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12101281 | Differential localization of IL-2- and -15 receptor chains in membrane rafts of human T cells. | We studied whether cytokine receptors (Rs) on T cells associate with lipid microdomains ("rafts"). Low-dose phytohemagglutinin (PHA)-stimulated human T cells were separated into cytoplasmic, membrane, and raft fractions by buoyant density centrifugation. Examination of these fractions for the presence of interleukin (I... |
12100860 | In vitro experiment optimization for measuring tetrahydrocannabinol skin permeation. | The purpose of this study was to optimize in vitro experimental conditions for the measurement of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) permeation across human skin using a flow-through diffusion cell system. The drug permeation rates through intact and stripped (stratum corneum (SC) removed) skin were also comp... |
12099876 | Synthesis, characterization, and crystal structures of two new divalent metal complexes of N,N'-bis(phosphonomethyl)-1,10-diaza-18-crown-6: a hydrogen-bonded 1D array and a 3D network with a large channel. | Reaction of N,N'-bis(phosphonomethyl)-1,10-diaza-18-crown-6 (H(4)L) with copper(II) acetate in 1:1 ethanol/water mixed solvents afforded a new crystal-engineered supramolecular metal phosphonate, Cu(H(2)L) (complex 1). By reaction of the same ligand with cadmium(II) nitrate in a 2:1 (M/L) ratio in methanol, a cadmium(I... |
12099869 | Linear trimer analogues of calixarene as chiral coordinating ligands: X-ray crystallographic and NMR spectroscopic characterization of chiral and achiral trisphenolates complexed to titanium(IV) and aluminum(III). | Achiral and chiral linear trisphenol analogues of calixarene (HOArCH(2)Ar'(OH)C(R)HArOH, Ar = 4,6-di-tert-butylphenyl; Ar' = 4-tert-butylphenyl; R = H (achiral), Me (chiral)) were prepared in anticipation of their adoption of a chiral conformation upon coordination to Lewis acidic metal centers. The trisphenols react w... |
12101093 | The binding site of the RNA-dependent protein kinase (PKR) on EBER1 RNA from Epstein-Barr virus. | The RNA-dependent protein kinase (PKR) is an interferon-induced, RNA-activated enzyme that phosphorylates the eukaryotic initiation factor 2alpha, rendering the translation machinery inactive. Viruses have developed strategies for preventing the action of PKR, one of which is the production of small RNAs that inhibit t... |
12098240 | Peracetylated sugar derivatives show high solubility in liquid and supercritical carbon dioxide. | [structure: see text] Acetylated sugars derivatives exhibit high solubility in liquid and supercritical carbon dioxide (scCO(2)). Peracetylated sorbitol and beta-D-galactose are soluble under mild conditions in scCO(2), high pressures are required to dissolve peracetylated beta-cyclodextrin, and peracetoxyalkyl chains ... |
12098235 | Sequence-selective visual recognition of nonprotected dipeptides. | [structure: see text] A receptor 1 with phenolphthalein and two crown ethers in the molecule develops brilliant purple color in the presence of dipeptides with a specific amino acid-sequence containing a C-terminal lysine. This type of color development could be extended to the detection of oligopeptides of a specific ... |
12098229 | Ring-in-ring structures from phenanthroline macrocycles with exo- and endotopic binding sites. | [structure: see text] Three metallosupramolecular ring-in-ring structures are assembled using the HETPHEN concept (in the presence of copper(I)) with macrocyclic phenanthrolines exhibiting exotopic and endotopic coordination sites. |
12098301 | Synthesis of macrocyclic, potential protease inhibitors using a generic scaffold. | A generic macrocyclic peptide structure 2 was designed as a potential inhibitor of a range of proteinases, by using as a basis for the design the known structures of a series of enzyme-inhibitor complexes. The macrocyclic nature of the target 2 was chosen so as to reduce the entropic advantage in the hydrolytic enzymat... |
12098299 | Conjugated macrocycles related to the porphyrins. 21. Synthesis, spectroscopy, electrochemistry, and structural characterization of carbaporphyrins. | The "3 + 1" variant of the MacDonald condensation has been shown to be an excellent methodology for synthesizing carbaporphyrins. In particular, 1,3-indenedicarbaldehyde condenses with tripyrranes in the presence of TFA to give, following oxidation with DDQ, a series of benzocarbaporphyrins in excellent yields. Triform... |
12098292 | Kinetic stabilities of double, tetra-, and hexarosette hydrogen-bonded assemblies. | A study of the kinetic stabilities of hydrogen-bonded double, tetra-, and hexarosette assemblies, comprising 36, 72, and 108 hydrogen bonds, respectively, is described. The kinetic stabilities are measured using both chiral amplification and racemization experiments. The chiral amplification studies show that solvent p... |
12098291 | New artificial host compounds containing galactose end groups for binding chiral organic amine guests: chiral discrimination and their complex structures. | New linear host (1) and cyclic hosts (2 and 3), which have galactopyranose skeletons as chiral origins and oxyethylenes skeletons as binding sites, were designed based on the structural features extracted from the fructo-oligosaccharide derivatives, having a large chiral discrimination ability, and were then synthesize... |
