id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
9294137 | Cloning and characterization of a specific receptor for the novel CC chemokine MIP-3alpha from lung dendritic cells. | Dendritic cells are potent antigen-presenting cells involved in the initiation of immune responses. The trafficking of these cells to tissues and lymph nodes is mediated by members of the chemokine family. Recently, a novel CC chemokine known as MIP-3alpha or liver and activation-regulated chemokine has been identified... |
9307046 | Targeting of the HIV-1 long terminal repeat with chromomycin potentiates the inhibitory effects of a triplex-forming oligonucleotide on Sp1-DNA interactions and in vitro transcription. | We have studied the effects of chromomycin and of a triple-helix-forming oligonucleotide (TFO) that recognizes Sp1 binding sites on protein-DNA interactions and HIV-1 transcription. Molecular interactions between chromomycin, the Sp1 TFO and target DNA sequences were studied by gel retardation, triplex affinity capture... |
9307027 | alpha-1,4-D-glucan phosphorylase of gram-positive Corynebacterium callunae: isolation, biochemical properties and molecular shape of the enzyme from solution X-ray scattering. | The alpha-1,4-D-glucan phosphorylase from gram-positive Corynebacterium callunae has been isolated and characterized. The enzyme is inducible approx. 2-fold by maltose, but remarkably not repressed by D-glucose. The phosphorylase is a homodimer with a stoichiometric content of the cofactor pyridoxal 5'-phosphate per 88... |
9293187 | DNA gyrase, topoisomerase IV, and the 4-quinolones. | For many years, DNA gyrase was thought to be responsible both for unlinking replicated daughter chromosomes and for controlling negative superhelical tension in bacterial DNA. However, in 1990 a homolog of gyrase, topoisomerase IV, that had a potent decatenating activity was discovered. It is now clear that topoisomera... |
9293186 | Biogenesis of respiratory cytochromes in bacteria. | Biogenesis of respiratory cytochromes is defined as consisting of the posttranslational processes that are necessary to assemble apoprotein, heme, and sometimes additional cofactors into mature enzyme complexes with electron transfer functions. Different biochemical reactions take place during maturation: (i) targeting... |
9293183 | Mechanisms of Giardia lamblia differentiation into cysts. | Microbiologists have long been intrigued by the ability of parasitic organisms to adapt to changes in the environment. Since most parasites occupy several niches during their journey between vectors and hosts, they have developed adaptive responses which allow them to survive under adverse conditions. Therefore, the li... |
9293009 | Cloning, sequencing, and expression of the gene encoding amylopullulanase from Pyrococcus furiosus and biochemical characterization of the recombinant enzyme. | The gene encoding the Pyrococcus furiosus hyperthermophilic amylopullulanase (APU) was cloned, sequenced, and expressed in Escherichia coli. The gene encoded a single 827-residue polypeptide with a 26-residue signal peptide. The protein sequence had very low homology (17 to 21% identity) with other APUs and enzymes of ... |
9293008 | Cloning, sequencing, and expression of the gene encoding extracellular alpha-amylase from Pyrococcus furiosus and biochemical characterization of the recombinant enzyme. | The gene encoding the hyperthermophilic extracellular alpha-amylase from Pyrococcus furiosus was cloned by activity screening in Escherichia coli. The gene encoded a single 460-residue polypeptide chain. The polypeptide contained a 26-residue signal peptide, indicating that this Pyrococcus alpha-amylase was an extracel... |
9290111 | The route of nutritional support in the critically ill: physiological and economical considerations. | Although it generally is accepted that early enteral nutrition is of benefit to critically ill patients, there is little evidence to support this assertion. Nevertheless, enteral nutrition has many advantages over total parenteral nutrition (TPN), the latter being associated with several complications. Animal studies h... |
9288453 | On the nature of hereditary cataract in strain 13/N guinea pigs. | <h4>Purpose</h4>Congenital nuclear cataracts in strain 13/N guinea pigs are caused by a single splice-site mutation in the zeta-crystallin gene. Very little is known of the physical factors involved in lens opacification of this system. The aim of this study is to elucidate the biophysical processes causing the nuclear... |
9286666 | Genetic interactions between HOP1, RED1 and MEK1 suggest that MEK1 regulates assembly of axial element components during meiosis in the yeast Saccharomyces cerevisiae. | During meiosis, axial elements are generated by the condensation of sister chromatids along a protein core as precursors to the formation of the synaptonemal complex (SC). Functional axial elements are essential for wild-type levels of recombination and proper reductional segregation at meiosis I. Genetic and cytologic... |
9287012 | Analysis of the interaction of FtsZ with itself, GTP, and FtsA. | The interaction of FtsZ with itself, GTP, and FtsA was examined by analyzing the sensitivity of FtsZ to proteolysis and by using the yeast two-hybrid system. The N-terminal conserved domain consisting of 320 amino acids bound GTP, and a central region of FtsZ, encompassing slightly more than half of the protein, was cr... |
