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11804486 | Spectroscopic anatomy of molecular-imprinting of cyclodextrin. Evidence for preferential formation of ordered cyclodextrin assemblies. | The processes of molecular-imprinting of beta-cyclodextrin (beta-CyD) with cholesterol and stigmasterol (cross-linking agent = diisocyanate) have been analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. These templates enormously promote the formation of dimers and trimers of beta-... |
11804471 | Phosphorus phenyl-group activation by reduced zirconium and niobium complexes stabilized by the [P2N2] macrocycle. | Reduction of [P2N2]ZrCl2 (where [P2N2] = PhP(CH2SiMe2NSiMe2CH2)2PPh) with KC8 under argon generates the phosphorus phenyl bridged bimetallic complex where the bridging phenyl groups are formally reduced to bis(allyl) dianions. Similar reduction of [P2N2]NbCl caused the one-electron reduction of the phosphorus phenyl gr... |
11800629 | Sonochemical synthesis and mechanistic study of copper selenides Cu(2-x)Se, beta-CuSe, and Cu(3)Se(2). | Nanocrystallites of nonstoichiometric copper selenide (Cu(2-x)Se) and stoichiometric copper selenides (beta-CuSe and Cu(3)Se(2)) were synthesized in different solutions via sonochemical irradiation at room temperature. The influence of solvents, surfactants, and ultrasonic irradiation on the morphology and phase of pro... |
11800618 | Activation barriers to meso-aryl group rotation in titanyl tetraaryltetrapyrroles. An investigation of the out-of-plane flexibility of hydroporphyrins. | The free-base and titanyl (Ti(IV)O) complexes of meso-tetratolyl- and meso-tetra(3,5-xylyl)hydroporphyrins were synthesized and characterized. Metalation of the hydroporphyrins with titanium was achieved by reaction of the lithium salts of the hydroporphyrin with TiCl(4). Other methods used to metalate porphyrins with ... |
11800615 | Halide-templated assembly of polynuclear lanthanide-hydroxo complexes. | A series of pentadecanuclear lanthanide-hydroxo complexes possessing a common core of the formula [Ln(15)(mu(3)-OH)(20)(mu(5)-X)](24+)(1, Ln = Eu, X = Cl(-); 2, Ln = Nd, X = Cl(-); 3, Ln = Gd, X = Cl(-); 4, Ln = Pr, X = Br(-); 5, Ln = Eu, X = Br(-)) were prepared by L-tyrosine-controlled hydrolysis of corresponding lan... |
11800407 | Fiber release during the removal of asbestos-containing gaskets: a work practice simulation. | Work practice studies were conducted involving the removal of asbestos-containing sheet gaskets from steam flanges. These studies were performed to determine potential exposure levels to individuals who have worked with these types of materials in the past and may still work with these products today. The work practice... |
11799235 | Systematic design of pore size and functionality in isoreticular MOFs and their application in methane storage. | A strategy based on reticulating metal ions and organic carboxylate links into extended networks has been advanced to a point that allowed the design of porous structures in which pore size and functionality could be varied systematically. Metal-organic framework (MOF-5), a prototype of a new class of porous materials ... |
11798330 | Recurrence of carboxylic acid-pyridine supramolecular synthon in the crystal structures of some pyrazinecarboxylic acids. | X-ray crystal structures of pyrazinic acid 1 and isomeric methylpyrazine carboxylic acids 2-4 are analyzed to examine the occurrence of carboxylic acid-pyridine supramolecular synthon V in these heterocyclic acids. Synthon V, assembled by (carboxyl)O-H...N(pyridine) and (pyridine)C-H...O(carbonyl) hydrogen bonds, contr... |
11798308 | Enediynes in 11-membered rings. Synthesis, structure, and reactivity of highly strained but unusually stable macrocycles. | The synthesis of two new aromatic cyclic enediynes 1a and 1b using a double Wittig condensation, followed by bromination and di-dehydrobromination, is reported. The structures were determined using X-ray crystallography. The observed C(1)-C(6) distances of the enediyne moiety in the oxygen- and sulfur-containing eleven... |
11796042 | Stoichiometry-controlled supramolecular chirality induction and inversion in bisporphyrin systems. | [reaction: see text] Stoichiometry is found to be an effective tool for controlling supramolecular chirality induction and inversion processes. Chirality induction in the achiral syn ethane-bridged bis(zinc octaethylporphyrin) is achieved upon interaction with the enantiopure (R,R)-1,2-diphenylethylenediamine at the lo... |
11796202 | A naphthalocyanine-based EPR probe for localized measurements of tissue oxygenation. | A new electron paramagnetic resonance (EPR) oximetry probe, based on a naphthalocyanine macrocycle, is reported to exhibit high oxygen sensitivity and favorable EPR characteristics for biological applications. The free radical probe, lithium naphthalocyanine (LiNc), is synthesized as fine microcrystalline powder with p... |
11795818 | Tuning and enhancing enantioselective quenching of calixarene hosts by chiral guest amines. | The synthesis of a propranolol amide derivative of p-allylcalix[4]arene is described, which has been designed to behave as a molecular sensor capable of distinguishing chiral amines on the basis of their shape and chirality. This molecule can discriminate between the enantiomers of phenylalaninol through the quenching ... |