12098281 | Glycoside-clustering round calixarenes toward the development of multivalent ligands. Synthesis and conformational analysis of Calix[4]arene O- and C-glycoconjugates. | Bis- and tetra-O- and C-glycosyl calixarenes (calixsugars) have been prepared by tethering carbohydrate moieties to a tetrapropoxycalix[4]arene scaffold through alkyl chains. Two methodologies have been employed. One consisted of the stereoselective multiple glycosylation of upper rim calix[4]arene polyols leading to c... |
12097500 | Enhanced rate of nerve regeneration and directional errors after sciatic nerve injury in receptor protein tyrosine phosphatase sigma knock-out mice. | The receptor protein tyrosine phosphatase sigma (PTPsigma) is a member of the mammalian leukocyte common antigen-related (LAR) family. Its expression is developmentally regulated in neuronal tissues. The Drosophila homolog of the mammalian LAR family of phosphatases (DLAR) controls axon guidance during Drosophila embry... |
12096205 | Diaphragm plication following phrenic nerve injury: a comparison of paediatric and adult patients. | <h4>Background</h4>A study was undertaken to evaluate whether adults differ from children in the indications and outcome of diaphragmatic plication following phrenic nerve injury.<h4>Methods</h4>A retrospective study was performed of 21 patients, 10 below the age of 5 and 11 older than 37 years. The indication for surg... |
12095356 | Electronic absorption, resonance Raman, and electrochemical studies of planar and saddled copper(III) meso-triarylcorroles. Highly substituent-sensitive Soret bands as a distinctive feature of high-valent transition metal corroles. | We present here a first systematic study of substituent effects in metallocorroles, based on electronic absorption, resonance Raman (RR), and infrared (IR) spectroscopic studies and electrochemical measurements on 10 copper(III) meso-triarylcorroles, Cu(III)[beta-Y(8)TArC], where the beta-substituent Y = H or Br and th... |
12095343 | Stereochemical effects in supramolecular self-assembly at surfaces: 1-D versus 2-D enantiomorphic ordering for PVBA and PEBA on Ag(111). | We present investigations on noncovalent bonding and supramolecular self-assembly of two related molecular building blocks at a noble metal surface: 4-[trans-2-(pyrid-4-yl-vinyl)]benzoic acid (PVBA) and 4-[(pyrid-4-yl-ethynyl)]benzoic acid (PEBA). These rigid, rodlike molecules comprising the same complementary moietie... |
12095342 | Highly enantioselective intra- and intermolecular [2 + 2] photocycloaddition reactions of 2-quinolones mediated by a chiral lactam host: host-guest interactions, product configuration, and the origin of the stereoselectivity in solution. | The [2 + 2] photocycloaddition of 4-alkoxy-2-quinolones was conducted in the presence of the chiral lactams 5 or ent-5. At -60 degrees C in toluene as the solvent the intramolecular reaction of quinolones 6 and 8 as well as the intermolecular photocycloaddition of various alkenes 13 to quinolone 12 proceeded with excel... |
12095338 | Electron-induced switching of the supramolecular chirality of optically active polythiophene aggregates. | A chiral regioregular polythiophene (PT), poly[3-[4-((R)-4-ethyl-2-oxazolin-2-yl)phenyl]thiophene] (poly-1), forms chiral aggregates which exhibit a unique induced circular dichroism (ICD) in the pi-pi transition region derived from the supramolecular chirality in the presence of various poor solvents or metal salts in... |
12095325 | Molecular recognition in methanol: the first example of hydrogen-bond-mediated self-association of a calix[4]arene in polar, protic solvent. | Tetraalaninecalixarene was prepared by coupling of tetraaminocalix[4]arene with alanine. It dimerizes in methanol, providing the first example of a substituted calixarene that undergoes self-association through hydrogen bonding in polar, protic solvent. The association constant in 24:1 MeOH:H2O was determined to be 29 ... |
12095127 | Bioactive oxidized lipids in the plasma of cardiac surgical intensive care patients. | Critical illness is associated with increased oxidative stress that may give rise to the formation of lipid hydroperoxides (LOOH) and various secondary degradation products such as fragmented phosphatidylcholine (FPC) and lipids related to the platelet-activating factor (PAF). Because some oxidized phospholipids are po... |
12093894 | Human cholesterol 7alpha-hydroxylase (CYP7A1) deficiency has a hypercholesterolemic phenotype. | Bile acid synthesis plays a critical role in the maintenance of mammalian cholesterol homeostasis. The CYP7A1 gene encodes the enzyme cholesterol 7alpha-hydroxylase, which catalyzes the initial step in cholesterol catabolism and bile acid synthesis. We report here a new metabolic disorder presenting with hyperlipidemia... |
12093730 | Structural basis for the reversible activation of a Rho protein by the bacterial toxin SopE. | The bacterial enteropathogen Salmonella typhimurium employs a type III secretion system to inject bacterial toxins into the host cell cytosol. These toxins transiently activate Rho family GTP-binding protein-dependent signaling cascades to induce cytoskeletal rearrangements. One of these translocated Salmonella toxins,... |
12093289 | (13)C MAS NMR and photo-CIDNP reveal a pronounced asymmetry in the electronic ground state of the special pair of Rhodobacter sphaeroides reaction centers. | Reaction centers of wild-type Rhodobacter sphaeroides were selectively (13)C-isotope labeled in bacteriochlorophyll and bacteriopheophytin. (13)C solid-state CP/MAS NMR and photo-CIDNP were used to provide insight into the electronic structure of the primary electron donor and acceptor on the atomic scale. The first 2-... |
