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11387327 | Proteomic analysis of nucleoporin interacting proteins. | The Saccharomyces cerevisiae nuclear pore complex is a supramolecular assembly of 30 nucleoporins that cooperatively facilitate nucleocytoplasmic transport. Thirteen nucleoporins that contain FG peptide repeats (FG Nups) are proposed to function as stepping stones in karyopherin-mediated transport pathways. Here, prote... |
11381114 | RNA editing activity is associated with splicing factors in lnRNP particles: The nuclear pre-mRNA processing machinery. | Multiple members of the ADAR (adenosine deaminases acting on RNA) gene family are involved in A-to-I RNA editing. It has been speculated that they may form a large multicomponent protein complex. Possible candidates for such complexes are large nuclear ribonucleoprotein (lnRNP) particles. The lnRNP particles consist ma... |
11375996 | The NC1 domain of collagen IV encodes a novel network composed of the alpha 1, alpha 2, alpha 5, and alpha 6 chains in smooth muscle basement membranes. | Type IV collagen, the major component of basement membranes (BMs), is a family of six homologous chains (alpha1-alpha6) that have a tissue-specific distribution. The chains assemble into supramolecular networks that differ in the chain composition. In this study, a novel network was identified and characterized in the ... |
11371622 | Synaptic pattern formation during cellular recognition. | Cell-cell recognition often requires the formation of a highly organized pattern of receptor proteins (a synapse) in the intercellular junction. Recent experiments [e.g., Monks, C. R. F., Freiberg, B. A., Kupfer, H., Sciaky, N. & Kupfer, A. (1998) Nature (London) 395, 82-86; Grakoui, A., Bromley, S. K., Sumen, C., Davi... |
11353844 | Corepressor-induced organization and assembly of the biotin repressor: a model for allosteric activation of a transcriptional regulator. | The Escherichia coli biotin repressor binds to the biotin operator to repress transcription of the biotin biosynthetic operon. In this work, a structure determined by x-ray crystallography of a complex of the repressor bound to biotin, which also functions as an activator of DNA binding by the biotin repressor (BirA), ... |
11353835 | Conformational coupling in the chemotaxis response regulator CheY. | CheY, a response regulator protein in bacterial chemotaxis, serves as a prototype for the analysis of response regulator function in two-component signal transduction. Phosphorylation of a conserved aspartate at the active site mediates a conformational change at a distal signaling surface that modulates interactions w... |
11353266 | N-(2-Amino-1,6-dihydro-5-nitroso-6-oxopyrimidin-4-yl)-L-isoleucine-water (4/1): interplay of molecular and supramolecular structures. | In the title compound, 2C10H15N5O4-0.5H2O, there are two independent molecules of the pyrimidinylisoleucine in general positions and a water molecule lying on a twofold rotation axis. The bond lengths within the organic moieties demonstrate significant polarization of the electronic structure. Each of the organic molec... |
11353247 | (C-rac-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane-kappa4N)(nicotinato-O,O')nickel(II) perchlorate. | In the title compound, [Ni(C(6)H(4)NO(2))(C(16)H(36)N(4))]ClO(4), the macrocyclic unit adopts a folded conformation, allowing the two carboxyl O atoms to occupy two neighbouring coordination sites and thus form an additional four-membered chelate ring. The less crowded side of the macrocycle (that with the two asymmetr... |
11352913 | The role of cholesterol and glycosylphosphatidylinositol-anchored proteins of erythrocyte rafts in regulating raft protein content and malarial infection. | Human erythrocytes are terminally differentiated, nonendocytic cells that lack all intracellular organelles. Here we show that their plasma membranes contain detergent-resistant membrane rafts that constitute a small fraction (4%) of the total membrane protein, with a complex mixture of proteins that differentially ass... |
11352921 | Cholesteryl ester transfer protein biosynthesis and cellular cholesterol homeostasis are tightly interconnected. | Cholesteryl ester transfer protein (CETP) mediates triglyceride and cholesteryl ester (CE) transfer between lipoproteins, and its activity is strongly modulated by dietary cholesterol. To better understand the regulation of CETP synthesis and the relationship between CETP levels and cellular lipid metabolism, we select... |
11344270 | Evidence in support of a four transmembrane-pore-transmembrane topology model for the Arabidopsis thaliana Na+/K+ translocating AtHKT1 protein, a member of the superfamily of K+ transporters. | The Arabidopsis thaliana AtHKT1 protein, a Na(+)/K(+) transporter, is capable of mediating inward Na(+) currents in Xenopus laevis oocytes and K(+) uptake in Escherichia coli. HKT1 proteins are members of a superfamily of K(+) transporters. These proteins have been proposed to contain eight transmembrane segments and f... |
18968281 | Electrochemical studies of rutin interacting with hemoglobin and determination of hemoglobin. | Electrochemical investigation of the interaction of rutin (Rt) with hemoglobin (Hb) at a glassy carbon electrode is reported for the first time. With the addition of hemoglobin in a rutin solution, both the reduction and oxidation currents decrease with few changes in the peak potentials. The reaction of rutin with hem... |
