UK PubMed Central (United Kingdom)

Transcription activation of sulfur metabolism in yeast is dependent on two DNA binding factors, the centromere binding factor 1 (Cbf1) and Met4. While the role of Met4 was clearly established by showing...Full Text Available

UK PubMed Central (United Kingdom)

Dysregulation of the alternative pathway of complement activation, caused by mutations or polymorphisms in the genes encoding factor H, membrane co-factor protein, factor I or factor B, is associated...Full Text Available

UK PubMed Central (United Kingdom)

Cellular cholesterol homeostasis is controlled by sterol-regulated proteolysis of membrane-bound transcription factors called sterol-regulatory element binding proteins (SREBPs). CPP32, a cysteine protease,...Full Text Available

UK PubMed Central (United Kingdom)

Most antibodies to factor VIII have recently been shown to react with discrete regions of the factor VIII light chain (within the C2 domain) and/or the factor VIII heavy chain (within the amino-terminal...Full Text Available

UK PubMed Central (United Kingdom)

Binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) initiates signal transduction, ultimately leading to altered gene expression. Ligand-activated EGFR is also rapidly internalized...Full Text Available

UK PubMed Central (United Kingdom)

Epidermal growth factor (EGF) stimulates adenylyl cyclase in the heart via activation of the stimulatory GTP-binding protein Gs. Therefore, employing peptides corresponding to regions in the cytosolic...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The cAMP response element-binding protein (CREB) is a highly conserved transcription factor that integrates signaling through the cAMP-dependent protein kinase A (PKA) in many eukaryotes. PKA plays a critical role in Dictyostelium development but no CREB homologue has been identified in this system. Here we show that Dictyostelium utilizes a CREB-like protein, BzpF, to integrate PKA signaling during late development. bzpF^- mutants produce compromised spores, which are extremely unstable and germination defective. Previously, we have found that BzpF binds the canonical CRE motif in vitro. In this paper, we determined the DNA binding specificity of BzpF using protein binding microarray (PBM) and showed that the motif with the highest specificity is a CRE-like sequence. BzpF is necessary to ...

UK PubMed Central (United Kingdom)

Transforming growth factor (TGF)-βs are secreted in large latent complexes consisting of TGF-β, its N-terminal latency-associated peptide (LAP) propeptide, and latent TGF-β...Full Text Available

UK PubMed Central (United Kingdom)

The CCAAT/enhancer-binding protein β (C/EBPβ) is required for adipocyte differentiation and maturation. We have studied the role of the transcription factor, C/EBPβ,...Full Text Available

UK PubMed Central (United Kingdom)

The acyl coenzyme A (CoA) binding protein AcbA is secreted unconventionally and processed into spore differentiation factor 2 (SDF-2), a peptide that coordinates sporulation in Dictyostelium...Full Text Available

UK PubMed Central (United Kingdom)

CBP and its paralog p300 are histone acetyl transferases that regulate gene expression by interacting with multiple transcription factors via specialized domains. The structure...Full Text Available

UK PubMed Central (United Kingdom)

How transcription factors interpret the cis-regulatory logic encoded within enhancers to mediate quantitative changes in spatiotemporally restricted expression patterns during animal...Full Text Available

UK PubMed Central (United Kingdom)

The sequence-dependent structural variability and conformational dynamics of DNA play pivotal roles in many biological milieus, such as in the site-specific binding of transcription factors to target...Full Text Available

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Basic fibroblast growth factor (bFGF) exhibits specific binding to the extracellular matrix (ECM) produced by cultured endothelial cells. Binding was saturable as a function both of time and of concentration of {sup 125}I-bFGF. Scatchard analysis of FGF binding revealed the presence of about 1.5 x 10{sup 12} binding sites/mm{sup 2} ECM with an apparent k{sub D} of 610 nM. FGF binds to heparan sulfate (HS) in ECM as evidenced by (i) inhibition of binding in the presence of heparin or HS at 0.1-1 {mu}g/mL, but not by chondroitin sulfate, keratan sulfate, or hyaluronic acid at 10 {mu}g/mL, (ii) lack of binding to ECM pretreated with heparitinase, but not with chondroitinase ABC, and (iii) rapid release of up to 90% of ECM-bound FGF by exposure to heparin, HS, or heparitinase, but not to chondroitin sulfate, keratan sulfate, ...

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Evolutionary conservation of DNA sequences provides a tool for the identification of functional elements in genomes. We have created a database of evolutionary conserved regions (ECRs) in vertebrate genomes entitled ECRbase that is constructed from a collection of pairwise vertebrate genome alignments produced by the ECR Browser database. ECRbase features a database of syntenic blocks that recapitulate the evolution of rearrangements in vertebrates and a collection of promoters in all vertebrate genomes presented in the database. The database also contains a collection of annotated transcription factor binding sites (TFBS) in all ECRs and promoter elements. ECRbase currently includes human, rhesus macaque, dog, opossum, rat, mouse, chicken, frog, zebrafish, and two pufferfish genomes. It is freely accessible at http://ECRbase.dcode.org.

Science.gov (United States)

Background: Protein disulfide isomerase (PDI) controls platelet integrin function, tissue-factor (TF) activation, and concentrates at fibrin and thrombus formation sites of vascular injury. Objective: We investigated involvement of surface thiol isomerases and especially PDI, in thrombin-mediated thrombin amplification on human platelets. Methods/Results: Using a new developed thrombin-dependent platelet thrombin generation assay we observed that the feedback activation of thrombin generation on the platelet surface does not depend on TF, as anti-TF antibodies inhibiting TF-induced thrombin formation in platelet-depleted plasma had no effect compared to vehicle-treated controls. Feedback activation of thrombin generation in the presence of platelets was significantly diminished by membrane impermeant thiol blockers or by the thiol isomerase-inhibitors bacitracin and anti-PDI antibody RL90, respectively. Platelet thrombin formation depends on ...

Science.gov (United States)

The GTPases comprise a protein superfamily of highly conserved molecular switches adapted to many diverse functions. These proteins are found in all domains of life and often perform essential roles in fundamental cellular processes. Analysis of data from genome sequencing projects demonstrates that bacteria possess a core of 11 universally conserved GTPases (elongation factor G and Tu, initiation factor 2, LepA, Era, Obg, ThdF/TrmE, Ffh, FtsY, EngA and YchF). Investigations aimed at understanding the function of GTPases indicate that a second conserved feature of these proteins is that they elicit their function through interaction with RNA and/or ribosomes. An emerging concept suggests that the 11 universal GTPases are either necessary for ribosome function or transmitting information from the ribosome to downstream targets for the purpose of generating specific cellular responses. Furthermore, it is suggested that progenitor GTPases were ...

UK PubMed Central (United Kingdom)

The cell cycle-regulatory transcription factor E2F-1 is regulated by interactions with proteins such as the retinoblastoma gene product and by cell cycle-dependent alterations in E2F-1 mRNA abundance....Full Text Available

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

We study the Anderson model on a two-dimensional square lattice with an applied weak magnetic field B which causes the hopping matrix elements to have Peierls phase factors. The recursion method is applied and B dependent conductivity ?(B) is calculated from the Kubo formula for different system sizes and degree of disorder W . For large W there is no systematic change of ?(B) with B, it shows a fluctuating behavior.

UK PubMed Central (United Kingdom)

BackgroundTristetraprolin (TTP/ZFP36) family proteins have anti-inflammatory activity by binding to and destabilizing pro-inflammatory mRNAs such as Tnf mRNA, and represent a potential...Full Text Available

Science.gov (United States)

Friction opposes tooth motion whenever sliding mechanics is employed. Understanding what friction is and how to manage it is of paramount importance to the successful practitioner. In this article, the coefficients of friction are summarized between different arch wire-bracket couples as a function of material, geometric, and external parameters. From this vantage point, friction can then be evaluated within the context of other factors that affect sliding-binding and notching. PMID:9573878

International Nuclear Information System (INIS)

A unified calculation of neutron-rich isotopes in lithium is performed using the hyperspherical basis in which the underlying symmetry of each isotope exhibits a simple structure. The variation of the binding energy as a function of mass number is qualitatively reproduced, and the asymptotic of radial distribution of each isotope decreases exponentially. The form factors of the lithium isotopes are calculated and display diffraction minima. 27 refs., 3 figs., 3 tabs.

Science.gov (United States)

Myostatin is a member of the transforming growth factor-{beta} (TGF-{beta}) family and a strong negative regulator of muscle growth. Here, we present the crystal structure of myostatin in complex with the antagonist follistatin 288 (Fst288). We find that the prehelix region of myostatin very closely resembles that of TGF-{beta} class members and that this region alone can be swapped into activin A to confer signalling through the non-canonical type I receptor Alk5. Furthermore, the N-terminal domain of Fst288 undergoes conformational rearrangements to bind myostatin and likely acts as a site of specificity for the antagonist. In addition, a unique continuous electropositive surface is created when myostatin binds Fst288, which significantly increases the affinity for heparin. This translates into stronger interactions with the cell surface and enhanced myostatin degradation in the presence of either Fst288 or Fst315. ...

Energy Technology Data Exchange (ETDEWEB)

Platelets from dogs with Basset Hound Hereditary Thrombopathy (BHT) display a thrombasthenia-like aggregation defect but have been shown to have normal amounts of platelet membrane glycoproteins IIb and IIIa (GP IIb-IIIa). In order to investigate the possibility of a functionally abnormal GPIIb-IIIa complex, which might be unable to bind fibrinogen after stimulation, fibrinogen binding in BHT was evaluated. Two canine fibrinogen preparations were used, one from BHT dogs and one from normal control dogs, as well as a human fibrinogen preparation. Platelets from BHT and normal dogs were activated with 1 x 10/sup -5/M ADP in the presence of /sup 125/I-labeled fibrinogen and the surface bound radioactivity quantitated. For all fibrinogen preparations, the amount of fibrinogen bound by BHT platelets was not significantly different than that bound by normal dog platelets. BHT platelets bound 23,972 +/- 3612 and normal dog platelets bound 23,033 +/- ...

Science.gov (United States)

Poncirin, flavanone glycoside, isolated from the fruit of Poncirus trifoliata, has anti-bacterial and anti-inflammatory activities. In this study, the effects of poncirin on the differentiation of mesenchymal stem cells were investigated. The C3H10T1/2 mesenchymal stem cells and primary bone marrow mesenchymal stem cells were studied. In the C3H10T1/2 cells, poncirin prevented adipocyte differentiation, as demonstrated by inhibition of cytoplasm lipid droplet accumulation and peroxisome proliferator-activating receptor-? (PPAR-?) and CCAAT-enhancer-binding protein-? (C/EBP-?) mRNA expression. By contrast, poncirin enhanced the expression of the key osteogenic transcription factors, runt-related transcription factor 2 (Runx2) and transcriptional coactivator with PDZ-binding motif (TAZ). Poncirin also enhanced expression of the osteogenic marker genes including alkaline phosphatase (ALP) and osteocalcin ...

