nadph oxidase subunits: Topics by WorldWideScience.org

Simultaneous activation of NADPH oxidase-related proton and electron currents in human neutrophils

Background and purpose:Diphenyleneiodonium (DPI) is often used as an NADPH oxidase inhibitor, but is increasingly being found to have unrelated side effects. We investigated its...Full Text Available

2009-10-01

The Antibacterial Activity of Human Neutrophils and Eosinophils Requires Proton Channels but Not BK Channels

Generation of reactive oxygen species by the NADPH oxidase complex is an important bactericidal weapon of phagocytes. Phorbol myristate acetate (PMA) is a potent agonist for this “respiratory...Full Text Available

2000-06-06

Genetic Ablation of NADPH Oxidase Enhances Susceptibility to Cigarette Smoke-Induced Lung Inflammation and Emphysema in Mice

Electrophysiological events are of central importance during the phagocyte respiratory burst, because NADPH oxidase is electrogenic and voltage sensitive. We investigated the recent suggestion that...Full Text Available

2006-06-01

Charge compensation for NADPH oxidase activity in microglia in rat brain slices does not involve a proton current

Cigarette smoke (CS) induces recruitment of inflammatory cells in the lungs leading to the generation of reactive oxygen species (ROS), which are involved in lung inflammation and injury. Nicotinamide...Full Text Available

2008-05-01

Superoxide production by NAD(P)H oxidase and mitochondria is increased in genetically obese and hyperglycemic rat heart and aorta before the development of cardiac dysfunction. The role of glucose-6-phosphate dehydrogenase-derived NADPH

The membrane properties of isolated cultured microglia have been extensively studied but it is important to understand their properties in situ, where they protect the brain against...Full Text Available

2008-09-01

Reconstructing Mammalian Phylogenies: A Detailed Comparison of the Cytochrome b and Cytochrome Oxidase Subunit I Mitochondrial Genes

Increased oxidative stress is a known cause of cardiac dysfunction in animals and patients with diabetes, but the sources of reactive oxygen species [e.g., superoxide anion (O₂⁻)]...Full Text Available

2009-07-01

Synergistic Activation of Glucose-6-Phosphate Dehydrogenase and NAD(P)H oxidase by Src kinase Elevates Superoxide in Type 2 Diabetic, Zucker fa/fa, Rat Liver

The phylogeny and taxonomy of mammalian species were originally based upon shared or derived morphological characteristics. However, genetic analyses have more recently played an increasingly important...Full Text Available

NADPH oxidase-mediated reactive oxygen species production activates hypoxia-inducible factor-1 (HIF-1) via the ERK pathway after hyperthermia treatment

Glucose metabolism through glycolysis and hexosamine pathway has been shown to be altered in type 2 diabetes. However, its fate through the pentose phosphate pathway (PPP) is currently unclear....Full Text Available

2009-08-01

Distinct Roles of Nox1 and Nox4 in Basal and Angiotensin II-Stimulated Superoxide and Hydrogen Peroxide Production

Hyperthermia (HT) is a strong adjuvant treatment with radiotherapy and chemotherapy because it causes tumor reoxygenation. However, the detailed molecular mechanisms of how HT enhances tumor oxygenation...Full Text Available

2010-11-23

Mechanisms of Reproductive Thermotolerance in Gossypium hirsutum: The Effect of Genotype and Exogenous Calcium Application

NADPH oxidases are major sources of superoxide (O₂^∸) and hydrogen peroxide (H₂O₂) in vascular cells. Production of these reactive oxygen species...Full Text Available

2008-11-01

British Library Electronic Table of Contents (United Kingdom)

Abstract Although photosynthetic thermotolerance has been investigated extensively in cotton leaves, reports on the biochemical influence of the pistil in promoting fertilization thermostability are limited. To evaluate the effect of temperature, genotype, and exogenous calcium application on fertilization and pistil biochemistry in cotton, thermosensitive (cv. ST4554 B2RF) and thermotolerant (cv. VH260) plants were grown under control (30/20-C) or high-temperature (38/20-C) conditions during flowering, and exogenous CaCl2 was applied to flowers 1-day prior to anthesis. Measured pistil parameters included fertilization efficiency; protein concentration; glutathione reductase, superoxide dismutase (SOD) and NADPH oxidase activities; and ATP and calcium levels. Exogenous calcium had no effec...

2011-01-01

Molecular phylogeography of the microturbellarian Monocelis lineata (Platyhelminthes: Proseriata) in the North-East Atlantic

British Library Electronic Table of Contents (United Kingdom)

Monocelis lineata is a complex of cryptic species (three in the Mediterranean and one in the Atlantic) widespread in midlittoral habitats. Throughout the range, populations with or without an ocular pigmented shield are found. We investigated the genetic structure of the North-East Atlantic populations with the aim of shedding light on their phylogeography and reconstructing possible patterns of recolonization after the Wrmian glaciation. Fourteen samples were investigated using cytochrome c oxidase subunit I (COI) and 13 by inter-simple sequence repeats (ISSRs). COI did not exhibit a clear pattern of decreased genetic diversity along a latitudinal gradient. Populations from Ferrol (Spain), Doolin (Ireland), and Helsingr (Denmark) showed a higher genetic variability, whereas a reduction in...

2011-01-01

Feeding ecology of Xenoturbella bocki (phylum Xenoturbellida) revealed by genetic barcoding

British Library Electronic Table of Contents (United Kingdom)

Abstract The benthic marine worm Xenoturbella is frequently contaminated with molluscan DNA, which had earlier caused confusion resulting in a suggested bivalve relationship. In order to find the source of the contaminant, we have used molluscan sequences derived from Xenoturbella and compared them to barcodes obtained from several individuals of the nonmicroscopic molluscs sharing the same environment as Xenoturbella. Using cytochrome oxidase 1, we found the contaminating sequences to be 98% similar to the bivalve Ennucula tenuis. Using the highly variable D1-D2 region of the large ribosomal subunit in Xenoturbella, we found three distinct species of contaminating molluscs, one of which is 99% similar to the bivalve Abra nitida, one of the most abundant bivalves in the Gullmarsfjord where...

2008-01-01

Pyridine Nucleotide Specificity of Barley Nitrate Reductase ¹

Induction of biotransformation in the liver of Eel (Anguilla anguilla L. ) by sublethal exposure to dinitro-o-cresol: An ultrastructural and biochemical study

NADPH nitrate reductase activity in higher plants has been attributed to the presence of NAD(P)H bispecific nitrate reductases and to the presence of phosphatases capable of hydrolyzing NADPH to NADH....Full Text Available

1982-05-01

Effect of Ethanol-pretreatment on the Liver Xanthine Oxidase Activity in Xylene-treated Rats

Structural and functional alterations in hepatocytes of the European eel, Anguilla anguilla, following a 4-week-exposure to 5, 50, and 250 micrograms/liter dinitro-o-cresol (DNOC) were investigated by means of electron microscopy and biochemistry and compared to liver pathology in eels exposed to the chemical spill into the Rhine river at Basle in November 1986. Whereas phenological parameters (growth, condition factor) are unaffected, ultrastructural and biochemical alterations are detectable at greater than or equal to 50 and 5 micrograms/liter DNOC, respectively. Structural modifications include: rounding-up of the nuclei; fractionation and reduction of the rough endoplasmic reticulum; proliferation of the smooth endoplasmic reticulum (SER), mitochondria, peroxisomes, and lysosomes; bundles of rod-shaped SER profiles; annulate lamellae; membrane whorls within mitochondria; crystallization of the peroxisomal matrix and glycogen bodies; glycogen depletion and lipid augmentation. ...

1991-04-01

KoreaScience (Korea)

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1998-08-01

Antimutagenic effects of browning products reacted with polyphenol oxidase extracted from peach

KoreaScience (Korea)

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1992-04-01

Regulation of expression of a soybean storage protein subunit gene. Progress report

Reactive biomolecular divergence in genetically altered yeast cells and isolated mitochondria as measured by biocavity laser spectroscopy : a rapid diagnostic method for studying cellular responses to stress and disease.

We have found that the methionine repression of the ..beta..-subunit gene expression is not due to degradation of the ..beta..-subunit but is due to an effect on synthesis of the ..beta..-subunit. The effect of methionine on the synthesis of the ..beta..-is due to an inhibition of ..beta..-subunit mRNA synthesis. 3 references, 1 figure.

1984-04-23

Polyamine Oxidase from Water Hyacinth

We report an analysis of four strains of baker's yeast (Saccharomyces cerevisiae) using biocavity laser spectroscopy. The four strains are grouped in two pairs (wild type and altered), in which one strain differs genetically at a single locus, affecting mitochondrial function. In one pair, the wild-type rho+ and a rho0 strain differ by complete removal of mitochondrial DNA (mtDNA). In the second pair, the wild-type rho+ and a rho- strain differ by knock-out of the nuclear gene encoding Cox4, an essential subunit of cytochrome c oxidase. The biocavity laser is used to measure the biophysical optic parameter Deltalambda, a laser wavelength shift relating to the optical density of cell or mitochondria that uniquely reflects its size and biomolecular composition. As such, Deltalambda is a powerful parameter that rapidly interrogates the biomolecular state of single cells and mitochondria. Wild-type cells and mitochondria produce ...

2006-12-01

Evaluation of Acyl Coenzyme A Oxidase (Aox) Isozyme Function in the n-Alkane-Assimilating Yeast Yarrowia lipolytica

Polyamine oxidase was purified to homogeneity from leaves of water hyacinth by the criterion of sodium dodecyl sulfate gel electrophoresis (SDS disc PAGE). The enzyme showed a high specificity for spermidine...Full Text Available

1987-12-01

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Cloning of an insecticidal cholesterol oxidase gene and its expression in bacteria and in plant protoplasts.

We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n-alkane-assimilating yeast Yarrowia lipolytica, encoded by the POX1...Full Text Available

1999-09-01

(+)-Larreatricin hydroxylase, an enantio-specific polyphenol oxidase from the creosote bush (Larrea tridentata)

We cloned and sequenced structural gene choM, which encodes an insecticidally active cholesterol oxidase in Streptomyces sp. strain A19249. The primary translation product was predicted to be a 547-amino-acid...Full Text Available

1994-12-01

Effect of Carbon Tetrachloride on the Changes of Xanthine Oxidase Activity in Rate Previously Fed Low or High Protein Diet

An enantio-specific polyphenol oxidase (PPO) was purified ≈1,700-fold to apparent homogeneity from the creosote bush (Larrea tridentata), and its encoding gene was cloned. The...Full Text Available

2003-09-16

KoreaScience (Korea)

Full Text Available

1991-12-01

The opposite effect of bivalent cations on cytochrome b5 reduction by NADH:cytochrome b5 reductase and NADPH:cytochrome c reductase.

New Insights into Type II NAD(P)H:Quinone Oxidoreductases

The effects of bivalent cations on cytochrome b5 reduction by NADH:cytochrome b5 reductase and NADPH:cytochrome c reductase were studied with the proteinase-solubilized enzymes. Cytochrome b5 reduction...Full Text Available

1988-05-01

Impaired mitochondrial energy metabolism and kinetic properties of cytochrome oxidase following acute aluminium phosphide exposure in rat liver

Type II NAD(P)H:quinone oxidoreductases (NDH-2) catalyze the two-electron transfer from NAD(P)H to quinones, without any energy-transducing site. NDH-2 accomplish the turnover of NAD(P)H, regenerating...Full Text Available

2004-12-01

British Library Electronic Table of Contents (United Kingdom)

The present study was designed with an aim to analyze the effect of acute aluminium phosphide (ALP) exposure (10mg/kg b.wt, intragastrically) on the kinetic characteristics of cytochrome oxidase and energy metabolism in male Wistar rat liver mitochondria. Liver mitochondrial preparations from ALP-treated rats exhibited significant decrease (66%) in the activity of cytochrome oxidase suggesting that there was a decrease in the catalytic efficiency of the active oxidase molecules on ALP treatment. The decreased activity of cytochrome oxidase with altered NADH and succinic dehydrogenase activities might have contributed towards a significant decline in state 3 and state 4 respiration as observed. These alterations in the electron transport chain complexes in turn adversely affected the ATP sy...

2010-01-01

NMR assignment of the cAMP-binding domain A of the PKA regulatory subunit

Distribution of NADPH-diaphorase activity in the central nervous system of the young and adult land snail Megalobulimus abbreviatus

No abstract prepared.

2006-12-15

British Library Electronic Table of Contents (United Kingdom)

Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a neurotransmitter in the central nervous system (CNS) of adult gastropod mollusks. There are no known reports of the presence of NOS-containing neurons and glial cells in young and adult Megalobulimus abbreviatus. Therefore, NADPH-d histochemistry was employed to map the nitrergic distribution in the CNS of young and adult snails in an attempt to identify any transient enzymatic activity in the developing CNS. Reaction was observed in neurons and fibers in all CNS ganglia of both age groups, but in the pedal and cerebral ganglia, positive neurons were more intense than in other ganglia, forming clusters symmetrically located in both paired ganglia. However, neuronal NADPH-d activity in the mesocer...

2010-01-01

Clinical outcomes and management of mechanism-based inhibition of cytochrome P450 3A4

A Hyperactive NAD(P)H:Rubredoxin Oxidoreductase from the Hyperthermophilic Archaeon Pyrococcus furiosus

Mechanism-based inhibition of cytochrome P450 (CYP) 3A4 is characterized by NADPH-, time-, and concentration-dependent enzyme inactivation, occurring when some drugs are converted by CYPs to reactive...Full Text Available

2005-03-01

Antioxidant action of antimalarials.