18968269 | Molecular recognition and self-assembled polymer films for vapor phase detection of explosives. | Selective and sensitive polymer films for detecting explosives were studied and fabricated onto surface acoustic wave (SAW) devices. Polymers and molecular host species were self-assembled on functionalized silicon oxide surfaces through a catalytic hydrosilylation reaction. The covalently attached thin polymer films a... |
18432861 | Synthesis and application of peptide dendrimers as protein mimetics. | The multiple antigenic peptide (MAP) is a novel approach to preparing peptide immunogens. The MAP consists of an inner core matrix built up of a large layer of Lys residues and a surface of peptide chains attached to the core matrix. Because of its dendrimeric structure, MAP can be very useful as a template for assembl... |
18429141 | Synthesis and application of peptide dendrimers as protein mimetics. | The use of peptides to mimic a portion of a protein structure is a challenging and powerful tool in the discovery of new drugs. In native proteins, discontinuous bioactive peptide surfaces are held together in a particular conformation by the structural rigidity of the protein. Approaches to mimicking a structural surf... |
18428532 | Saturation assays of radioligand binding to receptors and their allosteric modulatory sites. | The protocols in this unit describe methods for measuring radioligand binding to sites on the GABA-A receptor complex. This system was chosen because of the fundamental role of GABA-A receptors in central nervous system function and the presence of multiple binding sites on one supramolecular complex. However, these ba... |
11385652 | Transition Metal Catalysis Using Functionalized Dendrimers. | Dendrimers are well-defined hyperbranched macromolecules with characteristic globular structures for the larger systems. These novel polymers have inspired many chemists to develop new materials and several applications have been explored, catalysis being one of them. The recent impressive strides in synthetic procedur... |
11334530 | Interactions of Methyl Orange with Cyclodextrin/Sodium-Montmorillonite Systems Probed by UV-Visible Spectroscopy. | Clay mineral colloids play important roles in the adsorption of polar organic contaminants in the environment. Similarly, cyclodextrins (CD) can entrap poorly water-soluble organic compounds. A combination of CDs and clay minerals affords great opportunities to investigate simultaneously complexation and adsorption pro... |
11828462 | Pure and scrambled self-aggregates prepared with zinc analogues of bacteriochlorophylls c and d. | Zinc analogues of bacteriochlorophylls c and d self-assembled in aqueous media with phospholipids. A methanol solution of zinc chlorin and alpha-lecithin was put in a cellulose tube and the inner methanol solvent was gradually replaced with water by dialysis to form the self-assembled oligomers. Visible absorption spec... |
11708140 | Voltammetric determination of lead at chemically modified electrodes based on crown ethers. | The feasibility of fabricating lead-sensitive chemically modified electrodes (CMEs) for trace analysis in aqueous and 40% (v/v) ethanol-water media was investigated. Carbon paste electrodes modified with crown ethers were constructed by mixing the crown ethers into a graphite powder-paraffin oil matrix. The thus-formed... |
11558310 | [Supramolecular regulation of the activity of some oxidoreductases in the norm and in pathology]. | Regulation metabolism in a cell is realised by enzymes arranged into supramolecular complexes. Lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) are involved into formation of various supramolecular complexes. It is supposed that oxidoreductases LDH and ADH can form uniform functional supramolecular complex, ... |
11510362 | [Multiple organ failure as a manifestation of immune dysregulation of reparative processes in the organs during critical states]. | The authors claim that the specific clinical symptoms of multiple organ failure (MOF) are explained by impaired interactions of two functionally related systems: the immune system (IS) responsible for regeneration and the reticuloendothelial system (RES) responsible for inflammation. Organ regeneration during MOF is su... |
11504391 | Molecular self-assembly of partially hydrolysed alpha-lactalbumin resulting in strong gels with a novel microstructure. | Gelation of alpha-lactalbumin (alpha-la) incubated with a protease from Bacillus licheniformis (BLP) at 50 degrees C for 4 h was monitored using small oscillatory shear and the large deformation properties of final gels were characterized by uniaxial compression. Transmission electron microscopy was used to visualize t... |
11491303 | Structural requirements for cooperative binding of HMG1 to DNA minicircles. | DNA minicircles, where the length of DNA is below the persistence length, are highly effective, preferred, ligands for HMG-box proteins. The proteins bind to them "structure-specifically" with affinities in the nanomolar range, presumably to an exposed widened minor groove. To understand better the basis of this prefer... |
11474578 | Expression and characterization of six mutations in the protoporphyrinogen oxidase gene among Finnish variegate porphyria patients. | <h4>Background</h4>Variegate porphyria (VP) is an inherited disorder of heme biosynthesis that results from a partial deficiency of protoporphyrinogen oxidase (PPOX). Patients with VP may experience acute neurovisceral attacks and cutaneous photosensitivity. To date we have characterized 109 VP patients representing 19... |
