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11162516 | Microenvironment of endosomal aqueous phase investigated by the mobility of microparticles using fluorescence correlation spectroscopy. | Temporal observation of the dynamic behavior of molecules in cells gives information about the physiological environment at the region of interest. Here we report the direct measurement of the mobility of rhodamine-labeled microparticles (14 and 35 nm in diameter) ingested in endosomes of cultured bovine aortic endothe... |
11162501 | Spectroscopic evidence for amyloid-like interfacial self-assembly of hydrophobin Sc3. | Amphipathic fungal proteins called hydrophobins are able to self-assemble into insoluble supramolecular structures at hydrophobic/hydrophilic interfaces, but the molecular mechanism and underlying protein conformation changes are not known. Secondary-structure prediction indicated that hydrophobin Sc3 is an all-beta pr... |
11271533 | A new type of calixarene: octahydroxypyridin. | A new type of calixarene has been synthesised. Like resorcinol and a number of resorcinol derivatives, 2,6-dihydroxypyridine has been proven to form cyclic tetramers in moderate yields with a number of aliphatic and two aromatic aldehydes in acidic media. The problem of the formation of configurational isomers can be r... |
11271531 | Tetrathiafulvalene crowns: redox-switchable ligands. | A series of redox-responsive ligands that associate the electroactive tetrathiafulvalene core with polyether subunits of various lengths has been synthesized. X-ray structures are provided for each of the free ligands. The requisite structural criteria for reaching switchable ligands are satisfied for the largest macro... |
11271530 | Stirring effects on the spontaneous formation of chirality in the homoassociation of diprotonated meso-tetraphenylsulfonato porphyrins. | Homoassociates of the achiral title porphyrins in acid solutions show spontaneous symmetry breaking, which can be detected by circular dichroism (CD). The CD spectra are due to differential scattering and differential absorption contributions, the relative significance of which is related to the shape and size of the h... |
11271525 | The self-assembly of a lipophilic guanosine nucleoside into polymeric columnar aggregates: the nucleoside strucutre contains sufficient information to drive the process towards a strikingly regular polymer. | Lipophilic guanosine derivatives act as self-assembled ionophores. In the presence of alkali metal ions in organic solvents, these G derivatives can form tubular polymeric structures. The molecular aggregates formed by 3',5'-didecanoyl-2'-deoxyguanosine (1) have been characterised by SANS and NMR spectroscopy. The poly... |
11271523 | Reactivity of calix-tetrapyrrole SmII and SmIII complexes with acetylene: isolation of an "N-confused" calix-tetrapyrrole ring. | The nature of the substituents present on the calix-tetrapyrrole tetra-anion ligand [[R2C(C4H2N)]4]4- (R = [-(CH2)5-]0.5, Et) determines the type of reactivity of the corresponding SmII compounds with acetylene. With R = [-(CH2)5-]0.5, dehydrogenation occurred to yield the nearly colorless dinuclear diacetylide complex... |
11271517 | Dendrimers and hyperbranched polymers as high-loading supports for organic synthesis. | Polymeric supports have become a big necessity for automated synthesis and combinatorial chemistry, yet, the loading capacities of most polystyrene resins are very limited (typically < 1.5 mmol x g(-1)). Dendrimers and hyperbranched polymers have been discussed for this application and now became readily available. The... |
11219548 | Pharmacology of itraconazole. | Itraconazole is a triazole antifungal agent that has a broad spectrum of activity and is well tolerated. Itraconazole is highly efficacious, particularly because its main metabolite, hydroxy-itraconazole, also has considerable antifungal activity. The original capsule formulation of itraconazole may lead to variability... |
11217038 | Trace analysis of gamma-cyclodextrin in a sample of beta-cyclodextrin by capillary electrophoresis. | A new capillary electrophoretic method for trace analysis of gamma-cyclodextrin, gamma-CD, in a sample of beta-CD has been developed, building on our recent work in which the tetraphenylborate ion, Ph4B-, was found to bind to gamma-CD three orders of magnitude more strongly than to beta-CD. The method involves measurem... |
11217036 | Laser-induced fluorescence detection at 266 nm in capillary electrophoresis. Polycyclic aromatic hydrocarbon metabolites in biota. | The separation of five phenolic polycyclic aromatic hydrocarbon metabolites (hydroxy-PAHs) has been performed by cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) using a 30 mM borate buffer (pH 9.0) containing 60 mM sodium dodecyl sulfate and varying concentrations of gamma-cyclodextrin (gamma-CD)... |
11217047 | Chiral beta-cyclodextrin-based polymer supports prepared via ring-opening metathesis graft-polymerization. | A series of norborn-2-ene-derivatized beta-cyclodextrins (beta-CDs), 6-O-(norborn-2-ene-5-carboxyl)-beta-CD (1), tetrakis(6-O-norborn-2-ene-5-carboxyl)-beta-CD (2), (3), 6-O-(6-norborn-2-ene-5-car-6-O-(7-oxanorborn-2-ene-5-carboxyl)-beta-CD bonylaminohexoyl)-beta-CD (4), 6-O-(norborn-2-ene-5-ylmethoxymethylsilyl)-beta-... |
11215892 | Separation of enantiomers by gas chromatography. | The separation of enantiomers by gas chromatography is performed on chiral stationary phases (CSPs) via hydrogen bonding, coordination and inclusion. Thus, typical chiral selectors are amino acid derivatives, terpene-derived metal coordination compounds and modified cyclodextrins. In Chirasil-type stationary phases the... |
