WorldWideScience

Sample records for prsv coat protein

  1. Development of transgenic papayas expressing the coat protein gene from a Brazilian isolate of Papaya ringspot virus (PRSV) = Desenvolvimento de mamoeiros transgênicos resistentes a vírus expressando o gene da capa protéica de um isolado brasileiro de Papaya ringspot virus

    NARCIS (Netherlands)

    Souza, M.T.; Níckel, O.; Gonsalves, D.

    2005-01-01

    Translatable and nontranslatable versions of the coat protein (cp) gene of a Papaya ringspot virus (PRSV) isolate collected in the state of Bahia, Brazil, were engineered for expression in Sunrise and Sunset Solo varieties of papaya (Carica papaya). The biolistic system was used to transform

  2. Influence of coat protein transgene copy number on resistance in transgenic line 63-1 against Papaya ringspot virus isolates

    NARCIS (Netherlands)

    Souza, M.T.; Níckel, O.; Gonsalves, D.

    2005-01-01

    Line 63-1 is a 'Sunset'-derived transgenic papaya expressing the coat protein (CP) gene from a mild mutant of a Hawaiian isolate of Papaya ringspot virus (PRSV). Previous work showed that line 63-1 R, plants exhibited a range of resistance to severe PRSV isolates from Hawaii (HA), Jamaica (JA),

  3. Genetic diversity in the 3'-terminal region of papaya ringspot virus (PRSV-W) isolates from watermelon in Oklahoma.

    Science.gov (United States)

    Abdalla, Osama A; Ali, Akhtar

    2012-03-01

    The 3'-terminal region (1191 nt) containing part of the NIb gene, complete coat protein (CP) and poly-A tail of 64 papaya ringspot virus (PRSV-W) isolates collected during 2008-2009 from watermelon in commercial fields of four different counties of Oklahoma were cloned and sequenced. Nucleotide and amino acid sequence identities ranged from 95.2-100% and 97.1-100%, respectively, among the Oklahoman PRSV-W isolates. Phylogenetic analysis showed that PRSW-W isolates clustered according to the locations where they were collected within Oklahoma, and each cluster contained two subgroups. All subgroups of Oklahoman PRSV-W isolates were on separate branches when compared to 35 known isolates originating from other parts of the world, including the one reported previously from the USA. This study helps in our understanding about the genetic diversity of PRSV-W isolates infecting cucurbits in Oklahoma.

  4. Isolation and Characterisation of PRSV-P Resistance Genes in Carica and Vasconcellea

    Directory of Open Access Journals (Sweden)

    M. R. Razean Haireen

    2014-01-01

    Full Text Available Papaya (Carica papaya L. is one of the major tropical fruit crops worldwide, but it is limited throughout its range by papaya ringspot virus type P (PRSV-P. Previous genetic studies identified a functional PRSV-P resistance marker in a mapping population of F2 plants of Vasconcellea pubescens (resistant to PRSV-P × Vasconcellea parviflora (susceptible to PRSV-P and showed that the marker exhibited homology to a serine threonine protein kinase (STK gene. Full length cDNAs of putative PRSV-P resistance genes designated CP_STK from C. papaya and VP_STK1 and VP_STK2 from V. pubescens were cloned by rapid amplification of cDNA ends (RACE. Due to a frame-shift mutation, the two homologous sequences are transcribed and edited differently such that the gene product in V. pubescens is two separate transcripts, whereas in C. papaya they are fused into a single message. A peroxisomal targeting signal (PTS2 present in VP_STK2 but absent in the other transcripts may be the functional source of PRSV resistance in V. pubescens. The STK gene from V. pubescens may have been derived from an alternative splicing to confer resistance. The putative resistance gene, VP_STK2, that was identified in this study is a potential new source of PRSV-P resistance for papaya genotypes.

  5. New species in the papaya ringspot virus cluster: insights into the evolution of the PRSV lineage

    OpenAIRE

    Romay, Gustavo; Millot, Pauline; Wipf-Scheibel, Catherine; Dafalla, Gasim; Lecoq, Hervé

    2017-01-01

    The “Papaya ringspot virus (PRSV) cluster” of cucurbit-infecting potyviruses contains five acknowledged species that have similar biological, serological and molecular properties. Additional data suggest there are other uncharacterized species from various locations in the world that likely belong to the PRSV cluster including a new PRSV-like virus reported from Sudan in 2003. Molecular and biological data indicated that the virus from Sudan belongs to a new species, tentatively named wild me...

  6. Interlaboratory validation data on real-time polymerase chain reaction detection for unauthorized genetically modified papaya line PRSV-YK

    Directory of Open Access Journals (Sweden)

    Kosuke Nakamura

    2016-06-01

    Real-time polymerase chain reaction (PCR detection method for unauthorized genetically modified (GM papaya (Carica papaya L. line PRSV-YK (PRSV-YK detection method was developed using whole genome sequence data (DDBJ Sequenced Read Archive under accession No. PRJDB3976. Interlaboratory validation datasets for PRSV-YK detection method were provided. Data indicating homogeneity of samples prepared for interlaboratory validation were included. Specificity and sensitivity test data for PRSV-YK detection method were also provided.

  7. Protection and coexistence of conventional papaya productions with PRSV resistant transgenic papaya

    Science.gov (United States)

    Papaya ringspot virus (PRSV) is a devastating disease that has a detrimental impact on both commercial papaya production and Caricaceae germplasm conservation. Transgenic line 55-1 and derived progeny ‘SunUp’ and ‘Rainbow’ are resistant to PRSV and have saved the papaya industry in Hawaii. In small...

  8. Algerian watermelon mosaic virus (AWMV): a new potyvirus species in the PRSV cluster.

    Science.gov (United States)

    Yakoubi, Soumaya; Lecoq, Hervé; Desbiez, Cécile

    2008-08-01

    A potyvirus was isolated from a naturally infected squash plant in Algeria in 1986. Biological and serological data have revealed that the virus, initially described as H4, is related to other cucurbit-infecting potyviruses, particularly Moroccan watermelon mosaic virus (MWMV) and Papaya ringspot virus (PRSV). To establish unequivocally the taxonomic status of H4, its full-length genome sequence was established. H4 shared identities of 70% and 65% at the amino acid level with MWMV and PRSV, respectively, indicating that H4 is a distinct species of the PRSV cluster. The name Algerian watermelon mosaic virus (AWMV) is proposed for this new potyvirus species.

  9. New species in the papaya ringspot virus cluster: Insights into the evolution of the PRSV lineage.

    Science.gov (United States)

    Desbiez, C; Wipf-Scheibel, C; Millot, P; Verdin, E; Dafalla, G; Lecoq, H

    2017-09-15

    The "Papaya ringspot virus (PRSV) cluster" of cucurbit-infecting potyviruses contains five acknowledged species that have similar biological, serological and molecular properties. Additional data suggest there are other uncharacterized species from various locations in the world that likely belong to the PRSV cluster including a new PRSV-like virus reported from Sudan in 2003. Molecular and biological data indicated that the virus from Sudan belongs to a new species, tentatively named wild melon vein banding virus (WMVBV). The complete nucleotide sequence of a second virus from Sudan revealed it was a divergent relative of Moroccan watermelon mosaic virus (MWMV). Based on sequence similarity this virus was determined to be a distinct species and tentatively named Sudan watermelon mosaic virus (SuWMV). Molecular analyses indicate that SuWMV is a recombinant between WMVBV- and MWMV-related viruses. Based on surveys performed in Sudan between 1992 and 2012, SuWMV appeared 10 times more frequent than WMVBV in that country (14.6% vs. 1.5% of the samples tested). The geographic structure and molecular diversity patterns of the putative and acknowledged species suggest that the PRSV-like cluster originated in the Old World about 3600 years ago, with an important diversification in Africa. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Combining ability of summer-squash lines with different degrees of parthenocarpy and PRSV-W resistance

    Directory of Open Access Journals (Sweden)

    Douglas Willian Nogueira

    2011-01-01

    Full Text Available The aim was to assess heterosis in a set of 16 summer-squash hybrids, and evaluate the combining capacity of the respective parental lines, which differed as to the degree of parthenocarpy and resistance to PRSV-W (Papaya Ringspot Virus-Watermelon strain. The hybrids were obtained using a partial diallel cross design (4 x 4. The lines of parental group I were 1 = ABX-037G-77-03-05-01-01-bulk, 2 = ABX-037G-77-03-05-03-10-bulk, 3 = ABX-037G77-03-05-01-04-bulk and 4 = ABX-037G-77-03-05-05-01-bulk, and of group II, 1' = ABX-037G-77-03-05-04-08-bulk, 2' = ABX-037G-77-03-05-02-11-bulk, 3' = Clarice and 4' = Caserta. The 16 hybrids and eight parental lines were evaluated for PRSV-W resistance, parthenocarpic expression and yield in randomized complete-block designs, with three replications. Parthenocarpy and the resistance to PRSV-W were rated by means of a scale from 1 to 5, where 1 = non-parthenocarpic or high resistance to PRSV-W, and 5 = parthenocarpic or high susceptibility to PRSV-W. Both additive and non-additive gene effects were important in the expression of parthenocarpy and resistance to PRSV-W. Whereas estimates of heterosis in parthenocarpy usually tended towards a higher degree, resistance to PRSV-W was towards higher susceptibility. At least one F1 hybrid was identified with a satisfactory degree of parthenocarpy, resistance to PRSV-W and high fruit-yield.

  11. A novel PEG coating immobilized onto capillary through polydopamine coating for separation of proteins in CE.

    Science.gov (United States)

    Zeng, Rongju; Luo, Zhaofeng; Zhou, Dan; Cao, Fuhu; Wang, Yanmei

    2010-10-01

    The antifouling PEG-immobilized capillary was introduced for the protein separation in CE through mussel adhesive protein inspired polydopamine coating for the first time. The polydopamine, formed by spontaneous oxidative polymerization of dopamine at alkaline in the inner surface of capillary, was exploited to immobilize amine-functionalized PEG onto the capillary surface. During the process, polydopamine-graft-PEG copolymer was formed via Michael addition or Schiff base reactions. The polymer coating was observed using X-ray photoelectron spectroscopy and SEM. And both of them indicated the formation of the polymer coating. A comparative study of EOF showed that the novel coating could provide effective suppression of EOF and minimized adsorption of proteins. As a consequence, fast and efficient separations of three proteins such as lysozyme, cytochrome c, and ribonuclease A were obtained within a broad pH range. Furthermore, the long-term stability of polydopamine-graft-PEG coating in consecutive protein separation runs and the high separation efficiency proved that this novel coating was capable of minimizing protein adsorption during the capillary separation. The successful capillary performance also was demonstrated in the separation of protein mixture and milk powder samples at acidic pH.

  12. Inheritance of resistance to papaya ringspot virus-watermelon strain (PRSV-W in ‘Whitaker’ summer squash line

    Directory of Open Access Journals (Sweden)

    Cícero B Menezes

    2015-12-01

    Full Text Available The objective of this work was to study the genetic control of the PRSV-W (Papaya Ringspot Virus – Watermelon Strain resistance in Cucurbita pepo ‘Whitaker’ line. Plants of parental lines Whitaker (resistant and Caserta (susceptible, and of the generations F1, F2, BC11 and BC12 were evaluated for their reactions to PRSV-W. Caserta plants showed severe mosaic symptoms, while Whitaker grew vigorously and remained almost totally symptom-free. Most of the F1, F2and backcross plants also presented severe mosaic symptoms. Data were used to test a hypothesis of monogenic inheritance under different presumed degrees of dominance, and genetic models were tested using maximum likelihood tests of genetic control. Broad-sense heritability was of 0.57 for the first evaluation. Resistance to PRSV-W in C. pepo ‘Whitaker’ is due to a major gene effect summed to polygenic effects.

