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21171616 | Bottom-up Assembly of RNA Arrays and Superstructures as Potential Parts in Nanotechnology. | DNA and protein have been extensively scrutinized for feasibility as parts in nanotechnology, but another natural building block, RNA, has been largely ignored. RNA can be manipulated to form versatile shapes, thus providing an element of adaptability to DNA nanotechnology, which is predominantly based upon a double-he... |
17191913 | 13C-CPMAS and 1H-NMR study of the inclusion complexes of beta-cyclodextrin with carvacrol, thymol, and eugenol prepared in supercritical carbon dioxide. | Beta-cyclodextrin (beta-CD) inclusion complexes with carvacrol (1), thymol (2), and eugenol (3) (components of essential oils of vegetable origin) were prepared by the supercritical CO2 technique, and their structural characterization was achieved by means of 1H-NMR in aqueous solution and 13C-CPMAS NMR in the solid st... |
17191912 | Sequence-specific binding of the Schizosaccharomyces pombe His1 protein to fission yeast telomeric DNA. | Sequence-specific protein-DNA interaction is critical for many important cellular processes such as transcription, DNA replication, and chromosome segregation. Identification of additional proteins that bind to DNA in a sequence-specific manner will contribute to the understanding of the mechanism of molecular recognit... |
17191909 | Bimetallic complexes of spiro-azacrown ligands as catalysts of phosphoester and phosphoric anhydride cleavage. | The ability of bimetallic homo- and heteronuclear complexes of two spiro-linked ligands, viz. a biazacrown (i.e., 2,6,10,14,18,22-hexaazaspiro[11.11]tricosane (1)) and an azacrown-crown ether (i.e., 14,17,20,23,26-pentaoxa-2,6,10-triaza-spiro[11.15]heptacosane (2)), to promote the cleavage of the phosphoester linkage o... |
16026011 | Reduction of drug toxicity using dendrimers based on melamine. | Dendrimers based on melamine can reduce the organ toxicity of solubilized cancer drugs administered by intraperitoneal injection. Methotrexate and 6-mercaptopurine, both FDA approved anticancer drugs, are known hepatotoxins. The solubility of these molecules can be increased by mixing them with a dendrimer based on mel... |
15974007 | [Effect of supercritical CO2 to cellulase reaction]. | The effects of pretreatment of supercritical carbon dioxide (SC-CO2) on the supramolecular structure of cellulose and the cellulase catalyzed reaction were investigated. The cellulase activity was not affected when it was treated with SC-CO2 at 10MPa and at 50 degrees C for 30 min. But when the cellulase was treated by... |
15762533 | [Study on the inclusion complexation interaction of beta-cyclodextrin and beta-carotene by UV-Vis spectra]. | Beta-cyclodextrin (beta-CD), a kind of cyclic oligosaccharides, was found to possess a strong inclusion ability with beta-carotene. The inclusion compounds of beta-CD with beta-carotene were prepared by the coprecipitation method, and studied by UV-Vis spectra of different mole ratio beta-CD/beta-carotene in the H2O+ e... |
15762318 | Long-term shelf stability of amphiphilic beta-cyclodextrin nanosphere suspensions monitored by dynamic light scattering and cryo-transmission electron microscopy. | Amphiphilic beta-cyclodextrins (betaCDa) were synthesized by statistically grafting hexanoyl carbon chains on the secondary hydroxyl functions of the betaCD glucopyranosyl units. The obtained derivative was used to prepare submicronic colloidal nanosphere suspensions using a nano-precipitation method. The fresh suspens... |
15706932 | [Characteristics and applications of amide bridged calix [ 4 ] arene solid-phase microextraction fiber]. | A novel solid-phase microextraction (SPME) fiber coated with 25,27-dihydroxy-26, 28-(1', 10'-dioxa-4', 7'-diaza-3', 8'-dioxooctylene ) -p-tert-butylcalix [ 4 ] arene/hydroxy-terminated silicone oil (amide bridged -C[4]/OH-TSO) was prepared with sol-gel technology and applied to the analysis of aliphatic amines and arom... |
15621683 | Solubility enhancement of indomethacin with poly(amidoamine) dendrimers and targeting to inflammatory regions of arthritic rats. | This work includes investigation on solubility enhancement of indomethacin (IND) in the presence of poly(amidoamine) (PAMAM) dendrimers and passive targeting of the PAMAM/IND complex so formed to the inflamed regions in an animal model. The complex formation was confirmed by infrared and (1)H nuclear magnetic resonance... |
15617268 | Macrocycle-derived functional xanthenes and progress towards concurrent detection of glucose and fructose. | The detection of saccharides in biological media is of great current importance for the monitoring of disease states. We have previously reported that solutions of boronic acid-functionalized macrocycles form acyclic oligomeric materials in situ. The oligomers contain fluorescent xanthene moieties. Current efforts are ... |
15617265 | Glucose-sensitive nanoassemblies comprising affinity-binding complexes trapped in fuzzy microshells. | A new design for glucose monitoring with "smart" materials based on self assembly, competitive binding, and resonance energy transfer (RET) is presented. The basic transduction principle is changing RET efficiency from fluorescein isothiocyanate (FITC) to tetramethylrhodamine isothiocyanate (TRITC), as FITC-dextran is ... |
