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9579806 | A molecular modelling study of the interaction between beta-cyclodextrin and the organophosphorothioate pesticide parathion. | The interaction between parathion and beta-cyclodextrin was investigated by Molecular Dynamics. Several in vacuo trajectories were calculated for the system imposing a 1:1 stoichiometry. The influence of the solvent and temperature was considered. The results account for the formation of adducts which are stable at roo... |
9577354 | Compared with parenteral nutrition, enteral feeding attenuates the acute phase response and improves disease severity in acute pancreatitis. | <h4>Background</h4>In patients with major trauma and burns, total enteral nutrition (TEN) significantly decreases the acute phase response and incidence of septic complications when compared with total parenteral nutrition (TPN). Poor outcome in acute pancreatitis is associated with a high incidence of systemic inflamm... |
9577348 | Gut barrier function in malnourished patients. | <h4>Background</h4>The integrity of the gastrointestinal mucosa is a key element in preventing systemic absorption of enteric toxins and bacteria. In the critically ill, breakdown of gut barrier function may fuel sepsis. Malnourished patients have an increased risk of postoperative sepsis; however, the effects of malnu... |
9575336 | Enzyme action in glycoprotein synthesis. | Just a few decades ago, the saccharides bound to glycoproteins were considered little more than an irritation. They increased the difficulty of purifying and characterizing proteins, making proteins run as several bands on gels and smearing them on columns. They were considered a nuisance and were typically cleaved awa... |
9570607 | Alkalinizing water-soluble local anesthetic solutions by addition of cyclodextrin. | <h4>Background and objectives</h4>The use of sodium bicarbonate for alkalinization of local anesthetics to improve their efficacy has some disadvantages including decreased stability of the solutions. The present study was performed to evaluate usefulness of cyclodextrins (CDs) in improving the solubility and stability... |
9570403 | A rolling circle replication initiator protein with a nucleotidyl-transferase activity encoded by the plasmid pGT5 from the hyperthermophilic archaeon Pyrococcus abyssi. | The plasmid pGT5 from the hyperthermophilic archaeon Pyrococcus abyssi presents similarities to plasmids from the pC194 family that replicate by the rolling circle mechanism. These plasmids encode a replication initiator protein, which activates the replication origin by nicking one of the two DNA strands. The gene enc... |
9568276 | Chromatographic analysis of polysaccharides extracted from Chinese Indocalamus tesselatus. | Three fractions of polysaccharides that have high biological activity were extracted from Chinese bamboo leaves (Indocalamus Tesselatus) with 0.9% sodium chloride, 1% ammonium oxalate and 85% ethanol. Their component sugars were investigated by paper chromatography developed with n-butanol-pyridine-water (6:4:3 by vol)... |
9569121 | What holds us together? Why do some of us fall apart? What can we do about it? | One of the intriguing questions about complex organisms is, What holds them together? One of the principal answers is the tough, fibrous material known as collagen. A related question is, How is collagen made? The biosynthesis of the protein has several unusual features. One is the extensive use of the principle of spo... |
9556215 | Carbohydrates regulate the dimerization of angiotensin-converting enzyme. | Regulation of the catalytic activity and supramolecular structure of angiotensin-converting enzyme was studied in reverse micelles of Aerosol OT in octane as biomembrane model. The kinetic experiments and the sedimentation analysis demonstrated that the enzyme can function both in monomeric and dimeric form. The degree... |
9545583 | Self-assembled alpha-hemolysin pores in an S-layer-supported lipid bilayer. | The effects of a supporting proteinaceous surface-layer (S-layer) from Bacillus coagulans E38-66 on a 1,2-diphytanoyl-sn-glycero-3-phosphatidylcholine (DPhPC) bilayer were investigated. Comparative voltage clamp studies on plain and S-layer supported DPhPC bilayers revealed no significant difference in the capacitance.... |
9545428 | Self-assembly and steric stabilization at heterogeneous, biological surfaces using adsorbing block copolymers. | <h4>Background</h4>We present the synthesis, characterization and initial structure-function analysis of a new class of bioactive agent that allows the application of techniques from colloid science to biological surfaces. Stable colloidal suspensions can be generated by immobilizing a dense brush of soluble polymer at... |
9545426 | Sequencing and analysis of genes involved in the biosynthesis of a vancomycin group antibiotic. | <h4>Background</h4>The emergence of resistance to vancomycin, the drug of choice against methicillin-resistant Staphylococcus aureus, in enterococci has increased the need for new antibiotics. As chemical modification of the antibiotic structure is not trivial, we have initiated studies towards enzymatic modification b... |
9551801 | Separation of the enantiomers of ibuprofen and its major phase I metabolites in urine using capillary electrophoresis. | A capillary electrophoresis method for determination of the enantiomers of ibuprofen and its major phase I metabolites: 2'-hydroxyibuprofen and 2'-carboxyibuprofen in urine samples have been developed. Cyclodextrins and linear dextrins have been investigated as chiral selectors. Simultaneous chiral separation of the en... |