NAD(P)H:rubredoxin oxidoreductase (NROR) has been purified from the hyperthermophilic archaeon Pyrococcus furiosus. The enzyme is exceedingly active in catalyzing the NADPH-dependent...Full Text Available

1999-09-01

Use of Dimethyl Suberimidate, a Cross-Linking Reagent, in Studying the Subunit Structure of Oligomeric Proteins^*

The effects of antimalarials, chloroquine and quinacrine, on the generation of reactive oxygen species were examined both in polymorphonuclear leucocytes and in the xanthine-xanthine oxidase system....Full Text Available

1986-03-01

The human peripheral subunit-binding domain folds rapidly while overcoming repulsive Coulomb forces

Amidination of aldolase, glyceraldehyde-3-phosphate dehydrogenase, tryptophan synthetase B protein, L-arabinose isomerase, and the catalytic subunit of E. coli aspartate transcarbamylase...Full Text Available

1970-07-01

Structure-Function Study of the N-terminal Domain of Exocyst Subunit Sec3*

Peripheral subunit binding domains (PSBDs) are integral parts of large multienzyme complexes involved in carbohydrate metabolism. PSBDs facilitate shuttling of prosthetic groups between different catalytic...Full Text Available

2010-09-01

Steady-state levels of G-protein beta-subunit expression are regulated by treatment of cells with bacterial toxins

The exocyst is an evolutionarily conserved octameric complex involved in polarized exocytosis from yeast to humans. The Sec3 subunit of the exocyst acts as a spatial landmark for exocytosis through...Full Text Available

2010-04-02

MAPPING THE INITIATOR BINDING TAF2 SUBUNIT IN THE STRUCTURE OF HYDRATED YEAST TFIID

Cultures of 3T3-L1 cells were incubated with either 10 ng/ml cholera toxin or 10 ng/ml pertussis toxin from 4 days prior to the initiation of differentiation and throughout the subsequent incubation. Toxin concentrations were sufficient to completely prevent the labelling of alpha-subunits with ["3"2P]NAD"+ and pertussis toxin and to prevent by more than 90% the labelling with ["3"2P]NAD"+ and cholera toxin in membranes prepared from these cells. Neither toxin prevented the differentiation to the adipocyte phenotype. Neither toxin prevented the increases in the relative amounts of G-proteins which occur upon differentiation. Both toxins dramatically decreased the amount of beta-subunits. As measured by quantitative immunoblotting with antisera specific for both the 35 kDa and 36 kDa beta-subunits, levels of beta-subunit were decreased by more than 50% of steady-state level of control cells. Thus, ...

1987-06-07

Increased degradation of MYPT1 contributes to the development of tolerance to nitric oxide in porcine pulmonary artery

SummaryThe general transcription factor TFIID is a large multi-subunit complex required for the transcription of most protein-encoding genes by RNA polymerase II. Taking advantage...Full Text Available

2009-03-11

Analysis of the Type IV Fimbrial-Subunit Gene fimA of Xanthomonas hyacinthi: Application in PCR-Mediated Detection of Yellow Disease in Hyacinths

Myosin phosphatase target subunit 1 (MYPT1) is the regulatory subunit of myosin light chain phosphatase (MLCP). It plays a critical role in vasodilatation induced by cGMP-elevating agents such as nitric...Full Text Available

2010-07-01

An Analysis of the Subunit Structure of the Crystalloid Protein Complex from Castor Bean Endosperm 1

A sensitive and specific detection method was developed for Xanthomonas hyacinthi; this method was based on amplification of a subsequence of the type IV fimbrial-subunit gene fimA...Full Text Available

2001-02-01

Quantitative transfer of the molybdenum cofactor from xanthine oxidase and from sulphite oxidase to the deficient enzyme of the nit-1 mutant of Neurospora crassa to yield active nitrate reductase.

Chromatographic and electrophoretic studies have shown that the subunits of the crystalloid protein, isolated from mature castor bean (Ricinus communis L. cv Hale) seed endosperm protein...Full Text Available

1983-06-01

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Differences in sensitivity of Schistosoma mansoni schistosomula, Dirofilaria immitis microfilariae, and Nematospiroides dubius third-stage larvae to damage by the polyamine oxidase-polyamine system.

An assay method is described for measurement of absolute concentrations of the molybdenum cofactor, based on complementation of the defective nitrate reductase ('apo nitrate reductase') in extracts...Full Text Available

1984-04-15

Mitochondrial NADH:ubiquinone oxidoreductase (complex I) in eukaryotes: A highly conserved subunit composition highlighted by mining of protein databases

The effect of the polyamine oxidase (PAO)-polyamine system on some helminths was examined in vitro. Both Schistosoma mansoni schistosomula and Dirofilaria immitis microfilariae were highly sensitive...Full Text Available

1986-09-01

British Library Electronic Table of Contents (United Kingdom)

Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has almost tripled its subunit composition during evolution of eukaryotes, by recruitment of so-called accessory subunits, part of them being specific to distinct evolutionary lineages. The increasing availability of numerous broadly sampled eukaryotic genomes now enables the reconstruction of the evolutionary history of this large protein complex. Here, a combination of profile-based sequence comparisons and basic structural properties analyses at the protein level enabled to pinpoint homology relationships between complex I subunits from fungi, mammals or green plants, previously identified...

2011-01-01

Localization of sites of photoaffinity labeling of the large subunit of Escherichia coli ribosomes by arylazide derivative of puromycin

Localization of sites of photoaffinity labeling of the large subunit of Escherichia coli ribosomes by arylazide derivative of puromycin

Previous work showed that (TH)p-azidopuromycin photoaffinity labeled 70 S Escherichia coli ribosomes and that photoincorporation into 50 S subunit proteins was in the order L23 greater than L18/22 greater than L15. In the present work the authors report on immunoelectron microscopic studies of the complexes formed by p-azidopuromycin-modified 50 S subunits with antibodies to the N6,N6-dimethyladenosine moiety of the antibiotic. The p-azidopuromycin-modified 50 S subunits appear to be identical to unmodified control subunits in electron micrographs. Complexes of modified subunits with antibodies to the N6,N6-dimethyladenosine moiety of p-azidopuromycin were visualized in micrographs. Two regions of p-azidopuromycin photoincorporation were identified. The primary site, seen in about 75% of the complexes, is between the central protuberance and small projection, on the side away from ...

1985-08-25

Detection of constitutive heterodimerization of the integrin Mac-1 subunits by fluorescence resonance energy transfer in living cells

Previous work showed that ["3H]p-azidopuromycin photoaffinity labeled 70 S Escherichia coli ribosomes and that photoincorporation into 50 S subunit proteins was in the order L23 greater than L18/22 greater than L15. In the present work the authors report on immunoelectron microscopic studies of the complexes formed by p-azidopuromycin-modified 50 S subunits with antibodies to the N6,N6-dimethyladenosine moiety of the antibiotic. The p-azidopuromycin-modified 50 S subunits appear to be identical to unmodified control subunits in electron micrographs. Complexes of modified subunits with antibodies to the N6,N6-dimethyladenosine moiety of p-azidopuromycin were visualized in micrographs. Two regions of p-azidopuromycin photoincorporation were identified. The primary site, seen in about 75% of the complexes, is between the central protuberance and small projection, on the side away from ...

Erratum to: Inhibition of triclabendazole metabolism in vitro by ketoconazole increases disruption to the tegument of a triclabendazole-resistant isolate of Fasciola hepatica

Macrophage differentiation antigen associated with complement three receptor function (Mac-1) belongs to #beta#_2 subfamily of integrins that mediate important cell-cell and cell-extracellular matrix interactions. Biochemical studies have indicated that Mac-1 is a constitutive heterodimer in vitro. Here, we detected the heterodimerization of Mac-1 subunits in living cells by means of two fluorescence resonance energy transfer (FRET) techniques (fluorescence microscopy and fluorescence spectroscopy) and our results demonstrated that there is constitutive heterodimerization of the Mac-1 subunits and this constitutive heterodimerization of the Mac-1 subunits is cell-type independent. Through FRET imaging, we found that heterodimers of Mac-1 mainly localized in plasma membrane, perinuclear, and Golgi area in living cells. Furthermore, through analysis of the estimated physical distances between cyan fluorescent protein (CFP) ...

2006-08-04

British Library Electronic Table of Contents (United Kingdom)

A study has been carried out to investigate whether the action of triclabendazole (TCBZ) against Fasciola hepatica is altered by inhibition of drug metabolism. The cytochrome P450 (CYP 450) enzyme pathway was inhibited using ketoconazole (KTZ) to see whether a TCBZ-resistant isolate could be made more sensitive to TCBZ action. The Oberon TCBZ-resistant and Cullompton TCBZ-susceptible isolates were used for these experiments. The CYP 450 system was inhibited by a 2-h pre-incubation in ketoconazole (40??M), then incubated for a further 22?h in NCTC medium containing either KTZ, KTZ?+?nicotinamide adenine dinucleotide phosphate (NADPH) (1?nM), KTZ?+?NADPH?+?TCBZ (15??g/ml), or KTZ?+?NADPH?+?triclabendazole sulphoxide (TCBZ.SO; 15??g/ml). Changes to fluke ultrastructure following drug treatmen...

2011-01-01

Effect of paraquat on microsomal lipid peroxidation in vitro and in vivo. [Rats, rabbits, man, mice

Treatment of atypical depression with cognitive therapy or phenelzine: a double-blind, placebo-controlled trial.

Rat lung and liver microsomes did not undergo lipid peroxidation in the absence of iron when incubated with NADPH and concentrations of paraquat ranging from 10/sup -7/ to 10/sup -2/ M. Paraquat also did not stimulate rat liver and lung microsomal peroxidation induced by added iron and NADPH, and was inhibitory at concentrations above 10 ..mu..M. Similarly, no stimulation of peroxidation was produced by paraquat in rabbit or human lung microsomes; however, under similar conditions, paraquat enhanced NADPH/iron-dependent peroxidation in mouse lung and liver microsomes obtained from rats sacrificed at 12, 18, and 24 hr following a lethal dose of paraquat (50 mg/kg, ip), there was no loss of vitamin E or increase in susceptibility to in vitro peroxidation which would be expected if lipid peroxidation had occurred in vivo although extensive lung damage developed during this time period. These results indicate that paraquat does ...

1980-01-01

Microfluidic Devices Integrating Microcavity Surface-Plasmon-Resonance Sensors: Glucose Oxidase Binding-Activity Detection

Background: Patients with a typical depression are more likely to respond to monoamine oxidase inhibitors than to tricyclic antidepressants. They are frequently offered psychotherapy...Full Text Available

1999-05-01

In Vivo Measurement of Indole-3-acetic Acid Decarboxylation in Aging Coleus Petiole Sections

We have developed miniature (≈1 μm diameter) microcavity surface-plasmon-resonance sensors (MSPRS), integrated them with microfluidics and tested...Full Text Available

2010-01-01

Genetic Susceptibility for Individual Cooperation Preferences: The Role of Monoamine Oxidase A Gene (MAOA) in the Voluntary Provision of Public Goods

The concentration of indoleacetic acid (IAA) in plant tissues is regulated, in part, by its rate of decarboxylation. However, the commonly used in vitro assays for IAA oxidase may not...Full Text Available

1983-09-01

Biochemical Conservation and Evolution of Germacrene A Oxidase in Asteraceae*

In the context of social dilemmas, previous research has shown that human cooperation is mainly based on the social norm of conditional cooperation. While in most cases individuals behave according...Full Text Available

Betaxanthins as Substrates for Tyrosinase. An Approach to the Role of Tyrosinase in the Biosynthetic Pathway of Betalains1

Sesquiterpene lactones are characteristic natural products in Asteraceae, which constitutes ∼8% of all plant species. Despite their physiological and pharmaceutical importance, the biochemistry...Full Text Available

2010-05-28

Aldehyde Oxidase and Xanthine Dehydrogenase in a flacca Tomato Mutant with Deficient Abscisic Acid and Wilty Phenotype1

Tyrosinase or polyphenol oxidase (EC 1.14.18.1) is the key enzyme in melanin biosynthesis and in the enzymatic browning of fruits and vegetables. The role of tyrosinase in the secondary metabolism of...Full Text Available

2005-05-01

Albumin interacts specifically with a 60-kDa microvascular endothelial glycoprotein.

The flacca tomato (Lycopersicon esculentum) mutant displays a wilty phenotype as a result of abscisic acid (ABA) deficiency. The Mo cofactor (MoCo)-containing aldehyde...Full Text Available

1999-06-01

Abnormalities in the microsomal oxidases of the WHO standard reference strain of Musca domestica*

Confluent monolayers of microvascular endothelial cells, derived from the rat epididymal fat pad and grown in culture, were radioiodinated by using the lactoper-oxidase method. Their radioiodinated...Full Text Available

1988-09-01

Structure and function of an acetylcholine receptor.

Observations made during biochemical and toxicological studies of the housefly, in which the WHO standard reference (SR) strain was used as a standard, indicated that this strain differs from other...Full Text Available

1975-01-01

AMPA-receptor trafficking and injury-induced cell death

Structural analysis of an acetylcholine receptor from Torpedo californica leads to a three-dimensional model in which a "monomeric" receptor is shown to contain subunits arranged around a central ionophoretic...Full Text Available

1982-01-01

Differential use of two cyclic electron flows around photosystem I for driving CO₂-concentration mechanism in C₄ photosynthesis

AMPA receptors (AMPARs) are critical for synaptic plasticity, and are subject to alterations based on subunit composition and receptor trafficking to and from the plasma membrane. One of the...Full Text Available

2010-07-01

Yeast ribosomal protein L1 is required for the stability of newly synthesized 5S rRNA and the assembly of 60S ribosomal subunits.

Whereas linear electron flow (LEF) in photosynthesis produces both ATP and NADPH, the cyclic electron flow (CEF) around photosystem I has been shown to produce only ATP. Two alternative routes have...Full Text Available

2005-11-15

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Production and characterization of monoclonal antibodies recognizing the alpha-chain subunits of human ia alloantigens.

Ribosomal protein L1 from Saccharomyces cerevisiae binds 5S rRNA and can be released from intact 60S ribosomal subunits as an L1-5S ribonucleoprotein (RNP) particle. To understand the nature of the...Full Text Available

1993-05-01

Polygalacturonase ?-Subunit Antisense Gene Expression in Tomato Plants Leads to a Progressive Enhanced Wound Response and Necrosis in Leaves and Abscission of Developing Flowers

Two monoclonal antibodies, TAL-1B5 and TAL-3C3, specific for human Ia alpha-chain subunits have been produced by fusing P3/NSI/1-Ag4-1 mouse myeloma cells with spleen cells from a BALB/c mouse immunized...Full Text Available

1983-12-01

Identification of a Drosophila G protein alpha subunit (dGq alpha-3) expressed in chemosensory cells and central neurons.

