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15283854 | An arthritogenic monoclonal antibody to type II collagen, CII-C1, impairs cartilage formation by cultured chondrocytes. | Antibodies to type II collagen (CII) cause articular damage in collagen-induced arthritis (CIA) in mice as judged by passive transfer to naive animals of mAb to CII. We tested the hypothesis that mAb degrade cartilage structure by reacting with functionally important regions of the collagen molecule by examining the ef... |
15284216 | The role of structural disorder in the function of RNA and protein chaperones. | Chaperones are highly sophisticated protein machines that assist the folding of RNA molecules or other proteins. Their function is generally thought to require a fine-tuned and highly conserved structure: despite the recent recognition of the widespread occurrence of structural disorder in the proteome, this structural... |
15283581 | Reflective interferometric detection of label-free oligonucleotides. | New chip-based methods for the detection of unmodified biomolecular targets have significant potential as enabling technology in fundamental biology and biomedical analysis. We report a method based on changes in reflectivity from specially fabricated substrates that is capable of detecting the binding of as little as ... |
15281740 | Pi-conjugated dendrimers based on bis(enediynyl)benzene units. | We have synthesized a new family of pi-conjugated dendrimers that are based on bis(enediynyl)benzene units by using both divergent and convergent approaches. The compounds at all three generations have strong bluish-green fluorescence, especially the third-generation dendrimer, which has the highest extinction coeffici... |
15281739 | Binding selectivity of cucurbit[7]uril: bis(pyridinium)-1,4-xylylene versus 4,4'-bipyridinium guest sites. | The binding interactions between the host cucurbit[7]uril (CB7) and a series of linear guests containing bis(pyridinium)-1,4-xylylene and/or 4,4'-bipyridinium residues were investigated by (1)H NMR spectroscopy. CB7 was found to exhibit considerable binding selectivity for bis(pyridinium)-1,4-xylylene over 4,4'-bipyrid... |
15281166 | Toward a 6pi+6pi zwitterion or a bioinhibitors-related OH-substituted aminoquinone: identification of a key intermediate in their pH controlled synthesis. | Their pH-controlled reactivity places the N,N'-dialkyl-2-amino-5-lithium alcoholate-1,4-benzoquinonemonoimines [C(6)H(2)(NHCH(2)R') (=NCH(2)R')(=O)(OLi)] 7 (R'=tBu) and 8 (R'=p-C(6)H(4)-tBu) at the crossroads of a new versatile strategy for the preparation of two very different classes of substituted quinones. We descr... |
15281164 | Thermodynamic analysis of receptors based on guanidinium/boronic acid groups for the complexation of carboxylates, alpha-hydroxycarboxylates, and diols: driving force for binding and cooperativity. | The thermodynamics of guanidinium and boronic acid interactions with carboxylates, alpha-hydroxycarboxylates, and diols were studied by determination of the binding constants of a variety of different guests to four different hosts (7-10). Each host contains a different combination of guanidinium groups and boronic aci... |
15281163 | Does hydrogen bonding matter in crystal engineering? Crystal structures of salts of isomeric ions. | The preparation and structure determinations of the crystalline salts [3,3'-H(2)bipy][PtCl(4)] (2), [2,2'-H(2)bipy][PtCl(4)] (3) and [1,4'-Hbipy][PtCl(4)] (4) and [3,3'-H(2)bipy][SbCl(5)] (6) and [1,4'-Hbipy][SbCl(5)] (8) are reported. In addition a redetermination of the structure of the metastable salt [4,4'-H(2)bipy... |
15281160 | A new system in organooxotin cluster chemistry incorporating inorganic and organic spacers between two ladders each containing five tin atoms. | Hydrolysis of dibenzyltin dichloride in ethanol has been found to give an unprecedented carbonate anion (CO(3) (2-))-bridged double-ladder organooxotin cluster, [(R(2)SnO)(3)(R(2)SnOH)(2)(CO(3))](2) (1, R = C(6)H(5)CH(2)), with five tin atoms in each ladder. With the aim of obtaining organooxotin clusters with large ca... |
15281155 | De novo design, synthesis, and function of semiartificial myoglobin conjugated with coiled-coil two-alpha-helix peptides. | The introduction of a flavin chromophore on the myoglobin (Mb) surface and an effective electron-transfer (ET) reaction through the flavin were successfully achieved by utilizing the self-assembly of heterostranded coiled-coil peptides. We have prepared a semiartificial Mb, named Mb-1alphaK, in which an amphiphilic and... |
15281153 | A series of redox active, tetrathiafulvalene-based amidopyridines and bipyridines ligands: syntheses, crystal structures, a radical cation salt and group 10 transition-metal complexes. | Amidopyridine and -2,2'-bipyridine derivatives of EDT-TTF and BTM-TTF (EDT=ethylenedithio, BTM=bis(thiomethyl), TTF=tetrathiafulvalene) have been synthesized and crystallographically characterized. In the solid state, the different supramolecular organization of all these donors results from the competition between the... |
15281152 | Biquinolino-modified beta-cyclodextrin dimers and their metal complexes as efficient fluorescent sensors for the molecular recognition of steroids. | A series of bridged beta-cyclodextrin (beta-CyD) dimers possessing functional tethers of various lengths was synthesized in moderate yield by the treatment of 2,2'-biquinoline- 4,4'-dicarboxylic dichloride with beta-CyD or mono[6-oligo(ethylenediamino)-6-deoxy]-beta-CyDs. The products were 2,2'-biquinoline-4,4'-dicarbo... |