9287004 | TRAP transporters: a new family of periplasmic solute transport systems encoded by the dctPQM genes of Rhodobacter capsulatus and by homologs in diverse gram-negative bacteria. | The dct locus of Rhodobacter capsulatus encodes a high-affinity transport system for the C4-dicarboxylates malate, succinate, and fumarate. The nucleotide sequence of the region downstream of the previously sequenced dctP gene (encoding a periplasmic C4-dicarboxylate-binding protein) was determined. Two open reading fr... |
9286993 | Mutational characterization of promoter regions recognized by the Salmonella dublin virulence plasmid regulatory protein SpvR. | The virulence plasmid-encoded spv regulon is essential for virulence of Salmonella dublin in mice. The spvR gene product belongs to the LysR family of transcriptional regulator proteins. SpvR induces the expression of the spvABCD operon and positively regulates its own expression. DNase I protection analysis with purif... |
9281613 | A mutational analysis of residues essential for ligand recognition at the human P2Y1 receptor. | We conducted a mutational analysis of residues potentially involved in the adenine nucleotide binding pocket of the human P2Y1 receptor. Mutated receptors were expressed in COS-7 cells with an epitope tag that permitted confirmation of expression in the plasma membrane, and agonist-promoted inositol phosphate accumulat... |
9283088 | Cholesterol as modulator of receptor function. | The modulatory effect of cholesterol on the function of two structurally related peptide receptors, the oxytocin receptor and the brain cholecystokinin receptor in plasma membranes as well as in intact cells, was analyzed. Different approaches for cholesterol modification were applied: (i) depletion and reloading of ch... |
9283083 | Helix propensities are identical in proteins and peptides. | Our understanding of the factors stabilizing alpha-helical structure has been greatly enhanced by the study of model alpha-helical peptides. However, the relationship of these results to the folding of helices in intact proteins is not well characterized. Helix propensities measured in model peptides are not in good ag... |
9284331 | Rapid kinetics of insertion and accessibility of spin-labeled phospholipid analogs in lipid membranes: a stopped-flow electron paramagnetic resonance approach. | Spin-labeled phospholipid analogs have been employed to probe the transbilayer distribution of endogenous phospholipids in various membrane systems. To determine the transmembrane distribution of the spin-labeled analogs, the analogs are usually inserted into the membrane of interest and subsequently the amount of anal... |
9284326 | Smooth muscle myosin light chain kinase, supramolecular organization, modulation of activity, and related conformational changes. | It has recently been suggested that activation of smooth muscle myosin light chain kinase (MLCK) can be modulated by formation of supramolecular structures (Sobieszek, A. 1991. Regulation of smooth muscle myosin light chain kinase. Allosteric effects and co-operative activation by CaM. J. Mol. Biol. 220:947-957). The p... |
9284321 | Conformational transitions of the phosphodiester backbone in native DNA: two-dimensional magic-angle-spinning 31P-NMR of DNA fibers. | Solid-state 31P-NMR is used to investigate the orientation of the phosphodiester backbone in NaDNA-, LiDNA-, MgDNA-, and NaDNA-netropsin fibers. The results for A- and B-DNA agree with previous interpretations. We verify that the binding of netropsin to NaDNA stabilizes the B form, and find that in NaDNA, most of the p... |
9284313 | The heat of transfer of lipid and surfactant from vesicles into micelles in mixtures of phospholipid and surfactant. | We study the heat associated with the transformation of vesicles into micelles in mixtures of bilayer-forming phospholipids and micelle-forming surfactants. We subdivide the total heat evolution deltaQ(coex) within the range of coexistence of vesicles and micelles into three contributions related to the transition of d... |
9284312 | Partitioning of octyl glucoside between octyl glucoside/phosphatidylcholine mixed aggregates and aqueous media as studied by isothermal titration calorimetry. | Stepwise dilution of lipid-surfactant mixed micelles first results in extraction of surfactant from the mixed micelles into the aqueous medium. Subsequently mixed micelles transform into vesicles, within a range of compositions that corresponds to equilibrium coexistence between these two types of aggregates. Further d... |
9284146 | A proposed role for the lutropin receptor in contact-inducible gonococcal invasion of Hec1B cells. | We previously reported the existence of a contact-inducible, enhanced invasion phenotype in the obligate human pathogen Neisseria gonorrhoeae. Our present studies showed that the ability of glutaraldehyde-fixed eucaryotic cells to convert gonococci (GC) to this invasive phenotype (Inv+) is limited to cells derived from... |
9278491 | Substrate DNA and cofactor regulate the activities of a multi-functional restriction-modification enzyme, BcgI. | The BcgI restriction-modification system consists of two subunits, A and B. It is a bifunctional protein complex which can cleave or methylate DNA. The regulation of these competing activities is determined by the DNA substrates and cofactors. BcgI is an active endonuclease and a poor methyltransferase on unmodified DN... |
9275214 | Evidence for rapid disappearance of initially expanded HIV-specific CD8+ T cell clones during primary HIV infection. | Down-regulation of the initial burst of viremia during primary HIV infection is thought to be mediated predominantly by HIV-specific cytotoxic T lymphocytes, and the appearance of this response is associated with major perturbations of the T cell receptor repertoire. Changes in the T cell receptor repertoire of virus-s... |