9551790 | The effects of a mixture of charged and neutral additives on analyte migration behavior in capillary electrophoresis. | Multicomponent additives, such as derivatized cyclodextrins with various degrees of substitution, can be considered single-component additives as long as the fraction of each component remains constant. In this paper, equations are derived describing the effect of such additives on the migration behavior of analytes. T... |
9550108 | Chiral and nonchiral determination of ketoprofen in pharmaceuticals by capillary zone electrophoresis. | The new method for the enantiomeric resolution of various 2-arylpropionic acids by capillary zone electrophoresis (CZE) using heptakis-tri-O-methyl-beta-cyclodextrin as chiral selector was applied to the determination of ketoprofen in different commercially-available pharmaceutical preparations. The analyte was determi... |
9546656 | Oligomeric structure of the repressor of the bacteriophage Mu early operon. | The regulation of the lytic and lysogenic development in the life cycle of bacteriophage Mu is regulated in part by its repressor, c, which binds to three operator sites, O1, O2 and O3, overlapping two divergent promoters. The oligomeric structure of this repressor protein was investigated by hydrodynamic and biochemic... |
9545149 | Food interaction and steady-state pharmacokinetics of itraconazole oral solution in healthy volunteers. | <h4>Study objectives</h4>To evaluate the effect of food on the bioavailability of itraconazole (ITR) hydroxypropyl-beta-cyclodextrin (HP-beta-CD) solution under multiple-dose to steady-state conditions, and to determine the pharmacokinetics of ITR solution at steady state.<h4>Design</h4>Open-label, randomized, multiple... |
9541413 | S100B(betabeta) inhibits the protein kinase C-dependent phosphorylation of a peptide derived from p53 in a Ca2+-dependent manner. | S100B(betabeta) is a dimeric Ca2+-binding protein that is known to inhibit the protein kinase C (PKC)-dependent phosphorylation of several proteins. To further characterize this inhibition, we synthesized peptides based on the PKC phosphorylation domains of p53 (residues 367-388), neuromodulin (residues 37-53), and the... |
9541389 | Crystallization of phycoerythrin 545 of Rhodomonas lens using detergents and unusual additives. | Phycoerythrin 545 from the cryptomonad alga, Rhodomonas lens, has been crystallized under a wide variety of conditions. Although this type of photosynthetic light-harvesting protein is water soluble, detergents were always required for crystallization. The crystals were typically poorly ordered, or ordered in only two ... |
9537522 | Specific association of photosystem II and light-harvesting complex II in partially solubilized photosystem II membranes. | In this study, we report the structural characterization of photosystem II complexes obtained from partially solubilized photosystem II membranes. Direct observation by electron microscopy, within a few minutes after a mild disruption of the membranes with the detergent n-dodecyl-alpha,D-maltoside, revealed the presenc... |
9537504 | Comparative molecular analysis of Na+/H+ exchangers: a unified model for Na+/H+ antiport? | Despite 30 years of study on Na+/H+ exchange, the molecular mechanisms of antiport remain obscure. Most challenging, the identity of amino acids involved in binding transported cations is still unknown. We review data examining the identity of residues that are involved in cation binding and translocation of prokaryoti... |
9537740 | Porphyrin binding to quadrupled T4G4. | We have recently reported the cation-induced self-assembly of DNA oligomers of the general sequence C4T4G4T1-4G4 into high-molecular weight multistranded structures [Marotta, S.P., Tamburri, P.A., and Sheardy, R.D. (1996) Biochemistry 35, 10484-10492]. The architecture of the proposed structure consists of a series of ... |
9532614 | Physiological effects of macrocycle 1 on the rabbit corpus cavernosum. | When the penis is in the flaccid state, the corpus cavernosum smooth muscle is under adrenergic control in order to maintain the sinusoids in a contracted condition (primarily via alpha-adrenergic stimulation). Penile erection is mediated by relaxation of corporal smooth muscle through a variety of direct and indirect ... |
9521706 | Labeling and identification of the postulated acid/base catalyst in the alpha-glucosidase from Saccharomyces cerevisiae using a novel bromoketone C-glycoside. | alpha-Glucosidase from Saccharomyces cerevisiae is a member of a sequence-related family of alpha-glycosidases (family 13) that includes digestive alpha-amylases and commercially important cyclodextrin glucanotransferases. These enzymes catalyze the hydrolysis of alpha-linked oligosaccharides by a two-step mechanism in... |
9529892 | Maltose/maltodextrin system of Escherichia coli: transport, metabolism, and regulation. | The maltose system of Escherichia coli offers an unusually rich set of enzymes, transporters, and regulators as objects of study. This system is responsible for the uptake and metabolism of glucose polymers (maltodextrins), which must be a preferred class of nutrients for E. coli in both mammalian hosts and in the envi... |
9529890 | Cell wall and secreted proteins of Candida albicans: identification, function, and expression. | The cell wall is essential to nearly every aspect of the biology and pathogenicity of Candida albicans. Although it was initially considered an almost inert cellular structure that protected the protoplast against osmotic offense, more recent studies have demonstrated that it is a dynamic organelle. The major component... |