Tomato (Lycopersicon esculentum var. Better Boy) plants were transformed with a tomato leaf wound-inducible polygalacturonase (PG) β-subunit gene in the antisense orientation...Full Text Available

2003-10-01

Assembly of 60S ribosomal subunits is perturbed in temperature-sensitive yeast mutants defective in ribosomal protein L16.

We have identified another Drosophila GTP-binding protein (G protein) alpha subunit, dGq alpha-3. Transcripts encoding dGq alpha-3 are derived from alternative splicing of the dGq alpha locus previously...Full Text Available

1995-12-05

Absence of the A4 peptide in the G4 glycinin subunit of soybean cultivar Enrei is caused by a point mutation in the Gy4 gene

Temperature-sensitive mutants defective in 60S ribosomal subunit protein L16 of Saccharomyces cerevisiae were isolated through hydroxylamine mutagenesis of the RPL16B gene and plasmid shuffling. Two...Full Text Available

1991-11-01

Scientific Electronic Library Online (English)

Abstract in english Functional properties of soy proteins for food are closely related to the composition of their storage protein subunits. Using base excision sequence scanning (BESS), we show that the absence of the A4 peptide in the G4 glycinin subunit of the soybean (Glycine max L.) cultivar Enrei was caused by the same point mutation in the Gy4 gene as previously reported in the soybean cultivar Raiden. Although the genetic relationship between Raiden and Enrei is not known, the same p (more) oint mutation in their Gy4 genes may indicate that they probably share a related origin. The application of BESS to identify single nucleotide polymorphisms (SNPs) as co-dominant markers for marker-assisted selection (MAS) of a recessive null allele is also discussed.

2005-09-01

Determination of microsomal lauric acid hydroxylase activity by HPLC with flow-through radiochemical quantitation

Resistance pattern and antioxidant enzyme profiles of protoporphyrinogen oxidase (PROTOX) inhibitor-resistant transgenic rice

An assay for the microsomal hydroxylation of lauric acid (LA), based on HPLC with flow-through radiochemical detection, has been developed. Conditions were optimized for resolution and quantitation of three microsomal metabolites of "1"4C-LA, one of which has not been reported previously as a metabolite of LA in mammalian microsomal incubations. These products, 12-(omega)-hydroxy-LA, 11-(omega-1)-hydroxy-LA, and a novel metabolite, 10-(omega-2)-hydroxy-LA, were isolated by HPLC and identified by gas chromatography/mass spectrometry. In the presence of NADPH, the formation of all three metabolites was linear with time and microsomal protein concentration. Hydrogen peroxide also supported the microsomal metabolism of LA, although the ratio of metabolites was substantially different than that produced by NADPH-supported microsomes. Several biochemical probes (metyrapone, #alpha#-naphthoflavone, 2-diethylaminoethyl-2,2-diphenylvalerate ...

British Library Electronic Table of Contents (United Kingdom)

We quantified the resistance levels of transgenic rice plants, expressing Myxococcus xanthus protoporphyrinogen oxidase (PROTOX) in chloroplasts and mitochondria, to PROTOX inhibitors, acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon. We also determined whether active oxygen species-scavenging enzymes are involved in the resistance mechanism of transgenic rice. The transgenic rice line M4 was about >200-fold more resistant to oxyfluorfen than the wild-type (WT). M4 was also resistant to acifluorfen, carfentrazone-ethyl, and oxadiazon, but did not show multiple resistance to imazapyr and paraquat, which have different target sites. Acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon reduced the chlorophyll content in leaves of WT, but had minimal or no effect on M4. The...

2008-01-01

GREEN TEA PHENOLS INTERFERENCE IN THE GLUCOSE OXIDASE/PEROXIDASE TEST

British Library Electronic Table of Contents (United Kingdom)

Abstract Green tea extract showed false-negative results in the determination of glucose via glucose oxidase (GOD) test. This investigation was undertaken to verify and find out the precise mechanism underlying this interference by determining the reaction kinetics of production and reduction of end-point chromophore. The peroxidase step of the GOD test was found to be interfered and phenols of the green tea were the interfering compounds. Green tea interfered and exerted its influence in a dual fashion. A part of the interference was observed as a result of the reduction of the finally formed chromophore, whereas the other form of interference was due to its hydrogen peroxide/free radical-scavenging activity. Reducing potential and the free radical-scavenging activity of the phenols in th...

2011-01-01

Structures of trihydroxynaphthalene reductase-fungicide complexes: implications for structure-based design and catalysis

narI region of the Escherichia coli nitrate reductase (nar) operon contains two genes.

Trihydroxynaphthalene reductase catalyzes two intermediate steps in the fungal melanin biosynthetic pathway. The enzyme, a typical short-chain dehydrogenase, is the biochemical target of three commercial fungicides. The fungicides bind preferentially to the NADPH form of the enzyme. Three X-ray structures of the Magnaporthe grisea enzyme complexed with NADPH and two commercial and one experimental fungicide were determined at 1.7 {angstrom} (pyroquilon), 2.0 {angstrom} (2,3-dihydro-4-nitro-1H-inden-1-one, 1), and 2.1 {angstrom} (phthalide) resolutions. The chemically distinct inhibitors occupy similar space within the enzyme's active site. The three inhibitors share hydrogen bonds with the side chain hydroxyls of Ser-164 and Tyr-178 via a carbonyl oxygen (pyroquilon and 1) or via a carbonyl oxygen and a ring oxygen (phthalide). Active site residues occupy similar positions among the three structures. A buried water molecule that is ...

2010-03-08

Unexpected diversity of RNase P, an ancient tRNA processing enzyme: challenges and prospects

In previous studies it has been established that in Escherichia coli the three known subunits of anaerobic nitrate reductase are encoded by the narGHI operon. From the nucleotide sequence of the narI...Full Text Available

1988-04-01

Trichoderma atroviride G-Protein ?-Subunit Gene tga1 Is Involved in Mycoparasitic Coiling and Conidiation

For an enzyme functioning predominantly in a seemingly housekeeping role of 5′ tRNA maturation, RNase P displays a remarkable diversity in subunit make-up across the three domains of...Full Text Available

2010-01-21

The reactivity of thiol groups and the subunit structure of aldolase

The soil fungus Trichoderma atroviride, a mycoparasite, responds to a number of external stimuli. In the presence of a fungal host, T. atroviride produces...Full Text Available

2002-08-01

The potential role of phrenic nucleus glutamate receptor subunits in mediating spontaneous crossed phrenic activity in neonatal rat

1. Seven unique carboxymethylcysteine-containing peptides have been isolated from tryptic digests of rabbit muscle aldolase carboxymethylated with iodo[2-¹⁴C]acetic acid in 8m-urea....Full Text Available

1970-04-01

The influence of MHC polymorphism on the selection of T-cell determinants of FMDV in cattle.

Cervical spinal cord hemisection rostral to the phrenic nucleus leads to paralysis of the ipsilateral hemidiaphragm in adult rats. Respiratory function can be restored to the paralyzed hemidiaphragm...Full Text Available

2009-08-01

Subunits of the Drosophila CCR4-NOT complex and their roles in mRNA deadenylation

There is a quest for the development of a new generation of vaccines consisting of well-defined subunit antigens. For a number of practical reasons it is attractive to develop vaccines on the basis...Full Text Available

1995-01-01

Red Light-Regulated Growth ¹

The CCR4-NOT complex is the main enzyme catalyzing the deadenylation of mRNA. We have investigated the composition of this complex in Drosophila melanogaster by immunoprecipitation...Full Text Available

2010-07-01

Multiple Functions of the 37/67-kd Laminin Receptor Make It a Suitable Target for Novel Cancer Gene Therapy

We examined the changes in the levels of indoleacetic acid (IAA), IAA esters, and a 22-kilodalton subunit auxin-binding protein (ABP1) in apical mesocotyl tissue of maize (Zea mays...Full Text Available

1991-09-01

Modeling RNA polymerase competition: the effect of ?-subunit knockout and heat shock on gene transcription level

The 37/67-kd laminin receptor, LAMR, is a multifunctional protein that associates with the 40S ribosomal subunit and also localizes to the cell membrane to interact with the extracellular matrix. LAMR...Full Text Available

2010-01-01

Human Immunodeficiency Virus type-1 reverse transcriptase exists as post-translationally modified forms in virions and cells

BackgroundModeling of a complex biological process can explain the results of experimental studies and help predict its characteristics. Among such processes is transcription in...Full Text Available

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Genetics of the mammalian phenylalanine hydroxylase system. Studies of human liver phenylalanine hydroxylase subunit structure and of mutations in phenylketonuria.

BackgroundHIV-1 reverse transcriptase (RT) is a heterodimer composed of p66 and p51 subunits and is responsible for reverse transcription of the viral RNA genome into DNA. RT can...Full Text Available

Dimeric subunit stoichiometry of the human voltage-dependent proton channel Hv1

Phenylalanine hydroxylase was purified from crude extracts of human livers which show enzyme activity by usine two different methods: (a) affinity chromatography and (b) immunoprecipitation with an...Full Text Available

1979-08-01

Differential targeting of Tetrahymena ORC to ribosomal DNA and non-rDNA replication origins

In voltage-gated Na⁺, K⁺, and Ca²⁺ channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated...Full Text Available

2008-06-03

Dengue virus protein recognition by virus-specific murine CD8+ cytotoxic T lymphocytes.

The Tetrahymena thermophila origin recognition complex (ORC) contains an integral RNA subunit, 26T RNA, which confers specificity to the amplified ribosomal DNA (rDNA) origin by base...Full Text Available

2009-02-04

Cloning and expression of Drosophila TAFII60 and human TAFII70 reveal conserved interactions with other subunits of TFIID.

The identification of the protein targets for dengue virus-specific T lymphocytes may be useful for planning the development of subunit vaccines against dengue. We studied the recognition by murine...Full Text Available

1993-02-01

Characterization of T-Even Bacteriophage Substructures

Regulation of transcription initiation by RNA polymerase II requires TFIID, a multisubunit complex composed of the TATA binding protein (TBP) and at least seven tightly associated factors (TAFs). Some TAFs act as direct targets or coactivators for promoter-specific activators while others serve as interfaces for TAF-TAF interactions. Here, we report the molecular cloning, expression and characterization of Drosophila dTAFII60 and its human homolog, hTAFII70. Recombinant TAFII60/70 binds weakly to TBP and tightly to the largest subunit of TFIID, TAFII250. In the presence of TAFII60/70, TBP and TAFII250, a stable ternary complex is formed. Both the human and Drosophila proteins directly interact with another TFIID subunit, dTAFII40. Our findings reveal that Drosophila TAFII60 and human TAFII70 share a high degree of structural similarity and that their interactions with other subunits of TFIID are conserved.Images

1993-12-15

Chaperonin Containing T-Complex Polypeptide Subunit Eta (CCT-eta) Is a Specific Regulator of Fibroblast Motility and Contractility

Tail plates obtained from T4D amber mutants were examined with respect to sedimentation behavior, subunit molecular weights, amino acid composition, isoelectric points, and morphology. Intact plates...Full Text Available

1970-10-01

Antisense Expression of the CK2 ?-Subunit Gene in Arabidopsis. Effects on Light-Regulated Gene Expression and Plant Growth1

Integumentary wounds in mammalian fetuses heal without scar; this scarless wound healing is intrinsic to fetal tissues and is notable for absence of the contraction seen in postnatal (adult) wounds....Full Text Available

Antibodies to synthetic peptides from the tubulin regulatory domain interact with tubulin and microtubules.

The protein kinase CK2 (formerly casein kinase II) is thought to be involved in light-regulated gene expression in plants because...Full Text Available

1999-03-01

Altering the ribosomal subunit ratio in yeast maximizes recombinant protein yield

The carboxyl-terminal region of tubulin alpha and beta subunits plays a major role in regulating its assembly into microtubules and constitutes an essential domain for the selective interaction of microtubule-associated...Full Text Available

1988-09-01

A model for the single stranded random coil form of polydeoxyadenylic acid from minimum energy conformations of the dimeric subunit.

BackgroundThe production of high yields of recombinant proteins is an enduring bottleneck in the post-genomic sciences that has yet to be addressed in a truly rational manner. Typically...Full Text Available

A Mitochondrial Superoxide Signal Triggers Increased Longevity in Caenorhabditis elegans

The minimum energy conformations of dApdA have been examined for their suitability as buildings blocks of the single stranded coil form of polynucleotides. Calculations of the characteristic ratio C...Full Text Available

1978-09-01

The molybdenum iron-sulphur protein from Desulfovibrio gigas as a form of aldehyde oxidase.

The nuo-6 and isp-1 genes of C. elegans encode, respectively, subunits of complex I and III of the mitochondrial respiratory chain. Partial loss-of-function...Full Text Available

2010-12-01

Neutrophil-endothelial cell interaction. Evidence for and mechanisms of the self-protection of bovine microvascular endothelial cells from hydrogen peroxide-induced oxidative stress.

The molybdenum iron-sulphur protein originally isolated from Desulfovibrio gigas by Moura, Xavier, Bruschi, Le Gall, Hall & Cammack [(1976) Biochem. Biophys. Res. Commun. 72, 782-789] has been...Full Text Available

1987-05-01

Exploiting the beneficial effects of PPO on the utilisation of protein and lipids in grazed forages

Bovine microvascular endothelial cells (MEC) were able to degrade the H2O2 generated by phorbol myristate acetate-activated bovine neutrophils or by glucose oxidase with a maximal capacity of 4.0 +/-...Full Text Available

1986-08-01

Environmental Research Database

DescriptionThe plant enzyme polyphenol oxidase (PPO) has been demonstrated to reduce both proteolysis and lipolysis during the ensiling of red clover. The purpose of this work is to explore the potential for exploiting this beneficial trait in other dietary regimes for grazing ruminants. These studies will focus on the development of new strategies for forage management and livestock feeding by increasing the efficiency of feed protein-N utilisation and reducing saturated fatty acid production by ruminan [continued...

