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9545068 | Depolarized resonance light scattering by porphyrin and chlorophyll a aggregates. | A quantum mechanical model is developed for the observed resonance enhancement of light scattering by aggregates of electronically interacting chromophores. Aggregate size, monomer oscillator strength, extent of electronic coupling, and aggregate geometry are all important determinants of intensity in resonance light s... |
9545064 | Structural characterization of the hydrophobin SC3, as a monomer and after self-assembly at hydrophobic/hydrophilic interfaces. | Hydrophobins are small fungal proteins that self-assemble at hydrophilic/hydrophobic interfaces into amphipathic membranes that, in the case of Class I hydrophobins, can be disassembled only by treatment with agents like pure trifluoroacetic acid. Here we characterize, by spectroscopic techniques, the structural change... |
9545063 | Flavin fluorescence dynamics and photoinduced electron transfer in Escherichia coli glutathione reductase. | Time-resolved polarized flavin fluorescence was used to study the active site dynamics of Escherichia coli glutathione reductase (GR). Special consideration was given to the role of Tyr177, which blocks the access to the NADPH binding-site in the crystal structure of the enzyme. By comparing wild-type GR with the mutan... |
9545054 | Electrochemical measurement of lateral diffusion coefficients of ubiquinones and plastoquinones of various isoprenoid chain lengths incorporated in model bilayers. | The long-range diffusion coefficients of isoprenoid quinones in a model of lipid bilayer were determined by a method avoiding fluorescent probe labeling of the molecules. The quinone electron carriers were incorporated in supported dimyristoylphosphatidylcholine layers at physiological molar fractions (<3 mol%). The el... |
9542066 | Molecular recognition of siderophores: a study with cloned ferrioxamine receptors (FoxA) from Erwinia herbicola and Yersinia enterocolitica. | The outer membrane receptor for ferrioxamines (FoxAErw) of Erwinia herbicola (Pantoea agglomerans) was cloned from a cosmid gene bank and partially sequenced. A comparison of the partial amino acid sequence of FoxAErw with the amino acid sequence of FoxAYer from Yersinia enterocolitica revealed a high sequence homology... |
9533885 | Structural basis for molecular recognition between nuclear transport factor 2 (NTF2) and the GDP-bound form of the Ras-family GTPase Ran. | Nuclear transport factor 2 (NTF2) and the Ras-family GTPase Ran are two soluble components of the nuclear protein import machinery. NTF2 binds GDP-Ran selectively and this interaction is important for efficient nuclear protein import in vivo. We have used X-ray crystallography to determine the structure of the macromol... |
9542911 | Use of immunoblot assay to define serum antibody patterns associated with Helicobacter pylori infection and with H. pylori-related ulcers. | Serology has been used worldwide to detect Helicobacter pylori infection. Using an immunoblot assay with an antigen from strain ATCC 43579, we sought to determine the antibodies which were good markers of colonization and the antibody patterns associated with ulcers or atrophy. Out of 98 dyspeptic patients, 41 were col... |
9531511 | Insulin targeting to the regulated secretory pathway after fusion with green fluorescent protein and firefly luciferase. | We have prepared recombinant cDNAs encoding chimaeras between human preproinsulin (sp.B.C.A., for B-, Connecting- and A-peptides) and a thermostable mutant of green fluorescent protein (GFPS65T,V163A, GFP*). The subcellular localization of the expressed chimaeras was monitored in living insulin-secreting INS-1 beta-cel... |
9531490 | Inactivating peptide of the Shaker B potassium channel: conformational preferences inferred from studies on simple model systems. | Previous studies on the interaction between the inactivating peptide of the Shaker B K+ channel (ShB peptide, H2N-MAAVAGLYGLGEDRQHRKKQ) and anionic phospholipid vesicles, used as model targets, have shown that the ShB peptide: (i) binds to the vesicle surface with high affinity; (ii) readily adopts a strongly hydrogen-... |
9531469 | Bacterial expression and characterization of human secretory class V phospholipase A2. | Mammalian secretory class V phospholipase A2 (PLA2) is a newly discovered PLA2 that is implicated in eicosanoid formation in inflammatory cells. As a first step towards understanding the structure, function and regulation of this PLA2, we constructed a bacterial expression vector for human secretory class V PLA2 (hV-PL... |
9537386 | Chemotactic adaptation is altered by changes in the carboxy-terminal sequence conserved among the major methyl-accepting chemoreceptors. | In Escherichia coli and Salmonella typhimurium, methylation and demethylation of receptors are responsible for chemotactic adaptation and are catalyzed by the methyltransferase CheR and the methylesterase CheB, respectively. Among the chemoreceptors of these species, Tsr, Tar, and Tcp have a well-conserved carboxy-term... |
9537377 | Identification of a novel Salmonella invasion locus homologous to Shigella ipgDE. | Genes essential for Salmonella typhimurium invasion have been localized to Salmonella pathogenicity island 1 (SPI1) on the chromosome. However, it is clear that other genes are required for the invasion process. Mutations that abolish the SPI1 invasion type III secretion system do not significantly reduce invasion into... |