11215804 | Modification of the lyotropic liquid crystalline microstructure of amphiphilic block copolymers in the presence of cosolvents. | This article reviews the results of recent investigations on the macroscopic (phase behavior) and microscopic (microstructure) aspects of the role of cosolvents on the self-assembly of amphiphilic copolymers. A comprehensive account of the systematic studies performed in ternary isothermal systems consisting of a repre... |
11215790 | Association of surfactants and polymers studied by luminescence techniques. | Light emission spectroscopy has unique possibilities for the study of central issues of surfactants and associating polymers. With the help of luminescent probes, information may be obtained on matters such as molecular association, microstructure, and molecular dynamics; this constitutes an important contribution to t... |
11214727 | In vitro behavior of marine lipid-based liposomes. Influence of pH, temperature, bile salts, and phospholipase A2. | To deliver polyunsaturated fatty acids (PUFA) by the oral route, liposomes based on a natural mixture of marine lipids were prepared by filtration and characterized in media that mimic gastrointestinal fluids. First the influence of large pH variations from 1.5-2.5 (stomach) to 7.4 (intestine) at the physiological temp... |
11213940 | Multicenter trial of prolonged infusions of rocuronium bromide in critically ill patients: effects of multiple organ failure. | <h4>Background</h4>This study was done to determine the safety, efficacy, dosing requirements, and spontaneous recovery profiles of prolonged infusions of rocuronium bromide in the critically ill.<h4>Methods</h4>This multicenter, prospective, nonrandomized, open label trial enrolled 32 patients at two university-based ... |
11211932 | Supramolecular dynamics of gap junctions. | During the life cycle of a membrane protein its molecular structure may change and for aggregated proteins this process may be observed on the supramolecular level. Here we demonstrate that this is the case for gap junction channels which maintain cell-cell communication. Freshly synthesized connexins are integrated as... |
11209604 | Supramolecular squares with Mo2(4+) corners. | Seven complexes obtained by reacting the quadruply bonded complex [Mo2(cis-DAniF)2(CH3CN)4](BF4)2 (DAniF = N,N'-di-p-anisylformamidinate) and (Bun4N+)2(Carb2-), where Carb2- is a dicarboxylate anion, have been found to have a ratio of dimetal unit to dicarboxylate of 1:1. As noted by the carboxylate linker, the compoun... |
11209856 | Spectroscopy study on the photochromism of Schiff bases N,N'-bis(salicylidene)-1,2-diaminoethane and N,N'-bis(salicylidene)-1,6-hexanediamine. | The photochromism of Schiff bases N,N'-bis(salicylidene)-1,2-diaminoethane (BSE) and N,N'-bis(salicylidene)-1,6-cyclohexanediamine (BSH) was studied by steady-state and time-dependent fluorescence, UV Vis absorption spectroscopy and theoretical chemistry calculations. The experimental results show that BSH can perform ... |
11209851 | Protonation effects on the inclusion complexation of 6-deoxy-6-diethylamino-beta-cyclodextrin with 2-anthracenesulfonate, 2-naphthalenesulfonate, 2,6-naphthalenedisulfonate, and 2,7-naphthalenedisulfonate in aqueous solutions. | At pH values 5.5 and 10.3, 6-deoxy-6-diethylamino-beta-cyclodextrin (DD-beta-CD) as well as beta-CD forms 1:1 inclusion complexes with 2-anthracenesulfonate (2AS), 2-naphthalenesulfonate (2NS), 2,6-naphthalenedisulfonate (2,6NDS), and 2,7-naphthalenedisulfonate (2,7NDS). The equilibrium constants (K) for the formation ... |
11206784 | Semi-preparative gas chromatographic separation of all-trans-perhydrotriphenylene enantiomers on a chiral cyclodextrin stationary phase. | Enantiomers of all-trans-perhydrotriphenylene (PHTP) were separated by gas chromatography using heptakis(6-O-tert.-butyldimethylsilyl-2,3-di-O-methyl)-beta-cyclodextrin (TBDMS-beta-CD) as the chiral selector. Conditions for semi-preparative separations were established using a 2 m x 2 mm I.D. packed column and subseque... |
11206808 | Consequences of variable purity of heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin determined by liquid chromatography-mass spectrometry on the enantioselective separation of polychlorinated compounds. | The composition of 10 batches of heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (PM-CD) from different suppliers was determined by high-performance liquid chromatography combined with atmospheric pressure chemical ionisation mass spectrometry (MS). Considerable differences were found. Some batches consisted of more tha... |
11206463 | Design, synthesis, and biological evaluation of HIV/FIV protease inhibitors incorporating a conformationally constrained macrocycle with a small P3' residue. | A series of norstatine-based HIV/FIV protease inhibitors incorporating a 15-membered macrocycle as a mimic of the tripeptide (Ala-Val-Phe), a motif with a small P3' residue elective against the FIV protease and the drug-resistant HIV proteases, has been synthesized. It was found that the macrocycle is important to the ... |
11201162 | [Software development for calculation of molecular surface area and its application to hydrophobic interaction]. | A novel method of calculating the water-accessible molecular surface area from the number of points generated on the molecular surface was developed. This method yielded a molecular surface area with high accuracy and speed. The molecular surface area of lecithin shows an excellent linear correlation with the logarithm... |
