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Sample records for affinity chromatography imac

  1. Enrichment and characterization of phosphopeptides by immobilized metal affinity chromatography (IMAC) and mass spectrometry

    DEFF Research Database (Denmark)

    Thingholm, Tine E; Jensen, Ole N

    2009-01-01

    The combination of immobilized metal affinity chromatography (IMAC) and mass spectrometry is a widely used technique for enrichment and sequencing of phosphopeptides. In the IMAC method, negatively charged phosphate groups interact with positively charged metal ions (Fe3+, Ga3+, and Al3+) and this...... phosphopeptides. The retained phosphopeptides are released from the IMAC resin by using alkaline buffers (pH 10-11), EDTA, or phosphate-containing buffers. We have described a detailed and robust protocol for IMAC for phosphopeptide enrichment from semi-complex mixtures....

  2. Comprehensive and Reproducible Phosphopeptide Enrichment Using Iron Immobilized Metal Ion Affinity Chromatography (Fe-IMAC) Columns

    OpenAIRE

    2014-01-01

    Advances in phosphopeptide enrichment methods enable the identification of thousands of phosphopeptides from complex samples. Current offline enrichment approaches using TiO2, Ti, and Fe immobilized metal ion affinity chromatography (IMAC) material in batch or microtip format are widely used, but they suffer from irreproducibility and compromised selectivity. To address these shortcomings, we revisited the merits of performing phosphopeptide enrichment in an HPLC column format. We found that ...

  3. Cromatografia de afinidade por íons metálicos imobilizados (IMAC) de biomoléculas: aspectos fundamentais e aplicações tecnológicas Immobilized metal-ion affinity chromatography (IMAC) of biomolecules: fundamental aspects and technological applications

    OpenAIRE

    Igor Tadeu Lazzarotto Bresolin; Everson Alves Miranda; Sônia Maria Alves Bueno

    2009-01-01

    Immobilized Metal Ion Affinity Cromatography - IMAC - is a group-specific based adsorption applied to the purification and structure-function studies of proteins and nucleic acids. The adsorption is based on coordination between a metal ion chelated on the surface of a solid matrix and electron donor groups at the surface of the biomolecule. IMAC is a highly selective, low cost, and easily scaled-up technique being used in research and commercial operations. A separation process can be design...

  4. Cromatografia de afinidade por íons metálicos imobilizados (IMAC de biomoléculas: aspectos fundamentais e aplicações tecnológicas Immobilized metal-ion affinity chromatography (IMAC of biomolecules: fundamental aspects and technological applications

    Directory of Open Access Journals (Sweden)

    Igor Tadeu Lazzarotto Bresolin

    2009-01-01

    Full Text Available Immobilized Metal Ion Affinity Cromatography - IMAC - is a group-specific based adsorption applied to the purification and structure-function studies of proteins and nucleic acids. The adsorption is based on coordination between a metal ion chelated on the surface of a solid matrix and electron donor groups at the surface of the biomolecule. IMAC is a highly selective, low cost, and easily scaled-up technique being used in research and commercial operations. A separation process can be designed for a specific molecule by just selecting an appropriate metal ion, chelating agent, and operational conditions such as pH, ionic strength, and buffer type.

  5. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10–11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe 3+ for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide......Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...

  6. Enrichment of Phosphopeptides via Immobilized Metal Affinity Chromatography.

    Science.gov (United States)

    Swaney, Danielle L; Villén, Judit

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) is a frequently used method for the enrichment of phosphorylated peptides from complex, cellular lysate-derived peptide mixtures. Here we outline an IMAC protocol that uses iron-chelated magnetic beads to selectively isolate phosphorylated peptides for mass spectrometry-based proteomic analysis. Under acidic conditions, negatively charged phosphoryl modifications preferentially bind to positively charged metal ions (e.g., Fe(3+), Ga(3+)) on the beads. After washing away nonphosphorylated peptides, a pH shift to basic conditions causes the elution of bound phosphopeptides from the metal ion. Under optimal conditions, very high specificity for phosphopeptides can be achieved. PMID:26933247

  7. Phosphopeptide Enrichment by Immobilized Metal Affinity Chromatography.

    Science.gov (United States)

    Thingholm, Tine E; Larsen, Martin R

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively charged metal ions such as Fe(3+), Ga(3+), Al(3+), Zr(4+), and Ti(4+) has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from nonspecific binding of non-phosphorylated peptides. This problem is mainly caused by highly acidic peptides that also share high binding affinity towards these metal ions. By lowering the pH of the loading buffer nonspecific binding can be reduced significantly, however with the risk of reducing specific binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10-11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe(3+) for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide mixture. PMID:26584922

  8. PREPARATION OF CHITOSAN COATED METAL AFFINITY CHROMATOGRAPHY ADSORBENT

    Institute of Scientific and Technical Information of China (English)

    AanTianwei; XuWeijiang; 等

    1998-01-01

    A new and an inexpensive adsorbent of chitosan coated silica for immobilized metal affinity chromatography(IMAC) was studied.After a double coating,the chitosan coated on silica beads could be up to 53.4mg/g silica beads.When pH>3.8,the metal ligand Cu2+ was chelated on the coated chitosan with a bound capacity of 14.6mg/g chitosan without introducing iminodiacetic acid(IDA).

  9. Immobilised metal-ion affinity chromatography purification of histidine-tagged recombinant proteins : a wash step with a low concentration of EDTA

    NARCIS (Netherlands)

    Westra, DF; Welling, GW; Koedijk, DGAM; Scheffer, AJ; The, TH; Welling-Wester, S

    2001-01-01

    Immobilised metal-ion affinity chromatography (IMAC) is widely used for the purification of recombinant proteins in which a poly-histidine tag is introduced. However, other proteins may also bind to IMAC columns. We describe the use of a washing buffer with a low concentration of EDTA (0.5 mM) for t

  10. Removal of PCR error products and unincorporated primers by metal-chelate affinity chromatography.

    Directory of Open Access Journals (Sweden)

    Indhu Kanakaraj

    Full Text Available Immobilized Metal Affinity Chromatography (IMAC has been used for decades to purify proteins on the basis of amino acid content, especially surface-exposed histidines and "histidine tags" genetically added to recombinant proteins. We and others have extended the use of IMAC to purification of nucleic acids via interactions with the nucleotide bases, especially purines, of single-stranded RNA and DNA. We also have demonstrated the purification of plasmid DNA from contaminating genomic DNA by IMAC capture of selectively-denatured genomic DNA. Here we describe an efficient method of purifying PCR products by specifically removing error products, excess primers, and unincorporated dNTPs from PCR product mixtures using flow-through metal-chelate affinity adsorption. By flowing a PCR product mixture through a Cu(2+-iminodiacetic acid (IDA agarose spin column, 94-99% of the dNTPs and nearly all the primers can be removed. Many of the error products commonly formed by Taq polymerase also are removed. Sequencing of the IMAC-processed PCR product gave base-calling accuracy comparable to that obtained with a commercial PCR product purification method. The results show that IMAC matrices (specifically Cu(2+-IDA agarose can be used for the purification of PCR products. Due to the generality of the base-specific mechanism of adsorption, IMAC matrices may also be used in the purification of oligonucleotides, cDNA, mRNA and micro RNAs.

  11. Large-scale analysis of in Vivo phosphorylated membrane proteins by immobilized metal ion affinity chromatography and mass spectrometry

    DEFF Research Database (Denmark)

    Nühse, Thomas S; Stensballe, Allan; Jensen, Ole N;

    2003-01-01

    Global analyses of protein phosphorylation require specific enrichment methods because of the typically low abundance of phosphoproteins. To date, immobilized metal ion affinity chromatography (IMAC) for phosphopeptides has shown great promise for large-scale studies, but has a reputation for poo...

  12. Protein isolation using affinity chromatography

    OpenAIRE

    Besselink, T.

    2012-01-01

    Many product or even waste streams in the food industry contain components that may have potential for e.g. functional foods. These streams are typically large in volume and the components of interest are only present at low concentrations. A robust and highly selective separation process should be developed for efficient isolation of the components. Affinity chromatography is such a selective method. Ligands immobilized to a stationary phase (e.g., a resin or membrane) are used to bind the c...

  13. Affinity Purification of Insulin by Peptide-Ligand Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The affinity heptapeptide (HWWWPAS) for insulin, selected from phage display library,was coupled to EAH Sepharose 4B gel and packed to a 1-mL column. The column was used for the affinity purification of insulin from protein mixture and commercial insulin preparation. It was observed that the minor impurity in the commercial insulin was removed by the affinity chromatography. Nearly 40 mg of insulin could be purified with the 1-mL affinity column. The results revealed the high specificity and capacity of the affinity column for insulin purification. Moreover, based on the analysis of the amino acids in the peptide sequence, shorter peptides were designed and synthesized for insulin chromatography. As a result, HWWPS was found to be a good alternative to HWWWPAS, while the other two peptides with three or four amino acids showed weak affinity for insulin. The results indicated that the peptide sequence of HWWWPAS was quite conservative for specific binding of insulin.

  14. Fast and Efficient IMAC Protocol for Phosphopeptide enrichment for phosphoproteomic Studies via LC-MS/MS

    OpenAIRE

    McKennan, C.; Spruce, L.; Seeholzer, S; Ding, H.

    2014-01-01

    Recent developments in first dimension High-Performance Liquid Chromatography (HPLC) separation of complex peptide mixtures, followed by a subsequent immobilized metal ion affinity chromatography (IMAC) for phosphopeptide enrichment have shown great promise in both selectivity and quantification of phosphopeptides via LC-MS/MS analysis. The first dimension HPLC, such as hydrophilic interaction chromatography (HILIC) or high pH Reverse Phase chromatography, was employed for its being orthogona...

  15. Evaluation of immobilized metal affinity chromatography kits for the purification of histidine-tagged recombinant CagA protein.

    Science.gov (United States)

    Karakus, Cebrail; Uslu, Merve; Yazici, Duygu; Salih, Barik A

    2016-05-15

    Immobilized metal affinity chromatography (IMAC) technique is used for fast and reliable purification of histidine(His)-tagged recombinant proteins. The technique provides purification under native and denaturing conditions. The aim of this study is to evaluate three commercially available IMAC kits (Thermo Scientific, GE Healthcare and Qiagen) for the purification of a 6xHis-tagged recombinant CagA (cytotoxin-associated gene A) protein from IPTG-induced Escherichia coli BL21(DE3) culture. The kits were tested according to the manufacturer instructions and the protein was purified with only GE Healthcare and Qiagen kits under denaturing conditions. 1% (w/v) SDS was used as denaturing agent in PBS instead of extraction reagent of Thermo Scientific kit to lyse bacterial cells from 100ml culture. The 6xHis-tagged recombinant protein was purified by the three kits equally. PMID:26657801

  16. Immobilized Metal Affinity Chromatography Coupled to Multiple Reaction Monitoring Enables Reproducible Quantification of Phospho-signaling.

    Science.gov (United States)

    Kennedy, Jacob J; Yan, Ping; Zhao, Lei; Ivey, Richard G; Voytovich, Uliana J; Moore, Heather D; Lin, Chenwei; Pogosova-Agadjanyan, Era L; Stirewalt, Derek L; Reding, Kerryn W; Whiteaker, Jeffrey R; Paulovich, Amanda G

    2016-02-01

    A major goal in cell signaling research is the quantification of phosphorylation pharmacodynamics following perturbations. Traditional methods of studying cellular phospho-signaling measure one analyte at a time with poor standardization, rendering them inadequate for interrogating network biology and contributing to the irreproducibility of preclinical research. In this study, we test the feasibility of circumventing these issues by coupling immobilized metal affinity chromatography (IMAC)-based enrichment of phosphopeptides with targeted, multiple reaction monitoring (MRM) mass spectrometry to achieve precise, specific, standardized, multiplex quantification of phospho-signaling responses. A multiplex immobilized metal affinity chromatography- multiple reaction monitoring assay targeting phospho-analytes responsive to DNA damage was configured, analytically characterized, and deployed to generate phospho-pharmacodynamic curves from primary and immortalized human cells experiencing genotoxic stress. The multiplexed assays demonstrated linear ranges of ≥3 orders of magnitude, median lower limit of quantification of 0.64 fmol on column, median intra-assay variability of 9.3%, median inter-assay variability of 12.7%, and median total CV of 16.0%. The multiplex immobilized metal affinity chromatography- multiple reaction monitoring assay enabled robust quantification of 107 DNA damage-responsive phosphosites from human cells following DNA damage. The assays have been made publicly available as a resource to the community. The approach is generally applicable, enabling wide interrogation of signaling networks. PMID:26621847

  17. OPTIMIZATION OF IMMOBILIZED METAL ION AFFINITY CHROMATOGRAPHY FOR PHOSPHOPEPTIDE ENRICHMENT  PRIOR TO MASS SPECTROMETRY

    DEFF Research Database (Denmark)

    Ye, Juanying; Zhang, Xumin; Young, Clifford; Rudashevskaya, Elena L; Nawrocki, Arek; G. Palmgren, Michael; T. Fuglsang, Anja; Jensen, Ole Nørregaard

    progress.   Results Fe(III)-IMAC using NTA-silica from Qiagen  showed a better performance than two other commercially available resins under the testing conditions. Increase of the acetonitrile content to 60% in loading and washing buffer significantly improved the specificity of IMAC enrichment. It was...... ionization degree   References Stensballe, A., Andersen, S. & Jensen, O. N. Characterization of phosphoproteins from electrophoretic gels by nanoscale Fe(III) affinity chromatography with off-line mass spectrometry analysis. Proteomics 1, 207-22 (2001)....

  18. Exploring Fluorous Affinity by Liquid Chromatography.

    Science.gov (United States)

    Catani, Martina; Guzzinati, Roberta; Marchetti, Nicola; Pasti, Luisa; Cavazzini, Alberto

    2015-07-01

    Terms such as "fluorous affinity" and "fluorophilicity" have been used to describe the unique partition and sorption properties often exhibited by highly fluorinated organic compounds, that is molecules rich in sp(3) carbon-fluorine bonds. In this work, we made use of a highly fluorinated stationary phase and a series of benzene derivatives to study the effect of one single perfluorinated carbon on the chromatographic behavior and adsorption properties of molecules. For this purpose, the adsorption equilibria of α,α,α-trifluorotoluene, toluene, and other alkylbenzenes have been studied by means of nonlinear chromatography in a variety of acetonitrile/water eluents. Our results reveal that one single perfluorinated carbon is already enough to induce a drastic change in the adsorption properties of molecules on the perfluorinated stationary phase. In particular, it has been found that adsorption is monolayer if the perfluoroalkyl carbon is present but that, when this unit is missing, molecules arrange as multilayer stack structures. These findings can contribute to the understanding of molecular mechanisms of fluorous affinity. PMID:26047527

  19. Phosphopeptide Purification by IMAC with Fe(III) and Ga(III)

    DEFF Research Database (Denmark)

    Steen, Hanno; Stensballe, Allan

    2007-01-01

    INTRODUCTIONImmobilized metal ion affinity chromatography (IMAC) makes use of matrix-bound metals to affinity-purify phosphoproteins and phosphopeptides. Commonly used metals in early studies such as Ni(2+), Co(2+), Zn(2+), and Mn(2+) were shown to bind strongly to proteins with a high density of...... histidines. More recently, immobilized Fe(3+), Ga(3+), and Al(3+) metal ions have been used for the selective enrichment of phosphopeptides from complex proteolytic digest mixtures containing both phosphorylated and nonphosphorylated components. The use of a nitrilotriacetic acid (NTA) matrix over...... iminodiacetic-acid-modified matrices has been reported to provide an advantage in selectivity. The development of elution conditions that are directly compatible with MS analysis of the enriched phosphopeptide samples provides the option to interface IMAC and MS online. This protocol describes the enrichment of...

  20. RECOVERY OF CYCLODEXTRIN GLUCANOTRANSFERASE (CGTase USING IMMOBILIZED METAL CHELATING AFFINITY CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    M. Sivapragasam

    2015-03-01

    Full Text Available Abstract Immobilized metal affinity chromatography (IMAC was chosen as a method of purification for the recovery of CGTase from E. coli homogenate. E. coli harbouring the Bacillus sp. G1 gene expressed extracellularly secreted CGTase into ampicillin supplied LB broth. Culture was pre-purified using SnakeSkin dialysis tubing (3.5 MWCO with an enzyme activity of 147.80 U/mL. Three strategies (A, B and C were employed for the purification of CGTase using column adsorption chromatography with Ni2+-Sepharose resin. Strategy A employed an elution buffer of 50 mM EDTA, pH 7, Strategy B used 0.1 M imidazole, pH 7 and Strategy C employed 45 mM imidazole pH 7 as the elution buffer. Strategy C was found to be most suitable yielding a total CGTase recovery of 87.04% from an initial activity of 147.80 U/mL.

  1. Optimization of conditions for the single step IMAC purification of miraculin from Synsepalum dulcificum.

    Science.gov (United States)

    He, Zuxing; Tan, Joo Shun; Lai, Oi Ming; Ariff, Arbakariya B

    2015-08-15

    In this study, the methods for extraction and purification of miraculin from Synsepalum dulcificum were investigated. For extraction, the effect of different extraction buffers (phosphate buffer saline, Tris-HCl and NaCl) on the extraction efficiency of total protein was evaluated. Immobilized metal ion affinity chromatography (IMAC) with nickel-NTA was used for the purification of the extracted protein, where the influence of binding buffer pH, crude extract pH and imidazole concentration in elution buffer upon the purification performance was explored. The total amount of protein extracted from miracle fruit was found to be 4 times higher using 0.5M NaCl as compared to Tris-HCl and phosphate buffer saline. On the other hand, the use of Tris-HCl as binding buffer gave higher purification performance than sodium phosphate and citrate-phosphate buffers in IMAC system. The optimum purification condition of miraculin using IMAC was achieved with crude extract at pH 7, Tris-HCl binding buffer at pH 7 and the use of 300 mM imidazole as elution buffer, which gave the overall yield of 80.3% and purity of 97.5%. IMAC with nickel-NTA was successfully used as a single step process for the purification of miraculin from crude extract of S. dulcificum. PMID:25794715

  2. Immobilized metal affinity chromatography on collapsed Langmuir-Blodgett iron(III) stearate films and iron(III) oxide nanoparticles for bottom-up phosphoproteomics.

    Science.gov (United States)

    Gladilovich, Vladimir; Greifenhagen, Uta; Sukhodolov, Nikolai; Selyutin, Artem; Singer, David; Thieme, Domenika; Majovsky, Petra; Shirkin, Alexey; Hoehenwarter, Wolfgang; Bonitenko, Evgeny; Podolskaya, Ekaterina; Frolov, Andrej

    2016-04-22

    Phosphorylation is the enzymatic reaction of site-specific phosphate transfer from energy-rich donors to the side chains of serine, threonine, tyrosine, and histidine residues in proteins. In living cells, reversible phosphorylation underlies a universal mechanism of intracellular signal transduction. In this context, analysis of the phosphoproteome is a prerequisite to better understand the cellular regulatory networks. Conventionally, due to the low contents of signaling proteins, selective enrichment of proteolytic phosphopeptides by immobilized metal affinity chromatography (IMAC) is performed prior to their LC-MS or -MS/MS analysis. Unfortunately, this technique still suffers from low selectivity and compromised analyte recoveries. To overcome these limitations, we propose IMAC systems comprising stationary phases based on collapsed Langmuir-Blodgett films of iron(III) stearate (FF) or iron(III) oxide nanoparticles (FO) and mobile phases relying on ammonia, piperidine and heptadecafluorooctanesulfonic acid (PFOS). Experiments with model phosphopeptides and phosphoprotein tryptic digests showed superior binding capacity, selectivity and recovery for both systems in comparison to the existing commercial analogs. As evidenced by LC-MS/MS analysis of the HeLa phosphoproteome, these features of the phases resulted in increased phosphoproteome coverage in comparison to the analogous commercially available phases, indicating that our IMAC protocol is a promising chromatographic tool for in-depth phosphoproteomic research. PMID:27016113

  3. iMac pocket genius

    CERN Document Server

    Hart-Davis, Guy

    2010-01-01

    If you want to get the very most out of your iMac, put this savvy Portable Genius guide to work. Want to make the most of the new Magic Mouse and the latest iLife apps? Set up a wireless network using your iMac's AirPort card? Watch television on your iMac, or show iMac videos and movies on your television? You'll find cool and useful Genius tips, full-color screenshots, and pages of easy-to-access shortcuts and tools that will save you time and let you enjoy your iMac to the max.

  4. Immobilized metal affinity chromatography of phosphorylated proteins using highperformance sorbents

    Czech Academy of Sciences Publication Activity Database

    Novotná, L.; Hrubý, Martin; Beneš, Milan J.; Kučerová, Z.

    2008-01-01

    Roč. 68, 5-6 (2008), s. 381-386. ISSN 0009-5893 Grant ostatní: GA MŠk(CZ) LC06044 Institutional research plan: CEZ:AV0Z40500505 Keywords : immobilized metal affinity chromatography * phosphorylation * metal ions Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.312, year: 2008

  5. Study of pepsin phosphorylation using immobilized metal affinity chromatography

    Czech Academy of Sciences Publication Activity Database

    Novotná, L.; Hrubý, Martin; Beneš, Milan J.; Kučerová, Z.

    2008-01-01

    Roč. 31, č. 10 (2008), s. 1662-1668. ISSN 1615-9306 Institutional research plan: CEZ:AV0Z40500505 Keywords : Fe(III) * Ga(III) * immobilized metal affinity chromatography * modification of carboxyl groups Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.746, year: 2008

  6. The Purification of a Blood Group A Glycoprotein: An Affinity Chromatography Experiment.

    Science.gov (United States)

    Estelrich, J.; Pouplana, R.

    1988-01-01

    Describes a purification process through affinity chromatography necessary to obtain specific blood group glycoproteins from erythrocytic membranes. Discusses the preparation of erythrocytic membranes, extraction of glycoprotein from membranes, affinity chromatography purification, determination of glycoproteins, and results. (CW)

  7. The IMACS Occultation Survey

    Science.gov (United States)

    Payne, Matthew John; Holman, Matthew; Alcock, Charles; Osip, David; Schlichting, Hilke

    2015-11-01

    We report the results of our extended campaign to search for occultations of background stars by small (sub-km) Kuiper belt objects (KBOs) using the IMACS instrument on the Magellan Telescope.We implemented a novel shutterless continuous readout mode on the IMACS instrument, with custom-made aperture masks, permitting simultaneous high-speed (~40 Hz) photometry for numerous stars, while minimizing the effects of stellar crowding and sky background. Observing in the southern hemisphere allows us to target the intersection of the ecliptic and galactic planes, where hundreds of stars can be monitored with a single field of view.We observed for a total of ~28 hours spread over eight nights, obtaining over 10,000 star-hours of light curves with per-point SNR > 10. This represents an order of magnitude increase in star hours compared to the previous best ground-based survey by Bianco et al. (2009). Our results allow us to place strong constraints on the surface density of sub-km objects in the Kuiper-Belt, as well as to complement the HST FGS results of Schlichting et al. (2009, 2012).

  8. iMac for dummies

    CERN Document Server

    Chambers, Mark L

    2014-01-01

    Do it all with your iMac and this bestselling For Dummies guide! You're still a little giddy from finally scoring your new iMac, and you can't wait to get started. Even if you're already in love with your iMac, it helps to have a little guidance to really get the most out of this ultimate all-in-one computer. This updated edition of iMac For Dummies is the ideal way to learn the iMac fundamentals from setting up and personalizing your machine to importing files, making FaceTime video calls, surfing the web, using your favorite programs and apps, and everything in between. Trusted Mac guru Mark

  9. iMac for dummies

    CERN Document Server

    Chambers, Mark L

    2012-01-01

    The bestselling guide to the ultimate all-in-one computer—now updated and revised throughout! If you're looking for speed, performance, and power, the iMac is the ultimate all-in-one computer. From its superior performance, powerful operating system, and amazing applications, the iMac is one awesome machine, and the fun, friendly, and approachable style of iMac For Dummies is an ideal way to get started with the basics. You'll learn the fundamentals of the iMac including setting up and customizing your iMac and the software that comes with it, importing files from your old computer, send

  10. iMac portable genius

    CERN Document Server

    Hart-Davis, Guy

    2010-01-01

    The most up-to-date coverage on the latest iMac advice, tools, and shortcuts Cool and useful tips, full-color screenshots, and savvy advice show you how to get the most out of your iMac. Fully updated to cover the iMac's latest features and capabilities, this guide is packed with indispensible information on iLife '09 and Mac OS X Snow Leopard, and shows you how to customize your iMac in a way that it will work best for you.Explores all the bells and whistles of the iMac, including the new Magic Mouse, iLife apps such as iPhoto and iMovie, and Mac OS X Snow LeopardShows yo

  11. iMac portable genius

    CERN Document Server

    Binder, Kate

    2008-01-01

    Cool and useful tips, full-color screenshots, and savvy advice show you how to get the most out of your iMac. You'll discover exactly what the Apple remote is capable of, how to set up your iMac so that it's customized for multiple users, and all there is to know about Mac OS X's built-in organizational tools. This indispensable guide ramps up the pace and offers you easy-to-access shortcuts so you can start enjoying your iMac to the max.

  12. [Fractionation of lymphocytes using affinity chromatography with 9 lectins].

    Science.gov (United States)

    de Dios, I; Manso, M; López-Borrasca, A

    1983-12-01

    Lymphocyte subclasses from normal peripheral blood have been fractionated by affinity chromatography with lectins. Concanavalin A (Con A), Lens culinaris lectin (LC), Pisum sativum lectin (PS), Phaseolus vulgaris lectin (PHA), Dolichos biflours lectin (DB), Glicine max lectin (SBA), Ricinus communis lectin (RCA II), Tetragonolobus purpureus lectin (TP) and Triticum vulgaris lectin (WGA), were coupled to Sepharose 6MB, and lymphocytes labelled with 125I were eluted through the chromatographic columns. The binding of lymphocytes to WGA and SBA lectins was 32% and 13% respectively. The binding to the other lectins tested were found to be between 32% and 13%. When solutions of increasing concentrations of specific sugar were added to the columns a progressive elution of bound lymphocytes was observed. These results indicate the existence of a large range of lymphocyte subclasses, with different binding capacity to lectins, which was a function of the receptor number or/and receptor affinity to each lectin. Furthermore, these two parameters were found to vary in each functional population. Even though all the lymphocytes had lectin receptors, T lymphocytes showed higher affinity for Con A, PHA and TP lectins, while B lymphocytes appeared to be more specific for LC, PS, SBA, DB, RCAII and WGA lectins. PMID:6675094

  13. Affinity chromatography of native and irradiated lactate dehydrogenase

    International Nuclear Information System (INIS)

    LDH V was irradiated in aqueous solution at a concentration of 1mg/ml in the presence of nitrogen or oxygen. The dose given was 1700 Gy. The irradiated enzyme was separated on 5'AMP Sepharose 4B. The NADH-gradient-eluted fraction was then further studied by determinations of activity, protein, and SH-groups. Gel electrophoresis was also performed on some of the samples. It could be shown that radiation-damaged protein was, overall, less firmly specificially bound. Completely inactivated protein was not bound at all and could be eluted with a buffer immediately after spreading. A wide flat peak was shown in activity determinations of NADH-gradient eluted samples. Radiosensitivity was increased by the presence of oxygen. With the aid of SH-group determination, three further peaks could be identified whereby peaks I and II were bound less strongly, and peak III more strongly than native enzyme. These three peaks are thought to represent different modifications of irradiated LDH. A detailed analysis could be the subject of further investigation. The presence of protein fragments was established by electrophoresis for samples irradiated under oxygen but were not found for samples irradiated under nitrogen. Affinity chromatography is an elegant and safe method for establishing the purity of substances from mixtures. It is, however, only of limited value for studying irradiated proteins. (orig.)

  14. Preliminary study of the metal binding site of an anti-DTPA-indium antibody by equilibrium binding immunoassays and immobilized metal ion affinity chromatography.

    Science.gov (United States)

    Boden, V; Colin, C; Barbet, J; Le Doussal, J M; Vijayalakshmi, M

    1995-01-01

    Creating metal coordination sites by modifying an existing enzyme or by eliciting antibodies against metal chelate haptens is of great interest in biotechnology to create enzyme catalysts with novel specificities. Here, we investigate the metal binding potential of a monoclonal antibody raised against a DTPA-In(III) hapten (mAb 734). We study its relative binding efficiency to metals of biological relevance by equilibrium binding immunoassays and immobilized metal ion affinity chromatography, two approaches which can give complementary information regarding composition and/or structure of the metal binding site(s). Fe(III), Fe(II), Cu(II), Mg(II), Ca(II), and Zn(II) binding was compared to In(III). All of them were shown to displace indium, but their affinity for mAb 734 decreased by 100-fold compared to indium. Competitive metal binding immunoassays between Zn(II) and In(III) revealed an unusual behavior by Zn(II) which remains to be explained. Moreover, IMAC allowed us to predict the metal binding amino acids involved in the antibody paratope. The antibody metal binding site was shown to contain at least two histidine residues in a cluster, and the presence of aspartic and glutamic acid as well as cysteine residues could not be excluded. Thus, simple competition studies allows us to obtain some partial information on the metal binding structural features of this anti-metal chelate antibody and to guide our screening of its catalytic potential. PMID:7578356

  15. The Binding of Biotin to Sepharose-Avidin Column: Demonstration of the Affinity Chromatography Technique

    Science.gov (United States)

    Landman, A. D.; Landman, N. N.

    1976-01-01

    Describes a biochemistry experiment that illustrates the methodology of affinity chromatography by attaching avidin, a glycoprotein in egg white, to a Sepharose matrix in order to bind biotin-containing proteins. (MLH)

  16. PHARMACEUTICAL AND BIOMEDICAL APPLICATIONS OF AFFINITY CHROMATOGRAPHY: RECENT TRENDS AND DEVELOPMENTS

    OpenAIRE

    Hage, David S.; Anguizola, Jeanethe A.; Bi, Cong; Li, Rong; Matsuda, Ryan; Papastavros, Efthimia; Pfaunmiller, Erika; Vargas, John; Zheng, Xiwei

    2012-01-01

    Affinity chromatography is a separation technique that has become increasingly important in work with biological samples and pharmaceutical agents. This method is based on the use of a biologically-related agent as a stationary phase to selectively retain analytes or to study biological interactions. This review discusses the basic principles behind affinity chromatography and examines recent developments that have occurred in the use of this method for biomedical and pharmaceutical analysis....

  17. Studies with an immobilized metal affinity chromatography cassette system involving binuclear triazacyclononane-derived ligands: automation of batch adsorption measurements with tagged recombinant proteins.

    Science.gov (United States)

    Petzold, Martin; Coghlan, Campbell J; Hearn, Milton T W

    2014-07-18

    This study describes the determination of the adsorption isotherms and binding kinetics of tagged recombinant proteins using a recently developed IMAC cassette system and employing automated robotic liquid handling procedures for IMAC resin screening. These results confirm that these new IMAC resins, generated from a variety of different metal-charged binuclear 1,4,7-triaza-cyclononane (tacn) ligands, interact with recombinant proteins containing a novel N-terminal metal binding tag, NT1A, with static binding capacities similar to those obtained with conventional hexa-His tagged proteins, but with significantly increased association constants. In addition, higher kinetic binding rates were observed with these new IMAC systems, an attribute that can be positively exploited to increase process productivity. The results from this investigation demonstrate that enhancements in binding capacities and affinities were achieved with these new IMAC resins and chosen NT1A tagged protein. Further, differences in the binding performances of the bis(tacn) xylenyl-bridged ligands were consistent with the distance between the metal binding centres of the two tacn moieties, the flexibility of the ligand and the potential contribution from the aromatic ring of the xylenyl group to undergo π/π stacking interactions with the tagged proteins. PMID:24891160

  18. APPLICATION OF IMMUNOGLOBULIN-BINDING PROTEINS A, G, L IN THE AFFINITY CHROMATOGRAPHY

    OpenAIRE

    Sviatenko, О.; Gorbatiuk, O.; Vasylchenko, О.

    2014-01-01

    Proteins A, G and L are native or recombinant proteins of microbial origin that bind to mammalian immunoglobulins. Preferably recombinant variants of proteins A, G, L are used in biotechnology for affinity sorbents production. Сomparative characteristics of proteins A, G, L and affinity sorbents on the basis of them, advantages and disadvantages of these proteins application as ligands in the affinity chromatography are done. Analysis of proteins A, G, L properties is presented. Binding speci...

  19. Expression of cold-adapted β-1,3-xylanase as a fusion protein with a ProS2 tag and purification using immobilized metal affinity chromatography with a high concentration of ArgHCl.

    Science.gov (United States)

    Kudou, Motonori; Okazaki, Fumiyoshi; Asai-Nakashima, Nanami; Ogino, Chiaki; Kondo, Akihiko

    2015-01-01

    Cold-adapted β-1,3-xylanase (P.t.Xyn26A) from the psychrotrophic bacterium, Psychroflexus torquis, was expressed as a fusion protein with tandem repeats of the N-terminal domain of Protein S from Myxocuccus xanthus (ProS2) in Escherichia coli. After cell lysis in phosphate buffer, most of the ProS2-P.t.Xyn26A was located in the insoluble fraction and aggregated during purification. Arginine hydrochloride (ArgHCl) efficiently solubilized the ProS2-P.t.Xyn26A. The solubilized ProS2-P.t.Xyn26A was purified using immobilized metal affinity chromatography (IMAC) with 500 mM ArgHCl. After cleavage of ProS2-P.t.Xyn26A by human rhinovirus 3C protease, we confirmed that recombinant P.t.Xyn26A maintained its native fold. This is the first report of the expression of a cold-adapted enzyme fused with a ProS2 tag under IMAC purification using a high concentration of ArgHCl. These insights into the expression and purification should be useful during the handling of cold-adapted enzymes. PMID:25214227

  20. Optimized IMAC-IMAC protocol for phosphopeptide recovery from complex biological samples

    DEFF Research Database (Denmark)

    Ye, Juanying; Zhang, Xumin; Young, Clifford; Zhao, Xiaolu; Hao, Qin; Cheng, Lei; Jensen, Ole Nørregaard

    2010-01-01

    that the ionization efficiencies of the phosphoryl group and carboxylic group changed differently when the acetonitrile concentration was increased. A magnified difference was achieved in high acetonitrile content solutions. On the basis of this concept, an optimized phosphopeptide enrichment protocol...... separation of multiply phosphorylated peptides from singly phosphorylated peptides with successive IMAC enrichments. The rational improvements to the IMAC protocol described in this study provide more insights into the factors that affect IMAC performance for phosphopeptide recovery. The improved IMAC......-IMAC method should allow more detailed characterization of phosphoproteins in functional phosphoproteomics research projects....

  1. Adsorption and Step Elution of Urokinase Using, Affinity Chromatography -Comparison of Data with Rate Model Simulation

    Institute of Scientific and Technical Information of China (English)

    MohammadRezaAboudzadehRovais; JiawenZhu; BinWu

    2004-01-01

    A non-equilibrium chromatographic rate model was employed to simulate the affinity chromatography of urokinase. The chromatography process was developed to a yield of high purity product of urokinase from crude materials. The affinity gel used in the process was prepared by an epichlorohydrin-activation method using epichlorohydrin activated Sepharose 4B as a matrix and p-aminobenzamidine as a ligand. The chromatographic process were numerically simulated and analyzed with the aid of VERSE-LC computer simulator. Considering the basic principles, rate model with the back mixing in column inlet was utilized in simulating and studying the effect of the column inlet pattern on other parameters. Comparison of the simulation results with the experimental data showed that the rate model can be used to describe the affinity chromatography of urokinase in a fixed bed column with satisfactory accuracy.

  2. Affinity chromatography based on a combinatorial strategy for rerythropoietin purification.

    Science.gov (United States)

    Martínez-Ceron, María C; Marani, Mariela M; Taulés, Marta; Etcheverrigaray, Marina; Albericio, Fernando; Cascone, Osvaldo; Camperi, Silvia A

    2011-05-01

    Small peptides containing fewer than 10 amino acids are promising ligand candidates with which to build affinity chromatographic systems for industrial protein purification. The application of combinatorial peptide synthesis strategies greatly facilitates the discovery of suitable ligands for any given protein of interest. Here we sought to identify peptide ligands with affinity for recombinant human erythropoietin (rhEPO), which is used for the treatment of anemia. A combinatorial library containing the octapeptides X-X-X-Phe-X-X-Ala-Gly, where X = Ala, Asp, Glu, Phe, His, Leu, Asn, Pro, Ser, or Thr, was synthesized on HMBA-ChemMatrix resin by the divide-couple-recombine method. For the library screening, rhEPO was coupled to either Texas Red or biotin. Fluorescent beads or beads showing a positive reaction with streptavidin-peroxidase were isolated. After cleavage, peptides were sequenced by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Fifty-seven beads showed a positive reaction. Peptides showing more consensuses were synthesized, and their affinity to rhEPO was assessed using a plasma resonance biosensor. Dissociation constant values in the range of 1-18 μM were obtained. The best two peptides were immobilized on Sepharose, and the resultant chromatographic matrixes showed affinity for rhEPO with dissociation constant values between 1.8 and 2.7 μM. Chinese hamster ovary (CHO) cell culture supernatant was spiked with rhEPO, and the artificial mixture was loaded on Peptide-Sepharose columns. The rhEPO was recovered in the elution fraction with a yield of 90% and a purity of 95% and 97% for P1-Sepharose and P2-Sepharose, respectively. PMID:21495625

  3. Supramolecular Affinity Chromatography for Methylation-Targeted Proteomics.

    Science.gov (United States)

    Garnett, Graham A E; Starke, Melissa J; Shaurya, Alok; Li, Janessa; Hof, Fraser

    2016-04-01

    Proteome-wide studies of post-translationally methylated species using mass spectrometry are complicated by high sample diversity, competition for ionization among peptides, and mass redundancies. Antibody-based enrichment has powered methylation proteomics until now, but the reliability, pan-specificity, polyclonal nature, and stability of the available pan-specific antibodies are problematic and do not provide a standard, reliable platform for investigators. We have invented an anionic supramolecular host that can form host-guest complexes selectively with methyllysine-containing peptides and used it to create a methylysine-affinity column. The column resolves peptides on the basis of methylation-a feat impossible with a comparable commercial cation-exchange column. A proteolyzed nuclear extract was separated on the methyl-affinity column prior to standard proteomics analysis. This experiment demonstrates that such chemical methyl-affinity columns are capable of enriching and improving the analysis of methyllysine residues from complex protein mixtures. We discuss the importance of this advance in the context of biomolecule-driven enrichment methods. PMID:26973166

  4. Comparison of different transition metal ions for immobilized metal affinity chromatography of selenoprotein P from human plasma

    DEFF Research Database (Denmark)

    Sidenius, U; Farver, O; Jøns, O; Gammelgaard, Bente

    1999-01-01

    Cu2+, Ni2+, Zn2+, Co2+ and Cd2+ were evaluated in metal ion affinity chromatography for enrichment of selenoprotein P, and immobilized Co2+ affinity chromatography was found to be the most selective chromatographic method. The chromatography was performed by fast protein liquid chromatography and...... selenoprotein P. The purity of the protein was determined by SDS-PAGE and by sequencing from polyvinylidene difluoride blots of SDS-PAGE gels....

  5. Quantitation of protein phosphorylation in pregnant rat uteri using stable isotope dimethyl labeling coupled with IMAC.

    Science.gov (United States)

    Huang, Sheng-Yu; Tsai, Mei-Ling; Wu, Chin-Jen; Hsu, Jue-Liang; Ho, Shih-Hsin; Chen, Shu-Hui

    2006-03-01

    Quantitative analysis of protein phosphorylation provides important insights into molecular signaling mechanisms and a better understanding of many cellular processes. In this study, we coupled stable isotope dimethyl labeling with immobilized metal affinity chromatography (IMAC) enrichment to quantify protein phosphorylation at MS-determined phosphorylation sites. The proposed method was first characterized using alpha- and beta-casein as two model phosphoproteins, and further applied to the analysis of pregnant rat uteri with and without treatment with 8-bromo-cGMP. Dimethyl labeling has several significant advantages: global, fast (within 5 min) and complete (near 100%). Our results indicate that the labeling has no adverse effect on the IMAC enrichment for tryptic peptides having single and multiple phosphorylation sites. Moreover, the enhanced a1 signal and the complete reaction by dimethyl labeling provide unequivocal identification of both the N-terminal amino acid and the number of the labeling site. Using these two criteria in data validation, which is particularly important for identifying phosphoproteins, we found that the confidence in interpreting dimethyl-labeled peptides had greatly increased. In the analysis of late gestation rat uteri, the abundance ratio between treated and un-treated phosphopeptide signals ranged from 0.51 to 1.69 with an average of around 1.01 +/- 0.25. The obtained ratio of the phosphorylation levels at Ser 15 of HSP27 was further confirmed by the consistent results obtained from Western blot analyses. Based on the analysis of the results, it is interesting to note that the activated cGMP dependent protein kinase G (PKG) seems to affect the phosphorylation of proteins associated with the inhibition of cell migration and proliferation, redistribution of actin-associated proteins, and the increase of protein synthesis in late-gestation uteri. These observations provide important evidence suggesting that activated PKG may play a

  6. A chimeric affinity tag for efficient expression and chromatographic purification of heterologous proteins from plants

    OpenAIRE

    Frank eSainsbury; Philippe V. Jutras; Juan eVorster; Marie-Claire eGoulet; Dominique eMichaud

    2016-01-01

    The use of plants as expression hosts for recombinant proteins is an increasingly attractive option for the production of complex and challenging biopharmaceuticals. Tools are needed at present to marry recent developments in high-yielding gene vectors for heterologous expression with routine protein purification techniques. In this study we designed the Cysta-tag, a new purification tag for immobilized metal affinity chromatography (IMAC) of plant-made proteins based on the protein-stabilizi...

  7. Displacement affinity chromatography of protein phosphatase one (PP1 complexes

    Directory of Open Access Journals (Sweden)

    Gourlay Robert

    2008-11-01

    Full Text Available Abstract Background Protein phosphatase one (PP1 is a ubiquitously expressed, highly conserved protein phosphatase that dephosphorylates target protein serine and threonine residues. PP1 is localized to its site of action by interacting with targeting or regulatory proteins, a majority of which contains a primary docking site referred to as the RVXF/W motif. Results We demonstrate that a peptide based on the RVXF/W motif can effectively displace PP1 bound proteins from PP1 retained on the phosphatase affinity matrix microcystin-Sepharose. Subsequent co-immunoprecipitation experiments confirmed that each identified binding protein was either a direct PP1 interactor or was in a complex that contains PP1. Our results have linked PP1 to numerous new nuclear functions and proteins, including Ki-67, Rif-1, topoisomerase IIα, several nuclear helicases, NUP153 and the TRRAP complex. Conclusion This modification of the microcystin-Sepharose technique offers an effective means of purifying novel PP1 regulatory subunits and associated proteins and provides a simple method to uncover a link between PP1 and additional cellular processes.

  8. Antibody purification using affinity chromatography: a case study with a monoclonal antibody to ractopamine.

    Science.gov (United States)

    Wang, Zhanhui; Liang, Qi; Wen, Kai; Zhang, Suxia; Shen, Jianzhong

    2014-11-15

    The application of antibodies to small molecules in the field of bioanalytics requires antibodies with stable biological activity and high purity; thus, there is a growing interest in developing rapid, inexpensive and effective procedures to obtain such antibodies. In this work, a ractopamine (RAC) derivative, N-4-aminobutyl ractopamine (ABR), was synthesized for preparing new specific affinity chromatography to purify a murine monoclonal antibody (mAb) against RAC from ascites. The performance of the new specific chromatography was compared with four other purification methods in terms of recovery, purity and biological activity of mAb. These four purification methods were prepared by using specific ligands (RAC and RAC-ovalbumin) and commercial ligands (protein G and protein A), respectively. The results showed that the highest recovery (88.1%) was achieved using the new chromatography; in comparison, the recoveries from the other methods were all below 70%. The purity of the mAbs from the new chromatography was 88.3%, while, the highest purity of 97.6% was from protein G chromatography and the lowest purity of 84.7% was from protein A chromatography. The biological activity of the purified mAb from all of the chromatography methods was comparable in enzyme-linked immunosorbent immunoassay (ELISA). PMID:25261834

  9. Modification of silica-based monolithic capillary columns for boronate affinity chromatography

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Planeta, Josef; Kahle, Vladislav; Roth, Michal

    2011. P2-G-471-WE. ISBN 978-963-89335-0-8. [International Symposium on High - Performance Liquid Phase Separations and Related Techniques /36./. 19.06.2011-23.06.2011, Budapest] R&D Projects: GA AV ČR IAAX00310701; GA MŠk LC06023 Institutional research plan: CEZ:AV0Z40310501 Keywords : silicagel monolithic column * boronate affinity chromatography Subject RIV: CB - Analytical Chemistry, Separation

  10. Purification of Staphylococcus aureus beta-lactamases by using sequential cation-exchange and affinity chromatography.

    OpenAIRE

    Kernodle, D S; Zygmunt, D J; McGraw, P A; Chipley, J R

    1990-01-01

    Boronic acids are active-site inhibitors of serine beta-lactamases, and a phenylboronic acid-agarose affinity column has been used to purify beta-lactamase from crude cell extracts of several bacterial species. We applied phenylboronic acid-agarose chromatography to the purification of Staphylococcus aureus beta-lactamase. Two factors interfered with the success of the previously described single-step chromatographic protocol. First, staphylococcal beta-lactamase exhibited non-active-site-med...

  11. Automated Immobilized Metal Affinity Chromatography System for Enrichment of Escherichia coli Phosphoproteome

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Yi; Wu, Si; Zhao, Rui; Zink, Erika M.; Orton, Daniel J.; Moore, Ronald J.; Meng, Da; Clauss, Therese RW; Aldrich, Joshua T.; Lipton, Mary S.; Pasa-Tolic, Ljiljana

    2013-06-05

    Enrichment of bacterial phosphopeptides is an essential step prior to bottom-up mass spectrometry-based analysis of the phosphoproteome, which is fundamental to understanding the role of phosphoproteins in cell signaling and regulation of protein activity. We developed an automated IMAC system to enrich strong cation exchange-fractionated phosphopeptides from the soluble proteome of Escherichia coli MG1655 grown on minimal medium. Initial demonstration of the system resulted in identification of 75 phosphopeptides covering 52 phosphoproteins. Consistent with previous studies, many of these phosphoproteins are involved in the carbohydrate portion of central metabolism. The automated system utilizes a large capacity IMAC column that can effectively enrich phosphopeptides from a bacterial sample by increasing peptide loading and reducing the wash time. An additional benefit of the automated IMAC system is reduced labor and associated costs.

  12. Affinity chromatography and capillary electrophoresis for analysis of the yeast ribosomal proteins

    Directory of Open Access Journals (Sweden)

    Miriam S. Goyder

    2012-04-01

    Full Text Available We present a top down separation platform for yeast ribosomalproteins using affinity chromatography and capillary electrophoresiswhich is designed to allow deposition of proteins ontoa substrate. FLAG tagged ribosomes were affinity purified, andrRNA acid precipitation was performed on the ribosomes followedby capillary electrophoresis to separate the ribosomalproteins. Over 26 peaks were detected with excellent reproducibility(<0.5% RSD migration time. This is the first reportedseparation of eukaryotic ribosomal proteins using capillaryelectrophoresis. The two stages in this workflow, affinity chromatographyand capillary electrophoresis, share the advantagesthat they are fast, flexible and have small sample requirementsin comparison to more commonly used techniques. This methodis a remarkably quick route from cell to separation that hasthe potential to be coupled to high throughput readout platformsfor studies of the ribosomal proteome. [BMB reports2012; 45(4: 233-238

  13. Affinity chromatography purification of angiotensin II reactor using photoactivable biotinylated probes

    Energy Technology Data Exchange (ETDEWEB)

    Marie, J.; Seyer, R.; Lombard, C.; Desarnaud, F.; Aumelas, A.; Jard, A.; Bonnafous, J.C. (Centre CNRS-INSERM de Pharmacologie-Endocrinologie, Montpellier (France))

    1990-09-25

    The authors have developed biotinylated photoactivable probes that are suitable for covalent labeling of angiotensin II (AII) receptors and the subsequent purification of covalent complexes through immobilized avidin or streptavidin. One of these probes, biotin-NH(CH{sub 2}){sub 2}SS(CH{sub 2}){sub 2}CO-(Ala{sup 1}, Phe(4N{sub 3}){sup 8})AII, which contains a cleavage disulfide bridge in its spacer arm and which displays, in its radioiodinated form, very high affinity for AII receptors (K{sub d}{approximately}1 nM), proved to be suitable for indirect affinity chromatography of rate liver receptor with facilitated recovery from avidin gels by use of reducing agents. This constituted the central step of an efficient partial purification scheme involving hydroxylapatite chromatography, streptavidin chromatography, and thiopropyl-Sepharose chromatography. SDS-PAGE analysis and autoradiography established the identity of the purified entity (molecular weight 65K) as the AII receptor. Possible ways of completing purification to homogeneity and extrapolation of the protocols to a preparative scale are discussed, as well as the potential contribution of our new probes to the study of the structural properties of angiotensin receptors.

  14. Affinity chromatography purification of angiotensin II reactor using photoactivable biotinylated probes

    International Nuclear Information System (INIS)

    The authors have developed biotinylated photoactivable probes that are suitable for covalent labeling of angiotensin II (AII) receptors and the subsequent purification of covalent complexes through immobilized avidin or streptavidin. One of these probes, biotin-NH(CH2)2SS(CH2)2CO-[Ala1, Phe(4N3)8]AII, which contains a cleavage disulfide bridge in its spacer arm and which displays, in its radioiodinated form, very high affinity for AII receptors (Kd∼1 nM), proved to be suitable for indirect affinity chromatography of rate liver receptor with facilitated recovery from avidin gels by use of reducing agents. This constituted the central step of an efficient partial purification scheme involving hydroxylapatite chromatography, streptavidin chromatography, and thiopropyl-Sepharose chromatography. SDS-PAGE analysis and autoradiography established the identity of the purified entity (molecular weight 65K) as the AII receptor. Possible ways of completing purification to homogeneity and extrapolation of the protocols to a preparative scale are discussed, as well as the potential contribution of our new probes to the study of the structural properties of angiotensin receptors

  15. Sequential elution from IMAC (SIMAC)

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    titanium dioxide chromatography provide varying degrees of selectivity and specificity for phosphopeptide enrichment. The number of multi-phosphorylated peptides identified in most published studies is rather low. Here we describe a protocol for a strategy that separates mono-phosphorylated peptides from...... monophosphorylated peptides using titanium dioxide chromatography. The two separate phosphopeptide fractions are then subsequently analyzed by mass spectrometric methods optimized for mono-phosphorylated and multi-phosphorylated peptides, respectively, resulting in improved identification of especially...

  16. Kosmotropes enhance the yield of antibody purified by affinity chromatography using immobilized bacterial immunoglobulin binding proteins.

    Science.gov (United States)

    Ngo, That T; Narinesingh, Dyer

    2008-01-01

    The yield of antibody purified using affinity chromatography on immobilized Protein A or Protein G was increased up to 5-fold (500%) by including kosmotropic salts in the binding buffer. The binding buffer is used to equilibrate the affinity column before applying a sample to the column and also to dilute the sample prior to loading onto the affinity column to optimize conditions for a maximal binding of antibodies to affinity gels. In this study, the kosmotropic salts that were effective in greatly increasing antibody binding to Protein A included both inorganic and organic salts of ammonium; sodium; or potassium sulfate, phosphate, polycarboxylates; for example, succinate, citrate, isocitrate, N-(2-hydroxyethylene diamine triacetate (HEDTA), ethylene diamine tetraacetate (EDTA), and ethylene glycol-O,O'-bis(2-aminoethyl)-N,N,N'N'-tetra acetate(EGTA). On an equal-molar basis, the greater the number of carboxylic groups within the polycarboxylate molecule, the greater the increase in the yield of the purified antibody that was observed. The data show that kosmotropes can be used as effective additives to enhance the binding of immunoglobulins to Protein A or Protein G gels with a resultant increase in the yield of the purified antibodies. Thus, it appears that strongly hydrated anions (citrate, sulfate, and phosphate) and weakly hydrated cations (ammonium, potassium) increase the yield of antibody purified on either Protein A or Protein G affinity gels. PMID:18080884

  17. Characteristics of the interaction of calcium with casein submicelles as determined by analytical affinity chromatography

    International Nuclear Information System (INIS)

    Interaction of calcium with casein submicelles was investigated in CaCl2 and calcium phosphate buffers and with synthetic milk salt solutions using the technique of analytical affinity chromatography. Micelles that had been prepared by size exclusion chromatography with glycerolpropyl controlled-pore glass from fresh raw skim milk that had never been cooled, were dialyzed at room temperature against calcium-free imidazole buffer, pH 6.7. Resulting submicelles were covalently immobilized on succinamidopropyl controlled-pore glass (300-nm pore size). Using 45Ca to monitor the elution retardation, the affinity of free Ca2+ and calcium salt species was determined at temperatures of 20 to 40 degrees C and pH 6.0 to 7.5. Increasing the pH in this range or increasing the temperature strengthened the binding of calcium to submicelles, similar to previous observations with individual caseins. However, the enthalpy change obtained from the temperature dependence was considerably greater than that reported for alpha s1- and beta-caseins. Furthermore, the elution profiles for 45Ca in milk salt solutions were decidedly different from those in CaCl2 or calcium phosphate buffers and the affinities were also greater. For example, at pH 6.7 and 30 degrees C the average dissociation constant for the submicelle-calcium complex is 0.074 mM for CaCl2 and calcium phosphate buffers, vs 0.016 mM for the milk salt solution. The asymmetric frontal boundaries and higher average affinities observed with milk salts may be due to binding of calcium salts with greater affinity in addition to the binding of free Ca2+ in these solutions

  18. Determination of residual fluoroquinolones in honey by liquid chromatography using metal chelate affinity chromatography.