11465424 | Effect of cyclodextrin charge on complexation of neutral and charged substrates: comparison of (SBE)7M-beta-CD to HP-beta-CD. | <h4>Purpose</h4>To understand the role of charge in substrate/cyclodextrin complexation by comparing the binding of neutral and charged substrates to a neutral cyclodextrin, such as hydroxypropyl beta-CD (HP-beta-CD) with 3.5 degrees of substitution, and an anionically charged cyclodextrin, such as sulfobutyl ether bet... |
11465415 | Mutual inhibition of the insulin absorption-enhancing properties of dodecylmaltoside and dimethyl-beta-cyclodextrin following nasal administration. | <h4>Purpose</h4>To determine if a nasal insulin formulation containing two distinct absorption-enhancing agents exhibits an additive or synergistic increase in the rate of systemic insulin absorption.<h4>Methods</h4>The pharmacokinetics and pharmacodynamics of insulin absorption were measured in hyperglycemic anestheti... |
11465114 | CTL activation is induced by cross-linking of TCR/MHC-peptide-CD8/p56lck adducts in rafts. | To investigate the role of the coreceptor CD8 and lipid rafts in cytotoxic T lymphocyte (CTL) activation, we used soluble mono-and multimeric H-2Kd-peptide complexes and cloned S14 CTL specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite (PbCS) peptide 252-260 [PbCS(ABA)]. We report that a... |
11457331 | Extradiol oxidative cleavage of catechols by ferrous and ferric complexes of 1,4,7-triazacyclononane: insight into the mechanism of the extradiol catechol dioxygenases. | The major oxygenation product of catechol by dioxygen in the presence of FeCl(2) or FeCl(3), 1,4,7-triazacyclononane (TACN), and pyridine in methanol is the extradiol cleavage product 2-hydroxymuconic semi-aldehyde methyl ester (Lin, G.; Reid, G.; Bugg, T. D. H. J. Chem. Soc. Chem. Commun. 2000, 1119--1120). Under thes... |
11457325 | Selective lithium ion binding involving inositol-based tris(spirotetrahydrofuranyl) ionophores: formation of a rodlike supramolecular ionic polymer from a homoditopic dimer. | The stereoselective replacement of all three hydroxyl groups in myo-inositol orthoformate by spirotetrahydrofuran rings in that manner which projects the C--O bonds in the molecular interior has been examined. The heterocyclic components were introduced sequentially, a protocol that demonstrated the utility of precompl... |
11457322 | Charge-transfer forces in the self-assembly of heteromolecular reactive solids: successful design of unique (single-crystal-to-single-crystal) Diels--Alder cycloadditions. | Electron donor/acceptor (EDA) interactions are found to be a versatile methodology for the engineering of reactive heteromolecular crystals. In this way, a series of the charge-transfer pi-complexes between bis(alkylimino)-1,4-dithiin acceptors and anthracene donors are shown to form heteromolecular (1:1) crystalline s... |
11457320 | DFT study of the effect of sigma-ligands on the structure of ester enolates in THF, as models of the active center in the anionic polymerization of methyl methacrylate. | A Density Functional Theory (DFT) study was carried out on structures of the lithium ester enolate of methyl isobutyrate (MIB-Li) in THF solution, in the presence of TMEDA, dimethoxyethane (DME), crown ether 12-crown-4, and cryptand-2,1,1, as electron donor ligands (sigma-ligands). Both specific solvation with THF and/... |
11457292 | Elastic bounded diffusion and electron propagation: dynamics of the wiring of a self-assembly of immunoglobulins bearing terminally attached ferrocene poly(ethylene glycol) chains according to a spatially controlled organization. | Molecular monolayers of immunoglobulins bearing terminally attached ferrocene poly(ethylene glycol) chains (IgG-PEG-Fc) were self-assembled at an electrode surface in a step-by-step manner involving antigen-antibody recognition reactions. The total number N of assembled IgG-PEG-Fc monolayers and the number of spacers n... |
11457284 | Supramolecular origins of product selectivity for methanol-to-olefin catalysis on HSAPO-34. | Ethylene selectivity in methanol-to-olefin (MTO) catalysis is related to the number of methyl groups on benzene rings trapped in the nanocages of the preferred catalyst HSAPO-34. By correlating the time evolutions of the catalysts' 13C NMR spectra and the volatile product distribution following abrupt cessation of meth... |
11457283 | Solitaire and gemini metallocene porphyrazines. | We report the synthesis and physical characterization of a series of peripherally functionalized porphyrazines (pzs) of the forms H2[pz(A;B3)] and trans-H2[pz(A2);B2], where A is a dithiolene chelate of molybdocene or vanadocene and B is a solublizing group. The precursor pz's 8 and 9, of the form H2[pz(A;B3)], where A... |
11457275 | Structure and conformation of DAB dendrimers in solution via multidimensional NMR techniques. | NOESY-HSQC 3D-NMR and NOESY 2D-NMR techniques have been used on a 750 MHz spectrometer to study the chain conformations of different generation DAB dendrimers (poly[propylene imine] dendrimers) in chloroform and benzene solutions. The high-field multidimensional NMR techniques provided the chemical shift dispersion nee... |
11457227 | The generality of architectural isomerism in designer inclusion frameworks. | We describe herein new structural isomers of a lamellar host system based on organodisulfonate "pillars" that connect opposing hydrogen-bonded sheets, consisting of topologically complementary guanidinium (G) ions and sulfonate (S) groups, to generate inclusion cavities between the sheets. These new isomers-zigzag bric... |
11457226 | First synthesis of phenylazomethine dendrimer ligands and structural studies. | Novel dendritic polyphenylazomethines (DPAs), which consist of a pi-conjugated backbone, were synthesized up to the fourth generation by the convergent method via dehydration of aromatic ketones with aromatic amines in the presence of titanium(IV) tetrachloride. The obtained dendrimers, DPA G1-4 (designated as GX, wher... |