15606027 | [The complexation of prostaglandin E1 with hydroxylpropyl-beta-cyclodextrin in aqueous solution]. | <h4>Aim</h4>To investigate the complexation of prostaglandin E1 (PGE1) with hydroxylpropyl-beta-cyclodextrin (HP-beta-CD) in aqueous solutions, inclusion molar ratio of the host and guest molecules and change of thermodynamic parameters during the complexation process.<h4>Methods</h4>The measurements of the complexatio... |
15377828 | Biochemical and immunological properties of cytokines conjugated to dendritic polymers. | Here we describe a post-translational modification of SC-63032, a variant of the species restricted, multi-lineage hematopoeitic factor human interleukin-3 (hIL-3). We have made two new dendritic polymer (polyamidoamine or PAMAM dendrimers, generation 5)-SC-63032 bioconjugates. Using two distinct chemistries (one of wh... |
15570981 | Clustering effects on discontinuous gold film NanoCells. | Reproducible negative differential resistance (NDR)-like switching behavior is observed in NanoCells. This behavior is attributed to the formation of filaments and clusters between the discontinuous gold films. Control experiments are performed by self-assembly of insulating molecules between the gold islands and condu... |
15342647 | Trafficking of exogenous peptides into proteasome-dependent major histocompatibility complex class I pathway following enterotoxin B subunit-mediated delivery. | The B-subunit component of Escherichia coli heat-labile enterotoxin (EtxB), which binds to cell surface GM1 ganglioside receptors, was recently shown to be a highly effective vehicle for delivery of conjugated peptides into the major histocompatibility complex (MHC) class I pathway. In this study we have investigated t... |
15562974 | [Synthesis and chemical transformations of N-hydroxy- and N-hydroxyalkylcycloimides of chlorin p6]. | Two series of chlorin p6 13,15-cycloimides that differ in their substituents at the nitrogen atom of the additional six-membered ring were synthesized. The compounds of the first series have a hydroxyl, alkoxyl, or acyloxy group at the 13,15-cycloimide nitrogen and those of the second series, residues of aliphatic alco... |
15342644 | "Respirasome"-like supercomplexes in green leaf mitochondria of spinach. | Higher plant mitochondria have many unique features compared with their animal and fungal counterparts. This is to a large extent related to the close functional interdependence of mitochondria and chloroplasts, in which the two ATP-generating processes of oxidative phosphorylation and photosynthesis, respectively, tak... |
15499937 | Thermodynamic study on the gas chromatographic separation of the enantiomers of aromatic alcohols using heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin as a stationary phase. | Gas chromatographic separation of the enantiomers of nineteen structurally related aromatic alcohols was investigated as a function of temperature using a heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin-coated capillary column. Thermodynamic parameters were determined and compared with those obt... |
15499935 | Rapid determination of aristolochic acid I and II in Aristolochia plants from different regions by beta-cyclodextrin-modified capillary zone electrophoresis. | Chinese herbs nephropathy (CHN) is a kind of severe kidney disease caused by excessively taking aristolochic acid (AA). Hence, it is essential for health security and quality control of related herbal medicines to develop an efficient method for separation and determination of these two important components in Traditio... |
15499933 | Chiral capillary electrophoretic method for quantification of apomorphine. | A new method for chiral determination of apomorphine enantiomers was developed and validated. Seven different neutral and charged cyclodextrins were tested for enantioselectivity on R,S-apomorphine. Sulfobutylether-beta-cyclodextrin was found to offer the best resolution, but with this system, four peaks were detected ... |
15499931 | Generic, highly selective and robust capillary electrophoresis method for separation of a racemic mixture of glitazone compounds. | A generic, highly selective, and robust capillary electrophoresis (CE) method was developed for separation of a racemic mixture of three available glitazone compounds (also known as thiazolidinediones) in active pharmaceutical ingredients (API) and tablets. The method separated the R and S enantiomers of balaglitazone,... |
15499915 | Evaluation of apparent formation constants of pentacyclic triterpene acids complexes with derivatized beta- and gamma-cyclodextrins by reversed phase liquid chromatography. | A reversed phase HPLC method has been investigated in order to resolve three main pentacyclic triterpene acids (oleanolic-, betulinic- and ursolic acid) found in a lot of plants. Some of them (oleanolic and ursolic acids) are position isomers and their resolution is highly improved by the addition of derivatized cyclod... |
15499846 | Molecular origins of the remarkable chiral sensitivity of second-order nonlinear optics. | Recent observations of remarkably large chiroptical effects in second-harmonic generation (SHG) and sum-frequency generation (SFG) measurements suggest exciting possibilities for the development of new chiral-specific spectroscopies and novel chiral materials for nonlinear optics. Several fundamental studies designed t... |
15497750 | Hydroxypropyl methylcellulose microspheres with piroxicam and piroxicam-hydroxypropyl-beta-cyclodextrin inclusion complex. | Inclusion complexation between piroxicam (PX) and hydroxypropyl-beta-cyclodextrin (HPbetaCD) in the presence of hydroxypropyl methylcellulose (HPMC) was studied in aqueous solution and in the solid state. Phase solubility studies were used to evaluate the HPbetaCD complexation in the presence of HPMC. Stability constan... |