15281150 | Hollow boron nitride (BN) nanocages and BN-nanocage-encapsulated nanocrystals. | Hollow boron nitride (BN) nanocages (nanospheres, image on the left) and BN-nanocage-encapsulated GaN nanocrystals (right) have been synthesized by using a homemade B-N-O precursors. The as-prepared BN hollow nanocages have typically spherical morphologies with diameters ranging from 30 to 200 nm. The nanocages have cr... |
15281146 | Thermodynamic stability of hydrogen-bonded nanostructures: a calorimetric study. | The self-assembly of hydrogen-bonded aggregates (rosettes) in solvent mixtures of different polarity has been studied by calorimetry. The C(50) parameter, the concentration when 50 % of the components are incorporated in the assembly, is used to compare assemblies with different stoichiometry. C(50) for the single rose... |
15280056 | Crystal architecture and conformational properties of the inclusion complex, neohesperidin dihydrochalcone-cyclomaltoheptaose (beta-cyclodextrin), by X-ray diffraction. | The crystal structure of the host-guest noncovalent complex of cyclomaltoheptaose (beta-cyclodextrin, betaCD) with the O-diglycosyl flavonoid neohesperidin dihydrochalcone [(3,5-dihydroxy-4-(3-hydroxy-4-methoxyhydrocinnamoyl)phenyl-2-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside, NDC] has been determined from sing... |
15279173 | Symmetry breaking by spontaneous crystallization--is it the most plausible source of terrestrial handedness we have long been looking for?--A reappraisal. | In the light of recent and controversial findings on spontaneous resolution of racemates and their implications in the origin of homochirality on earth, we present here a detailed review of this important topic. Although spontaneous resolution cannot at this moment be reliably predicted, there has also been considerabl... |
15274596 | Isothermal titration calorimetry of supramolecular polymers. | A method to characterize the self-association of supramolecular polymers by isothermal titration calorimetry (ITC) has been designed. Association constants in the range 10(4)-10(6) dm(3) mol(-1) have been successfully determined from the heat exchange occurring when a supramolecular polymer solution is injected into a ... |
15274589 | Dendrimer-functionalized self-assembled monolayers as a surface plasmon resonance sensor surface. | We report here a multistep route for the immobilization of DNA and proteins on chemically modified gold substrates using fourth-generation NH(2)-terminated poly(amidoamine) dendrimers supported by an underlying amino undecanethiol (AUT) self-assembled monolayer (SAM). Bioactive ultrathin organic films were prepared via... |
15274583 | Spider-web amphiphiles as artificial lipid clusters: design, synthesis, and accommodation of lipid components at the air-water interface. | As a novel category of two-dimensional lipid clusters, dendrimers having an amphiphilic structure in every unit were synthesized and labeled "spider-web amphiphiles". Amphiphilic units based on a Lys-Lys-Glu tripeptide with hydrophobic tails at the C-terminal and a polar head at the N-terminal are dendrically connected... |
15274558 | One-component gels based on peptidic dendrimers: dendritic effects on materials properties. | This paper describes the gelation of symmetric dendrimers based on building blocks constructed from L-lysine. These dendrimers form gel-phase materials in nonpolar organic solvents. The thermal properties and concentration dependence of the gelation were investigated, and it was found that there was a clear dendritic e... |
15277575 | Toll-like receptor 4 (TLR4) of retinal pigment epithelial cells participates in transmembrane signaling in response to photoreceptor outer segments. | Retinal pigment epithelial (RPE) cells mediate the recognition and clearance of effete photoreceptor outer segments (POS), a process central to the maintenance of normal vision. Given the emerging importance of Toll-like receptors (TLRs) in transmembrane signaling in response to invading pathogens as well as endogenous... |
15273309 | Detecting hidden sequence propensity for amyloid fibril formation. | The preponderance of evidence implicates protein misfolding in many unrelated human diseases. In all cases, normal correctly folded proteins transform from their proper native structure into an abnormal beta-rich structure known as amyloid fibril. Here we introduce a computational algorithm to detect nonnative (hidden)... |
15139852 | Mutational analysis of the triclosan-binding region of enoyl-ACP (acyl-carrier protein) reductase from Plasmodium falciparum. | Triclosan, a known antibacterial, acts by inhibiting enoyl-ACP (acyl-carrier protein) reductase (ENR), a key enzyme of the type II fatty acid synthesis (FAS) system. Plasmodium falciparum, the human malaria-causing parasite, harbours the type II FAS; in contrast, its human host utilizes type I FAS. Due to this striking... |
15130090 | Recruitment of the cross-linked opsonic receptor CD32A (FcgammaRIIA) to high-density detergent-resistant membrane domains in human neutrophils. | We have previously shown that CD32A (or FcgammaRIIA), one of the main opsonin receptors, was rapidly insolubilized and degraded in intact neutrophils after its cross-linking. In view of these experimental difficulties, the early signalling steps in response to CD32A activation were studied in purified plasma membranes ... |