11792198 | Cu(2)[o-Br-C(6)H(3)(CO(2))(2)](2)(H(2)O)(2).(DMF)(8)(H(2)O)(2): a framework deliberately designed to have the NbO structure type. | The synthesis of an NbO-type metal-organic framework was achieved by design: o-Br-BDC (BDC = benzenedicarboxylate) was used to direct the formation of Cu2(CO2)4 paddle wheel units at 90 degrees to each other and thus yield the target network. The compound was formulated as Cu2[o-Br-BDC]2(H2O)2.(DMF)8(H2O)2 (MOF-101) an... |
11790823 | Tubular system volume changes in twitch fibres from toad and rat skeletal muscle assessed by confocal microscopy. | The volume of the extracellular compartment (tubular system) within intact muscle fibres from cane toad and rat was measured under various conditions using confocal microscopy. Under physiological conditions at rest, the fractional volume of the tubular system (t-sys(Vol)) was 1.38 +/- 0.09 % (n = 17), 1.41 +/- 0.09 % ... |
11790501 | Cross-linked beta-cyclodextrin microcapsules. II. Retarding effect on drug release through semi-permeable membranes. | Microcapsules were prepared by interfacial cross-linking of beta-cyclodextrins (beta-CD) with terephthaloylchloride (TC) as described previously. Complexation assays were conducted with propranolol HCl. After 1 h incubation of 50 mg lyophilized microcapsules in 10 ml propranolol solution, the amounts of fixed drug were... |
11790499 | Effect of dendrimer on entrapment and release of bioactive from liposomes. | An active encapsulation method to obtain high entrapment in liposomes is described. The method harnesses the ability of dendrimer to interact with oppositely charged phospholipid and solubilize acidic drugs in their interior. The high drug entrapment in liposomes is due to the enhanced entrapment of dendrimer, which cr... |
11790488 | Cyclodextrins and drug permeability through semi-permeable cellophane membranes. | Determinations of drug fluxes through semi-permeable cellophane membranes are used to evaluate cyclodextrin complexes and cyclodextrin containing drug formulations. In the present study we investigated how the cyclodextrin concentration, the membrane thickness and the molecular weight cut off (MWCO) of the membrane inf... |
11790091 | Structural evidence for a dominant role of nonpolar interactions in the binding of a transport/chemosensory receptor to its highly polar ligands. | The receptor, a maltose/maltooligosaccharide-binding protein, has been found to be an excellent system for the study of molecular recognition because its polar and nonpolar binding functions are segregated into two globular domains. The X-ray structures of the "closed" and "open" forms of the protein complexed with mal... |
11788736 | DNA microarrays with PAMAM dendritic linker systems. | The DNA microarray-based analysis of single nucleotide polymorphisms (SNPs) is important for the correlation of genetic variations and individual phenotypes, and for locating disease-causing genes. To facilitate the development of surfaces suitable for immobilization of oligonucleotides, we report here a novel method f... |
11788721 | Rolling-circle amplification under topological constraints. | We have performed rolling-circle amplification (RCA) reactions on three DNA templates that differ distinctly in their topology: an unlinked DNA circle, a linked DNA circle within a pseudorotaxane-type structure and a linked DNA circle within a catenane. In the linked templates, the single-stranded circle (dubbed earrin... |
11787056 | Heat shock proteins of adult and embryonic human ocular lenses. | We investigated the presence and distribution of heat shock proteins, HSP-70 [Horwitz, J. 1992. Proc Natl Acad Sci 89:10449-10453], HSP-40, HSc-70, HSP-27, and alphabeta-crystallin in different regions of adult and fetal human lenses and in aging human lens epithelial cells. This study was undertaken because heat shock... |
11786492 | The pharmacology of the acute hyperthermic response that follows administration of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') to rats. | 1. The pharmacology of the acute hyperthermia that follows 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') administration to rats has been investigated. 2. MDMA (12.5 mg kg(-1) i.p.) produced acute hyperthermia (measured rectally). The tail skin temperature did not increase, suggesting that MDMA may impair heat dis... |
11786335 | Fluorescence studies on PAMAM dendrimers interactions with bovine serum albumin. | Polyamidoamine (PAMAM) dendrimers (generation 3.5 and 4) interaction with bovine serum albumin (BSA) was studied. The intensity of intrinsic fluorescence of two tryptophan residues and a shift in wavelength of their emission maxima were chosen as indicators of protein conformational changes. It is shown that the genera... |
11784151 | Radiolabeling and in vivo behavior of copper-64-labeled cross-bridged cyclam ligands. | Macrocyclic chelators and their metal complexes have widespread applications in the biomedical sciences, including radiopharmaceutical chemistry. The use of copper radionuclides in radiopharmaceuticals is increasing. Macrocyclic chelators have been found to have enhanced in vivo stability over acyclic chelators such as... |
11784141 | Beta-strand mimicking macrocyclic amino acids: templates for protease inhibitors with antiviral activity. | New amino acids are reported in which component macrocycles are constrained to mimic tripeptides locked in a beta-strand conformation. The novel amino acids involve macrocycles functionalized with both an N- and a C-terminus enabling addition of appendages at either end to modify receptor affinity, selectivity, or memb... |
