id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
10741960 | Isolating the spectroscopic signature of a hydration shell with the use of clusters: superoxide tetrahydrate | Cluster spectroscopy, aided by ab initio theory, was used to determine the detailed structure of a complete hydration shell around an anion. Infrared spectra of size-selected O(2)-. (H(2)O)(n) (n = 1 to 4) cluster ions were obtained by photoevaporation of an argon nanomatrix. Four water molecules are required to comple... |
10740878 | Permeation liquid membrane metal transport: studies of complex stoichiometries and reactions in Cu(II) extraction with the mixture 22DD-laurate in toluene/phenylhexane | The role of lauric acid (LAH) in the transport of copper(II) through a permeation liquid membrane (PLM) comprising 1,10-didecyldiaza-18-crown-6 (22DD) and lauric acid (ratio 1:1) in 1:1 v/v toluene/phenylhexane has been investigated by determining the stoichiometry of metal extraction and of the metal complex formed in... |
10740868 | Degree of solute inclusion in native beta-cyclodextrin: chromatographic approach | The reversed-phase liquid chromatography retention and separation of a series of D,L dansyl amino acids were investigated over a wide range of salting-out agent (sucrose) concentrations using native beta-cyclodextrin as a chiral stationary phase. An original treatment was developed to determine the number of sucrose mo... |
10739193 | Multilayered assembly of dendrimers with enzymes on gold: thickness-controlled biosensing interface | A new approach to construct a multilayered enzyme film on the Au surface for use as a biosensing interface is described. The film was prepared by alternate layer-by-layer depositions of G4 poly(amidoamine) dendrimers and periodate-oxidized glucose oxidase (GOx). The cyclic voltammograms obtained from the Au electrodes ... |
10732446 | On the photochromism of spiro | The recently synthesized spiro[cyclohexadiene-dihydroacridines] consisting of perpendicularly arranged aroylcyclohexadiene and N-methyl-dihydroacridine moieties were found to have photochromic properties. The reversible photoisomerization from the spiro compound toward a colored merocyanine caused by C-C bond cleavage ... |
12541606 | [Synthesis and application of sulfonated beta-cyclodextrins as chiral additives in capillary electrophoresis]. | Three new kinds of the sodium salt of sulfonated beta-cyclodextrins with different degrees of substitution were synthesized and characterized. A simple synthesis method was employed by direct sulfonating reaction with concentrated sulfuric acid. Sulfonated beta-cyclodextrins were used as chiral resolving agents for the... |
12541593 | [Enantiomeric separation of N-FMOC amino acids with sulfobutyl ether-beta-cyclodextrin as chiral additive by capillary electrokinetic chromatography]. | Enantiomeric separation of N-FMOC amino acids by capillary electrophoresis with an anionic chiral resolving agent, sulfobutyl ether-beta-cyclodextrin (SBE-beta-CD) with average substitution degree of 3.8, employed as chiral additive was studied. Chiral separation was achieved with the mode of electrokinetic chromatogra... |
12526405 | Pd(II) complexes with polydentate nitrogen ligands. Molecular recognition and dynamic behavior involving Pd-N bond rupture. X-ray molecular structures of [[Pd(C6HF4)2](bpzpm)] and [[Pd(eta 3-C4H7)]2(bpzpm)] (CF3SO3)2 [bpzpm = 4,6-bis(pyrazol-1-yl)pyrimidine]. | The ligands 4,6-bis(pyrazol-1-yl)pyrimidine (bpzpm) and 4,6-bis(4-methylpyrazol-1-yl)pyrimidine (Me-bpzpm) were synthesized and their reactions with some palladium derivatives explored. Mononuclear or dinuclear neutral or cationic complexes were obtained by reaction of the ligands with 1 or 2 equiv of Pd(C6XF4)2(cod) (... |
12526393 | Microcalorimetric determination of thermodynamic parameters for ionophore-siderophore host-guest complex formation. | Thermodynamic parameters (delta H, delta S, and delta G) were determined by microcalorimetry in wet chloroform for host-guest assembly formation involving second-sphere complexation of the siderophore ferrioxamine B by crown ether (18-crown-6, cis-dicyclohexano-18-crown-6, benzo-18-crown-6) and cryptand (2.2.2 cryptand... |
12526391 | From simple trans-[a2Pt(2-hydroxypyrimidine)2]2+ (a = NH3, CH3NH2) complexes to structures of higher complexity. Molecular recognition of 2-aminopyrimidine by hydrogen bond formation and reactivity toward additional metal ions. | The new complexes trans-[a2Pt(Hpymo-N1)2]X2 (a = NH3, X = NO3 (1a); a = CH3NH2, X = NO3 (1b); a = CH3NH2, X = ClO4 (1c); Hpymo = 2-hydroxypyrimidine) have been prepared by reaction of trans-[a2Pt(H2O)2]-X2 with 2-hydroxypyrimidine at 80 degrees C in water. Complex 1c cocrystallizes in water with 2-aminopyrimidine (ampy... |
12526375 | Xanthene-bridged cofacial bisporphyrins. | The synthesis and characterization of cofacial bisporphyrins juxtaposed by xanthene-bridged pillars are presented. The one-pot preparation of the xanthene dialdehyde avoids the lengthy bridge synthesis accompanying other cofacial porphyrin systems, thus allowing for the facile preparation of homobimetallic zinc (10), c... |
12526365 | Structural, spectroscopic, and electrochemical studies of binuclear manganese(II) complexes of bis(pentadentate) ligands derived from bis(1,4,7-triazacyclononane) macrocycles. | Structural, electrochemical, ESR, and H2O2 reactivity studies are reported for [Mn(dmptacn)Cl]ClO4 (1, dmptacn = 1,4-bis(2-pyridylmethyl)-1,4,7-triazacyclononane) and binuclear complexes of bis(pentadentate) ligands, generated by attaching 2-pyridylmethyl arms to each secondary nitrogen in bis(1,4,7-triazacyclononane) ... |