11457173 | Long-range cooperativity in molecular recognition of RNA by oligodeoxynucleotides with multiple C5-(1-propynyl) pyrimidines. | A heptamer composed of C5-(1-propynyl) pyrimidines (Y(p)'s) is a potent and specific antisense agent against the mRNA of SV40 large T antigen (Wagner, R. W.; Matteucci, M. D.; Grant, D.; Huang, T.; Froehler, B. C. Nat. Biotechnol. 1996, 14, 840-844). To characterize the role of the propynyl groups in molecular recognit... |
11457144 | Supramolecular chemistry: molecular recognition and self-assembly using rigid spacer-chelators bearing cofacial terpyridyl palladium(II) complexes separated by 7 A. | Partially and fully aromatic molecular spacers bearing two symmetrically bound terpyridyl chelators have been prepared. These spacer-chelators were constructed to dispose the two terpyridyl ligands and their complexes with square planar metals cofacially with a separation of about 7 A between the two metals. Dipalladiu... |
11457141 | Pseudopolymorphism in tetradeca-2,6-O-methyl-beta-cyclodextrin: the crystal structures for two new hydrates-conformational variability in the alkylated beta-cyclodextrin molecule. | Tetradeca-2,6-O-methyl-beta-cyclodextrin, per-2,6-OMe-beta-CD, is an unusual beta-cyclodextrin, beta-CD, derivative because it has a negative thermal solubility coefficient in aqueous solution. This report describes two new crystal structures for hydrates of per-2,6-OMe-beta-CD crystallized at different temperatures: p... |
11448053 | Evaluation of stereoselective dissolution of racemic salbutamol matrices prepared with commonly used excipients and 1H-NMR study. | The purpose of this work was to examine the in vitro enantioselective dissolution of salbutamol from matrix tablets containing various chiral excipients, such as gamma cyclodextrin (gamma-CD), heptakis (2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD), sulfobutyl-beta-cyclodextrin (SBE-beta-CD), hydroxypropylmethylcellu... |
11437238 | Analysing structure-function relationships with biosensors. | Elucidating the nature of the relationship between the structure and function of biomolecules remains one of the major challenges in biology. Biomolecules are dynamic entities that possess a variety of structures, and their functions at the molecular, cellular and organismic levels are quite different. Since there is n... |
11437235 | Cytochromes P450 and metabolism of xenobiotics. | Cytochromes P450 (henceforth P450s) are involved in a variety of metabolic and biosynthetic processes. The number of known P450 enzymes exceeds 1000, while the endogenous substrates of most of them remain unknown. All P450 enzymes exhibit similarity in their structure and general mechanism of action; however, there are... |
11437231 | Structure and function of histone acetyltransferases. | Histone acetyltranferase (HAT) enzymes are the catalytic subunit of large multisubunit HAT complexes that acetylate the epsilon-amino group of specific lysine residues on histone tails to promote transcriptional activation. Recent structural and functional studies on the divergent HAT enzymes Gcn5/PCAF, Esa1 and Hat1 h... |
11437230 | Mammalian histone acetyltransferases and their complexes. | One of the key questions in the current molecular genetics of eukaryotes is how genetic information is retrieved from tightly packed chromatin. Acetylation of core histone N-termini is implicated in the regulation of chromatin function, and I summarize what is known about the mammalian enzymes that promote this posttra... |
11434383 | Crystal structures of cyclomaltohexaose (alpha-cyclodextrin) complexes with p-bromophenol and m-bromophenol. | Crystal structures of cyclomaltohexose (alpha-cyclodextrin) complexes with p-bromophenol and m-bromophenol have been determined by single-crystal X-ray diffraction. The space group of the alpha-cyclodextrin-p-bromophenol complex is P2(1)2(1)2(1) with unit cell dimensions of a = 15.318(3), b = 24.733(3), c = 13.457(2) A... |
11434378 | Metal ion coordination of macromolecular bioligands: formation of zinc(II) complex of hyaluronic acid. | The coordination of zinc(II) ion to hyaluronate (Hya), a natural copolymer, in aqueous solution at pH 6 was investigated by potentiometric and circular dichroism (CD) spectroscopic methods, and by monitoring the changes in macroscopic properties by high-precision measurements. The zinc(II)-selective electrode, and CD m... |
11430759 | Domain orientation in beta-cyclodextrin-loaded maltose binding protein: diffusion anisotropy measurements confirm the results of a dipolar coupling study. | Maltose binding protein (MBP) is a 370-residue two-domain molecule involved in bacterial chemotaxis and sugar uptake. Rotational diffusion tensors were calculated for a complex between MBP and beta-cyclodextrin using backbone 15N T1 and T1rho relaxation times and steady state 1H-15N NOE values. The tensors obtained for... |
11430537 | Neostigmine resolves critical illness-related colonic ileus in intensive care patients with multiple organ failure--a prospective, double-blind, placebo-controlled trial. | <h4>Objective</h4>Critical illness-related colonic ileus (CIRCI) is characterized by the non-passage of stools in critically ill patients as a result of the absence of prokinetic movements of the colon, while the upper gastrointestinal tract functions properly and mechanical ileus is absent: We investigated whether neo... |
