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7534907 | Bulged-out nucleotides in an antisense RNA are required for rapid target RNA binding in vitro and inhibition in vivo. | Naturally occurring antisense RNAs in prokaryotes are generally short, highly structured and untranslated. Stem-loops are always present, and loop regions serve as primary recognition structures in most cases. Single-stranded tails or internal unstructured regions are required for initiation of stable pairing between a... |
7534906 | Bulged-out nucleotides protect an antisense RNA from RNase III cleavage. | Bulged-out nucleotides or internal loops are present in the stem-loop structures of several antisense RNAs. We have used the antisense/target RNA system (CopA/CopT) that controls the copy number of plasmid R1 to examine the possible biological function of bulged-out nucleotides. Two regions within the major stem-loop o... |
7895819 | Trophic-factor modulation of cortical acetylcholinesterase reappearance following transection of the medial cholinergic pathway in the adult rat. | Laminar patterns of cortical acetylcholinesterase (AChE) activity are reestablished in the adult, pharmacologically unmanipulated rat following axotomy of the medial cholinergic pathway. The extent to which trophic and/or growth promoting or inhibiting agents modulate AChE fiber reappearance is not fully understood. Su... |
7885849 | High sensitivity multianalyte immunoassay using covalent DNA-labeled antibodies and polymerase chain reaction. | A multianalyte immunoassay for simultaneous detection of three analytes (hTSH, hCG and beta-Gal) has been demonstrated using DNA-labeled antibodies and polymerase chain reaction (PCR) for amplification of assay response. The labeled antibodies were prepared by covalently coupling uniquely designed DNA oligonucleotides ... |
7885835 | Identity elements of Saccharomyces cerevisiae tRNA(His). | Recognition of tRNA(His) by Saccharomyces cerevisiae histidyl-tRNA synthetase was studied using in vitro transcripts. Histidine tRNA is unique in possessing an extra nucleotide, G-1, at the 5' end. Mutation studies indicate that this irregular secondary structure at the end of the acceptor stem is important for aminoac... |
7878052 | Targeted gene transfer into hepatoma cells with lipopolyamine-condensed DNA particles presenting galactose ligands: a stage toward artificial viruses. | Optimal in vitro gene delivery with cationic lipids requires an excess of cationic charges with respect to DNA phosphates. In these conditions, in vivo delivery will be hampered by interference from cationic lipid-binding macromolecules either circulating or in the extracellular matrix. To overcome this problem, we are... |
7878027 | Display of peptides and proteins on the surface of bacteriophage lambda. | The display of peptides or proteins on the surface of viruses is an important technology for studying peptides or proteins and their interaction with other molecules. Here we describe a display vehicle based on bacteriophage lambda that incorporates a number of features distinct from other currently used display system... |
7873597 | The role of histidine residues in the catalytic act of cyclomaltodextrin glucanotransferase from Bacillus circulans var. alkalophilus. | Our previous study on cyclomaltodextrin glucanotransferase (CGTase) by chemical modification implied the importance of one or two histidine residues in the cyclization reaction of the enzyme. Based on a computer modelled three-dimensional structure of the CGTase, five histidine residues were chosen as targets for the s... |
7873539 | Electron tunneling in substrate-reduced trimethylamine dehydrogenase: kinetics of electron transfer and analysis of the tunneling pathway. | The reoxidation of substrate-reduced trimethylamine dehydrogenase by the artificial electron acceptor ferricenium hexafluorophosphate was studied by stopped-flow spectroscopy. The rate constants for the two sequential one-electron transfers from the reduced 4Fe-4S center to ferricenium ions were measured, the first (ka... |
7869916 | Effect of cyclodextrin on plasma lipids and cholesterol metabolism in the rat. | beta-Cyclodextrin (beta-CD) is a bile acid and sterol sequestrant produced by enzymatic modification of starch; this product has the potential to decrease plasma cholesterol. In contrast to the sequestrants having resin- or saponin-like properties, beta-CD is rapidly broken down by the large intestine microflora. beta-... |
7864827 | The structural origins of the unusual specificities observed in the isolation of chymopapain M and actinidin by covalent chromatography and the lack of inhibition of chymopapain M by cystatin. | 1. The selectivity observed when the potentially general technique for the isolation of fully active forms of cysteine proteinases, covalent chromatography by thiol-disulphide interchange, is applied to chymopapain M and to actinidin was investigated by a combination of experimentation and computer modelling. Neither o... |
7862662 | Hydrogen bonding in water using synthetic receptors. | Four water-soluble adenine receptors were synthesized to study the influence of hydrophobic interactions and hydrogen bonding on molecular recognition in aqueous solution. Association constants were measured in aqueous solution at five temperatures from 3-27 degrees C (pH 6, 51 mM ionic strength). For the mono(imide) r... |