2007-01-31

The neuronal nicotinic acetylcholine receptor {alpha}7 subunit gene: Cloning, mapping, structure, and targeting in mouse

Structural determinants of alpha-bungarotoxin binding to the sequence segment 181-200 of the muscle nicotinic acetylcholine receptor #alpha# subunit: Effects of cysteine/cystine modification and species-specific amino acid substitution

The neuronal nicotinic acetylcholine receptor {alpha}7 subunit is a member of a family of ligand-gated ion channels, and is the only subunit know to bind {alpha}-bungarotoxin in mammalian brain. {alpha}-Bungarotoxin binding sites are known to be more abundant in the hippocampus of mouse strains that are particularly sensitive to nicotine-induced seizures. The {alpha}7 receptor is highly permeable to calcium, which could suggest a role in synaptic plasticity in the nervous system. Auditory gating deficiency, an abnormal response to a second auditory stimulus, is characteristic of schizophrenia. Mouse strains that exhibit a similar gating deficit have reduced hippocampal expression of the {alpha}7 subunit. We have cloned and sequenced the full length cDNA for the mouse {alpha}7 gene (Acra-7) and characterized its gene structure. The murine {alpha}7 shares amino acid identity of 99% and 93% with the rat and human {alpha}7 ...

1994-09-01

Engineered ketol-acid reductoisomerase and alcohol dehydrogenase enable anaerobic 2-methylpropan-1-ol production at theoretical yield in Escherichia coli

The sequence segment 181-200 of the Torpedo nicotinic acetylcholine receptor (nAChR) #alpha#subunit forms a binding site for #alpha#-bungarotoxin (#alpha#-BTX). Synthetic peptides corresponding to the homologous sequences of human, calf, mouse, chicken, frog, and cobra muscle nAChR #alpha#1 subunits were tested for their ability to bind "1"2"5I-#alpha#-BTX, and differences in #alpha#-BTX affinity were determined by using solution (IC_5_0s) and solid-phase (K_ds) assays. Panels of overlapping peptides corresponding to the complete #alpha#1 subunit of mouse and human were also tested for #alpha#-BTX binding, but other sequence segments forming the #alpha#-BTX site were not consistently detectable. The role of a putative vicinal disulfide bound between Cys-192 and -193, relative to the Torpedo sequence, was determined by modifying the peptides with sulfhydryl reagents. Reduction and alkylation of the peptides decreased ...

British Library Electronic Table of Contents (United Kingdom)

2-methylpropan-1-ol (isobutanol) is a leading candidate biofuel for the replacement or supplementation of current fossil fuels. Recent work has demonstrated glucose to isobutanol conversion through a modified amino acid pathway in a recombinant organism. Although anaerobic conditions are required for an economically competitive process, only aerobic isobutanol production has been feasible due to an imbalance in cofactor utilization. Two of the pathway enzymes, ketol-acid reductoisomerase and alcohol dehydrogenase, require nicotinamide dinucleotide phosphate (NADPH); glycolysis, however, produces only nicotinamide dinucleotide (NADH). Here, we compare two solutions to this imbalance problem: (1) over-expression of pyridine nucleotide transhydrogenase PntAB and (2) construction of an NADH-de...

2011-01-01

100

Distinguishing two groups of flavin reductases by analyzing the protonation state of an active site carboxylic acid

British Library Electronic Table of Contents (United Kingdom)

Abstract Flavin-containing reductases are involved in a wide variety of physiological reactions such as photosynthesis, nitric oxide synthesis, and detoxification of foreign compounds, including therapeutic drugs. Ferredoxin-NADP(H)-reductase (FNR) is the prototypical enzyme of this family. The fold of this protein is highly conserved and occurs as one domain of several multidomain enzymes such as the members of the diflavin reductase family. The enzymes of this family have emerged as fusion of a FNR and a flavodoxin. Although the active sites of these enzymes are very similar, different enzymes function in opposite directions, that is, some reduce oxidized nicotinamide adenine dinucleotide phosphate (NADP+) and some oxidize reduced nicotinamide adenine dinucleotide phosphate (NADPH). In t...

2011-01-01

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Differentiation to adipocytes in accompanied by an increase in the amounts of Gi- and Go-proteins in 3T3-L1 cells

Cloning and mapping of the mouse {alpha}7-neuronal nicotinic acetylcholine receptor

Treatment of cultures of 3T3-L1 cells with methylisobutyl-xanthine and dexamethasone has been shown to result in accumulation of lipid and conversion to the morphology of adipocytes in more than 90% of the cells. The status of the stimulatory (Gs), inhibitory (Gi) and Go-proteins during the course of 3T3-L1 differentiation was examined. The amount of alpha subunit of Gs (#alpha#Gs), assayed by radiolabeling in the presence of cholera toxin and ["3"2P]NAD"+, increased upon differentiation as previously described by others. The amounts of #alpha#Gi and #alpha#Go assayed by radiolabeling in the presence of pertussis toxin and ["3"2P]NAD"+ increased 3-fold upon differentiation. Immunoblots of cell membranes subjected to gel electrophoresis in sodium dodecyl sulfate were probed with two rabbit antisera raised against bovine brain #alpha#Go and with one raised against the#beta#-subunit of the bovine rod-outer-segment G-protein, referred to as ...

1986-06-08

102

Microwave radiation effects on the thermally driven oxidase of erythrocytes

We report the isolation of cDNA clones for the mouse {alpha}7 neuronal nicotinic acetylcholine receptor subunit (gene symbol Acra7), the only nicotinic receptor subunit known to bind a-bungarotoxin in mammalian brain. This gene may have relevance to nicotine sensitivity and to some electrophysiologic findings in schizophrenia. The mouse {alpha}7 subunit gene encodes a protein of 502 amino acids with substantial identity to the rat (99.6%), human (92.8%), and chicken (87.5%) amino acid sequences. The {alpha}7 gene was mapped to mouse chromosome 7 near the p locus with the following gene order from proximal to distal: Myod1-3.5 {+-}1.7 cM-Gas2-0.9 cM {+-} 0.9 cM-D7Mit70-1.8 {+-} 1.2 cM- Acra7-4.4 {+-}1.0 cM-Hras1-ps11/Igf1r/Snrp2a. The human gene was confirmed to map to the homologous region of human chromosome 15q13-q14. 26 refs., 3 figs.

1995-03-20

103

The Morphology, Ontogeny, and Small Subunit rRNA Gene Sequence Analysis of Diophrys parappendiculata n. sp. (Protozoa, Ciliophora, Euplotida), a New Marine Ciliate from Coastal Waters of Southern China

Sheep red blood cells (SRBCs) were labelled with a concanavalin A-luminol-bovine serum albumin conjugate specific for the transmembrane anion transport protein (Band 3) and exposed to 2450-MHz continuous-wave microwave radiation at an average specific absorption rate of 91W/kg for 10 min. The temperature was held constant at 25, 37, 40, 42, or 45C with an airflow heat-exchange system. Following exposure to microwave or air heating, the decrease in residual base-activated chemiluminescence (CL) of the SRBCs was measured as an indication of infield oxidase activity. Air heating resulted in a significant decrease in residual CL at temperatures above 37C (74% decrease at 45C). Microwave radiation inhibited the decline in residual CL above 37C. At 45C the inhibition was 40%. The results suggest microwave radiation either reversibly altered the thermodynamics of oxygen binding to haemoglobin or failed to energize a significant portion of the haemoglobin molecules in each ...

1986-01-01

104

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT. The morphology, morphogenesis, and phylogeny of Diophrys parappendiculata n. sp., a large marine ciliate isolated from the coastal waters of Daya Bay, southern China, were investigated. This new species is characterized by a combination of its large size, appendiculata-pattern of ciliature, and bipartite adoral zone of membranelles. The main stages of morphogenesis during binary fission were also recorded and described. Comparisons of morphological characteristics with similar congeners support the validity of the new species. The small subunit rRNA gene sequence of D. parappendiculata is 96.3-99.94% similar to those of four other congeners; it differs in four nucleotides from that of Diophrys appendiculata (i.e. structural similarity was 99.94%). Phylogenetic analysis indicates ...

2011-01-01

105

Synthesis and luminescence of Eu"3"+ and Tb"3"+ complexes with novel calix[4]arene ligands carrying 2,2'-bipyridine subunits

Molecular environment of the IIId subdomain of the IRES element of hepatitits C virus RNA on the human 40S ribosomal subunit

Eu"3"+ and Tb"3"+ complexes with novel branched calix[4]arene ligands incorporating 2,2' -bipyridine subunits functionalized in the 6- or 5,5'-positions have been synthesized and their photophysical properties investigated. High luminescence intensity was obtained for the Eu"3"+ complex of the calix[4]arene ligand carrying four 5,5' -substituted- 2,2' -bipyridines, which has high molar extinction coefficients (#epsilon#_m_a_x 39 600 M"-"1 cm"-"1) and a high luminescence quantum yield (15%). (authors). 12 refs., 2 figs., 1 tab.

1995-01-01

106

British Library Electronic Table of Contents (United Kingdom)

The molecular environment of the key subdomain IIId of the internal ribosome entry site (IRES) element of hepatitis C virus (HCV) RNA in the binary complex with the human 40S ribosomal subunit was studied. To this end, HCV IRES derivatives bearing perfluorophenylazido groups activatable by mild UV at nucleotides G263 or A275 in the subdomain IIId stem were used. They were prepared by the complementary addressed modification of the corresponding RNA transcript with alkylating oligodeoxyribonucleotide derivatives. None of the RNA derivatives were shown to be crosslinked to the 18S rRNA. It was found that the photoreactive groups of the IRES G263 and A275 nucleotides are crosslinked to ribosomal proteins S3a, S14, and S16. For the IRES derivative with the photoreactive group in nucleotide G26...

2009-01-01

107

Human and rat mast cell high-affinity immunoglobulin E receptors: Characterization of putative. alpha. -chain gene products

Cardiac Channelopathies and Sudden Infant Death Syndrome

The authors have cloned and determined the entire nucleotide sequence of cDNAs corresponding to the putative {alpha} subunits of the human and rat mast cell high-affinity IgE receptors. Both human and rat cDNAs encode an NH{sub 2}-terminal signal peptide, two immunoglobulin-like extracellular domains (encoded by discrete exons), a hydrophobic transmembrane region, and a positively charged cytoplasmic tail. The human and rat {alpha} subunits share an overall homology with one another and the immunoglobulin gene family, suggesting that they arose from a common ancestral gene and continue to share structural homology with their ligands. In addition, the rat gene is transcribed into at least three distinct forms, each of which yields a somewhat different coding sequence.

1988-03-01

108

British Library Electronic Table of Contents (United Kingdom)

Abstract Sudden infant death syndrome (SIDS) is always a devastating and unexpected occurrence. SIDS is the leading cause of death in the first 6 months after birth in the industrialized world. Since the discovery in 1998 of long QT syndrome as an underlying substrate for SIDS, around 10-20% of SIDS cases have been proposed as being caused by genetic variants in either ion channel or ion channel-associated proteins. Until now, 10 cardiac channelopathy susceptibility genes have been found to be implicated in the pathogenesis of SIDS. Four of the genes encode cardiac ion channel a-subunits, 3 genes encode ion channel b-subunits, and 3 genes encode other channel-interacting proteins. All 10 genes have been associated with primary electrical heart diseases. SIDS may hereby be the initial sympt...

2011-01-01

109

Spectral studies of intermediate species formed in one-electron reactions of bovine liver catalase at room and low temperatures. A comparison with peroxidase reactions

[The indicators of biological age and accelerated aging in liquidators of the consequences of radiation emergency].

The reactions of native bovine catalase with superoxide and solvated electrons have been investigated using three different methods for generating these reducing substrates: [gamma]-radiolysis of oxygenated or deaerated buffer solutions in the presence of an OH radical scavenger; either xanthine or acetaldehyde with xanthine oxidase; and low-temperature (77 K) [gamma]-radiolysis of buffered ethylene glycol/water solutions with subsequent annealing of samples at 183 K. (Author).

1992-11-01

110

Wake-up-call, a lin-52 paralogue, and Always early, a lin-9 homologue physically interact, but have opposing functions in regulating testis-specific gene expression

The biological age (BA) of the majority of the liquidators of the consequences of the radiation accidents in the Navy and of the liquidators of the Chernobyl' APS accident exceeds the medium standard and the DBA (due BA). The index of the BA can be a characteristic of the influence of the social-hygienic factors on the health condition of the Special Risk Subunit--the liquidators of the consequences of the radiation accidents. It was established, that the radiation influence concerns to the factors dramatically increasing the BA and the rate of senescence of the liquidators of the consequences of the radiation accidents. PMID:21809627

2011-01-01

111

The k43 gene, required for chorion gene amplification and diploid cell chromosome replication, encodes the Drosophila homolog of yeast origin recognition complex subunit 2

A conserved multi-subunit complex (MybMuvB, MMB), regulates transcriptional activity of many different target genes in Drosophila somatic cells. A paralogous complex, tMAC, controls...Full Text Available

2011-07-15

112

The ?-Subunit of the Arabidopsis Heterotrimeric G Protein, GPA1, Is a Regulator of Transpiration Efficiency¹^[C]^[W]^[OA]

Lethal alleles of the Drosophila k43 gene result in small or missing imaginal discs, greatly reduced mitotic index, and fragmented and abnormally condensed chromosomes. A female-sterile...Full Text Available

1997-04-15

113

Structural features underlying selective inhibition of protein kinase CK2 by ATP site-directed tetrabromo-2-benzotriazole

Land plants must balance CO₂ assimilation with transpiration in order to minimize drought stress and maximize their reproductive success. The ratio of assimilation to transpiration is called...Full Text Available

2010-04-01

114

Protein dynamics. Vibrational coupling, spectral broadening mechanisms, and anharmonicity effects in carbonmonoxy heme proteins studied by the temperature dependence of the Soret band lineshape.