    Science.gov (United States)

    Yatsukawa, Yoh-Ichi; Ito, Hironobu; Matsuda, Takahiro; Nakamura, Munetomo; Watai, Masatoshi; Fujita, Kazuhiro

    2011-01-01

    A new analytical method for the simultaneous determination of seven fluoroquinolones, namely, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin, and difloxacin, especially in dark-colored honey, has been developed. Fluoroquinolone antibiotics were extracted from samples with MacIlvaine buffer solution (pH 4.0) containing EDTA disodium salt dihydrate. The extracts were treated with both a polymeric cartridge and a metal chelate affinity column preloaded with ferric ion (Fe3+). LC separation with fluorescence detection was performed at 40 degrees C using an Inertsil ODS-4 analytical column (150 x 4.6 mm, 3 microm). The mobile phase was composed of 20 mM/L citrate buffer solution (pH 3.1)-acetonitrile mixture (70 + 30, v/v) containing 1 mM/L sodium dodecyl sulfate. Lomefloxacin was used as an internal standard. The developed method was validated according to the criteria of European Commission Decision 2002/657/EC. Decision limits and detection capabilities were below 2.9 and 4.4 microg/kg, respectively. PMID:21919363

  19. In-column ATR-FTIR spectroscopy to monitor affinity chromatography purification of monoclonal antibodies

    Science.gov (United States)

    Boulet-Audet, Maxime; Kazarian, Sergei G.; Byrne, Bernadette

    2016-07-01

    In recent years many monoclonal antibodies (mAb) have entered the biotherapeutics market, offering new treatments for chronic and life-threatening diseases. Protein A resin captures monoclonal antibody (mAb) effectively, but the binding capacity decays over repeated purification cycles. On an industrial scale, replacing fouled Protein A affinity chromatography resin accounts for a large proportion of the raw material cost. Cleaning-in-place (CIP) procedures were developed to extend Protein A resin lifespan, but chromatograms cannot reliably quantify any remaining contaminants over repeated cycles. To study resin fouling in situ, we coupled affinity chromatography and Fourier transform infrared (FTIR) spectroscopy for the first time, by embedding an attenuated total reflection (ATR) sensor inside a micro-scale column while measuring the UV 280 nm and conductivity. Our approach quantified the in-column protein concentration in the resin bed and determined protein conformation. Our results show that Protein A ligand leached during CIP. We also found that host cell proteins bound to the Protein A resin even more strongly than mAbs and that typical CIP conditions do not remove all fouling contaminants. The insights derived from in-column ATR-FTIR spectroscopic monitoring could contribute to mAb purification quality assurance as well as guide the development of more effective CIP conditions to optimise resin lifespan.

  20. Fibulin-1 purification from human plasma using affinity chromatography on Factor H-Sepharose.

    Science.gov (United States)

    DiScipio, Richard G; Liddington, Robert C; Schraufstatter, Ingrid U

    2016-05-01

    A method is reported to purify Fibulin-1 from human plasma resulting in a 36% recovery. The steps involve removal of the cryoglobulin and the vitamin K dependent proteins followed by polyethylene glycol and ammonium sulfate precipitations, DEAE-Sephadex column chromatography and finally Factor H-Sepharose affinity purification. The procedure is designed to be integrated into an overall scheme for the isolation of over 30 plasma proteins from a single batch of human plasma. Results from mass spectroscopy, SDS-PAGE, and Western blotting indicate that human plasma Fibulin-1 is a single chain of the largest isotype. Functional binding assays demonstrated calcium ion dependent interaction of Fibulin-1 for fibrinogen, fibronectin, and Factor H. The procedure described is the first to our knowledge that enables a large scale purification of Fibulin-1 from human plasma. PMID:26826315

  1. Characterization of the human cerebrospinal fluid phosphoproteome by titanium dioxide affinity chromatography and mass spectrometry

    DEFF Research Database (Denmark)

    Bahl, Justyna Maria Czarna; Jensen, Søren Skov; Larsen, Martin R;

    2008-01-01

    investigations based on knowledge of the molecular pathology of the disease in question. In Alzheimer's disease, hyperphosphorylation of the tau protein is a characteristic feature and thus a comprehensive characterization of the phosphoproteome of the CSF may be pursued to obtain a complete picture of...... phosphorylation aberrations in health and disease. Toward that goal we here describe a method for a comprehensive isolation and identification of phosphorylated tryptic peptides derived from CSF proteins using a simple sample preparation step and titanium dioxide-affinity chromatography followed by MALDI-TOF or...... LC-MS/MS linear ion-trap-FT mass spectrometry. Whereas not all previously reported phosphoproteins were found in normal CSF, we detected 56 putative novel phosphorylation sites in 38 proteins in addition to known sites. The approach seems to be a promising foundation for the discovery of new...

  2. Purification of infective bluetongue virus particles by immuno-affinity chromatography using anti-core antibody.

    Science.gov (United States)

    Chand, Karam; Biswas, Sanchay K; Mondal, Bimalendu

    2016-03-01

    An immuno-affinity chromatography technique for purification of infective bluetongue virus (BTV) has been descried using anti-core antibodies. BTV anti-core antibodies (prepared in guinea pig) were mixed with cell culture-grown BTV-1 and then the mixture was added to the cyanogens bromide-activated protein-A Sepharose column. Protein A binds to the antibody which in turn binds to the antigen (i.e. BTV). After thorough washing, antigen-antibody and antibody-protein A couplings were dissociated with 4M MgCl2, pH6.5. Antibody molecules were removed by dialysis and virus particles were concentrated by spin column ultrafiltration. Dialyzed and concentrated material was tested positive for BTV antigen by a sandwich ELISA and the infectivity of the chromatography-purified virus was demonstrated in cell culture. This method was applied for selective capture of BTV from a mixture of other viruses. As group-specific antibodies (against BTV core) were used to capture the virus, it is expected that virus of all BTV serotypes could be purified by this method. This method will be helpful for selective capture and enrichment of BTV from concurrently infected blood or tissue samples for efficient isolation in cell culture. Further, this method can be used for small scale purification of BTV avoiding ultracentrifugation. PMID:26925450

  3. 31st IMAC Conference on Structural Dynamics

    CERN Document Server

    Adams, Douglas; Carrella, Alex; Mayes, Randy; Rixen, Daniel; Allen, Matt; Cunha, Alvaro; Catbas, Fikret; Pakzad, Shamim; Racic, Vitomir; Pavic, Aleksandar; Reynolds, Paul; Simmermacher, Todd; Cogan, Scott; Moaveni, Babak; Papadimitriou, Costas; Allemang, Randall; Clerck, James; Niezrecki, Christopher; Wicks, Alfred

    2013-01-01

    Topics in Nonlinear Dynamics, Volume 1: Proceedings of the 31st IMAC, A Conference and Exposition on Structural Dynamics, 2013, the first volume of seven from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on:   Nonlinear Oscillations Nonlinearities In Practice Nonlinear System Identification: Methods Nonlinear System Identification: Friction & Contact Nonlinear Modal Analysis Nonlinear Modeling & Simulation Nonlinear Vibration Absorbers Constructive Utilization of Nonlinearity.

  4. INTERFERENCE OF CARBAMYLATED AND ACETYLATED HEMOGLOBINS IN ASSAYS OF GLYCOHEMOGLOBIN BY HPLC, ELECTROPHORESIS, AFFINITY-CHROMATOGRAPHY, AND ENZYME-IMMUNOASSAY

    NARCIS (Netherlands)

    WEYKAMP, CW; PENDERS, TJ; SIEBELDER, CWM; MUSKIET, FAJ; VANDERSLIK, W

    1993-01-01

    In vitro-synthesized carbamylated and acetylated hemoglobins interfered in assays of glycohemoglobin by HPLC and electrophoresis but had no effects on results obtained by affinity chromatography and enzyme immunoassay. Correlations between long-term serum urea concentrations and glycohemoglobin perc

  5. Recombinant Passenger Proteins Can Be Conveniently Purified by One-Step Affinity Chromatography.

    Directory of Open Access Journals (Sweden)

    Hua-zhen Wang

    Full Text Available Fusion tag is one of the best available tools to date for enhancement of the solubility or improvement of the expression level of recombinant proteins in Escherichia coli. Typically, two consecutive affinity purification steps are often necessitated for the purification of passenger proteins. As a fusion tag, acyl carrier protein (ACP could greatly increase the soluble expression level of Glucokinase (GlcK, α-Amylase (Amy and GFP. When fusion protein ACP-G2-GlcK-Histag and ACP-G2-Amy-Histag, in which a protease TEV recognition site was inserted between the fusion tag and passenger protein, were coexpressed with protease TEV respectively in E. coli, the efficient intracellular processing of fusion proteins was achieved. The resulting passenger protein GlcK-Histag and Amy-Histag accumulated predominantly in a soluble form, and could be conveniently purified by one-step Ni-chelating chromatography. However, the fusion protein ACP-GFP-Histag was processed incompletely by the protease TEV coexpressed in vivo, and a large portion of the resulting target protein GFP-Histag aggregated in insoluble form, indicating that the intracellular processing may affect the solubility of cleaved passenger protein. In this context, the soluble fusion protein ACP-GFP-Histag, contained in the supernatant of E. coli cell lysate, was directly subjected to cleavage in vitro by mixing it with the clarified cell lysate of E. coli overexpressing protease TEV. Consequently, the resulting target protein GFP-Histag could accumulate predominantly in a soluble form, and be purified conveniently by one-step Ni-chelating chromatography. The approaches presented here greatly simplify the purification process of passenger proteins, and eliminate the use of large amounts of pure site-specific proteases.

  6. IMMOBILIZED CIBACRON BLUE F3G-A ON CROSSLINKED POLY (VINYL ALCOHOL) FOR AFFINITY CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    YUAN Jing; YAN Husheng; CHENG Xiaohui; HE Binglin

    2001-01-01

    Immobilized triazine dye affinity chromatography has been widely used for protein purification. In this paper, cibacron Blue F3G-A was immobilized,through a spacer arm, onto a rigid hydrophilic porous polymer by reacting an epoxy-group-containing poly(vinyl alcohol) with 6-aminohexyl-N'-Cibacron Blue F3G-A,which was obtained by reacting Cibacron Blue F3G-A with excess of 1,6-diaminohexane, in a pH 8.6 buffer. The epoxy-group-containing poly(vinyl alcohol) was prepared by hydrolysis of macroporous crosslinded poly(vinyl acetate),which was synthesized by suspension copolymerization of vinyl acetate and triallyl isocyanurate in the presence of butyl acetate and n-heptane as diluents. The cibacron Blue F3G-A-immobilized poly(vinyl alcohol)was packed in a stainless steel column (250×5 mm I. D.) and the chromatographic behaviors of several proteins (cytochrome c, lysozyme, bovine serum albumin, insulin, and lactate dehydrogenase) were determined.

  7. Advance chromatin extraction improves capture performance of protein A affinity chromatography.

    Science.gov (United States)

    Nian, Rui; Zhang, Wei; Tan, Lihan; Lee, Jeremy; Bi, Xeuzhi; Yang, Yuansheng; Gan, Hui Theng; Gagnon, Pete

    2016-01-29

    Practical effects of advance chromatin removal on performance of protein A affinity chromatography were evaluated using a caprylic acid-allantoin-based extraction method. Lacking this treatment, the practice of increasing loading residence time to increase capacity was shown to increase host protein contamination of the eluted IgG. Advance chromatin extraction suspended that compromise. Protein A ligand leakage from columns loaded with chromatin-extracted harvest was half the level observed on protein A columns loaded with non-extracted harvest. Columns loaded with chromatin-extracted harvest were cleaned more effectively by 50-100mM NaOH than columns loaded with non-extracted harvest that were cleaned with 250-500mM NaOH. Two protein A media with IgG capacities in excess of 50g/L were loaded with chromatin-extracted harvest, washed with 2.0M NaCl before elution, and the eluted IgG fraction titrated to pH 5.5 before microfiltration. Host protein contamination in the filtrate was reduced to <1ppm, DNA to <1ppb, protein A leakage to 0.5ppm, and aggregates to 1.0%. Caprylic acid and allantoin were both reduced below 5ppm. Step recovery of IgG was 99.4%. Addition of a single polishing step reduced residual protein A beneath the level of detection and aggregates to <0.1%. Overall process recovery including chromatin extraction was 90%. PMID:26774119

  8. Characterization of the galactomannans from Parkinsonia aculeata seeds and their application on affinity chromatography

    Directory of Open Access Journals (Sweden)

    Ivone Garros-Rosa

    2006-06-01

    Full Text Available Successive aqueous (10 ºC, 25 ºC and 80 ºC and alkaline (1M NaOH; 25 ºC extractions of milled Parkinsonia aculeata endosperms gave rise to four galactomannan fractions. These extractions furnished viscous galactomannans with Man:Gal ratios ranging from 3.1:1; 3.7:1; 4.9:1 and 6.1:1 (P1, P2, P3 and P4, respectively. Fraction P1 was used for structural studies by using methylation analysis, periodate oxidation and 13C-NMR. It showed a linear backbone of beta(1->4 linked D-mannose units, to which single alpha(1->6-linked D-galactose are attached. This galactomannan has Mw 775700 g/mol and intrinsic viscosity of 558 mL/g. The four fractions and the crude endosperm were treated with epichlorydrin and used as matrix for affinity chromatography. All columns tested showed ability to bind lectin samples. The efficiency is related to the degree and pattern of substitution of galactosyl units on the D-mannan backbone.

  9. The Lectin Frontier Database (LfDB, and Data Generation Based on Frontal Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Jun Hirabayashi

    2015-01-01

    Full Text Available Lectins are a large group of carbohydrate-binding proteins, having been shown to comprise at least 48 protein scaffolds or protein family entries. They occur ubiquitously in living organisms—from humans to microorganisms, including viruses—and while their functions are yet to be fully elucidated, their main underlying actions are thought to mediate cell-cell and cell-glycoconjugate interactions, which play important roles in an extensive range of biological processes. The basic feature of each lectin’s function resides in its specific sugar-binding properties. In this regard, it is beneficial for researchers to have access to fundamental information about the detailed oligosaccharide specificities of diverse lectins. In this review, the authors describe a publicly available lectin database named “Lectin frontier DataBase (LfDB”, which undertakes the continuous publication and updating of comprehensive data for lectin-standard oligosaccharide interactions in terms of dissociation constants (Kd’s. For Kd determination, an advanced system of frontal affinity chromatography (FAC is used, with which quantitative datasets of interactions between immobilized lectins and >100 fluorescently labeled standard glycans have been generated. The FAC system is unique in its clear principle, simple procedure and high sensitivity, with an increasing number (>67 of associated publications that attest to its reliability. Thus, LfDB, is expected to play an essential role in lectin research, not only in basic but also in applied fields of glycoscience.

  10. Analysis of free drug fractions in human serum by ultrafast affinity extraction and two-dimensional affinity chromatography.

    Science.gov (United States)

    Zheng, Xiwei; Podariu, Maria; Matsuda, Ryan; Hage, David S

    2016-01-01

    Ultrafast affinity extraction and a two-dimensional high performance affinity chromatographic system were used to measure the free fractions for various drugs in serum and at typical therapeutic concentrations. Pooled samples of normal serum or serum from diabetic patients were utilized in this work. Several drug models (i.e., quinidine, diazepam, gliclazide, tolbutamide, and acetohexamide) were examined that represented a relatively wide range of therapeutic concentrations and affinities for human serum albumin (HSA). The two-dimensional system consisted of an HSA microcolumn for the extraction of a free drug fraction, followed by a larger HSA analytical column for the further separation and measurement of this fraction. Factors that were optimized in this method included the flow rates, column sizes, and column switching times that were employed. The final extraction times used for isolating the free drug fractions were 333-665 ms or less. The dissociation rate constants for several of the drugs with soluble HSA were measured during system optimization, giving results that agreed with reference values. In the final system, free drug fractions in the range of 0.7-9.5% were measured and gave good agreement with values that were determined by ultrafiltration. Association equilibrium constants or global affinities were also estimated by this approach for the drugs with soluble HSA. The results for the two-dimensional system were obtained in 5-10 min or less and required only 1-5 μL of serum per injection. The same approach could be adapted for work with other drugs and proteins in clinical samples or for biomedical research. PMID:26462924

  11. Wide Range of Biotin (Vitamin H) Content in Foodstuffs and Powdered Milks as Assessed by High-performance Affinity Chromatography

    OpenAIRE

    Hayakawa, Kou; Katsumata, Noriyuki; Abe, Kiyomi; Hirano, Masahiko; Yoshikawa, Kazuyuki; Ogata, Tsutomu; Horikawa, Reiko; Nagamine, Takeaki

    2009-01-01

    The biotin (vitamin H) contents of various foodstuffs were determined by using a newly developed high-performance affinity chromatography with a trypsin-treated avidin-bound column. Biotin was derivatized with 9-anthryldiazomethane (ADAM) to fluorescent biotin-ADAM ester. A wide range of biotin contents were found in various foodstuffs depending upon the species (strain), season, organ (of plants and animals), geography, freshness, preparation method and storage method. Among the foodstuffs a...

  12. Reaction of Native and Denatured Brucella abortus (S19) Proteins with Antibody Using Affinity Chromatography and Immunoblotting

    OpenAIRE

    Karimi, R.; A Mostafaie; B. Tabaraie; Y. Bahrami; J. Abdolalizadeh

    2005-01-01

    Western blotting or immunoblotting commonly use for study of reaction between antigens and antibodies. Denaturation of many proteins in immunoblotting can affect greatly the reactivity of antibodies and outcome of the procedure.In this study proteins of Brucella abortus (S19) was extracted by a mild method and reaction of the extracted proteins with serum of infected human and goat and immunized rabbit compared by affinity chromatography and immunoblotting. Gamma globulin (m...

  13. Physicochemical and Biological Characterization of Fucoidan from Fucus vesiculosus Purified by Dye Affinity Chromatography.

    Science.gov (United States)

    Zayed, Ahmed; Muffler, Kai; Hahn, Thomas; Rupp, Steffen; Finkelmeier, Doris; Burger-Kentischer, Anke; Ulber, Roland

    2016-04-01

    A comparative study concerning the physicochemical, monomeric composition and biological characters among different fucoidan fractions is presented. Common purification techniques for fucoidan usually involve many steps. During these steps, the important structural features might be affected and consequently alter its biological activities. Three purified fractions were derived from Fucus vesiculosus water extract which, afterwards, were purified by a recently-developed dye affinity chromatography protocol. This protocol is based on dye-sulfated polysaccharide interactions. The first two fractions were obtained from crude precipitated fucoidan at different pH values of the adsorption phase: pH 1 and 6. This procedure resulted in fucoidan_1 and 6 fractions. The other, third, fraction: fucoidan_M, however, was obtained from a buffered crude extract at pH 1, eliminating the ethanol precipitation step. All of the three fractions were then further evaluated. Results revealed that fucoidan_M showed the highest sulfur content (S%), 12.11%, with the lowest average molecular weight, 48 kDa. Fucose, galactose, and uronic acid/glucose dimers were detected in all fractions, although, xylose was only detected in fucoidan_1 and 6. In a concentration of 10 µg·mL(-1), Fucoidan_6 showed the highest heparin-like anticoagulant activity and could prolong the APTT and TT significantly to 66.03 ± 2.93 and 75.36 ± 1.37 s, respectively. In addition, fucoidan_M demonstrated the highest potency against HSV-1 with an IC50 of 2.41 µg·mL(-1). The technique proved to be a candidate for fucoidan purifaction from its crude extract removing the precipitation step from common purification protocols and produced different fucoidan qualities resulted from the different incubation conditions with the immobilized thiazine toluidine blue O dye. PMID:27092514

  14. Reaction of Native and Denatured Brucella abortus (S19 Proteins with Antibody Using Affinity Chromatography and Immunoblotting

    Directory of Open Access Journals (Sweden)

    R. Karimi

    2005-01-01

    Full Text Available Western blotting or immunoblotting commonly use for study of reaction between antigens and antibodies. Denaturation of many proteins in immunoblotting can affect greatly the reactivity of antibodies and outcome of the procedure.In this study proteins of Brucella abortus (S19 was extracted by a mild method and reaction of the extracted proteins with serum of infected human and goat and immunized rabbit compared by affinity chromatography and immunoblotting. Gamma globulin (mostly IgG fraction of the sera was precipitated by half saturation of ammonium sulfate and linked to activated sepharose 4B. The extracted proteins were loaded on the affinity column. Attached proteins was eluted by low pH and analyzed by SDS-PAGE. Reaction of the total extract and eluted fractions with IgG fraction of sera was evaluated by Western blotting.Upon the results of affinity chromatography and immunoblotting, Brucella proteins can be classified in four groups: 1- The proteins that adsorbed to the affinity column and react with IgG in westernblotting. 2- Proteins that react with IgG in native state but no in denatured state. 3- Proteins that do not react with IgG in native state but react in denatured state. 4- Proteins that do not react with IgG in native and denatured state.

  15. Identification of novel in vivo MAP kinase substrates in Arabidopsis thaliana through use of tandem metal oxide affinity chromatography.

    Science.gov (United States)

    Hoehenwarter, Wolfgang; Thomas, Martin; Nukarinen, Ella; Egelhofer, Volker; Röhrig, Horst; Weckwerth, Wolfram; Conrath, Uwe; Beckers, Gerold J M

    2013-02-01

    Mitogen-activated protein kinase (MPK) cascades are important for eukaryotic signal transduction. They convert extracellular stimuli (e.g. some hormones, growth factors, cytokines, microbe- or damage-associated molecular patterns) into intracellular responses while at the same time amplifying the transmitting signal. By doing so, they ensure proper performance, and eventually survival, of a given organism, for example in times of stress. MPK cascades function via reversible phosphorylation of cascade components MEKKs, MEKs, and MPKs. In plants the identity of most MPK substrates remained elusive until now. Here, we provide a robust and powerful approach to identify and quantify, with high selectivity, site-specific phosphorylation of MPK substrate candidates in the model plant Arabidopsis thaliana. Our approach represents a two-step chromatography combining phosphoprotein enrichment using Al(OH)(3)-based metal oxide affinity chromatography, tryptic digest of enriched phosphoproteins, and TiO(2)-based metal oxide affinity chromatography to enrich phosphopeptides from complex protein samples. When applied to transgenic conditional gain-of-function Arabidopsis plants supporting in planta activation of MPKs, the approach allows direct measurement and quantification ex vivo of site-specific phosphorylation of several reported and many yet unknown putative MPK substrates in just a single experiment. PMID:23172892

  16. Study on peptide-peptide interaction using high-performance affinity chromatography and quartz crystal microbalance biosensor

    Institute of Scientific and Technical Information of China (English)

    LUO Jia; HUANG YanYan; XIONG ShaoXiang; LIU GuoQuan; ZHAO Rui

    2007-01-01

    The specific interaction between sense and antisense peptides was studied by high-performance affinity chromatography (HPAC) and quartz crystal microbalance (QCM) biosensor. Fragment 1-14 of human interferon-β (hlFN-β) was chosen as sense peptide and its three antisense peptides (AS-IFN 1,AS-IFN 2, and AS-IFN 3) were designed according to the degeneracy of genetic codes. The affinity column was prepared with sense peptide as ligand and the affinity chromatographic behavior was evaluated. Glu-substituted antisense peptide (AS-IFN 3) showed the strongest binding to immobilized sense peptide at pH 7.5. A quartz crystal microbalance-flow injection analysis (QCM-FIA) system was introduced to investigate the recognition process in real-time. The equilibrium dissociation constants between sense peptide and AS-IFN 1, AS-IFN 2 and AS-IFN 3 measured 2.08×10-4, 1.31×10-4 and 2.22×10-5 mol/L, respectively. The mechanism study indicated that the specific recognition between sense peptide and AS-IFN 3 was due to sequence-dependent and multi-modal affinity interaction.

  17. Purification of the Rous sarcoma virus src kinase by casein-agarose and tyrosine-agarose affinity chromatography.

    OpenAIRE

    Fukami, Y.; Lipmann, F

    1985-01-01

    A simple and effective purification method for the src kinase, the transforming gene product of Rous sarcoma virus, has been developed by using affinity chromatography on casein-agarose and tyrosine-agarose columns. NaDodSO4/polyacrylamide gel electrophoresis and silver staining analysis showed that the purified kinase preparation was composed of a predominant polypeptide of 60,000-Da. In most of the preparations, however, three minor proteins (54,000, 52,000, and 15,000 Da) were also detecte...

  18. Purification of F plasmid-encoded native TraC from Escherichia coli by affinity chromatography on calmodulin Sepharose.

    Science.gov (United States)

    Hellstern, Simon; Mutzel, Rupert

    2016-06-01

    We have enriched several native bacterial proteins from Escherichia coli by chromatography on the immobilized eukaryotic Ca(2+)-binding protein, calmodulin. These bacterial proteins bound in a Ca(2+)-dependent manner to calmodulin, and were released by the addition of the Ca(2+)-chelator, EGTA, similar to many eukaryotic calmodulin-binding proteins. One of the bacterial proteins, F factor-encoded TraC, was purified to apparent homogeneity by an additional chromatographic step, anion exchange chromatography on MonoQ. Experiments with four chemically distinct calmodulin antagonists (R24571, Compound 48/80, melittin, and W7) showed that all of these substances inhibited the binding of purified TraC to calmodulin at effective concentrations comparable to those required for inhibiting in vitro binding of eukaryotic calmodulin-binding proteins. Three further bacterial proteins were identified as calmodulin-binding proteins: SecA, GlpD, and GlpC. We suggest that also these native bacterial proteins might be isolated by the unusual purification procedure including affinity chromatography on calmodulin Sepharose. Whether the identified proteins bind to, and are regulated by, putative bacterial calmodulin-like proteins in Escherichia coli remains to be established. PMID:26892535

  19. Isolation of new pregnancy-associated glycoproteins from water buffalo (Bubalus bubalis) placenta by Vicia villosa affinity chromatography.

    Science.gov (United States)

    Barbato, O; Sousa, N M; Klisch, K; Clerget, E; Debenedetti, A; Barile, V L; Malfatti, A; Beckers, J F

    2008-12-01

    The present study describes the isolation and characterization of new pregnancy-associated glycoprotein molecules (PAG) from midpregnancy and late-pregnancy placentas in the water buffalo (Bubalus bubalis). After extraction, the homogenates are subjected to acid and ammonium sulfate precipitations followed by DEAE chromatography. Subsequently, the water buffalo PAG (wbPAG) from these solutions are enriched by Vicia villosa agarose (VVA) affinity chromatography. As determined by western blotting with anti-PAG sera, the apparent molecular masses of the immunoreactive bands from the VVA peaks range from 59.5 to 75.8kDa and from 57.8 to 73.3kDa in the midpregnancy and late-pregnancy placentas, respectively. Amino-terminal microsequencing of the immunoreactive proteins has allowed the identification of three distinct wbPAG sequences, which have been deposited in the SwissProt database: RGSXLTIHPLRNIRDFFYVG (acc. no. P85048), RGSXLTILPLRNIID (acc. no. P85049), and RGSXLTHLPLRNI (acc. no. P85050). Their comparison to previously identified proteins has shown that two of them are new because they have not been described before. Our results confirm the suitability of VVA chromatography for the enrichment of the multiple PAG molecules expressed in buffalo placenta. PMID:18308351

  20. Separation of Binding Protein of Celangulin V from the Midgut of Mythimna separata Walker by Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Lina Lu

    2015-05-01

    Full Text Available Celangulin V, an insecticidal compound isolated from the root bark of Chinese bittersweet, can affect the digestive system of insects. However, the mechanism of how Celangulin V induces a series of symptoms is still unknown. In this study, affinity chromatography was conducted through coupling of Celangulin V-6-aminoacetic acid ester to the CNBr-activated Sepharose 4B. SDS-PAGE was used to analyze the collected fraction eluted by Celangulin V. Eight binding proteins (Zinc finger protein, Thioredoxin peroxidase (TPx, Glyceraldehyde 3-phosphate dehydrogenase (GAPDH, SUMO E3 ligase RanBP2, Transmembrane protein 1, Actin, APN and V-ATPase were obtained and identified by LC/Q-TOF-MS from the midgut of Mythimna separata larvae. The potential of these proteins to serve as target proteins involved in the insecticidal activity of Celangulin V is discussed.

  1. Fractionation of phenolase from green table olives (Ascolana tenera var. by immobilized copper affinity chromatography

    Directory of Open Access Journals (Sweden)

    Sciancalepore, V.

    1995-10-01

    Full Text Available Phenolase from green table olives (Ascolana tenera var. was fractionated by immobilized copper affinity chromatography. Four chromatographic fractions with high specific activities were obtained. The highest activity was found for the fraction eluted with L-histidine buffer. The four active fractions were characterized by. their response to both specificity and concentration of the substrate.

    Fenolasa de aceitunas verdes de mesa de la variedad Ascolana tenera ha sido fraccionada mediante cromatografía de afinidad sobre cobre inmovilizado. Se han obtenido cuatro fracciones cromatográficas con elevada actividad específica. La fracción obtenida con tampon L-histidina fue la que presentó mayor actividad. Las cuatro fracciones activas se caracterizaron por sus respuestas a la especificidad y concentración del sustrato.

  2. β2-Adrenoceptor affinity chromatography and its application in the screening of the active compounds from Semen Armeniacae Amarum

    Institute of Scientific and Technical Information of China (English)

    ZHENG XiaoHui; ZHAO XinFeng; YANG Rong; WANG ShiXiang; WEI YinMao; ZHENG JianBin

    2008-01-01

    β2-Adrenoceptor (β2-AR) was purified from the rabbit lung tissue by sepharose-salbutamol affinity chromatographic column. To prepare the β2-AR stationary phase, β2-AR was evenly immobilized on the surface of macro-pore silica with a mild chemical coupling method through covalent bond. The reten-tion properties of β2-AR stationary phase were characterized by four ligands, salbutamol sulfate, noradrenaline bitartrate, adrenaline hydrochloride and propranolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the sta-tionary phase could keep its original bioactivity and selectivity. Amygdalin retained in the chroma-tographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed a good stability and high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine (TCM) could be screened efficiently by this method, providing a new way to screen the active compounds in complicated samples such as TCM.

  3. Affinity chromatography of tetanus toxin, tetanus toxoid, and botulinum A toxin on synaptosomes, and differentiation of their acceptors

    International Nuclear Information System (INIS)

    125I-labelled tetanus toxin and 125I-labelled botulinum A neurotoxin are known to be specifically bound to brain synaptosomes. In order to discriminate between active toxin and inactive admixtures present in the starting material or arising during iodination, synaptosome columns were prepared using bromacetylcellulose and/or kieselgur (Celite) as carriers. Both types of columns adsorb the toxins from low ionic strength medium and release them if the pH and ionic strength are raised. Botulinum toxin was eluted with lower ionic strength than tetanus toxin, and could be freed from nontoxic admixtures. Analysis by affinity chromatography disclosed partially toxoided tetanus toxin in both labelled and unlabelled toxin samples. High concentrations of formaldehyde (0.5%) destroyed both toxicity and affinity to the synaptosomes of tetanus toxin. Low concentrations of formaldehyde (0.05%) yielded a derivative of low toxicity which was still, however less firmly, bound to synaptosomes. Tetanus and botulinum toxin differ by their acceptors. Whereas unlabelled botulinum toxin is unable to compete with labelled tetanus toxin, unlabelled tetanus toxin slightly competes with botulinum toxin. Both labelled toxins display anomalous binding behaviour in that they cannot be displaced completely even with a large excess of unlabelled toxin. (orig.)

  4. Characterization of phosphoproteins from electrophoretic gels by nanoscale Fe(III) affinity chromatography with off-line mass spectrometry analysis

    DEFF Research Database (Denmark)

    Stensballe, A; Andersen, Søren; Jensen, Ole Nørregaard

    2001-01-01

    determination of phosphorylation sites. The advantages and limitations of the experimental strategy was demonstrated by enrichment, identification and sequencing of phosphopeptides from the model proteins ovalbumin and bovine beta-casein isolated by gel electrophoresis. Furthermore, an autophosphorylation site...... at Ser-3 in recombinant human casein kinase-2 beta subunit was determined. The potential of miniaturized Fe(III)-IMAC and MALDI-MS for characterization of in vivo phosphorylated proteins was demonstrated by identification of tryptic phosphopeptides derived from the human p47/phox phosphoprotein...

  5. Analysis of glipizide binding to normal and glycated human serum albumin by high-performance affinity chromatography.

    Science.gov (United States)

    Matsuda, Ryan; Li, Zhao; Zheng, Xiwei; Hage, David S

    2015-07-01

    In diabetes, the elevated levels of glucose in the bloodstream can result in the nonenzymatic glycation of proteins such as human serum albumin (HSA). This type of modification has been shown to affect the interactions of some drugs with HSA, including several sulfonylurea drugs that are used to treat type II diabetes. This study used high-performance affinity chromatography (HPAC) to examine the interactions of glipizide (i.e., a second-generation sulfonylurea drug) with normal HSA or HSA that contained various levels of in vitro glycation. Frontal analysis indicated that glipizide was interacting with both normal and glycated HSA through two general groups of sites: a set of relatively strong interactions and a set of weaker interactions with average association equilibrium constants at pH 7.4 and 37 °C in the range of 2.4-6.0 × 10(5) and 1.7-3.7 × 10(4) M(-1), respectively. Zonal elution competition studies revealed that glipizide was interacting at both Sudlow sites I and II, which were estimated to have affinities of 3.2-3.9 × 10(5) and 1.1-1.4 × 10(4) M(-1). Allosteric effects were also noted to occur for this drug between the tamoxifen site and the binding of R-warfarin at Sudlow site I. Up to an 18% decrease in the affinity for glipizide was observed at Sudlow site I ongoing from normal HSA to glycated HSA, while up to a 27% increase was noted at Sudlow site II. This information should be useful in indicating how HPAC can be used to investigate other drugs that have complex interactions with proteins. These results should also be valuable in providing a better understanding of how glycation may affect drug-protein interactions and the serum transport of drugs such as glipizide during diabetes. PMID:25912461

  6. Affinely Recursive Functions and Neural Networks

    Czech Academy of Sciences Publication Activity Database

    Kůrková, Věra; Kainen, P.C.

    Atlanta : Georgia Institute of Technology, 1994 - ( Ames , W.), s. 776-779 [IMACS World Congress /14./. Atlanta (US), 11.07.1994-15.07.1994] R&D Projects: GA AV ČR IA23057; GA ČR GA201/93/0427 Keywords : neural networks * affinely recursive functions

  7. Isolation and identification of actin-binding proteins in Plasmodium falciparum by affinity chromatography

    Directory of Open Access Journals (Sweden)

    Claudia Forero

    2000-06-01

    Full Text Available The invasion of the erythrocyte by Plasmodium falciparum depends on the ability of the merozoite to move through the membrane invagination. This ability is probably mediated by actin dependent motors. Using affinity columns with G-actin and F-actin we isolated actin binding proteins from the parasite. By immunoblotting and immunoprecipitation with specific antibodies we identified the presence of tropomyosin, myosin, a-actinin, and two different actins in the eluate corresponding to F-actin binding proteins. In addition to these, a 240-260 kDa doublet, different in size from the erythrocyte spectrin, reacted with an antibody against human spectrin. All the above mentioned proteins were metabolically radiolabeled when the parasite was cultured with 35S-methionine. The presence of these proteins in P. falciparum is indicative of a complex cytoskeleton and supports the proposed role for an actin-myosin motor during invasion.

  8. Technical advance: identification of plant actin-binding proteins by F-actin affinity chromatography

    Science.gov (United States)

    Hu, S.; Brady, S. R.; Kovar, D. R.; Staiger, C. J.; Clark, G. B.; Roux, S. J.; Muday, G. K.

    2000-01-01

    Proteins that interact with the actin cytoskeleton often modulate the dynamics or organization of the cytoskeleton or use the cytoskeleton to control their localization. In plants, very few actin-binding proteins have been identified and most are thought to modulate cytoskeleton function. To identify actin-binding proteins that are unique to plants, the development of new biochemical procedures will be critical. Affinity columns using actin monomers (globular actin, G-actin) or actin filaments (filamentous actin, F-actin) have been used to identify actin-binding proteins from a wide variety of organisms. Monomeric actin from zucchini (Cucurbita pepo L.) hypocotyl tissue was purified to electrophoretic homogeneity and shown to be native and competent for polymerization to actin filaments. G-actin, F-actin and bovine serum albumin affinity columns were prepared and used to separate samples enriched in either soluble or membrane-associated actin-binding proteins. Extracts of soluble actin-binding proteins yield distinct patterns when eluted from the G-actin and F-actin columns, respectively, leading to the identification of a putative F-actin-binding protein of approximately 40 kDa. When plasma membrane-associated proteins were applied to these columns, two abundant polypeptides eluted selectively from the F-actin column and cross-reacted with antiserum against pea annexins. Additionally, a protein that binds auxin transport inhibitors, the naphthylphthalamic acid binding protein, which has been previously suggested to associate with the actin cytoskeleton, was eluted in a single peak from the F-actin column. These experiments provide a new approach that may help to identify novel actin-binding proteins from plants.

  9. 32nd IMAC Conference and Exposition on Structural Dynamics

    CERN Document Server

    Mayes, Randy; Rixen, Daniel; Catbas, Fikret; Atamturktur, H; Moaveni, Babak; Papadimitriou, Costas; Schoenherr, Tyler; Foss, Gary; Niezrecki, Christopher; Allemang, Randall; Kerschen, Gaetan

    2014-01-01

    This critical collection examines a range of topics in modal analysis, from experimental techniques to acoustics to biodynamics,  as presented in early findings and case studies from the Proceedings of the 32nd IMAC, A Conference and Exposition on Structural Dynamics, 2014. The collection includes papers in the following general technical research areas: Experimental Techniques, Processing Modal Data, Rotating Machinery, Acoustics, Adaptive Structures, Biodynamics, Damping

  10. Fabrication of Ceramic Membrane Chromatography for Biologics Purification

    Directory of Open Access Journals (Sweden)

    Maizirwan Mel

    2011-12-01

    pemfabrikatan membran. Dalam projek ini, serbuk HA dihasilkan menggunakan kanji sebagai agen penghasilan liang. Proses pencirian dilakukan terhadap membran seramik menggunakan radas yang sesuai. Tiga parameter proses pemfabrikatan (peratusan berat kanji, tekanan padatan dan suhu pensinteran dimanipulasikan untuk mendapatkan prestasi membran yang optima. Membran yang difabrikatkan diletakkan dalam sistem FPLC (Fast Protein Liquid Chromatography untuk diuji prestasinya sebagai membran serap. Proses IMAC (Immobilized Metal Affinity Chromatography dijalankan dengan memegunkan ion Ni2+ pada permukaan zarah membran. Nucleoprotein dari NDV (Newcastle disease virus digunakan untuk menguji kebolehan membran terikat dengan protein yang dilabelkan dengan Hisditina. Set parameter proses yang optima yang menghasilkan keliangan tertinggi dan kromatogram yang baik ditentukan pada berat kanji 5 %, tekanan padatan 3000 psi dan suhu pensinteran 1100°C.KEYWORDS: Membrane Chromatography, Porous Ceramic Membrane, IMAC, Hydroxyapatite, Chromatography.

  11. TiO2-ZrO2 affinity chromatography polymeric microchip for phosphopeptide enrichment and separation.

    Science.gov (United States)

    Tsougeni, Katerina; Zerefos, Panagiotis; Tserepi, Angeliki; Vlahou, Antonia; Garbis, Spiros D; Gogolides, Evangelos

    2011-09-21

    We fabricated a TiO(2)-ZrO(2) affinity chromatography micro-column on 2 mm PMMA plates, and demonstrated the enrichment and separation of (a) a standard mono- and tetra-phosphopeptide, and (b) phosphopeptides contained in a tryptic digest of β-Casein. The chromatography column consisted of 32 parallel microchannels with common input and output ports and was fabricated by lithography directly on the polymeric substrate followed by plasma etching (i.e. standard MEMS processing) and sealed with lamination. The liquid deposited TiO(2)-ZrO(2) stationary phase was characterized by X-ray diffraction and was found to be mostly TiO(2) and ZrO(2) in crystalline phases. Off-chip UV detection and MALDI MS identification of the separated effluents were used. The chip had a capacity of >1.4 μg (0.7 nmol) of a prototype mono-phosphopeptide and a recovery of 94 ± 3%, and can be used with small samples (less than 0.1 μL depending on the syringe pump used). The chip design allows an expansion of its capacity by means of increasing the number of parallel microchannels at a constant sample volume. Our approach provided an alternative to off-line extraction tips (with typical capacities of 1-2 μg and sample volumes of 1-10 μL), and to on-chip efforts based on packed bed and frit formats. PMID:21796280

  12. Metal oxide affinity chromatography platform-polydopamine coupled functional two-dimensional titania graphene nanohybrid for phosphoproteome research.

    Science.gov (United States)

    Yan, Yinghua; Sun, Xueni; Deng, Chunhui; Li, Yan; Zhang, Xiangmin

    2014-05-01

    In this work, a facile route was initially developed for preparation of a novel metal oxide affinity chromatography (MOAC) material by grafting titania nanoparticles on polydopamine (PD)-coated graphene (denoted as G@PD@TiO2). In the first step, self-assemble polymerization of dopamine on graphene was performed in basic solution at room temperature, which not only offered the coupling linker between titania and graphene but also improved the hydrophilicity and biological compatibility of the nanohybrids. Thereafter, the titania nanoparticles were grafted on the surface of the PD-coated graphene via a simple hydrothermal treatment. The as-prepared G@PD@TiO2 nanohybrids exhibited high sensitivity (detection limit of 5 fmol) and high selectivity for phosphopeptides at a low molar ratio of phosphopeptides/nonphosphopeptides (1:1000). Moreover, the as-prepared nanohybrids were also investigated for enrichment of phosphopeptides from real biological samples (human serum and mouse brain). A total number of 556 phosphorylation sites were identified from the digest of mouse brain proteins, showing great potential in the practical application. PMID:24673251

  13. Use of Aleuria alantia Lectin Affinity Chromatography to Enrich Candidate Biomarkers from the Urine of Patients with Bladder Cancer

    Directory of Open Access Journals (Sweden)

    Sarah R. Ambrose

    2015-09-01

    Full Text Available Developing a urine test to detect bladder tumours with high sensitivity and specificity is a key goal in bladder cancer research. We hypothesised that bladder cancer-specific glycoproteins might fulfill this role. Lectin-ELISAs were used to study the binding of 25 lectins to 10 bladder cell lines and serum and urine from bladder cancer patients and non-cancer controls. Selected lectins were then used to enrich glycoproteins from the urine of bladder cancer patients and control subjects for analysis by shotgun proteomics. None of the lectins showed a strong preference for bladder cancer cell lines over normal urothlelial cell lines or for urinary glycans from bladder cancer patients over those from non-cancer controls. However, several lectins showed a strong preference for bladder cell line glycans over serum glycans and are potentially useful for enriching glycoproteins originating from the urothelium in urine. Aleuria alantia lectin affinity chromatography and shotgun proteomics identified mucin-1 and golgi apparatus protein 1 as proteins warranting further investigation as urinary biomarkers for low-grade bladder cancer. Glycosylation changes in bladder cancer are not reliably detected by measuring lectin binding to unfractionated proteomes, but it is possible that more specific reagents and/or a focus on individual proteins may produce clinically useful biomarkers.

  14. IMMOBILIZED CIBACRON BLUE F3G—A ON CROSSLINKED POLY9VINYL ALCOHOL) FOR AFFINITY CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    YUANJing; YANHusheng; 等

    2001-01-01

    Immobilized triazine dye affinity chromatography has been widely used for protein purification.In this paper,Cibacron Blue F3G-4 was immobilized,through a spacer arm,onto a rigid hydroplhilic porous polymer by reacting an epoxy-group-containing poly(vinyl alcohol)with 6-aminohexyl-N'-Cibacron Blue F3G-A,which was obtained by reacting Cibacron Blue F3G-4 with excess of 1,6-diaminohexane,in a pH 8.6buffer,The epoxy-group-containing poly(vinyl alcohol)was prepared by treating macroporous poly(vinyl alcohol)with excess epichlorohydrin in the presence of NaOH in dimethyl sulfoxide.The macroporous poly(vinyl alcohol)was prepared by hydrolysis of macroporous crosslinked poly(vinyl acetate),which was synthesized by suspension copolymerization of vinyl acetate and triallyl isocyanurate in the presence of butyl acetate and n-heptane as diluents.The Cibacron Blue F3G-A-immobilized poly(vinyl alcohol)was packed in a stainless steel column (250×5mm I.D.)and the chromatographic behaviors of several proteins(cytochrome c, lysozyme,bovine serum albumin,insulin,and lactate dehydrogenase)were determined.

  15. Glycopeptide Site Heterogeneity and Structural Diversity Determined by Combined Lectin Affinity Chromatography/IMS/CID/MS Techniques

    Science.gov (United States)

    Zhu, Feifei; Trinidad, Jonathan C.; Clemmer, David E.

    2015-07-01

    Glycopeptides from a tryptic digest of chicken ovomucoid were enriched using a simplified lectin affinity chromatography (LAC) platform, and characterized by high-resolution mass spectrometry (MS) as well as ion mobility spectrometry (IMS)-MS. The LAC platform effectively enriched the glycoproteome, from which a total of 117 glycopeptides containing 27 glycan forms were identified for this protein. IMS-MS analysis revealed a high degree of glycopeptide site heterogeneity. Comparison of the IMS distributions of the glycopeptides from different charge states reveals that higher charge states allow more structures to be resolved. Presumably the repulsive interactions between charged sites lead to more open configurations, which are more readily separated compared with the more compact, lower charge state forms of the same groups of species. Combining IMS with collision induced dissociation (CID) made it possible to determine the presence of isomeric glycans and to reconstruct their IMS profiles. This study illustrates a workflow involving hybrid techniques for determining glycopeptide site heterogeneity and evaluating structural diversity of glycans and glycopeptides.

  16. Serodiagnosis of human neurocysticercosis using antigenic components of Taenia solium metacestodes derived from the unbound fraction from jacalin affinity chromatography

    Directory of Open Access Journals (Sweden)

    Gleyce Alves Machado

    2013-05-01

    Full Text Available The aim of the present study was to analyse Taenia solium metacestode antigens that were derived from the unbound fraction of jacalin affinity chromatography and subsequent tert-octylphenoxy poly (oxyethylene ethanol Triton X-114 (TX-114 partitioning in the diagnosis of human neurocysticercosis (NCC. Immunoassays were designed to detect T. solium-specific IgG antibodies by ELISA and immunoblot. Serum samples were collected from 132 individuals who were categorised as follows: 40 had NCC, 62 presented Taenia spp or other parasitic diseases and 30 were healthy individuals. The jacalin-unbound (J unbound fraction presented higher sensitivity and specificity rates than the jacalin-bound fraction and only this fraction was subjected to subsequent TX-114 partitioning, resulting in detergent (DJ unbound and aqueous (AJ unbound fractions. The ELISA sensitivity and specificity were 85% and 84.8% for J unbound , 92.5% and 93.5% for DJ unbound and 82.5% and 82.6% for AJ unbound . By immunoblot, the DJ unbound fraction showed 100% sensitivity and specificity and only serum samples from patients with NCC recognised the 50-70 kDa T. solium-specific components. We conclude that the DJ unbound fraction can serve as a useful tool for the differential immunodiagnosis of NCC by immunoblot.

  17. Liver- and bone-derived isoenzymes of alkaline phosphatase in serum as determined by high-performance affinity chromatography.

    Science.gov (United States)

    Anderson, D J; Branum, E L; O'Brien, J F

    1990-02-01

    To separate liver and bone alkaline phosphatase (ALP) isoenzymes in human serum, we used high-performance affinity chromatography (HPAC) on a column of wheat-germ lectin conjugated to 7-microns-diameter silica particles and an eluent containing N-acetyl-D-glucosamine (NAG). On-line spectrophotometric detection of ALP involved pumping diethanolamine-buffered p-nitrophenyl phosphate solution post-column. Bone and liver isoenzymes could be separated into two peaks with only 10% overlap when an exponential gradient was used. A linear-step gradient separated 80.9% of liver ALP and 91.6% of bone ALP in two distinct peaks. True bone and liver ALP peak areas for the linear-step gradient were determined by using correction factors, because each peak contained a co-eluted portion of the other ALP isoenzyme. The detection limit improved 10-fold over those of other techniques for ALP isoenzymes, owing to the relatively large sample that could be applied to the column. Correlation with a urea-inactivation procedure was reasonable for patients' serum samples (r = 0.98 and 0.79 for liver ALP and bone ALP, respectively). PMID:2302767

  18. Combining metal oxide affinity chromatography (MOAC and selective mass spectrometry for robust identification of in vivo protein phosphorylation sites

    Directory of Open Access Journals (Sweden)

    Weckwerth Wolfram

    2005-11-01

    Full Text Available Abstract Background Protein phosphorylation is accepted as a major regulatory pathway in plants. More than 1000 protein kinases are predicted in the Arabidopsis proteome, however, only a few studies look systematically for in vivo protein phosphorylation sites. Owing to the low stoichiometry and low abundance of phosphorylated proteins, phosphorylation site identification using mass spectrometry imposes difficulties. Moreover, the often observed poor quality of mass spectra derived from phosphopeptides results frequently in uncertain database hits. Thus, several lines of evidence have to be combined for a precise phosphorylation site identification strategy. Results Here, a strategy is presented that combines enrichment of phosphoproteins using a technique termed metaloxide affinity chromatography (MOAC and selective ion trap mass spectrometry. The complete approach involves (i enrichment of proteins with low phosphorylation stoichiometry out of complex mixtures using MOAC, (ii gel separation and detection of phosphorylation using specific fluorescence staining (confirmation of enrichment, (iii identification of phosphoprotein candidates out of the SDS-PAGE using liquid chromatography coupled to mass spectrometry, and (iv identification of phosphorylation sites of these enriched proteins using automatic detection of H3PO4 neutral loss peaks and data-dependent MS3-fragmentation of the corresponding MS2-fragment. The utility of this approach is demonstrated by the identification of phosphorylation sites in Arabidopsis thaliana seed proteins. Regulatory importance of the identified sites is indicated by conservation of the detected sites in gene families such as ribosomal proteins and sterol dehydrogenases. To demonstrate further the wide applicability of MOAC, phosphoproteins were enriched from Chlamydomonas reinhardtii cell cultures. Conclusion A novel phosphoprotein enrichment procedure MOAC was applied to seed proteins of A. thaliana and to

  19. HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY AND THE ANALYSIS OF DRUG INTERACTIONS WITH MODIFIED PROTEINS: BINDING OF GLICLAZIDE WITH GLYCATED HUMAN SERUM ALBUMIN

    OpenAIRE

    Matsuda, Ryan; Anguizola, Jeanethe; Joseph, K S; Hage, David S.

    2011-01-01

    This study used high-performance affinity chromatography (HPAC) to examine the binding of gliclazide (i.e., a sulfonylurea drug used to treat diabetes) with the protein human serum albumin (HSA) at various stages of modification due to glycation. Frontal analysis conducted with small HPAC columns was first used to estimate the number of binding sites and association equilibrium constants (Ka) for gliclazide with normal HSA and glycated HSA. Both normal and glycated HSA interacted with gliclaz...

  20. Hepatitis C virus expressing flag-tagged envelope protein 2 has unaltered infectivity and density, is specifically neutralized by flag antibodies and can be purified by affinity chromatography

    DEFF Research Database (Denmark)

    Prentø, Jannick Cornelius; Bukh, Jens

    2011-01-01

    Hepatitis C virus (HCV) purification by ultracentrifugation is difficult because of the low and heterogeneous density of native and cultured viruses. It was recently shown that inserting flag tag into envelope protein 2 (E2) of HCV permitted virus purification by affinity chromatography. However,...... physiochemical properties of flag-tagged HCV is an important improvement for utilizing these viruses for imaging, virion composition analysis and possibly vaccine development....

  1. 34th IMAC, A Conference and Exposition on Structural Dynamics

    CERN Document Server

    Brandt, Anders; Singhal, Raj

    2016-01-01

    Nonlinear Dynamics, Volume 1. Proceedings of the 34th IMAC, A Conference and Exposition on Dynamics of Multiphysical Systems: From Active Materials to Vibroacoustics, 2016, the fi rst volume of ten from the Conference, brings together contributions to this important area of research and engineering. Th e collection presents early fi ndings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on: • Nonlinear Oscillations • Nonlinear Modal Analysis • Nonlinear System Identifi cation • Nonlinear Modeling & Simulation • Nonlinearity in Practice • Nonlinearity in Multi-Physics Systems • Nonlinear Modes and Modal Interactions.

  2. 30th IMAC, A Conference on Structural Dynamics

    CERN Document Server

    Catbas, FN; Mayes, R; Rixen, D; Griffith, DT; Allemang, R; Clerck, J; Klerk, D; Simmermacher, T; Cogan, S; Chauhan, S; Cunha, A; Racic, V; Reynolds, P; Salyards, K; Adams, D; Kerschen, G; Carrella, A; Voormeeren, SN; Allen, MS; Horta, LG; Barthorpe, R; Niezrecki, C; Blough, JR; Vol.1 Topics on the Dynamics of Civil Structures; Vol.2 Topics in Experimental Dynamics Substructuring and Wind Turbine Dynamics; Vol.3 Topics in Nonlinear Dynamics; Vol.4 Topics in Model Validation and Uncertainty Quantification; Vol.5 Topics in Modal Analysis I; Vol.6 Topics in Modal Analysis II

    2012-01-01

    Topics on the Dynamics of Civil Structures, Volume 1, Proceedings of the 30th IMAC, A Conference and Exposition on Structural Dynamics, 2012, the first volume of six from the Conference, brings together 45 contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on: Human Induced Vibrations Bridge Dynamics Operational Modal Analysis Experimental Techniques and Modeling for Civil Structures System Identification for Civil Structures Method and Technologies for Bridge Monitoring Damage Detection for Civil Structures Structural Modeling Vibration Control Method and Approaches for Civil Structures Modal Testing of Civil Structures.

  3. Lanthanide-IMAC enrichment of carbohydrates and polyols.

    Science.gov (United States)

    Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

    2014-03-01

    In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions. PMID:24097333

  4. Affinity chromatography of GroEL chaperonin based on denatured proteins: role of electrostatic interactions in regulation of GroEL affinity for protein substrates.

