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11671154
Crystallographic Characterization of Stepwise Changes in Ligand Conformations as Their Internal Topology Changes and Two Novel Cross-Bridged Tetraazamacrocyclic Copper(II) Complexes.
The parallel syntheses of two new cross-bridged tetraazamacrocyclic complexes whose ligands are derived from 1,4,8,11-tetraazacyclotetradecane (cyclam = 14N4) and rac-1,4,8,11-tetraaza-5,5,7,12,12,14-hexamethylcyclotetradecane (tetB = 14N4Me(6)) have been characterized through the crystal structure determination of eve...
15822265
[Spectroscopic study on the structure and orientation of 1-hydroxyl-5-dodecyloxy-naphthalene LB films].
Ultraviolet-visible (UV-Vis), infrared transmission reflection absorption (RA) and ATR spectra were used to study the mono-and multi-layer Langmuir-Blodgett (LB) films of C12H25ONaph (1,5)OH at various temperatures to investigate dependencies of the aggregation and phase transitions on the number of monolayers. The UV-...
11213261
Antigen-specific T cells in autoimmune diseases with a focus on multiple sclerosis and experimental allergic encephalomyelitis.
Although the pathogenesis of autoimmune diseases remains poorly understood, the current view is that autoaggresive antigen-specific T cells play a central role in the cascade of events leading to most autoimmune diseases. A major event in the development of autoimmune diseases is the activation of antigen-specific T ce...
11212360
Chlorophyll breakdown in higher plants and algae.
Leaf senescence is accompanied by the metabolism of chlorophyll (Chl) to nonfluorescent catabolites (NCCs). The pathway of Chl degradation comprises several reactions and includes the occurrence of intermediary catabolites. After removal of phytol and the central Mg atom from Chl by chlorophyllase and Mg dechelatase, r...
11212353
Molecular genetics of Usher syndrome.
The Usher syndrome, an autosomal recessive deafness and blindness, is genetically and clinically heterogeneous. In the past 4 years, genes mutated in Usher syndrome type Ib and type IIa have been described. The Usher Ib gene encodes the motor protein myosin VIIa and was identified as the human homolog of the mouse shak...
10842635
Biological effects of electric shock and heat denaturation and oxidation of molecules, membranes, and cellular functions.
Direct exposure of cells in suspension to intense electric pulses is known to produce damages to cell membranes and supramolecular organizations of cells, and denaturation of macromolecules, much like injuries and tears seen in electric trauma patients. Thus, the system has been used as a laboratory model for investiga...
10825982
The first total synthesis of (-)-tamandarin A.
[formula: see text] Tamandarin A (1), a newly isolated natural product similar in structure to didemnin B (2), was shown to be somewhat more active in vitro than 2 against pancreatic carcinoma with an ED50 value 1.5 to 2 ng/mL. We report here the first total synthesis of 1. The key steps include a practical stereoselec...
10825974
Lower rim functionalized resorcinarenes: useful modules for supramolecular chemistry.
[formula: see text] A synthetic scheme for the selective functionalization of all-cis (rccc) resorcinarene platform at the "lower rim" was developed. Self-folding and self-complementary cavitands were prepared for molecular recognition and self-assembly, bearing functionality at remote sites. These molecules promise ap...
10825952
A new cryptand: synthesis and complexation with paraquat.
[formula: see text] Inspired by folded, nonpseudorotaxane complexes of bis(m-phenylene)-32-crown-10 systems, we synthesized a new bicyclic crown ether containing two 1,3,5-phenylene units linked by three tetra(ethyleneoxy) units. The new cryptand forms a "pseudorotaxane-like" inclusion complex with N,N'-dimethyl-4,4'-b...
10763810
Bacteria-host cell interaction mediated by cellular cholesterol/glycolipid-enriched microdomains.
Gram negative bacterial infection is a leading cause of fatality and is attributed, at least in part, to the bacteria's capacity to persist in the host in spite of appropriate antibiotic therapy. It has been suggested that bacteria evade antibiotics by hiding within host cells. We sought to investigate this important a...
10660437
Application of a macrocycle immobilized silica gel sorbent to flow injection on-line microcolumn preconcentration and separation coupled with flame atomic absorption spectrometry for interference-free determination of trace lead in biological and environmental samples.
A simple and highly selective flow injection on-line pre-concentration and separation-flame atomic absorption spectrometric method was developed for routine analysis of trace amounts of lead in biological and environmental samples. The selective preconcentration of lead was achieved in a wide range of sample acidity (0...
10602778
Circular antisense oligonucleotides inhibit growth of chronic myeloid leukemia cells.
<h4>Background</h4>Antisense represents a conceptually powerful method for regulating gene expression. However, antisense oligonucleotides developed to date manifest two serious limitations-nuclease susceptibility and nonspecific hybridization. Circular oligonucleotides may be superior to conventional linear oligonucle...
10596832
Determination of surfactants by capillary electrophoresis.