11782545 | Dynamin at actin tails. | Dynamin, the product of the shibire gene of Drosophila, is a GTPase critically required for endocytosis. Some studies have suggested a functional link between dynamin and the actin cytoskeleton. This link is of special interest, because there is evidence implicating actin dynamics in endocytosis. Here we show that endo... |
11782912 | The solid-state stability of amorphous quinapril in the presence of beta-cyclodextrins. | The major objective of this study was to investigate the effects of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the solid-state chemical reactivity of the drug, quinapril, when amorphous samples are prepared by colyophilization of quinapril and each of these beta-CDs. For comparison,... |
11782901 | Topical formulation studies with DEET (N,N-diethyl-3-methylbenzamide) and cyclodextrins. | The purpose of this study was to investigate the utility of cyclodextrins as a safer alternative to the commonly used cosolvent ethanol in topical N,N-diethyl-3-methylbenzamide (DEET) formulations. Ethanol is a known penetration enhancer and would ideally not be used in a formulation containing DEET, a compound known f... |
11782177 | A joint structural, kinetic, and thermodynamic investigation of substituent effects on host-guest complexation of bicyclic azoalkanes by beta-cyclodextrin. | Derivatives of the azoalkane 2,3-diazabicyclo[2,2,2]oct-2-ene (1a) with bridgehead 1,4-dialkyl (1b), 1,4-dichloro (1c), 1-hydroxymethyl (1d), 1-aminomethyl (1e), and 1-ammoniummethyl (1f) substituents form host-guest inclusion complexes with beta-cyclodextrin. They were employed as probes to assess substituent effects ... |
11782174 | The effect of mechanical interlocking on crystal packing: predictions and testing. | The first statistical analyses of the X-ray crystal structures of mechanically interlocked molecular architectures, the first molecular mechanics-based solid-state calculations on such structures and atomic force microscopy (AFM) experiments are used in combination to predict and test which types of benzylic amide macr... |
11782163 | A general strategy to determine a target DNA sequence of a short peptide: application to a d-peptide. | Short peptides could potentially provide a novel element to read-out DNA sequences from the major groove. However, it is difficult to determine sequence-preference of de novo designed monomeric short peptides. Because DNS-binding affinity and specificity of short peptides are usually much lower than those of native DNA... |
11782158 | Direct observation of host-guest hydrogen bonding in the zeolite NaY/chloroform system by neutron scattering. | The differential H pair distribution function obtained from neutron scattering contrast measurements on hydrogenous and deuterated chloroform adsorbed into zeolite NaY (two molecules per supercage) reveals direct evidence for hydrogen bonding between hydrogen atoms on the sorbate molecule and oxygen atoms of the zeolit... |
11780115 | A robust DNA mechanical device controlled by hybridization topology. | Controlled mechanical movement in molecular-scale devices has been realized in a variety of systems-catenanes and rotaxanes, chiroptical molecular switches, molecular ratchets and DNA-by exploiting conformational changes triggered by changes in redox potential or temperature, reversible binding of small molecules or io... |
11779169 | In vitro self-assembled HCV core virus-like particles induce a strong antibody immune response in sheep. | The in vitro self-assembly properties of the entire hepatitis C virus core protein (HCcAg) obtained from Pichia pastoris cells and the induction of specific antibody immune response were studied. HCcAg was purified as a low-molecular-weight species by electroelution under denaturing conditions for confirmation of its s... |
11777443 | Synthesis of isoquinolines and pyridines by the palladium/copper-catalyzed coupling and cyclization of terminal acetylenes and unsaturated imines: the total synthesis of decumbenine B. | Monosubstituted isoquinolines and pyridines have been prepared in good to excellent yields via coupling of terminal acetylenes with the tert-butylimines of o-iodobenzaldehydes and 3-halo-2-alkenals in the presence of a palladium catalyst and subsequent copper-catalyzed cyclization of the intermediate iminoalkynes. In a... |
11772081 | Malonate crown ethers as building blocks for novel D-pi-A chromophores. | [reaction: see text] A series of new crown ethers, incorporating a malonate ester functionality, have been synthesized and derivatized with pi-electron rich aldehydes to give, conjugated, extended "push-pull" compounds. Their ability to bind Lewis acid-like metal cations, such as Mg(2+) and Eu(3+), has been characteriz... |
11772078 | A novel strained undecadiyne cyclophane with interesting dienophilic character. | [reaction: see text] Copper-mediated oxidative coupling of 3 afforded the strained product 4 from intramolecular cyclization rather than the triply bridged cyclophane 5 from dimerization. X-ray analysis of the bromo derivative 15 confirmed the distorted nature of the butadiyne bridge (bond angles 164.1 degrees and 153.... |
11772077 | The lectin-binding properties of six generations of mannose-functionalized dendrimers. | [structure: see text] First- through sixth-generation PAMAM dendrimers have been functionalized with mannose residues. Characterization with MALDI-TOF MS and (1)H NMR is reported. Different binding enhancements consistent with monovalent interaction, glycoside clustering, and multivalent binding are observed for differ... |