7862639 | Cooperative action of cellular proteins YB-1 and Pur alpha with the tumor antigen of the human JC polyomavirus determines their interaction with the viral lytic control element. | Human JC polyomavirus (JCV) is the etiologic agent of the neurodegenerative disease progressive mulifocal leukoencephalopathy. By using JCV as a model, we investigated the role of the viral early protein tumor antigen (TAg) in the binding of two cellular proteins, Pura alpha and YB-1, to JCV regulatory sequences. Resul... |
7862629 | Structure, stereochemistry, and thermal isomerization of the male sex pheromone of the longhorn beetle Anaglyptus subfasciatus. | Male-released sex pheromone constituents of the longhorn beetle Anaglyptus subfasciatus (Coleoptera: Cerambycidae) are identified by GC-MS and GC-Fourier transform infrared as a 7:1 molar mixture of 3-hydroxy-2-hexanone and 3-hydroxy-2-octanone. These two compounds undergo thermal isomerization during GC analyses to gi... |
7862628 | Application of chiral gas chromatography with electroantennographic detection to the determination of the stereochemistry of a cockroach sex pheromone. | The coupling of an electroantennographic detector to a chiral capillary gas chromatographic system provides a highly sensitive technique for the determination of pheromone stereochemistry. Electronic modification of the usual electroantennographic detector enables the detector to respond to the relatively broad peaks p... |
7860775 | Congenital erythropoietic porphyria: identification and expression of 10 mutations in the uroporphyrinogen III synthase gene. | To investigate the molecular basis of the phenotypic heterogeneity in congenital erythropoietic porphyria, the mutations in the uroporphyrinogen III synthase gene from unrelated patients were determined. Six missense (L4F, Y19C, V82F, V99A, A104V, and G225S), a nonsense (Q249X), a frameshift (633insA), and two splicing... |
7532170 | Architecture of the cell envelope of Chlamydia psittaci 6BC. | The cysteine-rich envelope proteins of the elementary body form of chlamydiae are thought to be located in the outer membrane on the basis of their insolubility in the weak anionic detergent N-lauryl sarcosinate (Sarkosyl). We found, however, that the insolubility of the small (EnvA) and the large (EnvB) cysteine-rich ... |
7859732 | Suppression of villin expression by antisense RNA impairs brush border assembly in polarized epithelial intestinal cells. | We have used an antisense RNA strategy to investigate the role of the actin-associated protein, villin, in the brush-border morphogenesis of human intestinal CaCO2 cells. Stable expression of a cDNA encoding antisense villin RNA resulted in the permanent down-regulation of the endogenous villin message and dramatically... |
7859376 | Solid matrix, room temperature phosphorescence identification and quantitation of the tetrahydrotetrols derived from the acid hydrolysis of benzo[a]pyrene-DNA adducts from human lung. | A new method, suitable for human biomonitoring, that uses room temperature phosphorescence for the detection of DNA damage by carcinogenic metabolites of polycyclic aromatic hydrocarbons is described. Samples of human lung DNA (1 mg) that had been subjected to immunoaffinity chromatography (anti-benzo[a]pyrene-diol-epo... |
7857935 | X-ray structure of cyclodextrin glycosyltransferase complexed with acarbose. Implications for the catalytic mechanism of glycosidases. | Crystals of cyclodextrin glycosyltransferase (CGTase) from Bacillus circulans strain 251 were soaked in buffer solutions containing the pseudotetrasaccharide acarbose, a strong amylase- and CGTase inhibitor. The X-ray structure of the complex was elucidated at 2.5-A resolution with a final crystallographic R value of 1... |
7855591 | Cooperative organization of inorganic-surfactant and biomimetic assemblies. | A model that makes use of the cooperative organization of inorganic and organic molecular species into three dimensionally structured arrays is generalized for the synthesis of nanocomposite materials. In this model, the properties and structure of a system are determined by dynamic interplay among ion-pair inorganic a... |
7853348 | Three-dimensional structure of cyclohexapeptides containing a phosphinic bond in aqueous solution: a template for zinc metalloprotease inhibitors. A NMR and restrained molecular dynamics study. | The 3D structures of two phosphinic cyclic hexapeptide inhibitors of bacterial collagenase, cyclo-(Gly1-Pro2-Phe3 psi[PO2-CH2]Gly4-Pro5-Nle6) (compound I) and cyclo(Gly1-Pro2-D-Phe3 psi[PO2-CH2]-Gly4-Pro5-Nle6) (compound II), in aqueous solution, as derived from NMR spectroscopy and molecular dynamics simulations, are ... |
7853333 | Self-assembly of a quinobenzoxazine-Mg2+ complex on DNA: a new paradigm for the structure of a drug-DNA complex and implications for the structure of the quinolone bacterial gyrase-DNA complex. | The quinobenzoxazine compounds A-62176 and A-85226 belong to a novel class of antineoplastic agents that are catalytic inhibitors of topoisomerase II and also structural analogs of the antibacterial DNA gyrase inhibitor Norfloxacin. In vitro studies have shown that their antineoplastic activity is dependent upon the pr... |
7852399 | Structure of the nicotinic receptor acetylcholine-binding site. Identification of acidic residues in the delta subunit within 0.9 nm of the 5 alpha subunit-binding. | In the nicotinic receptor, the quaternary ammonium group of acetylcholine (ACh) binds to a negative subsite at most 1 nm from a readily reducible disulfide formed between alpha-subunit residues Cys192 and Cys193. The cross-linker S-(2-[3H]glycylamidoethyl)dithio-2-pyridine formed a disulfide bond with reduced alpha Cys... |
