id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
10986243 | Footprinting studies of specific complexes formed by RepA, a replication initiator of plasmid pCU1, and its binding site. | The basic replicon of plasmid pCU1 contains three different replication origins. Replication initiated from the oriB origin requires pCU1-encoded protein RepA. Previously, information analysis of 19 natural RepA binding sequences predicted a 20-bp sequence as a RepA binding site. Guanines contacting RepA in the major g... |
10986237 | Binding of ferric enterobactin by the Escherichia coli periplasmic protein FepB. | The periplasmic protein FepB of Escherichia coli is a component of the ferric enterobactin transport system. We overexpressed and purified the binding protein 23-fold from periplasmic extracts by ammonium sulfate precipitation and chromatographic methods, with a yield of 20%, to a final specific activity of 15,500 pmol... |
10986231 | Site-specific mutational analysis of a novel cysteine motif proposed to ligate the 4Fe-4S cluster in the iron-sulfur flavoprotein of the thermophilic methanoarchaeon Methanosarcina thermophila. | Isf (iron-sulfur flavoprotein) from Methanosarcina thermophila has been produced in Escherichia coli as a dimer containing two 4Fe-4S clusters and two FMN (flavin mononucleotide) cofactors. The deduced sequence of Isf contains six cysteines (Cys 16, Cys 47, Cys 50, Cys 53, Cys 59, and Cys 180), four of which (Cys 47, C... |
10984743 | Development and application of a chiral high performance liquid chromatography assay for pharmacokinetic studies of methadone. | Methadone enantiomers and EDDP, the main metabolite of methadone, were separated (R(s) = 2.0 for methadone enantiomers) following liquid-liquid extraction from human serum and urine followed by reverse-phase high-performance liquid chromatography on a derivatized beta-cyclodextrin column and quantified at therapeutic c... |
10982845 | Isoforms of vascular endothelial growth factor act in a coordinate fashion To recruit and expand tumor vasculature. | Vascular endothelial growth factor (VEGF) is an essential regulator of vascularization. It is expressed as several splice variants; the major forms contain 120 amino acids, 164 amino acids, and 188 amino acids. We utilized transformed cells nullizygous for VEGF to specifically express each of these isoforms in isolatio... |
10982323 | The 60-residue C-terminal region of the single-stranded DNA binding protein of herpes simplex virus type 1 is required for cooperative DNA binding. | ICP8 is the major single-stranded DNA (ssDNA) binding protein of the herpes simplex virus type 1 and is required for the onset and maintenance of viral genomic replication. To identify regions responsible for the cooperative binding to ssDNA, several mutants of ICP8 have been characterized. Total reflection X-ray fluor... |
10944399 | Measured and calculated effects of mutations in bacteriophage T4 lysozyme on interactions in solution. | Understanding the molecular determinants of protein interactions in solution has fundamental implications for understanding protein solution thermodynamics and, hence, processes as diverse as separations performance and cellular self-organization. Our earlier theoretical calculations indicate that the protein-protein i... |
10867637 | Design and synthesis of AB(3)-type (A = 1,3,5-benzenetricarbonyl unit; B = Glu diOME or Glu(7) octa OMe) peptide dendrimers: crystal structure of the first generation. | The first generation molecule of glutamic acid-based dendrons on a 1, 3,5-benzenetricarbonyl core leads to a cylindrical assembly as demonstrated by single crystal x-ray diffraction. The benzene pi-pi stack (A) is stabilized by vertical NH...O===C hydrogen bonding with each subunit participating in three intermolecular... |
10867633 | Design, synthesis, and crystal structure of self-assembling norbornene (NBE)-supported two-helix bundles: a unique example of Janus helicity in the solid-state structure of NBE(Aib(5))(2). | Norbornene-supported bis-helical peptides with the general structure NBE(Aib(n) )(2) (NBE: 2,3-trans-norbornene dicarbonyl unit; Aib: alpha,alpha'-dimethyl glycine unit; n = 4,5) have been synthesized and examined for self-assembly preferences in the solid state. An x-ray study has revealed a phenomenon of Janus helici... |
10758270 | Determination of the three-dimensional structure of toxins by protein crystallography. | Protein crystallography has significantly contributed to the development of many areas of biochemical research, particularly in the understanding of phenomena related to molecular recognition. Examples include the formation of enzyme-substrate complexes (and their subsequent catalysis), host cell invasion by viruses, a... |
22745520 | Purification and Recognition of Recombinant Mouse P2X(1) Receptors Expressed in a Baculovirus System. | Strategy, Management and Health Policy Venture Capital Enabling TechnologyPreclinical ResearchPreclinical Development Toxicology, Formulation Drug Delivery, PharmacokineticsClinical Development Phases I-III Regulatory, Quality, ManufacturingPostmarketing Phase IVThe hexahistidine-tagged mouse P2X(1) receptor (H-mP2X(1)... |
19649883 | Signal transduction drug discovery: targets, mechanisms and structure-based design. | Signal transduction targets include catalytic and/or non-catalytic domains, which are critical to various aspects of cell growth, differentiation, metabolism and function, mitogenesis, motility and gene transcription. Specific examples of molecular targets include the catalytic domains of protein tyrosine kinases (PTKs... |