11428163 | Structure and function in extracellular matrices depend on interactions between anionic glycosaminoglycans. | Connective tissue extracellular matrices define and maintain shape. Collagen fibrils transmit and resist pulling forces and soluble interfibrillar carbohydrate-rich polymers (anionic glycosaminoglycans AGAGs) resist compressive forces. This article shows that AGAGs (chondroitin, dermochondan and keratan sulphates) form... |
11421451 | Wavelength shifts correlation between near infrared and ultraviolet regions of the LHII bacteriochlorophyll spectrum from Ectothiorhodospira sp. | Bacteriochlorophyll a has a maximum at 258 nm previously related to the ring E ester system interacting with the pi-system of the macrocycle. In this work, we compared the effect of lauryldimethylamine-N-oxide (LDAO) and alkaline pH on both the near infrared and the ultraviolet region of the LHII spectrum from Ectothio... |
11420639 | Transfection of urothelial cells using methyl-beta-cyclodextrin solubilized cholesterol and Dotap. | the murine urothelial cell line, mb49 was transfected with the reporter gene pcmvlacz using a number of commercial transfection agents. the transfection efficiency of these agents, as determined by beta-galactosidase activity, is in the order of dotap>superfect>Fugene. The addition of methyl-beta-cyclodextrin solubiliz... |
11412556 | [Suitability of antibiotic prescription in primary care in the Basque Autonomous Community]. | <h4>Objective</h4>To study the variability and suitability of antibiotic prescription in primary care in the Basque Country.<h4>Design</h4>Prospective, descriptive study.<h4>Setting</h4>Basque Country health care centres both within and not in the reformed network.<h4>Measurements and main results</h4>3182 infections f... |
11411995 | A logical concept of structure prediction derived from supramolecular polymers of alkaline Earth metal halides formed by hydrogen bonding and complexation of the metal ion. | Several different dimensional polymers derived from alkaline earth metal iodides are obtained as a result of supramolecular noncovalent bonding modes of the metal ion, namely complexation and hydrogen bonding. These polymers consist of complex cations linked to the halide ions by hydrogen bonds of the water ligands coo... |
11411993 | Precise adjustment of nanometric-scale diffusion layers within a redox dendrimer molecule by ultrafast cyclic voltammetry: an electrochemical nanometric microtome. | Performing cyclic voltammetry at scan rates into the megavolt per second range allows the exploration of the nanosecond time scale as well as the creation of nanometric diffusion layers adjacent to the electrode surface. This latter property is used here to adjust precisely the diffusion layer width within the outer sh... |
11410068 | Molecular complexity and its impact on the probability of finding leads for drug discovery. | Using a simple model of ligand-receptor interactions, the interactions between ligands and receptors of varying complexities are studied and the probabilities of binding calculated. It is observed that as the systems become more complex the chance of observing a useful interaction for a randomly chosen ligand falls dra... |
11405679 | Unique fluorescence behavior of rhodamine B upon inclusion complexation with novel bis(beta-cyclodextrin-6-yl) 2,2'-bipyridine-4,4'-dicarboxylate. | Newly synthesized bis(beta-cyclodextrin-6-yl) 2,2'-bipyridine-4,4'-dicarboxylate was found to induce an unusual fluorescence enhancement of Rhodamine B (RhB) upon complexation. This effect is attributable to the equilibium shift of RhB to the highly fluorescent carboxylate ion form, which is induced by the cooperative ... |
11405676 | Photoinduced electron transfer within porphyrin-containing poly(amide) dendrimers. | The synthesis and photophysical characterization of a series of free base porphyrin-containing polyamide dendrimers terminated with anthraquinone groups (FbP-Ga-AQ(n)(), a = 1-3, n = 12, 36, 108) are described. Substantial quenching (58-75%) of the porphyrin fluorescence of FbP-Ga-AQ(n)() is observed when compared to t... |
11405666 | Remarkable alkali cation template effect in 1,5-bridged calix[8]arenes. | Treatment of 1,5-bridged calix[8]arenes 2-4 with alkali metal carbonates produces salts in which an included cation acts as a conformational template. This induces the folding of calix[8]arene skeleton in a conformation in which the triads of contiguous OH-bearing rings adopt a 3/4-cone conformation with all hydroxyls ... |
11405483 | Diastereoselective formation of host-guest complexes between a series of phosphate-bridged cavitands and alkyl- and arylammonium ions studied by liquid secondary-ion mass spectrometry. | The reactions occurring between a new class of cavitands that carry up to four dioxaphosphocin binding units and alkyl- and arylammonium ions was investigated by liquid secondary-ion mass spectrometry (LSIMS). As the cavitands existed as distinct diastereomers with different spatial orientation of their binding groups,... |
11405473 | Resorcarenes in the boat conformation as building blocks for hydrogen-bonded assemblies including two ammonium cations. | Crystal structures are reported for various co-crystals of rccc-resorcarenes with triethylammonium chloride. Usually, two molecules of a C2v-symmetric tetraester 2 in the boat conformation are linked through four hydrogen-bonded chloride anions to give dimeric assemblies. Two of the chloride anions may be replaced by f... |