9524109 | Genetic selection of intragenic suppressor mutations that reverse the effect of common p53 cancer mutations. | Several lines of evidence suggest that the presence of the wild-type tumor suppressor gene p53 in human cancers correlates well with successful anti-cancer therapy. Restoration of wild-type p53 function to cancer cells that have lost it might therefore improve treatment outcomes. Using a systematic yeast genetic approa... |
9529103 | Enhancement of susceptibility to Shiga toxin-producing Escherichia coli O157:H7 by protein calorie malnutrition in mice. | Infection with Shiga toxin (Stx)-producing enterohemorrhagic Escherichia coli is increasing among children. In this study, 5-week-old C57BL/6 mice with protein calorie malnutrition (PCM) that had been fed a 5% protein diet for 2 weeks since ablactation were inoculated intragastrically with 2 x 106 CFU of Stx-producing ... |
9529092 | Nuclear translocation of NF-kappaB in lipopolysaccharide-treated macrophages fails to correspond to endotoxicity: evidence suggesting a requirement for a gamma interferon-like signal. | Elucidation of a signal transduction pathway essential to lipopolysaccharide (LPS)-induced macrophage activation has the capacity to provide new targets for the treatment of septic shock. In this regard, activation of the transcription factor NF-kappaB is commonly thought to be critical to LPS-stimulated macrophage inf... |
9518498 | Phosphorothioate oligodeoxyribonucleotides dissociate from cationic lipids before entering the nucleus. | Antisense oligonucleotides complementary to specific mRNA sequences are widely used inhibitors of gene expression in vitro and in vivo . In vitro cationic lipids have been demonstrated to increase the pharmacological activity of antisense oligonucleotides by increasing cellular uptake and facilitating nuclear accumulat... |
9518491 | The use of sequence comparison to detect 'identities' in tRNA genes. | We have developed a computational method that detects 'identities' in tRNA genes by using principal component analysis to classify the sequences of bases in tRNA genes into groups of similar sequences and then comparing the distribution of sequences of bases, in order to extract characteristic bases that are conserved ... |
29711172 | The Weak-Link Approach to the Synthesis of Inorganic Macrocycles. | Homobimetallic macrocycles are prepared from flexible ligands in high yield by means of a new and general synthetic strategy called the "weak-link approach" [Eq. (a)]. Small aromatic molecules can be aligned inside the cage based on their interactions with the two Rh centers of the macrocycle. |
29711088 | Soft Lithography. | Elastomeric stamps and molds provide a great opportunity to eliminate some of the disadvantages of photolithograpy, which is currently the leading technology for fabricating small structures. In the case of "soft lithography" there is no need for complex laboratory facilities and high-energy radiation. Therefore, this ... |
29711082 | Carbohydrate-Arene Interactions Direct Conformational Equilibrium of a Flexible Glycophane in Water. | Water, the flexibility of the maltose molecule, and sugar/arene interactions are responsible for the equilibrium between a folded (I) and nonfolded (II) conformation in a glycophane (III is an intermediate). Glycophanes are cyclodextrin-cyclophane hybrids, which are of interest as models of receptors. |
29711081 | Stilbenoid Dendrimers. | A convergent synthesis in which all trans double bonds were constructed by Wittig-Horner reactions produces dendrimers of the general structure 1. With long-chain alkoxy residues on the periphery of the benzene rings, the first two generations display liquid crystalline behavior. |
29711076 | A Bifunctional Lewis Acidic Spacer in Self-Assembled Molecular Stairs and Ladders. | Depending on the stoichiometry, diindacycle 1 and pyrazine in THF reversibly form a stair- or a ladderlike self-organized coordination polymer. In both cases, the building blocks are assembled at angles close to 90°. |
29711073 | A Chemosensor for Citrate in Beverages. | Competitive binding like that in immunoassays is the principle behind the chemosensor based on receptor 1, which was used to measure the concentration of citrate (2) in a series of common beverages. Citrate displaces the fluorescent colorimetric probe 5-carboxylfluorescein (3) from 1, and the process can be monitored b... |
29711071 | Cubic and Columnar Supramolecular Architectures of Rod-Coil Molecules in the Melt State. | The liquid crystalline behavior of compounds 1 (n = 7, 12, 15) differs significantly from that exhibited for conventional rodlike molecules. They organize into layered smectic, bicontinuous cubic or hexagonal columnar mesophases depending on the temperature or the volume fraction of coil segments. |
29711068 | Strain-Induced "Band Flips" in Cyclodecaamylose and Higher Homologues. | The cavity of the larger molecule has less space for guests! Unlike the structure of the smaller annular cyclodextrins, that of the higher homologues of cycloamyloses (CAs) with more than ten glucose units contains a 90° kink between adjacent glucose residues within one half of the molecule and a 180° band flip between... |
29711067 | A Boron-Bridged Tetrathiaporphyrinogen. | Lewis acid and Lewis base centers are simultaneously present in the boron-bridged thiophene-containing porphyrinogen 1 that has been synthesized in high yield. Its crystal structure reveals a nonplanar macrocycle; this and the colorless aspect suggest the absence of a delocalized π-electron system. R = NiPr<sub>2</sub>... |
