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9736628 | An ATP-ADP switch in MuB controls progression of the Mu transposition pathway. | MuB protein, an ATP-dependent DNA-binding protein, collaborates with Mu transposase to promote efficient transposition. MuB binds target DNA, delivers this target DNA segment to transposase and activates transposase's catalytic functions. Using ATP-bound, ADP-bound and ATPase-defective MuB proteins we investigated how ... |
9736623 | Structure of the double-stranded RNA-binding domain of the protein kinase PKR reveals the molecular basis of its dsRNA-mediated activation. | Protein kinase PKR is an interferon-induced enzyme that plays a key role in the control of viral infections and cellular homeostasis. Compared with other known kinases, PKR is activated by a distinct mechanism that involves double-stranded RNA (dsRNA) binding in its N-terminal region in an RNA sequence-independent fash... |
9736618 | Complex formation by the Drosophila MSL proteins: role of the MSL2 RING finger in protein complex assembly. | Drosophila MSL proteins are thought to act within a complex to elevate transcription from the male X chromosome. We found that the MSL1, MSL2 and MSL3 proteins are associated in immunoprecipitations, chromatographic steps and in the yeast two-hybrid system, but that the MLE protein is not tightly complexed in these ass... |
9736607 | Crystal structure of the amphiphysin-2 SH3 domain and its role in the prevention of dynamin ring formation. | The amphiphysins are brain-enriched proteins, implicated in clathrin-mediated endocytosis, that interact with dynamin through their SH3 domains. To elucidate the nature of this interaction, we have solved the crystal structure of the amphiphysin-2 (Amph2) SH3 domain to 2.2 A. The structure possesses several notable fea... |
9736605 | Phospholipid-assisted protein folding: phosphatidylethanolamine is required at a late step of the conformational maturation of the polytopic membrane protein lactose permease. | Previously we presented evidence that phosphatidylethanolamine (PE) acts as a molecular chaperone in the folding of the polytopic membrane protein lactose permease (LacY) of Escherichia coli. Here we provide more definitive evidence supporting the chaperone properties of PE. Membrane insertion of LacY prevents its irre... |
9737844 | Identification of protein folding patterns using site-directed spin labeling. Structural characterization of a beta-sheet and putative substrate binding regions in the conserved domain of alpha A-crystallin. | The folding pattern of the segment of alphaA-crystallin encoded by exon 2 and containing putative substrate binding sites was explored using site-directed spin labeling (SDSL). For this purpose, a nitroxide scan was carried out between residues 60 and 108. At each site, structural constraints describing the local envir... |
9738965 | The nuclear pore complex. | The nuclear pore complex is the largest supramolecular complex that assembles in the eukaryotic cell. This structure is highly dynamic and must disassemble prior to mitosis and reassemble after the event. The directed movement of macromolecules into and out of the nucleus occurs through the nuclear pore complex, a pote... |
9738502 | Three-dimensional segregation of supramolecular activation clusters in T cells. | Activation of T cells by antigen-presenting cells (APCs) depends on the complex integration of signals that are delivered by multiple antigen receptors. Most receptor-proximal activation events in T cells were identified using multivalent anti-receptor antibodies, eliminating the need to use the more complex APCs. As t... |
9733647 | GlnK, a PII-homologue: structure reveals ATP binding site and indicates how the T-loops may be involved in molecular recognition. | GlnK is a recently discovered homologue of the PII signal protein, an indicator of the nitrogen status of bacteria. PII occupies a central position in the dual cascade that regulates the activity of glutamine synthetase and the transcription of its gene. The complete role of Escherichia coli GlnK is yet to be determine... |
9733696 | The Bacteroides fragilis BtgA mobilization protein binds to the oriT region of pBFTM10. | The Bacteroides fragilis conjugal plasmid pBFTM10 contains two genes, btgA and btgB, and a putative oriT region necessary for transfer in Bacteroides fragilis and Escherichia coli. The BtgA protein was predicted to contain a helix-turn-helix motif, indicating possible DNA binding activity. DNA sequence analysis of the ... |
9733684 | Phosphorylation of the periplasmic binding protein in two transport systems for arginine incorporation in Escherichia coli K-12 is unrelated to the function of the transport system. | In Escherichia coli K-12, the accumulation of arginine is mediated by two distinct periplasmic binding protein-dependent transport systems, one common to arginine and ornithine (AO system) and one for lysine, arginine, and ornithine (LAO system). Each of these systems includes a specific periplasmic binding protein, th... |
9732999 | Miniaturization of analytical systems. | Miniaturization has been a long-term trend in clinical diagnostics instrumentation. Now a range of new technologies, including micromachining and molecular self-assembly, are providing the means for further size reduction of analyzers to devices with micro- to nanometer dimensions and submicroliter volumes. Many analyt... |