International Nuclear Information System (INIS)

It is now known that various growth factors may also act in the central nervous system. Among them, it has recently been shown that epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) may possess trophic effects in the mammalian brain. We report here on the respective autoradiographic distribution of ["1"2"5I]EGF and ["1"2"5I]IGF-I receptor binding sites in the rat brain, both during ontogeny and in adulthood. It appears that ["1"2"5I]EGF sites are mostly found in the rat forebrain during brain development. On the other hand, ["1"2"5I]IGF-I sites are more widely distributed both during ontogeny and in adulthood. These results reveal the plasticity of the expression of EGF and IGF-I receptor sites in the mammalian brain. This could be relevant for the respective role of these two growth factors in the development and maintenance of neuronal function.

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'The objective of this project is to provide a means to optimize ligand architecture for f-block metal recognition. The authors strategy builds on an innovative and successful molecular modeling approach in developing polyether ligand design criteria for the alkali and alkaline earth cations. The hypothesis underlying this proposal is that differences in metal ion binding with multidentate ligands bearing the same number and type of donor groups are primarily attributable to intramolecular steric factors. They propose quantifying these steric factors through the application of molecular mechanics models. The research involves close integration of theoretical and experimental chemistry. The experimental work entails synthesizing novel ligands and experimentally determining structures and binding constants for metal ion complexation by series of ligands in which architecture is systematically ...

International Nuclear Information System (INIS)

ADP-ribosylation factors (ARFs) are small guanine nucleotide-binding proteins that enhance the enzymatic activities of cholera toxin. Two ARF cDNAs, ARF1 and ARF3, were cloned from a human cerebellum library. Based on deduced amino acid sequences and patterns of hybridization of cDNA and oligonucleotide probes with mammalian brain poly(A)"+ RNA, human ARF1 is the homologue of bovine ARF1. Human ARF3, which differs from bovine ARF1 and bovine ARF2, appears to represent a newly identified third type of ARF. Hybridization patterns of human ARF cDNA and clone-specific oligonucleotides with poly(A)"+ RNA are consistent with the presence of at least two, and perhaps four, separate ARF messages in human brain. In vitro translation of ARF1, ARF2, and ARF3 produced proteins that behaved, by SDS/PAGE, similar to a purified soluble brain ARF. Deduced amino acid sequences of human ARF1 and ARF3 contain regions, similar to those in other G proteins, that ...

International Nuclear Information System (INIS)

Human Hb, the monomeric Hb of Glycera dibranchiata and horse Mb were modified by replacement of the protoheme with 2,4-dibromodeuteroheme. Following neutron capture by "7"9Br and "8"1Br, the locations of radioactive Br were determined. Although human Hb had approximately four times the mass and volume of the other proteins, about 9% of the activated Br was inserted into each of the three globins. These results suggest that the insertion is short-range (within 15 angstrom) and that this method could be used to label target sites in various proteins and other biological structures. Carp Hb's containing proto-, meso-, deutero- and dibromoheme were prepared. Kinetic and thermodynamic parameters for oxygen and CO binding were determined at Ph 6 (+IHP) (T-state, low-affinity protein) and Ph 9 (R-state, high-affinity protein). Parameters for the binding of oxygen and CO were related to the properties of the four hemes to estimate the inductive and ...

International Nuclear Information System (INIS)

Neuron-restrictive silencer factor (NRSF) binds its consensus element to repress the transcription of various genes. The dominant-negative form (dnNRSF) has a hypertrophic effect on cardiogenesis through an unidentified mechanism. We examined the involvement of transient receptor potential (TRP) channel proteins, using transgenic mice overexpressing dnNRSF (dnNRSF mice). Electrophoretic mobility-shift assays revealed an interaction between NRSF and a neuron-restrictive silencer element-like sequence in intron 4 of TRPC1 genomic DNA. According to RT-PCR and Western analyses, TRPC1 was up-regulated in dnNRSF mouse heart. Transient overexpression of TRPC1 in HEK 293T cells increased the activity of the nuclear factor in activated T cells (NFAT) promoter and stimulated store-operated Ca"2"+ channel (SOCC)-mediated Ca"2"+ entry. Transfection of TRPC1 into primary cardiomyocytes increased NFAT activity, indicating a major role ...

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When preadipocytes differentiate into adipocytes, several differentiation-linked genes are activated. Lipo-protein lipase (LPL) is one of the first genes induced during this process. To investigate early events in adipocyte development, we have focused on the transcriptional activation of the LPL gene. For this purpose, we have cloned and fused different parts of intragenic and flanking sequences with a chloramphenicol acetyltransferase reporter gene. Transient transfection experiments and DNase I hypersensitivity assays indicate that several positive as well as negative elements contribute to transcriptional regulation of the LPL gene. When reporter gene constructs were stably introduced into preadipocytes, we were able to monitor and compare the activation patterns of different promoter deletion mutants at selected time points representing the process of adipocyte development. We could delimit two cis-regulatory elements important for gradual activation of the LPL gene during ...

Energy Technology Data Exchange (ETDEWEB)

One of the research challenges in oncology is to develop new biochemical methods for noninvasive tumor therapy evaluation to determine whether the chemotherapeutics is effective. Vascular endothelial growth factor (VEGF) was labeled with radioiodine and evaluated in vitro as well as in vivo, using A2058, a melanoma cell line overexpressing VEGFR-1 and -2. Saturation binding analysis with [{sup 125}I]-VEGF resulted in a K {sub d} of 0.1 nM. Internalization assays indicate the preserved ligand induced internalization and metabolization of the tracer. Biodistribution studies with [{sup 123}I]-VEGF in wild type and A2058 tumor-bearing athymic mice showed low background activity and a tumor to reference tissue ratio of maximum 6.12. These results suggest that [{sup 123}I]-VEGF is a potentially suitable tracer for tumor therapy evaluation.

UK PubMed Central (United Kingdom)

HMGA2 is a DNA minor-groove binding protein. We previously demonstrated that HMGA2 binds to AT-rich DNA with very high binding affinity where the binding of HMGA2 to poly(dA-dT)₂ is enthalpy-driven...Full Text Available

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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 ...

Science.gov (United States)

The Drosophila sequence-specific DNA binding protein, Adf-1, is capable of activating transcription of the alcohol dehydrogenase gene, Adh, and is implicated in the transcriptional control of other developmentally regulated genes. We have cloned the cDNA encoding Adf-1 by generating specific DNA probes deduced from partial amino acid sequence of the protein. Several cDNA clones encoding an extended open reading frame were isolated from a phage lambda library. The complete amino acid sequence of Adf-1 deduced from the longest cDNA reveals structural similarities to the putative helix-turn-helix DNA binding motif of Myb and Myb-related proteins. DNA sequence analysis of genomic clones and Northern blot analysis of mRNA suggest that Adf-1 is a single-copy gene encoding a 1.9-kb transcript. Purified recombinant Adf-1 expressed in Escherichia coli binds specifically to Adf-1 recognition sites and activates transcription of a ...

UK PubMed Central (United Kingdom)

In vitro the binding of polyribosomes to smooth endoplasmic-reticulum membranes is more sensitive to ionic strength than is the binding to rough endoplasmic-reticulum membranes. Polyribosomes...Full Text Available

UK PubMed Central (United Kingdom)

Parasitic nematodes cause serious diseases in humans, animals, and plants. They have limited lipid metabolism and are reliant on lipid-binding proteins to acquire these metabolites from their hosts....Full Text Available

UK PubMed Central (United Kingdom)

The binding interactions of four ligands differing in acid-base properties with human serum albumin (HSA) were examined as a function of temperature. Binding to HSA decreased with increasing temperature...Full Text Available

UK PubMed Central (United Kingdom)

The sequences of the peptide binding domains of 33 70 kd heat shock proteins (hsp70) have been aligned and a consensus secondary structure has been deduced. Individual members showed no significant...Full Text Available

Science.gov (United States)

Endoreduplication represents a cell cycle variant during which multiple rounds of DNA replication occur without subsequent chromosome separation and cytokinesis, resulting into a cellular increase of the DNA content. Although the DNA ploidy level of cells is controlled by external stimuli such as light, currently limited knowledge is available on how environmental signals regulate the endoreduplication cycle at the molecular level. Previously, we have demonstrated that the conversion from the mitotic cell cycle into an endoreduplication cycle is mediated by the atypical E2F transcription factor DEL1 that operates as a repressor of endocycle onset. Here, we identified DEL1 as a transcriptional target of the classical E2Fb and E2Fc transcription factors that antagonistically control DEL1 transcript levels through competition for a single E2F cis-acting binding site. Correspondingly with the reported opposite effect of light ...

Science.gov (United States)

The Drosophila melanogaster tissue-specific transcription factor NTF-1 was originally identified in vitro as a protein that could bind to and activate transcription from the Dopa decarboxylase (Ddc) gene. A structure-function analysis of NTF-1 led to the identification of a discrete amino-terminal activation domain. Here, we report that an NTF-1 mutant lacking the activation domain acts as a trans-dominant inhibitor of NTF-1 activation in tissue culture cells by forming inactive heterodimers with the full-length protein. Ectopically expressing this dominant-negative protein or the full-length protein in developing Drosophila embryos leads to dire developmental consequences. Overexpressing the trans-dominant NTF-1 leads to lethality, while overexpressing full-length NTF-1 results in both lethality and morphogenetic defects. Our results suggest that both the activity and the regulation of NTF-1 are critical for viability and proper development of ...

UK PubMed Central (United Kingdom)

SummaryMammalian iron homeostasis is regulated by the interaction of the liver-produced peptide hepcidin and its receptor, the iron transporter ferroportin. Hepcidin binds to...Full Text Available

International Nuclear Information System (INIS)

We examined the effect of the trophic protein, nerve growth factor (NGF), on cultures of fetal rat neostriatum and basal forebrain-medial septal area (BF-MS) to define its role in brain development. Treatment of cultures with NGF resulted in an increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT) in both brain areas. CAT was immunocytochemically localized to neurons. In the BF-MS, NGF treatment elicited a marked increase in staining intensity and an apparent increase in the number of CAT-positive neurons. Moreover, treatment of BF-MS cultures with NGF increased the activity of acetylcholinesterase, suggesting that the cholinergic neuron as a whole was affected. To begin defining mechanisms of action of NGF in the BF-MS, we detected NGF receptors by two independent methods. Receptors were localized to two different cellular populations: neuron-like cells, and non-neuron-like cells. Dissociation studies with ["1"2"5I]NGF ...