15495412 | Characterization of sulfated beta-cyclodextrins and determination of enantiomeric purity of (1 R,2S)-ephedrine by capillary zone electrophoresis. | Matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize two different sulfated beta-cyclodextrins (HS-beta-CD). It was found that the HS-beta-CDs have broad heterogeneity in terms of sulfation degree. T... |
15493506 | Cooperativity between selectins and beta2-integrins define neutrophil capture and stable adhesion in shear flow. | A cooperative, sequential process of molecular recognition governs leukocyte capture, rolling, and arrest on inflamed endothelium. Flowing neutrophils are captured via heterotypic adhesive interactions mediated by endothelial E-selectin, whereas homotypic interactions between neutrophils are mediated by L-selectin. To ... |
15491683 | Cellular cholesterol enrichment impairs T cell activation and chemotaxis. | Human aging is associated with an increase in immune cell cholesterol levels, independent of circulating cholesterol levels. The effects of such an increase in membrane cholesterol on lipid raft-associated immune cell function have not been investigated. We sought to examine the effects of in vitro cholesterol loading ... |
15489990 | Electronic and vibrational properties of a MOF-5 metal-organic framework: ZnO quantum dot behaviour. | UV-Vis DRS and photoluminescence (PL) spectroscopy, combined with excitation selective Raman spectroscopy, allow us to understand the main optical and vibrational properties of a metal-organic MOF-5 framework. A O(2-)Zn(2+)[rightward arrow] O(-)Zn(+) ligand to metal charge transfer transition (LMCT) at 350 nm, testifie... |
15483714 | Pentaaza macrocyclic ytterbium(III) complex and solvent controlled supramolecular self-assembly of its dimeric mu-eta 2:eta 2 peroxo-bridged derivatives. | The unprecedented template action of ytterbium ion in the synthesis of pentaaza macrocyclic Schiff bases is exemplified by isolation and definitive identification of the seven-coordinate pentagonal bipyramidal complex with the formula of [YbLCl(2)]ClO(4) (1), where L is 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1... |
15481263 | Determination of ammonium and metal ions by capillary electrophoresis-potential gradient detection using ionic liquid as background electrolyte and covalent coating reagent. | A capillary zone electrophoresis (CZE)-potential gradient detection (PGD) method coupled with field-amplified sample injection was developed to determine alkali metal, alkaline-earth metal, nickel, lead and ammonium ions. The capillary surface was coated with dialkylimidazolium-based ionic liquid and thus the electroos... |
15473700 | Suffocation of nerve fibers by living nanovesicles: a model simulation--part II. | Nanobacteria may cause peripheral neuropathy by adhesion to the perineurium. This hypothesis receives support from five independent observations: (1) identification of perineurial apatite in diabetic patients with peripheral neuropathy, (2) massive presence of nanobacteria in a diabetic patient, (3) beneficial effect o... |
15473688 | Proteome analysis of rhoptry-enriched fractions isolated from Plasmodium merozoites. | The rhoptries of Plasmodium species participate in merozoite invasion and modification of the host erythrocyte. However, only a few rhoptry proteins have been identified using conventional gene identification protocols. To investigate the protein organization of this organelle and to identify new rhoptry proteins, mero... |
15473670 | Enantioselective pharmacokinetics of carvedilol in human volunteers. | Carvedilol is administered as a racemic mixture of the R(+)- and S(-)-enantiomers, although they exhibit different pharmacological effects. To investigate the stereoselective pharmacokinetics, the enantiomeric separation of carvedilol in human plasma was undertaken using capillary electrophoresis (CE). Resolution of th... |
15473265 | [D-Ala2]-Deltorphin I peptoid and retropeptoid analogues: synthesis, biological activity and conformational investigations. | The synthesis is described of a [D-Ala2]-deltorphin I peptoid analogue in which all amino acid residues have been substituted by the corresponding N-alkylglycine residues. The [D-Ala2]-deltorphin I retropeptoid was also prepared as well as [Ala1 ,D-Ala2]-deltorphin 1 and the corresponding peptoid. Structural investigat... |
15386746 | Influence of droplet size, capillary-cone distance and selected instrumental parameters for the analysis of noncovalent protein-ligand complexes by nano-electrospray ionization mass spectrometry. | It has been suggested in the literature that nano-electrospray ionization (nano-ESI) mass spectrometry better reflects the equilibrium between complex and free protein in solution than pneumatically assisted electrospray ionization (ESI) in noncovalent interaction studies. However, no systematic studies of the effects ... |
15452147 | Regulation of Notch signaling by Drosophila heparan sulfate 3-O sulfotransferase. | Heparan sulfate (HS) regulates the activity of various ligands and is involved in molecular recognition events on the cell surface and in the extracellular matrix. Specific binding of HS to different ligand proteins depends on the sulfation pattern of HS. For example, the interaction between antithrombin and a particul... |