18968077 | Selective transport of cesium ion in polymeric CTA membrane containing calixcrown ethers. | A series of calixcrown ethers for which the cavity size of the crown ring is varied from crown-6 to crown-7 to crown-8 were examined for the transport abilities toward alkali metal ions. These ligands were incorporated into supported liquid membranes (SLMs) and into polymer inclusion membranes (PIMs) composed of cellul... |
10987924 | Thermal polymorphic transformation of p-tert-Butylcalix | Studies were made on the polymorphism of p-tert-butylcalix[4]arene derivatives having amino acid groups on the lower rim to stabilize their hydrophilic pseudocavity by circular intramolecular hydrogen bonding. The calixarenes exhibit a polymorphic transformation upon heating in the solid state. This transformation is c... |
10986486 | catena-Poly | In the title complex, [Ag(C(12)H(10)N(2))]NO(3)(n), the Ag atom, which is in a linear AgN(2) geometry, is surrounded by two trans-related N atoms of two bpe ligands [Ag-N = 2.173 (3) and 2.176 (3) A; bpe is trans-1,2-bis(2-pyridyl)ethylene]. The bpe ligands bridge neighbouring Ag atoms to form zigzag polymeric chains i... |
10985843 | Characteristics of Cyclodextrin Adsorption onto Activated Carbons. | Whereas the amount of cyclodextrin (CD) adsorbed onto the large-pore activated carbon A (AC-A) increased with the number of glucose units, the amount adsorbed onto the small-pore activated carbon B (AC-B) showed the opposite tendency. This behavior can be accounted for in terms of a molecular exclusion. It is known tha... |
10985835 | Silver Nanoparticles by PAMAM-Assisted Photochemical Reduction of Ag(+). | The photochemical synthesis of Ag(0) nanoparticles in the presence of amino- and carboxylate-terminated PAMAM dendrimers is reported. The formation of Ag(0) nanoparticles was followed spectrophotometrically and by transmission electron microscopy (TEM). According to TEM investigations Ag(0) nanoparticles with the avera... |
10970322 | Designing large triangular chiral macrocycles: efficient | Triangular 30- and 27-membered hexaiminomacrocycles 4 and 5 of D(3) and C(3) symmetry, respectively, are readily obtained by unprecedented [3 + 3] cyclocondensation of (R,R)-1, 2-diaminocyclohexane with, accordingly, terephthalaldehyde and isophthalaldehyde. The course of the reaction, leading to macrocyclization, is g... |
10942572 | Preparation of Hydrophobically Modified Poly(amidoamine) Dendrimer-Encapsulated Gold Nanoparticles in Organic Solvents. | HAuCl(4) in aqueous solution was extracted to toluene or chloroform using a hydrophobically modified poly(amidoamine) dendrimer. Then, by reduction of Au(3+) ions with dimethylamineborane, gold nanoparticles in the size range of 2-4 nm were obtained in toluene or chloroform. It is suggested that gold nanoparticles are ... |
11039533 | Novel artificial receptors for alkylammonium ions with remarkable selectivity and affinity | The benzene-based tripodal tris(oxazolines) have been developed as the most selective and strong receptors toward linear alkylammonium ions reported to date. Among six tris(oxazolines) based on 2,4,6-trimethylbenzene framework, the phenylglycinol-derived receptor 4 exhibits the largest association constant toward nBuNH... |
11039528 | Synthesis and molecular geometry of an achiral 30-crown-12 polyacetal from alpha-cyclodextrin | Periodate oxidation of alpha-cyclodextrin followed by borohydride reduction readily provided an octadeca-hydroxymethyl-substituted 30-crown-12 polyacetal 1, its 30-membered macrocycle being composed of six meso-butanetetrol/glycolaldehyde acetal units, which is, consequently, optically inactive. Its solid-state molecul... |
11039526 | Giant vesicles from 72-membered macrocyclic archaeal phospholipid analogues: initiation of vesicle formation by molecular recognition between membrane components | Stereochemically pure archeal acyclic bola-amphiphilic diphosphates 4 and 5, with the basic structure of the phospholipids found in Sulfolobus, have been synthesized for the first time. The self-assembly properties have been compared with those of the nearly identical 72-membered macrocyclic tetraether phosphates 3a an... |
11039523 | Optically active dioxatetraazamacrocycles: chemoenzymatic syntheses and applications in chiral anion recognition | Two new C2 and D2 symmetrical dioxatetraaza 18-membered macrocycles [(R,R)-1 and (S,S,S,S)-2] are efficiently synthesized in enantiomerically pure forms by a chemoenzymatic method starting from (+/-)-trans-cyclohexane-1,2-diamine. The protonation constants and the binding constants with different chiral dicarboxylates ... |
11028062 | Force Spectroscopy of Molecular Systems-Single Molecule Spectroscopy of Polymers and Biomolecules. | How do molecules interact with each other? What happens if a neurotransmitter binds to a ligand-operated ion channel? How do antibodies recognize their antigens? Molecular recognition events play a pivotal role in nature: in enzymatic catalysis and during the replication and transcription of the genome; it is also impo... |
11023232 | Visualization of artificial lignin supramolecular structures | In this paper we are presenting the results of our environmental scanning electron microscopy (ESEM) investigation of the lignin model compound--enzymatically polymerized coniferyl alcohol, also known as dehydrogenate polymer (DHP). The goals of this study were to visualize the supramolecular organization of DHP polyme... |