11771966 | Transmembrane domain mediated self-assembly of major coat protein subunits from Ff bacteriophage. | The 50-residue major coat protein (MCP) of Ff bacteriophage exists as a single-spanning membrane protein in the Escherichia coli host inner membrane prior to assembly into lipid-free virions. Here, the molecular bases for the specificity and stoichiometry that govern the protein-protein interactions of MCP in the host ... |
11772052 | Design of three-dimensional, millimeter-scale models for molecular folding. | This communication describes the fabrication of three-dimensional structures of organic polymers using principles of design inspired by protein folding. The structures consist of rigid polyhedral components with dimensions of a few millimeters ("microdomains"), representing alpha-helical and beta-sheet secondary struct... |
11772939 | A possible role for pi-stacking in the self-assembly of amyloid fibrils. | Amyloid fibril formation is assumed to be the molecular basis for a variety of diseases of unrelated origin. Despite its fundamental clinical importance, the mechanism of amyloid formation is not fully understood. When we analyzed a variety of short functional fragments from unrelated amyloid-forming proteins, a remark... |
11772524 | Modulation of human lymphocyte proliferative response with aging. | Previously, we have demonstrated age-associated alterations in transmembrane signaling. One of the most reproducible alterations found in the immune response with aging is the decrease of lymphocyte proliferation on stimulation with various different mitogens. Here, we confirm that proliferative responses to stimulatio... |
11772038 | High selectivity of human tissue transglutaminase for immunoactive gliadin peptides: implications for celiac sprue. | Celiac Sprue is an HLA DQ2 (or DQ8)-associated autoimmune disorder of the human small intestine that is induced by dietary exposure to wheat gliadin and related proteins from barley, rye, and possibly other food grains. Recently, tissue transglutaminase (tTGase)-catalyzed deamidation of gliadin peptides has been shown ... |
11772403 | Kinetic study of various binding modes between human DNA polymerase beta and different DNA substrates by surface-plasmon-resonance biosensor. | The interaction of a series of DNA substrates with human DNA polymerase beta has been studied in real time by using a surface-plasmon-resonance (SPR) biosensor technique. We have prepared the sensor surfaces comprising different DNA targets, including single-stranded DNA, blunt-end double-stranded DNA, gapped DNA and D... |
11772656 | Characterization of a Sinorhizobium isolate and its extracellular polymer implicated in pollutant transport in soil. | A bacterium isolated from soil (designated 9702-M4) synthesizes an extracellular polymer that facilitates the transport of such hydrophobic pollutants as polynuclear aromatic hydrocarbons, as well as the toxic metals lead and cadmium in soil. Biolog analysis, growth rate determinations, and percent G+C content identify... |
11755764 | Optimization of preparative electrophoretic chiral separation of ritalin enantiomers. | Continuous free flow electrophoresis (CFFE) was applied to the preparative chiral separation of ritalin enantiomers. Sulfated beta-cyclodextrin (sbeta-CD) was used as the chiral additive. Liquid chromatography-mass spectrometry (LC-MS) experiments were applied to study the time averaged concentration of sbeta-CD in the... |
11755762 | Use of negatively charged cyclodextrins for the simultaneous enantioseparation of selected anesthetic drugs by capillary electrophoresis-mass spectrometry. | The simultaneous enantioseparation of selected anesthetic drugs was studied by capillary electrophoresis (CE) in presence of three different negatively charged cyclodextrins (CDs). Among the chiral selectors tested, namely carboxymethyl, sulfobutyl ether and sulfated-beta-CD, the latter appeared to be the most effectiv... |
11755759 | Development and validation of a capillary electrophoresis method for ximelagatran assay and related substance determination in drug substance and tablets. | The advantages of simplicity, selectivity, versatility and ease of use of free solution capillary electrophoresis (CE) present an orthogonal and complementary separation technique to the established methods of liquid chromatography (LC) for pharmaceutical analysis. This work presents the development and performance of ... |
11755758 | Enantiomer separation by capillary electrophoresis utilizing carboxymethyl derivatives of polysaccharides as chiral selectors. | Enantiomer separations of various drugs by capillary electrophoresis (CE) were investigated utilizing carboxymethyl (CM) derivatives of some polysaccharides. Three types of CM-polysaccharides, namely CM-dextran, -amylose and -cellulose were employed as chiral selectors in the CE enantiomer separation. Capability of ena... |
11755757 | Enantioselective stabilization of inclusion complexes of metoprolol in carboxymethylated beta-cyclodextrin. | The inclusion complexes of metoprolol (MT) and carboxymethyl-beta-cyclodextrin (CMCD) were prepared and the stability constants of the complexes were determined. Binding studies performed using high performance liquid chromatography (HPLC), UV spectrometry and capillary electrophoresis (CE) indicated that a complex wit... |