12526364 | Magnetic interactions in the high-spin iron(III) oxooctaethylchlorinato derivative [Fe(oxoOEC)(Cl)] and its pi-cation radical [Fe(oxoOEC.)(Cl)]SbCl6. | The preparation and characterization of the beta-oxochlorin derivative [3,3,7,8,12,13,17,18-octaethyl-(3H)-porphin-2-onato(2-)]iron(III) chloride, [Fe(oxoOEC)(Cl)], and its pi-cation radical derivative [Fe(oxoOEC.)(Cl)]SbCl6 is described. Both compounds have been characterized by single-crystal X-ray structure determin... |
11201790 | Signaling through sphingolipid microdomains of the plasma membrane: the concept of signaling platform. | Transmembrane signaling requires modular interactions between signaling proteins, phosphorylation or dephosphorylation of the interacting protein partners and temporary elaboration of supramolecular structures, to convey the molecular information from the cell surface to the nucleus. Such signaling complexes at the pla... |
10965493 | Human breast carcinoma cells express type II IL-4 receptors and are sensitive to antitumor activity of a chimeric IL-4-Pseudomonas exotoxin fusion protein in vitro and in vivo. | <h4>Background</h4>Human breast carcinoma cell lines express high-affinity interleukin-4 receptors (IL-4R). We examined the expression and structure of these receptors on primary and cultured breast carcinoma cell lines and normal breast epithelial cells. We also tested the antitumor activity in vitro and in vivo of a ... |
10943569 | In vitro selection of nucleic acids for diagnostic applications. | In vitro selection methods have proven to be extraordinarily adept at generating a wide variety of nucleic acid-binding species (aptamers) and catalysts (ribozymes). To date, selected nucleic acids have primarily been of academic interest. However, just as antibodies have proven utility as 'universal receptors' that ca... |
10857916 | Synthesis, crystal structure, spectral properties and cytotoxic activity of platinum(II) complexes of 2-acetyl pyridine and pyridine-2-carbaldehyde N(4)-ethyl-thiosemicarbazones. | The reactions of Na2PtCl4 with pyridine-2-carbaldehyde and 2-acetyl pyridine N(4)-ethyl-thiosemicarbazones, HFo4Et and HAc4Et respectively, afforded the complexes [Pt(Fo4Et)Cl], [Pt(HFo4Et)2]Cl2, [Pt(Fo4Et)2] and [Pt(Ac4Et)Cl], [Pt(HAc4Et)2]Cl2 x 2H2O, [Pt(Ac4Et)2]. The new complexes have been characterized by elementa... |
10857906 | Zinc tetraruthenated porphyrin binding and photoinduced oxidation of calf-thymus DNA. | The photooxidation of calf-thymus DNA has been investigated in the presence of a supramolecular tetraruthenated zincporphyrin (ZnTRP) sensitizer. A strong interaction of ZnTRP with DNA has been observed, exhibiting a gradual transition from a non-specific electrostatic binding mode to a more specific one at high DNA co... |
10831129 | Recognition of trophoblast HLA class I molecules by decidual NK cell receptors--a review. | During placentation the extravillous trophoblast (EVT) cells migrate through the decidua towards the maternal spiral arteries. The walls of the arteries are then destroyed by trophoblast resulting in an increased blood flow to the fetus. These EVT express HLA-G, HLA-E and HLA-C, an unusual combination of two non-classi... |
10822254 | Molecular recognition and binding of thermal hysteresis proteins to ice. | Molecular recognition and binding are two very important processes in virtually all biological and chemical processes. An extremely interesting system involving recognition and binding is that of thermal hysteresis proteins at the ice-water interface. These proteins are of great scientific interest because of their ant... |
10822253 | Fluorescence correlation spectroscopy: molecular recognition at the single molecule level. | Fluorescence correlation spectroscopy (FCS) is a fluorescence microscopy technique that allows the study of molecular interactions in extremely low volumes, at nanomolar concentrations, even when binding is not accompanied by a fluorescence change. It can be applied directly in living cells. FCS clearly considerably ex... |
10822252 | Structures of the platelet calcium- and integrin-binding protein and the alphaIIb-integrin cytoplasmic domain suggest a mechanism for calcium-regulated recognition; homology modelling and NMR studies. | Calcium- and integrin-binding protein (CIB) binds to the 20-residue alphaIIb cytoplasmic domain of platelet alphaIIbbeta3 integrin. Amino acid sequence similarities with calmodulin (CaM) and calcineurin B (CnB) allowed the construction of homology-based models of calcium-saturated CIB as well as apo-CIB. In addition, t... |
10822251 | Influence of three-dimensional structure on the immunogenicity of a peptide expressed on the surface of a plant virus. | The influence of peptide structure on immunogenicity has been investigated by constructing a series of cowpea mosaic virus (CPMV) chimaeras expressing the 14 amino acid NIm-1A epitope from human rhinovirus 14 (HRV-14) at different positions on the capsid surface. Biochemical and crystallographic analysis of a CPMV/HRV ... |
10822250 | Structure-activity relationships of omega-conotoxins at N-type voltage-sensitive calcium channels. | Due to their selectivity towards voltage-sensitive calcium channels (VSCCs) omega-conotoxins are being exploited as a new class of therapeutics in pain management and may also have potential application in ischaemic brain injury. Here, the structure-activity relationships (SARs) of several omega-conotoxins including GV... |