11003008 | Altering the inclusion properties of CTV through crystal engineering: CTV, carborane, and DMF supramolecular assemblies | The complexes [Na(CTV)2(OH)(H2O)](H2O)(DMF)2(o-carborane) (3; CTV = cyclotriveratrylene), [K(OH)(CTV)(DMF)]2(o-carborane) (4), [(DMF)(CTV)]2(H2O)4(o-carborane) (5), and (o-carborane)(CTV)(DMF)2 (6) all form as crystalline inclusion complexes from N,N'-dimethylformamide (DMF) solution. Complexes 3 and 4 are the first re... |
11003002 | The self-assembly of lipophilic guanosine derivatives in solution and on solid surfaces | The self-assembly of lipophilic deoxyguanosine derivatives 1 and 2 has been studied in solution by NMR spectroscopy and ESI-MS (electrospray ionization mass spectrometry). NMR data show the existence of two types of self-assembled, ribbonlike structures (A and B), which are connected at the guanine moieties through two... |
11256602 | Composing life. | Textbooks often assert that life began with specialized complex molecules, such as RNA, that are capable of making their own copies. This scenario has serious difficulties, but an alternative has remained elusive. Recent research and computer simulations have suggested that the first steps toward life may not have invo... |
11198869 | C-substituted macrocycles as candidates for radioimmunotherapy. | The reaction between aryl aldehydes, the macrocyclic ligand 6-methyl-1,4,8,11-tetraazacyclotetradecane-6-amine (L1), and NaBH3CN produces the corresponding benzyl-substituted ligands in good yield. Copper(II) complexes of the ligands derived from salicylaldehyde (L2), p-hydroxybenzaldehyde (L4), and p-carboxybenzaldehy... |
11198865 | Calix[4]arene rhenium(V) complexes as potential radiopharmaceuticals. | The calix[4]arene platform was used for the syntheses of novel rhenium(V) complexes, that may have potential applications as radiopharmaceuticals. The reaction of ReO(PPh3)2Cl3 with tetradentate N2O2-calix[4]arene ligand 8 in ethanol gave the novel mixed-ligand rhenium complex 9 with the structure ReO(N2O2-calix)OEt. T... |
11198861 | Ligand macrocycle structural effects on copper-dioxygen reactivity. | With the goal of understanding how the nature of the tridentate macrocyclic supporting ligand influences the relative stability of isomeric mu-eta 2:eta 2-peroxo- and bis(mu-oxo)dicopper complexes, a comparative study was undertaken of the O2 reactivity of Cu(I) compounds supported by the 10- and 12-membered macrocycle... |
11198850 | An integrated approach to the mid-spin state (S = 3/2) in six-coordinate iron(III) chiroporphyrins. | An intermediate-spin state very close to the mid-spin state (S = 3/2) can be stabilized in a ferric porphyrin by an integrated approach which combines the favorable effects of a weak axial field strength and of a small macrocycle hole. Axial ligand exchange by reaction of chloroiron(III)tetramethylchiroporphyrin [(TMCP... |
11196922 | 2-D interwoven and 3-D 5-fold interpenetrating silver(I) complexes of 1-(isocyanidomethyl)-1H-benzotriazole and 1,3-bis(dicyanomethylidene)indan. | This paper presents novel and distinctive organosilver polymers with intriguing structure motifs, constructed from iodoacetonitrile (L1), 1-(isocyanidomethyl)-1H-benzotriazole (L2), 1,3-bis(dicyanomethylidene)indan (L3), and silver(I) salts, respectively. Treatment of L1 with AgClO4 generated [Ag(L1)(ClO4)]n (1), whose... |
11126028 | Interaction of trimeprazine with cyclodextrins in aqueous solution. | The synergistic effect of pH and complexation with cyclodextrins on some properties of phenothiazine derivative--trimeprazine (TM) was investigated. Inclusion complexes of TM with beta-cyclodextrin (beta-CD) and its substituted derivatives (DM-beta-CD, HP-beta-CD, beta-CDsulf) were obtained in phosphate buffer solution... |
11315672 | [Establishment of the phylogenetic relationship between the microbial producers of cyclodextrin glucanotransferases using their complete amino acid sequences]. | A phylogenetic tree was constructed on the basis of the amino acid sequences of the known cyclodextrin glucanotransferases (CDGTs), including those deduced from the nucleotide sequences of Bacillus sp. strain 6.6.3 and Paenibacillus macerans IB-7 genes encoding alpha- and beta-CDGTs. The tree clearly demonstrates the e... |
11143799 | S-layer-supported lipid membranes. | Many prokaryotic organisms (archaea and bacteria) are covered by a regularly ordered surface layer (S-layer) as the outermost cell wall component. S-layers are built up of a single protein or glycoprotein species and represent the simplest biological membrane developed during evolution. Pores in S-layers are of regular... |
11091961 | Polymerization of humic substances by an enzyme-catalyzed oxidative coupling. | A novel understanding of the structural features of humic substances supports the self-assembly supramolecular association of relatively small molecules rather than their polymeric nature. An increase in the conformational stability of humus may thus be achieved through promotion of intermolecular covalent bondings bet... |
11089753 | Pre-operative tonometry is predictive for mortality and morbidity in high-risk surgical patients. | <h4>Objective</h4>To determine whether a) pre-operative measurement of gastric intramucosal pHi is predictive for mortality and morbidity in high-risk surgical patients and b) peri-operative improvement of global oxygen delivery (DO2) with fluids and dopexamine leads to increased gastric pHi and c) either improved glob... |
11087046 | Near infrared with principal component analysis as a novel analytical approach for nanoparticle technology. | <h4>Purpose</h4>To progress in the characterization of a poly(MePEGcyanoacrylate-co-hexadecylcyanoacrylate) (poly(PEGCA-co-HDCA) copolymer and the nanoparticles formed from this copolymer.<h4>Methods</h4>Poly(PEGCA-co-HDCA) at a MePEG/hexadecyl ratio of 1:4 was investigated by 1H-NMR and near infrared spectroscopy. The... |