15387907 | [Liver transplantation for primary biliary cirrhosis: retrospective analysis of 52 patients in QLTS]. | <h4>Objective</h4>Retrospectively analyzing post-transplant primary biliary cirrhosis patients to document the actual survival time, the cause of post-transplant death, and recurrences after liver transplantation in patients followed up by the Queensland Liver Transplant Service (QLTS).<h4>Methods</h4>The case notes of... |
15387548 | Noncovalent multivalent assembly of jun peptides on a leucine zipper dendrimer displaying fos peptides. | [reaction: see text] The synthesis and characterization of a new leucine-zipper dendrimer (LZD) is reported that displays four copies of the peptide corresponding to the coiled-coiled dimerization domain of Fos. Circular dichroism spectroscopy, fluorescence titration, and sedimentation equilibrium experiments demonstra... |
15388325 | Loss of filament-forming ability of myosin by non-enzymatic glycosylation and its molecular mechanism. | Carp and scallop myosin and their subfragments (S-1 and rod) were reacted with glucose to investigate the effect of non-enzymatic glycosylation on the functionality of myosin. The filament-forming ability of the myosin rod diminished with the progress of non-enzymatic glycosylation and myosin became soluble in 0.1 M Na... |
15385617 | Role of purpurin as a retinol-binding protein in goldfish retina during the early stage of optic nerve regeneration: its priming action on neurite outgrowth. | Unlike mammals, the fish optic nerve can regenerate after injury. So far, many growth or trophic factors have been shown as an axon-regenerating molecule. However, it is totally unknown what substance regulates or triggers the activity of these factors on axonal elongation. Therefore, we constructed a goldfish retina c... |
15382945 | Computational study of the structure-directing effect of benzylpyrrolidine and its fluorinated derivatives in the synthesis of the aluminophosphate ALPO-5. | Using a combination of computer modeling techniques, we have investigated the ability of benzylpyrrolidine and its fluorinated derivatives in ortho, meta, and para positions of the phenyl ring to direct the synthesis of the aluminophosphate AlPO-5. The o- and p-fluoro derivatives are not good templates because of the p... |
15382943 | Photosensitized hydrogen evolution from water using conjugated polymers wrapped in dendrimeric electrolytes. | High-efficiency light-driven hydrogen evolution from water was demonstrated by using poly(phenyleneethynylene) bearing negatively charged, [G3] poly(benzyl ether) dendrimeric side groups 3(L4) as photosensitizer. Three-dimensional wrapping of the conjugated backbone suppressed self-quenching of the photoexcited state, ... |
15382929 | Stimuli-responsive supramolecular assemblies of linear-dendritic copolymers. | With the goal of developing a pH-responsive micelle system, linear-dendritic block copolymers comprising poly(ethylene oxide) and either a polylysine or polyester dendron were prepared and hydrophobic groups were attached to the dendrimer periphery by highly acid-sensitive cyclic acetals. These copolymers were designed... |
15382926 | A self-assembled multivalent pseudopolyrotaxane for binding galectin-1. | A self-assembled pseudopolyrotaxane consisting of lactoside-displaying cyclodextrin (CD) "beads" threaded onto a linear polyviologen "string" was investigated for its ability to inhibit galectin-1-mediated T-cell agglutination. The CDs of the pseudopolyrotaxane are able to spin around the axis of the polymer chain as w... |
15382924 | Electronic delocalization in discotic liquid crystals: a joint experimental and theoretical study. | Discotic liquid crystals emerge as very attractive materials for organic-based (opto)electronics as they allow efficient charge and energy transport along self-organized molecular columns. Here, angle-resolved photoelectron spectroscopy (ARUPS) is used to investigate the electronic structure and supramolecular organiza... |
15379521 | Fabrication of DNA microarrays on nanoengineered polymeric ultrathin film prepared by self-assembly of polyelectrolyte multilayers. | Microarray-based technology is in need of flexible and cost-effective chemistry for fabrication of oligonucleotide microarrays. We have developed a novel method for the fabrication of oligonucleotide microarrays with unmodified oligonucleotide probes on nanoengineered three-dimensional thin films that are deposited on ... |
15379519 | Morphological investigation of hybrid Langmuir-Blodgett films of arachidic acid with a hydrotalcite/dendrimer nanocomposite. | A hydrotalcite clay/dendrimer nanocomposite prepared by the ionic exchange process was adsorbed from suspension of the nanocomposite on a Langmuir monolayer of arachidic acid at the air/water interface, followed by compressing and transferring onto an arachidic acid monolayer Langmuir-Blodgett (LB) film on mica. For co... |
15379508 | Effect of structure on the reduction potentials of films of constitutional isomers of iron-sulfur cluster core dendrimers. | The thermodynamic redox potentials of films of constitutional isomers of iron-sulfur cluster core dendrimers were measured and compared. It was determined that the primary structure of the dendrimer influences its reduction potential. Dendrimers containing so-called backfolded linkages were more difficult to reduce tha... |
15379486 | Amyloid-like formation by self-assembly of peptidolipids in two dimensions. | The accumulation of beta-amyloid peptide (Abeta) in the human brain is known to be the major cause that drives Alzheimer's disease pathogenesis. Abeta, a 39-42 amino acid peptide, is the cleavage product of amyloid precursor protein in the hydrophobic transmembrane region. The present study employs a two-dimensional (2... |