12093285 | DNA sequence recognition by the antitumor drug ditercalinium. | The antitumor drug ditercalinium is a rare example of a noncovalent DNA-binding ligand that forms bisintercalation complexes via the major groove of the double helix. Previous structural studies have revealed that the two connected pyridocarbazolium chromophores intercalate into DNA with the positively charged bis(ethy... |
12088732 | Effect of vehicle on brain uptake of [11C]toluene. | With the goal of investigating the pharmacokinetics of the abused solvent, toluene we have adapted the rapid coupling of methyl iodide with tributylphenylstannane mediated by palladium(0) complex to the synthesis of no-carrier-added [11C]toluene starting with 11CH(3)I. Two methods for purification and formulation of th... |
12089562 | Amine-modified random primers to label probes for DNA microarrays. | DNA microarrays have been used to study the expression of thousands of genes at the same time in a variety of cells and tissues. The methods most commonly used to label probes for microarray studies require a minimum of 20 microg of total RNA or 2 microg of poly(A) RNA. This has made it difficult to study small and rar... |
12089001 | Molecular characterization of the S-layer gene, sbpA, of Bacillus sphaericus CCM 2177 and production of a functional S-layer fusion protein with the ability to recrystallize in a defined orientation while presenting the fused allergen. | The nucleotide sequence encoding the crystalline bacterial cell surface (S-layer) protein SbpA of Bacillus sphaericus CCM 2177 was determined by a PCR-based technique using four overlapping fragments. The entire sbpA sequence indicated one open reading frame of 3,804 bp encoding a protein of 1,268 amino acids with a th... |
12087174 | DNA bending and unwinding due to the major 1,2-GG intrastrand cross-link formed by antitumor cis-diamminedichloroplatinum(II) are flanking-base independent. | Antitumor cisplatin [cis-diamminedichloroplatinum(II)] forms on DNA predominantly intrastrand cross-links between neighboring purine residues. Several discoveries suggested that the toxicity of cisplatin originated from these lesions. The formation of 1,2-GG intrastrand cross-link of cisplatin leads to marked conformat... |
12087164 | Modulation of enzymatic activities of Escherichia coli DnaB helicase by single-stranded DNA-binding proteins. | The modulation of enzymatic activities of Escherichia coli DnaB helicase by homologous and heterologous single-stranded DNA-binding proteins (SSBs) and its DNA substrates were analyzed. Although DnaB helicase can unwind a variety of DNA substrates possessing different fork-like structures, the rate of DNA unwinding was... |
12087162 | Use of fluorescent sequence-specific polyamides to discriminate human chromosomes by microscopy and flow cytometry. | In this paper, we demonstrate the use of synthetic polyamide probes to fluorescently label heterochromatic regions on human chromosomes for discrimination in cytogenetic preparations and by flow cytometry. Polyamides bind to the minor groove of DNA in a sequence-specific manner. Unlike conventional sequence-specific DN... |
12087161 | DNA assembly using bis-peptide nucleic acids (bisPNAs). | DNA nanostructures are ordered oligonucleotide arrangements that have applications for DNA computers, crystallography, diagnostics and material sciences. Peptide nucleic acid (PNA) is a DNA/RNA mimic that offers many advantages for hybridization, but its potential for application in the field of DNA nanotechnology has ... |
12087159 | Non-contact positions impose site selectivity on Cre recombinase. | A first step in Cre-mediated site-specific DNA recombination is binding to the two 13 bp repeats of the 34 bp site loxP. Several nucleotides within loxP do not directly contact the bound enzyme, yet mutation at two of these base pairs, at positions 11 and 12 in each repeat, results in a 100 000-fold reduction in recomb... |
12086730 | Development of hemoglobin aquasomes from spherical hydroxyapatite cores precipitated in the presence of half-generation poly(amidoamine) dendrimer. | Spherical hydroxyapatite cores were prepared by using carboxylic acid terminated half-generation poly(amidoamine) (PAMAM) dendrimer as templates or crystal modifiers. The hydroxyapatite cores were characterized by infrared spectroscopy (IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The spheri... |
12086831 | Polymer-bound 1-aryl-3-alkyltriazenes as modular ligands for catalysis. Part 1: synthesis and metal coordination. | A range of di- and tri-substituted triazenes have been synthesized from a polymer-supported diazonium salt and various primary and secondary amines. The triazenes obtained were treated with transition metal salts to form polymer-supported metal complexes in firstly a general screen and then in a specific manner. |
12085229 | Analysing c-kit internalization using a functional c-kit-EGFP chimera containing the fluorochrome within the extracellular domain. | In order to investigate activation and internalization of c-kit we created a functional c-kit-EGFP chimera by inserting EYFP (enhanced yellow fluorescent protein) within the extracellular domain of c-kit immediately downstream of the signal sequence, SS-EYFP-kit. This location was chosen because the C-terminal fusion o... |
12084779 | Cysteine mutagenesis and computer modeling of the S6 region of an intermediate conductance IKCa channel. | Cysteine-scanning mutagenesis (SCAM) and computer-based modeling were used to investigate key structural features of the S6 transmembrane segment of the calcium-activated K(+) channel of intermediate conductance IKCa. Our SCAM results show that the interaction of [2-(trimethylammonium)ethyl] methanethiosulfonate bromid... |
