id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
12484457 | Hydrogen/deuterium exchange of hydrophobic peptides in model membranes by electrospray ionization mass spectrometry. | We demonstrate here that the hydrogen/deuterium solvent exchange (HDX) properties of the transmembrane fragment of the M2 protein of Influenza A (M2-TM) incorporated into lipid vesicles or detergent micelles can be studied with straightforward electrospray (ESI) and nanospray mass spectrometry (MS) configurations provi... |
12480328 | Modulation of the cellular immune response after oral or subcutaneous immunization with microparticles containing Brucella ovis antigens. | An antigenic extract (HS) from Brucella ovis was encapsulated in either poly-epsilon-caprolactone (PEC) or poly-lactic-co-glycolic acid 75:25 (PLGA) microparticles containing beta-cyclodextrin and Pluronic F-68 as stabilising agents. The resulting microparticles displayed sub-5 microm sizes. Antigen loading was 5.2 and... |
12480310 | Oral bioavailability in sheep of albendazole from a suspension and from a solution containing hydroxypropyl-beta-cyclodextrin. | Albendazole (ABZ) is a benzimidazole derivative with a broad spectrum of activity against human and animal helminthe parasites. ABZ has a very poor aqueous solubility. This study shows that hydroxypropyl-beta-cyclodextrin (HP-beta-CD) is able to form inclusion complexes with ABZ and that is able to increase its aqueous... |
12481269 | Enantioseparation of chiral aromatic amino acids by capillary electrophoresis in neutral and charged cyclodextrin selector modes. | Simultaneous enantioseparations of 15 racemic aromatic amino acids and L-mimosine for their chiral discrimination were achieved by neutral selector-modified capillary electrophoresis (CE) and by charged selector-modified CE. Among the diverse cyclodextrins (CDs) examined, hydroxypropyl (HP)-alpha-CD as the neutral sele... |
12481268 | Capillary zone electrophoresis study of cyclodextrin--lipoic acid host-guest interaction. | Lipoic acid is a naturally occurring compound which is being widely investigated for its therapeutic effects in the treatment or prevention of a variety of diseases associated with oxidative injury, particularly diabetes. The diversity of therapeutic applications of lipoic acid requires an appropriate formulation to co... |
12478791 | Formation of a remarkably robust 2:1 complex between beta-cyclodextrin and a phenyl-substituted icosahedral carborane. | The structure of the 2:1 complex between beta-cyclodextrin and 1-phenyl-1,2-dicarba-closo-dodecaborane(12) is demonstrated by NOE and NOESY spectroscopy; this complex is remarkably refractory. |
12478785 | Cationic beta-cyclodextrin bilayer vesicles. | Cationic amphiphilic beta-cyclodextrins, substituted with hydrophobic n-alkylthio chains at the primary hydroxyl side and hydrophilic omega-amino-oligo(ethylene glycol) units at the secondary side, form bilayer vesicles with a diameter of 30-35 nm (when alkyl = hexadecyl) or nanoparticles with a diameter of ca. 120 nm ... |
12478783 | Biosynthesis of aminoglycoside antibiotics: cloning, expression and characterisation of an aminotransferase involved in the pathway to 2-deoxystreptamine. | The gene btrR from Bacillus circulans has been cloned and expressed and shown to produce a protein which catalyses the transamination of 2-deoxy-scyllo-inosose to give 2-deoxy-scyllo-inosamine, an intermediate in the biosynthesis of 2-deoxystreptamine. |
12478768 | Thin layer cyclic voltammetry: an efficient tool to determine the redox characteristics of large dendrimers. | Dendrimers with an electroactive bis(phenanthroline) copper(I) core have been prepared and thin layer cyclic voltammetry (TLCV) found to be an efficient tool to determine their redox characteristics in spite of the slow electron transfer kinetics observed for the largest compounds. |
12478749 | Supramolecular fixation of NO2 with calix[4]arenes. | Reaction of NO2 with simple calix[4]arenes in chloroform in the presence of a Lewis acid rapidly results in intense coloration caused by the encapsulation of nitrosonium cation. |
12478746 | p-Hydroquinone-metal compounds: synthesis and crystal structure of two novel VV-p-hydroquinonate and VIV-p-semiquinonate species. | Reaction of the p-hydroquinone derivative H2Na4bicah.4H2O with either VIVOSO(4).3H2O and NaVVO3 in equivalent quantities or with NaVVo3 yields the tetranuclear VIVO2+ macrocycle-semiquinonate compound Na6[(VIVO)4-(mu2-O)2[mu2-bicas.(-5)-N,O,O,O]2].Na2SO(4).20H2O (1.Na2SO(4).20H2O) and the dinuclear cis-VVO2(+)-hydroqui... |
12478735 | Uranium complexes supported by an aryloxide functionalised triazacyclononane macrocycle: synthesis and characterisation of a six-coordinate U(III) species and insights into its reactivity. | A reactive low-valent uranium(III) complex supported by an aryloxide functionalised triazacyclononane has been synthesised and provides a platform for enhanced uranium reactivity. |
12478038 | Systemic inflammatory response secondary to abdominal compartment syndrome: stage for multiple organ failure. | <h4>Background</h4>The abdominal compartment syndrome (ACS) has been implicated in the pathogenesis of postinjury multiple organ failure. The ACS is defined as intra-abdominal hypertension causing adverse physiologic response. This study was designed to determine the effects of IAH on the production of interleukin-1b (... |