    Science.gov (United States)

    Marchenko, N Iu; Marchenkov, V V; Kaĭsheva, A L; Kashparov, I A; Kotova, N V; Kaliman, P A; Semisotnov, G V

    2006-12-01

    The chaperonin GroEL of the heat shock protein family from Escherichia coli cells can bind various polypeptides lacking rigid tertiary structure and thus prevent their nonspecific association and provide for acquisition of native conformation. In the present work we studied the interaction of GroEL with six denatured proteins (alpha-lactalbumin, ribonuclease A, egg lysozyme in the presence of dithiothreitol, pepsin, beta-casein, and apocytochrome c) possessing negative or positive total charge at neutral pH values and different in hydrophobicity (affinity for a hydrophobic probe ANS). To prevent the influence of nonspecific association of non-native proteins on their interaction with GroEL and make easier the recording of the complexing, the proteins were covalently attached to BrCN-activated Sepharose. At low ionic strength (lower than 60 mM), tight binding of the negatively charged denatured proteins with GroEL (which is also negatively charged) needed relatively low concentrations (approximately 10 mM) of bivalent cations Mg2+ or Ca2+. At the high ionic strength (approximately 600 mM), a tight complex was produced also in the absence of bivalent cations. In contrast, positively charged denatured proteins tightly interacted with GroEL irrespectively of the presence of bivalent cations and ionic strength of the solution (from 20 to 600 mM). These features of GroEL interaction with positively and negatively charged denatured proteins were confirmed by polarized fluorescence (fluorescence anisotropy). The findings suggest that the affinity of GroEL for denatured proteins can be determined by the balance of hydrophobic and electrostatic interactions. PMID:17223789

  5. Isolation of specific anti-T3 and anti-T4 antibodies by affinity chromatography and their application for solid phase radioimmunoassay

    International Nuclear Information System (INIS)

    For laboratory, clinical and experimental purposes highly purified and high avidity antibodies, devoid of other plasma proteins, are required. Hitherto physical and chemical methods have not provided antibodies of sufficient purity, and it was only the introduction of affinity chromatography which achieved antibodies of required purity. Various suports /Affi-Gel 10, CNBr-activated Sepharose 4B, AH-Sepharose 4B and Epoxy-activated Sepharose 6B/ were tried for immobilization of iodothyronines. From these materials Epoxy-activated Sepharose 6B gave most satisfactory results, hence some details of the coupling procedure are given

  6. Affinity Chromatography Method for Determination of Binding of Drugs to Melanin and Evaluation of Side Effect Potential of Antipsychotic Agents

    OpenAIRE

    Marszałł, Michał Piotr; Proszowska, Anna; Buciński, Adam; Kaliszan, Roman

    2014-01-01

    The extrapyramidal side effect parameters of typical and atypical antypsychotics were correlated with affinity chromatographic data determined on the melanin-based column. The chromatographic study was performed according to the hypothesis that extrapyramidal symptoms (EPS) as side effects of the use of antipsychotic drugs at clinically effective doses are correlated to the affinity of these drugs to neuromelanin. For that aim the polymerization product of L-DOPA (melanin) was immobilized ont...

  7. Isolation and Identification of Zn2+ Binding Proteins in Streptococcus pyogenes by IMAC and LC-MS/MS%利用IMAC与LC-MS/MS技术分离和鉴定化脓链球菌中的锌结合蛋白

    Institute of Scientific and Technical Information of China (English)

    阳小燕; 银兴峰; 张留辉; 贺翔; 孙雪松

    2011-01-01

    Streptococcus pyogenes is a gram-positive pathogen that causes a variety of human diseases. The zinc binding proteins of S. pyogenes were enriched through Immobilized-metal affinity chromatography (IMAC) .The proteins were further digested in-solution and analyzed by the advanced LC-MS/MS. In total, forty-eight zinc binding proteins involved in protein translation, glucose metabolism, metal transport, oxidation and other physiological processes were identified. The data presented here are helpful in understanding of the pathological mechanisms of S. pyogenes and facilitate the discovery of potential antibacterial drug targets and vaccine candidates.%化脓链球菌是一种革兰氏阳性致病菌,能引起一系列疾病.运用固定化金属离子亲和层析技术(IMAC)富集化脓链球菌中锌结合蛋白,进行溶液酶解,利用先进的LC-MS/MS技术对富集的锌结合蛋白进行质谱分析.鉴定到48个在化脓链球菌中与锌结合相关蛋白,这些蛋白主要涉及到蛋白翻译、糖代谢、金属转运、氧化等重要生理过程.这些结果对于深入研究化脓链球菌的致病机制,寻找新的抗菌药物作用靶点和疫苗候选物具有重要意义.

  8. High-performance liquid chromatography of amino acids, peptides and proteins. CIII. Mass transfer resistances in ion-exchange and dye-affinity chromatography of proteins.

    Science.gov (United States)

    Johnston, A; Hearn, M T

    1990-07-20

    Adsorption equilibria and rate kinetics have been investigated for the binding of several proteins, with different molecular geometries, to several ion-exchange and dye-affinity chromatographic resins with varying pore size and protein accessibilities. The pore geometry was shown to play a significant role in the protein capacity and loadability of both the ion-exchange and dye-affinity resins. For example the Fractogel HW75-Cibacron Blue F3GA affinity sorbent had the greatest capacity for the small protein, lysozyme, compared to the other Fractogel HW-Cibacron Blue F3GA sorbents, and similarly, the ion-exchange resins, such as DEAE-Fractogel 65, bound more human serum albumin (HSA), as opposed to the larger protein, ferritin. The apparent diffusion of protein from the bulk phase to the ligands/ionic sites was calculated to be considerably restricted when the pore to protein size ratio was small, as is the case of DEAE Fractogel 65/ferritin system, and the dye-affinity Fractogel HW55/HSA system. In these circumstances, pore diffusivity was calculated to be up to 100-fold smaller than bulk diffusivity. PMID:2229222

  9. Hydrophilic Nb{sup 5+}-immobilized magnetic core–shell microsphere – A novel immobilized metal ion affinity chromatography material for highly selective enrichment of phosphopeptides

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xueni; Liu, Xiaodan; Feng, Jianan [Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai 201203 (China); Li, Yan, E-mail: yanli@fudan.edu.cn [Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai 201203 (China); Deng, Chunhui [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China); Duan, Gengli [Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai 201203 (China)

    2015-06-23

    Highlights: • A new IMAC material (Fe{sub 3}O{sub 4}@PD-Nb{sup 5+}) was synthesized. • The strong magnetic behaviors of the microspheres ensure fast and easy separation. • The enrichment ability was tested by human serum and nonfat milk. • The results were compared with other IMAC materials including the commercial kits. • All results proved the good enrichment ability, especially for multiphosphopeptides. - Abstract: Rapid and selective enrichment of phosphopeptides from complex biological samples is essential and challenging in phosphorylated proteomics. In this work, for the first time, niobium ions were directly immobilized on the surface of polydopamine-coated magnetic microspheres through a facile and effective synthetic route. The Fe{sub 3}O{sub 4}@polydopamine-Nb{sup 5+} (denoted as Fe{sub 3}O{sub 4}@PD-Nb{sup 5+}) microspheres possess merits of high hydrophilicity and good biological compatibility, and demonstrated low limit of detection (2 fmol). The selectivity was also basically satisfactory (β-casein:BSA = 1:500) to capture phosphopeptides. They were also successfully applied for enrichment of phosphopeptides from real biological samples such as human serum and nonfat milk. Compared with Fe{sub 3}O{sub 4}@PD-Ti{sup 4+} microspheres, the Fe{sub 3}O{sub 4}@PD-Nb{sup 5+} microspheres exhibit superior selectivity to multi-phosphorylated peptides, and thus may be complementary to the conventional IMAC materials.

  10. Enrichment and separation of mono- and multiply phosphorylated peptides using sequential elution from IMAC prior to mass spectrometric analysis

    DEFF Research Database (Denmark)

    Thingholm, Tine E; Jensen, Ole N; Larsen, Martin R

    2009-01-01

    Phospho-proteomics relies on methods for efficient purification and sequencing of phosphopeptides from highly complex biological systems using low amounts of starting material. Current methods for phosphopeptide enrichment, e.g., immobilized metal affinity chromatography and titanium dioxide...

  11. The combination of lectin affinity chromatography, gel electrophoresis and mass spectrometry in the study of plant glycoproteome: Preliminary insights

    Czech Academy of Sciences Publication Activity Database

    Laštovičková, Markéta; Smětalová, D.; Bobálová, Janette

    2011-01-01

    Roč. 73, Suppl 1 (2011), S113–S122. ISSN 0009-5893 R&D Projects: GA MŠk 1M0570; GA AV ČR IAA600040701 Institutional research plan: CEZ:AV0Z40310501 Keywords : lectin chromatography * MALDI-TOF mass spectrometry * Glycoproteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.195, year: 2011

  12. Sialic acid-specific affinity chromatography for the separation of erythropoietin glycoforms using serotonin as a ligand.

    Science.gov (United States)

    Meininger, M; Stepath, M; Hennig, R; Cajic, S; Rapp, E; Rotering, H; Wolff, M W; Reichl, U

    2016-02-15

    Recombinant human erythropoietin (rhEPO) is an important CHO cell-derived glycoprotein and the degree of sialylation of this hormone is crucial for its in vivo bioactivity. In order to improve the purification process serotonin as a potential affinity ligand was tested for preparative chromatographic separation of rhEPO glycoforms into fractions of different degrees of sialylation. Therefore, two chromatographic matrices were prepared by immobilizing serotonin on CNBr- and NHS-Sepharose™. First it was shown both matrices bind rhEPO only in its sialylated form. Results indicate that binding is pH independent between pH 3.5 to 8 suggesting it is not only based on electrostatic interactions. Second, after optimal binding conditions were identified, semi-purified rhEPO was loaded onto both matrices and eluted using a stepwise elution gradient of sodium chloride. For comparison same affinity purification experiments were performed using wheat germ agglutinin-coupled agarose, a lectin known for its affinity towards sialylated glycoproteins. To monitor changes in N-glycan fingerprint, eluate fractions were analyzed by multiplexed capillary gel electrophoresis coupled to laser-induced fluorescence (xCGE-LIF). For the serotonin matrices an increasing degree of sialylation was observed from the first to the third elution fraction while purity of rhEPO could be increased at the same time. The late elution fractions of serotonin-coupled CNBr- and NHS-Sepharose™ also showed an overall sialylation degree exceeding that of the starting material. In contrast, for rhEPO bound to wheat germ agglutinin-coupled agarose, no distinct change in the degree of sialylation could be observed after elution. Overall, these encouraging results highlight the potential of serotonin as a chromatographic ligand for the improvement of pharmaceutical purification processes of rhEPO. PMID:26851523

  13. An automated method for high-throughput protein purification applied to a comparison of His-tag and GST-tag affinity chromatography

    Directory of Open Access Journals (Sweden)

    Büssow Konrad

    2003-07-01

    Full Text Available Abstract Background Functional Genomics, the systematic characterisation of the functions of an organism's genes, includes the study of the gene products, the proteins. Such studies require methods to express and purify these proteins in a parallel, time and cost effective manner. Results We developed a method for parallel expression and purification of recombinant proteins with a hexahistidine tag (His-tag or glutathione S-transferase (GST-tag from bacterial expression systems. Proteins are expressed in 96-well microplates and are purified by a fully automated procedure on a pipetting robot. Up to 90 microgram purified protein can be obtained from 1 ml microplate cultures. The procedure is readily reproducible and 96 proteins can be purified in approximately three hours. It avoids clearing of crude cellular lysates and the use of magnetic affinity beads and is therefore less expensive than comparable commercial systems. We have used this method to compare purification of a set of human proteins via His-tag or GST-tag. Proteins were expressed as fusions to an N-terminal tandem His- and GST-tag and were purified by metal chelating or glutathione affinity chromatography. The purity of the obtained protein samples was similar, yet His-tag purification resulted in higher yields for some proteins. Conclusion A fully automated, robust and cost effective method was developed for the purification of proteins that can be used to quickly characterise expression clones in high throughput and to produce large numbers of proteins for functional studies. His-tag affinity purification was found to be more efficient than purification via GST-tag for some proteins.

  14. Hydrophilic Nb⁵⁺-immobilized magnetic core-shell microsphere--A novel immobilized metal ion affinity chromatography material for highly selective enrichment of phosphopeptides.

    Science.gov (United States)

    Sun, Xueni; Liu, Xiaodan; Feng, Jianan; Li, Yan; Deng, Chunhui; Duan, Gengli

    2015-06-23

    Rapid and selective enrichment of phosphopeptides from complex biological samples is essential and challenging in phosphorylated proteomics. In this work, for the first time, niobium ions were directly immobilized on the surface of polydopamine-coated magnetic microspheres through a facile and effective synthetic route. The Fe3O4@polydopamine-Nb(5+) (denoted as Fe3O4@PD-Nb(5+)) microspheres possess merits of high hydrophilicity and good biological compatibility, and demonstrated low limit of detection (2 fmol). The selectivity was also basically satisfactory (β-casein:BSA=1:500) to capture phosphopeptides. They were also successfully applied for enrichment of phosphopeptides from real biological samples such as human serum and nonfat milk. Compared with Fe3O4@PD-Ti(4+) microspheres, the Fe3O4@PD-Nb(5+) microspheres exhibit superior selectivity to multi-phosphorylated peptides, and thus may be complementary to the conventional IMAC materials. PMID:26092339

  15. Designed synthesis of Graphene @titania @mesoporous silica hybrid material as size-exclusive metal oxide affinity chromatography platform for selective enrichment of endogenous phosphopeptides.

    Science.gov (United States)

    Yao, Jizong; Sun, Nianrong; Deng, Chunhui; Zhang, Xiangming

    2016-04-01

    In this work, a novel size-exclusive metal oxide affinity chromatography (SE-MOAC) platform was built for phosphoproteome research. The operation for preparing graphene @titania @mesoporous silica nanohybrids (denoted as G@TiO2@mSiO2) was facile and easy to conduct by grafting titania nanoparticles on polydopamine (PD)-covered graphene, following a layer of mesoporous silica was coated on the outermost layer. The G@TiO2@mSiO2 nanohybrids exhibited high sensitivity with a low detection limit of 5amol/μL (a total amount of 1fmol) and high selectivity for phosphopeptides at a mass ratio of phosphopeptides to non-phosphopeptides (1:1000). The size-exclusive capability of the nanohybrids were also demonstrated by enriching the phosphopeptides from the mixture of Bovine Serum Albumin (BSA), α-casein, and β-casein digests with a high mass ratio (β-casein digests: α-casein: BSA, 1:500:500), which was attributed to the large surface area and ordered mesoporous channels. In addition, the G@TiO2@mSiO2 nanohybrids were employed to capture the endogenous phosphopeptides from human serum successfully. PMID:26838411

  16. Quantitative Phosphoproteome Analysis of Lysophosphatidic Acid Induced Chemotaxis applying Dual-step ¹⁸O Labeling Coupled with Immobilized Metal-ion Affinity Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shi-Jian; Wang, Yingchun; Jacobs, Jon M.; Qian, Weijun; Yang, Feng; Tolmachev, Aleksey V.; Du, Xiuxia; Wang, Wei; Moore, Ronald J.; Monroe, Matthew E.; Purvine, Samuel O.; Waters, Katrina M.; Heibeck, Tyler H.; Adkins, Joshua N.; Camp, David G.; Klemke, Richard L.; Smith, Richard D.

    2008-10-01

    Reversible protein phosphorylation is a central cellular regulatory mechanism in modulating protein activity and propagating signals within cellular pathways and networks. Development of more effective methods for the simultaneous identification of phosphorylation sites and quantification of temporal changes in protein phosphorylation could provide important insights into molecular signaling mechanisms in a variety of different cellular processes. Here we present an integrated quantitative phosphoproteomics approach and its applications for comparative analysis of Cos-7 cells in response to lysophosphatidic acid (LPA) gradient stimulation. The approach combines trypsin-catalyzed 16O/18O labeling plus 16O/18O-methanol esterification labeling for quantitation, a macro- Immobilized Metal-ion Affinity Chromatography trap for phosphopeptide enrichment, and a monolithic capillary column with integrated electrospray emitter. LC separation and MS/MS is followed by neutral loss-dependent MS/MS/MS for phosphopeptide identification using a linear ion trap (LTQ)-FT mass spectrometer and complementary searching algorithms for interpreting MS/MS spectra. Protein phosphorylation involved in various signaling pathways of cell migration were identified and quantified, such as mitogen-activated protein kinase 1, dual-specificity mitogen-activated protein kinase kinase 2, and dual-specificity tyrosine-phosphorylation regulated kinase 1b, and a number of Rho GTPase-activating proteins. These results demonstrate the efficiency of this quantitative phosphoproteomics approach and its application for rapid discovery of phosphorylation events associated with gradient sensing and cell chemotaxis.

  17. Recognition and binding of β-lactam antibiotics to bovine serum albumin by frontal affinity chromatography in combination with spectroscopy and molecular docking.

    Science.gov (United States)

    Li, Qian; Zhang, Tianlong; Bian, Liujiao

    2016-03-01

    Serum albumins are the most abundant carrier proteins in blood plasma and participate in the binding and transportation of various exogenous and endogenous compounds in the body. This work was designed to investigate the recognition and binding of three typical β-lactam antibiotics including penicillin G (Pen G), penicillin V (Pen V) and cefalexin (Cef) with bovine serum albumin (BSA) by frontal affinity chromatography in combination with UV-vis absorption spectra, fluorescence emission spectra, binding site marker competitive experiment and molecular docking under simulated physiological conditions. The results showed that a BSA only bound with one antibiotic molecule in the binding process, and the binding constants for Pen G-BSA, Pen V-BSA and Cef-BSA complexes were 4.22×10(1), 4.86×10(2) and 3.32×10(3) (L/mol), respectively. All the three β-lactam antibiotics were mainly inserted into the subdomain IIA (binding site 1) of BSA by hydrogen bonds and Van der Waals forces. The binding capacity between the antibiotics and BSA was closely related to the functional groups and flexibility of side chains in antibiotics. This study provided an important insight into the molecular recognition and binding interaction of BSA with β-lactam antibiotics, which may be a useful guideline for the innovative clinical medications and new antibiotic designs with effective pharmacological properties. PMID:26882128

  18. Molecular insight in the purification of immunoglobulin by pseudobiospecific ligand l-histidine and histidyl moieties in histidine ligand affinity chromatography (HLAC) by molecular docking.

    Science.gov (United States)

    Savane, Tushar S; Kumar, Sanjit; Janakiraman, Vignesh Narasimhan; Kamalanathan, Agamudi S; Vijayalakshmi, Mookambeswaran A

    2016-05-15

    Pseudobiospecific ligand l-histidine is an inexpensive, highly stable, non-toxic ligand explored successfully over the last twenty years for the purification of immunoglobulins in immobilised histidine ligand affinity chromatography. It is of great interest to know the molecular recognition sites of IgG to immobilized l-histidine. Here, we have used an in silico approach to explore the molecular recognition of l-histidine by IgG. We have assessed the feasible binding modes of histidine and its moieties at different sites of IgG and considered only those binding conformations which are exhibited via the imidazole ring NH group or any other OH donating group apart from the ones which are terminally conjugated with the support matrix. We categorised binding site into two categories; category I: inner binding groove and category II: surface binding groove and observed that the hinge region of IgG has most favourable binding pocket for l-histidine and histidyl moieties. Ser and Tyr residues on the hinge region make several significant interactions with l-histidine and histidyl moieties. In case of Fc region of IgG, l-histidine and histidyl moieties closely resemble the binding modes of Protein A, biomimetic ligand 22/8 and B domain of SpA to IgG. In addition to these we have also observed a significant binding site for l-histidine and histidyl moieties at Fab region of IgG. PMID:26476866

  19. Simultaneous high-throughput determination of interaction kinetics for drugs and cyclodextrins by high performance affinity chromatography with mass spectrometry detection.

    Science.gov (United States)

    Wang, Caifen; Wang, Xiaobo; Xu, Xiaonan; Liu, Botao; Xu, Xu; Sun, Lixin; Li, Haiyan; Zhang, Jiwen

    2016-02-25

    The individual determination of the apparent dissociation rate constant (kd,app) using high performance affinity chromatography (HPAC) is a tedious process requiring numerous separate tests and massive data fitting, unable to provide the apparent association rate constant (ka) and equilibrium binding constant (Ka). In this study, a HPAC with mass spectrometry detection (HPAC-MS/MS) was employed to determine the drug-cyclodextrin (CD) interaction kinetics with low sample loading quantity (ketoprofen, trimethoprim, indapamide and acetaminophen, with kd,app for acetaminophen consistent with that from the HPAC method with UV detector in our previous studies. For twenty drugs with diverse structures and chemical properties, good correlationship was found between kd,app measured by single compound analysis method and high-throughput HPAC-MS/MS approach, with the correlation coefficient of 0.987 and the significance F less than 0.001. Comprehensive quantification of ka,app, kd,app and Ka values was further performed based on the measurement of kd,app by peak profiling method and Ka by the peak fitting method. And the investigation of the drug-CD interaction kinetics under different conditions indicated that the column temperature and mobile phase composition significantly affected the determination of ka,app, kd,app and Ka while also dependent on the acidity and basicity of drugs. In summary, the high-throughput HPAC-MS/MS approach has been demonstrated high efficiency in determination of the drug-CD primary interaction kinetic parameter, especially, kd,app, being proven as a novel tool in screening the right CD for the solubilization of the right drug. PMID:26851087

  20. Reproducible Automated Phosphopeptide Enrichment Using Magnetic TiO2 and Ti-IMAC

    OpenAIRE

    Tape, Christopher J.; Worboys, Jonathan D.; Sinclair, John; Gourlay, Robert; Vogt, Janis; McMahon, Kelly M.; Trost, Matthias; Lauffenburger, Douglas A.; Lamont, Douglas J.; Jørgensen, Claus

    2014-01-01

    Reproducible, comprehensive phosphopeptide enrichment is essential for studying phosphorylation-regulated processes. Here, we describe the application of hyper-porous magnetic TiO2 and Ti-IMAC microspheres for uniform automated phosphopeptide enrichment. Combining magnetic microspheres with a magnetic particle-handling robot enables rapid (45 min), reproducible (r2 ≥ 0.80) and high-fidelity (>90% purity) phosphopeptide purification in a 96-well format. Automated phosphopeptide enrichment demo...

  1. Sequential Elution from IMAC (SIMAC): An Efficient Method for Enrichment and Separation of Mono- and Multi-phosphorylated Peptides.

    Science.gov (United States)

    Thingholm, Tine E; Larsen, Martin R

    2016-01-01

    Phosphoproteomics relies on methods for efficient purification and sequencing of phosphopeptides from highly complex biological systems, especially when using low amounts of starting material. Current methods for phosphopeptide enrichment, e.g., Immobilized Metal ion Affinity Chromatography and titanium dioxide chromatography provide varying degrees of selectivity and specificity for phosphopeptide enrichment. The number of multi-phosphorylated peptides identified in most published studies is rather low. Here we describe a protocol for a strategy that separates mono-phosphorylated peptides from multiply phosphorylated peptides using Sequential elution from Immobilized Metal ion Affinity Chromatography. The method relies on the initial enrichment and separation of mono- and multi-phosphorylated peptides using Immobilized Metal ion Affinity Chromatography and a subsequent enrichment of the mono-phosphorylated peptides using titanium dioxide chromatography. The two separate phosphopeptide fractions are then subsequently analyzed by mass spectrometric methods optimized for mono-phosphorylated and multi-phosphorylated peptides, respectively, resulting in improved identification of especially multi-phosphorylated peptides from a minimum amount of starting material. PMID:26584924

  2. Optimization of Traffic System using TCL Algorithm through FMSA and IMAC Agents

    Directory of Open Access Journals (Sweden)

    T.Karthikeyan , S.Sujatha

    2012-08-01

    Full Text Available Based on Agent Technology, Service Oriented Architecture and RFID,this paper puts forward a ‘real time paradigm’ traffic congestion control strategy in metropolitan cities. This strategy uses TCL algorithm in order to provide optimal traffic performance evaluation considering the parameter, velocity of vehicles by implementing RMI & SOAP interfaces. This building block of traffic and transportation system is more suited for the proposed mobile agents FMSA(Fixed Monitor Stationary Agent & IMAC(Interactive Mobile Agent for Client because this model works on the Agent technology that can be developed using Java and JADE Agent platform under dynamic changing environments. The developed FMSA & IMAC agents makes real time decisions for choosing the best path in road traffic network to avoid congestion by considering the parameters for optimization like mainly the velocity of vehicles in the existing lane. This paper also compares the experimental results obtained by the system before and after the implementation of FMSA & IMAC agents to prove the significant performance for finding the best path by confirming the better efficiency & scalability improvement of our framework.

  3. Validation of Process for Virus Removal from Recombinant Monoclonal Antibody Product by Affinity Chromatography%重组单抗药物亲和层析病毒去除工艺验证

    Institute of Scientific and Technical Information of China (English)

    程立均; 马翠卿; 杨建岭; 魏敬双; 张世雄; 刘俊乐; 魏林; 贾茜

    2011-01-01

    Objective To verify the process for virus removal from recombinant monoclonal antibody product by affinity chromatography.Methods The efficacies of virus removal from recombinant monoclonal antibody against rabies virus by novel and traditional rProtein A Sepharose Fast Flow (rProtein A SFF) chromatography were evaluated using influenza virus subtype H1N1, herpes simplex virus type 1 and adenovirus type 5 as model viruses. Results All the titers of three kinds of model viruses decreased by more than 4. 0 log10 after purification by novel and traditional rProtein A SFF chromatography. Conclusion The rProtein A SFF affinity chromatography is effective in removal of potential virus contamination from recombinant monoclonal antibody products.%目的 对重组单抗药物亲和层析病毒去除工艺进行验证.方法 以甲型流感病毒H1N1亚型、单纯疱疹病毒1型和腺病毒5型作为指示病毒,分别使用新、旧rProtein A Sepharose Fast Flow(rProtein A SFF)层析介质考察重组抗狂犬病病毒单抗亲和层析步骤对病毒的去除效果.结果 经新、旧rProtein A SFF介质亲和层析后,3种指示病毒的滴度均下降4.0log10以上.结论 rProtein A SFF亲和层析工艺能有效去除重组单抗药物的潜在病毒污染.

  4. Cockpit Interfaces, Displays, and Alerting Messages for the Interval Management Alternative Clearances (IMAC) Experiment

    Science.gov (United States)

    Baxley, Brian T.; Palmer, Michael T.; Swieringa, Kurt A.

    2015-01-01

    This document describes the IM cockpit interfaces, displays, and alerting capabilities that were developed for and used in the IMAC experiment, which was conducted at NASA Langley in the summer of 2015. Specifically, this document includes: (1) screen layouts for each page of the interface; (2) step-by-step instructions for data entry, data verification and input error correction; (3) algorithm state messages and error condition alerting messages; (4) aircraft speed guidance and deviation indications; and (5) graphical display of the spatial relationships between the Ownship aircraft and the Target aircraft. The controller displays for IM will be described in a separate document.

  5. Isolation of pregnancy-associated glycoproteins (PAG) from water buffalo (Bubalus bubalis) placenta by use of Vicia villosa bound agarose affinity chromatography

    OpenAIRE

    Beckers, J. F.; Malfatti, A.; V. Barile; Debenedetti, A.; Clerget, E.; K. Klisch; Sousa, N.M.; O. Barbato

    2010-01-01

    The present study describes the isolation and characterisation of new PAG molecules extracted from mid- and late-pregnancy placentas in the water buffalo (Bubalis bubalis). After extraction, acid and ammonium sulphate precipitation and DEAE chromatography water buffalo PAG (wbPAG) were enriched by Vicia villosa agarose (VVA) affininity chromatography. As determined by Western blotting with anti-PAG-sera, apparent molecular masses of immunoreactive bands from VVA peaks ranged from 59.5 to 75.8...

  6. THE IMACS CLUSTER BUILDING SURVEY. I. DESCRIPTION OF THE SURVEY AND ANALYSIS METHODS

    International Nuclear Information System (INIS)

    The IMACS Cluster Building Survey uses the wide field spectroscopic capabilities of the IMACS spectrograph on the 6.5 m Baade Telescope to survey the large-scale environment surrounding rich intermediate-redshift clusters of galaxies. The goal is to understand the processes which may be transforming star-forming field galaxies into quiescent cluster members as groups and individual galaxies fall into the cluster from the surrounding supercluster. This first paper describes the survey: the data taking and reduction methods. We provide new calibrations of star formation rates (SFRs) derived from optical and infrared spectroscopy and photometry. We demonstrate that there is a tight relation between the observed SFR per unit B luminosity, and the ratio of the extinctions of the stellar continuum and the optical emission lines. With this, we can obtain accurate extinction-corrected colors of galaxies. Using these colors as well as other spectral measures, we determine new criteria for the existence of ongoing and recent starbursts in galaxies.

  7. The IMACS Cluster Building Survey. I. Description of the Survey and Analysis Methods

    Science.gov (United States)

    Oemler Jr., Augustus; Dressler, Alan; Gladders, Michael G.; Rigby, Jane R.; Bai, Lei; Kelson, Daniel; Villanueva, Edward; Fritz, Jacopo; Rieke, George; Poggianti, Bianca M.; Vulcani, Benedetta

    2013-01-01

    The IMACS Cluster Building Survey uses the wide field spectroscopic capabilities of the IMACS spectrograph on the 6.5 m Baade Telescope to survey the large-scale environment surrounding rich intermediate-redshift clusters of galaxies. The goal is to understand the processes which may be transforming star-forming field galaxies into quiescent cluster members as groups and individual galaxies fall into the cluster from the surrounding supercluster. This first paper describes the survey: the data taking and reduction methods. We provide new calibrations of star formation rates (SFRs) derived from optical and infrared spectroscopy and photometry. We demonstrate that there is a tight relation between the observed SFR per unit B luminosity, and the ratio of the extinctions of the stellar continuum and the optical emission lines.With this, we can obtain accurate extinction-corrected colors of galaxies. Using these colors as well as other spectral measures, we determine new criteria for the existence of ongoing and recent starbursts in galaxies.

  8. Separation of human IgG fragments using copper, nickel, zinc, and cobalt chelated to CM-Asp-agarose by positive and negative chromatography.

    Science.gov (United States)

    Mourão, Cecília Alves; Carmignotto, Gabriela Pannunzio; Bueno, Sonia Maria Alves

    2016-04-01

    This study evaluated the feasibility of using immobilized metal-ion affinity chromatography (IMAC) for separation of human Fab fragments using four different transition metal ions copper, nickel, zinc, and cobalt chelated to CM-Asp (carboxymethylaspartate) immobilized on the agarose gel. The Fab and Fc fragments (from human IgG digested with papain) interacted differently with the chelates studied, depending on the adsorption buffer system. The interaction between chelate and Fc fragment is predominantly based on the coordination bonds using adsorption buffer containing NaCl. Negative chromatography was performed on Cu(II)-CM-Asp-agarose obtaining 2.9mg of Fab per mL of adsorbent in nonretained fractions (Fc fragment-free without uncleaved IgG). The adsorption of Fab fragments is governed by electrostatic forces in the absence of NaCl in the adsorption buffer. High selectivity was achieved on Co(II)-CM-Asp-agarose and 5.7mg of Fab per mL of adsorbent was obtained in eluted fractions without Fc fragments, although having uncleaved IgG. The results showed that chromatography on transition metal ions chetated to CM-Asp-agarose is a promising approach to separation of Fab fragments from papain-digested human IgG solution. PMID:26974869

  9. High-productivity membrane adsorbers: Polymer surface-modification studies for ion-exchange and affinity bioseparations

    Science.gov (United States)

    Chenette, Heather C. S.

    membrane adsorbers were found to have a static binding capacity for con A (6.0 mg/mL) that is nearly the same as the typical dextran-based separation media used in practice. Binding under dynamic conditions was tested using flow rates of 0.1-1.0 mL/min. No bound lectin was observed for the higher flow rate. The first Damkohler number was used to assess whether adsorption kinetics or mass transport contributed the limitation to conA binding. Analyses indicate that this system is not limited by the accessibility of the binding sites, but by the inherently low rate of adsorption of conA onto the glycopolymer. The research described in Chapter 4 focuses on reaction chemistry experiments to incorporate a phosphonate-based polymer in the membrane platform to develop a new class of affinity adsorbers that function based on their affinity for Arginine (Arg) amino acid residues. The hypothesis was that benzyl phosphonate-containing functional polymers would form strong complexes with Arg-rich proteins as a result of multivalent binding. Introducing a new class of affinity membranes for purification of Arg-rich and Arg-tagged proteins may have an impact similar to the introduction of immobilized metal ion affinity chromatography (IMAC), which would be a significant achievement. Using Arg-tags would overcome some of the associated drawbacks of using metal ions in IMAC. Additionally, some cell penetrating peptides are said to be Arg-rich, and this would be a convenient feature to exploit for their isolation and purification. Lysozyme was used as a model Arg-rich protein. The affinity membranes show a static binding capacity of 3 mg/mL. (Abstract shortened by UMI.)

  10. The IMACS Cluster Building Survey: V. Further Evidence for Starburst Recycling from Quantitative Galaxy Morphologies

    CERN Document Server

    Abramson, Louis E; Gladders, Michael D; Oemler,, Augustus; Poggianti, Bianca M; Monson, Andrew; Persson, Eric; Vulcani, Benedetta

    2013-01-01

    Using J and K_s band imaging obtained as part of the IMACS Cluster Building Survey (ICBS) we measure S\\'ersic indices for 2160 field and cluster galaxies at 0.31 < z < 0.54. We compare the distributions for spectroscopically determined passive, continuously starforming, starburst, and poststarburst systems and show that previously established spatial/statistical connections between these types extend to their gross morphologies. Outside of cluster cores, we find close structural ties between starburst and continuously starforming, as well as poststarburst and passive types, but not between starbursts and poststarbursts. These results independently support two conclusions presented in a previous ICBS paper (Dressler et al.): 1) most starbursts are the product of a non-disruptive triggering mechanism that is insensitive to global environment, such as minor-mergers; 2) starbursts and poststarbursts largely represent transient phases in the lives of "normal" starforming and quiescent galaxies, respectively,...

  11. Isolation of pregnancy-associated glycoproteins (PAG from water buffalo (Bubalus bubalis placenta by use of Vicia villosa bound agarose affinity chromatography

    Directory of Open Access Journals (Sweden)

    J.F. Beckers

    2010-02-01

    Full Text Available The present study describes the isolation and characterisation of new PAG molecules extracted from mid- and late-pregnancy placentas in the water buffalo (Bubalis bubalis. After extraction, acid and ammonium sulphate precipitation and DEAE chromatography water buffalo PAG (wbPAG were enriched by Vicia villosa agarose (VVA affininity chromatography. As determined by Western blotting with anti-PAG-sera, apparent molecular masses of immunoreactive bands from VVA peaks ranged from 59.5 to 75.8 kDa and from 57.8 to 80.9 kDa in the mid- and late- pregnancy placenta respectively. Aminoterminal microsequencing of proteins allowed the identification of three distinct wbPAG sequences wich have ben deposed in the SwissProt database: RGSXLTIHPLRNIRDFFYUG (Acc. n. P85048, RGSXLTILPLRNIID (P85049 and RGSXLTHLPLRNI (P85050. Their comparison to those previously identified revealed that two of them were new since they have not been described yet. Our results confirm the suitability of VVA chromatography in enrichment of multiple PAG molecules expressed in buffalo placenta. Productions of specific antisera can be very useful in immonoistochemical and immunocyitochemical studies of PAG expression in fetomaternal interfaces. Purified native PAG are also required for development on specific immoassays (RIA/ELISA currently used for pregnancy diagnosis and physiological investigation in farm animal.

  12. Short communication: Identification of iron-binding peptides from whey protein hydrolysates using iron (III)-immobilized metal ion affinity chromatography and reversed phase-HPLC-tandem mass spectrometry.

    Science.gov (United States)

    Cruz-Huerta, Elvia; Martínez Maqueda, Daniel; de la Hoz, Lucia; da Silva, Vera S Nunes; Pacheco, Maria Teresa Bertoldo; Amigo, Lourdes; Recio, Isidra

    2016-01-01

    Peptides with iron-binding capacity obtained by hydrolysis of whey protein with Alcalase (Novozymes, Araucaria, PR, Brazil), pancreatin, and Flavourzyme (Novozymes) were identified. Hydrolysates were subjected to iron (III)-immobilized metal ion affinity chromatography, and the bound peptides were sequenced by mass spectrometry. Regardless of the enzyme used, the domains f(42-59) and f(125-137) from β-lactoglobulin enclosed most of identified peptides. This trend was less pronounced in the case of peptides derived from α-lactalbumin, with sequences deriving from diverse regions. Iron-bound peptides exhibited common structural characteristics, such as an abundance of Asp, Glu, and Pro, as revealed by mass spectrometry and AA analysis. In conclusion, this characterization of iron-binding peptides helps clarify the relationship between peptide structure and iron-chelating activity and supports the promising role of whey protein hydrolysates as functional ingredients in iron supplementation treatments. PMID:26601589

  13. On-line coupling of surface plasmon resonance optical sensing to size-exclusion chromatography for affinity assessment of antibody samples.

    Science.gov (United States)

    Lakayan, Dina; Haselberg, Rob; Niessen, Wilfried M A; Somsen, Govert W; Kool, Jeroen

    2016-06-24

    Surface plasmon resonance (SPR) is an optical technique that measures biomolecular interactions. Stand-alone SPR cannot distinguish different binding components present in one sample. Moreover, sample matrix components may show non-specific binding to the sensor surface, leading to detection interferences. This study describes the development of coupled size-exclusion chromatography (SEC) SPR sensing for the separation of sample components prior to their on-line bio-interaction analysis. A heterogeneous polyclonal human serum albumin antibody (anti-HSA) sample, which was characterized by proteomics analysis, was used as test sample. The proposed SEC-SPR coupling was optimized by studying system parameters, such as injection volume, flow rate and sample concentration, using immobilized HSA on the sensor chip. Automated switch valves were used for on-line regeneration of the SPR sensor chip in between injections and for potential chromatographic heart cutting experiments, allowing SPR detection of individual components. The performance of the SEC-SPR system was evaluated by the analysis of papain-digested anti-HSA sampled at different incubation time points. The new on-line SEC-SPR methodology allows specific label-free analysis of real-time interactions of eluting antibody sample constituents towards their antigenic target. PMID:27215465

  14. Rapid screening method for quinolone residues in livestock and fishery products using immobilised metal chelate affinity chromatographic clean-up and liquid chromatography-fluorescence detection.

    Science.gov (United States)

    Takeda, N; Gotoh, M; Matsuoka, T

    2011-09-01

    An efficient LC method was developed for screening the presence of quinolones (QLs)--comprising fluoroquinolones (FQs) and acidic quinolones (AQs)--residues in various livestock and fishery products. Targeted analytes were for nine FQs of marbofloxacin (MAR), ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), danofloxacin (DAN), orbifloxacin (ORB), difloxacin (DIF) and sarafloxacin (SAR), and three AQs of oxolinic acid (OXA), nalidixic acid (NAL) and flumequine (FMQ). Samples comprised ten different food products covering five matrices: muscle (cattle, swine and chicken), liver (chicken), raw fish (shrimp and salmon), egg (chicken), and processed food (ham, sausage and fish sausage). This method involved a simple extraction with (1:1) acetonitrile-methanol, a highly selective clean-up with an immobilised metal chelate affinity column charged with Fe(3+), a fast isocratic LC analysis using a short column (20 mm × 4.6 mm, 3 µm) with a mobile phase of (15:85:0.1) methanol/water/formic acid, and fluorescence detection (excitation/emission wavelengths of 295 nm/455 nm for FQs (495 nm for MAR), and 320 nm/365 nm for AQs). Among FQs, pairs of NOR/OFL, ORB/DIF and ENR/DAN were incompletely resolved. A confirmatory LC run with a Mg(2+) containing methanolic mobile phase was also proposed for the samples suspected of being positive. The optimised method gave satisfactory recoveries of 88.5% (56.1-108.6%) and 78.7% (44.1-99.5%) for intra- and inter-day assays with relative standard deviations of 7.2% (0.7-18.4%) and 6.8% (1.4-16.6%), respectively. Limits of quantitation ranged from 0.8 µg kg(-1) (DAN) to 6.5 µg kg(-1) (SAR). This method was successfully employed to analyse 113 real samples and two positive samples were found: fish sausage (CIP 990 µg kg(-1)) and shrimp (ENR 20 µg kg(-1)). PMID:21749230

  15. THE IMACS CLUSTER BUILDING SURVEY. V. FURTHER EVIDENCE FOR STARBURST RECYCLING FROM QUANTITATIVE GALAXY MORPHOLOGIES

    International Nuclear Information System (INIS)

    Using J- and Ks-band imaging obtained as part of the IMACS Cluster Building Survey (ICBS), we measure Sérsic indices for 2160 field and cluster galaxies at 0.31 < z < 0.54. Using both mass- and magnitude-limited samples, we compare the distributions for spectroscopically determined passive, continuously star-forming, starburst, and post-starburst systems and show that previously established spatial and statistical connections between these types extend to their gross morphologies. Outside of cluster cores, we find close structural ties between starburst and continuously star-forming, as well as post-starburst and passive types, but not between starbursts and post-starbursts. These results independently support two conclusions presented in Paper II of this series: (1) most starbursts are the product of a non-disruptive triggering mechanism that is insensitive to global environment, such as minor mergers; (2) starbursts and post-starbursts generally represent transient phases in the lives of 'normal' star-forming and quiescent galaxies, respectively, originating from and returning to these systems in closed 'recycling' loops. In this picture, spectroscopically identified post-starbursts constitute a minority of all recently terminated starbursts, largely ruling out the typical starburst as a quenching event in all but the densest environments

  16. Flight Crew Responses to the Interval Management Alternative Clearances (IMAC) Experiment

    Science.gov (United States)

    Baxley, Brian T.; Wilson, Sara R.; Swieringa, Kurt A.; Roper, Roy D.

    2016-01-01

    Interval Management Alternative Clearances (IMAC) was a human-in-the-loop simulation experiment conducted to explore the efficacy and acceptability of three IM operations: CAPTURE, CROSS, and MAINTAIN. Two weeks of data collection were conducted, with each week using twelve subject pilots and four subject controllers flying ten high-density arrival scenarios into the Denver International Airport. Overall, both the IM operations and procedures were rated very favorably by the flight crew in terms of acceptability, workload, and pilot head down time. However, several critical issues were identified requiring resolution prior to real-world implementation, including the high frequency of IM speed commands, IM speed commands requiring changes to aircraft configuration, and ambiguous IM cockpit displays that did not trigger the intended pilot reaction. The results from this experiment will be used to prepare for a flight test in 2017, and to support the development of an advanced IM concept of operations by the FAA (Federal Aviation Agency) and aviation industry.

  17. Single-step purification of Proteus mirabilis urease accessory protein UreE, a protein with a naturally occurring histidine tail, by nickel chelate affinity chromatography.

    Science.gov (United States)

    Sriwanthana, B; Island, M D; Maneval, D; Mobley, H L

    1994-11-01

    Proteus mirabilis urease, a nickel metalloenzyme, is essential for the virulence of this species in the urinary tract. Escherichia coli containing cloned structural genes ureA, ureB, and ureC and accessory genes ureD, ureE, ureF, and ureG displays urease activity when cultured in M9 minimal medium. To study the involvement of one of these accessory genes in the synthesis of active urease, deletion mutations were constructed. Cultures of a ureE deletion mutant did not produce an active urease in minimal medium. Urease activity, however, was partially restored by the addition of 5 microM NiCl2 to the medium. The predicted amino acid sequence of UreE, which concludes with seven histidine residues among the last eight C-terminal residues (His-His-His-His-Asp-His-His-His), suggested that UreE may act as a Ni2+ chelator for the urease operon. To exploit this potential metal-binding motif, we attempted to purify UreE from cytoplasmic extracts of E. coli containing cloned urease genes. Soluble protein was loaded onto a nickel-nitrilotriacetic acid column, a metal chelate resin with high affinity for polyhistidine tails, and bound protein was eluted with a 0 to 0.5 M imidazole gradient. A single polypeptide of 20-kDa apparent molecular size, as shown by sodium dodecyl sulfate-10 to 20% polyacrylamide gel electrophoresis, was eluted between 0.25 and 0.4 M imidazole. The N-terminal 10 amino acids of the eluted polypeptide exactly matched the deduced amino acid sequence of P. mirabilis UreE. The molecular size of the native protein was estimated on a Superdex 75 column to be 36 kDa, suggesting that the protein is a dimer. These data suggest that UreE is a Ni(2)+-binding protein that is necessary for synthesis of a catalytically active urease at low Ni(2+) concentrations. PMID:7961442

  18. Providing affinity

    DEFF Research Database (Denmark)

    Guglielmi, Michel; Johannesen, Hl

    , Essex, Hertfordshire, Norfolk and Suffolk. Research found that there was a lack of identity or sense of belonging and nothing anchoring people to the region as a whole. Common affinity is somehow forced to the people of East England and thereby we came to the conclusion that a single landmark or a...... a sense of belonging to people sharing deterritorialized synchronic experiences. But at the same time, the immersion experience is highly low tech and desperately analog, mainly based on fabulation, cartoons, and mushrooms growing in local forests. It ultimately appeals to the experienced sense of...

  19. Optimization of MALDI-TOF MS Detection for Enhanced Sensitivity of Affinity-Captured Proteins Spanning a 100 kDa Mass Range

    OpenAIRE

    Gatlin-Bunai, Christine L.; Lisa H. Cazares; Cooke, William E.; Semmes, Oliver J.; Malyarenko, Dariya I.

    2007-01-01

    Analysis of complex biological samples by MALDI-TOF mass spectrometry has been generally limited to the detection of low-mass protein (or protein fragment) peaks. We have extended the mass range of MALDI-TOF high-sensitivity detection by an order of magnitude through the combined optimization of instrument parameters, data processing, and sample preparation procedures for affinity capture. WCX, C3, and IMAC magnetic beads were determined to be complementary and most favorable for broad mass r...

  20. Affinity purification of aprotinin from bovine lung.

    Science.gov (United States)

    Xin, Yu; Liu, Lanhua; Chen, Beizhan; Zhang, Ling; Tong, Yanjun

    2015-05-01

    An affinity protocol for the purification of aprotinin from bovine lung was developed. To simulate the structure of sucrose octasulfate, a natural specific probe for aprotinin, the affinity ligand was composed of an acidic head and a hydrophobic stick, and was then linked with Sepharose. The sorbent was then subjected to adsorption analysis with pure aprotinin. The purification process consisted of one step of affinity chromatography and another step of ultrafiltration. Then purified aprotinin was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, trypsin inhibitor activity, gel-filtration, and thin-layer chromatography analysis. As calculated, the theoretical maximum adsorption (Qmax ) of the affinity sorbent was 25,476.0 ± 184.8 kallikrein inactivator unit/g wet gel; the dissociation constant of the complex "immobilized ligand-aprotinin" (Kd ) was 4.6 ± 0.1 kallikrein inactivator unit/mL. After the affinity separation of bovine lung aprotinin, reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis and gel-filtration chromatography revealed that the protein was a single polypeptide, and the purities were ∼ 97 and 100%, respectively; the purified peptide was also confirmed with aprotinin standard by gel-filtration chromatography and thin-layer chromatography. After the whole purification process, protein, and bioactivity recoveries were 2.2 and 92.6%, respectively; and the specific activity was up to 15,907.1 ± 10.2 kallikrein inactivator unit/mg. PMID:25677462

  1. The purification of affinity-labelled active-site peptides

    International Nuclear Information System (INIS)

    The isolation of the labelled peptide from the protein digest, following the affinity labelling of the active sites of enzymes or antibodies, is described. Single-step affinity chromatography utilises the affinity of the native enzymes or antibody for the ligand used to label the same protein. The labelled peptide is the only one in the digest that displays affinity for the immobilised protein and can be released with eluants that dissociate the protein-ligand complex. (Auth.)

  2. Limitations in SELDI-TOF MS whole serum proteomic profiling with IMAC surface to specifically detect colorectal cancer

    International Nuclear Information System (INIS)

    Surface enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF-MS) analysis on serum samples was reported to be able to detect colorectal cancer (CRC) from normal or control patients. We carried out a validation study of a SELDI-TOF MS approach with IMAC surface sample processing to identify CRC. A retrospective cohort of 338 serum samples including 154 CRCs, 67 control cancers and 117 non-cancerous conditions was profiled using SELDI-TOF-MS. No CRC 'specific' classifier was found. However, a classifier consisting of two protein peaks separates cancer from non-cancerous conditions with high accuracy. In this study, the SELDI-TOF-MS-based protein expression profiling approach did not perform to identify CRC. However, this technique is promising in distinguishing patients with cancer from a non-cancerous population; it may be useful for monitoring recurrence of CRC after treatment

  3. Affine functors and duality

    OpenAIRE

    J. Navarro; Sancho, C.; Sancho, P.

    2009-01-01

    A functor of sets $\\mathbb X$ over the category of $K$-commutative algebras is said to be an affine functor if its functor of functions, $\\mathbb A_{\\mathbb X}$, is reflexive and $\\mathbb X=\\Spec \\mathbb A_{\\mathbb X}$. We prove that affine functors are equal to a direct limit of affine schemes and that affine schemes, formal schemes, the completion of affine schemes along a closed subscheme, etc., are affine functors. Endowing an affine functor $\\mathbb X$ with a functor of monoids structure...

  4. 亲和层析微柱法测定肝癌特异性AFP及其在肝癌诊断中的临床价值%Quantitative analysis of hepatoma-specific α-fetoprotein (HS-AFP) by a new mini-column affinity chromatography and its clinical value in diagnosis of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Wei Wu; Dengfu Yao; Liwei Qiu; Xiaoxiao Gu; Xinhua Wu

    2008-01-01

    Objective: To establish a convenient and economic method to determine hepatoma-specific α-fetoprotein (HS-AFP) for diagnosis of hepatocellular carcinoma (HCC). Methods: HS-AFP from serum of HCC patients was separated by a mini-column Lens culinaris agglutinin (LCA)-affinity chromatography. The levels of serum total AFP and separated HS-AFP were detected by radioimmunoassay (RIA). Results: Circulating AFP was separated into three peaks (AFP-1, AFP-2, and AFP-3) by LCA-affinity chromatography. During the elution course, the AFP-1 and AFP-2 could be eluted with TE buffer. HS-AFP (AFP-3) from sera of HCC patients was eluted dearly on the LCA-sepharose gel mini-column with a solution containing a-methyl-D-mannoside. It was a part of total AFP and only found in sera of HCC patients. A ratio of more than 15% for HS-AFP to total AFP in serum was considered as a specific marker for HCC diagnosis with higher sensitivity (92.7%) and specificity(88.2%). Conclusion: The new assay for circulating HS-AFP analysis is more sensitive, repeatable, and convenient. Its clinical application would be useful to early diagnosis of HCC.

  5. The Carnegie-Spitzer-IMACS Redshift Survey of Galaxy Evolution since z=1.5: I. Description and Methodology and More!

    CERN Document Server

    Kelson, Daniel D; Dressler, Alan; McCarthy, Patrick J; Shectman, Stephen A; Mulchaey, John S; Villanueva, Edward V; Crane, Jeffrey D; Quadri, Ryan F

    2014-01-01

    We describe the Carnegie-Spitzer-IMACS (CSI) Survey, a wide-field, near-IR selected spectrophotometric redshift survey with IMACS on Magellan-Baade. CSI uses a flux-limited sample of galaxies in Spitzer IRAC 3.6micron imaging of SWIRE fields to efficiently trace the stellar mass of average galaxies to z~1.5. This paper provides an overview of the survey selection, observations, and processing of the photometry and spectrophotometry. We also describe the analysis of the data: new methods of fitting synthetic SEDs are used to derive redshifts, stellar masses, emission line luminosities, and coarse information on recent star-formation. Our unique methodology for analyzing low-dispersion spectra taken with multilayer prisms in IMACS, combined with panchromatic photometry from the ultraviolet to the IR, has yielded high quality redshifts for 43,347 galaxies in our first 5.3 sq. degs of the SWIRE XMM-LSS field. A new approach to assessing data quality is also described, and three different approaches are used to es...

  6. Phosphopeptide enrichment: Development of magnetic solid phase extraction method based on polydopamine coating and Ti(4+)-IMAC.

    Science.gov (United States)

    Piovesana, Susy; Capriotti, Anna Laura; Cavaliere, Chiara; Ferraris, Francesca; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

    2016-02-25

    Protein post translational modifications currently represent one of the main challenges with proteomic analysis, due to the important biological role they play within cells. Protein phosphorylation is one of the most important, with several approaches developed for phosphopeptides enrichment and analysis, essential for comprehensive phosphoproteomic analysis. However, the development of new materials for phosphopeptides enrichment may overcome previous drawbacks and improve enrichment of such peptides. In this regard, new magnetic stationary phases based on polydopamine coating and Ti(4+) immobilization exploit the potential of IMAC enrichment and couple it with the versatility of magnetic solid phase extraction. In this work the use of such stationary phase was extended from the MALDI proof of concept stage with the development of an optimized method for phosphopeptides enrichment compatible with typical shotgun proteomics experimental workflows. Different loading and elution buffers were tested to improve phosphopeptides recovery and enrichment selectivity. Finally, the analysis of isolated peptides pointed out that polydopamine alone is an ideal support matrix for polar post translational modifications because it enables to reduce unspecific binding and preferentially binds hydrophilic peptides. PMID:26851086

  7. Dual Affine invariant points

    OpenAIRE

    Meyer, Mathieu; Schuett, Carsten; Werner, Elisabeth M.

    2013-01-01

    An affine invariant point on the class of convex bodies in R^n, endowed with the Hausdorff metric, is a continuous map p which is invariant under one-to-one affine transformations A on R^n, that is, p(A(K))=A(p(K)). We define here the new notion of dual affine point q of an affine invariant point p by the formula q(K^{p(K)})=p(K) for every convex body K, where K^{p(K)} denotes the polar of K with respect to p(K). We investigate which affine invariant points do have a dual point, whether this ...

  8. Affine Grassmann codes

    DEFF Research Database (Denmark)

    Høholdt, Tom; Beelen, Peter; Ghorpade, Sudhir Ramakant

    2010-01-01

    We consider a new class of linear codes, called affine Grassmann codes. These can be viewed as a variant of generalized Reed-Muller codes and are closely related to Grassmann codes.We determine the length, dimension, and the minimum distance of any affine Grassmann code. Moreover, we show that...... affine Grassmann codes have a large automorphism group and determine the number of minimum weight codewords....

  9. Bioaffinity chromatography on monolithic supports

    NARCIS (Netherlands)

    Tetala, K.K.R.; Beek, van T.A.

    2010-01-01

    Affinity chromatography on monolithic supports is a powerful analytical chemical platform because it allows for fast analyses, small sample volumes, strong enrichment of trace biomarkers and applications in microchips. In this review, the recent research using monolithic materials in the field of bi

  10. Multidimensional Strategy for Sensitive Phosphoproteomics Incorporating Protein Prefractionation Combined with SIMAC, HILIC, and TiO(2) Chromatography Applied to Proximal EGF Signaling

    DEFF Research Database (Denmark)

    Engholm-Keller, Kasper; Hansen, Thomas Aarup; Palmisano, Giuseppe; Larsen, Martin R

    2011-01-01

    applied to 400 µg of protein from EGF stimulated HeLa cells. The proteins are separated into membrane and cytoplasmic fractions using sodium carbonate combined with ultracentrifugation. The phosphopeptides were separated into mono-phosphorylated and multi-phosphorylated pools using Sequential elution from...... IMAC (SIMAC) followed by hydrophilic interaction liquid chromatography of the mono- and non-phosphorylated peptides and subsequent titanium dioxide chromatography of the HILIC fractions. This strategy facilitated the identification of >4,700 unique phosphopeptides, while 636 phosphosites were changing...