7848264 | The expression of interstitial collagenase in human endometrium is controlled by progesterone and by oestradiol and is related to menstruation. | Human endometrial tissue, sampled at different periods of the reproductive cycle, expressed interstitial collagenase mRNA, protein and activity only just before and during the menstrual period. This clear-cut correlation and the inhibition of collagenase expression by progesterone and oestradiol in tissue culture point... |
7844151 | Mammalian alpha 1- and beta 1-syntrophin bind to the alternative splice-prone region of the dystrophin COOH terminus. | The carboxy-terminal region of dystrophin has been suggested to be crucially important for its function to prevent muscle degeneration. We have previously shown that this region is the locus that interacts with the sarcolemmal glycoprotein complex, which mediates membrane anchoring of dystrophin, as well as with the cy... |
7834620 | Translocation and activation of protein kinase C by the plasma cell tumor-promoting alkane pristane. | Pristane (2,6,10,14-tetramethylpentadecane) is a C19-isoalkane that promotes the development of plasmacytomas in genetically susceptible BALB/c mice. Similarities between the effects of pristane and protein kinase C (PKC)-activating phorbol esters suggested that the tumor promoting activity of pristane might involve th... |
7829269 | Effect of VK framework-1 glycosylation on the binding affinity of lymphoma-specific murine and chimeric LL2 antibodies and its potential use as a novel conjugation site. | A potential asparagine (Asn)-linked glycosylation site was identified in the VK FRI sequence of an anti-B lymphoma monoclonal antibody (MAb), LL2.SDS-PAGE analysis and endo-F treatment of both murine and chimeric LL2 antibodies indicated that this site was glycosylated; however, no differences in the binding affinity t... |
7823963 | Characterization of a mammalian homolog of the Escherichia coli MutY mismatch repair protein. | A protein homologous to the Escherichia coli MutY protein, referred to as MYH, has been identified in nuclear extracts of calf thymus and human HeLa cells. Western blot (immunoblot) analysis using polyclonal antibodies to the E. coli MutY protein detected a protein of 65 kDa in both extracts. Partial purification of MY... |
7815552 | An N-terminal domain of the Sendai paramyxovirus P protein acts as a chaperone for the NP protein during the nascent chain assembly step of genome replication. | Two domains involved in RNA synthesis have recently been found within the N-terminal 77 amino acids of the Sendai virus P protein. One domain is required for RNA synthesis per se and has properties in common with the transactivation domains of cellular transcription factors. The second domain is thought to be specifica... |
7815528 | cis-Acting components of human papillomavirus (HPV) DNA replication: linker substitution analysis of the HPV type 11 origin. | Papillomavirus DNA replication requires the viral trans-acting factors E1 and E2 in addition to the host cell's general replication machinery. The origins of DNA replication in bovine and human papillomavirus genomes have been localized to a specific part of the upstream regulatory region (URR) which includes recogniti... |
7815501 | Regions required for CD4 binding in the external glycoprotein gp120 of simian immunodeficiency virus. | The external domain of the envelope glycoprotein, gp120, of simian immunodeficiency virus (SIV) has been expressed as a mature secreted product using recombinant baculoviruses and the expressed protein, which has an observed molecular mass of 110 kDa, was purified by monoclonal antibody (MAb) affinity chromatography. N... |
7815490 | Hepatitis B virus X protein interacts with a probable cellular DNA repair protein. | The mechanism of action of hepatitis B virus (HBV) X protein in transcriptional transactivation and in tumorigenesis remains obscure. We have used the yeast two-hybrid system to identify a cellular protein that can interact with HBV X protein. This protein, designated X-associated protein 1 (XAP-1), is a human homolog ... |
7815484 | Virus-induced immunosuppression: immune system-mediated destruction of virus-infected dendritic cells results in generalized immune suppression. | Despite the clinical importance of virus-induced immunosuppression, how virus infection may lead to a generalized suppression of the host immune response is poorly understood. To elucidate the principles involved, we analyzed the mechanism by which a lymphocytic choriomeningitis virus (LCMV) variant produces a generali... |
33874553 | Chlorophyll breakdown in senescent cotyledons of rape, Brassica napus L.: Enzymatic cleavage of phaeophorbide a in vitro. | Solubilization of senescent thylakoids from rape cotyledons in the presence of Triton X-100 was employed to establish an in vitro system that allowed the assessment of enzymatic conversion of phaeophorbide a into an uncoloured fluorescent chlorophyll catabolite, Bn-FCC-2. The action of the putative dioxygenase responsi... |
33874551 | Chlorophyll breakdown in senescent leaves identification of the biochemical lesion in a stay-green genotype of Festuca pratensis Huds. | Chlorophyll breakdown in senescent leaves proceeds in essentially three steps: dephytylation by the action of chlorophyllase; conversion of chlorophyllide to phaeophorbide by Mg-dechelatase; and oxygenolytic cleavage of the chlorine-macrocycle by a newly discovered dioxygenase. The metabolic lesion responsible for high... |