  13. Protein and bacterial interactions with nanostructured polymer coatings.

    Science.gov (United States)

    Juvonen, Helka; Oja, Terhi; Määttänen, Anni; Sarfraz, Jawad; Rosqvist, Emil; Riihimäki, Tiina A; Toivakka, Martti; Kulomaa, Markku; Vuorela, Pia; Fallarero, Adyary; Peltonen, Jouko; Ihalainen, Petri

    2015-12-01

    Adsorption of proteins and adhesion of bacteria to a surface is affected by chemical and physical interactions. In this study, polymer coatings and their ability to adsorb avidin and Staphylococcus aureus were investigated. The surface chemistry and topography of the polymer coatings was modified by changing the weight ratio of the hydrophobic polystyrene (PS) and the hydrophilic acrylonitrile butadiene styrene (ABS) components in the polymer blend. Avidin adsorbed less to the ABS phase compared with the PS phase. The side-on orientation of avidin on the ABS surface, however, resulted in a higher specific binding of biotinylated bovine serum albumin. Steric effects and hydrophobic protein-surface interactions decreased the activity of avidin on the PS phase. The increased hydrophobicity and roughness of the polymer coatings enhanced the adhesion of S. aureus. The avidin-coated latex surface with 55% relative surface coverage of the PS phase showed anti-microbial behavior. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Resistance to papaya ringspot virus-watermelon strain (PRSV-W) in the desert watermelon Citrullus colocynthis

    Science.gov (United States)

    The bitter desert watermelon (Citrullus colocynthis) is a valuable source for improving disease or pest resistance in watermelon cultivars. The objective of this study was to identify C. colocynthis accessions displaying resistance to the papaya ringspot virus-watermelon strain (PRSV-W) that could ...

  15. Protein-Coated Microcrystals, Combi-Protein-Coated Microcrystals, and Cross-Linked Protein-Coated Microcrystals of Enzymes for Use in Low-Water Media.

    Science.gov (United States)

    Mukherjee, Joyeeta; Gupta, Munishwar N

    2017-01-01

    Protein-coated microcrystals (PCMC) are a high-activity preparation of enzymes for use in low-water media. The protocols for the preparation of PCMCs of Subtilisin Carlsberg and Candida antarctica lipase B (CAL B) are described. The combi-PCMC concept is useful both for cascade and non-cascade reactions. It can also be beneficial to combine two different specificities of a lipase when the substrate requires it. Combi-PCMC of CALB and Palatase used for the conversion of coffee oil present in spent coffee grounds to biodiesel is described. Cross-linked protein-coated microcrystals (CL-PCMC) in some cases can give better results than PCMC. Protocols for the CLPCMC of Subtilisin Carlsberg and Candida antarctica lipase B (CAL B) are described. A discussion of their applications is also provided.

  16. The movement protein and coat protein of alfalfa mosaic virus accumulate in structurally modified plasmodesmata

    NARCIS (Netherlands)

    van der Wel, N. N.; Goldbach, R. W.; van Lent, J. W.

    1998-01-01

    In systemically infected tissues of Nicotiana benthamiana, alfalfa mosaic virus (AMV) coat protein (CP) and movement protein (MP) are detected in plasmodesmata in a layer of three to four cells at the progressing front of infection. Besides the presence of these viral proteins, the plasmodesmata are

  17. Quantification of protein-lipid selectivity using FRET: Application of the M13 major coat protein

    NARCIS (Netherlands)

    Fernandes, F.; Loura, L.M.S.; Koehorst, R.B.M.; Spruijt, R.B.; Hemminga, M.A.; Federov, A.; Prieto, M.

    2004-01-01

    Quantification of lipid selectivity by membrane proteins has been previously addressed mainly from electron spin resonance studies. We present here a new methodology for quanti. cation of protein-lipid selectivity based on fluorescence resonance energy transfer. A mutant of M13 major coat protein

  18. Coated vesicles as protein release mechanism in myeloma cells.

    Science.gov (United States)

    Trombetta, L D; Lazarus, S S

    An electron microscopic study was undertaken of the protein release mechanism within myeloma cells showing a very high degree of protein production. Smooth surfaced vesicles (50 millimicrons) were seen to originate from the outer margin of the perinuclear cistern. Similar vesicles were also associated with distended Golgi sacs. Possible function of these vesicles could not be determined. Coated vesicles (60 millimicrons) originated as evaginations from endoplasmic reticulum in the transitional region. They were present throughout the cytoplasm and were seen to fuse with the cell membrane discharging an electron dense material. These vesicles are, therefore, thought to transport protein from the rough endoplasmic reticulum and discharge it at the cell surface.

  19. Molecular characterization, cloning and sequencing of coat protein ...

    African Journals Online (AJOL)

    Belal

    2013-03-13

    Mar 13, 2013 ... Key words: Potato, potato leaf roll virus (PLRV), coat protein (CP) gene, reverse transcriptase polymerase chain reaction (RT-PCR), ..... s Z im. 13 P. 0+ po ly pr ot ei.. P. leafr oll v ir us V. IRUB. RA. 1/. 046 P. 0+. P. P. leafr oll v ir us t he p olish iso la te. P. leafr oll v ir us. P. leafr oll v ir us co at p ro tein. P. leafr.

  20. Relationship of the syntheses of spore coat protein and parasporal crystal protein in Bacillus thuringiensis.

    Science.gov (United States)

    Aronson, A I; Tyrell, D J; Fitz-James, P C; Bulla, L A

    1982-07-01

    Two major classes of polypeptides were extracted from the spore surface of Bacillus thuringiensis subsp. kurstaki: the 134,000-dalton protoxin that is the major component of the crystalline inclusion and spore coat polypeptides very similar to those found on Bacillus cereus spores. The quantity of spore coat polypeptides produced was reduced when compared with that produced by certain acrystalliferous mutants or by B. thuringiensis subsp. israelensis. The latter organism produced an inclusion toxic to mosquito larvae, but deposited very little of the inclusion protein on the spore surface. The reduction in spore coat protein in B. thuringiensis subsp. kurstaki was also seen in freeze-etched electron micrographs of spores. B. thuringiensis subsp. kurstaki spores germinated rather slowly when compared with related species, a property previously correlated with a deficiency or defect of the spore coat. Many mutants of B. thuringiensis subsp. kurstaki unable to form a crystalline inclusion were nontoxic and lacked a well-defined spore coat. Other mutants isolated either directly from the wild type or from coat-deficient mutants produced spores that were identical to those produced by the closely related species. Bacillus cereus, on the basis of morphology, germination rate, and the size and antigenicity of the spore coat polypeptides. Most of the protein extractable from the inclusion produced by B. thuringiensis subsp. israelensis was about 26,000 daltons, considerably smaller than the major polypeptide extractable from other inclusions. Some of the B. thuringiensis subsp. israelensis inclusion protein was found on the spore surface, but the majority of the extractable spore coat protein was the same size and antigenicity as that found on B. cereus spores. The B. thuringiensis subsp. israelensis spores germinated at a rate close to that of B. cereus, especially when the spores were formed at 37 degrees C, and the morphology of the spore surface was very similar to

  1. Assaying for pollen drift from transgenic Rainbow to nontransgenic Kapoho papaya under commercial and experimental field conditions in Hawaii

    Science.gov (United States)

    In 1992 papaya ringpsot virus (PRSV) was discovered in Puna district of Hawaii Island where 95% of the state of Hawaii’s papaya was being grown. By 1998 production in Puna had decreased 50% from 1998 levels. A PRSV-resistant transgenic papaya ‘Rainbow’ expressing the coat protein gene of PRSV was ...

  2. Determining sex and screening for the adventitious presence of transgenic material in Carica papaya L. seed germplasm

    Science.gov (United States)

    Papaya Ringspot Virus (PRSV) is a devastating disease that has a detrimental impact on both commercial papaya production and Caricaceae germplasm conservation. The PRSV coat protein transgenic line 55-1 and derived progeny are resistant to PRSV and have saved the papaya industry in Hawaii. However,...

  3. Prediction of protein-protein interactions in dengue virus coat proteins guided by low resolution cryoEM structures

    Directory of Open Access Journals (Sweden)

    Srinivasan Narayanaswamy

    2010-06-01

    Full Text Available Abstract Background Dengue virus along with the other members of the flaviviridae family has reemerged as deadly human pathogens. Understanding the mechanistic details of these infections can be highly rewarding in developing effective antivirals. During maturation of the virus inside the host cell, the coat proteins E and M undergo conformational changes, altering the morphology of the viral coat. However, due to low resolution nature of the available 3-D structures of viral assemblies, the atomic details of these changes are still elusive. Results In the present analysis, starting from Cα positions of low resolution cryo electron microscopic structures the residue level details of protein-protein interaction interfaces of dengue virus coat proteins have been predicted. By comparing the preexisting structures of virus in different phases of life cycle, the changes taking place in these predicted protein-protein interaction interfaces were followed as a function of maturation process of the virus. Besides changing the current notion about the presence of only homodimers in the mature viral coat, the present analysis indicated presence of a proline-rich motif at the protein-protein interaction interface of the coat protein. Investigating the conservation status of these seemingly functionally crucial residues across other members of flaviviridae family enabled dissecting common mechanisms used for infections by these viruses. Conclusions Thus, using computational approach the present analysis has provided better insights into the preexisting low resolution structures of virus assemblies, the findings of which can be made use of in designing effective antivirals against these deadly human pathogens.

  4. ϕX174 Procapsid Assembly: Effects of an Inhibitory External Scaffolding Protein and Resistant Coat Proteins In Vitro.

    Science.gov (United States)

    Cherwa, James E; Tyson, Joshua; Bedwell, Gregory J; Brooke, Dewey; Edwards, Ashton G; Dokland, Terje; Prevelige, Peter E; Fane, Bentley A

    2017-01-01

    During ϕX174 morphogenesis, 240 copies of the external scaffolding protein D organize 12 pentameric assembly intermediates into procapsids, a reaction reconstituted in vitro In previous studies, ϕX174 strains resistant to exogenously expressed dominant lethal D genes were experimentally evolved. Resistance was achieved by the stepwise acquisition of coat protein mutations. Once resistance was established, a stimulatory D protein mutation that greatly increased strain fitness arose. In this study, in vitro biophysical and biochemical methods were utilized to elucidate the mechanistic details and evolutionary trade-offs created by the resistance mutations. The kinetics of procapsid formation was analyzed in vitro using wild-type, inhibitory, and experimentally evolved coat and scaffolding proteins. Our data suggest that viral fitness is correlated with in vitro assembly kinetics and demonstrate that in vivo experimental evolution can be analyzed within an in vitro biophysical context. Experimental evolution is an extremely valuable tool. Comparisons between ancestral and evolved genotypes suggest hypotheses regarding adaptive mechanisms. However, it is not always possible to rigorously test these hypotheses in vivo We applied in vitro biophysical and biochemical methods to elucidate the mechanistic details that allowed an experimentally evolved virus to become resistant to an antiviral protein and then evolve a productive use for that protein. Moreover, our results indicate that the respective roles of scaffolding and coat proteins may have been redistributed during the evolution of a two-scaffolding-protein system. In one-scaffolding-protein virus assembly systems, coat proteins promiscuously interact to form heterogeneous aberrant structures in the absence of scaffolding proteins. Thus, the scaffolding protein controls fidelity. During ϕX174 assembly, the external scaffolding protein acts like a coat protein, self-associating into large aberrant spherical

  5. The coat morphogenetic protein SpoVID is necessary for spore encasement in Bacillus subtilis

    Science.gov (United States)

    Wang, Katherine H.; Isidro, Anabela L.; Domingues, Lia; Eskandarian, Haig A.; McKenney, Peter T.; Drew, Kevin; Grabowski, Paul; Chua, Ming-Hsiu; Barry, Samantha N.; Guan, Michelle; Bonneau, Richard; Henriques, Adriano O.; Eichenberger, Patrick