UK PubMed Central (United Kingdom)

1. The fluorescent fatty acid probe 11-(dansylamino)undecanoic acid (DAUDA) binds with high affinity to bovine and human serum albumin (BSA and HSA) at three sites. 2. The Kd of the primary binding...Full Text Available

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Energy Technology Data Exchange (ETDEWEB)

To study the regulation of adipose tissue lipoprotein lipase (LPL) in human adipocytes, omental adipose tissue was obtained from healthy subjects and digested in collagenase. The isolated adipocytes thus obtained were suspended in Medium 199 and cultured at 37 degrees C. Cell viability was demonstrated in adipocytes cultured for up to 72 h by constancy of cell number, cell size, trypan-blue exclusion, and specific /sup 125/I-insulin binding. In addition, chloroquine induced an increase in cell-associated /sup 125/I-insulin at 24, 48, and 72 h after preparation. Thus, isolated adipocytes retained their ability to bind, internalize, and degrade insulin. LPL was measured as activity secreted into the culture medium (CM), released from cells by heparin (HR), and extracted from cell digests. A broad range of heparin concentrations produced a prompt release of LPL from a rapidly replenishable pool of cellular activity. When cells were cultured in ...

Energy Technology Data Exchange (ETDEWEB)

Nuclear testing at and around the Nevada Test Site (NTS) resulted in widespread contamination from transuranic and other radionuclides, as well as from other toxic inorganic and organic contaminants. The type of contamination, including spatial distribution and type of radionuclides present, depends on the type of testing performed. Remediation of the contaminated areas is currently under way. The optimum in situ or ex situ remediation technology depends on the degree of interaction between the particular radionuclide, or contaminant in general, and the soil matrix, among other factors. The objective of this project was to evaluate the sorption affinity of NTS soils for common non-transuranic radionuclides. The sorption of cobalt (Co) on soils from two different areas of the NTS, namely the Little Feller and Cabriolet event sites, was studied. Experiments were conducted as a function of pH, solid concentration, total Co concentration, ionic strength, and particle ...

International Nuclear Information System (INIS)

The primary E1, M1 and E2 #gamma#-radiation in "8"7","8"8","8"9Sr observed after thermal neutron capture was compared with the predictions of single particle and giant resonance models. The nuclei feature a wide range of neutron binding energies between 6.3 and 11.1 MeV, which makes a 5.5 MeV spectrum of primary transition energies available for investigation. The (n, #gamma#) reaction was used to estimate the parameters of the spin-flip M1 giant resonance in strontium. The total energy weighted M1 strength of this resonance exceeds the results of shell model and random phase approximation calculations for "9"0Zr by a factor of 3-4. The E1 strengths were found to agree with the established giant dipole resonance model. The few data on primary E2 transitions do not allow to differentiate between the giant quadrupole resonance and the single particle models. (orig.).

International Nuclear Information System (INIS)

Constitutive activation of the oncogenic transcription factor STAT3 frequently occurs in various human malignancies. STAT3 activation involves dimerization via intermolecular pTyr-SH2 interaction. Thus, antagonizing this interaction is a feasible approach to inhibit STAT3 activation for cancer therapy. In order to identify selective STAT3 inhibitors, we developed a biochemical HTS system based on AlphaScreen technology, which measures the abilities of test compounds to antagonize pTyr-SH2 interactions. We screened our chemical libraries using this system and identified 5,15-diphenylporphyrin (5,15-DPP) as a selective STAT3-SH2 antagonist. Selective inhibition of STAT3 nuclear translocation and DNA biding activity was observed in cells treated with 5,15-DPP. IL-6-dependent dimerization of STAT3, c-myc promoter binding and c-myc protein expression were all suppressed by 5,15-DPP, whereas no decrement in either expression or phosphorylation level ...

Science.gov (United States)

The interaction of the globular protein lysozyme with silica nanoparticles of diameter 20 nm was studied in a pH range between the isoelectric points (IEPs) of silica and the protein (pH 3-11). The adsorption affinity and capacity of lysozyme on the silica particles is increasing progressively with pH, and the adsorbed protein induces bridging aggregation of the silica particles. Structural properties of the aggregates were studied as a function of pH at a fixed protein-to-silica concentration ratio which corresponds to a surface concentration of protein well below a complete monolayer in the complete-binding regime at pH > 6. Sedimentation studies indicate the presence of compact aggregates at pH 4-6 and a loose flocculated network at pH 7-9, followed by a sharp decrease of aggregate size near the IEP of lysozyme. The structure of the bridged silica aggregates was studied by cryo-transmission electron microscopy (cryo-TEM) and small-angle X-ray scattering. The ...

International Nuclear Information System (INIS)

A correlation investigation was carried out on the series of atomic coordinates (MPV) and temperature factor (T _f), respectively for human hemoglobin and HIV-1 protease protein main chains. The MPV series revealed resemblances to the corresponding T _f series. Each minor or major peak in a series had a corresponding peak in the related series. This brings a qualitative evidence for the connection of the two parameters. The series were further subjected to spectral and detrended fluctuation analysis which all revealed long-range correlation properties. This combined analysis revealed that the data were controlled both by the correlation of stationary fluctuation and trends or non-stationary contribution to correlation. The correlation of all MPV series was found to be much less sensitive to ligand binding than the corresponding T _f series. Thus the long-range correlation properties of the protein main chain structure and mobility revealed two ...

Energy Technology Data Exchange (ETDEWEB)

Measurements were made of the cross sections for the /sup 27/Al(/sup 16/O,/sup 15/N)/sup 28/Si, /sup 89/Y(/sup 15/N,/sup 16/O)/sup 88/Sr and /sup 89/Y(/sup 27/Al,/sup 28/Si)/sup 88/Sr reactions at energies near and below the Coulomb barrier. The first reaction required separate measurements of the transfer to elastic cross section ratio for particular charge states, the charge state distribution for /sup 27/Al and /sup 28/Si ions, and the absolute elastic scattering cross section for the /sup 27/Al + /sup 16/O system. The ratio measurement required the combined use of two relatively new scientific instruments: the momentum filter and the Bragg curve spectrometer. The latter two transfer measurements were performed using the same setup involving surface barrier detectors at backward angles. Additional elastic scattering data for the /sup 15/N + /sup 28/Si, /sup 89/Y + /sup 15/N, /sup 89/Sr + /sup 27/Al, and /sup 88/Sr + /sup 28/Si systems was collected to provide entrance and exit ...

Energy Technology Data Exchange (ETDEWEB)

This poster describes single-molecule tracking and total internal reflection fluorescence microscopy. It discusses whether the carbohydrate-binding module (CBM) moves on cellulose, how the CBM binds to cellulose, and the mechanism of cellulosome assembly.

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

The homologous sequences observed for many calcium binding proteins such as parvalbumin, troponin C, the myosin light chains, and calmodulin has lead to the hypothesis that these proteins have homologous...Full Text Available

International Nuclear Information System (INIS)

Starting with a #LAMBDA#-nucleus potential, a semi-empirical formula, which gives a fairly satisfactory account of the ground state #LAMBDA#-binding energy of light hypernuclei, if the very light nuclei are ignored has been obtained. (author).

UK PubMed Central (United Kingdom)

1. The structural requirements of an allosteric barbiturate binding site on acetylcholine receptor-rich membranes isolated from Torpedo electroplaques have been characterized by the ability of fourteen...Full Text Available

UK PubMed Central (United Kingdom)

It has been sixty years since the Millers first described the covalent binding of carcinogens to tissue proteins. Protein covalent binding was gradually overshadowed by the emergence of DNA...Full Text Available

UK PubMed Central (United Kingdom)

The purpose of the present work was to study the pharmacokinetics and the protein binding (free fraction of the drug) of ceftriaxone (CTX) during pregnancy. Nine pregnant women (ages, 20 to 34 years)...Full Text Available

UK PubMed Central (United Kingdom)

Cd-binding protein was extracted from tomato roots and purified on QAE-Sephadex A-25 and on Sephadex G-75 in 1 molar KCl buffer. The protein preparation was light brown and contained predominantly Cd...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe binding of peptide fragments of antigens to class II MHC is a crucial step in initiating a helper T cell immune response. The identification of such peptide epitopes...Full Text Available

Science.gov (United States)

... 2003)050[0600:LBOTMP]2.0.CO;2 Lectin Binding of the Major Polar Tube Protein (PTP1) ... PTP1. We, therefore, undertook a study ...

Energy Technology Data Exchange (ETDEWEB)

The effect of chronic administration of phenobarbital on the binding of phorbol-12,13-dibutyrate (({sup 3}H)PDBu), an activator of protein kinase C (PKC), was examined in rat liver microsomes. A significant increase in the number of binding sites was observed in microsomes of Fisher 344 rats. However, no change appeared in liver cytosol binding of PDBu. Consequently, a translocation process of PKC is unlikely. The increase in ({sup 3}H)PDBu binding in liver microsomes is significant 24 h. after one injection of phenobarbital and reaches its maximum in 2 days. In other strains of rats (ACI and lean Zucker), significant differences were found in the increase of ({sup 3}H)PDBu binding in microsomes. Fisher 344 were the most sensitive, lean Zucker rats, the least sensitive. Those results parallel the pentoxy-resorufin O demethylase activity in the microsomes of the same animals. EC{sub ...

UK PubMed Central (United Kingdom)

It has been postulated that thrombin binds to endothelial cells through, at least in part, cell surface glycosaminoglycans such as heparan sulfate, which could serve as antithrombin cofactor on the...Full Text Available

UK PubMed Central (United Kingdom)

During antibiotic drug development, media are frequently spiked with either serum/plasma or protein supplements to evaluate the effect of protein binding. Usually, previously reported serum or plasma...Full Text Available

UK PubMed Central (United Kingdom)

1 The plasma protein binding of theophylline was determined after addition of [14C]-theophylline (15 micrograms/ml) to plasma from 24 healthy drug-free volunteers and equilibrium dialysis for 2 h at...Full Text Available

UK PubMed Central (United Kingdom)

The binding mode of telomestatin to G-quadruplex DNA has been investigated using electrospray mass spectrometry, by detecting the intact complexes formed in ammonium acetate. The mass measurements show...Full Text Available

UK PubMed Central (United Kingdom)

Recombinant biotin-binding phages were affinity-selected from a random peptide library expressed on the surface of filamentous phage. Phage binding to biotinylated proteins was half-maximally inhibited...Full Text Available

UK PubMed Central (United Kingdom)

The Protein Data Bank contains the description of more than 45,000 three-dimensional protein and nucleic-acid structures today. Started to exist as the computer-readable depository of crystallographic...Full Text Available

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BackgroundA relevant problem in drug design is the comparison and recognition of protein binding sites. Binding sites recognition is generally based on geometry often combined with...Full Text Available

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Full text: Magnetic multilayer materials are becoming technologically important as they provide a more efficient means of magnetic reading and storage through utilisation of their giant magnetoresistance and oscillatory magnetic coupling. This study presents preliminary tight-binding calculations with a view of developing a consistent tight-binding model of `spin valve` Fe-Cu-Fe tri-layer materials. Further work involves using a self-consistent tight-binding approach to obtain a more accurate picture of this system and a better understanding of surface effects at the Fe-Cu interface 1 fig., 4 refs.