20882111 | Hydrophobic, Non-Hydrogen-Bonding Bases and Base Pairs in DNA. | We report the properties of hydrophobic isosteres of pyrimidines and purines in synthetic DNA duplexes. Phenyl nucleosides 1 and 2 are nonpolar isosteres of the natural thymidine nucleoside, and indole nucleoside 3 is an analog of the complementary purine 2-aminodeoxyadenosine. The nucleosides were incorporated into sy... |
17813916 | A neutral templating route to mesoporous molecular sieves. | A neutral templating route for preparing mesoporous molecular sieves is demonstrated based on hydrogen-bonding interactions and self-assembly between neutral primary amine micelles (S degrees ) and neutral inorganic precursors (l degrees ). The S degrees l degrees templating pathway produces ordered mesoporous material... |
16534936 | Biopreservation of Brined Shrimp (Pandalus borealis) by Bacteriocins from Lactic Acid Bacteria. | In brined shrimp (ca. 3% NaCl), the effects of three different lactic acid bacteria bacteriocins (crude [6.54 x 10(sup10) U of bacteriocin activity {BU}/g] and purified [8.13 x 10(sup23) BU/g] nisin Z, carnocin UI49 [2.32 x 10(sup4) BU/g], and crude bavaricin A [2.78 BU/g]) on bacterial growth and shelf life were compa... |
9634757 | An allosteric hammerhead ribozyme. | We have constructed an RNA molecule containing a hammerhead ribozyme that is under allosteric control. In the inactive state, the RNA enzyme is unable to cleave a suitable substrate. The formation of the active state of the ribozyme is triggered by a specific interaction with a DNA oligonucleotide effector that is comp... |
9383410 | An intermediate in the assembly of a pore-forming protein trapped with a genetically-engineered switch. | <h4>Background</h4>Studies of the mechanisms by which certain water-soluble proteins can assemble into lipid bilayers are relevant to several areas of biology, including the biosynthesis of membrane and secreted proteins, virus membrane fusion and the action of immune proteins such as complement and perforin. The alpha... |
7574609 | Mechanisms of yeast flocculation: comparison of top- and bottom-fermenting strains. | The flocculation of two brewing yeast strains, top-fermenting strain Saccharomyces cerevisiae MUCL 38485 and bottom-fermenting strain Saccharomyces carlsbergensis MUCL 28285, has been investigated by means of a turbidimetric test. The two strains showed different electrical properties, a different hydrophobicity, and a... |
7574598 | Isolation and characterization of a heat-stable pullulanase from the hyperthermophilic archaeon Pyrococcus woesei after cloning and expression of its gene in Escherichia coli. | The gene encoding an extremely heat-stable pullulanase from the hyperthermophilic archaeon Pyrococcus woesei was cloned and expressed in Escherichia coli. Purification of the enzyme to homogeneity was achieved after heat treatment of the recombinant E. coli cells, affinity chromatography on a maltotriose-coupled Sephar... |
7663397 | Human thrombin receptors are insensitive to thrombin-like snake venom enzymes. | Thrombin-like snake venoms enzymes, flavoxobin, and okinaxobin I isolated from Trimeresurus flavoviridis and Trimeresurus okinavensis, respectively, were examined in SH-EP cells and evaluated whether or not they can activate human thrombin receptors. Flavoxobin was almost completely inactive in both assays for phosphoi... |
7602466 | In-vivo and in-vitro correlation for delayed-release behaviour of a molsidomine/O-carboxymethyl-O-ethyl-beta-cyclodextrin complex in gastric acidity-controlled dogs. | The in-vivo absorption behaviour of molsidomine from the delayed-release tablets of an O-carboxymethyl-O-ethyl-beta-cyclodextrin complex was investigated using gastric acidity-controlled dogs under fasted and non-fasted conditions. The in-vitro release profiles were generated by changing the pH of the dissolution mediu... |
7602465 | Differential effects of modified beta-cyclodextrins on pharmacological activity and bioavailability of 4-biphenylacetic acid in rats after oral administration. | Gastric tolerability, absorption and pharmacological activity of the non-steroidal anti-inflammatory drug 4-biphenylacetic acid (BPAA), as an inclusion complex with beta-cyclodextrin (beta-CyD) or chemically modified beta-CyDs: 2,6-di-O-methyl-beta-CyD (DM-beta-CyD), 2,3,6-tri-O-methyl-beta-CyD (TM-beta-CyD) and 2-hydr... |
7541456 | Aggregation of proteins and its prevention by carbohydrate excipients: albumins and gamma-globulin. | Moisture-induced (2-10 microL added to 10 mg) aggregation of solid-state albumin and gamma-globulin was investigated by incubation at 37 degrees C for 24 h. The insoluble aggregates were centrifuged from a reconstituted solution, dissolved in a solution containing denaturant and reducing agent, and analysed by a Bio-Ra... |
7782160 | Peptide aggregates: a novel model system to study self-assembly of peptides. | Ordered aggregates of Val-Leu-Pro-Phe, tetrapeptide 1, have been found in aqueous solutions. Evidence for the formation of aggregates for the above peptide was obtained by conductometric, pH metric, UV and fluorescence spectroscopic techniques. Values of critical micelle concentration (CMC) for the above peptide obtain... |
7777485 | Crystallization, molecular replacement solution, and refinement of tetrameric beta-amylase from sweet potato. | Sweet potato beta-amylase is a tetramer of identical subunits, which are arranged to exhibit 222 molecular symmetry. Its subunit consists of 498 amino acid residues (Mr 55,880). It has been crystallized at room temperature using polyethylene glycol 1500 as precipitant. The crystals, growing to dimensions of 0.4 mm x 0.... |