  11. A Method to Site-Specifically Identify and Quantitate Carbonyl End Products of Protein Oxidation Using Oxidation-Dependent Element Coded Affinity Tags (O-ECAT) and NanoLiquid Chromatography Fourier Transform Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Young, N L; Whetstone, P A; Cheal, S M; Benner, W H; Lebrilla, C B; Meares, C F

    2005-08-25

    Protein oxidation is linked to cellular stress, aging, and disease. Protein oxidations that result in reactive species are of particular interest, since these reactive oxidation products may react with other proteins or biomolecules in an unmediated and irreversible fashion, providing a potential marker for a variety of disease mechanisms. We have developed a novel system to identify and quantitate, relative to other states, the sites of oxidation on a given protein. A specially designed Oxidation-dependent carbonyl-specific Element-Coded Affinity Mass Tag (O-ECAT), AOD, ((S)-2-(4-(2-aminooxy)-acetamido)-benzyl)-1, 4, 7, 10-tetraazacyclododecane-N, N', N'', N'''-tetraacetic acid, is used to covalently tag the residues of a protein oxidized to aldehyde or keto end products. After proteolysis, the resulting AOD-tagged peptides are affinity purified, and analyzed by nanoLC-FTICR-MS, which provides high specificity in extracting co-eluting AOD mass pairs with a unique mass difference and affords relative quantitation based on isotopic ratios. Using this methodology, we have mapped the surface oxidation sites on a model protein, recombinant human serum albumin (rHSA) in its native form (as purchased) and after FeEDTA oxidation. A variety of modified amino acid residues including lysine, arginine, proline, histidine, threonine, aspartic and glutamic acids, were found to be oxidized to aldehyde and keto end products. The sensitivity of this methodology is shown by the number of peptides identified, twenty peptides on the native protein and twenty-nine after surface oxidation using FeEDTA and ascorbate. All identified peptides map to the surface of the HSA crystal structure validating this method for identifying oxidized amino acids on protein surfaces. In relative quantitation experiments between FeEDTA oxidation and native protein oxidation, identified sites showed different relative propensities towards oxidation independent of amino acid

  12. Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

    Directory of Open Access Journals (Sweden)

    Renata Angeli

    2009-01-01

    Full Text Available A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A and Cratylia mollis (Cramoll 1 and Cramoll 1,4 did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.

  13. Ferromagnetic levan composite: an affinity matrix to purify lectin.

    Science.gov (United States)

    Angeli, Renata; da Paz, Nathalia V N; Maciel, Jackeline C; Araújo, Flávia F B; Paiva, Patrícia M G; Calazans, Glícia M T; Valente, Ana Paula; Almeida, Fábio C L; Coelho, Luana C B B; Carvalho, Luiz B; Silva, Maria da Paz C; dos Santos Correia, Maria Tereza

    2009-01-01

    A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column. PMID:19547713

  14. Affine and Projective Geometry

    CERN Document Server

    Bennett, M K

    1995-01-01

    An important new perspective on AFFINE AND PROJECTIVE GEOMETRY. This innovative book treats math majors and math education students to a fresh look at affine and projective geometry from algebraic, synthetic, and lattice theoretic points of view. Affine and Projective Geometry comes complete with ninety illustrations, and numerous examples and exercises, covering material for two semesters of upper-level undergraduate mathematics. The first part of the book deals with the correlation between synthetic geometry and linear algebra. In the second part, geometry is used to introduce lattice theory

  15. Affine dynamics with torsion

    Energy Technology Data Exchange (ETDEWEB)

    Gueltekin, Kemal [Izmir Institute of Technology, Department of Physics, Izmir (Turkey)

    2016-03-15

    In this study, we give a thorough analysis of a general affine gravity with torsion. After a brief exposition of the affine gravities considered by Eddington and Schroedinger, we construct and analyze different affine gravities based on the determinants of the Ricci tensor, the torsion tensor, the Riemann tensor, and their combinations. In each case we reduce equations of motion to their simplest forms and give a detailed analysis of their solutions. Our analyses lead to the construction of the affine connection in terms of the curvature and torsion tensors. Our solutions of the dynamical equations show that the curvature tensors at different points are correlated via non-local, exponential rescaling factors determined by the torsion tensor. (orig.)

  16. Affine and degenerate affine BMW algebras: Actions on tensor space

    CERN Document Server

    Daugherty, Zajj; Virk, Rahbar

    2012-01-01

    The affine and degenerate affine Birman-Murakami-Wenzl (BMW) algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic quantum groups and Lie algebras, respectively. Cyclotomic BMW algebras, affine and cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper we explain how the affine and degenerate affine BMW algebras are tantalizers (tensor power centralizer algebras) by defining actions of the affine braid group and the degenerate affine braid algebra on tensor space and showing that, in important cases, these actions induce actions of the affine and degenerate affine BMW algebras. We then exploit the connection to quantum groups and Lie algebras to determine universal parameters for the affine and degenerate affine BMW algebras. Finally, we show that the universal parameters are central elements--the higher Casimir elements for orthogonal and symplectic enveloping algebras and quantum groups.

  17. Optimizing TiO2-based phosphopeptide enrichment for automated multidimensional liquid chromatography coupled to tandem mass spectrometry

    OpenAIRE

    Cantin, Greg T.; Shock, Teresa R.; Park, Sung Kyu; Madhani, Hiten D.; Yates, John R.

    2007-01-01

    An automated online multidimensional liquid chromatography system coupled to ESI-based tandem mass spectrometry was used to assess the effectiveness of TiO2 in the enrichment of phosphopeptides from tryptic digests of protein mixtures. By monitoring the enrichment of phosphopeptides, an optimized set of loading, wash, and elution conditions were realized for TiO2. A comparison of TiO2 with other resins used for phosphopeptide enrichment, Fe(III)-IMAC and ZrO2, was also carried out using trypt...

  18. Gas Chromatography.

    Science.gov (United States)

    Karasek, Francis W.; And Others

    1984-01-01

    This review covers fundamental developments in gas chromatography during 1982 and 1983. Literature is considered under these headings: columns; liguid phases; solid supports; sorption processes and solvents; open tubular column gas chromatography; instrumentation; high-resolution columns and applications; other techniques; qualitative and…

  19. Single Bead Affinity Detection (SINBAD) for the Analysis of Protein-Protein Interactions

    OpenAIRE

    Schulte, Roberta; Talamas, Jessica; Doucet, Christine; Hetzer, Martin W.

    2008-01-01

    We present a miniaturized pull-down method for the detection of protein-protein interactions using standard affinity chromatography reagents. Binding events between different proteins, which are color-coded with quantum dots (QDs), are visualized on single affinity chromatography beads by fluorescence microscopy. The use of QDs for single molecule detection allows the simultaneous analysis of multiple protein-protein binding events and reduces the amount of time and material needed to perform...

  20. Antibody affinity maturation

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise

    Yeast surface display is an effective tool for antibody affinity maturation because yeast can be used as an all-in-one workhorse to assemble, display and screen diversified antibody libraries. By employing the natural ability of yeast Saccharomyces cerevisiae to efficiently recombine multiple DNA...

  1. Affine and degenerate affine BMW algebras: The center

    CERN Document Server

    Daugherty, Zajj; Virk, Rahbar

    2011-01-01

    The degenerate affine and affine BMW algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic Lie algebras and quantum groups, respectively. Cyclotomic BMW algebras, affine Hecke algebras, cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper the theory is unified by treating the orthogonal and symplectic cases simultaneously; we make an exact parallel between the degenerate affine and affine cases via a new algebra which takes the role of the affine braid group for the degenerate setting. A main result of this paper is an identification of the centers of the affine and degenerate affine BMW algebras in terms of rings of symmetric functions which satisfy a "cancellation property" or "wheel condition" (in the degenerate case, a reformulation of a result of Nazarov). Miraculously, these same rings also arise in Schubert calculus, as the cohomology and K-theory of isotropic Grassmanians and symplectic loop Grassmanians. We also establish new inte...

  2. Histidine-tag-directed chromophores for tracer analyses in the analytical ultracentrifuge

    OpenAIRE

    Hellman, Lance M.; Zhao, Chunxia; Melikishvili, Manana; Tao, Xiaorong; Hopper, James E.; Whiteheart, Sidney W.; Fried, Michael G.

    2010-01-01

    Many recombinant proteins carry an oligohistidine (HisX)-tag that allows their purification by immobilized metal affinity chromatography (IMAC). This tag can be exploited for the site-specific attachment of chromophores and fluorophores, using the same metal ion–nitrilotriacetic acid (NTA) coordination chemistry that forms the basis of popular versions of IMAC. Labeling proteins in this way can allow their detection at wavelengths outside of the absorption envelopes of un-modified proteins an...

  3. Proteomic analysis of phosphoproteins sensitive to a phosphatidylinositol 3-kinase inhibitor, ZSTK474, by using SELDI-TOF MS

    OpenAIRE

    Akashi, Tetsuyuki; Yamori, Takao

    2009-01-01

    Background Phosphoproteins play important roles in a vast series of biological processes. Recent proteomic technologies offer the comprehensive analyses of phosphoproteins. Recently, we demonstrated that surface-enhanced laser desorption/ionization time of flight mass (SELDI-TOF MS) would detect phosphoproteins quantitatively, which was a new application of SELDI-TOF MS. Results We combined immobilized metal affinity chromatography (IMAC) with SELDI-TOF MS. After SELDI-TOF MS analysis of IMAC...

  4. Hierarchical Affinity Propagation

    CERN Document Server

    Givoni, Inmar; Frey, Brendan J

    2012-01-01

    Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the hierarchical clustering problem, which arises in a variety of domains including biology, sensor networks and decision making in operational research. We derive an inference algorithm that operates by propagating information up and down the hierarchy, and is efficient despite the high-order potentials required for the graphical model formulation. We demonstrate that our method outperforms greedy techniques that cluster one layer at a time. We show that on an artificial dataset designed to mimic the HIV-strain mutation dynamics, our method outperforms related methods. For real HIV sequences, where the ground truth is not available, we show our method achieves better results, in terms of the underlying objective function, and show the results correspond meaningfully to geographi...

  5. Affinity driven social networks

    Science.gov (United States)

    Ruyú, B.; Kuperman, M. N.

    2007-04-01

    In this work we present a model for evolving networks, where the driven force is related to the social affinity between individuals of a population. In the model, a set of individuals initially arranged on a regular ordered network and thus linked with their closest neighbors are allowed to rearrange their connections according to a dynamics closely related to that of the stable marriage problem. We show that the behavior of some topological properties of the resulting networks follows a non trivial pattern.

  6. Affine General Equilibrium Models

    OpenAIRE

    Bjørn Eraker

    2008-01-01

    No-arbitrage models are extremely flexible modelling tools but often lack economic motivation. This paper describes an equilibrium consumption-based CAPM framework based on Epstein-Zin preferences, which produces analytic pricing formulas for stocks and bonds under the assumption that macro growth rates follow affine processes. This allows the construction of equilibrium pricing formulas while maintaining the same flexibility of state dynamics as in no-arbitrage models. In demonstrating the a...

  7. Gaussian Affine Feature Detector

    OpenAIRE

    Xu, Xiaopeng; Zhang, Xiaochun

    2011-01-01

    A new method is proposed to get image features' geometric information. Using Gaussian as an input signal, a theoretical optimal solution to calculate feature's affine shape is proposed. Based on analytic result of a feature model, the method is different from conventional iterative approaches. From the model, feature's parameters such as position, orientation, background luminance, contrast, area and aspect ratio can be extracted. Tested with synthesized and benchmark data, the method achieve...

  8. 免疫亲和柱净化-高效液相色谱法同时检测小麦中脱氧雪腐镰刀菌烯醇及其衍生物%Simultaneous determination of deoxynivalenol and ramification in wheat by immune affinity column and high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    王培; 徐广超; 尹丽梅; 黎睿; 谢刚

    2015-01-01

    建立脱氧雪腐镰刀菌烯醇(DON)及其衍生物3-乙酰基—脱氧雪腐镰刀菌烯醇(3-A-DON)和15-乙酰基—脱氧雪腐镰刀菌烯醇(15-A-DON)的免疫亲和柱净化—高效液相色谱同时检测方法。小麦样品经超纯水提取、免疫亲和柱净化、吹干、定容后,用配有紫外检测器的高效液相色谱仪进行DON、3-A-DON和15-A-DON三种毒素的同时检测,并与液相色谱质谱法比对。结果表明:该方法检出限,DON、3-A-DON和15-A-DON均为100μg/kg,样品加标回收率范围86.6%~96.5%,变异系数小于10%,具有较好的准确性和精密度。该方法简单、快速、灵敏度高、选择性好,适用于小麦中DON、3-A-DON和15-A-DON的同时检测。%The method to determine deoxynivalenol (DON),3-acetyl- deoxynivalenol (3-A-DON) and 15-acetyl-deoxynivalenol (15 -A -DON )in wheat simultaneously by immune affinity column clean-up and high performance liquid chromatography was established. The wheat samples were extrac-ted by ultrapure water,cleared up with the immuno-affinity column (IAC). After drying and constant volume,three toxins,DON、3-A-DON and15-A-DON,were detected simultaneously by high per-formance liquid chromatograph with UV detector,and compared with that by Liquid chromatography mass spectrometry. The result showed that the detection limit of method was 100μg/kg for DON,3-A-DON and 15-A-DON respectively. Recovery rates in wheat spiked with DON,3-A-DON,and 15-A-DON,ranged from 86. 6% to 96. 5%. The variation coefficient was less than 10%. This method was suitable for determination of DON,3 -A-DON,and 15 -A-DON in wheat,with the advantages of simplicity,rapidness,sensitivity and good selectivity,veracity and precision.

  9. Purificación de IgG1, IgG2 e IgG3 mediante cromatografía de afinidad a partir de intacglobín Purification of IgG1, IgG2 and IgG3 by affinity chromatography starting from Intacglobin

    Directory of Open Access Journals (Sweden)

    Ada A Arce Hernández

    2001-08-01

    Full Text Available Se describe un método de purificación de las subclases IgG1, IgG2 e IgG3 a partir de Intacglobin mediante cromatografía de afinidad con el empleo de proteína A Sepharose y la aplicación de un gradiente lineal de pH. Se detectó la presencia de IgG1, IgG2 e IgG3 en las fracciones eluidas mediante doble inmunodifusión e inmunoelectroforesis, utilizando sueros comerciales anti IgG, anti IgG1, anti IgG2 y anti IgG3. El procedimiento desarrollado se caracterizó por su sencillez, elevada resolución y la relativa pureza de las subclases aisladas. Se logró un rendimiento total del 53,7 %, lo que indica la eficiencia del métodoA method for the purification of IgG1, IgG2, and IgG3 subclasses starting from Intacglobin by affinity chromatography with the use of protein A Sepharose and the application of a lineal gradient of pH is described. IgG1, IgG2 and IgG3 were detected in the eluted fractions by doble immunodifussion and immunoelectrophoresis by using anti IgG, anti IgG1, anti IgG2 and anti IgG3 commercial sera. The procedure developed was characterized by its simplicity, high resolution and the relative purity of the isolated subclasses. A total yield of 53.7 % was attained, which demonstrates the efficiency of this method

  10. Complementary PTM Profiling of Drug Response in Human Gastric Carcinoma by Immunoaffinity and IMAC Methods with Total Proteome Analysis

    Directory of Open Access Journals (Sweden)

    Matthew P. Stokes

    2015-08-01

    Full Text Available Gaining insight into normal cellular signaling and disease biology is a critical goal of proteomic analyses. The ability to perform these studies successfully to extract the maximum value and discovery of biologically relevant candidate biomarkers is therefore of primary importance. Many successful studies in the past have focused on total proteome analysis (changes at the protein level combined with phosphorylation analysis by metal affinity enrichment (changes at the PTM level. Here, we use the gastric carcinoma cell line MKN-45 treated with the c-Met inhibitor SU11274 and PKC inhibitor staurosporine to investigate the most efficient and most comprehensive strategies for both total protein and PTM analysis. Under the conditions used, total protein analysis yielded few changes in response to either compound, while analysis of phosphorylation identified thousands of sites that changed differentially between the two treatments. Both metal affinity and antibody-based enrichments were used to assess phosphopeptide changes, and the data generated by the two methods was largely complementary (non-overlapping. Label-free quantitation of peptide peak abundances was used to accurately determine fold-changes between control and treated samples. Protein interaction network analysis allowed the data to be placed in a biologically relevant context, and follow-up validation of selected findings confirmed the accuracy of the proteomic data. Together, this study provides a framework for start-to-finish proteomic analysis of any experimental system under investigation to maximize the value of the proteomic study and yield the best chance for uncovering actionable target candidates.

  11. On the Affine Isoperimetric Inequalities

    Indian Academy of Sciences (India)

    Wuyang Yu; Gangsong Leng

    2011-11-01

    We obtain an isoperimetric inequality which estimate the affine invariant -surface area measure on convex bodies. We also establish the reverse version of -Petty projection inequality and an affine isoperimetric inequality of $_{-p}K$.

  12. Adjoint affine fusion and tadpoles

    OpenAIRE

    Urichuk, Andrew; Walton, Mark A.

    2016-01-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-pol...

  13. Gaussian Affine Feature Detector

    CERN Document Server

    Xu, Xiaopeng

    2011-01-01

    A new method is proposed to get image features' geometric information. Using Gaussian as an input signal, a theoretical optimal solution to calculate feature's affine shape is proposed. Based on analytic result of a feature model, the method is different from conventional iterative approaches. From the model, feature's parameters such as position, orientation, background luminance, contrast, area and aspect ratio can be extracted. Tested with synthesized and benchmark data, the method achieves or outperforms existing approaches in term of accuracy, speed and stability. The method can detect small, long or thin objects precisely, and works well under general conditions, such as for low contrast, blurred or noisy images.

  14. Ion Chromatography.

    Science.gov (United States)

    Mulik, James D.; Sawicki, Eugene

    1979-01-01

    Accurate for the analysis of ions in solution, this form of analysis enables the analyst to directly assay many compounds that previously were difficult or impossible to analyze. The method is a combination of the methodologies of ion exchange, liquid chromatography, and conductimetric determination with eluant suppression. (Author/RE)

  15. An affine framework for analytical mechanics

    OpenAIRE

    Urbanski, Pawel

    2003-01-01

    An affine Cartan calculus is developed. The concepts of special affine bundles and special affine duality are introduced. The canonical isomorphisms, fundamental for Lagrangian and Hamiltonian formulations of the dynamics in the affine setting are proved.

  16. The Protocol for Phosphoprotein Enrichment in Rice (Oryza sativa L.)——Phenol Extraction Combined with Immobilized Metal Affinity Chromatography%一种适用于双向电泳的水稻磷酸化蛋白富集方法——酚提取法结合固相金属离子亲和层析法

    Institute of Scientific and Technical Information of China (English)

    邓湘雄; 张晓勤; 胡江; 徐祥彬; 郭龙彪; 陈慧男; 应奇才; 王慧中; 薛大伟

    2012-01-01

    磷蛋白在植物信号传导和胁迫响应中有着非常重要的作用,磷蛋白质组学研究已经成为蛋白质组学研究领域中备受瞩目的一个部分.本研究用酚提取法以水稻日本晴苗期叶片为材料提取叶片总蛋白,提取率达3.5%;用固相金属离子亲和层析柱纯化富集磷蛋白,得到磷蛋白占总蛋白约6.4%.对过柱洗涤液、不同阶段洗脱液等各个组分进行SDS-PAGE,粗略检测其蛋白含量,并根据单向SDS-PAGE结果对总蛋白、高峰段磷蛋白、非高峰段磷蛋白以及富集后再纯化的总磷蛋白进行双向电泳,比较其中的蛋白差异.本研究提出的方法和程序可在7 cm聚丙烯酰胺凝胶上检测到多达856个磷蛋白,是一种非常有效的磷蛋白富集、纯化和分离鉴定的方法.%Phosphoproteins play very important roles in plant signal transduction and stress responses. Phosphoproteomics has become a big concern for proteomic researchers. Total protein was extracted from rice (Oryza sativa L. Japonica nipponbare) leaves via phenol extraction in this study. Protein mass obtained is up to 3.5% in fresh rice leaves; phosphoprotein was enriched by an immobilized metal affinity chromatography column, which takes a proportion of 6. 4% in the total protein. Protein profiles of washing solution, elution solutions and others were approximately exhibited by SDS-PAGE. Based on the results, two-dimensional polyacrylamide gel eleclrophoresis (2D-PAGE) for total proteins, proteins from peak fraction, non-peak fractions and purified phosphoprotein after enrichment were carried out to better understand the variance among these samples on two dimensional gels. The protocol and procedure described here could dissociate as more as 856 spots per polyacrylamide gel of 7 cm. It is a highly effective way to separate and detecte phosphoproteins.

  17. Adjoint affine fusion and tadpoles

    Science.gov (United States)

    Urichuk, Andrew; Walton, Mark A.

    2016-06-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  18. Adjoint affine fusion and tadpoles

    CERN Document Server

    Urichuk, Andrew

    2016-01-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows, and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  19. Ion chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Tarter, J.G.

    1987-01-01

    Similar in many ways to other liquid chromatographic techniques, ion chromatography (IC) is an invaluable method that is used all too rarely in chemical analysis. Its application is particularly promising in the analysis of inorganic anions, an area where more information is needed. Ion Chromatogrphy identifies the merits of this technique. Serving as a review and reference for experienced ion chromatographers and as a teaching aid for individuals new to the field, it provides the information necessary for determining the potential usefulness of IC for a given situation. Among the areas treated, this volume focuses on eluant-suppressed IC, especially for anion and cation analysis, single-column IC, plus ancillary techniques and applications, electrochemical, spectroscopic, and other detecting methods, ion chromatography exclusion (ICE), including its limits and applications.

  20. Affinity approaches in RNAi-based therapeutics purification.

    Science.gov (United States)

    Pereira, Patrícia; Queiroz, João A; Figueiras, Ana; Sousa, Fani

    2016-05-15

    The recent investigation on RNA interference (RNAi) related mechanisms and applications led to an increased awareness of the importance of RNA in biology. Nowadays, RNAi-based technology has emerged as a potentially powerful tool for silencing gene expression, being exploited to develop new therapeutics for treating a vast number of human disease conditions, as it is expected that this technology can be translated onto clinical applications in a near future. This approach makes use of a large number of small (namely short interfering RNAs, microRNAs and PIWI-interacting RNAs) and long non-coding RNAs (ncRNAs), which are likely to have a crucial role as the next generation therapeutics. The commercial and biomedical interest in these RNAi-based therapy applications have fostered the need to develop innovative procedures to easily and efficiently purify RNA, aiming to obtain the final product with high purity degree, good quality and biological activity. Recently, affinity chromatography has been applied to ncRNAs purification, in view of the high specificity. Therefore, this article intends to review the biogenesis pathways of regulatory ncRNAs and also to discuss the most significant and recent developments as well as applications of affinity chromatography in the challenging task of purifying ncRNAs. In addition, the importance of affinity chromatography in ncRNAs purification is addressed and prospects for what is forthcoming are presented. PMID:26830537

  1. Preparation of Affinity Column Based on Zr{sup 4+} Ion for Phosphoproteins Isolation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seon Mi; Bae, In Ae; Park, Jung Hyen; Kim, Tae Dong; Choi, Seong Ho [Hannam University, Daejeon (Korea, Republic of)

    2009-06-15

    This paper has described about preparation of Zr{sup 4+} affinity column based on the poly(styreneco- glycidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The Zr{sup 4+} ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of Zr{sup 4+}-immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for Zr{sup 4+} affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for Zr{sup 4+} affinity polymeric microsphere by liquid chromatography. This Zr{sup 4+} affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography.

  2. Preparation of Affinity Column Based on Zr4+ Ion for Phosphoproteins Isolation

    International Nuclear Information System (INIS)

    This paper has described about preparation of Zr4+ affinity column based on the poly(styreneco- glycidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The Zr4+ ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of Zr4+-immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for Zr4+ affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for Zr4+ affinity polymeric microsphere by liquid chromatography. This Zr4+ affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography

  3. Purification of recombinant aprotinin produced in transgenic corn seed: separation from CTI utilizing ion-exchange chromatography

    Directory of Open Access Journals (Sweden)

    A. R. Azzoni

    2005-09-01

    Full Text Available Protein expression in transgenic plants is considered one of the most promising approaches for producing pharmaceutical proteins. As has happened with other recombinant protein production schemes, the downstream processing (dsp of these proteins produced in plants is key to the technical and economic success of large-scale applications. Since dsp of proteins produced transgenically in plants has not been extensively studied, it is necessary to broaden the investigation in this field in order to more precisely evaluate the commercial feasibility of this route of expression. In this work, we studied the substitution of an IMAC chromatographic step, described in previous work (Azzoni et al., 2002, with ion-exchange chromatography on SP Sepharose Fast Flow resin as the second step in the purification of recombinant aprotinin from transgenic maize seed. The main goal of this second purification step is to separate the recombinant aprotinin from the native corn trypsin inhibitor. Analysis of the adsorption isotherms determined at 25°C under different conditions allowed selection of 0.020 M Tris pH 8.5 as the adsorption buffer. The cation-exchange chromatographic process produced a high-purity aprotinin that was more than ten times more concentrated than that generated using an IMAC step.

  4. Titanium dioxide as chemo-affinity chromatographic sorbent of biomolecular compounds - Applications in acidic modification-specific proteomics

    DEFF Research Database (Denmark)

    Engholm-Keller, Kasper; Larsen, Martin R

    2011-01-01

    matrices for further characterization is affinity chromatography, which relies on the specific interaction between an analyte in solution and a solid adsorbent. Titanium dioxide-based affinity chromatography has proven to be a versatile tool in enrichment of various compounds such as phosphorylated...... biomolecules due to its unique ion and ligand exchange properties and high stability towards pH and temperature. Recently, titanium dioxide chromatography was introduced in proteomics as a highly specific method for enriching phosphorylated peptides - a method, which has been widely adapted by the field of...

  5. Infinite transitivity on affine varieties

    OpenAIRE

    Arzhantsev, Ivan; Flenner, Hubert; Kaliman, Shulim; Kutzschebauch, Frank; ZAIDENBERG, MIKHAIL

    2012-01-01

    In this note we survey recent results on automorphisms of affine algebraic varieties, infinitely transitive group actions and flexibility. We present related constructions and examples, and discuss geometric applications and open problems.

  6. Representations of affine Hecke algebras

    CERN Document Server

    Xi, Nanhua

    1994-01-01

    Kazhdan and Lusztig classified the simple modules of an affine Hecke algebra Hq (q E C*) provided that q is not a root of 1 (Invent. Math. 1987). Ginzburg had some very interesting work on affine Hecke algebras. Combining these results simple Hq-modules can be classified provided that the order of q is not too small. These Lecture Notes of N. Xi show that the classification of simple Hq-modules is essentially different from general cases when q is a root of 1 of certain orders. In addition the based rings of affine Weyl groups are shown to be of interest in understanding irreducible representations of affine Hecke algebras. Basic knowledge of abstract algebra is enough to read one third of the book. Some knowledge of K-theory, algebraic group, and Kazhdan-Lusztig cell of Cexeter group is useful for the rest

  7. Affine toric SL(2)-embeddings

    International Nuclear Information System (INIS)

    In the theory of affine SL(2)-embeddings, which was constructed in 1973 by Popov, a locally transitive action of the group SL(2) on a normal affine three-dimensional variety X is determined by a pair (p/q,r), where 0GV//T-hat. In the substantiation of this result a key role is played by Cox's construction in toric geometry. Bibliography: 12 titles

  8. Cromatografia unificada Unified chromatography

    Directory of Open Access Journals (Sweden)

    Carin von Mühlen

    2004-10-01

    Full Text Available The scope of this study encompasses an overview of the principles of unified chromatography as well as the principles of chromatographic techniques as applied to unified systems, which include gas chromatography, liquid chromatography, supercritical fluid chromatography, high temperature and high pressure liquid chromatography, micro-liquid chromatography, enhanced fluidity chromatography, and solvating gas chromatography. Theoretical considerations and individual instrumental parameters such as mobile phase, sample introduction system, columns, and detection system are also discussed. Future applications of this separation approach are discussed.

  9. Electrochemical affinity biosensors for detection of mycotoxins: A review.

    Science.gov (United States)

    Vidal, Juan C; Bonel, Laura; Ezquerra, Alba; Hernández, Susana; Bertolín, Juan R; Cubel, Carlota; Castillo, Juan R

    2013-11-15

    This review discusses the current state of electrochemical biosensors in the determination of mycotoxins in foods. Mycotoxins are highly toxic secondary metabolites produced by molds. The acute toxicity of these results in serious human and animal health problems, although it has been only since early 1960s when the first studied aflatoxins were found to be carcinogenic. Mycotoxins affect a broad range of agricultural products, most important cereals and cereal-based foods. A majority of countries, mentioning especially the European Union, have established preventive programs to control contamination and strict laws of the permitted levels in foods. Official methods of analysis of mycotoxins normally requires sophisticated instrumentation, e.g. liquid chromatography with fluorescence or mass detectors, combined with extraction procedures for sample preparation. For about sixteen years, the use of simpler and faster analytical procedures based on affinity biosensors has emerged in scientific literature as a very promising alternative, particularly electrochemical (i.e., amperometric, impedance, potentiometric or conductimetric) affinity biosensors due to their simplicity and sensitivity. Typically, electrochemical biosensors for mycotoxins use specific antibodies or aptamers as affinity ligands, although recombinant antibodies, artificial receptors and molecular imprinted polymers show potential utility. This article deals with recent advances in electrochemical affinity biosensors for mycotoxins and covers complete literature from the first reports about sixteen years ago. PMID:23743326

  10. Affine density in wavelet analysis

    CERN Document Server

    Kutyniok, Gitta

    2007-01-01

    In wavelet analysis, irregular wavelet frames have recently come to the forefront of current research due to questions concerning the robustness and stability of wavelet algorithms. A major difficulty in the study of these systems is the highly sensitive interplay between geometric properties of a sequence of time-scale indices and frame properties of the associated wavelet systems. This volume provides the first thorough and comprehensive treatment of irregular wavelet frames by introducing and employing a new notion of affine density as a highly effective tool for examining the geometry of sequences of time-scale indices. Many of the results are new and published for the first time. Topics include: qualitative and quantitative density conditions for existence of irregular wavelet frames, non-existence of irregular co-affine frames, the Nyquist phenomenon for wavelet systems, and approximation properties of irregular wavelet frames.

  11. Inhomogeneous self-affine carpets

    OpenAIRE

    Fraser, Jonathan M.

    2013-01-01

    We investigate the dimension theory of inhomogeneous self-affine carpets. Through the work of Olsen, Snigireva and Fraser, the dimension theory of inhomogeneous self-similar sets is now relatively well-understood, however, almost no progress has been made concerning more general non-conformal inhomogeneous attractors. If a dimension is countably stable, then the results are immediate and so we focus on the upper and lower box dimensions and compute these explicitly for large classes of inhomo...

  12. A Comparative Study of Lectin Affinity Based Plant N-Glycoproteome Profiling Using Tomato Fruit as a Model*

    OpenAIRE

    Ruiz-May, Eliel; Hucko, Simon; Kevin J. Howe; Zhang, Sheng; Sherwood, Robert W.; Thannhauser, Theodore W; Rose, Jocelyn K. C.

    2013-01-01

    Lectin affinity chromatography (LAC) can provide a valuable front-end enrichment strategy for the study of N-glycoproteins and has been used to characterize a broad range eukaryotic N-glycoproteomes. Moreover, studies with mammalian systems have suggested that the use of multiple lectins with different affinities can be particularly effective. A multi-lectin approach has also been reported to provide a significant benefit for the analysis of plant N-glycoproteins; however, it has yet to be de...

  13. Isolation, Affinity Purification, and Identification of Piglet Small Intestine Mucosa Receptor for Enterotoxigenic Escherichia coli K88ac+ Fimbriae

    OpenAIRE

    Fang, Lin; Gan, Zhibo; Marquardt, Ronald R.

    2000-01-01

    An affinity chromatography technique was utilized to isolate and purify the receptors of Escherichia coli K88ac+ fimbriae from the mucus of the small intestines of newborn piglets. Purified K88ac+ fimbriae were covalently immobilized onto a beaded agarose matrix (Sepharose 4B). The immobilized fimbriae were used for the affinity purification of the K88ac+ receptors. Only two major proteins were tightly and specifically bound to the immobilized fimbriae after the column containing bound recept...

  14. Alternative affinity tools: more attractive than antibodies?

    NARCIS (Netherlands)

    Ruigrok, V.J.B.; Levisson, M.; Eppink, M.H.M.; Smidt, H.; Oost, van der J.

    2011-01-01

    Antibodies are the most successful affinity tools used today, in both fundamental and applied research (diagnostics, purification and therapeutics). Nonetheless, antibodies do have their limitations, including high production costs and low stability. Alternative affinity tools based on nucleic acids

  15. Spectral affinity in protein networks

    Directory of Open Access Journals (Sweden)

    Teng Shang-Hua

    2009-11-01

    Full Text Available Abstract Background Protein-protein interaction (PPI networks enable us to better understand the functional organization of the proteome. We can learn a lot about a particular protein by querying its neighborhood in a PPI network to find proteins with similar function. A spectral approach that considers random walks between nodes of interest is particularly useful in evaluating closeness in PPI networks. Spectral measures of closeness are more robust to noise in the data and are more precise than simpler methods based on edge density and shortest path length. Results We develop a novel affinity measure for pairs of proteins in PPI networks, which uses personalized PageRank, a random walk based method used in context-sensitive search on the Web. Our measure of closeness, which we call PageRank Affinity, is proportional to the number of times the smaller-degree protein is visited in a random walk that restarts at the larger-degree protein. PageRank considers paths of all lengths in a network, therefore PageRank Affinity is a precise measure that is robust to noise in the data. PageRank Affinity is also provably related to cluster co-membership, making it a meaningful measure. In our experiments on protein networks we find that our measure is better at predicting co-complex membership and finding functionally related proteins than other commonly used measures of closeness. Moreover, our experiments indicate that PageRank Affinity is very resilient to noise in the network. In addition, based on our method we build a tool that quickly finds nodes closest to a queried protein in any protein network, and easily scales to much larger biological networks. Conclusion We define a meaningful way to assess the closeness of two proteins in a PPI network, and show that our closeness measure is more biologically significant than other commonly used methods. We also develop a tool, accessible at http://xialab.bu.edu/resources/pnns, that allows the user to

  16. Crystal structures of fusion proteins with large-affinity tags.

    Science.gov (United States)

    Smyth, Douglas R; Mrozkiewicz, Marek K; McGrath, William J; Listwan, Pawel; Kobe, Bostjan

    2003-07-01

    The fusion of a protein of interest to a large-affinity tag, such as the maltose-binding protein (MBP), thioredoxin (TRX), or glutathione-S-transferase (GST), can be advantageous in terms of increased expression, enhanced solubility, protection from proteolysis, improved folding, and protein purification via affinity chromatography. Unfortunately, crystal growth is hindered by the conformational heterogeneity induced by the fusion tag, requiring that the tag is removed by a potentially problematic cleavage step. The first three crystal structures of fusion proteins with large-affinity tags have been reported recently. All three structures used a novel strategy to rigidly fuse the protein of interest to MBP via a short three- to five-amino acid spacer. This strategy has the potential to aid structure determination of proteins that present particular experimental challenges and are not conducive to more conventional crystallization strategies (e.g., membrane proteins). Structural genomics initiatives may also benefit from this approach as a way to crystallize problematic proteins of significant interest. PMID:12824478

  17. Con A affinity glycoproteomics of normal human liver tissue

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to establish the novel high throughput, high efficiency and low cost technological platform for the research of N-glycoproteomics, to resolve the significance of characteristic expression profile of glycoprotein and to find the proteins with biological functional importance, the glycoproteins with high-mannose core and the two antennary types were purified and enriched by the Con A affinity chromatography. Con A affinity protein expression profiles of normal human liver tissue were gener- ated by using SDS-PAGE, two-dimensional electrophoresis (2-DE) followed by fast fluorescence stain- ing based on multiplexed proteomics (MP) technology. 301 visible protein spots on the gel were de- tected and 85 of glycoproteins were further successfully identified via peptide mass fingerprinting (PMF) by a matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF- MS/MS) and annotated to IPI databases. Identified glycoproteins definitely take part in the regulation of cell cycle and metabolic processes. The glycosylation sites were predicted with NetNGlyc 1.0 and NetOGlyc 3.1 software, meanwhile they were classified according to the geneontology methods. The construction of Con A affinity glycoprotein database of normal human liver tissue would contribute to the subsequent research.

  18. Manifolds with integrable affine shape operator

    Directory of Open Access Journals (Sweden)

    Daniel A. Joaquín

    2005-05-01

    Full Text Available This work establishes the conditions for the existence of vector fields with the property that theirs covariant derivative, with respect to the affine normal connection, be the affine shape operatorS in hypersurfaces. Some results are obtained from this property and, in particular, for some kind of affine decomposable hypersurfaces we explicitely get the actual vector fields.

  19. Affinity ultrafiltration of DNA topoisomerases-targeted compounds determined with HPLC/ESI-MS for drug candidate screening

    Institute of Scientific and Technical Information of China (English)

    张虹; 潘远江

    2004-01-01

    A method of screening assay is demonstrated. The approach is based on the affinity ofantitumor candidates for topoisomerases. In this method, antitumor candidates are fished out using topoisomerases as targets. Traditional analysis of complex compounds typically encounters signal suppression due to the relatively low concentrations, but enzyme-affinity screening for the active compounds can effectively concentrate the desired analysts into a small volume of high concentration. Active compounds are separated from non-affinity compounds by ultrafiltration. The molecules-enzymes complexes that are retained on the filter are subsequently separated by acidification to obtain the topoisomerases-affinity compounds for analysis on High Performance Liquid Chromatography coupled with electrospray ionization mass spectrometric detection (ESI-MS). This enzyme-affinity based screening assay provides a highly specific and efficient method that can directly screen, identify, and acquire drug candidates thus improving the accuracy and speed of high-throughput screening activities.

  20. Affinity ultrafiltration of DNA topoisomerases-targeted compounds determined with HPLC/ESI-MS for drug candidate screening

    Institute of Scientific and Technical Information of China (English)

    张虹; 潘远江

    2004-01-01

    A method of screening assay is demonstrated. The approach is based on the affinity of antitumor candidates for topoisomerases. In this method, antitumor candidates are fished out using topoisomerases as targets. Traditional analysis of complex compounds typically encounters signal suppression due to the relatively low concentrations, but enzyme-affinity screening for the active compounds can effectively concentrate the desired analysts into a small volume of high concen-tration. Active compounds are separated from non-affinity compounds by ultrafiltration. The molecules-enzymes complexes that are retained on the filter are subsequently separated by acidification to obtain the topoisomerases-affinity compounds for analysis on High Performance Liquid Chromatography coupled with electrospray ionization mass spectrometric detec-tion (ESI-MS). This enzyme-affinity based screening assay provides a highly specific and efficient method that can directly screen, identify, and acquire drug candidates thus improving the accuracy and speed of high-throughput screening activities.

  1. Improved Thermal Modulator for Gas Chromatography

    Science.gov (United States)

    Hasselbrink, Ernest Frederick, Jr.; Hunt, Patrick J.; Sacks, Richard D.

    2008-01-01

    An improved thermal modulator has been invented for use in a variant of gas chromatography (GC). The variant in question denoted as two-dimensional gas chromatography (2DGC) or GC-GC involves the use of three series-connected chromatographic columns, in the form of capillary tubes coated interiorly with suitable stationary phases (compounds for which different analytes exhibit different degrees of affinity). The two end columns are relatively long and are used as standard GC columns. The thermal modulator includes the middle column, which is relatively short and is not used as a standard GC column: instead, its temperature is modulated to affect timed adsorption and desorption of analyte gases between the two end columns in accordance with a 2DGC protocol.

  2. Rational self-affine tiles

    CERN Document Server

    Steiner, Wolfgang

    2012-01-01

    An integral self-affine tile is the solution of a set equation $\\mathbf{A} \\mathcal{T} = \\bigcup_{d \\in \\mathcal{D}} (\\mathcal{T} + d)$, where $\\mathbf{A}$ is an $n \\times n$ integer matrix and $\\mathcal{D}$ is a finite subset of $\\mathbb{Z}^n$. In the recent decades, these objects and the induced tilings have been studied systematically. We extend this theory to matrices $\\mathbf{A} \\in \\mathbb{Q}^{n \\times n}$. We define rational self-affine tiles as compact subsets of the open subring $\\mathbb{R}^n\\times \\prod_\\mathfrak{p} K_\\mathfrak{p}$ of the ad\\'ele ring $\\mathbb{A}_K$, where the factors of the (finite) product are certain $\\mathfrak{p}$-adic completions of a number field $K$ that is defined in terms of the characteristic polynomial of $\\mathbf{A}$. Employing methods from classical algebraic number theory, Fourier analysis in number fields, and results on zero sets of transfer operators, we establish a general tiling theorem for these tiles. We also associate a second kind of tiles with a rational matr...

  3. The affine quantum gravity programme

    International Nuclear Information System (INIS)

    The central principle of affine quantum gravity is securing and maintaining the strict positivity of the matrix { g-hat ab(x)} composed of the spatial components of the local metric operator. On spectral grounds, canonical commutation relations are incompatible with this principle, and they must be replaced by noncanonical, affine commutation relations. Due to the partial second-class nature of the quantum gravitational constraints, it is advantageous to use the recently developed projection operator method, which treats all quantum constraints on an equal footing. Using this method, enforcement of regularized versions of the gravitational operator constraints is formulated quite naturally by means of a novel and relatively well-defined functional integral involving only the same set of variables that appears in the usual classical formulation. It is anticipated that skills and insight to study this formulation can be developed by studying special, reduced-variable models that still retain some basic characteristics of gravity, specifically a partial second-class constraint operator structure. Although perturbatively nonrenormalizable, gravity may possibly be understood nonperturbatively from a hard-core perspective that has proved valuable for specialized models. Finally, developing a procedure to pass to the genuine physical Hilbert space involves several interconnected steps that require careful coordination

  4. Protein digestion and phosphopeptide enrichment on a glass microchip

    OpenAIRE

    Yue, Guihua Eileen; Roper, Michael G.; Balchunas, Catherine; Pulsipher, Abigail; Coon, Joshua J.; Shabanowitz, Jeffery; Hunt, Donald F.; Landers, James P.; Ferrance, Jerome P.

    2005-01-01

    This work describes an integrated glass microdevice for proteomics, which directly couples proteolysis with affinity selection. Initial results with standard phosphopeptide fragments from β-casein in peptide mixtures showed selective capture of the phosphorylated fragments using immobilized metal affinity chromatography (IMAC) beads packed into a microchannel. Complete selectivity was seen with angiotensin, with capture of only the phosphorylated form. On-chip proteolysis, using immobilized t...

  5. Fun with Paper Chromatography.

    Science.gov (United States)

    Coleman, Dava; Hounshell, Paul B.

    1982-01-01

    Discusses paper chromatographic techniques and provides examples of typical classroom activities. Includes description of retardation values obtained during chromatography exercises and suggests using them for math lessons. (JN)

  6. A comparative study of lectin affinity based plant n-glycoproteome profiling using tomato fruit as a model

    Science.gov (United States)

    Lectin affinity chromatography (LAC) can provide a valuable front-end enrichment strategy for the study of N-glycoproteins and has been used to characterize a broad range eukaryotic N-glycoproteomes. Moreover, studies with mammalian systems have suggested that the use of multiple lectins with differ...

  7. Conformal field theory on affine Lie groups

    International Nuclear Information System (INIS)

    Working directly on affine Lie groups, we construct several new formulations of the WZW model, the gauged WZW model, and the generic affine-Virasoro action. In one formulation each of these conformal field theories (CFTs) is expressed as a one-dimensional mechanical system whose variables are coordinates on the affine Lie group. When written in terms of the affine group element, this formulation exhibits a two-dimensional WZW term. In another formulation each CFT is written as a two-dimensional field theory, with a three- dimensional WZW term, whose fields are coordinates on the affine group. On the basis of these equivalent formulations, we develop a translation dictionary in which the new formulations on the affine Lie group are understood as mode formulations of the conventional formulations on the Lie group. Using this dictionary, we also express each CFT as a three-dimensional field theory on the Lie group with a four-dimensional WZW term. 36 refs

  8. Conformal field theory on affine Lie groups

    Energy Technology Data Exchange (ETDEWEB)

    Clubok, K.S.

    1996-04-01

    Working directly on affine Lie groups, we construct several new formulations of the WZW model, the gauged WZW model, and the generic affine-Virasoro action. In one formulation each of these conformal field theories (CFTs) is expressed as a one-dimensional mechanical system whose variables are coordinates on the affine Lie group. When written in terms of the affine group element, this formulation exhibits a two-dimensional WZW term. In another formulation each CFT is written as a two-dimensional field theory, with a three- dimensional WZW term, whose fields are coordinates on the affine group. On the basis of these equivalent formulations, we develop a translation dictionary in which the new formulations on the affine Lie group are understood as mode formulations of the conventional formulations on the Lie group. Using this dictionary, we also express each CFT as a three-dimensional field theory on the Lie group with a four-dimensional WZW term. 36 refs.

  9. Maximin affinity learning of image segmentation

    CERN Document Server

    Turaga, Srinivas C; Helmstaedter, Moritz; Denk, Winfried; Seung, H Sebastian

    2009-01-01

    Images can be segmented by first using a classifier to predict an affinity graph that reflects the degree to which image pixels must be grouped together and then partitioning the graph to yield a segmentation. Machine learning has been applied to the affinity classifier to produce affinity graphs that are good in the sense of minimizing edge misclassification rates. However, this error measure is only indirectly related to the quality of segmentations produced by ultimately partitioning the affinity graph. We present the first machine learning algorithm for training a classifier to produce affinity graphs that are good in the sense of producing segmentations that directly minimize the Rand index, a well known segmentation performance measure. The Rand index measures segmentation performance by quantifying the classification of the connectivity of image pixel pairs after segmentation. By using the simple graph partitioning algorithm of finding the connected components of the thresholded affinity graph, we are ...

  10. A Lectin Purified from Blood Red Bracket Mushroom, Pycnoporus sanguineus (Agaricomycetidae), Mycelium Displayed Affinity Toward Bovine Transferrin.

    Science.gov (United States)

    Albores, Silvana; Moros, Maria; Cerdeiras, Maria Pia; de la Fuente, Jesus Martinez; Grazu, Valeria; Fraguas, Laura Franco

    2016-01-01

    Fungal lectins constitute excellent ligands for development of affinity adsorbents useful in affinity chromatography. In this work, a lectin was purified from Pycnoporus sanguineus (PSL) mycelium using 3 procedures: by affinity chromatography, using magnetic galactosyl-nanoparticles or galactose coupled to Sepharose, and by ionic exchange chromatography (IEC). The highest lectin yield was achieved by IEC (55%); SDS-PAGE of PSL showed 2 bands with molecular mass of 68.7 and 55.2 kDa and IEC displayed 2 bands at pi 5.5 and 5.2. The lectin agglutinates rat erythrocytes, exhibiting broad specificity toward several monosaccharides, including galactose. The agglutination was also inhibited by the glycoproteins fetal calf fetuin, bovine lactoferrin, bovine transferrin, and horseradish peroxidase. The lectin was then used to synthesize an affinity adsorbent (PSL-Sepharose) and the interaction with glycoproteins was evaluated by analyzing their chromatographic behaviors. The strongest interaction with the PSL-derivative was observed with transferrin, although lower interactions were also displayed toward fetuin and lactoferrin. These results indicate that the purified PSL constitutes an interesting ligand for the design of affinity adsorbents to be used (i.e., in glycoprotein purification). PMID:27279446

  11. Moringa oleifera lectin and binding affinity to humic acids : application to water treatment

    OpenAIRE

    Santos, Andréa F. S.; Luz, Luciana A.; Cunha, M. G. C.; Paiva, Patrícia M.G.; Teixeira, J.A.; Brito, A. G.; R. Nogueira; L. C. B. B. Coelho

    2007-01-01

    Humic acids, natural organic matter, constitute a problem in water treatment; they react with chlorine forming undesirable disinfection byproducts. The aim of this work was the purification of a saline soluble Moringa oleifera lectin (SSMoL) and characterization of its affinity to humic acids. SSMoL isolation included extraction of seed flour, saline fractionation and guar gel chromatography. Hemagglutinating activity (HA) of extract (E), fraction (0-60F) and SSMoL was assessed...

  12. Stability of the Neurotensin Receptor NTS1 Free in Detergent Solution and Immobilized to Affinity Resin

    OpenAIRE

    White, Jim F.; Reinhard Grisshammer

    2010-01-01

    BACKGROUND: Purification of recombinant membrane receptors is commonly achieved by use of an affinity tag followed by an additional chromatography step if required. This second step may exploit specific receptor properties such as ligand binding. However, the effects of multiple purification steps on protein yield and integrity are often poorly documented. We have previously reported a robust two-step purification procedure for the recombinant rat neurotensin receptor NTS1 to give milligram q...

  13. Affinity capillary electrophoresis and density functional theory employed for characterization of (bio)molecular interactions

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Ehala, Sille; Růžička, Martin; Dybal, Jiří; Toman, Petr

    Salzburg: Society of Analytical Chemistry, 2014. OR28. [ISC 2014. International Symposium on Chromatography /30./. 14.09.2014-18.09.2014, Salzburg] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 ; RVO:61389013 Keywords : affinity capillary electrophoresis * density functional theory * biomolecular complexes Subject RIV: CB - Analytical Chemistry, Separation

  14. Stability of the Neurotensin Receptor NTS1 Free in Detergent Solution and Immobilized to Affinity Resin

    OpenAIRE

    White, Jim F.; Grisshammer, Reinhard

    2010-01-01

    Background Purification of recombinant membrane receptors is commonly achieved by use of an affinity tag followed by an additional chromatography step if required. This second step may exploit specific receptor properties such as ligand binding. However, the effects of multiple purification steps on protein yield and integrity are often poorly documented. We have previously reported a robust two-step purification procedure for the recombinant rat neurotensin receptor NTS1 to give milligram qu...

  15. Methods for Improving Aptamer Binding Affinity

    OpenAIRE

    Hijiri Hasegawa; Nasa Savory; Koichi Abe; Kazunori Ikebukuro

    2016-01-01

    Aptamers are single stranded oligonucleotides that bind a wide range of biological targets. Although aptamers can be isolated from pools of random sequence oligonucleotides using affinity-based selection, aptamers with high affinities are not always obtained. Therefore, further refinement of aptamers is required to achieve desired binding affinities. The optimization of primary sequences and stabilization of aptamer conformations are the main approaches to refining the binding properties of a...

  16. Covariant Functional Calculi from the Affine Groups

    OpenAIRE

    Gong, Yafang

    2009-01-01

    Invoking the Clifford-Hermite Wavelets from Clifford analysis, we use the covariances of affine groups to construct a kind of functional calculi for several non-commuting bounded operators. Functional calculi are the intertwining transforms between the representations of affine groups in the space $L^2(\\mathbb R^m)$ and in the space of bounded operators. It turns out that the Weyl calculus is the value of this new functional calculus at the identity of affine groups. Our app...

  17. Multipole solutions in metric-affine gravity

    CERN Document Server

    Socorro, J; Macías, A; Mielke, E W; Socorro, José; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.

    1998-01-01

    Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging the affine group, a metric affine gauge theory emerges as dynamical framework. Here, by using the harmonic map ansatz, a new class of multipole like solutions in the metric affine gravity theory (MAG) is obtained.

  18. Maximin affinity learning of image segmentation

    OpenAIRE

    Srinivas C Turaga; Briggman, Kevin L; Helmstaedter, Moritz; Denk, Winfried; Seung, H. Sebastian

    2009-01-01

    Images can be segmented by first using a classifier to predict an affinity graph that reflects the degree to which image pixels must be grouped together and then partitioning the graph to yield a segmentation. Machine learning has been applied to the affinity classifier to produce affinity graphs that are good in the sense of minimizing edge misclassification rates. However, this error measure is only indirectly related to the quality of segmentations produced by ultimately partitioning the a...

  19. Discrete Affine Minimal Surfaces with Indefinite Metric

    OpenAIRE

    Craizer, Marcos; Anciaux, Henri; Lewiner, Thomas

    2008-01-01

    Inspired by the Weierstrass representation of smooth affine minimal surfaces with indefinite metric, we propose a constructive process producing a large class of discrete surfaces that we call discrete affine minimal surfaces. We show that they are critical points of an affine area functional defined on the space of quadrangular discrete surfaces. The construction makes use of asymptotic coordinates and allows defining the discrete analogs of some differential geometric objects, such as the n...

  20. A Novel Vertex Affinity for Community Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    We propose a novel vertex affinity measure in this paper. The new vertex affinity quantifies the proximity between two vertices in terms of their clustering strength and is ideal for such graph analytics applications as community detection. We also developed a framework that combines simple graph searches and resistance circuit formulas to compute the vertex affinity efficiently. We study the properties of the new affinity measure empirically in comparison to those of other popular vertex proximity metrics. Our results show that the existing metrics are ill-suited for community detection due to their lack of fundamental properties that are essential for correctly capturing inter- and intra-cluster vertex proximity.

  1. Compact noncontraction semigroups of affine operators

    Science.gov (United States)

    Voynov, A. S.; Protasov, V. Yu

    2015-07-01

    We analyze compact multiplicative semigroups of affine operators acting in a finite-dimensional space. The main result states that every such semigroup is either contracting, that is, contains elements of arbitrarily small operator norm, or all its operators share a common invariant affine subspace on which this semigroup is contracting. The proof uses functional difference equations with contraction of the argument. We look at applications to self-affine partitions of convex sets, the investigation of finite affine semigroups and the proof of a criterion of primitivity for nonnegative matrix families. Bibliography: 32 titles.

  2. Protein Complex Purification by Affinity Capture.

    Science.gov (United States)

    LaCava, John; Fernandez-Martinez, Javier; Hakhverdyan, Zhanna; Rout, Michael P

    2016-01-01

    Affinity capture has become a powerful technique for consistently purifying endogenous protein complexes, facilitating biochemical and biophysical assays on otherwise inaccessible biological assemblies, and enabling broader interactomic exploration. For this procedure, cells are broken and their contents separated and extracted into a solvent, permitting access to target macromolecular complexes thus released in solution. The complexes are specifically enriched from the extract onto a solid medium coupled with an affinity reagent-usually an antibody-that recognizes the target either directly or through an appended affinity tag, allowing subsequent characterization of the complex. Here, we discuss approaches and considerations for purifying endogenous yeast protein complexes by affinity capture. PMID:27371601

  3. Structural determinants of sigma receptor affinity

    International Nuclear Information System (INIS)

    The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-[3H]3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent

  4. Structural determinants of sigma receptor affinity

    Energy Technology Data Exchange (ETDEWEB)

    Largent, B.L.; Wikstroem, H.G.; Gundlach, A.L.; Snyder, S.H.

    1987-12-01

    The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-(/sup 3/H)3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent.

  5. Liquid Chromatography in 1982.

    Science.gov (United States)

    Freeman, David H.