Capillary electrophoresis has been increasingly used during the past few years for the separation and determination of surfactants. These substances are applied in many household and industrial products such as laundry detergents, cosmetics and pharmaceuticals, often as homologous and isomeric mixtures. Product develop...
10596812
Selectivity in capillary electrokinetic separations.
This review gives a survey of selectivity modes in capillary electrophoresis separations in pharmaceutical analysis and bioanalysis. Despite the high efficiencies of these separation techniques, good selectivity is required to allow quantitation or identification of a particular analyte. Selectivity in capillary electr...
10591040
Predicted three-dimensional structural models of venom serine protease inhibitors and their interactions with trypsin and chymotrypsin.
Three homology models of trypsin and chymotrypsin inhibitor polypeptides from snake venom of Naja naja naja and Leaf-nosed viper in the unbound state and in complex with trypsin and chymotrypsin were built based on homology to bovine pancreatic trypsin inhibitor (BPTI). These venom inhibitors belong to the Kunitz-type ...
10586495
Enzymatic synthesis of N-acetylglucosaminyl-cyclodextrin by the reverse reaction of N-acetylhexosaminidase from jack bean.
Novel heterobranched cyclodextrins (CDs), N-acetylglucosaminyl-cyclodextrins (GlcNAc-CD), were synthesized from a mixture of GlcNAc and alpha, beta, or gamma CD by the reverse reaction of N-acetylhexosaminidase from jack bean. Optimum pH and temperature for the production of GlcNAc-alpha CD by N-acetylhexosaminidase we...
10584296
Polyketides from dinoflagellates: origins, pharmacology and biosynthesis.
Dinoflagellates, unicellular marine protists, produce some of the largest and most complex polyketides identified to date. The biological activities of these compounds are quite diverse. Compounds having potential therapeutic value as anti-cancer agents as well as deadly neurotoxins, whose production has resulted in se...
10582165
The B-cell system of human mucosae and exocrine glands.
The mucosae and exocrine glands harbour the largest activated B-cell system of the body, amounting to some 80-90% of all immunoglobulin (Ig)-producing cells. The major product of these immunocytes is polymeric (p)IgA (mainly dimers) with associated J chain. Both pIgA and pentameric IgM contain a binding site for the po...
10571997
Domain structure of gpNu1, a phage lambda DNA packaging protein.
The terminase enzyme from bacteriophage lambda is responsible for the insertion of a dsDNA genome into the confines of the viral capsid. The holoenzyme is composed of gpA and gpNu1 subunits in a gpA(1) x gpNu1(2) stoichiometry. While genetic studies have described regions within the two proteins responsible for DNA bin...
10570774
[Evaluation of severity in shock].
Shock is defined as organ failure due to the disturbance of perfusion in vital organs and various humoral mediators. Multiple organ failure (MOF) is a typical pathophysiologic condition subsequent to shock. Therefore the severity of shock should be evaluated based on the severity of organ failure. Recent advances in ou...
10564479
Dual control by regulatory gene fdsR of the fds operon encoding the NAD+-linked formate dehydrogenase of Ralstonia eutropha.
The transcriptional regulator gene fdsR was identified 150 bp upstream of the divergently oriented fdsGBACD operon encoding the soluble, NAD+-linked formate dehydrogenase in the chemoautotrophic bacterium Ralstonia eutropha H16. Its deduced product, FdsR, displays a basal sequence similarity to the regulatory proteins ...
10552798
Cyclodextrin-based optosensor for the determination of warfarin in waters.
A flow-through optosensor for warfarin is described. The sensor is developed in conjunction with flow analysis systems and uses a commercial bound beta-cyclodextrin material as the sensing phase. A strong fluorescence signal was observed as a result of the formation of an inclusion complex between warfarin and beta-cyc...
10554534
[Low T3 syndrome in multiple trauma patients--a phenomenon or important pathogenetic factor?].
<h4>Background</h4>Many nonthyroidal illnesses, such as major trauma, severe burn injury, sepsis or immune deficiency are associated with a reduced T3 concentration without increased serum TSH secretion. The pathopysiologic meaning of this phenomenon was controversely discussed since its investigation 20 years ago. The...
10553912
A kinetic proofreading mechanism for disentanglement of DNA by topoisomerases.
Cells must remove all entanglements between their replicated chromosomal DNAs to segregate them during cell division. Entanglement removal is done by ATP-driven enzymes that pass DNA strands through one another, called type II topoisomerases. In vitro, some type II topoisomerases can reduce entanglements much more than...
10549285
Heterochromatin dynamics in mouse cells: interaction between chromatin assembly factor 1 and HP1 proteins.
Mechanisms contributing to the maintenance of heterochromatin in proliferating cells are poorly understood. We demonstrate that chromatin assembly factor 1 (CAF-1) binds to mouse HP1 proteins via an N-terminal domain of its p150 subunit, a domain dispensable for nucleosome assembly during DNA replication. Mutations in ...
