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11412083 | On the way to rotaxane-based molecular motors: studies in molecular mobility and topological chirality. | ATP synthase represents a machine at the molecular level which couples the rotation of an axle in a wheel with the endergonic production of ATP, the general source of chemical energy in the cell. The natural system prototypically bears all features of a macroscopic motor: a rotor within a stator held by a membrane and ... |
11412082 | Cyclodextrin-based molecular machines. | Cyclodextrins have been used as a cyclic component in the construction of supramolecular architectures. Recently they have been studied as a component in the construction of rotaxanes and catenanes. A cyclodextrin ring can translocate in some rotaxane and catenane structures. Therefore, much attention has been given to... |
11412080 | Switching devices based on interlocked molecules. | An architectural rationale and an experimental program aimed at the development of molecular electronics switching devices for memory and computing applications are discussed. Two-terminal molecular switch tunnel junctions are identified as the critical device components of molecular electronics-based circuitry. They c... |
11412079 | Electronically transduced molecular mechanical and information functions on surfaces. | Supramolecular chemistry and nanotechnology, along with their use in the construction of functional assemblies and devices, have merged into a challenging field of study. The development of methodologies for the integration and interfacing of molecular building blocks with solid supports and electronic transducers is e... |
11411943 | Inhibition of Cryptosporidium infection in mice treated with a cyclodextrin inclusion complex with diloxanide furoate. | The efficacies of diloxanide furoate, beta-cyclodextrin and a cyclodextrin inclusion complex against Cryptosporidium parvum were evaluated in a suckling murine model. Efficacy was established by numbers of oocysts recovered from the intestinal tract of mice on day 7 postinfection. The level of infection in treated mice... |
11410677 | Differential DNA recognition and glycosylase activity of the native human MutY homolog (hMYH) and recombinant hMYH expressed in bacteria. | Human MutY homolog (hMYH), an adenine DNA glycosylase, can effectively remove misincorporated adenines opposite template G or 8-oxoG bases, thereby preventing G:C-->T:A transversions. Human cell extracts possess the adenine DNA glycosylase activity of hMYH and can form protein-DNA complexes with both A/G and A/8-oxoG m... |
11410243 | Sterically hindered cisplatin derivatives with multiple carboxylate auxiliary arms: synthesis and reactions with guanosine-5'-monophosphate and plasmid DNA. | Two novel sterically hindered cisplatin derivatives with the ligand L=NH(2)C(CH(2)CH(2)COOH)(3) were prepared: cis-PtCl(2)L(2) and cis-PtCl(2)L(NH(3)). The starting compound for the syntheses was NH(2)C(CH(2)CH(2)COOtBu)(3), also known as a building block for dendrimers. cis-PtCl(2)L(2) was prepared from K(2)PtCl(4) in... |
11410373 | Canonical binding arrays as molecular recognition elements in the immune system: tetrahedral anions and the ester hydrolysis transition state. | The structures, obtained by X-ray crystallography, of the binding sites of catalytic antibodies raised to bind different phosphonates are compared. Although the amino acid sequences differ, all exhibit a tetrahedral array of hydrogen bond donors (a 'canonical binding array') complementary to the tetrahedral anion, whic... |
11408991 | Intravenous itraconazole. | <h4>Objective</h4>To review the pharmacology, mycology, chemistry, pharmacokinetics, efficacy, safety, tolerability, dosage, administration, and economic issues of intravenous itraconazole.<h4>Data sources</h4>A MEDLINE search from 1978 to June 2000 of the English-language literature and an extensive review of meeting ... |
11408588 | Sphingomyelin-enriched microdomains at the Golgi complex. | Sphingomyelin- and cholesterol-enriched microdomains can be isolated as detergent-resistant membranes from total cell extracts (total-DRM). It is generally believed that this total-DRM represents microdomains of the plasma membrane. Here we describe the purification and detailed characterization of microdomains from Go... |
11408580 | Distribution and transport of cholesterol in Caenorhabditis elegans. | Cholesterol transport is an essential process in all multicellular organisms. In this study we applied two recently developed approaches to investigate the distribution and molecular mechanisms of cholesterol transport in Caenorhabditis elegans. The distribution of cholesterol in living worms was studied by imaging its... |
11408573 | Lysosomal hydrolase mannose 6-phosphate uncovering enzyme resides in the trans-Golgi network. | A crucial step in lysosomal biogenesis is catalyzed by "uncovering" enzyme (UCE), which removes a covering N-acetylglucosamine from the mannose 6-phosphate (Man-6-P) recognition marker on lysosomal hydrolases. This study shows that UCE resides in the trans-Golgi network (TGN) and cycles between the TGN and plasma membr... |
11405755 | Toward globular macromolecules with functionalized interiors: design and synthesis of dendrons with an interesting twist. | [see reaction]. Design and synthesis of a novel class of monodendrons, in which the functional units can potentially be directed toward the concave interiors of dendrimers, are described. The key feature of the design is the placement of the amphiphilic and the AB2 functional groups in orthogonal planes. |