11403482 | A capillary electrophoresis study on the influence of beta-cyclodextrin on the critical micelle concentration of sodium dodecyl sulfate. | The influence of beta-cyclodextrin (beta-CD) on the critical micelle concentration (CMC) of sodium dodecyl sulfate (SDS) was investigated by capillary electrophoresis using anionic chlorophenols as probe molecules at pH 7.0. The variations of the electrophoretic mobility of probe molecules as a function of surfactant c... |
11403091 | Structure of the complex of beta-cyclodextrin with beta-naphthyloxyacetic acid in the solid state and in aqueous solution. | The structure of the complex of beta-cyclodextrin (cyclomaltoheptaose) with beta-naphthyloxyacetic acid was studied in solid state by X-ray diffraction and in aqueous solution by 1H NMR spectroscopy. The complex crystallizes in the channel mode, space group C2, with a stoichiometry of 2:1; two beta-cyclodextrin molecul... |
11397992 | [Cyclosporin A eyedrops: manufacturing, toxicity, pharmacokinetics and indications in 2000]. | <h4>Introduction</h4>Cyclosporin eye-drops allow local immunoregulation without systemic side effects and is an alternate to local steroids. In this article we review specific problems of product setup and clinical studies published over the past 20 years. PRODUCT SETUP: The main problems in eye-drop preparation are st... |
11396437 | Clinical impact of continuous renal replacement therapy on multiple organ failure. | Because continuous renal replacement therapy (CRRT) may enhance inflammatory mediator removal, this review assesses its impact on multiple organ failure (MOF). Regarding MOF with acute renal failure (ARF), the overall mortality of 2313 CRRT patients (43 studies) was 62.8% compared with 59.1% (p = 0.046) in 961 intermit... |
11390265 | Specific targeting of folate-dendrimer MRI contrast agents to the high affinity folate receptor expressed in ovarian tumor xenografts. | The need to develop target-specific MRI contrast agents to aid in disease characterization remains highly essential. In this study, we present a generation four polyamidoamine (PAMAM) folate-dendrimer that specifically targets the high affinity folate receptor (hFR) overexpressed on more than 80% of ovarian tumors. In ... |
11391789 | Optical biosensor investigation of interactions of biomembrane and water-soluble cytochromes P450 and their redox partners with covalently immobilized phosphatidylethanolamine layers. | A phospholipid-containing biochip was created by covalently immobilizing phospholipids on the optical biosensor's aminosilane cuvette and employed to monitor the interactions of the membrane and water-soluble proteins in cytochrome P450-containing monooxygenase systems with planary layers of dilauroylphosphatidylethano... |
11391788 | Docking of combinatorial peptide libraries into a broadly cross-reactive human IgM. | A monoclonal IgM cryoglobulin with diverse binding behavior was isolated from a patient (Mez) with Waldenström's macroglobulinemia. It gave very high titers in the binding of combinatorially synthesized libraries of peptides ranging in size from two to eight residues. The crystal structure of Mez Fv revealed that the b... |
11391787 | NMR chemical shift mapping of the binding site of a protein proteinase inhibitor: changes in the (1)H, (13)C and (15)N NMR chemical shifts of turkey ovomucoid third domain upon binding to bovine chymotrypsin A(alpha). | The substrate-like inhibition of serine proteinases by avian ovomucoid domains has provided an excellent model for protein inhibitor-proteinase interactions of the standard type. 1H,15N and 13C NMR studies have been undertaken on complexes formed between turkey ovomucoid third domain (OMTKY3)2 and chymotrypsin A(alpha)... |
11391786 | Effects of tail-like substituents on the binding of competitive inhibitors to the Q(B) site of photosystem II. | The QB quinone-binding site of photosystem II is an important target for herbicides. Two major classes of herbicides are based on s-triazine and phenylurea moieties. A small library of triazine and phenylurea compounds has been synthesized which have tail-like substituents in order to test the effects of charge, hydrop... |
11391785 | Molecularly imprinted polymers from nicotinamide and its positional isomers. | Imprinted polymers were prepared for nicotinamide and its positional isomers. The influence of porogenic solvent and functional monomer on recognition properties of the polymer was compared. The results indicated that two functional groups, the heterocyclic nitrogen and the amide group, in the nicotinamide or isonicoti... |
11391784 | Actinomycin D binding to unstructured, single-stranded DNA. | Actinomycin D is an anticancer antibiotic best know for inhibiting transcription by binding double-stranded DNA. Tight, sequence selective binding of actinomycin to single-stranded DNA is also known, however, and is implicated in biological activities including inhibition of (-) strand transfer by HIV reverse transcrip... |
11389992 | Drug permeation enhancement via buccal route: possibilities and limitations. | Over the last decade, there has been a particular interest in delivering drugs, especially peptides and proteins via the buccal route. It provides direct entry into the systemic circulation thus avoiding the hepatic first-pass effect and degradation in the gastrointestinal tract, ease of administration, and the ability... |
11391677 | Enantioseparation of aminoglutethimide and thalidomide by high performance liquid chromatography or supercritical fluid chromatography on mono-2 and mono-6-O-pentenyl-beta-cyclodextrin-based chiral stationary phases. | Mono-2 and mono-6-O-pentenyl-beta-cyclodextrin (mono-2-pent-beta-CD and mono-6-pent-beta-CD), covalently linked to mercaptopropylsilica gel (thiol-Si) through thioether or sulfone linkage, reveal differentiated enantioselectivities in the separation of piperidine-2,6-dione-related drugs, namely aminoglutethimide and th... |