10549863
Release characteristics of endogenous constituents by exposure of small intestine to modified beta-cyclodextrins.
The aim of the present research is to characterize the leakage of intestinal constituents induced by beta-cyclodextrin (beta-CyD) derivatives using an in situ perfusion and an in vitro everted sac. The efficacy of 6-O-alpha-D-glucosyl (G1)- and 6-O-alpha-D-maltosyl (G2)-beta-CyDs as oral carriers was also compared with...
10548053
Barrel structures in proteins: automatic identification and classification including a sequence analysis of TIM barrels.
Automated methods for identifying and characterizing regular beta-barrels from coordinate data have been developed to analyze and classify various kinds of barrel structures based on geometric parameters such as the barrel strand number (n) and shear number (S). In total, we find 1,316 barrels in the January 1998 relea...
10548050
Backbone dynamics of the human CC chemokine eotaxin: fast motions, slow motions, and implications for receptor binding.
Eotaxin is a member of the chemokine family of about 40 proteins that induce cell migration. Eotaxin binds the CC chemokine receptor CCR3 that is highly expressed by eosinophils, and it is considered important in the pathology of chronic respiratory disorders such as asthma. The high resolution structure of eotaxin is ...
10546551
Effect of beta-cyclodextrin complexation on the photochemical and photosensitizing properties of tolmetin: a steady-state and time-resolved study.
The effects of beta-cyclodextrin complexation on the photochemical and photosensitizing properties of tolmetin have been investigated. Absorption, emission, circular dichroism and NMR measurements were used to characterize the host-guest complex. Nanosecond laser flash photolysis and steady-state photolysis experiments...
10546546
Effect of self-association and protein binding on the photochemical reactivity of triarylmethanes. Implications of noncovalent interactions on the competition between photosensitization mechanisms type I and type II.
We have explored the photochemical behavior of cationic triarylmethane dye monomers and dimers free in solution and noncovalently bound to bovine serum albumin (BSA) and examined how self-association and the formation of host-guest complexes involving biopolymers and photosensitizers affect the competition between the ...
10544085
Minor displacements in the insertion site provoke major differences in the induction of antibody responses by chimeric parvovirus-like particles.
An antigen-delivery system based on hybrid virus-like particles (VLPs) formed by the self-assembly of the capsid VP2 protein of canine parvovirus (CPV) and expressing foreign peptides was investigated. In this report, we have studied the effects of inserting the poliovirus C3:B epitope in the four loops and the C termi...
10536021
Attenuated sensitivity to neuroactive steroids in gamma-aminobutyrate type A receptor delta subunit knockout mice.
gamma-Aminobutyric acid (GABA) type A receptors mediate fast inhibitory synaptic transmission and have been implicated in responses to sedative/hypnotic agents (including neuroactive steroids), anxiety, and learning and memory. Using gene targeting technology, we generated a strain of mice deficient in the delta subuni...
10535981
A genetic method for dissecting the mechanism of transcriptional activator synergy by identical activators.
Pairs of transcriptional activators in prokaryotes have been shown to activate transcription synergistically from promoters with two activator binding sites. In some cases, such synergistic effects result from cooperative binding, but in other cases each DNA-bound activator plays a direct role in the activation process...
10535954
Self-assembly of fibronectin into fibrillar networks underneath dipalmitoyl phosphatidylcholine monolayers: role of lipid matrix and tensile forces.
The cell-mediated assembly of fibronectin (Fn) into fibrillar matrices is a complex multistep process that is incompletely understood because of the chemical complexity of the extracellular matrix and a lack of experimental control over molecular interactions and dynamic events. We have identified conditions under whic...
10535920
Conversion of agonist site to metal-ion chelator site in the beta(2)-adrenergic receptor.
Previously metal-ion sites have been used as structural and functional probes in seven transmembrane receptors (7TM), but as yet all the engineered sites have been inactivating. Based on presumed agonist interaction points in transmembrane III (TM-III) and -VII of the beta(2)-adrenergic receptor, in this paper we const...
10535915
DNA packing in stable lipid complexes designed for gene transfer imitates DNA compaction in bacteriophage.
The structure of complexes made from DNA and suitable lipids (lipoplex, Lx) was examined by cryo-electron microscopy (cryoEM). We observed a distinct concentric ring-like pattern with striated shells when using plasmid DNA. These spherical multilamellar particles have a mean diameter of 254 nm with repetitive spacing o...
10535914
Highly sensitive biological and chemical sensors based on reversible fluorescence quenching in a conjugated polymer.
The fluorescence of a polyanionic conjugated polymer can be quenched by extremely low concentrations of cationic electron acceptors in aqueous solutions. We report a greater than million-fold amplification of the sensitivity to fluorescence quenching compared with corresponding "molecular excited states." Using a combi...
10531047
Seven-transmembrane proteins as odorant and chemosensory receptors.