12478028 | The injured child is resistant to multiple organ failure: a different inflammatory response? | <h4>Background</h4>Although postinjury multiple organ failure (MOF) is a well-described phenomenon in adults, the incidence of this syndrome in children is unknown. The purpose of this study was to describe the incidence, course, and severity of pediatric postinjury MOF. We hypothesized that the incidence and severity ... |
12477357 | Structure-activity relationships of the melanocortin tetrapeptide Ac-His-D-Phe-Arg-Trp-NH2 at the mouse melanocortin receptors. 4. Modifications at the Trp position. | The melanocortin pathway is involved in the regulation of several physiological functions including skin pigmentation, steroidogenesis, obesity, energy homeostasis, and exocrine gland function. This melanocortin pathway consists of five known G-protein coupled receptors, endogenous agonists derived from the proopiomela... |
12477353 | Acyclic analogues of adenosine bisphosphates as P2Y receptor antagonists: phosphate substitution leads to multiple pathways of inhibition of platelet aggregation. | Activation by ADP of both P2Y(1) and P2Y(12) receptors in platelets contributes to platelet aggregation, and antagonists at these receptor subtypes have antithrombotic properties. In an earlier publication, we have characterized the SAR as P2Y(1) receptor antagonists of acyclic analogues of adenine nucleotides, contain... |
12475961 | Lamin A/C binding protein LAP2alpha is required for nuclear anchorage of retinoblastoma protein. | The phosphorylation-dependent anchorage of retinoblastoma protein Rb in the nucleus is essential for its function. We show that its pocket C domain is both necessary and sufficient for nuclear anchorage by transiently expressing green fluorescent protein (GFP) chimeras of Rb fragments in tissue culture cells and by ext... |
12475949 | Peroxisome senescence in human fibroblasts. | The molecular mechanisms of peroxisome biogenesis have begun to emerge; in contrast, relatively little is known about how the organelle functions as cells age. In this report, we characterize age-related changes in peroxisomes of human cells. We show that aging compromises peroxisomal targeting signal 1 (PTS1) protein ... |
12475350 | Creating new supramolecular materials by architecture of three-dimensional nanocrystal fiber networks. | The architecture of three-dimensional interconnecting self-organized nanofiber networks from separate needlelike crystals of L-DHL (lanosta-8,24-dien-3beta-ol:24,25-dihydrolanosterol = 56:44) in di-isooctylphthalate has been achieved for the first time, on the basis of the completely new concept of branching creation b... |
12475347 | Responsive hydrogels from the intramolecular folding and self-assembly of a designed peptide. | A general peptide design is presented that links the pH-dependent intramolecular folding of beta-hairpin peptides to their propensity to self-assemble, affording hydrogels rich in beta-sheet. Chemical responsiveness has been specifically engineered into the material by linking intramolecular folding to changes in solut... |
12475338 | Ion-pairing molecular recognition in water: aggregation at low concentrations that is entropy-driven. | Investigations into the thermodynamic parameters that characterize the binding of citrate to tris-guanidinium host 1 in water are reported. The parameters K(a), DeltaH degrees, DeltaS degrees, and DeltaG degrees for the binding event were quantified using isothermal titration calorimetry (ITC) techniques. The 1:1 bindi... |
12475319 | Evidence for a new ferroelectric switching liquid crystalline phase formed by a carbosilane based dendrimer with banana-shaped mesogenic units. | The first carbosilane dendrimer with peripheral bent-core mesogenic units is reported. This material forms a liquid crystalline phase which is stable over a wide temperature range and forms an LC glass on cooling. Polarizing microscopy, X-ray diffraction, and dielectric and electrooptic investigations reveal the presen... |
12475283 | Green-leaf-derived C6-aroma compounds with potent antibacterial action that act on both Gram-negative and Gram-positive bacteria. | All eight C6-aliphatic alcohol and aldehyde compounds in naturally occurring green leaves showed bacteriostatic effects against Staphylococcus aureus IFO 12732, methicillin-resistant S. aureus, Escherichia coli IFO 3301, E. coli O157:H7, and Salmonella enteritidis, with bacteriostatic activities of less than 12.5 micro... |
12475926 | Attraction within the membrane. Forces behind transmembrane protein folding and supramolecular complex assembly. | Biological membranes are fascinating two-dimensional microenvironments that exhibit unique solvent behaviours due to their varying lipid composition. Although many important bioenergetic and signalling events involve the transient or permanent assembly of membrane protein complexes, the characterization of the thermody... |
12475247 | Molecular recognition in purine-rich internal loops: thermodynamic, structural, and dynamic consequences of purine for adenine substitutions in 5'(rGGCAAGCCU)2. | The contribution of amino groups to the thermodynamics, structure, and dynamics of tandem A.A mismatches is investigated by substitution of purine (P) for adenine (A) within the RNA duplex, 5'(rGGCAAGCCU)(2), to give 5'(rGGCPAGCCU)(2), 5'(rGGCAPGCCU)(2), and 5'(rGGCPPGCCU)(2). The 5'(rGGCAAGCCU)(2) duplex has sheared A... |