9732980 | Simple method for the routine determination of betaine and N,N-dimethylglycine in blood and urine. | A simple and convenient method using commercially available derivatization reagents is described for the measurement of betaine and N,N-dimethylglycine (DMG) in blood and urine. Precolumn derivatization of plasma or urine is performed directly in acetonitrile without extraction with p-bromophenacyl bromide and crown et... |
9726951 | The photoexcited triplet state as a probe of chromophore-protein interaction in myoglobin. | The photoexcited metastable triplet state of Mg(2+)-mesoporphyrin IX (MgMPIX) or Mg(2+)-protoporphyrin IX (MgPPIX) located in the heme pocket of horse myoglobin (Mb) was investigated by optical and electron paramagnetic resonance (EPR) spectroscopy, and its properties were compared with the model complexes, MgMPIX, MgP... |
9726939 | A mechanism of protein-mediated fusion: coupling between refolding of the influenza hemagglutinin and lipid rearrangements. | Although membrane fusion mediated by influenza virus hemagglutinin (HA) is the best characterized example of ubiquitous protein-mediated fusion, it is still not known how the low-pH-induced refolding of HA trimers causes fusion. This refolding involves 1) repositioning of the hydrophobic N-terminal sequence of the HA2 ... |
9726937 | Molecular ordering of interfacially localized tryptophan analogs in ester- and ether-lipid bilayers studied by 2H-NMR. | Perdeuterated indole-d6 and N-methylated indole-d6 were solubilized in lamellar liquid crystalline phases composed of either 1,2-diacyl-glycero-3-phosphocholine (14:0)/water or 1,2-dialkyl-glycero-3-phosphocholine(14:0/water. The molecular ordering of the tryptophan analogs was determined from deuteron quadrupole split... |
9726932 | Binding of transducin and transducin-derived peptides to rhodopsin studies by attenuated total reflection-Fourier transform infrared difference spectroscopy. | Fourier transform infrared difference spectroscopy combined with the attenuated total reflection technique allows the monitoring of the association of transducin with bovine photoreceptor membranes in the dark. Illumination causes infrared absorption changes linked to formation of the light-activated rhodopsin-transduc... |
9730889 | The specificity of peptides bound to human histocompatibility leukocyte antigen (HLA)-B27 influences the prevalence of arthritis in HLA-B27 transgenic rats. | Human histocompatibility leukocyte antigen B27 is highly associated with the rheumatic diseases termed spondyloarthropathies, but the mechanism is not known. B27 transgenic rats develop a spontaneous disease resembling the human spondyloarthropathies that includes arthritis and colitis. To investigate whether this dise... |
9730947 | Voltage-dependent block of endothelial volume-regulated anion channels by calix[4]arenes. | We have studied the effects of calix[4]arenes on the volume-regulated anion channel (VRAC) currents in cultured calf pulmonary artery endothelial cells. TS- and TS-TM-calix[4]arenes induced a fast inhibition at positive potentials but were ineffective at negative potentials. Maximal block occurred at potentials between... |
9731771 | Engineering an intertwined form of CD2 for stability and assembly. | The amino-terminal domain of CD2 has the remarkable ability to fold in two ways: either as a monomer or as an intertwined, metastable dimer. Here we show that it is possible to differentially stabilize either fold by engineering the CD2 sequence, mimicking random mutagenesis events that could occur during molecular evo... |
9729609 | Bacillus thuringiensis and its pesticidal crystal proteins. | During the past decade the pesticidal bacterium Bacillus thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism's pesticidal crystal proteins, and a coherent picture o... |
9729530 | Selection of recombinant, library-derived antibody fragments against p24 for human immunodeficiency virus type 1 diagnostics. | By application of combinatorial library technology, we generated the first recombinant antibody fragments directed against the major capsid protein p24 of human immunodeficiency virus type 1 (HIV-1). A library of single-chain Fv fragments (scFvs) was constructed by using the antibody variable-region (V) genes of B cell... |
9729481 | Mechanism for basal expression of rat mitochondrial branched-chain-2-oxo-acid dehydrogenase kinase [corrected]. | The rat branched-chain-2-oxo-acid dehydrogenase (BCOD) kinase mRNA is transcribed from a TATA-less promoter that has GC-rich sequences and two putative Sp1 binding sites near the transcription start site. We demonstrated previously that the 5' region of the kinase gene, base pairs -128 to +264, contained promoter activ... |
9727076 | Human infection with Trypanosoma cruzi induces parasite antigen-specific cytotoxic T lymphocyte responses. | Experimental models of Chagas' disease, an infection caused by the intracellular protozoan Trypanosoma cruzi, have demonstrated the crucial immunoprotective role played by CD8(+) T lymphocytes. These cells dominate inflammatory foci in parasitized tissues and their elimination from mice leads to uncontrolled parasite r... |
9727074 | Clonal expansion and somatic hypermutation of V(H) genes of B cells from cerebrospinal fluid in multiple sclerosis. | The cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients is characterized by increased concentrations of immunoglobulin (Ig), which on electrophoretic analysis shows restricted heterogeneity (oligoclonal bands). CSF Ig is composed of both serum and intrathecally produced components. To examine the properties o... |