The olfactory systems of various species solve the challenging problem of general molecular recognition in widely differing ways. Despite this variety, the molecular receptors are invariably G protein-coupled seven-transmembrane proteins, and are encoded by the largest gene families known to exist in a given animal gen...
10529408
Recovery of catalytic activity from an inactive aggregated mutant of l-aspartase.
Two highly conserved lysyl residues have been replaced with an arginine to examine their role in the mechanism of l-aspartase from Escherichia coli. Replacement of an active-site lysine results in a significant loss of catalytic efficiency [A. S. Saribas, J. F. Schindler, and R. E. Viola (1994) J. Biol. Chem. 269, 6313...
10534236
Current status of radionuclide tracer imaging of thrombi and atheroma.
The imaging of thrombi and atherosclerotic plaques has great potential for decision making in the management of patients with all types of disease within the circulatory system. This importance is owing to the developments showing that areas of moderate stenosis with underlying atheroma are physiologically reactive and...
10527730
Exploring biomolecular recognition using optical biosensors.
Understanding the basic forces that determine molecular recognition helps to elucidate mechanisms of biological processes and facilitates discovery of innovative biotechnological methods and materials for therapeutics, diagnostics, and separation science. The ability to measure interaction properties of biological macr...
10527727
Isothermal titration calorimetry of protein-protein interactions.
The interaction of biologicalmacromolecules, whether protein-DNA, antibody-antigen, hormone-receptor, etc., illustrates the complexity and diversity of molecular recognition. The importance of such interactions in the immune response, signal transduction cascades, and gene expression cannot be overstated. It is of grea...
10527874
Enhancement of dendrimer-mediated transfection using synthetic lung surfactant exosurf neonatal in vitro.
Pulmonary surfactants enhance adenovirus-mediated gene transfer but inhibit cationic liposome-mediated transfection in lung epithelial cells in vitro. This study examines the effect of the synthetic lung surfactant Exosurf on dendrimer-mediated transfection in eukaryotic cells. Exosurf significantly enhanced dendrimer-...
10530704
Influence of cyclodextrins on the in vitro corneal permeability and in vivo ocular distribution of thalidomide.
The aim of the present study has been to develop aqueous Thalidomide (THA) eye drops in order to minimize systemic side effects and to improve bioavailability following topical application. Cyclodextrins (CDs), suitable vehicles to improve aqueous solubility of THA, were evaluated with regard to their ability to influe...
10525547
Aggregation of lipid rafts accompanies signaling via the T cell antigen receptor.
The role of lipid rafts in T cell antigen receptor (TCR) signaling was investigated using fluorescence microscopy. Lipid rafts labeled with cholera toxin B subunit (CT-B) and cross-linked into patches displayed characteristics of rafts isolated biochemically, including detergent resistance and colocalization with raft-...
10525530
PML is critical for ND10 formation and recruits the PML-interacting protein daxx to this nuclear structure when modified by SUMO-1.
Nuclear domain 10 (ND10), also referred to as nuclear bodies, are discrete interchromosomal accumulations of several proteins including promyelocytic leukemia protein (PML) and Sp100. In this study, we investigated the mechanism of ND10 assembly by identifying proteins that are essential for this process using cells li...
10526161
The regiochemical distribution of positive charges along cholesterol polyamine carbamates plays significant roles in modulating DNA binding affinity and lipofection.
We have quantified the effects of the regiochemical distribution of positive charges along the polyamine moiety in lipopolyamines for DNA molecular recognition. High affinity binding leads to charge neutralisation, DNA condensation and ultimately to lipofection. Binding affinities for calf thymus DNA were determined us...
10528852
A molecular investigation of true dominance in Huntington's disease.
Huntington's disease (HD) is thought to show true dominance, since subjects with two mutant alleles have been reported to have similar ages at onset of disease compared to heterozygous sibs. We have investigated this phenomenon using a cell culture model. Protein aggregate formation was used as an indicator for patholo...
10527122
Growth factors controlling muscle development.
The enlarged muscles of certain breeds of cattle, such as the Belgian Blue, have been shown to result from a marked increase in the number of normal sized muscle fibers. Originally insulin-like growth factors (IGFs) were implicated in this myofiber hyperplasia, as IGFs have been shown to stimulate myoblast proliferatio...
10522691
A direct method for the formation of peptide and carbohydrate dendrimers.
Two new methods for the modification of PAMAM dendrimers have been developed which allow the covergent synthesis of either peptide or carbohydrate-bearing dendrimer molecules. Both methods involve condensation between hydroxylamino nucleophiles and appropriate carbonyl-bearing reaction partners.
10520482
Cyclodextrin inclusion: catalytic effects on the degradation of organophosphorus pesticides in neutral aqueous solution.
alpha-, beta and gamma-Cyclodextrins were found to have promotive inclusion-catalytic effects on the degradation of organophosphorus pesticides solubilized in neutral aqueous media. Pesticide degradations were especially accelerated in such systems as alpha-cyclodextrin plus diazinon and beta-cyclodextrin plus chloropy...