11202367 | The photochemistry of flutamide and its inclusion complex with beta-cyclodextrin. Dramatic effect of the microenvironment on the nature and on the efficiency of the photodegradation pathways. | The photochemistry of the anticancer drug flutamide (FM), 2-methyl-N-[4-nitro-3-(trifluoromethyl)phenyl]propanamide, in homogeneous media and in the beta-cyclodextrin (beta-CD) cavity has been investigated. The photoreactivity of the free molecule has been rationalized on the basis of an intramolecular nitro to nitrite... |
11170529 | Synthesis, characterization, and photophysical properties of a series of supramolecular mixed-valence compounds. | The synthesis and characterization of 10 cyano-bridged trinuclear mixed-valence compounds of the form [(NH3)5M-NC-FeII(CN)4-CN-M'(NH3)5]n+ (M = RuIII, OsIII, CrIII, or PtIV; n = 2, 3, or 4) is reported. The electronic spectra of these supramolecular compounds exhibit a single intervalent (IT) absorption band for each n... |
11205024 | Self-assembly and selective guest binding of three-dimensional open-framework solids from a macrocyclic complex as a trifunctional metal building block. | The nickel(II) hexaazamacrocyclic complex (1) containing pendant pyridine groups has been synthesized by the one-pot template condensation reaction of amine and formaldehyde. From the self-assembly of 1 with deprotonated cis,cis-1,3,5-cyclohexanetricarboxylic acid, H2CTC- and CTC3-, three-dimensional supramolecular ope... |
11205020 | Synthesis and metal binding properties of salicylate-, catecholate-, and hydroxypyridinonate-functionalized dendrimers. | The synthesis, characterization, and metal-binding studies of chelate-functionalized dendrimers is reported. Salicylate, catecholate, and hydroxypyridinonate bidentate chelators have been coupled to the surface of both poly(propyleneimine) (Astramol) and poly(amidoamine) (Starburst, PAMAM) dendrimers up to the fifth ge... |
11205014 | X-H (X = C, N, O, P, S) bond activations induced by beta-heterosubstituted zirconaindenes. | The azazirconacyclopentene-substituted phosphines 3 and 4 have been found to activate the C-H bonds of acetylenic systems, such as methylpropiolate, diphenylphosphinoacetylene and phenylacetylene, or of methylene compounds, such as malonitrile and diethylmalonate, to give complexes 5a-c, 6a and 6b. C-H bond activation ... |
11205013 | Importance of packing coefficients of host cavities in the isomerization of open host frameworks: guest-size-dependent isomerization in cholic acid inclusion crystals with monosubstituted benzenes. | The crystal structures of inclusion compounds of cholic acid (CA) with 28 monosubstituted benzenes have been systematically investigated. All of the crystals belong to the monoclinic space group P2(1) and have bilayer structures with one-dimensional molecular channels that can include guest compounds. They are classifi... |
11205010 | Polycationic (mixed) core-shell dendrimers for binding and delivery of inorganic/organic substrates. | The convergent synthesis of a series of polycationic aryl ether dendrimers has been accomplished by a convenient procedure involving quantitative quaternarization of aryl(poly)amine core molecules. The series has been expanded to the preparation of the first polycationic, mixed core-shell dendrimer. All these dendrimer... |
11205005 | Spectroelectrochemical characterisation of poly[Ni(saltMe)]-modified electrodes. | Electrogenerated polymers based on the nickel(II) complex 2,3-dimethyl-N,N'-bis(salicylidene)butane-2,3-diaminatonickel(II), poly[Ni(saltMe)], were characterised by in situ FTIR and UV/Vis spectroscopy and ex-situ EPR spectroscopy in order to gain insights into film structure, electronic states and charge conduction. T... |
11205030 | Supramolecular detection of metal ion binding: ligand conformational control of cholesteric induction in nematic liquid crystalline phases. | Tripodal tetradentate ligands may act as chemosensor molecules. Their ability to torque a nematic into a cholesteric phase increases upon complexation with copper ion. Moreover, changes in overall shape of the complexes induced by different metals and counter ions were transferred sensitively to the supramolecular leve... |
11204935 | Piroxicam concentrations in plasma and synovial fluid after a single dose of piroxicam-beta-cyclodextrin. | <h4>Aims</h4>The efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) in rheumatic diseases depends on their concentrations within the joint. We determined piroxicam concentrations in plasma and synovial fluid (SF) after a single oral dose of 20 mg in the form of one tablet of piroxicam-beta-cyclodextrin.<h4>Metho... |
11195367 | Structural and electronic properties of Co-corrole, Co-corrin, and Co-porphyrin. | A quantitative study of the structure and electronic properties of Co-corrole, Co-corrin, and Co-porphyrin, using density functional theory, is reported. The structure of each macrocycle is optimized, with no symmetry constraints, by considering different spin states. The ground-state structures and spin states (S = 1 ... |
11154902 | Quantitative relationship between the chemical structure of antisense nucleosides and their capacity to interact with cyclomalto-octaose. | The interaction of twelve 8-substituted-2'-deoxyadenosine and seventeen 5-substituted-2'-deoxyuridine derivatives (antisense nucleosides) with cyclomalto-octaose (GCD) was determined by charge-transfer chromatography and the relative strength of the interaction was calculated. The majority of antisense nucleosides (14 ... |