9275213 | The CXC chemokine stromal cell-derived factor 1 is not responsible for CD8+ T cell suppression of syncytia-inducing strains of HIV-1. | Primary CD8+ T cells from HIV+ asymptomatics can suppress virus production from CD4(+) T cells acutely infected with either non-syncytia-inducing (NSI) or syncytia-inducing (SI) HIV-1 isolates. NSI strains of HIV-1 predominantly use the CCR5 chemokine receptor as a fusion cofactor, whereas fusion of T cell line-adapted... |
9275206 | Frequency of HLA allele-specific peptide motifs in HIV-1 proteins correlates with the allele's association with relative rates of disease progression after HIV-1 infection. | An HLA allele-specific cytotoxic T lymphocyte response is thought to influence the rate of disease progression in HIV-1-infected individuals. In a prior study of 139 HIV-1-infected homosexual men, we identified HLA class I alleles and observed an association of specific alleles with different relative hazards for progr... |
9275159 | Heterogeneous nuclear ribonucleoprotein A1 binds to the transcription-regulatory region of mouse hepatitis virus RNA. | A cellular protein, previously described as p35/38, binds to the complementary (-)-strand of the leader RNA and intergenic (IG) sequence of mouse hepatitis virus (MHV) RNA. The extent of the binding of this protein to IG sites correlates with the efficiency of the subgenomic mRNA transcription from that IG site, sugges... |
9276420 | Study of Norwalk virus and Mexico virus infections at Ga-Rankuwa Hospital, Ga-Rankuwa, South Africa. | Small round-structured viruses (SRSVs) or Norwalk-like viruses have been implicated as an important causative agent of gastroenteritis outbreaks. We used the relatively newly developed recombinant enzyme immunoassays (EIAs) to determine the seroprevalence of Norwalk virus (NV) and Mexico virus (MxV) in a family-based c... |
9271505 | Functional effects on the acetylcholine receptor of multiple mutations of gamma Asp174 and delta Asp180. | Residues gamma Asp174 and delta Asp180, previously implicated in the binding of acetylcholine (ACh) by the mouse muscle ACh receptor, were each mutated to nine other residues, Asn, Glu, Thr, Ala, Cys, His, Val, Tyr, and Lys. The effects of the mutations on ACh-induced current was determined on surface receptors contain... |
9291112 | Preparation of a recombinant chimaera of insulin-like growth factor II and interleukin 3 with high proliferative potency for haemopoietic cells. | We have found that a slightly modified insulin-like growth factor II (IGF II) consisting of a chimaera of bombyxin and human IGF II (BOMIGF) is properly secreted in insect cells by using the baculovirus expression system. Human interleukin 3 (IL-3) was attached to the C-terminal amino acid residue of BOMIGF with peptid... |
9291102 | Mechanism and ion-dependence of in vitro autoactivation of yeast proteinase A: possible implications for compartmentalized activation in vivo. | Yeast proteinase A is synthesized as a zymogen which transits through the endoplasmic reticulum, the Golgi complex and the endosome to the vacuole. On arrival in the vacuole, activation takes place. It has previously been found that proteinase A can activate autocatalytically; however, the propeptide of proteinase A sh... |
9271433 | Groucho-dependent and -independent repression activities of Runt domain proteins. | Runt domain proteins are transcriptional regulators that specify cell fates for processes extending from pattern formation in insects to leukemogenesis in humans. Runt domain family members are defined based on the presence of the 128-amino-acid Runt domain, which is necessary and sufficient for sequence-specific DNA b... |
9271393 | Anchoring of CREB binding protein to the human T-cell leukemia virus type 1 promoter: a molecular mechanism of Tax transactivation. | The human T-cell leukemia virus type 1 (HTLV-1)-encoded Tax protein activates viral transcription through interaction with the cellular transcription factor CREB (cyclic AMP response element [CRE] binding protein). Although Tax stabilizes the binding of CREB to the Tax-responsive viral CREs in the HTLV-1 promoter, the ... |
9261435 | The UL84 protein of human cytomegalovirus acts as a transdominant inhibitor of immediate-early-mediated transactivation that is able to prevent viral replication. | The 86-kilodalton immediate-early (IE) 2 protein (IE2-p86) of human cytomegalovirus (HCMV) is a multifunctional regulator of HCMV gene expression which appears to be essential for triggering the lytic replicative cycle. IE2-p86 functions as a promiscuous transactivator of both viral and cellular gene expression and can... |
9261433 | The protease and the assembly protein of Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8). | A genomic clone encoding the protease (Pr) and the assembly protein (AP) of Kaposi's sarcoma-associated herpesvirus (KSHV) (also called human herpesvirus 8) has been isolated and sequenced. As with other herpesviruses, the Pr and AP coding regions are present within a single long open reading frame. The mature KSHV Pr ... |
9261424 | Cell-type-specific separate regulation of the E6 and E7 promoters of human papillomavirus type 6a by the viral transcription factor E2. | Gene expression of human papillomaviruses (HPV) is tightly controlled by cellular factors and by the virally encoded E2 protein through binding to distinct sites within the regulatory noncoding region. While for the high-risk genital papillomaviruses a single promoter drives the expression of all early genes, a second ... |