9725912 | Rho and Rab small G proteins coordinately reorganize stress fibers and focal adhesions in MDCK cells. | The Rho subfamily of the Rho small G protein family (Rho) regulates formation of stress fibers and focal adhesions in many types of cultured cells. In moving cells, dynamic and coordinate disassembly and reassembly of stress fibers and focal adhesions are observed, but the precise mechanisms in the regulation of these ... |
9726888 | Purification and characterization of three thermostable endochitinases of a noble Bacillus strain, MH-1, isolated from chitin-containing compost. | A thermophilic and actinic bacterium strain, MH-1, which produced three different endochitinases in its culture fluid was isolated from chitin-containing compost. The microorganism did not grow in any of the usual media for actinomyces but only in colloidal chitin supplemented with yeast extract and (2, 6-O-dimethyl)-b... |
9726872 | Enzymatic properties of a novel liquefying alpha-amylase from an alkaliphilic Bacillus isolate and entire nucleotide and amino acid sequences. | A novel liquefying alpha-amylase (LAMY) was found in cultures of an alkaliphilic Bacillus isolate, KSM-1378. The specific activity of purified LAMY was approximately 5,000 U mg of protein-1, a value two- to fivefold greater between pH 5 and 10 than that of an industrial, thermostable Bacillus licheniformis enzyme. The ... |
9724815 | The negative feedback actions of progesterone on gonadotropin-releasing hormone secretion are transduced by the classical progesterone receptor. | Progesterone (P) powerfully inhibits gonadotropin-releasing hormone (GnRH) secretion in ewes, as in other species, but the neural mechanisms underlying this effect remain poorly understood. Using an estrogen (E)-free ovine model, we investigated the immediate GnRH and luteinizing hormone (LH) response to acute manipula... |
9724736 | A method for directed evolution and functional cloning of enzymes. | A general scheme is described for the in vitro evolution of protein catalysts in a biologically amplifiable system. Substrate is covalently and site specifically attached by a flexible tether to the pIII coat protein of a filamentous phage that also displays the catalyst. Intramolecular conversion of substrate to produ... |
9724734 | The location of the carboxy-terminal region of gamma chains in fibrinogen and fibrin D domains. | Elongated fibrinogen molecules are comprised of two outer "D" domains, each connected through a "coiled-coil" region to the central "E" domain. Fibrin forms following thrombin cleavage in the E domain and then undergoes intermolecular end-to-middle D:E domain associations that result in double-stranded fibrils. Factor ... |
9724726 | Design, synthesis, and characterization of a photoactivatable flavocytochrome molecular maquette. | We report the construction of a synthetic flavo-heme protein that incorporates two major physiological activities of flavoproteins: light activation of flavin analogous to DNA photolyase and rapid intramolecular electron transfer between the flavin and heme cofactors as in several oxidoreductases. The functional tetra-... |
9724721 | Redesigning an FKBP-ligand interface to generate chemical dimerizers with novel specificity. | FKBP ligand homodimers can be used to activate signaling events inside cells and animals that have been engineered to express fusions between appropriate signaling domains and FKBP. However, use of these dimerizers in vivo is potentially limited by ligand binding to endogenous FKBP. We have designed ligands that bind s... |
9724567 | Comparison of the effects of potential parenteral vehicles for poorly water soluble anticancer drugs (organic cosolvents and cyclodextrin solutions) on cultured endothelial cells (HUV-EC). | The effect of dilution of parenteral vehicles (organic cosolvent and 0.1 M cyclodextrin solutions) on cultured endothelial cells (HUV-EC) were compared in vitro. Cell morphology was observed by phase contrast light microscopy and cell viability by measuring 3-[4, 5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide ... |
9725829 | Identification of functional connections between calmodulin and the yeast actin cytoskeleton. | One of four intragenic complementing groups of temperature-sensitive yeast calmodulin mutations, cmd1A, results in a characteristic functional defect in actin organization. We report here that among the complementing mutations, a representative cmd1A mutation (cmd1-226: F92A) is synthetically lethal with a mutation in ... |
9724648 | Active recruitment of sigma54-RNA polymerase to the Pu promoter of Pseudomonas putida: role of IHF and alphaCTD. | The sequence elements determining the binding of the sigma54-containing RNA polymerase (sigma54-RNAP) to the Pu promoter of Pseudomonas putida have been examined. Contrary to previous results in related systems, we show that the integration host factor (IHF) binding stimulates the recruitment of the enzyme to the -12/-... |
9724631 | Clathrin coats at 21 A resolution: a cellular assembly designed to recycle multiple membrane receptors. | We present a map at 21 A resolution of clathrin assembled into cages with the endocytic adaptor complex, AP-2. The map was obtained by cryo-electron microscopy and single-particle reconstruction. It reveals details of the packing of entire clathrin molecules as they interact to form a cage with two nested polyhedral la... |