11405745 | Solid state NMR of a molecular self-assembly: multinuclear approach to the cyanuric acid-melamine system. | [see structure]. Trinuclear MAS NMR, involving naturally abundant (13C, 15N) and easily deuterated (2H) nuclei, is shown to offer newer opportunities to study molecular self-assembly in noncrystalline supramolecular systems. |
11405725 | Dithiane- and trithiane-based photolabile scaffolds for molecular recognition. | [see structure]. A modular synthetic approach to novel dithiane- and trithiane-based photolabile molecular hosts equipped with elements of molecular recognition is developed. The approach provides ready access to a family of amino-derivatized photocleavable molecular systems capable of hydrogen-bonding-based recognitio... |
11405723 | Digital communication through intermolecular fluorescence modulation. | [see reaction]. Ultraminiaturized processors incorporating molecular components can be developed only after devising efficient strategies to communicate signals at the molecular level. We have demonstrated that a three-state molecular switch responds to ultraviolet light, visible light, and H+, attenuating the emission... |
11405661 | Characterization of melanocortin NDP-MSH agonist peptide fragments at the mouse central and peripheral melanocortin receptors. | The central melanocortin receptors, melanocortin-4 (MC4R) and melanocortin-3 (MC3R), are involved in the regulation of satiety and energy homeostasis. The MC4R in particular has become a pharmaceutical industry drug target due to its direct involvement in the regulation of food intake and its potential therapeutic appl... |
11405646 | Adenosine analogues as selective inhibitors of glyceraldehyde-3-phosphate dehydrogenase of Trypanosomatidae via structure-based drug design. | In our continuation of the structure-based design of anti-trypanosomatid drugs, parasite-selective adenosine analogues were identified as low micromolar inhibitors of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Crystal structures of Trypanosoma brucei, Trypanosoma cruzi, Leishmania mexicana, and human GAPDH's pro... |
11406602 | A broad host range replicon with different requirements for replication initiation in three bacterial species. | Plasmid RK2 is unusual in its ability to replicate stably in a wide range of Gram-negative bacteria. The replication origin (oriV) and a plasmid-encoded initiation protein (TrfA; expressed as 33 and 44 kDa forms) are essential for RK2 replication. To examine initiation events in bacteria unrelated to Escherichia coli, ... |
11406583 | A switch in disulfide linkage during minicollagen assembly in Hydra nematocysts. | The smallest known collagens with only 14 Gly-X-Y repeats referred to as minicollagens are the main constituents of the capsule wall of nematocysts. These are explosive organelles found in Hydra, jellyfish, corals and other Cnidaria. Minicollagen-1 of Hydra recombinantly expressed in mammalian 293 cells contains disulf... |
11406579 | High-resolution AFM topographs of Rubrivivax gelatinosus light-harvesting complex LH2. | Light-harvesting complexes 2 (LH2) are the accessory antenna proteins in the bacterial photosynthetic apparatus and are built up of alphabeta-heterodimers containing three bacteriochlorophylls and one carotenoid each. We have used atomic force microscopy (AFM) to investigate reconstituted LH2 from Rubrivivax gelatinosu... |
11404605 | A stepwise surgical technique using the medial orbital floor as the key landmark in performing endoscopic sinus surgery. | <h4>Hypothesis</h4>The medial orbital floor (MOF) and adjacent bony ridge of the antrostomy, when combined with columellar measurements, are easily identifiable and consistent anatomic reference points from which critical orbital and skull base structures can be found during endoscopic sinus surgery.<h4>Methods</h4>Two... |
11403596 | Synthesis, aggregation, and adsorption phenomena of shape-persistent macrocycles with extraannular polyalkyl substituents. | The synthesis of shape-persistent macrocycles based on the phenyl-ethynyl backbone containing various extraannular alkyl side chains is described. Although compound solubility increases with increasing size of the side groups, decreasing the solvent polarity induces aggregation of the rings by nonspecific interactions.... |
11404352 | A histone deacetylation inhibitor and mutant promote colony-type switching of the human pathogen Candida albicans. | Most strains of Candida albicans undergo high frequency phenotypic switching. Strain WO-1 undergoes the white-opaque transition, which involves changes in colony and cellular morphology, gene expression, and virulence. We have hypothesized that the switch event involves heritable changes in chromatin structure. To test... |
11404316 | Defining cosQ, the site required for termination of bacteriophage lambda DNA packaging. | Bacteriophage lambda is a double-stranded DNA virus that processes concatemeric DNA into virion chromosomes by cutting at specific recognition sites termed cos. A cos is composed of three subsites: cosN, the nicking site; cosB, required for packaging initiation; and cosQ, required for termination of chromosome packagin... |
11403282 | Solid-phase microextraction using fused-silica fibers coated with sol-gel-derived hydroxy-crown ether. | A novel solid-phase microextraction (SPME) fiber containing hydroxydibenzo-14-crown-4 (OH-DB14C4)/hydroxy-terminated silicone oil (OH-TSO) was first prepared by a sol-gel method and investigated for the determination of phenols. The possible mechanism is discussed and confirmed by IR spectra. The coating has stable per... |