7775690 | Treatment of surgical and non-surgical septic multiorgan failure with bicarbonate hemodialysis and sequential hemofiltration. | <h4>Objective</h4>Hospital mortality of patients with septic multiorgan failure (MOF) is still around 95%. The present study investigates whether this high mortality could be significantly reduced by the addition of sequential hemofiltration (SH) with bicarbonate hemodialysis (HD) to the currently used life supportive ... |
7774659 | The effects of adenosine A3 receptor stimulation on seizures in mice. | We have previously shown that acute preischemic adenosine A3 receptor stimulation results in an increased postischemic damage, while chronic stimulation of this receptor diminishes it. Since several pathophysiological phenomena are common for both ischemia and seizures, we have explored the effect of acute and chronic ... |
7758323 | The chemistry of contact allergy: why is a molecule allergenic? | This review concentrates on some specific aspects of the chemistry of allergic contact dermatitis. The way low molecular weight chemicals react with skin proteins to form complete antigens will be discussed and the development of molecular modelling techniques to analyse molecular recognition presented. Subsequently, h... |
7738806 | Safety of parenteral hydroxypropyl beta-cyclodextrin. | Post-treatment data were collected on a patient who received intravenous hydroxypropyl beta-cyclodextrin in a dose of 1.5 g/kg in 1985. Although no untoward effects were observed in this patient, rarely occurring agitation and pulmonary edema have been noted after injections into rabbits and dogs, respectively. These c... |
7737595 | [Protective effects of LipoPGE1, prostaglandin E1 incorporated in lipid microspheres, against liver injury caused by ischemia-reperfusion]. | Effect of LipoPGE1 on liver injury caused by ischemia-reperfusion were compared with that of PGE1-CD, cyclodextrin clathrated PGE1, in rats. LipoPGE1 (10 micrograms/kg) and PGE1-CD (10 micrograms/kg) were gradually injected into the portal vein 5 min both prior to ischemia and prior to reperfusion. In only the group re... |
7726484 | Intranasal pirodavir (R77,975) treatment of rhinovirus colds. | A randomized, double-blind, placebo-controlled trial assessed the therapeutic efficacy of intranasal pirodavir in naturally occurring rhinovirus colds. Adults with symptoms of < or = 2 days' duration were randomly assigned to intranasal sprays of pirodavir (2 mg per treatment) or placebo six times daily for 5 days. In ... |
7718633 | Determination of the enantiomer of a cholesterol-lowering drug by cyclodextrin-modified micellar electrokinetic chromatography. | The development, optimization and application of a chiral CE (capillary electrophoresis) method for the determination of the enantiomer content of a new cholesterol-lowering drug (BMS-180431-09) is discussed. The chiral CE technique, cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC), was employed w... |
7714736 | Modification of rectal absorption of morphine from hollow-type suppositories with a combination of alpha-cyclodextrin and viscosity-enhancing polysaccharide. | An attempt was made to optimize the rectal delivery of morphine, using cyclodextrins as an absorption enhancer and polysaccharides as a swelling hydrogel in Witepsol H-15 hollow-type suppositories, and this was tested in rabbits. alpha- and beta-cyclodextrins enhanced the rate and extent of bioavailability, the former ... |
7712525 | [Cytokine levels in patients with multiple injuries]. | <h4>Background</h4>The role of cytokines in trauma still has not been satisfactorily elucidated. Multiorgan failure (MOF) development should be also under the direction of cytokines, endotoxin, and other mediators.<h4>Methods and results</h4>Therefore we prospectively studied 88 patients with multiple trauma admitted t... |
7711268 | Polymer- and salt-induced toroids of hexagonal DNA. | A model is proposed for polymer- and salt-induced toroidal condensates of DNA, based on a recent theory of the undulation enhancement of the electrostatic interaction in the bulk hexagonal phase of semiflexible polyions. In a continuum approximation, the thermodynamic potential of a monomolecular toroid may be split up... |
7711259 | Aggregation of chlorophyll a probed by resonance light scattering spectroscopy. | We report the resonance light scattering (RLS) spectra of chlorophyll a aggregated in a 9:1 solution of formamide and pH 6.8 phosphate buffer. The aggregate formed after 2 h of mixing, referred to as Chl469, shows a strong scattering feature at 469 nm (Soret band) and a much weaker feature at 699 nm (Qy band). A kineti... |
7711256 | X-ray diffraction of a protein crystal anchored at the air/water interface. | We report the first successful in situ x-ray diffraction experiment with a 2D protein array at the lipid/water interface and demonstrate that the order can be controlled via lateral pressure or density. A protein (streptavidin) was bound to a monolayer of biotinylated lipid at the air/water interface, and diffraction o... |
7711248 | Functional interactions in bacteriorhodopsin: a theoretical analysis of retinal hydrogen bonding with water. | The light-driven proton pump, bacteriorhodopsin (bR) contains a retinal molecule with a Schiff base moiety that can participate in hydrogen-bonding interactions in an internal, water-containing channel. Here we combine quantum chemistry and molecular mechanics techniques to determine the geometries and energetics of re... |
7711239 | The structure and stability of phospholipid bilayers by atomic force microscopy. | Atomic force microscopy (AFM) was used to investigate the structure, stability, and defects of the hydrophilic surfaces of Langmuir-Blodgett bilayer films of distearoylphosphatidylcholine (DSPC) and dipalmitoylphosphatidylethanolamine (DPPE) in the solid phase, and dilinoleoylphosphatidylethanolamine (DLPE) in the flui... |