12084773 | Molecular proximity of Kv1.3 voltage-gated potassium channels and beta(1)-integrins on the plasma membrane of melanoma cells: effects of cell adherence and channel blockers. | Tumor cell membranes have multiple components that participate in the process of metastasis. The present study investigates the physical association of beta1-integrins and Kv1.3 voltage-gated potassium channels in melanoma cell membranes using resonance energy transfer (RET) techniques. RET between donor-labeled anti-b... |
12083938 | Development of a molecular recognition ion gating membrane and estimation of its pore size control. | We have fabricated a molecular recognition ion gating membrane. This synthetic membrane spontaneously opens and closes its pores in response to specific solvated ions. In addition to this switching function, we found that this membrane could control its pore size in response to a known concentration of a specific ion. ... |
12083900 | Molecular "chaperones" guide the spontaneous formation of a 15-component hydrogen-bonded assembly. | Chaperones are small molecules that assist in the folding of naturally occurring peptides. There are no examples of small molecules acting as chaperones in the self-assembly of synthetic noncovalent assemblies. In this communication we describe an unprecedented example of the "chaperone effect" in the noncovalent synth... |
12084504 | Improved dissolution behaviour of steam-granulated piroxicam. | In this paper we prepared and characterized improved release granulates containing Piroxicam and beta-cyclodextrins (1:2.5 molar ratio), obtained by steam-aided granulation, using a one-step rotogranulator, Rotolab. These granulates were compared to those prepared by traditional wet granulation, to the physical mixture... |
12082159 | The molecular mechanism of translocation through the nuclear pore complex is highly conserved. | In this report we investigated the activity of vertebrate nuclear transport factors in a primitive organism, Amoeba proteus, to better understand evolutionary changes in the transport mechanisms of organisms expected to have different requirements for nucleocytoplasmic exchange. It was initially determined that FxFG-co... |
12082155 | Membrane ruffling and macropinocytosis in A431 cells require cholesterol. | Cholesterol is important for the formation of caveolea and deeply invaginated clathrin-coated pits. We have now investigated whether formation of macropinosomes is dependent on the presence of cholesterol in the plasma membrane. Macropinocytosis in A431 cells was induced by the phorbol ester 12-O-tetradecanoylphorbol 1... |
12081969 | The gonococcal fur regulon: identification of additional genes involved in major catabolic, recombination, and secretory pathways. | In this study, we have characterized the in vitro binding of Neisseria gonorrhoeae Fur to several well-defined iron transport genes, as well as to additional genes involved in major catabolic, secretory, and recombination pathways of gonococci. The gonococcal Fur protein was recombinantly expressed in Escherichia coli ... |
12079473 | Tetrakis(N,N'-dimethylbenzamidinato)diruthenium(III) compounds bearing axial chloro and alkynyl ligands: a new family of redox rich diruthenium compounds. | Novel diruthenium(III) compound Ru(2)(DMBA)(4)Cl(2) (1, DMBA = N,N'-dimethylbenzamidinate) was obtained via refluxing Ru(2)(OAc)(4)Cl with dimethylbenzamidine in the presence of LiCl and Et(3)N under ambient atmosphere. Metathesis reactions between 1 and MC(2)Y (M = Li and Na) yielded bis-alkynyl derivatives Ru(2)(DMBA... |
12080379 | Lipoplex-induced hemagglutination: potential involvement in intravenous gene delivery. | We report a study aiming to characterize the interaction of blood and blood components with lipoplexes under conditions relevant to in vivo intravenous transfection. In this study we focus on the interaction of lipoplexes with red blood cells (RBC). It was found that no significant hemolysis occurred during several hou... |
12080143 | Metal ion-induced lateral aggregation of filamentous viruses fd and M13. | We report a detailed comparison between calculations of inter-filament interactions based on Monte-Carlo simulations and experimental features of lateral aggregation of bacteriophages fd and M13 induced by a number of divalent metal ions. The general findings are consistent with the polyelectrolyte nature of the virus ... |
12080142 | Thermodynamics of cationic lipid-DNA complex formation as studied by isothermal titration calorimetry. | The detailed analysis of the cationic lipid-DNA complex formation by means of isothermal titration calorimetry is presented. Most experiments were done using 1,2-dioleyl-sn-glycero-3-ethylphosphocholine (EDOPC), but basic titrations were also done using DOTAP, DOTAP:DOPC, and DOTAP:DOPE mixtures. Complex formation was ... |
12080132 | Light harvesting in photosystem I: modeling based on the 2.5-A structure of photosystem I from Synechococcus elongatus. | The structure of photosystem I from the thermophilic cyanobacterium Synechococcus elongatus has been recently resolved by x-ray crystallography to 2.5-A resolution. Besides the reaction center, photosystem I consists also of a core antenna containing 90 chlorophyll and 22 carotenoid molecules. It is their function to h... |
12080123 | Biophysical characterization of triacyl monosaccharide lipid a partial structures in relation to bioactivity. | Synthetic triacyl glucosamine monosaccharide lipid A part structures corresponding to the non-reducing moiety of enterobacterial lipid A with an acyloxyacyl chain linked to position 3 of the glucosamine and an unbranched chain linked to position 2 (group 1) and vice versa (group 2) were analyzed biophysically: Fourier-... |