9724546 | Probing the backbone dynamics of oxidized and reduced rat microsomal cytochrome b5 via 15N rotating frame NMR relaxation measurements: biological implications. | Rotating frame 15N relaxation NMR experiments have been performed to study the local mobility of the oxidized and reduced forms of rat microsomal cytochrome b5, in the microsecond to millisecond time range. Measurements of rotating frame relaxation rates (R1rho) were performed as a function of the effective magnetic fi... |
9724537 | Channel-lining residues in the M3 membrane-spanning segment of the cystic fibrosis transmembrane conductance regulator. | The cystic fibrosis transmembrane conductance regulator (CFTR) forms a chloride-selective channel. Residues from the 12 putative membrane-spanning segments form at least part of the channel lining. We need to identify the channel-lining residues in order to understand the structural basis for the channel's functional p... |
9724523 | Selective recognition and cleavage of RNA loop structures by Ni(II).Xaa-Gly-His metallopeptides. | The recognition and cleavage of tRNAPhe and the TAR RNA of HIV-1 by metallopeptides of the general form Ni(II).Xaa-Gly-His (where Xaa is Gly, Lys, or Arg) were investigated. The results of RNA cleavage analyses suggest that KHSO5- or magnesium monoperoxyphthalate-activated metallopeptides (1) induce nucleobase damage w... |
9722638 | Self-assembly of DNA-polymer complexes using template polymerization. | The self-assembly of supramolecular complexes of nucleic acids and polymers is of relevance to several biological processes including viral and chromatin formation as well as gene therapy vector design. We now show that template polymerization facilitates condensation of DNA into particles that are <150 nm in diameter.... |
9721317 | Mutations in toxR and toxS that separate transcriptional activation from DNA binding at the cholera toxin gene promoter. | ToxR and ToxS are integral membrane proteins that activate the transcription of virulence genes in Vibrio cholerae. ToxR can be separated into three different domains: an N-terminal cytoplasmic DNA binding domain, a central transmembrane domain, and a C-terminal periplasmic domain. ToxS is thought to enhance ToxR-media... |
9721315 | Intracellular alpha-amylase of Streptococcus mutans. | Sequencing upstream of the Streptococcus mutans gene for a CcpA gene homolog, regM, revealed an open reading frame, named amy, with homology to genes encoding alpha-amylases. The deduced amino acid sequence showed a strong similarity (60% amino acid identity) to the intracellular alpha-amylase of Streptococcus bovis an... |
9721279 | Genetic linkage and cotransfer of a novel, vanB-containing transposon (Tn5382) and a low-affinity penicillin-binding protein 5 gene in a clinical vancomycin-resistant Enterococcus faecium isolate. | Mechanisms for the intercellular transfer of VanB-type vancomycin resistance determinants and for the almost universal association of these determinants with those for high-level ampicillin resistance remain poorly defined. We report the discovery of Tn5382, a ca. 27-kb putative transposon encoding VanB-type glycopepti... |
9721267 | Efficiency and frequency of translational coupling between the bacteriophage T4 clamp loader genes. | The bacteriophage T4 DNA polymerase holoenzyme is composed of the core polymerase, gene product 43 (gp43), in association with the "sliding clamp" of the T4 system, gp45. Sliding clamps are the processivity factors of DNA replication systems. The T4 sliding clamp comes to encircle DNA via the "clamp loader" activity in... |
9716740 | Immunohistochemical observation of growth-associated protein 43 (GAP-43) in the developing circumvallate papilla of the rat. | The distribution and development of growth-associated protein 43 (GAP-43)-like immunoreactivity (-LI) in the rat circumvallate papilla (CVP) were compared to those of protein gene product 9.5 (PGP 9.5)-LI. In the adult, thick GAP-43-like immunoreactive (-IR) structures gathered densely in the subgemmal region. Some of ... |
9716503 | Detailed characterization of a cyclophilin from the human malaria parasite Plasmodium falciparum. | Cyclosporin (Cs) A has pronounced antimalarial activity in vitro and in vivo. In other organisms, the drug is thought to exert its effects either by inhibiting the peptidylprolyl cis/trans isomerase activity of cyclophilin (CyP) or by forming a CyP-CsA complex that inhibits the phosphatase activity of calcineurin. We h... |
9712811 | The Helicobacter pylori UreI protein is not involved in urease activity but is essential for bacterial survival in vivo. | We produced defined isogenic Helicobacter pylori ureI mutants to investigate the function of UreI, the product of one of the genes of the urease cluster. The insertion of a cat cassette had a strong polar effect on the expression of the downstream urease genes, resulting in very weak urease activity. Urease activity, m... |
9712787 | Deletion of repeats in the alpha C protein enhances the pathogenicity of group B streptococci in immune mice. | The alpha C protein is a protective surface-associated antigen of group B streptococci (GBS). The prototype alpha C protein of GBS (strain A909) contains nine identical tandem repeats, each comprising 82 amino acids, flanked by N- and C-terminal domains. Clinical isolates of GBS show variable numbers of repeats with a ... |
9710633 | Methyl-CpG-binding protein MeCP2 represses Sp1-activated transcription of the human leukosialin gene when the promoter is methylated. | Human leukosialin (CD43) is expressed in a cell lineage-specific as well as a differentiation stage-specific fashion. The leukosialin promoter, made up of an Sp1 binding site and a sequence similar to that of an initiator, possesses high transcriptional potential. Previous data have demonstrated that the leukosialin ge... |