21644626 | Understanding molecular association and isomers recognition in isomer-cyclodextrin multiple complex formation by improved liquid chromatographic studies. | Equations are derived that allow the determination of guest-cyclodextrin primary (K(11)), secondary (K(12)), and higher order (K(1)(n)) binding constants as well as the degree of complexation n̄ (the percent of complexed guest), by monitoring the observed capacity factor k'(obs) for guests that can be structural, geome... |
21644622 | Separation of chiral biodegradation intermediates of linear alkylbenzenesulfonates by capillary electrophoresis. | High-performance capillary electrophoresis (HPCE) with α-cyclodextrin as the chiral selector was applied to separate the enantiomers of p-sulfophenyl-2-butyrate (SP2B) and p-sulfophenyl-3-butyrate (SP3B), which occur as biodegradation intermediates of linear alkylbenzenesulfonates (LAS), the widely used anionic surfact... |
21644621 | A water-soluble tetraethylsulfonate derivative of 2-methylresorcinarene as an additive for capillary electrophoresis. | A water-soluble tetraethylsulfonate derivative of 2-methylresorcinarene (TESMR), an aromatic-based, bowl-shaped macrocycle, was used as an additive in capillary electrophoresis. Several phenol derivatives are used as analytes to demonstrate the effect of this highly charged additive. TESMR is observed to interact diffe... |
18967076 | Simultaneous fluorometric determination of nalidixic acid and 7-hydroxymethylnalidixic acid by partial least squares calibration. | The resolution of binary mixtures of nalidixic acid (NA) and 7-hydroxymethylnalidixic acid (OH-NA) has been accomplished by partial least squares (PLS) and principal component regression (PCR) multivariate calibration. The method of determination is based on the fluorescence emission of these compounds in the presence ... |
9533922 | A new method for measuring diffusion coefficients by 2D NMR using accordion spectroscopy | Translational diffusion measurements are a useful tool for studying supramolecular complexes and for characterizing the association state of molecules that aggregate at NMR concentrations. Pulsed field gradients can be used to measure diffusion coefficients. Spectral overlap problems in complex mixtures can be alleviat... |
9520372 | Biochemical evolution. I. Polymerization On internal, organophilic silica surfaces of dealuminated zeolites and feldspars. | Catalysis at mineral surfaces might generate replicating biopolymers from simple chemicals supplied by meteorites, volcanic gases, and photochemical gas reactions. Many ideas are implausible in detail because the proposed mineral surfaces strongly prefer water and other ionic species to organic ones. The molecular siev... |
9525316 | Efficient transfer of genes into murine cardiac grafts by Starburst polyamidoamine dendrimers. | Starburst dendrimer, a structurally defined, spherical macromolecule composed of repeating polyamidoamino subunits, was investigated to augment plasmid-mediated gene transfer efficiency in a murine cardiac transplantation model. The grafts were directly injected with naked pCH110, a plasmid encoding beta-galactosidase ... |
9523705 | Alpha-glucan binding of potato-tuber starch-branching enzyme I as determined by tryptophan fluorescence quenching, affinity electrophoresis and steady-state kinetics. | The affinity of potato tuber starch-branching enzyme-I (PSBE-I) for various linear malto-oligosaccharides, cyclodextrins, (CDs) and macromolecular alpha-glucans was investigated by alpha-glucan induced fluorescence quenching of intrinsic PSBE-I tryptophan residues and by affinity electrophoresis. alpha-Glucan binding w... |
9514740 | Formation of the gap junction intercellular channel requires a 30 degree rotation for interdigitating two apposing connexons. | Intercellular communication via gap junction membrane channels cannot occur until two apposing hemichannels (connexons) meet and dock to form a sealed cell-cell conduit. In particular, an important question is how does the structure at the extracellular surface influence the molecular recognition of the two connexons. ... |
9519843 | Assembly of Amsacta moorei entomopoxvirus spheroidin into spheroids following synthesis in insect cells using a baculovirus vector. | The gene encoding the major occlusion body protein, spheroidin, of Amsacta moorei entomopoxvirus (AmEPV) was introduced into a baculovirus vector under control of the polyhedrin gene promoter. A recombinant virus produced large, ovoid occlusion body-like structures in both Spodoptera frugiperda and Trichoplusia ni cell... |
9508770 | The pathway of membrane fusion catalyzed by influenza hemagglutinin: restriction of lipids, hemifusion, and lipidic fusion pore formation. | The mechanism of bilayer unification in biological fusion is unclear. We reversibly arrested hemagglutinin (HA)-mediated cell-cell fusion right before fusion pore opening. A low-pH conformation of HA was required to form this intermediate and to ensure fusion beyond it. We present evidence indicating that outer monolay... |
9508769 | Cholesterol is required for surface transport of influenza virus hemagglutinin. | Transport from the TGN to the basolateral surface involves a rab/N-ethylmaleimide-sensitive fusion protein (NSF)/soluble NSF attachment protein (SNAP)/SNAP receptor (SNARE) mechanism. Apical transport instead is thought to be mediated by detergent-insoluble sphingolipid-cholesterol rafts. By reducing the cholesterol le... |