11391676 | Reversed-phase planar chromatography of some enantiomeric amino acids and oxazolidinones. | The resolution of two enantiomeric amino acids and four structurally related oxazolidinones was evaluated by reversed-phase planar chromatography using both home-made microcrystalline cellulose triacetate (MCTA) layers and mobile phase additivies, such as beta-cyclodextrins (beta-Cy), modified alpha, beta, gamma cyclod... |
11391675 | Simultaneous determination of D-lactic acid and 3-hydroxybutyric acid in rat plasma using a column-switching HPLC with fluorescent derivatization with 4-nitro-7-piperazino-2,1,3-benzoxadiazole (NBD-PZ). | A highly sensitive method for the determination of D-lactic acid and 3-hydroxybutyric acid (3-HB) in rat plasma was developed using high-performance liquid chromatography with octadecylsilica (ODS) connected to a chiral column. At first, (D + L)-lactic acid and 3-HB in the plasma were derivatized with a fluorescent rea... |
11391674 | Hybridation of different chiral separation techniques with ICP-MS detection for the separation and determination of selenomethionine enantiomers: chiral speciation of selenized yeast. | Enantioseparation and determination of selenomethionine enantiomers in selenized yeast was investigated using chiral separation techniques based on different principles, coupled on-line to inductively coupled plasma mass spectrometry (ICP-MS) for selenium-specific detection. High performance liquid chromatography (HPLC... |
11393712 | Enantioselective determination of metoprolol and major metabolites in human urine by capillary electrophoresis. | The enantiomeric separation of metoprolol and its metabolites in human urine was undertaken using capillary electrophoresis (CE). Resolution of the enantiomers was achieved using carboxymethyl-beta-cyclodextrin (CM-beta-CD) as the chiral selector. A 100-mM acetate buffer (pH 4.0) containing 5% 2-propanol and 10 mM CM-b... |
11393728 | A dual-mode approach to the selective separation of antibodies and their fragments. | A novel chromatography method for the separation of antibodies is described. The adsorption of antibodies on the solid phase involves interaction with a ligand that combines mild hydrophobic characteristics and some degree of molecular recognition with a derivative of pyridine. This combined effect results in the adsor... |
11393233 | Maltodextrins as new chiral selectors in the design of potentiometric, enantioselective membrane electrodes. | Maltodextrins (dextrose equivalent (DE) 4.0-7.0, 13.0-17.0, and 16.5-19.5) are proposed as novel chiral selectors for the construction of potentiometric, enantioselective membrane electrodes. The potentiometric, enantioselective membrane electrodes can be used reliably for the assay of S-captopril as raw material and i... |
11393226 | Cyclodextrins as electrode modifiers. | Complexation abilities and analytical applications of working electrodes with attached cyclodextrins (CDs) are reviewed. For the immobilization of CDs, their adsorption and formation of self-assembled monolayers, preparation of polymer films, as well as incorporation within plasticized membranes and composites such as ... |
11392549 | Ring-Constrained (N)-methanocarba nucleosides as adenosine receptor agonists: independent 5'-uronamide and 2'-deoxy modifications. | Novel methanocarba adenosine analogues, having the pseudo-ribose northern (N) conformation preferred at adenosine receptors (ARs), were synthesized and tested in binding assays. The 5'-uronamide modification preserved [N6-(3-iodobenzyl)] or enhanced (N6-methyl) affinity at A3ARs, while the 2'-deoxy modification reduced... |
11392448 | Progress in the development of alternative pharmaceutical formulations of taxanes. | The currently available taxanes paclitaxel (Taxol) and docetaxel (Taxotere) are clinically effective against advanced breast, ovarian and non-small cell lung cancer. Due to their low aqueous solubility, both taxanes posed difficulties to the pharmaceutical scientists with respect to the development of an intravenous do... |
11388843 | Novel alkali cation chemosensors based on n-9-anthrylaza-crown ethers. | [structure: see text] A novel alkali cation selective probe is described which exhibits unique ICT and binding properties, allowing the ratiometric titration of sodium cations in the presence of other alkali metal ions. |
11384761 | Stereoselective synthesis of (S)-(+)-Naproxen catalyzed by carboxyl esterase in a multicompartment electrolyzer. | The stereoselective hydrolysis of racemic 2-substituted propionates, catalyzed by carboxyl esterase, provides a cost-competitive route to produce the optically pure, anti-inflammatory drug Naproxen. In the present work, we describe the application of the multicompartment electrolyzer reactor (ME) for the stereoselectiv... |
11381084 | The small muscle-specific protein Csl modifies cell shape and promotes myocyte fusion in an insulin-like growth factor 1-dependent manner. | We have isolated a murine cDNA encoding a 9-kD protein, Chisel (Csl), in a screen for transcriptional targets of the cardiac homeodomain factor Nkx2-5. Csl transcripts were detected in atria and ventricles of the heart and in all skeletal muscles and smooth muscles of the stomach and pulmonary veins. Csl protein was di... |