12472691 | Multiple plastid signals regulate the expression of the pea plastocyanin gene in pea and transgenic tobacco plants. | The expression of nuclear genes encoding photosynthesis-related proteins is regulated by signals from plastids. To investigate how the pea PetE gene encoding plastocyanin is regulated by plastid signals, the effects of norflurazon, lincomycin and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), specific inhibitors of pl... |
12471100 | Cutting edge: dynamic redistribution of tetraspanin CD81 at the central zone of the immune synapse in both T lymphocytes and APC. | The tetraspanin CD81 has been involved in T-dependent B cell-mediated immune responses. However, the behavior of CD81 during immune synapse (IS) formation has not been elucidated. We determined herein that CD81 redistributed to the contact area of T cell-B cell and T cell-dendritic cell conjugates in an Ag-dependent ma... |
12470085 | [N.1.1]-(2,6)-Pyridinophanes: a new ligand type imposing unusual metal coordination geometries. | A series of new ligands with three pyridines linked into a macrocycle by various CH(2), CMe(2), and CH(2)CH(2) groups at all sites ortho to the pyridine nitrogen have been synthesized and attached to PdCl(2) or PtMe(2). The ligands bind to them through only two nitrogens, and the third pyridine is constrained in close ... |
12470079 | The rhodafluor family. An initial study of potential ratiometric fluorescent sensors for Zn2+. | A new class of ratiometric Zn(2+) sensors that employ a hybrid fluorescein and rhodamine fluorophore has been designed, and two members of the rhodafluor family of sensors, RF1 and RF2, have been synthesized. The preparation of RF1 (9-(o-carboxyphenyl)-2-chloro-6-[bis(2-pyridylmethyl)amino]-3-xanthanone, Rhodafluor-1),... |
12470075 | New oxamidato-bridged Cu(II)-Ni(II) complexes: supramolecular structures with thiocyanate ligands and hydrogen bonds. Magnetostructural studies: DFT calculations. | Four new supramolecular compounds of Cu(II)-Ni(II) have been synthesized and characterized: [Cu(Me(2)oxpn)Ni(mu-NCS)(H(2)O)(tmen)](2)(ClO(4))(2) (1), [Cu(Me(2)oxpn)Ni(mu-NCS)(H(2)O)(tmen)](2)(PF(6))(2) (2), [Cu(oxpn)Ni(mu-NCS)(NCS) (tmen)](n) (3), and [Cu(Me(2)oxpn)Ni(mu-NCS)(NCS)(tmen)](n) (4), where oxpn = N,N'-bis(3... |
12470070 | Heterobimetallic coordination polymers incorporating [M(CN)(2)](-) (M = Cu, Ag) and [Ag(2)(CN)(3)](-) units: increasing structural dimensionality via M-M' and M...NC interactions. | A series of new heterometallic coordination polymers has been prepared from the reaction of metal-ligand cations and KAg(CN)(2) units. Many of these contain silver-silver (argentophilic) interactions, analogous to gold-gold interactions, which serve to increase supramolecular structural dimensionality. Compared to [Au(... |
12470065 | Synthesis, crystal structures, and redox potentials of 2,3,12,13-tetrasubstituted 5,10,15,20-tetraphenylporphyrin zinc(II) complexes. | Zinc(II) complexes of antipodal beta-tetrasubstituted meso-tetraphenylporphyrin with trifluoromethyl (Zn(TPP(CF(3))(4)) (1a)), bromine (Zn(TPPBr(4)) (2a)), and methyl groups (Zn(TPP(CH(3))(4)) (3a)) were synthesized in order to examine the steric and the electronic effects of trifluoromethyl groups on the macrocycle. T... |
12470062 | Influence of electronic and structural effects on the oxidative behavior of nickel porphyrins. | With the aim of better understanding the electronic and structural factors which govern electron-transfer processes in porphyrins, the electrochemistry of 29 nickel(II) porphyrins has been examined in dichloromethane containing either 0.1 M tetra-n-butylammonium perchlorate (TBAP) or tetra-n-butylammonium hexafluoropho... |
12470057 | Fluorometric chemosensors. Interaction of toxic heavy metal ions Pb(II), Cd(II), and Hg(II) with novel mixed-donor phenanthroline-containing macrocycles: spectrofluorometric, conductometric, and crystallographic studies. | The macrocycles L(1)-L(3) incorporating N(2)S(3)-, N(2)S(2)O-, and N(2)S(2)-donor sets, respectively, and containing the 1,10-phenanthroline unit interact in acetonitrile solution with heavy metal ions such as Pb(II), Cd(II), and Hg(II) to give 1:1 ML, 1:2 ML(2), and 2:1 M(2)L complex species, which specifically modula... |
12470743 | Design of nanostructured biological materials through self-assembly of peptides and proteins. | Several self-assembling peptide and protein systems that form nanotubes, helical ribbons and fibrous scaffolds have recently emerged as biological materials. Peptides and proteins have also been selected to bind metals, semiconductors and ions, inspiring the design of new materials for a wide range of applications in n... |
12470728 | Multicomponent metal-ligand self-assembly. | Self-assembly of pre-designed organic ligands with transition metal atoms is a powerful method for construction of novel supramolecular architectures. Particularly, various discrete 3-D hollow structures such as cages, cones, capsules and boxes have been obtained by multicomponent self-assembly of exo-multidentate liga... |
12470726 | Biological applications of dendrimers. | In the past year, significant advances have been made in the synthesis and study of glycodendrimers and peptide dendrimers. Application of these dendrimers to the study of carbohydrate-protein and protein-protein interactions has facilitated the understanding of these processes. In addition, dendrimers show great promi... |