11087037 | Enhanced in vitro oligonucleotide and plasmid DNA transport by VP1 virus-like particles. | <h4>Purpose</h4>We developed a prokaryotic expression system to express the major capsid protein of Polyomavirus, VP1. Furthermore, we investigated the transport of single stranded (ss) and double stranded (ds) DNA, mediated through VP1 as drug delivery system into mouse fibroblasts.<h4>Methods</h4>To study DNA deliver... |
11079398 | Light-adaptive role of nitric oxide in the outer retina of lower vertebrates: a brief review. | The role of nitric oxide (NO) as a novel neurochemical mechanism controlling light adaptation of the outer retina is discussed by considering mainly published results. The emphasis is on the retinae of fishes and amphibia, but some data from the mammalian (rabbit) retinae have also been included for completeness. In th... |
11077730 | [Effect of temperature on drug solubility in complex formation of flubendazole and 2-hydroxypropyl-beta-cyclodextrin]. | Flubendazol is a veterinary antiparasitic agent which acts toxically on both adult and larval stages of round worms. It is nearly insoluble in water and it influences not only the selection of the dosage form, but also its biological availability. Its solubility can be increased by adding solutizers and tensides, or by... |
11078017 | Sticky-finger interaction sites on cytosolic lipid-binding proteins? | The cytosolic lipid-binding proteins (cLBPs) comprise a large family of small (14-15 kDa) intracellular proteins involved in the transport of small lipids, including fatty acids and retinoids within cells. Their presumed function is to solubilise, protect from chemical damage and deliver to the correct destination lipi... |
11078016 | A novel uterine lipocalin supporting pregnancy in equids. | Horses, donkeys, and therefore, probably all equids, secrete a nonglycosylated, progesterone-dependent, 19-kDa protein (P19) into the uterine lumen during early pregnancy, and significant quantities of it are taken up by the developing conceptus. Sequence analysis and structural modelling have identified P19 as a lipoc... |
11072847 | Crystal structure of octakis(2,3,6-tri-O-methyl)-gamma-cyclodextrin x 4.5 H2O: evidence for conformational flexibility of permethylated cyclodextrins. | Octakis(2,3,6-tri-O-methyl)-gamma-CD (TRIMEG) cocrystallized at 18 degrees C with 4.5 water molecules in the orthorhombic space group P2(1)2(1)2(1), unit cell dimensions a = 10.7879(3), b = 29.0580(9), c = 32.2909(11) A. The TRIMEG macrocycle is in a 'round' form with all glucose units oriented syn, and one O-6-CH3 met... |
11072846 | Monte Carlo simulations of the chiral recognition of fenoprofen enantiomers by cyclomaltoheptaose (beta-cyclodextrin). | Differential complexation of fenoprofen enantiomers by cyclomaltoheptaose (beta-cyclodextrin) was investigated by Monte Carlo docking simulations. The chiral discrimination of (R)- and (S)-fenoprofen by beta-cyclodextrin was discussed in terms of the difference in the interaction energies and the patterns of molecular ... |
11072834 | Synthesis and analytical characterization of the sodium salt of heptakis(2-O-methyl-3,6-di-O-sulfo)cyclomaltoheptaose, a chiral resolving agent candidate for capillary electrophoresis. | A pure, single isomer, strong electrolyte chiral resolving agent candidate for capillary electrophoresis, the sodium salt of heptakis(2-O-methyl-3,6-di-O-sulfo)cyclomaltoheptaose has been synthesized on the 100-g scale, in greater than 97% purity, through heptakis(2,6-di-O-tert-butyldimethylsilyl)cyclomaltoheptaose, he... |
11059583 | Microstructuring of solid-supported lipid layers using SAM pattern generation by scanning electrochemical microscopy and the chemical lens. | To prepare patterns of adsorption sites for alkanethiols with high lateral resolution, we used the scanning electrochemical microscopy (SECM) to etch masks into uniform layers of nickel coated on gold surfaces. The patterning of the nickel mask was accomplished in aqueous solutions by electrogenerating nitric acid out ... |
11052889 | Monitoring biomolecular interactions by time-lapse atomic force microscopy. | The atomic force microscope (AFM) is a unique imaging tool that enables the tracking of single macromolecule events in response to physiological effectors and pharmacological stimuli. Direct correlation can therefore be made between structural and functional states of individual biomolecules in an aqueous environment. ... |
11045623 | Crystal structure of the catalytic domain of human bile salt activated lipase. | Bile-salt activated lipase (BAL) is a pancreatic enzyme that digests a variety of lipids in the small intestine. A distinct property of BAL is its dependency on bile salts in hydrolyzing substrates of long acyl chains or bulky alcoholic motifs. A crystal structure of the catalytic domain of human BAL (residues 1-538) w... |
11045616 | Protein engineering as a strategy to avoid formation of amyloid fibrils. | The activation domain of human procarboxypeptidase A2 (ADA2h) aggregates following thermal or chemical denaturation at acidic pH. The aggregated material contains well-defined ordered structures with all the characteristics of the fibrils associated with amyloidotic diseases. Variants of ADA2h containing a series of mu... |