11381094 | Stonin 2: an adaptor-like protein that interacts with components of the endocytic machinery. | Endocytosis of cell surface proteins is mediated by a complex molecular machinery that assembles on the inner surface of the plasma membrane. Here, we report the identification of two ubiquitously expressed human proteins, stonin 1 and stonin 2, related to components of the endocytic machinery. The human stonins are ho... |
11381088 | Local photorelease of caged thymosin beta4 in locomoting keratocytes causes cell turning. | The broad aim of this work was to explore the feasibility of using light-directed perturbation techniques to study cell locomotion. Specifically, a caged form of thymosin beta4 (Tbeta4) was photoactivated in a defined local region of locomoting fish scale keratocytes and the resulting perturbation of locomotion was stu... |
11382303 | Rapid capillary electrophoretic method for the determination of clozapine and desmethylclozapine in human plasma. | A rapid and sensitive high-performance capillary electrophoretic method for the determination of clozapine and its main metabolite desmethylclozapine in human plasma was developed. The separation of the two analytes was carried out in an untreated fused-silica capillary [33 cm (8.5 cm effective length) x 50 microm I.D.... |
11382286 | Capillary zone electrophoresis of orotic acid in urine with on-line isotachophoresis sample pretreatment and diode array detection. | Potentialities of capillary zone electrophoresis with on-line isotachophoresis sample pretreatment and diode array detection (ITP-CZE-DAD) to the separation, detection and identification of trace analytes present in biological matrices were investigated. Urine represented a multicomponent, variable and high ionic stren... |
11382312 | Use of a fluorosurfactant in micellar electrokinetic capillary chromatography. | A fluorosurfactant, the anionic N-ethyl-N-[(heptadecafluorooctyl)sulfonyl]glycine potassium salt, trade name FC-129 [CAS 2991-51-7] was investigated for possible application in micellar electrokinetic capillary chromatography (MEKC). The surfactant was characterized with conductometric titration and test sample mixture... |
11382310 | Hemispherodextrins, a new class of cyclodextrin derivatives, in capillary electrophoresis. | A capped cyclodextrin derivative (THCMH), called hemispherodextrin, was observed to behave as a very efficient chiral selector for a variety of phenoxyacid enantiomeric pairs, both at pH 6 and pH 9. The very low concentration necessary to obtain separation was particularly impressive. The behaviour of THCMH was compare... |
11377689 | Platinum carboxylato-pendant-arm macrocycles: structure, redox properties and anti-cancer potential. | In an attempt to generate new platinum compounds that may be effective in the treatment of cancer, as well as having a lower toxicity than traditional platins and being orally viable, we are studing the synthesis and reactivity of platinum complexes of tetraazamacrocycles bearing carboxylato pendant arms. We have synth... |
11378609 | Secretory phospholipase A2 activity correlates with postinjury multiple organ failure. | <h4>Unlabelled</h4>Postinjury multiple organ failure (MOF) may result from overwhelming systemic hyperinflammation. Secretory phospholipase A2 (sPLA2) produces many inflammatory lipid mediators, and levels have been correlated with both the severity of patient injury and postinjury mortality. The objective of this stud... |
11353090 | Efficient new ribozyme mimics: direct mapping of molecular design principles from small molecules to macromolecular, biomimetic catalysts. | Dramatic improvements in ribozyme mimics have been achieved by employing the principles of small molecule catalysis to the design of macromolecular, biomimetic reagents. Ribozyme mimics derived from the ligand 2,9-dimethylphenanthroline (neocuproine) show at least 30-fold improvements in efficiency at sequence-specific... |
11367566 | Photochromism of viologens included in crown ether cavity. | The effect of a pi-electron-donating macrocyclic molecule on the photochromic behavior of viologen derivatives was investigated in a thin polymer film. The intermolecular interactions between the viologens and the macrocyclic molecule were investigated in a solution before photoirradiation. In acetone, benzylviologens,... |
11359939 | Activation-enhanced alpha(IIb)beta(3)-integrin-cytoskeleton interactions outside of focal contacts require the alpha-subunit. | Integrins link the cell's cytoskeleton to the extracellular matrix, as well as to receptors on other cells. These links occur not only at focal contacts but also at smaller integrin-containing protein complexes outside of focal contacts. We previously demonstrated the importance of focal contact-independent integrin-cy... |
11358518 | Calpha methylation in molecular recognition. Application to substance P and the two neurokinin-1 receptor binding sites. | Two binding sites NK-1M (major, more abundant) and NK-1m (minor) are associated with the neurokinin-1 receptor. For the first time with a bioactive peptide, the Calpha methylation constraint, shown to be a helix stabiliser in model peptides, was systematically used to probe the molecular requirements of NK-1M and NK-1m... |
11358694 | Engineering a polyketide with a longer chain by insertion of an extra module into the erythromycin-producing polyketide synthase. | <h4>Background</h4>Modular polyketide synthases catalyse the biosynthesis of medically useful natural products by stepwise chain assembly, with each module of enzyme activities catalysing a separate cycle of polyketide chain extension. Domain swapping between polyketide synthases leads to hybrid multienzymes that yield... |
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