10823238 | Nuclear calcium signalling. | The topic of nuclear Ca2+ signalling is beset by discrepant observations of substantial nuclear/cytoplasmic gradients. The reasons why some labs have recorded such gradients, whilst other workers see equilibration of Ca2+(cyt) and Ca2+(nuc) using the same cells and techniques, is unexplained. Furthermore, how such grad... |
10814113 | Synthesis and study of C(3)-symmetric hydropyran cyclooligolides with oriented aryl and alcohol appendages at 10 A spacing. | Modular syntheses of C(3)-symmetric macrocycles with pendant aryl and hydroxymethyl groups are described. These functional groups, amenable to further elaboration, were installed early in each synthesis and carried through an iterative sequence of module coupling and macrolactonization. Association constants for macrol... |
10801226 | Predicting the free energies of complexation between cyclodextrins and guest molecules: linear versus nonlinear models. | <h4>Purpose</h4>In the present paper, linear and nonlinear models for complexation of alpha- beta- and gamma-cyclodextrin with guest molecules are developed, with the aim of free energy prediction and interpretation of the association process.<h4>Methods</h4>Linear and nonlinear regression is used to correlate experime... |
10794443 | Ab initio studies on the vibrational spectra and conformational isomerism of 2,4-dimethyl-1,3-pentadiene. | Ab initio was used to study the structure of various conformational isomers and their vibrational spectra of 2,4-dimethyl-1,3-pentadiene (2,4-PD) in detail. Two stable conformations, s-trans and s-cis, were found in which s-trans is more stable. The geometry of stable conformations and charge distributions were studied... |
10788595 | Novel anti-RSV dianionic dendrimer-like compounds: design, synthesis and biological evaluation. | Human Respiratory Syncytial Virus (RSV) is considered to be the leading cause of lower respiratory tract disease in infants and young children. RSV is also a common pathogen in immunocompromised adults and in the elderly. RSV infection can be epidemic and is evident worldwide. Ribavirin, a small molecule agent, and Syn... |
10767767 | Quantitative determination of alpha-cyclodextrin in human plasma by liquid chromatography/positive ion electrospray mass spectrometry. | A sensitive and selective method for the determination of alpha-cyclodextrin in human plasma is described using beta-cyclodextrin as an internal standard. After protein precipitation with perchloric acid, the analytes were isolated from human plasma by solid-phase extraction on Bond Elut C18 cartridges. The compounds w... |
10767575 | Biochemistry of Indian summer: physiology of autumnal leaf coloration. | The autumnal coloration of foliage in deciduous trees represents a most spectacular phytogerontological phenomenon. It is primarily due to the progressive loss of chlorophyll coinciding with the partial retention of carotenoids. Leaf senescence is a developmental process that is aimed at the recycling of nutrients to p... |
10770588 | Effects of different types of injury to the inferior alveolar nerve on the behavior of Schwann cells during the regeneration of periodontal nerve fibers of rat incisor. | The present study reports on different regeneration patterns of axons and Schwann cells in the periodontal ligament of the rat incisor using immunohistochemistry of protein gene product 9.5 (PGP 9.5) and S-100 protein. Three kinds of injury (transection, crush and segmental resection) were applied to the inferior alveo... |
10768776 | New adsorbed coatings for capillary electrophoresis. | New acrylic polymers bearing oxirane groups were synthesized to be used in the production of coated capillaries. A fully automated coating procedure was devised based on the use of diluted water solutions of these polymers. The whole procedure required less than 30 min. The new polymers rapidly adsorbed from water onto... |
10768501 | Comparative study on camphor enantiomers behavior under the conditions of gas-liquid chromatography and reversed-phase high-performance liquid chromatography systems modified with alpha- and beta-cyclodextrins. | The dependence of retention and selectivity parameters of camphor enantiomers on the concentration of alpha- and beta-cyclodextrins were studied under conditions of GLC (matrix solvent: Glycerol, 95 degrees C) and RP-HPLC (matrix solvent: Aqueous methanolic, 20 degrees C). It has been found that beta-cyclodextrin forms... |
10686101 | Rational design of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 to increase alpha-cyclodextrin production. | Cyclodextrin glycosyltransferases (CGTase) (EC 2.4.1.19) are extracellular bacterial enzymes that generate cyclodextrins from starch. All known CGTases produce mixtures of alpha, beta, and gamma-cyclodextrins. A maltononaose inhibitor bound to the active site of the CGTase from Bacillus circulans strain 251 revealed su... |
10727206 | Catalytic macrocyclizations of thietanes and thiiranes by metal carbonyl complexes. | This Account summarizes our recent studies of the catalytic transformations of thietanes and thiiranes by metal carbonyl complexes of the third row of the transition elements. The goal of the work has been to prepare polythioether macrocycles (thiacrowns) catalytically. This has been achieved with high success for cert... |
10756542 | Effect of cyclodextrins on the solubility and stability of a novel soft corticosteroid, loteprednol etabonate. | To increase the aqueous solubility and stability of the soft corticosteroid loteprednol etabonate (LE), drug complexation using various cyclodextrins (CDs), such as gamma-cyclodextrin (gamma-CD), 2-hydroxypropyl-beta-cyclodextrin (HPBCD), maltosyl-beta-cyclodextrin (MBCD), mixture of glucosyl/maltosyl-alpha-, beta-, an... |