9521935 | Identification of human gene core promoters in silico. | Identification of the 5'-end of human genes requires identification of functional promoter elements. In silico identification of those elements is difficult because of the hierarchical and modular nature of promoter architecture. To address this problem, I propose a new stepwise strategy based on initial localization o... |
9520476 | Neuronal polarity: essential role of protein-lipid complexes in axonal sorting. | The viral glycoprotein hemagglutinin (HA) and the endogenous glycosylphosphatidylinositol-anchored protein Thy-1 are efficiently targeted to the axonal surface of fully polarized hippocampal neurons in culture. Here we have shown that in these cells HA and Thy-1 interact with sphingolipid-cholesterol rafts and are incl... |
9520409 | Structure-based prediction of the stability of transmembrane helix-helix interactions: the sequence dependence of glycophorin A dimerization. | The ability to predict the effects of point mutations on the interaction of alpha-helices within membranes would represent a significant step toward understanding the folding and stability of membrane proteins. We use structure-based empirical parameters representing steric clashes, favorable van der Waals interactions... |
9520405 | ESA1 is a histone acetyltransferase that is essential for growth in yeast. | Posttranslational acetylation of core histone amino termini has long been associated with transcriptionally active chromatin. Recent reports have demonstrated histone acetyltransferase activity in a small group of conserved transcriptional regulators directly linked to gene activation. In addition, the presence of a pu... |
9520392 | The glutathione redox couple modulates zinc transfer from metallothionein to zinc-depleted sorbitol dehydrogenase. | The release and transfer of zinc from metallothionein (MT) to zinc-depleted sorbitol dehydrogenase (EC 1.1.1.14) in vitro has been used to explore the role of MT in cellular zinc distribution. A 1:1 molar ratio of MT to sorbitol dehydrogenase is required for full reactivation, indicating that only one of the seven zinc... |
9528825 | Epidermal growth factor receptor activation in androgen-independent but not androgen-stimulated growth of human prostatic carcinoma cells. | These studies were undertaken to assess the relative expression and autocrine activation of the epidermal growth factor receptor (EGFR) in normal and transformed prostatic epithelial cells and to determine whether EGFR activation plays a functional role in androgen-stimulated growth of prostate cancer cells in vitro. E... |
29711274 | Breaking the Mold of Discotic Liquid Crystals. | Small molecules of the indene and pseudoazulene type like 1 and 2 form columnar mesophases! These compounds do not possess peripheral flexible chains like conventional columnar liquid crystals. Instead, polarizable chlorine and sulfur atoms, as well as the polar cyano group, function as unusual soft regions between the... |
29711273 | Electrochemistry of Supramolecular Systems. | What is the role of electrochemistry in supramolecular chemistry? On one hand, it provides information on energy and kinetics that is not available with spectroscopic and mass spectrometric techniques; on the other, it can be used to alter the electronic states and thus the interactions between molecules, resulting in ... |
29711270 | A Chemically and Electrochemically Switchable [2]Catenane Incorporating a Tetrathiafulvalene Unit. | A mechanical switch in a [2]catenane, made up of a cyclobis(paraquat-p-phenylene) tetracation interlocked with a macrocyclic polyether containing a redox-active tetrathiafulvalene (TTF) unit and a 1,5-dioxynaphthalene ring system, can be thrown either chemically or electrochemically. The neutral TTF unit resides "insid... |
29711264 | Template Assembly of Polyiodide Networks at Complexed Metal Cations: Synthesis and Structures of [Pd<sub>2</sub> Cl<sub>2</sub> ([18]aneN<sub>2</sub> S<sub>4</sub> )]<sub>1.5</sub> I<sub>5</sub> (I<sub>3</sub> )<sub>2</sub> and [K([15]aneO<sub>5</sub> )<sub>2</sub> ]I<sub>9</sub>. | The cations [Pd<sub>2</sub> Cl<sub>2</sub> L]<sup>2+</sup> and [KL<sub>2</sub><sup>'</sup><sup>+</sup> (L = [18]aneN<sub>2</sub> S<sub>4</sub> , L' =[15]aneO<sub>5</sub> ) have been used as templates for the synthesis of unique three-dimensional polyiodide networks. The metal cations in [Pd<sub>2</sub> Cl<sub>2</sub> L... |
29711256 | β-Homoalanyl PNAs: Synthesis and Indication of Higher Ordered Structures. | Self-pairing complexes with extraordinarily high stability are formed by β-PNAs with four to six units of the nucleo-β-amino acid 1. The key step in the synthesis is a Mitsunobu reaction between a β-homoserine and a purine derivative. |
29711250 | Isocyanate-Based Dendritic Building Blocks: Combinatorial Tier Construction and Macromolecular-Property Modification. | Used individually or combinatorially, unique isocyanate-based dendritic monomers generate homo- and heterofunctional materials (the sketch shows schematically a molecule with a heterofunctional surface). Tier construction by combinatorial monomer addition offers new avenues to macromolecular architectural design and th... |