11755756 | Capillary electrophoresis with (R)-(--)-N-(3,5-dinitrobenzoyl)-alpha-phenylglycine as chiral selector for separation of albendazole sulfoxide enantiomers and their analysis in human plasma. | The electrokinetic separation and analysis of the enantiomers of albendazole sulfoxide (ABZSO), a sulfoxide with a sulfur stereogenic center hepatically formed during therapy with the anthelmintic drug albendazole (ABZ), is reported. Using aqueous or nonaqueous alkaline background electrolytes, ABZSO enantiomers cannot... |
11755755 | A strategic approach to the development of capillary electrophoresis chiral methods for pharmaceutical basic compounds using sulfated cyclodextrins. | Enantioseparations of basic pharmaceutical compounds were investigated using different types of sulfated cyclodextrins as chiral selectors. A general strategy for method development was described, together with enantiomeric separations of a number of pharmaceutical related compounds. Based on this strategy, systematic ... |
11755754 | Do we know the mechanism of chiral recognition between cyclodextrins and analytes? | The resolution of chiral phenethylamine analogue compounds were studied in presence of single-isomer neutral and negatively charged cyclodextrins (CDs) by means of capillary electrophoresis (CE) and NMR spectroscopy. Whereas the native beta-CD and heptakis(2-N,N-dimethylcarbamoyl)beta-cyclodextrin were not able to sepa... |
11755753 | Knowledge-based system for method development of chiral separations with capillary electrophoresis using highly-sulphated cyclodextrins. | Method development for chiral separations is not easy because it requires experience and many experimental possibilities can be chosen. In order to help the analyst, a knowledge-based system (KBS) for the rapid determination of experimental parameters, which allow a baseline separation of enantiomers, has been develope... |
11755749 | The enantioselective determination of chlorpheniramine and its major metabolites in human plasma using chiral chromatography on a beta-cyclodextrin chiral stationary phase and mass spectrometric detection. | A sensitive enantioselective high-performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of plasma concentrations of (-)(R)- and (+)(S)-chlorpheniramine (CP) and their metabolites, desmethyl-chlorpheniramine (DCP), didesmethyl-chorpheniramine (DDCP) and chlorpheniramine N... |
11755748 | Comparative enantioseparation of selected chiral drugs on four different polysaccharide-type chiral stationary phases using polar organic mobile phases. | The enantiomers of randomly selected chiral drugs and drug analogs of various structural and pharmacological groups were resolved on four different polysaccharide-type chiral stationary phases (CSP) using pure methanol and acetonitrile as mobile phases. Polysaccharide phenylester type CSP, Chiralcel-OJ although resolvi... |
11755742 | Comparison of three chiral stationary phases with respect to their enantio- and diastereoselectivity for cyclic beta-substituted alpha-amino acids. | Three chiral stationary phases were examined for the enantio- and diastereoseparation of cycloaliphatic beta-substituted alpha-quaternary alpha-amino acids. Resolution of diastereomeric analytes is feasible with a chiral crown ether based column, whereas the separation of enantiomers, except for one pair of amino acids... |
11756499 | Synaptic activity-induced conversion of intronic to exonic sequence in Homer 1 immediate early gene expression. | Three Homer genes regulate the activity of metabotropic glutamate receptors mGluR1a and mGluR5 and their coupling to releasable intracellular Ca2+ pools and ion channels. Only the Homer 1 gene evolved bimodal expression of constitutive (Homer 1b and c) and immediate early gene (IEG) products (Homer 1a and Ania 3). The ... |
11754592 | Methanocarba modification of uracil and adenine nucleotides: high potency of Northern ring conformation at P2Y1, P2Y2, P2Y4, and P2Y11 but not P2Y6 receptors. | The potency of nucleotide antagonists at P2Y1 receptors was enhanced by replacing the ribose moiety with a constrained carbocyclic ring (Nandanan, et al. J. Med. Chem. 2000, 43, 829-842). We have now synthesized ring-constrained methanocarba analogues (in which a fused cyclopropane moiety constrains the pseudosugar rin... |
11754552 | Complexation of several benzimidazole-type fungicides with alpha- and beta-cyclodextrins. | The potential increase in water solubility of three benzimidazole-type fungicides (thiabendazole, carbendazim, and fuberidazole) due to complexation with alpha- and beta-cyclodextrins was investigated. Fluorescence emission spectra of the fungicides in the presence of different concentrations of the cyclodextrins were ... |
11755275 | Time-dependent loss of radioactivity counts associated with paracellular markers in the presence of cyclodextrin. | This communication reports an unexpected phenomenon observed during the counting of radiolabeled paracellular marker solutions in the presence of 2-hydroxypropyl-beta-cyclodextrin (HPbetaCD). The results revealed time-dependent loss of 14C-mannitol and 14C-polyethlene glycol 4000 radioactivity counts with increased per... |
11755529 | Mapping the receptor site for ergtoxin, a specific blocker of ERG channels. | We show here that ergtoxin (ErgTx) is a bona fide, specific blocker of the human ether-a-go-go-related gene (HERG) channels. It does not affect the function of either M-eag or M-elk channels. A chimeric construction containing a segment of the P-region of M-eag channel inserted into the HERG channel drastically diminis... |