9261416 | The autonomous growth of human papillomavirus type 16-immortalized keratinocytes is related to the endothelin-1 autocrine loop. | Some human papillomaviruses (HPVs) such as HPV type 16 (HPV16) and HPV18 are involved in cervical carcinoma, and they can immortalize and transform keratinocytes. Endothelin-1 (ET-1) is produced in keratinocytes and has been shown to act through ETA receptors as an autocrine growth factor for keratinocytes. This study ... |
9261415 | Interferon-independent and -induced regulation of Epstein-Barr virus EBNA-1 gene transcription in Burkitt lymphoma. | Replication of the Epstein-Barr virus (EBV) genome within latently infected cells is dependent on the EBV EBNA-1 protein. The objective of this study was to identify transcriptional regulatory proteins that mediate EBNA-1 expression via the viral promoter Qp, which is active in EBV-associated tumors such as Burkitt lym... |
9261396 | Specific interaction of polypyrimidine tract-binding protein with the extreme 3'-terminal structure of the hepatitis C virus genome, the 3'X. | We previously identified a highly conserved 98-nucleotide (nt) sequence, the 3'X, as the extreme 3'-terminal structure of the hepatitis C virus (HCV) genome (T. Tanaka, N. Kato, M.-J. Cho, and K. Shimotohno, Biochem. Biophys. Res. Commun. 215:744-749, 1995). Since the 3' end of positive-strand viral RNA is the initiati... |
9254714 | Competition between HMG-I(Y), HMG-1 and histone H1 on four-way junction DNA. | High mobility group proteins HMG-I(Y) and HMG-1, as well as histone H1, all share the common property of binding to four-way junction DNA (4H), a synthetic substrate commonly used to study proteins involved in recognizing and resolving Holliday-type junctions formed during in vivo genetic recombination events. The stru... |
9587873 | Recognition of superpotent sweetener ligands by a library of monoclonal antibodies. | Monoclonal antibodies (mAb) made to the superpotent guanidino sweet tasting ligand, N-(p-cyanophenyl)-N'-(diphenylmethyl)-guanidineacetic acid were examined for their molecular recognition specificities using 14 different sweetener analogues in a competitive radioimmunoassay. The effects of variations in pH on ligand b... |
9587872 | Dual specificity and the formation of stable autoimmune complexes. | Since dual specificity at the antibody active-site level involves new principles relative to monospecific antigen-antibody interactions and may be a general property of autoantibodies, it was important to further characterize such antibodies. Four lupus derived autoantibodies were studied to understand parameters and m... |
9587871 | Screening of a small set of random peptides: a new strategy to identify synthetic peptides that mimic epitopes. | Small diversity libraries, composed of 4550 synthetic dodecapeptides and 8000 synthetic tripeptides, have been used to identify sequences homologous to small linear and non-linear parts of epitopes. Here we report that synthetic peptides identified through alignment of dodecapeptides and tripeptides derived from these ... |
9587870 | Kinetics and energetics of specific intermolecular interactions. | Taking into account the energy vs. distance functions of the aspecific (macroscopic) repulsion that usually prevails between antigen (Ag) and antibody (Ab) molecules in polar media, as well as the specific (microscopic) attraction between epitope and paratope of Ag and Ab, it proved possible to determine the kinetic co... |
21639322 | Effect of crown ethers on the ion-exchange behavior of alkaline Earth metals. Toward improved ion-exchange methods for the separation and preconcentration of radium. | The effect of selected crown ethers on the uptake of alkaline earth cations by sulfonic acid and diphosphonic acid-based cation-exchange resins from hydrochloric acid media is examined. The effect observed is shown to vary with the hydrophobicity of the crown ether. Water-soluble crown ethers enhance the sorption of ce... |
18966878 | Determination of carboxylic acid vapour by a thickness-sheer-mode acoustic wave sensor coated with crown ethers. | The frequency response sensitivities for 39 organic vapours by thickness-sheer-mode (TSM) acoustic wave sensors coated with monobenzo-15-crown-5 (B15C5), monobenzo-18-crown-6 (B18C6) and dibenzo-30-crown-10 (DB30C10) have been reported. It shows that crown ethers are the most efficient adsorptively active material for ... |
18636515 | On-line monitoring of glucose in mammalian cell culture using a flow injection analysis (FIA) mediated biosensor. | A flow injection analysis (FIA) biosensor system has been developed for on-line determination of glucose during mammalian cell cultivation. The culture sample was peristaltically withdrawn from the bioreactor and after cell separation by a steam sterilizable ceramic microfilter, the filtrate was continuously fed to the... |
9268542 | Determination of Association Constants for Cyclodextrin-Surfactant Inclusion Complexes: A Numerical Method Based on Surface Tension Measurements | Inclusion complexes of beta-cyclodextrin (beta-CD) with sodium octyl sulfonate (C8As), sodium dodecyl sulfonate (C12As), and sodium hexadecyl sulfonate (C16As) in aqueous solutions are studied by surface tension measurement at the air/water interface at different temperatures. At fixed concentrations of the surfactants... |
11670062 | Metal- versus Ligand-Centered Oxidations in Phenolato-Vanadium and -Cobalt Complexes: Characterization of Phenoxyl-Cobalt(III) Species. | The coordination chemistry of the pendent-arm macrocycles 1,4,7-tris(3,5-dimethyl-2-hydroxybenzyl)-1,4,7-triazacyclononane, L(Me)H(3), 1,4,7-tris(3,5-di-tert-butyl-2-hydroxybenzyl)-1,4,7-triazacyclononane, L(Bu)H(3), 1,4,7-tris(3-tert-butyl-5-methoxy-2-hydroxybenzyl)-1,4,7-triazacyclononane, L(OCH)()3H(3), and Tolman's... |