11402165 | The chloroplast gene ycf9 encodes a photosystem II (PSII) core subunit, PsbZ, that participates in PSII supramolecular architecture. | We have characterized the biochemical nature and the function of PsbZ, the protein product of a ubiquitous open reading frame, which is known as ycf9 in Chlamydomonas and ORF 62 in tobacco, that is present in chloroplast and cyanobacterial genomes. After raising specific antibodies to PsbZ from Chlamydomonas and tobacc... |
11402062 | Focal contacts as mechanosensors: externally applied local mechanical force induces growth of focal contacts by an mDia1-dependent and ROCK-independent mechanism. | The transition of cell-matrix adhesions from the initial punctate focal complexes into the mature elongated form, known as focal contacts, requires GTPase Rho activity. In particular, activation of myosin II-driven contractility by a Rho target known as Rho-associated kinase (ROCK) was shown to be essential for focal c... |
11401318 | Peroxisome proliferator-activated receptor gamma ligand-induced growth inhibition of human hepatocellular carcinoma. | Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been implicated in the growth inhibition and differentiation of certain human cancers with diverse tissue origin. In this study, expression of PPARgamma in human hepatocellular carcinoma (HCC) and the effect of PPARgamma ligands on HCC cells were... |
11399073 | Folding of beta-sheets in membranes: specificity and promiscuity in peptide model systems. | The interactions that drive the folding of beta-barrel membrane proteins have not been well studied because there have been few available model systems for membrane beta-sheets. In this work, we expand on a recently described model system to explore the contributions of interstrand hydrogen bonds, side-chain/side-chain... |
11399072 | Ligand-induced structural changes to maltodextrin-binding protein as studied by solution NMR spectroscopy. | Solution NMR studies on the physiologically relevant ligand-free and maltotriose-bound states of maltodextrin-binding protein (MBP) are presented. Together with existing data on MBP in complex with beta-cyclodextrin (non-physiological, inactive ligand), these new results provide valuable information on changes in local... |
11399195 | Coordination chemistry of Rh(III) porphyrins: complexes with hydrazine, disulfide, and diselenide bridging ligands. | Rh(III) porphyrin complexes with bridging hydrazine and substituted hydrazine ligands were characterized in solution by (1)H NMR spectroscopy and in the solid state by X-ray diffraction. Addition of further ligand to these species afforded 1:1 complexes in which methylhydrazine and N,N-dimethylhydrazine preferentially ... |
11399187 | Self-assembly organometallic squares with terpyridyl metal complexes as bridging ligands. | A series of novel heterometallic square complexes with the general molecular formulas [fac-Br(CO)(3)Re[mu-(pyterpy)(2)M]](4)(PF(6))(8) and [(dppf)Pd[mu-(pyterpy)(2)Ru]](4)(PF(6))(8)(OTf(8) (4), where M = Fe (1), Ru (2), or Os (3), pyterpy is 4'-(4' "-pyridyl)-2,2':6',2' '-terpyridine, dppf = 1,1'-bis(diphenylphosphino)... |
11399184 | Oxamato-bridged trinuclear Ni(II)Cu(II)Ni(II) complexes with irregular spin state structures and a binuclear Ni(II)Cu(II) complex with an unusual supramolecular structure: crystal structure and magnetic properties. | Four oxamato-bridged heterotrinuclear Ni(II)Cu(II)Ni(II) complexes of formula ([Ni(bispictn)](2)Cu(pba))(ClO(4))(2).2.5H(2)O (1), ([Ni(bispictn)](2)Cu(pbaOH))(ClO(4))(2).H(2)O (2), ([Ni(cth)](2)Cu(pba))(ClO(4))(2) (3), and ([Ni(cth)](2)Cu(opba))(ClO(4))(2).H(2)O (4) and a binuclear Ni(II)Cu(II) complex of formula [Cu(o... |
11399175 | Synthesis, characterization, and magnetic properties of self-assembled compounds based on discrete homotrinuclear complexes of Cu(II). | Three new supramolecular entities of Cu(II) were synthesized and characterized: [(Cu(H(2)O)(tmen))(2)(mu-Cu(H(2)O)(opba))](2)[(ClO(4))(2)](2).2H(2)O (1), [(Cu(H(2)O)(tmen))(2) (mu-Cu(H(2)O) (Me(2)pba))](2)[(ClO(4))(2)](2) (2), and [(Cu(H(2)O)(tmen))(Cu(tmen))(mu-Cu(OHpba))](n)() ((ClO(4))(2))(n)().nH(2)O (3), where opb... |
11399162 | Protonation and Zn(II) coordination by dipyridine-containing macrocycles with different molecular architecture. A case of pH-controlled metal jumping outside-inside the macrocyclic cavity. | The synthesis of the macrocyclic ligand 4,4'-(2,5,8,11,14-pentaaza[15])-2,2'-bipyridylophane (L3), which contains a pentaamine chain linking the 4,4'-positions of a 2,2'-dipyridine moiety, is reported. Protonation and Zn(II) complexation by L3 and by macrocycle L2, containing the same pentaamine chain connecting the 6,... |
11399161 | Metal- and ligand-centered monoelectronic oxidation of mu-nitrido[((tetraphenylporphyrinato)manganese)phthalocyaninatoiron)], [(TPP)Mn-N-FePc]. X-ray crystal structure of the Fe(IV)-containing species [(THF)(TPP)Mn-N-FePc(H(2)O)](I(5))02THF. | The reaction of mu-nitrido[((tetraphenylporphyrinato)manganese)(phthalocyaninatoiron)], [(TPP)Mn-N-FePc], with I(2) in THF develops with the formation of two different species, i.e., [(THF)(TPP)Mn-N-FePc(H(2)O)](I(5)).2THF (I) and [(TPP)Mn(IV)-N-Fe(III)Pc](I(3)) (II). On the basis of single-crystal X-ray work and Mössb... |
11399662 | Influence of the 5-HT(2C) receptor antagonist SB242,084 on behaviour produced by the 5-HT(2) agonist Ro60-0175 and the indirect 5-HT agonist dexfenfluramine. | Ro60-0175 has been described as a selective agonist at the 5-HT(2C) receptor, yet it has only 10- fold higher affinity at the 5-HT(2C) compared to the 5-HT(2A) subtype, and equivalent affinity for the 5-HT(2B) receptor. The selective 5-HT(2C) receptor antagonist SB242,084 (0.5 mg kg(-1) i.p.), blocked the hypoactivity ... |