15379452 | Attachment of ferrocene nanotubes on beta-cyclodextrin self-assembled monolayers with molecular recognitions. | Ferrocene nanotubes were fabricated by binding carboxylic acid-derivatized ferrocenes onto template peptide nanotubes via hydrogen bonding. When these ferrocene-functionalized nanotubes were incubated with beta-cyclodextrin (beta-CD) self-assembled monolayers (SAMs) coated on patterned Au substrates in solution, the fe... |
15381822 | Intramolecular signaling in immunoglobulins -- new evidence emerging from the use of supramolecular protein ligands. | The postulated intramolecular signaling in immunoglobulins generated by antigen binding has been controversial for years. The high heterogeneity of immune complexes as signaling systems and the requirement of the immobilized antigen form for efficient triggering of effector activity is likely the reason for the lack of... |
15378640 | Supramolecular motifs in s-block metal-bound sulfonated monoazo dyes, part 1: structural class controlled by cation type and modulated by sulfonate aryl ring position. | The solid-state structures of 43 Li, Na, K, Rb, Mg, Ca and Ba salts of para- and meta-sulfonated azo dyes have been examined and can be categorised into three structural classes. All form alternating organic and inorganic layers, however, the nature of the coordination network that forms these layers differs from class... |
15378626 | Lead and mercury sensing by calixarene-based fluoroionophores bearing two or four dansyl fluorophores. | A detailed study on the photophysical and complexing properties of calixarenes bearing two and four dansyl derivatives (Calix-DANS2 and Calix-DANS4) in a CH3CN/H2O mixture (60:40 v/v) is reported. Calix-DANS2 shows a high selectivity towards Hg2+ over interfering cations (Na+, K+, Ca2+, Cu2+, Zn2+, Cd2+ and Pb2+) and a... |
15378621 | Dinuclear barium(II) complexes based on a calix[4]arene scaffold as catalysts of acyl transfer. | Two novel regioisomeric calix[4]arene derivatives (2 and 3), decorated with two aza[18]crown-6 units at vicinal (1,2) or diagonal (1,3) positions of the upper rim, were synthesized. The catalytic activities of their dinuclear Ba2+ complexes were investigated in the ethanolysis of esters 8-11, endowed with a carboxylate... |
15378619 | Topological analysis of electron densities: is the presence of an atomic interaction line in an equilibrium geometry a sufficient condition for the existence of a chemical bond? | The structure, energetics, and electron density in the inclusion complex of He in adamantane, C10H16, have been studied by density functional theory calculations at the B3LYP6-311++G(2p,2d) level. Topological analysis of the electron density shows that the He atom is connected to the four tertiary tC atoms in the cage ... |
15378617 | Intramolecular carbohydrate-aromatic interactions and intermolecular van der Waals interactions enhance the molecular recognition ability of GM1 glycomimetics for cholera toxin. | The design and synthesis of two GM1 glycomimetics, 6 and 7, and analysis of their conformation in the free state and when complexed to cholera toxin is described. These compounds, which include an (R)-cyclohexyllactic acid and an (R)-phenyllactic acid fragment, respectively, display significant affinity for cholera tox... |
15373444 | Monitoring neurotransmitter release from isolated retinas using online microdialysis-capillary electrophoresis. | Release of neurotransmitters and other primary amine-containing analytes from intact, isolated larval salamander (Ambystoma tigrinum) retinas maintained in a 6.5-microL perfusion chamber was monitored using online microdialysis-capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). Primary amines... |
15373439 | Solvent extraction and stripping of silver ions in room-temperature ionic liquids containing calixarenes. | We found that a calix[4]arene-bearing pyridine is soluble in a typical room-temperature ionic liquid (RTIL), 1-alkyl-3-methylimidazolium hexafluorophosphate. Pyridinocalix[4]arene showed a high extraction ability and selectivity for silver ions. The extraction performance of the calix[4]arene was greatly enhanced by di... |
15371519 | Beta1 integrins in muscle, but not in motor neurons, are required for skeletal muscle innervation. | In vitro studies have provided evidence that beta1 integrins in motor neurons promote neurite outgrowth, whereas beta1 integrins in myotubes regulate acetylcholine receptor (AChR) clustering. Surprisingly, using genetic studies in mice, we show here that motor axon outgrowth and neuromuscular junction (NMJ) formation i... |
15372105 | Disruption of cholesterol homeostasis by plant sterols. | The ABC transporters ABCG5 and ABCG8 limit absorption and promote excretion of dietary plant sterols. It is not known why plant sterols are so assiduously excluded from the body. Here we show that accumulation of plant sterols in mice lacking ABCG5 and ABCG8 (G5G8-/- mice) profoundly perturbs cholesterol homeostasis in... |
15367037 | Wavelength dependence of first molecular hyperpolarizability of a dendrimer in solution. | The frequency dependence of the first molecular hyperpolarizability of a dendrimer incorporated with thiophene-stilbene based charge-transfer chromophores is investigated by using a nanosecond 1907 nm laser and a number of wavelengths ranging from 1160 to 1760 nm emitted from an optical parametric amplifier pumped by a... |