10752612 | The effect of nucleotide bias upon the composition and prediction of transmembrane helices. | Transmembrane helices are the most readily predictable secondary structure components of proteins. They can be predicted to a high degree of accuracy in a variety of ways. Many of these methods compare new sequence data with the sequence characteristics of known transmembrane domains. However, the known transmembrane s... |
10752608 | An additional aromatic interaction improves the thermostability and thermophilicity of a mesophilic family 11 xylanase: structural basis and molecular study. | In a general approach to the understanding of protein adaptation to high temperature, molecular models of the closely related mesophilic Streptomyces sp. S38 Xyl1 and thermophilic Thermomonospora fusca TfxA family 11 xylanases were built and compared with the three-dimensional (3D) structures of homologous enzymes. Som... |
10752606 | The prion domain of yeast Ure2p induces autocatalytic formation of amyloid fibers by a recombinant fusion protein. | The Ure2 protein from Saccharomyces cerevisiae has been proposed to undergo a prion-like autocatalytic conformational change, which leads to inactivation of the protein, thereby generating the [URE3] phenotype. The first 65 amino acids, which are dispensable for the cellular function of Ure2p in nitrogen metabolism, ar... |
10752477 | Phage-selected primate antibodies fused to superantigens for immunotherapy of malignant melanoma. | The high-molecular-weight melanoma-associated antigen, HMW-MAA, has been demonstrated to be of potential interest for diagnosis and treatment of malignant melanoma. Murine monoclonal antibodies (mAb) generated in response to different epitopes of this cell-surface molecule efficiently localise to metastatic lesions in ... |
10750496 | Synthesis, electrochemistry, and interactions with beta-cyclodextrin of dendrimers containing a single ferrocene subunit located "off-center". | Two series of dendrimers containing a single ferrocene unit located in the focal point of these macromolecules have been synthesized and characterized. The first series of dendrimers has considerable lipophilic character, with tert-butyl ester groups located in their peripheral regions. In contrast, the second series o... |
10744973 | Phosphatidylinositol 4,5-bisphosphate induces actin-based movement of raft-enriched vesicles through WASP-Arp2/3. | <h4>Background</h4>Phosphatidylinositol 4,5-bisphosphate (PIP(2)) has been implicated in the regulation of the actin cytoskeleton and vesicle trafficking. It stimulates de novo actin polymerization by activating the pathway involving the Wiskott-Aldrich syndrome protein (WASP) and the actin-related protein complex Arp2... |
10749504 | Enantiomeric separation of enzymatic hydrolysis products of dihydropyrimidinone methyl ester with cationic cyclodextrin by capillary electrophoresis. | The achiral separation of dihydropyrimidinone (DHP) methyl ester and its corresponding carboxylic acid and the chiral separation of their respective enantiomers were achieved in a single analysis using capillary electrophoresis (CE) with quaternary ammonium-beta-cyclodextrin (QA-beta-CD) as a chiral buffer additive. Se... |
10749503 | Investigation of the effects of cyclodextrins and organic solvents on the separation of cationic surfactants in capillary electrophoresis. | The use of alpha- and beta-cyclodextrin (CD) to understand and to improve the separation of a series of cationic surfactants, homologues of alkylbenzyldimethyl ammonium compounds (ABDACs) with an alkyl chain of varying length (C10-C18), in capillary electrophoresis (CE) is reported for the first time. Similar to the ef... |
10743936 | Irreversible inhibition of type I dehydroquinase by substrates for type II dehydroquinase. | Mechanistic differences between type I and type II dehydroquinases have been exploited in the design of type specific inhibitors. (2R)-2-Bromo-3-dehydroquinic acid (3), (2R)-2-fluoro-3-dehydroquinic acid (5) and 2-bromo-3-dehydroshikimic acid (4), all excellent substrates for type II dehydroquinase, are shown to be irr... |
10740883 | Determination of biological toxins using capillary electrokinetic chromatography with multiphoton-excited fluorescence. | We report a highly sensitive and rapid strategy for characterizing biological toxins based on capillary electrokinetic chromatography with multiphoton-excited fluorescence. In this approach, aflatoxins B1, B2, and G1 and the cholera toxin A-subunit are fractionated in approximately 80 s in a narrow-bore electrophoretic... |
10739470 | Transmembrane ion transport by polyphosphate/poly-(R)-3-hydroxybutyrate complexes. | Transmembrane ion transport, a critical process in providing energy for cell functions, is carried out by pore-forming macromolecules capable of discriminating among very similar ions and responding to changes in membrane potential. It is widely regarded that ion channels are exclusively proteins, relatively late arriv... |
10741414 | Cholesterol depletion disrupts lipid rafts and modulates the activity of multiple signaling pathways in T lymphocytes. | Lipid rafts are specialized plasma membrane microdomains, in which glycosphingolipids and cholesterol are major structural components. In T lymphocytes, several signaling proteins are associated with lipid rafts including the protein tyrosine kinase LCK and the adapter protein LAT. To investigate their importance in T ... |