9710617 | Specific mismatch recognition in heteroduplex intermediates by p53 suggests a role in fidelity control of homologous recombination. | We demonstrate that wild-type p53 inhibits homologous recombination. To analyze DNA substrate specificities in this process, we designed recombination experiments such that coinfection of simian virus 40 mutant pairs generated heteroduplexes with distinctly unpaired regions. DNA exchanges producing single C-T and A-G m... |
9710605 | Control of PKR protein kinase by hepatitis C virus nonstructural 5A protein: molecular mechanisms of kinase regulation. | The PKR protein kinase is a critical component of the cellular antiviral and antiproliferative responses induced by interferons. Recent evidence indicates that the nonstructural 5A (NS5A) protein of hepatitis C virus (HCV) can repress PKR function in vivo, possibly allowing HCV to escape the antiviral effects of interf... |
9710578 | HSP90 interacts with and regulates the activity of heat shock factor 1 in Xenopus oocytes. | Transcriptional activation of heat shock genes is a reversible and multistep process involving conversion of inactive heat shock factor 1 (HSF1) monomers into heat shock element (HSE)-binding homotrimers, hyperphosphorylation, and further modifications that induce full transcriptional competence. HSF1 is controlled by ... |
9705498 | Staining of cell surface human CD4 with 2'-F-pyrimidine-containing RNA aptamers for flow cytometry. | We have used recombinant human CD4 presented on beads as an affinity matrix to screen a 2'-F-pyrimidine-containing RNA library with a complexity of approximately 10(14) molecules. Affinity-selected aptamers bind recombinant CD4 with low nanomolar equilibrium dissociation constants. These high-affinity aptamers conjugat... |
9699292 | Measurement of 90Sr in bone ash. | Bone is a critical organ for the accumulation of many radionuclides, including 90Sr. A bone ash has been prepared by NIST to become a standard reference material and the assaying of the 90Sr activity concentration is reported. A radiochemical procedure, based on extraction chromatography using a crown ether, has been d... |
9696804 | Phosphorylation of structural components promotes dissociation of the herpes simplex virus type 1 tegument. | The role of phosphorylation in the dissociation of structural components of the herpes simplex virus type 1 (HSV-1) tegument was investigated, using an in vitro assay. Addition of physiological concentrations of ATP and magnesium to wild-type virions in the presence of detergent promoted the release of VP13/14 and VP22... |
29711055 | Regioselective Synthesis of trans-1 Fullerene Bis-Adducts Directed by a Crown Ether Tether: Alkali Metal Cation Modulated Redox Properties of Fullerene-Crown Ether Conjugates. | Regioselective Bingel macrocyclization of C<sub>60</sub> with a bis-malonate containing a novel dibenzo[18] crown-6 tether provides a versatile access to trans-1 fullerene bis-adducts such as (±)-1. Complexation of a potassium ion by (±)-1 has a pronounced effect on the redox properties of the carbon sphere as a result... |
29711051 | A Strong Positive Allosteric Effect in the Molecular Recognition of Dicarboxylic Acids by a Cerium(IV) Bis[tetrakis(4-pyridyl)porphyrinate] Double Decker. | With increasing number of bound dicarboxylic acid molecules, the binding of further molecules by the title compound becomes more favorable (a 1:4 complex is depicted schematically on the right). The association constant for binding of the first guest molecule is small, since the increase in Gibbs free energy due to bin... |
29711041 | Self-Assembly of Nanometer-Sized Macrotricyclic Complexes from Ten Small Component Molecules. | Nanometer-sized bowls: six metal centers and four tridentate ligands self-assemble in aqueous solution to give the macrotricycle 1, which has approximate dimensions of 3×2×2 nm. Another macrocycle (not shown), obtained with a different ligand, is of similar size and topology but differs considerably from 1 in its host-... |
22267880 | Tobacco mosaic virus adsorption on self-assembled and Langmuir-Blodgett monolayers studied by TIRF and SFM. | The adsorption of tobacco mosaic virus (TMV) on self-assembled and Langmuir-Blodgett monolayers was investigated using total internal reflection fluorescence (TIRF) spectroscopy and scanning force microscopy (SFM). Substrates were chosen to probe electrostatic, hydrophobic and surface fluidity effects on TMV adsorption... |
21644662 | Higher order equilibria and their effect on analyte migration behavior in capillary electrophoresis. | This paper presents a quantitative investigation into the effect of analyte-additive interactions on analyte migration behavior in capillary electrophoresis (CE) when both 1:1 and 1:2 stoichiometries are present. Equations based on the individual capacity factors for each interaction are derived to account for the effe... |
18967228 | Sequential liquid-liquid extraction graphite furnace atomic absorption spectrometric (GFAAS) and spectrophotometric determination of zirconium(IV) with calixarene hydroxamic acid. | A new calixarene hydroxamic acid, 25,26,27,28-tetrahydroxy-5,11,17,23-tetrakis (N-p-chlorophenyl) calix[4]arene hydroxamic acid (CPCHA) is synthesized and used for the extraction and graphite furnace atomic absorption determination of zirconium(IV). The extract is also determined spectrophotometrically as CPCHA-SCN com... |