International Nuclear Information System (INIS)

... e Biologia Molecular (SBBq), Sao Paulo, SP (Brazil) 217 p. APPLIED LIFE

International Nuclear Information System (INIS)

The effect of in vitro and in vivo administration of ethanol on the binding of "3"5S-t-butyl-bicyclophosphorothionate ("3"5S-TBPS) to cortical brain membranes of C57B1 mice was investigated using KCl (100 mM) containing assay media. The in vitro addition of ethanol produced a dose-dependent inhibition of basal "3"5S-TBPS binding. In the presence of chloride ions, GABA and pentobarbital had a biphasic action (stimulation followed by inhibition) on "3"5S-TBPS binding, whereas diazepam only stimulated the binding. Ethanol reduced the stimulatory effects of GABA and pentobarbital in a dose-dependent manner, but had no effect on the enhancement of "3"5S-TBPS binding produced by diazepam. "3"5S-TBPS binding to cortical brain membranes was inhibited by the putative Cl"- channel blocking agent DIDS. This inhibitory action of DIDS was significantly, and dose-dependently ...

UK PubMed Central (United Kingdom)

Human serum albumin (HSA) has two primary binding sites for drug molecules. These sites selectively bind different dansylated amino acid compounds, which—due to their intrinsic fluorescence—have...Full Text Available

Science.gov (United States)

Vascular endothelial growth factor (VEGF) is a mitogen that is critically involved in vasculogenesis, angiogenesis, and hematopoiesis. However, what and how transcription factors participate in the regulation of vegf gene expression are not fully understood. Here we report the cloning and sequencing of the zebrafish vegf promoter which revealed that the promoter contains a number of bone morphogenetic protein (BMP)-activated Smad binding elements (SBE), implicating Smad1 and Smad5 in the regulation of BMP-induced expression of vegf. Electrophoretic mobility shift assays of adding recombinant Smad proteins to the SBE-containing DNA oligonucleotides that represent portions of zebrafish vegf promoter resulted in mobility shift of the oligonucleotides. These changes demonstrate potential interactions between Smad1/5 and the vegf promoter. Reporter activity assays using the wild-type or SBE-deleted vegf promoters to drive the ...

International Nuclear Information System (INIS)

Over the recent years the nuclear structure around the N = 50 shell closure, which is very pronounced in the strontium and zirconium isotopes, has been the subject of extensive experimental and theoretical work. On the proton side Z = 38 and Z = 40 provide fairly closed sub-shells. In the strontium isotopes the lg/sub 9/2/ neutron shell is closed at "8"8Sr, supplying relatively pure neutron-hole and neutron-particle states with large spectroscopic factors in "8"7Sr and "8"9Sr, as well as core-coupled states. The mass region is thus ideally suited to examine the transition from a correlated to an uncorrelated (chaotic?) excitational behavior. These two types are characterized e.g. by the density of excited states, the transition strengths, and the spectroscopic factors observed in transfer reactions. We conducted (n,#gamma#) and (d,p) reactions leading to /sup 87,88,89/Sr in addition to "8"8Sr(d,t)"8"7Sr and 24 keV neutron capture in "8"8Sr. The ...

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Incorporation of /sup 32/P from (gamma-32P)ATP into tyrosine residues of the insulin-like growth factor (IGF)-II receptor was observed in a Triton X-100-insoluble fraction of rat adipocyte plasma membranes. IGF-II receptor phosphorylation proceeded to a stoichiometry of approximately 0.5 mol of phosphate/IGF-II binding site after 10 min of incubation at 4 degrees C. A Km for ATP of 6 microM was calculated for this phosphorylation reaction. Addition of IGF-II caused an approximately 2-fold increase in tyrosine phosphorylation of the IGF-II receptor in this preparation. In contrast, phosphorylation of angiotensin II by the Triton X-100 washed membranes was not stimulated by IGF-II. Incubation of purified receptor immobilized on IGF-II agarose or of receptor-enriched low density microsomal membranes with (gamma-32P)ATP did not result in appreciable incorporation of (/sup 32/P)phosphate into the IGF-II receptor nor into exogenous substrates. These ...

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A study was made of the kinetics of L-(/sup 3/H)quinuclidinyl benzilate binding with membrane-bound muscarine cholinoreceptors from the rat brain. Determination was made of the rate constants of this process, and constants as a function of ligand concentration was investigated, indicating that there is a complex mechanism of interaction of antagonists with muscarine receptor. With up to 3.5 nM concentrations of L-(/sup 3/H)quinuclidinyl benzilate, the binding reaction occurs in two stages: rapid equilibrated binding is followed by a slow process of conformational isomerization of the receptor-ligand complex. At higher ligand concentrations, there is additional drastic increase in constant of rate of ligand binding a new plateau is reached. Such dependence of rate constant on ligand concentration is indicative of the cooperative nature of interaction between antagonists and muscarine receptors. This is ...

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Studies of various established human bladder and renal carcinoma cell lines cultured in vitro demonstrated the presence of specific, saturable, high affinity binding sites for /sup 125/I-labeled human interferon Beta ser IFN-beta ser). This recombinant produced interferon labeled with approximately one atom of /sup 125/I/molecule of IFN expressed minimal or no loss of antiviral activity. A single class of binding sites (1000-2000/cell) with an affinity constant of 10(10)-10(11) L/M was measured at 4 degrees C for cells exhibiting widely different sensitivity to the antiproliferative effect of IFN-beta ser. Major fluctuations in the binding of /sup 125/I-labeled IFN-beta ser to cellular receptors were observed during in vitro proliferation of four of five cell lines examined. A significant decrease (P less than 0.001) in specific binding was observed 48 h after cultures were established. Cell cycle ...

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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 ...

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The pharmacology of the alpha-2 adrenoceptor of the human adipocyte was improved by using some new alpha-2 antagonists from different chemical families (imidazolines, benzazepines and benzofuroquinolizines) in biological and binding assays. Moreover, investigations were also carried out to define the binding properties of a new imidazolinic antagonist, RX821002 (2-(2-methoxy-1,4-benzodioxan-2yl)-2-imidazoline), which could be a potential radioligand. (3H)RX821002 binding was very rapid and reversible. Saturation isotherms indicated that (3H)RX821002 labeled, with high affinity, a homogeneous population of noninteracting binding sites with a mean Kd of 0.98 +/- 0.05 nM (n = 6). The binding of (3H)RX821002 on the human fat cell alpha-2 adrenoceptor displayed a specificity which is strictly similar to that obtained with (3H)rauwolscine and which is classical for an alpha-2 A ...

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A relatively quick and simple assay for hyaluronate was developed using the specific binding protein, hyaluronectin. The hyaluronectin was obtained by homogenizing the brains of Sprague-Dawley rats, and then centrifuging the homogenate. The resulting supernatant was used as a source of crude hyaluronectin. In the binding assay, the hyaluronectin was mixed with (/sup 3/H)hyaluronate, followed by an equal volume of saturated (NH/sub 4/)/sub 2/SO/sub 4/, which precipitated the hyaluronectin and any (/sup 3/H)hyaluronate associated with it, but left free (/sup 3/H)hyaluronate in solution. The mixture was then centrifuged, and the amount of bound (/sup 3/H)hyaluronate in the precipitate was determined. Using this assay, the authors found that hyaluronectin specifically bound hyaluronate, since other glycosaminoglycans failed to compete for the binding protein. In addition, the interaction between hyaluronectin and hyaluronate ...

International Nuclear Information System (INIS)

Gel filtration of human erythrocyte (RBC) lysate incubated with labeled thyroxine (Tu) or triiodothyronine (Tt) revealed co-elution of a major iodothyronine-binding fraction (R-2) and hemoglobin. Solutions of purified human hemoglobin and Tt also showed co-elution of hormone and hemoglobin. Because hematin and protoporphyrin were shown to bind labeled Tt, the oxygen-binding site on hemoglobin was excluded as the site of iodothyronine-hemoglobin interaction. Analysis of hormone binding by heme and globin moieties showed Tt binding to be limited to the heme fraction. Addition of excess unlabeled Tt to hemoglobin or heme incubated with labeled Tt indicated 75% to 90% of hormone binding was poorly dissociable. These observations suggested that the presence of hemoglobin in RBC lysate or in serum could influence the measurement of Tu and Tt by specific ...

International Nuclear Information System (INIS)

Aim: There has been a great demand for developments of the radioligands to visualize the N-methyl-D-aspartate (NMDA) receptors by PET/SPECT. We have recently synthesized two C-11 labeled antagonists for the glycine-binding site on NMDA receptors. The aim of this work is to examine for their in vitro and in vivo binding characteristics, and to evaluate their potentials as PET radioligands for the NMDA receptors. Materials and methods: Two C-11 labeled 4-hydroxy-2-quinolones (1 and 2) were synthesized by conventional methylation of the corresponding phenols with ["1"1C]methyl iodide. In vitro and ex vivo quantitative autoradiographs with imaging plate, as well as animal PET, were employed in order to evaluate their in vitro and in vivo binding to the NMDA receptors. Results: The compound 1 showed the specific binding to rat brain slices with higher localization in the hippocampus and cerebral cortex than ...

British Library Electronic Table of Contents (United Kingdom)

Coordination of CoCl2 solutions to the silica polyamine composite, WP-1, made with the branched polymer polyethylenimine (PEI) shows irreversible binding resulting from surface oxidation of the Co2+-Co3+. This is not the case for the silica polyamine composite BP-1 made with the linear polymer polyallylamine where reversible binding and no oxidation is observed. These observations suggested that oxidation of the cobalt was related to the greater coordination number available with the branched polyamine relative to the linear polyamine. A study of the kinetics of cobalt binding to WP-1 indicated initial loading of Co2+ at relatively low coordination number followed by desorption of Co2+ leading to oxidation and irreversible binding. Exclusion of oxygen from the composite-cobalt solution mix...