11045507 | Enantiomer separations by nonaqueous capillary electrophoresis using octakis(2,3-diacetyl-6-sulfato)-gamma-cyclodextrin. | The newest member of the single-isomer isomer sulfated cyclodextrin family, octakis(2,3-diacetyl-6-sulfato)-gamma-cyclodextrin (ODAS-gamma-CD) was used for the first time as a resolving agent for the nonaqueous capillary electrophoretic separation of the enantiomers of 26 weak base pharmaceuticals in an acidic methanol... |
11045488 | Reversed migration micellar electrokinetic chromatography with off-line and on-line concentration analysis of phenylurea herbicides. | Three environmentally important phenylurea herbicides (monuron, isoproturon, diuron) were separated in reversed migration micellar electrokinetic chromatography (RM-MEKC) using 50 mM sodium dodecyl sulfate, 50 mM phosphoric acid, and 15 mM gamma-cyclodextrin. Three on-line concentration techniques are then evaluated to... |
11045485 | Capillary electrophoresis coupled to biosensor detection. | The present review highlights some modern aspects of biosensor revelation, a detection method which has already found a large number of applications in healthcare, food industry and environmental analysis. First, the concept of bio-recognition, which is at the heart of biosensor technology, is discussed, with emphasis ... |
11043599 | Determination of enantiomeric excess of alpha-hydroxy-3-phenoxybenzeneacetonitrile and its n-butyl ester by chiral high-performance liquid chromatography. | Determination of enantiomeric excess of alpha-hydroxy-3-phenoxybenzeneacetonitrile, an important intermediate in the production of several pyrethroid insecticides, is usually done after derivatization and gas chromatographic analysis on a beta-cyclodextrin-based column. In this communication we report a direct determin... |
11043598 | Enantiomeric separations of cationic and neutral compounds by capillary electrochromatography with monolithic chiral stationary phases of beta-cyclodextrin-bonded negatively charged polyacrylamide gels. | Enantiomeric separation by capillary electrochromatography with beta-cyclodextrin-bonded negatively charged polyacrylamide gels was examined. The columns used are capillaries filled with a negatively charged polyacrylamide gel, a so-called monolithic stationary phase, to which allyl carbamoylated beta-CD (AC-beta-CD) d... |
11033344 | Noradrenaline systems in the hypothalamus, amygdala and locus coeruleus are involved in the provocation of anxiety: basic studies. | A variety of stressful events, including emotional stress, cause a marked increase in noradrenaline release in several brain regions, and especially in the hypothalamus, amygdala and locus coeruleus, in the rat brain. These findings suggest that an increased noradrenaline release could be closely related to the provoca... |
11027156 | Growth of NS0 cells in protein-free, chemically defined medium. | Many hybridoma and recombinant myeloma cell lines have been successfully adapted to growth in protein-free media. Compared with serum-supplemented media, use of protein-free media promotes superior cell growth and protein expression and facilitates downstream purification of the expressed product. Owing to its sterol a... |
11028789 | Crystal structures of heptakis(2,6-di-O-tert-butyldimethylsilyl)cyclomaltoheptaose, heptakis(2-O-methyl-3,6-di-O-tert-butyldimethylsilyl)cyclomaltoheptaose and heptakis(2-O-methyl)cyclomaltoheptaose. | Crystal structures of heptakis(2,6-di-O-tert-butyldimethylsilyl)cyclomaltoheptaose, heptakis(2-O-methyl-3,6-di-O-tert-butyldimethylsilyl)cyclomaltohep taose and heptakis(2-O-methyl)cyclomaltoheptaose were determined from X-ray diffraction patterns obtained for single crystals of the title compounds grown from ethyl ace... |
11028781 | The crystal structure of the 1:1 complex of beta-cyclodextrin with trans-cinnamic acid. | The crystal structure of the 1:1 complex of beta-cyclodextrin (cyclomaltoheptaose) with trans-cinnamic acid was studied by X-ray diffraction. Two beta-cyclodextrin molecules related by a twofold crystal axis form dimers in the hydrophobic cavity of which, two guest molecules are entirely buried. The complex crystallize... |
11028541 | Hypertonic saline inhibits neutrophil (PMN) priming via attenuation of p38 MAPK signaling. | Priming of the neutrophil cytotoxic response is central to the pathogenesis of early postinjury multiple organ failure (MOF). Platelet-activating factor (PAF) has been implicated as a key inflammatory mediator in postinjury neutrophil priming and requires p38 MAPK signaling to produce its biologic effects. Hypertonic s... |
11026739 | The inclusion of fluoxetine into gamma-cyclodextrin increases its bioavailability: behavioral, electrophysiological and pharmacokinetic studies. | The inclusion of a drug into cyclodextrin generally results in the modification of its physical and chemical properties and sometimes can increase its oral bioavailability. The aim of this study was to compare the effects of the fluoxetine HCl/gamma-cyclodextrin complex to that of traditional fluoxetine HCl. In the for... |
11026536 | Template-constrained cyclic peptide analogues of somatostatin: subtype-selective binding to somatostatin receptors and antiangiogenic activity. | Beta-turns are a common secondary structure motif found in proteins that play a role in protein folding and stability and participate in molecular recognition interactions. Somatostatin, a peptide hormone possessing a variety of therapeutically-interesting biological activities, contains a beta-turn in its bioactive co... |