11397183 | Effect of beta-cyclodextrin on the hydrolysis of trifluoroacetate esters. | The hydrolysis of p-F, p-Cl, and m-Cl phenyl trifluoracetates was studied in the presence of beta-cyclodextrin (beta-CD). The reactions are inhibited by beta-CD at pH 6 while they are catalyzed in alkaline solution. MM3 calculations reproduce some of the experimental results. The substrates form inclusion complexes wit... |
11397182 | Reductive electrochemistry of spiromethanofullerenes. | The synthesis and electrochemical properties of spiromethanofullerenes 1-6 are described. The syntheses were achieved via the diazomethane route, and the regioisomeric distribution of bis-adducts 3 was determined by (1)H NMR, UV-vis, and HPLC analysis. The electrochemistry of these compounds in dichloromethane exhibits... |
11397150 | Synthesis and properties of a twistophane ion sensor: a new conjugated macrocyclic ligand for the spectroscopic detection of metal ions. | The synthesis of a structurally new type of conjugated macrocyclic ligand (1) is reported that comprises a dehydroannulene framework incorporating two 2,2'-bipyridine units. Modeling studies showed the ligand to possess an unusual chirally twisted and relatively rigid architecture capable of binding metal ions in an en... |
11397084 | Sequence-specific recognition of DNA in the nucleosome by pyrrole-imidazole polyamides. | The ability of DNA-binding proteins to recognize their cognate sites in chromatin is restricted by the structure and dynamics of nucleosomal DNA, and by the translational and rotational positioning of the histone octamer. Here, we use six different pyrrole-imidazole polyamides as sequence-specific molecular probes for ... |
11396942 | Constitutive activation of A(3) adenosine receptors by site-directed mutagenesis. | The objective of this study was to create constitutively active mutant human A(3) adenosine receptors (ARs) using single amino acid replacements, based on findings from other G protein-coupled receptors. A(3) ARs mutated in transmembrane helical domains (TMs) 1, 3, 6, and 7 were expressed in COS-7 cells and subjected t... |
11397701 | Polylysine as a vehicle for extracellular matrix-targeted local drug delivery, providing high accumulation and long-term retention within the vascular wall. | We present the first steps in the elaboration of an approach of extracellular matrix-targeted local drug delivery (ECM-LDD), designed to provide a high concentration, ubiquitous distribution, and long-term retention of a drug within the vessel wall after local intravascular delivery. The approach is based on the concep... |
11395764 | Self-assembly of regular hollow icosahedra in salt-free catanionic solutions. | Self-assembled structures having a regular hollow icosahedral form (such as those observed for proteins of virus capsids) can occur as a result of biomineralization processes, but are extremely rare in mineral crystallites. Compact icosahedra made from a boron oxide have been reported, but equivalent structures made of... |
11395595 | An enhanced fibrinolysis prevents the development of multiple organ failure in disseminated intravascular coagulation in spite of much activation of blood coagulation. | <h4>Objectives</h4>To investigate the relationship between fibrinolytic enhancement and the development of multiple organ failure (MOF) in disseminated intravascular coagulation (DIC). To detect the useful prognostic index for outcome in DIC.<h4>Design</h4>Case-control study.<h4>Setting</h4>A department of internal med... |
11395575 | Treatment of drug-resistant human neuroblastoma cells with cyclodextrin inclusion complexes of aphidicolin. | Treatment failure in most neuroblastoma (NB) patients is related to primary and/or acquired resistance to conventional chemotherapeutic agents. Aphidicolin (APH), a tetracyclic diterpene, exhibits specific cytotoxic action against NB cells. The purpose of this study was to compare antitumoral efficacy of APH in parenta... |
11395373 | Involvement of the receptor for formylated peptides in the in vivo anti-migratory actions of annexin 1 and its mimetics. | An innovative avenue for anti-inflammatory therapy is inhibition of neutrophil extravasation by potentiating the action of endogenous anti-inflammatory mediators. The glucocorticoid-inducible protein annexin 1 and derived peptides are effective in inhibiting neutrophil extravasation. Here we tested the hypothesis that ... |
11391002 | Kinetics and thermodynamics of T cell receptor- autoantigen interactions in murine experimental autoimmune encephalomyelitis. | In the current study, cellular and molecular approaches have been used to analyze the biophysical nature of T cell receptor (TCR)-peptide MHC (pMHC) interactions for two autoreactive TCRs. These two TCRs recognize the N-terminal epitope of myelin basic protein (MBP1-11) bound to the MHC class II protein, I-A(u), and ar... |
11390443 | Cutting edge: lipid raft integrity affects the efficiency of MHC class I tetramer binding and cell surface TCR arrangement on CD8+ T cells. | Physically distinct cholesterol/sphingolipid-rich plasma membrane microdomains, so-called lipid rafts, have been recognized to play an important regulatory role in various cellular processes, from membrane trafficking to signal transduction, in a number of cell types. We report here that the ability of TCR on activated... |