UK PubMed Central (United Kingdom)

BackgroundTacrolimus (FK-506) is an immunosuppressant that binds to a specific immunophilin, resulting in the suppression of the cellular immune response during transplant rejection....Full Text Available

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ObjectivesWe sought to identify a novel gene for dilated cardiomyopathy (DCM).BackgroundDCM is a heritable, genetically...Full Text Available

International Nuclear Information System (INIS)

Russian 1987. p. 99-100. USSR Sabalyauskas, L.Yu. Vanagas, VV Guseva,

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Existing oil reservoirs might be more fully exploited if the properties of the flow of oil and water in porous media were better known. In laboratory experiments it is important to collect as much information as possible to make a descriptive model of the system, including position imaging and chemical binding information. This thesis develops nuclear methods for obtaining position image and chemical binding information from flow experiments of porous media. A combined positron emission tomography and single photon emission computed tomography system to obtain position images, and a time-differential perturbed angular correlation system to obtain chemical binding information, have been built and thoroughly tested. 68 refs., 123 figs., 14 tabs.

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This paper describes attempts to isolate and characterize glycosaminoglycan (GAG)-binding molecules on the surface of lymphocytes and lymphoma cell lines and relate their expression to splenic and lymph...Full Text Available

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A fundamental study of the application of bacteria to the recovery of toxic heavy metals from aqueous environments was carried out. The biosorption characteristics of cadmium and lead ions were determined with purple nonsulfur bacteria, Rhodobacter sphaeroides and hydrogen bacteria, Alcaligenes eutrophus H16 that were inactivated by steam sterilization. A simplified version of the metal binding model proposed by Plette et al. was used for the description of meal binding data. The results showed that the biosorption of bivalent metal ions to whole cell bodies of the bacteria was due to monodentate binding to two different types of acidic sites: carboxilic and phosphatic-type sites. The number of metal binding sites of A. eutrophus was 2.4-fold larger than that of R. sphaeroides.

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The distribution of i.v. administered lead (/sup 203/Pb-acetate; 50 nmol/kg b.w.) was studied by means of autoradiography and impulse counting in pregnant C57BL mice (day 18) treated orally with dithiocarbamates. Diethyldithiocarbamate (DEDTC), disulfuram or thiram (2 X 1) mmol/kg b.w.) or vehicle (gelatine) alone, was given by gavage 2 h before and immediately after the injection of lead. All three dithiocarbamates, especially thiram, changed the distribution pattern of lead. Thiram and DEDTC had the greatest effect at 4 h after lead administration, disulfiram at 24 h. In the mother, most notably the brain concentration increased (70-fold for thiram at 4 h) while that of erythrocytes and skeleton decreased (50- and 4-fold, respectively). The total fetal concentration unexpectedly showed only a moderate increase (proportional 2-fold for thiram), which may be due partly to the low maternal plasma lead concentration. The partition within the fetal tissues was, however, changed by the ...

Science.gov (United States)

The thermostable Thermus aquaticus DNA polymerase (Taq Pol) has been the key factor in transforming the initial PCR method into one with huge impact in molecular biology and biotechnology. Therefore, the development of effective affinity adsorbents for the purification of Taq Pol, as well as other DNA polymerases, attracts the attention of the enzyme manufacturers and the research laboratories. In this report we describe a simple protocol for the purification of Taq Pol from E. coli lysates, leading to enzymes of high specific activity and purity. The protocol is based on a single affinity chromatography step, featuring an immobilized ligand selected from a structure-biased combinatorial library of dNTP-mimetic synthetic ligands. The ligand library was screened for its ability to bind and purify Taq Pol from E. coli lysates. One immobilized ligand (mABSGu) of the general formula X-Trz-Y, bearing 9-aminoethylguanine (AEGu) and aniline-2-sulfonic ...

Science.gov (United States)

Receptor interacting protein 140 (RIP140) is a coregulator for numerous nuclear receptors and transcription factors and primarily exerts gene-repressive activities on various target genes. We previously identified a spectrum of posttranslational modifications on RIP140 that augment its property and biological activity. In T(3)-triggered biphasic regulation of cellular retinoic acid binding protein 1 (Crabp1) gene along the course of fibroblast-adipocyte differentiation, we found TRAP220(MED1) critical for T(3)-activated chromatin remodeling whereas RIP140 essential for T(3)-repressive chromatin remodeling of this gene promoter. In this current study, we aim to examine whether and how RIP140 replaces TRAP220(MED1) on the CrabpI promoter in differentiating adipocyte cultures. We find increasing recruitment of RIP140 to this promoter, with corresponding reduction in TRAP220(MED1) recruitment during the T(3)-repressive phase. We also uncover direct ...

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The synthesis of (/sup 14/C)-10,11-Epoxy-(2E,6E)-farnesyl diazoacetate in one vessel, starting from (/sup 14/C)-glyoxylic acid, is described. This compound is useful as a potential photoaffinity labeling agent for juvenile hormone binding sites.

UK PubMed Central (United Kingdom)

Seventeen clinical isolates of Staphylococcus aureus (from the United States and Europe) selected for low (borderline)-level methicillin resistance (MIC of methicillin, 2 to 4 micrograms/ml; MIC of...Full Text Available

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The amino acid residues 114-118 in actin were found to be implicated strongly in the binding of nucleotide, and as would be expected for such an important binding site, they are located in a completely conserved region of the actin sequence. A 19-residue peptide with the actin sequence 106-124 was synthesized in order to span the putative triphosphate binding site. Proton NMR spectra of the actin peptide 114-118 in the presence and absence of ATP indicated that Arg-116 and Lys-118 are particularly involved in binding ATP. A strong binding of ATP to the peptide 106-124 also was measured. Tripolyphosphate bound to the peptide 106-124 somewhat more weakly than ATP. Binding involved residues 115-118 and 121-124, indicating the presence of a reverse turn between these segments. Proton resonances were assigned by using two-dimensional double quantum correlated ...

UK PubMed Central (United Kingdom)

The discovery of a specific high-affinity growth hormone (GH) binding protein (GH-BP) in plasma adds complexity to the dynamics of GH secretion and clearance. Intuitive predictions are that such a protein...Full Text Available

International Nuclear Information System (INIS)

The PbII binding characteristics of the previously reported PbII binding proteins of rat kidney cytosol were investigated further. Saturation and Scatchard analysis of "2"0"3Pb binding in whole cytosol and in 40% saturated ammonium sulfate precipitated fractions disclosed a class of relatively high-affinity sites with an apparent Kd of approximately 50 nM and binding capacities of approximately 41 and 9 pmol/mg of protein, respectively. Two "2"0"3Pb binding proteins with approximate molecular masses of 63K and 11.5K daltons and a high molecular weight component (greater than 200K) were isolated by Sepharose-6B column chromatography. The time course of association of "2"0"3Pb with cytosol and the 63K protein showed maximum binding at 18 hr which was stable up to 25 hr at 4 degrees C. The approximate half-time dissociation rate (T 1/2) of specifically bound ...

UK PubMed Central (United Kingdom)

1 The decreased binding of drugs and dyes to plasma proteins from male and female rats with acute renal failure has been investigated using equilibrium dialysis at 37 degrees C. 2 Acute renal failure...Full Text Available

UK PubMed Central (United Kingdom)

The DNA-binding properties of Ru(bpy)₂(eilatin)²⁺ have been investigated to determine if the sterically expansive eilatin ligand confers specificity for destabilized single-base...Full Text Available

UK PubMed Central (United Kingdom)

Ingestion or inhalation of botulinum neurotoxin (BoNT) results in botulism, a severe and frequently fatal disease. Current treatments rely on antitoxins, which while effective cannot reverse...Full Text Available

KoreaScience (Korea)

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International Nuclear Information System (INIS)

The authors used radioligand binding and studies of cell contraction to characterize muscarinic receptors on dispersed smooth muscle cells from rabbit proximal and distal colon. Cells obtained after serial incubations in collagenase were used to measure binding of tritiated quinuclidinyl benzilate (["3H]QNB). At 37 degree C, specific ["3H]QNB binding was saturable and linearly related to cell number. Nonlinear regression analysis was used to determine the affinity of ["3H]QNB for its receptor. The IC_5_0 for the muscarinic agonists bethanechol and oxotremorine were 80 and 0.57 #mu#M, respectively. Hill coefficients were 0.67 for both, suggesting more complex interaction involving receptors of different affinities. In studies of cell contraction, bethanechol stimulated a dose-dependent decrease in cell length with half the maximal contraction occurring at 100 pM. These results suggest that (1) contraction is mediated by ...

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Ex vivo (/sup 3/H)-8-hydroxy-2-(di-n-propylamino)-tetraline ((/sup 3/H)-DPAT) binding to the hippocampus has been utilized to determine the pharmacokinetic parameters of buspirone after i.v. and oral administration of this drug to rats. Intravenous buspirone rapidly penetrated the brain as demonstrated by a maximum inhibition of (/sup 3/H)-DPAT binding at 1 min. Elimination of drug from the brain was biphasic, with a first component half-life of 24.8 min and a second component half-life of 96 min. Oral buspirone at 3 times the i.v. dose produced less than one-third the maximum inhibition of (/sup 3/H)-DPAT binding compared to that observed with i.v. buspirone. The pharmacokinetic parameters of buspirone observed in the present study are in agreement with those reported previously. Thus, the ex vivo binding assay could be utilized to determine the bioavailability of the drug to the brain, and its ...

International Nuclear Information System (INIS)

Human erythrocyte glucose-6-phosphate is normally quite stable in the presence of 10 #mu#M NADP"+. Certain glucose-6-phosphate dehydrogenase variants lose virtually all their activity at this concentration of NADP"+ but are reactivated by 200 #mu#M NADP"+. Such variants presumably have a defect in their NADP"+-binding site. The authors analyzed the sequence of cDNA or genomic DNA from seven unrelated patients with hemolytic anemia due to the inheritance of variants that are reactivated by NADP"+. Six patients had substitutions of one of three adjacent amino acids, and the seventh patient had another amino acid substitution 23 residues downstream. These amino acids are highly conserved, all being present in rat and all but one being found also in Drosophila. The anomalous electrophoretic behavior of some of the variants can be explained by their loss of ability to bind NADP"+. The conclude that the region in which these mutations occur defines ...

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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 ...

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Radiation inactivation and sedimentation equilibrium analysis were used to determine the functional and physical size of the chicken hepatic membrane receptor that binds N-acetylglucosamine-terminated glycoproteins. Purified plasma membranes from chicken liver were irradiated with high energy electrons and assayed for 125I-agalactoorosomucoid binding. Increasing the dose of ionizing radiation resulted in a monoexponential decay in binding activity due to a progressive loss of binding sites. The molecular mass of the chicken lectin, determined in situ by target analysis, was 69,000 +/- 9,000 Da. When the same irradiated membranes were solubilized in Brij 58 and assayed, the binding protein exhibited a target size of 62,000 +/- 4,000 Da; in Triton X-100, the functional size of the receptor was 85,000 +/- 10,000 Da. Sedimentation equilibrium measurements of the purified ...