11020321 | Surface plasmon resonance-based immunoassays. | Surface plasmon resonance (SPR) has been successfully incorporated into an immunosensor format for the simple, rapid, and nonlabeled assay of various biochemical analytes. Proteins, complex conjugates, toxins, allergens, drugs, and pesticides can be determined directly using either natural antibodies or synthetic recep... |
11023196 | Targeted killing of carcinoembryonic antigen (CEA)-producing cholangiocarcinoma cells by polyamidoamine dendrimer-mediated transfer of an Epstein-Barr virus (EBV)-based plasmid vector carrying the CEA promoter. | The present study reports a novel nonviral method to efficiently and specifically target carcinoembryonic antigen (CEA)-producing cholangiocarcinoma (CC) cells in vitro. Epstein-Barr virus (EBV)-based and conventional plasmid vectors were constructed that possess the beta-galactosidase (beta-gal) or herpes simplex viru... |
11018712 | A bis-cyclodextrin diselenide with glutathione peroxidase-like activity. | A diselenide, 2,2'-diseleno-bis-beta-cyclodextrin (2-SeCD), was synthesized to imitate the antioxidant enzyme glutathione peroxidase (GPX). The GPX mimic accepts a variety of hydroperoxides as substrates. The GPX activities, reduction of H(2)O(2), tert-butyl hydroperoxide and cumenyl hydroperoxide by glutathione, are 7... |
11018470 | Activation of phospholipase D by PKC and GTPgammaS in human neuroblastoma cells overexpressing MARCKS. | Regulation of phospholipase D (PLD) activity participating in signal transduction involves complex interactions with small G-proteins (ARF, Rho) and protein kinase C isoforms (PKCalpha). In SK-N-MC human neuroblastoma cells, phorbol ester (TPA) activation of PLD was enhanced by overexpressing myristoylated alanine-rich... |
11014199 | Chromodomains are protein-RNA interaction modules. | In Drosophila, compensation for the reduced dosage of genes located on the single male X chromosome involves doubling their expression in relation to their counterparts on female X chromosomes. Dosage compensation is an epigenetic process involving the specific acetylation of histone H4 at lysine 16 by the histone acet... |
11008778 | Functionalization of a poly(amidoamine) dendrimer with ferrocenyls and its application to the construction of a reagentless enzyme electrode. | Poly(amidoamine) dendrimers having various degrees of modification with the redox-active ferrocenyls were prepared by controlling the molar ratio of ferrocenecarboxaldehyde to amine groups of dendrimers. By alternate layer-by-layer depositions of partial ferrocenyl-tethered dendrimers (Fc-D) with periodate-oxidized glu... |
11008760 | A mass spectrometry method for the determination of enantiomeric excess in mixtures of D,L-amino acids. | A mass spectrometry method based on ion/molecule reactions for determining enantiomeric excess in mixtures of amino acids is illustrated. Protonated complexes of amino acids with beta-cyclodextrin are produced in the gas phase using electrospray ionization. Under a background pressure of N-propylamine, the amino acid i... |
10984518 | Contribution of Salmonella typhimurium type III secretion components to needle complex formation. | The prgHIJK operon encodes components of the Salmonella typhimurium pathogenicity island 1 type III secretion system (TTSS). Previously, prgH and prgK were shown to be required for formation of the supramolecular type III secretion needle complex (NC) [Kubori, T., et al. (1998) Science 280, 602-605]. This work indicate... |
10984523 | Unraveling the mechanism of the lactose permease of Escherichia coli. | We studied the effect of pH on ligand binding in wild-type lactose permease or mutants in the four residues-Glu-269, Arg-302, His-322, and Glu-325-that are the key participants in H(+) translocation and coupling between sugar and H(+) translocation. Although wild-type permease or mutants in Glu-325 and Arg-302 exhibit ... |
10984501 | Directed evolution of antibody fragments with monovalent femtomolar antigen-binding affinity. | Single-chain antibody mutants have been evolved in vitro with antigen-binding equilibrium dissociation constant K(d) = 48 fM and slower dissociation kinetics (half-time > 5 days) than those for the streptavidin-biotin complex. These mutants possess the highest monovalent ligand-binding affinity yet reported for an engi... |
11007515 | Monoclonal antibody-dendrimer conjugates enable radiolabeling of antibody with markedly high specific activity with minimal loss of immunoreactivity. | For the purpose of radioimmunotherapy, labelling of monoclonal antibody with high specific activity is often necessary, especially when using a radionuclide with a shorter half-life. Polyamine dendrimers (PAMAM) are novel synthetic polymeric molecules with large numbers of amine residues on their spherical surface. In ... |
10887176 | A novel pharmacological approach to treating cardiac ischemia. Binary conjugates of A1 and A3 adenosine receptor agonists. | Adenosine released during cardiac ischemia exerts a potent, protective effect in the heart via activation of A(1) or A(3) receptors. However, the interaction between the two cardioprotective adenosine receptors and the question of which receptor is the more important anti-ischemic receptor remain largely unexplored. Th... |
10903322 | Trans complementation of variant Cre proteins for defects in cleavage and synapsis. | The Cre recombinase is a member of the integrase family of conservative site-specific recombinases. These proteins share five conserved catalytic residues, one of which is a tyrosine that acts as the nucleophile to attack the scissile phosphodiester bond in the DNA target. Recombination by the Cre recombinase takes pla... |