11154905 | Influence of wet granulation and lubrication on the powder and tableting properties of codried product of microcrystalline cellulose with beta-cyclodextrin. | The individual influence of wet granulation and lubrication on the powder and tableting properties of codried product of microcrystalline cellulose (MCC) with beta-cyclodextrin (beta-CD) was examined in this study. Avicel PH 101 and 301 were included for comparison. The codried product, Avicel PH 101 and 301 were granu... |
11152752 | Electrical dimension of the nuclear envelope. | Eukaryotic chromosomes are confined to the nucleus, which is separated from the rest of the cell by two concentric membranes known as the nuclear envelope (NE). The NE is punctuated by holes known as nuclear pore complexes (NPCs), which provide the main pathway for transport of cellular material across the nuclear-cyto... |
11148223 | The immunogenicity of a new human minor histocompatibility antigen results from differential antigen processing. | Minor histocompatibility antigens (mHAgs) present a significant impediment to organ and bone marrow transplantation between HLA-identical donor and recipient pairs. Here we report the identification of a new HLA-A*0201-restricted mHAg, HA-8. Designation of this mHAg as HA-8 is based on the nomenclature of Goulmy (Goulm... |
11148142 | Structural models for the self-assembly and microtubule interactions of gamma-, delta- and epsilon-tubulin. | alphabeta-tubulin heterodimers self-assemble to form microtubules nucleated by gamma-tubulin in the cell. Gamma-tubulin is believed to recruit the alphabeta-tubulin dimers that form the minus ends of microtubules, but the molecular mechanism of this action remains a matter of heated controversy. Still less is known abo... |
11149927 | NXT1 is necessary for the terminal step of Crm1-mediated nuclear export. | Soluble factors are required to mediate nuclear export of protein and RNA through the nuclear pore complex (NPC). These soluble factors include receptors that bind directly to the transport substrate and regulators that determine the assembly state of receptor-substrate complexes. We recently reported the identificatio... |
11139379 | Haem-linked interactions in horseradish peroxidase revealed by spectroscopic analysis of the Phe-221-->Met mutant. | A gene encoding a Phe-221-to-Met substitution in the haem enzyme horseradish peroxidase has been constructed and expressed in Escherichia coli. In the wild-type enzyme the side chain of Phe-221 is tightly stacked against the imidazole ring of His-170, which provides the only axial ligand to the haem iron atom. The Phe-... |
11139385 | Fatty-acyl-CoA thioesters inhibit recruitment of steroid receptor co-activator 1 to alpha and gamma isoforms of peroxisome-proliferator-activated receptors by competing with agonists. | Peroxisome-proliferator-activated receptors (PPARs) alpha and gamma are ligand-dependent transcription factors that are key regulators of lipid and carbohydrate homoeostasis. Fatty acids bind to the ligand-binding domains (LBDs) of PPARalpha and PPARgamma and activate these receptors. To clarify whether fatty-acyl-CoAs... |
11136249 | An amino acid code for protein folding. | Direct structural information obtained for many proteins supports the following conclusions. The amino acid sequences of proteins can stabilize not only the final native state but also a small set of discrete partially folded native-like intermediates. Intermediates are formed in steps that use as units the cooperative... |
11135193 | Influence of environment on piroxicam polymorphism: vibrational spectroscopic study. | FTIR and FT-Raman spectroscopies were used to evaluate the mechanism of transformation of piroxicam into its different forms (alpha, beta, and monohydrate), depending on the environment. These vibrational techniques allowed us to identify the forms of piroxicam that crystallize from different solvents at different cool... |
11135314 | Abalone lysin: the dissolving and evolving sperm protein. | Abalone sperm lysin is a non-enzymatic protein that creates a hole for sperm passage in the envelope surrounding the egg. Lysin exhibits species-specificity in making the hole and it evolves rapidly by positive selection. Our studies have focused on combining structural, biochemical, and evolutionary data to understand... |
11114396 | Effects of membrane cholesterol on the sensitivity of the GABA(A) receptor to GABA in acutely dissociated rat hippocampal neurones. | The effects of membrane cholesterol on the GABA(A) receptor were investigated in acutely dissociated rat hippocampal neurones, using the whole-cell patch clamp technique. Neuronal cholesterol was manipulated within the range 56-250% control by incubation with methyl-beta-cyclodextrin for depletion and a complex of chol... |
11113637 | A study of the binding requirements of calyculin A and dephosphonocalyculin A with PP1, development of a molecular recognition model for the binding interactions of the okadaic acid class of compounds with PP1. | The interactions of the okadaic acid class of compounds, with special emphasis on the solution structures of calyculin A and dephosphonocalyculin A with PP1 are reported. After examination of the interactions of all docked structures, a receptor based pharmacophore model for the interactions of the protein phosphatase ... |