12467441 | Synthesis of new tren-based tris-macrocycles. Anion cluster assembling inside the cavity generated by a bowl-shaped receptor. | The synthesis of three new tris-macrocycles, containing three [12]aneN(4) (L1), [12]aneN(3)O (L2), or [14]aneN(4) (L3) moieties appended to a tren unit, is reported. The crystal structure of the [(Na(ClO(4))(6)) subset L1(2)H(13)]Na(6)Cl(2)(ClO(4))(12) compound shows the anionic cluster [Na(ClO(4))(6)](5)(-) assembled ... |
12467438 | An efficient route to pentasubstituted acylferrocenes. | A number of pentasubstituted acylferrocenes were selectively prepared from ferrous chloride, sodium acylcyclopentadienides, and the corresponding pentasubstituted lithium cyclopentadienides in good yields. The selectivity is governed by the different steric and electronic properties of the acylcyclopentadienides vs the... |
12467409 | Alkylation of the inverted porphyrin nickel(II) complex by dihalogenalkanes: formation of monomeric and dimeric derivatives. | An efficient and simple method of modification of "inverted" porphyrin is provided by reactions of 5,10,15,20-tetraaryl-2-aza-21-carbaporphyrinatonickel(II) 2 with dihalogenalkanes under basic conditions. The substituents are bound to the internal carbon or external nitrogen of the inverted pyrrole depending on dihalog... |
12465911 | Synthesis of the unnatural amino acid AGDHE, a constituent of the cyclic depsipeptides callipeltins A and D. | [reaction: see text] The novel amino acid residue (2R,3R,4S)-4-amido-7-guanidino-2,3-dihydroxyheptanoic acid (AGDHE, 3), a constituent of the cyclic depsipeptides callipeltins A and D, and its (2S,3S,4S) diastereomer were synthesized from a protected L-ornithine derivative in 13 steps (15% overall yield), and its confi... |
12466549 | A Hoogsteen base pair embedded in undistorted B-DNA. | Hoogsteen base pairs within duplex DNA typically are only observed in regions containing significant distortion or near sites of drug intercalation. We report here the observation of a Hoogsteen base pair embedded within undistorted, unmodified B-DNA. The Hoogsteen base pair, consisting of a syn adenine base paired wit... |
12466544 | Regulation of site-specific recombination by the C-terminus of lambda integrase. | Site-specific recombination catalyzed by bacteriophage lambda integrase (Int) is essential for establishment and termination of the viral lysogenic life cycle. Int is the archetype of the tyrosine recombinase family whose members are responsible for DNA rearrangement in prokaryotes, eukaryotes and viruses. The mechanis... |
12466528 | Bacillus subtilis tau subunit of DNA polymerase III interacts with bacteriophage SPP1 replicative DNA helicase G40P. | Genetic evidence suggests that the Bacillus subtilis dnaX gene only encodes for the tau subunit of both DNA polymerases III (Pol IIIs). The B.subtilis full-length protein and their mutant derivatives tau(373- 563) (lacking the N-terminal, domains I-III or amino acid residues 1-372) and tau(1-372) (lacking the C-termina... |
12466481 | Studies on the different conditions for rabies virus neutralization by monoclonal antibodies #1-46-12 and #7-1-9. | Virus-neutralizing activity of two monoclonal antibodies (mAbs), #7-1-9 and #1-46-12, against rabies virus glycoprotein (G) was compared. Although these mAbs affected the virion's ability to bind to host cells similarly, a big difference was found in the titres of virus neutralization (1:7132 and 1:32 for mAbs #1-46-12... |
12465989 | C3-symmetrical supramolecular architectures: fibers and organic gels from discotic trisamides and trisureas. | Hydrogen bonded C(3)-symmetrical molecules that associate into supramolecular stacks are described. Structural mutation on these molecules has been performed to elucidate the contribution of the different secondary interactions (hydrogen bonding, pi-pi stacking) to the self-assembly of the disks into chiral stacks. Twe... |
12465975 | Photophysical properties of porphyrin tapes. | The novel fused Zn(II)porphyrin arrays (Tn, porphyrin tapes) in which the porphyrin macrocycles are triply linked at meso-meso, beta-beta, beta-beta positions have been investigated by steady-state and time-resolved spectroscopic measurements along with theoretical MO calculations. The absorption spectra of the porphyr... |
12465974 | Enantioselective formation of a dynamic hydrogen-bonded assembly based on the chiral memory concept. | In this paper, we report the enantioselective formation of a dynamic noncovalent double rosette assembly 1a(3).(CYA)(6) composed of three 2-pyridylcalix[4]arene dimelamines (1a) and six butylcyanuric acid molecules (BuCYA). The six 2-pyridyl functionalities of the assembly interact stereoselectively with chiral dicarbo... |
12465956 | Self-directed assembly of photoactive hybrid silicates derived from an azobenzene-bridged silsesquioxane. | Hybrid silicate materials derived from organo-bridged silsesquioxane precursors, RO3-Si-R'-Si-OR3, where R and R' are organic ligands, represent a remarkably diverse class of nanocomposites capable of forming both Si-O-Si and Si-C-Si bonds with molecular scale homogeneity. Recently, in an effort to better control their... |
12465954 | Non-covalent synthesis in aqueous solution of discrete multi-porphyrin aggregates with programmable stoichiometry and sequence. | This unprecedented calixarene templated, noncovalent synthesis of multi-porphyrin complexes in aqueous solution makes it possible to plan the nature, stoichiometry, and sequence of porphyrins. The proposed method presents the same accuracy of the covalent approach and a 100% yield, but it is not as time-consuming as th... |