    2009-01-01

    SUMMARY Endospores formed by Bacillus subtilis are encased in a tough protein shell known as the coat, which consists of at least 70 different proteins. We investigated the process of spore coat morphogenesis using a library of 40 coat proteins fused to GFP and demonstrate that two successive steps can be distinguished in coat assembly. The first step, initial localization of proteins to the spore surface, is dependent on the coat morphogenetic proteins SpoIVA and SpoVM. The second step, spore encasement, requires a third protein, SpoVID. We show that in spoVID mutant cells, most coat proteins assembled into a cap at one side of the developing spore but failed to migrate around and encase it. We also found that SpoIVA directly interacts with SpoVID. A domain analysis revealed that the N-terminus of SpoVID is required for encasement and is a structural homolog of a virion protein, whereas the C-terminus is necessary for the interaction with SpoIVA. Thus, SpoVM, SpoIVA and SpoVID are recruited to the spore surface in a concerted manner and form a tripartite machine that drives coat formation and spore encasement. PMID:19775244

  6. Isolation of nuclear proteins from flax (Linum usitatissimum L. seed coats for gene expression regulation studies

    Directory of Open Access Journals (Sweden)

    Renouard Sullivan

    2012-01-01

    Full Text Available Abstract Background While seed biology is well characterized and numerous studies have focused on this subject over the past years, the regulation of seed coat development and metabolism is for the most part still non-elucidated. It is well known that the seed coat has an essential role in seed development and its features are associated with important agronomical traits. It also constitutes a rich source of valuable compounds such as pharmaceuticals. Most of the cell genetic material is contained in the nucleus; therefore nuclear proteins constitute a major actor for gene expression regulation. Isolation of nuclear proteins responsible for specific seed coat expression is an important prerequisite for understanding seed coat metabolism and development. The extraction of nuclear proteins may be problematic due to the presence of specific components that can interfere with the extraction process. The seed coat is a rich source of mucilage and phenolics, which are good examples of these hindering compounds. Findings In the present study, we propose an optimized nuclear protein extraction protocol able to provide nuclear proteins from flax seed coat without contaminants and sufficient yield and quality for their use in transcriptional gene expression regulation by gel shift experiments. Conclusions Routinely, around 250 μg of nuclear proteins per gram of fresh weight were extracted from immature flax seed coats. The isolation protocol described hereafter may serve as an effective tool for gene expression regulation and seed coat-focused proteomics studies.

  7. Structural Properties of Potexvirus Coat Proteins Detected by Optical Methods.

    Science.gov (United States)

    Semenyuk, P I; Karpova, O V; Ksenofontov, A L; Kalinina, N O; Dobrov, E N; Makarov, V V

    2016-12-01

    It has been shown by X-ray analysis that cores of coat proteins (CPs) from three potexviruses, flexible helical RNA-containing plant viruses, have similar α-helical structure. However, this similarity cannot explain structural lability of potexvirus virions, which is believed to determine their biological activity. Here, we used circular dichroism (CD) spectroscopy in the far UV region to compare optical properties of CPs from three potexviruses with the same morphology and similar structure. CPs from Alternanthera mosaic virus (AltMV), potato aucuba mosaic virus (PAMV), and potato virus X (PVX) have been studied in a free state and in virions. The CD spectrum of AltMV virions was similar to the previously obtained CD spectrum of papaya mosaic virus (PapMV) virions, but differed significantly from the CD spectrum of PAMV virions. The CD spectrum of PAMV virions resembled in its basic characteristics the CD spectrum of PVX virions characterized by molar ellipticity that is abnormally low for α-helical proteins. Homology modeling of the CP structures in AltMV, PAMV, and PVX virions was based on the known high-resolution structures of CPs from papaya mosaic virus and bamboo mosaic virus and confirmed that the structures of the CP cores in all three viruses were nearly identical. Comparison of amino acid sequences of different potexvirus CPs and prediction of unstructured regions in these proteins revealed a possible correlation between specific features in the virion CD spectra and the presence of disordered N-terminal segments in the CPs.

  8. 40 CFR 174.515 - Coat Protein of Papaya Ringspot Virus; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Coat Protein of Papaya Ringspot Virus...-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.515 Coat Protein of Papaya Ringspot Virus; exemption from the requirement of a tolerance. Residues of Coat Protein of Papaya Ringspot Virus are exempt...

  9. 40 CFR 174.531 - Coat protein of plum pox virus; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Coat protein of plum pox virus...-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.531 Coat protein of plum pox virus; exemption from the requirement of a tolerance. Residues of the coat protein of plum pox virus in or on the...

  10. Application of protein-phenolic based coating on tomatoes (Lycopersicum esculentum

    Directory of Open Access Journals (Sweden)

    Eliane Pereira Cipolatti

    2012-09-01

    Full Text Available The aim of this study was to investigate the use of protein-phenolic based coating made from fermented rice bran on cherry tomatoes (Lycopersicum esculentum. Tests were performed with glycerol 3% (v/v, glycerol with protein-phenolic rice bran extract (5%, glycerol with protein-phenolic extract after 96 hours of fermentation (5%, and a control (without coating. The coated cherry tomatoes were kept at room temperature for 28 days. Mass loss, pH and acidity, total soluble solids, and carotenoids were determined every 96 hours. The coating made from the biomass extract reduced the carotenoid and acidity levels in the fruits studied by 17 and 21.1%, respectively, compared to the control. The coating proved an efficient barrier to water vapor with mass loss of 57% less than the control suggesting that it can be used as an alternative for vegetable tissue conservation.

  11. Cellular response to poly(vinyl alcohol) nanofibers coated with biocompatible proteins and polysaccharides

    Science.gov (United States)

    Lee, So Young; Jang, Da Hyun; Kang, Yun Ok; Kim, O. Bok; Jeong, Lim; Kang, Hyun Ki; Lee, Seung Jin; Lee, Chong-Heon; Park, Won Ho; Min, Byung-Moo

    2012-07-01

    A PVA nanofibrous matrix was prepared by electrospinning an aqueous 10 wt% PVA solution. The mean diameter of the PVA nanofibers electrospun from the aqueous PVA solution was 240 nm. The water resistance of the as-spun PVA nanofibrous matrix was improved by physically crosslinking the PVA nanofibers by heat treatment at 150 °C for 10 min. In addition, the heat-treated PVA nanofibrous matrix was coated with biocompatible polysaccharides (chitosan (CHI) or hyaluronic acid (HA)) and proteins (collagen (COL) or silk fibroin (SF)) to construct biomimetic nanofibrous scaffolds. The coating of proteins or polysaccharides on the PVA nanofibrous matrix was confirmed by ATR-IR spectra, and the degree of coating was determined by elemental analysis based on nitrogen content. The coated PVA matrices exhibited less hydrophilicity, except for the HA coating, and better tensile properties than the pure PVA nanofibrous matrix. The increase in tensile properties was due to interfiber bonds formed by the coating. The effect of protein and polysaccharide coating on normal human keratinocytes (NHEKs) and fibroblasts (NHEFs) was examined by cytocompatibility assessment in vitro. Among the CHI-, COL-, HA- and SF-coated PVA matrices, the SF-coated PVA nanofibrous matrix was found to be the most promising scaffold for the attachment and spreading of NHEKs and NHEFs as compared to the pure PVA matrix. This approach to controlling the surface properties of nanofibrous structures with SF may be useful in the design and tailoring of novel matrices for skin regeneration.

  12. Protein Corona Composition of Superparamagnetic Iron Oxide Nanoparticles with Various Physico-Chemical Properties and Coatings

    Science.gov (United States)

    Sakulkhu, Usawadee; Mahmoudi, Morteza; Maurizi, Lionel; Salaklang, Jatuporn; Hofmann, Heinrich

    2014-05-01

    Because of their biocompatibility and unique magnetic properties, superparamagnetic iron oxide nanoparticles NPs (SPIONs) are recognized as some of the most prominent agents for theranostic applications. Thus, understanding the interaction of SPIONs with biological systems is important for their safe design and efficient applications. In this study, SPIONs were coated with 2 different polymers: polyvinyl alcohol polymer (PVA) and dextran. The obtained NPs with different surface charges (positive, neutral, and negative) were used as a model study of the effect of surface charges and surface polymer materials on protein adsorption using a magnetic separator. We found that the PVA-coated SPIONs with negative and neutral surface charge adsorbed more serum proteins than the dextran-coated SPIONs, which resulted in higher blood circulation time for PVA-coated NPs than the dextran-coated ones. Highly abundant proteins such as serum albumin, serotransferrin, prothrombin, alpha-fetoprotein, and kininogen-1 were commonly found on both PVA- and dextran-coated SPIONs. By increasing the ionic strength, soft- and hard-corona proteins were observed on 3 types of PVA-SPIONs. However, the tightly bound proteins were observed only on negatively charged PVA-coated SPIONs after the strong protein elution.

  13. Impact of protein pre-coating on the protein corona composition and nanoparticle cellular uptake.

    Science.gov (United States)

    Mirshafiee, Vahid; Kim, Raehyun; Park, Soyun; Mahmoudi, Morteza; Kraft, Mary L

    2016-01-01

    Nanoparticles (NPs) are functionalized with targeting ligands to enable selectively delivering drugs to desired locations in the body. When these functionalized NPs enter the blood stream, plasma proteins bind to their surfaces, forming a protein corona that affects NP uptake and targeting efficiency. To address this problem, new strategies for directing the formation of a protein corona that has targeting capabilities are emerging. Here, we have investigated the feasibility of directing corona composition to promote targeted NP uptake by specific types of cells. We used the well-characterized process of opsonin-induced phagocytosis by macrophages as a simplified model of corona-mediated NP uptake by a desired cell type. We demonstrate that pre-coating silica NPs with gamma-globulins (γ-globulins) produced a protein corona that was enriched with opsonins, such as immunoglobulins. Although immunoglobulins are ligands that bind to receptors on macrophages and elicit phagocytois, the opsonin-rich protein corona did not increase NP uptake by macrophage RAW 264.7 cells. Immunolabeling experiments indicated that the binding of opsonins to their target cell surface receptors was impeded by other proteins in the corona. Thus, corona-mediated NP targeting strategies must optimize both the recruitment of the desired plasma proteins as well as their accessibility and orientation in the corona layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Blocking of bacterial biofilm formation by a fish protein coating

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Klemm, Per

    2008-01-01

    , this proteinaceous coating is characterized with regards to its biofilm-reducing properties by using a range of urinary tract infectious isolates with various pathogenic and adhesive properties. The antiadhesive coating significantly reduced or delayed biofilm formation by all these isolates under every condition...

  15. Constructing fluorogenic Bacillus spores (F-spores via hydrophobic decoration of coat proteins.

    Directory of Open Access Journals (Sweden)

    Linda Ferencko

    Full Text Available BACKGROUND: Bacterial spores are protected by a coat consisting of about 60 different proteins assembled as a biochemically complex structure with intriguing morphological and mechanical properties. Historically, the coat has been considered a static structure providing rigidity and mainly acting as a sieve to exclude exogenous large toxic molecules, such as lytic enzymes. Over recent years, however, new information about the coat's architecture and function have emerged from experiments using innovative tools such as automated scanning microscopy, and high resolution atomic force microscopy. PRINCIPAL FINDINGS: Using thin-section electron microscopy, we found that the coat of Bacillus spores has topologically specific proteins forming a layer that is identifiable because it spontaneously becomes decorated with hydrophobic fluorogenic probes from the milieu. Moreover, spores with decorated coat proteins (termed F-spores have the unexpected attribute of responding to external germination signals by generating intense fluorescence. Fluorescence data from diverse experimental designs, including F-spores constructed from five different Bacilli species, indicated that the fluorogenic ability of F-spores is under control of a putative germination-dependent mechanism. CONCLUSIONS: This work uncovers a novel attribute of spore-coat proteins that we exploited to decorate a specific layer imparting germination-dependent fluorogenicity to F-spores. We expect that F-spores will provide a model system to gain new insights into structure/function dynamics of spore-coat proteins.

