lymphocytes and T cells is necessary for their expansion during an immune response. It has been shown that B lymphocytes receive signals from T cells, such as IL-4 and cross-linking of CD40, which are crucial for their differentiation. We previously found that these factors induce formatio... |
14729308 | Two azurins with unusual redox and spectroscopic properties isolated from the Pseudomonas chlororaphis strains DSM 50083T and DSM 50135. | Two azurins (Az624 and Az626) were isolated from the soluble extract of two strains of Pseudomonas chlororaphis, DSM 50083(T) and DSM 50135, respectively, grown under microaerobic conditions with nitrate as final electron acceptor. The azurins, purified to electrophoretic homogeneity in three chromatographic steps, exh... |
14729306 | Coordination features of difunctionalized beta-cyclodextrins with carnosine: ESI-MS and spectroscopic investigations on 6A,6D-di-(beta-alanyl-L-histidine)-6A,6D-dideoxy-beta-cyclodextrin and 6A,6C-di-(beta-alanyl-L-histidine)-6A,6C-dideoxy-beta-cyclodextrin and their copper(II) complexes. | The synthesis and characterization of two beta-cyclodextrins (beta-CD) functionalized with two units of carnosine (beta-alanyl-L-histidine) through the amino group, 6A,6C-(beta-alanyl-L-histidine)-6A,6C-dideoxy-beta-cyclodextrin (ACCDAH) and 6A,6D-(beta-alanyl-L-histidine)-6A,6D-dideoxy-beta-cyclodextrin (ADCDAH), are ... |
14726133 | Synergism in gene delivery by small PEIs and three different nonviral vectors. | We have reported earlier that a combination of low-molecular weight polyethylenimines (PEIs) with the cationic liposome, Dosper, results in a synergistic increase in the transfection efficiency. Now we have investigated whether this synergism is a general mechanism seen with other transfection reagents as well. Therefo... |
14726131 | The physicochemical characteristics and bioavailability of indomethacin from beta-cyclodextrin, hydroxyethyl-beta-cyclodextrin, and hydroxypropyl-beta-cyclodextrin complexes. | In an effort to improve the bioavailability of the insoluble drug indomethacin, three complexes were prepared with indomethacin and the soluble complexing agents beta-, hydroxyethyl-beta-, and hydroxypropyl-beta-cyclodextrin. The indomethacin content was similar among the complexes (P</=0.05). To confirm complex format... |
14722314 | Ability of wild-type and mutant lysyl-tRNA synthetase to facilitate tRNA(Lys) incorporation into human immunodeficiency virus type 1. | The major human tRNA(Lys) isoacceptors, tRNA1,2Lys and tRNA3Lys, are selectively packaged into human immunodeficiency virus type 1 (HIV-1) during assembly, where tRNA3Lys acts as a primer for reverse transcription. Lysyl-tRNA synthetase (LysRS) is also incorporated into HIV-1, independently of tRNA(Lys), via its intera... |
14722300 | CD81 is required for hepatitis C virus glycoprotein-mediated viral infection. | CD81 has been described as a putative receptor for hepatitis C virus (HCV); however, its role in HCV cell entry has not been characterized due to the lack of an efficient cell culture system. We have examined the role of CD81 in HCV glycoprotein-dependent entry by using a recently developed retroviral pseudotyping syst... |
14722297 | Human immunodeficiency virus type 1-derived lentivirus vectors pseudotyped with envelope glycoproteins derived from Ross River virus and Semliki Forest virus. | Ross River virus (RRV) and Semliki Forest virus (SFV) are two alphaviruses that have a high degree of amino acid homology, as well as a very broad host range. We show here that envelope glycoproteins derived from both viruses can pseudotype human immunodeficiency virus type 1 (HIV-1)-derived lentivirus vectors. Both RR... |
14722285 | Fusion proteins consisting of human immunodeficiency virus type 1 integrase and the designed polydactyl zinc finger protein E2C direct integration of viral DNA into specific sites. | In order to establish a productive infection, a retrovirus must integrate the cDNA of its RNA genome into the host cell chromosome. While this critical process makes retroviruses an attractive vector for gene delivery, the nonspecific nature of integration presents inherent hazards and variations in gene expression. On... |
14722283 | Quinoline derivatives are therapeutic candidates for transmissible spongiform encephalopathies. | We previously reported that quinacrine inhibited the formation of an abnormal prion protein (PrPres), a key molecule in the pathogenesis of transmissible spongiform encephalopathy, or prion disease, in scrapie-infected neuroblastoma cells. To elucidate the structural aspects of its inhibiting action, various chemicals ... |
14720222 | Homodimerization of adenosine A2A receptors: qualitative and quantitative assessment by fluorescence and bioluminescence energy transfer. | The results presented in this paper show that adenosine A2A receptor (A2AR) form homodimers and that homodimers but not monomers are the functional species at the cell surface. Fluorescence resonance energy transfer (FRET) and bioluminescence resonance energy transfer (BRET) techniques have been used to demonstrate in ... |
14722210 | Dual effects of 17beta-oestradiol on interleukin 1beta-induced proteoglycan degradation in chondrocytes. | <h4>Objective</h4>To determine whether 17beta-oestradiol (E2) modulates interleukin (IL) 1beta-induced proteoglycan degradation in chondrocytes, and to analyse the part played by metalloproteinases (MMPs) in this process.<h4>Methods</h4>Primary cultured rabbit articular chondrocytes were prepared and treated with 10 ng... |
14712472 | NMR studies of chiral recognition by cyclodextrins. | Chiral recognition by cyclodextrins is of considerable importance, especially for pharmaceutical industry, in view of the possible side effects of the second enantiometer of chiral drugs. In general, it manifests itself in all NMR parameters (chemical shifts, coupling constants, NOE and ROE effects, and relaxation rate... |
14709395 | Transition metal half-sandwich complexes as redox mediators to glucose oxidase. | Chromium and manganese half-sandwich complexes are evaluated as mediators to glucose oxidase (GOx) since they are of similar size to ferrocene derivatives (sandwich complexes) and contain a single pi-ligand for interaction with the enzyme co-factor. A series of seven amino derivatives of [(eta-C(6)H(6))Cr(CO)(3)] were ... |
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