11201230 | Analysis of the phase solubility diagram of a phenacetin/competitor/beta-cyclodextrin ternary system, involving competitive inclusion complexation. | The competitive inclusion complexations in the ternary phenacetin/competitors/beta-cyclodextrin (beta-CyD) systems were investigated by the solubility method, where m-bromobenzoic acid (m-BBA) and o-toluic acid (o-TA) were used as competitors. The solubility changes of the drug and competitors as a function of beta-CyD... |
11197160 | Chiral analysis of baclofen by alpha-cyclodextrin-modified capillary electrophoresis and laser-induced fluorescence detection. | An enantioselective method for baclofen (4-amino-3-p-chlorophenylbutyric acid) based on capillary electrophoresis (CE) separation and laser-induced fluorescence (LIF) detection has been developed. Naphthalene-2,3-dicarboxaldehyde (NDA) was used for precolumn derivatization of the nonfluorescent drug. alpha-Cyclodextrin... |
11197158 | Comparison of binding of tetraphenylborate and tetraphenylphosphonium ions to cyclodextrins studied by capillary electrophoresis. | Binding constants for tetraphenylborate and tetraphenylphosphonium ions (Ph4B- and Ph4P+) to cyclodextrins (CDs) to give 1:1 host-guest complexes have been measured using capillary electrophoresis. Mobilities of the ions as a function of gamma-CD concentration give binding constants, K, of 1.08 x 10(5) M-1 for Ph4B- an... |
11197157 | Evaluation of norbornene- beta-cyclodextrin-based monomers and oligomers as chiral selectors by means of nonaqueous capillary electrophoresis. | Norbornen-5-yl carboxylic acid and norbornen-5-ylmethylsilyl ether-based beta-cyclodextrins (beta-CDs) containing up to three norbornene ester and up to five norbornene silyl ether units have been prepared from beta-CD and norbornen-5-carboxylic chloride and norbornen-5-ylmethyldichlorosilane, respectively. Oligomers (... |
11197184 | Molecular recognition by chiral cationic micellar and micelle-like aggregates in electrokinetic capillary chromatography. | We examined the enantiomer separation with micelles and a micelle-like polymer made with trimethylammonium-terminated surfactants all of whose hydrocarbon chains contain hydrogen bonding valinediamide moieties in electrokinetic chromatography (EKC). The surfactants used were 3-(N-dodecanoyl-L-valylamino)-propyltrimethy... |
11176168 | Beneficial effects of tempol, a membrane-permeable radical scavenger, on the multiple organ failure induced by zymosan in the rat. | <h4>Background and methods</h4>We investigated the effects of tempol, a membrane-permeable radical scavenger, on the multiple organ failure (MOF) caused by zymosan in the rat. Zymosan (500 mg/kg, suspended in saline solution, ip) enhances formation of reactive oxygen species, which contribute to the pathophysiology of ... |
11199994 | Screening metal binding selectivities of macrocycle mixtures by HPLC--ESI-MS and postcolumn reactions. | A rapid method for the screening of metal binding selectivities of host compounds in mixtures is presented. This method involves the separation of mixtures of hosts by HPLC, followed by postcolumn complexation with one or more metals, then analysis by mass spectrometry. The intensities of the host-guest complexes in th... |
11198350 | Post-injury multiple organ failure: the role of the gut. | Despite intensive investigation, the pathogenesis of post-injury multiple organ failure (MOF) remains elusive. Laboratory and clinical research strongly suggests that the gastrointestinal tract (i.e., the gut) plays a pivotal pathogenic role. Since its inception in 1988, the Trauma Research Center (TRC) at the Universi... |
11192701 | Comparison of three fungal laccases from Rigidoporus lignosus and Pleurotus ostreatus: correlation between conformation changes and catalytic activity. | The conformation changes in solution of three fungal laccases in different environmental conditions were examined by circular dichroism (CD) and electron paramagnetic resonance (EPR) spectroscopy. CD measurements indicate that the secondary structure of proteins depends slightly on the pH or ionic strength, though the ... |
11191832 | Pharmacologically elevated levels of endogenous kynurenic acid prevent nicotine-induced activation of nigral dopamine neurons. | Previous studies have shown that systemically administered nicotine is associated with an activation of rat midbrain dopamine neurons. The aim of the present electrophysiological study was to investigate if manipulation of brain kynurenic acid, an endogenous excitatory amino acid receptor antagonist, can affect the res... |
11191074 | Effects of methyl-beta-cyclodextrin on cryosurvival of boar spermatozoa. | Methyl-beta-cyclodextrin (MBCD), which leads to the stimulation of cholesterol efflux from the cell membrane, was examined for its ability to increase the cryosurvival of spermatozoa from Göttingen miniature pigs. The intactness of the acrosome and various motion parameters of spermatozoa after freezing and thawing wer... |
11142364 | A study of peptide--peptide interaction by matrix-assisted laser desorption/ionization. | Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was used to study peptide-peptide interaction. The interaction was seen when 6-aza-2-thiothymine was used as a matrix (pH 5.4), but was disrupted with a more acidic matrix, alpha-cyano-4-hydroxycinnamic acid (pH 2.0). In the present study, we show th... |
11148003 | Emergence of diverse Helicobacter species in the pathogenesis of gastric and enterohepatic diseases. | Since Helicobacter pylori was first cultivated from human gastric biopsy specimens in 1982, it has become apparent that many related species can often be found colonizing the mucosal surfaces of humans and other animals. These other Helicobacter species can be broadly grouped according to whether they colonize the gast... |