Two novel crystal structures of Zea mays protein kinase CK2α catalytic subunit, one in complex with the specific inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) and another...Full Text Available

2001-11-01

115

Pore properties and pharmacological features of the P2X receptor channel in airway ciliated cells

In this work we study the temperature dependence of the Soret band lineshape of the carbonmonoxy derivatives of sperm whale myoglobin, human hemoglobin, and its isolated alpha and beta subunits. To...Full Text Available

1992-08-01

116

Mutations at the accommodation gate of the ribosome impair RF2-dependent translation termination

Airway ciliated cells express an ATP-gated P2X receptor channel of unknown subunit composition (P2X_cilia) which is modulated by Na⁺ and by long exposures to ATP. P2X_cilia...Full Text Available

2006-03-15

117

Molecular basis of adult-onset and chronic GM2 gangliosidoses in patients of Ashkenazi Jewish origin: substitution of serine for glycine at position 269 of the alpha-subunit of beta-hexosaminidase.

During protein synthesis, aminoacyl-tRNA (aa-tRNA) and release factors 1 and 2 (RF1 and RF2) have to bind at the catalytic center of the ribosome on the 50S subunit where they take part in peptide bond...Full Text Available

2010-09-01

118

Interdependent Roles for Accessory KChIP2, KChIP3 and KChIP4 Subunits in the Generation of Kv4-encoded I_A Channels in Cortical Pyramidal Neurons

Chronic and adult-onset GM2 gangliosidoses are neurological disorders caused by marked deficiency of the A isoenzyme of beta-hexosaminidase; they occur in the Ashkenazi Jewish population, though less...Full Text Available

1989-04-01

119

Fusion of GFP to the M.EcoKI DNA methyltransferase produces a new probe of Type I DNA restriction and modification enzymes

The rapidly activating and inactivating voltage-dependent outward K⁺ (Kv) current, I_A, is widely expressed in central and peripheral neurons. I_A has long been...Full Text Available

2010-10-13

120

False-Positive Results in a Recombinant Severe Acute Respiratory Syndrome-Associated Coronavirus (SARS-CoV) Nucleocapsid-Based Western Blot Assay Were Rectified by the Use of Two Subunits (S1 and S2) of Spike for Detection of Antibody to SARS-CoV

AbstractWe describe the fusion of enhanced green fluorescent protein to the C-terminus of the HsdS DNA sequence-specificity subunit of the Type I DNA modification methyltransferase M.EcoKI....Full Text Available

2010-07-23

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121

Application of a Newly Developed ARB Software-Integrated Tool for In Silico Terminal Restriction Fragment Length Polymorphism Analysis Reveals the Dominance of a Novel pmoA Cluster in a Forest Soil

To evaluate the reactivity of the recombinant proteins expressed in Escherichia coli strain BL21(DE3), a Western blot assay was performed by using a panel of 78 serum samples obtained,...Full Text Available

2006-03-01

122

Activation and Stiffness of the Inhibited States of F₁-ATPase Probed by Single-molecule Manipulation

TRF-CUT, an ARB-implemented tool, was developed to predict in silico the terminal restriction fragments of aligned small-subunit rRNA gene or functional gene sequences. Application of this new tool...Full Text Available

2005-03-01

123

The anti-snake venom properties of Tamarindus indica (leguminosae) seed extract

F₁-ATPase (F₁), a soluble portion of F_oF₁-ATP synthase (F_oF₁), is an ATP-driven motor in which γϵ subunits rotate in...Full Text Available

2010-04-09

124

British Library Electronic Table of Contents (United Kingdom)

In Indian traditional medicine, various plants have been used widely as a remedy for treating snakebites. The aim of this study was to evaluate the effect of Tamarindus indica seed extract on the pharmacological as well as the enzymatic effects induced by V. russelli venom. Tamarind seed extract inhibited the PLA2, protease, hyaluronidase, L-amino acid oxidase and 5prime-nucleotidase enzyme activities of venom in a dose-dependent manner. These are the major hydrolytic enzymes responsible for the early effects of envenomation, such as local tissue damage, inflammation and hypotension. Furthermore, the extract neutralized the degradation of the Bb chain of human fibrinogen and indirect hemolysis caused by venom. It was also observed that the extract exerted a moderate effect on the clotting ...

2006-01-01

125

Specialized Circuits from Primary Visual Cortex to V2 and Area MT

British Library Electronic Table of Contents (United Kingdom)

SummaryPrimary visual cortex recombines inputs from magnocellular (M) and parvocellular (P) streams to create functionally specialized outputs. Understanding these input-output relationships is complicated by the fact that layer 4B, which provides outputs to dorsal visual areas, contains multiple cell types. Using a modified rabies virus that expresses green fluorescent protein, we show that layer 4B neurons projecting to MT are a majority spiny stellate, whereas those projecting to V2 are overwhelmingly pyramidal. Regardless of cell type, MT-projecting neurons have larger cell bodies, more dendritic length, and are deeper within layer 4B. Furthermore, MT-projecting pyramidal neurons are located preferentially underneath cytochrome oxidase blobs, indicating that MT-projecting neurons of bo...

2007-01-01

126

Molecular prospecting for cryptic species in Phyllodistomum lacustri (Platyhelminthes, Gorgoderidae)

British Library Electronic Table of Contents (United Kingdom)

Rosas-Valdez, R., Choudhury, A. & Prez-Ponce de Len, G. (2011). Molecular prospecting for cryptic species in Phyllodistomum lacustri (Platyhelminthes, Gorgoderidae). -Zoologica Scripta, 40, 296-305. Partial sequences of the 28S ribosomal RNA and cytochrome c oxidase I (COI) genes were compared among populations of a widely distributed and morphologically uniform digenean species in North America, Phyllodistomum lacustri, a parasite characteristically associated with ictalurid catfishes. Specimens were collected from the urinary bladder of ictalurid hosts in six localities of North America, spanning most of the latitudinal range of this freshwater fish group. Sequences of other congeneric species, including a potentially close relative, P.-staffordi, were also obtained and used for comparis...

2011-01-01

127

Glucose Biosensor Based on the Fabrication of Glucose Oxidase in the Bio-Inspired Polydopamine-Gold Nanoparticle Composite Film

British Library Electronic Table of Contents (United Kingdom)

Abstract A highly efficient enzyme immobilization method has been developed for electrochemical biosensors using polydopamine films with gold nanoparticles (AuNPs) embedded. This simple enzyme fabrication method can be performed in very mild conditions and stored in a long time with high bioactivity. The fabricated amperometric glucose biosensor exhibited a high and reproducible sensitivity, wide linear dynamic range and low limit of detection (LOD) (0.1 molL-1). A low value of 1.5 mmolL-1 for the apparent Michaelis-Menten constant KappM was obtained. The high sensitivity, wide linear range, good reproducibility and stability make this biosensor a promising candidate for portable amperometric glucose biosensor.

2010-01-01

128

Detection of glycoproteins in the Acanthamoeba plasma membrane

Transcription Factor IIA t Is Associated with Undifferentiated Cells and Its Gene Expression Is Repressed in Primary Neurons at the Chromatin Level In Vivo

In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by "1"2"5I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB"3H_4 and galactose oxidase/NaB"3H_4 labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M_r of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with ["3"5S]methionine followed by lectin-Sepharose affinity chromatography and polyacrylamide gel electrophoresis.

129

British Library Electronic Table of Contents (United Kingdom)

The levels of General Transcription Factor (TF) IIA were examined during mammalian brain development and in rat embryo fibroblasts and transformed cell lines. The large TFIIA subunit paralogues ab and t are largely produced in unsynchronized cell lines, yet only TFIIA ab is observed in a number of differentiated tissue extracts. Steady-state protein levels of the TFIIA t, ab, and g subunits were significantly reduced when human embryonal (ec) and hepatic carcinoma cell lines were stimulated to differentiate with either all-trans-retinoic acid (ATRA) or sodium butyrate. ATRA-treated NT2-ec cells required replating to induce a neuronal phenotype and loss of detectable TFIIA t and g proteins. High levels of TFIIA t, ab, and g and Sp factors were identified in extracts from human fetal and rat...

2006-01-01

130

Expression of ribosomal genes in pea cotyledons at the initial stages of germination

Alteration of alpha 1 Na+,K(+)-ATPase "8"6Rb"+ influx by a single amino acid substitution

The time of appearance of newly synthesized rRNAs and ribosomal proteins (r-proteins) in the ribosomes of pea cotyledons (Pisum sativum L.) during germination was investigated. The ribosomal fraction was isolated and analyzed according to the method of germination of the embryo in the presence of labeled precursors or after pulse labeling of the embryos at different stages of germination. For the identification of newly synthesized rRNAs in the ribosomes we estimated the relative stability of labeled RNAs to the action of RNase, the sedimentation rate, the ability to be methylated in vivo in the presence of (/sup 14/C)CH/sub 3/-methionine, and the localization in the subunits of dissociated ribosomes. The presence of newly synthesized r-proteins in the ribosomes was judged on the basis of the electrophoretic similarity in SDS-disc electrophoresis of labeled polypeptides of purified ribosome preparations and of genuine r-proteins, as well as according to the ...

1986-01-20

131

Unraveling photosystems. Final technical report

The sodium- and potassium-dependent adenosine triphosphatase (Na+,K(+)-ATPase) maintains the transmembrane Na+ gradient to which is coupled all active cellular transport systems. The R and S alleles of the gene encoding the Na+,K(+)-ATPase alpha 1 subunit isoform were identified in Dahl salt-resistant (DR) and Dahl salt-sensitive (DS) rats, respectively. Characterization of the S allele-specific Na+,K(+)-ATPase alpha 1 complementary DNA identified a leucine substitution of glutamine at position 276. This mutation alters the hydropathy profile of a region in proximity to T3(Na), the trypsin-sensitive site that is only detected in the presence of Na+. This mutation causes a decrease in the rubidium-86 influx of S allele-specific sodium pumps, thus marking a domain in the Na+,K(+)-ATPase alpha subunit important for K+ transport, and supporting the hypothesis of a putative role of these pumps in hypertension.

132

Single protein omission reconstitution studies of tetracycline binding to the 30S subunit of Escherichia coli ribosomes

This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 leads to the activation of the cryptic psbG2 gene. The genes psbG1 and psbG2 in ...

1997-09-01

133

Dissociation of insulin receptor phosphorylation and stimulation of glucose transport in BC3H-1 myocytes

In previous work the authors showed that on photolysis of Escherichia coli ribosomes in the presence of ({sup 3}H)tetracycline (TC) the major protein labeled is S7, and they presented strong evidence that such labeling takes place from a high-affinity site related to the inhibitory action of TC. In this work they use single protein omission reconstitution (SPORE) experiments to identify those proteins that are important for high-affinity TC binding to the 30S subunit, as measured by both cosedimentation and filter binding assays. With respect to both sedimentation coefficients and relative Phe-tRNA{sup Phe} binding, the properties of the SPORE particles they obtain parallel very closely those measured earlier, with the exception of the SPORE particle lacking S13. A total of five proteins, S3, S7, S8, S14, and S19, are shown to be important for TC binding, with the largest effects seen on omission of proteins S7 and S14. Determination of the protein compositions of ...

1990-06-05

134

B chain is a functional subunit of beta-bungarotoxin for inducing apoptotic death of human neuroblastoma SK-N-SH cells.

The authors have investigated insulin receptor phosphorylation in differentiated cultured BC3H-1 myocytes. As for other insulin-responsive cell systems in partially purified wheat germ agglutinin receptor preparations, insulin stimulates the phosphorylation of its own receptor (95K ..beta..-subunits) in a dose dependent manner (0-400 nM), as identified by immunoprecipitation with antiinsulin receptor antibodies and SDS-PAGE. In the same preparations they show that 12-0-tetradecanyl phorbol acetate (TPA), which in many respect ..beta..-subunits in the same dose dependent manner (0-5 ..mu..M). In addition, antiinsulin receptor antibodies (B-10) also induced phosphorylation of mimics insulin action, also induced phosphorylation of the insulin receptor and HPLC tryptic maps of the /sup 32/P-labeled ..beta..-subunit were identical to those for insulin-induced receptor phosphorylation. However, while insulin and TPA are potent ...

1986-05-01

135

The role of Computerized Tomography in osteoid-osteoma diagnosis

beta-Bungarotoxin (beta-Bgt), a presynaptic phospholipase A(2) (PLA(2)) neurotoxin isolated from the venom of Bungarus multicinctus, consists of A chain and B chain. The goal of the present study is to explore the functional contribution of the two subunits to the toxicity of beta-Bgt. beta-Bgt was found to induce apoptotic death of SK-N-SH cells via elevating intracellular Ca(2+) and intracellular ROS production. Moreover, an activation of p38 MAPK was associated with the cytotoxicity of beta-Bgt. SB202190 (p38 MAPK inhibitor), N-acetylcysteine (antioxidant reagent), 1,2-bis(2-aminophenoxy)ethane-N,N,N,N-tetraacetic acid (BAPTA) (Ca(2+) chelator) and the inhibitors of Ca(2+) release from intracellular depots (ruthenium red and 2-aminoethoxydiphenyl borate) effectively attenuated the cytotoxicity of beta-Bgt. In sharp contrast to the inability of A chain, B chain was able to induce cytotoxic effects on SK-N-SH cells as beta-Bgt did. Abolishment of PLA(2) activity ...

2007-10-13

136

Systems Biology Approach in Chlamydomonas Reveals Connections between Copper Nutrition and Multiple Metabolic Steps[C][W][OA

Alcaptonuria is a rare autosomal recessive metabolic disease, due to the lack of homogentisic acid oxidase. The following accumulation of homogentisic acid brings about a black discoloration of both the urine alcaptonuria) and connective tissue (ochronosis). The ochronotic alterations into joint cartilages cause degenerative arthropathy and osteopenia. The radiological features of three unrelated cases of alcaptonuria are reported. Radiographic abnormalities of ochconotic arthropathy are found in both the spine and the extraspinal joints. In the spine, the progressive calcification and ''vacuum'' phenomenon of disc spaces are the most characteristic findings. Disc space narrowing is associated with calcification and marginal sclerosis of vertebral bodies and is accentuated by osteopenia. Osteophytes are usually absent or of small size; neverthless progressive formation of marginal intervertebral bridges and obliteration of disc spaces at multiple levels ...