7711237 | Structural changes in Escherichia coli membranes induced by bacteriophage T4 at different temperatures. | This paper presents some further evidence for our model of DNA translocation into Escherichia coli cells by bacteriophage T4 (see Tarahovsky, Y. S., Khusainov, A. A., Deev, A. A., Kim, Y. V. 1991. FEBS Lett. 289:18-22). When lowering the temperature, we succeeded in slowing down the infection process and in observing a... |
7705645 | Multiple pathways for homologous recombination in Saccharomyces cerevisiae. | The genes in the RAD52 epistasis group of Saccharomyces cerevisiae are necessary for most mitotic and meiotic recombination events. Using an intrachromosomal inverted-repeat assay, we previously demonstrated that mitotic recombination of this substrate is dependent upon the RAD52 gene. In the present study the requirem... |
7705635 | Identification of target genes regulated by homeotic proteins in Drosophila melanogaster through genetic selection of Ultrabithorax protein-binding sites in yeast. | A method based on the transcriptional activation of a selectable reporter in yeast cells was used to identify genes regulated by the Ultrabithorax homeoproteins in Drosophila melanogaster. Fifty-three DNA fragments that can mediate activation by UBX isoform Ia in this test were recovered after screening 15% of the Dros... |
7705629 | Structural analysis of mutations in the Drosophila beta 2-tubulin isoform reveals regions in the beta-tubulin molecular required for general and for tissue-specific microtubule functions. | We have determined the lesions in a number of mutant alleles of beta Tub85D, the gene that encodes the testis-specific beta 2-tubulin isoform in Drosophila melanogaster. Mutations responsible for different classes of functional phenotypes are distributed throughout the beta 2-tubulin molecule. There is a telling correl... |
7704894 | The family of bacterial ADP-ribosylating exotoxins. | Pathogenic bacteria utilize a variety of virulence factors that contribute to the clinical manifestation of their pathogenesis. Bacterial ADP-ribosylating exotoxins (bAREs) represent one family of virulence factors that exert their toxic effects by transferring the ADP-ribose moiety of NAD onto specific eucaryotic targ... |
7704420 | Detecting 'hidden' exchange events within X-ray-induced aberrations using multicolour chromosome paints. | In a recent series of papers we pointed out that any complex exchange (an interaction involving three or more breaks) can yield a wide range of aberration configurations. If these aberrations are detected with a single chromosome paint and total centromere probe, the majority will be scored as either 'simple' exchanges... |
7704419 | The chromosomes of Festuca pratensis Huds. (Poaceae): fluorochrome banding, heterochromatin and condensation. | The karyotype of meadow fescue Festuca pratensis Huds. (2n = 14) has been studied by means of fluorescence banding techniques. AT-enriched heterochromatic bands were revealed in the metaphase chromosomes 1-6. A single GC-rich band was associated with the chromosome 2 secondary constriction. Delay of condensation of the... |
7704418 | The sex-determining region of the Megaselia scalaris (Diptera) Y chromosome. | In Megaselia scalaris (Loew) the presence or absence of a male-determining factor, M, is responsible for sex determination. In two wild-type strains, M is located on the homomorphic chromosome pair 2. In the laboratory line Except42 a new Y chromosome was created by recombination between the original Y and the original... |
7704417 | Colocalization of (TTAGGG)n telomeric sequences and ribosomal genes in Atlantic eels. | The distribution of (TTAGGG)n telomeric repeats was studied in chromosomes of two Atlantic eels, Anguilla anguilla and A. rostrata. We found that these sequences hybridize to all the telomeres but also to the entire nucleolar organizer region (NOR) localized in both species at the short arm of chromosome 8. This was co... |
7704416 | Organization of retro-element and stem-loop repeat families in the genomes and nuclei of cereals. | Sequences homologous to the retro-element BIS-1 and the stem-loop repeat Hi-10 are present in the genomes of a number of cereal species. A detailed characterization of these elements indicated that they are non-randomly organized in the genomes of at least two of these species, namely barley and rye. In contrast to the... |
7704415 | Detection of chromosome malsegregation to the daughter nuclei in cytokinesis-blocked transgenic mouse splenocytes. | Most of the recently developed tests for detecting aneugenic activity of chemicals are based on the induction of micronuclei (MN) in cytokinesis-blocked (CB) binucleated cells. In such a test, aneugens can be discriminated from clastogens by checking for the presence of centromeres in the MN, indicating the loss of who... |
7704414 | Simultaneous detection of centromere-specific probes and chromosome painting libraries by a combination of primed in situ labelling and chromosome painting (PRINS-painting). | In situ techniques for the detection of specific chromosomes using centromeric probes and the decoration of entire chromosomes using chromosome painting are well established. However, in the deciphering of complex chromosomal aberrations it is valuable to be able to detect the centromere and the entire DNA of a specifi... |