18967223 | Electrocatalysis of cytochrome c at a C(60)-gamma-cyclodextrin and Nafion chemically modified electrode. | The C(60)-gamma-cyclodextrin and Nafion chemically modified electrode exhibits two redox waves by cyclic voltammetry. Such an electrode will effect reduction and oxidation of cytochrome c and be capable of mediating the electron transfer to cytochrome c. |
18967200 | Separation of enantiomers of drugs by capillary electrophoresis Part 8. beta-Cyclodextrin as chiral solvating agent. | As part of a comprehensive screening program on the separation of chiral drugs by capillary zone electrophoresis, we have investigated the enantio-separation of 54 drug racemates with beta-cyclodextrin as a chiral solvating agent (CSA), thus complementing previous studies on 34 drug racemates. Fourteen out of the 54 an... |
18967179 | Response of a benzoxainone derivative linked to monoaza-15-crown-5 with divalent heavy metals. | The response of a monoaza-15-crown-5 with an optically active aminobenzoxazinone moiety to divalent cations was investigated. The crown ether was found to undergo a strong emission shift to the blue when complexed with specific divalent metals that have ionic diameters between 1.9-2.4 A. Consequently the photoactive ma... |
11672181 | Porphyrazines and Norphthalocyanines Bearing Nitrogen Donor Pockets: Metal Sensor Properties. | The amino-functionalized porphyrazines 1, 2, and 4 and norphthalocyanines 3 and 5, which were prepared via Linstead macrocyclization reactions of dinitrile precusors, were subject to UV-vis titrations in the presence of inorganic ions. These polydentate macrocycles are able to bind metal ions by the peripheral ligating... |
11670583 | Crown Ether Encapsulation Effects on the Optical Properties of Delocalized and Partially Localized Bridged Ruthenium Dimers. | The effects of crown ether encapsulation on the position of the near-IR-vis bands of [(NH(3))(5)Ru-pyz-Ru(NH(3))(5)](m)()(+) and [(NH(3))(5)Ru-(4,4'-bpy)-Ru(NH(3))(5)](m)()(+) (m = 4, 5) have been investigated within a purely electronic picture. The model accounts for the observed behavior and furnishes a theoretical e... |
11670577 | Axial Coordination and Conformational Heterogeneity of Nickel(II) Tetraphenylporphyrin Complexes with Nitrogenous Bases. | Axial ligation of nickel(II) 5,10,15,20-tetraphenylporphyrin (NiTPP) with pyrrolidine or piperidine has been investigated using X-ray crystallography, UV-visible spectroscopy, resonance Raman spectroscopy, and molecular mechanics (MM) calculations. By varying the pyrrolidine concentration in dichloromethane, distinct n... |
11670576 | Helical Figure-of-Eight Loop Dicopper(I) Compounds: Syntheses, Structures, and Dynamics. | The synthesis of a series of nine large macrocyclic ligands with two N(2)S(2) (thioether and Schiff-base imine) binding sites each, with different bridges between the donor atoms of each site (ethylene, o-xylylene, propylene, butylene) and different spacer groups between the two binding sites (p-xylylene, 2,5-dimethyl-... |
11670554 | Aminotriazines as Locking Fragments in Macrocyclic Synthesis. | The macrocyclic compounds (6-(4',6'-diamino-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) triperchlorate dihydrate, [Cu(HL(2))](ClO(4))(3).2H(2)O, (6-(6'-amino-4'-oxo-1'H-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) diperchlorate hydrate, [CuL(3)](ClO(4))(2).H(2)O, and [(6-(4'... |
11670551 | Rhenium(V)-Salen Complexes: Configurational Control and Ligand Exchange. | Reactions of ReO(PPh(3))(2)Cl(3) with tetradentate bis(salicylideneamine) ligands, H(2)salpd (1) and H(2)salbd (2), in different alcohols gave the novel mixed-ligand rhenium complexes ReO(sal)OAlk (OAlk = variety of alkoxy ligands). Configurational studies show that the rhenium complexes ReO(salpd)OAlk (1a-f) display e... |
11670523 | Methylation of Tethered Thiolates in [(bme-daco)Zn](2) and [(bme-daco)Cd](2) as a Model of Zinc Sulfur-Methylation Proteins. | The dimeric dithiolate complex [1,5-bis(mercaptoethyl)-1,5-diazacyclooctanato]zinc(II), [(bme-daco)Zn](2) or Zn-1, and its cadmium analogue, Cd-1, were investigated as models for the active site of zinc-dependent methylation proteins. The key issue addressed was whether alkylation of a thiolate in a relatively rigid te... |
11670514 | Effect of Mixed Pendent Groups on the Solution and Catalytic Properties of Europium(III) Macrocyclic Complexes: Bifunctional and Monofunctional Amide and Alcohol Pendents in Septadentate or Octadentate Ligands. | Five new Eu(III) macrocyclic complexes have been prepared and their solution and catalytic properties studied. The Eu(III) complexes with septadentate ligands TRED and NB-TRED dissociate rapidly at pH 7.4, 37 degrees C (TRED = 1,4,7-tris(hydroxyethyl)-1,4,7,10-tetraazacyclododecane, NB-TRED = 1-(nitrobenzyl)-4,7,10-tri... |
11670506 | Thermodynamic and Steady-State Fluorescence Emission Studies on Metal Complexes of Receptors Containing Benzene Subunits. | The thermodynamic properties of the Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), and Pb(2+) complexes of a family of N,N'-dibenzylated open-chain polyamines are described. For comparison, similar studies are reported for polyazacyclophane macrocyclic receptors containing an aromatic subunit linking the ends of a polyamine b... |
15825344 | [Synthesis and molecular recognition study of 6-Cs-beta-CD]. | The reagents 6-Cs-beta-CD with molecular recognition function were synthesized and confirmed. Both basic condition and enough illumination were necessary for obtaining stable and strong fluorescence. With 6-Cs-beta-CD as the host, cyclohexanol, cyclohexene, cyclohexane and bromocyclohexane as the guest, the recognition... |