29711248 | Artificial Photosynthesis: Mimicking Redox Asymmetry. | Directional light-induced electron transfer takes place in the catenane shown schematically on the right. This catenane is similar to the photosynthetic reaction center: The two chemically identical electron acceptors (rectangles) bound to a ruthenium complex as donor have different reduction potentials because their e... |
29711246 | Self-Assembly of Novel Polyrotaxanes: Main-Chain Pseudopolyrotaxanes with Poly(ester crown ether) Backbones. | Not threading rings on chains, but chains through rings results in a new class of main-chain polyrotaxanes. The cations of bipyridinium salts thread through the crown ether units of a poly(ester crown ether) chain (shown below). The threading efficiency m/n of the polyrotaxane is controlled by stoichiometry and tempera... |
29711245 | Completely Stereospecific Self-Assembly of a Circular Helicate. | A nanoscale turbine wheel is an apt description of the structure of the enantiomerically pure helicate [Ag<sub>6</sub> (L2)<sub>6</sub> ]<sup>6+</sup> (1), which precipitates as PF<sub>6</sub> salt on mixing dissolved AgPF<sub>6</sub> with the ligand L2 (a bis-bidentate ligand comprising two condensed α-pinene/bipyridi... |
21644756 | A Family of Single-Isomer Chiral Resolving Agents for Capillary Electrophoresis. 3. Heptakis(2,3-dimethyl-6-sulfato)-β-cyclodextrin. | The third member of a new family of single-isomer charged cyclodextrins, the sodium salt of heptakis(2,3-dimethyl-6-sulfato)-β-cycldextrin, has been synthesized, characterized, and used for the capillary electrophoretic separation of the enantiomers of neutral, acidic, basic, and zwitterionic analytes. Though heptakis(... |
20700829 | A Sensitive Pulse Scheme for Measuring the Backbone Dihedral Angle psi Based on Cross-correlation Between (13)C (alpha)- (1)Halpha Dipolar and Carbonyl Chemical Shift Anisotropy Relaxation Interactions. | A pulse scheme for measuring cross-correlation between 13Calpha-1Halpha dipolar and carbonyl chemical shift anisotropy relaxation mechanisms is presented from which the protein backbone dihedral angle psi is measured. The method offers significant sensitivity gains relative to our recently published scheme for measurin... |
10554296 | Analytical and Sensory Characterization of gamma- and delta-Thiolactones. | gamma-Thiolactones [5-alkyldihydro-2(3H)-thiophenones] and delta-thiolactones (6-alkyltetrahydro-2H-thiopyran-2-ones) were synthesized via isothiouronium salts by reaction of the corresponding oxygen-containing lactones with thiourea and hydrobromic acid. The identity of the compounds was confirmed by means of IR, MS, ... |
11672068 | The Principle of Maximum Chiral Discrimination: Chiral Recognition in Permethyl-beta-cyclodextrin. | Five guest molecules, isomenthone, pulegone, 1-fluoro-1-phenylethane, 1-phenylethanol, and 2-methylbutanoic acid, binding to permethyl-beta-cyclodextrin, a chiral host molecule, have been simulated by molecular dynamics techniques. From the simulations we find the preferred binding site to be the interior of the macroc... |
11672037 | Cation Complexation by Chemically Modified Calixarenes. 11. Complexation and Extraction of Alkali Cations by Calix[5]- and -[6]arene Ketones. Crystal and Molecular Structures of Calix[5]arene Ketones and Na(+) and Rb(+) Complexes. | A series of four calix[5]arenes and three calix[6]arenes (R-calixarene-OCH(2)COR(1)) (R = H or Bu(t)) with alkyl ketone residues (R(1) = Me or Bu(t)) on the lower rim have been synthesized, and their affinity for complexation of alkali cations has been assessed through phase-transfer experiments and stability constant ... |
11670306 | Supramolecular Multiporphyrin Architecture. Coordination Polymers and Open Networks in Crystals of Tetrakis(4-cyanophenyl)- and Tetrakis(4-nitrophenyl)metalloporphyrin. | Crystalline solids based on the tetrakis(4-cyanophenyl) and tetrakis(4-nitrophenyl) derivatives of zinc(II)-porphyrin or copper(II)-porphyrin as building blocks have been prepared and structurally analyzed by X-ray diffraction in order to elucidate the characteristic modes of self-assembly of these functionalized moiet... |
15810322 | [Study of the circular dichroism for tribasic complex of amine derivative of beta-cyclodextrindien-Cu2+ -benzoic acid]. | The circular dichroism spectra of beta-cyclodextrindien, beta-cyclodextrindien-Cu2+ complex, beta-cyclodextrindien-benzoic acid complex, tribasic complex of beta-cyclodextrindien-Cu2+ -benzoic acid were determined by using JASCO J-20C automatic recording spectropolarimeter. The attribution of the bands obtained were ma... |
15605453 | Analytical study of photodegradation of inclusion complexes of nimodipine with alpha-, gamma-cyclodextrin, methyl-beta-cyclodextrin, and hydroxypropyl-beta-Cyclodextrin. | The inclusion behavior of alpha-cyclodextrin (alpha-CD), gamma-cyclodextrin (gamma-CD), hydroxypropyl-beta-cyclodextrin (HP-betaCD), and methyl-beta-cyclodextrin (M-betaCD) with nimodipine (NM) in solution and in the solid state was investigated. Inclusion complexes of nimodipine with cyclodextrins (at a molar ratio of... |
9524357 | Molecular recognition in procollagen chain assembly. | Recent advances in the understanding of the molecular recognition events occurring during the assembly of procollagen during biosynthesis have come from the use of a semi-permeabilized cell-system that reconstitutes the initial steps of chain assembly as they would occur in the endoplasmic reticulum of an intact cell. ... |