7704413 | Visualization of elementary DNA replication units in human nuclei corresponding in size to DNA loop domains. | Newly synthesized DNA in mammalian nuclei is concentrated in discrete nuclear granules called replication foci. These foci may be visualized using antibodies against 5-bromodeoxyuridine. In the early S-phase cells 100-250 foci are usually detected. On average, individual foci range between 0.5 and 2 microns in diameter... |
7704412 | Immunostaining and interphase arrangement of field bean kinetochores. | More than 100 sera from patients with scleroderma CREST (calcinosis, Raynaud phenomenon, esophageal dismotility, sclerodactyly, telangiectasia) were tested in order to detect antigenic nuclear components of the field bean Vicia faba (2n = 12). Kinetochores of mitotic chromosomes and prekinetochores of interphase cells ... |
7704411 | Local and global changes in the morphology and distribution of replication centres in rapidly expanding nuclei. | Sperm pronuclei assembled in Xenopus egg extracts undergo a 10-fold increase in volume over a typical 150-min incubation. Double immunofluorescence with anti-proliferating cell nuclear antigen (PCNA) antibodies and biotinylated anologues of thymidine can be used to distinguish different phases of S-phase. The mean diam... |
7697652 | Regioselectivity of alkylation of cyclomaltoheptaose (beta-cyclodextrin) and synthesis of its mono-2-O-methyl, -ethyl, -allyl, and -propyl derivatives. | Mono-2-O-methyl-, -2-O-ethyl-, and -2-O-allyl-cyclomaltoheptaose were prepared by alkylations of cyclomaltoheptaose in dilute aqueous alkali, and mono-2-O-propylcyclomaltoheptaose was obtained by hydrogenation of the allyl derivative. All the 2-O-alkyl derivatives were less soluble in water than was cyclomaltoheptaose.... |
7695289 | Point mutations in Staphylococcus aureus PBP 2 gene affect penicillin-binding kinetics and are associated with resistance. | In Staphylococcus aureus, penicillin-binding protein 2 (PBP 2) has been implicated in non-PBP 2a-mediated methicillin resistance. The PBP 2 gene (pbpB) was cloned from an expression library of a methicillin-susceptible strain of S. aureus (209P), and its entire sequence was compared with that of the pbpB gene from stra... |
7895256 | Initial enamel crystals are not spatially associated with mineralized dentine. | During epithelial-mesenchymal interactions associated with mammalian tooth development, epithelially-derived and mesenchymally-derived extracellular matrix molecules form a discrete dentine-enamel junction. The developmental and molecular processes required to form this junction are not known. To address this problem w... |
7894316 | [The dynamic trends of biological evolution]. | The available data on the thermodynamic stability of supramolecular biological structures and variations in the chemical composition of living organisms have allowed a macrothermodynamic model of biological evolution to be developed experimentally. In this model, the tendency toward a minimum of the specific Gibbs func... |
7765970 | Role of the carbohydrate moiety of a glucoamylase from Aspergillus awamori var. kawachi in the digestion of raw starch. | The digestion of raw starch by a glucoamylase (GA MU-H) from a mutant strain of Aspergillus awamori var. kawachi was closely correlated with mannoside chains O-linked to the Gp-I region (A470-V514), but not sugar chains N-linked to catalytic GAI' domain of GA MU-H. The partial replacement of mannose residues by glucose... |
7534441 | Air-water gas exchange and evidence for metabolism of hexachlorocyclohexanes in Resolute Bay, N.W.T. | Paired air and water samples were collected at Resolute Bay (74 degrees N, 95 degrees W) in summer 1992 to estimate the direction of gas exchange of hexachlorocyclohexanes (HCHs) and investigate possible loss processes in the water column. Average concentrations of alpha-HCH and gamma-HCH in ocean surface water were 4.... |
7887600 | Molecular characterization of a gene encoding extracellular serine protease isolated from a subtilisin inhibitor-deficient mutant of Streptomyces albogriseolus S-3253. | An extracellular serine protease produced by a mutant, M1, derived from Streptomyces albogriseolus S-3253 that no longer produces a protease inhibitor (Streptomyces subtilisin inhibitor [SSI]) was isolated. A 20-kDa protein was purified by its affinity for SSI and designated SAM-P20. The amino acid sequence of the amin... |
7886125 | Improvement of some pharmaceutical properties of drugs by cyclodextrin complexation. 1. Allopurinol. | The potentiality of molecular interaction of allopurinol (1) with beta-cyclodextrin (beta-CD) was investigated by spectrophotometric methods. Differential UV spectrophotometry revealed an increase in the optical density of 1 in presence of beta-CD. Application of the continuous variation method to spectrophotometric me... |
7883777 | Influence of hexadecylphosphocholine on the release of tumor necrosis factor and nitroxide from peritoneal macrophages in vitro. | Hexadecylphosphocholine (HPC) has been investigated intensively for its cancerostatic properties. One explanation for the mechanism of action of HPC assumes that it plays a role in stimulation of the immune system. In particular, its potency to activate macrophages has already been recognised for different lyso- and et... |
7881538 | Separation of estrogens by micellar electrokinetic chromatography. | Capillary electrophoresis of the sex hormone estrogens using different buffer components was investigated. Free zone electrophoresis with 10 mM phosphate buffer (pH 11.5) or 10 mM phosphate buffer with 10-20% methanol was not effective in separating the ten estrogens used in this study. However, nine estrogens were res... |