1988-01-01

137

Proteins of the kidney microvillar membrane

In this work, we query the Chlamydomonas reinhardtii copper regulon at a whole-genome level. Our RNA-Seq data simulation and analysis pipeline validated a 2-fold cutoff and 10 RPKM (reads per kilobase of mappable length per million mapped reads) (~1 mRNA per cell) to reveal 63 CRR1 targets plus another 86 copper-responsive genes. Proteomic and immunoblot analyses captured 25% of the corresponding proteins, whose abundance was also dependent on copper nutrition, validating transcriptional regulation as a major control mechanism for copper signaling in Chlamydomonas. The impact of copper deficiency on the expression of several O2-dependent enzymes included steps in lipid modification pathways. Quantitative lipid profiles indicated increased polyunsaturation of fatty acids on thylakoid membrane digalactosyldiglycerides, indicating a global impact of copper deficiency on the photosynthetic apparatus. Discovery of a putative plastid copper chaperone and a membrane protease in the thylakoid ...

2011-04-01

138

In-situ synthesis of poly(dimethylsiloxane)-gold nanoparticles composite films and its application in microfluidic systems.

Two methods were used to label pig kidney microvillar membrane proteins from the luminal and cytoplasmic surfaces of closed membrane vesicles. The first method was lactoperoxidase-catalysed radioiodination. Lactoperoxidase and glucose oxidase were positioned inside or outside the vesicles, iodination being initiated by adding glucose and "1"2"5I. After electrophoresis of the proteins, asymmetric labelling patterns on radioautographs were observed. However the major disadvantage of this method was the high degree of intramembrane labelling of the fatty acid chains of membrane lipids. The second method overcame this disadvantage. A new hydophilic photoreagent, 3,5-di("1"2"5I)iodo-4-azidobenzenesulphonate, was transported by a Na"+-dependent system into microvillar vesicles, thus permitting labelling from either side of the membrane when the vesicles were photolysed. The activity of several microvillar peptidases survived the labelling reaction and they could be ...

139

Enzymatic mechanism in low chloride media: influence of glucose oxidase on the electrochemical behaviour of AISI 316L stainless steel; Mecanisme enzymatique en milieux faiblement chlorures: influence de la glucose oxydase sur le comportement electrochimique de l'acier inoxydable AISI 316L

We presented a simple approach for in-situ synthesis of poly(dimethylsiloxane) (PDMS)-gold nanoparticles composite film based on the special characteristics of PDMS itself. It is an environmentally safe synthesis method without the requirement of additional reducing/stabilizing agents. The region where the resulting gold nanoparticles distribute (in the matrix or on the surface of the polymer) and the size of the nanoparticles, as well as the colour of the free-standing films, can be simply controlled by adjusting the ratio of curing agent and the PDMS monomer. The chemical and optical properties of these composite films were studied. Using such a method, gold nanoparticle micropatterns on PDMS surfaces can be performed. And based on the gold nanoparticles micropattern, further modification with antibodies, antigens, enzymes and other biomolecules can be achieved. To verify this ability, an immobilized glucose oxidase (GOx) reactor in microchannels was built and ...

2007-11-14

140

Unfolding analysis of the mature and unprocessed forms of Bacillus licheniformis ?-glutamyltranspeptidase

The open circuit potential (OCP) of stainless steels immersed in natural waters generally increases with time. This phenomenon is strongly linked to the formation of a bio-film on the surface. Several studies have proved that the bio-film modifies the reaction of reduction of dissolved oxygen and that it acts mainly on the cathodic processes. One of the hypotheses explaining the action of the bio-film involves certain bacteria which use dissolved oxygen and extracellular enzymes to produce reactive oxygen species. Among this kind of metabolites is hydrogen peroxide H{sub 2}O{sub 2}. This compound interacts with the passive layer of stainless steels and affects their electrochemical behaviour, even when the chloride concentration is low. The aim of this work is to study the influence of an enzymatic reaction (of the oxidoreductase type) on anodic and cathodic processes on AISI 316L stainless steel. Experiments are carried out in two artificial electrolytes simulating natural fresh ...

2006-07-01

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141

British Library Electronic Table of Contents (United Kingdom)

Bacillus licheniformis ?-glutamyltranspeptidase (BlGGT) undergoes an autocatalytic process to generate 44.9 and 21.7?kDa subunits; however, a mutant protein (T399A) loses completely the processing ability and mainly exists as a precursor. For a comprehensive understanding of their structural features, the biophysical properties of these two proteins were investigated by circular dichroism and fluorescence spectroscopy. Tryptophan fluorescence and circular dichroism spectra were nearly identical for BlGGT and T399A, but unfolding analyses revealed that these two proteins had a different sensitivity towards temperature- and guanidine hydrochloride (GdnHCl)-induced denaturation. BlGGT and the unprocessed T399A displayed T m values of 61.4?C and 68.1?C, respectively, and thermal unfolding of b...

2011-01-01

142

Synthetic enantiopure aziridinomitosenes: preparation, reactivity, and DNA alkylation studies.

Preliminary crystallographic analysis of a possible transcription factor encoded by the mimivirus L544 gene

An enantiocontrolled route to aziridinomitosenes had been developed from l-serine methyl ester hydrochloride. The tetracyclic target ring system was assembled by an internal azomethine ylide cycloaddition reaction based on silver ion-assisted intramolecular oxazole alkylation and cyanide-induced ylide generation via a labile oxazoline intermediate (62 to 66). Other key steps include reductive detritylation of 26, methylation of the N-H aziridine 56, oxidation of the sensitive cyclohexenedione 68 to quinone 70, and carbamoylation using Fmoc-NCO. Although the aziridinomitosene tetracycle is sensitive, a range of protecting group manipulations and redox chemistry can be performed if suitable precautions are taken. A study of DNA alkylation by the first C-6,C-7-unsubstituted aziridinomitosene 11a has been carried out, and evidence for DNA cross-link formation involving nucleophilic addition to the quinone subunit is described. PMID:14677970

2003-12-24

143

British Library Electronic Table of Contents (United Kingdom)

Mimivirus is the prototype of a new family (the Mimiviridae) of nucleocytoplasmic large DNA viruses (NCLDVs), which already include the Poxviridae, Iridoviridae, Phycodnaviridae and Asfarviridae. Mimivirus specifically replicates in cells from the genus Acanthamoeba. Proteomic analysis of purified mimivirus particles revealed the presence of many subunits of the DNA-directed RNA polymerase II complex. A fully functional pre-transcriptional complex appears to be loaded in the virions, allowing mimivirus to initiate transcription within the host cytoplasm immediately upon infection independently of the host nuclear apparatus. To fully understand this process, a systematic study of mimivirus proteins that are predicted (by bioinformatics) or suspected (by proteomic analysis) to be involved in...

2011-01-01

144

Mitochondrial DNA background modulates the assembly kinetics of OXPHOS complexes in a cellular model of mitochondrial disease

British Library Electronic Table of Contents (United Kingdom)

Lebers hereditary optic neuropathy (LHON), the most frequent mitochondrial disorder, is mostly due to three mitochondrial DNA (mtDNA) mutations in respiratory chain complex I subunit genes: 3460/ND1, 11778/ND4 and 14484/ND6. Despite considerable clinical evidences, a genetic modifying role of the mtDNA haplogroup background in the clinical expression of LHON remains experimentally unproven. We investigated the effect of mtDNA haplogroups on the assembly of oxidative phosphorylation (OXPHOS) complexes in transmitochondrial hybrids (cybrids) harboring the three common LHON mutations. The steady-state levels of respiratory chain complexes appeared normal in mutant cybrids. However, an accumulation of low molecular weight subcomplexes suggested a complex I assembly/stability defect, which was ...

2008-01-01

145

Mapping of the human cone transducin {alpha}-subunit (GNAT2) gene to 1p13 and negative mutation analysis in patients with Stargardt disease

Lack of Association of the Genotype in the GNAS Fok I Polymorphism and Prostate Cancer

We report localization of the human cone transducin (GNAT2) gene using fluorescence in situ hybridization on chromosome 1 in band p13. The recent assignment of a gene for Stargardt disease to the same chromosomal region by linkage analysis prompted us to investigate the possible role of GNAT2 in the pathogenesis of this disease. We investigated 66 unrelated patients for mutations in the coding region of the GNAT2 gene using polymerase chain reaction-single strand conformation polymorphism analysis (SSCP) and direct sequencing. No disease-specific mutations were found, indicating that GNAT2 is probably not involved in the pathogenesis of most cases of Stargardt disease. 19 refs., 1 fig., 1 tab.

1995-01-01

146

British Library Electronic Table of Contents (United Kingdom)

Abstract Background: G proteins are ubiquitously expressed signal transduction proteins playing a key role in multiple signal transduction pathways. The Gas subunit has been considered as an apoptosis factor. In this study the role of GNAS T393C genotypes of the GNAS gene encoding Gas was analyzed for its influence on the development and progression of prostate cancer. Methods: Genotyping of the GNAS T393C polymorphism in 196 prostate cancer patients and 200 healthy controls was performed by DNA extraction followed by PCR and restriction analysis. Results: We observed no evidence of effects related to GNAS T393C genotype as demonstrated by a comparison of the genotype distribution in prostate cancer patients and healthy controls, the genotype distribution dependent on grade of the primary ...

2011-01-01

147

Intravascular pressure augments cerebral arterial constriction by inducing voltage insensitive Ca2+ waves

British Library Electronic Table of Contents (United Kingdom)

This study examined whether elevated intravascular pressure stimulates asynchronous Ca2+ waves in cerebral arterial smooth muscle cells and if their generation contributes to myogenic tone development. The endothelium was removed from rat cerebral arteries, which were then mounted in an arteriograph, pressurized (20 100 mmHg) and examined under a variety of experimental conditions. Diameter and membrane potential (VM) were monitored using conventional techniques; Ca2+ wave generation and myosin light chain (MLC20)/MYPT1 (myosin phosphatase targeting subunit) phosphorylation were assessed by confocal microscopy and Western blot analysis, respectively. Elevating intravascular pressure increased the proportion of smooth muscle cells firing asynchronous Ca2+ waves as well as event frequency. C...

2010-01-01

148

Hydrophobic labelling of membrane-embedded proteins with lipophilic reagents

Degradation of leucine zipper-positive isoform of MYPT1 may contribute to development of nitrate tolerance

Hydrophobic labelling is frequently used in the study of membrane-inserted domains of intrinsic proteins. However, the published procedures, fail to incorporate sufficient radioactivity into membrane immunoglobulins of B lymhocytes to permit investigation of their subunit structures and associations with other proteins. In order to increase the specific radioactivity of ["1"2"5I]iodonaphtylazide ["1"2"5I]INA), an improved method for the synthesis of the reagent was developed. In addition, the optimal conditions for labelling B lymhpocytes with ["1"2"5I]INA and commercially available reagent 3-(trifluoromethyl)-3-(trifluoromethyl)-3-(3'-["1"2"5Iliodophenyl)diazirine (["1"2"5I]TID were isolated and analysed in detail by SDS-PAGE. The usefulness of the two reagents for the investigation of lipid-embedded domains of membrane proteins is discussed. (author). 28 refs.; 4 figs.

149

British Library Electronic Table of Contents (United Kingdom)

Aims A depressed cGMP-dependent protein kinase (PKG) activity is implicated in nitrate tolerance. The present study determines whether the leucine zipper-positive (LZ+) isoform of myosin phosphatase target subunit 1 (MYPT1), a key target protein for PKG actions, is involved in the development of nitrate tolerance. Methods and results Nitrate tolerance in in vitro preparations was obtained by a 24 h incubation with nitroglycerin (NTG). Nitrate tolerance in in vivo preparations was obtained by subcutaneous injection of mice with NTG, and the aortas were used. Protein levels of total MYPT1, MYPT1 (LZ+), PP1Cd, myosin light chain (MLC), and phosphorylated MLC were determined by Western blot analysis. Isometric vessel tension was determined by an organ chamber technique. Protein levels of MYPT1...

2010-01-01

150

Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins

Bacteriophage P22 capsid size determination: Roles for the coat protein telokin-like domain and the scaffolding protein amino-terminus

Cholera toxin catalyzes transfer of radiolabel from ["3"2P]NAD"+ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and ["3"2P]NAD"+ caused radiolabeling of purified microtubule and intermediate filament proteins.

1981-01-01

151

British Library Electronic Table of Contents (United Kingdom)

Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a sing...

2011-01-01

152

An oral nervous necrosis virus vaccine using Vibrio anguillarum as an expression host provides early protection

British Library Electronic Table of Contents (United Kingdom)

Oral vaccination is the most desirable immunization method by which to prevent fish disease occurring at the early larval stage. We developed an Escherichia coli-based oral nervous necrosis virus (NNV) subunit vaccine and demonstrated its effectiveness in orange spotted grouper (Epinephelus coioides) fry. However, the incubation period was determined to be over 2weeks. To enhance the efficacy and shorten the incubation period, a safe and digestible biological adjuvant should be found. Vibrio anguillarum, a common marine bacterium with immune-stimulatory capability was selected as an expression host. An expression vector containing its heat shock protein 60 gene (groE) as an inducible promoter was constructed to express recombinant NNV coat protein as an antigen. The recombinant V. anguilla...

2011-01-01

153

A PAC containing the human mitochondrial DNA polymerase gamma gene (POLG) maps to chromosome 15q25

Altered lauric acid metabolism in renal microsomes from spontaneously hypertensive rats (SHR)

The human mitochondrial DNA (mtDNA) is a closed circular, 16,569-bp double-stranded DNA, encoding 13 genes whose protein products are subunits of the oxidative phosphorylation system required for synthesis of most of the ATP consumed by eukaryotic cells. Point mutations of the mtDNA that cause multi-tissue, loss-of-energy syndromes, called mitochondrial encephalomyopathies (e.g., MERRF and MELAS), have been identified. In addition, large-scale deletions of the human mtDNA have been identified and are the molecular bases for the neonatal and adolescent onset loss-of-energy syndromes Pearson and Kearns-Sayer, respectively. 5 refs., 1 fig.