    1982-01-01

    Reviews trends in liquid chromatography including apparatus, factors affecting efficient separation of a mixture (peak sharpness and speed), simplified problem-solving, adsorption, bonded phase chromatography, ion selectivity, and size exclusion. The current trend is to control chemical selectivity by the liquid phase. (Author/JN)

  6. Structure of classical affine and classical affine fractional W-algebras

    International Nuclear Information System (INIS)

    We introduce a classical BRST complex (See Definition 3.2.) and show that one can construct a classical affine W-algebra via the complex. This definition clarifies that classical affine W-algebras can be considered as quasi-classical limits of quantum affine W-algebras. We also give a definition of a classical affine fractional W-algebra as a Poisson vertex algebra. As in the classical affine case, a classical affine fractional W-algebra has two compatible λ-brackets and is isomorphic to an algebra of differential polynomials as a differential algebra. When a classical affine fractional W-algebra is associated to a minimal nilpotent, we describe explicit forms of free generators and compute λ-brackets between them. Provided some assumptions on a classical affine fractional W-algebra, we find an infinite sequence of integrable systems related to the algebra, using the generalized Drinfel’d and Sokolov reduction

  7. Heparin-binding peptide as a novel affinity tag for purification of recombinant proteins.

    Science.gov (United States)

    Morris, Jacqueline; Jayanthi, Srinivas; Langston, Rebekah; Daily, Anna; Kight, Alicia; McNabb, David S; Henry, Ralph; Kumar, Thallapuranam Krishnaswamy Suresh

    2016-10-01

    Purification of recombinant proteins constitutes a significant part of the downstream processing in biopharmaceutical industries. Major costs involved in the production of bio-therapeutics mainly depend on the number of purification steps used during the downstream process. Affinity chromatography is a widely used method for the purification of recombinant proteins expressed in different expression host platforms. Recombinant protein purification is achieved by fusing appropriate affinity tags to either N- or C- terminus of the target recombinant proteins. Currently available protein/peptide affinity tags have proved quite useful in the purification of recombinant proteins. However, these affinity tags suffer from specific limitations in their use under different conditions of purification. In this study, we have designed a novel 34-amino acid heparin-binding affinity tag (HB-tag) for the purification of recombinant proteins expressed in Escherichia coli (E. coli) cells. HB-tag fused recombinant proteins were overexpressed in E. coli in high yields. A one-step heparin-Sepharose-based affinity chromatography protocol was developed to purify HB-fused recombinant proteins to homogeneity using a simple sodium chloride step gradient elution. The HB-tag has also been shown to facilitate the purification of target recombinant proteins from their 8 M urea denatured state(s). The HB-tag has been demonstrated to be successfully released from the fusion protein by an appropriate protease treatment to obtain the recombinant target protein(s) in high yields. Results of the two-dimensional NMR spectroscopy experiments indicate that the purified recombinant target protein(s) exist in the native conformation. Polyclonal antibodies raised against the HB-peptide sequence, exhibited high binding specificity and sensitivity to the HB-fused recombinant proteins (∼10 ng) in different crude cell extracts obtained from diverse expression hosts. In our opinion, the HB-tag provides a

  8. Biomimetic design of affinity peptide ligand for capsomere of virus-like particle.

    Science.gov (United States)

    Li, Yanying; Liu, Xiaodan; Dong, Xiaoyan; Zhang, Lin; Sun, Yan

    2014-07-22

    Virus-like particle (VLP) of murine polyomavirus (MPV) is a T = 7d icosahedral capsid that self-assembles from 72 capsomeres (Caps), each of which is a pentamer of major coat protein VP1. VLP has great potential in vaccinology, gene therapy, drug delivery, and materials science. However, its application is hindered by high cost downstream processes, leading to an urgent demand of a highly efficient affinity ligand for the separation and purification of Cap by affinity chromatography. Herein a biomimetic design strategy of an affinity peptide ligand of Cap has been developed on the basis of the binding structure of the C-terminus of minor coat protein (VP2-C) on the inner surface of Cap. The molecular interactions between VP2-C and Cap were first examined using all-atom molecular dynamics (MD) simulations coupled with the molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) method, where V283, P285, D286, W287, L289, and Y296 of VP2-C were identified as the hot spots. An affinity peptide library (DWXLXLXY, X denotes arbitrary amino acids except cysteine) was then constructed for virtual screening sequently by docking with AUTODOCK VINA, binding structure comparison, and final docking with ROSETTA FlexPepDock. Ten peptide candidates were selected and further confirmed by MD simulations and MM/PBSA, where DWDLRLLY was found to have the highest affinity to Cap. In DWDLRLLY, six residues are favorable for the binding, including W2, L4, L6 and Y8 inheriting from VP2-C, and R5 and L7 selected in the virtual screening. This confirms the high efficiency and accuracy of the biomimetic design strategy. DWDLRLLY was then experimentally validated by a one-step purification of Cap from crude cell lysate using affinity chromatography with the octapeptide immobilized on Sepharose gel. The purified Caps were observed to self-assemble into VLP with consistent structure of authentic MPV. PMID:24976378

  9. Scaling analysis of affinity propagation.

    Science.gov (United States)

    Furtlehner, Cyril; Sebag, Michèle; Zhang, Xiangliang

    2010-06-01

    We analyze and exploit some scaling properties of the affinity propagation (AP) clustering algorithm proposed by Frey and Dueck [Science 315, 972 (2007)]. Following a divide and conquer strategy we setup an exact renormalization-based approach to address the question of clustering consistency, in particular, how many cluster are present in a given data set. We first observe that the divide and conquer strategy, used on a large data set hierarchically reduces the complexity O(N2) to O(N((h+2)/(h+1))) , for a data set of size N and a depth h of the hierarchical strategy. For a data set embedded in a d -dimensional space, we show that this is obtained without notably damaging the precision except in dimension d=2 . In fact, for d larger than 2 the relative loss in precision scales such as N((2-d)/(h+1)d). Finally, under some conditions we observe that there is a value s* of the penalty coefficient, a free parameter used to fix the number of clusters, which separates a fragmentation phase (for ss*) of the underlying hidden cluster structure. At this precise point holds a self-similarity property which can be exploited by the hierarchical strategy to actually locate its position, as a result of an exact decimation procedure. From this observation, a strategy based on AP can be defined to find out how many clusters are present in a given data set. PMID:20866473

  10. Determinants of benzodiazepine brain uptake: lipophilicity versus binding affinity.

    Science.gov (United States)

    Arendt, R M; Greenblatt, D J; Liebisch, D C; Luu, M D; Paul, S M

    1987-01-01

    Factors influencing brain uptake of benzodiazepine derivatives were evaluated in adult Sprague Dawley rats (n = 8-10 per drug). Animals received single intraperitoneal doses of alprazolam, triazolam, lorazepam, flunitrazepam, diazepam, midazolam, desmethyldiazepam, or clobazam. Concentrations of each drug (and metabolites) in whole brain and serum 1 h after dosage were determined by gas chromatography. Serum free fraction was measured by equilibrium dialysis. In vitro binding affinity (apparent Ki) of each compound was estimated based on displacement of tritiated flunitrazepam in washed membrane preparations from rat cerebral cortex. Lipid solubility of each benzodiazepine was estimated using the reverse-phase liquid chromatographic (HPLC) retention index at physiologic pH. There was no significant relation between brain:total serum concentration ratio and either HPLC retention (r = 0.18) or binding Ki (r = -0.34). Correction of uptake ratios for free as opposed to total serum concentration yielded a highly significant correlation with HPLC retention (r = 0.78, P less than 0.005). However, even the corrected ratio was not correlated with binding Ki (r = -0.22). Thus a benzodiazepine's capacity to diffuse from systemic blood into brain tissue is much more closely associated with the physicochemical property of lipid solubility than with specific affinity. Unbound rather than total serum or plasma concentration most accurately reflects the quantity of drug available for diffusion. PMID:2888155

  11. Free C+ actions on affine threefolds

    OpenAIRE

    Kraft, H.

    2005-01-01

    We study algebraic actions of the additive group C+ on an affine threefold X and prove a smoothness property for the quotient morphism X -< X//C+. Then, following Shulim Kaliman, we give a proof of the conjecture that every free C+ action on affine 3-space C^3 is a translation.

  12. Lectures on extended affine Lie algebras

    CERN Document Server

    Neher, Erhard

    2010-01-01

    We give an introduction to the structure theory of extended affine Lie algebras, which provide a common framework for finite-dimensional semisimple, affine and toroidal Lie algebras. The notes are based on a lecture series given during the Fields Institute summer school at the University of Ottawa in June 2009.

  13. Affine Constellations Without Mutually Unbiased Counterparts

    CERN Document Server

    Weigert, Stefan

    2010-01-01

    It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations, mostly in dimension six. The observed discrepancies make a deeper relation between the two existence problems unlikely.

  14. Affine constellations without mutually unbiased counterparts

    Energy Technology Data Exchange (ETDEWEB)

    Weigert, Stefan [Department of Mathematics, University of York, York YO10 5DD (United Kingdom); Durt, Thomas, E-mail: slow500@york.ac.u, E-mail: thomdurt@vub.ac.b [IR-TONA, VUB, BE-1050 Brussels (Belgium)

    2010-10-08

    It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations. The observed discrepancies make a deeper relation between the two existence problems unlikely. (fast track communication)

  15. Dyes with high affinity for polylactide

    Institute of Scientific and Technical Information of China (English)

    Liang He; Shu Fen Zhang; Bing Tao Tang; Li Li Wang; Jin Zong Yang

    2007-01-01

    Attempts were made to develop dyes with high affinity for polylactide as an alternative to the existent commercial disperse dyes.The dyes synthesized according to the affinity concept of dye to polylactide exhibited excellent dyeing properties on polylactide compared with the commercial disperse dyes.

  16. Porosity of Self-affine Sets

    Institute of Scientific and Technical Information of China (English)

    Lifeng XI

    2008-01-01

    In this paper,it is proved that any self-affine set satisfying the strong separation condition is uniformly porous.The author constructs a self-affine set which is not porous,although the open set condition holds.Besides,the author also gives a C1 iterated function system such that its invariant set is not porous.

  17. Affine constellations without mutually unbiased counterparts

    International Nuclear Information System (INIS)

    It has been conjectured that a complete set of mutually unbiased bases in a space of dimension d exists if and only if there is an affine plane of order d. We introduce affine constellations and compare their existence properties with those of mutually unbiased constellations. The observed discrepancies make a deeper relation between the two existence problems unlikely. (fast track communication)

  18. Improving image segmentation by learning region affinities

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  19. Liquid Chromatography on chip

    OpenAIRE

    Faure, Karine

    2010-01-01

    Abstract Liquid chromatography is one of the most powerful separation techniques as illustrated by its leading role in analytical sciences through both academic and industrial communities. Its implementation in microsystems appears to be crucial in the development of ?TAS. If electrophoretic techniques have been widely used in miniaturized devices, liquid chromatography has faced multiple challenges in the downsizing process. During the past five years significant breakthroughs...

  20. Gas chromatography in space

    Science.gov (United States)

    Akapo, S. O.; Dimandja, J. M.; Kojiro, D. R.; Valentin, J. R.; Carle, G. C.

    1999-01-01

    Gas chromatography has proven to be a very useful analytical technique for in situ analysis of extraterrestrial environments as demonstrated by its successful operation on spacecraft missions to Mars and Venus. The technique is also one of the six scientific instruments aboard the Huygens probe to explore Titan's atmosphere and surface. A review of gas chromatography in previous space missions and some recent developments in the current environment of fiscal constraints and payload size limitations are presented.

  1. Optimized Affinity Capture of Yeast Protein Complexes.

    Science.gov (United States)

    LaCava, John; Fernandez-Martinez, Javier; Hakhverdyan, Zhanna; Rout, Michael P

    2016-01-01

    Here, we describe an affinity isolation protocol. It uses cryomilled yeast cell powder for producing cell extracts and antibody-conjugated paramagnetic beads for affinity capture. Guidelines for determining the optimal extraction solvent composition are provided. Captured proteins are eluted in a denaturing solvent (sodium dodecyl sulfate polyacrylamide gel electrophoresis sample buffer) for gel-based proteomic analyses. Although the procedures can be modified to use other sources of cell extract and other forms of affinity media, to date we have consistently obtained the best results with the method presented. PMID:27371596

  2. Affinity Proteomics in the mountains: Alpbach 2015.

    Science.gov (United States)

    Taussig, Michael J

    2016-09-25

    The 2015 Alpbach Workshop on Affinity Proteomics, organised by the EU AFFINOMICS consortium, was the 7th workshop in this series. As in previous years, the focus of the event was the current state of affinity methods for proteome analysis, including complementarity with mass spectrometry, progress in recombinant binder production methods, alternatives to classical antibodies as affinity reagents, analysis of proteome targets, industry focus on biomarkers, and diagnostic and clinical applications. The combination of excellent science with Austrian mountain scenery and winter sports engender an atmosphere that makes this series of workshops exceptional. The articles in this Special Issue represent a cross-section of the presentations at the 2015 meeting. PMID:27118167

  3. Corner Transfer Matrices and Quantum Affine Algebras

    CERN Document Server

    Foda, O E; Foda, Omar; Miwa, Tetsuji

    1992-01-01

    Let H be the corner-transfer-matrix Hamiltonian for the six-vertex model in the anti-ferroelectric regime. It acts on the infinite tensor product W = V . V . V ....., where is the 2-dimensional irreducible representation of the quantum affine sl(2). We observe that H is the derivation of quantum affine sl(2), and conjecture that the eigenvectors of H form the level-1 vacuum representation of quantum affine sl(2). We report on checks in support of our conjecture.

  4. Partial purification of the 5-hydroxytryptophan-reuptake system from human blood platelets using a citalopram-derived affinity resin

    Energy Technology Data Exchange (ETDEWEB)

    Biessen, E.A.L; Horn, A.S.; Robillard, G.T. (Univ. of Groningen (Netherlands))

    1990-04-03

    This paper describes a procedure for the synthesis and application of a citalopram-derived affinity resin in purifying the 5HT-reuptake system from human blood platelets. A two-step scheme has been developed for partial purification, based on wheat germ agglutinin-lectin (WGA) affinity and citalopram affinity chromatographies. Upon solubilization of the carrier with 1% digitonin, a 50-70-fold increase in specific ({sup 3}H) imipramine binding activity with a 70% recovery could be accomplished through WGA-lectin chromatography. The WGA pool was then subjected to affinity chromatography on citalopram-agarose. At least 90% of the binding capacity adsorbed to the column. Specific elution using 10 {mu}M citalopram resulted in a 22% recovery of binding activity. A 10,000-fold overall purification was obtained by using this two-step procedure. Analysis of the fractions on SDS-PAGE after {sup 125}I labeling revealed specific elution of 78- and 55-kDa proteins concomitant with the appearance of ({sup 3}H) imipramine binding activity. The pharmacological profile of the partially purified reuptake system correlated well with that derived from the crude membrane-bound reuptake system, suggesting a copurification of the 5HT binding activity and ({sup 3}H)imipramine binding activity.

  5. 超高效液相色谱法快速检测粮食中黄曲霉毒素的含量%Rapid Analysis of Aflatoxins (B1, B2, G1, G2) in Grain by Immuno-affinity Clear-up Column and Ultra Performance Liquid Chromatography without Derivation

    Institute of Scientific and Technical Information of China (English)

    谢刚; 王松雪; 张艳

    2013-01-01

    建立了免疫亲和柱净化-超高效液相色谱法快速测定粮食中黄曲霉毒素(Aflatoxins,AF)的检测方法.样品经提取后,用免疫亲和柱净化、浓缩,Waters Acquity UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7 um)分离.以甲醇-水(40∶60,V/V)为流动相,流速为0.2 mL/min,进样量为1μL,荧光检测器检测,激发波长为360 nm,发射波长为440 nm,无需衍生.黄曲霉毒素B1,B2,G1,G2的保留时间小于5min,从样品前处理到结果分析整个过程小于45 min.根据3倍信噪比的峰响应值,确定黄曲霉毒素(B1,B2,G1,G2)检出限分别为0.15,0.05,0.40,0.06 pg,4种毒素在0.4 ~ 60.0 pg,0.2~15.0 pg,1.5~ 60.0 pg和0.2~15.0 pg范围内分别呈线性相关,相关系数R2值分别为0.9999,0.9999,0.9998和0.9992;在小麦、玉米、稻谷3类样品中加标回收率为77.4% ~ 104.2%,精密度为1.8% ~ 8.9%.本方法无需衍生即可同时测定粮食中4种黄曲霉毒素,适用于粮食中黄曲霉毒素的快速定量测定.%A rapid and environmental-friendly analytical method without any derivation was established for the determination of aflatoxins (B1, B2, G1, G2) in grain samples. The samples were extracted by methanol-water, cleared up with the immuno-affinity column (IAC). The separation of target compound was performed on a Waters Acquity UPLC BEH C18(50 mmx2. 1 mm, 1. 7μ,m) using methanol; water (40 = 60, V/V) as mobile phase with a flow rate of 0. 2 mL/min at 25 ℃. The injection volume was 1 μL and detection wavelengths were set at 360 nm (λem) and 440 nm (λeX) using fluorescence detector (FLD). The retention time was less than 5 min, and the whole analytical time was less than 45 min. The detection limits of AFB1, AFB2, AFG1, and AFG2 were 0.15, 0.05, 0.40 and 0.06 pg, respectively. The linear detection ranges of AFB1, AFB2, AFG1, and AFG2 were 0. 4-60. 0, 0. 2-15. 0, 1. 5-60, 0. 2-15. 00 pg with correlation coefficients (R2) of 0.9999, 0.9999, 0.9998, 0.9992, respectively

  6. Automorphisms in Birational and Affine Geometry

    CERN Document Server

    Ciliberto, Ciro; Flenner, Hubert; McKernan, James; Prokhorov, Yuri; Zaidenberg, Mikhail

    2014-01-01

    The main focus of this volume is on the problem of describing the automorphism groups of affine and projective varieties, a classical subject in algebraic geometry where, in both cases, the automorphism group is often infinite dimensional. The collection covers a wide range of topics and is intended for researchers in the fields of classical algebraic geometry and birational geometry (Cremona groups) as well as affine geometry with an emphasis on algebraic group actions and automorphism groups. It presents original research and surveys and provides a valuable overview of the current state of the art in these topics. Bringing together specialists from projective, birational algebraic geometry and affine and complex algebraic geometry, including Mori theory and algebraic group actions, this book is the result of ensuing talks and discussions from the conference “Groups of Automorphisms in Birational and Affine Geometry” held in October 2012, at the CIRM, Levico Terme, Italy. The talks at the conference high...

  7. Synthesis of a New Series of Bone Affinity Compounds

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new series of bone affinity compounds were synthesized by linking chrysophanol with 5-fluorouracil derivatives. Their bone affinity was established by hydroxyapafive (HA)affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.

  8. Affine Moment Invariants Generated by Graph Method

    Czech Academy of Sciences Publication Activity Database

    Suk, Tomáš; Flusser, Jan

    2011-01-01

    Roč. 44, č. 9 (2011), 2047 – 2056. ISSN 0031-3203 R&D Projects: GA ČR(CZ) GA102/08/1593 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image moments * Object recognition * Affine transformation * Affine moment invariants * Pseudoinvariants * Graph representation * Irreducibility * Independence Subject RIV: IN - Informatics, Computer Science Impact factor: 2.292, year: 2011 http://library.utia.cas.cz/separaty/2011/ZOI/suk-0359752.pdf

  9. On Affine Fusion and the Phase Model

    OpenAIRE

    Walton, Mark A.

    2012-01-01

    A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the $su(n)$ Wess-Zumino-Novikov-Witten (WZNW) conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connec...

  10. Purely affine elementary su(N) fusions

    OpenAIRE

    Rasmussen, Jorgen; Walton, Mark A.

    2001-01-01

    We consider three-point couplings in simple Lie algebras -- singlets in triple tensor products of their integrable highest weight representations. A coupling can be expressed as a linear combination of products of finitely many elementary couplings. This carries over to affine fusion, the fusion of Wess-Zumino-Witten conformal field theories, where the expressions are in terms of elementary fusions. In the case of su(4) it has been observed that there is a purely affine elementary fusion, i.e...

  11. Complete algebraic vector fields on affine surfaces

    OpenAIRE

    Kaliman, Shulim; Kutzschebauch, Frank; Leuenberger, Matthias

    2014-01-01

    Let $\\AAutH (X)$ be the subgroup of the group $\\AutH (X)$ of holomorphic automorphisms of a normal affine algebraic surface $X$ generated by elements of flows associated with complete algebraic vector fields. Our main result is a classification of all normal affine algebraic surfaces $X$ quasi-homogeneous under $\\AAutH (X)$ in terms of the dual graphs of the boundaries $\\bX \\setminus X$ of their SNC-completions $\\bX$.

  12. Fan affinity laws from a collision model

    International Nuclear Information System (INIS)

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan. (paper)

  13. A MEMS Dielectric Affinity Glucose Biosensor

    OpenAIRE

    Xian HUANG; Li, SiQi; Davis, Erin; Li, Dachao; Wang, Qian; Lin, Qiao

    2013-01-01

    Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concent...

  14. Affine modifications and affine hypersurfaces with a very transitive automorphism group

    OpenAIRE

    Kaliman, Shulim; ZAIDENBERG, MIKHAIL

    1998-01-01

    We study a kind of modification of an affine domain which produces another affine domain. First appeared in passing in the basic paper of O. Zariski (1942), it was further considered by E.D. Davis (1967). The first named author applied its geometric counterpart to construct contractible smooth affine varieties non-isomorphic to Euclidean spaces. Here we provide certain conditions which guarantee preservation of the topology under a modification. As an application, we show that the group of bi...

  15. UNIFIED THEORETICAL MOMENT EXPRESSIONS FOR ELUTION CHROMATOGRAPHY AND FRONTAL CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    YANGGengliang; TAOZuyi

    1992-01-01

    The unified theoretical moment expressions for elution chromatography and frontal chromatography when the sorption process is described by a linear model were derived. The moment expressions derived by previous authors can be obtained from these unified theoretical moment expressions. In this paper, a mathematical analysis has been carried out so as to set up a unified theoretical basis for elution and frontal chromatography.

  16. Congophilicity (Congo red affinity) of different beta2-microglobulin conformations characterized by dye affinity capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, N H; Sen, J W; Nissen, Mogens Holst

    2000-01-01

    The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of...

  17. Recent development of multi-dimensional chromatography strategies in proteome research.

    Science.gov (United States)

    Tang, Jia; Gao, Mingxia; Deng, Chunhui; Zhang, Xiangming

    2008-04-15

    As a complementary approach to two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), multi-dimensional chromatography separation methods have been widely applied in all kinds of biological sample investigations. Multi-dimensional liquid chromatography (MDLC) coupled with bio-mass spectrometry (MS) is playing important roles in proteome research due to its high speed, high resolution and high sensitivity. Proteome analysis strategies mainly include bottom-up and top-down approaches which carry out biological sample separation based on peptide and protein levels, respectively. Electrophoretic methods combined with liquid chromatography like IEF-HPLC and HPLC-SDS-PAGE have been successful applied for protein separations. As for MDLC strategy, ion-exchange chromatography (IEX) together with reversed phase liquid chromatography (RPLC) is still a most widely used chromatography in proteome analysis, other chromatographic methods are also frequently used in protein pre-fractionations, while affinity chromatography is usually adopted for specific functional protein analysis. Recent MDLC technologies and applications to variety of proteome analysis have been achieved great development. A digest peptide-based approach as so-called "bottom-up" and intact protein-based approach "top-down" analysis of proteome samples were briefly reviewed in this paper. The diversity of combinations of different chromatography modes to set up MDLC systems was demonstrated and discussed. Novel developments of MDLC techniques such as high-abundance protein depletion and chromatography array were also included in this review. PMID:18289947

  18. On Affine Fusion and the Phase Model

    Directory of Open Access Journals (Sweden)

    Mark A. Walton

    2012-11-01

    Full Text Available A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n Wess-Zumino-Novikov-Witten (WZNW conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connection to the modular S matrix and fusion of the su(n WZNW model. The noncommutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.

  19. On affine fusion and the phase model

    CERN Document Server

    Walton, Mark A

    2012-01-01

    A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n) Wess-Zumino-Novikov-Witten (WZNW) conformal field theories appears in a simple integrable system known as the phase model. The algebraic Bethe ansatz constructs the commuting operators of the phase model as Schur polynomials, with non-commuting hopping operators as arguments. These non-commutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n) fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.

  20. Introduction of structural affinity handles as a tool in selective nucleic acid separations

    Science.gov (United States)

    Willson, III, Richard Coale (Inventor); Cano, Luis Antonio (Inventor)

    2011-01-01

    The method is used for separating nucleic acids and other similar constructs. It involves selective introduction, enhancement, or stabilization of affinity handles such as single-strandedness in the undesired (or desired) nucleic acids as compared to the usual structure (e.g., double-strandedness) of the desired (or undesired) nucleic acids. The undesired (or desired) nucleic acids are separated from the desired (or undesired) nucleic acids due to capture by methods including but not limited to immobilized metal affinity chromatography, immobilized single-stranded DNA binding (SSB) protein, and immobilized oligonucleotides. The invention is useful to: remove contaminating genomic DNA from plasmid DNA; remove genomic DNA from plasmids, BACs, and similar constructs; selectively separate oligonucleotides and similar DNA fragments from their partner strands; purification of aptamers, (deoxy)-ribozymes and other highly structured nucleic acids; Separation of restriction fragments without using agarose gels; manufacture recombinant Taq polymerase or similar products that are sensitive to host genomic DNA contamination; and other applications.

  1. Proteomic analysis of Trypanosoma cruzi developmental stages using isotope-coded affinity tag reagents.

    Science.gov (United States)

    Paba, Jaime; Ricart, Carlos A O; Fontes, Wagner; Santana, Jaime M; Teixeira, Antonio R L; Marchese, Jason; Williamson, Brian; Hunt, Tony; Karger, Barry L; Sousa, Marcelo V

    2004-01-01

    Comparative proteome analysis of developmental stages of the human pathogen Trypanosoma cruzi was carried out by isotope-coded affinity tag technology (ICAT) associated with liquid cromatography-mass spectrometry peptide sequencing (LC-MS/MS). Protein extracts of the protozoan trypomastigote and amastigote stages were labeled with heavy (D8) and light (D0) ICAT reagents and subjected to cation exchange and avidin affinity chromatographies followed by LC-MS/MS analysis. High confidence sequence information and expression levels for 41 T. cruzi polypeptides, including metabolic enzymes, paraflagellar rod components, tubulins, and heat-shock proteins were reported. Twenty-nine proteins displayed similar levels of expression in both forms of the parasite, nine proteins presented higher levels in trypomastigotes, whereas three were more expressed in amastigotes. PMID:15253433

  2. Proteomic analysis of phosphoproteins sensitive to a phosphatidylinositol 3-kinase inhibitor, ZSTK474, by using SELDI-TOF MS

    OpenAIRE

    Yamori Takao; Akashi Tetsuyuki

    2009-01-01

    Abstract Background Phosphoproteins play important roles in a vast series of biological processes. Recent proteomic technologies offer the comprehensive analyses of phosphoproteins. Recently, we demonstrated that surface-enhanced laser desorption/ionization time of flight mass (SELDI-TOF MS) would detect phosphoproteins quantitatively, which was a new application of SELDI-TOF MS. Results We combined immobilized metal affinity chromatography (IMAC) with SELDI-TOF MS. After SELDI-TOF MS analysi...

  3. Enrichment and Analysis of Intact Phosphoproteins in Arabidopsis Seedlings

    OpenAIRE

    Aryal, Uma K.; Ross, Andrew R.S.; Krochko, Joan E.

    2015-01-01

    Protein phosphorylation regulates diverse cellular functions and plays a key role in the early development of plants. To complement and expand upon previous investigations of protein phosphorylation in Arabidopsis seedlings we used an alternative approach that combines protein extraction under non-denaturing conditions with immobilized metal-ion affinity chromatography (IMAC) enrichment of intact phosphoproteins in Rubisco-depleted extracts, followed by identification using two-dimensional ge...

  4. Simple detection of phosphoproteins in SDS-PAGE by quercetin

    OpenAIRE

    Xi Wang; Maowei Ni; Chao Niu; Xinliang Zhu; Ting Zhao; Zhongxin Zhu; Yuanhu Xuan; Weitao Cong

    2014-01-01

    A novel fluorescence-based staining method was developed for phosphoprotein analysis in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Similar to the mechanism of immobilized metal ion affinity chromatography (IMAC), the method employed quercetin–aluminum (III)-appended complex as a fluoroprobe to selectively visualize phosphorylated proteins among total proteins. According to the results, as low as 16–32 ng of phosphoproteins (α-casein, β-casein and phosvitin) could be...

  5. Expression of a Vacuole-Localized BURP-Domain Protein from Soybean (SALI3-2) Enhances Tolerance to Cadmium and Copper Stresses

    OpenAIRE

    Tang, Yulin; Cao, Yan; Qiu, Jianbin; Gao, Zhan; Ou, Zhonghua; Wang, Yajing; Zheng, Yizhi

    2014-01-01

    The plant-specific BURP family proteins play diverse roles in plant development and stress responses, but the function mechanism of these proteins is still poorly understood. Proteins in this family are characterized by a highly conserved BURP domain with four conserved Cys-His repeats and two other Cys, indicating that these proteins potentially interacts with metal ions. In this paper, an immobilized metal affinity chromatography (IMAC) assay showed that the soybean BURP protein SALI3-2 cou...

  6. Affine Projection Algorithm Using Regressive Estimated Error

    OpenAIRE

    Zhang, Shu; Zhi, Yongfeng

    2011-01-01

    An affine projection algorithm using regressive estimated error (APA-REE) is presented in this paper. By redefining the iterated error of the affine projection algorithm (APA), a new algorithm is obtained, and it improves the adaptive filtering convergence rate. We analyze the iterated error signal and the stability for the APA-REE algorithm. The steady-state weights of the APA-REE algorithm are proved to be unbiased and consist. The simulation results show that the proposed algorithm has a f...

  7. Control and estimation of piecewise affine systems

    CERN Document Server

    Xu, Jun

    2014-01-01

    As a powerful tool to study nonlinear systems and hybrid systems, piecewise affine (PWA) systems have been widely applied to mechanical systems. Control and Estimation of Piecewise Affine Systems presents several research findings relating to the control and estimation of PWA systems in one unified view. Chapters in this title discuss stability results of PWA systems, using piecewise quadratic Lyapunov functions and piecewise homogeneous polynomial Lyapunov functions. Explicit necessary and sufficient conditions for the controllability and reachability of a class of PWA systems are

  8. Periodic cyclic homology of affine Hecke algebras

    CERN Document Server

    Solleveld, Maarten

    2009-01-01

    This is the author's PhD-thesis, which was written in 2006. The version posted here is identical to the printed one. Instead of an abstract, the short list of contents: Preface 5 1 Introduction 9 2 K-theory and cyclic type homology theories 13 3 Affine Hecke algebras 61 4 Reductive p-adic groups 103 5 Parameter deformations in affine Hecke algebras 129 6 Examples and calculations 169 A Crossed products 223 Bibliography 227 Index 237 Samenvatting 245 Curriculum vitae 253

  9. The Affine q-Schur algebra

    OpenAIRE

    Green, R. M.

    1997-01-01

    We introduce an analogue of the $q$-Schur algebra associated to Coxeter systems of type $\\hat A_{n-1}$. We give two constructions of this algebra. The first construction realizes the algebra as a certain endomorphism algebra arising from an affine Hecke algebra of type $\\hat A_{r-1}$, where $n \\geq r$. This generalizes the original $q$-Schur algebra as defined by Dipper and James, and the new algebra contains the ordinary $q$-Schur algebra and the affine Hecke algebra as subalgebras. Using th...

  10. Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

    OpenAIRE

    Chin-Soon Chee; Irene Kit-Ping Tan; Zazali Alias

    2014-01-01

    Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was r...

  11. Study of DNA oligonucleotides interactions with ethidium bromide by partial-filling affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Růžička, Martin; Koval, Dušan; Kašička, Václav

    Olomouc: Palacký University, 2014 - (Maier, V.; Ševčík, J.), s. 194-195 ISBN 978-80-244-3950-1. ISSN 0232-0061. [Advances in Chromatography and Electrophoresis & Chiranal 2014. Olomouc (CZ), 10.02.2014-14.02.2014] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * binding constant * oligonucleotide Subject RIV: CB - Analytical Chemistry, Separation

  12. Dephosphorylation of Phytate by Using the Aspergillus niger Phytase with a High Affinity for Phytate

    OpenAIRE

    Nagashima, Tadashi; Tange, Tatsuya; Anazawa, Hideharu

    1999-01-01

    A phytase (EC 3.1.3.8) with a high affinity for phytic acid was found in Aspergillus niger SK-57 and purified to homogeneity in four steps by using ion-exchange chromatography (two types), gel filtration, and chromatofocusing. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme gave a single stained band at a molecular mass of approximately 60 kDa. The Michaelis constant of the enzyme for phytic acid (18.7 ± 4.6 μM) was statistically analyzed. In regard to the ort...

  13. Crossing Chris: Some Markerian Affinities

    Directory of Open Access Journals (Sweden)

    Adrian Martin

    2010-01-01

    -pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

    Abstract (E: This essay creatively explores a group of artists, writers, and other special individuals whose work or life story can be described as having an intriguing affinity with the protean career of Chris Marker. Avoiding the ‘usual suspects’ (such as Godard or Sebald, it discusses gossip columnist Milt Machlin, record collector Harry Smith, painter Gianfranco Baruchello, writer-filmmaker Edgardo Cozarinsky, and several others. From this constellation, a particular view of Markerian poetics emerges, touching upon the meanings of anonymity, storytelling, history and archiving.

     

    Abstract (F: Cet essai brosse de manière créative le portrait d’un groupe d'artistes, d'écrivains et d'autres personnes particulières dont le travail ou la biographie peuvent être décrits comme montrant une étrange mais certaine connivence avec la carrière protéiforme de Chris Marker. Evitant les lieux communs (comme Godard ou Sebald, cet article trace des références moins attendues :

  14. Isolation of chimaeric forms of elongation factor EF-Tu by affinity chromatography

    Czech Academy of Sciences Publication Activity Database

    Šanderová, Hana; Krásný, Libor; Jonák, Jiří

    2002-01-01

    Roč. 770, 1-2 (2002), s. 129-135. ISSN 1570-0232 R&D Projects: GA ČR GA204/98/0863 Institutional research plan: CEZ:AV0Z5052915 Keywords : elongation factor EF-Tu, chimeric protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.913, year: 2002

  15. Affinity chromatography reveals RuBisCO as an ecdysteroid-binding protein

    Czech Academy of Sciences Publication Activity Database

    Uhlík, Ondřej; Kamlar, Marek; Kohout, Ladislav; Ježek, Rudolf; Harmatha, Juraj; Macek, Tomáš

    2008-01-01

    Roč. 73, č. 14 (2008), s. 1433-1440. ISSN 0039-128X R&D Projects: GA MŠk 1M06030 Institutional research plan: CEZ:AV0Z40550506 Keywords : ecdysteroids * RuBisCO * regulation * binding protein Subject RIV: CC - Organic Chemistry Impact factor: 2.588, year: 2008

  16. Conformational plasticity of IgG during protein A affinity chromatography.

    Science.gov (United States)

    Gagnon, Pete; Nian, Rui

    2016-02-12

    Single step elution of a protein A column with 100mM acetate pH 3.5 produced a curvilinear gradient with pH dropping steeply at first then more gradually as it approached endpoint. IgG with a native hydrodynamic diameter of 11.5 nm began to elute at pH 6.0 with a size of 9.4 nm. IgG size continued to decrease across the peak, reaching a minimum of 2.2 nm at pH 3.9. Secondary structure of early eluting IgG was only mildly affected but later eluting fractions became increasingly non-native with the 2.2 nm population exhibiting the highest proportion of β-sheet and lowest random coil of all conformations. Size reduction and structural change of IgG through this portion of the elution peak were attributed dominantly to a pre-existing tendency of highly concentrated IgG to adopt reduced size conformations at low pH and conductivity, facilitated by the known conformational relaxation of IgG by its interaction with protein A. IgG size increased to 10.4 nm as elution pH approached 3.5 across the tailing fractions. Major loss of β-sheet and increase of α-helix and random coil were observed in parallel. Late elution of this population was attributed to it being eluted from interactions with 2 distinct protein A domains, one bound to each side of the Fc region, creating a higher dissociation constant than single-site Fc-protein A interactions, and requiring more severely disruptive conditions for elution. The high degree of conformational disruption was attributed to simultaneous interaction of both heavy chains with protein A. PMID:26805601

  17. Streamlining the Pipeline for Generation of Recombinant Affinity Reagents by Integrating the Affinity Maturation Step

    Directory of Open Access Journals (Sweden)

    Renhua Huang

    2015-09-01

    Full Text Available Often when generating recombinant affinity reagents to a target, one singles out an individual binder, constructs a secondary library of variants, and affinity selects a tighter or more specific binder. To enhance the throughput of this general approach, we have developed a more integrated strategy where the “affinity maturation” step is part of the phage-display pipeline, rather than a follow-on process. In our new schema, we perform two rounds of affinity selection, followed by error-prone PCR on the pools of recovered clones, generation of secondary libraries, and three additional rounds of affinity selection, under conditions of off-rate competition. We demonstrate the utility of this approach by generating low nanomolar fibronectin type III (FN3 monobodies to five human proteins: ubiquitin-conjugating enzyme E2 R1 (CDC34, COP9 signalosome complex subunit 5 (COPS5, mitogen-activated protein kinase kinase 5 (MAP2K5, Splicing factor 3A subunit 1 (SF3A1 and ubiquitin carboxyl-terminal hydrolase 11 (USP11. The affinities of the resulting monobodies are typically in the single-digit nanomolar range. We demonstrate the utility of two binders by pulling down the targets from a spiked lysate of HeLa cells. This integrated approach should be applicable to directed evolution of any phage-displayed affinity reagent scaffold.

  18. Streamlining the Pipeline for Generation of Recombinant Affinity Reagents by Integrating the Affinity Maturation Step.

    Science.gov (United States)

    Huang, Renhua; Gorman, Kevin T; Vinci, Chris R; Dobrovetsky, Elena; Gräslund, Susanne; Kay, Brian K

    2015-01-01

    Often when generating recombinant affinity reagents to a target, one singles out an individual binder, constructs a secondary library of variants, and affinity selects a tighter or more specific binder. To enhance the throughput of this general approach, we have developed a more integrated strategy where the "affinity maturation" step is part of the phage-display pipeline, rather than a follow-on process. In our new schema, we perform two rounds of affinity selection, followed by error-prone PCR on the pools of recovered clones, generation of secondary libraries, and three additional rounds of affinity selection, under conditions of off-rate competition. We demonstrate the utility of this approach by generating low nanomolar fibronectin type III (FN3) monobodies to five human proteins: ubiquitin-conjugating enzyme E2 R1 (CDC34), COP9 signalosome complex subunit 5 (COPS5), mitogen-activated protein kinase kinase 5 (MAP2K5), Splicing factor 3A subunit 1 (SF3A1) and ubiquitin carboxyl-terminal hydrolase 11 (USP11). The affinities of the resulting monobodies are typically in the single-digit nanomolar range. We demonstrate the utility of two binders by pulling down the targets from a spiked lysate of HeLa cells. This integrated approach should be applicable to directed evolution of any phage-displayed affinity reagent scaffold. PMID:26437402

  19. Experimental Immunization Based on Plasmodium Antigens Isolated by Antibody Affinity

    Science.gov (United States)

    Kamali, Ali N.; Marín-García, Patricia; Azcárate, Isabel G.; Puyet, Antonio; Diez, Amalia; Bautista, José M.

    2015-01-01

    Vaccines blocking malaria parasites in the blood-stage diminish mortality and morbidity caused by the disease. Here, we isolated antigens from total parasite proteins by antibody affinity chromatography to test an immunization against lethal malaria infection in a murine model. We used the sera of malaria self-resistant ICR mice to lethal Plasmodium yoelii yoelii 17XL for purification of their IgGs which were subsequently employed to isolate blood-stage parasite antigens that were inoculated to immunize BALB/c mice. The presence of specific antibodies in vaccinated mice serum was studied by immunoblot analysis at different days after vaccination and showed an intensive immune response to a wide range of antigens with molecular weight ranging between 22 and 250 kDa. The humoral response allowed delay of the infection after the inoculation to high lethal doses of P. yoelii yoelii 17XL resulting in a partial protection against malaria disease, although final survival was managed in a low proportion of challenged mice. This approach shows the potential to prevent malaria disease with a set of antigens isolated from blood-stage parasites. PMID:26539558

  20. General super Virasoro construction on affine G

    International Nuclear Information System (INIS)

    We consider a bosonic current algebra and a theory of free fermions and construct a general N = 1 super Virasoro current algebra. We obtain a master-set of equations which comprises the bosonic master equation for general Virasoro construction on affine G. As an illustration we study the case of the group SU(2). (author). 13 refs

  1. Classification of neocortical interneurons using affinity propagation

    Directory of Open Access Journals (Sweden)

    Roberto eSantana

    2013-12-01

    Full Text Available In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. Neuronal classification has been a difficult problem because it is unclear what a neuronal cell class actually is and what are the best characteristics are to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological or molecular characteristics, when applied to selected datasets, have provided quantitative and unbiased identification of distinct neuronal subtypes. However, better and more robust classification methods are needed for increasingly complex and larger datasets. We explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. In fact, using a combined anatomical/physiological dataset, our algorithm differentiated parvalbumin from somatostatin interneurons in 49 out of 50 cases. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits.

  2. Colliding waves in metric-affine gravity

    CERN Document Server

    García, A; Macías, A; Mielke, E W; Socorro, J; García, Alberto; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.; Socorro, José

    1998-01-01

    We generalize the formulation of the colliding gravitational waves to metric-affine theories and present an example of such kind of exact solutions. The plane waves are equipped with five symmetries and the resulting geometry after the collision possesses two spacelike Killing vectors.

  3. Spin projection chromatography

    OpenAIRE

    Danieli, Ernesto P.; Pastawski, Horacio M.; Levstein, Patricia R.

    2003-01-01

    We formulate the many-body spin dynamics at high temperature within the non-equilibrium Keldysh formalism. For the simplest XY interaction, analytical expressions in terms of the one particle solutions are obtained for linear and ring configurations. For small rings of even spin number, the group velocities of excitations depend on the parity of the total spin projection. This should enable a dynamical filtering of spin projections with a given parity i.e. a Spin projection chromatography.

  4. Hydrophobic interaction chromatography

    OpenAIRE

    O'Connor, Brendan; Cummins, Phil

    2011-01-01

    Most proteins and large polypeptides have hydrophobic regions at their surface. These hydrophobic ‘patches’ are due to the presence of the side chains of hydrophobic or non-polar amino acids such as phenylalanine, tryptophan, alanine and methionine. These surface hydrophobic regions are interspersed between more hydrophilic or polar regions and the number, size and distribution of them is a specific characteristic of each protein. Hydrophobic Interaction Chromatography (HIC) is a commonly use...

  5. Spin projection chromatography

    Science.gov (United States)

    Danieli, E. P.; Pastawski, H. M.; Levstein, P. R.

    2004-01-01

    We formulate the many-body spin dynamics at high temperature within the non-equilibrium Keldysh formalism. For the simplest XY interaction, analytical expressions in terms of the one particle solutions are obtained for linear and ring configurations. For small rings of even spin number, the group velocities of excitations depend on the parity of the total spin projection. This should enable a dynamical filtering of spin projections with a given parity i.e., a spin projection chromatography.

  6. Artificial Affinity Proteins as Ligands of Immunoglobulins

    Directory of Open Access Journals (Sweden)

    Barbara Mouratou

    2015-01-01

    Full Text Available A number of natural proteins are known to have affinity and specificity for immunoglobulins. Some of them are widely used as reagents for detection or capture applications, such as Protein G and Protein A. However, these natural proteins have a defined spectrum of recognition that may not fit specific needs. With the development of combinatorial protein engineering and selection techniques, it has become possible to design artificial affinity proteins with the desired properties. These proteins, termed alternative scaffold proteins, are most often chosen for their stability, ease of engineering and cost-efficient recombinant production in bacteria. In this review, we focus on alternative scaffold proteins for which immunoglobulin binders have been identified and characterized.

  7. Improved native affinity purification of RNA.

    Science.gov (United States)

    Batey, Robert T; Kieft, Jeffrey S

    2007-08-01

    RNA biochemical or structural studies often require an RNA sample that is chemically pure, and most protocols for its in vitro production use denaturing polyacrylamide gel electrophoresis to achieve this. Unfortunately, many RNAs do not quantitatively refold into an active conformation after denaturation, creating significant problems for downstream characterization or use. In addition, this traditional purification method is not amenable to studies demanding high-throughput RNA production. Recently, we presented the first general method for producing almost any RNA sequence that employs an affinity tag that is removed during the purification process. Because technical difficulties prevented application of this method to many RNAs, we have developed an improved version that utilizes a different activatable ribozyme and affinity tag that are considerably more robust, rapid, and broadly applicable. PMID:17548432

  8. AFFINITY OF LIGNIN PREPARATIONS TOWARDS GENOTOXIC COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Božena Košíková

    2009-02-01

    Full Text Available The carcinogenicity and mutagenicity of chemicals may be modulated by other chemicals, including those prepared by organic synthesis. Consid-ering the several drawbacks of synthetic compounds vis-a-vis the human organism, the lignin biomass component was examined for this purpose. The binding affinity of lignin samples prepared by chemical and biological modification of lignin products derived from chemical wood treatment towards for N-nitrosodiethylamine (NDA was examined. The protective role of the lignin samples against carcinogenesis was tested on a well-known model carcinogen, N-methyl-N´-nitro-N-nitrosoguanidine (MNNG. The observed ability of a series of lignin preparations to reduce alkylation damage of deoxyribonucleic acid (DNA on hamster cells in vitro could be explained by their affinity to bind N-nitrosoamines. The results indicate that lignin has potential to protect living organisms against damaging effects of different genotoxicants.

  9. Purification of high affinity benzodiazepine receptor binding site fragments from rat brain

    International Nuclear Information System (INIS)

    In central nervous system benzodiazepine recognition sites occur on neuronal cell surfaces as one member of a multireceptor complex, including recognition sites for benzodiazepines, gamma aminobutyric acid (GABA), barbiturates and a chloride ionophore. During photoaffinity labelling, the benzodiazepine agonist, 3H-flunitrazepam, is irreversibly bound to central benzodiazepine high affinity recognition sites in the presence of ultraviolet light. In these studies a 3H-flunitrazepam radiolabel was used to track the isolation and purification of high affinity agonist binding site fragments from membrane-bound benzodiazepine receptor in rat brain. The authors present a method for limited proteolysis of 3H-flunitrazepam photoaffinity labeled rat brain membranes, generating photolabeled benzodiazepine receptor fragments containing the agonist binding site. Using trypsin chymotrypsin A4, or a combination of these two proteases, they have demonstrated the extent and time course for partial digestion of benzodiazepine receptor, yielding photolabeled receptor binding site fragments. These photolabeled receptor fragments have been further purified on the basis of size, using ultrafiltration, gel permeation chromatography, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) as well as on the basis of hydrophobicity, using a high performance liquid chromatography (HPLC) precolumn, several HPLC elution schemes, and two different HPLC column types. Using these procedures, they have purified three photolabeled benzodiazepine receptor fragments containing the agonist binding site which appear to have a molecular weight of less than 2000 daltons each

  10. High-affinity neuropeptide Y receptor antagonists.

    OpenAIRE

    Daniels, A J; Matthews, J. E.; Slepetis, R J; Jansen, M; Viveros, O. H.; Tadepalli, A.; Harrington, W; Heyer, D; Landavazo, A; Leban, J J

    1995-01-01

    Neuropeptide Y (NPY) is one of the most abundant peptide transmitters in the mammalian brain. In the periphery it is costored and coreleased with norepinephrine from sympathetic nerve terminals. However, the physiological functions of this peptide remain unclear because of the absence of specific high-affinity receptor antagonists. Three potent NPY receptor antagonists were synthesized and tested for their biological activity in in vitro, ex vivo, and in vivo functional assays. We describe he...

  11. Staircase models from affine Toda field theory

    International Nuclear Information System (INIS)

    The authors propose a class of purely elastic scattering theories generalizing the staircase model of Al. B. Zamolodchikov, based on the affine Toda field theories for simply-laced Lie algebras g = A,D,E at suitable complex values of their coupling constants. Considering their Thermodynamic Bethe Ansatz equations, they give analytic arguments in support of a conjectured renormalization group flow visiting the neighborhood of each Wg minimal model in turn

  12. AFFINE TRANSFORMATION IN RANDOM ITERATED FUNCTION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    熊勇; 史定华

    2001-01-01

    Random iterated function systems (IFSs) is discussed, which is one of the methods for fractal drawing. A certain figure can be reconstructed by a random IFS. One approach is presented to determine a new random IFS, that the figure reconstructed by the new random IFS is the image of the origin figure reconstructed by old IFS under a given affine transformation. Two particular examples are used to show this approach.

  13. Homogeneous grading affine Toda quantum solitons

    Czech Academy of Sciences Publication Activity Database

    Zuevsky, Alexander

    Vol. 563. Bristol : IOP Science, 2014 - (Burdik, C.; Navratil, O.; Posta, S.), 012036 ISSN 1742-6588. [International Conference on Integrable Systems and Quantum Symmetries (ISQS-22) /22./. Prague (CZ), 26.06.2014-29.06.-2014] Institutional support: RVO:67985840 Keywords : exactly solvable models * conformal and affine Toda systems * quantum groups Subject RIV: BA - General Mathematics http://iopscience.iop.org/1742-6596/563/1/012036

  14. Denominators in cluster algebras of affine type

    OpenAIRE

    Buan, Aslak Bakke; Marsh, Robert J.

    2008-01-01

    The Fomin-Zelevinsky Laurent phenomenon states that every cluster variable in a cluster algebra can be expressed as a Laurent polynomial in the variables lying in an arbitrary initial cluster. We give representation-theoretic formulas for the denominators of cluster variables in cluster algebras of affine type. The formulas are in terms of the dimensions of spaces of homomorphisms in the corresponding cluster category, and hold for any choice of initial cluster.

  15. Thermodynamics. Using Affinities to define reversible processes

    CERN Document Server

    Ritacco, Hernán A

    2016-01-01

    In this article a definition of reversible processes in terms of differences in intensive Thermodynamics properties (Affinities) is proposed. This definition makes it possible to both define reversible processes before introducing the concept of entropy and avoid the circularity problem that follows from the Clausius definition of entropy changes. The convenience of this new definition compared to those commonly found in textbooks is demonstrated with examples.

  16. On constructing purely affine theories with matter

    Science.gov (United States)

    Cervantes-Cota, Jorge L.; Liebscher, D.-E.

    2016-08-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schrödinger's purely affine theory (Schrödinger in Space-time structure. Cambridge UP, Cambridge, 1950), where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  17. On constructing purely affine theories with matter

    CERN Document Server

    Cervantes-Cota, Jorge L

    2016-01-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schroedinger's purely affine theory [21], where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  18. Overview of affinity biosensors in food analysis.

    Science.gov (United States)

    Patel, Pradip D

    2006-01-01

    The 4 major driving forces that are expected to lead to increased use of affinity biosensors that meet crucial industrial test specifications, e.g., fast, reliable, cost-effective, and use of low-skilled personnel, are (1) strict legislative framework, e.g., recent changes proposed to the European food safety and hygiene legislation, EC No. 178/2002; (2) industrial shift from quality control to quality assurance procedures, e.g., Hazard Analysis Critical Control Point, ensuring effective positioning in the global competitive trade; (3) just-in-time production resulting in 'right' product every time; and (4) consumer demand for safe and wholesome products. The affinity biosensors field has expanded significantly over the past decade, with a projected global biosensors market growth from $6.1 billion in 2004 to $8.2 billion in 2009, representing major industrial sectors (e.g., Pharma, Medicare, and Food). This brief review is targeted to affinity biosensors developed for the food industry and includes research and development leading to biosensors for microbiological and chemical analytes of industrial concern, commercial biosensors products on the market, and examples of future prospects in this diagnostic field. PMID:16792079

  19. A MEMS Dielectric Affinity Glucose Biosensor.

    Science.gov (United States)

    Huang, Xian; Li, Siqi; Davis, Erin; Li, Dachao; Wang, Qian; Lin, Qiao

    2013-06-20

    Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concentrations. This sensor features simplicity in sensor design, and possesses high specificity and accuracy in glucose detection. However, lack of glucose diffusion passage, this device is unable to fulfill real-time in-vivo monitoring. As a major improvement to this device, we present in this paper a fully implantable MEMS dielectric affinity glucose biosensor that contains a perforated electrode embedded in a suspended diaphragm. This capacitive-based sensor contains no moving parts, and enables glucose diffusion and real-time monitoring. The experimental results indicate that this sensor can detect glucose solutions at physiological concentrations and possesses good reversibility and reliability. This sensor has a time constant to glucose concentration change at approximately 3 min, which is comparable to commercial systems. The sensor has potential applications in fully implantable CGM that require excellent long-term stability and reliability. PMID:24511215

  20. Selection of a high-affinity and in vivo bioactive ssDNA aptamer against angiotensin II peptide.

    Science.gov (United States)

    Heiat, Mohammad; Ranjbar, Reza; Latifi, Ali Mohammad; Rasaee, Mohammad Javad

    2016-08-01

    Unique features of aptamers have attracted interests for a broad range of applications. Aptamers are able to specifically bind to targets and inhibit their functions. This study, aimed to isolate the high affinity ssDNA aptamers against bio-regulator peptide angiotensin II (Ang II) and investigate their bioactivity in cellular and animal models. To isolate ssDNA aptamers, 12 rounds of affinity chromatography SELEX (Systematic Evolution of Ligands by EXponential enrichment) procedure were carried out. The SPR (surface plasmon resonance) and ELONA (enzyme linked oligonucleotide assay) analysis were used to determine the affinity and specificity of aptamers. The ability of selected aptamers to inhibit the proliferative effect of Ang II on human aortic vascular smooth muscle cells (HA-VSMCs) and their performance on Wistar rat urinary system and serum electrolyte levels were investigated. Two full-length aptamers (FLC112 and FLC125) with high affinity of respectively 7.52±2.44E-10 and 5.87±1.3E-9M were isolated against Ang II. The core regions of these aptamers (CRC112 and CRC125) also showed affinity of 5.33±1.15E-9 and 4.11±1.09E-9M. In vitro analysis revealed that FLC112 and FLC125 can inhibit the proliferative effect of Ang II on HA-VSMCs (Psodium level and increased the urine volume (Pbioactive aptamers may lead to excellent results in blocking Ang II activity. PMID:27298205

  1. Quelques remarques sur la notion de modification affine

    OpenAIRE

    Dubouloz, Adrien

    2005-01-01

    in french We construct a global counterpart to the notion of affine modification due to Kaliman and Zaidenberg. This leads to a simple explicit description of the structure of birational affine morphisms between arbitrary quasi-projective varieties.