12080121 | Adhesion of nanoparticles to vesicles: a Brownian dynamics simulation. | We studied the interaction of bilayer vesicles and adhesive nanoparticles using a Brownian dynamics simulation. The nanoparticles are simple models of proteins or colloids. The adhering nanoparticle induces the morphological change of the vesicle: budding, formation of two vesicles in which only outer monolayers are co... |
12080116 | Thermodynamically irreversible gating of ryanodine receptors in situ revealed by stereotyped duration of release in Ca(2+) sparks. | For a single or a group of Markov channels gating reversibly, distributions of open and closed times should be the sum of positively weighted decaying exponentials. Violation of this microscopic reversibility has been demonstrated previously on a number of occasions at the single channel level, and has been attributed ... |
12080104 | Molecular dynamics study of the folding of hydrophobin SC3 at a hydrophilic/hydrophobic interface. | Hydrophobins are fungal proteins that self-assemble at hydrophilic/hydrophobic interfaces into amphipathic membranes. These assemblages are extremely stable and posses the remarkable ability to invert the polarity of the surface on which they are adsorbed. Neither the three-dimensional structure of a hydrophobin nor th... |
12077338 | The Dorsal Rel homology domain plays an active role in transcriptional regulation. | The Dorsal morphogen directs formation of the Drosophila dorsoventral axis by both activating and repressing transcription. It contains an N-terminal Rel homology domain (RHD), which is responsible for DNA binding and regulated nuclear import, and a C-terminal domain (CTD) that contains activation and repression motifs... |
12076685 | High-performance liquid chromatographic determination of 2-hydroxypropyl-gamma-cyclodextrin in different biological fluids based on cyclodextrin enhanced fluorescence. | A high-performance size exclusion chromatographic method with analyte enhanced fluorescence detection is described for the analysis of 2-hydroxypropyl-gamma-cyclodextrin (HPGCD) in different biological fluids. The principle of detection was the in situ complexation of 8-anilinonaphthalene-1-sulfonic acid (ANS) by HPGCD... |
12072529 | The broadly neutralizing anti-human immunodeficiency virus type 1 antibody 2G12 recognizes a cluster of alpha1-->2 mannose residues on the outer face of gp120. | 2G12 is a broadly neutralizing human monoclonal antibody against human immunodeficiency virus type-1 (HIV-1) that has previously been shown to bind to a carbohydrate-dependent epitope on gp120. Here, site-directed mutagenesis and carbohydrate analysis were used to define further the 2G12 epitope. Extensive alanine scan... |
12072508 | Analysis of a temperature-sensitive mutant rotavirus indicates that NSP2 octamers are the functional form of the protein. | Evidence that NSP2 plays a role in packaging and replication comes from studies on tsE(1400), a rotavirus mutant with a temperature-sensitive (ts) lesion in the NSP2 gene. Cells infected with tsE and maintained at nonpermissive temperature contain few replication-assembly factories (viroplasms) or replication intermedi... |
12072505 | Complementary roles of multiple nuclear targeting signals in the capsid proteins of the parvovirus minute virus of mice during assembly and onset of infection. | This report describes the distribution of conventional nuclear localization sequences (NLS) and of a beta-stranded so-called nuclear localization motif (NLM) in the two proteins (VP1, 82 kDa; VP2, 63 kDa) forming the T=1 icosahedral capsid of the parvovirus minute virus of mice (MVM) and their functions in viral biogen... |
12072495 | Template requirements for de novo RNA synthesis by hepatitis C virus nonstructural protein 5B polymerase on the viral X RNA. | The hepatitis C virus (HCV)-encoded NS5B protein is an RNA-dependent RNA polymerase which plays a substantial role in viral replication. We expressed and purified the recombinant NS5B of an HCV genotype 3a from Esherichia coli, and we investigated its ability to bind to the viral RNA and its enzymatic activity. The res... |
12071842 | Lipid-restricted recognition of mycobacterial lipoglycans by human pulmonary surfactant protein A: a surface-plasmon-resonance study. | The human pulmonary surfactant protein A (hSP-A), a member of the mammalian collectin family, is thought to play a key defensive role against airborne invading pulmonary pathogens, among which is Mycobacterium tuberculosis, the aetiologic agent of tuberculosis. hSP-A has been shown to promote the uptake and the phagocy... |
12070339 | The fibril_one on-line database: mutations, experimental conditions, and trends associated with amyloid fibril formation. | The association of amyloid fibril formation with a number of important diseases, and the extensive study of this process in vitro, has resulted in a large literature containing a vast amount of information about the fibril formation process. This includes mutations and experimental conditions that promote or protect ag... |
12070338 | Prediction of the membrane-spanning beta-strands of the major outer membrane protein of Chlamydia. | There is preliminary experimental evidence indicating that the major outer-membrane protein (MOMP) of Chlamydia is a porin. We tested this hypothesis for the MOMP of the mouse pneumonitis serovar of Chlamydia trachomatis using two secondary structure prediction methods. First, an algorithm that calculates the mean hydr... |