International Nuclear Information System (INIS)

High-resolution "1H and "3"1P nuclear magnetic resonance spectroscopy has been used to investigate the binding of 2,3-diphosphoglycerate to human normal adult hemoglobin and the molecular interactions involved in the allosteric effect of the 2,3-diphosphoglycerate molecule on hemoglobin. Individual hydrogen ion NMR titration curves have been obtained for 22-26 histidyl residues of hemoglobin and for each phosphate group of 2,3-diphosphoglycerate with hemoglobin in both the deoxy and carbonmonoxy forms. The results indicate that 2,3-diphosphoglycerate binds to deoxyhemoglobin at the central cavity between the two #beta# chains and the binding involves the #beta#2-histidyl residues. Moreover, the results suggest that the binding site of 2,3-diphosphoglycerate to carbonmonoxyhemoglobin contains the same (or at least some of the same) amino acid residues responsible for binding in the ...

International Nuclear Information System (INIS)

The binding energy parameter #lambda# plays an important role in common envelope evolution. Previous works have already pointed out that #lambda# varies throughout the stellar evolution, though it has been adopted as a constant in most of the population synthesis calculations. We have systematically calculated the binding energy parameter #lambda# for both Population I and Population II stars of masses 1-20 M _s_u_n, taking into account the contribution from the internal energy of stellar matter. We present fitting formulae for #lambda# that can be incorporated into future population synthesis investigations. We also briefly discuss the possible applications of the results in binary evolutions.

UK PubMed Central (United Kingdom)

A summary of the effects presented here is given in the table. The designation "factor present" implies that there is knowledge (from human or animal studies, or both) of a specific factor(s) present...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundHarbour porpoises Phocoena phocoena from the southern North Sea are known to display high levels of Zn and Hg in their tissues linked to their nutritional...Full Text Available

UK PubMed Central (United Kingdom)

ObjectivesThe aim of this study was to assess the diagnostic and prognostic value of heart-type fatty acid-binding protein (H-FABP) in elective percutaneous coronary intervention...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...

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Sucrose phosphate synthase (SPS) catalyzes the transfer of a glycosyl group from an activated donor sugar, such as uridine diphosphate glucose (UDP-Glc), to a saccharide acceptor D-fructose 6-phosphate (F6P), resulting in the formation of UDP and D-sucrose-6'-phosphate (S6P). This is a central regulatory process in the production of sucrose in plants, cyanobacteria, and proteobacteria. Here, we report the crystal structure of SPS from the nonphotosynthetic bacterium Halothermothrix orenii and its complexes with the substrate F6P and the product S6P. SPS has two distinct Rossmann-fold domains with a large substrate binding cleft at the interdomain interface. Structures of two complexes show that both the substrate F6P and the product S6P bind to the A-domain of SPS. Based on comparative analysis of the SPS structure with other related enzymes, the donor substrate, nucleotide diphosphate glucose, binds to the ...

UK PubMed Central (United Kingdom)

Dal82p binds to the UIS_ALL sites of allophanate-induced genes of the allantoin-degradative pathway and functions synergistically with the GATA family Gln3p and Gat1p transcriptional...Full Text Available

UK PubMed Central (United Kingdom)

On rod disc membranes, single photoactivated rhodopsin (R*) molecules catalytically activate many copies of the G-protein (Gt), which in turn binds and activates the effector (phosphodiesterase). We...Full Text Available

UK PubMed Central (United Kingdom)

The length polymorphism of the serotonin (5-HT) transporter gene promoter region has been implicated in altered 5-HT function and, in turn, neuropsychiatric illnesses, such as anxiety and depression....Full Text Available

UK PubMed Central (United Kingdom)

The sequence information available for homeodomains reveals that salt bridges connecting pairs 19/30, 31/42, and 17/52 are frequent, whereas aliphatic residues at these sites are rare and mainly restricted...Full Text Available

UK PubMed Central (United Kingdom)

The presence of albumin structures with the capacity to bind to a surface receptor in group C and G streptococci was studied in serum samples from 45 mammalian species representing 15 different orders,...Full Text Available

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The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior ...

UK PubMed Central (United Kingdom)

The characterization of the single-chain protein in Chinese-cobra (Naja naja atra) blood serum, which yields strong specific protection against the venom of the same snake, is reported. The protein,...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundBaculovirus, which has a width of 40 nm and a length of 250-300 nm, can display functional peptides, receptors and antigens on its surface by their fusion with a baculovirus...Full Text Available

UK PubMed Central (United Kingdom)

The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both...Full Text Available

UK PubMed Central (United Kingdom)

1 Measuring total plasma levels of disopyramide (DP) and the main metabolite mono-N-dealkyldisopyramide (MND) in patients on maintenance therapy with DP has shown concentrations of MND comparable with...Full Text Available

UK PubMed Central (United Kingdom)

PurposeTo report unusual ocular manifestations of branchio-oculo-facial syndrome (BOFS) caused by a novel mutation in activating enhancer binding protein 2 alpha (TFAP2A).MethodsFull...Full Text Available

Wastenet

Up-flow anaerobic attached-growth bioreactors filled with pre-treated coir fibres ...coir-fibre arranged in bottle-brush configuration bounded by a novel plastic binding technique ...-three anaerobic filter reactors in series -coir fibre as the bacteria growth media a sedimentation

UK PubMed Central (United Kingdom)

The Far UpStream Element (FUSE) regulatory system promotes a peak in the concentration of c-Myc during cell cycle. First, the FBP transcriptional activator binds to the FUSE DNA element upstream...Full Text Available

UK PubMed Central (United Kingdom)

Our goal was to determine whether chlorpyrifos oxon, dichlorvos, diisopropylfluorophosphate (DFP), and sarin covalently bind to human albumin. Human albumin or plasma was treated with organophosphorus...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe VP2 outer capsid protein Bluetongue Virus (BTV) is responsible for receptor binding, haemagglutination and eliciting host-specific immunity. However, the assembly of...Full Text Available

UK PubMed Central (United Kingdom)

Local anesthetics are able to induce pain relief by binding to the sodium channels of excitable membranes, blocking the influx of sodium ions and the propagation of the nervous impulse. Ropivacaine...Full Text Available

UK PubMed Central (United Kingdom)

Over 200 mutations in the retina specific member of the ATP-binding cassette transporter super-family (ABCA4) have been associated with a diverse group of human retinal diseases....Full Text Available

International Nuclear Information System (INIS)

Human complement protein C9 is shown to be a metalloprotein that binds 1 mol of Ca"2"+/mol of C9 with a dissociation constant of 3 #mu#m as measured by equilibrium dialysis. Incubation with EDTA removes the bound calcium, resulting in a apoprotein with decreased thermal stability. This loss in stability leads to aggregation and, therefore, to loss of hemolytic activity upon heating to a few degrees above the physiological temperature. Heat-induced aggregation of apoC9 can be prevented by salts that stabilize proteins according to the Hofmeister series of lyotropic ions, suggesting that the ion in native C9 may ligand with more than one structural element of domain of the protein. Ligand blotting indicates that the calcium binding site is located in the amino-terminal half of the protein. Removal of calcium by inclusion of EDTA in assay mixtures has no effect on the hemolytic activity of C9, and its capacity to bind to C8 in ...

International Nuclear Information System (INIS)

A high sensitivity (titer 60-150,000) radioimmunoassay for arginine vasopressin (AVP) has been developed using synthetic AVP as antigen and standard. The specificity of the antiserum has been characterized in detail by measuring the relative binding affinities of 29 analogs and fragments of AVP. In general, single amino acid substitution or deletion in the AVP molecule caused a reduction in binding to the antiserum; binding was further impaired for analogs which had multiple substitutions. ''Ring'' and ''tail'' fragments of the neurohypophysial hormones did not bind to the antiserum, and the only analog which the antiserum could not differentiate from AVP was deamino-AVP. More specifically, the antiserum exhibited the following properties: position 1, no requirement for a position charge at "1/_2 Cys; positions 2 and 3, requirements for #pi#-#pi# interacting pair of aromatic side chains and for Tyr at ...

UK PubMed Central (United Kingdom)

To analyse the binding of sugar chains to proteins, viruses and cells, the surface plasmon resonance (SPR) technique is very convenient and effective because it is a real-time, non-destructive detection...Full Text Available

UK PubMed Central (United Kingdom)

Moenomycin A (MmA) belongs to a family of natural products that inhibit peptidoglycan biosynthesis by binding to the peptidoglycan glycosyltransferases (PGTs), the enzymes that make the glycan...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Attention deficit hyperactivity disorder (ADHD) is known as a psychiatric disorder in childhood associated with dopamine dysregulation. We investigated dopamine transporter (DAT) density in children with ADHD in the present study using {sup 123}I-IPT SPECT and postulated that an alteration in DAT density in the basal ganglia (BG) is responsible for dopaminergic dysfunction in children with ADHD. 9 durg-naive children with ADHD and 6 normal children were included in the study. We performed brain SPECT 2 hours after administration of {sup 123}I-IPT and made both quantitative and qualitative analyses for assessment of specific/nonspecific DAT binding ratio in the BG. We investigated the correlation between the severity scores of ADHD symptoms in children with ADHD assessed with ADHD rating scale and specific/nonspecific DAT binding ratio in the BG. Drug-naive children with ADHD showed a significantly incresed specific/nonspecific DAT ...