9521573 | Application of capillary electrophoresis to the separation of structurally diverse N-(substituted)-glycine-peptoid combinatorial mixtures. | The capillary electrophoresis (CE)-based separation of five N-(substituted)-glycine (NSG)-peptoid mixtures with a wide range of physical and chemical properties was studied. A CE separation, initially developed using a single representative peptoid mixture, with a background electrolyte (BGE) modified by the addition o... |
9521116 | 15N backbone dynamics of the S-peptide from ribonuclease A in its free and S-protein bound forms: toward a site-specific analysis of entropy changes upon folding. | Backbone 15N relaxation parameters (R1, R2, 1H-15N NOE) have been measured for a 22-residue recombinant variant of the S-peptide in its free and S-protein bound forms. NMR relaxation data were analyzed using the "model-free" approach (Lipari & Szabo, 1982). Order parameters obtained from "model-free" simulations were u... |
9521102 | An interaction-based analysis of calcium-induced conformational changes in Ca2+ sensor proteins. | Calcium sensor proteins translate transient increases in intracellular calcium levels into metabolic or mechanical responses, by undergoing dramatic conformational changes upon Ca2+ binding. A detailed analysis of the calcium binding-induced conformational changes in the representative calcium sensors calmodulin (CaM) ... |
9521099 | Hirunorms are true hirudin mimetics. The crystal structure of human alpha-thrombin-hirunorm V complex. | A novel class of synthetic, multisite-directed thrombin inhibitors, known as hirunorms, has been described recently. These compounds were designed to mimic the binding mode of hirudin, and they have been proven to be very strong and selective thrombin inhibitors. Here we report the crystal structure of the complex form... |
9519147 | Remarkable increase in nuclease resistance of plasmid DNA through supramolecular assembly with poly(ethylene glycol)-poly(L-lysine) block copolymer. | Supramolecular associates of DNA with Poly(ethylene glycol)-poly(L-lysine) block copolymers (PEG-PLL) were prepared in aqueous milieu, and the water solubility under charge-neutralized (stoichiometric) conditions was maintained. Associates thus prepared achieved remarkable resistance against nuclease attack, probably d... |
9514729 | Solution structure of calmodulin-W-7 complex: the basis of diversity in molecular recognition. | The solution structure of calcium-bound calmodulin (CaM) complexed with an antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), has been determined by multidimensional NMR spectroscopy. The structure consists of one molecule of W-7 binding to each of the two domains of CaM. In each domain, the W-7 chlo... |
9508787 | Molecular characterization of a dual endothelin-1/Angiotensin II receptor. | <h4>Background</h4>The molecular recognition theory (MRT) provides a conceptual framework that could explain the evolution of intermolecular and intramolecular interaction of peptides and proteins. As such, it predicts that binding sites of peptide hormones, and its receptor binding sites were originally encoded by and... |
9517547 | Characterization of receptors with a new negative image: use in molecular docking and lead optimization. | The characterization of receptor binding sites is an important aspect of molecular docking, molecular recognition, and the structure-based design process. This characterization can take several forms: the receptor surface itself can be delineated or described, the space adjacent to the surface can be chemically mapped,... |
9513085 | High-level expression of biologically active recombinant bovine follicle stimulating hormone in a baculovirus system. | Superovulation treatment of cows can benefit from the application of very pure recombinant bovine FSH (rbFSH), which is produced in nonmammalian cells. rbFSH is completely free of LH, and therefore can possibly reduce the variability in the results of superovulation. Furthermore, it does not contain brain-tissue-derive... |
9495829 | Triplex-directed self-assembly of an artificial sliding clamp on duplex DNA. | <h4>Background</h4>Circular triplex-forming oligonucleotides (CTFOs) have previously been shown to bind tightly to short single-stranded homopurine DNAs in a sequence-specific manner. In view of the importance of double-stranded DNA as a target in the development of gene-specific therapeutic and diagnostic agents, we h... |
9510503 | Significance of water solubility in the gastrointestinal absorption of trans-bis(n-valerato)(1R,2R-cyclohexanediamine)(oxalato)platinum(IV), an orally active antitumor platinum complex, and its analogs. | Trans-bis(n-valerato)(1R,2R-cyclohexanediamine)(oxalato++ +)platinum(IV) (C5-OHP) is an orally active platinum complex we prepared. The gastrointestinal absorption of C5-OHP was examined in rats and compared with those of C5-OHP analogs which have a general formula of trans-bis(n-OCOCnH2n+1)(1R,2R-cyclohexanediamine)(o... |
9507997 | Regulation of caveolin and caveolae by cholesterol in MDCK cells. | We have examined the expression of caveolin in MDCK cells under conditions that vary cellular cholesterol concentration. Caveolin mRNA levels dropped to one-sixth of control levels after treatment with simvastatin, an inhibitor of cholesterol synthesis, or beta-trimethyl cyclodextrin (CD), a cholesterol sequestering dr... |
9501475 | Hydrophobins and repellents: proteins with fundamental roles in fungal morphogenesis. | Fungal hydrophobins are secreted proteins which react to interfaces between fungal cell walls and the air or between fungal cell walls and solid surfaces. They have been shown to be important in many morphogenetic processes, including sporulation, fruit body development, and infection structure formation. Hydrophobins ... |