10518679
Spray-drying of trypsin - surface characterisation and activity preservation.
In the present study trypsin mixed with various carbohydrates, i.e. lactose, sucrose, mannitol, alpha-cyclodextrin and dextrin, was spray-dried in order to investigate the effects of spray-drying on this enzyme, with particular emphasis on the effects of interactions between trypsin and the surface formed during spray-...
10518599
Pain modulation by release of the endogenous cannabinoid anandamide.
Synthetic cannabinoids produce behavioral analgesia and suppress pain neurotransmission, raising the possibility that endogenous cannabinoids serve naturally to modulate pain. Here, the development of a sensitive method for measuring cannabinoids by atmospheric pressure-chemical ionization mass spectrometry permitted m...
10518592
Mimicry of erythropoietin by a nonpeptide molecule.
Erythropoietin (EPO) controls the proliferation and differentiation of erythroid progenitor cells into red blood cells. EPO induces these effects by dimerization of the EPO receptors (EPOR) present on these cells. To discover nonpeptide molecules capable of mimicking the effects of EPO, we identified a small molecule c...
10518514
Simulation of biomimetic recognition between polymers and surfaces.
Many biological processes, such as transmembrane signaling and pathogen-host interactions, are initiated by a protein recognizing a specific pattern of binding sites on part of a membrane or cell surface. By recognition, we imply that the polymer quickly finds and then adsorbs strongly on the pattern-matched region and...
10516763
Genetic manipulation of primitive leukemic and normal hematopoietic cells using a novel method of adenovirus-mediated gene transfer.
Gene transfer into early hematopoietic cells has been problematic due to the quiescent nature of primitive cells and the lack of gene transfer vehicles with high efficiency for hematopoietic cell types. Previously, we have shown that adenoviral vectors can be used for the transduction of normal human progenitors with g...
10516644
Novel strategies for the design of receptor-selective vasopressin analogues: Aib-substitution and retro-inverso transformation.
1. We determined the pharmacological profile of novel backbone-modified peptides designed as protease-resistant, selective analogues of AVP. Binding affinities of peptides were determined at both V1A and V2 subtypes of vasopressin receptor (VPR). Biological potencies of selected peptides were tested in pressor and anti...
10517142
Fluorescence polarization studies of affinity interactions in capillary electrophoresis.
Capillary electrophoresis (CE) combined with molecular recognition for ultrasensitive bioanalytical applications often requires the formation of stable complexes between an analyte and its binding partner. Previous studies of binding interactions using CE involve multiple-step titration experiments and are time-consumi...
10514349
Biopharmaceutics and pharmacokinetics of 5-phenyl-1, 2-dithiole-3-thione complexed with sulfobutyl ether-7-beta-cyclodextrin in rabbits.
The biopharmaceutics and pharmacokinetics of 5-phenyl-1, 2-dithiole-3-thione (5PDTT) were investigated in rabbits, after administration as a complex with sulfobutyl-ether-7-beta-cyclodextrin (SBE7-beta-CD) by intravenous and oral routes and as a micronized powder by oral route. 5PDTT had a rapid and large red blood cel...
10514341
Heptakis(2,6-di-O-methyl-3-O-acetyl)-beta-cyclodextrin: A water-soluble cyclodextrin derivative with low hemolytic activity.
Acetyl groups were introduced to the hydroxyl groups of heptakis(2, 6-di-O-methyl)-beta-cyclodextrin (DM-beta-CyD), and the resulting heptakis(2,6-di-O-methyl-3-O-acetyl)-beta-CyD (DMA-beta-CyD) was evaluated for the inclusion property and hemolytic activity. It was confirmed by means of NMR and mass spectroscopies tha...
10514340
Solubilization of fluasterone.
Solubilization of nonpolar drugs constitutes one of the most important tasks in parenteral formulations design. This study investigates and assesses the solubility enhancement of Fluasterone by various techniques including cosolvency, micellization, and complexation. Of the solubilizing agents used, the modified beta-c...
10514293
Selective A(3) adenosine receptor antagonists: water-soluble 3, 5-diacyl-1,2,4-trialkylpyridinium salts and their oxidative generation from dihydropyridine precursors.
A(3) adenosine receptor antagonists are sought for their potential antiinflammatory, antiasthmatic, and antiischemic properties. We have found that 3,5-diacyl-1,2,4-trialkyl-6-phenylpyridinium derivatives constitute a novel class of selective A(3) adenosine receptor antagonists. The structure-activity relationships of ...
10515926
Growth phase-dependent variation in protein composition of the Escherichia coli nucleoid.
The genome DNA of Escherichia coli is associated with about 10 DNA-binding structural proteins, altogether forming the nucleoid. The nucleoid proteins play some functional roles, besides their structural roles, in the global regulation of such essential DNA functions as replication, recombination, and transcription. Us...