  16. The coat protein complex II, COPII, protein Sec13 directly interacts with presenilin-1

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Anders Lade, E-mail: aln@humgen.au.dk [Department of Human Genetics, The Bartholin Building, University of Aarhus, DK-8000 Aarhus C (Denmark)

    2009-10-23

    Mutations in the human gene encoding presenilin-1, PS1, account for most cases of early-onset familial Alzheimer's disease. PS1 has nine transmembrane domains and a large loop orientated towards the cytoplasm. PS1 locates to cellular compartments as endoplasmic reticulum (ER), Golgi apparatus, vesicular structures, and plasma membrane, and is an integral member of {gamma}-secretase, a protein protease complex with specificity for intra-membranous cleavage of substrates such as {beta}-amyloid precursor protein. Here, an interaction between PS1 and the Sec13 protein is described. Sec13 takes part in coat protein complex II, COPII, vesicular trafficking, nuclear pore function, and ER directed protein sequestering and degradation control. The interaction maps to the N-terminal part of the large hydrophilic PS1 loop and the first of the six WD40-repeats present in Sec13. The identified Sec13 interaction to PS1 is a new candidate interaction for linking PS1 to secretory and protein degrading vesicular circuits.

  17. Constructing fluorogenic Bacillus spores (F-spores) via hydrophobic decoration of coat proteins

    National Research Council Canada - National Science Library

    Ferencko, Linda; Rotman, Boris

    2010-01-01

    ... atomic force microscopy. Using thin-section electron microscopy, we found that the coat of Bacillus spores has topologically specific proteins forming a layer that is identifiable because it spontaneously...

  18. Cofolding Organizes Alfalfa Mosaic Virus RNA and Coat Protein for Replication

    OpenAIRE

    Guogas, Laura M.; Filman, David J.; Hogle, James M.; Gehrke, Lee

    2004-01-01

    Alfalfa mosaic virus genomic RNAs are infectious only when the viral coat protein binds to the RNA 3´ termini. The crystal structure of an alfalfa mosaic virus RNA-peptide complex reveals that conserved AUGC repeats and Pro-Thr-x-Arg-Ser-x-x-Tyr coat protein amino acids cofold upon interacting. Alternating AUGC residues have opposite orientation, and they base pair in different adjacent duplexes. Localized RNA backbone reversals stabilized by arginine-guanine interactions place the adenosines...

  19. Albumen foam stability and s-ovalbumin contents in eggs coated with whey protein concentrate

    Directory of Open Access Journals (Sweden)

    ACC Alleoni

    2004-06-01

    Full Text Available Food products such as breads, cakes, crackers, meringues, ice creams and several bakery items depend on air incorporation to maintain their texture and structure during or after processing. Proteins are utilized in the food industry since they improve texture attributes through their ability to encapsulate and retain air. The objectives of this work were to quantify s-ovalbumin contents in albumen and to determine alterations in egg white foam stability in fresh eggs, and in eggs coated and non-coated with a whey protein-based concentrate film (WPC, stored at 25°C for 28 days. The volume of drained liquid was higher in non-coated eggs than in coated eggs stored at 25°C at all storage periods. The difference on the third day of storage was in the order of 59% between coated and non-coated eggs, while on the twenty-eighth day it was 202%. During the storage period, an increase in pH and drainage volume was observed for non-coated eggs. After three days, the non-coated eggs showed a s-ovalbumin content 33% higher than coated eggs; this increase jumped to 205% at 28 days of storage. There was a positive correlation between s-ovalbumin content and the volume of drained liquid for coated and non-coated eggs; in other words, when the s-ovalbumin content increased, there was an increase in the volume of drained liquid and a decrease in foam stability. WPC coating maintain egg quality, since it is an effective barrier against the loss of CO2, avoiding changes in the pH of egg white.

  20. Polydopamine-coated open tubular column for the separation of proteins by capillary electrochromatography.

    Science.gov (United States)

    Xiao, Xing; Wang, Wentao; Chen, Jia; Jia, Li

    2015-08-01

    The separation and determination of proteins in food is an important aspect in food industry. Inspired by the self-polymerization of dopamine under alkaline conditions and the natural adhesive properties of polydopamine, in this paper, a simple and economical method was developed for the preparation of polydopamine-coated open tubular column, in which ammonium persulfate was used as the source of oxygen to induce and facilitate the polymerization of dopamine to form polydopamine. In comparison with a naked fused-silica capillary, the direction and magnitude of the electro-osmotic flow of the as-prepared polydopamine-coated open tubular column could be manipulated by varying the pH values of background solutions due to the existence of amine and phenolic hydroxyl groups on polydopamine coating. The surface morphology of the polydopamine-coated open tubular column was studied by scanning electron microscopy, and the thickness of polydopamine coating was 106 nm. The performance of the polydopamine-coated open tubular column was validated by analysis of proteins. The relative standard deviations of migration times of proteins representing run-to-run, day-to-day, and column-to-column were less than 3.5%. In addition, the feasibility of the polydopamine-coated open tubular column for real samples was verified by the separation of proteins in chicken egg white and pure milk. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The Role of the Coat Protein A-Domain in P22 Bacteriophage Maturation

    Directory of Open Access Journals (Sweden)

    David S. Morris

    2014-07-01

    Full Text Available Bacteriophage P22 has long been considered a hallmark model for virus assembly and maturation. Repurposing of P22 and other similar virus structures for nanotechnology and nanomedicine has reinvigorated the need to further understand the protein-protein interactions that allow for the assembly, as well as the conformational shifts required for maturation. In this work, gp5, the major coat structural protein of P22, has been manipulated in order to examine the mutational effects on procapsid stability and maturation. Insertions to the P22 coat protein A-domain, while widely permissive of procapsid assembly, destabilize the interactions necessary for virus maturation and potentially allow for the tunable adjustment of procapsid stability. Future manipulation of this region of the coat protein subunit can potentially be used to alter the stability of the capsid for controllable disassembly.

  2. Enhanced protein adsorption and patterning on nanostructured latex-coated paper.

    Science.gov (United States)

    Juvonen, Helka; Määttänen, Anni; Ihalainen, Petri; Viitala, Tapani; Sarfraz, Jawad; Peltonen, Jouko

    2014-06-01

    Specific interactions of extracellular matrix proteins with cells and their adhesion to the substrate are important for cell growth. A nanopatterned latex-coated paper substrate previously shown to be an excellent substrate for cell adhesion and 2D growth was studied for directed immobilization of proteins. The nanostructured latex surface was formed by short-wavelength IR irradiation of a two-component latex coating consisting of a hydrophilic film-forming styrene butadiene acrylonitrile copolymer and hydrophobic polystyrene particles. The hydrophobic regions of the IR-treated latex coating showed strong adhesion of bovine serum albumin (cell repelling protein), fibronectin (cell adhesive protein) and streptavidin. Opposite to the IR-treated surface, fibronectin and streptavidin had a poor affinity toward the untreated pristine latex coating. Detailed characterization of the physicochemical surface properties of the latex-coated substrates revealed that the observed differences in protein affinity were mainly due to the presence or absence of the protein repelling polar and charged surface groups. The protein adsorption was assisted by hydrophobic (dehydration) interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Molecular characterization and coat protein serology of watermelon leaf mottle virus (Potyvirus).

    Science.gov (United States)

    De Sa, P B; Hiebert, E; Purcifull, D E

    2000-01-01

    A cDNA library was generated from purified RNA of watermelon leaf mottle virus (WLMV) (Genus Potyvirus). Two overlapping clones totaling 2,316 nucleotides at the 3' terminus of the virus were identified by immunoscreening with coat protein antiserum. The sequence analyses of the clones indicated an open reading frame (ORF) of 2,050 nucleotides which encoded part of the replicase and the coat protein, a 243-nucleotide non-coding region (3'UTR), and 23 adenine residues of the poly (A) tail. The taxonomic status of WLMV was determined by comparisons of the sequence of the cloned coat protein gene and 3'UTR with potyvirus sequences obtained from GenBank. The nucleotide sequence identities of WLMV compared with 17 other potyviruses ranged from 55.6 to 63.5% for the coat protein, and from 37.2 to 48.3% for the 3'UTR. Phylogenetic analyses of the coat protein region and the 3'UTR indicated that WLMV did not cluster with other potyviruses in a clade with high bootstrap support. The coat protein gene was expressed in Escherichia coli and a polyclonal antiserum was prepared to the expressed coat protein. In immunodiffusion tests, WLMV was found to be serologically distinct from papaya ringspot virus type W, watermelon mosaic virus 2, zucchini yellow mosaic virus, and Moroccan watermelon mosaic virus. In Western blots and ELISA, serological cross-reactivity with other cucurbit potyviruses was observed. Serological and sequence comparisons indicated that watermelon leaf mottle virus is a distinct member of the Potyvirus genus.

  4. NMR assignments for the insertion domain of bacteriophage Sf6 coat protein.

    Science.gov (United States)

    Tripler, Therese N; Teschke, Carolyn M; Alexandrescu, Andrei T

    2017-04-01

    The P22 bacteriophage group is a subgroup of the λ phage supercluster, comprised of the three major sequence types Sf6, P22, and CUS-3, based on their capsid proteins. Our goal is to investigate the extent to which structure-function relationships are conserved for the viral coat proteins and I-domains in this subgroup. Sf6 is a phage that infects the human pathogen Shigella flexneri. The coat protein of Sf6 assembles into a procapsid, which further undergoes maturation during DNA packaging into an infectious virion. The Sf6 coat protein contains a genetically inserted domain, termed the I-domain, similar to the ones present in the P22 and CUS-3 coat proteins. Based on the P22 example, I-domains play important functional roles in capsid assembly, stability, viability, and size-determination. Here we report the 1H, 15N, and 13C chemical shift assignments for the I-domain of the Sf6 phage coat protein. Chemical shift-based secondary structure prediction and hydrogen-bond patterns from a long-range HNCO experiment indicate that the Sf6 I-domain adopts a 6-stranded β-barrel fold like those of P22 and CUS-3 but with important differences, including the absence of the D-loop that is critical for capsid assembly and the addition of a novel disordered loop region.

  5. In situ spatial organization of Potato virus A coat protein subunits as assessed by tritium bombardment.

    Science.gov (United States)

    Baratova, L A; Efimov, A V; Dobrov, E N; Fedorova, N V; Hunt, R; Badun, G A; Ksenofontov, A L; Torrance, L; Järvekülg, L

    2001-10-01

    Potato virus A (PVA) particles were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the label in the amino acids of the coat protein was determined to assess their in situ steric accessibility. This method revealed that the N-terminal 15 amino acids of the PVA coat protein and a region comprising amino acids 27 to 50 are the most accessible at the particle surface to labeling with tritium atoms. A model of the spatial arrangement of the PVA coat protein polypeptide chain within the virus particle was derived from the experimental data obtained by tritium bombardment combined with predictions of secondary-structure elements and the principles of packing alpha-helices and beta-structures in proteins. The model predicts three regions of tertiary structure: (i) the surface-exposed N-terminal region, comprising an unstructured N terminus of 8 amino acids and two beta-strands, (ii) a C-terminal region including two alpha-helices, as well as three beta-strands that form a two-layer structure called an abCd unit, and (iii) a central region comprising a bundle of four alpha-helices in a fold similar to that found in tobacco mosaic virus coat protein. This is the first model of the three-dimensional structure of a potyvirus coat protein.

  6. Performance optimization of soy and whey protein isolates as coating materials on chicken meat.

    Science.gov (United States)

    Kurt, S; Kilinççeker, O

    2011-01-01

    To determine the optimal coating performance of soy protein isolate (SPI) and whey protein isolate (WPI) on chicken meat, the effects of SPI (0 to 10%), WPI (0 to 10%), and pH (3 to 8) on coating pickup, frying loss, yield, moisture, and fat content of chicken meat were investigated by response surface methodology. Chicken breast meat samples were dipped in protein solutions with different pH and then drained. Subsequently, they were coated with a dry commercial coating mixture, and the coated samples were deep-fat fried in margarine. Soy protein isolate had better performance on chicken meat than WPI. The performance increased significantly at higher pH values. Optimal responses were the minimum for coating pickup, yield, and moisture content and the maximum for frying loss and fat content. Critical values for the optimal responses were between 5.05 and 5.80 pH, 2.74 and 4.65% SPI, and 3.10 and 4.74% WPI, respectively. However, the optimal breading performance combination was 7.13 pH, 9.0% SPI, and 0.6% WPI.