15128269 | Targeting of Helicobacter pylori vacuolating toxin to lipid raft membrane domains analysed by atomic force microscopy. | The Helicobacter pylori vacuolating toxin VacA causes several effects on mammalian cells in vitro, including intracellular vacuolation, formation of pores in the plasma membrane and apoptosis. When added to cells, VacA becomes associated with detergent-resistant membranes, indicating that it binds preferentially to lip... |
15113281 | Binding of alpha2-macroglobulin to GRAB (Protein G-related alpha2-macroglobulin-binding protein), an important virulence factor of group A streptococci, is mediated by two charged motifs in the DeltaA region. | GRAB (Protein G-related alpha2M-binding protein) is a surface protein of group A streptococci and exhibits high affinity for alpha2-macroglobulin (alpha2M), a broad-range protease inhibitor. It is the sole alpha2M-binding protein of group A streptococci that has been shown to promote bacterial virulence in a mouse mode... |
15101818 | Binding of proteins to the PDZ domain regulates proteolytic activity of HtrA1 serine protease. | HtrA1, a member of the mammalian HtrA (high temperature requirement A) serine protease family, has a highly conserved protease domain followed by a PDZ domain. Accumulating evidence has indicated that PDZ domains regulate protease activity of HtrA proteins. We searched for binding partners of the PDZ domain of mouse Ht... |
15265556 | Influence of cyclodextrins on in vitro human skin absorption of the sunscreen, butyl-methoxydibenzoylmethane. | The effects of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and sulfobutylether-beta-CD (SBE7-beta-CD) on in vitro human skin penetration and retention of the sunscreen agent butyl-methoxydibenzoylmethane (BM-DBM) were investigated. The interaction between the UV filter and the cyclodextrins was studied in water by pha... |
15265550 | Beta-cyclodextrin as a suitable solubilizing agent for in situ absorption study of poorly water-soluble drugs. | To evaluate the intestinal permeability of poorly water-soluble compounds, it is of importance to completely dissolve them in a medium and to avoid precipitation during experiments. This study was undertaken to find an agent possessing a high-solubilizing capacity and exhibiting minimal modulating impact on membrane in... |
15265519 | A Raman spectroscopic study of the diclofenac sodium-beta-cyclodextrin interaction. | The inclusion complex of diclofenac sodium (DCFNa) and beta-cyclodextrin (betaCD) was prepared and analyzed by using Raman and SERS spectroscopy. The interaction between DCFNa and betaCD molecules was evidenced by monitoring the change in the peak positions and the widths of some guest molecule bands relative to those ... |
15265514 | NMR studies of the inclusion complex between beta-cyclodextrin and paroxetine. | A 1H and 13C NMR study on the inclusion complex of paroxetine with beta-cyclodextrin was carried out in order to define the stoichiometry of the association and its strength. Proton and carbon chemical shift measurements of paroxetine and beta-cyclodextrin were performed at several molar ratios and temperatures, allowi... |
15260800 | Optically nonlinear energy transfer in light-harvesting dendrimers. | Dendrimeric polymers are the subject of intense research activity geared towards their implementation in nanodevice applications such as energy harvesting systems, organic light-emitting diodes, photosensitizers, low-threshold lasers, and quantum logic elements, etc. A recent development in this area has been the const... |
15262029 | Association between urokinase-plasminogen activator gene T4065C polymorphism and risk of mitral valve prolapse. | <h4>Background</h4>Abnormalities of collagen and elastic fibers were found in floppy mitral valves (FMV). Urokinase-plasminogen activator (PLAU) was suggested to be involved in the pathogenesis of elastin and collagen degradation in arterial aneurysm. The role of PLAU genetic variant in mitral valve prolapse (MVP) has ... |
15261589 | Molecular dynamics (MD) simulations for the prediction of chiral discrimination of N-acetylphenylalanine enantiomers by cyclomaltoheptaose (beta-cyclodextrin, beta-CD) based on the MM-PBSA (molecular mechanics-Poisson-Boltzmann surface area) approach. | Molecular dynamics (MD) simulations were performed for the prediction of chiral discrimination of N-acetylphenylalanine enantiomers by cyclomaltoheptaose (beta-cyclodextrin, beta-CD). Binding free energies and various conformational properties were obtained using by the MM-PBSA (molecular mechanics Poisson-Boltzmann/su... |
15262812 | Prediction of class I T-cell epitopes: evidence of presence of immunological hot spots inside antigens. | <h4>Motivation</h4>Processing and presentation of major histocompatibility complex class I antigens to cytotoxic T-lymphocytes is crucial for immune surveillance against intracellular bacteria, parasites, viruses and tumors. Identification of antigenic regions on pathogen proteins will play a pivotal role in designer v... |
15249035 | Synthesis of a novel host molecule of cross-linking-polymeric-beta-cyclodextrin-o-vanillin furfuralhydrazone and spectrofluorimetric analysis of its identifying cadmium. | A novel host inclusion complex of cross-linking-polymeric-beta-cyclodextrin-o-vanillin furfuralhydrazone (beta-CDP-OVFH) was synthesized and characterized with IR and 1H NMR spectra to confirm its structure. The coordination reaction of the host reagent with Cd(2+) was studied and the optimum reacting conditions were o... |