11389622 | A triangle-square equilibrium of metallosupramolecular assemblies based on pd(II) and pt(II) corners and diazadibenzoperylene bridging ligands. | Tetraaryloxy-substituted diazadibenzoperylene bridging ligands 1a,b were employed in transition metal-directed self-assembly with Pd(II) and Pt(II) phosphane triflates 2a,b which resulted in complex dynamic equilibria between molecular triangles 3a-d and molecular squares 4a-d in solution. Characterization of the equil... |
11389716 | HMG-1 enhances HMG-I/Y binding to an A/T-rich enhancer element from the pea plastocyanin gene. | High-mobility-group proteins HMG-1 and HMG-I/Y bind at overlapping sites within the A/T-rich enhancer element of the pea plastocyanin gene. Competition binding experiments revealed that HMG-1 enhanced the binding of HMG-I/Y to a 31-bp region (P31) of the enhancer. Circularization assays showed that HMG-1, but not HMG-I... |
11389693 | Cholesterol-dependent interaction of syncollin with the membrane of the pancreatic zymogen granule. | Syncollin is a protein of the pancreatic zymogen granule that was isolated through its ability to bind to syntaxin. Despite this in vitro interaction, it is now clear that syncollin is present on the luminal side of the zymogen granule membrane. Here we show that there are two pools of syncollin within the zymogen gran... |
11389686 | Identification of novel beta-mannan- and beta-glucan-binding modules: evidence for a superfamily of carbohydrate-binding modules. | Many glycoside hydrolases, which degrade long-chain carbohydrate polymers, possess distinct catalytic modules and non-catalytic carbohydrate-binding modules (CBMs). On the basis of conserved protein secondary structure, we describe here the identification and experimental characterization of novel type of mannanase-ass... |
11389682 | Reducible cationic lipids for gene transfer. | One of the main challenges of gene therapy remains the increase of gene delivery into eukaryotic cells. We tested whether intracellular DNA release, an essential step for gene transfer, could be facilitated by using reducible cationic DNA-delivery vectors. For this purpose, plasmid DNA was complexed with cationic lipid... |
11388794 | Expression and purification of monospecific and bispecific recombinant antibody fragments derived from antibodies that block the CD80/CD86-CD28 costimulatory pathway. | The development of recombinant techniques for rapid cloning, expression, and characterization of cDNAs encoding antibody (Ab) subunits has revolutionized the field of antibody engineering. By fusion to heterologous protein domains, chain shuffling, or inclusion of self-assembly motifs, novel molecules such as bispecifi... |
11389467 | The junction-resolving enzymes. | Junction-resolving enzymes are ubiquitous nucleases that are important for DNA repair and recombination and act on DNA molecules containing branch points, especially four-way junctions. They show a pronounced selectivity for the structure of the DNA substrate but, despite its importance, the structural selectivity is n... |
11388899 | Detergent-resistant membrane domains are required for mast cell activation but dispensable for tyrosine phosphorylation upon aggregation of the high affinity receptor for IgE. | Aggregation of the high affinity receptor for IgE (FceRI) on mast cells results in the rapid phosphorylation of tyrosines on the beta and gamma chains of the receptor by the Src family kinase Lyn, which initiates the signaling cascades leading to secretion of inflammatory mediators. The detergent-resistant membranes (D... |
11387007 | Avoidance of abdominal compartment syndrome in damage-control laparotomy after trauma. | <h4>Hypothesis</h4>Abdominal compartment syndrome (ACS) is a morbid complication of damage-control laparotomy. Moreover, the technique of abdominal closure influences the frequency of ACS.<h4>Design</h4>Retrospective cohort study.<h4>Setting</h4>Urban level I trauma center.<h4>Patients</h4>We studied 52 patients with t... |
11384856 | Improvement of water solubility of sulfamethizole through its complexation with beta- and hydroxypropyl-beta-cyclodextrin. Characterization of the interaction in solution and in solid state. | The aim of this study was to increase the solubility of sulfamethizole in water by complexing it with beta-cyclodextrin (BCD) and hydroxypropyl-beta-cyclodextrin (HPBCD). The interaction of sulfamethizole with the cyclodextrins was evaluated by the solubility, 1H NMR spectrometry and molecular modelling. The stability ... |
11384851 | Liposomes encapsulating prednisolone and prednisolone-cyclodextrin complexes: comparison of membrane integrity and drug release. | Inclusion complexes of prednisolone (PR) with beta-cyclodextrin (beta-CD) and hydropropyl-beta-cyclodextrin (HPbeta-CD) were formed by the solvation method, and were characterized by DSC, X-ray diffractometry and FT-IR spectroscopy. PC liposomes incorporating PR as plain drug or inclusion complex were prepared using th... |
11384849 | Molecular modeling study of beta- and gamma-cyclodextrin complexes with miconazole. | Different authors have demonstrated the inclusion of miconazole in cyclodextrins (CD). Miconazole can be included in the CD cavity both in the neutral and in the ionized form. The present study tries to understand which fragment of the miconazole molecule is involved in the inclusion. Austin Model 1 approximate molecul... |
11382808 | Inactivation of BK channels mediated by the NH(2) terminus of the beta3b auxiliary subunit involves a two-step mechanism: possible separation of binding and blockade. | A family of auxiliary beta subunits coassemble with Slo alpha subunit to form Ca(2)+-regulated, voltage-activated BK-type K(+) channels. The beta subunits play an important role in regulating the functional properties of the resulting channel protein, including apparent Ca(2)+ dependence and inactivation. The beta3b au... |