  7. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Gordaliza, Estefanía, E-mail: emorenog@ucm.es [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid (Spain); Stigter, Edwin C.A. [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Molecular Cancer Research, Universitair Medisch Centrum Utrecht, Wilhelmina Kinder Ziekenhuis, Lundlaan 6, 3584, EA Utrecht (Netherlands); Lindenburg, Petrus W.; Hankemeier, Thomas [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands)

    2016-06-07

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10{sup −9} m{sup 2} V{sup −1} s{sup −1}) when compared with unmodified fused silica (5.9 ± 0.1 10{sup −8} m{sup 2} V{sup −1} s{sup −1}). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1–1.8% coefficient-of-variation (CV) within a day) and 2–3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. - Highlights: • New coating using recrystallized surface-layer proteins on

  8. Role of Charge Regulation and Size Polydispersity in Nanoparticle Encapsulation by Viral Coat Proteins

    NARCIS (Netherlands)

    Kusters, Remy; Lin, Hsiang-Ku; Zandi, Roya; Tsvetkova, Irina; Dragnea, Bogdan; van der Schoot, Paul|info:eu-repo/dai/nl/102140618

    2015-01-01

    Nanoparticles can be encapsulated by virus coat proteins if their surfaces are functionalized to acquire a sufficiently large negative charge. A minimal surface charge is required to overcome (i) repulsive interactions between the positively charged RNA-binding domains on the proteins and (ii) the

  9. Structure of membrane embedded M13 major coat protein is insensitive to hydrophobic stress

    NARCIS (Netherlands)

    Vos, W.L.; Schor, M.; Nazarov, P.V.; Koehorst, R.B.M.; Spruijt, R.B.; Hemminga, M.A.

    2007-01-01

    The structure of a membrane-embedded -helical reference protein, the M13 major coat protein, is characterized under different conditions of hydrophobic mismatch using fluorescence resonance energy transfer in combination with high-throughput mutagenesis. We show that the structure is similar in both

  10. Whey protein solution coating for fat-uptake reduction in deep-fried chicken breast strips.

    Science.gov (United States)

    Dragich, Ann M; Krochta, John M

    2010-01-01

    This study investigated the use of whey protein, as an additional coating, in combination with basic, well-described predust, batter, and breading ingredients, for fat-uptake reduction in fried chicken. Chicken breasts were cut into strips (1 x 5 x 10 cm) and coated with wheat flour (WF) as a predust, dipped in batter, coated with WF as a breading, then dipped in 10% denatured whey protein isolate (DWPI) aqueous solution (wet basis). A WF-batter-WF treatment with no DWPI solution dip was included as a control. Coated chicken strips were deep-fried at 160 degrees C for 5 min. A Soxhlet-type extraction was performed to determine the fat content of the meat fraction of fried samples, the coating fraction of fried samples, raw chicken, and raw coating ingredients. The WF-batter-WF-10% DWPI solution had significantly lower fat uptake than the WF-batter-WF control, by 30.67% (dry basis). This article describes applied research involving fat reduction in coated deep-fried chicken. The methods used in this article were intended to achieve maximized fat reduction while maintaining a simple procedure applicable to actual food processing lines.

  11. Matrix Pre-coated Targets for High Throughput MALDI Imaging of Proteins

    OpenAIRE

    Yang, Junhai; Caprioli, Richard M.

    2014-01-01

    We have developed matrix pre-coated targets for imaging proteins in thin tissue sections by MALDI MS (matrix-assisted laser desorption/ionization mass spectrometry). Gold covered microscope slides were coated with sinapinic acid (SA) in batches in advance and were shown to be stable for over 6 months when kept in the dark. The sample preparation protocol using these SA pre-coated targets involves treatment with diisopropylethylamine (DIEA)-H2O vapor, transforming the matrix layer to a viscous...

  12. Sequence variability in the coat protein gene of two groups of banana bunchy top isolates.

    Science.gov (United States)

    Wanitchakorn, R; Harding, R M; Dale, J L

    2000-01-01

    Complete nucleotide sequences of the coat protein gene (DNA-3) of banana bunchy top virus (BBTV) were obtained from five geographical isolates by PCR. Analysis of these sequences revealed two distinct groups of BBTV isolates with those from the Philippines, Taiwan and Vietnam forming the Asian group while the South Pacific/African group consisted of isolates from Australia, Burundi and Fiji. At the nucleotide level, the sequences of DNA-3 were more similar between isolates from the same group (maximum 5.86%) than between members of the two different groups (maximum 13.05%). At the amino acid level, the BBTV coat protein remained highly conserved, with a maximum of bananas. The high level of conservation in the BBTV coat protein suggests that any of the DNA-3 sequences presented in this study would probably be equally effective as transgene in attempts to generate transgenic banana plants with resistance to both groups of BBTV isolates.

  13. Micro patterning of cell and protein non-adhesive plasma polymerized coatings for biochip applications

    DEFF Research Database (Denmark)

    Bouaidat, Salim; Berendsen, C.; Thomsen, P.

    2004-01-01

    conventional cleanroom photolithography and lift-off. Single cell arrays showed sharp contrast in cell adhesion between the untreated glass surface and the ppCrown layer. Similarly, proteins adsorbed selectively to untreated glass but not to ppCrown. The simplicity of the liftoff technique and the sturdiness...... cells ( HeLa) and fluorescence labeled proteins (isothiocyanate-labeled bovine serum albumin, i.e. FITC-BSA). The PEO-like coatings were fabricated by plasma polymerization of 12-crown-4 (ppCrown) with plasma polymerized hexene (ppHexene) as adhesion layer. The coatings were micro patterned using...

  14. Coating nanoparticles with tunable surfactants facilitates control over the protein corona.

    Science.gov (United States)

    Müller, J; Bauer, K N; Prozeller, D; Simon, J; Mailänder, V; Wurm, F R; Winzen, S; Landfester, K

    2017-01-01

    Nanoparticles with long blood circulation time are a prerequisite for targeted drug delivery. To make the nanoparticles invisible for phagocytizing cells, functional moieties on the particle surface are believed to be necessary to attract specific so-called 'stealth' proteins forming a protein 'corona'. Currently, covalent attachment of those moieties represents the only way to achieve that attraction. However, that approach requires a high synthetic effort and is difficult to control. Therefore, we present the coating of model nanoparticles with biodegradable polymeric surfactants as an alternative method. The thermodynamic parameters of the coating process can be tuned by adjusting the surfactants' block lengths and hydrophilicity. Consequently, the unspecific protein adsorption and aggregation tendency of the particles can be controlled, and stealth proteins inhibiting cell uptake are enriched on their surface. This non-covalent approach could be applied to any particle type and thus facilitates tuning the protein corona and its biological impact. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Facile Photoimmobilization of Proteins onto Low-Binding PEG-Coated Polymer Surfaces

    DEFF Research Database (Denmark)

    Larsen, Esben Kjær Unmack; Mikkelsen, Morten Bo Lindholm; Larsen, Niels Bent

    2014-01-01

    Immobilization of proteins onto polymer surfaces usually requires specific reactive functional groups. Here, we show an easy one-step method to conjugate protein covalently onto almost any polymer surface, including low protein-binding poly(ethylene glycol) (PEG), without the requirement...... for the presence of specific functional groups. Several types of proteins, including alkaline phosphatase, bovine serum albumin, and polyclonal antibodies, were photoimmobilized onto a PEG-coated polymer surface using a water-soluble benzophenone as photosensitizer. Protein functionality after immobilization...... was verified for both enzymes and antibodies, and their presence on the surface was confirmed by X-ray photoelectron spectroscopy (XPS) and confocal fluorescence microscopy. Conjugation of capture antibody onto the PEG coating was employed for a simplified ELISA protocol without the need for blocking uncoated...

  16. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations.

    Science.gov (United States)

    Moreno-Gordaliza, Estefanía; Stigter, Edwin C A; Lindenburg, Petrus W; Hankemeier, Thomas

    2016-06-07

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10(-9) m(2) V(-1) s(-1)) when compared with unmodified fused silica (5.9 ± 0.1 10(-8) m(2) V(-1) s(-1)). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1-1.8% coefficient-of-variation (CV) within a day) and 2-3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. The epitope structure of Citrus tristeza virus coat protein mapped by recombinant proteins and monoclonal antibodies.

    Science.gov (United States)

    Wu, Guan-Wei; Tang, Min; Wang, Guo-Ping; Wang, Cai-Xia; Liu, Yong; Yang, Fan; Hong, Ni

    2014-01-05

    It has been known that there exists serological differentiation among Citrus tristeza virus (CTV) isolates. The present study reports three linear epitopes (aa 48-63, 97-104, and 114-125) identified by using bacterially expressed truncated coat proteins and ten monoclonal antibodies against the native virions of CTV-S4. Site-directed mutagenesis analysis demonstrated that the mutation D98G within the newly identified epitope (97)DDDSTGIT(104) abolished its reaction to MAbs 1, 4, and 10, and the presence of G98 in HB1-CP also resulted in its failure to recognize the three MAbs. Our results suggest that the conformational differences in the epitope I (48)LGTQQNAALNRDLFLT(63) between the CPs of isolates S4 and HB1 might contribute to the different reactions of two isolates to MAbs 5 and 6. This study provides new information for the antigenic structures of CTV, and will extend the understanding of the processes required for antibody binding and aid the development of epitope-based diagnostic tools. © 2013 Published by Elsevier Inc.

  18. The influence of sporulation conditions on the spore coat protein composition of Bacillus subtilis spores.

    Directory of Open Access Journals (Sweden)

    Wishwas R. Abhyankar

    2016-10-01

    Full Text Available Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14N spores prepared on solid SG agar plates and 15N metabolically labelled spores prepared in shake flasks containing MOPS buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14N: 15N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the differences in the coat protein composition and

  19. The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores

    Science.gov (United States)

    Abhyankar, Wishwas R.; Kamphorst, Kiki; Swarge, Bhagyashree N.; van Veen, Henk; van der Wel, Nicole N.; Brul, Stanley; de Koster, Chris G.; de Koning, Leo J.

    2016-01-01

    Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14N spores prepared on solid Schaeffer’s-glucose (SG) agar plates and 15N metabolically labeled spores prepared in shake flasks containing 3-(N-morpholino) propane sulfonic acid (MOPS) buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14N:15N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the

  20. Low affinity binding of plasma proteins to lipid-coated quantum dots as observed by in situ fluorescence correlation spectroscopy.

    Science.gov (United States)

    Klapper, Yvonne; Maffre, Pauline; Shang, Li; Ekdahl, Kristina N; Nilsson, Bo; Hettler, Simon; Dries, Manuel; Gerthsen, Dagmar; Nienhaus, G Ulrich

    2015-06-14

    Protein binding to lipid-coated nanoparticles has been pursued quantitatively by using fluorescence correlation spectroscopy. The binding of three important plasma proteins to lipid-enwrapped quantum dots (QDs) shows very low affinity, with an apparent dissociation coefficient in the range of several hundred micromolar. Thus, the tendency to adsorb is orders of magnitude weaker than for QDs coated with dihydrolipoic acid.

  1. Fabrication of Calixarene Based Protein Scaffold by Electrospin Coating for Tissue Engineering.

    Science.gov (United States)

    Cagil, Esra Maltas; Ozcan, Fatih; Ertul, Seref

    2018-08-01

    In this study, calixarene was synthesized by using different functional groups as p-tert-butyl-Calix[4]arene ester and amides. Calixarene nanofibers were produced by electrospin coating. Protein immobilization onto the calixarene nanofibers was carried out with human serum albumin (HSA). The maximum amount of binding on produced three different calixarene nanofibers (DE, 2-AMP and 3-AMP) was compared by using a fluorescence technique for protein analysis. Result showed that maximum binding amount was found to be as 177.85 mg cm-2 for 3-AMP surface. The protein binding was also characterized by using SEM, TEM, AFM and FT-IR. From obtained results, calixarene-albumin nanofiber was also fabricated by spin coating using 3-AMP which has ability max binding of protein.