15249019 | Photophysical behaviour of 4-(imidazole-1-yl) phenol and its complexation with beta-cyclodextrin in ground and excited states. | This paper mainly dwells on photophysics of 4-(imidazole-1-yl) phenol (IDP) in different solvents and temperatures from the investigations of absorption, emission and laser flash photolysis and also on the nature of complexation with beta-cyclodextrin (CD) in ground and excited states. IDP makes 1:1 inclusion complex w... |
15249007 | Spectroscopic characterization of intramolecular charge transfer of sodium 4-(N,N-dimethylamino)naphthalene-1-sulfonate. | In this paper, a new dual fluorescent N,N-dimethylaminonaphthalene derivative, sodium 4-(N,N-dimethylamino)naphthalene-1-sulfonate (SDMDNS), was reported. It was found that SDMDNS emits dual fluorescence only in highly polar solvent water but not in organic solvents such as methanol, dioxane and acetonitrile. Only a si... |
15245999 | The development of a continuous isothermal titration calorimetric method for equilibrium studies. | A continuous isothermal titration calorimetry (cITC) method for microcalorimeters has been developed. The method is based on continuous slow injection of a titrant into the calorimetric vessel. The experimental time for a cITC binding experiment is 12-20 min and the number of data points obtained is on the order of 100... |
15236687 | Immobilization of a (dextran-adamantane-COOH) polymer onto beta-cyclodextrin-modified silica. | Adamantane-modified compounds are known to form stable complexes with beta-cyclodextrins (beta-CD) by host-guest interactions. In this study, the inclusion complex formed between beta-CD cavities and the adamantane group was evaluated for the elaboration of a cation-exchange support. The synthesis of the chromatographi... |
15236456 | Nuclear magnetic resonance and molecular modeling analysis of the interaction of the antimalarial drugs artelinic acid and artesunic acid with beta-cyclodextrin. | The artemisinin derivatives artelinic acid and artesunic acid are members of a class of compounds that have shown promise for the treatment of multidrug resistant strains of Plasmodium falciparum. Unfortunately, these compounds exhibit poor solubility and stability in aqueous solution. The research presented herein was... |
15214808 | Molecular dynamics study of the effect of the gamma-Abu insert on the conformational behavior of the glycopeptide dendrimers based on the oligolysine scaffold in N, N'-dimethylformamide. | Glycodendrimers bearing Tn (alpha-D-GalNAc-(1 --> O)-Ser/Thr), an identified tumor-associated carbohydrate antigen, hold promise in the post-surgery treatment of a variety of tumors such as metastatic breast cancer. We used molecular dynamics (MD) techniques to examine structural differences taking place during synthes... |
15210337 | Evidence for the 2:1 molecular recognition and inclusion behaviour between beta- and gamma-cyclodextrins and cinchonine. | Cinchonine (Cin) is the primary drug of choice in the treatment of malaria, but its poor solubility has restricted its use via the oral route. Cyclodextrins (CDs) form inclusion complexes with cinchonine to form soluble complexes. This interaction was investigated by solubility studies, electrospray ionization mass spe... |
15203043 | Experimental design-based development of a rapid capillary electrophoresis method for determining impurities in the tetrapeptide H-Tyr-(D)Arg-Phe-Phe-NH2. | A capillary electrophoresis (CE) method has been developed and validated for separating the tetrapeptide H-Tyr-(D)Arg-Phe-Phe-NH2 and nine related substances. The method was developed using experimental design in a four-step procedure, in which eight variables were investigated in a total of 47 experiments. The preferr... |
15462568 | Ultrastructure of the Lyonet's glands in larvae of Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae). | The Lyonet's gland is found in Lepidoptera larvae, close to the excretory duct of the silk gland. The role played by this gland is still uncertain. This work aims to describe the ultrastructure of the Lyonet's gland in Diatraea saccharalis larvae, offering suggestions regarding its possible function. The insects were r... |
15382875 | Hindered gas-phase partitioning of trichloroethylene from aqueous cyclodextrin systems: implications for treatment and analysis. | Chemically enhanced flushing has shown great promise for attenuating subsurface nonaqueous phase liquid (NAPL) contamination. One particular chemically enhanced remediation technology is cyclodextrin enhanced flushing (CDEF). CDEF has been demonstrated as a viable alternative to conventional and innovative remediation ... |
15378861 | Complexation of roxatidine acetate hydrochloride with beta-cyclodextrin: NMR spectroscopic study. | A NMR spectroscopic study of mixtures of varying ratios of roxatidine acetate hydrochloride (RAH) and beta-cyclodextrin (beta-CD) in D2O revealed the formation of a 1:1 inclusion compound. The aromatic ring of RAH selectively penetrates the beta-CD cavity in preference to the piperidine ring. |
15378853 | Improvement of physical stability and dissolution rate of celecoxib suspensions by complexation with beta-cyclodextrins. | Solid dispersions of celecoxib with beta-cyclodextrins were prepared by physical mixing, slugging and kneading methods at 1:1 and 1:2 molar ratios and characterized by differential scanning calorimetry. Celecoxib suspensions were formulated employing its solid dispersions with sodium carboxymethylcellulose as the suspe... |
15358143 | Nucleocapsid protein of SARS coronavirus tightly binds to human cyclophilin A. | Severe acute respiratory syndrome coronavirus (SARS-CoV) is responsible for SARS infection. Nucleocapsid protein (NP) of SARS-CoV (SARS_NP) functions in enveloping the entire genomic RNA and interacts with viron structural proteins, thus playing important roles in the process of virus particle assembly and release. Pro... |