10738642 | Study of omeprazole-gamma-cyclodextrin complexation in the solid state. | The possibility of obtaining inclusion complexes between omeprazole (OME) and gamma-cyclodextrin (gamma-CD) by kneading, spray-drying, coprecipitation, and freeze-drying was evaluated. All these methods lead to the isolation of a true inclusion compound, as evidenced by differential scanning calorimetry (DSC), infrared... |
10716712 | New studies on the heat resistance of hamster-adapted scrapie agent: threshold survival after ashing at 600 degrees C suggests an inorganic template of replication. | One-gram samples from a pool of crude brain tissue from hamsters infected with the 263K strain of hamster-adapted scrapie agent were placed in covered quartz-glass crucibles and exposed for either 5 or 15 min to dry heat at temperatures ranging from 150 degrees C to 1,000 degrees C. Residual infectivity in the treated ... |
10716728 | NF-kappa B activation induced by T cell receptor/CD28 costimulation is mediated by protein kinase C-theta. | Protein kinase C-theta (PKCtheta) is a Ca(2+)-independent member of the PKC family that is selectively expressed in skeletal muscle and T lymphocytes and plays an important role in T cell activation. However, the molecular basis for the important functions of PKCtheta in T cells and the manner in which it becomes coupl... |
10716729 | Lipid rafts function in biosynthetic delivery of proteins to the cell surface in yeast. | Lipid rafts, formed by lateral association of sphingolipids and cholesterol, have been implicated in membrane traffic and cell signaling in mammalian cells. Sphingolipids also have been shown to play a role in protein sorting in yeast. Therefore, we wanted to investigate whether lipid rafts exist in yeast and whether t... |
10716695 | Heterologous expression in Escherichia coli of the first module of the nonribosomal peptide synthetase for chloroeremomycin, a vancomycin-type glycopeptide antibiotic. | The gene cluster from Amycolotopsis orientalis responsible for biosynthesis of the vancomycin-type glycopeptide antibiotic chloroeremomycin was recently sequenced, indicating that this antibiotic derives from a seven-residue peptide synthesized by a three-subunit (CepA, CepB, and CepC) modular nonribosomal peptide synt... |
10737749 | Anilide derivatives of an 8-phenylxanthine carboxylic congener are highly potent and selective antagonists at human A(2B) adenosine receptors. | No highly selective antagonists of the A(2B) adenosine receptor (AR) have been reported; however such antagonists have therapeutic potential as antiasthmatic agents. Here we report the synthesis of potent and selective A(2B) receptor antagonists. The structure-activity relationships (SAR) of 8-phenyl-1, 3-di-(n-propyl)... |
10725882 | In vivo MR measurements of regional arterial and venous blood volume fractions in intact rat brain. | In vivo measurement of cerebral arterial and venous volume fractions is important to the understanding of brain physiology and function. By using an intravascular perfluorocarbon and 19F NMR at 4.7 T, regional arterial and venous volume fractions from an intact rat brain were resolved based on the pseudodiffusion coeff... |
10698630 | The 1.3 A crystal structure of a biotin-binding pseudoknot and the basis for RNA molecular recognition. | A pseudoknot-containing aptamer isolated from a pool of random sequence molecules has been shown previously to represent an optimal RNA solution to the problem of binding biotin. The affinity of this RNA molecule is nonetheless orders of magnitude weaker than that of its highly evolved protein analogs, avidin and strep... |
10731709 | Crystal structure of alkalophilic asparagine 233-replaced cyclodextrin glucanotransferase complexed with an inhibitor, acarbose, at 2.0 A resolution. | The product specificity of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. #1011 is improved to near-uniformity by mutation of histidine-233 to asparagine. Asparagine 233-replaced CGTase (H233N-CGTase) no longer produces alpha-cyclodextrin, while the wild-type CGTase from the same bacterium prod... |
10735511 | Activated mesothelial cells produce heparin-binding growth factors: implications for tumour metastases. | Curative surgery for gastrointestinal malignancy is commonly thwarted by local tumour recurrence. The heparin-binding growth factors, basic fibroblast growth factor (bFGF), heparin-binding epidermal growth factor-like growth factor (HB-EGF) and vascular epidermal growth factor (VEGF) are all implicated in the metastati... |
10733219 | Preparative-scale isoelectric focusing separation of enantiomers using a multicompartment electrolyzer with isoelectric membranes. | The IsoPrime multicompartment electrolyzer, equipped with a series of isoelectric membranes with closely spaced pI values, was used for the first time for the preparative-scale separation of the enantiomers of dansyl phenylalanine with hydroxypropyl beta-cyclodextrin as resolving agent. The final separation conditions ... |
10732981 | Origin of rate-acceleration in ester hydrolysis with metalloprotease mimics. | Mimics of carboxypeptidase A, a prototypical metalloprotease, were synthesized by linking macrocyclicpolyamines to the primary side of beta-cyclodextrin followed by complexing with Zn(II). These enzyme mimics exhibit saturation kinetics in hydrolysis of p-nitrophenyl acetate (PNPA) and enhance the rate of hydrolysis re... |
10732976 | Syntheses of R and S isomers of AF-DX 384, a selective antagonist of muscarinic M2 receptors. | Enantiomers of 5,11-dihydro-11-[2-[2-[(N,N-dipropylaminomethyl)piperidin-1- yl]ethylamino]-carbonyl]-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one (AF-DX 384) 1, have been synthesized from (S)-(+) and (R)-(-)-2-[N,N-dipropylaminomethyl]piperidine 4. The enantiomeric excess of 1 has been determined by capillary electrophores... |