11148001 | Diagnosis of noncultivatable gastroenteritis viruses, the human caliciviruses. | Gastroenteritis is one of the most common illnesses of humans, and many different viruses have been causally associated with this disease. Of those enteric viruses that have been established as etiologic agents of gastroenteritis, only the human caliciviruses cannot be cultivated in vitro. The cloning of Norwalk virus ... |
11145701 | Role of C5a in multiorgan failure during sepsis. | In humans with sepsis, the onset of multiorgan failure (MOF), especially involving liver, lungs, and kidneys, is a well known complication that is associated with a high mortality rate. Our previous studies with the cecal ligation/puncture (CLP) model of sepsis in rats have revealed a C5a-induced defect in the respirat... |
11139624 | Cnr interferes with dimerization of the replication protein alpha in phage-plasmid P4. | DNA replication of phage-plasmid P4 in its host Escherichia coli depends on its replication protein alpha. In the plasmid state, P4 copy number is controlled by the regulator protein Cnr (copy number regulation). Mutations in alpha (alpha(cr)) that prevent regulation by Cnr cause P4 over-replication and cell death. Usi... |
11139621 | DNA binding sites for the Mlc and NagC proteins: regulation of nagE, encoding the N-acetylglucosamine-specific transporter in Escherichia coli. | The NagC and Mlc proteins are homologous transcriptional regulators that control the expression of several phosphotransferase system (PTS) genes in Escherichia coli. NagC represses nagE, encoding the N:-acetylglucosamine-specific transporter, while Mlc represses three PTS operons, ptsG, manXYZ and ptsHIcrr, involved in... |
11139616 | TectoRNA: modular assembly units for the construction of RNA nano-objects. | Structural information on complex biological RNA molecules can be exploited to design tectoRNAs or artificial modular RNA units that can self-assemble through tertiary interactions thereby forming nanoscale RNA objects. The selective interactions of hairpin tetraloops with their receptors can be used to mediate tectoRN... |
11141056 | Inhibition of gene expression inside cells by peptide nucleic acids: effect of mRNA target sequence, mismatched bases, and PNA length. | Genome sequencing has revealed thousands of novel genes, placing renewed emphasis on chemical approaches for controlling gene expression. Antisense oligomers designed directly from the information generated by sequencing are one option for achieving this control. Here we explore the rules governing the inhibition of ge... |
11139202 | Use of two-dimensional gel electrophoresis to measure changes in synovial fluid proteins from patients with rheumatoid arthritis treated with antibody to CD4. | Synovial fluid proteins from microliter volumes of synovial fluid were resolved by two-dimensional polyacrylamide gel electrophoresis and detected by silver staining to investigate the feasibility of using two-dimensional (2D) electrophoresis in the clinical research setting and provide global disease information of di... |
11136817 | B cell development is arrested at the immature B cell stage in mice carrying a mutation in the cytoplasmic domain of immunoglobulin beta. | The B cell receptor (BCR) regulates B cell development and function through immunoglobulin (Ig)alpha and Ig beta, a pair of membrane-bound Ig superfamily proteins, each of which contains a single cytoplasmic immunoreceptor tyrosine activation motif (ITAM). To determine the function of Ig beta, we produced mice that car... |
11134286 | Identification of key residues in subgroup A avian leukosis virus envelope determining receptor binding affinity and infectivity of cells expressing chicken or quail Tva receptor. | To better understand retroviral entry, we have characterized the interactions between subgroup A avian leukosis virus [ALV(A)] envelope glycoproteins and Tva, the receptor for ALV(A), that result in receptor interference. We have recently shown that soluble forms of the chicken and quail Tva receptor (sTva), expressed ... |
11134228 | Light adaptation in Drosophila photoreceptors: I. Response dynamics and signaling efficiency at 25 degrees C. | Besides the physical limits imposed on photon absorption, the coprocessing of visual information by the phototransduction cascade and photoreceptor membrane determines the fidelity of photoreceptor signaling. We investigated the response dynamics and signaling efficiency of Drosophila photoreceptors to natural-like flu... |
11133958 | Urea utilization in the phototrophic bacterium Rhodobacter capsulatus is regulated by the transcriptional activator NtrC. | The phototrophic nonsulfur purple bacterium Rhodobacter capsulatus can use urea as a sole source of nitrogen. Three transposon Tn5-induced mutations (Xan-9, Xan-10, and Xan-19), which led to a Ure(-) phenotype, were mapped to the ureF and ureC genes, whereas two other Tn5 insertions (Xan-20 and Xan-22) were located wit... |
11133954 | Specificity of signal peptide recognition in tat-dependent bacterial protein translocation. | The bacterial twin arginine translocation (Tat) pathway translocates across the cytoplasmic membrane folded proteins which, in most cases, contain a tightly bound cofactor. Specific amino-terminal signal peptides that exhibit a conserved amino acid consensus motif, S/T-R-R-X-F-L-K, direct these proteins to the Tat tran... |
11125087 | The non-coding RNAs as riboregulators. | The non-coding RNAs database (http://biobases.ibch.poznan.pl/ncRNA/) contains currently available data on RNAs, which do not have long open reading frames and act as riboregulators. Non-coding RNAs are involved in the specific recognition of cellular nucleic acid targets through complementary base pairing to control ce... |