15357060 | Depletion of Schistosoma mansoni lung-stage schistosomula cholesterol by methyl-beta-cyclodextrin dramatically increases specific antibody binding to surface membrane antigens. | Schistosoma mansoni lung-stage larvae appear to not bind antibodies from radiation vaccine or infection sera in the membrane immunofluorescence test. However, treatment of ex vivo lung-stage schistosomula with methyl-beta-cyclodextrin, a hydrophobic oligosaccharide that specifically extracts cholesterol from plasma mem... |
15352716 | Study of the mechanism of enantioseparation part VI: thermodynamic study of HPLC separation of some enantiomers of phenylcarbamic acid derivatives on a (S,S) Whelk-O 1 column. | The enantiomers of thirteen 2-, 3-, and 4-alkoxyphenylcarbamic acid 2-methoxy-1-[(4-methylpiperazino)methyl]ethyl ester were separated on a (S,S) Whelk-O 1 CSP column isothermally in the range of 0-50 degrees C at 10 degrees C increments, using methanol/ water (90/10, v/v) containing 17.5 mmol L(-1) acetic acid and 14.... |
15352477 | Use of cyclodextrin and calcium chloride for enhanced removal of mercury from soil. | The use of solutions containing carboxymethyl-beta-cyclodextrin (CMCD) or CaCl2 for enhancing the removal of Hg from a sandy soil was investigated using batch and column experiments. The retention of Hg appeared to be controlled by specific adsorption reactions, which greatly constrained Hg removal when using water (KN... |
15345984 | Chemiluminescence: comparison of whole blood with isolated polymorphonuclear leukocytes after major trauma. | <h4>Introduction</h4>Neutrophil (PMN) mediated tissue injury is central to the development of post-traumatic ARDS/MOF. Changes in activity caused by PMN isolation may be avoided by studying respiratory burst activity using whole blood chemiluminescence (WBCL).<h4>Methods</h4>WBCL and PMNCL were measured in 5 normal lab... |
15337781 | Role of lipid rafts in E-cadherin-- and HGF-R/Met--mediated entry of Listeria monocytogenes into host cells. | Listeria monocytogenes uptake by nonphagocytic cells is promoted by the bacterial invasion proteins internalin and InlB, which bind to their host receptors E-cadherin and hepatocyte growth factor receptor (HGF-R)/Met, respectively. Here, we present evidence that plasma membrane organization in lipid domains is critical... |
15266309 | Targeting cytotoxic T lymphocytes for cancer immunotherapy. | In light of their preeminent role in cellular immunity, there is considerable interest in targeting of cytotoxic T-lymphocytes to cancer. This review summarises the active and passive immunotherapeutic approaches under development to achieve this goal, emphasising how recent advances in tumour immunology and gene trans... |
15328059 | A review on experimental studies of surfactant adsorption at the hydrophilic solid-water interface. | The progresses of understanding of the surfactant adsorption at the hydrophilic solid-liquid interface from extensive experimental studies are reviewed here. In this respect the kinetic and equilibrium studies involves anionic, cationic, non-ionic and mixed surfactants at the solid surface from the solution. Kinetics a... |
15323552 | Efficient synthesis and photodynamic activity of porphyrin-saccharide conjugates: targeting and incapacitating cancer cells. | Since the role of saccharides in cell recognition, metabolism, and cell labeling is well-established, the conjugation of saccharides to drugs is an active area of research. Thus, one goal in the use of saccharide-drug conjugates is to impart a greater specificity toward a given cell type or other targets. Although wide... |
15320709 | Polyplexes and lipoplexes for mammalian gene delivery: from traditional to microarray screening. | Gene therapy requires the development of non-toxic and highly efficient delivery systems for DNA and RNAi. Polycations, especially dendrimers, have shown enormous potential as gene transfer vehicles, displaying minimal toxicity with a broad range of cell lines. In this paper, a total of 13 dendrimers, up to G3.0, were ... |
15317453 | Molecular recognition in purinergic receptors. 2. Diastereoselectivity of the h-P2Y1-receptor. | In the companion paper, part 1, we described the construction of an improved molecular model for the h-P2Y1 receptor (h-P2Y1-R) and proposed a rational for the stereoelectronic selectivity of the receptor. Here, we extend our studies on the molecular recognition of the h-P2Y1-R to the exploration of the diastereoselect... |
15317452 | Molecular recognition in purinergic receptors. 1. A comprehensive computational study of the h-P2Y1-receptor. | P2Y receptors (P2Y-Rs) are attractive pharmaceutical targets due to their involvement in the modulation of many tissues and organs. The lack of experimental structural data on P2Y-Rs impedes structure-based drug design. The need to elucidate the receptor's molecular recognition, together with the limitations of previou... |
15315452 | Unexpected change in charge transfer behavior in a cobalt(II) porphyrin-fullerene conjugate that stabilizes radical ion pair states. | Two cobalt(II) porphyrin-C(60) malonate-linked conjugates, the mono-connected Co1 and the bis-connected trans-2 isomer Co3, have been synthesized for the first time either by direct cyclopropanation with the precursor malonate Co4 or by metalation of the bisadduct H(2)3. For the investigation of the interaction between... |