  2. On-Chip Manipulation of Protein-Coated Magnetic Beads via Domain-Wall Conduits

    DEFF Research Database (Denmark)

    Donolato, Marco; Vavassori, Paolo; Gobbi, Marco

    2010-01-01

    Geometrically constrained magnetic domain walls (DWs) in magnetic nanowires can be manipulated at the nanometer scale. The inhomogeneous magnetic stray field generated by a DW can capture a magnetic nanoparticle in solution. On-chip nanomanipulation of individual magnetic beads coated with proteins...

  3. Coat protein-mediated resistance against an Indian isolate of the ...

    Indian Academy of Sciences (India)

    Coat protein (CP)-mediated resistance against an Indian isolate of the Cucumber mosaic virus (CMV) subgroup IB was demonstrated in transgenic lines of Nicotiana benthamiana through Agrobacterium tumefaciens-mediated transformation. Out of the fourteen independently transformed lines developed, two lines were ...

  4. NMR assignments for the insertion domain of bacteriophage CUS-3 coat protein.

    Science.gov (United States)

    Tripler, Therese N; Maciejewski, Mark W; Teschke, Carolyn M; Alexandrescu, Andrei T

    2015-10-01

    CUS-3 is a P22-like tailed dsDNA bacteriophage that infects Escherichia coli serotype K1. The CUS-3 coat protein, which forms the icosahedral capsid, has a conserved HK97-fold but with a non-conserved accessory domain known as the insertion domain (I-domain). Sequence alignment of the coat proteins from CUS-3 and P22 shows higher sequence similarity for the I-domains (35 %) than for the HK97-cores, suggesting the I-domains play important functional roles. The I-domain of the P22 coat protein, which has an NMR structure comprised of a six-stranded β-barrel, has been shown to govern the assembly, stability and size of the resulting capsid particles. Here, we report the (1)H, (15)N, and (13)C assignments for the I-domain from the coat protein of bacteriophage CUS-3. The secondary structure and dynamics of the CUS-3 I-domain, predicted from the assigned NMR chemical shifts, agree with those of the P22 I-domain, suggesting the CUS-3 and P22 I-domains may have similar structures and functions in capsid assembly.

  5. High genetic diversity in the coat protein and 3'untranslated regions ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 28; Issue 5. High genetic diversity in the coat protein and 3' untranslated regions among geographical isolates of Cardamom mosaic virus from south India. T Jacob T Jebasingh M N Venugopal R Usha. Articles Volume 28 Issue 5 September 2003 pp 589-595 ...

  6. The lipid droplet coat protein perilipin 5 also localizes to muscle mitochondria

    NARCIS (Netherlands)

    Bosma, M.; Minnaard, R.; Sparks, L.M.; Schaart, G.; Losen, M.; Baets, de M.H.; Duimel, H.; Kersten, A.H.; Bickel, P.E.; Schrauwen, P.; Hesselink, M.K.C.

    2012-01-01

    Perilipin 5 (PLIN5/OXPAT) is a lipid droplet (LD) coat protein mainly present in tissues with a high fat-oxidative capacity, suggesting a role for PLIN5 in facilitating fatty acid oxidation. Here, we investigated the role of PLIN5 in fat oxidation in skeletal muscle. In human skeletal muscle, we

  7. Generation of PVY coat protein siRNAs in transgenic potatoes resistant to PVY.

    Science.gov (United States)

    Transgenic potatoes expressing the potato virus Y coat protein (PVY-CP) inverted hairpin RNA (ihRNA) construct driven by the Solanum bulbocastanum ubiquitin 409s promoter exhibited resistance to PVY in glass house studies using PVYNTN and PVYO as inocula and in field studies using naturally occurrin...

  8. Design and self-assembly of simple coat proteins for artificial viruses

    Science.gov (United States)

    Hernandez-Garcia, Armando; Kraft, Daniela J.; Janssen, Anne F. J.; Bomans, Paul H. H.; Sommerdijk, Nico A. J. M.; Thies-Weesie, Dominique M. E.; Favretto, Marco E.; Brock, Roland; de Wolf, Frits A.; Werten, Marc W. T.; van der Schoot, Paul; Stuart, Martien Cohen; de Vries, Renko

    2014-09-01

    Viruses are among the simplest biological systems and are highly effective vehicles for the delivery of genetic material into susceptible host cells. Artificial viruses can be used as model systems for providing insights into natural viruses and can be considered a testing ground for developing artificial life. Moreover, they are used in biomedical and biotechnological applications, such as targeted delivery of nucleic acids for gene therapy and as scaffolds in material science. In a natural setting, survival of viruses requires that a significant fraction of the replicated genomes be completely protected by coat proteins. Complete protection of the genome is ensured by a highly cooperative supramolecular process between the coat proteins and the nucleic acids, which is based on reversible, weak and allosteric interactions only. However, incorporating this type of supramolecular cooperativity into artificial viruses remains challenging. Here, we report a rational design for a self-assembling minimal viral coat protein based on simple polypeptide domains. Our coat protein features precise control over the cooperativity of its self-assembly with single DNA molecules to finally form rod-shaped virus-like particles. We confirm the validity of our design principles by showing that the kinetics of self-assembly of our virus-like particles follows a previous model developed for tobacco mosaic virus. We show that our virus-like particles protect DNA against enzymatic degradation and transfect cells with considerable efficiency, making them promising delivery vehicles.

  9. Albizia lebbeck Seed Coat Proteins Bind to Chitin and Act as a Defense against Cowpea Weevil Callosobruchus maculatus.

    Science.gov (United States)

    Silva, Nadia C M; De Sá, Leonardo F R; Oliveira, Eduardo A G; Costa, Monique N; Ferreira, Andre T S; Perales, Jonas; Fernandes, Kátia V S; Xavier-Filho, Jose; Oliveira, Antonia E A

    2016-05-11

    The seed coat is an external tissue that participates in defense against insects. In some nonhost seeds, including Albizia lebbeck, the insect Callosobruchus maculatus dies during seed coat penetration. We investigated the toxicity of A. lebbeck seed coat proteins to C. maculatus. A chitin-binding protein fraction was isolated from seed coat, and mass spectrometry showed similarity to a C1 cysteine protease. By ELM program an N-glycosylation interaction motif was identified in this protein, and by molecular docking the potential to interact with N-acetylglucosamine (NAG) was shown. The chitin-binding protein fraction was toxic to C. maculatus and was present in larval midgut and feces but not able to hydrolyze larval gut proteins. It did not interfere, though, with the intestinal cell permeability. These results indicate that the toxicity mechanism of this seed coat fraction may be related to its binding to chitin, present in the larvae gut, disturbing nutrient absorption.

  10. Nucleotide Sequence-Homology-Independent Breakdown of Transgenic Resistance by More Virulent Virus Strains and a Potential Solution

    OpenAIRE

    Kung, Yi-Jung; You, Bang-Jau; Raja, Joseph A. J.; Chen, Kuan-Chun; Huang, Chiung-Huei; Bau, Huey-Jiunn; Yang, Ching-Fu; Huang, Chung-Hao; Chang, Chung-Ping; Yeh, Shyi-Dong

    2015-01-01

    Controlling plant viruses by genetic engineering, including the globally important Papaya ringspot virus (PRSV), mainly involves coat protein (CP) gene mediated resistance via post-transcriptional gene silencing (PTGS). However, the breakdown of single- or double-virus resistance in CP-gene-transgenic papaya by more virulent PRSV strains has been noted in repeated field trials. Recombination analysis revealed that the gene silencing suppressor HC-Pro or CP of the virulent PRSV strain 5-19 is ...

  11. Improved protein-adsorption resistance of digital microfluidic device via surface coating and structure modification

    Science.gov (United States)

    Chen, Shun-Yuan; Hu, Heng-Cang; Yu, Chih-Sheng; Hu, Yi-Chiuen

    2007-12-01

    The surface of solid indium tin oxide (ITO) glass supports for samples in electrowetting system needs to be protein-resistant. Since Teflon is the most conventional coating material used to improve the contact angle between the glass and solvent, it still unable to prevent nonspecific proteins adsorption absolutely under the applied potential. In this paper, we described a feasible method that could minimize non-specific proteins adsorption most probably during droplet processing. A regular micro-scale structure was patterned by photolithography, and dielectric layer was covered on the electrodes. Finally a thin layer of Sigmacoat® was coated by physical vapor deposition. The surface characteristic of our chip was analyzed by atomic force microscopy and Contact Angle Analyzer. We found that the adhesion of bio-molecule was efficiently decreased by this modified processing, and could prevent electrolysis more efficiently.

  12. Temperature-Triggered Protein Adsorption on Polymer-Coated Nanoparticles in Serum.

    Science.gov (United States)

    Koshkina, Olga; Lang, Thomas; Thiermann, Raphael; Docter, Dominic; Stauber, Roland H; Secker, Christian; Schlaad, Helmut; Weidner, Steffen; Mohr, Benjamin; Maskos, Michael; Bertin, Annabelle

    2015-08-18

    The protein corona, which forms on the nanoparticle's surface in most biological media, determines the nanoparticle's physicochemical characteristics. The formation of the protein corona has a significant impact on the biodistribution and clearance of nanoparticles in vivo. Therefore, the ability to influence the formation of the protein corona is essential to most biomedical applications, including drug delivery and imaging. In this study, we investigate the protein adsorption on nanoparticles with a hydrodynamic radius of 30 nm and a coating of thermoresponsive poly(2-isopropyl-2-oxazoline) in serum. Using multiangle dynamic light scattering (DLS) we demonstrate that heating of the nanoparticles above their phase separation temperature induces the formation of agglomerates, with a hydrodynamic radius of 1 μm. In serum, noticeably stronger agglomeration occurs at lower temperatures compared to serum-free conditions. Cryogenic transmission electron microscopy (cryo-TEM) revealed a high packing density of agglomerates when serum was not present. In contrast, in the presence of serum, agglomerated nanoparticles were loosely packed, indicating that proteins are intercalated between them. Moreover, an increase in protein content is observed upon heating, confirming that protein adsorption is induced by the alteration of the surface during phase separation. After cooling and switching the surface back, most of the agglomerates were dissolved and the main fraction returned to the original size of approximately 30 nm as shown by asymmetrical flow-field flow fractionation (AF-FFF) and DLS. Furthermore, the amounts of adsorbed proteins are similar before and after heating the nanoparticles to above their phase-separation temperature. Overall, our results demonstrate that the thermoresponsivity of the polymer coating enables turning the corona formation on nanoparticles on and off in situ. As the local heating of body areas can be easily done in vivo, the thermoresponsive

  13. Extracellular matrix proteins as temporary coating for thin-film neural implants

    Science.gov (United States)

    Ceyssens, Frederik; Deprez, Marjolijn; Turner, Neill; Kil, Dries; van Kuyck, Kris; Welkenhuysen, Marleen; Nuttin, Bart; Badylak, Stephen; Puers, Robert

    2017-02-01

    Objective. This study investigates the suitability of a thin sheet of extracellular matrix (ECM) proteins as a resorbable coating for temporarily reinforcing fragile or ultra-low stiffness thin-film neural implants to be placed on the brain, i.e. microelectrocorticographic (µECOG) implants. Approach. Thin-film polyimide-based electrode arrays were fabricated using lithographic methods. ECM was harvested from porcine tissue by a decellularization method and coated around the arrays. Mechanical tests and an in vivo experiment on rats were conducted, followed by a histological tissue study combined with a statistical equivalence test (confidence interval approach, 0.05 significance level) to compare the test group with an uncoated control group. Main results. After 3 months, no significant damage was found based on GFAP and NeuN staining of the relevant brain areas. Significance. The study shows that ECM sheets are a suitable temporary coating for thin µECOG neural implants.

  14. Relationship of the syntheses of spore coat protein and parasporal crystal protein in Bacillus thuringiensis.

    OpenAIRE

    Aronson, A I; Tyrell, D J; Fitz-James, P. C.; Bulla, L A

    1982-01-01

    Two major classes of polypeptides were extracted from the spore surface of Bacillus thuringiensis subsp. kurstaki: the 134,000-dalton protoxin that is the major component of the crystalline inclusion and spore coat polypeptides very similar to those found on Bacillus cereus spores. The quantity of spore coat polypeptides produced was reduced when compared with that produced by certain acrystalliferous mutants or by B. thuringiensis subsp. israelensis. The latter organism produced an inclusion...