15366952 | Specific antitumor targetable beta-cyclodextrin-poly(ethylene glycol)-folic acid drug delivery bioconjugate. | The tumor targeting properties of a new drug carrier synthesized by bioconjugation of folic acid (FA) to beta-cyclodextrins through a poly(ethylene glycol) (PEG) spacer (CD-PEG-FA) were investigated. Surface plasmon resonance demonstrated that CD-PEG-FA specifically interacts with immobilized folate binding protein (FB... |
15362111 | Neutron scattering measurements of intact cells show changes after heat shock consistent with an increase in molecular crowding. | Molecular crowding has been shown to be important in many cellular processes. The crowded environment in the cell results in a significant proportion of the cellular water being in contact with macromolecules such as proteins and DNA. These interfacial water molecules show a reduced dynamic motion that has been observe... |
15362110 | Crowding and the polymerization of sickle hemoglobin. | Under physiological conditions, sickle hemoglobin, a natural mutant of human hemoglobin A with a surface hydrophobic valine in place of a negatively charged glutamic acid, polymerizes at high volume occupancy. Equilibrium solubility of sickle hemoglobin entails activity coefficients that can approach 10(3) at high conc... |
15362109 | Large changes in cytoplasmic biopolymer concentration with osmolality indicate that macromolecular crowding may regulate protein-DNA interactions and growth rate in osmotically stressed Escherichia coli K-12. | From determination of amounts and concentrations of biopolymers and solutes in the cytoplasm of Escherichia coli, we are obtaining information needed to assess the effect of macromolecular crowding on cytoplasmic properties and processes of osmotically stressed bacteria. We observe that growth rate, and the amount of c... |
15362108 | Genomic channeling in bacterial cell division. | The bacterial dcw cluster is a group of genes involved in cell division and peptidoglycan synthesis. Comparison of the cluster across several bacterial genomes shows that its gene content and its gene order are conserved in distant bacterial lineages and, moreover, that, being most conserved in rod-shaped bacteria, the... |
15362107 | Cell volume and the regulation of apoptotic cell death. | Apoptosis is a physiological mechanism allowing for the removal of abundant or potentially harmful cells. The hallmarks of apoptosis include degradation of cellular DNA, exposure of phosphatidylserine at the outer leaflet of the cell membrane and cell shrinkage. Phosphatidylserine exposure favours adhesion to macrophag... |
15362106 | Chaperonin function--effects of crowding and confinement. | Chaperonins assist in the acquisition of native protein structure in the cell by providing a shielded environment for a folding polypeptide chain, generated by the interior surface of their cylindrical structure. The folding chain is isolated from the highly crowded cytoplasm, but at the same time confined within the c... |
15362105 | The effect of macromolecular crowding on protein aggregation and amyloid fibril formation. | Macromolecular crowding is expected to have several significant effects on protein aggregation; the major effects will be those due to excluded volume and increased viscosity. In this report we summarize data demonstrating that macromolecular crowding may lead to a dramatic acceleration in the rate of protein aggregati... |
15362104 | Applications of time-resolved resonance energy transfer measurements in studies of the molecular crowding effect. | The native structures of many globular proteins are only weakly stabilized and form in solution ensembles of multiple conformers. The energy differences between the conformers are assumed to be small. This is the case of flexible multidomain proteins where domain motions were observed. High concentrations of inert macr... |
15362103 | Molecular crowding reduces to a similar extent the diffusion of small solutes and macromolecules: measurement by fluorescence correlation spectroscopy. | Aqueous environments in living cells are crowded, with up to >50 wt% small and macromolecule-size solutes. We investigated quantitatively one important consequence of molecular crowding--reduced diffusion of biologically important solutes. Fluorescence correlation spectroscopy (FCS) was used to measure the diffusion of... |
15362102 | Studies of effects of macromolecular crowding and confinement on protein folding and protein stability. | In cells, proteins execute specific tasks in crowded environments; these environments influence their stability and dynamics. Similarly, for an enzyme molecule encapsulated in an inorganic cavity as in biosensors or biocatalysts, confinement or excluded volume plays an important role in its stability and dynamics. In t... |
15362101 | Effect of molecular crowding on self-association of phosphorylase kinase and its interaction with phosphorylase b and glycogen. | Self-association of phosphorylase kinase (PhK) and its interaction with glycogen (M=5500 kDa) and phosphorylase b (Phb) has been studied using analytical ultracentrifugation and turbidimetry under the conditions of molecular crowding arising from the presence of high concentrations of osmolytes. In accordance with the ... |
15362100 | Crowding effects in binary mixtures of rod-like and spherical particles. | Crowding effects relevant to the phase stability of binary mixtures of rod-like and spherical particles are investigated by means of Monte Carlo simulations in the isobaric NPT ensemble. The two types of particles are represented, respectively, by freely rotating hard spherocylinders of a moderate aspect ratio (L/sigma... |