9508764 | Changes in chromosomal localization of heterochromatin-binding proteins during the cell cycle in Drosophila. | We examined the heterochromatic binding of GAGA factor and proliferation disrupter (Prod) proteins during the cell cycle in Drosophila melanogaster and sibling species. GAGA factor binding to the brownDominant AG-rich satellite sequence insertion was seen at metaphase, however, no binding of GAGA factor to AG-rich sequ... |
9517940 | Treatment of invasive fungal infections in renally impaired patients with amphotericin B colloidal dispersion. | Amphotericin B colloidal dispersion (ABCD) is a new formulation of conventional amphotericin B designed to minimize drug distribution in the kidney and reduce nephrotoxicity. We studied the safety and efficacy of ABCD in 133 renally compromised patients with invasive fungal infections. Patients had either nephrotoxicit... |
9517590 | Elevated circulating E-selectin, intercellular adhesion molecule 1, and von Willebrand factor in patients with severe infection. | To investigate interactions between the endothelium and leukocytes in patients with sepsis, we measured soluble adhesion molecules (sE-selectin and sICAM-1), von Willebrand factor antigen (vWf:Ag), myeloperoxidase (MPO), and lactoferrin (Lacto-f) as plasma markers of endothelial and neutrophil activation. We tested whe... |
9515918 | The S-layer proteins of two Bacillus stearothermophilus wild-type strains are bound via their N-terminal region to a secondary cell wall polymer of identical chemical composition. | Two Bacillus stearothermophilus wild-type strains were investigated regarding a common recognition and binding mechanism between the S-layer protein and the underlying cell envelope layer. The S-layer protein from B. stearothermophilus PV72/p6 has a molecular weight of 130,000 and assembles into a hexagonally ordered l... |
9515916 | Helicobacter pylori ribBA-mediated riboflavin production is involved in iron acquisition. | In this study, we cloned and sequenced a DNA fragment from an ordered cosmid library of Helicobacter pylori NCTC 11638 which confers to a siderophore synthesis mutant of Escherichia coli (EB53 aroB hemA) the ability to grow on iron-restrictive media and to reduce ferric iron. Sequence analysis of the DNA fragment revea... |
9515908 | Loss of the plasma membrane-bound protein Gas1p in Saccharomyces cerevisiae results in the release of beta1,3-glucan into the medium and induces a compensation mechanism to ensure cell wall integrity. | Deletion of GAS1/GGP1/CWH52 results in a lower beta-glucan content of the cell wall and swollen, more spherical cells (L. Popolo, M. Vai, E. Gatti, S. Porello, P. Bonfante, R. Balestrini, and L. Alberghina, J. Bacteriol. 175:1879-1885, 1993; A. F. J. Ram, S. S. C. Brekelmans, L. J. W. M. Oehlen, and F. M. Klis, FEBS Le... |
9515905 | Identification of a sequence motif that confers SecB dependence on a SecB-independent secretory protein in vivo. | SecB is a cytosolic chaperone which facilitates the transport of a subset of proteins, including membrane proteins such as PhoE and LamB and some periplasmic proteins such as maltose-binding protein, in Escherichia coli. However, not all proteins require SecB for transport, and proteins such as ribose-binding protein a... |
9515902 | Contribution of the disulfide bond of the A subunit to the action of Escherichia coli heat-labile enterotoxin. | Escherichia coli heat-labile enterotoxin (LT) consists of an A subunit and five B subunits. These subunits oligomerize into an assembled holotoxin within the periplasm. Structural analysis of LT has revealed that the A subunit interacts with the B subunit through its carboxy terminus. This indicates that the carboxy-te... |
9514004 | Separation of aromatic acids, DOPA, and methyl-DOPA by capillary electrophoresis with dendrimers as buffer additives. | Polyamidoamine starburst dendrimers with terminal carboxylate groups are used as a pseudo-stationary phase in electrokinetic chromatography for separating the selected aromatic amino acids phenylalanine, phenylglycine, homophenylalanine, and tyrosine and the catecholamines 3-(3,4-dihydroxyphenyl)alanine and 3-(3,4-dihy... |
9514411 | Effects of intracellular free cholesterol accumulation on macrophage viability: a model for foam cell death. | This study was designed to identify cellular responses associated with free cholesterol (FC) accumulation in model macrophage foam cells. Mouse peritoneal macrophages (MPMs) or J774 macrophages were loaded with cholesteryl esters using acetylated LDL and FC/phospholipid dispersions and were subsequently exposed to an a... |
9510857 | Homogeneous assay for measuring low-density lipoprotein cholesterol in serum with triblock copolymer and alpha-cyclodextrin sulfate. | We have developed a fully automated method for measuring LDL-cholesterol (LDL-C) in human serum without the need for prior separation, using a nonionic surfactant, polyoxyethylene-polyoxypropylene block copolyether (POE-POP), and a sodium salt of sulfated cyclic maltohexaose, alpha-cyclodextrin sulfate. Of the surfacta... |
9512048 | Specific interaction and two-dimensional crystallization of histidine tagged yeast RNA polymerase I on nickel-chelating lipids. | Nickel-chelating lipid monolayers were used to generate two-dimensional crystals from yeast RNA polymerase I that was histidine-tagged on one of its subunits. The interaction of the enzyme with the spread lipid layers was found to be imidazole dependent, and the formation of two-dimensional crystals required small amou... |