11381104 | Cytokinesis in prokaryotes and eukaryotes: common principles and different solutions. | Cytokinesis requires duplication of cellular structures followed by bipolarization of the predivisional cell. As a common principle, this applies to prokaryotes as well as eukaryotes. With respect to eukaryotes, the discussion has focused mainly on Saccharomyces cerevisiae and on Schizosaccharomyces pombe. Escherichia ... |
11381102 | Phi29 family of phages. | Continuous research spanning more than three decades has made the Bacillus bacteriophage phi29 a paradigm for several molecular mechanisms of general biological processes, such as DNA replication, regulation of transcription, phage morphogenesis, and phage DNA packaging. The genome of bacteriophage phi29 consists of a ... |
11381101 | Tetracycline antibiotics: mode of action, applications, molecular biology, and epidemiology of bacterial resistance. | Tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. They are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy o... |
11380251 | Calcium-dependent conformation of a heme and fingerprint peptide of the diheme cytochrome c peroxidase from Paracoccus pantotrophus. | The structural changes in the heme macrocycle and substituents caused by binding of Ca(2+) to the diheme cytochrome c peroxidase from Paracoccus pantotrophus were clarified by resonance Raman spectroscopy of the inactive fully oxidized form of the enzyme. The changes in the macrocycle vibrational modes are consistent w... |
11377020 | LC determination of the enantiomeric purity of levamisole using stationary phase with bonded naphthylethylcarbamoylated-beta-cyclodextrin. | A direct enantioselective high-performance liquid chromatography was employed successfully for determination of the enantiomeric purity of levamisole. The elaborated method used S-naphthylethylcarbamoylated beta-cyclodextrin stationary phase in reversed-phase mode. The optimized mobile phase composition was acetonitril... |
11378859 | A flow cytometry technique for measuring chromosome-mediated gene transfer. | <h4>Background</h4>Using artificial chromosome expression systems (ACes), we have developed a unique and rapid screening technique to quantify delivery of foreign DNA into cells in vitro. Delivery was measured within 24 h after transfection, using flow cytometry to detect the transfer of ACes labeled with thymidine ana... |
11376632 | Alteration of plasmalemmal caveolae mimics endothelial dysfunction observed in atheromatous rabbit aorta. | <h4>Objective</h4>In endothelial cells, nitric oxide (NO) is produced by the endothelial isoform of nitric oxide synthase (eNOS), which is localized in the cholesterol-rich plasmalemmal microdomains involved in signal transduction, known as caveolae. The present study was undertaken to evaluate the effect of hyperchole... |
11376144 | Triple-helix formation in the antiparallel binding motif of oligodeoxynucleotides containing N(9)- and N(7)-2-aminopurine deoxynucleosides. | Triplex-forming oligodeoxynucleotide 15mers, designed to bind in the antiparallel triple-helical binding motif, containing single substitutions (Z) of the four isomeric alphaN(7)-, betaN(7)-, alphaN(9)- and betaN(9)-2-aminopurine (ap)-deoxyribonucleosides were prepared. Their association with double-stranded DNA target... |
11375705 | Ion pair cooperative binding of potassium salts by new rhenium(I) bipyridine crown ether receptors. | The new rhenium(I) bipyridine crown ether receptors 1-4 have been prepared and their ion pair recognition properties examined. The crystal structure of [1.KCl](2).2H(2)O demonstrates that potassium is coordinated by benzo-18-crown-6 and chloride is hydrogen bonded to the amide groups. Receptor 3 extracts solid KCl and ... |
11375690 | Lanthanide coordination with alpha-amino acids under near physiological pH conditions: polymetallic complexes containing the cubane-like [Ln4(mu3-OH)4]8+ cluster core. | Tetranuclear lanthanide-hydroxo complexes of the general formula [Ln(4)(mu(3)-OH)(4)(AA)(x)(H(2)O)(y)](8+) (1, Ln = Sm, AA = Gly, x = 5, y = 11; 2, Ln = Nd, AA = Ala, x = 6, y = 10; 3, Ln = Er, AA = Val, x = 5, y = 10) have been prepared by alpha-amino acid controlled hydrolysis of lanthanide ions under near physiologi... |
11375025 | Cavitand zn(II)-porphyrin capsules with high affinities for pyridines and N-methylimidazole. | Covalent cavitand Zn(II)-porphyrins 17-20 were prepared via multistep syntheses. These host molecules show moderate to excellent binding affinities to N-methylimidazole and pyridine guests. The complexing behavior strongly depends on the spacer's length, number, and rigidity, in addition to the guest size. Cavitand cap... |
11375012 | Carbon networks based on dehydrobenzoannulenes. 4. Synthesis of "star" and "trefoil" graphdiyne substructures via sixfold cross-coupling of hexaiodobenzene. | The synthesis and characterization of star- and trefoil-shaped polyethynyl aromatic structures, which represent model substructures of the all-carbon network graphdiyne, are described. Assembly of these macrocycles is accomplished via 6-fold Sonogashira cross-coupling of hexaiodobenzene using Pd[P(o-Tol)(3)](2) and CuI... |
11375262 | Regional haemodynamic responses to the cannabinoid agonist, WIN 55212-2, in conscious, normotensive rats, and in hypertensive, transgenic rats. | Regional haemodynamic responses to the cannabinoid agonist, WIN 55212-2 (5 - 250 microg kg(-1) i.v.) were assessed in conscious, normotensive, Hannover, Sprague-Dawley (HSD) rats, and in hypertensive, transgenic ((mRen-2)27) (abbreviated to TG) rats. In HSD rats, WIN 55212-2 caused pressor, and renal and mesenteric vas... |