12465950 | Molecular rectification through electric field induced conformational changes. | A new approach for the design of a molecular rectifier is proposed. Using a simple model, we have shown that conformational changes induced by the electric field may lead to a rectifying junction. The simplest possible rectifier of this kind presents two almost isoenergetic conformations, with different conductances an... |
12465105 | Magnetic resonance relaxivity of dendrimer-linked nitroxides. | The relaxivity and bioreduction rates of eight dendrimer-linked nitroxides varying in the number of nitroxides per molecule were measured and the potential use of these compounds as MR contrast agents was demonstrated. The T(1) and T(2) relaxivities, measured at room temperature and 1.5 T, varied linearly with the numb... |
12465031 | Dissecting the streptavidin-biotin interaction by phage-displayed shotgun scanning. | Shotgun scanning the streptavidin-biotin interaction identifies long-range hydrophobic interactions that contribute to one of the strongest naturally occurring noncovalent protein-ligand interactions. The femtomolar dissociation constant for this interaction makes it a useful model system to dissect the forces that gov... |
12464472 | Septicaemia after burn injury: a comparative study. | Seventy-nine (8.4%) patients during June 1992-May 1996 (Group-1) and 68 (7.2%) patients from June 1996 to May 2000 (Group-2) who developed septicaemia at the burns unit of Al-Babtain Centre for Plastic Surgery and Burns, Kuwait, were retrospectively studied and compared. The mean age of 26 years, male predominance, fla... |
12460674 | Refined structure of c-phycocyanin from the cyanobacterium Synechococcus vulcanus at 1.6 A: insights into the role of solvent molecules in thermal stability and co-factor structure. | The crystal structure of the light-harvesting phycobiliprotein, c-phycocyanin from the thermophilic cyanobacterium Synechococcus vulcanus has been refined to 1.6 A resolution based on the previously determined lower resolution structure (PDB entry 1I7Y). The improved data was collected using synchrotron radiation at 10... |
12456785 | Helicobacter pylori interactions with host serum and extracellular matrix proteins: potential role in the infectious process. | Helicobacter pylori, a gram-negative spiral-shaped bacterium, specifically colonizes the stomachs of humans. Once established in this harsh ecological niche, it remains there virtually for the entire life of the host. To date, numerous virulence factors responsible for gastric colonization, survival, and tissue damage ... |
12456659 | A role for nucleosome assembly protein 1 in the nuclear transport of histones H2A and H2B. | Import of core histones into the nucleus is a prerequisite for their deposition onto DNA and the assembly of chromatin. Here we demonstrate that nucleosome assembly protein 1 (Nap1p), a protein previously implicated in the deposition of histones H2A and H2B, is also involved in the transport of these two histones. We d... |
12456656 | Recognition of ERK MAP kinase by PEA-15 reveals a common docking site within the death domain and death effector domain. | PEA-15 is a multifunctional protein that modulates signaling pathways which control cell proliferation and cell death. In particular, PEA-15 regulates the actions of the ERK MAP kinase cascade by binding to ERK and altering its subcellular localization. The three-dimensional structure of PEA-15 has been determined usin... |
12456651 | Lack of mitochondrial citrate synthase discloses a new meiotic checkpoint in a strict aerobe. | Mitochondrial citrate synthase (mCS) is the initial enzyme of the tricarboxylic acid (TCA) cycle. Despite the key position of this protein in respiratory metabolism, very few studies have addressed the question of the effects of the absence of mCS in development. Here we report on the characterization of 15 point mutat... |
12456648 | Oncostatin M regulates membrane traffic and stimulates bile canalicular membrane biogenesis in HepG2 cells. | Hepatocytes are the major epithelial cells of the liver and they display membrane polarity: the sinusoidal membrane representing the basolateral surface, while the bile canalicular membrane is typical of the apical membrane. In polarized HepG2 cells an endosomal organelle, SAC, fulfills a prominent role in the biogenes... |
12454271 | Evidence for vesicles that mediate long-chain fatty acid uptake by human microvascular endothelial cells. | This study analyzes the mechanisms of long-chain fatty acid (LCFA) uptake by human microvascular endothelial cells (HMEC). The time course revealed the presence of an early, carrier-mediated uptake component and a later component mediated by clathrin-coated vesicles (CCV) and caveolae, as evidenced by three different e... |
12454270 | cAMP induces ABCA1 phosphorylation activity and promotes cholesterol efflux from fibroblasts. | ATP-binding cassette transporter A1 (ABCA1) plays a crucial role in apoA-I lipidation, a key step in reverse cholesterol transport. cAMP induces apoA-I binding activity and promotes cellular cholesterol efflux. We investigated the role of the cAMP/protein kinase A (PKA) dependent pathway in the regulation of cellular c... |
12452718 | A high-yielding supramolecular reaction. | The X-ray crystal structure determinations of twelve cocrystals involving iso-nicotinamide and a variety of carboxylic acids have revealed a very consistent pattern of hydrogen-bond preferences. The combination of a monocarboxylic acid, an amide, and a pyridine moiety leads, in every case, to discrete "supermolecules" ... |