15315450 | Optimizing saccharide-directed molecular delivery to biological receptors: design, synthesis, and biological evaluation of glycodendrimer-cyclodextrin conjugates. | Dendritic beta-cyclodextrin (betaCD) derivatives bearing multivalent mannosyl ligands have been prepared and assessed for their binding efficiency toward the tetrameric plant lectin concanavalin A (Con A) and a mammalian mannose/fucose specific cell surface receptor from macrophages. The synthetic strategy exploits the... |
15315432 | Molecular dynamics simulation of a reverse micelle self assembly in supercritical CO2. | In this communication we report on molecular dynamics computer simulations of self-assembly of reverse micelles in supercritical carbon dioxide. The reverse micelles contain perfluoropolyether ammonium carboxylate surfactants and an aqueous core. We observed a quick self-assembly of these micelles over time periods of ... |
15315361 | Separation of flavanone-7-O-glycoside diastereomers and analysis in citrus juices by multidimensional liquid chromatography coupled with mass spectrometry. | The major flavanone-7-O-glycoside constituents in citrus fruit juices (naringin, hesperidin, neohesperidin, narirutin, and eriocitrin) were separated as diastereomers by multidimensional liquid chromatography. The method consisted of coupling two HPLC columns: a reversed-phase (RP(18)) column was used for the separatio... |
15316652 | Acetyl-coenzyme A synthetase (AMP forming). | Acetyl-coenzyme A synthetase (AMP forming; Acs) is an enzyme whose activity is central to the metabolism of prokaryotic and eukaryotic cells. The physiological role of this enzyme is to activate acetate to acetyl-coenzyme A (Ac-CoA). The importance of Acs has been recognized for decades, since it provides the cell the ... |
15316651 | Phosphinic peptides as zinc metalloproteinase inhibitors. | Solid-phase synthesis of phosphinic peptides was introduced 10 years ago. A major application of this chemistry has been the development of potent synthetic inhibitors of zinc metalloproteases. Specific properties of the inhibitors produced in recent years are reviewed, supporting the notion that phosphinic pseudo-pept... |
15316650 | Scaffolds, levers, rods and springs: diverse cellular functions of long coiled-coil proteins. | Long alpha-helical coiled-coil proteins are involved in a variety of organizational and regulatory processes in eukaryotic cells. They provide cables and networks in the cyto- and nucleoskeleton, molecular scaffolds that organize membrane systems, motors, levers, rotating arms and possibly springs. A growing number of ... |
15314692 | Poor immunogenicity of a self/tumor antigen derives from peptide-MHC-I instability and is independent of tolerance. | Understanding the mechanisms underlying the poor immunogenicity of human self/tumor antigens is challenging because of experimental limitations in humans. Here, we developed a human-mouse chimeric model that allows us to investigate the roles of the frequency and self-reactivity of antigen-specific T cells in determina... |
15314685 | Temporal perturbations in sonic hedgehog signaling elicit the spectrum of holoprosencephaly phenotypes. | One of the most perplexing questions in clinical genetics is why patients with identical gene mutations oftentimes exhibit radically different clinical features. This inconsistency between genotype and phenotype is illustrated in the malformation spectrum of holoprosencephaly (HPE). Family members carrying identical mu... |
15314068 | T cell receptor antagonism interferes with MHC clustering and integrin patterning during immunological synapse formation. | T cell activation by nonself peptide-major histocompatibility complex (MHC) antigenic complexes can be blocked by particular sequence variants in a process termed T cell receptor antagonism. The inhibition mechanism is not understood, although such variants are encountered in viral infections and may aid immune evasion... |
15311936 | Factor XIIIa incorporates thymosin beta4 preferentially into the fibrin(ogen) alphaC-domains. | It was shown recently that tissue transglutaminase and presumably plasma transglutaminase, factor XIIIa, can covalently incorporate into fibrin(ogen) a physiologically active peptide, thymosin beta(4) [(Huff et al. (2002) FASEB J. 16, 691-696]. To clarify the mechanism of this incorporation, we studied the interaction ... |
15310896 | DNA-functionalized nanotube membranes with single-base mismatch selectivity. | We describe synthetic membranes in which the molecular recognition chemistry used to accomplish selective permeation is DNA hybridization. These membranes contain template-synthesized gold nanotubes with inside diameters of 12 nanometers, and a "transporter" DNA-hairpin molecule is attached to the inside walls of these... |
15310470 | Endocytosis of influenza viruses. | Receptor-mediated endocytosis is known to play an important role in the entry of many viruses into host cells. However, the exact internalization mechanism has, until recently, remained poorly understood for many medically important viruses, including influenza. Developments in real-time imaging of single viruses as we... |
15310230 | Syntheses and characterizations of a series of novel Ln6Cu24 clusters with amino acids as ligands. | With glycine or L-alanine as ligands, a series of novel 3d-4f heterometallic Ln(6)Cu(24) clusters with the formulas of [Sm(6)Cu(24)(mu(3)-OH)(30)(Gly)(12)(Ac)(12)(ClO(4))(H(2)O)(16)].(ClO(4))(9).(OH)(2).(H(2)O)(31) (1) and [Ln(6)Cu(24)(mu(3)-OH)(30)(Ala)(12)(Ac)(6)(ClO(4))(H(2)O)(12)].(ClO(4))(10).(OH)(7).(H(2)O)(34) (... |