15362099 | Fluorescence anisotropy as a probe to study tracer proteins in crowded solutions. | Fluorescence anisotropy has been widely used to study the dynamics and interactions of biomolecules in diluted solutions. Comparable studies on single tracer macromolecules at the cellular level are now feasible because of the recent development of non-invasive fluorescence markers, like the growing family of the green... |
15362098 | Macromolecular crowding in biological systems: hydrodynamics and NMR methods. | Most biologically relevant environments involve highly concentrated macromolecular solutions and most biological processes involve macromolecules that diffuse and interact with other macromolecules. Macromolecular crowding is a general phenomenon that strongly affects the transport properties of macromolecules (rotatio... |
15362097 | Bacteriophage Ø29 protein p6: an architectural protein involved in genome organization, replication and control of transcription. | Protein p6 of B. subtilis bacteriophage Ø29 binds to DNA forming a nucleoprotein complex in which the DNA wraps a protein core forming a right-handed superhelix, therefore restraining positive supercoiling and compacting the DNA. The protein does not specifically recognize a nucleotide sequence but rather a structural ... |
15362096 | Crowding in extremophiles: linkage between solvation and weak protein-protein interactions, stability and dynamics, provides insight into molecular adaptation. | The study of the molecular adaptation of microorganisms to extreme environments (solvent, temperature, etc.) has provided tools to investigate the complex relationships between protein-solvent and protein-protein interactions, protein stability and protein dynamics, and how they are modulated by the crowded environment... |
15362095 | Crowding-induced organization in cells: spontaneous alignment and sorting of filaments with physiological control points. | Under sufficiently crowded conditions, elongated particles spontaneously align along a common axis and separate from particles with dissimilar packing parameters. Clarifying the relevance of these entropy-driven phenomena to intact cells has required the development of theoretical approaches that tractably take into ac... |
15362094 | Protein folding and binding in confined spaces and in crowded solutions. | Simple theoretical models are presented to illustrate the effects of spatial confinement and macromolecular crowding on the equilibria and rates of protein folding and binding. Confinement is expected to significantly stabilize the folded state, but for crowding only a marginal effect on protein stability is expected. ... |
15362093 | Non-ideal tracer sedimentation equilibrium: a powerful tool for the characterization of macromolecular interactions in crowded solutions. | Non-ideal tracer sedimentation equilibrium is a technique devised to quantify the effect of high concentrations of unrelated macromolecules on the self- or hetero-associations of dilute macromolecules. Principles and experimental techniques are reviewed, and previous experimental work summarized. A new analysis of expe... |
15362092 | A potential role for isothermal calorimetry in studies of the effects of thermodynamic non-ideality in enzyme-catalyzed reactions. | Attention is drawn to the feasibility of using isothermal calorimetry for the characterization of enzyme reactions under conditions bearing greater relevance to the crowded biological environment, where kinetic parameters are likely to differ significantly from those obtained by classical enzyme kinetic studies in dilu... |
15360324 | Combined biotin-terpyridine systems: a new versatile bridge between biology, polymer science and metallo-supramolecular chemistry. | Biotin, a well-known binding unit for the proteins avidin and streptavidin, was combined with the chelating ligand terpyridine via polymeric and nonpolymeric spacers. An omega-amino-functionalized terpyridyl-poly(ethylene glycol) was prepared and utilized for complex formation with iron(II), nickel(II), and ruthenium(I... |
15360317 | Preliminary evaluation of the behavior of fifth-generation thiophosphate dendrimer in biological systems. | The quickly growing number of newly synthesized families of dendrimers is not always followed by the information about their properties. Especially, the biological aspect seems not to be explored sufficiently. The aim of this study was to examine the hemotoxicity and cytotoxicity of water-insoluble, fifth-generation th... |
15360302 | Versatile and efficient formation of colloids of biopolymer-based polyelectrolyte complexes. | The formation of colloids based on polyelectrolyte complexes (PECs) of biopolymers was investigated through the complexation between two charged polysaccharides, chitosan as polycation, and dextran sulfate as polyanion. The slow dropwise addition of components, generally used for the formation of PECs, allowed to elabo... |
15360291 | Photoresponsive nanogels formed by the self-assembly of spiropyrane-bearing pullulan that act as artificial molecular chaperones. | Novel photoresponsive nanogels were prepared by the self-assembly of spiropyrane-bearing pullulan (SpP). The solution properties of the nanogels could be controlled by photostimulation via isomerization between hydrophobic spiropyrane and hydrophilic merocyanine. The molecular chaperone-like activity of the nanogels in... |