10731034 | Activation of the A3 adenosine receptor affects cell cycle progression and cell growth. | The A3 adenosine receptor has been implicated in modulation of cell growth. As a first step to the characterization of the underlying mechanisms, we exposed Chinese hamster ovary (CHO) cells transfected with the human A3 receptor (A3R-CHO) to selective A3 receptor ligands. At micromolar concentrations, the A3 agonists ... |
10731013 | Changes in glutamine and glutamate concentrations for tracking training tolerance. | <h4>Purpose</h4>The purpose was to monitor high-performance athletes throughout training macrocycles and competitions and examine the changes in plasma glutamine (Gm) and glutamate (Ga) concentrations in order to develop a model of tolerance to training.<h4>Methods</h4>Plasma glutamine and glutamate concentrations of 5... |
10725206 | The interaction of heparin sulfate and adeno-associated virus 2. | Recently heparan sulfate was proposed as the host cell receptor for the dependovirus, adeno-associated virus type 2 (AAV2). We show that although heparan sulfate on the cell surface may contribute to the binding of AAV2 to permissive cells, the amount of heparan sulfate on the cell surface as determined by flow cytomet... |
10725326 | Caspase recruitment domain (CARD)-dependent cytoplasmic filaments mediate bcl10-induced NF-kappaB activation. | Mucosa-associated lymphoid tissue (MALT) lymphomas are associated with overexpression and constitutive activity of bcl10, a caspase recruitment domain (CARD)-containing protein that activates NF-kappaB. Here, we show that arrangement of overexpressed bcl10 protein in cytoplasmic filaments is essential for recruitment o... |
10725182 | Cycloamylose (cyclodextrin) glucanotransferase degrades intact granules of potato raw starch. | Cycloamylose (cyclodextrin) glucanotransferase (EC 2.4.1.19, CGTase) originated from Bacillus macerans degraded intact granules of potato raw starch and converted them into cyclodextrins (CDs). The degradation required sufficient stirring of starch-CGTase suspension. The morphology of the degraded starch granules was u... |
10725132 | Effect of pH on the thermal denaturation of whey proteins in milk. | The effect of pH on thermal denaturation of four main whey protein fractions in skim milk was examined by gel permeation FPLC. On heating skim milk at 80 degrees C for 0.5-20.0 min over the pH range 5.2-8.8, the extent of denaturation, based on loss of solubility at pH 4.6, increased with heating time and was usually i... |
10727101 | Highly fluorescent protein labeling using dendritic peptide derivatives. | Non-specific fluorescent dyes and photosensitizers are routinely used in clinical practice for the photodetection and photoablation of superficial lesions. Future applications in photomedicine are likely to rely on the selective delivery of photoactive compounds to diseased areas, using specific targeting agents such a... |
10726876 | Novel catalytic asymmetric sulfoxidation in water using the hypervalent iodine reagent iodoxybenzene. | A new catalytic asymmetric oxidation of sulfides to sulfoxides in water using the hypervalent iodine(V) reagent iodoxybenzene (PhIO2) has been developed. This methodology is distinctly different from the previously reported use of cyclodextrins or biological catalysts and provides a new route to asymmetric sulfoxidatio... |
10726682 | A comparison of neonatal and adult multiorgan failure in a rat model. | <h4>Background/purpose</h4>To establish a neonatal animal model of multiorgan failure (MOF) for the histological study of the sequence and severity of neonatal MOF in comparison to a model of adult MOF.<h4>Methods</h4>Neonatal and adult Sprague-Dawley rats received a single intraperitoneal injection of the inflammatory... |
10722722 | Phragmoplastin polymerizes into spiral coiled structures via intermolecular interaction of two self-assembly domains. | Phragmoplastin, a high molecular weight GTPase belonging to the dynamin superfamily of proteins, becomes associated with the cell plate during cytokinesis in plants. Growth of the cell plate requires continuous fusion of vesicles, and phragmoplastin appears to play a role in the formation of vesicle-tubule-vesicle stru... |
10716919 | Secreted cathepsin L generates endostatin from collagen XVIII. | Endostatin, an inhibitor of angiogenesis and tumor growth, was identified originally in conditioned media of murine hemangioendothelioma (EOMA) cells. N-terminal amino acid sequencing demonstrated that it corresponds to a fragment of basement membrane collagen XVIII. Here we report that cathepsin L is secreted by EOMA ... |
10715151 | Synthesis, biological activity, and molecular modeling of ribose-modified deoxyadenosine bisphosphate analogues as P2Y(1) receptor ligands. | The structure-activity relationships of adenosine-3', 5'-bisphosphates as P2Y(1) receptor antagonists have been explored, revealing the potency-enhancing effects of the N(6)-methyl group and the ability to substitute the ribose moiety (Nandanan et al. J. Med. Chem. 1999, 42, 1625-1638). We have introduced constrained c... |
10713386 | Role of dopamine receptor subtypes in the acquisition of a testosterone conditioned place preference in rats. | The present experiments investigated the neurochemical bases of the rewarding properties of testosterone, focusing on the role of dopaminergic function in the acquisition of a testosterone conditioned place preference (CPP). In two experiments for 8 alternating days adult male Long-Evans rats received peripheral inject... |