11373617 | Supramolecular assembly and acid resistance of Helicobacter pylori urease. | Helicobacter pylori, an etiologic agent in a variety of gastroduodenal diseases, produces a large amount of urease, which is believed to neutralize gastric acid by producing ammonia for the survival of the bacteria. Up to 30% of the enzyme associates with the surface of intact cells upon lysis of neighboring bacteria. ... |
11371161 | The protein capsid of filamentous bacteriophage PH75 from Thermus thermophilus. | The PH75 strain of filamentous bacteriophage (Inovirus) grows in the thermophilic bacterium Thermus thermophilus at 70 degrees C. We have characterized the viral DNA and determined the amino acid sequence of the major coat protein, p8. The p8 protein is synthesized without a leader sequence, like that of bacteriophage ... |
11371468 | Visualization and tracking of single protein molecules in the cell nucleus. | A recently developed laser fluorescence videomicroscopy method was used to determine for the first time the intranuclear trajectories of single protein molecules. Using the recombinant Escherichia coli beta-galactosidase protein P4K, labeled with an average of 4.6 ALEXA 488 chromophores per tetramer, single P4K molecul... |
11371463 | Plasticity in protein-peptide recognition: crystal structures of two different peptides bound to concanavalin A. | The structures of concanavalin A (ConA) in complex with two carbohydrate-mimicking peptides, 10-mer (MYWYPYASGS) and 15-mer (RVWYPYGSYLTASGS) have been determined at 2.75 A resolution. In both crystal structures four independent peptide molecules bind to each of the crystallographically independent subunits of ConA tet... |
11371462 | Detergents as probes of hydrophobic binding cavities in serum albumin and other water-soluble proteins. | As an extension of our studies on the interaction of detergents with membranes and membrane proteins, we have investigated their binding to water-soluble proteins. Anionic aliphatic compounds (dodecanoate and dodecylsulfate) were bound to serum albumin with high affinity at nine sites; related nonionic detergents (C12E... |
11371460 | High-resolution probing of local conformational changes in proteins by the use of multiple labeling: unfolding and self-assembly of human carbonic anhydrase II monitored by spin, fluorescent, and chemical reactivity probes. | Two different spin labels, N-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolidinyl)iodoacetamide (IPSL) and (1-oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate (MTSSL), and two different fluorescent labels 5-((((2-iodoacetyl)amino)-ethyl)amino)naphtalene-1-sulfonic acid (IAEDANS) and 6-bromoacetyl-2-dimetylaminona... |
11369864 | Interaction energies between beta-lactam antibiotics and E. coli penicillin-binding protein 5 by reversible thermal denaturation. | Penicillin-binding proteins (PBPs) catalyze the final stages of bacterial cell wall biosynthesis. PBPs form stable covalent complexes with beta-lactam antibiotics, leading to PBP inactivation and ultimately cell death. To understand more clearly how PBPs recognize beta-lactam antibiotics, it is important to know their ... |
11369853 | Structure of a malaria parasite antigenic determinant displayed on filamentous bacteriophage determined by NMR spectroscopy: implications for the structure of continuous peptide epitopes of proteins. | The NANP repeating sequence of the circumsporozoite protein of Plasmodium falciparum was displayed on the surface of fd filamentous bacteriophage as a 12-residue insert (NANP)(3) in the N-terminal region of the major coat protein (pVIII). The structure of the epitope determined by multidimensional solution NMR spectros... |
11370023 | Supramolecular chirality induction in bis(zinc porphyrin) by amino acid derivatives: rationalization and applications of the ligand bulkiness effect. | The achiral syn conformer (face-to-face) of the ethane-bridged bis(zinc porphyrin) (syn-ZnD) transforms into the corresponding chiral extended anti bis-ligated species (anti-ZnD.L2) in the presence of enantiopure ligands (L: amino acid derivatives). The mechanism of the supramolecular chirality induction is based on ch... |
11370017 | Chiral separation of pheniramine-like 3-phenyl-3-heteroarylpropylamines by CE and HPLC methods. | Analytical CE and HPLC methods were developed for the chiral separation of halogen-substituted 3-phenyl-3-(2-pyridyl)propylamines 1-4 (1: 3-(4-fluorophenyl) approximately, 2: 3-(3,4-difluorophenyl) approximately, 3: 3-(4-chlorophenyl) approximately, 4: 3-(3,4-dichlorophenyl) approximately ), 3-(4-fluorophenyl)-3-(2-thi... |
11368796 | Intracellular energetic units in red muscle cells. | The kinetics of regulation of mitochondrial respiration by endogenous and exogenous ADP in muscle cells in situ was studied in skinned cardiac and skeletal muscle fibres. Endogenous ADP production was initiated by addition of MgATP; under these conditions the respiration rate and ADP concentration in the medium were de... |
11368785 | Modifications of eukaryotic initiation factor 4F (eIF4F) in adult cardiocytes by adenoviral gene transfer: differential effects on eIF4F activity and total protein synthesis rates. | In adult feline cardiocytes, increases in eukaryotic initiation factor 4F (eIF4F) activity are correlated with accelerated rates of total protein synthesis produced in response to increased load. Adenoviral gene transfer was employed to increase either eIF4F complex formation or the phosphorylation of eIF4E on Ser-209.... |