15360278 | Micropatterned carbohydrate displays by self-assembly of glycoconjugate polymers on hydrophobic templates on silicon. | We report a novel strategy for micropatterned carbohydrate displays on Si substrates. This method exploited the hydrophobic-hydrophilic microfabrication by photolithography of ODS-SAM on Si substrates and the subsequent selective self-assembly of glycoconjugate polymers onto the hydrophobic regions. Protein micropatter... |
15360273 | Multilayer biomimetics: reversible covalent stabilization of a nanostructured biofilm. | Designed polypeptides and electrostatic layer-by-layer self-assembly form the basis of promising research in bionanotechnology and medicine on development of polyelectrolyte multilayer films (PEMs). We show that PEMs can be formed from oppositely charged 32mers containing several cysteine residues. The polypeptides in ... |
15360271 | Resonance energy transfer nanobiosensors based on affinity binding between apo-enzyme and its substrate. | Systems for glucose monitoring based on resonance energy transfer (RET) and competitive binding using Concanavalin A (Con A) are problematic as a result of problems of toxicity, aggregation, and irreversible binding. This paper presents an improved RET assay wherein Con A was replaced by apo-glucose oxidase (apo-GOx). ... |
15360270 | Living polypeptides. | Block copolypeptides, which combine the self-assembly of block copolymers and the highly ordered 3D structures of proteins, are potential candidates for novel supramolecular structures and biotech applications, such as biosensors, tissue engineering, and selective drug delivery. The synthesis of model block copolypepti... |
15360269 | Artificial receptor-attached amphiphilic copolymer for barbiturate binding in aqueous media. | A water-soluble self-associating amphiphilic copolymer was employed to provide a microenvironment for the solvation of a hydrogen-bonding barbiturate artificial receptor, to facilitate molecular recognition in water. The receptor-attached amphiphilic polymer (RP) was synthesized through random copolymerization of 3% (m... |
15357601 | Meso-substituted [34]octaphyrin(1.1.1.0.1.1.1.0) and corrole formation in reactions of a dipyrromethanedicarbinol with 2,2'-bipyrrole. | The reaction of a dipyrromethanedicarbinol with 2,2'-bipyrrole leading to meso-substituted [34]octaphyrin(1.1.1.0.1.1.1.0) and/or corrole was investigated to determine the effect of key reaction parameters on the distribution of the two macrocycles. Solvent, acid catalyst, acid quantity, oxidant, oxidant quantity, and ... |
15357600 | Multinuclear calixarene synthons with covalently linked aryl-palladium(II) complexes. | New synthetic procedures have been developed for potentially useful metallacalixarene building blocks. The metal sites were covalently connected to calix[n]arenes (n = 4, 6) by oxidative addition of 4-iodobenzyl precursors to either Pd(PPh(3))(4) or Pd(2)(dba)(3)/tmeda (dba = dibenzylideneacetone) to furnish calixarene... |
15357587 | Macrocyclic bisbinaphthyl fluorophores and their acyclic analogues: signal amplification and chiral recognition. | A series of optically active macrocyclic and acyclic bisbinaphthyls have been synthesized and characterized. The structure of one of the bisbinaphthyl macrocycles has been established by a single-crystal X-ray analysis. The UV and fluorescence spectra of these chiral compounds in various solvents and at different conce... |
15357582 | Synthesis of chiral amino epoxyaziridines: useful intermediates for the preparation of chiral trisubstituted piperidines. | Chiral aminoalkyl epoxyaziridine 1 is synthesized in high yield and diastereoselectivity from L-serine. Ring opening of epoxyaziridine 1 with primary amines is carried out with total chemo- and regioselectivity, affording chiral polyfunctionalized piperidines 8. The structure of these trisubstituted piperidines is esta... |
15357579 | Hydrogen-bonding-induced planar, rigid, and zigzag oligoanthranilamides. Synthesis, characterization, and self-assembly of a metallocyclophane. | Four oligoanthranilamides 1-4, which are incorporated with three, five, seven, or nine benzene units, respectively, have been synthesized and characterized. X-ray analysis, 1D and 2D (1)H NMR, and IR experiments reveal that all the new oligoamides adopt rigid, planar and zigzagged conformations in both solution and sol... |
15357573 | Social self-sorting in aqueous solution. | Self-sorting-the ability to efficiently distinguish between self and nonself-is common in nature but is still relatively rare in synthetic supramolecular systems. We report a 12-component mixture comprising 1-11 and KCl that undergoes thermodynamically controlled self-sorting in aqueous solution based on metal-ligand, ... |
15358661 | Membrane-anchored CD14 is important for induction of interleukin-8 by lipopolysaccharide and peptidoglycan in uroepithelial cells. | We investigated the induction of interleukin-8 (IL-8) by bacterial lipopolysaccharide (LPS) and peptidoglycan (PGN) in the bladder cancer cell lines T24, 5637, UM-UC-3, and HT1197. T24 and 5637 cells strongly induced IL-8 after stimulation with LPS or PGN in a dose- and time-dependent manner, whereas UM-UC-3 and HT1197... |
15355027 | Horning-crown macrocycles: novel hybrids of calixarenes and crown ethers. | [reaction: see text] Novel macrocycles possessing ether linkages and 2,6-disubstituted phenolics were produced in one step and with 100% atom economy by isoaromatization of chameleon macrocyclic precursors possessing 2,6-diarylidenecyclohexanone moieties. Intramolecular hydrogen bonding of the phenolic hydrogen atoms i... |
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