11755520 | F-actin assembly in Dictyostelium cell locomotion and shape oscillations propagates as a self-organized reaction-diffusion wave. | The crawling locomotion and shape of eukaryotic cells have been associated with the stochastic molecular dynamics of actin and its protein regulators, chiefly Arp2/3 and Rho family GTPases, in making a cytoskeleton meshwork within cell extensions. However, the cell's actin-dependent oscillatory shape and extension dyna... |
11755346 | Facile synthesis of beta-cyclodextrin dithiols. | Nucleophilic addition of 4-methoxy-alpha-toluenethiol to capped cyclodextrins followed by deprotection in TFA affords cyclodextrin dithiols in good yields with no disulfide formation and requires only minimal purification. |
11752331 | The Histone Database. | Histone proteins are often noted for their high degree of sequence conservation. It is less often recognized that the histones are a heterogeneous protein family. Furthermore, several classes of non-histone proteins containing the histone fold motif exist. Novel histone and histone fold protein sequences continue to be... |
11752163 | Systemic, mucosal, and heterotypic immune induction in mice inoculated with Venezuelan equine encephalitis replicons expressing Norwalk virus-like particles. | Norwalk-like viruses (NLVs) are a diverse group of single-stranded, nonenveloped, positive-polarity RNA viruses and are the leading cause of epidemic acute gastroenteritis in the United States. In this study, the major capsid gene of Norwalk virus, the prototype NLV, has been cloned and expressed in mammalian cells usi... |
11750033 | Resonance Raman spectroscopy and density functional theoretical calculations of manganese corroles. A parallelism between high-valent metallocorroles and metalloporphyrins, relevant to horseradish peroxidase and chloroperoxidase compound I and II intermediates. | Soret-excited resonance Raman (RR) spectra are reported for the Mn(III) and Mn(IV)Cl derivatives of meso-tris(p-(trifluoromethyl)phenyl)corrole, H(3)T(p-CF(3)-P)Cor, and the Mn(III) derivative of beta-octabromo-meso-tris(p-(trifluoromethyl)phenyl)corrole, H(3)Br(8)T(p-CF(3)-P)Cor. Three high-frequency bands in the RR s... |
11751821 | Genes required for plasmid R64 thin-pilus biogenesis: identification and localization of products of the pilK, pilM, pilO, pilP, pilR, and pilT genes. | We have previously shown that the pilL, pilN, pilQ, pilS, pilU, and pilV genes of plasmid R64 encode outer membrane lipoprotein, secretin, cytoplasmic ATPase, major pilin, prepilin peptidase, and minor pilin, respectively, which are required for thin-pilus formation. In this work, we characterized the products of the r... |
11751811 | Identification of target genes regulated by the two-component system HP166-HP165 of Helicobacter pylori. | Two-component systems are signal transduction systems which enable bacteria to regulate cellular functions in response to changing environmental conditions. In most cases regulation is accomplished on the transcriptional level by a response regulator protein, which, according to the phosphorylation state of its receive... |
11753927 | Effects of humic substances on the bioavailability and aerobic biodegradation of polychlorinated biphenyls in a model soil. | The very high hydrophobicity of polychlorinated biphenyls (PCBs) strongly reduces their bioavailability in aged contaminated soils, thus limiting their bioremediation. The biodegradability of PCBs in heavily contaminated soils can be significantly enhanced by soil treatment with surface-active agents. In this work, the... |
11751324 | The calculated in vitro and in vivo chlorophyll a absorption bandshape. | The room temperature absorption bandshape for the Q transition region of chlorophyll a is calculated using the vibrational frequency modes and Franck-Condon (FC) factors obtained by line-narrowing spectroscopies of chlorophyll a in a glassy (Rebane and Avarmaa, Chem. Phys. 1982; 68:191-200) and in a native environment ... |
11751323 | Thermodynamic and kinetic characterization of antisense oligodeoxynucleotide binding to a structured mRNA. | Antisense oligonucleotides act as exogenous inhibitors of gene expression by binding to a complementary sequence on the target mRNA, preventing translation into protein. Antisense technology is being applied successfully as a research tool and as a molecular therapeutic. However, a quantitative understanding of binding... |
11751321 | Salt-induced conformation and interaction changes of nucleosome core particles. | Small angle x-ray scattering was used to follow changes in the conformation and interactions of nucleosome core particles (NCP) as a function of the monovalent salt concentration C(s). The maximal extension (D(max)) of the NCP (145 +/- 3-bp DNA) increases from 137 +/- 5 A to 165 +/- 5 A when C(s) rises from 10 to 50 mM... |
11751315 | Relationship of lipid rafts to transient confinement zones detected by single particle tracking. | We examined the physical and chemical characteristics of transient confinement zones (TCZs) that are detected in single particle trajectories of molecules moving within the membrane of C3H 10T1/2 murine fibroblasts and their relationship to "rafts." We studied the lateral movement of different membrane molecules though... |
11751313 | A Monte Carlo study of peptide insertion into lipid bilayers: equilibrium conformations and insertion mechanisms. | The membrane insertion behavior of two peptides, Magainin2 and M2 delta, was investigated by applying the Monte Carlo simulation technique to a theoretical model. The model included many novel aspects, such as a new semi-empirical lipid bilayer model and a new set of semi-empirical transfer energies, which reproduced t... |