15310222 | Acid-catalyzed oxidation of iodide ions by superoxo complexes of rhodium and chromium. | Superoxometal complexes L(H(2)O)MOO(2+) (L = (H(2)O)(4), (NH(3))(4), or N(4)-macrocycle; M = Cr(III), Rh(III)) react with iodide ions according to the stoichiometry L(H(2)O)MOO(2+) + 3I(-) + 3H(+) --> L(H(2)O)MOH(2+) + 1.5I(2) + H(2)O. The rate law is -d[L(H(2)O)MOO(2+)]/dt = k [L(H(2)O)MOO(2+)][I(-)][H(+)], where k = ... |
15310211 | Self-recognition in the coordination driven self-assembly of 2-D polygons. | Self-recognition in the transition-metal-mediated self-assembly of some 2-D polygons is presented. Prolonged heating of two or three organoplatinum reagents with 4,4'-dipyridyl in aqueous acetone results in the predominant formation of a rectangle, triangle, and/or square. All mixtures are characterized with NMR and el... |
15310189 | Puckered-boat conformation hexameric water clusters stabilized in a 2D metal-organic framework structure built from CuII and 1,2,4,5-benzenetetracarboxylic acid. | 1,2,4,5-Benzenetetracarboxylic acid (btcH(4)) reacts with Cu(NO(3))(2).6H(2)O to form 2D coordination polymeric structure [[Cu(2)(btc)(Py)(4).2H(2)O].4H(2)O](n), 1, in the presence of pyridine from water at room temperature. Puckered-boat-shaped hexameric water clusters resulting from four free water molecules and two ... |
15307745 | Studies on the regio- and stereoselectivity of halohydroxylation of 1,2-allenyl sulfides or selenides. | It was observed that the halohydroxylation of 1,2-allenyl sulfides or selenides with Br2 (CuBr2 or NBS) or I2 and water demonstrated a fairly good regioselectivity (i.e., the C=C bond that is remote from the S or Se atom was halohydroxylated with the halogen atom connecting to the middle carbon atom and the hydroxyl gr... |
15306382 | Probing the role of water in protein conformation and function. | Life began in a bath of water and has never escaped it. Cellular function has forced the evolution of many mechanisms ensuring that cellular water concentration has never changed significantly. To free oneself of any conceptual distinction among all small molecules, solutes and solvents, means that experiments to probe... |
15306376 | Water-protein interactions from high-resolution protein crystallography. | To understand the role of water in life at molecular and atomic levels, structures and interactions at the protein-water interface have been investigated by cryogenic X-ray crystallography. The method enabled a much clearer visualization of definite hydration sites on the protein surface than at ambient temperature. Us... |
15306375 | Structure, dynamics and reactions of protein hydration water. | The apparent simplicity of the water molecule belies the wide range of fascinating protein phenomena in which it participates. We review recent computer simulation work on buried, internal water molecules, discussing the thermodynamics of water molecule binding and the participation of water in proton transfer reaction... |
15306805 | Self-assembly of amphiphilic dendritic dipeptides into helical pores. | Natural pore-forming proteins act as viral helical coats and transmembrane channels, exhibit antibacterial activity and are used in synthetic systems, such as for reversible encapsulation or stochastic sensing. These diverse functions are intimately linked to protein structure. The close link between protein structure ... |
15303883 | Thermodynamic and kinetic stability of synthetic multifunctional rigid-rod beta-barrel pores: evidence for supramolecular catalysis. | The lessons learned from p-octiphenyl beta-barrel pores are applied to the rational design of synthetic multifunctional pore 1 that is unstable but inert, two characteristics proposed to be ideal for practical applications. Nonlinear dependence on monomer concentration provided direct evidence that pore 1 is tetrameric... |
15303879 | Cytotoxicity, hemolysis, and acute in vivo toxicity of dendrimers based on melamine, candidate vehicles for drug delivery. | A small library of dendrimers was prepared from a common precursor that is available in 5 g scale in five linear steps at 56% overall yield. The precursor is a generation three dendrimer that displays 48 peripheral sites by incorporating AB4 surface groups. Manipulation of these sites provided six dendrimers that vary ... |
15303876 | Synthesis of n-type perylene bisimide derivatives and their orthogonal self-assembly with p-type oligo(p-phenylene vinylene)s. | Four different (chiral) electron-deficient (n-type) perylene bisimides containing aliphatic, aromatic, or ethyleneoxide side chaines have been synthesized and fully characterized. All of them form supramolecular stacks in apolar methylcyclohexane (MCH) solution as demonstrated by concentration- and temperature-dependen... |
15303874 | Synthesis and supramolecular assemblies of bipolar archaeal glycolipid analogues containing a cis-1,3-disubstituted cyclopentane ring. | Unsymmetrical archaeal tetraether glycolipid analogues 1-2 incorporating a 1,3-disubstituted cyclopentane ring into the bridging chain have been synthesized. The cyclopentane has been introduced with a totally controlled cis configuration, either into the middle of the aliphatic chain or at three methylene groups from ... |
15303864 | Low-temperature growth of carbon nanotubes from the catalytic decomposition of carbon tetrachloride. | Multiwall carbon nanotubes (MWNTs) were synthesized via the decomposition of CCl4 in supercritical CO2 at 175 degrees C and 27.6 MPa using an iron-encapsulated dendrimer as a growth catalyst. The average diameter of resultant nanotubes was 20-25 nm, obtained after a 24-h reaction time. Our conditions represent the firs... |