11670059 | Molecular Recognition Effects in Metal Complex Mediated Double-Strand Cleavage of DNA: Reactivity and Binding Studies with Model Substrates. | Double-strand breaks in duplex DNA are thought to be significant sources of cell lethality because they appear to be less readily repaired by DNA repair mechanisms. We recently described the design and cleavage chemistry of ((2S,8R)-5-amino-2,8-dibenzyl-5-methyl-3,7-diazanonanedioato)copper(II) (1), which effects nonra... |
9373902 | NMR study of solid C60(gamma-cyclodextrin)2. | A solid complex of C60 with gamma-cyclodextrin (gamma-CyD) was examined with NMR spectroscopic methods in order to understand the dynamics of C60, and the interaction between C60 and gamma-CyD. A 13C solid-state cross-polarization magic angle spinning (CP/MAS) NMR spectra shows C60 resonance at 142.6 ppm. This provides... |
9338011 | The influence of polymer structure on the interactions of cationic polymers with DNA and morphology of the resulting complexes. | Four cationic polymers used to deliver DNA into cultured cells: polylysine, intact polyamidoamine dendrimer, fractured polyamidoamine dendrimer and polyethylenimine, are examined for their ability to interact with DNA. Complexes between the polymers and DNA were examined using electron microscopy. Similar toroidal stru... |
9337857 | Reaction of variant sperm-whale myoglobins with hydrogen peroxide: the effects of mutating a histidine residue in the haem distal pocket. | The reaction of hydrogen peroxide with a number of variants of sperm-whale myoglobin in which the distal pocket histidine residue (His64) had been mutated was studied with a combination of stopped-flow spectroscopy and freeze-quench EPR. The rate of the initial bimolecular reaction with hydrogen peroxide in all the pro... |
9335122 | Analysis of gangliosides by capillary zone electrophoresis and capillary zone electrophoresis-electrospray mass spectrometry. | Gangliosides, sialic acid(s)-containing glycosphingolipids, were separated by capillary zone electrophoresis and detected with either UV or electrospray mass spectrometry. Several electrolyte system were evaluated for the separation of underivatized gangliosides. The best result was obtained by using 50 mM borate and 5... |
9313852 | Design, synthesis and evaluation of synthetic receptors for the recognition of aspartate pairs in an alpha-helical conformation. | The specific targeting of protein surface functional groups remains a largely unexplored aspect in molecular recognition. In this study, a series of zwitterionic, 16-mer peptides serve as models for the recognition of carboxylate pairs in proteins. A receptor is described that contains two guanidinium groups separated ... |
9310801 | Elevated plasma levels of soluble tumor necrosis factor receptor (sTNFRp60) reflect severity of acute pancreatitis. | <h4>Objective</h4>To investigate the role of activated leukocytes in acute pancreatitis, we measured soluble receptors of tumour necrosis factor alpha (sTNFR, p60 subtype) in plasma and evaluated the association of sTNFR with the clinical severity of the disease.<h4>Design</h4>Prospective, descriptive study.<h4>Setting... |
9304112 | DNA binding and transactivation properties of Fos variants with homodimerization capacity. | The mammalian Fos and Fos-related proteins are unable to form homodimers and to bind DNA in the absence of a second protein, like c-Jun for example. In order to study the implications of hydrophobic point mutations in the c-Fox leucine zipper on DNA binding of the entire c-Fos protein, we have constructed and purified ... |
9303305 | Molecular mechanism of desensitization of the chemokine receptor CCR-5: receptor signaling and internalization are dissociable from its role as an HIV-1 co-receptor. | The chemokine receptor, CCR-5, a G protein-coupled receptor (GPCR) which mediates chemotactic responses of certain leukocytes, has been shown to serve as the primary co-receptor for macrophage-tropic human immunodeficiency virus type 1 (HIV-1). Here we describe functional coupling of CCR-5 to inhibition of forskolin-st... |
9299746 | Direct determination of prolintane and its metabolite oxoprolintane in human urine by capillary zone electrophoresis and beta-cyclodextrin-modified micellar electrokinetic chromatography. | This paper describes a fast and simple method for the direct determination of the stimulant prolintane and its principal urinary metabolite, oxoprolintane, in human urine by capillary zone electrophoresis and beta-cyclodextrin-modified micellar electrokinetic chromatography. The determination was performed in phosphate... |
9296382 | Inhibition of mineralocorticoid and glucocorticoid receptor function by the heat shock protein 90-binding agent geldanamycin. | The effects of mineralocorticoids and glucocorticoids are mediated by the intracellular mineralocorticoid glucocorticoid receptor (MR) and glucocorticoid receptor (GR), respectively. Several studies suggest that hormone binding and, thus, receptor activation depend on the association of both MR and GR with the 90-kDa h... |
9295158 | Kinetic characteristics of the enzymatic conversion in presence of cyclodextrins: study of the oxidation of polyunsaturated fatty acids by lipoxygenase. | The capability of cyclodextrins (CDs) to greatly enhance the solubility in water of poorly water-soluble substances makes them an ideal alternative system for studying the expression of enzyme activity with such substrates in aqueous solution. In order to evaluate the behaviour of the enzymes in presence of CDs a study... |