10713569 | Differentiation of mitral cell dendrites in the developing main olfactory bulbs of normal and naris-occluded rats. | The morphological differentiation of mitral cell dendrites during embryonic and early postnatal development was examined in the main olfactory bulb of rats to determine a possible role of afferent activity in the development of the dendrites. Mitral cells and olfactory nerve fibers were labeled with 1,1'-dioctadecyl-3,... |
10712605 | The role of amino-acid residues in the hydrophobic patch surrounding the haem group of cytochrome f in the interaction with plastocyanin. | Soluble turnip cytochrome f has been purified from the periplasmic fraction of Escherichia coli expressing a truncated petA gene encoding the precursor protein lacking the C-terminal 33 amino-acid residues. The protein is identical [as judged by 1H-NMR spectroscopy, midpoint redox potential (+ 365 mV) and electron tran... |
10712203 | Functional analysis of the neurofibromatosis type 2 protein by means of disease-causing point mutations. | Despite intense study of the neurofibromatosis type 2 (NF2) tumor-suppressor protein merlin, the biological properties and tumor-suppressor functions of merlin are still largely unknown. In this study, we examined the molecular activities of NF2-causing mutant merlin proteins in transfected mammalian cells, to elucidat... |
10714834 | Impact of acute renal failure on antioxidant status in multiple organ failure. | <h4>Background</h4>Acute renal failure (ARF) can be triggered or aggravated by reactive oxygen species (ROS) but established ARF per se might also affect the antioxidant defence mechanisms of the organism. We evaluated a broad pattern of antioxidants in critically ill patients with multiple organ failure with (MOF-ARF)... |
10704811 | Polyamidoamine Starburst dendrimers as solubility enhancers. | The solubility of the hydrophobic drug ibuprofen has been compared in an aqueous solution of polyamidoamine (PAMAM) G4 dendrimer and sodium dodecyl sulphate (SDS). The PAMAM G4 dendrimer solution significantly enhanced the solubility of ibuprofen compared to 2% SDS solution. It was found that the solubility of ibuprofe... |
10704793 | Chitosans as nasal absorption enhancers of peptides: comparison between free amine chitosans and soluble salts. | A total of three free amine chitosans (CS J, CS L and CS H) and two soluble chitosan salts (CS G and CS HCl) were evaluated for their efficacy and safety as nasal absorption enhancers of peptides based on in situ nasal perfusion and subacute histological evaluation in rat. At 0.5% w/v, all chitosans were effective in e... |
10704788 | Mechanisms by which cyclodextrins modify drug release from polymeric drug delivery systems. | For many drug candidates a modified in vivo drug release is desired to improve efficacy, sustain effect or minimise toxicity. Polymeric delivery systems, such as microspheres, nanospheres and polymeric films, have been extensively researched in an attempt to achieve modified drug release. Cyclodextrins offer an alterna... |
10704894 | Improvement of availability of allopurinol from pharmaceutical dosage forms I - suppositories. | Solid dispersion and crystallization of a very slightly water-soluble drug, allopurinol, were prepared using urea, sodium salicylate and beta-cyclodextrin (beta-CD) as carriers. The spectroscopic infra-red (IR), differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) data indicate a role of these... |
10704499 | Neural cell adhesion molecule-stimulated neurite outgrowth depends on activation of protein kinase C and the Ras-mitogen-activated protein kinase pathway. | The signal transduction pathways associated with neural cell adhesion molecule (NCAM)-induced neuritogenesis are only partially characterized. We here demonstrate that NCAM-induced neurite outgrowth depends on activation of p59(fyn), focal adhesion kinase (FAK), phospholipase Cgamma (PLCgamma), protein kinase C (PKC), ... |
10704318 | Structural and mechanistic basis of porphyrin metallation by ferrochelatase. | Ferrochelatase, the enzyme catalyzing metallation of protoporphyrin IX at the terminal step of heme biosynthesis, was co-crystallized with an isomer mixture of the potent inhibitor N-methylmesoporphyrin (N-MeMP). The X-ray structure revealed the active site of the enzyme, to which only one of the isomers was bound, and... |
10706592 | Regulation of 25- and 27-hydroxylation side chain cleavage pathways for cholic acid biosynthesis in humans, rabbits, and mice. Assay of enzyme activities by high-resolution gas chromatography;-mass spectrometry. | In classic cholic acid biosynthesis, a series of ring modifications of cholesterol precede side chain cleavage and yield 5beta-cholestane-3alpha, 7alpha, 12alpha-triol. Side chain reactions of the triol then proceed either by the mitochondrial 27-hydroxylation pathway or by the microsomal 25-hydroxylation pathway. We h... |
10704449 | Sphingolipid-cholesterol rafts diffuse as small entities in the plasma membrane of mammalian cells. | To probe the dynamics and size of lipid rafts in the membrane of living cells, the local diffusion of single membrane proteins was measured. A laser trap was used to confine the motion of a bead bound to a raft protein to a small area (diam < or = 100 nm) and to measure its local diffusion by high resolution single par... |
10704441 | Mechanism of residence of cytochrome b(5), a tail-anchored protein, in the endoplasmic reticulum. | Endoplasmic reticulum (ER) proteins maintain their residency by static retention, dynamic retrieval, or a combination of the two. Tail-anchored proteins that contain a cytosolic domain associated with the lipid bilayer via a hydrophobic stretch close to the COOH terminus are sorted within the secretory pathway by large... |