12070330 | Structural basis for cyclodextrins' suppression of human growth hormone aggregation. | Many therapeutic proteins require storage at room temperature for extended periods of time. This can lead to aggregation and loss of function. Cyclodextrins (CDs) have been shown to function as aggregation suppressors for a wide range of proteins. Their potency is often ascribed to their affinity for aromatic amino aci... |
12070325 | Alpha-crystallin binds to the aggregation-prone molten-globule state of alkaline protease: implications for preventing irreversible thermal denaturation. | Alpha-crystallin, the major eye-lens protein with sequence homology with heat-shock proteins (HSPs), acts like a molecular chaperone by suppressing the aggregation of damaged crystallins and proteins. To gain more insight into its chaperoning ability, we used a protease as the model system that is known to require a pr... |
12070209 | Dynamics of microvascular oxygen pressure in the rat diaphragm. | The relative amplitudes and rates of increase of muscle blood flow (and O(2) delivery) and O(2) uptake responses determine the O(2) pressure within the muscle microvasculature (Pm(O(2))) across the rest-to-contraction transition. Skeletal muscle function is a primary determinant of pulmonary O(2) uptake kinetics; howev... |
12070038 | Nuclear magnetic resonance studies of mutations at the tetramerization region of human alpha spectrin. | Many spectrin mutations that destabilize tetramer formation and lead to hereditary hemolytic anemias are located at the N-terminal region of alpha-spectrin, with the Arg28 position considered to be a mutation hot spot. We have introduced mutations at positions 28 and 45 into a model peptide, Sp alpha 1-156, consisting ... |
12069997 | In vivo activity of posaconazole against Mucor spp. in an immunosuppressed-mouse model. | The in vivo activities of posaconazole, itraconazole, and amphotericin B in neutropenic mice with zygomycosis were compared. The in vitro MICs of posaconazole and itraconazole for the strains of Mucor spp. used in this study ranged from 0.125 to 8 microg/ml and 0.25 to 8 microg/ml, respectively. The in vitro MIC range ... |
12065758 | Selective allosteric enhancement of agonist binding and function at human A3 adenosine receptors by a series of imidazoquinoline derivatives. | We have identified a series of 1H-imidazo-[4,5-c]quinolines as selective allosteric enhancers of human A3 adenosine receptors. Several of these compounds potentiated both the potency and maximal efficacy of agonist-induced responses and selectively decreased the dissociation of the agonist N6-(4-amino-3-[125I]iodobenzy... |
12065739 | Metabolism and disposition of resveratrol in rats: extent of absorption, glucuronidation, and enterohepatic recirculation evidenced by a linked-rat model. | Pharmacokinetics of trans-resveratrol in its aglycone (RES(AGL)) and glucuronide (RES(GLU)) forms were studied following intravenous (15 mg/kg i.v.) and oral (50 mg/kg p.o.) administration of trans-resveratrol in a solution of beta-cyclodextrin to intact rats. In addition, the enterohepatic recirculation of RES(AGL) an... |
12065487 | Plasmodium vivax promiscuous T-helper epitopes defined and evaluated as linear peptide chimera immunogens. | Clinical trials of malaria vaccines have confirmed that parasite-derived T-cell epitopes are required to elicit consistent and long-lasting immune responses. We report here the identification and functional characterization of six T-cell epitopes that are present in the merozoite surface protein-1 of Plasmodium vivax (... |
12065482 | Identification of a receptor-binding domain of Bordetella dermonecrotic toxin. | Bordetella dermonecrotic toxin (DNT) stimulates the assembly of actin stress fibers and focal adhesions by deamidating or polyaminating Gln63 of the small GTPase Rho. DNT is an A-B toxin which is composed of an N-terminal receptor-binding (B) domain and a C-terminal enzymatically active (A) domain. In this study, to an... |
12065480 | Protein disulfide isomerase, a component of the estrogen receptor complex, is associated with Chlamydia trachomatis serovar E attached to human endometrial epithelial cells. | Chlamydia trachomatis serovar E, the leading bacterial agent responsible for sexually transmitted diseases, is required to invade genital epithelial cells for its growth and survival, yet little is known about the adhesin-receptor interactions promoting its entry. In contrast, much has been published on the heparan sul... |
12065478 | Proteome analysis of secreted proteins of the gastric pathogen Helicobacter pylori. | Secreted proteins (the secretome) of the human pathogen Helicobacter pylori may mediate important pathogen-host interactions, but such proteins are technically difficult to analyze. Here, we report on a comprehensive secretome analysis that uses protein-free culture conditions to minimize autolysis, an efficient recove... |
12062976 | Lessons from nature: stimuli-responsive polymers and their biomedical applications. | Response to stimulus is a basic process of living systems. Based on the lessons from nature, scientists have been designing useful materials that respond to external stimuli such as temperature, pH, light, electric field, chemicals and ionic strength. These responses are manifested as dramatic changes in one of the fol... |