  2. A multiscale framework for affine invariant pattern recognition and registration

    OpenAIRE

    Rahtu, E. (Esa)

    2007-01-01

    Abstract This thesis presents a multiscale framework for the construction of affine invariant pattern recognition and registration methods. The idea in the introduced approach is to extend the given pattern to a set of affine covariant versions, each carrying slightly different information, and then to apply known affine invariants to each of them separately. The key part of the framework is the construction of the affine covariant set, and this is done by combining several scaled represen...

  3. Duals of Affine Grassmann Codes and Their Relatives

    DEFF Research Database (Denmark)

    Beelen, P.; Ghorpade, S. R.; Hoholdt, T.

    2012-01-01

    Affine Grassmann codes are a variant of generalized Reed-Muller codes and are closely related to Grassmann codes. These codes were introduced in a recent work by Beelen Here, we consider, more generally, affine Grassmann codes of a given level. We explicitly determine the dual of an affine Grassm...

  4. Multiplex gas chromatography

    Science.gov (United States)

    Valentin, Jose R.

    1990-01-01

    The principles of the multiplex gas chromatography (GC) technique, which is a possible candidate for chemical analysis of planetary atmospheres, are discussed. Particular attention is given to the chemical modulators developed by present investigators for multiplex GC, namely, the thermal-desorption, thermal-decomposition, and catalytic modulators, as well as to mechanical modulators. The basic technique of multiplex GC using chemical modulators and a mechanical modulator is demonstrated. It is shown that, with the chemical modulators, only one gas stream consisting of the carrier in combination with the components is being analyzed, resulting in a simplified instrument that requires relatively few consumables. The mechanical modulator demonstrated a direct application of multiplex GC for the analysis of gases in atmosphere of Titan at very low pressures.

  5. Microemulsion electrokinetic chromatography.

    Science.gov (United States)

    Buchberger, Wolfgang W

    2008-01-01

    Microemulsion electrokinetic chromatography (MEEKC) is an attractive capillary electrophoretic technique in which a microemulsion is used as carrier electrolyte. Analytes may partition between the aqueous phase of the microemulsion and its oil droplets, which act as a pseudostationary phase. It is well suited for the separation of neutral analytes, but can also be employed for charged analytes. A single set of separation parameters may be sufficient for separation of a wide range of analytes. Fine-tuning of the separation may be achieved by addition of organic solvents to the microemulsion or by changes in the nature of the surfactant used for stabilization of the microemulsion. In this chapter, MEEKC conditions are summarized that have proven their reliability for routine purposes. Furthermore, microemulsions can be used for on-capillary preconcentration of analytes so that the problem of poor concentration sensitivity of ultraviolet detection in capillary electrophoresis is circumvented. PMID:18392591

  6. Avoiding degenerate coframes in an affine gauge approach to quantum gravity

    International Nuclear Information System (INIS)

    This report discusses the following concepts on quantum gravity: The affine gauge approach; affine gauge transformations versus active differomorphisms; affine gauge approach to quantum gravity with topology change

  7. On Metrizability of Invariant Affine Connections

    CERN Document Server

    Tanaka, Erico

    2011-01-01

    The metrizability problem for a symmetric affine connection on a manifold, invariant with respect to a group of diffeomorphisms G, is considered. We say that the connection is G-metrizable, if it is expressible as the Levi-Civita connection of a G-invariant metric field. In this paper we analyze the G-metrizability equations for the rotation group G = SO(3), acting canonically on three- and four-dimensional Euclidean spaces. We show that the property of the connection to be SO(3)-invariant allows us to find complete explicit description of all solutions of the SO(3)-metrizability equations.

  8. Quantum affine symmetry in vertex models

    CERN Document Server

    Idzumi, M; Jimbo, M; Miwa, T; Nakashima, T; Tokihiro, T; Idzumi, Makoto; Iohara, Kenji; Jimbo, Michio; Miwa, Tetsuji; Nakashima, Toshiki; Tokihiro, Tetsuji

    1993-01-01

    We study the higher spin anologs of the six vertex model on the basis of its symmetry under the quantum affine algebra $U_q(\\slth)$. Using the method developed recently for the XXZ spin chain, we formulate the space of states, transfer matrix, vacuum, creation/annihilation operators of particles, and local operators, purely in the language of representation theory. We find that, regardless of the level of the representation involved, the particles have spin $1/2$, and that the $n$-particle space has an RSOS-type structure rather than a simple tensor product of the $1$-particle space. This agrees with the picture proposed earlier by Reshetikhin.

  9. Connection between the Affine and conformal Affine Toda models and their Hirota's solution

    International Nuclear Information System (INIS)

    It is shown that the Affine Toda models (AT) constitute a gauge fixed version of the Conformal Affine Toda model (CAT). This result enables one to map every solution of the AT models into an infinite number of solutions of the corresponding CAT models, each one associated to a point of the orbit of the conformal group. The Hirota's τ-function are introduced and soliton solutions for the AT and CAT models associated to SL (r+1) and SP (r) are constructed. (author)

  10. A novel phosphate-affinity bead with immobilized Phos-tag for separation and enrichment of phosphopeptides and phosphoproteins

    Directory of Open Access Journals (Sweden)

    Chika Inoue

    2011-01-01

    Full Text Available A simple and efficient method was developed for separating and enriching phosphoproteins from crude biological samples containing solubil-ized cellular proteins by immobilized zinc(II affinity chromatography. The phosphate-binding site of the affinity gel is an alkoxide-bridged dinuclear zinc(II complex, Phos-tag, which is linked to a hydrophilic vinylic polymer bead. A novel phosphate-affinity bead (Phos-tag Toyopearl was prepared by reaction of N-hydroxysuccinimide-activated Toyopearl AF-Carboxy-650M gel with a 2-aminoethylcarbamoyl de-rivative of Phos-tag. Phosphopeptides were retrieved quantitatively and selectively on a µL-scale column at room temperature. The column was stable for long-term storage and could be reused many times. The technique was used to separate and enrich phosphoproteins from an epider-mal growth factor-stimulated human epidermoid carcinoma A431 cell lysate. The operations necessary for 1-mL-scale open-column chroma-tography were conducted at a physiological pH during 1 h. The strong enrichment of the phosphoproteins into the eluted fraction was evaluat-ed by gel electrophoresis, followed by Western blotting with Phos-tag Biotin and several antibodies, Pro-Q Diamond phosphoprotein gel stain-ing, and mass spectrometry.

  11. Aptamer Affinity Maturation by Resampling and Microarray Selection.

    Science.gov (United States)

    Kinghorn, Andrew B; Dirkzwager, Roderick M; Liang, Shaolin; Cheung, Yee-Wai; Fraser, Lewis A; Shiu, Simon Chi-Chin; Tang, Marco S L; Tanner, Julian A

    2016-07-19

    Aptamers have significant potential as affinity reagents, but better approaches are critically needed to discover higher affinity nucleic acids to widen the scope for their diagnostic, therapeutic, and proteomic application. Here, we report aptamer affinity maturation, a novel aptamer enhancement technique, which combines bioinformatic resampling of aptamer sequence data and microarray selection to navigate the combinatorial chemistry binding landscape. Aptamer affinity maturation is shown to improve aptamer affinity by an order of magnitude in a single round. The novel aptamers exhibited significant adaptation, the complexity of which precludes discovery by other microarray based methods. Honing aptamer sequences using aptamer affinity maturation could help optimize a next generation of nucleic acid affinity reagents. PMID:27346322

  12. Induced Modules for Affine Lie Algebras

    Directory of Open Access Journals (Sweden)

    Vyacheslav Futorny

    2009-03-01

    Full Text Available We study induced modules of nonzero central charge with arbitrary multiplicities over affine Lie algebras. For a given pseudo parabolic subalgebra P of an affine Lie algebra G, our main result establishes the equivalence between a certain category of P-induced G-modules and the category of weight P-modules with injective action of the central element of G. In particular, the induction functor preserves irreducible modules. If P is a parabolic subalgebra with a finite-dimensional Levi factor then it defines a unique pseudo parabolic subalgebra P^{ps}, P subset P^{ps}. The structure of P-induced modules in this case is fully determined by the structure of P^{ps}-induced modules. These results generalize similar reductions in particular cases previously considered by V. Futorny, S. König, V. Mazorchuk [Forum Math. 13 (2001, 641-661], B. Cox [Pacific J. Math. 165 (1994, 269-294] and I. Dimitrov, V. Futorny, I. Penkov [Comm. Math. Phys. 250 (2004, 47-63].

  13. Aspects of affine Toda field theory

    International Nuclear Information System (INIS)

    The report is devoted to properties of the affine Toda field theory, the intention being to highlight a selection of curious properties that should be explicable in terms of the underlying group theory but for which in most cases there are no explanation. The motivation for exploring the ideas contained in this report came principally from the recent work of Zamolodchikov concerning the two dimensional Ising model at critical temperature perturbed by a magnetic field. Hollowood and Mansfield pointed out that since Toda field theory is conformal the perturbation considered by Zamolodchikov might well be best regarded as a perturbation of a Toda field theory. This work made it seem plausible that the theory sought by Zamolodchikov was actually affine E8 Toda field theory. However, this connection required an imaginary value of the coupling constant. Investigations here concerning exact S-matrices use a perturbative approach based on real coupling and the results differ in various ways from those thought to correspond to perturbed conformal field theory. A further motivation is to explore the connection between conformal and perturbed conformal field theories in other contexts using similar ideas. (N.K.)

  14. Automated Hydrophobic Interaction Chromatography Column Selection for Use in Protein Purification

    OpenAIRE

    Murphy, Patrick J. M.; Stone, Orrin J.; Anderson, Michelle E.

    2011-01-01

    In contrast to other chromatographic methods for purifying proteins (e.g. gel filtration, affinity, and ion exchange), hydrophobic interaction chromatography (HIC) commonly requires experimental determination (referred to as screening or "scouting") in order to select the most suitable chromatographic medium for purifying a given protein 1. The method presented here describes an automated approach to scouting for an optimal HIC media to be used in protein purification.

  15. Novel approaches to ionic chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, P.K.

    1990-11-01

    Research during this reporting period, continued on ionic chromatography. Major progress has been made towards on-line on-demand generation of ultrapure chemicals by electrochemical means. The concentration of the generated material is governed electrochemically.

  16. Gas chromatography: mass selective detector

    International Nuclear Information System (INIS)

    The mechanism of mass spectrometry technique directed for detecting molecular structures is described, with some considerations about its operational features. This mass spectrometer is used as a gas chromatography detector. (author)

  17. Data Stream Clustering With Affinity Propagation

    KAUST Repository

    Zhang, Xiangliang

    2014-07-09

    Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.

  18. Generalized affine transformation monoids on Galois rings

    OpenAIRE

    Yonglin Cao

    2006-01-01

    Let A be a ring with identity. The generalized affine transformation monoid Gaff(A) is defined as the set of all transformations on A of the form x↦xu+a (for all x∈A), where u,a∈A. We study the algebraic structure of the monoid Gaff(A) on a finite Galois ring A. The following results are obtained: an explicit description of Green's relations on Gaff(A); and an explicit description of the Schützenberger group of every ðÂ’Ÿ-class, which is shown to be isomorphic to the aff...

  19. Gravitational Goldstone fields from affine gauge theory

    CERN Document Server

    Tresguerres, R

    2000-01-01

    In order to facilitate the application of standard renormalization techniques, gravitation should be decribed, if possible, in pure connection formalism, as a Yang-Mills theory of a certain spacetime group, say the Poincare or the affine group. This embodies the translational as well as the linear connection. However, the coframe is not the standard Yang-Mills type gauge field of the translations, since it lacks the inhomogeneous gradient term in the gauge transformations. By explicitly restoring the "hidden" piece responsible for this behavior within the framework of nonlinear realizations, the usual geometrical interpretation of the dynamical theory becomes possible, and in addition one can avoid the metric or coframe degeneracy which would otherwise interfere with the integrations within the path integral. We claim that nonlinear realizations provide a general mathematical scheme clarifying the foundations of gauge theories of spacetime symmetries. When applied to construct the Yang-Mills theory of the aff...

  20. Effectively nonlocal metric-affine gravity

    CERN Document Server

    Golovnev, Alexey; Sandstad, Marit

    2015-01-01

    In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with non-singular and cosmologically interesting properties may be recovered. Relations between different formulations are analysed at both perturbative and nonperturbative levels taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.

  1. Effectively nonlocal metric-affine gravity

    Science.gov (United States)

    Golovnev, Alexey; Koivisto, Tomi; Sandstad, Marit

    2016-03-01

    In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric, and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with nonsingular and cosmologically interesting properties may be recovered. Relations between different formulations are analyzed at both perturbative and nonperturbative levels, taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.

  2. Affine connection form of Regge calculus

    CERN Document Server

    Khatsymovsky, V M

    2015-01-01

    Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the 3-simplices which play a role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4,R) of the connection matrices. As a result, we have some action invariant w. r. t. arbitrary change of coordinates of the vertices (and related GL(4,R) transformations in...

  3. In vitro affinity maturation of a natural human antibody overcomes a barrier to in vivo affinity maturation

    Science.gov (United States)

    Li, Bing; Fouts, Ashley E; Stengel, Katharina; Luan, Peng; Dillon, Michael; Liang, Wei-Ching; Feierbach, Becket; Kelley, Robert F; Hötzel, Isidro

    2014-01-01

    Antibodies isolated from human donors are increasingly being developed for anti-infective therapeutics. These antibodies undergo affinity maturation in vivo, minimizing the need for engineering of therapeutic leads for affinity. However, the affinities required for some therapeutic applications may be higher than the affinities of the leads obtained, requiring further affinity maturation in vitro. To improve the neutralization potency of natural human antibody MSL-109 targeting human cytomegalovirus (CMV), we affinity matured the antibody against the gH/gL glycoprotein complex. A phage display library where most of the six complementary-determining regions (CDRs) were allowed to vary in only one amino acid residue at a time was used to scan for mutations that improve binding affinity. A T55R mutation and multiple mutations in position 53 of the heavy chain were identified that, when present individually or in combination, resulted in higher apparent affinities to gH/gL and improved CMV neutralization potency of Fab fragments expressed in bacterial cells. Three of these mutations in position 53 introduced glycosylation sites in heavy chain CDR 2 (CDR H2) that impaired binding of antibodies expressed in mammalian cells. One high affinity (KD < 10 pM) variant was identified that combined the D53N and T55R mutations while avoiding glycosylation of CDR H2. However, all the amino acid substitutions identified by phage display that improved binding affinity without introducing glycosylation sites required between two and four simultaneous nucleotide mutations to avoid glycosylation. These results indicate that the natural human antibody MSL-109 is close to a local affinity optimum. We show that affinity maturation by phage display can be used to identify and bypass barriers to in vivo affinity maturation of antibodies imposed by glycosylation and codon usage. These constraints may be relatively prevalent in human antibodies due to the codon usage and the amino acid

  4. Classical affine W-algebras associated to Lie superalgebras

    International Nuclear Information System (INIS)

    In this paper, we prove classical affine W-algebras associated to Lie superalgebras (W-superalgebras), which can be constructed in two different ways: via affine classical Hamiltonian reductions and via taking quasi-classical limits of quantum affine W-superalgebras. Also, we show that a classical finite W-superalgebra can be obtained by a Zhu algebra of a classical affine W-superalgebra. Using the definition by Hamiltonian reductions, we find free generators of a classical W-superalgebra associated to a minimal nilpotent. Moreover, we compute generators of the classical W-algebra associated to spo(2|3) and its principal nilpotent. In the last part of this paper, we introduce a generalization of classical affine W-superalgebras called classical affine fractional W-superalgebras. We show these have Poisson vertex algebra structures and find generators of a fractional W-superalgebra associated to a minimal nilpotent

  5. Classical affine W-algebras associated to Lie superalgebras

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Uhi Rinn, E-mail: uhrisu1@math.snu.ac.kr [Department of Mathematical Sciences, Seoul National University, GwanAkRo 1, Gwanak-Gu, Seoul 151-747 (Korea, Republic of)

    2016-02-15

    In this paper, we prove classical affine W-algebras associated to Lie superalgebras (W-superalgebras), which can be constructed in two different ways: via affine classical Hamiltonian reductions and via taking quasi-classical limits of quantum affine W-superalgebras. Also, we show that a classical finite W-superalgebra can be obtained by a Zhu algebra of a classical affine W-superalgebra. Using the definition by Hamiltonian reductions, we find free generators of a classical W-superalgebra associated to a minimal nilpotent. Moreover, we compute generators of the classical W-algebra associated to spo(2|3) and its principal nilpotent. In the last part of this paper, we introduce a generalization of classical affine W-superalgebras called classical affine fractional W-superalgebras. We show these have Poisson vertex algebra structures and find generators of a fractional W-superalgebra associated to a minimal nilpotent.

  6. Two-dimensional turbulent flow chromatography coupled on-line to liquid chromatography-mass spectrometry for solution-based ligand screening against multiple proteins.

    Science.gov (United States)

    Zhou, Jian-Liang; An, Jing-Jing; Li, Ping; Li, Hui-Jun; Jiang, Yan; Cheng, Jie-Fei

    2009-03-20

    We present herein a novel bioseparation/chemical analysis strategy for protein-ligand screening and affinity ranking in compound mixtures, designed to increase screening rates and improve sensitivity and ruggedness in performance. The strategy is carried out by combining on-line two-dimensional turbulent flow chromatography (2D-TFC) with liquid chromatography-mass spectrometry (LC-MS), and accomplished through the following steps: (1) a reversed-phase TFC stage to separate the protein/ligand complex from the unbound free molecules, (2) an on-line dissociation process to release the bound ligands from the complexes, and (3) a second mixed-mode cation-exchange/reversed-phase TFC stage to trap the bound ligands and to remove the proteins and salts, followed by LC-MS analysis for identification and determination of the binding affinities. The technique can implement an ultra-fast isolation of protein/ligand complex with the retention time of a complex peak in about 5s, and on-line prepare the "clean" sample to be directly compatible with the LC-MS analysis. The improvement in performance of this 2D-TFC/LC-MS approach over the conventional approach has been demonstrated by determining affinity-selected ligands of the target proteins acetylcholinesterase and butyrylcholinesterase from a small library with known binding affinities and a steroidal alkaloid library composed of structurally similar compounds. Our results show that 2D-TFC/LC-MS is a generic and efficient tool for high-throughput screening of ligands with low-to-high binding affinities, and structure-activity relationship evaluation. PMID:19203758

  7. A simple nonradioactive method for the determination of the binding affinities of antibodies induced by hapten bioconjugates for drugs of abuse

    OpenAIRE

    Torres, Oscar B.; Antoline, Joshua F. G.; Li, Fuying; Jalah, Rashmi; Jacobson, Arthur E; Rice, Kenner C.; Alving, Carl R.; Matyas, Gary R.

    2015-01-01

    The accurate analytical measurement of binding affinities of polyclonal antibody in sera to heroin, 6-acetylmorphine (6-AM), and morphine has been a challenging task. A simple nonradioactive method that uses deuterium-labeled drug tracers and equilibrium dialysis (ED) combined with ultra performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) to measure the apparent dissociation constant (K d) of antibodies to 6-AM and morphine is described. The method can readily detect antib...

  8. Non-affine displacements in flexible polymer networks

    OpenAIRE

    Basu, Anindita; Wen, Qi; Mao, Xiaoming; Lubensky, T. C.; Janmey, Paul A.; Yodh, A. G.

    2010-01-01

    The validity of the affine assumption in model flexible polymer networks is explored. To this end, the displacements of fluorescent tracer beads embedded in polyacrylamide gels are quantified by confocal microscopy under shear deformation, and the deviations of these displacements from affine responses are recorded. Non-affinity within the gels is quantified as a function of polymer chain density and cross-link concentration. Observations are in qualitative agreement with current theories of ...

  9. Affine Vertex Operator Algebras and Modular Linear Differential Equations

    Science.gov (United States)

    Arike, Yusuke; Kaneko, Masanobu; Nagatomo, Kiyokazu; Sakai, Yuichi

    2016-05-01

    In this paper, we list all affine vertex operator algebras of positive integral levels whose dimensions of spaces of characters are at most 5 and show that a basis of the space of characters of each affine vertex operator algebra in the list gives a fundamental system of solutions of a modular linear differential equation. Further, we determine the dimensions of the spaces of characters of affine vertex operator algebras whose numbers of inequivalent simple modules are not exceeding 20.

  10. Affine Vertex Operator Algebras and Modular Linear Differential Equations

    Science.gov (United States)

    Arike, Yusuke; Kaneko, Masanobu; Nagatomo, Kiyokazu; Sakai, Yuichi

    2016-04-01

    In this paper, we list all affine vertex operator algebras of positive integral levels whose dimensions of spaces of characters are at most 5 and show that a basis of the space of characters of each affine vertex operator algebra in the list gives a fundamental system of solutions of a modular linear differential equation. Further, we determine the dimensions of the spaces of characters of affine vertex operator algebras whose numbers of inequivalent simple modules are not exceeding 20.

  11. Extended affine Weyl groups: Presentation by conjugation via integral collection

    OpenAIRE

    Azam, Saeid; Shahsanaei, Valiollah

    2009-01-01

    We give several necessary and sufficient conditions for the existence of {\\it the presentation by conjugation} for a non-simply laced extended affine Weyl group. We invent a computational tool by which one can determine simply the existence of the presentation by conjugation for an extended affine Weyl group. As an application, we determine the existence of the presentation by conjugation for a large class of extended affine Weyl groups.

  12. Dirac cohomology for the degenerate affine Hecke Clifford algebra

    OpenAIRE

    Chan, Kei Yuen

    2013-01-01

    We define an analogue of the Dirac operator for the degenerate affine Hecke-Clifford algebra. A main result is to relate the central characters of the degenerate affine Hecke-Clifford algebra with the central characters of the Sergeev algebra via Dirac cohomology. The action of the Dirac operator on certain modules is also computed. Results in this paper could be viewed as a projective version of the Dirac cohomology of the degenerate affine Hecke algebra.

  13. DECISION TREE ANALYSIS OF THE PREDICTORS OF INTERNET AFFINITY

    OpenAIRE

    BUBAŠ, Goran; Kliček, Božidar; Hutinski, Željko

    2001-01-01

    A recently developed model of Internet affinity was used for survey design and data collection on variables that have potential influence on affinity for Internet use. A total of 600 Croatian students with access to the Internet at their college participated in this survey. The collected data were used for investigation of the relation between decision tree analysis and regression analysis of predictor variables of Internet affinity. Different predictors were found to influence two distinct c...

  14. Nonspecific native elution of proteins and mumps virus in immunoaffinity chromatography.

    Science.gov (United States)

    Brgles, Marija; Sviben, Dora; Forčić, Dubravko; Halassy, Beata

    2016-05-20

    Immunoaffinity chromatography, based on the antigen-antibody recognition, enables specific purification of any antigen (protein, virus) by its antibody. The problem with immunoaffinity chromatography is the harsh elution conditions required for disrupting strong antigen-antibody interactions, such as low pH buffers, which are often deleterious for the immobilized protein and the protein to be isolated since they can also disrupt the intramolecular forces. Therefore, immunoaffinity chromatography can only be partially used for protein and virus purification. Here we report on a nonspecific elution in immunoaffinity chromatography using native conditions by elution with amino acid solution at physiological pH for which we suppose possible competing mechanism of action. Elution potential of various amino acid solutions was tested using immunoaffinity columns specific for ovalbumin and mumps virus, and protein G affinity column. Results have shown that the most successful elution solutions were those containing imidazole and arginine of high molarity. Imidazole represents aromatic residues readily found at the antigen-antibody interaction surface and arginine is most frequently found on protein surface in general. Therefore, results on their eluting power in immunoaffinity chromatography, which increases with increasing molarity, are in line with the competing mechanism of action. Virus immunoaffinity chromatography resulted in removal on nonviable virus particles, which is important for research and biotechnology purposes. In addition, amino acids are proven stabilizers for proteins and viruses making approach presented in this work a very convenient purification method. PMID:27090389

  15. Comparison of zonal elution and nonlinear chromatography in determination of the interaction between seven drugs and immobilised β(2)-adrenoceptor.

    Science.gov (United States)

    Li, Qian; Wang, Jing; Zheng, Yuqing Yuan; Yang, Lingjian; Zhang, Yajun; Bian, Liujiao; Zheng, Jianbin; Li, Zijian; Zhao, Xinfeng; Zhang, Youyi

    2015-07-01

    Zonal elution and nonlinear chromatography are two mainstream models for the determination of drug-protein interaction in affinity chromatography. This work intended to compare the results by zonal elution with that by nonlinear chromatography when it comes to the analysis of the interaction between seven drugs and immobilised β2-adrenoceptor (β2-AR). The results of the zonal elution showed that clorprenaline, clenbuterol, methoxyphenamine, salbutamol, terbutaline, tulobuterol and bambuterol have only one type of binding site on immobilised β2-AR, while nonlinear chromatography confirmed the existence of at least two types of binding sites between β2-AR and clorprenaline, clenbuterol and bambuterol. On these sites, both zonal elution and nonlinear chromatography presented the same rank order for the association constants of the seven drugs. Compared with the data from zonal elution, the association constants calculated using nonlinear chromatography gave a good linear response to the corresponding values by radio-ligand binding assay. The sampling efficiencies of nonlinear chromatography were clearly higher than zonal elution. Nonlinear chromatography will probably become a powerful alternative for the high throughput determination of drug-protein interaction. PMID:26002106

  16. Self-affine sets and the continuity of subadditive pressure

    OpenAIRE

    Shmerkin, Pablo

    2013-01-01

    The affinity dimension is a number associated to an iterated function system of affine maps, which is fundamental in the study of the fractal dimensions of self-affine sets. De-Jun Feng and the author recently solved a folklore open problem, by proving that the affinity dimension is a continuous function of the defining maps. The proof also yields the continuity of a topological pressure arising in the study of random matrix products. I survey the definition, motivation and main properties of...

  17. On invariant measures of finite affine type tilings

    OpenAIRE

    Petite, S.

    2004-01-01

    In this paper, we consider tilings of the hyperbolic 2-space, built with a finite number of polygonal tiles, up to affine transformation. To such a tiling T, we associate a space of tilings: the continuous hull Omega(T) on which the affine group acts. This space Omega(T) inherits a solenoid structure whose leaves correspond to the orbits of the affine group. First we prove the finite harmonic measures of this laminated space correspond to finite invariant measures for the affine group action....

  18. Smooth affine shear tight frames: digitization and applications

    Science.gov (United States)

    Zhuang, Xiaosheng

    2015-08-01

    In this paper, we mainly discuss one of the recent developed directional multiscale representation systems: smooth affine shear tight frames. A directional wavelet tight frame is generated by isotropic dilations and translations of directional wavelet generators, while an affine shear tight frame is generated by anisotropic dilations, shears, and translations of shearlet generators. These two tight frames are actually connected in the sense that the affine shear tight frame can be obtained from a directional wavelet tight frame through subsampling. Consequently, an affine shear tight frame indeed has an underlying filter bank from the MRA structure of its associated directional wavelet tight frame. We call such filter banks affine shear filter banks, which can be designed completely in the frequency domain. We discuss the digitization of affine shear filter banks and their implementations: the forward and backward digital affine shear transforms. Redundancy rate and computational complexity of digital affine shear transforms are also investigated in this paper. Numerical experiments and comparisons in image/video processing show the advantages of digital affine shear transforms over many other state-of-art directional multiscale representation systems.

  19. Experimental characterization of the transport phenomena, adsorption, and elution in a protein A affinity monolithic medium.

    Science.gov (United States)

    Herigstad, M Omon; Dimartino, Simone; Boi, Cristiana; Sarti, Giulio C

    2015-08-14

    A commercially available convective interaction media (CIM) Protein A monolithic column was fully characterized in view of its application for the affinity capture of IgG in monoclonal antibody production processes. By means of moment analysis, the interstitial porosity and axial dispersion coefficient were determined. The frontal analysis method of characteristic points was employed, for the first time with monolithic media, to determine the dynamic binding capacity. The effects of the flow rate and pH on the total recovery of polyclonal IgG and elution profile were evaluated. A comparison with literature data for Protein A chromatography beads demonstrate the superior bed utilization of monolithic media, which gave better performance at lower residence times. PMID:26143608

  20. Two-parameter quantum affine algebra Ur,s(sln-circumflex), Drinfeld realization and quantum affine Lyndon basis

    International Nuclear Information System (INIS)

    We further find the defining structure of a two-parameter quantum affine algebra Ur,s(sln-circumflex) (n > 2) in the sense of Benkart-Witherspoon [BW1] after the work of [BGH1], [HS] and [BH], which turns out to be a Drinfeld double. Of more importance for the 'affine' cases is that we work out the compatible two-parameter version of the Drinfeld realization as a quantum affinization of Ur,s(sln) and establish the Drinfeld isomorphism Theorem in the two-parameter setting via developing a new remarkable combinatorial approach - quantum 'affine' Lyndon basis with an explicit valid algorithm, based on the Drinfeld realization. (author)

  1. Lipid A-based affinity biosensor for screening anti-sepsis components from herbs

    Directory of Open Access Journals (Sweden)

    Jie Yao

    2014-05-01

    Full Text Available LPS (lipopolysaccharide, an outer membrane component of Gram-negative bacteria, plays an important role in the pathogenesis of sepsis and lipid A is known to be essential for its toxicity. Therefore it could be an effective measure to prevent sepsis by neutralizing or destroying LPS. Numerous studies have indicated that many traditional Chinese medicines are natural antagonists of LPS in vitro and in vivo. The goal of this study is to develop a rapid method to screen anti-sepsis components from Chinese herbs by use of a direct lipid A-based affinity biosensor technology based on a resonant mirror. The detergent OG (n-octyl β-D-glucopyranoside was immobilized on a planar non-derivatized cuvette which provided an alternative surface to bind the terminal hydrophilic group of lipid A. A total of 78 herbs were screened based on the affinity biosensor with a target of lipid A. The aqueous extract of PSA (Paeonia suffruticosa Andr was found to possess the highest capability of binding lipid A. Therefore an aqueous extraction from this plant was investigated further by our affinity biosensor, polyamide chromatography and IEC–HPLC. Finally, we obtained a component (PSA-I-3 from Paeonia suffruticosa Andr that was evaluated with the affinity biosensor. We also studied the biological activities of PSA-I-3 against sepsis in vitro and in vivo to further confirm the component we screened with the biosensor. In vitro, we found that PSA-I-3 could decrease TNFα (tumour necrosis factor α release from RAW264.7 cells induced by LPS in a dose-dependent manner. In vivo, it increased remarkably the survival of KM (KunMing mice by challenging both lethal-dose LPS and heat-killed Escherichia coli compared with control groups. Our results suggest that the constructed affinity biosensor can successfully screen the anti-sepsis component from Chinese herbs.

  2. Affinity of guanosine derivatives for polycytidylate revisited

    Science.gov (United States)

    Kanavarioti, A.; Hurley, T. B.; Baird, E. E.

    1995-01-01

    Evidence is presented for complexation of guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) with polycytidylate (poly(C)) at pH 8.0 and 23 degrees C in the presence of 1.0 M NaCl2 and 0.2 M MgCl2 in water. The association of 2-MeImpG with poly(C) was investigated using UV-vis spectroscopy as well as by monitoring the kinetics of the nucleophilic substitution reaction of the imidazole moiety by amines. The results of both methods are consistent with moderately strong poly(C) 2-MeImpG complexation and the spectrophotometric measurements allowed the construction of a binding isotherm with a concentration of 2-MeImpG equal to 5.55 +/- 0.15 mM at half occupancy. UV spectroscopy was employed to establish the binding of other guanosine derivatives on poly(C). These derivatives are guanosine 5'-monophosphate (5'GMP), guanosine 5'-monophosphate imidazolide (ImpG), and guanosine 5'-monophosphate morpholidate (morpG). Within experimental error these guanosine derivatives exhibit the same affinity for poly(C) as 2-MeImpG.

  3. Development of DNA affinity techniques for the functional characterization of purified RNA polymerase II transcription factors

    International Nuclear Information System (INIS)

    Affinity adsorption, precipitation, and partitioning techniques have been developed to purify and characterize RNA Pol II transcription components from whole cell extracts (WCE) (HeLa) and nuclear extracts (K562). The titration of these extracts with multicopy constructs of the Ad2 MLP but not pUC8, inhibits transcriptional activity. DNA-binding factors precipitated by this technique are greatly enriched by centrifugation. Using this approach, factors binding to the upstream promoter sequence (UPS) of the Ad2 MLP have been rapidly isolated by Mono Q, Mono S, and DNA affinity chromatography. By U.V. crosslinking to nucleotides containing specific 32P-phosphodiester bonds within the recognition sequence, this factor is identified as a M/sub r/ = 45,000 polypeptide. To generate an assay system for the functional evaluation of single transcription components, a similar approach using synthetic oligonucleotide sequences spanning single promoter binding sites has been developed. The addition of a synthetic 63-mer containing the UPS element of the Ad2 MLP to HeLa WCE inhibited transcription by 60%. The addition of partially purified UPS binding protein, but not RNA Pol II, restored transcriptional activity. The addition of synthetic oligonucleotides containing other regulatory sequences not present in the Ad2 MLP was without effect

  4. Affine group formulation of the Standard Model coupled to gravity

    International Nuclear Information System (INIS)

    In this work we apply the affine group formalism for four dimensional gravity of Lorentzian signature, which is based on Klauder’s affine algebraic program, to the formulation of the Hamiltonian constraint of the interaction of matter and all forces, including gravity with non-vanishing cosmological constant Λ, as an affine Lie algebra. We use the hermitian action of fermions coupled to gravitation and Yang–Mills theory to find the density weight one fermionic super-Hamiltonian constraint. This term, combined with the Yang–Mills and Higgs energy densities, are composed with York’s integrated time functional. The result, when combined with the imaginary part of the Chern–Simons functional Q, forms the affine commutation relation with the volume element V(x). Affine algebraic quantization of gravitation and matter on equal footing implies a fundamental uncertainty relation which is predicated upon a non-vanishing cosmological constant. -- Highlights: •Wheeler–DeWitt equation (WDW) quantized as affine algebra, realizing Klauder’s program. •WDW formulated for interaction of matter and all forces, including gravity, as affine algebra. •WDW features Hermitian generators in spite of fermionic content: Standard Model addressed. •Constructed a family of physical states for the full, coupled theory via affine coherent states. •Fundamental uncertainty relation, predicated on non-vanishing cosmological constant

  5. Synthesis of tetracycline analogs and their bone affinities

    Institute of Scientific and Technical Information of China (English)

    Wen Cai Huang; Hu Zheng; Ling Ling Weng

    2008-01-01

    Tetracycline analogs were designed and synthesized and their bone affinities were tested on hydroxyapatite. The results showedthat the carbonyl-amide-enol structure in A ring and phenol-ketone structure in BCD ring may be responsible for tetracycline's highbone affinity and either A ring or BCD ring has a planar conformation is essential.

  6. Self-affine roughness influence on redox reaction charge admittance

    NARCIS (Netherlands)

    Palasantzas, G

    2005-01-01

    In this work we investigate the influence of self-affine electrode roughness on the admittance of redox reactions during facile charge transfer kinetics. The self-affine roughness is characterized by the rms roughness amplitude w, the correlation length xi and the roughness exponent H (0

  7. Striving for Empathy: Affinities, Alliances and Peer Sexuality Educators

    Science.gov (United States)

    Fields, Jessica; Copp, Martha

    2015-01-01

    Peer sexuality educators' accounts of their work reveal two approaches to empathy with their students: affinity and alliance. "Affinity-based empathy" rests on the idea that the more commonalities sexuality educators and students share (or perceive they share), the more they will be able to empathise with one another, while…

  8. Tending to Change: Toward a Situated Model of Affinity Spaces

    Science.gov (United States)

    Bommarito, Dan

    2014-01-01

    The concept of affinity spaces, a theoretical construct used to analyze literate activity from a spatial perspective, has gained popularity among scholars of literacy studies and, particularly, video-game studies. This article seeks to expand current notions of affinity spaces by identifying key assumptions that have limited researchers'…

  9. Affinity labeling and characterization of the active site histidine of glucosephosphate isomerase

    International Nuclear Information System (INIS)

    N-bromoacetylethanolamine phosphate was found to act as a specific affinity label for the active center of glucosephosphate isomerase. The inactivation process followed pseudo-first order kinetics, was irreversible, and exhibited rate saturation kinetics with minimal half-lives of inactivation of 4.5 and 6.3 min for the enzyme isolated from human placenta and rabbit muscle, respectively. The pH dependence of the inactivation process closely paralleled the pH dependence of the overall catalytic process with pK/sub a/ values at pH 6.4 and 9.0. The stoichiometry of labeling of either enzyme, as determined with N-bromo[14C2]acetylethanolamine phosphate, was 1 eq of the affinity label/subunit of enzyme. After acid hydrolysis and amino acid analysis of the radioactive affinity-labeled human enzyme, only radioactive 3-carboxymethyl histidine was found. In the case of the rabbit enzyme, the only radioactive derivative obtained was 1-carboxymethyl histidine. Active site tryptic peptides were isolated by solvent extraction, thin layer peptide fingerprinting, and ion exchange chromatography before and after removal of the phosphate from the active site peptide. Amino acid analysis of the labeled peptides from the two species were very similar. Using high sensitivity methods for sequence analysis, the primary structure of the active site was established as Val-Leu-His-Ala-Glu-Asn-Val-Asp (Gly,Thr,Ser) Glu-Ile (Thr-Gly-His-Lys-Glx)-Tyr-Phe. Apparent sequence homology between the catalytic center of glucosephosphate isomerase and triosephosphate isomerase suggest that the two enzymes may have evolved from a common ancestral gene

  10. Properties of the resin Levextrel HDEHP in extraction and chromatography. Application to uranium and some transuranium elements

    International Nuclear Information System (INIS)

    Study of extraction chromatography with a macroporous structure made of a copolymer styrene-divinylbenzene containing di-2-ethylhexylphosphoric acid commercialized under the name Levextrel OC 1026. Uranium, neptunium and plutonium with an oxidation degree of 4 or 6 have a great affinity for Levextrel in perchloric or nitric acid, fixation of neptunium V is low and affinity of americium III varies with acidity this leads to a separation method of actinides. Europium behavior has been specially studied and application to separation of Eu/Nd has been made

  11. IMPLEMENTASI ENKRIPSI DEKRIPSI ALGORITMA AFFINE CIPHER BERBASIS ANDROID

    Directory of Open Access Journals (Sweden)

    Sasono Wibowo

    2014-11-01

    Full Text Available Perkembangan Teknologi Informasi yang cukup pesat khususnya dalam bidang komunikasi menjadikan komunikasi sangat mudah namun dalam implementasinya perlu adanya keamanan tentang informasi yang disampaikan. Dalam komunikasi antar orang pasti memiliki pembicaraan informasi yang bersifat privat atau orang lain tidak boleh tahu tentang pembicaraan yang terjadi. Diperlukannya keamanan untuk menjaga kerahasiaan informasi pada saat komunikasi. Masyarakat lebih sering menggunakan komunikasi dengan telepon seluler karena dinilai mudah dibawa dan tidak repot menggunakannya. Kriptografi yang biasa dikenal sebagai ilmu yang mempelajari bagaimana cara menyembunyikan pesan bisa diterapkan dalam aplikasi pada telepon seluler sebagai contoh smartphone android. Dengan mengimplementasikan algoritma affine cipher maka aplikasi yang akan dibuat bisa mengubah isi pesan yang ada dan dapat mengamankan informasi yang ada. Algoritma affine cipher merupakan perkembangan dari algoritma caesar dimana algoritma affine cipher menggunakan dua kunci. Dengan mengimplementasikan algoritma affine cipher ke dalam android maka diharapkan kita bisa menyimpan informasi dari siapapun tanpa terbaca. Kata Kunci : Kriptografi, Affine Cipher, android, Implementasi, Informasi

  12. Chasing polys: Interdisciplinary affinity and its connection to physics identity

    Science.gov (United States)

    Scott, Tyler D.

    This research is based on two motivations that merge by means of the frameworks of interdisciplinary affinity and physics identity. First, a goal of education is to develop interdisciplinary abilities in students' thinking and work. But an often ignored factor is students interests and beliefs about being interdisciplinary. Thus, this work develops and uses a framework called interdisciplinary affinity. It encompasses students interests in making connections across disciplines and their beliefs about their abilities to make those connections. The second motivation of this research is to better understand how to engage more students with physics. Physics identity describes how a student sees themselves in relation to physics. By understanding how physics identity is developed, researchers and educators can identify factors that increase interest and engagement in physics classrooms. Therefore, physics identity was used in conjunction with interdisciplinary affinity. Using a mixed methods approach, this research used quantitative data to identify the relationships interdisciplinary affinity has with physics identity and the physics classroom. These connections were explored in more detail using a case study of three students in a high school physics class. Results showed significant and positive relationships between interdisciplinary affinity and physics identity, including the individual interest and recognition components of identity. It also identified characteristics of physics classrooms that had a significant, positive relationship with interdisciplinary affinity. The qualitative case study highlighted the importance of student interest to the relationship between interdisciplinary affinity and physics identity. It also identified interest and mastery orientation as key to understanding the link between interdisciplinary affinity and the physics classroom. These results are a positive sign that by understanding interdisciplinary affinity and physics identity

  13. Extraction chromatography: Progress and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, M.L.; Horwitz, E.P.; Bond, A.H. [Argonne National Lab., IL (United States). Chemistry Div.

    1997-10-01

    Extraction chromatography provides a simple and effective method for the analytical and preparative-scale separation of a variety of metal ions. Recent advances in extractant design, particularly the development of extractants capable of metal ion recognition or of strong complex formation in highly acidic media, have significantly improved the utility of the technique. Advances in support design, most notably the introduction of functionalized supports to enhance metal ion retention, promise to yield further improvements. Column instability remains a significant obstacle, however, to the process-scale application of extraction chromatography. 79 refs.

  14. Atomic Force Microscope Mediated Chromatography

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  15. Convulsant bicuculline modifies CNS muscarinic receptor affinity

    Directory of Open Access Journals (Sweden)

    Rodríguez de Lores Arnaiz Georgina

    2006-04-01

    Full Text Available Abstract Background Previous work from this laboratory has shown that the administration of the convulsant drug 3-mercaptopropionic acid (MP, a GAD inhibitor, modifies not only GABA synthesis but also binding of the antagonist [3H]-quinuclidinyl benzilate ([3H]-QNB to central muscarinic receptors, an effect due to an increase in affinity without modifications in binding site number. The cholinergic system has been implicated in several experimental epilepsy models and the ability of acetylcholine to regulate neuronal excitability in the neocortex is well known. To study the potential relationship between GABAergic and cholinergic systems with seizure activity, we analyzed the muscarinic receptor after inducing seizure by bicuculline (BIC, known to antagonize the GABA-A postsynaptic receptor subtype. Results We analyzed binding of muscarinic antagonist [3H]-QNB to rat CNS membranes after i.p. administration of BIC at subconvulsant (1.0 mg/kg and convulsant (7.5 mg/kg doses. Subconvulsant BIC dose failed to develop seizures but produced binding alteration in the cerebellum and hippocampus with roughly 40% increase and 10% decrease, respectively. After convulsant BIC dose, which invariably led to generalized tonic-clonic seizures, binding increased 36% and 15% to cerebellar and striatal membranes respectively, but decreased 12% to hippocampal membranes. Kd value was accordingly modified: with the subconvulsant dose it decreased 27% in cerebellum whereas it increased 61% in hippocampus; with the convulsant dose, Kd value decreased 33% in cerebellum but increased 85% in hippocampus. No change in receptor number site was found, and Hill number was invariably close to unity. Conclusion Results indicate dissimilar central nervous system area susceptibility of muscarinic receptor to BIC. Ligand binding was modified not only by a convulsant BIC dose but also by a subconvulsant dose, indicating that changes are not attributable to the seizure process

  16. Electron affinities of atoms, molecules, and radicals

    International Nuclear Information System (INIS)

    We review briefly but comprehensively the theoretical, semiempirical and experimental methods employed to determine electron affinities (EAs) of atoms, molecules and radicals, and summarize the EA data obtained by these methods. The detailed processes underlying the principles of the experimental methods are discussed very briefly. It is, nonetheless, instructive to recapitulate the definition of EA and those of the related quantities, namely, the vertical detachment energy, VDE, and the vertical attachment energy, VAE. The EA of an atom is defined as the difference in total energy between the ground state of the neutral atom (plus the electron at rest at infinity) and its negative ion. The EA of a molecule is defined as the difference in energy between the neutral molecule plus an electron at rest at infinity and the molecular negative ion when both, the neutral molecules and the negative ion, are in their ground electronic, vibrational and rotational states. The VDE is defined as the minimum energy required to eject the electron from the negative ion (in its ground electronic and nuclear state) without changing the internuclear separation; since the vertical transition may leave the neutral molecule in an excited vibrational/rotational state, the VDE, although the same as the EA for atoms is, in general, different (larger than), from the EA for molecules. Similarly, the VAE is defined as the difference in energy between the neutral molecule in its ground electronic, vibrational and rotational states plus an electron at rest at infinity and the molecular negative ion formed by addition of an electron to the neutral molecule without allowing a change in the intermolecular separation of the constituent nuclei; it is a quantity appropriate to those cases where the lowest negative ion state lies above the ground states of the neutral species and is less or equal to EA

  17. Magnetic graphitic carbon nitride anion exchanger for specific enrichment of phosphopeptides.

    Science.gov (United States)

    Zhu, Gang-Tian; He, Xiao-Mei; Chen, Xi; Hussain, Dilshad; Ding, Jun; Feng, Yu-Qi

    2016-03-11

    Anion-exchange chromatography (AEX) is one of the chromatography-based methods effectively being used for phosphopeptide enrichment. However, the development of AEX materials with high specificity toward phosphopeptides is still less explored as compared to immobilized metal affinity chromatography (IMAC) or metal oxide affinity chromatography (MOAC). In this work, magnetic graphitic carbon nitride (MCN) was successfully prepared and introduced as a promising AEX candidate for phosphopeptide enrichment. Due to the extremely abundant content of nitrogen with basic functionality on the surface, this material kept excellent retention for phosphopeptides at pH as low as 1.8. Benefiting from the large binding capacity at such low pH, MCN showed remarkable specificity to capture phosphopeptides from tryptic digests of standard protein mixtures as well as nonfat milk and human serum. In addition, MCN was also applied to selective enrichment of phosphopeptides from the tryptic digests of rat brain lysate and 2576 unique phosphopeptides were successfully identified. PMID:26884140

  18. Characterization of the somatogenic receptor in rat liver. Hydrodynamic properties and affinity cross-linking

    International Nuclear Information System (INIS)

    Rat liver somatogenic receptors have been characterized by gel permeation chromatography, sucrose density gradients in H2O and D2O, and affinity cross-linking using 125I-bovine growth hormone (bGH) as a specific somatogenic receptor ligand. Cross-linking of 125I-bovine growth hormone to a Triton X-100-treated low density fraction isolated from livers of late pregnant rats followed by sodium dodecylsulfate-polyacrylamide gel electrophoresis under reducing conditions showed three major binders with Mr 95,000, 86,000, and 43,000 and a minor binder of Mr 55,000, after correction for bound ligand assuming a 1:1 binding ratio of ligand-receptor. The Mr 86,000, 55,000, and 43,000 species were recovered in the detergent-soluble supernatant after high-speed centrifugation, whereas the Mr 95,000 species remained Triton X-100 insoluble. Detergent-soluble 125I-bGH-receptor complexes were further analyzed by sedimentation into sucrose density gradients. The sedimentation coefficient was S20,w = 5.2 S and the partial specific volume v = 0.72 ml/g. Gel permeation chromatography on a Sepharose S-400 column indicated a Stokes radius of 61 A for the 125I-bGH-receptor-Triton X-100 complex. Based on these figures, the molecular weight of the complex was calculated as 131,100. The molecular weight of the ligand-free receptor-Triton X-100 complex was calculated as Mr 109,100. Affinity cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the 61 A peak from Sephacryl S-400 chromatography (cf. above) showed two binding entities, one major and one minor with Mr values 86,000 and 43,000, respectively, in the absence of reductant. When electrophoresis was run in the presence of reductant the Mr 43,000 species was the major binding entity

  19. Tetrahydroprotoberberine alkaloids with dopamine and σ receptor affinity.

    Science.gov (United States)

    Gadhiya, Satishkumar; Madapa, Sudharshan; Kurtzman, Thomas; Alberts, Ian L; Ramsey, Steven; Pillarsetty, Nagavara-Kishore; Kalidindi, Teja; Harding, Wayne W

    2016-05-01

    Two series of analogues of the tetrahydroprotoberberine (THPB) alkaloid (±)-stepholidine that (a) contain various alkoxy substituents at the C10 position and, (b) were de-rigidified with respect to (±)-stepholidine, were synthesized and evaluated for affinity at dopamine and σ receptors in order to evaluate effects on D3 and σ2 receptor affinity and selectivity. Small n-alkoxy groups are best tolerated by D3 and σ2 receptors. Among all compounds tested, C10 methoxy and ethoxy analogues (10 and 11 respectively) displayed the highest affinity for σ2 receptors as well as σ2 versus σ1 selectivity and also showed the highest D3 receptor affinity. De-rigidification of stepholidine resulted in decreased affinity at all receptors evaluated; thus the tetracyclic THPB framework is advantageous for affinity at dopamine and σ receptors. Docking of the C10 analogues at the D3 receptor, suggest that an ionic interaction between the protonated nitrogen atom and Asp110, a H-bond interaction between the C2 phenol and Ser192, a H-bond interaction between the C10 phenol and Cys181 as well as hydrophobic interactions of the aryl rings to Phe106 and Phe345, are critical for high affinity of the compounds. PMID:27032890

  20. Genetic Algorithm-based Affine Parameter Estimation for Shape Recognition

    Directory of Open Access Journals (Sweden)

    Yuxing Mao

    2014-06-01

    Full Text Available Shape recognition is a classically difficult problem because of the affine transformation between two shapes. The current study proposes an affine parameter estimation method for shape recognition based on a genetic algorithm (GA. The contributions of this study are focused on the extraction of affine- invariant features, the individual encoding scheme, and the fitness function construction policy for a GA. First, the affine-invariant characteristics of the centroid distance ratios (CDRs of any two opposite contour points to the barycentre are analysed. Using different intervals along the azimuth angle, the different numbers of CDRs of two candidate shapes are computed as representations of the shapes, respectively. Then, the CDRs are selected based on predesigned affine parameters to construct the fitness function. After that, a GA is used to search for the affine parameters with optimal matching between candidate shapes, which serve as actual descriptions of the affine transformation between the shapes. Finally, the CDRs are resampled based on the estimated parameters to evaluate the similarity of the shapes for classification. The experimental results demonstrate the robust performance of the proposed method in shape recognition with translation, scaling, rotation and distortion.

  1. Einstein-Maxwell dynamics as a P(4) affine theory

    International Nuclear Information System (INIS)

    In Newtonian mechanics the energy of a particle is defined only up to an arbitrary additive constant. By using affine functions to model the Newtonian energy we show that it is possible to reformulate arbitrary time- and velocity-independent forces as R1 affine gauge potentials. Solutions of Newton's second law then define R1 affine energy geodesics, and the R1 flat gauge potentials are shown to correspond to conservative Newtonian forces. We generalize these ideas to relativistic mechanics by modeling the energy-momentum of classical particles as R4 affine four-vectors. If this R4 affine structure is to be compatible with the O(1,3) Riemannian structure of spacetime, then the R4 gauge potential must correspond to an antisymmetric tensor field on spacetime, and this field is identified with the electromagnetic field tensor. We are eventually led to a reformulation of the Einstein-Maxwell theory as a P(4) = O(1,3) x R4 affine gauge theory in which the timelike affine geodesics correspond to Lorentz-force-law trajectories, and the Einstein-Maxwell field equations are reformulated as gauge field equations in terms of the P(4) curvature

  2. Illustrating Chromatography with Colorful Proteins

    Science.gov (United States)

    Lefebvre, Brian G.; Farrell, Stephanie; Dominiak, Richard S.

    2007-01-01

    Advances in biology are prompting new discoveries in the biotechnology, pharmaceutical, medical technology, and chemical industries. This paper presents a detailed description of an anion exchange chromatography experiment using a pair of colorful proteins and summarizes the effect of operating parameters on protein separation. This experiment…

  3. Thermal modulation for gas chromatography

    Science.gov (United States)

    Hasselbrink, Ernest F. (Inventor); Libardoni, Mark (Inventor); Stewart, Kristine (Inventor); Waite, J. Hunter (Inventor); Block, Bruce P. (Inventor); Sacks, Richard D. (Inventor)

    2007-01-01

    A thermal modulator device for gas chromatography and associated methods. The thermal modulator device includes a recirculating fluid cooling member, an electrically conductive capillary in direct thermal contact with the cooling member, and a power supply electrically coupled to the capillary and operable for controlled resistive heating of the capillary. The capillary can include more than one separate thermally modulated sections.

  4. Selectivity in microemulsion electrokinetic chromatography

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, S; Gabel-Jensen, Charlotte; Honoré Hansen, S

    2000-01-01

    Microemulsion electrokinetic chromatography (MEEKC) is a most promising separation technique providing good selectivity and high separation efficiency of anionic, cationic as well as neutral solutes. In MEEKC lipophilic organic solvents dispersed as tiny droplets in an aqueous buffer by the use of...

  5. [Recent applications of microemulsion electrokinetic chromatography].

    Science.gov (United States)

    Peng, Zhenlei; Lin, Jin-Ming

    2009-09-01

    The separation principle of microemulsion electrokinetic chromatography (MEEKC) is similar to micellar electrokinetic chromatography (MEKC). Within the last eight years, a number of papers have appeared in the literature. An overview about the applications of MEEKC is given. PMID:20073197

  6. Affine deformation tensor - a necessary object in GRT

    International Nuclear Information System (INIS)

    Einstein notions about the nature of gravitation are refined. The geometric gravitation theory (GGT) grounds are discussed. It is noted that there is no one of the important geometrical object in the Einstein gravitation theory (EGT) i.e. background affinity, which along with the metric tensor determines the gravitational gield energy density. Considering that it is not necessary to introduce background metrics, the author has introduced the background affinity and affine deformation tensor. The theory of black holes is considered as an alternative of EGT. 53 refs

  7. Synthesis and Image Matching On Structural Patterns Using Affine Transformation

    Directory of Open Access Journals (Sweden)

    S.Vandana

    2012-06-01

    Full Text Available This paper focuses in explaining a Fourier based affine estimator which is applied to the task of Image Synthesis. An affine transformation is an important class of linear 2-D geometric transformations which maps variables into new by applying a linear combination of translation, rotation, scaling and/or shearing operations. Conventional retrieval systems are very effective when knowledge information and query information are in a uniform orientation but fails in recognition when effects such as scaling, orientation exist. But as this technique is based on texture analysis, which is termed the affine estimator, it will even match the images with non-uniform orientation.