11000116 | Topologically linked protein rings in the bacteriophage HK97 capsid. | The crystal structure of the double-stranded DNA bacteriophage HK97 mature empty capsid was determined at 3.6 angstrom resolution. The 660 angstrom diameter icosahedral particle contains 420 subunits with a new fold. The final capsid maturation step is an autocatalytic reaction that creates 420 isopeptide bonds between... |
10998247 | Characterization of apolipoprotein-mediated HDL generation induced by cAMP in a murine macrophage cell line. | Murine macrophage RAW264 were investigated for their response to lipid-free apolipoproteins. Preincubation of the cells with 300 microM dibutyryl cyclic (dBc) AMP for 16 h induced specific binding of apolipoprotein (apo) A-I to the cells and apoA-I-mediated HDL formation with cellular lipids, neither of which was detec... |
10998241 | Self-assembly of heme A and heme B in a designed four-helix bundle: implications for a cytochrome c oxidase maquette. | Heme A, a prosthetic group of cytochrome c oxidase [EC 1.9.3.1], has been introduced into two de novo designed four helix bundle proteins, [H10A24](2) and [H10H24](2), known to bind 2-4 equiv of heme B, respectively [Robertson, D. E., Farid, R. S., Moser, C. C., Mulholland, S. E., Pidikiti, R., Lear, J. D., Wand, A., J... |
11001226 | Investigation of the stereoselective in vitro biotransformation of thalidomide using a dual cyclodextrin system in capillary electrophoresis. | A previously developed capillary electrophoresis method for the simultaneous separation and enantioseparation of thalidomide (TD) and its hydroxylated metabolites was extended to one additional biotransformation product. The dual chiral selector system using native beta-cyclodextrin (beta-CD) and the negatively charged... |
11001225 | Enantiomeric separation of dihydroxyphenylalanine (DOPA), methyldihydroxyphenylalanine (MDOPA) and hydrazinomethyldihydroxyphenylalanine (CDOPA) by using capillary electrophoresis with sulfobutyl ether-beta-cyclodextrin as a chiral selector. | Capillary electrophoresis (CE) was successfully applied to the enantiomer resolution of racemic structurally related compounds, namely dihydroxyphenylalanine (DOPA), methyldihydroxyphenylalanine (MDOPA) and hydrazinomethyldihydroxyphenylalanine (CDOPA). The chiral resolution was performed in an untreated fused-silica c... |
11001224 | On-chip chiral and achiral separation of amphetamine and related compounds labeled with 4-fluoro-7-nitrobenzofurazane. | Amphetamine and analogous compounds have been labeled with 4-fluoro-7-nitrobenzofurazane and analyzed on a microfabricated chip. Separation of norephedrine, ephedrine, cathinone, pseudoephedrine, methcathinone, amphetamine and methamphetamine is demonstrated using micellar electrokinetic capillary chromatography (MEKC)... |
11001223 | Experimental verification of a predicted, previously unseen separation selectivity pattern in the capillary electrophoretic separation of noncharged enantiomers by octakis(2,3-diacetyl-6-sulfato)-gamma-cyclodextrin. | The capillary electrophoretic separation of noncharged enantiomers with single-isomer anionic resolving agents is reexamined here with the help of the charged resolving agent migration model. Two general model parameters have been identified that influence the effective mobility, separation selectivity and mobility dif... |
11001222 | Fast enantiomeric separation of uniconazole and diniconazole by electrokinetic chromatography using an anionic cyclodextrin: application to the determination of analyte-selector apparent binding constants for enantiomers. | The enantiomeric resolution of the fungicides uniconazole and diniconazole was performed using electrokinetic chromatography with cyclodextrins as pseudostationary phase (CD-EKC). A systematic evaluation of several chiral selectors was made. The anionic derivative carboxymethylated-gamma-cyclodextrin (CM-gamma-CD) was ... |
11001221 | Recent innovations in the use of charged cyclodextrins in capillary electrophoresis for chiral separations in pharmaceutical analysis. | A review is presented on the use of charged cyclodextrins (CDs) as chiral selectors in capillary electrophoresis (CE) for the separation of analytes in pharmaceutical analysis. An overview is given of theoretical models that have been developed for a better prediction of the enantiomeric resolution and for a better und... |
11001218 | Analysis of colistin sulfate by capillary zone electrophoresis with cyclodextrins as additive. | A method for the quantitative analysis of colistin sulfate by capillary zone electrophoresis is described. Since colistin components have five free amino groups, they tend to adsorb onto the capillary wall and cause peak tailing. It was found that triethanolamine (TEA)-phosphate buffer at pH 2.5 was useful to reduce su... |
11001214 | Recent innovation in capillary electrokinetic chromatography with replaceable charged pseudostationary phases or additives. | Recent developments of separation of neutral analytes in capillary systems with the mobile phase driven by the electroosmotic flow (EOF) and charged additives acting as a pseudostationary phase are reviewed. As pseudostationary phases a number of additives are used. Soluble polymers, either anionic or cationic, were ap... |
11001213 | Enantiomer separation by capillary electrochromatography on a cyclodextrin-modified monolith. | A chiral monolithic stationary phase was prepared by packing a capillary with bare porous silica and sintering the silica bed at high temperature. The resulting silica monolith was polymer-coated with Chirasil-Dex, a permethylated beta-cyclodextrin covalently linked via an octamethylene spacer to dimethylpolysiloxane. ... |