10515913
A second operator is involved in Pseudomonas aeruginosa elastase (lasB) activation.
Pseudomonas aeruginosa LasB elastase gene (lasB) transcription is controlled by the two-component quorum-sensing system of LasR, and the autoinducer, 3OC(12)-HSL (N-3-[oxododecanoyl]homoserine lactone). LasR and 3OC(12)-HSL-mediated lasB activation requires a functional operator sequence (OP1) in the lasB promoter regi...
10515900
Antifungal agents: mode of action, mechanisms of resistance, and correlation of these mechanisms with bacterial resistance.
The increased use of antibacterial and antifungal agents in recent years has resulted in the development of resistance to these drugs. The significant clinical implication of resistance has led to heightened interest in the study of antimicrobial resistance from different angles. Areas addressed include mechanisms unde...
10514392
Increased mucosal production of monomeric IgA1 but no IgA1 protease activity in Helicobacter pylori gastritis.
Immunoglobulin A and IgM are subjected to epithelial transport only when they are produced as polymers with incorporated J chain. Immunocytes containing various Ig isotypes and associated J chain in gastric mucosa, as well as IgA-degrading protease activity in Helicobacter pylori cultures, were examined. Gastric body s...
10517508
Fibrillogenesis of tau: insights from tau missense mutations in FTDP-17.
Frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17) is a neurological disorder associated with tau pathology.Tau deposits in FTDP-17 brains consist of polymerized filaments of hyperphosphorylated tau, the morphology of which is determined by the nature of the tau gene mutation observed in each ca...
10515046
Supramolecular interactions of solid human serum albumin with binary mixtures of solvent vapors.
Sorption isotherms of organic compounds on solid human serum albumin (HSA) from binary vapor mixtures were determined by gas chromatographic headspace analysis. The shape of sorption isotherms depends on molecular structure of studied sorbates. The 'active' compounds capable to sorb effectively on dry HSA increase the ...
10512843
Properties of spin and fluorescent labels at a receptor-ligand interface.
Site-directed labeling was used to obtain local information on the binding interface in a receptor-ligand complex. As a model we have chosen the specific association of the extracellular part of tissue factor (sTF) and factor VIIa (FVIIa), the primary initiator of the blood coagulation cascade. Different spectroscopic ...
10512827
The effect of S-layer protein adsorption and crystallization on the collective motion of a planar lipid bilayer studied by dynamic light scattering.
A dedicated dynamic light scattering (DLS) setup was employed to study the undulations of freely suspended planar lipid bilayers, the so-called black lipid membranes (BLM), over a previously inaccessible spread of frequencies (relaxation times ranging from 10(-2) to 10(-6) s) and wavevectors (250 cm(-1) < q < 38,000 cm...
10512812
Intersegment hydrogen bonds as possible structural determinants of the N/Q/R site in glutamate receptors.
Specific electrophysiological and pharmacological properties of ionic channels in NMDA, AMPA, and kainate subtypes of ionotropic glutamate receptors (GluRs) are determined by the Asn (N), Gln (Q), and Arg (R) residues located at homologous positions of the pore-lining M2 segments (the N/Q/R site). Presumably, the N/Q/R...
10512808
Brownian dynamics simulation of DNA condensation.
DNA condensation observed in vitro with the addition of polyvalent counterions is due to intermolecular attractive forces. We introduce a quantitative model of these forces in a Brownian dynamics simulation in addition to a standard mean-field Poisson-Boltzmann repulsion. The comparison of a theoretical value of the ef...
10512805
Does Ca2+ reach millimolar concentrations after single photon absorption in Drosophila photoreceptor microvilli?
The quantum bump, the elementary event of fly phototransduction induced by the absorption of a single photon, is a small, transient current due to the opening of cation-channels permeable to Ca2+. These channels are located in small, tube-like protrusions of the cell membrane, the microvilli. Using a modeling approach,...
10512803
Structure, interaction, dynamics and solvent effects on the DNA-EcoRI complex in aqueous solution from molecular dynamics simulation.
A 0.7-ns molecular dynamics simulation of the DNA-EcoRI complex in a 7.0-A solvent shell indicated a stable behavior of the system. No significant evaporation or smearing of the solvent's outer boundary occurred. The structure and the intermolecular interactions were found to be well maintained during the simulation. T...
10512859
Exogenous administration of gangliosides displaces GPI-anchored proteins from lipid microdomains in living cells.
Exogenous application of gangliosides to cells affects many cellular functions. We asked whether these effects could be attributed to the influence of gangliosides on the properties of sphingolipid-cholesterol microdomains on the plasma membrane, also termed rafts. The latter are envisaged as lateral assemblies of sphi...
10512856
Distinct effects of Rac1 on differentiation of primary avian myoblasts.