1997-03-01

154

Yeast allosteric chorismate mutase is locked in the activated state by a single amino acid substitution

Studies investigated whether changes in omega- and (omega-1)-hydroxylation (OH) of lauric acid (LA) occurred in renal microsomes prepared from SHR compared to Wistar-Kyoto (WK) control rats. Systolic blood pressure in age-matched adult SHR and WKR were 189 +/- 3 and 123 +/- 4 mm Hg(anti X +/- SE) respectively (p < 0.001). No significant differences between SHR and WKR were seen in body weight, kidney weight or renal microsomal protein content. Renal microsomes, prepared from whole kidneys, were incubated with 10 mM NADPH and ["1"4C]LA at concentrations between 5-50 #mu#M. The 11- and 12-OH metabolites of LA were separated by HPLC using a reverse phase column with a methanol:water:acetic acid (62:37.8:0.2) mobile phase. Apparent (app) V/sub max/ values for 12-OH in WKR and SHR were 0.87 +/- 0.19 vs 1.48 +/- .11 nmoles/mg protein/min (p < 0.05), respectively, while values for 11-OH were 0.51 +/- 0.12 vs 0.60 +/- .07, respectively. No significant differences ...

1986-04-13

155

The application of high resolution sequence stratigraphy to reservoir zonation and management of the Beryl Field

Chorismate mutase, a branch-point enzyme in the aromatic amino acid pathway of Saccharomyces cerevisiae, and also a mutant chorismate mutase with a single amino acid substitution in the C-terminal part of the protein have been purified approximately 20-fold and 64-fold from overproducing strains, respectively. The wild-type enzyme is activated by tryptophan and subject to feedback inhibition by tyrosine, whereas the mutant enzyme does not respond to activation by tryptophan nor inhibition by tyrosine. Both enzymes are dimers consisting of two identical subunits of M_r 30,000, each one capable of binding one substrate and one activator molecule. Each subunit of the wild-type enzyme also binds one inhibitor molecule, whereas the mutant enzyme lost this ability. The enzyme reaction was observed by "1H NMR and shows a direct and irreversible conversion of chorismate to prephenate without the accumulation of any enzyme-free intermediates. The ...

156

Structural definition of the active site and catalytic mechanism of 3,4-dihydroxy-2-butanone 4-phosphate synthase

Tidally dominated sections from the Middle Jurassic Beryl Formation of the Beryl Field, Viking Graben (UKCS) were deposited during rapid changes in relative sea level. High density well coverage in this key producing interval has allowed the construction of an integrated high resolution sequence stratigraphic scheme based on sedimentological, ichnofaunal, wireline, biostratigraphic and engineering data. From this database a number of high resolution sequences in the Bajocian-Bathonian Beryl Formation have been identified composed of interbedded sandstones, siltstones and mudstones. These sediments formed tidally-influenced deltas and estuaries deposited in actively subsiding half-grabens during regionally extensive base-level changes. For reservoir management purposes, the formation has been split into 5 units. The thickest interval, Unit 3, is considered here. In the northern part of the Beryl Field, Unit 3 is bounded above and below by regionally extensive, biostratigraphically ...

1996-08-01

157

Regulation of NMDA and AMPA receptors during the maturation phase of chicken brain development

X-ray crystal structures of L-3,4-dihydroxy-2-butanone-4-phosphate synthase from Magnaporthe grisea are reported for the E-SO{sub 4}{sup 2-}, E-{sub 4}{sup 2-}-Mg{sup 2+}, E-SO{sub 4}{sup 2-}-Mn{sup 2+}, E-SO{sub 4}{sup 2-}-Mn{sup 2+}-glycerol, and E-SO{sub 4}{sup 2-}-Zn{sup 2+} complexes with resolutions that extend to 1.55, 0.98, 1.60, 1.16, and 1.00 {angstrom}, respectively. Active-site residues of the homodimer are fully defined. The structures were used to model the substrate ribulose 5-phosphate in the active site with the phosphate group anchored at the sulfate site and the placement of the ribulose group guided by the glycerol site. The model includes two Mg{sup 2+} cations that bind to the oxygen substituents of the C2, C3, C4, and phosphate groups of the substrate, the side chains of Glu37 and His153, and water molecules. The position of the metal cofactors and the substrate's phosphate group are further stabilized by an extensive hydrogen-bond and salt-bridge ...

2010-03-08

158

Mapping of the human cone transducin {alpha} subunit (GNAT2) gene to 1p13 and mutation analysis in patients with Stargardt`s disease

Full text: The maturation of chicken forebrain is protracted and occurs well after synapse formation providing a good model for studying mechanisms of brain maturation. Using microslices from immature (10 day) and adult chicken forebrain prepared after decapitation, we have examined functional properties of NMDA and AMPA receptors by measuring agonist-induced uptake of "4"5Ca"2"+ . The rate and extent of NMDA induced "4"5Ca"2"+ accumulation decreased during maturation with no change in EC_5_0. The rate and extent of the AMPA induced response also decreased with a 60-fold increase in EC_5_0. However, the total NMDA receptor content did not change as indicated by 3 H-MK801 binding and NR1 immunoreactivity in P2 fractions. Similarly, there was no change in the B_m_a_x of "3H-AMPA, though there was a two-fold increase in K_D, and little or no change in the immunoreactivity in GluR1, 2, 2/3 or 4. These results suggest that it is the regulation of receptors, their ...

2002-02-04

159

Half-Heusler phase related structural perturbations near stoichiometric composition FeZnSb

Transducin {alpha} subunits are members of a large family of G-proteins and play an important role in phototransduction in rod and cone photoreceptors. We report the localization of the human cone {alpha} transducin (GNAT2) gene using fluorescence in situ hybridization (FISH) on chromosome 1 in band p13. The recent assignment of a gene for Stargardt`s disease to the same chromosomal region by linkage analysis prompted us to investigate the possible role of GNAT2 in the pathogenesis of this disease. Stargardt`s disease is characterized by degeneration in late childhood or early adulthood of the macula of the retina, a region rich in cones. We screened patients with Stargardt`s disease, with or without peripheral cone involvement as monitored by the full-field ERG, for mutations in this gene. We investigated 66 unrelated patients including 22 with peripheral cone dysfunction for mutations in the coding region of the GNAT2 gene using polymerase chain reaction-single ...

1994-09-01

160

Cysteinyl peptides of rabbit muscle pyruvate kinase labeled by the affinity label 8-((4-bromo-2,3-dioxobutyl)thio)adenosine 5 prime -triphosphate

Half-Heusler phases XYZ (Pearson symbol cF12) are chemically versatile and rich in physical properties. The half-Heusler phase in the Fe-Zn-Sb ternary system was reported in the year 2000. In this work, two new ternary phases are identified in the vicinity of the equiatomic composition FeZnSb in the same system: Fe1-xZnSb (tetragonal, space group P4/nmm, Pearson symbol tP6-?, Z=2: a=4.1113(6) A, c=6.0127(12) A for x=0.08 (1), and a=4.1274(6) A, c=6.0068(12) A for x=0.12 (2)); and Fe7.87Zn6.72Sb8 (Fe0.98Zn0.84Sb) (3) (cubic, space group Fm-3m, Pearson symbol cF96-?, Z=4, a=11.690(13) A). 1 and 2 crystallize in the PbFCl-type structure, and 3 adopts a unique 2x2x2 supercell of a normal half-Heusler structure. The structures of both the tetragonal and cubic phases can be described as assemblies of half-Heusler structure related subunits. Electrical resistivity measurement on the pure sample of 2 shows it has metallic-like behavior, and its thermal and magnetic ...

2011-05-01

1 2 3 4 5 6 7 8 9 10

161

The TSG-6/HC2-mediated transfer is a dynamic process shuffling heavy chains between glycosaminoglycans

The affinity label 8-((4-bromo-2,3-dioxobutyl)thio)adenosine 5{prime}-triphosphate (8-BDB-TA-5{prime}-TP) reacts covalently with rabbit muscle pyruvate kinase, incorporating 2 mol of reagent/mol of enzyme subunit upon complete inactivation. Protection against inactivation is provided by phosphoenolpyruvate, K{sup +}, and Mn{sup 2+} and only 1 mol of reagent/mol of subunit is incorporated. The authors have now identified the resultant modified residues. After reaction with 8-BDB-TA-5{prime}-TP at pH 7.0, modified enzyme was incubated with ({sup 3}H)NaBH{sub 4} to reduce the carbonyl groups of enzyme-bound 8-BDB-TA-5{prime}-TP and to introduce a radioactive tracer into the modified residues. Following carboxymethylation and digestion with trypsin, the radioactive peptides were separated on a phenylboronate agarose column followed by reverse-phase high-performance liquid chromatography in 0.1% trifluoroacetic acid with an acetonitrile gradient. ...

1990-03-13

162

DEFF Research Database (Denmark)

The heavy chain (HC) subunits of the bikunin proteins are covalently attached to a single chondroitin sulfate (CS) chain originating from bikunin and can be transferred to different hyaluronan (HA) molecules by TSG-6/HC2. In the present study, we demonstrate that HCs transferred to HA may function as HC donors in subsequent transfer reactions, and we show that the CS of bikunin may serve as an HC acceptor, analogous to HA. Our data suggest that TSG-6/HC2 link HCs randomly on the CS chain of bikunin, in contrast to the ordered attachment observed during the biosynthesis. Moreover, the results show that the transfer activity is indifferent to the new HC position, and the relocated HCs are thus prone to further TSG-6/HC2-induced transfer reactions. The data suggest that HCs may be transferred directly from HA to HA without the involvement of the bikunin CS chain. The results demonstrate reversibility of the interactions between HCs and glycosaminoglycans and suggest ...

2010-01-01

163

Synthesis, structural activity-relationships, and biological evaluation of novel amide-based allosteric binding site antagonists in NR1A/NR2B N-methyl-d-aspartate receptors

British Library Electronic Table of Contents (United Kingdom)

The synthesis and structure-activity relationship analysis of a novel class of amide-based biaryl NR2B-selective NMDA receptor antagonists are presented. Some of the studied compounds are potent, selective, non-competitive, and voltage-independent antagonists of NR2B-containing NMDA receptors. Like the founding member of this class of antagonists (ifenprodil), several interesting compounds of the series bind to the amino terminal domain of the NR2B subunit to inhibit function. Analogue potency is modulated by linker length, flexibility, and hydrogen bonding opportunities. However, unlike previously described classes of NR2B-selective NMDA antagonists that exhibit off-target activity at a variety of monoamine receptors, the compounds described herein show much diminished effects against the...

2009-01-01

164

Polymorphism in HTR3D shows different risks for acute chemotherapy-induced vomiting after anthracycline chemotherapy

British Library Electronic Table of Contents (United Kingdom)

Aims: Serotonin (5-hydroxytryptamine 3; 5-HT3) receptors are involved in chemotherapy-induced nausea and vomiting (CINV), and 5-HT3 antagonists are part of the `gold standard' antiemetic treatment during chemotherapy. We investigated the correlation of common variants in 5-HT3 receptor subunit genes with the occurrence of CINV. Materials & methods: A total of 110 previously characterized chemotherapy-naive women with primary breast cancer treated with anthracycline-containing chemotherapy served as a study group for mutational analysis by direct sequencing. Eight common SNPs in the 5-HT3 receptor genes, HTR3A, HTR3B, HTR3D and HTR3E, were selected for association analysis. Results: A nonsynonymous variant in HTR3D, p.G36A (rs6443930), was found to be over-represented in nonresponders, assu...

2010-01-01

165

Phosphorylation of sites 3 and 2 in rabbit skeletal muscle glycogen synthase by a multifunctional protein kinase (ATP-citrate lyase kinase)

Peru-15, an improved live attenuated oral vaccine candidate for Vibrio cholerae O1.

A multifunctional protein kinase, purified from rat liver as ATP-citrate lyase kinase, has been identified as a glycogen synthase kinase. This kinase catalyzed incorporation of up to 1.5 mol of and)2numberSPO4/mol of synthase subunit associated with a decrease in the glycogen synthase activity ratio from 0.85 to a value of 0.15. Approximately 65-70% of the TUPO4 was incorporated into site 3 and 30-35% into site 2 as determined by reverse phase high performance liquid chromatography. This multifunctional kinase was distinguished from glycogen synthase kinase-3 on the basis of nucleotide and protein substrate specificities. Since the phosphate contents in glycogen synthase of sites 3 and 2 are altered in diabetes and by insulin administration, the possible involvement of the multifunctional kinase was explored. Glycogen synthase purified from diabetic rabbits was phosphorylated in vitro by this multifunctional kinase at only 10% of the rate compared to synthase ...

1985-10-05

166

Long-term Retinal Function and Structure Rescue Using Capsid Mutant AAV8 Vector in the rd10 Mouse, a Model of Recessive Retinitis Pigmentosa

Cholera vaccine candidate Peru-15 was derived from a Vibrio cholerae O1 El Tor Inaba strain by deleting the cholera toxin genetic element, introducing the gene encoding cholera toxin B subunit into recA, and screening for nonmotility. In a controlled study, Peru-15 (2 x 10(8) cfu) was administered to 11 volunteers. No vaccinee developed diarrhea, and 10 of 11 had > 4-fold rises in vibriocidal antibody titers. One month later, 5 vaccinees and 5 control volunteers were challenged with wild type V. cholerae O1. Four of 5 controls developed diarrhea (mean, 1.9 L). Two Peru-15 vaccinees developed diarrhea, 1 with < 0.3 L and 1 with approximately 1.0 L; this latter volunteer had not developed a significant vibriocidal immune response to vaccination. Peru-15 shows promise as a single-dose, oral cholera vaccine that is safe, immunogenic, and protective. PMID:7561195

1995-10-01

167

British Library Electronic Table of Contents (United Kingdom)

The retinal degeneration 10 (rd10) mouse is a well-characterized model of autosomal recessive retinitis pigmentosa (RP), which carries a spontaneous mutation in the ? subunit of rod cGMP-phosphodiesterase (PDE?). Rd10 mouse exhibits photoreceptor dysfunction and rapid rod photoreceptor degeneration followed by cone degeneration and remodeling of the inner retina. Here, we evaluate whether gene replacement using the fast-acting tyrosine-capsid mutant AAV8 (Y733F) can provide long-term therapy in this model. AAV8 (Y733F)-smCBA-PDE? was subretinally delivered to postnatal day 14 (P14) rd10 mice in one eye only. Six months after injection, spectral domain optical coherence tomography (SD-OCT), electroretinogram (ERG), optomotor behavior tests, and immunohistochemistry showed tha...