UK PubMed Central (United Kingdom)

The hepatic uptake rate for certain albumin-bound drugs and metabolites correlates poorly with their equilibrium unbound concentration in the plasma, suggesting that binding equilibrium may not always...Full Text Available

UK PubMed Central (United Kingdom)

Proteins that metabolize or bind the nucleotide second messenger cyclic diguanylate regulate a wide variety of important processes in bacteria. These processes include motility, biofilm formation, cell...Full Text Available

UK PubMed Central (United Kingdom)

Dicarboxylic acids are prominent features of several diseases, including Reye's syndrome and inborn errors of mitochondrial and peroxisomal fatty acid oxidation. Moreover, dicarboxylic acids are potentially...Full Text Available

UK PubMed Central (United Kingdom)

Cd36 is a small-molecular-weight integral membrane protein expressed in a diverse, but select, range of cell types. It has an equally diverse range of ligands and physiological functions, which has...Full Text Available

UK PubMed Central (United Kingdom)

E-cadherins belong to a family of membrane-bound, cellular adhesion proteins. Their adhesive properties mainly involve the two N-terminal extracellular domains (EC1 and EC2). The junctions between these...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundHealth risk from exposure of perfluorochemicals (PFCs) to wildlife and human has been a subject of great interest for understanding their molecular mechanism of toxicity....Full Text Available

UK PubMed Central (United Kingdom)

Familial defective apolipoprotein (apo) B-100 is a genetic disease that leads to hypercholesterolemia and to an increased serum concentration of low density lipoproteins that bind defectively to the...Full Text Available

UK PubMed Central (United Kingdom)

Essential in mitosis, the human Kinesin-5 protein is a target for >80 classes of allosteric compounds that bind to a surface-exposed site formed by the L5 loop. Not established is why there...Full Text Available

UK PubMed Central (United Kingdom)

Ataxin-3, the protein involved in Machado-Joseph disease, is able to bind ubiquitylated substrates and act as a deubiquitylating enzyme in vitro, and it has been involved in the modulation of protein...Full Text Available

UK PubMed Central (United Kingdom)

Abs facilitate humoral immunity via the classical mechanisms of opsonization, complement activation, Ab-dependent cellular cytotoxicity, and toxin/viral neutralization. There is also evidence that some...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundProteins may evolve through the recruitment and modification of discrete domains, and in many cases, protein action can be dissected at the domain level. PDZ domains are...Full Text Available

UK PubMed Central (United Kingdom)

DNA antoantibodies in serum will bind to antigen-coated polystyrene tubes and can be detected by radiolabelled anti-immunoglobulin. The method is quantitative, gives information on the antibody class...Full Text Available

UK PubMed Central (United Kingdom)

The identification of MHC class II restricted peptide epitopes is an important goal in immunological research. A number of computational tools have been developed for this purpose, but there is a lack...Full Text Available

KoreaScience (Korea)

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UK PubMed Central (United Kingdom)

Human Factor VIII/von Willebrand factor, purified by calcium citrate-cellulose chromatography and 4% agarose gel filtration was subjected to sodium dodecyl sulfate gel electrophoresis on gels containing...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

We have investigated the effect of the rho tensor coupling on binding energies, matter root-mean-square radii and spin orbit splittings of Ca isotopes in the relativistic mean-field theory with sigma, omega, and rho mesons. It is shown that binding energies and matter root-mean-square radii are insensitive to an alteration in the strength of the rho tensor coupling and an explanation of this is given. We have further shown that inclusion of the rho tensor coupling will give isospin-dependent spin-orbit splittings and this will greatly affect spin-orbit splittings of nuclei near the neutron drip line. (author). Letter-to-the-editor.

British Library Electronic Table of Contents (United Kingdom)

The interactions of flavonoid, quercetin with sodium dodecyl sulfate (anionic surfactant) and cetyltrimethyl ammonium bromide (cationic surfactant) micelles were investigated. The average location site of quercetin in different micelles was determined by the cyclic voltammetry method with the aid of molecular optimization. The interaction parameters of quercetin with micelles of different charges such as binding constant K and normal binding energy DG were calculated. Furthermore, the morphologic change of the SDS and CTAB spherical micelles and rod-like micelles upon their interaction with quercetin was also observed.

International Nuclear Information System (INIS)

2-Azido[#alpha#-"3"2P]adenosine diphosphate (2-azido[#alpha#-"3"2P]ADP) has been used to photolabel the ADP/ATP carrier in beef heart mitochondria. In reversible binding assays carried out in the dark, this photoprobe was found to inhibit ADP/ATP transport in beef heart mitochondria and to bind to two types of specific sites of the ADP/ATP carrier characterized by high-affinity binding (K/sub d/ = 20 #mu#M) and low-affinity binding (K/sub d/ = 400 #mu#M). In contrast, it was unable to bind to specific carrier sites in inverted submitochondrial particles. Upon photoirradiation of beef heart mitochondria in the presence of 2-azido[#alpha#-"3"2P]ADP, the ADP/ATP carrier was covalently labeled. After purification, the photolabeled carrier protein was cleaved chemically by acidolysis or cyanogen bromide and enzymatically with the Staphylococcus aureus V8 protease. In the ADP/ATP carrier ...

Energy Technology Data Exchange (ETDEWEB)

The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g{sup -1}) and proton binding parameters (pK{sup '}{sub H}=5.0,5.3and4.4;m{sub H} = 0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A ...

International Nuclear Information System (INIS)

We have previously shown that avian reovirus (ARV) #sigma#A and #sigma#NS proteins possess dsRNA and ssRNA binding activity and suggested that there are two epitopes on #sigma#A (I and II) and three epitopes (A, B, and C) on #sigma#NS. To further define the location of epitopes on #sigma#A and #sigma#NS proteins and to further elucidate the biological functions of these epitopes by using monoclonal antibodies (MAbs) 62, 1F9, H1E1, and 4A123 against the ARV S1133 strain, the full-length and deletion fragments of S2 and S4 genes of ARV generated by polymerase chain reaction (PCR) were cloned into pET32 expression vectors and the fusion proteins were overexpressed in Escherichia coli BL21 strain. Epitope mapping using MAbs and E. coli-expressed deletion fragments of #sigma#A and #sigma#NS of the ARV S1133 strain, synthetic peptides, and the cross reactivity of MAbs to heterologous ARV strains demonstrated that epitope II on #sigma#A was located at amino acid residues ...

Science.gov (United States)

S100A4, a member of the Ca(2+)-activated S100 protein family, regulates the motility and invasiveness of cancer cells. Moreover, high S100A4 expression levels correlate with poor patient survival in several cancers. Although biochemical, biophysical, and structural data indicate that S100A4 is a noncovalent dimer, it is unknown if two functional S100A4 monomers are required for the productive recognition of protein targets and the promotion of cell invasion. To address this question, we created covalently linked S100A4 dimers using a glycine rich flexible linker. The single-chain S100A4 (sc-S100A4) proteins exhibited wild-type affinities for calcium and nonmuscle myosin-IIA, retained the ability to regulate nonmuscle myosin-IIA assembly, and promoted tumor cell invasion when expressed in S100A4-deficient colon carcinoma cells. Mutation of the two calcium-binding EF-hands in one monomer, while leaving the other monomer intact, caused a 30-60-fold reduction in ...

International Nuclear Information System (INIS)

Administration of [ring-U-14C]propanil (3,4-dichloropropionanilide) to male Sprague-Dawley rats (30, 100, and 300 mg/kg, ip) increased the formation of methemoglobin at the two highest doses. Following a propanil dose of 100 mg/kg, methemoglobin formation attained a maximum level of 5% by 1.5 hr and declined to normal levels (approximately 2.5%) by 12 hr. Hemoglobin binding attained a maximum level of 50 pmol/mg protein by 12 hr, and remained constant for 24 hr. Following a propanil dose of 300 mg/kg, methemoglobin formation attained a maximum level of 24% by 4.5 hr, and declined to a level of 5% by 24 hr. Hemoglobin binding attained a maximum level of 425 pmol/mg protein by 12 hr, and remained constant for 24 hr. Hemoglobin binding was also detected at the lowest propanil dose (10 pmol/mg protein) even though methemoglobin formation was not observed. HPLC analysis of alkaline-treated hemoglobin from propanil-treated rats ...

Energy Technology Data Exchange (ETDEWEB)

Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding ...

International Nuclear Information System (INIS)

The spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) has two major functions: interacting with the receptor to mediate virus entry and inducing protective immunity. Coincidently, the receptor-binding domain (RBD, residues 318-510) of SAR-CoV S protein is a major antigenic site to induce neutralizing antibodies. Here, we used RBD-Fc, a fusion protein containing the RBD and human IgG1 Fc, as a model in the studies and found that a single amino acid substitution in the RBD (R441A) could abolish the immunogenicity of RBD to induce neutralizing antibodies in immunized mice and rabbits. With a panel of anti-RBD mAbs as probes, we observed that R441A substitution was able to disrupt the majority of neutralizing epitopes in the RBD, suggesting that this residue is critical for the antigenic structure responsible for inducing protective immune responses. We also demonstrated that the RBD-Fc bearing R441A mutation could not ...

CERN Document Server

We analyse how the structure of the inner curst is influenced by the pairing correlations. The inner-crust matter, formed by nuclear clusters immersed in a superfluid neutron gas and ultra-relativistic electrons, is treated in the Wigner-Seitz approximation. The properties of the Wigner-Seitz cells, i.e., their neutron to proton ratio and their radius at a given baryonic density, are obtained from the energy minimization at beta equilibrium. To obtain the binding energy of baryonic matter we perform Skyrme-HFB calculations with zero-range density-dependent pairing forces of various intensities. We find that the Wigner-Seitz cells have much smaller numbers of protons compared to previous calculations. For the dense cells the binding energy of the configurations with small proton numbers do not converge to a well-defined minimum value which precludes the determination of their structure. We show that for these cells there is a significant ...

Energy Technology Data Exchange (ETDEWEB)

The effects of muscarinic agonists and diisopropylfluorophosphate (DFP) on muscarinic receptor density and muscarinic receptor-mediated responses was assessed in mouse brain and mouse neuroblastoma cells (clone N1E-115). Utilizing the antagonist ({sup 3}H)quinuclidinyl benzilate (({sup 3}H)QNB), there was no difference in the maximal binding capacity (B{sub max}) or equilibrium dissociation constant (K{sub d}) between untreated and 24 hour DFP-treated mice. However, one administration of DFP produced a 24% and 33% decrease in B{sub max} measured by ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) after 18 and 24 hours which was rapidly reversible within 36 hours after DFP treatment. The loss of ({sup 3}H)NMS binding sites following acute DFP treatment was not accompanied by a change in a particular muscarinic receptor binding conformation. Furthermore, the magnitude of muscarinic receptor-mediated phosphoinositide hydrolysis ...

CERN Document Server

Two headed motor proteins, such as kinesin and dynein, hidrolyze environmental ATP in order to propel unidirectionally along cytoskeletal filaments such as microtubules. In the case of kinesin, protein heads bind primarily on the alpha tubulin site of asymmetric alpha-beta 8nm-long tubulin dimers that constitute the microtubular protofilaments. Kinesin dimers overcome local binding forces up to 5pN and are known to move on protofilaments with ATP concentration-dependent speeds while hydrolizing on average one ATP molecule per 8nm step. The salient features of protein trajectories are the distinct abrupt usually 8nm-long steps from one tubulin dimer to the next interlaced with long quiescent binding periods at a tubulin site. Discrete walks of this type are characterized by substantially reduced variances compared to pure biased random walks, and as a result rule out flashing-type ratchet models as possible mechanisms for ...

Energy Technology Data Exchange (ETDEWEB)

Modification of DNA and double-stranded deoxyoligonucleotides with antitumor 1,2-diamino-cyclohexanedinitroplatinum(II) (Pt-dach) complexes was investigated with the aid of physico-chemical methods and chemical probes of nucleic acid conformation. The three Pt-dach complexes were used which differed in isomeric forms of the dach non-leaving ligand-Pt(1R,2R-dach), Pt(1S,2S-dach) and Pt(1R,2S-dach) complexes. The latter complex has lower antitumor activity than the other two Pt-dach complexes. Pt(1R,2S-dach) complex exhibits the slowest kinetics of its binding to DNA and of the conversion of monofunctional binding to bifunctional lesions. The anomalously slow electrophoretic mobility of multimers of the platinated and ligated oligomers suggests that bifunctional binding of Pt-dach complexes to a d(GG) site within double-stranded oligonucleotides induces bending of the oligomer. It is proposed that different effects of the ...