12062649 | Kinetic degradation study of insulin complexed with methyl-beta cyclodextrin. Confirmation of complexation with electrospray mass spectrometry and (1)H NMR. | Hydrolysis of insulin has been studied during storage of various preparations at different temperatures. Deamidation is the predominant degradation process in acid solution resulting in a desamido product. The current study examines whether the interaction of insulin with methyl-beta cyclodextrin (met beta CD) improves... |
12062643 | Chromatographic determination of the association constants between nimesulide and native and modified beta-cyclodextrins. | The retention of a non-steroidal anti-inflammatory drug (NSAID), i.e. nimesulide, in high performance liquid chromatography (HPLC) was investigated using a phenyl bond silica column and beta-cyclodextrin (beta-CD) or hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as mobile phase additive (0-10 mM). Such a study was carri... |
12060854 | Noradrenergic and cholinergic innervation of the bone marrow. | Bone marrow is supplied by sensory and autonomic innervation. Although it is well established that hematopoiesis is regulated by cytokines and cell-to-cell contacts, the role played by neuromediators on the proliferation, differentiation and release of hematopoietic cells is still controversial. We studied the innervat... |
12055092 | C2C12 myoblast/osteoblast transdifferentiation steps enhanced by epigenetic inhibition of BMP2 endocytosis. | We investigated the modulation of critical transcriptional steps of C2C12 myoblast/osteoblast transdifferentiation triggered by the bone morphogenetic protein 2 (BMP2) signaling protein, in response to epigenetic inhibition of the endocytotic internalization of exogenous BMP2. BMP2 endocytosis was inhibited chemically ... |
12050383 | Asymmetric requirement for cholesterol in receptor-bearing but not envelope-bearing membranes for fusion mediated by ecotropic murine leukemia virus. | We show that fusion mediated by ecotropic murine leukemia virus envelope is dependent on cholesterol in receptor-bearing membranes. The effect is >10 times larger in insect cells than mammalian cells, probably because the former can be more extensively depleted of cholesterol. The fact that cholesterol is apparently no... |
12050382 | Human immunodeficiency virus type 1 enters brain microvascular endothelia by macropinocytosis dependent on lipid rafts and the mitogen-activated protein kinase signaling pathway. | Brain microvascular endothelial cells (BMVECs) present an incomplete barrier to human immunodeficiency virus type 1 (HIV-1) neuroinvasion. In order to clarify the mechanisms of HIV-1 invasion, we have examined HIV-1 uptake and transcellular penetration in an in vitro BMVEC model. No evidence of productive infection was... |
12050359 | Phosphorylation of transcription factor Sp1 during herpes simplex virus type 1 infection. | The expression of most herpes simplex virus type 1 (HSV-1) immediate-early (IE) and early (E) genes decreases late in productive infection. IE and E promoters contain various binding sites for cellular activators, including sites for Sp1, upstream of the TATA box, while late gene promoters generally lack such sites. To... |
11979517 | Monte Carlo study of cycloamylose: chain conformation, radius of gyration, and diffusion coefficient. | Cyclic (1 --> 4)-alpha-D-glucan chains with or without excluded volume have been collected from a huge number (about 10(7)) of linear amylosic chains generated by the Monte Carlo method with a conformational energy map for maltose, and their mean-square radii of gyration <S(2)> and translational diffusion coefficients ... |
29973856 | Molecular Binding Interactions: Their Estimation and Rationalization in QSARs in Terms of Theoretically Derived Parameters. | An extensive survey of molecular binding interactions and parameters used in QSARs is reported, which includes consideration of lipophilicity and the derivation of Linear Free Energy Relationships associated with drug-receptor binding, together with an overview of the various contributions to binding energy. The lipoph... |
12082118 | Is there a toxicological advantage for non-hyperbolic kinetics in cytochrome P450 catalysis? Functional allostery from "distributive catalysis". | The cytochrome P450s (CYPs) are the major enzymatic detoxification and drug metabolism system. Recently, it has become clear that several CYP isoforms exhibit positive and negative homotropic cooperativity. However, the toxicological implications of allosteric kinetics have not been considered, nor understood. The allo... |
12082085 | Matrix assembly, regulation, and survival functions of laminin and its receptors in embryonic stem cell differentiation. | Laminin-1 is essential for early embryonic basement membrane assembly and differentiation. Several steps can be distinguished, i.e., the expression of laminin and companion matrix components, their accumulation on the cell surface and assembly into basement membrane between endoderm and inner cell mass, and the ensuing... |
12077149 | (-)-Doliculide, a new macrocyclic depsipeptide enhancer of actin assembly. | The cytotoxic, cyclic depsipeptide (-)-doliculide was originally isolated by Ishiwata et al. (Ishiwata, H., Nemoto, T., Ojika, M., and Yamada, K. (1994) J. Org. Chem. 59, 4710-4711 and Ishiwata, H., Sone, H., Kigoshi, H., and Yamada, K. (1994) J. Org. Chem. 59, 4712-4713) from the sea hare Dolabella auricularia collect... |
12073155 | Ultrastructure of forming enamel in mouse bearing a transgene that disrupts the amelogenin self-assembly domains. | The mouse X-chromosomal amelogenin gene promoter was used to drive the expression of mutated amelogenin proteins in vivo. Two different transgenic mouse lines based on deletions to either the amino-terminal (A-domain deletions) or to the carboxyl-region (B-domain deletions) were bred. In the molars of newborn A-domain ... |