  8. Affinity- and topology-dependent bound on current fluctuations

    CERN Document Server

    Pietzonka, Patrick; Seifert, Udo

    2016-01-01

    We provide a proof of a recently conjectured universal bound on current fluctuations in Markovian processes. This bound establishes a link between the fluctuations of an individual observable current, the cycle affinities driving the system into a non-equilibrium steady state, and the topology of the network. The proof is based on a decomposition of the network into independent cycles with both positive affinity and positive stationary cycle current. This formalism allows for a refinement of the bound for systems in equilibrium or with locally vanishing affinities.

  9. Pepsin-modified chiral monolithic column for affinity capillary electrochromatography.

    Science.gov (United States)

    Hong, Tingting; Chi, Cuijie; Ji, Yibing

    2014-11-01

    Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation. PMID:25146884

  10. ODE/IM correspondence and modified affine Toda field equations

    CERN Document Server

    Ito, Katsushi

    2014-01-01

    We study the two-dimensional affine Toda field equations for affine Lie algebra $\\hat{\\mathfrak{g}}$ modified by a conformal transformation and the associated linear equations. In the conformal limit, the associated linear problem reduces to a (pseudo-)differential equation. For classical affine Lie algebra $\\hat{\\mathfrak{g}}$, we obtain a (pseudo-)differential equation corresponding to the Bethe equations for the Langlands dual of the Lie algebra $\\mathfrak{g}$, which were found by Dorey et al. in study of the ODE/IM correspondence.

  11. Centro-affine hypersurface immersions with parallel cubic form

    OpenAIRE

    HILDEBRAND, Roland

    2012-01-01

    We consider non-degenerate centro-affine hypersurface immersions in R^n whose cubic form is parallel with respect to the Levi-Civita connection of the affine metric. There exists a bijective correspondence between homothetic families of proper affine hyperspheres with center in the origin and with parallel cubic form, and K\\"ochers conic omega-domains, which are the maximal connected sets consisting of invertible elements in a real semi-simple Jordan algebra. Every level surface of the omega ...

  12. Comparative determination of phenytoin by spectrophotometry, gas chromatography, liquid chromatography, enzyme immunoassay, and radioimmunoassay

    International Nuclear Information System (INIS)

    Sera from patients being treated with phenytoin were analyzed for the drug by spectrophotometry, gas chromatography, radioimmunoasay, enzyme immunoassay, and liquid chromatography. The assay values obtained were intercompared statistically. Enzyme immunoassay and liquid chromatography appear to be attractive alternatives to the more traditional methods of spectrophotometry and gas chromatography. Our radioimmunoassay data correlated poorly with results by the four other methods

  13. Simultaneous purification and refolding of proteins by affinity precipitation and macro (affinity ligand)-facilitated three phase partitioning (MLFTPP).

    Science.gov (United States)

    Roy, Ipsita; Mondal, Kalyani; Gupta, Munishwar N

    2014-01-01

    This chapter describes two simple interrelated non-chromatographic methods of protein purification. In the first method, called affinity precipitation, inherent affinity of reversibly soluble-insoluble polymers (also called stimuli-sensitive or smart polymers) is exploited to form an affinity complex in free solution with target protein. The affinity complex is precipitated by a suitable change in the medium. The desired protein is dissociated from the smart polymer. In the second method called macro (affinity ligand)-facilitated three phase partitioning (MLFTPP), the affinity complex is precipitated at an interface between upper t-butanol-rich phase and lower aqueous phase. These three phases are achieved by adding appropriate amounts of ammonium sulfate and t-butanol to the initial crude extract. In the first protocol, sequential MLFTPP is used with two different smart polymers to purify pectinase and cellulase from a single crude preparation. The second protocol illustrates the application of the affinity precipitation in simultaneous purification and refolding of a urea-denatured xylanase. PMID:24648072

  14. Syntheses of 7-Substituted α-Cyperone Derivatives for Selective Sigma-1 Receptor over Cannabinoid-1 Receptor Binding Affinities

    International Nuclear Information System (INIS)

    We have successfully synthesized seven α-cyperone derivatives and found that the presence of a hydrogen bond donor/acceptor groups at the C7 position of α-cyperone significantly affects specificity and potency of CB1 receptor binding affinity over sigma-1 receptor binding affinity. In particular, the presence of the amino moiety at the C7 position of α-cyperone is beneficial for binding to sigmia-1 receptor. The molecular mechanism of compound 8 involved in the high binding affinity to sigma-1 receptor is under investigation. We first synthesized α-cyperone 1 by following the previously reported synthetic routes.15-19 In brief, azeotropic imination of (+)-dihydrocarvone and (R)-(+)-1-phenylethylamine followed by alkylation with a slight excess of ethyl vinyl ketone (EVK) in THF at 40 .deg. C produced the Micheal adduct. The resulting adduct was hydrolyzed and then treated with sodium methoxide at room temperature to give an easily separable mixture of α-cyperone 1 and its side product. Flash chromatography resulted in pure α-cyperone 1 in a 30% yield from (+)-dihydrocarvone

  15. Volatility Components, Affine Restrictions and Non-Normal Innovations

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Dorian, Christian;

    Recent work by Engle and Lee (1999) shows that allowing for long-run and short-run components greatly enhances a GARCH model's ability fit daily equity return dynamics. Using the risk-neutralization in Duan (1995), we assess the option valuation performance of the Engle-Lee model and compare it to...... GARCH models to four conditionally non-normal versions. As in Hsieh and Ritchken (2005), we find that non-affine models dominate affine models both in terms of fitting return and in terms of option valuation. For the affine models we find strong evidence in favor of the component structure for both...... returns and options, but for the non-affine models the evidence is much less strong in option valuation. The evidence in favor of the non-normal models is strong when fitting daily returns, but the non-normal models do not provide much improvement when valuing options....

  16. Antibody Affinity Maturation in Fishes—Our Current Understanding

    Science.gov (United States)

    Magor, Brad G.

    2015-01-01

    It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig) mutator enzyme activation-induced cytidine deaminase (AID). We also consider the protein and molecular evidence for Ig somatic hypermutation and antibody affinity maturation. In the context of recent evidence for a putative proto-germinal center in fishes we propose some possible reasons that observed affinity maturation in fishes often seems lacking and propose future work that might shed further light on this process in fishes. PMID:26264036

  17. Antibody Affinity Maturation in Fishes-Our Current Understanding.

    Science.gov (United States)

    Magor, Brad G

    2015-01-01

    It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig) mutator enzyme activation-induced cytidine deaminase (AID). We also consider the protein and molecular evidence for Ig somatic hypermutation and antibody affinity maturation. In the context of recent evidence for a putative proto-germinal center in fishes we propose some possible reasons that observed affinity maturation in fishes often seems lacking and propose future work that might shed further light on this process in fishes. PMID:26264036

  18. Rigid affine surfaces with isomorphic A2-cylinders

    OpenAIRE

    Dubouloz, Adrien

    2015-01-01

    We construct families of smooth affine surfaces with pairwise non isomorphic A 1-cylinders but whose A 2-cylinders are all isomorphic. These arise as complements of cuspidal hyperplane sections of smooth projective cubic surfaces.

  19. Note on Dilogarithm Identities from Nilpotent Double Affine Hecke Algebras

    Directory of Open Access Journals (Sweden)

    Tomoki Nakanishi

    2012-12-01

    Full Text Available Recently Cherednik and Feigin [arXiv:1209.1978] obtained several Rogers-Ramanujan type identities via the nilpotent double affine Hecke algebras (Nil-DAHA. These identities further led to a series of dilogarithm identities, some of which are known, while some are left conjectural. We confirm and explain all of them by showing the connection with Y-systems associated with (untwisted and twisted quantum affine Kac-Moody algebras.

  20. An affine sphere equation associated to Einstein toric surfaces

    OpenAIRE

    Mabuchi, Toshiki

    2007-01-01

    As seen in the works of Calabi, Cheng-Yau and Loftin, affine sphere equations have a close relationship with Kaehler-Einstein metrics. The main purpose of this note is to show that an equation analogous to those of hyperbolic affine spheres arises naturally from Kaehler-Einstein metrics on Einstein toric surfaces. The case for the remaining toric surfaces with Kaehler-Ricci solitons will also be discussed.

  1. The ABC's of affine Grassmannians and Hall-Littlewood polynomials

    OpenAIRE

    Dalal, Avinash J.; Morse, Jennifer

    2016-01-01

    We give a new description of the Pieri rule for k-Schur functions using the Bruhat order on the affine type-A Weyl group. In doing so, we prove a new combinatorial formula for representatives of the Schubert classes for the cohomology of affine Grassmannians. We show how new combinatorics involved in our formulas gives the Kostka-Foulkes polynomials and discuss how this can be applied to study the transition matrices between Hall-Littlewood and k-Schur functions.

  2. Peculiarities of Matter Motion in Metric-Affine Gravitational Theory

    OpenAIRE

    Babourova, O. V.; Frolov, B. N.; Koroliov, M. Yu.

    1995-01-01

    On the basis of the Lie derivative method in a metric-affine space-time it is shown that in the metric-affine gravitational theory the energy-momentum conservation law and therefore the equations of the matter motion are the consequence (as in the GR) of the gravitational field equations. The possi- bility of the detection of the space-time non-metric properties is discussed.

  3. Euclidean Reconstruction and Affine Camera Calibration Using Controlled Robot Motions

    OpenAIRE

    Horaud, Radu; Christy, Stéphane; Mohr, Roger

    1997-01-01

    We are addressing the problem of Euclidean reconstruction with an uncalibrated affine camera and the calibration of this camera. We investigate constraints under which the Euclidean shape and motion problem becomes linear. The theoretical study described in this paper leads us to impose some practical constraints that the camera is mounted onto a robot arm and that the robot is executing controlled motions whose parameters are known. The affine camera model considered here is just an approxim...

  4. Algebraic volume density property of affine algebraic manifolds

    OpenAIRE

    Kaliman, Shulim; Kutzschebauch, Frank

    2009-01-01

    We introduce the notion of algebraic volume density property for affine algebraic manifolds and prove some important basic facts about it, in particular that it implies the volume density property. The main results of the paper are producing two big classes of examples of Stein manifolds with volume density property. One class consists of certain affine modifications of $\\C^n$ equipped with a canonical volume form, the other is the class of all Linear Algebraic Groups equipped with the left i...

  5. Quantized gauge-affine gravity in the superfiber bundle approach

    OpenAIRE

    Meziane, A.; Tahiri, M

    2004-01-01

    The quantization of gauge-affine gravity within the superfiber bundle formalism is proposed. By introducing an even pseudotensorial 1-superform over a principal superfibre bundle with superconnection, we obtain the geometrical Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST transformations of the fields occurring in such a theory. Reducing the four-dimensional general affine group double-covering to the Poincare group double-covering we also find the BRST and anti-BRST transformations of the f...

  6. Affine invariant texture analysis based on structural properties

    OpenAIRE

    Zhang, Jianguo; Tan, Tieniu

    2002-01-01

    This paper presents a new texture analysis method based on structural properties. The texture features extracted using this algorithm are invariant to affine transform (including rotation, translation, scaling, and skewing). Affine invariant structural properties are derived based on texel areas. An area-ratio map utilizing these properties is introduced to characterize texture images. Histogram based on this map is constructed for texture classification. Efficiency of this algorithm for affi...

  7. Several Affinity Tags Commonly Used in Chromatographic Purification

    OpenAIRE

    Xinyu Zhao; Guoshun Li; Shufang Liang

    2013-01-01

    Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, Strep II tag, streptavidin-binding peptide (SBP) tag, calmodulin-binding peptide (CBP), glutathione S...

  8. Skein Modules from Skew Howe Duality and Affine Extensions

    OpenAIRE

    Queffelec, Hoel

    2013-01-01

    We show that we can release the rigidity of the skew Howe duality process for ${\\mathfrak sl}_n$ knot invariants by rescaling the quantum Weyl group action, and recover skein modules for web-tangles. This skew Howe duality phenomenon can be extended to the affine ${\\mathfrak sl}_m$ case, corresponding to looking at tangles embedded in a solid torus. We investigate the relations between the invariants constructed by evaluation representations (and affinization of them) and usual skein modules,...

  9. Minimum information about a protein affinity reagent (MIAPAR).

    OpenAIRE

    Bourbeillon, Julie; Orchard, Sandra; Benhar, Itai; Borrebaeck, Carl; de Daruvar, Antoine; Dübel, Stefan; Frank, Ronald; Gibson, Frank; Gloriam, David; Haslam, Niall; Hiltker, Tara; Humphrey-Smith, Ian; Hust, Michael; Juncker, David; Koegl, Manfred

    2010-01-01

    We wish to alert your readers to MIAPAR, the minimum information about a protein affinity reagent. This is a proposal developed within the community as an important first step in formalizing standards in reporting the production and properties of protein binding reagents, such as antibodies, developed and sold for the identification and detection of specific proteins present in biological samples. It defines a checklist of required information, intended for use by producers of affinity reagen...

  10. Affinity Solvents for Intensified Organics Extraction: Development Challenges and Prospects

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In most organics extraction processes, the commonly used solvents employ solely physical interactions. Therefore, for the recovery and purification of products from complex mixtures, the selectivity and/or capacity of classical solvents towards the desired solutes is usually insufficient, enforcing the need for complex and thus expensive separation schemes. Significant simplification and cost-reduction can be achieved when affinity solvents would be available that are able to recognize the solutes of interest by their molecular structure. The main development challenges to establish such affinity solvents are: Selection and incorporation of molecular recognition and complexation capabilities; Evaluation of extraction capabilities; Efficient recovery and recycling of the affinity solvents; Implementation in industrial extraction equipment. This paper presents how these development challenges are addressed at the University of Twente, going all the way from affinity solvent design and synthesis, via high throughput screening and characterization up to pilot plant evaluation. Essential in the successful development of affinity solvents are structural cooperations with molecular chemists and custom synthesis companies for their design and synthesis. The various aspects are illustrated by several examples where newly developed environmentally benign affinity solvents appeared able to create major breakthroughs. The applications addressed involve oxygenates, sugars, and pharmaceutical ingredients, such as optical isomers and biomolecules.

  11. Lipidomics by Supercritical Fluid Chromatography

    Directory of Open Access Journals (Sweden)

    Laurent Laboureur

    2015-06-01

    Full Text Available This review enlightens the role of supercritical fluid chromatography (SFC in the field of lipid analysis. SFC has been popular in the late 1980s and 1990s before almost disappearing due to the commercial success of liquid chromatography (LC. It is only 20 years later that a regain of interest appeared when new commercial instruments were introduced. As SFC is fully compatible with the injection of extracts in pure organic solvent, this technique is perfectly suitable for lipid analysis and can be coupled with either highly universal (UV or evaporative light scattering or highly specific (mass spectrometry detection methods. A short history of the use of supercritical fluids as mobile phase for the separation oflipids will be introduced first. Then, the advantages and drawbacks of SFC are discussed for each class of lipids (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, prenols, polyketides defined by the LIPID MAPS consortium.

  12. Lipidomics by Supercritical Fluid Chromatography.

    Science.gov (United States)

    Laboureur, Laurent; Ollero, Mario; Touboul, David

    2015-01-01

    This review enlightens the role of supercritical fluid chromatography (SFC) in the field of lipid analysis. SFC has been popular in the late 1980s and 1990s before almost disappearing due to the commercial success of liquid chromatography (LC). It is only 20 years later that a regain of interest appeared when new commercial instruments were introduced. As SFC is fully compatible with the injection of extracts in pure organic solvent, this technique is perfectly suitable for lipid analysis and can be coupled with either highly universal (UV or evaporative light scattering) or highly specific (mass spectrometry) detection methods. A short history of the use of supercritical fluids as mobile phase for the separation oflipids will be introduced first. Then, the advantages and drawbacks of SFC are discussed for each class of lipids (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, prenols, polyketides) defined by the LIPID MAPS consortium. PMID:26090714

  13. Lipidomics by Supercritical Fluid Chromatography

    Science.gov (United States)

    Laboureur, Laurent; Ollero, Mario; Touboul, David

    2015-01-01

    This review enlightens the role of supercritical fluid chromatography (SFC) in the field of lipid analysis. SFC has been popular in the late 1980s and 1990s before almost disappearing due to the commercial success of liquid chromatography (LC). It is only 20 years later that a regain of interest appeared when new commercial instruments were introduced. As SFC is fully compatible with the injection of extracts in pure organic solvent, this technique is perfectly suitable for lipid analysis and can be coupled with either highly universal (UV or evaporative light scattering) or highly specific (mass spectrometry) detection methods. A short history of the use of supercritical fluids as mobile phase for the separation oflipids will be introduced first. Then, the advantages and drawbacks of SFC are discussed for each class of lipids (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, prenols, polyketides) defined by the LIPID MAPS consortium. PMID:26090714

  14. Lagrangian description of nonlinear chromatography

    Institute of Scientific and Technical Information of China (English)

    LIANG; Heng; LIU; Xiaolong

    2004-01-01

    Under the framework of non-equilibrium thermodynamic separation theory (NTST), Local Lagrangian approach (LLA) was proposed to deal with the essential issues of the convection and diffusion (shock waves) phenomena in nonlinear chromatography with recursion equations based on the three basic theorems, Lagrangian description, continuity axiom and local equilibrium assumption (LEA). This approach remarkably distinguished from the system of contemporary chromatographic theories (Eulerian description-partial differential equations), and can felicitously match modern cybernetics.

  15. Studying protein–protein affinity and immobilized ligand–protein affinity interactions using MS-based methods

    OpenAIRE

    Kool, J.; N. Jonker; Irth, H.; Niessen, W.M.A.

    2011-01-01

    This review discusses the most important current methods employing mass spectrometry (MS) analysis for the study of protein affinity interactions. The methods are discussed in depth with particular reference to MS-based approaches for analyzing protein–protein and protein–immobilized ligand interactions, analyzed either directly or indirectly. First, we introduce MS methods for the study of intact protein complexes in the gas phase. Next, pull-down methods for affinity-based analysis of prote...

  16. Evidence for monomeric and oligomeric hormone-binding domains in affinity-purified gonadotropin receptor from rat ovary

    International Nuclear Information System (INIS)

    Rat ovarian lutropin/choriogonadotropin receptor was purified from a Triton X-100-solubilized membrane preparation by affinity chromatography with Affi-Gel 10 coupled to purified human choriogonadotropin. The affinity-purified receptor preparations contained a single class of high-affinity binding sites for 125I-labeled human choriogonadotropin, with an equilibrium dissociation constant (Kd) of 2.5 x 10-9 M, which is comparable to the Kd values for membrane-bound and solubilized receptors. The purified receptor appeared as two dominant bands with molecular weights of 135,000 and 92,000 after sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE) under nonreducing conditions. When the individual affinity-purified receptor bands were electroeluted from the gel and analyzed again by SDS/PAGE under nonreducing conditions, both the Mr 92,000 and the 135,000 proteins retained their original molecular form even when 8 M urea was included in the gel. However, when the electrophoretically purified Mr 92,000 and 135,000 bands were subjected to SDS/PAGE under reducing conditions, the Mr 135,000 species was almost completely converted to a Mr 92,000 band, but the Mr 92,000 species did not undergo any alteration in molecular weight. The results suggest that the lutropin/choriogonadotropin receptor from rat ovary exists in two molecular forms, and the higher molecular weight form appears to be composed of disulfide-linked Mr 92,000 subunit, which comprises the hormone-binding domain

  17. Topography of the high-affinity lysine binding site of plasminogen as defined with a specific antibody probe

    International Nuclear Information System (INIS)

    An antibody population that reacted with the high-affinity lysine binding site of human plasminogen was elicited by immunizing rabbits with an elastase degradation product containing kringles 1-3 (EDP I). This antibody was immunopurified by affinity chromatography on plasminogen-Sepharose and elution with 0.2 M 6-aminohexanoic acid. The eluted antibodies bound [125I]EDP I, [125I]Glu-plasminogen, and [125I]Lys-plasminogen in radioimmunoassays, and binding of each ligand was at least 99% inhibited by 0.2 M 6-aminohexanoic acid. The concentrations for 50% inhibition of [125I]EDP I binding by tranexamic acid, 6-aminohexanoic acid, and lysine were 2.6, 46, and l730 μM, respectively. Similar values were obtained with plasminogen and suggested that an unoccupied high-affinity lysine binding site was required for antibody recognition. The antiserum reacted exclusively with plasminogen derivatives containing the EDP I region and did not react with those lacking an EDP I region, or with tissue plasminogen activator or prothrombin, which also contains kringles. By immunoblotting analyses, a chymotryptic degradation product of M/sub r/ 20,000 was derived from EDP I that retained reactivity with the antibody. α2-Antiplasmin inhibited the binding of radiolabeled EDP I, Glu-plasminogen, or Lys-plasminogen by the antiserum, suggesting that the recognized site is involved in the noncovalent interaction of the inhibitor with plasminogen. The binding of [125I]EDP I to fibrin was also inhibited by the antiserum. The observations provide independent evidence for the role of the high-affinity lysine binding site in the functional interactions of plasminogen with its primary substrate and inhibitor

  18. Increased hemoglobin O2 affinity protects during acute hypoxia.

    Science.gov (United States)

    Yalcin, Ozlem; Cabrales, Pedro

    2012-08-01

    Acclimatization to hypoxia requires time to complete the adaptation mechanisms that influence oxygen (O(2)) transport and O(2) utilization. Although decreasing hemoglobin (Hb) O(2) affinity would favor the release of O(2) to the tissues, increasing Hb O(2) affinity would augment arterial O(2) saturation during hypoxia. This study was designed to test the hypothesis that pharmacologically increasing the Hb O(2) affinity will augment O(2) transport during severe hypoxia (10 and 5% inspired O(2)) compared with normal Hb O(2) affinity. RBC Hb O(2) affinity was increased by infusion of 20 mg/kg of 5-hydroxymethyl-2-furfural (5HMF). Control animals received only the vehicle. The effects of increasing Hb O(2) affinity were studied in the hamster window chamber model, in terms of systemic and microvascular hemodynamics and partial pressures of O(2) (Po(2)). Pimonidazole binding to hypoxic areas of mice heart and brain was also studied. 5HMF decreased the Po(2) at which the Hb is 50% saturated with O(2) by 12.6 mmHg. During 10 and 5% O(2) hypoxia, 5HMF increased arterial blood O(2) saturation by 35 and 48% from the vehicle group, respectively. During 5% O(2) hypoxia, blood pressure and heart rate were 58 and 30% higher for 5HMF compared with the vehicle. In addition, 5HMF preserved microvascular blood flow, whereas blood flow decreased to 40% of baseline in the vehicle group. Consequently, perivascular Po(2) was three times higher in the 5HMF group compared with the control group at 5% O(2) hypoxia. 5HMF also reduced heart and brain hypoxic areas in mice. Therefore, increased Hb O(2) affinity resulted in hemodynamics and oxygenation benefits during severe hypoxia. This acute acclimatization process may have implications in survival during severe environmental hypoxia when logistic constraints prevent chronic acclimatization. PMID:22636677

  19. Measurement of interactions between polysaccharides and flavour compounds by exclusion size chromatography: advantages and limits.

    Science.gov (United States)

    Guichard, E; Etiévant, P

    1998-12-01

    Interactions between flavour compounds and polysaccharides have been studied by exclusion size chromatography, the Hummel and Dreyer method. Hydrogen bonding was found between 2-acetyl thiazole and dextrines of different degrees of polymerisation. The number of binding sites and the affinity constant increase by increasing the degree of polymerisation. Hydrogen bonding was also responsible for the interactions between xanthane and 1-octen-3-ol or 2-acetyl pyrazine, with 1 mole of 1-octen-3-ol bound per pentasaccharide repeating unit. Unfortunately, the number of flavour compounds, which can be studied with this method, is limited due to their low water solubility and their low UV absorption. PMID:9881364

  20. Purification of organic acids by chromatography with strong anionic resins: Investigation of uptake mechanisms.

    Science.gov (United States)

    Lemaire, Julien; Blanc, Claire-Line; Lutin, Florence; Théoleyre, Marc-André; Stambouli, Moncef; Pareau, Dominique

    2016-08-01

    Bio-based organic acids are promising renewable carbon sources for the chemical industry. However energy-consuming purification processes are used, like distillation or crystallization, to reach high purities required in some applications. That is why preparative chromatography was studied as an alternative separation technique. In a previous work dealing with the purification of lactic, succinic and citric acids, the Langmuir model was insufficient to explain the elution profiles obtained with a strong anionic resin. Consequently the Langmuir model was coupled with a usual ion-exchange model to take into account the retention of their conjugate bases (tailing and apparent delay observed with succinic and citric acids can be explained by the high affinity of succinate and citrate for resin cationic sites. The model was implemented in a preparative chromatography simulation program in order to optimize operating parameters of our pilot-scale ISMB unit (Improved Simulated Moving Bed). The comparison with experimental ISMB profiles was conclusive. PMID:27373374

  1. Developmentally-Dynamic Murine Brain Proteomes and Phosphoproteomes Revealed by Quantitative Proteomics

    Directory of Open Access Journals (Sweden)

    Peter F. Doubleday

    2014-04-01

    Full Text Available Developmental processes are governed by a diverse suite of signaling pathways employing reversible phosphorylation. Recent advances in large-scale phosphoproteomic methodologies have made possible the identification and quantification of hundreds to thousands of phosphorylation sites from primary tissues. Towards a global characterization of proteomic changes across brain development, we present the results of a large-scale quantitative mass spectrometry study comparing embryonic, newborn and adult murine brain. Using anti-phosphotyrosine immuno-affinity chromatography and strong cation exchange (SCX chromatography, coupled to immobilized metal affinity chromatography (IMAC, we identified and quantified over 1,750 phosphorylation sites and over 1,300 proteins between three developmental states. Bioinformatic analyses highlight functions associated with the identified proteins and phosphoproteins and their enrichment at distinct developmental stages. These results serve as a primary reference resource and reveal dynamic developmental profiles of proteins and phosphoproteins from the developing murine brain.

  2. Expression of Major Capsid Protein of Cainine Parvovirus by Yeast (Pichia pastoris and Efficient Purification using Arginine in Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Ying He

    2016-06-01

    Full Text Available An immunochromatographic (IC assay was developed for rapid detection of canine parvovirus using the monoclonal antibodies (McAbs against canine parvovirus (CPV-2. To prepare the McAbs, gene encoding the VP2 protein of CPV-2a was expressed in a Pichia pastoris expression vector pPICZ-A. The recombinant VP2 was similar antigenically function to the native capsid protein as demonstrated by Western blotting using CPV- 2 polyclonal antiserum. McAbs against CPV-2 were produced by fusing myeloma cell line SP2/0 with spleen cells from Balb/C mice immunized with purified recombinant VP2 protein. By ELISA it was shown that the McAbs specifically recognized VP2 epitopes of CPV-2 but not those of other canine viruses such as Canine distemper virus (CDV or canine adenovirus (CAV. An IC assay developed with the McAbs was suitable for rapid detection of canine parvovirus. Fecal samples (120 from dogs suspected of CPV-2 infection were analyzed by both haemaglutination (HA assay and the IC assay, and 52 and 53 samples were found positive for CPV-2, respectively. Comparison between the two different assays revealed that IC assay is as sensitive as HA; the sensitivity and specificity for the IC assay is 98.6% and 98.1%, respectively.

  3. Overexpression of (His)6-tagged human arginase I in Saccharomyces cerevisiae and enzyme purification using metal affinity chromatography

    Czech Academy of Sciences Publication Activity Database

    Zakalskiy, A. E.; Zakalska, O. M.; Rzhepetskyy, Y. A.; Potocka, N.; Stasyk, O. V.; Horák, Daniel; Gonchar, M. V.

    2012-01-01

    Roč. 81, č. 1 (2012), s. 63-68. ISSN 1046-5928 R&D Projects: GA ČR GA203/09/1242 Institutional research plan: CEZ:AV0Z40500505 Keywords : human arginase I * (His)6-tag * Saccharomyces cerevisiae Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.429, year: 2012

  4. Using Nonionic Surfactants for Production of Semiconductor-type Carbon Nanotubes by Gel-based Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Varun Shenoy Gangoli

    2014-07-01

    characterization of the particulate suspension. Semiconductor- type SWCNTs are recovered in solid form by evaporating the suspension fluid, and heating the dried sample in air to a temperature just above the Pluronic decomposition temperature. Using Pluronic and other nonionic-type surfactants can aid the scalability of the chromatographic production of semiconducting SWCNT samples.

  5. Affinity chromatography of serine proteases on the triazine dye ligand Cibacron Blue F3G-A

    DEFF Research Database (Denmark)

    Koch, C; Borg, L; Skjødt, K;

    1998-01-01

    The interaction between complement component factor B and the triazine dye ligand Cibacron Blue F3G-A coupled to a cross-linked agarose matrix (Blue Sepharose) was found to involve the Bb part of the molecule, and to be inhibited by benzamidine. Human, chicken and rainbow trout factor B which had...

  6. Investigation of different molecular forms of IGFBP-1 using immobilised metal-, immuno- and lectin-affinity chromatography

    OpenAIRE

    Lagundžin Dragana; Masnikosa Romana; Miljuš Goran; Robajac Dragana; Nedić Olgica

    2010-01-01

    Insulin-like growth factor-binding protein 1 (IGFBP-1) is a member of a family of six homologous proteins that regulate the action of the insulin-like growth factors. IGFBP-1 is a 25 kDa protein that beside its native form, may exist in several phosphoforms (30 kDa), which are predominant in the circulation of humans. Phosphorylation of IGFBP-1 is a post-translational modification that has a great influence on the IGF-I action. IGFBP-1 forms multimers and complexes with α2-macroglobulin (α2M)...

  7. Using Affinity Chromatography to Investigate Novel Protein-Protein Interactions in an Undergraduate Cell and Molecular Biology Lab Course

    Science.gov (United States)

    Belanger, Kenneth D.

    2009-01-01

    Inquiry-driven lab exercises require students to think carefully about a question, carry out an investigation of that question, and critically analyze the results of their investigation. Here, we describe the implementation and assessment of an inquiry-based laboratory exercise in which students obtain and analyze novel data that contribute to our…

  8. Isotope shift in the electron affinity of beryllium

    International Nuclear Information System (INIS)

    The study of the isotope shift in the electron affinity is interesting for probing correlation effects. Experiments that allow this property to be measured are rare, being difficult to realize, while accurate calculations remain a challenge for atomic theory. The present work focuses on the theoretical estimation of the isotope shift in the electron affinity of Be (2s2p 3Po), using correlated electronic wavefunctions obtained from multiconfiguration Hartree-Fock and configuration interaction variational calculations. The reliability of the correlation models is assessed from a comparison between the observed and theoretical electron affinities, and between theoretical isotope shift values for the 2s2p 3Po 2s21S transition of neutral beryllium. The sign and the magnitude of the difference between the mass polarization term expectation values obtained for the neutral atom and the negative ion are such that the resulting isotope shift in the electron affinity is 'anomalous', corresponding to a smaller electron affinity for the heavier isotope

  9. Coenzyme-like ligands for affinity isolation of cholesterol oxidase.

    Science.gov (United States)

    Xin, Yu; Lu, Liushen; Wang, Qing; Zhang, Ling; Tong, Yanjun; Wang, Wu

    2016-05-15

    Two coenzyme-like chemical ligands were designed and synthesized for affinity isolation of cholesterol oxidase (COD). To simulate the structure of natural coenzyme of COD (flavin adenine dinucleotide (FAD)), on Sepharose beads, 5-aminouracil, cyanuric chloride and 1, 4-butanediamine were composed and then modified. The COD gene from Brevibacterium sp. (DQ345780) was expressed in Escherichia coli BL21 (DE3), and then the sorbents were applied to adsorption analysis with the pure enzyme. Subsequently, the captured enzyme was applied to SDS-PAGE and activity analysis. As calculated, the theoretical maximum adsorption (Qmax) of the two affinity sorbents (RL-1 and RL-2) were ∼83.5 and 46.3mg/g wet gel; and the desorption constant Kd of the two sorbents were ∼6.02×10(-4) and 1.19×10(-4)μM. The proteins after cell lysis were applied to affinity isolation, and then after one step of affinity binding on the two sorbents, the protein recoveries of RL-1 and RL-2 were 9.2% and 9.7%; the bioactivity recoveries were 92.7% and 91.3%, respectively. SDS-PAGE analysis revealed that the purities of COD isolated with the two affinity sorbents were approximately 95%. PMID:26856529

  10. Craniodental affinities of Southeast Asia's "negritos" and the concordance with their genetic affinities.

    Science.gov (United States)

    Bulbeck, David

    2013-01-01

    Genetic research into Southeast Asia's "negritos" has revealed their deep-rooted ancestry, with time depth comparable to that of Southwest Pacific populations. This finding is often interpreted as evidence that negritos, in contrast to other Southeast Asians, can trace much of their ancestry directly back to the early dispersal of Homo sapiens in the order of 70 kya from Africa to Pleistocene New Guinea and Australia. One view on negritos is to lump them and Southwest Pacific peoples into an "Australoid" race whose geographic distribution had included Southeast Asia prior to the Neolithic incursion of "Mongoloid" farmers. Studies into Semang osteology have revealed some hints of Southwest Pacific affinities in cranial shape, dental morphology, and dental metrical "shape." On the other hand, the Andamanese have been shown to resemble Africans in their craniometrics and South Asians in their dental morphology, while Philippine negritos resemble Mongoloid Southeast Asians in these respects and also in their dental metrics. This study expands the scope of negrito cranial comparisons by including Melayu Malays and additional coverage of South Asians. It highlights the distinction between the Mongoloid-like Philippine negritos and the Andamanese and Semang (and Senoi of Malaya) with their non-Mongoloid associations. It proposes that the early/mid-Holocene dispersal of the B4a1a mitochondrial DNA clade across Borneo, the Philippines, and Taiwan may be important for understanding the distinction between Philippine and other negritos. PMID:24297222

  11. Chromatography is Alive and Well

    OpenAIRE

    Frank L. Dorman

    2014-01-01

    It is my great pleasure to serve as the first editor-in-chief for Chromatography, and welcome you all to the readership. This journal will enable us to communicate our findings in “open access” while maintaining the very high scientific requirements of the few other journals that are focused on the type of science that we all find so very interesting. It is safe to say that chromatographic separations are the single most heavily used techniques in the larger field of analytical chemistry, whe...

  12. k-Schur functions and affine Schubert calculus

    CERN Document Server

    Lam, Thomas; Morse, Jennifer; Schilling, Anne; Shimozono, Mark; Zabrocki, Mike

    2014-01-01

    This book gives an introduction to the very active field of combinatorics of affine Schubert calculus, explains the current state of the art, and states the current open problems. Affine Schubert calculus lies at the crossroads of combinatorics, geometry, and representation theory. Its modern development is motivated by two seemingly unrelated directions. One is the introduction of k-Schur functions in the study of Macdonald polynomial positivity, a mostly combinatorial branch of symmetric function theory. The other direction is the study of the Schubert bases of the (co)homology of the affine Grassmannian, an algebro-topological formulation of a problem in enumerative geometry. This is the first introductory text on this subject. It contains many examples in Sage, a free open source general purpose mathematical software system, to entice the reader to investigate the open problems. This book is written for advanced undergraduate and graduate students, as well as researchers, who want to become familiar with ...

  13. Enhancing Community Detection By Affinity-based Edge Weighting Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    Community detection refers to an important graph analytics problem of finding a set of densely-connected subgraphs in a graph and has gained a great deal of interest recently. The performance of current community detection algorithms is limited by an inherent constraint of unweighted graphs that offer very little information on their internal community structures. In this paper, we propose a new scheme to address this issue that weights the edges in a given graph based on recently proposed vertex affinity. The vertex affinity quantifies the proximity between two vertices in terms of their clustering strength, and therefore, it is ideal for graph analytics applications such as community detection. We also demonstrate that the affinity-based edge weighting scheme can improve the performance of community detection algorithms significantly.

  14. Semisupervised Clustering for Networks Based on Fast Affinity Propagation

    Directory of Open Access Journals (Sweden)

    Mu Zhu

    2013-01-01

    Full Text Available Most of the existing clustering algorithms for networks are unsupervised, which cannot help improve the clustering quality by utilizing a small number of prior knowledge. We propose a semisupervised clustering algorithm for networks based on fast affinity propagation (SCAN-FAP, which is essentially a kind of similarity metric learning method. Firstly, we define a new constraint similarity measure integrating the structural information and the pairwise constraints, which reflects the effective similarities between nodes in networks. Then, taking the constraint similarities as input, we propose a fast affinity propagation algorithm which keeps the advantages of the original affinity propagation algorithm while increasing the time efficiency by passing only the messages between certain nodes. Finally, by extensive experimental studies, we demonstrate that the proposed algorithm can take fully advantage of the prior knowledge and improve the clustering quality significantly. Furthermore, our algorithm has a superior performance to some of the state-of-art approaches.

  15. Single-cell measurement of red blood cell oxygen affinity

    CERN Document Server

    Caprio, Di; Higgins, John M; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...

  16. Properties of the Affine Invariant Ensemble Sampler in high dimensions

    CERN Document Server

    Huijser, David; Brewer, Brendon J

    2015-01-01

    We present theoretical and practical properties of the affine-invariant ensemble sampler Markov chain Monte Carlo method. In high dimensions the affine-invariant ensemble sampler shows unusual and undesirable properties. We demonstrate this with an $n$-dimensional correlated Gaussian toy problem with a known mean and covariance structure, and analyse the burn-in period. The burn-in period seems to be short, however upon closer inspection we discover the mean and the variance of the target distribution do not match the expected, known values. This problem becomes greater as $n$ increases. We therefore conclude that the affine-invariant ensemble sampler should be used with caution in high dimensional problems. We also present some theoretical results explaining this behaviour.

  17. Evaluation Codes from an Affine Veriety Code Perspective

    DEFF Research Database (Denmark)

    Geil, Hans Olav

    2008-01-01

    Evaluation codes (also called order domain codes) are traditionally introduced as generalized one-point geometric Goppa codes. In the present paper we will give a new point of view on evaluation codes by introducing them instead as particular nice examples of affine variety codes. Our study...... includes a reformulation of the usual methods to estimate the minimum distances of evaluation codes into the setting of affine variety codes. Finally we describe the connection to the theory of one-pointgeometric Goppa codes. Contents 4.1 Introduction...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 4.2 Affine variety codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 4.3 Some Gr¨obner basis theoretical tools . . . . . . . . . . . . . . . . . . . . . . . 155 4.4 A bound on the minimum distance of C(I,L) . . . . . . . . . . . . . . . . . . 157 4.5 The Feng-Rao bound for...

  18. Can we beat the biotin-avidin pair?: cucurbit[7]uril-based ultrahigh affinity host-guest complexes and their applications.

    Science.gov (United States)

    Shetty, Dinesh; Khedkar, Jayshree K; Park, Kyeng Min; Kim, Kimoon

    2015-12-01

    The design of synthetic, monovalent host-guest molecular recognition pairs is still challenging and of particular interest to inquire into the limits of the affinity that can be achieved with designed systems. In this regard, cucurbit[7]uril (CB[7]), an important member of the host family cucurbit[n]uril (CB[n], n = 5-8, 10, 14), has attracted much attention because of its ability to form ultra-stable complexes with multiple guests. The strong hydrophobic effect between the host cavity and guests, ion-dipole and dipole-dipole interactions of guests with CB portals helps in cooperative and multiple noncovalent interactions that are essential for realizing such strong complexations. These highly selective, strong yet dynamic interactions can be exploited in many applications including affinity chromatography, biomolecule immobilization, protein isolation, biological catalysis, and sensor technologies. In this review, we summarize the progress in the development of high affinity guests for CB[7], factors affecting the stability of complexes, theoretical insights, and the utility of these high affinity pairs in different challenging applications. PMID:26434388

  19. Affinity purification and partial characterization of a yeast multiprotein complex for nucleotide excision repair using histidine-tagged Rad14 protein

    International Nuclear Information System (INIS)

    The nucleotide excision repair (NER) pathway of eukaryotes involves approximately 30 polypeptides. Reconstitution of this pathway with purified components is consistent with the sequential assembly of NER proteins at the DNA lesion. However, recent studies have suggested that NER proteins may be pre-assembled in a high molecular weight complex in the absence of DNA damage. To examine this model further, we have constructed a histidine-tagged version of the yeast DNA damage recognition protein Rad14. Affinity purification of this protein from yeast nuclear extracts resulted in the co-purification of Rad1, Rad7, Rad10, Rad16, Rad23, RPA, RPB1, and TFIIH proteins, whereas none of these proteins bound to the affinity resin in the absence of recombinant Rad14. Furthermore, many of the co-purifying proteins were present in approximately equimolar amounts. Co-elution of these proteins was also observed when the nuclear extract was fractionated by gel filtration, indicating that the NER proteins were associated in a complex with a molecular mass of >1000 kDa prior to affinity chromatography. The affinity purified NER complex catalyzed the incision of UV-irradiated DNA in an ATP-dependent reaction. We conclude that active high molecular weight complexes of NER proteins exist in undamaged yeast cells

  20. Affinity purification and characterization of (2'-5')oligo(adenylate)-dependent RNase from mouse spleen.

    Science.gov (United States)

    Bayard, B; Bette-Bobillo, P; Aliau, S

    1994-07-15

    Murine (2'-5')An-dependent RNase, a key enzyme of the interferon system, was purified from mouse spleen by affinity chromatography to immobilized (2'-5')An. Since the ribonuclease has high affinity to (2'-5')An, optimal non-denaturing conditions were obtained to disrupt the (2'-5')An-nuclease complex. Low-pH buffers in the presence of 0.1% Triton X-100 removed almost 80% of the enzyme from the (2'-5')An-agarose, preserving its (2'-5')An binding activity and RNA cleavage function. Purification was monitored using a classical radiobinding assay, ultraviolet covalent crosslinking method and denaturing-renaturing affinity blotting assay. The purified enzyme was a 160-kDa dimer that migrated with an apparent molecular mass of 78 kDa and was > 80% pure, as assessed by silver-stained SDS gels. Both a 160-kDa dimer and 78-kDa monomer were found in the cellular extract at a 5:1 ratio. Binding of radiolabeled (2'-5')An to (2'-5')An-dependent RNase either in crude extract or in purified form reached equilibrium by 5 h at 4 degrees C. 2-Mercaptoethanol was required to obtain (2-'5')An-binding activity but, interestingly, in the absence of this reducing agent, (2'-5')An-binding activity was initiated by preincubation with poly(U), a synthetic substrate of the nuclease. This new mechanistic feature indicates that interaction of poly(U) with nuclease induced a conformational modification allowing, in a second step, the binding of (2'-5')An. Furthermore, when activated by low amounts of (2'-5')An, the eluted purified enzyme degraded mRNA but there was still degradation in the absence of (2'-5')An. This suggested a loss of regulatory protein(s) during the purification step. Scatchard analysis showed that the purified enzyme had a Kd of 106 pM for (2'-5')An, similar to estimates obtained using crude spleen extracts (Kd 112 pM), indicating that the purified nuclease had almost identical (2'-5')An-binding properties to those identified in spleen extracts. PMID:8055909

  1. Fundamentals of preparative and nonlinear chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Guiochon, Georges A [ORNL; Felinger, Attila [ORNL; Katti, Anita [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Shirazi, Dean G [unknown

    2006-02-01

    The second edition of Fundamentals of Preparative and Nonlinear Chromatography is devoted to the fundamentals of a new process of purification or extraction of chemicals or proteins widely used in the pharmaceutical industry and in preparative chromatography. This process permits the preparation of extremely pure compounds satisfying the requests of the US Food and Drug Administration. The book describes the fundamentals of thermodynamics, mass transfer kinetics, and flow through porous media that are relevant to chromatography. It presents the models used in chromatography and their solutions, discusses the applications made, describes the different processes used, their numerous applications, and the methods of optimization of the experimental conditions of this process.

  2. Extremely high negative electron affinity of diamond via magnesium adsorption

    OpenAIRE

    O'Donnell, Kane M.; Edmonds, Mark T.; Tadich, Anton; Thomsen, Lars; Stacey, Alastair; Schenk, Alex; Pakes, Chris I.; Ley, Lothar

    2015-01-01

    We report large negative electron affinity (NEA) on diamond (100) using magnesium adsorption on a previously oxygen-terminated surface. The measured NEA is up to $(-2.01\\pm0.05)$ eV, the largest reported negative electron affinity to date. Despite the expected close relationship between the surface chemistry of Mg and Li species on oxygen-terminated diamond, we observe differences in the adsorption properties between the two. Most importantly, a high-temperature annealing step is not required...

  3. Combinatorial topology of three-dimensional self-affine tiles

    CERN Document Server

    Bandt, Christoph

    2010-01-01

    We develop tools to study the topology and geometry of self-affine fractals in dimension three and higher. We use the self-affine structure and obtain rather detailed information about the connectedness of interior and boundary sets, and on the dimensions and intersections of boundary sets. As an application, we describe in algebraic terms the polyhedral structure of the six fractal three-dimensional twindragons. Only two of them can be homeomorphic to a ball but even these have faces which are not homeomorphic to a disk.

  4. and as Vertex Operator Extensionsof Dual Affine Algebras

    Science.gov (United States)

    Bowcock, P.; Feigin, B. L.; Semikhatov, A. M.; Taormina, A.

    We discover a realisation of the affine Lie superalgebra and of the exceptional affine superalgebra as vertex operator extensions of two algebras with ``dual'' levels (and an auxiliary level-1 algebra). The duality relation between the levels is . We construct the representation of on a sum of tensor products of , , and modules and decompose it into a direct sum over the spectral flow orbit. This decomposition gives rise to character identities, which we also derive. The extension of the construction to is traced to the properties of embeddings into and their relation with the dual pairs. Conversely, we show how the representations are constructed from representations.

  5. SMOOTH AFFINE SURFACES WITH NON-UNIQUE C*-ACTIONS

    OpenAIRE

    Flenner, Hubert; Kaliman, Shulim; ZAIDENBERG, MIKHAIL

    2008-01-01

    In this paper we complete the classification of effective C*-actions on smooth affine surfaces up to conjugation in the full automorphism group and up to inversion of C*. If a smooth affine surface V admits more than one C*-action then it is known to be Gizatullin i.e., it can be completed by a linear chain of smooth rational curves. In our previous paper we gave a sufficient condition, in terms of the Dolgachev- Pinkham-Demazure (or DPD) presentation, for the uniqueness of a C*-action on a G...

  6. Algebraic volume density property of affine algebraic manifolds

    CERN Document Server

    Kaliman, Shulim

    2009-01-01

    We introduce the notion of algebraic volume density property for affine algebraic manifolds and prove some important basic facts about it, in particular that it implies the volume density property. The main results of the paper are producing two big classes of examples of Stein manifolds with volume density property. One class consists of certain affine modifications of $\\C^n$ equipped with a canonical volume form, the other is the class of all Linear Algebraic Groups equipped with the left invariant volume form.

  7. Affine Moment Invariants Generated by Automated Solution of the Equations

    Czech Academy of Sciences Publication Activity Database

    Suk, Tomáš; Flusser, Jan

    Los Alamitos : IEEE Press, 2008, s. 3270-3273. ISBN 978-1-4244-2174-9. [19th International Conference on Pattern Recognition. Tampa (US), 07.12.2008-11.12.2008] R&D Projects: GA ČR GA102/08/1593 Institutional research plan: CEZ:AV0Z10750506 Keywords : affine moment invariants * object recognition * Cayley-Aronhold differential equation Subject RIV: JD - Computer Applications, Robotics http://library.utia.cas.cz/separaty/2008/ZOI/suk-affine moment invariants generated by automated solution of the equations. pdf

  8. Affine diffusions and related processes simulation, theory and applications

    CERN Document Server

    Alfonsi, Aurélien

    2015-01-01

    This book gives an overview of affine diffusions, from Ornstein-Uhlenbeck processes to Wishart processes and it considers some related diffusions such as Wright-Fisher processes. It focuses on different simulation schemes for these processes, especially second-order schemes for the weak error. It also presents some models, mostly in the field of finance, where these methods are relevant and provides some numerical experiments. The book explains the mathematical background to understand affine diffusions and analyze the accuracy of the schemes.  

  9. Double affine Hecke algebras and 2-dimensional local fields

    OpenAIRE

    Kapranov, M.

    1998-01-01

    We give an interpretation of the double affine Hecke algebra of Cherednik as the (suitably regularized) algebra of double cosets of a group G by a subgroup J, extending the well known interpretations of finite and affine Hecke algebras. In this interpretation, G consists of K-points of a split reductive group where K is a 2-dimensional local field such as Q_p((t)) or F_q((t_1))((t_2)), and J is a certain analog of the Iwahori subgroup.

  10. Affinity based and molecularly imprinted cryogels: Applications in biomacromolecule purification.

    Science.gov (United States)

    Andaç, Müge; Galaev, Igor Yu; Denizli, Adil

    2016-05-15

    The publications in macro-molecularly imprinted polymers have increased drastically in recent years with the development of water-based polymer systems. The macroporous structure of cryogels has allowed the use of these materials within different applications, particularly in affinity purification and molecular imprinting based methods. Due to their high selectivity, specificity, efficient mass transfer and good reproducibility, molecularly imprinted cryogels (MICs) have become attractive for researchers in the separation and purification of proteins. In this review, the recent developments in affinity based cryogels and molecularly imprinted cryogels in protein purification are reviewed comprehensively. PMID:26454622

  11. Kinetic controlled affinity labeling of target enzyme with thioester chemistry.

    Science.gov (United States)

    Tomohiro, Takenori; Nakabayashi, Masahiro; Sugita, Yuka; Morimoto, Shota

    2016-08-01

    High specificity has been an important feature in affinity labeling for target profiling. Especially, to label targets via rapidly progressing reactions with consumption of ligand (probe), high specificity of reaction with common functional groups of target protein should be achieved without reactions with similar groups of non-target proteins. Herein, we demonstrate the kinetic controlled affinity labeling of acyl CoA synthetase using a fatty acid analogue containing a phenylthioester linkage. High specificity was attained by accelerating the labeling rate in the binding pocket. This approach could be useful for profiling a series of target enzymes and transporters in signal transduction pathways. PMID:27298000

  12. Affine Hecke algebras associated to Kac-Moody groups

    CERN Document Server

    Garland, H

    1995-01-01

    In this paper we give a geometric construction of Cherednik's double affine Hecke algebra. We construct the algebra as the equivariant K-theory of the Lagrangian subvariety of the cotangent variety of the square of the flag variety of G, the variety being given by the union of the conormal bundles to the G-orbits on \\flag\\times\\flag. This is a generalisation of work of Kazhdan and Lusztig to the Kac-Moody case, and is suitable for describing a certain class of modules for this algebra. In a paper in preparation we will do this, in the case G is affine (Cherednik's case).

  13. Multiple poes and other features of affine Toda field theory

    International Nuclear Information System (INIS)

    Some perturbative features of affine Toda field theory are explored, in particular the mechanisms responsible for the first-, second- and third-order poles in the conjectured exact factorisable S-matrices in the ADE series of models. It is found that generic collections of Feynman diagrams are responsible for the leading order poles in any of the theories. However, the complexity is such that it has not yet proved possible to analyse all the singularities that occur up to order twelve. Some comments are made on an associated tiling problem and on an interesting connection between the affine Toda couplings and the Clebsch-Gordan decomposition of tensor products. (orig.)

  14. Deciphering Ligand Specificity of a Clostridium thermocellum Family 35 Carbohydrate Binding Module (CtCBM35) for Gluco- and Galacto- Substituted Mannans and Its Calcium Induced Stability

    OpenAIRE

    Ghosh, Arabinda; Luís, Ana Sofia; Brás, Joana L. A.; Pathaw, Neeta; Nikhil K. Chrungoo; Fontes, Carlos M. G. A.; Goyal, Arun

    2013-01-01

    This study investigated the role of CBM35 from Clostridium thermocellum (CtCBM35) in polysaccharide recognition. CtCBM35 was cloned into pET28a (+) vector with an engineered His6 tag and expressed in Escherichia coli BL21 (DE3) cells. A homogenous 15 kDa protein was purified by immobilized metal ion chromatography (IMAC). Ligand binding analysis of CtCBM35 was carried out by affinity electrophoresis using various soluble ligands. CtCBM35 showed a manno-configured ligand specific binding displ...

  15. A Comment on a Novel Approach for the Registration of Weak Affine Images

    Czech Academy of Sciences Publication Activity Database

    Flusser, Jan; Zitová, Barbara

    2013-01-01

    Roč. 34, č. 12 (2013), s. 1381-1385. ISSN 0167-8655 R&D Projects: GA ČR GAP103/11/1552 Keywords : Image registration * Affine transform * Affine subgroups * Weak affine transform * Area-preserving affine transform Subject RIV: JD - Computer Applications, Robotics Impact factor: 1.062, year: 2013 http://library.utia.cas.cz/separaty/2013/ZOI/flusser-a comment on a novel approach for the registration of weak affine images.pdf

  16. Thin-Layer Chromatography Experiments That Illustrate General Problems in Chromatography.

    Science.gov (United States)

    Lederer, M.; Leipzig-Pagani, E.