14987563 | Cobra cardiotoxin and phospholipase A2 as GAG-binding toxins: on the path from structure to cardiotoxicity and inflammation. | Glycosaminoglycans (GAGs) represent the sulfated carbohydrate moieties of proteoglycans which occur abundantly in tissues of the cardiovascular system. Many proteins bind specifically to GAGs and perform an important role in inflammation, cell proliferation, and blood coagulation processes. Recently, in vitro GAG-bindi... |
9482727 | Clathrin self-assembly is regulated by three light-chain residues controlling the formation of critical salt bridges. | Clathrin self-assembly into a polyhedral lattice mediates membrane protein sorting during endocytosis and organelle biogenesis. Lattice formation occurs spontaneously in vitro at low pH and, intracellularly, is triggered by adaptors at physiological pH. To begin to understand the cellular regulation of clathrin polymer... |
10082379 | Opposite behavior of two isozymes when refolding in the presence of non-ionic detergents. | GroEL has a greater affinity for the mitochondrial isozyme (mAAT) of aspartate aminotransferase than for its cytosolic counterpart (cAAT) (Mattingly JR Jr, Iriarte A, Martinez-Carrion M, 1995, J Biol Chem 270:1138-1148), two proteins that share a high degree of sequence similarity and an almost identical spatial struct... |
10082369 | Role of P225 and the C136-C201 disulfide bond in tissue plasminogen activator. | The protease domain of tissue plasminogen activator (tPA), a key fibrinolytic enzyme, was expressed in Escherichia coli with a yield of 1 mg per liter of media. The recombinant protein was titrated with the Erythrina caraffa trypsin inhibitor (ETI) and characterized in its interaction with plasminogen and the natural i... |
9872671 | A rare chromosome 5 heterochromatic variant derived from insertion of 9qh satellite 3 sequences. | A rare chromosome 5 heterochromatic variant not linked to any clinical sign was identified in a three-generation family. After performing conventional cytogenetics characterization, fluorescence in situ hybridization of D9Z1 indicated that the unusually large qh region of chromosome 5 originated from 9qh, whereas the c... |
9872670 | Electron microscopic in situ hybridization of digoxigenin-dUTP-labelled DNA probes with Drosophila melanogaster polytene chromosomes. | We report a simplified method of electron microscopic (EM) in situ hybridization for standard squashes of Drosophila melanogaster polytene chromosomes using digoxigenin-11-dUTP labelled DNA probes. The method is efficient and reproducible: its high resolution and specificity were demonstrated for the transformed strain... |
9872669 | Comparative methylation analysis of murine transgenes that undergo or escape X-chromosome inactivation. | We analyzed an X-linked metallothionein-vasopressin (MTVP) fusion transgene that undergoes X-chromosome inactivation (X inactivation) and an X-linked transferrin (TFN) transgene that escapes X inactivation with respect to methylation in the 5' regulatory regions. The MTVP transgene promoter region is unmethylated when ... |
9872668 | Pattern of chromosomal localization of the Hoppel transposable element family in the Drosophila melanogaster subgroup. | We have isolated a Hoppel-like transposon from heterochromatin of the second chromosome of Drosophila melanogaster and used a conserved DNA sequence between the different elements of this family to determine their distribution in both mitotic and polytene chromosomes. The hybridization pattern of polytene chromosomes e... |
9872667 | XY sex reversal in the wood lemming is associated with deletion of Xp21-23 as revealed by chromosome microdissection and fluorescence in situ hybridization. | In the wood lemming (Myopus schisticolor), XY sex reversal occurs naturally because of the presence of an X chromosome variant designated X*. The two types of X chromosome, X and X*, can be distinguished by G-banding, and analyses have demonstrated complex rearrangements of the short arm of X*. Here, chromosomal microd... |
9872666 | Torsional state of DNA in a transcriptionally hyperactive Balbiani ring of polytene chromosomes. | The torsional tension of unconstrained double-helical DNA was determined in transcriptionally hyperactive Balbiani ring 2 (BR2) and in inactive polytene chromosome bands of Chironomus tentans. The method used is based on the dual ability of small intercalating ligands to (a) sense, by differential binding, twists that ... |
9872665 | Characterization of reciprocal translocations in pigs using dual-colour chromosome painting and primed in situ DNA labelling. | We report the use of dual-colour chromosome painting to determine the exact nature of certain chromosome rearrangements observed in the pig (Sus scrofa domestica). The chromosomal abnormalities were detected by GTG- and RBG-banding techniques. The initially proposed interpretations were: (1) rcp(6;13)(p1.5;q4.1); (2) r... |
9872664 | Repetitive DNA sequences in the common vole: cloning, characterization and chromosome localization of two novel complex repeats MS3 and MS4 from the genome of the East European vole Microtus rossiaemeridionalis. | We have characterized two novel, complex, heterochromatic repeat sequences, MS3 and MS4, isolated from Microtus rossiaemeridionalis genomic DNA. Sequence analysis indicates that both repeats consist of unique sequences interrupted by repeat elements of different origin and can be classified as long complex repeat units... |