UK PubMed Central (United Kingdom)

Background:Tobacco smoking is the most important risk factor for chronic obstructive pulmonary disease (COPD) development. Inhaled cigarette smoke can induce tumor necrosis factor-α...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The experiments at the incinerator for low-level wastes processing, (containing transuranium radionuclides) are described. Air decontamination factors and detector readings correction factors for efficiency and absorption are indicated.

UK PubMed Central (United Kingdom)

A fluid-phase immunoradiometric assay has been developed which identifies an antigen on the Factor VIII (antihemophilic factor) procoagulant protein. This sensitive and quantitative assay is not influenced...Full Text Available

UK PubMed Central (United Kingdom)

Caries is a multifactorial disease, and studies aiming to unravel the factors modulating its etiology must consider all known predisposing factors. One major factor is bacterial colonization,...Full Text Available

UK PubMed Central (United Kingdom)

The extracellular domain of human fibroblast growth factor receptor (XC-FGF-R) was expressed in Escherichia coli. The protein was purified to homogeneity and the interaction with basic fibroblast growth...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract. The potential effects of synthetic unmethylated oligodeoxynucleotides (ODN) containing CpG motifs, mimicking bacterial DNA, has never been evaluated on the immune response in the teleost fish gilthead seabream (Sparus aurata), the most important fish species in Mediterranean aquaculture. First, binding and competition studies have demonstrated that binding is saturated and promiscuous, suggesting the participation of several receptors. Moreover, leucocyte cytotoxic (NCC) activity, production of ROIs (reactive oxygen intermediates), and expression of immune-relevant genes was greatly primed by ODNs. Focusing on the mechanism, the TLR9 gene is widely distributed in seabream tissues and differently regulated in vitro by several stimuli. Moreover, and for the first time in fish, TLR9...

British Library Electronic Table of Contents (United Kingdom)

Eight selected sulfonamide drugs were investigated as inhibitors of heat shock protein 90 (Hsp90). The investigation included simulated docking experiments to fit the selected compounds within the binding pocket of Hsp90. The selected molecules were found to readily fit within the ATP-binding pocket of Hsp90 in low-energy poses. The sulfonamides torsemide, sulfathiazole, and sulfadiazine were found to inhibit the ATPase activity of Hsp90 with IC50 values of 1.0, 2.6, and 1.5 mM, respectively. Our results suggest that these well-established sulfonamides can be good leads for subsequent optimization into potent Hsp90 inhibitors.

Science.gov (United States)

Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In particular, the study of transition metal complexes that bind DNA with specificity has been a burgeoning field. This growth has been due in large part to the useful properties of metal complexes, which possess a wide array of photophysical properties and allow for the modular assembly of an ensemble of recognition elements. Here we review recent experiments in our laboratory aimed at the design and study of octahedral metal complexes that bind DNA non-covalently and target reactions to specific sites. Emphasis is placed both on the variety of methods employed to confer site-specificity and upon the many applications for these complexes. Particular attention is given to the family of complexes recently designed that target single base mismatches in duplex ...

British Library Electronic Table of Contents (United Kingdom)

Objective. Preterm neonates are susceptible to infection due to a combination of sub-optimal immunity and increased exposure to invasive organisms. Invasive fungal infections are associated with significant morbidity and mortality among preterm infants cared for in the neonatal intensive care unit (NICU). Mannose-binding lectin (MBL) is a component of the innate immune system, which may be especially important in the neonatal setting. The objective of this study was to investigate the presence of any association between MBL gene polymorphism and nosocomial invasive fungal infection in preterm neonates. Methods. Codon 54 (B allele) polymorphism in exon 1 of the MBL gene was investigated in 31 patients diagnosed as nosocomial invasive fungal infection and 30 control preterm neonates. Results...

Energy Technology Data Exchange (ETDEWEB)

The anticonvulsant drugs carbamazepine, phenobarbital, trimethadione, valproic acid and ethosuximide at pharmacologically relevant concentrations inhibit (/sup 3/H)diazepam binding to astrocytes in primary cultures but have much less effect on a corresponding preparation of neurons. Phenytoin as well as pentobarbital (which is not used chronically as an anticonvulsant) are equipotent in the two cell types. The convulsants picrotoxinin and pentylenetetrazol, the convulsant benzodiazepine RO 5-3663 and the two convulsant barbiturates DMBB and CHEB similarly inhibit diazepam binding to astrocytes but have little effect on neurons. On the basis of these findings it is suggested that these convulsants and anticonvulsants owe at least part of their effect to an interaction with the astrocytic benzodiazepine receptor, perhaps by interference with a calcium channel.

British Library Electronic Table of Contents (United Kingdom)

Conformationally constrained analogue synthesis was undertaken to aid in pharmacophore mapping and 3D-QSAR analysis of nitrobenzylmercaptopurine riboside (NBMPR) congeners as equilibriative nucleoside transporter 1 (ENT1) inhibitors. In our previous study [J. Med. Chem. 2003, 46, 831-837], novel regioisomeric nitro-1,2,3,4-tetrahydroisoquinoline conformationally constrained analogues of NBMPR were synthesized and evaluated as ENT1 ligands. 7-NO2-1,2,3,4-Tetrahydroisoquino-2-yl purine riboside was identified as the analogue with the nitro group in the best orientation at the NBMPR binding site of ENT1. In the present study, further conformational constraining was introduced by synthesizing 5prime-O,8-cyclo derivatives. The flow cytometrically determined binding affinities indicated that the...

Energy Technology Data Exchange (ETDEWEB)

Radium is known to be taken up by aquatic animals, and tends to accumulate in bone, shell and exoskeleton. The most common approach to estimating the uptake of a radionuclide by aquatic animals for use in health and environmental risk assessments is the concentration factor method. The concentration factor method relates the concentration of a contaminant in an organism to the concentration in the surrounding water. Site specific data are not usually available, and generic, default values are often used in risk assessment studies. This paper describes the concentration factor method, summarizes some of the variables which may influence the concentration factor for radium, reviews reported concentration factors measured in marine environments and presents concentration factors derived from data collected in a study in coastal Louisiana. The use of generic default ...

Science.gov (United States)

... implementation." 4 1 Factors Affecting Rural Construction. Two new factors profoundly modify today's pacification equa- tion. ...

Energy Technology Data Exchange (ETDEWEB)

The data base for the form factors of the nucleon obtained from elastic ep scattering is discussed, as well as some recent developments in their calculation.

Energy Technology Data Exchange (ETDEWEB)

This is a presentation on Human Factors in reactor operations. It discusses issues that deal with power plant operations, training and design, operational effectiveness and safety, supporting people to achieve effective and error free performance.

CERN Document Server

The stock market has been known to form homogeneous stock groups with a higher correlation among different stocks according to common economic factors that influence individual stocks. We investigate the role of common economic factors in the market in the formation of stock networks, using the arbitrage pricing model reflecting essential properties of common economic factors. We find that the degree of consistency between real and model stock networks increases as additional common economic factors are incorporated into our model. Furthermore, we find that individual stocks with a large number of links to other stocks in a network are more highly correlated with common economic factors than those with a small number of links. This suggests that common economic factors in the stock market can be understood in terms of deterministic factors.

International Nuclear Information System (INIS)

The U.S. Department of Energy's (DOE) Savannah River Site (SRS) is decommissioning many of its excess facilities through removal of the facility structures leaving only the concrete-slab foundations in place. Site-specific, risk-based derived concentration guideline levels (DCGLs) for radionuclides have been determined for a future industrial worker potentially exposed to residual contamination on these concrete slabs as described in Jannik. These risk-based DCGLs were estimated for an exposure area of 100 m2. During deactivation and decommissioning (D and D) operations at SRS, the need for area factors for larger and smaller contaminated areas arose. This paper compares the area factors determined for an industrial worker exposed to a concrete slab end-state for several radionuclides of concern at SRS with 1) the illustrative area factors provided in MARSSIM, 2) the area correction factors provided in ...

International Nuclear Information System (INIS)

The photoaffinity probes [#gamma#-"3"2P]2-azidoATP (2-N_3ATP) and [#alpha#-"3"2P]8-azido-ATP (8-N_3ATP) were used to investigate the binding of ATP to highly purified 2-5A synthetase. 2-N_3APT and 8-N_3ATP are substrates for 2-5A synthetase. In this study the authors show that 2- and 8-N_3ATP are competitive inhibitors of the enzymatic conversion of ATP to 2-5A. Ultraviolet irradiation results in the photoinsertion of 2-N_3ATP and 8-N_3ATP into the enzyme. The covalent photoinsertion of [#alpha#-"3"2P]8-N_3ATP into the 2-5A synthetase is proportional to the inactivation of the enzyme as UV irradiation is increased. Photolabeling of 2-5A synthetase is saturated at 1.5 mM 2-N_3ATP and 2.0 mM 8-N_3ATP. Computer analysis of the curvilinear Scatchard plots of the 2-5A synthetase suggest the presence of high-affinity and low-affinity binding sites that may correspond to the acceptor and the 2'-adenylation sites of the enzyme. The competition of ...

UK PubMed Central (United Kingdom)

1. Novel methods, using L-[ring-2-14C]tryptophan, are described for the measurement of tryptophan 2,3-dioxygenase activity and tryptophan accumulation in isolated rat liver cells. 2. The effects of...Full Text Available

UK PubMed Central (United Kingdom)

1. Several ring-substituted derivatives of diphenyleneiodonium catalyse the exchange of Cl- and OH- ions across the inner membrane of rat liver mitochondria. They also inhibit state 3 and state 3u oxidations...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Neurodegeneration observed in Alzheimer disease (AD) is believed to be related to the toxicity from reactive oxygen species (ROS) produced in the brain by the amyloid-{beta} (A{beta}) protein bound primarily to copper ions. The evidence for an oxidative stress role of A{beta}-Cu redox chemistry is still incomplete. Details of the copper binding site in A{beta} may be critical to the etiology of AD. Here we present the structure determined by combining x-ray absorption spectroscopy (XAS) and density functional theory analysis of A{beta} peptides complexed with Cu{sup 2+} in solution under a range of buffer conditions. Phosphate-buffered saline buffer salt (NaCl) concentration does not affect the high-affinity copper binding mode but alters the second coordination sphere. The XAS spectra for truncated and full-length A{beta}-Cu{sup 2+} peptides are similar. The novel distorted six-coordinated (3N3O) geometry around copper in the A{beta}-Cu{sup ...

International Nuclear Information System (INIS)