10704987 | Synthesis and structural characterization of poly(LGGVG), an elastin-like polypeptide. | Poly(LGGVG) a potential elastin-like biomaterial has been synthesized and studied both in solution (by circular dicroism and nuclear magnetic resonance) and in the aggregated state (by transmission electron microscopy). For sake of comparison, also the conformation of the protected (Boc-LGGVG-OEt) and free (H(2)(+)-LGG... |
10704201 | Porphyrin interactions with wild-type and mutant mouse ferrochelatase. | Ferrochelatase (EC 4.99.1.1), the terminal enzyme of the heme biosynthetic pathway, catalyzes Fe(2+) chelation into protoporphyrin IX. Resonance Raman and UV-vis absorption spectroscopies of wild-type and engineered variants of murine ferrochelatase were used to examine the proposed structural mechanism for iron insert... |
10705351 | Cell death in denervated skeletal muscle is distinct from classical apoptosis. | Denervation of skeletal muscle is followed by the progressive loss of tissue mass and impairment of its functional properties. The purpose of the present study was to investigate the occurrence of cell death and its mechanism in rat skeletal muscle undergoing post-denervation atrophy. We studied the expression of speci... |
10699069 | Randomized trial of postoperative adjuvant chemotherapy with or without radiotherapy for carcinoma of the rectum: National Surgical Adjuvant Breast and Bowel Project Protocol R-02. | <h4>Background</h4>The conviction that postoperative radiotherapy and chemotherapy represent an acceptable standard of care for patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the rectum evolved in the absence of data from clinical trials designed to determine whether the addition of radiotherap... |
10699285 | Oral uptake and translocation of a polylysine dendrimer with a lipid surface. | A series of lipidic peptide dendrimers based on lysine with 16 surface alkyl (C(12)) chains has been synthesised in our laboratories. One of the series, a fourth generation dendrimer with a diameter of 2.5 nm was chosen to study its absorption after oral administration to female Sprague-Dawley rats (180 g, 9 weeks old)... |
10699277 | Dendrimers: relationship between structure and biocompatibility in vitro, and preliminary studies on the biodistribution of 125I-labelled polyamidoamine dendrimers in vivo. | Dendrimers are highly branched macromolecules of low polydispersity that provide many exciting opportunities for design of novel drug-carriers, gene delivery systems and imaging agents. They hold promise in tissue targeting applications, controlled drug release and moreover, their interesting nanoscopic architecture mi... |
10698944 | Loss of FBP function arrests cellular proliferation and extinguishes c-myc expression. | The c-myc regulatory region includes binding sites for a large set of transcription factors. The present studies demonstrate that in the absence of FBP [far upstream element (FUSE)-binding protein], which binds to the single-stranded FUSE, the remainder of the set fails to sustain endogenous c-myc expression. A dominan... |
10698793 | A new Shiga toxin 2 variant (Stx2f) from Escherichia coli isolated from pigeons. | We have isolated Shiga toxin (Stx)-producing Escherichia coli (STEC) strains from the feces of feral pigeons which contained a new Stx2 variant gene designated stx(2f). This gene is most similar to sltIIva of patient E. coli O128:B12 isolate H.I.8. Stx2f reacted only weakly with commercial immunoassays. The prevalence ... |
10697818 | Noncovalent association phenomena of 2,5-dihydroxybenzoic acid with cyclic and linear oligosaccharides. A matrix-assisted laser desorption/ionization time-of-flight mass spectrometric and X-ray crystallographic study. | D-Glucose and 19 glucose derivatives were investigated by positive and negative ion matrix assisted laser desorption/ionization time-of-flight mass spectrometry using 2,5-dihydroxybenzoic acid (DHB) as the matrix. The set of substrates includes oligomers of amylose and cellulose, native alpha-, beta-, and gamma-cyclode... |
10694491 | Aminopeptidase N/CD13 is associated with raft membrane microdomains in monocytes. | Ectopeptidases play important roles in cell activation, proliferation, and communication. Human monocytic cells express considerable amounts of aminopeptidase N/CD13, a transmembrane protein previously proposed to play a role in the regulation of neuropeptides and chemotactic mediators as well as in adhesion and cell-c... |
10692374 | Biochemical and physical properties of the Methanococcus jannaschii 20S proteasome and PAN, a homolog of the ATPase (Rpt) subunits of the eucaryal 26S proteasome. | The 20S proteasome is a self-compartmentalized protease which degrades unfolded polypeptides and has been purified from eucaryotes, gram-positive actinomycetes, and archaea. Energy-dependent complexes, such as the 19S cap of the eucaryal 26S proteasome, are assumed to be responsible for the recognition and/or unfolding... |
10692365 | Specificity mutants of the binding protein of the oligopeptide transport system of Lactococcus lactis. | The kinetic properties of wild-type and mutant oligopeptide binding proteins of Lactococcus lactis were determined. To observe the properties of the mutant proteins in vivo, the oppA gene was deleted from the chromosome of L. lactis to produce a strain that was totally defective in oligopeptide transport. Amplified exp... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.