9872663 | Multiple locations of the rDNA sites in holocentric chromosomes of Rhynchospora (Cyperaceae). | Several cytogenetic studies have shown that representatives of the family Cyperaceae have holocentric chromosomes. Despite their interesting chromosome morphology, the chromosome organization has not been studied. This paper reports on the number and distribution of 18S-5.8S-26S ribosomal RNA sites by fluorescence in s... |
9872662 | Meiosis of wheat x lymegrass hybrids. | Meiosis was examined in pollen mother cells of F1 hybrids made from crosses between wheat (Triticum aestivum) and lymegrass (Leymus arenarius and L. mollis). Fluorescence genomic in situ hybridization detected pairing between wheat and lymegrass chromosomes during prophase I and metaphase I. Such pairing, when resultin... |
9867418 | Crystal structure of a new alpha-cyclodextrin hydrate form. Molecular geometry and packing features: disordered solvent contribution. | The crystallographic study of a new hydrated form of alpha-cyclodextrin (cyclohexaamylose) is reported. C36H60O30 . 11H2O; space group P2(1)2(1)2(1) with cell constants a = 13.839(3), b = 15.398(3), c = 24.209(7) A; final discrepancy index R = 0.057 for the 5182 observed reflections and 632 refined parameters. Besides ... |
9821261 | Isolation and structural analyses of positional isomers of 6(1),6m-di-O-alpha-D-mannopyranosyl-cyclomaltooctaose (m = 2-5) and 6-O-alpha-(n-O-alpha-D-mannopyranosyl)-alpha-D-mannopyranosyl- cyclomaltooctaose (n = 2, 3, 4, and 6). | Eight positional isomers of 6(1),6m-di-O-alpha-D-mannopyranosyl-cyclomaltooctaose (gamma CD) (m = 2-5) and 6-O-alpha-(n-O-alpha-D-mannopyranosyl)-D-mannopyranosyl-gamma CD (n = 2, 3, 4, and 6) in a mixture of products from gamma CD and D-mannose by condensation reaction of alpha-mannosidase from jack bean were isolated... |
9794531 | Fluorinated materials for in vivo oxygen transport (blood substitutes), diagnosis and drug delivery. | Fluorocarbons are characterized by exceptional chemical and biological inertness, extreme hydrophobicity, lipophobicity, high gas-dissolving capacities, low surface tensions, high fluidity and spreading coefficients, high density, absence of protons, and magnetic susceptibilities comparable to that of water. These uniq... |
9789289 | [Critical care for organ failure]. | We retrospectively studied the critical care regimen for multiple organ failure (MOF) in 141 surgical MOF patients treated in the intensive care unit of Chiba University Hospital between January 1988 and April 1998. Patients with gut failure received parenteral instead of enteral nutrition for various reasons such as c... |
9789287 | [Organ failure during the perioperative period: pathophysiology and strategy]. | After the establishment of the theoretical and clinical background of SIRS, the mechanism of organ failure induction during the perioperative period was gradually clarified. The deterioration of the mutual regulation of cytokines after surgical stress is considered to be a major cause of organ failure. Hypercytokinemia... |
9789286 | [Ischemia/reperfusion injury and organ failure]. | Reperfusion injury is recognized as a syndrome which impairs an ischemic organ as well as remote organs throughout the entire body. Previous research has revealed that the various inflammatory mediators, such as cytokines, platelet-activating factors, and free radicals, are involved and interact with each other in repe... |
9789284 | [Bacterial translocation in multiple organ failure]. | Bacterial translocation has been defined as the passage of both viable and nonviable bacteria and their products (e.g., endotoxins) across the intestinal barrier to extraintestinal sites such as the mesenteric lymph nodes, liver, etc. It has been hypothesized that intestinally derived bacteria or endotoxins serve as tr... |
9789283 | [Inflammatory mediator and organ dysfunction syndrome]. | Inflammatory mediators include endotoxin (ETX), cytokines (interleukins [ILs], tumor necrosis factors [TNFs], and interferons), eicosanoids (prostaglandins and thromboxanes), reactive oxygen species (O2-, NO, and ONOO-), complements (C3 and C4), and stress hormones (catecholamine, cortisol, vasopressin, and growth horm... |
9789282 | [Mechanism of the development of organ failure]. | Multiple organ failure (MOF) is a critical condition developing in patients with overwhelming bodily injury resulting from major surgical insult, severe trauma, extensive burns, acute pancreatitis, and sepsis. It has recently become evident that the host response to such injury is the main pathogenetic factor contribut... |
9784861 | Design, synthesis and biological evaluation of nonpeptide integrin antagonists. | Recent studies demonstrated that peptide and antibody antagonists of integrin alpha v beta 3 block angiogenesis and tumor growth. In this article, the design, synthesis and biological evaluation of a series of nitroaryl ether-based, nonpeptide mimetics are described. The design of these compounds was based on Merck's a... |
9780840 | Nuclear domain 10, the site of DNA virus transcription and replication. | Within the highly organized nuclear structure, specific nuclear domains (ND10) are defined by accumulations of proteins that can be interferon-upregulated, implicating ND10 as sites of a nuclear defense mechanism. Compatible with such a mechanism is the deposition of herpesvirus, adenovirus, and papovavirus genomes at ... |
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