9512031 | Vectorially oriented monolayers of the cytochrome c/cytochrome oxidase bimolecular complex. | Vectorially oriented monolayers of yeast cytochrome c and its bimolecular complex with bovine heart cytochrome c oxidase have been formed by self-assembly from solution. Both quartz and Ge/Si multilayer substrates were chemical vapor deposited with an amine-terminated alkylsiloxane monolayer that was then reacted with ... |
9501253 | Alpha2-macroglobulin associates with beta-amyloid peptide and prevents fibril formation. | We have used the yeast two-hybrid system to isolate cDNAs encoding proteins that specifically interact with the 42-aa beta-amyloid peptide (Abeta), a major constituent of senile plaques in Alzheimer's disease. The carboxy terminus of alpha2-macroglobulin (alpha2M), a proteinase inhibitor released in response to inflamm... |
9501198 | Abnormality in catalase import into peroxisomes leads to severe neurological disorder. | Peroxisomal disorders are lethal inherited diseases caused by either defects in peroxisome assembly or dysfunction of single or multiple enzymatic function(s). The peroxisomal matrix proteins are targeted to peroxisomes via the interaction of peroxisomal targeting signal sequences 1 and 2 (PTS1 or PTS2) with their resp... |
9501168 | Tritium planigraphy: from the accessible surface to the spatial structure of a protein. | The method of tritium planigraphy, which provides comprehensive information on the accessible surface of macromolecules, allows an attempt at reconstructing the three-dimensional structure of a protein from the experimental data on residue accessibility for labeling. The semiempirical algorithm proposed for globular pr... |
9501084 | Crystal structure and mapping by site-directed mutagenesis of the collagen-binding epitope of an activated form of BM-40/SPARC/osteonectin. | The extracellular calcium-binding domain (positions 138-286) of the matrix protein BM-40 possesses a binding epitope of moderate affinity for several collagen types. This epitope was predicted to reside in helix alphaA and to be partially masked by helix alphaC. Here we show that deletion of helix alphaC produces a 10-... |
9501082 | Mac-2 binding protein is a cell-adhesive protein of the extracellular matrix which self-assembles into ring-like structures and binds beta1 integrins, collagens and fibronectin. | Human Mac-2 binding protein (M2BP) was prepared in recombinant form from the culture medium of 293 kidney cells and consisted of a 92 kDa subunit. The protein was obtained in a native state as indicated by CD spectroscopy, demonstrating alpha-helical and beta-type structure, and by protease resistance and immunological... |
9501077 | Proteolytic refolding of the HIV-1 capsid protein amino-terminus facilitates viral core assembly. | After budding, the human immunodeficiency virus (HIV) must 'mature' into an infectious viral particle. Viral maturation requires proteolytic processing of the Gag polyprotein at the matrix-capsid junction, which liberates the capsid (CA) domain to condense from the spherical protein coat of the immature virus into the ... |
9500921 | Cooperativity in Bacillus stearothermophilus pyruvate kinase. | The enzyme pyruvate kinase (PK) from the moderate thermophile Bacillus stearothermophilus has been used as a model system with which to investigate the homotropic and heterotropic cooperative interactions of the enzyme. Cooperative ligand binding by the wild-type enzyme was measured using pre-steady-state and steady-st... |
9501440 | Development and testing of a bacterial biosensor for toluene-based environmental contaminants. | A bacterial biosensor for benzene, toluene, and similar compounds has been constructed, characterized, and field tested on contaminated water and soil. The biosensor is based on a plasmid incorporating the transcriptional activator xylR from the TOL plasmid of Pseudomonas putida mt-2. The XylR protein binds a subset of... |
9501422 | Engineering of plasmin-resistant forms of streptokinase and their production in Bacillus subtilis: streptokinase with longer functional half-life. | The short in vivo half-life of streptokinase limits its efficacy as an efficient blood clot-dissolving agent. During the clot-dissolving process, streptokinase is processed to smaller intermediates by plasmin. Two of the major processing sites are Lys59 and Lys386. We engineered two versions of streptokinase with eithe... |
9494086 | Large-scale production and purification of the human green cone pigment: characterization of late photo-intermediates. | We present the first characterization of the late photo-intermediates (Meta I, Meta II and Meta III) of a vertebrate cone pigment in a lipid environment. Marked differences from the same pathway in the rod pigment were observed. The histidine-tagged human green cone pigment was functionally expressed in large-scale sus... |
9490785 | Single chain dimers of MASH-1 bind DNA with enhanced affinity. | By designing recombinant genes containing tandem copies of the coding region of the BHLH domain of MASH-1 (MASH-BHLH) with intervening DNA sequences encoding linker sequences of 8 or 17 amino acids, the two subunits of the MASH dimer have been connected to form the single chain dimers MM8 and MM17. Despite the long and... |
9490734 | Cytoplasmic regulation of the movement of E-cadherin on the free cell surface as studied by optical tweezers and single particle tracking: corralling and tethering by the membrane skeleton. | The translational movement of E-cadherin, a calcium-dependent cell-cell adhesion molecule in the plasma membrane in epithelial cells, and the mechanism of its regulation were studied using single particle tracking (SPT) and optical tweezers (OT). The wild type (Wild) and three types of artificial cytoplasmic mutants of... |