11751301 | Simulations of cell-surface integrin binding to nanoscale-clustered adhesion ligands. | Clustering of ligated integrins strongly influences integrin signaling and mechanical linkages between integrins and intracellular structures. Extracellular spatial organization of integrin ligands in clusters may facilitate clustering of bound integrins and thus potentially regulate cellular responses to a defined ave... |
11751117 | D-Ala:D-Ala ligase gene flanking the vanC cluster: evidence for presence of three ligase genes in vancomycin-resistant Enterococcus gallinarum BM4174. | An open reading frame located 230 nucleotides downstream from the stop codon of vanS(c) and in the opposite direction relative to the other genes of the vanC cluster was identified in Enterococcus gallinarum BM4174. This gene (designated ddl2) encoded a protein of 343 amino acids that had significant predicted structur... |
11742121 | Unique oligomeric intermediates of bovine liver catalase. | Catalases, although synthesized from single genes and built up from only one type of subunit, exist in heterogeneous form with respect to their conformations and association states in biological systems. This heterogeneity is not of genetic origin, but rather reflects the instability of this oligomeric heme enzyme. To ... |
11741714 | A differential vapor-pressure equipment for investigations of biopolymer interactions. | The design and performance of an equipment for the measurement of vapor pressures over liquid or solid samples is presented. The equilibrium pressure difference, DeltaP, between a sample and a reference of known vapor pressure is recorded as a function of composition and/or temperature. Through the use of high-accuracy... |
11741709 | Synthesis and characterization of polyrotaxane-based polymeric continuous beds for capillary electrochromatography. | The continuous bed technique with its attractive features, such as fritless design, one-step in situ synthesis, low back pressure and no need for pressurising the electrode vessels to suppress bubble formation was applied to form polyrotaxane-based stationary phases for capillary electrochromatography (CEC). Rotaxanes ... |
11748293 | Immunoelectron microscopic localization of cholesterol using biotinylated and non-cytolytic perfringolysin O. | We used a proteolytically modified and biotinylated derivative of the cholesterol-binding Theta-toxin (perfringolysin O) to localize cholesterol-rich membranes in cryosections of cultured human lymphoblastoid cells (RN) by electron microscopy. We developed a fixation and immunolabeling procedure to improve the preserva... |
11748166 | Identification of a promiscuous T-cell epitope in Mycobacterium tuberculosis Mce proteins. | The characterization of Mycobacterium tuberculosis antigens inducing CD4(+) T-cell responses could critically contribute to the development of subunit vaccines for M. tuberculosis. Here we performed computational analysis by using T-cell epitope prediction software (known as TEPITOPE) to predict promiscuous HLA-DR liga... |
11748802 | Enantiomeric separation of drugs and herbicides on a beta-cyclodextrin-bonded stationary phase. | A chemically bonded beta-cyclodextrin chiral stationary phase for HPLC was prepared in a "one pot" process by the reaction of a phenylated beta-cyclodextrin with silica gel. Various racemic analytes such as drugs (aminoalcohol adrenergic beta-blockers, benzodiazepine anxiolytics, arylpropionic acid antiinflammatory age... |
11748801 | Absolute configuration of 3-hydroxy acids formed by Stenotrophomonas maltophilia: application of multidimensional gas chromatography and circular dichroism spectroscopy. | The soil bacterium Stenotrophomonas maltophilia was found to transform various long-chain fatty acids selectively into 3-hydroxy fatty acids of shorter chain length. Their chiral evaluation was performed by multidimensional gas chromatography (MDGC) on modified cyclodextrin phase comparing the enantiodistribution of 1,... |
11748795 | Toward catalytic rigid-rod beta-barrels: a hexamer with multiple histidines. | Rigid-rod beta-barrels are composed of interdigitating, short, amphiphilic peptide strands that are flanked by stabilizing rigid-rod "staves." As a first step toward the construction of catalytic rigid-rod beta-barrels, we here report synthesis and study of a new barrel designed to comprise alternating leucine and hist... |
11744654 | Phenotypic adaptations in human muscle fibers 6 and 24 wk after spinal cord injury. | The effects of spinal cord injury (SCI) on the profile of sarco(endo) plasmic reticulum calcium-ATPase (SERCA) and myosin heavy chain (MHC) isoforms in individual vastus lateralis (VL) muscle fibers were determined. Biopsies from the VL were obtained from SCI subjects 6 and 24 wk postinjury (n = 6). Biopsies from nondi... |
11744653 | Acute hormonal response to sublingual androstenediol intake in young men. | The effectiveness of orally ingested androstenediol in raising serum testosterone concentrations may be limited because of hepatic breakdown of the ingested androgens. Because androstenediol administered sublingually with cyclodextrin bypasses first-pass hepatic catabolism, we evaluated the acute hormonal response to s... |