  15. Protein-losing nephropathy associated with Borrelia burgdorferi seropositivity in a soft-coated wheaten terrier: response to therapy.

    Science.gov (United States)

    Horney, Barbara S; Stojanovic, Vladimir

    2013-04-01

    A soft-coated wheaten terrier was examined for lameness with subsequent identification of protein-losing nephropathy, hypoalbuminemia, hyperglobulinemia, and seroconversion to Borrelia burgdorferi. Following doxycycline therapy, the urine protein loss decreased significantly and serum albumin concentration remained close to or within the reference interval for over 3 years, contrary to the reported poor prognosis for renal disease associated with B. burgdorferi or protein-losing nephropathy of soft-coated wheaten terriers.

  16. Tritium planigraphy study of structural alterations in the coat protein of Potato virus X induced by binding of its triple gene block 1 protein to virions.

    Science.gov (United States)

    Lukashina, Elena; Badun, Gennady; Fedorova, Natalia; Ksenofontov, Alexander; Nemykh, Maria; Serebryakova, Marina; Mukhamedzhanova, Anna; Karpova, Olga; Rodionova, Nina; Baratova, Lyudmila; Dobrov, Evgeny

    2009-12-01

    Alterations in Potato virus X (PVX) coat protein structure after binding of the protein, encoded by the first gene of PVX triple gene block (triple gene block 1 protein, TGBp1), to the virions were studied using tritium planigraphy. Previously, it has been shown that TGBp1 molecules interact with the PVX particle end, containing the 5'-terminus of PVX RNA, and that this interaction results in a strong decrease in virion stability and its transformation to a translationally active state. In this work, it has been shown that the interaction of TGBp1 with PVX virions leads to an increase of approximately 50% in tritium label incorporation into the 176-198 segment of the 236-residue-long PVX coat protein subunit, with some decrease in label incorporation into the N-terminal coat protein region. According to the new 'sandwich' variant of our recently proposed model of the three-dimensional structure of the intravirus PVX coat protein, the 176-198 segment is assigned to the beta-sheet region located at the subunit surface, presumably participating in coat protein interactions with the intravirus RNA and/or in protein-protein interactions, whereas the N-terminal coat protein region corresponds to the other part of the same beta-sheet. For the remaining segments of the PVX coat protein subunit, no significant difference between tritium incorporation into untreated and TGBp1-treated PVX was observed. A detailed description of the 'sandwich' version of the intravirus PVX coat protein model is presented.

  17. Structural basis of cargo membrane protein discrimination by the human COPII coat machinery

    Energy Technology Data Exchange (ETDEWEB)

    Mancias, Joseph D.; Goldberg, Jonathan (MSKCC)

    2008-11-18

    Genomic analysis shows that the increased complexity of trafficking pathways in mammalian cells involves an expansion of the number of SNARE, Rab and COP proteins. Thus, the human genome encodes four forms of Sec24, the cargo selection subunit of the COPII vesicular coat, and this is proposed to increase the range of cargo accommodated by human COPII-coated vesicles. In this study, we combined X-ray crystallographic and biochemical analysis with functional assays of cargo packaging into COPII vesicles to establish molecular mechanisms for cargo discrimination by human Sec24 subunits. A conserved IxM packaging signal binds in a surface groove of Sec24c and Sec24d, but the groove is occluded in the Sec24a and Sec24b subunits. Conversely, LxxLE class transport signals and the DxE signal of VSV glycoprotein are selectively bound by Sec24a and Sec24b subunits. A comparative analysis of crystal structures of the four human Sec24 isoforms establishes the structural determinants for discrimination among these transport signals, and provides a framework to understand how an expansion of coat subunits extends the range of cargo proteins packaged into COPII-coated vesicles.

  18. Viral protein-coating of magnetic nanoparticles using simian virus 40 VP1.

    Science.gov (United States)

    Enomoto, Teruya; Kawano, Masaaki; Fukuda, Hajime; Sawada, Wataru; Inoue, Takamasa; Haw, Kok Chee; Kita, Yoshinori; Sakamoto, Satoshi; Yamaguchi, Yuki; Imai, Takeshi; Hatakeyama, Mamoru; Saito, Shigeyoshi; Sandhu, Adarsh; Matsui, Masanori; Aoki, Ichio; Handa, Hiroshi

    2013-08-10

    Artificial beads including magnetite and fluorescence particles are useful to visualize pathologic tissue, such as cancers, from harmless types by magnetic resonance imaging (MRI) or fluorescence imaging. Desirable properties of diagnostic materials include high dispersion in body fluids, and the ability to target specific tissues. Here we report on the development of novel magnetic nanoparticles (MNPs) intended for use as diagnosis and therapy that are coated with viral capsid protein VP1-pentamers of simian virus 40, which are monodispersive in body fluid by conjugating epidermal growth factor (EGF) to VP1. Critically, the coating of MNPs with VP1 facilitated stable dispersion of the MNPs in body fluids. In addition, EGF was conjugated to VP1 coating on MNPs (VP1-MNPs). EGF-conjugated VP1-MNPs were successfully used to target EGF receptor-expressing tumor cells in vitro. Thus, using viral capsid protein VP1 as a coating material would be useful for medical diagnosis and therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Matrix pre-coated targets for high throughput MALDI imaging of proteins.

    Science.gov (United States)

    Yang, Junhai; Caprioli, Richard M

    2014-05-01

    We have developed matrix pre-coated targets for imaging proteins in thin tissue sections by matrix-assisted laser desorption/ionization mass spectrometry. Gold covered microscope slides were coated with sinapinic acid (SA) in batches in advance and were shown to be stable for over 6 months when kept in the dark. The sample preparation protocol using these SA pre-coated targets involves treatment with diisopropylethylamine (DIEA)-H2 O vapor, transforming the matrix layer to a viscous ionic liquid. This SA-DIEA ionic liquid layer extracts proteins and other analytes from tissue sections that are thaw mounted to this target. DIEA is removed by the immersion of the target into diluted acetic acid, allowing SA to co-crystallize with extracted analytes directly on the target. Ion images (3-70 kDa) of sections of mouse brain and rat kidney at spatial resolution down to 10 µm were obtained. Use of pre-coated slides greatly reduces sample preparation time for matrix-assisted laser desorption/ionization imaging while providing high throughput, low cost and high spatial resolution images. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Cofolding Organizes Alfalfa Mosaic Virus RNA and Coat Protein for Replication

    Science.gov (United States)

    Guogas, Laura M.; Filman, David J.; Hogle, James M.; Gehrke, Lee

    2006-01-01

    Alfalfa mosaic virus genomic RNAs are infectious only when the viral coat protein binds to the RNA 3´ termini. The crystal structure of an alfalfa mosaic virus RNA-peptide complex reveals that conserved AUGC repeats and Pro-Thr-x-Arg-Ser-x-x-Tyr coat protein amino acids cofold upon interacting. Alternating AUGC residues have opposite orientation, and they base pair in different adjacent duplexes. Localized RNA backbone reversals stabilized by arginine-guanine interactions place the adenosines and guanines in reverse order in the duplex. The results suggest that a uniform, organized 3´ conformation, similar to that found on viral RNAs with transfer RNA-like ends, may be essential for replication. PMID:15604410

  1. Electron cryotomography of measles virus reveals how matrix protein coats the ribonucleocapsid within intact virions.

    Science.gov (United States)

    Liljeroos, Lassi; Huiskonen, Juha T; Ora, Ari; Susi, Petri; Butcher, Sarah J

    2011-11-01

    Measles virus is a highly infectious, enveloped, pleomorphic virus. We combined electron cryotomography with subvolume averaging and immunosorbent electron microscopy to characterize the 3D ultrastructure of the virion. We show that the matrix protein forms helices coating the helical ribonucleocapsid rather than coating the inner leaflet of the membrane, as previously thought. The ribonucleocapsid is folded into tight bundles through matrix-matrix interactions. The implications for virus assembly are that the matrix already tightly interacts with the ribonucleocapsid in the cytoplasm, providing a structural basis for the previously observed regulation of RNA transcription by the matrix protein. Next, the matrix-covered ribonucleocapsids are transported to the plasma membrane, where the matrix interacts with the envelope glycoproteins during budding. These results are relevant to the nucleocapsid organization and budding of other paramyxoviruses, where isolated matrix has been observed to form helices.

  2. Structure of Coatomer Cage Proteins and the Relationship among COPI, COPII, and Clathrin Vesicle Coats

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Changwook; Goldberg, Jonathan (MSKCC)

    2010-09-13

    COPI-coated vesicles form at the Golgi apparatus from two cytosolic components, ARF G protein and coatomer, a heptameric complex that can polymerize into a cage to deform the membrane into a bud. Although coatomer shares a common evolutionary origin with COPII and clathrin vesicle coat proteins, the architectural relationship among the three cages is unclear. Strikingly, the {alpha}{beta}-COP core of coatomer crystallizes as a triskelion in which three copies of a {beta}-COP {beta}-propeller domain converge through their axial ends. We infer that the trimer constitutes the vertex of the COPI cage. Our model proposes that the COPI cage is intermediate in design between COPII and clathrin: COPI shares with clathrin an arrangement of three curved {alpha}-solenoid legs radiating from a common center, and COPI shares with COPII highly similar vertex interactions involving the axial ends of {beta}-propeller domains.

  3. Tyrosinase-catalysed coating of wool fibres with different protein-based biomaterials

    OpenAIRE

    Jus, Suzana; Kokol, Vanja; Gübitz, Georg M.

    2012-01-01

    The potential of tyrosinases to activate tyrosine residues of wool protein fibres for cross-linking with different materials like collagen, elastin and gelatine was assessed. Natural fibres like wool offer an excellent environment for the growth of micro-organisms when the conditions like moisture, oxygen and temperature are appropriate. Coating with collagen, a very useful biomaterial with bactericidal and fungicidal properties, could be used to improve the properties of wool-based materials...

  4. Analyses of protein corona on bare and silica-coated gold nanorods against four mammalian cells.

    Science.gov (United States)

    Das, Minakshi; Yi, Dong Kee; An, Seong Soo A

    2015-01-01

    The purpose of this study was to investigate the mechanisms responsible for the toxic effects of gold nanorods (AuNRs). Here, a comprehensive study was performed by examining the effects of bare (uncoated) AuNRs and AuNRs functionalized with silica (SiO2-AuNRs) against various mammalian cell lines, including cervical cancer cells, fibroblast cells, human umbilical vein endothelial cells, and neuroblastoma cells. The interactions between AuNRs and mammalian cells were investigated with cell viability and mortality assays. Dihydrorhodamine-123 assay was carried out for evaluating reactive oxygen species (ROS) generation, along with mass spectroscopy analysis for determining the composition of the protein corona. Our results suggest that even the lowest concentrations of AuNRs (0.7 μg/mL) induced ROS production leading to cell mortality. On the other hand, cellular viability and ROS production were maintained even at a higher concentration of SiO2-coated AuNRs (12 μg/mL). The increased production of ROS by AuNRs seemed to cause the toxicity observed in all four mammalian cell types. The protein corona on the bare AuNRs did not appear to reduce ROS generation; however, different compositions of the protein corona on bare and SiO2-coated AuNRs may affect cellular behavior differently. Therefore, it was determined that SiO2-coated AuNRs would be more advantageous than bare AuNRs for cellular applications.