12452697 | Antibunching in the emission of a single tetrachromophoric dendritic system. | The photophysics of a dendrimer containing four chromophores are investigated at the single-molecule level. First, the multichromophoric character of single dendrimers' absorption is probed by modulating the linear polarization of the excitation beam. Subsequently, using circular polarization, the same dendrimers are e... |
12452691 | Chiral crown ether pillared lamellar lanthanide phosphonates. | A new chiral bridging ligand, 2,2'-pentaethylene glycol-1,1'-binaphthyl-6,6'-bis(phosphonic acid), was synthesized in 40.7% overall yield in five steps and used to generate single crystals of the first porous lanthanide phosphonates with chiral crown ether pillars. Single-crystal and powder X-ray crystallography establ... |
12452687 | Preparation and characterization of porphyrin nanoparticles. | The synthesis, characterization, and stability of porphyrin nanoparticles of 20-200 nm diameter presented herein is general for meso arylporphyrins. The elegance of the method lies in its simplicity. This work shows that the agent used to prevent agglomeration can be covalently attached to the dye forming the particle ... |
12452647 | Removal of cholesterol from Cheddar cheese by beta-cyclodextrin. | This study was carried out to determine the cholesterol removal rate and resulting changes in flavor, fatty acid and bitter amino acid production in reduced-cholesterol Cheddar cheese, made by cream separation followed by 10% beta-cyclodextrin (beta-CD) treatment. The cholesterol removal from the cheese was 92.1%. The ... |
12452808 | Stabilization of alpha-chymotrypsin by modification with beta-cyclodextrin derivatives. | Bovine pancreatic alpha -chymotrypsin was chemically modified with two different beta -cyclodextrin derivatives, named mono-6-formyl-beta-cyclodextrin and mono-6-succinyl-6-deoxy-beta-cyclodextrin. The modified enzymes contained approx. 3-5 mol of oligosaccharide/mol of protein, and retained full proteolytic and estero... |
12451113 | PKA modulation of Kv4.2-encoded A-type potassium channels requires formation of a supramolecular complex. | A-type channels, encoded by the pore-forming alpha-subunits of the Kv4.x family, are particularly important in regulating membrane excitability in the CNS and the heart. Given the key role of modulation of A currents by kinases, we sought to investigate the protein structure-function relationships underlying the regula... |
12450388 | Molecular recognition at the dimer interface of a class mu glutathione transferase: role of a hydrophobic interaction motif in dimer stability and protein function. | Cytosolic glutathione (GSH) transferases (GSTs) exist as stable homo- and heterodimers. Interactions at the subunit interface serve an important role in stabilizing the subunit tertiary structures of all GSH transferases. In addition, the dimer is required to maintain functional conformations at the active site on each... |
12450859 | A novel fluorescent protein-based biosensor for gram-negative bacteria. | Site-directed mutagenesis of enhanced green fluorescent protein (EGFP) based on rational computational design was performed to create a fluorescence-based biosensor for endotoxin and gram-negative bacteria. EGFP mutants (EGFP(i)) bearing one (G10) or two (G12) strands of endotoxin binding motifs were constructed and ex... |
12450814 | Surface display of foreign epitopes on the Lactobacillus brevis S-layer. | So far, the inability to establish viable Lactobacillus surface layer (S-layer) null mutants has hampered the biotechnological applications of Lactobacillus S-layers. In this study, we demonstrate the utilization of Lactobacillus brevis S-layer subunits (SlpA) for the surface display of foreign antigenic epitopes. With... |
12446770 | Heat shock protein 90 modulates the unfolded protein response by stabilizing IRE1alpha. | The molecular chaperone HSP90 regulates stability and function of multiple protein kinases. The HSP90-binding drug geldanamycin interferes with this activity and promotes proteasome-dependent degradation of most HSP90 client proteins. Geldanamycin also binds to GRP94, the HSP90 paralog located in the endoplasmic reticu... |
12446644 | Differential regulation of the Bordetella bipA gene: distinct roles for different BvgA binding sites. | The BvgAS signal transduction system of Bordetella controls an entire spectrum of gene expression states in response to differences in environmental conditions. In particular, the Bordetella Bvg-intermediate-phase gene bipA displays a complex regulatory pattern in response to various concentrations of modulators. Expre... |
12446624 | Identification of the cis-acting site involved in activation of promoters regulated by activity of the type III secretion apparatus in Shigella flexneri. | Bacteria of Shigella spp. use a virulence plasmid-encoded type III secretion (TTS) system to invade the colonic epithelium in humans. The activity of the TTS apparatus is tightly regulated in the wild-type strain and is induced upon contact of bacteria with epithelial cells, whereas it is deregulated, i.e., constitutiv... |
12444768 | Light-driven tyrosine radical formation in a ruthenium-tyrosine complex attached to nanoparticle TiO2. | We demonstrate a possibility of multistep electron transfer in a supramolecular complex adsorbed on the surface of nanocrystalline TiO(2). The complex mimics the function of the tyrosine(Z)() and chlorophyll unit P(680) in natural photosystem II (PSII). A ruthenium(II) tris(bipyridyl) complex covalently linked to a L-t... |