Rho family GTPases have been implicated in the regulation of the actin cytoskeleton in response to extracellular cues and in the transduction of signals from the membrane to the nucleus. Their role in development and cell differentiation, however, is little understood. Here we show that the transient expression of cons...
10512853
Caldesmon inhibits nonmuscle cell contractility and interferes with the formation of focal adhesions.
Caldesmon is known to inhibit the ATPase activity of actomyosin in a Ca(2+)-calmodulin-regulated manner. Although a nonmuscle isoform of caldesmon is widely expressed, its functional role has not yet been elucidated. We studied the effects of nonmuscle caldesmon on cellular contractility, actin cytoskeletal organizatio...
10512851
Functional hierarchy of simultaneously expressed adhesion receptors: integrin alpha2beta1 but not CD44 mediates MV3 melanoma cell migration and matrix reorganization within three-dimensional hyaluronan-containing collagen matrices.
Haptokinetic cell migration across surfaces is mediated by adhesion receptors including beta1 integrins and CD44 providing adhesion to extracellular matrix (ECM) ligands such as collagen and hyaluronan (HA), respectively. Little is known, however, about how such different receptor systems synergize for cell migration t...
10510309
Common structural features determine the effectiveness of carvedilol, daunomycin and rolitetracycline as inhibitors of Alzheimer beta-amyloid fibril formation.
One of the major pathological features of Alzheimer's disease is the deposition of beta-amyloid peptide (Abeta). Cellular toxicity has been shown to be associated with fibrillar forms of Abeta; preventing this fibril formation is therefore viewed as a possible method of slowing disease progression in Alzheimer's diseas...
10510296
Plant mitochondrial 2-oxoglutarate dehydrogenase complex: purification and characterization in potato.
The 2-oxoglutarate dehydrogenase complex (OGDC) in potato (Solanum tuberosum cv. Romano) tuber mitochondria is largely associated with the membrane fraction of osmotically ruptured organelles, whereas most of the other tricarboxylic acid cycle enzymes are found in the soluble matrix fraction. The purification of OGDC f...
10508667
Analysis of molecular recognition using optical biosensors.
Optical biosensors have made the analysis of molecular interactions rapid and convenient. The field is still young, with commercial instrumentation having been available for less than ten years. For this reason instrument development is still an important factor and the past year has seen continuing advances in instrum...
10508677
Knowledge-based design of bimodular and trimodular polyketide synthases based on domain and module swaps: a route to simple statin analogues.
<h4>Background</h4>Polyketides are structurally diverse natural products that have a range of medically useful activities. Nonaromatic bacterial polyketides are synthesised on modular polyketide synthase (PKS) multienzymes, in which each cycle of chain extension requires a different 'module' of enzymatic activities. At...
10508864
Plasma membrane microdomains act as concentration platforms to facilitate intoxication by aerolysin.
It has been proposed that the plasma membrane of many cell types contains cholesterol-sphingolipid-rich microdomains. Here, we analyze the role of these microdomains in promoting oligomerization of the bacterial pore-forming toxin aerolysin. Aerolysin binds to cells, via glycosyl phosphatidylinositol-anchored receptors...
10508862
Aczonin, a 550-kD putative scaffolding protein of presynaptic active zones, shares homology regions with Rim and Bassoon and binds profilin.
Neurotransmitter exocytosis is restricted to the active zone, a specialized area of the presynaptic plasma membrane. We report the identification and initial characterization of aczonin, a neuron-specific 550-kD protein concentrated at the presynaptic active zone and associated with a detergent-resistant cytoskeletal s...
10508851
Spatial relationship between transcription sites and chromosome territories.
We have investigated the spatial relationship between transcription sites and chromosome territories in the interphase nucleus of human female fibroblasts. Immunolabeling of nascent RNA was combined with visualization of chromosome territories by fluorescent in situ hybridization (FISH). Transcription sites were found ...
10508200
Sterol synthesis is up-regulated in cholesterol-loaded pigeon macrophages during induction of cholesterol efflux.
The extent to which cholesterol synthesis is modulated in macrophage foam cells by changes in cholesterol influx and efflux was determined using thioglycollate-elicited peritoneal macrophages from normal and cholesterol-fed White Carneau (WC) and Show Racer (SR) pigeons. In peritoneal macrophages from normocholesterole...
10508199
Regulation of adrenal scavenger receptor-BI expression by ACTH and cellular cholesterol pools.
Scavenger receptor BI (SR-BI) mediates selective uptake of high density lipoprotein (HDL) cholesteryl ester in the liver and adrenal gland. Adrenal SR-BI is increased both in adrenocorticotropic hormone (ACTH)-treated mice and also in apolipoprotein A-I knock-out (apoA-I0) mice which have depleted adrenal cholesterol s...
10506577
Angiogenesis inhibitor endostatin is a distinct component of elastic fibers in vessel walls.