11745178 | Exploitation of a library of alpha-galactosidases for the synthesis of building blocks for glycopolymers. | After screening a library of fungal alpha-galactosidases for the synthesis of functionalized alkyl alpha-D-galactopyranosides, four enzymes (isolated from Aspergillus terreus CCM55, Aspergillus commune CCM 2969, Penicillium vinaceum CCM 2384, or Penicillium brasilianum 2155) proved to be suitable for these biotransform... |
11742731 | A nano-molar sensitive disposable biosensor for determination of dopamine. | The studies on a nano-molar sensitive disposable biosensor based on the screen-printing basal electrode and the supramolecular assembly of dual mediators, tetramethylbenzidine and ferrocene, by beta-cyclodextrin inclusion complexation have been reported in this paper. This biosensor shows the high quality of analytical... |
11739735 | Molecular ordering of the initial signaling events of CD95. | Binding of either ligand or agonistic antibodies to the death receptor CD95 (APO-1/Fas) induces the formation of the death-inducing signaling complex (DISC). We now show that signal initiation of CD95 in type I cells can be further separated into at least four distinct steps. (i) The first step is ligand-induced format... |
11739697 | Envelope glycoprotein cytoplasmic domains from diverse lentiviruses interact with the prenylated Rab acceptor. | Lentivirus envelope glycoproteins have unusually long cytoplasmic domains compared to those of other retroviruses. To identify cellular binding partners of the simian immunodeficiency virus (SIV) envelope transmembrane protein (gp41) cytoplasmic domain (CD), we performed a yeast two-hybrid screen of a phytohemagglutini... |
11738602 | Synthesis and protein binding properties of T-antigen containing GlycoPAMAM dendrimers. | Allyl O-(beta-D-galactopyranosyl)-(1-3)-2-acetamido-2-deoxy-alpha-D-galactopyranoside (8) was prepared in excellent yield from the corresponding galactosyl bromide (6, 7) and allyl 2-acetamido-4,6-benzylidene-2-deoxy-alpha-D-galactopyranoside (5) using Hg(CN)2 as a promoter. Compound 5 was obtained from N-acetylglucosa... |
11762841 | Control of self-assembling oligopeptide matrix formation through systematic variation of amino acid sequence. | In order to elucidate design principles for biocompatible materials that can be created by in situ transformation from self-assembling oligopeptides, we investigate a class of oligopeptides that can self-assemble in salt solutions to form three-dimensional matrices. This class of peptides possesses a repeated sequence ... |
11762846 | Production of ordered collagen matrices for three-dimensional cell culture. | The aim of this study was to produce collagen gels with controlled fibrillar order as matrices for cell culture. Their structural characterization and colonization by human dermal fibroblasts arc presently reported. Ordered matrices are obtained by using the property of type I collagen monomers to self-assemble in liqu... |
11761152 | The use of synthetic polymers for delivery of therapeutic antisense oligodeoxynucleotides. | Developed over the past two decades, the antisense strategy has become a technology of recognised therapeutic potential, and many of the problems raised earlier in its application have been solved to varying extents. However, the adequate delivery of antisense oligodeoxynucleotides to individual cells remains an import... |
11731718 | Effects of silymarin MZ-80 on hepatic oxidative stress in rats with biliary obstruction. | This study was designed to evaluate the effects of three pharmaceutical forms of silymarin (silymarin MZ-80, silybinin-beta-cyclodextrin, and silybinin) on the liver oxidative status in vitro and after oral administration to rats with extrahepatic biliary obstruction (EBO) and sham-operated animals. We evaluated thioba... |
11682221 | Enantioseparation of chiral vasodilator drug isoxsuprine in high-performance liquid chromatography and capillary electrophoresis. | Two independent methods using high-performance liquid chromatography (HPLC) on polysaccharide type chiral stationary phase (CSP) and capillary electrophoresis (CE) with native and derivatised cyclodextrins (CD) have been proposed for the enantioseparation of chiral vasodilator drug isoxsuprine (ISP). The methods have b... |
15070681 | Lipid rafts are necessary for tonic inhibition of cellular tissue factor procoagulant activity. | A fraction of total cellular tissue factor procoagulant activity remains masked or "encrypted" in intact cells. Decryption of this activity partly involves the extracellular exposure of anionic phospholipids such as phosphatidylserine. Because of the potential association of tissue factor and phospholipid scramblase ac... |
14701844 | Molecular recognition between glyconectins as an adhesion self-assembly pathway to multicellularity. | The appearance of multicellular forms of life has been tightly coupled to the ability of an organism to retain its own anatomical integrity and to distinguish self from non-self. Large glycoconjugates, which make up the outermost cell surface layer of all Metazoans, are the primary candidates for the primordial adhesio... |
14699046 | Entropic switch regulates myristate exposure in the HIV-1 matrix protein. | The myristoylated matrix protein (myr-MA) of HIV functions as a regulator of intracellular localization, targeting the Gag precursor polyprotein to lipid rafts in the plasma membrane during virus assembly and dissociating from the membrane during infectivity for nuclear targeting of the preintegration complex. Membrane... |
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