12444759 | Visible light induced photocleavage of DNA by a mixed-metal supramolecular complex: [[(bpy)(2)Ru(dpp)](2)RhCl2]5+. | The mixed-metal supramolecular complex, [[(bpy)(2)Ru(dpp)](2)RhCl(2)](PF(6))(5) (bpy = 2,2'-bipyridine and dpp = 2,3-bis(2-pyridyl)pyrazine) coupling two ruthenium light absorbers (LAs) to a central rhodium, has been shown to photocleave DNA. This system possesses a lowest lying metal to metal charge transfer (MMCT) ex... |
12444757 | Interligand interactions controlling the mu-N7,N9-metal bonding of adenine (AdeH) to the N-benzyliminodiacetato(2-) copper(II) chelate and promoting the N9 versus N3 tautomeric proton transfer: molecular and crystal structure of [Cu2(NBzIDA)(2)(H2O)(2)(mu-N7,N9-Ade(N3)H)].(3)H2O. | The reaction in water of the N-benzyliminodiacetate-copper(II) chelate ([Cu(NBzIDA)]) and the adenine:thymine base pair complex (AdeH:ThyH) with a Cu/NBzIDA/AdeH/ThyH molar ratio of 2:2:1:1 yields [Cu(2)(NBzIDA)(2)(H(2)O)(2)(mu-N7,N9-Ade(N3)H)].3H(2)O and free ThyH. The compound has been studied by thermal, spectral, a... |
12444978 | Role of electrostatics in the interaction between plastocyanin and photosystem I of the cyanobacterium Phormidium laminosum. | The interactions between photosystem I and five charge mutants of plastocyanin from the cyanobacterium Phormidium laminosum were investigated in vitro. The dependence of the overall rate constant of reaction, k2, on ionic strength was investigated using laser flash photolysis. The rate constant of the wild-type reactio... |
12445473 | Two novel toxins from the Amazonian scorpion Tityus cambridgei that block Kv1.3 and Shaker B K(+)-channels with distinctly different affinities. | Two novel toxic peptides (Tc30 and Tc32) were isolated and characterized from the venom of the Brazilian scorpion Tityus cambridgei. The first have 37 and the second 35 amino acid residues, with molecular masses of 3,871.8 and 3,521.5, respectively. Both contain three disulfide bridges but share only 27% identity. They... |
12444134 | Making sense of the diverse ligand recognition by NKG2D. | NKG2D recognizes multiple diverse ligands. Despite recent efforts in determining the crystal structures of NKG2D-ligand complexes, the principle governing this receptor-ligand recognition and hence the criteria for identifying unknown ligands of NKG2D remain central issues to be resolved. Here we compared the molecular... |
12441381 | Definition of the tempo of sequence diversity across an alignment and automatic identification of sequence motifs: Application to protein homologous families and superfamilies. | It is often possible to identify sequence motifs that characterize a protein family in terms of its fold and/or function from aligned protein sequences. Such motifs can be used to search for new family members. Partitioning of sequence alignments into regions of similar amino acid variability is usually done by hand. H... |
12441375 | Mechanically unfolding proteins: the effect of unfolding history and the supramolecular scaffold. | The mechanical resistance of a folded domain in a polyprotein of five mutant I27 domains (C47S, C63S I27)(5)is shown to depend on the unfolding history of the protein. This observation can be understood on the basis of competition between two effects, that of the changing number of domains attempting to unfold, and the... |
12366374 | Transglutaminases: nature's biological glues. | Transglutaminases (Tgases) are a widely distributed group of enzymes that catalyse the post-translational modification of proteins by the formation of isopeptide bonds. This occurs either through protein cross-linking via epsilon-(gamma-glutamyl)lysine bonds or through incorporation of primary amines at selected peptid... |
12201818 | The first biantennary bacterial secondary cell wall polymer and its influence on S-layer glycoprotein assembly. | The cell surface of Aneurinibacillus thermoaerophilus DSM 10155 is covered with a square surface (S)-layer glycoprotein lattice. This S-layer glycoprotein, which was extracted with aqueous buffers after a freeze-thaw cycle of the bacterial cells, is the only completely water-soluble S-layer glycoprotein to be reported ... |
12438671 | sFas and sFas ligand and pediatric sepsis-induced multiple organ failure syndrome. | The Fas-Fas ligand system is important for apoptosis of activated immune cells. Perturbation of this system occurs in diseases with dysregulated inflammation. Increased soluble Fas (sFas) occurs in systemic inflammatory response syndrome (SIRS) and can block apoptosis. Increased shedding of FasL (sFasL) occurs in viral... |
12438639 | Identification of neutralizing epitopes within structural domain III of the West Nile virus envelope protein. | Using a panel of neutralizing monoclonal antibodies, we have mapped epitopes in domain III of the envelope protein of the New York strain of West Nile virus. The ability of monoclonal antibodies that recognize these epitopes to neutralize virus appeared to differ between lineage I and II West Nile virus strains, and ep... |
12438625 | Oligosaccharides as receptors for JC virus. | JC virus (JCV) belongs to the polyomavirus family of double-stranded DNA viruses and in humans causes a demyelinating disease of the central nervous system, progressive multifocal leukoencephalopathy. Its hemagglutination activity and entry into host cells have been reported to depend on an N-linked glycoprotein contai... |