12077323 | GATA-factor dependence of the multitype zinc-finger protein FOG-1 for its essential role in megakaryopoiesis. | The function of GATA transcription factors in diverse developmental contexts depends in part on physical interaction with cofactors of the Friend of GATA (FOG) family. However, previous studies indicate that FOG-1 may play a GATA-1-independent role in early megakaryopoiesis, suggesting that FOG proteins might act in a ... |
12077322 | CD28 plays a critical role in the segregation of PKC theta within the immunologic synapse. | The signaling pathways that lead to the localization of cellular protein to the area of interaction between T cell and antigen-presenting cell and the mechanism by which these molecules are further sorted to the peripheral supramolecular activation cluster or central supramolecular activation cluster regions of the imm... |
12077319 | Overexpression, purification, and site-directed spin labeling of the Nramp metal transporter from Mycobacterium leprae. | It has long been recognized that the pathogenicity of a broad range of intracellular parasites depends on the availability of transition metal ions, especially iron. Nramp1 (natural resistance-associated macrophage protein 1), a proton-coupled divalent metal ion transporter, has been identified as a controlling factor ... |
12077305 | On the evolution of cells. | A theory for the evolution of cellular organization is presented. The model is based on the (data supported) conjecture that the dynamic of horizontal gene transfer (HGT) is primarily determined by the organization of the recipient cell. Aboriginal cell designs are taken to be simple and loosely organized enough that a... |
12077294 | Zinc finger as distance determinant in the flexible linker of intron endonuclease I-TevI. | I-TevI, the phage T4 td intron-encoded endonuclease, recognizes a lengthy DNA target and initiates intron mobility by introducing a double-strand break in the homing site. The enzyme uses both sequence and distance determinants to cleave the DNA 23-25 bp upstream of the intron insertion site. I-TevI consists of an N-te... |
12072564 | Probing solvent accessibility of amyloid fibrils by solution NMR spectroscopy. | Amyloid is the result of an anomalous protein and peptide aggregation, leading to the formation of insoluble fibril deposits. At present, 18 human diseases have been associated with amyloid deposits-e.g., Alzheimer's disease and Prion-transmissible Spongiform Encephalopathies. The molecular structure of amyloid is to a... |
12070352 | Design of protein struts for self-assembling nanoconstructs. | Bacteriophage T4 tail fibers have a quaternary structure of bent rigid rods, 3 x 160 nm in size. The four proteins which make up these organelles are able to self-assemble in an essentially irreversible manner. To use the self-assembly domains of these proteins as elements in construction of mesoscale structures, we mu... |
12060710 | Bone patterning is altered in the regenerating zebrafish caudal fin after ectopic expression of sonic hedgehog and bmp2b or exposure to cyclopamine. | Amputation of the zebrafish caudal fin stimulates regeneration of the dermal skeleton and reexpression of sonic hedgehog (shh)-signaling pathway genes. Expression patterns suggest a role for shh signaling in the secretion and patterning of the regenerating dermal bone, but a direct role has not been demonstrated. We es... |
12058021 | Phospholipids undergo hop diffusion in compartmentalized cell membrane. | The diffusion rate of lipids in the cell membrane is reduced by a factor of 5-100 from that in artificial bilayers. This slowing mechanism has puzzled cell biologists for the last 25 yr. Here we address this issue by studying the movement of unsaturated phospholipids in rat kidney fibroblasts at the single molecule lev... |
12050151 | Rapid nonvesicular transport of sterol between the plasma membrane domains of polarized hepatic cells. | We studied the transport of the fluorescent cholesterol analog dehydroergosterol (DHE) in polarized HepG2 human hepatoma cells. DHE delivered via methyl-beta-cyclodextrin was delivered to both the apical and basolateral membranes and became concentrated in the apical membrane within 1 min. Intracellular DHE was targete... |
12048247 | TAR RNA loop: a scaffold for the assembly of a regulatory switch in HIV replication. | Replication of HIV requires the Tat protein, which activates elongation of RNA polymerase II transcription at the HIV-1 promoter by interacting with the cyclin T1 (CycT1) subunit of the positive transcription elongation factor complex b (P-TEFb). The transactivation domain of Tat binds directly to the CycT1 subunit of ... |
28230373 | A Novel Dendrimeric "Glue" for Adhesion of Phosphatidyl Choline-Based Liposomes. | The interaction of phosphatidyl choline-cholesterol liposomes incorporating dihexadecyl phosphate as recognizable lipid with complementary guanidinylated diaminobutane poly(propylene imine) dendrimers of the fourth and fifth generation afforded liposome-dendrimer aggregates which were redispersed by the addition of an ... |
23345771 | Morphological and topological transformation of membrane vesicles. | Liposomes are micro-compartments made of lipid bilayer membranes withcharacteristics quite similar to those of biological membranes. To formartificial cell-like structures, we generated liposomes that containedsubunit proteins of cytoskeletons: tubulin or actin. Spherical liposomeswere transformed into bipolar or cell-... |
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