11124904 | Multiple display of peptides and proteins on a macromolecular scaffold derived from a multienzyme complex. | The acyltransferase components (E2) from the family of 2-oxo acid dehydrogenase multienzyme complexes form large protein scaffolds, to which multiple copies of peripheral enzymes bind tightly but non-covalently. Sixty copies of the E2 polypeptide from the pyruvate dehydrogenase multienzyme complex of Bacillus stearothe... |
11120956 | Molecular modeling approach to understanding the mode of action of L-nucleosides as antiviral agents. | A series of unnatural L-nucleosides such as 3TC, FTC and L-FMAU have been found to be potent antiviral agents. The mode of action of L-nucleosides has been found to be similar to that of D-nucleosides as antiviral agents, despite their unnatural stereochemistry, that is, nucleotide formation by kinases followed by inte... |
11119622 | The ability of integrin alpha(v)beta(3) To function as a receptor for foot-and-mouth disease virus is not dependent on the presence of complete subunit cytoplasmic domains. | The integrin alpha(v)beta(3) has been shown to function as one of the integrin receptors on cultured cells for foot-and-mouth disease virus (FMDV), and high-efficiency utilization of the bovine homolog of this integrin is dependent on the cysteine-rich repeat region of the bovine beta(3) subunit. In this study we have ... |
11119613 | Differences in affinity of binding of lymphocytic choriomeningitis virus strains to the cellular receptor alpha-dystroglycan correlate with viral tropism and disease kinetics. | alpha-Dystroglycan (alpha-DG) was recently identified as a receptor for lymphocytic choriomeningitis virus (LCMV) and several other arenaviruses, including Lassa fever virus (W. Cao, M. D. Henry, P. Borrow, H. Yamada, J. H. Elder, E. V. Ravkov, S. T. Nichol, R. W. Compans, K. P. Campbell, and M. B. A. Oldstone, Science... |
11119574 | Roles of disulfide linkage and calcium ion-mediated interactions in assembly and disassembly of virus-like particles composed of simian virus 40 VP1 capsid protein. | The simian virus 40 capsid is composed of 72 pentamers of VP1 protein. Although the capsid is known to dissociate to pentamers in vitro following simultaneous treatment with reducing and chelating agents, the functional roles of disulfide linkage and calcium ion-mediated interactions are not clear. To elucidate the rol... |
11115820 | Epidermal growth factor reduces multiorgan failure induced by thioacetamide. | <h4>Background</h4>Multiorgan failure is a severe life threatening state where present therapeutic approaches are suboptimal. Epidermal growth factor (EGF) is a potent stimulant of repair in in vitro and in vivo models. We therefore examined its potential beneficial effect in reducing mortality and injury induced by th... |
11114604 | Influence of dehydroepiandrosterone on rabbit intraocular pressure. | <h4>Purpose</h4>The systemic concentration of dehydroepiandrosterone decreases with age in primates while in humans intraocular pressure (IOP) increases with aging. This study was designed to investigate if a relationship existed between dehydroepiandrosterone and IOP in pigmented rabbits.<h4>Methods</h4>Animals were t... |
11114246 | Recognition of the lipoyl domain is the ultimate determinant of substrate channelling in the pyruvate dehydrogenase multienzyme complex. | Reductive acetylation of the lipoyl domain (E2plip) of the dihydrolipoyl acetyltransferase component of the pyruvate dehydrogenase multienzyme complex of Escherichia coli is catalysed specifically by its partner pyruvate decarboxylase (E1p), and no productive interaction occurs with the analogous 2-oxoglutarate decarbo... |
11114923 | Role of the dinitrogenase reductase arginine 101 residue in dinitrogenase reductase ADP-ribosyltransferase binding, NAD binding, and cleavage. | Dinitrogenase reductase is posttranslationally regulated by dinitrogenase reductase ADP-ribosyltransferase (DRAT) via ADP-ribosylation of the arginine 101 residue in some bacteria. Rhodospirillum rubrum strains in which the arginine 101 of dinitrogenase reductase was replaced by tyrosine, phenylalanine, or leucine were... |
11100924 | Effects of cyclodextrins on photodegradation of organophosphorus pesticides in humic water. | Cyclodextrin (CyD) effects on photodegradations of organophosphorus pesticides in humic water were monitored on the basis of the increase percentage of the photodegradation rate constant for CyD-containing humic water. Remarkable promotion effects of CyDs were observed in humic water for photo-induced radical generatio... |
11051762 | Exoribonucleases and their multiple roles in RNA metabolism. | In recent years there has been a dramatic shift in our thinking about ribonucleases (RNases). Although they were once considered to be nonspecific, degradative enzymes, it is now clear that RNases play a central role in every aspect of cellular RNA metabolism, including decay of mRNA, conversion of RNA precursors to th... |
11034543 | Dimensions of antigen recognition and levels of immunological specificity. | Although recognition and specificity are among the most fundamental concepts in immunology, there is a common tendency to equate these notions with the fit, especially in terms of molecular shape, between interacting molecules. Even in the case of monovalent recognition, there are factors that contribute to the energet... |