9490717 | A dominant-negative clathrin mutant differentially affects trafficking of molecules with distinct sorting motifs in the class II major histocompatibility complex (MHC) pathway. | The role of clathrin in intracellular sorting was investigated by expression of a dominant-negative mutant form of clathrin, termed the hub fragment. Hub inhibition of clathrin-mediated membrane transport was established by demonstrating a block of transferrin internalization and an alteration in the intracellular dist... |
9488711 | Engineering of cyclodextrin product specificity and pH optima of the thermostable cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1. | The product specificity and pH optimum of the thermostable cyclodextrin glycosyltransferase (CGTase) from Thermoanaerobacterium thermosulfurigenes EM1 was engineered using a combination of x-ray crystallography and site-directed mutagenesis. Previously, a crystal soaking experiment with the Bacillus circulans strain 25... |
9488668 | Characterization of two polyubiquitin binding sites in the 26 S protease subunit 5a. | Ubiquitylated proteins are degraded by the 26 S protease, an enzyme complex that contains 30 or more unique subunits. One of these proteins, subunit 5a (S5a), has been shown to bind ubiquitin-lysozyme conjugates and free polyubiquitin chains. Using deletional analysis, we have identified in the carboxyl-terminal half o... |
9496923 | Protein-to-protein interactions: criteria defining the assembly of the enamel organic matrix. | Enamel crystallites form in a protein matrix located proximal to the ameloblast cell layer. This unique organic extracellular matrix is constructed from structural protein components biosynthesized and secreted by ameloblasts. To date, three distinct classes of enamel matrix proteins have been cloned. These are the ame... |
9486977 | Native low density lipoprotein-induced calcium transients trigger VCAM-1 and E-selectin expression in cultured human vascular endothelial cells. | Low density lipoprotein (LDL) interactions with the endothelium are thought to play a major role in the development of atherosclerosis. The mechanism(s) involved are not fully understood, although several lines of evidence support the idea that oxidation of LDL increases its atherogenicity. In this study we report for ... |
9482868 | Cleaving DNA with DNA. | A DNA structure is described that can cleave single-stranded DNA oligonucleotides in the presence of ionic copper. This "deoxyribozyme" can self-cleave or can operate as a bimolecular complex that simultaneously makes use of duplex and triplex interactions to bind and cleave separate DNA substrates. Bimolecular deoxyri... |
9482865 | Germacrene C synthase from Lycopersicon esculentum cv. VFNT cherry tomato: cDNA isolation, characterization, and bacterial expression of the multiple product sesquiterpene cyclase. | Germacrene C was found by GC-MS and NMR analysis to be the most abundant sesquiterpene in the leaf oil of Lycopersicon esculentum cv. VFNT Cherry, with lesser amounts of germacrene A, guaia-6,9-diene, germacrene B, beta-caryophyllene, alpha-humulene, and germacrene D. Soluble enzyme preparations from leaves catalyzed t... |
9482860 | Changes in solvation during DNA binding and cleavage are critical to altered specificity of the EcoRI endonuclease. | Restriction endonucleases such as EcoRI bind and cleave DNA with great specificity and represent a paradigm for protein-DNA interactions and molecular recognition. Using osmotic pressure to induce water release, we demonstrate the participation of bound waters in the sequence discrimination of substrate DNA by EcoRI. C... |
9482839 | A highly conserved lysine residue on the head domain of type II keratins is essential for the attachment of keratin intermediate filaments to the cornified cell envelope through isopeptide crosslinking by transglutaminases. | We have addressed the question of how keratin intermediate filaments are associated with the cell envelope at the periphery of cornified epidermal cells. Many peptides from human epidermal cell envelopes containing isopeptide crosslinks inserted by transglutaminases in vivo have been characterized. A major subset invol... |
9482716 | The structure of the tetratricopeptide repeats of protein phosphatase 5: implications for TPR-mediated protein-protein interactions. | The tetratricopeptide repeat (TPR) is a degenerate 34 amino acid sequence identified in a wide variety of proteins, present in tandem arrays of 3-16 motifs, which form scaffolds to mediate protein-protein interactions and often the assembly of multiprotein complexes. TPR-containing proteins include the anaphase promoti... |
9492229 | In vitro evaluation of a new injectable calcium phosphate material. | The purpose of this study was to develop an injectable bone substitute (IBS) for percutaneous orthopedic surgery. The multiphasic material used was composed of a 2% aqueous solution of methylhydroxypropylcellulose (MHPC) and biphasic calcium phosphate (BCP, 60% hydroxyapatite and 40% beta-tricalcium phosphate) in which... |
9480873 | Selective detergent-extraction from mixed detergent/lipid/protein micelles, using cyclodextrin inclusion compounds: a novel generic approach for the preparation of proteoliposomes. | A novel generic approach is described for the selective extraction of detergents from mixed detergent/lipid/protein micelles for the preparation of proteoliposomes of defined lipid-protein ratio. The approach is based on the much higher affinity of inclusion compounds of the cyclodextrin type for detergents in comparis... |