    1996-01-01

    Describes experiments that illustrate a number of general principles such as pattern identification, displacement chromatography, and salting-out adsorption, plus an experiment that demonstrates that identification by chromatography alone is impossible. Illustrates that chromatography is still possible with quite simple means, notwithstanding the…

  17. Chromatography and its hyphenation to mass spectrometry for extracellular vesicle analysis.

    Science.gov (United States)

    Pocsfalvi, Gabriella; Stanly, Christopher; Fiume, Immacolata; Vékey, Károly

    2016-03-25

    Extracellular vesicles (EVs), such as exosomes, microvesicles and apoptotic bodies are released by cells, both under physiological and pathological conditions. EVs can participate in a novel type of intercellular communication and deliver cargo of nucleic acids, proteins and lipids near or to distant host cells. EV research is proceeding at a fast pace; now they start to appear as promising therapeutic targets, diagnostic tools and drug delivery systems. Isolation and analysis of EVs are prerequisites for understanding their biological roles and for their clinical exploitation. In this process chromatography and mass spectrometry (MS)-based strategies are rapidly gaining importance; and are reviewed in the present communication. Isolation and purification of EVs is mostly performed by ultracentrifugation at present. Chromatography-based strategies are gaining ground, among which affinity and size exclusion chromatography (SEC) are particularly strong contenders. Their major advantages are the relative simplicity, robustness and throughput. Affinity chromatography has the added advantage of separating EV subtypes based on molecular recognition of EV surface motifs. SEC has the advantage that isolated EVs may retain their biological activity. EVs are typically isolated in small amounts, therefore high sensitivity is required for their analysis. Study of the molecular content of EVs (all compounds beside nucleic acids) is predominantly based on liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The chromatographic separation is mostly performed by reverse phase, nanoscale, ultra high performance LC technique. The MS analysis relying typically on nano-electrospray ionization MS/MS provides high sensitivity, selectivity and resolution, so that thousand(s) of proteins can be detected/identified/quantified in a EV sample. Beside protein identification, quantitation and characterization of protein post-translational modifications (PTMs), like glycosylation

  18. Affinity Purification of O-Acetylserine(thiollyase from Chlorella sorokiniana by Recombinant Proteins from Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Giovanna Salbitani

    2014-08-01

    Full Text Available In the unicellular green alga Chlorella sorokiniana (211/8 k, the protein O-acetylserine(thiollyase (OASTL, representing the key-enzyme in the biosynthetic cysteine pathway, was isolated and purified to apparent homogeneity. The purification was carried out in cells grown in the presence of all nutrients or in sulphate (S deprived cells. After 24 h of S-starvation, a 17-fold increase in the specific activity of OASTL was measured. In order to enable the identification of OASTL proteins from non-model organisms such as C. sorokiniana, the recombinant his-tagged SAT5 protein from Arabidopsis thaliana was immobilized by metal chelate chromatography. OASTL proteins from C. sorokiniana were affinity purified in one step and activities were enhanced 29- and 41-fold, from S-sufficient and S-starved (24 h cells, respectively. The successful application of SAT/OASTL interaction for purification confirms for the first time the existence of the cysteine synthase complexes in microalgae. The purified proteins have apparent molecular masses between 32–34 kDa and are thus slightly larger compared to those found in Arabidopsis thaliana and other vascular plants. The enhanced OASTL activity in S-starved cells can be attributed to increased amounts of plastidic and the emergence of cytosolic OASTL isoforms. The results provide proof-of-concept for the biochemical analysis of the cysteine synthase complex in diverse microalgal species.

  19. Solid-phase radioimmunoassay for morphine, with use of an affinity-purified morphine antibody

    International Nuclear Information System (INIS)

    Morphine antibody purified by affinity chromatography was used to develop a solid-phase radioimmunoassay for morphine in polystyrene tubes. The tubes are coated with an appropriate concentration of the purified antibody, rinsed three times with buffered saline, and stored at -150C. Using tritiated dihydromorphine, we determined competitive morphine binding by difference when the radioactivity in the assay supernates was measured after incubation (1 h, 370C). Five standard curves, with use of serum equivalents of morphine ranging from 0 to 6 μg/liter, were linear and had a mean correlation coefficient of 0.98. Under conditions of the assay, levorphanol was comparable to morphine in its inhibitory effect on binding of labeled dihydromorphine, whereas dextrorphan was essentially inactive. Morphine-3-glucuronide, a major metabolite, is 55-fold less inhibitory in terms of its capacity to displace the radiolabel. We believe that the sensitivity of the technique, coupled with the simplicity of nonseparatory sampling, renders the system suitable for rapid determination of morphine and related compounds in biological fluids

  20. Solid-phase radioimmunoassay for morphine, with use of an affinity-purified morphine antibody

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, M.; Spratt, J.L.

    1978-02-01

    Morphine antibody purified by affinity chromatography was used to develop a solid-phase radioimmunoassay for morphine in polystyrene tubes. The tubes are coated with an appropriate concentration of the purified antibody, rinsed three times with buffered saline, and stored at -15/sup 0/C. Using tritiated dihydromorphine, we determined competitive morphine binding by difference when the radioactivity in the assay supernates was measured after incubation (1 h, 37/sup 0/C). Five standard curves, with use of serum equivalents of morphine ranging from 0 to 6 ..mu..g/liter, were linear and had a mean correlation coefficient of 0.98. Under conditions of the assay, levorphanol was comparable to morphine in its inhibitory effect on binding of labeled dihydromorphine, whereas dextrorphan was essentially inactive. Morphine-3-glucuronide, a major metabolite, is 55-fold less inhibitory in terms of its capacity to displace the radiolabel. We believe that the sensitivity of the technique, coupled with the simplicity of nonseparatory sampling, renders the system suitable for rapid determination of morphine and related compounds in biological fluids.

  1. Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

    Directory of Open Access Journals (Sweden)

    Chin-Soon Chee

    2014-01-01

    Full Text Available Glutathione transferases (GST were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW of 23 kDa. 2-dimensional (2-D gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5 and GST2 (pI 6.2 with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase and F0KKB0 (glutathione S-transferase III of Acinetobacter calcoaceticus strain PHEA-2, respectively.

  2. High-affinity cannabinoid binding site in brain: A possible marijuana receptor

    Energy Technology Data Exchange (ETDEWEB)

    Nye, J.S.

    1988-01-01

    The mechanism by which delta{sup 9} tetrahydrocannabinol (delta{sup 9}THC), the major psychoactive component of marijuana or hashish, produces its potent psychological and physiological effects is unknown. To find receptor binding sites for THC, we designed a water-soluble analog for use as a radioligand. 5{prime}-Trimethylammonium-delta{sup 8}THC (TMA) is a positively charged analog of delta-{sup 8}THC modified on the 5{prime} carbon, a portion of the molecule not important for its psychoactivity. We have studied the binding of ({sup 3}H)-5{prime}-trimethylammonium-delta-{sup 8}THC (({sup 3}H)TMA) to rat neuronal membranes. ({sup 3}H)TMA binds saturably and reversibly to brain membranes with high affinity to apparently one class of sites. Highest binding site density occurs in brain, but several peripheral organs also display specific binding. Detergent solubilizes the sites without affecting their pharmacologial properties. Molecular sieve chromatography reveals a bimodal peak of ({sup 3}H)TMA binding activity of approximately 60,000 daltons apparent molecular weight.

  3. High-affinity cannabinoid binding site in brain: A possible marijuana receptor

    International Nuclear Information System (INIS)

    The mechanism by which delta9 tetrahydrocannabinol (delta9THC), the major psychoactive component of marijuana or hashish, produces its potent psychological and physiological effects is unknown. To find receptor binding sites for THC, we designed a water-soluble analog for use as a radioligand. 5'-Trimethylammonium-delta8THC (TMA) is a positively charged analog of delta-8THC modified on the 5' carbon, a portion of the molecule not important for its psychoactivity. We have studied the binding of [3H]-5'-trimethylammonium-delta-8THC ([3H]TMA) to rat neuronal membranes. [3H]TMA binds saturably and reversibly to brain membranes with high affinity to apparently one class of sites. Highest binding site density occurs in brain, but several peripheral organs also display specific binding. Detergent solubilizes the sites without affecting their pharmacologial properties. Molecular sieve chromatography reveals a bimodal peak of [3H]TMA binding activity of approximately 60,000 daltons apparent molecular weight

  4. A molecular determinant of phosphoinositide affinity in mammalian TRPV channels.

    Science.gov (United States)

    Velisetty, Phanindra; Borbiro, Istvan; Kasimova, Marina A; Liu, Luyu; Badheka, Doreen; Carnevale, Vincenzo; Rohacs, Tibor

    2016-01-01

    Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is an important cofactor for ion channels. Affinity for this lipid is a major determinant of channel inhibition by depletion of PI(4,5)P2 upon phospholipase C (PLC) activation. Little is known about what determines PI(4,5)P2 affinity in mammalian ion channels. Here we report that two members of the Transient Receptor Potential Vanilloid (TRPV) ion channel family, TRPV5 and TRPV6 lack a positively charged residue in the TM4-TM5 loop that was shown to interact with PI(4,5)P2 in TRPV1, which shows high affinity for this lipid. When this positively charged residue was introduced to either TRPV6 or TRPV5, they displayed markedly higher affinities for PI(4,5)P2, and were largely resistant to inhibition by PI(4,5)P2 depletion. Furthermore, Ca(2+)-induced inactivation of TRPV6 was essentially eliminated in the G488R mutant, showing the importance of PLC-mediated PI(4,5)P2 depletion in this process. Computational modeling shows that the introduced positive charge interacts with PI(4,5)P2 in TRPV6. PMID:27291418

  5. Affine Toda Solitons and Systems of Calogero-Moser Type

    OpenAIRE

    Braden, H. W.; Hone, Andrew N. W.

    1996-01-01

    The solitons of affine Toda field theory are related to the spin-generalised Ruijsenaars-Schneider (or relativistic Calogero-Moser) models. This provides the sought after extension of the correspondence between the sine-Gordon solitons and the Ruijsenaars-Schneider model.

  6. On representation theory of affine Hecke algebras of type B

    OpenAIRE

    Miemietz, Vanessa

    2007-01-01

    Ariki's and Grojnowski's approach to the representation theory of affine Hecke algebras of type $A$ is applied to type $B$ with unequal parameters to obtain -- under certain restrictions on the eigenvalues of the lattice operators -- analogous multiplicity-one results and a classification of irreducibles with partial branching rules as in type $A$.

  7. Soliton solutions for higher grading affine Toda from quantum algebras

    Czech Academy of Sciences Publication Activity Database

    Zuevsky, Alexander

    Bristol: IOP, 2015, 012001. ISSN 1755-1307. [2nd International Conference on Geological, Geographical, Aerospace and Earth Sciences 2014 (AeroEarth 2014). Bali (ID), 11.10.2014-12.10.2014] Institutional support: RVO:67985840 Keywords : Lie algebra s * integrable models * affine Toda model Subject RIV: BA - General Mathematics http://iopscience.iop.org/1755-1315/23/1/012001

  8. PP-waves with torsion and metric-affine gravity

    OpenAIRE

    Pasic, Vedad; Vassiliev, Dmitri

    2005-01-01

    A classical pp-wave is a 4-dimensional Lorentzian spacetime which admits a nonvanishing parallel spinor field; here the connection is assumed to be Levi-Civita. We generalise this definition to metric compatible spacetimes with torsion and describe basic properties of such spacetimes. We use our generalised pp-waves for constructing new explicit vacuum solutions of quadratic metric-affine gravity.

  9. Canonical bases and affine Hecke algebras of type B

    CERN Document Server

    Varagnolo, Michela

    2009-01-01

    We prove a series of conjectures of Enomoto and Kashiwara on canonical bases and branching rules of affine Hecke algebras of type B. The main ingredient of the proof is a new graded Ext-algebra associated with quiver with involutions that we compute explicitly.

  10. Several Affinity Tags Commonly Used in Chromatographic Purification

    Directory of Open Access Journals (Sweden)

    Xinyu Zhao

    2013-01-01

    Full Text Available Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, Strep II tag, streptavidin-binding peptide (SBP tag, calmodulin-binding peptide (CBP, glutathione S-transferase (GST, maltose-binding protein (MBP, S-tag, HA tag, and c-Myc tag. In some cases, a large-size affinity tag, such as GST or MBP, can significantly impact on the structure and biological activity of the fusion partner protein. So it is usually necessary to excise the tag by protease. The most commonly used endopeptidases are enterokinase, factor Xa, thrombin, tobacco etch virus, and human rhinovirus 3C protease. The proteolysis features of these proteases are described in order to provide a general guidance on the proteolytic removal of the affinity tags.

  11. Toward an Affinity Space Methodology: Considerations for Literacy Research

    Science.gov (United States)

    Lammers, Jayne C.; Curwood, Jen Scott; Magnifico, Alecia Marie

    2012-01-01

    As researchers seek to make sense of young people's online literacy practices and participation, questions of methodology are important to consider. In our work to understand the culture of physical, virtual and blended spheres that adolescents inhabit, we find it necessary to expand Gee's (2004) notion of affinity spaces. In this article, we draw…

  12. Self-Affine Sets with Positive Lebesgue Measure

    NARCIS (Netherlands)

    Dajani, Karma; Jiang, Kan; Kempton, Tom

    2014-01-01

    Using techniques introduced by C. G ̈unt ̈urk, we prove that the attractors of a family of overlapping self-affine iterated function systems contain a neighbourhood of zero for all parameters in a certain range. This corresponds to giving conditions under which a single sequence may serve as a ‘simu

  13. Native Elution of Yeast Protein Complexes Obtained by Affinity Capture.

    Science.gov (United States)

    LaCava, John; Fernandez-Martinez, Javier; Rout, Michael P

    2016-01-01

    This protocol describes two options for the native (nondenaturing) elution of protein complexes obtained by affinity capture. The first approach involves the elution of complexes purified through a tag that includes a human rhinovirus 3C protease (PreScission protease) cleavage site sequence between the protein of interest and the tag. Incubation with the protease cleaves immobilized complexes from the affinity medium. The second approach involves the release of protein A-tagged protein complexes using a competitive elution reagent called PEGylOx. The degree of purity of the native assemblies eluted is sample dependent and strongly influenced by the affinity capture. It should be noted that the efficiency of native elution is commonly lower than that of elution by a denaturing agent (e.g., SDS) and the release of the complex will be limited by the activity of the protease or the inhibition constant (Ki) of the competitive release agent. However, an advantage of native release is that some nonspecifically bound materials tend to stay adsorbed to the affinity medium, providing an eluted fraction of higher purity. Finally, keep in mind that the presence of the protease or elution peptide could potentially affect downstream applications; thus, their removal should be considered. PMID:27371597

  14. Harmonic fusion and pitch affinity: Is there a direct link?

    Science.gov (United States)

    Bonnard, Damien; Dauman, René; Semal, Catherine; Demany, Laurent

    2016-03-01

    Simultaneous pure tones approximately one octave apart tend to be fused perceptually and to evoke a single pitch sensation. Besides, sequentially presented pure tones show a subjective "affinity" or similarity in pitch when their frequency ratio is close to one octave. The aim of the study reported here was to determine if these two perceptual phenomena are directly related. Each stimulus was a triplet of simultaneous or successive pure tones forming frequency ratios varying across stimuli between 0.96 and 1.04 octaves. The tones were presented at a low sensation level (15 dB) within broadband threshold-equalizing noise, in order to prevent them from interacting in the cochlea when they were simultaneous. A large set of stimulus comparisons made by 18 listeners indicated that: (1) when the tones were simultaneous, maximal fusion was obtained for a mean frequency ratio deviating by less than 0.2% from one octave, and fusion decreased less rapidly above this frequency ratio than below it; (2) when the tones were presented successively, maximal pitch affinity was obtained for a mean frequency ratio significantly larger than one octave, and pitch affinity decreased more rapidly above this frequency ratio than below it. The differences between the results obtained for simultaneous and successive tones suggest that harmonic fusion and pitch affinity are unrelated phenomena. PMID:26341475

  15. Soliton-preserving boundary condition in affine Toda field theories

    OpenAIRE

    Delius, Gustav W

    1998-01-01

    We give a new integrable boundary condition in affine Toda theory which is soliton-preserving in the sense that a soliton hitting the boundary is reflected as a soliton. All previously known integrable boundary conditions forced a soliton to be converted into an antisoliton upon reflection. We prove integrability of our boundary condition using a generalization of Sklyanin's formalism.

  16. Demazure modules and vertex models the affine sl(2) case

    CERN Document Server

    Foda, O E; Okado, M; Foda, Omar; Misra, Kailash C; Okado, Masato

    1996-01-01

    We characterize, in the case of affine sl(2), the crystal base of the Demazure module E_w(\\La) in terms of extended Young diagrams or paths for any dominant integral weight \\La and Weyl group element w. Its character is evaluated via two expressions, 'bosonic' and 'fermionic'.

  17. Demazure modules and vertex models: the affine sl(2) case

    OpenAIRE

    Foda, Omar; Misra, Kailash C.; Okado, Masato

    1996-01-01

    We characterize, in the case of affine sl(2), the crystal base of the Demazure module E_w(\\La) in terms of extended Young diagrams or paths for any dominant integral weight \\La and Weyl group element w. Its character is evaluated via two expressions, 'bosonic' and 'fermionic'.

  18. Soliton solutions for higher grading affine Toda from quantum algebras

    Czech Academy of Sciences Publication Activity Database

    Zuevsky, Alexander

    Bristol : IOP, 2015, 012001. ISSN 1755-1307. [2nd International Conference on Geological, Geographical, Aerospace and Earth Sciences 2014 (AeroEarth 2014). Bali (ID), 11.10.2014-12.10.2014] Institutional support: RVO:67985840 Keywords : Lie algebra s * integrable models * affine Toda model Subject RIV: BA - General Mathematics http://iopscience.iop.org/1755-1315/23/1/012001

  19. Combinatorial Vector Fields for Piecewise Affine Control Systems

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Larsen, Jesper Abildgaard

    2008-01-01

    This paper is intended to be a continuation of Habets and van Schuppen (2004) and Habets, Collins and van Schuppen (2006), which address the control problem for piecewise-affine systems on an arbitrary polytope or a family of these. Our work deals with the underlying combinatorics of the underlyi...

  20. Linear independence measure of logarithms over affine groups

    OpenAIRE

    Huicochea, Mario

    2015-01-01

    Linear forms in logarithms over connected commutative algebraic groups over the algebraic numbers field have been studied widely. However, the theory of linear forms in logarithms over noncommutative algebraic groups have not been developed as the one of the commutative algebraic groups and in this paper we start studying linear forms in logarithms over affine groups.

  1. An Affine Invariant $k$-Nearest Neighbor Regression Estimate

    CERN Document Server

    Biau, Gérard; Dujmovic, Vida; Krzyzak, Adam

    2012-01-01

    We design a data-dependent metric in $\\mathbb R^d$ and use it to define the $k$-nearest neighbors of a given point. Our metric is invariant under all affine transformations. We show that, with this metric, the standard $k$-nearest neighbor regression estimate is asymptotically consistent under the usual conditions on $k$, and minimal requirements on the input data.

  2. Smooth surfaces from bilinear patches: Discrete affine minimal surfaces

    KAUST Repository

    Käferböck, Florian

    2013-06-01

    Motivated by applications in freeform architecture, we study surfaces which are composed of smoothly joined bilinear patches. These surfaces turn out to be discrete versions of negatively curved affine minimal surfaces and share many properties with their classical smooth counterparts. We present computational design approaches and study special cases which should be interesting for the architectural application. 2013 Elsevier B.V.

  3. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2015-06-01

    Full Text Available Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant and 2-CEES (a blister agent simulant were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper.

  4. Research on the interaction of hydrogen-bond acidic polymer sensitive sensor materials with chemical warfare agents simulants by inverse gas chromatography.

    Science.gov (United States)

    Yang, Liu; Han, Qiang; Cao, Shuya; Huang, Feng; Qin, Molin; Guo, Chenghai; Ding, Mingyu

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper. PMID:26043177

  5. Thin Layer Chromatography (TLC) of Chlorophyll Pigments.

    Science.gov (United States)

    Foote, Jerry

    1984-01-01

    Background information, list of materials needed, procedures used, and discussion of typical results are provided for an experiment on the thin layer chromatography of chlorophyll pigments. The experiment works well in high school, since the chemicals used are the same as those used in paper chromatography of plant pigments. (JN)

  6. Instrument platforms for thin-layer chromatography.

    Science.gov (United States)

    Bernard-Savary, Pierre; Poole, Colin F

    2015-11-20

    High performance column and thin-layer chromatography are both instrumental techniques but differ in that column chromatography requires a fully integrated instrument platform with high pressure capability while for thin-layer chromatography separate devices are used for each unit operation, usually at or close to atmospheric pressure, and afford higher flexibility supporting on-line or off-line operation. The unit operations of thin-layer chromatography are defined as sample application, development and evaluation with derivatization as an optional step. The diversity of equipment for each operation contributes to the flexibility of analysis by thin-layer chromatography and supports manual, semi-automated or full-automation of the separation process. Instrument platforms are more than a convenience as they affect performance, repeatability, sample detectability, and time management. The current trend in thin-layer chromatography is to make the unit operations independent of the user so that analysts can perform other tasks while each step is performed. In addition, in thin-layer chromatography it is general practice to separate several samples simultaneously, and instrument platforms are required to accommodate this feature. In this article, we review contemporary instrumentation employed in thin-layer chromatography for sample application, development, derivatization, photodocumentation, densitometric evaluation, and hyphenation with spectroscopic detectors with an emphasis on the variety and performance of commercially available systems. Some suggestions for best practices and avoidance of common mistakes are included. PMID:26260842

  7. Myoglobin oxygen affinity in aquatic and terrestrial birds and mammals.

    Science.gov (United States)

    Wright, Traver J; Davis, Randall W

    2015-07-01

    Myoglobin (Mb) is an oxygen binding protein found in vertebrate skeletal muscle, where it facilitates intracellular transport and storage of oxygen. This protein has evolved to suit unique physiological needs in the muscle of diving vertebrates that express Mb at much greater concentrations than their terrestrial counterparts. In this study, we characterized Mb oxygen affinity (P50) from 25 species of aquatic and terrestrial birds and mammals. Among diving species, we tested for correlations between Mb P50 and routine dive duration. Across all species examined, Mb P50 ranged from 2.40 to 4.85 mmHg. The mean P50 of Mb from terrestrial ungulates was 3.72±0.15 mmHg (range 3.70-3.74 mmHg). The P50 of cetaceans was similar to terrestrial ungulates ranging from 3.54 to 3.82 mmHg, with the exception of the melon-headed whale, which had a significantly higher P50 of 4.85 mmHg. Among pinnipeds, the P50 ranged from 3.23 to 3.81 mmHg and showed a trend for higher oxygen affinity in species with longer dive durations. Among diving birds, the P50 ranged from 2.40 to 3.36 mmHg and also showed a trend of higher affinities in species with longer dive durations. In pinnipeds and birds, low Mb P50 was associated with species whose muscles are metabolically active under hypoxic conditions associated with aerobic dives. Given the broad range of potential globin oxygen affinities, Mb P50 from diverse vertebrate species appears constrained within a relatively narrow range. High Mb oxygen affinity within this range may be adaptive for some vertebrates that make prolonged dives. PMID:25987728

  8. Novel trends in affinity biosensors: current challenges and perspectives

    International Nuclear Information System (INIS)

    Molecular biorecognition processes facilitate physical and biochemical interactions between molecules in all crucial metabolic pathways. Perhaps the target analyte and the biorecognition element interactions have the most impactful use in biosensing applications. Traditional analytical sensing systems offer excellent biorecognition elements with the ability to detect and determine the presence of analytes. High affinity antibodies and DNA play an important role in the development of affinity biosensors based on electrochemical, optical and mass sensitive approaches. Advancements in this area routinely employ labels, label free, nanoparticles, multifunctional matrices, carbon nanotubes and other methods to meet the requirements of its own application. However, despite increasing affinity ceilings for conventional biosensors, the field draws back in meeting specifically important demands, such as long-term stability, ultrasensitivity, rapid detection, extreme selectivity, strong biological base, calibration, in vivo measurements, regeneration, satisfactory performance and ease of production. Nevertheless, recent efforts through this line have produced novel high-tech nanosensing systems such as ‘aptamers’ and ‘phages’ which exhibit high-throughput sensing. Aptamers and phages are powerful tools that excel over antibodies in sensibility, stability, multi-detection, in vivo measurements and regeneration. Phages are superior in stability, screening for affinity-based target molecules ranging from small to proteins and even cells, and easy production. In this review, we focus mainly on recent developments in affinity-based biosensors such as immunosensors, DNA sensors, emphasizing aptasensors and phage-based biosensors basing on novel electrochemical, optical and mass sensitive detection techniques. We also address enzyme inhibition-based biosensors and the current problems associated with the above sensors and their future perspectives. (topical review)

  9. Uranium separations using extraction chromatography

    International Nuclear Information System (INIS)

    In the analysis of environmental samples for uranium and thorium pollutants and at natural levels for the dating of geological samples there was felt a need to develop better uranium and thorium, separation procedures to replace the established anion exchange method used at AEA Technology plc. This was the first aim of the PhD research. Separation of uranium from thorium prior to measurement of the isotopes by alpha spectrometry was necessary due to the similar alpha energies of 234U and 230Th. TRU and UTEVA extraction chromatography resins (EIChroM Industries) were investigated as potential replacements to the anion exchange separation method. The resins are claimed by EIChroM to offer the advantage of providing an actinide specific separation while reducing the separation time from 2 to 0.5 days; the volume of acidic waste produced by a factor of 3, therefore, the cost of analysis was reduced. A uranium and thorium separation procedure using the UTEVA extraction chromatography resin was developed. The uranium and thorium were sorbed by the UTEVA resin from 2M nitric acid. The thorium was then eluted from the resin with 5M hydrochloric acid and the uranium with 0.02M hydrochloric acid. The separation procedure was then evaluated using uraninite ore, coral, granite and lake sediment reference materials. The uranium and thorium concentrations and the 234U/238U and 230Th/234U activity ratio values determined for the reference material were in good agreement with certified values. The presence of plutonium was found to interfere with the measurement of uranium and thorium by alpha spectrometry. This was due to the similar alpha energies of uranium, thorium and plutonium. The co-elution of plutonium with uranium and thorium from the UTEVA resin was prevented by the inclusion of a reduction step using iron (II) sulphamate. The resulting plutonium (III) was not retained by the UTEVA column. The chemical recoveries for the procedure were similar to those for anion

  10. Liquid phase chromatography on microchips

    DEFF Research Database (Denmark)

    Kutter, Jörg Peter

    2012-01-01

    almost explosive development of, in particular, chromatographic separation systems on microchips, has, however, slowed down in recent years. This review takes a closer, critical look at how liquid phase chromatography has been implemented in miniaturized formats over the past several years, what is......Over the past twenty years, the field of microfluidics has emerged providing one of the main enabling technologies to realize miniaturized chemical analysis systems, often referred to as micro-Total Analysis Systems (uTAS), or, more generally, Lab-on-a-Chip Systems (LOC) [1,2]. While microfluidics...... was driven forward a lot from the engineering side, especially with respect to ink jet and dispensing technology, the initial push and interest from the analytical chemistry community was through the desire to develop miniaturized sensors, detectors, and, very early on, separation systems. The initial...

  11. Identification of Novel O-Linked Glycosylated Toxoplasma Proteins by Vicia villosa Lectin Chromatography.

    Directory of Open Access Journals (Sweden)

    Kevin Wang

    Full Text Available Toxoplasma gondii maintains its intracellular life cycle using an extraordinary arsenal of parasite-specific organelles including the inner membrane complex (IMC, rhoptries, micronemes, and dense granules. While these unique compartments play critical roles in pathogenesis, many of their protein constituents have yet to be identified. We exploited the Vicia villosa lectin (VVL to identify new glycosylated proteins that are present in these organelles. Purification of VVL-binding proteins by lectin affinity chromatography yielded a number of novel proteins that were subjected to further study, resulting in the identification of proteins from the dense granules, micronemes, rhoptries and IMC. We then chose to focus on three proteins identified by this approach, the SAG1 repeat containing protein SRS44, the rhoptry neck protein RON11 as well as a novel IMC protein we named IMC25. To assess function, we disrupted their genes by homologous recombination or CRISPR/Cas9. The knockouts were all successful, demonstrating that these proteins are not essential for invasion or intracellular survival. We also show that IMC25 undergoes substantial proteolytic processing that separates the C-terminal domain from the predicted glycosylation site. Together, we have demonstrated that lectin affinity chromatography is an efficient method of identifying new glycosylated parasite-specific proteins.

  12. Identification of Novel O-Linked Glycosylated Toxoplasma Proteins by Vicia villosa Lectin Chromatography.

    Science.gov (United States)

    Wang, Kevin; Peng, Eric D; Huang, Amy S; Xia, Dong; Vermont, Sarah J; Lentini, Gaelle; Lebrun, Maryse; Wastling, Jonathan M; Bradley, Peter J

    2016-01-01

    Toxoplasma gondii maintains its intracellular life cycle using an extraordinary arsenal of parasite-specific organelles including the inner membrane complex (IMC), rhoptries, micronemes, and dense granules. While these unique compartments play critical roles in pathogenesis, many of their protein constituents have yet to be identified. We exploited the Vicia villosa lectin (VVL) to identify new glycosylated proteins that are present in these organelles. Purification of VVL-binding proteins by lectin affinity chromatography yielded a number of novel proteins that were subjected to further study, resulting in the identification of proteins from the dense granules, micronemes, rhoptries and IMC. We then chose to focus on three proteins identified by this approach, the SAG1 repeat containing protein SRS44, the rhoptry neck protein RON11 as well as a novel IMC protein we named IMC25. To assess function, we disrupted their genes by homologous recombination or CRISPR/Cas9. The knockouts were all successful, demonstrating that these proteins are not essential for invasion or intracellular survival. We also show that IMC25 undergoes substantial proteolytic processing that separates the C-terminal domain from the predicted glycosylation site. Together, we have demonstrated that lectin affinity chromatography is an efficient method of identifying new glycosylated parasite-specific proteins. PMID:26950937

  13. Detection in superheated water chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Chienthavorn, O

    1999-11-01

    Superheated water has been used successfully as an eluent in liquid chromatography and has been coupled to various modes of detection, ultraviolet (UV), fluorescence, and nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). A number of compounds were examined on poly(styrene-divinylbenzene) (PS-DVB), polybutadiene (PBD), and octadecylsilyl bonded silica (ODS) column with isothermal and temperature programmes. The PS-DVB column was mostly used throughout the project as it was the most stable. Not only pure water could serve as superheated water mobile phase; inorganic buffered water and ion-pairing reagent with a concentration of 1-3 mM of the buffer and reagent were also exploited. It was shown that the pH could be controlled during the separation without salt precipitation and the separations followed a conventional reversed-phase HPLC method. Results from fluorescence detection showed good separation of a series of vitamins, such as pyridoxine, riboflavin, thiamine, and some analgesics. The relationship of riboflavin using the detection was linear and the detection limit was seven times higher than that of a conventional method. Simultaneous separation and identification using superheated water chromatography-NMR was demonstrated. With using a stop flow method, NMR spectra of model drugs, namely barbiturates, paracetamol, caffeine and phenacetin were obtained and the results agreed with reference spectra, confirming a perfect separation. A demonstration to obtain COSY spectrum of salicylamide was also performed. The method was expanded to the coupling of superheated water LC to NMR-MS. Results from the hyphenated detection method showed that deuteration and degradation happened in the superheated water conditions. The methyl group hydrogens of pyrimidine ring of sulfonamide and thiamine were exchanged with deuterium. Thiamine was decomposed to 4-methyl-5-thiazoleethanol and both were deuterated under the conditions. (author)

  14. Detection in superheated water chromatography

    International Nuclear Information System (INIS)

    Superheated water has been used successfully as an eluent in liquid chromatography and has been coupled to various modes of detection, ultraviolet (UV), fluorescence, and nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). A number of compounds were examined on poly(styrene-divinylbenzene) (PS-DVB), polybutadiene (PBD), and octadecylsilyl bonded silica (ODS) column with isothermal and temperature programmes. The PS-DVB column was mostly used throughout the project as it was the most stable. Not only pure water could serve as superheated water mobile phase; inorganic buffered water and ion-pairing reagent with a concentration of 1-3 mM of the buffer and reagent were also exploited. It was shown that the pH could be controlled during the separation without salt precipitation and the separations followed a conventional reversed-phase HPLC method. Results from fluorescence detection showed good separation of a series of vitamins, such as pyridoxine, riboflavin, thiamine, and some analgesics. The relationship of riboflavin using the detection was linear and the detection limit was seven times higher than that of a conventional method. Simultaneous separation and identification using superheated water chromatography-NMR was demonstrated. With using a stop flow method, NMR spectra of model drugs, namely barbiturates, paracetamol, caffeine and phenacetin were obtained and the results agreed with reference spectra, confirming a perfect separation. A demonstration to obtain COSY spectrum of salicylamide was also performed. The method was expanded to the coupling of superheated water LC to NMR-MS. Results from the hyphenated detection method showed that deuteration and degradation happened in the superheated water conditions. The methyl group hydrogens of pyrimidine ring of sulfonamide and thiamine were exchanged with deuterium. Thiamine was decomposed to 4-methyl-5-thiazoleethanol and both were deuterated under the conditions. (author)

  15. Tuning Hydrophobicity in Abiotic Affinity Reagents: Polymer Hydrogel Affinity Reagents for Molecules with Lipid-like Domains.

    Science.gov (United States)

    Chou, Beverly; Mirau, Peter; Jiang, Tian; Wang, Szu-Wen; Shea, Kenneth J

    2016-05-01

    Hydrophobic interactions often dominate the associative forces between biomacromolecules. A synthetic affinity reagent must be able to exploit and optimize these interactions. We describe synthesis of abiotic affinity reagents that sequester biomacromolecules with lipid-like domains. NIPAm-based copolymer nanoparticles (NPs) containing C4-C8 hydrophobic groups were evaluated for their affinity for lipopolysaccharides (LPS), the lipophilic component of the outer membrane of Gram-negative bacteria. Optimal affinity was found for NPs incorporating a linear C4 hydrocarbon group. 1D and 2D (1)H NMR studies revealed that in water, the longer chain (C6 and C8) alkyl groups in the hydrogel NPs were engaged in intrachain association, rendering them less available to interact with LPS. Optimal LPS-NP interaction requires maximizing hydrophobicity, while avoiding side chain aggregation. Polymer compositions with high LPS binding were grafted onto agarose beads and evaluated for LPS clearance from solution; samples containing linear C4 groups also showed the highest LPS clearance capacity. PMID:27064286

  16. Affinity purification of human factor H on polypeptides derived from streptococcal m protein: enrichment of the Y402 variant.

    Directory of Open Access Journals (Sweden)

    O Rickard Nilsson

    Full Text Available Recent studies indicate that defective activity of complement factor H (FH is associated with several human diseases, suggesting that pure FH may be used for therapy. Here, we describe a simple method to isolate human FH, based on the specific interaction between FH and the hypervariable region (HVR of certain Streptococcus pyogenes M proteins. Special interest was focused on the FH polymorphism Y402H, which is associated with the common eye disease age-related macular degeneration (AMD and has also been implicated in the binding to M protein. Using a fusion protein containing two copies of the M5-HVR, we found that the Y402 and H402 variants of FH could be efficiently purified by single-step affinity chromatography from human serum containing the corresponding protein. Different M proteins vary in their binding properties, and the M6 and M5 proteins, but not the M18 protein, showed selective binding of the FH Y402 variant. Accordingly, chromatography on a fusion protein derived from the M6-HVR allowed enrichment of the Y402 protein from serum containing both variants. Thus, the exquisite binding specificity of a bacterial protein can be exploited to develop a simple and robust procedure to purify FH and to enrich for the FH variant that protects against AMD.

  17. Solubilization of high affinity corticotropin-releasing factor receptors from rat brain: Characterization of an active digitonin-solubilized receptor complex

    International Nuclear Information System (INIS)

    The binding characteristics of CRF receptors in rat frontal cerebral cortex membranes solubilized in 1% digitonin were determined. The binding of [125I]Tyro-ovine CRF ([125I]oCRF) to solubilized membrane proteins was dependent on incubation time, temperature, and protein concentration, was saturable and of high affinity, and was absent in boiled tissue. The solubilized receptors retained their high affinity for [125I] oCRF in the solubilized state, exhibiting a dissociation constant (KD) of approximately 200 pM, as determined by direct binding saturation isotherms. Solubilized CRF receptors maintained the rank order of potencies for various related and unrelated CRF peptides characteristic of the membrane CRF receptor: rat/human CRF congruent to ovine CRF congruent to Nle21,38-rat CRF greater than alpha-helical oCRF-(9-41) greater than oCRF-(7-41) much greater than vasoactive intestinal peptide, arginine vasopressin, or the substance-P antagonist. Furthermore, the absolute potencies (Ki values) for the various CRF-related peptides in solubilized receptors were almost identical to those observed in the membrane preparations, indicating that the CRF receptor retained its high affinity binding capacity in the digitonin-solubilized state. Chemical affinity cross-linking of digitonin-solubilized rat cortical membrane proteins revealed a specifically labeled protein with an apparent mol wt of 58,000 which was similar to the labeled protein in native membrane homogenates. Although solubilized CRF receptors retained their high affinity for agonists, their sensitivity for guanine nucleotide was lost. Size exclusion chromatography substantiated these results, demonstrating that in the presence or absence of guanine nucleotides, [125I]oCRF labeled the same size receptor complex

  18. Reversed-phase liquid chromatography of radiolabeled peptides using a C18 guard-PAK precolumn system

    International Nuclear Information System (INIS)

    In order to avoid radioactive contamination of high-performance liquid chromatography columns and injectors, we have investigated the use of a Guard-PAK precolumn system for the chromatography of [125I] labeled peptides. Two gonadotropin-releasing hormone analogs: (1) [D-Ala6-des-Gly10]-GnRH (GnRH-[Ala6]) and (2) [D-Ser(TBu)6-des-Gly10]-GnRH (GnRH-[Ser6]) and rat prolactin (r-PRL) were radiolabeled with 125I and subjected to reversed-phase liquid chromatography using a C18 Guard-PAK precolumn system. Major peak fractions of purified [125I]GnRH-[Ala6], [125I]GnRH-[Ser6], and [125I]r-PRL eluted at 24%, 28%, and 55% acetonitrile, respectively. Purified [125I]GnRH analogs showed specific high affinity binding to rat anterior pituitary gland membranes (specific activity: 1500-1700 Ci/mmol). Purified [125I]r-PRL showed high affinity binding to r-PRL antibody by RIA (specific activity: 70-75 microCi/micrograms). This rapid and efficient chromatographic method should be useful in the separation of a wide range of radiolabeled protein and peptide molecules

  19. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    OpenAIRE

    Liu Yang; Qiang Han; Shuya Cao; Feng Huang; Molin Qin; Chenghai Guo; Mingyu Ding

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical an...

  20. Development and Application of Aphosphoproteomic Strategy Based Ontitanium Dioxideaffinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    Mingquan Guo

    2012-01-01

    A sensitive and highly selective phosphoproteomic strategy,which allows simultaneous genome and transcriptome profiling from a single sample,has been developed by a combination of a highly selective titanium dioxide (TiO2)-based phosphopeptide enrichment method and a TRIzol-based protein extraction method.To establish more efficient phosphopeptide enrichment methods for complex cellular proteins,TiO2 method was comparedwith the most widely used IMAC method using model peptide mixturesbased on two criteria:one is the efficacy of the phosphopeptide enrichment (how many phosphopeptides each method can capture),and the other is the extent of exclusion of nonphosphopeptides from the pool of enriched phosphopeptides.The results indicate that the TiO2 enrichment method appears to be more effective than the IMAC method.This methodology was then further applied to the phosphoproteomic analysis of a small number of HeLa cells with and without calyculin A (CL-A) treatment.Significant increases in the number of identified phosphopeptides and phosphosites were observed in the CL-A-treated samples compared with nontreated samples as expected in the biological studies.Meanwhile,some novel phosphorylation sites,such as T19 and S20 of the myosin regulatory light chain and S116 and S379 in the heterogeneous nuclear ribonucleoprotein K transcript variant in the CL-A-treated samples,were revealed as well.Thus,the robustness,generality,and simplicity of this strategy should enable this methodology to find broad applications for phosphoproteomic analyses in systems biology,especially in cases of limited starting material requiring a systems-level analysis such as small clinical specimens.

  1. The Weyl-Cartan Space Problem in Purely Affine Theory

    Science.gov (United States)

    von Borzeszkowski, Horst-Heino; Treder, Hans-Jürgen

    1997-04-01

    According to Poincaré, only the ``epistemological sum of geometry and physics is measurable". Of course, there are requirements of measurement to be imposed on geometry because otherwise the theory resting on this geometry cannot be physically interpreted. In particular, the Weyl--Cartan space problem must be solved, i.e., it must be guaranteed that the comparison of distances is compatible with the Levi-Civita transport. In the present paper, we discuss these requirements of measurement and show that in the (purely affine) Einstein-Schrödinger unified field theory the solution of the Weyl-Cartan space problem simultaneously determines the matter via Einstein's equations. Here the affine field $\\Gamma^ikl$ represents Poincaré's sum, and the solution of the space problem means its splitting in a metrical space and in matter fields, where the latter are given by the torsion tensor $\\Gamma^i_{[kl]}$.

  2. Improved Energy-Momentum Currents in Metric-Affine Spacetime

    CERN Document Server

    Hecht, R D; McCrea, J D; Mielke, E W; Ne'eman, Yuval; Hecht, Ralf; Hehl, Friedrich W.; Mielke, Eckehard W.; Ne'eman, Yuval

    1992-01-01

    In Minkowski spacetime it is well-known that the canonical energy-momentum current is involved in the construction of the globally conserved currents of energy-momentum and total angular momentum. For the construction of conserved currents corresponding to (approximate) scale and proper conformal symmetries, however, an improved energy-momentum current is needed. By extending the Minkowskian framework to a genuine metric-affine spacetime, we find that the affine Noether identities and the conformal Killing equations enforce this improvement in a rather natural way. So far, no gravitational dynamics is involved in our construction. The resulting dilation and proper conformal currents are conserved provided the trace of the energy-momentum current satisfies a (mild) scaling relation or even vanishes.

  3. The affine theory of gravitation and electromagnetism I

    CERN Document Server

    Poplawski, N J

    2006-01-01

    The affine variational principle of Eddington generates the Einstein field equations of general relativity in vacuum with a non-zero cosmological constant. We generalize this principle to include electromagnetism, obtaining the Einstein--Maxwell field equations and the Lorentz equation of motion. We vary the action with respect to the quantities that appear in the definition of the electromagnetic covariant derivative: the affine (nonsymmetric) connection and the electromagnetic potential, while the Lagrangian density is taken to be the square root of the determinant of a linear combination of the symmetrized Ricci tensor and the electromagnetic field tensor. This construction generates a symmetric metric tensor and a connection with torsion that depends only on the torsion vector. The whole formulation is valid only for very weak electromagnetic fields on the order of the magnetic field in interstellar space.

  4. An angular momentum conserving Affine-Particle-In-Cell method

    CERN Document Server

    Jiang, Chenfanfu; Teran, Joseph

    2016-01-01

    We present a new technique for transferring momentum and velocity between particles and grid with Particle-In-Cell (PIC) calculations which we call Affine-Particle-In-Cell (APIC). APIC represents particle velocities as locally affine, rather than locally constant as in traditional PIC. We show that this representation allows APIC to conserve linear and angular momentum across transfers while also dramatically reducing numerical diffusion usually associated with PIC. Notably, conservation is achieved with lumped mass, as opposed to the more commonly used Fluid Implicit Particle (FLIP) transfers which require a 'full' mass matrix for exact conservation. Furthermore, unlike FLIP, APIC retains a filtering property of the original PIC and thus does not accumulate velocity modes on particles as FLIP does. In particular, we demonstrate that APIC does not experience velocity instabilities that are characteristic of FLIP in a number of Material Point Method (MPM) hyperelasticity calculations. Lastly, we demonstrate th...

  5. Affinity of four polar neurotransmitters for lipid bilayer membranes

    DEFF Research Database (Denmark)

    Wang, Chunhua; Ye, Fengbin; Valardez, Gustavo F.;

    2011-01-01

    Weak interactions of neurotransmitters and the lipid matrix in the synaptic membrane have been hypothesized to play a role in synaptic transmission of nerve signals, particularly with respect to receptor desensitization (Cantor, R. S. Biochemistry 2003, 42, 11891). The strength of such interactions......, however, was not measured, and this is an obvious impediment for further evaluation and understanding of a possible role for desensitization. We have used dialysis equilibrium to directly measure the net affinity of selected neurotransmitters for lipid membranes and analyzed this affinity data with...... respect to calorimetric measurements and molecular dynamics simulations. We studied an anionic (glutamate), a cationic (acetylcholine), and two zwitterionic (-aminobutyric acid and glycine) neurotransmitters, and membranes of pure dimyristoyl phosphatidylcholine (DMPC), DMPC doped with 10% anionic lipid...

  6. On purely transmitting defects in affine Toda field theory

    CERN Document Server

    Corrigan, E

    2007-01-01

    Affine Toda field theories with a purely transmitting integrable defect are considered and the model based on a_2 is analysed in detail. After providing a complete characterization of the problem in a classical framework, a suitable quantum transmission matrix, able to describe the interaction between an integrable defect and solitons, is found. Two independent paths are taken to reach the result. One is an investigation of the triangle equations using the S-matrix for the imaginary coupling bulk affine Toda field theories proposed by Hollowood, and the other uses a functional integral approach together with a bootstrap procedure. Evidence to support the results is collected in various ways: for instance, through the calculation of the transmission factors for the lightest breathers. While previous discoveries within the sine-Gordon model motivated this study, there are several new phenomena displayed in the a_2 model including intriguing disparities between the classical and the quantum pictures. For example...

  7. Del Pezzo surfaces and affine 7-brane backgrounds

    CERN Document Server

    Hauer, T; Hauer, Tamas; Iqbal, Amer

    2000-01-01

    A map between string junctions in the affine 7-brane backgrounds and vector bundles on del Pezzo surfaces is constructed using mirror symmetry. It is shown that the lattice of string junctions with support on an affine 7-brane configuration is isomorphic to the K-theory group of the corresponding del Pezzo surface. This isomorphism allows us to construct a map between the states of the N=2, D=4 theories with E_N global symmetry realized in two different ways in Type IIB and Type IIA string theory. A subgroup of the SL(2,Z) symmetry of the \\hat{E}_9 7-brane background appears as the Fourier-Mukai transform acting on the D-brane configurations realizing vector bundles on elliptically fibered B_9.

  8. Evolution based on chromosome affinity from a network perspective

    Science.gov (United States)

    Monteiro, R. L. S.; Fontoura, J. R. A.; Carneiro, T. K. G.; Moret, M. A.; Pereira, H. B. B.

    2014-06-01

    Recent studies have focused on models to simulate the complex phenomenon of evolution of species. Several studies have been performed with theoretical models based on Darwin's theories to associate them with the actual evolution of species. However, none of the existing models include the affinity between individuals using network properties. In this paper, we present a new model based on the concept of affinity. The model is used to simulate the evolution of species in an ecosystem composed of individuals and their relationships. We propose an evolutive algorithm that incorporates the degree centrality and efficiency network properties to perform the crossover process and to obtain the network topology objective, respectively. Using a real network as a starting point, we simulate its evolution and compare its results with the results of 5788 computer-generated networks.

  9. Affinity purification of proteins binding to GST fusion proteins.

    Science.gov (United States)

    Swaffield, J C; Johnston, S A

    2001-05-01

    This unit describes the use of proteins fused to glutathione-S-transferase (GST fusion proteins) to affinity purify other proteins, a technique also known as GST pulldown purification. The describes a strategy in which a GST fusion protein is bound to agarose affinity beads and the complex is then used to assay the binding of a specific test protein that has been labeled with [35S]methionine by in vitro translation. However, this method can be adapted for use with other types of fusion proteins; for example, His6, biotin tags, or maltose-binding protein fusions (MBP), and these may offer particular advantages. A describes preparation of an E. coli extract that is added to the reaction mixture with purified test protein to reduce nonspecific binding. PMID:18265191

  10. Craniomandibular morphology and phylogenetic affinities of panthera atrox

    DEFF Research Database (Denmark)

    Christiansen, Per; Harris, J.M.

    2009-01-01

    The great North American Pleistocene pantherine felid Panthera atrox has had a turbulent phylogenetic history, and has been claimed to show affinities to both the jaguar and the tiger; currently, it is most often regarded as a subspecies of the extant lion. The cranial, mandibular, and dental...... morphology of Panthera atrox was compared with those of extant lions, jaguars, and tigers using bivariate, multivariate, and shape analyses. Results indicate that the skull of Panthera atrox shows lion affinities, but also deviates from lions in numerous aspects. Mandibular morphology is more similar to...... jaguars and tigers and, as with cranial morphology, the mandible shows a number of traits not present among extant pantherines. Multivariate analyses grouped Panthera atrox separately from other pantherines. Panthera atrox was no lion, and cannot be assigned to any of the extant pantherines; it...

  11. Theoretical Estimate of Hydride Affinities of Aromatic Carbonyl Compounds

    Institute of Scientific and Technical Information of China (English)

    AI Teng; ZHU Xiao-Qing; CHENG Jin-Pei

    2003-01-01

    @@ Aromatic carbonyl compounds are one type of the most important organic compounds, and the reductions ofthem by hydride agents such as LiAlH4 or NaBH4 are widely used in organic synthesis. The reactivity of carbonyl compounds generally increases in the following order: ketone < aldehyde, and amide < acid < ester < acid halide, which could be related to their hydride affinities (HA). In the previous paper, Robert[1] calculated the absolute HAof a series of small non-aromatic carbonyl compounds. In this paper, we use DFT method at B3LYP/6-311 + + G (2d, 2p)∥B3LYP/6-31 + G* level to estimate hydride affinities of five groups of aromatic carbonyl compounds. The detailed results are listed in Table 1.

  12. Nonspectrality of Certain Self-Affine Measures on ℝ3

    Directory of Open Access Journals (Sweden)

    Gui-Bao Gao

    2014-01-01

    Full Text Available We will determine the nonspectrality of self-affine measure μB,D corresponding to B=diag[p1,p2,p3]  (p1∈(2ℤ+1∖{±1}, p2∈2ℤ∖{0}, and D={0,e1,e2,e3} in the space ℝ3 is supported on T(B,D, where e1,  e2, and e3 are the standard basis of unit column vectors in ℝ3, and there exist at most 4 mutually orthogonal exponential functions in L2(μB,D, where the number 4 is the best. This generalizes the known results on the spectrality of self-affine measures.

  13. Black Hole Singularity and Generalized Quantum Affine Parameter

    OpenAIRE

    Hosoya, Akio; Oda, Ichiro

    1996-01-01

    We study a behavior of quantum generalized affine parameter (QGAP), which has been recently proposed by one of the present authors, near the singularity and the event horizon in three and four spacetime dimensions in terms of a minisuperspace model of quantum gravity. It is shown that the QGAP is infinite to the singularity while it remains finite to the event horizon. This fact indicates a possible interpretation that the singularity is wiped out in quantum gravity in this particular model o...

  14. Symbolic Dynamics for a Piecewise-Affine System with Hysteresis

    OpenAIRE

    Sella, Lorenzo; Collins, Pieter

    2008-01-01

    In this paper we present the computation of symbolic dynamics of a one dimensional return map of a piecewise-affine hybrid system. The system arises as a simple electrical circuit with hysteresis switching, and exhibits chaotic dynamics. Our method allows us to rigorously obtain a qualitative description of the discrete behaviour of the system. We show how the discrete dynamics changes as a parameter is varied, and we compute bounds for the topological entropy to provide a measure of the comp...

  15. Chitinolytic activity of the rumen ciliates Diploplastron affine

    Czech Academy of Sciences Publication Activity Database

    Belzecki, G.; Miltko, R.; Michalowski, T.; Šimůnek, Jiří; Kopečný, Jan

    2008-01-01

    Roč. 53, č. 3 (2008), s. 201-203. ISSN 0015-5632 R&D Projects: GA ČR GA525/05/2584 Grant ostatní: Ministry of Scientific Research and Information Technology Poland(PL) 2 P06Z 052 30 Institutional research plan: CEZ:AV0Z50450515 Keywords : Diploplastron affine Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

  16. Affine Correlation Method for Direct Vorticity, Skew and Displacement Estimation

    Czech Academy of Sciences Publication Activity Database

    Gronát, Petr

    Praha : Ústav termomechaniky, AV ČR, v. v. i., 2010 - (Příhoda, J.; Kozel, K.), s. 59-62 ISBN 978-80-87012-25-3. [Topical Problems of Fluid Mechanics 2010. Praha (CZ), 10.02.2010-11.02.2010] R&D Projects: GA ČR GA101/08/1112 Institutional research plan: CEZ:AV0Z20760514 Keywords : normalized cross correlation * affine correlation Subject RIV: BK - Fluid Dynamics

  17. Proton Affinities of Organocatalysts Derived from Pyridine N-oxide

    Czech Academy of Sciences Publication Activity Database

    Váňa, J.; Roithová, J.; Kotora, Martin; Beran, Pavel; Rulíšek, Lubomír; Kočovský, Pavel

    2014-01-01

    Roč. 87, č. 4 (2014), s. 349-356. ISSN 0011-1643 R&D Projects: GA ČR(CZ) GA14-31419S Grant ostatní: GA ČR(CZ) GAP207/11/0587 Institutional support: RVO:61388963 Keywords : density functional theory * isodesmic reactions * kinetic method * mass spectrometry * organocatalysis * proton affinity * superbases Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.728, year: 2014

  18. Communication: Revised electron affinity of SF6 from kinetic data.

    OpenAIRE

    Troe, J.; Miller, T; Viggiano, A.

    2012-01-01

    Previously determined experimental data for thermal attachment of electrons to SF 6 and thermal detachment from SF 6 − over the range 590–670 K are reevaluated by a third-law analysis. Recent high precision calculations of SF 6 − harmonic frequences and anharmonicities (for several of the modes) lead to considerable changes in modeled vibrational partition functions which then have to be accommodated for by a smaller value of the derived adiabatic electron affinity EA of SF 6 . The previously...

  19. An Early Cambrian problematic fossil: Vetustovermis and its possible affinities

    OpenAIRE

    Chen, Jun-Yuan; Huang, Di-Ying; Bottjer, David J.

    2005-01-01

    The Early Cambrian problematic fossil Vetustovermis (Glaessner 1979 Alcheringa 3, 21–31) was described as an annelid or arthropod. Anatomical analysis of 17 new specimens from the Lower Cambrian Maotianshan Shale at Anning, Kunming (South China) does not support its affinities with annelids or arthropods. Anatomical features instead resemble other animal groups including modern flatworms, nemertines and molluscs. The presence of a pelagic slug-like form and ventral foot, as well as a head wit...

  20. Agonist binding to high-affinity dopamine sites

    Energy Technology Data Exchange (ETDEWEB)

    Tedesco, J.L.

    1985-01-01

    The authors have characterized the dopamine D/sub 3/ site and its binding requirements. The dopamine D/sub 3/ site in calf caudate crude homogenate has a site density of 214-230 fmoles/mg. protein by both /sup 3/H-apomorphine (/sup 3/H-AOP) and /sup 3/H-dopamine (/sup 3/H-DA) Scatchard analysis of specific binding (SB). Stereospecific subsets of /sup 3/H-APO and /sup 3/H-DA sites were defined by the use of agonist and antagonist enantiomer-pairs as a rigorous test for D/sub 3/ site heterogeneity. IC/sub 50/ values for both /sup 3/H-APO and /sup 3/H-DA SB sites were assessed for 55 agonist ligands and an excellent correlation was obtained. The authors conclude that both /sup 3/H-ligands label the same D/sub 3/ site. The D/sub 3/ site affinities of 105 dopamine-agonist ligands, in particular 2-aminotetralins,, aporphines and flexible dopamine analogues were measured. Low D/sub 3/-site affinities of N-quaternary analogues confirm the need for a lone pair. Subadditivity of substituents' effects in semi-flexible DA analogues confirms their postulate that sidechain conformation is the critical determinant of affinity. They conclude that there are at least two high-affinity ligand conformations of the DA sidechain pharmacophore. These binding requirements are presented as two interface-Geometry tetrahedral models of the double H-bond interface between the D/sub 3/ site and the ideal ligand.