10936620 | Twenty years of dendrotoxins. | Dendrotoxins are small proteins that were isolated 20 years ago from mamba (Dendroaspis) snake venoms (Harvey, A.L., Karlsson, E., 1980. Dendrotoxin from the venom of the green mamba, Dendroaspis angusticeps: a neurotoxin that enhances acetylcholine release at neuromuscular junctions. Naunyn-Schmiedebergs Arch. Pharmac... |
10900384 | The cell in absence of aggregation artifacts. | Eduard Kellenberger understood that the conventional resin-embedding, he helped to develop (Ryter, A., Kellenberger, E., 1958. L'inclusion au polyester pour l'ultramicrotomie. J. Ultrastruct. Res. , 2, 200-214), was prone to aggregation artifacts (Kellenberger, E., 1987. The response to biological macromolecules and su... |
10900378 | Confocal laser scanning microscopy and scanning electron microscopy of tissue Ti-implant interfaces. | Microscopic inspection of heterogenous three-dimensional (3D) objects such as oral implants, or implants in general, is conventionally performed either on ground sections of methyl-metacrylate-embedded material, at the cellular level by histologic analysis of the peri-implant tissue by light microscopy (LM), or at the ... |
12612008 | Computational diversity in the cochlear nucleus angularis of the barn owl. | The cochlear nucleus angularis (NA) is widely assumed to form the starting point of a brain stem pathway for processing sound intensity in birds. Details of its function are unclear, however, and its evolutionary origin and relationship to the mammalian cochlear-nucleus complex are obscure. We have carried out extracel... |
12506193 | Photoisomerization of a rotaxane hydrogen bonding template: light-induced acceleration of a large amplitude rotational motion. | Establishing methods for controlling aspects of large amplitude submolecular movements is a prerequisite for the development of artificial devices that function through rotary motion at the molecular level. Here we demonstrate that the rate of rotation of the interlocked components of fumaramide-derived [2]rotaxanes ca... |
12499380 | Association of the death-inducing signaling complex with microdomains after triggering through CD95/Fas. Evidence for caspase-8-ganglioside interaction in T cells. | In this investigation we show that the death-inducing signaling complex (DISC) associates with glycosphingolipid-enriched microdomains (GEM) upon CD95/Fas engagement. We primarily analyzed the ganglioside pattern and composition of GEM after triggering through CD95/Fas and observed that GM3 is the main ganglioside cons... |
12518056 | Flexibility and molecular recognition in the immune system. | Photon echo spectroscopy has been used to measure the response of three antibody-binding sites to perturbation from electronic excitation of a bound antigen, fluorescein. The three antibodies show motions that range in time scale from tens of femtoseconds to nanoseconds. Relative to the others, one antibody, 4-4-20, po... |
12518054 | Addition of the keto functional group to the genetic code of Escherichia coli. | Although the keto group is the most versatile of the functional groups in organic chemistry, it is absent in the genetically encoded amino acids. To overcome this natural limitation on protein biosynthesis, we have evolved an orthogonal tRNA-synthetase pair that makes possible the efficient incorporation of a keto amin... |
12499360 | Migration of nerve growth cones requires detergent-resistant membranes in a spatially defined and substrate-dependent manner. | Motility of nerve growth cones (GCs) is regulated by region-specific activities of cell adhesion molecules (CAMs). CAM activities could be modified by their localization to detergent-resistant membranes (DRMs), specialized microdomains enriched in signaling molecules. This paper deals with a question of whether DRMs ar... |
12499388 | Lipid raft-dependent and -independent signaling through HLA-DR molecules. | Lipid rafts are plasma membrane microdomains that are highly enriched in signaling molecules and that act as signal transduction platforms for many immune receptors. The involvement of these microdomains in HLA-DR-induced signaling is less well defined. We examined the constitutive presence of HLA-DR molecules in lipid... |
12496460 | Analysis of voids in crystal structures: the methods of 'dual' crystal chemistry. | The theoretical basics of the analysis of voids in crystal structures by means of Voronoi-Dirichlet polyhedra (VDP) and of the graph theory are stated. Topological relations are considered between VDPs and atomic domains in a crystal field. These relations allow the separation of two non-intersecting topological subspa... |
12496259 | The adipocyte plasma membrane caveolin functional/structural organization is necessary for the efficient endocytosis of GLUT4. | It is well established that insulin stimulation of glucose uptake requires the translocation of intracellular localized GLUT4 protein to the cell surface membrane. This plasma membrane-redistributed GLUT4 protein was partially co-localized with caveolin as determined by confocal fluorescent microscopy but was fully exc... |
12496294 | The fourth transmembrane segment forms the interface of the dopamine D2 receptor homodimer. | Considerable evidence suggests that G-protein-coupled receptors form homomeric and heteromeric dimers in vivo. Unraveling the structural mechanism for cross-talk between receptors in a dimeric complex must start with the identification of the presently unknown dimer interface. Here, by using cysteine cross-linking, we ... |
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