9488467 | The Mof2/Sui1 protein is a general monitor of translational accuracy. | Although it is essential for protein synthesis to be highly accurate, a number of cases of directed ribosomal frameshifting have been reported in RNA viruses, as well as in procaryotic and eucaryotic genes. Changes in the efficiency of ribosomal frameshifting can have major effects on the ability of cells to propagate ... |
9488438 | Overexpression of the nucleoporin CAN/NUP214 induces growth arrest, nucleocytoplasmic transport defects, and apoptosis. | The human CAN gene was first identified as a target of t(6;9)(p23;q34), associated with acute myeloid leukemia and myelodysplastic syndrome, which results in the expression of a DEK-CAN fusion gene. CAN, also called NUP214, is a nuclear pore complex (NPC) protein that contains multiple FG-peptide sequence motifs. It in... |
9488391 | Evidence for specific secretion rather than autolysis in the release of some Helicobacter pylori proteins. | We investigated whether Helicobacter pylori cells actively secrete proteins such as the urease subunits UreA and UreB and the GroES and GroEL homologs HspA and HspB or whether these proteins were present in the extracellular compartment as a consequence of autolysis. Using a subcellular fractionation approach associate... |
9499072 | Intercapsomeric disulfide bonds in papillomavirus assembly and disassembly. | In order to analyze bonding contacts that stabilize the virion or promote capsid assembly, bovine papillomavirus (BPV) virions were subjected to buffer conditions known to disrupt polyomavirus virions. At physiologic ionic strength, incubation with dithiothreitol (DTT), EGTA, or DTT plus EGTA did not disrupt BPV virion... |
9499065 | Modulation of feline immunodeficiency virus infection by stromal cell-derived factor. | The alpha-chemokine receptor CXCR4 has recently been shown to support syncytium formation mediated by strains of feline immunodeficiency virus (FIV) that have been selected for growth in the Crandell feline kidney cell line (CrFK-tropic virus). Given that both human and feline CXCR4 support syncytium formation mediated... |
9499047 | Mutational analysis of the virus and monoclonal antibody binding sites in MHVR, the cellular receptor of the murine coronavirus mouse hepatitis virus strain A59. | The primary cellular receptor for mouse hepatitis virus (MHV), a murine coronavirus, is MHVR (also referred to as Bgp1a or C-CAM), a transmembrane glycoprotein with four immunoglobulin-like domains in the murine biliary glycoprotein (Bgp) subfamily of the carcinoembryonic antigen (CEA) family. Other murine glycoprotein... |
9499033 | Receptor-binding properties of a soluble form of human cytomegalovirus glycoprotein B. | The human cytomegalovirus (HCMV) glycoprotein B (gB) (also known as gpUL55) homolog is an important mediator of virus entry and cell-to-cell dissemination of infection. To examine the potential ligand-binding properties of gB, a soluble form of gB (gB-S) was radiolabeled, purified, and tested in cell-binding experiment... |
9499022 | Cloning and characterization of a novel hepatitis B virus x binding protein that inhibits viral replication. | The hepatitis B virus and the mammalian hepadnavirus genomes encode for a short open reading frame called x. Expression of the protein product (HBx) appears necessary for establishment of natural infection. However, in vitro studies have suggested a multifunctional role for HBx as an indirect transcriptional transactiv... |
9469846 | Dissecting the key recognition features of the MS2 bacteriophage translational repression complex. | The MS2 RNA operator capsid offers an unparalleled opportunity to study sequence-specific protein-protein and RNA-protein interactions in molecular detail. RNA molecules encompassing the minimal translational operator recognition elements can be soaked into crystals of RNA-free coat protein shells, allowing the RNA to ... |
9469843 | In vitro gene transfer using human papillomavirus-like particles. | Recombinant papillomavirus-like particles have recently been shown to be highly effective for the prevention of papillomavirus infections and associated tumors, and a virus-like particle-based vaccine against the most prevalent HPV causing genital infection in humans will be developed in the near future. Another use of... |
9469825 | Site-selective inhibition of plastid RNA editing by heat shock and antibiotics: a role for plastid translation in RNA editing. | RNA editing in higher plant plastids changes single cytidine residues to uridine through an unknown mechanism. In order to investigate the relation of editing to physiological processes and to other steps in plastid gene expression, we have tested the sensitivity of chloroplast RNA editing to heat shock and antibiotics... |
9469817 | RNA editing in the free-living bodonid Bodo saltans. | In parasitic kinetoplastid protozoa, mitochondrial (mt) mRNAs are post-transcriptionally edited by insertion and deletion of uridylate residues, the information being provided by guide (g) RNAs. In order to further explore the role and evolutionary history of this process, we searched for editing in mt RNAs of the free... |