7870593 | DNA sequence-specific adenine alkylation by the novel antitumor drug tallimustine (FCE 24517), a benzoyl nitrogen mustard derivative of distamycin. | FCE 24517, a novel distamycin derivative possessing potent antitumor activity, is under initial clinical investigation in Europe. In spite of the presence of a benzoyl nitrogen mustard group this compound fails to alkylate the N7 position of guanine, the major site of alkylation by conventional nitrogen mustards. Chara... |
7870582 | Molecular recognition of tRNA(Pro) by Escherichia coli proline tRNA synthetase in vitro. | In this study, we identify a subset of nucleotides that specify aminoacylation of tRNA(Pro) by Escherichia coli proline tRNA synthetase in vitro. Twenty-two tRNA(Pro) variants were prepared by in vitro transcription and their efficiency of aminoacylation with proline (kcat/KM) was measured. From this analysis, we concl... |
7870581 | Fluorescent d(CGCGAATTCGCG): characterization of major groove polarity and study of minor groove interactions through a major groove semantophore conjugate. | The major and minor groove in duplex DNA are sites of specific molecular recognition by DNA-binding agents such as proteins, drugs and metal complexes and have functional significance. In view of this, understanding of the inherent differences in their environment and the allosteric information transfer between them in... |
7864388 | Capillary zone electrophoresis study of naphthylethylcarbamoylated beta-cyclodextrins. | Regiospecifically monosubstituted 1-(1-naphthyl)ethylcarbamoylated beta-cyclodextrins (NEC-beta-CDs) were successfully employed as chiral additives in capillary zone electrophoresis (CZE) to achieve chiral separation of N-(3,5-dinitrobenzoyl)phenylglycine (3,5-DNB-PG), phenylalanine (3,5-DNB-PA), and homophenylalanine ... |
7531946 | A mucin-like glycoprotein identified by MAG (mouse ascites Golgi) antibodies. Menstrual cycle-dependent localization in human endometrium. | Human endometrial glands synthesize and secrete a high molecular weight mucin-like glycoprotein in a menstrual cycle-dependent fashion. A novel moiety within this Golgi-associated glycoprotein is strongly reactive with IgG antibodies in numerous murine ascites, and has been termed MAG (mouse ascites Golgi). Immunohisto... |
7851430 | A reactive, surface cysteine residue of the class-II fructose-1,6-bisphosphate aldolase of Escherichia coli revealed by electrospray ionisation mass spectrometry. | The state of post-translational modification of the class-II fructose-1,6-bisphosphate aldolase (FBP-aldolase) purified from Escherichia coli was examined by electrospray ionisation mass spectrometry (ESI-MS). The mass was larger than that expected from the known DNA sequence by approximately 80 +/- 6 Da, suggesting th... |
7842743 | Localization of the undulin gene (UND) to human chromosome band 8q23. | Undulin, a large extracellular matrix (ECM) mosaic glycoprotein related to collagen type XIV, is associated with dense collagen matrices in soft tissues and is likely to be involved in the supramolecular organization of interstitial collagens. By fluorescence in situ hybridization (FISH), we have assigned the undulin l... |
7840676 | Isolation and identification of a protoheme IX derivative released during autolytic cleavage of human myeloperoxidase. | Myeloperoxidase (MPO) is a functionally important component of the normal human neutrophil host defense system. This enzyme possesses a dimeric structure composed of two heavy-subunit/light-subunit protomers, with a heme-like prosthetic group covalently linked to each heavy subunit. Although MPO exhibits unusual spectr... |
7837244 | Non-peptidic inhibitors of human leukocyte elastase. 4. Design, synthesis, and in vitro and in vivo activity of a series of beta-carbolinone-containing trifluoromethyl ketones. | A novel series of human leukocyte elastase (HLE) inhibitors containing the beta-carbolinone ring system are reported. The design of these trifluoromethyl ketone-based inhibitors used a combination of structural information obtained from X-ray crystallography and molecular modeling investigations. The beta-carbolinone r... |
7832772 | Catalytic-rate improvement of a thermostable malate dehydrogenase by a subtle alteration in cofactor binding. | The nucleotide-binding fold of many NAD(+)-dependent dehydrogenases contains a conserved acidic amino acid residue which hydrogen-bonds with the 2'- and 3'-hydroxy groups of the adenine-ribose of the cofactor. This residue is highly conserved as aspartate in malate dehydrogenases, except in the thermophilic enzyme from... |
7832769 | Escherichia coli dihydrodipicolinate synthase: characterization of the imine intermediate and the product of bromopyruvate treatment by electrospray mass spectrometry. | Simplified procedures for assaying and purifying dihydrodipicolinate synthase (EC 4.2.1.52), the first enzyme of the lysine biosynthetic pathway, have been developed and electrospray ionization m.s. has been used to observe the imine intermediate with pyruvate and to investigate the reaction of the enzyme with bromopyr... |
7831288 | Building zinc fingers by selection: toward a therapeutic application. | A phage display approach was utilized to modify the specificity of each of the three fingers of the murine transcription factor Zif268. Selections were performed by using the consensus binding sequence of the natural protein and a conserved sequence in the genome of the type 1 human immunodeficiency virus. By using an ... |
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