Theendothelial cell inhibitor endostatin (22 kDa) is part of the carboxyl-terminal globular domain of collagen XVIII and shows a widespread tissue distribution. Immunohistology of adult mouse tissues demonstrated a preferred localization in many vessel walls and some other basement membrane zones. A strong immunogold s...
10508157
Apg10p, a novel protein-conjugating enzyme essential for autophagy in yeast.
Autophagy is a cellular process for bulk degradation of cytoplasmic components. The attachment of Apg12p, a modifier with no significant similarity to ubiquitin, to Apg5p is crucial for autophagy in yeast. This reaction proceeds in a ubiquitination-like manner, and requires Apg7p and Apg10p. Apg7p exhibits a considerab...
10508151
Crystal structure and induction mechanism of AmiC-AmiR: a ligand-regulated transcription antitermination complex.
Inducible expression of the aliphatic amidase operon in Pseudomonas aeruginosa is controlled by an antitermination mechanism which allows production of the full-length transcript only in the presence of small-molecule inducers, such as acetamide. Ligand-regulated antitermination is provided by AmiC, the ligand-sensitiv...
10508102
Characteristics of two forms of alpha-amylases and structural implication.
Complete (Ba-L) and truncated (Ba-S) forms of alpha-amylases from Bacillus subtilis X-23 were purified, and the amino- and carboxyl-terminal amino acid sequences of Ba-L and Ba-S were determined. The amino acid sequence deduced from the nucleotide sequence of the alpha-amylase gene indicated that Ba-S was produced from...
10509626
A membrane-permeable radical scavenger reduces the organ injury in hemorrhagic shock.
Reactive oxygen species (ROS) contribute to the multiple organ failure (MOF) in hemorrhagic shock. Here we investigate the effects of a membrane-permeable radical scavenger (tempol) on the circulatory failure and the organ injury and dysfunction (kidney, liver, lung, intestine) associated with hemorrhagic shock in the ...
10504303
Fibrillin assembly: dimer formation mediated by amino-terminal sequences.
We have investigated recombinant fibrillin-1 (profib-1) and fibrillin-2 (glyfib-2) molecules encoding the proline- or glycine-rich regions with flanking domains (exons 9-11), in order to establish whether these sequences might mediate specific molecular recognition events important in fibrillin assembly. Our data demon...
10506174
Analysis of the rds/peripherin.rom1 complex in transgenic photoreceptors that express a chimeric protein.
Mice homozygous for the retinal degeneration slow (rds) mutation completely lack photoreceptor outer segments. The rds gene encodes rds/peripherin (rds), a membrane glycoprotein in the rims of rod and cone outer segment discs. rds is present as a complex with the related protein, rom1. Here, we generated transgenic mic...
10502630
Poly(acrylic acid) microspheres containing beta-cyclodextrin: loading and in vitro release of two dyes.
Microspheres containing poly(acrylic acid) and beta-cyclodextrin or maltose were prepared by a w/o solvent evaporation technique. The dispersed aqueous phase contained poly(acrylic acid) (800 mg) and beta-cyclodextrin or maltose (0, 200 or 800 mg). Food-grade olive oil was the continuous phase. Microsphere particle siz...
10502541
Linking iodine with autoimmune thyroiditis.
A great deal of circumstantial evidence has linked iodine with the rising incidence of autoimmune thyroiditis in the United States. In our investigations, we have shown directly that T cells from humans with chronic lymphocytic thyroiditis proliferate in the presence of iodinated but not in the presence of noniodinated...
10498726
Interactions of the integrase protein of the conjugative transposon Tn916 with its specific DNA binding sites.
The binding of two chimeric proteins, consisting of the N-terminal or C-terminal DNA binding domain of Tn916 Int fused to maltose binding protein, to specific oligonucleotide substrates was analyzed by gel mobility shift assay. The chimeric protein with the N-terminal domain formed two complexes of different electropho...
10498713
Plasmid RK2 ParB protein: purification and nuclease properties.
The parCBA operon of the 3.2-kb stabilization region of plasmid RK2 encodes three cotranslated proteins. ParA mediates site-specific recombination to resolve plasmid multimers, ParB has been shown to be a nuclease, and the function of ParC is unknown. In this study ParB was overexpressed by cotranslation with ParC in E...
10497268
Design of modified oligodeoxyribonucleotide probes to detect telomere repeat sequences in FISH assays.
A series of dye-labeled oligonucleotide probes containing base and sugar modifications were tested for the ability to detect telomeric repeat sequences in FISH assays. These modified oligonucleotides, all 18 nt in length, were complementary to either the cytidine-rich (C(3)TA(2))(n)or guanosine-rich (T(2)AG(3))(n)telom...
10497331
Protein machines and self assembly in muscle organization.
The remarkable order of striated muscle is the result of a complex series of protein interactions at different levels of organization. Within muscle, the thick filament and its major protein myosin are classical examples of functioning protein machines. Our understanding of the structure and assembly of thick filaments...