9501468 | Some properties and the inclusion behavior of three positional isomers of 6(1),6n-di-O-alpha-D-glucosyl-cyclomaltoheptaoses (beta-cyclodextrins). | Three positional isomers of 6(1),6n-di-O-alpha-D-glucosyl-cyclomaltoheptaose [1,n-(G)2-beta CDs; n = 2-4] which existed in the digests with glucoamylase of the products from cyclomaltoheptaose (beta-cyclodextrin, beta CD) and maltose with Klebsiella pneumoniae pullulanase, were purified by HPLC. The solubilities of two... |
9498283 | Tetravinyl-tetramethylcyclo-tetrasiloxane (tetravinyl D4) is a mutagen in Rat2lambda lacI fibroblasts. | Small fragments of silicone gels injected intraperitoneally have been used to induce plasmacytomas in genetically susceptible mice. Silicone oils, in contrast to silicone gels, are apparently not tumorigenic in the mouse plasmacytoma system. The reason for this difference as well as the mechanism of silicone gel-induce... |
9480768 | Evidence from flagelliform silk cDNA for the structural basis of elasticity and modular nature of spider silks. | Orb-web weaving spiders rely on their aerial nets to entrap flying prey. A key mechanical feature of orb-web design is the high elasticity of the capture spiral. We report the cloning of substantial cDNA for flagelliform gland silk protein, which forms the core fiber of the catching spiral. Like all silks, the flagelli... |
9487672 | Rapid simultaneous capillary electrophoretic determination of (R)- and (S)-secobarbital from serum and prediction of hydroxypropyl-gamma-cyclodextrin-secobarbital stereoselective interaction using molecular mechanics simulation. | Secobarbital is a hypnotic sedative that is used in the treatment of preoperative anxiety and to manage elevated intracranial pressures and cerebral ischemia due to neurosurgical procedures. Stereoselective resolution is first predicted using hydroxypropyl-gamma-cyclodextrin (HPGCD)-(R)- and (S)-secobarbital transient ... |
9487529 | Design, synthesis, and application of a protein A mimetic. | Low-molecular-weight synthetic molecules that mimic the activity of native biological macromolecules have therapeutic potential, utility in large-scale production of biopharmaceuticals, and the capacity to act as probes to study molecular recognition events. We have developed a nonpeptidyl mimic for Staphylococcus aure... |
9487372 | Total-body irradiation before bone marrow transplantation for acute leukemia in first or second complete remission. Results and prognostic factors in 326 consecutive patients. | <h4>Aim</h4>In order to assess the influence of total-body irradiation (TBI) on the outcome and incidence of complication after bone marrow transplantation (BMT), we retrospectively analyzed our patients treated for acute leukemia and conditioned with TBI prior to BMT.<h4>Patients and methods</h4>Between 1980 and 1993,... |
9478966 | Tryptophan 121 of subunit II is the electron entry site to cytochrome-c oxidase in Paracoccus denitrificans. Involvement of a hydrophobic patch in the docking reaction. | To investigate the contribution of hydrophobic residues to the molecular recognition of cytochrome c with cytochrome oxidase, we mutated several hydrophobic amino acids exposed on subunit II of the Paracoccus denitrificans oxidase. KM and kcat values and the bimolecular rate constant were determined under steady- or pr... |
9478962 | Neurofilament (NF) assembly; divergent characteristics of human and rodent NF-L subunits. | Previous studies have shown that rodent neurofilaments (NF) are obligate heteropolymers requiring NF-L plus either NF-M or NF-H for filament formation. We have assessed the competence of human NF-L and NF-M to assemble and find that unlike rat NF-L, human NF-L is capable of self-assembly. However, human NF-M cannot for... |
9486645 | DNA-templated assembly and electrode attachment of a conducting silver wire. | Recent research in the field of nanometre-scale electronics has focused on two fundamental issues: the operating principles of small-scale devices, and schemes that lead to their realization and eventual integration into useful circuits. Experimental studies on molecular to submicrometre quantum dots and on the electri... |
9484591 | Tubulin and microtubule structure. | Our knowledge of microtubule structure and its relationship to microtubule function continue to grow. Cryo-electron microscopy has given us new images of the microtubule polymerization and depolymerization processes and of the interaction of these polymers with motor proteins. We now know more about the effect of nucle... |
9473514 | Novel aspects of the electrophysiology of mitochondrial porin. | The recent findings that mitochondrial porin, VDAC, participates in supramolecular complexes and is present in the plasmamembrane need to be reconciled with its biophysical properties. We report here that VDAC often displays previously unobserved or unappreciated behaviors. Reconstituted VDAC can: a) exhibit fast gatin... |
9472032 | Caveolin-1 and -2 in the exocytic pathway of MDCK cells. | We have studied the biosynthesis and transport of the endogenous caveolins in MDCK cells. We show that in addition to homooligomers of caveolin-1, heterooligomeric complexes of caveolin-1 and -2 are formed in the ER. The oligomers become larger, increasingly detergent insoluble, and phosphorylated on caveolin-2 during ... |