9294012 | The interaction of plasmid DNA with polyamidoamine dendrimers: mechanism of complex formation and analysis of alterations induced in nuclease sensitivity and transcriptional activity of the complexed DNA. | The application of synthetic vectors for gene transfer has potential advantages over virus-based systems. However, little is known about the mechanisms involved in binding of synthetic materials to DNA and the nature of the DNA complexes that result from this interaction. Polyamidoamine (PAMAM) dendrimers are unique po... |
9292240 | Globular and fibrous structure in barley chromosomes revealed by high-resolution scanning electron microscopy. | Barley chromosomes were prepared for high-resolution scanning electron microscopy using a combination of enzyme maceration, treatment in acetic acid and osmium impregnation using thiocarbohydrazide. Using this technique, the three-dimensional ultrastructure of interphase nuclei and mitotic chromosomes was examined. In ... |
9292239 | FISH mapping of bovine U21, U1 and U7 molecular markers to river buffalo chromosomes 3p, 5q and 5p. | Three bovine cosmid-derived microsatellites (IDV-GA49, IDVGA7 and IDVGA47), previously assigned to cattle syntenic groups U1, U7 and U21, respectively, were fluorescence in situ hybridization (FISH) mapped to river buffalo (Bubalus bubalis, L., 2n = 50) chromosomes (BBU) 3p22 (IDVGA47, U21), BBU 5q21 (IDVGA49, U1) and ... |
9292238 | The formation of new nucleoli during macronuclear development of the hypotrichous ciliate Stylonychia lemnae visualized by in situ hybridization. | After sexual reproduction in ciliates, the old macronucleus degenerates and a new macronucleus is formed from a micronuclear derivative. Macronuclear development in hypotrichous ciliates includes the formation of polytene chromosomes, degradation of these chromosomes and elimination of DNA, specific fragmentation of ma... |
9292237 | Cytogenetics of the genus Leporinus (Pisces, Anostomidae). II. Molecular cytogenetics, organization and evolutionary conservation of a chromosome-specific satellite DNA from Leporinus obtusidens. | A chromosome-specific satellite DNA from the South American fish species Leporinus obtusidens has been isolated and characterized. Sequence analysis and Southern hybridization studies indicate that the cloned 483-bp fragment is 60% AT rich and appears to comprise two diverged monomers. A highly variable low-copy number... |
9292236 | Meiosis in carriers of heteromorphic bivalents: sex differences and implications for male fertility. | Mice that are double heterozygous for the semi-identical T(1;13)70H and T(1;13)1Wa reciprocal translocations display a great variation in male fertility. The synaptic behaviour of the different translocation chromosomes of adult males was studied in relation to this parameter. Juvenile males and embryonic females (16 a... |
9292235 | Primed in situ (PRINS) labelling with Alu and satellite primers for rapid characterization of human chromosomes in hybrid cell lines. | The primed in situ (PRINS) labelling method was developed as an alternative to classical cytogenetics and fluorescence in situ hybridization (FISH) for the characterization of interspecific somatic hybrids. Full karyotypes were performed by PRINS using Alu-specific primers to generate the painting of all human material... |
9292234 | Genes located in and near the human pseudoautosomal region are located in the X-Y pairing region in dog and sheep. | We cloned and mapped the dog and/or sheep homologues of two human pseudoautosomal genes CSF2RA and ANT3. We also cloned and mapped dog and/or sheep homologues of STS and PRKX, which are located nearby on the differential region of the human X and have related genes or pseudogenes on the Y. STS, as well as CSF2RA, mappe... |
9292233 | Compositional mapping of mouse chromosomes and identification of the gene-rich regions. | The mouse genome is a mosaic of isochores, consisting of long (> 300 kb), compositionally homogeneous DNA segments that can be divided into two GC-poor families, L1 and L2, representing 56% of the genome, and two GC-rich families, H1 and H2, representing 26% and 7% of the genome, respectively, the remaining 11% being f... |
9292232 | Sex chromosome differentiation in some species of Lepidoptera (Insecta). | Sex chromosome morphology of eight Lepidoptera species was studied, exploiting predominantly the pachytene stage when chromosomes display a remarkable chromomere pattern. Six species had a WZ/ ZZ sex chromosome system, one species a W1W2Z/ ZZ system and one species was of the Z/ZZ type. Much like XY chromosomes in grou... |
9292722 | Paranodin, a glycoprotein of neuronal paranodal membranes. | Ranvier nodes are flanked by paranodal regions, at the level of which oligodendrocytes or Schwann cells interact closely with axons. Paranodes play a critical role in the physiological properties of myelinated nerve fibers. Paranodin, a prominent 180 kDa transmembrane neuronal glycoprotein, was purified and cloned from... |
9300864 | Bioanalysis of p-trifluoromethylmandelic acid and Mosher's acid by chiral gas chromatography and fluorine nuclear magnetic resonance to study chiral inversion: application to rat urine samples. | Methods for the nuclear magnetic resonance and gas chromatographic analysis of the enantiomers of p-trifluoromethylmandelic acid (p-TFM) and Mosher's acid (alpha-methoxy-alpha-(trifluoromethyl)phenylacetic acid) present in rat urine samples are described. Gas chromartography was performed using cyclodextrin capillary c... |
9281524 | On the pairing rules for recognition in the minor groove of DNA by pyrrole-imidazole polyamides. | <h4>Background</h4>Cell-permeable small molecules that target predetermined DNA sequences with high affinity and specificity have the potential to control gene expression. A binary code has been developed to correlate DNA sequence with side-by-side pairings between N-methylpyrrole (Py) and N-methylimidazole (Im) carbox... |