12438615 | Conjugate-based targeting of recombinant adeno-associated virus type 2 vectors by using avidin-linked ligands. | The development of targeted vectors, capable of tissue-specific transduction, remains one of the important aspects of vector modification for gene therapy applications. Recombinant adeno-associated virus type 2 (rAAV-2)-based vectors are nonpathogenic, have relatively low immunogenicity, and are capable of long-term tr... |
12438613 | ICP27 interacts with the RNA export factor Aly/REF to direct herpes simplex virus type 1 intronless mRNAs to the TAP export pathway. | Herpes simplex virus type 1 (HSV-1) protein ICP27 facilitates the export of viral intronless mRNAs. ICP27 shuttles between the nucleus and cytoplasm, which has been shown to require a leucine-rich nuclear export sequence (NES). ICP27 export was reported to be sensitive to the CRM1 inhibitor leptomycin B (LMB) in HSV-1-... |
12438576 | The Epstein-Barr virus immediate-early protein BZLF1 regulates p53 function through multiple mechanisms. | The Epstein-Barr virus (EBV) immediate-early protein BZLF1 is a transcriptional activator that mediates the switch between the latent and the lytic forms of EBV infection. It was previously reported that BZLF1 inhibits p53 transcriptional function in reporter gene assays. Here we further examined the effects of BZLF1 o... |
12438566 | Tight binding of influenza virus hemagglutinin to its receptor interferes with fusion pore dilation. | Deletion of oligosaccharide side chains near the receptor binding site of influenza virus A/USSR/90/77 (H1N1) hemagglutinin (HA) enhanced the binding of HA to erythrocyte receptors, as was also observed with A/FPV/Rostock/34 (H7N1). Correlated with the enhancement of binding activity, the cell fusion activity of HA was... |
12438363 | A modified hepatitis B virus core particle containing multiple epitopes of the Plasmodium falciparum circumsporozoite protein provides a highly immunogenic malaria vaccine in preclinical analyses in rodent and primate hosts. | Despite extensive public health efforts, there are presently 200 to 400 million malaria infections and 1 to 2 million deaths each year due to the Plasmodium parasite. A prime target for malaria vaccine development is the circumsporozoite (CS) protein, which is expressed on the extracellular sporozoite and the intracell... |
12435805 | A3 adenosine receptors in human astrocytoma cells: agonist-mediated desensitization, internalization, and down-regulation. | A(3) adenosine receptor activation has been previously demonstrated to result in both neuroprotective and neurodegenerative effects, depending upon specific pathophysiological conditions. This dual effect may depend on receptor regulation mechanisms that are able to change receptor availability and/or function. In the ... |
12436411 | The nicotinic receptor ligand binding domain. | The ligand binding domain (LBD) of the nicotinic acetylcholine receptor has served as a prototype for understanding molecular recognition in the family of neurotransmitter-gated ion channels. During the past fifty years, studies progressed from fundamental electrophysiological analyses of ACh-evoked ion flow, to bioche... |
12435701 | env chimeric virus technology for evaluating human immunodeficiency virus susceptibility to entry inhibitors. | We describe the development of chimeric virus technology (CVT) for human immunodeficiency virus (HIV) type 1 (HIV-1) env genes gp120, gp41, and gp160 for evaluation of the susceptibilities of HIV to entry inhibitors. This env CVT allows the recombination of env sequences derived from different strains into a proviral w... |
12434403 | Preliminary pharmacokinetic study of different preparations of acyclovir with beta-cyclodextrin. | Acyclovir has absorption problems, because of its low solubility and/or its saturable absorption mechanism, that take place in the small intestine in a passive, variable, and incomplete manner. The oral bioavailability of acyclovir is thereby affected and reaches only 15-30%. The purpose of this study was to investigat... |
12433448 | 6-O-alpha-(4-O-alpha-D-glucuronyl)-D-glucosyl-beta-cyclodextrin: solubilizing ability and some cellular effects. | Some physicochemical and biopharmaceutical properties of a new branched cyclodextrin, 6-O-alpha-(4-O-alpha-D-glucuronyl)-D-glucosyl-beta-cyclodextrin (GUG-beta-CyD), were investigated. The interaction of GUG-beta-CyD with drugs was studied by spectroscopic and solubility methods, and compared with those of parent beta-... |
12432080 | Effects of Charcot-Marie-Tooth-linked mutations of the neurofilament light subunit on intermediate filament formation. | Neurofilaments (NFs) are the major intermediate filaments (IFs) of mature neurons. They play important roles in the structure and function of axons. Recently, two mutations in the neurofilament light (NFL) subunit have been identified in families affected by Charcot-Marie-Tooth (CMT) neuropathy type 2. We have characte... |
12432564 | Differential recognition of structural details of bacterial lipopeptides by toll-like receptors. | The question which detailed structures of bacterial modulins determine their relative biological activity and respective host cell receptors was examined with synthetic variants of mycoplasmal lipopeptides as model compounds, as well as recombinant outer surface protein A (OspA) of Borrelia burgdorferi and lipoteichoic... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.