9527794 | Repeated-dose pharmacokinetics of an oral solution of itraconazole in infants and children. | The safety, tolerability, and pharmacokinetics of an oral solution of itraconazole and its active metabolite hydroxyitraconazole were investigated in an open multicenter study of 26 infants and children aged 6 months to 12 years with documented mucosal fungal infections or at risk for the development of invasive fungal... |
9527773 | Evaluation of possible correlations between antifungal susceptibilities of filamentous fungi in vitro and antifungal treatment outcomes in animal infection models. | Nine isolates of filamentous fungi previously tested in 11 different laboratories for their susceptibilities to amphotericin B and itraconazole in vitro were injected intravenously into mice and guinea pigs, and responses to treatment with both agents were studied. The experiments were done in a single laboratory. Mean... |
9465097 | Chimeric papillomavirus virus-like particles elicit antitumor immunity against the E7 oncoprotein in an HPV16 tumor model. | Papillomavirus-like particles (VLPs) are a promising prophylactic vaccine candidate to prevent human papillomavirus (HPV) infections and associated epithelial neoplasia. However, they are unlikely to have therapeutic effects because the virion capsid proteins are not detected in the proliferating cells of the infected ... |
9465058 | Dynamics of surfactant release in alveolar type II cells. | Pulmonary surfactant, secreted via exocytosis of lamellar bodies (LB) by alveolar type II (AT II) cells, maintains low alveolar surface tension and is therefore essential for normal lung function. Here we describe real-time monitoring of exocytotic activity in these cells by visualizing and quantifying LB fusion with t... |
9465054 | Monitoring conformational dynamics of a single molecule by selective fluorescence spectroscopy. | A recently developed, real-time spectroscopic technique, burst-integrated fluorescence lifetime (BIFL), is shown to be well suited for monitoring the individual molecular conformational dynamics of a single molecule diffusing through the microscopic, open measurement volume (approximately 10 fl) of a confocal epi-illum... |
9465047 | A combinatorial approach to the discovery of efficient cationic peptoid reagents for gene delivery. | A family of N-substituted glycine oligomers (peptoids) of defined length and sequence are shown to condense plasmid DNA into small particles, protect it from nuclease degradation, and efficiently mediate the transfection of several cell lines. The oligomers were discovered by screening a combinatorial library of cation... |
9465031 | Monomolecular collapse of plasmid DNA into stable virus-like particles. | Cationic lipids are being widely used for cell transfection in vitro. The lipid/DNA complexes, however, tend to aggregate into large and polydisperse particle mixtures; this hampers their use in vivo. Cationic detergents, on the contrary, do not mediate cell transfection per se, yet are capable of condensing individual... |
9473033 | Mutational biosynthesis of novel rapamycins by a strain of Streptomyces hygroscopicus NRRL 5491 disrupted in rapL, encoding a putative lysine cyclodeaminase. | The gene rapL lies within the region of the Streptomyces hygroscopicus chromosome which contains the biosynthetic gene cluster for the immunosuppressant rapamycin. Introduction of a frameshift mutation into rapL by phiC31 phage-mediated gene replacement gave rise to a mutant which did not produce significant amounts of... |
9472990 | A synthetic model of intra-Golgi traffic. | We present a hypothesis on the mechanisms used by cells to transport cargo through the secretory system. We propose that at least three basic processes coordinately participate in membrane traffic: cisternal maturation-progression, controlled cargo diffusion along transient membrane continuities between different compa... |
9461487 | Mutagenesis of the aspartic acid ligands in human serum transferrin: lobe-lobe interaction and conformation as revealed by antibody, receptor-binding and iron-release studies. | Recombinant non-glycosylated human serum transferrin and mutants in which the liganding aspartic acid (D) in one or both lobes was changed to a serine residue (S) were produced in a mammalian cell system and purified from the tissue culture media. Significant downfield shifts of 20, 30, and 45 nm in the absorption maxi... |
9461432 | Chiral spaces: dissymmetric capsules through self-assembly. | Molecules with self-complementary surfaces interact through weak intermolecular forces to form assemblies, and the assembled states frequently exhibit distinctive properties. Described here are systems in which symmetrical molecules assemble through hydrogen bonding to produce capsules with dissymmetric cavities. The c... |
9466580 | Proteoglycan distribution in lesions of atherosclerosis depends on lesion severity, structural characteristics, and the proximity of platelet-derived growth factor and transforming growth factor-beta. | The accumulation of proteoglycans (PGs) in atherosclerosis contributes to disease progression and stenosis and may partly depend on local regulation by growth factors such as platelet-derived growth factor (PDGF) and transforming growth factor (TGF)-beta. In this study, the distribution of the major extracellular PGs i... |
9461079 | Crystal structure of an RNA aptamer-protein complex at 2.8 A resolution. | The crystal structure, at 2.8 A resolution, of an RNA aptamer bound to bacteriophage MS2 coat protein has been determined. It provides an opportunity to compare the interactions of MS2 coat protein and wild type operator with those of an aptamer, whose secondary structure differs from the wild type RNA in having a thre... |