9282893 | Ultrastructural organization of proteoglycans and fibrillar matrix of the tectorial membrane. | The molecular and supramolecular structure of the tectorial membrane (TM) was studied by transmission electron microscopy (TEM). Collagen (type A) fibrils in the TM were found associated with proteoglycans (PGs) and type B fibrils. Most PGs were orthogonally oriented and attached D-periodically to collagen fibrils. Com... |
9279341 | [The current status of postoperative adjuvant chemotherapy for colorectal cancer]. | To evaluate the significance of postoperative adjuvant chemotherapy, randomized controlled trials of adjuvant chemotherapy after curative resection for colorectal cancer were reviewed. Several multiple-drug systemic chemotherapy (MOF, MMC/FT p.o., MMC/5-FU p.o., MMC/ UFT po) were useful as adjuvant treatment to improve... |
9280309 | The catalytic domain of dihydrolipoyl acetyltransferase from the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. Expression, purification and reversible denaturation. | A sub-gene encoding the catalytic (acetyltransferase) domain (E2pCD) comprising residues 173-427 of the dihydrolipoyl acetyltransferase (E2p) chain of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus was expressed in Escherichia coli. The product assembled to form the characteristic icosahe... |
9276021 | 6A-O-[(4-biphenylyl)acetyl]-alpha-, -beta-, and -gamma-cyclodextrins and 6A-deoxy-6A-[[(4-biphenylyl)acetyl]amino]-alpha-, -beta-, and -gamma-cyclodextrins: potential prodrugs for colon-specific delivery. | Cyclodextrins (CyDs) are known to be fermented to small saccharides by colonic microflora, whereas they are only slightly hydrolyzable and thus are not easily absorbed in the stomach and small intestine. This property of CyDs is particularly useful for colon-specific delivery of drugs. In this study, an antiinflammator... |
9276476 | Mutagenesis of residues 27 and 78 modulates heme orientation in cytochrome b5. | A comparison of the primary sequences of the heme binding domains of bovine and rat microsomal cytochrome reveal differences at only six residues. These residues must therefore provide the origin for the observed variation in the ratio of the heme orientational isomers, the equilibrium constant of which ranges from app... |
9276473 | Novel components and enzymatic activities of the human erythrocyte plasma membrane calcium pump. | The plasma membrane Ca2+ pump is essential for the maintenance of cystolic calcium ion concentration levels in eukaryotes. Here we show that the Ca2+-ATPase, purified from human erythrocytes, contains two homopolymers, poly(3-hydroxybutyrate) (PHB) and inorganic polyphosphate (polyP), which form voltage-activated calci... |
9270972 | Use of cyclodextrin to deliver lipids and to modulate apolipoprotein B-100 production in HepG2 cells. | 2-Hydroxypropyl-beta-cyclodextrin (cyclodextrin), cyclodextrin-solubilized oleate, and cyclodextrin-solubilized cholesterol were used to modulate proteolysis and secretion of newly-synthesized apolipoprotein B-100 (apoB) in HepG2 cells. Following cyclodextrin and lipid treatments, cells were pulse-labeled with [3H] leu... |
9269872 | Mechanism of alpha-cyclodextrin-induced hemolysis. 1. The two-step extraction of phosphatidylinositol from the membrane. | It has been suggested that the interaction of cyclodextrins with the lipid components of the erythrocyte membranes is the determining factor in the hemolysis induced by these cyclic oligosaccharides. In the case of alpha-cyclodextrin (cyclomaltohexose), phospholipids have been identified as the cell target. In our stud... |
9267350 | Surgical therapy for coronary artery disease in patients with a left ventricular ejection fraction of 25% or less. | <h4>Background</h4>In patients with advanced coronary artery disease (CAD) and markedly decreased left ventricular ejection fraction (EF) symptoms of myocardial ischemia and insufficiency may be complicated by ventricular arrhythmias. Appropriate surgical therapy must be tailored to the individual symptoms. The aim of ... |
9265656 | Role of actin polymerization and adhesion to extracellular matrix in Rac- and Rho-induced cytoskeletal reorganization. | Most animal cells use a combination of actin-myosin-based contraction and actin polymerization- based protrusion to control their shape and motility. The small GTPase Rho triggers the formation of contractile stress fibers and focal adhesion complexes (Ridley, A.J., and A. Hall. 1992. Cell. 70:389-399) while a close re... |
9259546 | Prebiotic evolution: selecting for homochirality before RNA. | Recent results show that the self-assembly of long homochiral oligomers of a nucleotide analogue can be achieved by ligation of short oligomers of chirally mixed composition. Do these results show how the RNA world might have arisen? |
9261119 | Modification of arginine-198 in sarcoplasmic reticulum Ca2+-ATPase by 1,2-cyclohexanedione causes inhibition of formation of the phosphoenzyme intermediate from inorganic phosphate. | Sarcoplasmic reticulum vesicles were modified with 1,2-cyclohexanedione (CHD), a specific arginine-modifying reagent, in sodium borate (pH 8.0 or 8.8). Phosphoenzyme formation from Pi in the Ca2+-ATPase (reversal of hydrolysis of the phosphoenzyme intermediate) was almost completely inhibited by the modification with C... |