11001210 | Enantiomeric separation by capillary electrochromatography. II. Chiral separation of dansyl amino acids and phenoxy acid herbicides on sulfonated silica having surface-bound hydroxypropyl-beta-cyclodextrin. | A chiral silica-based stationary phase having surface-bound hydroxypropyl-beta-cyclodextrin (HP-beta-CD) with a relatively strong electroosmotic flow (EOF) was introduced for enantioseparation by capillary electrochromatography (CEC). The stationary phase contained a hydrophilic sulfonated sublayer to which a chiral to... |
11001209 | Enantiomeric separation by capillary electrochromatography. I. Chiral separation of dansyl amino acids and organochlorine pesticides on a diol-silica dynamically coated with hydroxypropyl-beta-cyclodextrin. | In this work, a commercially available diol-silica stationary phase was converted in situ to a chiral stationary phase by dynamically coating it with hydroxypropyl-beta-cyclodextrin (HP-beta-CD). This stationary phase was shown useful for the capillary electrochromatography (CEC) separation of neutral and anionic enant... |
11001208 | A new easy-to-prepare homogeneous continuous electrochromatographic bed for enantiomer recognition. | Completely homogeneous polyacrylamide-based gels were used for capillary electrochromatography (CEC) of drug enantiomers. Like continuous beds (also called continuous polymer rods, silica rods, monoliths) they do not require frits to support the bed because it is covalently linked to the capillary wall. A long lifetime... |
11001050 | Helical self-assembled polymers from cooperative stacking of hydrogen-bonded pairs. | The double helix of DNA epitomizes this molecule's ability to self-assemble in aqueous solutions into a complex chiral structure using hydrogen bonding and hydrophobic interactions. Non-covalently interacting molecules in organic solvents are used to design systems that similarly form controlled architectures. Peripher... |
10999640 | Determination of cyclodextrin content using periodate oxidation by capillary electrophoresis. | A simple and general method suitable for the determination of cyclodextrin content in various matrices is described. The proposed method involves selective cleavage of C-C bonds with vicinal hydroxyl groups by means of periodate (Malaprade's reaction). The amount of produced iodate is monitored by capillary electrophor... |
10999636 | Determination of fumaric acid in apple juice by on-line coupled capillary isotachophoresis-capillary zone electrophoresis with UV detection. | An on-line coupled capillary isotachophoresis-capillary zone electrophoresis (cITP-CZE) method for the determination of the fumaric acid content in apple juice is presented. A clear separation of fumaric acid in real samples is achieved within 20 min. The leading, terminating and background electrolyte of the employed ... |
10999604 | Convergence of natural and artificial evolution on an RNA loop-loop interaction: the HIV-1 dimerization initiation site. | Loop-loop interactions among nucleic acids constitute an important form of molecular recognition in a variety of biological systems. In HIV-1, genomic dimerization involves an intermolecular RNA loop-loop interaction at the dimerization initiation site (DIS), a hairpin located in the 5' noncoding region that contains a... |
10995202 | From boiling stones to smart crystals: supramolecular and magnetic isotope control of radical-radical reactions in zeolites. | The chemistry of radicals adsorbed on zeolites is remarkable in that the products of radical-radical reactions, which are nonselective in solution, can be made selective and can be controlled by supramolecular effects and magnetic isotope effects. The photolysis of ketones adsorbed on zeolites can be manipulated so tha... |
10995196 | Nucleic acid aptamers-from selection in vitro to applications in vivo. | Aptamers are nucleic acid ligands which are isolated from combinatorial oligonucleotide libraries by in vitro selection. They exhibit highly complex and sophisticated molecular recognition properties and are capable of binding tightly and specifically to targets ranging from small molecules to complex multimeric struct... |
10995445 | TRP and the PDZ protein, INAD, form the core complex required for retention of the signalplex in Drosophila photoreceptor cells. | The light response in Drosophila photoreceptor cells is mediated by a series of proteins that assemble into a macromolecular complex referred to as the signalplex. The central player in the signalplex is inactivation no afterpotential D (INAD), a protein consisting of a tandem array of five PDZ domains. At least seven ... |
10995292 | Improvement of oxidative stability of conjugated linoleic acid (CLA) by microencapsulation in cyclodextrins. | Oxidative stability of conjugated linoleic acid (CLA) encapsulated in alpha-, beta-, and gamma-cyclodextrins (designated CLA/CDs microencapsules) was studied by measuring the headspace-oxygen depletion in airtight serum bottles and by measuring the peroxide values (POV). The rate of oxygen depletion was reduced from 41... |
10995272 | Functional changes in beta-lactoglobulin upon conjugation with carboxymethyl cyclodextrin. | Bovine beta-lactoglobulin-carboxymethyl cyclodextrin (beta-LG-CMCyD) conjugate was prepared using water-soluble carbodiimide, in an effort to improve the functional properties of the protein. The molar ratio of beta-LG to CMCyD in the conjugate was 1:2. The isoelectric point of the conjugate was 4.1-5.8. Spectroscopic ... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.