9449714 | Infected cell protein (ICP)47 enhances herpes simplex virus neurovirulence by blocking the CD8+ T cell response. | The herpes simplex virus (HSV) infected cell protein (ICP)47 blocks CD8+ T cell recognition of infected cells by inhibiting the transporter associated with antigen presentation (TAP). In vivo, HSV-1 replicates in two distinct tissues: in epithelial mucosa or epidermis, where the virus enters sensory neurons; and in the... |
9451008 | Pankinetoplast DNA structure in a primitive bodonid flagellate, Cryptobia helicis. | The mitochondrial DNA (mtDNA) of a primitive kinetoplastid flagellate Cryptobia helicis is composed of 4.2 kb minicircles and 43 kb maxicircles. 85% and 6% of the minicircles are in the form of supercoiled (SC) and relaxed (OC) monomers, respectively. The remaining minicircles (9%) constitute catenated oligomers compos... |
9451006 | HMG box proteins bind to four-way DNA junctions in their open conformation. | The HMG box is an 80 amino acid domain found in a variety of eukaryotic chromosomal proteins and transcription factors. Binding to DNA is associated with recognition of structural distortion or manipulation of DNA structure. All the HMG box domains bind to four-way DNA junctions, which must therefore present some featu... |
9457876 | Genetic evaluation of physiological functions of thiolase isoenzymes in the n-alkalane-assimilating yeast Candida tropicalis. | The n-alkane-assimilating diploid yeast Candida tropicalis possesses three thiolase isozymes encoded by two pairs of alleles: cytosolic and peroxisomal acetoacetyl-coenzyme A (CoA) thiolases, encoded by CT-T1A and CT-T1B, and peroxisomal 3-ketoacyl-CoA thiolase, encoded by CT-T3A and CT-T3B. The physiological functions... |
9457875 | Archaeal binding protein-dependent ABC transporter: molecular and biochemical analysis of the trehalose/maltose transport system of the hyperthermophilic archaeon Thermococcus litoralis. | We report the cloning and sequencing of a gene cluster encoding a maltose/trehalose transport system of the hyperthermophilic archaeon Thermococcus litoralis that is homologous to the malEFG cluster encoding the Escherichia coli maltose transport system. The deduced amino acid sequence of the malE product, the trehalos... |
9457860 | Two roles for the DNA recognition site of the Klebsiella aerogenes nitrogen assimilation control protein. | The nitrogen assimilation control protein (NAC) binds to a site within the promoter region of the histidine utilization operon (hutUH) of Klebsiella aerogenes, and NAC bound at this site activates transcription of hutUH. This NAC-binding site was characterized by a combination of random and directed DNA mutagenesis. Mu... |
9448304 | HLA class I-specific inhibitory receptors in human T lymphocytes: interleukin 15-induced expression of CD94/NKG2A in superantigen- or alloantigen-activated CD8+ T cells. | A fraction of human T lymphocytes, predominantly CD8+, express receptors for HLA class I molecules typical of natural killer cells (natural killer receptors or NKRs) that inhibit T cell receptor-mediated functions. Herein, we analyzed possible mechanism(s) leading to the expression of NKRs by T cells responding to supe... |
9448274 | In vitro assembly of a ribonucleoprotein particle corresponding to the platform domain of the 30S ribosomal subunit. | A fragment of the 16S RNA of Thermus thermophilus corresponding to the central domain (nucleotides 547-895) has been prepared by transcription in vitro. Incubation of this fragment with the total 30S ribosomal proteins has resulted in the formation of a compact 12S ribonucleoprotein particle. This particle contained fi... |
9448266 | A translational repression assay procedure (TRAP) for RNA-protein interactions in vivo. | RNA-protein interactions are central to many aspects of cellular metabolism, cell differentiation, and development as well as the replication of infectious pathogens. We have devised a versatile, broadly applicable in vivo system for the analysis of RNA-protein interactions in yeast. TRAP (translational repression assa... |
9453618 | The role of sialic acid in opsonin-dependent and opsonin-independent adhesion of Listeria monocytogenes to murine peritoneal macrophages. | The adhesion of listeriae to host cells employs mechanisms which are complex and not well understood. Listeria monocytogenes is a facultative intracellular pathogen responsible for meningoencephalitis, septicemia, and abortion in susceptible and immunocompromised individuals. Subsequent to colonization and penetration ... |
9453617 | Anthrax toxin-mediated delivery in vivo and in vitro of a cytotoxic T-lymphocyte epitope from ovalbumin. | We reported earlier that a nontoxic form of anthrax toxin was capable of delivering a cytotoxic T-lymphocyte (CTL) epitope in vivo, such that a specific CTL response was primed against the epitope. The epitope, of bacterial origin, was fused to an N-terminal fragment (LFn) from the lethal-factor component of the toxin,... |
9445392 | Human insulin production from a novel mini-proinsulin which has high receptor-binding activity. | To increase the folding efficiency of the insulin precursor and the production yield of insulin, we have designed a mini-proinsulin (M2PI) having the central C-peptide region replaced with a sequence forming a reverse turn. The mini-proinsulin was fused at the N-terminus to a 21-residue fusion partner containing a His1... |
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