11368512 | Maintenance of quaternary structure in the frozen state stabilizes lactate dehydrogenase during freeze-drying. | Sugars inhibit protein unfolding during the drying step of lyophilization by replacing hydrogen bonds to the protein lost upon removal of water. In many cases, polymers fail to inhibit dehydration-induced damage to proteins because steric hindrance prevents effective hydrogen bonding of the polymer to the protein's sur... |
11359912 | Phospholipase D activity is required for actin stress fiber formation in fibroblasts. | Phospholipase D (PLD) is a ubiquitously expressed enzyme of ill-defined function. In order to explore its cellular actions, we inactivated the rat PLD1 (rPLD1) isozyme by tagging its C terminus with a V5 epitope (rPLD1-V5). This was stably expressed in Rat-2 fibroblasts to see if it acted as a dominant-negative mutant ... |
11356972 | Membrane-fusing capacity of the human immunodeficiency virus envelope proteins determines the efficiency of CD+ T-cell depletion in macaques infected by a simian-human immunodeficiency virus. | The mechanism of the progressive loss of CD4+ T lymphocytes, which underlies the development of AIDS in human immunodeficiency virus (HIV-1)-infected individuals, is unknown. Animal models, such as the infection of Old World monkeys by simian-human immunodeficiency virus (SHIV) chimerae, can assist studies of HIV-1 pat... |
11356970 | Adaptation of tick-borne encephalitis virus to BHK-21 cells results in the formation of multiple heparan sulfate binding sites in the envelope protein and attenuation in vivo. | Propagation of the flavivirus tick-borne encephalitis virus in BHK-21 cells selected for mutations within the large surface glycoprotein E that increased the net positive charge of the protein. In the course of 16 independent experiments, 12 different protein E mutation patterns were identified. These were located in a... |
11357177 | Stoichiometric and microenvironmental effects on hydrolysis of propantheline and oxyphenonium bromides in cyclodextrin solutions. | The effects of alpha-, beta-, and gamma-cyclodextrins (CDs) on the basic hydrolysis of propantheline bromide (PB) and oxyphenonium bromide (OB) are analyzed in terms of the stoichiometry and microenvironments of their complexes. The rate constant of each species is evaluated with binding constant data for the 1:1, 1:2,... |
11357172 | Comparative studies of the enhancing effects of cyclodextrins on the solubility and oral bioavailability of tacrolimus in rats. | The enhancing effects of cyclodextrins (CyDs) on the solubility, the dissolution rate, and the bioavailability of tacrolimus after oral administration to rats were examined and compared with those after administration of a PROGRAF capsule containing the solid dispersion formulation of tacrolimus. Here we used natural C... |
11356383 | Preservation and detection of lesion-induced collagenous scar in the CNS depend on the method of tissue processing. | After traumatic injury, adult central nervous system (CNS) axons fail to regenerate. We have previously shown that one major impediment for axon regeneration is the basement membrane (BM) forming at the lesion center, by means of a wound healing collagenous scar, after lesioning the postcommisural fornix of the adult r... |
11344152 | Regulation of expression of the vanD glycopeptide resistance gene cluster from Enterococcus faecium BM4339. | A new open reading frame, encoding a putative integrase-like protein, was detected downstream from the six genes of the vanD glycopeptide resistance cluster in Enterococcus faecium BM4339 (B. Casadewall and P. Courvalin, J. Bacteriol. 181:3644-3648, 1999). In this cluster, genes coding for the VanR(D)-VanS(D) two-compo... |
11340164 | Tissue-specific transgenic knockdown of Fos-related antigen 2 (Fra-2) expression mediated by dominant negative Fra-2. | Fos-related antigen 2 (Fra-2) is a member of the Fos family of immediate-early genes, most of which are rapidly induced by second messengers. All members of this family act by binding to AP-1 sites as heterodimeric complexes with other proteins. However, each appears to have a distinct role. The role and biology of Fra... |
11333906 | Autostimulation of the Epstein-Barr virus BRLF1 promoter is mediated through consensus Sp1 and Sp3 binding sites. | As an essential step in the lytic cascade, the Rta homologues of gammaherpesviruses all activate their own expression. Consistent with this biologic function, the Epstein-Barr virus (EBV) Rta protein powerfully stimulates the promoter of its own gene, Rp, in EBV-positive B cells in transient-transfection reporter-based... |
11333043 | Biotransformation of cholesterol using Lactobacillus bulgaricus in a glucose-controlled bioreactor. | A novel single-step microbial transformation process for the production of testosterone from cholestrol by Lactobacillus bulgaricus in an aerated fermenter was investigated. The metabolism of glucose possibly supplying reducing power as NADH was necessary for the reduction of androst-4-en-3,17-dione (AD) to testosteron... |
11285557 | Controlled proteolysis of amelogenins reveals exposure of both carboxy- and amino-terminal regions. | The matrix-mediated enamel biomineralization involves secretion of the enamel specific amelogenin proteins that through self-assembly into nanosphere structures provide the framework within which the initial enamel crystallites are formed. During enamel mineralization, amelogenin proteins are processed by tooth-specifi... |
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