12515170 | [A novel gene delivery system targeting to epidermal growth factor receptor overexpressing cancer cells]. | A polypeptide with 33 amino acid residues was designed and synthesized. Its C terminal was composed of multiple lysine residues, which played as a DNA condensing agent, whereas the N terminal was the receptor binding domain of Epidermal Growth Factor(N32-K48). Through a spontaneous self-assembly process with electrosta... |
9876589 | Solubilization and interaction of sulindac with beta-cyclodextrin in the solid state and in aqueous solution. | A sulindac-beta-cyclodextrin complex was obtained by the coprecipitation method. Kneaded solids and physical mixtures were also prepared. The complex was shown by x-ray powder diffraction to be noncrystalline whereas pure drug and any of the other sulindac-beta-CD system were crystalline. the endothermic peak of sulind... |
9876580 | Development of ointment formulations prepared with Achyrocline satureioides spray-dried extracts. | Achyrocline satureioides spray-dried extracts, prepared with colloidal silicon dioxide, microcrystalline cellulose + colloidal silicon dioxide (1:1), and beta-cyclodextrin + colloidal silicon dioxide (1:1), were incorporated in a glyceryl monostearate base. The influence of the spray-drying adjuvants on the formulation... |
9686316 | Glomerular extracellular matrix components and integrins. | It has become apparent that extracellular matrix components and their cellular receptors, the integrins, are important regulators of glomerular development and function. In this rapidly evolving field we studied the production of extracellular matrix components and integrins by rat glomerular visceral epithelial and me... |
9675355 | Solid state NMR spectroscopy study of molecular motion in cyclomaltoheptaose (beta-cyclodextrin) crosslinked with epichlorohydrin. | Dry and hydrated insoluble cyclomaltoheptaose (beta-cyclodextrin, beta-CD) polymers have been investigated by solid state 13C NMR spectroscopy techniques such as cross polarization/magic angle spinning with dipolar decoupling (CP/MAS), magic angle spinning both with (DD-MAS) and without (MAS) dipolar decoupling and CP/... |
9642771 | An approach to conductometric immunosensor based on phthalocyanine thin film. | A new approach to conductometric biosensors utilizing iodine-sensitive phthalocyanine thin films has been proposed. The excellent sensitivity of the tetra-tert-butyl copper phthalocyanine (ttb-CuPc) to free iodine was used for the first time to detect a peroxidase-initiated reaction in an aqueous medium. To minimize th... |
9642765 | Visual detection of protein adsorption onto electrochemically oxidized aluminum surfaces. | Adsorption of proteins onto electrochemically oxidized aluminum surfaces by a simple visual observation was investigated. For this purpose, Ta and then A1 were sputtered onto glass slides (Al/Ta/glass slides). Al/Ta/glass slides were electrochemically oxidized in 0.4 M H3PO4 under the potentiostatic conditions. After t... |
9634722 | [Quantitative dependence of structure-antiseizure activity in a series of macrocyclic compounds]. | In the present study we have further examined the influence of some structure parameters of macrocyclic polyethers upon their anticonvulsant activity in order to determine basic pharmacophore fragments. The anticonvulsant activity was studied experimentally for 25 new macrocyclic compounds, and their structure, physico... |
9623362 | High doses of immunoglobulins decrease mortality rate of surgical patients with severe intraabdominal infections and sepsis. | Two groups of 40 surgical Intensive Care Unit patients each, were included in the study. All patients had severe intraabdominal infections and sepsis, and septic score higher than 20. All were treated with individual specified conventional symptomatic therapy, and 40 of them received high doses of intravenous immunoglo... |
9600716 | Study of the interaction of dithranol with heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin in solution and in the solid state. | The interaction between dithranol and heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TMBCyD) has been investigated in aqueous solution containing isoascorbic acid (0.2% w/v) as antioxidant and in the solid state. The interaction in the solid state was studied by differential scanning calorimetry (DSC), infrared spectr... |
9595331 | All terrain vehicle ownership, use, and self reported safety behaviours in rural children. | <h4>Objectives</h4>To describe all terrain vehicle (ATV) ownership, access, use, and safety behaviours in rural Manitoba children.<h4>Methods</h4>Questionnaire administered to a convenience sample of grade 6 students attending an agricultural fair.<h4>Results</h4>162 grade 6 children participated. The mean age was 11.4... |
9592935 | [Optimization of bioavailability of pharmacons]. | The authors have investigated the optimization possibilities of bioavailability of drugs as spray-drying, spray-embedding, spray-freezing, inclusion complex formation with cyclodextrin derivatives, mineral complex formation with bentonite and in vitro diffusion of products. The bioavailability of drugs may be significa... |
9585700 | [Report of surveillance on streptococcal toxic shock syndrome in Japan and presentation of the criteria]. | A survey was made on the situation of Group A Streptococcal toxic shock syndrome (STSS) based on questionnaires. The survey was divided into two parts. The first survey was done by sending out an outline of the STSS inquiring if any STSS cases were observed by mail to university hospitals, residence training hospital a... |
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