15303840 | Hybrid photoactive assemblies: electron injection from host-guest complexes into semiconductor nanoparticles. | Novel ternary assemblies consisting of fully encapsulated host-guest complexes (hemicarceplexes) and wide band gap semiconductor nanoparticles were investigated. The water-soluble amphiphilic host (octacarboxyhemicarcerand) traps the hydrophobic chromophore within its cavity and binds to the surface of metal oxide nano... |
15303838 | Switchable neutral bistable rotaxanes. | Two switchable neutral bistable [2]rotaxanes have been synthesized, and their chemically induced mechanical switching has been studied in solution by 1H NMR spectroscopy. One of the rotaxanes was prepared by a thermodynamically controlled slippage mechanism, while the other rotaxane was obtained by a dynamic covalent c... |
15303837 | Dendronized protein polymers: synthesis and self-assembly of monodisperse cylindrical macromolecules. | Monodisperse dendronized protein polymers (DPPs), cylindrical dendrimers containing protein core, can be efficiently produced through a combined modular biosynthetic strategy. These DPP materials possess predictable size, shape, and solubility. In organic solutions, the DPPs self-assemble to form highly ordered liquid ... |
15301529 | Supramolecular organization and dual function of the IsiA chlorophyll-binding protein in cyanobacteria. | A significant part of global primary productivity is provided by cyanobacteria, which are abundant in most marine and freshwater habitats. In many oceanographic regions, however, the concentration of iron can be so low that it limits growth. Cyanobacteria respond to this condition by expressing a number of iron stress ... |
15300176 | Implications of lipid raft disintegration: enhanced anti-inflammatory macrophage phenotype. | <h4>Background</h4>Lipid rafts are membrane microdomains characterized by an enriched cholesterol environment and appear to serve as a platform for signaling. Their role within the macrophage during endotoxin exposure is unknown.<h4>Methods</h4>THP-1 cells were subjected to lipopolysaccharide stimulation with or withou... |
15295002 | Molecular recognition patterns of serum anti-DNA topoisomerase I antibody in systemic sclerosis. | Autoreactive anti-DNA topoisomerase I (anti-Topo I) Abs are commonly detected in sera of systemic sclerosis (SSc) patients. Our studies have established a positive correlation between the levels of serum anti-Topo I Abs and both disease severity and activity of SSc. The molecular targets of anti-Topo I Ab on Topo I dom... |
15294938 | Relevance of CD6-mediated interactions in T cell activation and proliferation. | CD6 is a cell surface receptor expressed on immature thymocytes and mature T and B1a lymphocytes. The ultimate function of CD6 has not been deciphered yet, but much evidence supports a role for CD6 in T cell activation and differentiation. In this study, we show that a fraction of CD6 molecules physically associates wi... |
15294797 | Construction of a chimeric thermostable pyrophosphatase to facilitate its purification and immobilization by using the choline-binding tag. | The thermophilic inorganic pyrophosphatase (Pyr) from Thermus thermophilus has been produced in Escherichia coli fused to the C terminus of the choline-binding tag (ChB tag) derived from the choline-binding domain (ChBD) of pneumococcal LytA autolysin. The chimeric ChBD-Pyr protein retains its thermostable activity and... |
15292153 | Escherichia coli serogroup O107/O117 lipopolysaccharide binds and neutralizes Shiga toxin 2. | The AB(5) toxin Shiga toxin 2 (Stx2) has been implicated as a major virulence factor of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli strains in the progression of intestinal disease to more severe systemic complications. Here, we demonstrate that supernatant from a normal E. coli isolate, FI-29, neu... |
15292124 | Differences in enzymatic properties allow SodCI but not SodCII to contribute to virulence in Salmonella enterica serovar Typhimurium strain 14028. | Salmonella enterica serovar Typhimurium produces two Cu/Zn cofactored periplasmic superoxide dismutases, SodCI and SodCII. While mutations in sodCI attenuate virulence eightfold, loss of SodCII does not confer a virulence phenotype, nor does it enhance the defect observed in a sodCI background. Despite this in vivo phe... |
15291578 | Adsorption of gases and vapors on nanoporous Ni2(4,4'-Bipyridine)3(NO3)4 metal-organic framework materials templated with methanol and ethanol: structural effects in adsorption kinetics. | Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of ... |
15291571 | Assembling of amphiphilic highly branched molecules in supramolecular nanofibers. | We found that the amplification of weak multiple interactions between numerous peripheral branches of irregular, flexible, polydisperse, and highly branched molecules can facilitate their self-assembly into nanofibrillar micellar structures at solid surfaces and the formation of perfect long microfibers in the course o... |
15291567 | Supramolecular control over donor-acceptor photoinduced charge separation. | A novel donor-bridge-acceptor system has been synthesized by covalently linking a p-phenylene vinylene oligomer (OPV) and a perylene diimid (PERY) at opposite ends of a m-phenylene ethynylene oligomer (FOLD) of twelve phenyl rings, containing nonpolar (S)-3,7-dimethyl-1-octanoxy side chains. For comparison, model compo... |
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