9260293 | Multiple conformations of a human interleukin-3 variant. | Interleukin-3 (IL-3) is a cytokine that stimulates the proliferation and differentiation of hematopoietic cells. The hyperactive hIL-3 variant SC-55494 was shown to have at least two major conformations by high-resolution NMR spectroscopy. Mutants of SC-55494 were constructed in which alanine was substituted for prolin... |
9260288 | Dimethyl sulfoxide binding to globular proteins: a nuclear magnetic relaxation dispersion study. | The 2H magnetic relaxation dispersion (NMRD) technique was used to characterize interactions of dimethyl sulfoxide (DMSO) with globular proteins. A difference NMRD experiment involving the N-acetylglucosamine trisaccharide inhibitor, demonstrated that the DMSO 2H NMRD profile in lysozyme solution is due to a single DMS... |
9260281 | The role of PII conformations in the calculation of peptide fractional helix content. | Changes in the temperature, pH, ionic strength, or denaturant concentration of aqueous solutions of the monomeric non-alpha-helical peptide acetylYEAAAKEAPAKEAAAKAamide generate changes in its dichroic spectrum characteristic for a conformational transition. This transition has the characteristic features of a residue ... |
9260956 | Cloning and characterization of the gene (farA) encoding the receptor for an extracellular regulatory factor (IM-2) from Streptomyces sp. strain FRI-5. | IM-2 is a butyrolactone autoregulator that controls production of blue pigment and nucleoside antibiotics in Streptomyces sp. strain FRI-5. An IM-2-specific receptor gene, farA, was cloned from strain FRI-5, and nucleotide sequencing revealed that the farA gene consists of 666 bp encoding a 221-amino-acid protein of 24... |
9262022 | High-resolution field-emission scanning electron microscopy of nuclear pore complex. | The nuclear pore complex (NPC) is a large macromolecular assembly inserted into the nuclear envelope (NE). It controls the traffic of proteins, RNA, and RNA proteins between nucleus and cytoplasm. It chemical composition and function are now intensively investigated in many organisms. To understand this unique membrane... |
9262003 | Enhancement of cyclodextrin production through use of debranching enzymes. | In the presence of a complexant and a debranching enzyme capable of cleaving alpha-(1-->6) linkages in alpha-D-glucans, Bacillus mascerans cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19) converted starch, maltodextrin and glycogen into cyclodextrin (CD) in yields higher than those obtainable in the absence of deb... |
9261871 | ESCHER: a new docking procedure applied to the reconstruction of protein tertiary structure. | Evaluation of Surface Complementarity, Hydrogen bonding, and Electrostatic interaction in molecular Recognition (ESCHER) is a new docking procedure consisting of three modules that work in series. The first module evaluates the geometric complementarity and produces a set of rough solutions for the docking problem. The... |
9261864 | Dichroic statistical model for prediction and analysis of peptide helicity. | Traditional statistical models for the prediction of peptide helicity are written in terms of the mean fractional helicity of the peptide residues. Far ultraviolet circular dichroic measurements of peptide solutions are converted to mean fractional helicity by partitioning the observed ellipticity between that of a per... |
9258367 | Structure-activity relationships of 4-(phenylethynyl)-6-phenyl-1,4-dihydropyridines as highly selective A3 adenosine receptor antagonists. | 4-(Phenylethynyl)-6-phenyl-1,4-dihydropyridine derivatives are selective antagonists at human A3 adenosine receptors, with Ki values in a radioligand binding assay vs [125I]AB-MECA (N6-(4-amino-3-iodobenzyl)-5'-(N-methylcarbamoyl)adenosine) in the submicromolar range. In this study, structure-activity relationships at ... |
9258366 | Mutagenesis reveals structure-activity parallels between human A2A adenosine receptors and biogenic amine G protein-coupled receptors. | Structure-affinity relationships for ligand binding at the human A2A adenosine receptor have been probed using site-directed mutagenesis in the transmembrane helical domains (TMs). The mutant receptors were expressed in COS-7 cells and characterized by binding of the radioligands [3H]CGS21680, [3H]NECA, and [3H]XAC. Th... |
9254596 | High-resolution NMR structure and backbone dynamics of the Bacillus subtilis response regulator, Spo0F: implications for phosphorylation and molecular recognition. | NMR has been employed for structural and dynamic studies of the bacterial response regulator, Spo0F. This 124-residue protein is an essential component of the sporulation phosphorelay signal transduction pathway in Bacillus subtilis. Three-dimensional 1H, 15N, and 13C experiments have been used to obtain full side chai... |
9257742 | Hypoxanthine phosphoribosyltransferase from Trypanosoma cruzi as a target for structure-based inhibitor design: crystallization and inhibition studies with purine analogs. | The hypoxanthine phosphoribosyltransferase (HPRT) from Trypanosoma cruzi is a potential target for enzyme structure-based inhibitor design, based on previous studies which indicate that these parasites lack the metabolic enzymes required for de novo synthesis of purine nucleotides. By using a bacterial complement selec... |
9245429 | Sodium Green as a potential probe for intracellular sodium imaging based on fluorescence lifetime. | We characterized the use of the fluorescent probe Sodium Green for measurements of intracellular free sodium using frequency-domain, phase-modulation fluorometry. The intensity decays were found to be strongly Na+ dependent, with mean lifetime increasing from 1.13 ns in the absence of Na+ to 2.39 ns in the presence of ... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.