2011-01-01

168

K"A"T"P channels in mesenchymal stromal stem cells: Strong up-regulation of Kir6.2 subunits upon osteogenic differentiation

British Library Electronic Table of Contents (United Kingdom)

The promising use of mesenchymal stromal cells (MSC) in regenerative technologies accounts for necessity of detailed study of their physiology. Proliferation and differentiation of multipotent cells often involve changes in their metabolic state. In the present study, we analyzed the expression of ATP-sensitive potassium (K"A"T"P) channels in MSC and upon in vitro differentiation. K"A"T"P channels are present in many cells and regulate a variety of cellular functions by coupling cell metabolism with membrane potential. Kir6.1, Kir6.2 and SUR2A were expressed in undifferentiated MSC, whereas SUR2B and SUR1 were not detected on cDNA and protein level. Upon adipogenic differentiation Kir6.1 and SUR2A showed a significant reduction of the amount of mRNA by 84% and 95%, respectively, whereas Ki...

2011-01-01

169

Identification of proteins important for tetracycline (TC) binding to ribosomes by single protein omission reconstitution (SPORE) experiments

Final report of the specific research. Investigations on the analysis of bio-protective factors against radiation. 1998-2000 FY (Research Group of NIRS)

TC inhibits protein synthesis in E. coli by interfering with aminoacyl-tRNA binding to the ribosomal A site, and there is strong evidence that such inhibition results from TC binding to a high affinity site on the 30S subunit. The SPORE approach has been used to define those 30S proteins that are potentially important for high affinity TC binding, measured as the (/sup 3/H)-TC co-sedimenting with the reconstitution particle through a sucrose density gradient. Reverse phase-HPLC has been used both to prepare ribosomal proteins and to analyze the protein content of reconstituted particles. The results obtained so far show that protein S7, as well as some proteins linked to S7 in the 30S assembly map, are important for TC binding, whereas other ribosomal proteins are not. These results are in very good accord with their earlier photoaffinity labeling studies that strongly implicated S7 as forming part of the TC binding site. Interestingly, protein S18, which is ...

1987-05-01

170

Doxycycline up-regulates the expression of IL-6 and GM-CSF via MAPK/ERK and NF-kB pathways in mouse thymic epithelial cells

This report concerns investigations in the title conducted by 8 groups of National Institute of Radiological Sciences (NIRS) during the period of 1998-2000. The groups are for investigation of: Effects of p53 tumor suppressor gene in radiation-induced leukemia, Role of atm-gene in dose rate effect of ionizing radiation, Function of DNA-dependent protein kinase catalytic subunit (DNA-PK{sub cs}), Functional complementation of radiation-sensitive mutant M10 cell line by human XRCC4 cDNA expression, Role of radiation-induced apoptosis in digital defects in embryonic mice, Functional analysis of S-phase specific novel nuclear protein NP95 by gene targeting, Role of chemokine in T cell development and lymphomagenesis, and establishment of production techniques of gene-modified mice using embryonic stem cells for genetic analysis of radiation-sensitive genes. The groups describe summaries of their studies and published original articles are also given. (N.I.)

2002-03-01

171

British Library Electronic Table of Contents (United Kingdom)

Thymic epithelial cells (TECs) constitute a major component of the thymic stroma which provides a microenvironment critical for developing thymocytes. We have previously demonstrated that doxycycline (Dox), a tetracycline derivative, enhances the proliferation of the mouse thymic epithelial cell line 1 (MTEC1) via MAPK/ERK signal pathway. Herein we provide evidence that Dox also has profound impact on the cytokine production by MTEC1. Specifically, the expression of IL-6 and GM-CSF, both at mRNA and protein levels, was found to be increased in a time- and dose-dependent manner with the addition of Dox. Western blotting analysis revealed that treatment with Dox-induced phosphorylation of the p65 subunit of NF-kB and ERK. Notably, Dox-induced up-regulation of IL-6 and GM-CSF was largely abol...

2011-01-01

172

Crystal structures of two novel sulfonylurea herbicides in complex with Arabidopsis thaliana acetohydroxyacid synthase

CHRNA5 as negative regulator of nicotine signaling in normal and cancer bronchial cells: effects on motility, migration and p63 expression

Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) is the first enzyme in the biosynthetic pathway of the branched-chain amino acids. It catalyzes the conversion of two molecules of pyruvate into 2-acetolactate or one molecule of pyruvate and one molecule of 2-ketobutyrate into 2-aceto-2-hydroxybutyrate. AHAS requires the cofactors thiamine diphosphate (ThDP), Mg{sup 2+} and FAD for activity. The herbicides that target this enzyme are effective in protecting a broad range of crops from weed species. However, resistance in the field is now a serious problem worldwide. To address this, two new sulfonylureas, monosulfuron and monosulfuron ester, have been developed as commercial herbicides in China. These molecules differ from the traditional sulfonylureas in that the heterocyclic ring attached to the nitrogen atom of the sulfonylurea bridge is monosubstituted rather than disubstituted. The structures of these compounds in complex with the catalytic subunit of Arabidopsis ...

2009-08-17

173

British Library Electronic Table of Contents (United Kingdom)

Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding a3, a5 and b4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR a5 with a-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addit...

2011-01-01

174

An arsenic metallochaperone for an arsenic detoxification pump

Toxicity of ultraviolet-irradiated halothane in mice

Environmental arsenic is a world-wide health issue, making it imperative for us to understand mechanisms of metalloid uptake and detoxification. The predominant intracellular form is the highly mephitic arsenite, which is detoxified by removal from cytosol. What prevents arsenite toxicity as it diffuses through cytosol to efflux systems? Although intracellular copper is regulated by metallochaperones, no chaperones involved in conferring resistance to other metals have been identified. In this article, we report identification of an arsenic chaperone, ArsD, encoded by the arsRDABC operon of Escherichia coli. ArsD transfers trivalent metalloids to ArsA, the catalytic subunit of an As(III)/Sb(III) efflux pump. Interaction with ArsD increases the affinity of ArsA for arsenite, thus increasing its ATPase activity at lower concentrations of arsenite and enhancing the rate of arsenite extrusion. Cells are consequently resistant to environmental concentrations of arsenic. ...

2006-10-17

175

Pyridoxine dependent epilepsy and antiquitin deficiency Clinical and molecular characteristics and recommendations for diagnosis, treatment and follow-up.

One such agent is the widely used anesthetic, halothane. To study the toxicity of u.v. decomposed halothane, mice were exposed to anesthetic concentrations (1.3%) of non- and u.v.-irradiated halothane in oxygen for 90 min. Halothane sleeping times increased from 14.3 min to 72.5 min. Microsomal mixed function oxidase activity decreased, as shown by prolonged pentobarbital sleeping times 1 day after exposure to halothane and irradiated halothane (54.6 min and 149.1 min, respectively, as compared to a 34.6-min control). Quantitative and qualitative differences were found in the amount of (/sup 14/C)-pentobarbital metabolites excreted by u.v. irradiated halothane-exposed mice compared to either oxygen or non-irradiated halothane-exposed groups. In addition, serum glutamic-oxalacetic transaminase (SGOT) of irradiated halothane-exposed mice increased to 233% of the control values, and serum glutamic-pyruvic transaminase (SGPT) were 377% of control values. No significant ...

1982-01-01

176

Characterization of monocyte differentiation-inducing (MDI) factors derived from human fetal membrane chorion cells undergoing apoptosis after influenza virus infection.

Antiquitin (ATQ) deficiency is the main cause of pyridoxine dependent epilepsy characterized by early onset epileptic encephalopathy responsive to large dosages of pyridoxine. Despite seizure control most patients have intellectual disability. Folinic acid responsive seizures (FARS) are genetically identical to ATQ deficiency. ATQ functions as an aldehyde dehydrogenase (ALDH7A1) in the lysine degradation pathway. Its deficiency results in accumulation of ?-aminoadipic semialdehyde (AASA), piperideine-6-carboxylate (P6C) and pipecolic acid, which serve as diagnostic markers in urine, plasma, and CSF. To interrupt seizures a dose of 100mg of pyridoxine-HCl is given intravenously, or orally/enterally with 30mg/kg/day. First administration may result in respiratory arrest in responders, and thus treatment should be performed with support of respiratory management. To make sure that late and masked response is not missed, treatment with oral/enteral pyridoxine should be continued until ATQ ...

2011-05-24

177

Phytoremediation of Ionic and Methyl Mercury P

Influenza virus infection during pregnancy has been implicated as one of cause of premature delivery, abortion and stillbirth. We have reported that cultured human fetal membrane chorion cells undergoing apoptosis by influenza virus infection secrete unidentified heat-stable monocyte differentiation-inducing (MDI) factors. In this study, cellular, biological and immunochemical characteristics of MDI factors were investigated using human monocytic leukemia THP-1 cells by nitroblue tetrazolium reduction and cell adhesion assays. The treatment of THP-1 cells with culture supernatants from the influenza virus-infected chorion cells induced the nitroblue tetrazolium reduction ability, which was inhibited by the addition of superoxide dismutase and diphenyleneiodonium chloride, an inhibitor for reduced nicotinamide adenine dinucleotide phosphate oxidase. The phenomenon was also observed in human peripheral blood monocytes and histiocytic leukemia U937 cells, but not in ...

2006-06-06

178

Ophidian envenomation strategies and the role of purines.

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and ...

1999-06-01

179

Biogenic iron oxyhydroxide formation at mid-ocean ridge hydrothermal vents: Juan de Fuca Ridge

Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to prey immobilization ...

2002-04-01

180

Tunable far infrared laser spectroscopy of Van der Waals molecules in a planar supersonic jet expansion

Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focused ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary sulfide and ...

2008-05-22

1 2 3 4 5 6 7 8 9 10

181

Rapid inhibition of vasoconstriction in renal afferent arterioles by aldosterone

The gas phase high resolution spectroscopic study of weakly bound clusters can provide the information necessary to develop an intermolecular potential energy surface. This surface can then be used to better understand condensed phases. In this work, a tunable far infrared laser spectrometer is used to study weakly bound dimers produced in the newly developed continuous planar supersonic jet expansion apparatus. The water dimer is an extensively studied hydrogen bonded dimer. It undergoes several tunneling motions which result in splittings and perturbations of the rovibrational energy levels. A review is presented of much of the experimental and theoretical work done on water dimer, including a description of the combined fit of all the high resolution spectroscopic results by Coudert and Hougen. Also included is a discussion of the measurement of the K = 1 lower {yields} K = 2 lower band performed using the tunable far infrared laser/planar jet apparatus. The preliminary results from ...

1990-12-01

182

DEFF Research Database (Denmark)

Aldosterone has been suggested to elicit vessel contraction via a nongenomic mechanism. We tested this proposal in microdissected, perfused rabbit renal afferent arterioles. Aldosterone had no effect on internal diameter in concentrations from 10(-10) to 10(-5) mol/L, but aldosterone abolished the ability of 100 mmol/L KCl to induce vascular contraction. The inhibitory effect of aldosterone was observed from 1 pmol/L. The inhibitory effect was significant after 5 minutes and maximal after 20 minutes and was fully reversible. Actinomycin D (10(-6) mol/L) prolonged the effect of aldosterone. The effect was abolished by the mineralocorticoid receptor antagonist spironolactone (10(-7) mol/L) but not by the glucocorticoid receptor antagonist mifepristone (10(-6) mol/L). The K+-mediated increase of intracellular calcium concentration in afferent arterioles was not affected by aldosterone. Mineralocorticoid receptor was detected by reverse transcription-polymerase chain reaction and ...

2003-01-01

183

Development of an assay for a biomarker of pregnancy and early fetal loss

Characterization of histamine H_1-receptor binding peptides in guinea pig brain using ["1"2"5I]iodoazidophenpyramine, an irreversible specific photoaffinity probe

Human chorionic gonadotropin (hCG) is a glycoprotein hormone, secreted by the syncytiotrophoblast cells of the fertilized ovum, that enters the maternal circulation at the time of endometrial implantation. It is composed of two nonidentical subunits; ..cap alpha.. and ..beta.., with molecular weights of 14 kD and 23 kD, respectively. Human chorionic gonadotropin binds to the same receptor as hLH and displays the same biological response, namely, to stimulate the declining function of the corpus luteum to produce progestins and estrogen late in the menstrual cycle. The differences in the structures of hCG and hLH have been exploited to develop antibodies that can measure hCG specifically in the presence of hLH. Two-site antibody binding assays have been developed, based on a surface immunological concept of hCG epitopes, that involve four distinct regions to which antibodies against hCG can bind simultaneously. Antibody cooperative effects, in conjunction with ...

1987-10-01

184

Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park

Aminophenpyramine, a derivative of mepyramine (pyrilamine), a typical antagonists of histamine at its H_1 receptor was synthesized and converted into ["1"2"5I]iodoazidophenpyramine, a potential photoaffinity probe for the H_1 receptor. In the dark, reversible binding of this probe to cerebellar membranes occurred with a K/sub d/ of 1.2 x 10"-"1"1 M and a B/sub max/ of 240 fmol/mg of protein and was inhibited by various H_1-receptor antagonists with the expected potencies. These features establish the compound as one of the most potent H_1-receptor antagonists known so far. Upon IV irradiation, 5% of the bound radioactivity was covalently incorporated into cerebellar membrane polypeptides as shown by standard NaDodSO_4/PAGE. Two bands of 47 and 56 kDa were consistently labeled, labeling being prevented by various H_1-receptor antagonists with the expected potencies and stereoselectivity. In the presence of protease inhibitors, labeling of the 56-kDa peptide increased at the expense of ...

185