  5. Influence of Sterilization and Preservation Procedures on the Integrity of Serum Protein-Coated Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Silvio Dutz

    2017-12-01

    Full Text Available Protein-coated magnetic nanoparticles are promising candidates for various medical applications. Prior to their application into a biological system, one has to guarantee that the particle dispersions are free from pathogens or any other microbiologic contamination. Furthermore, to find entrance into clinical routine, the nanoparticle dispersions have to be storable for several months. In this study, we tested several procedures for sterilization and preservation of nanoparticle containing liquids on their influence on the integrity of the protein coating on the surface of these particles. For this, samples were treated by freezing, autoclaving, lyophilization, and ultraviolet (UV irradiation, and characterized by means of dynamic light scattering, determination of surface potential, and gel electrophoresis afterwards. We found that the UV sterilization followed by lyophilization under the addition of polyethylene glycol are the most promising procedures for the preparation of sterilized long-term durable protein-coated magnetic nanoparticles. Ongoing work is focused on the optimization of used protocols for UV sterilization and lyophilization for further improvement of the storage time.

  6. Thickness and morphology of polyelectrolyte coatings on silica surfaces before and after protein exposure studied by atomic force microscopy.

    Science.gov (United States)

    Haselberg, Rob; Flesch, Frits M; Boerke, Arjan; Somsen, Govert W

    2013-05-24

    Analyte-wall interaction is a significant problem in capillary electrophoresis (CE) as it may compromise separation efficiencies and migration time repeatability. In CE, self-assembled polyelectrolyte multilayer films of Polybrene (PB) and dextran sulfate (DS) or poly(vinylsulfonic acid) (PVS) have been used to coat the capillary inner wall and thereby prevent analyte adsorption. In this study, atomic force microscopy (AFM) was employed to investigate the layer thickness and surface morphology of monolayer (PB), bilayer, (PB-DS and PB-PVS), and trilayer (PB-DS-PB and PB-PVS-PB) coatings on glass surfaces. AFM nanoshaving experiments providing height distributions demonstrated that the coating procedures led to average layer thicknesses between 1 nm (PB) and 5 nm (PB-DS-PB), suggesting the individual polyelectrolytes adhere flat on the silica surface. Investigation of the surface morphology of the different coatings by AFM revealed that the PB coating does not completely cover the silica surface, whereas full coverage was observed for the trilayer coatings. The DS-containing coatings appeared on average 1 nm thicker than the corresponding PVS-containing coatings, which could be attributed to the molecular structure of the anionic polymers applied. Upon exposure to the basic protein cytochrome c, AFM measurements showed an increase of the layer thickness for bare (3.1 nm) and PB-DS-coated (4.6 nm) silica, indicating substantial protein adsorption. In contrast, a very small or no increase of the layer thickness was observed for the PB and PB-DS-PB coatings, demonstrating their effectiveness against protein adsorption. The AFM results are consistent with earlier obtained CE data obtained for proteins using the same polyelectrolyte coatings. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Impact of surface coating and food-mimicking media on nanosilver-protein interaction

    Energy Technology Data Exchange (ETDEWEB)

    Burcza, Anna, E-mail: anna.burcza@mri.bund.de; Gräf, Volker; Walz, Elke; Greiner, Ralf [Max Rubner-Institute, Department of Food Technology and Bioprocess Engineering (Germany)

    2015-11-15

    The application of silver nanoparticles (AgNPs) in food contact materials has recently become a subject of dispute due to the possible migration of silver in nanoform into foods and beverages. Therefore, the analysis of the interaction of AgNPs with food components, especially proteins, is of high importance in order to increase our knowledge of the behavior of nanoparticles in food matrices. AgPURE™ W10 (20 nm), an industrially applied nanomaterial, was compared with AgNPs of similar size frequently investigated for scientific purposes differing in the surface capping agent (spherical AgNP coated with either PVP or citrate). The interactions of the AgNPs with whey proteins (BSA, α-lactalbumin and β-lactoglobulin) at different pH values (4.2, 7 or 7.4) were investigated using surface plasmon resonance, SDS-PAGE, and asymmetric flow field-flow fractionation. The data obtained by the three different methods correlated well. Besides the nature of the protein and the nanoparticle coating, the environment was shown to affect the interaction significantly. The strongest interaction was obtained with BSA and AgNPs in an acidic environment. Neutral and slightly alkaline conditions however, seemed to prevent the AgNP-protein interaction almost completely. Furthermore, the interaction of whey proteins with AgPURE™ W10 was found to be weaker compared to the interaction with the other two AgNPs under all conditions investigated.

  8. Capture of unstable protein complex on the streptavidin-coated single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zunfeng, E-mail: liuz2@chem.leidenuniv.nl; Voskamp, Patrick [Cell Observatory, Biophysical Structural Chemistry, Leiden Institute of Chemistry (Netherlands); Zhang Yue; Chu Fuqiang [Changzhou University, School of Pharmaceutical Engineering and Life Science (China); Abrahams, Jan Pieter, E-mail: abrahams@chem.leidenuniv.nl [Cell Observatory, Biophysical Structural Chemistry, Leiden Institute of Chemistry (Netherlands)

    2013-04-15

    Purification of unstable protein complexes is a bottleneck for investigation of their 3D structure and in protein-protein interaction studies. In this paper, we demonstrate that streptavidin-coated single-walled carbon nanotubes (Strep Bullet SWNT) can be used to capture the biotinylated DNA-EcoRI complexes on a 2D surface and in solution using atomic force microscopy and electrophoresis analysis, respectively. The restriction enzyme EcoRI forms unstable complexes with DNA in the absence of Mg{sup 2+}. Capturing the EcoRI-DNA complexes on the Strep Bullet SWNT succeeded in the absence of Mg{sup 2+}, demonstrating that the Strep Bullet SWNT can be used for purifying unstable protein complexes.

  9. Gene Technology for Papaya Ringspot Virus Disease Management

    Science.gov (United States)

    Azad, Md. Abul Kalam; Sidik, Nik Marzuki

    2014-01-01

    Papaya (Carica papaya) is severely damaged by the papaya ringspot virus (PRSV). This review focuses on the development of PRSV resistant transgenic papaya through gene technology. The genetic diversity of PRSV depends upon geographical distribution and the influence of PRSV disease management on a sequence of PRSV isolates. The concept of pathogen-derived resistance has been employed for the development of transgenic papaya, using a coat protein-mediated, RNA-silencing mechanism and replicase gene-mediated transformation for effective PRSV disease management. The development of PRSV-resistant papaya via post-transcriptional gene silencing is a promising technology for PRSV disease management. PRSV-resistant transgenic papaya is environmentally safe and has no harmful effects on human health. Recent studies have revealed that the success of adoption of transgenic papaya depends upon the application, it being a commercially viable product, bio-safety regulatory issues, trade regulations, and the wider social acceptance of the technology. This review discusses the genome and the genetic diversity of PRSV, host range determinants, molecular diagnosis, disease management strategies, the development of transgenic papaya, environmental issues, issues in the adoption of transgenic papaya, and future directions for research. PMID:24757435

  10. Gene technology for papaya ringspot virus disease management.

    Science.gov (United States)

    Azad, Md Abul Kalam; Amin, Latifah; Sidik, Nik Marzuki

    2014-01-01

    Papaya (Carica papaya) is severely damaged by the papaya ringspot virus (PRSV). This review focuses on the development of PRSV resistant transgenic papaya through gene technology. The genetic diversity of PRSV depends upon geographical distribution and the influence of PRSV disease management on a sequence of PRSV isolates. The concept of pathogen-derived resistance has been employed for the development of transgenic papaya, using a coat protein-mediated, RNA-silencing mechanism and replicase gene-mediated transformation for effective PRSV disease management. The development of PRSV-resistant papaya via post-transcriptional gene silencing is a promising technology for PRSV disease management. PRSV-resistant transgenic papaya is environmentally safe and has no harmful effects on human health. Recent studies have revealed that the success of adoption of transgenic papaya depends upon the application, it being a commercially viable product, bio-safety regulatory issues, trade regulations, and the wider social acceptance of the technology. This review discusses the genome and the genetic diversity of PRSV, host range determinants, molecular diagnosis, disease management strategies, the development of transgenic papaya, environmental issues, issues in the adoption of transgenic papaya, and future directions for research.

  11. Line 63-1: A New Virus-resistant Transgenic Papaya

    NARCIS (Netherlands)

    Tennant, P.; Souza, M.T.; Fitch, M.M.; Manshardt, R.; Slightom, J.L.; Gonsalves, D.

    2005-01-01

    The disease resistance of a transgenic line expressing the coat protein (CP) gene of the mild strain of the papaya ringspot virus (PRSV) from Hawaii was further analyzed against PRSV isolates from Hawaii and other geographical regions. Line 63-1 originated from the same transformation experiment

  12. Sequence similarity between the cp gene and the transgene in transgenic papayas = Similaridade de seqüência entre o gene cp do vírus e do transgene presente em mamoeiros transgênicos

    NARCIS (Netherlands)

    Souza, M.T.; Teixeira, M.; Gonsalves, D.

    2005-01-01

    The Papaya ringspot virus (PRSV) coat protein transgene present in 'Rainbow' and 'SunUp' papayas disclose high sequence similarity (>89%) to the cp gene from PRSV BR and TH. Despite this, both isolates are able to break down the resistance in 'Rainbow', while only the latter is able to do so in

  13. Facile synthesis of polydopamine-coated molecularly imprinted silica nanoparticles for protein recognition and separation.

    Science.gov (United States)

    Xia, Zhiwei; Lin, Zian; Xiao, Yun; Wang, Ling; Zheng, Jiangnan; Yang, Huanghao; Chen, Guonan

    2013-09-15

    Surface imprinting over nanostructured matrices is an effective solution to overcome template removal and achieve high binding capacity. In this work, a facile method was developed for synthesis of polydopamine-coated molecularly imprinted silica nanoparticles (PDA-coated MIP silica NPs) based on self-polymerization of dopamine (DA) on the surface of silica NPs in the presence of template protein. Transmission electronic microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) showed that PDA layers were successfully attached on the surface of silica NPs and the corresponding thickness was about 5nm, which enabled the MIP silica NPs to have fast binding kinetics and high binding capacity. Under the aqueous media, the imprinted silica NPs showed much higher binding affinity toward template than non-imprinted (NIP) silica NPs. The protein recognition properties were examined by single-protein or competitive batch rebinding experiments and rebinding kinetics study, validating that the imprinted silica NPs have high selectivity for the template. The resultant BHb-MIP silica NPs could not only selectively separate BHb from the protein mixture, but also specifically deplete high-abundance BHb from cattle whole blood. In addition, the stability and regeneration were also investigated, which indicated that the imprinted silica NPs had excellent reusability. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Decreased Bacterial Attachment and Protein Adsorption to Coatings Produced by Low Enegy Plasma Polymerization

    DEFF Research Database (Denmark)

    Andersen, T.E.; Kingshott, Peter; Benter, M.

    adsorption and bacteria attachment/colonization. This is emphasized by the fact that long dwelling urinary catheters, which is a typical silicone medical device, causes 5% per day incidence of urinary tract infection [1,2]. A demand therefore exists for surface modifications providing the silicone material......Introduction Silicone rubber is among the most biocompatible materials available, exhibiting low levels of extractables, absence of plasticizers and additives and fairly low activation of blood thrombogenesis components. However untreated silicone rubber does not efficiently resist protein...... and Methods: Coatings: Plasma polymerized poly(vinyl pyrrolidone) (PP-PVP), poly(2-methoxyethyl methacrylate) (PPPMEA) or an inorganic oxide (10) coating were applied onto medical grade silicon rubber sheets (Silopren LSR 2050, Momentive Performance Materials Inc.). Plasma polymerization chamber...

  15. DMSA-Coated Iron Oxide Nanoparticles Greatly Affect the Expression of Genes Coding Cysteine-Rich Proteins by Their DMSA Coating.

    Science.gov (United States)

    Zhang, Ling; Wang, Xin; Zou, Jinglu; Liu, Yingxun; Wang, Jinke

    2015-10-19

    The dimercaptosuccinic acid (DMSA) was widely used to coat iron oxide nanoparticles (FeNPs); however, its intracellular cytotoxicity remains to be adequately elucidated. This study analyzed the differentially expressed genes (DEGs) in four mammalian cells treated by a DMSA-coated magnetite FeNP at various doses at different times. The results revealed that about one-fourth of DEGs coded cysteine-rich proteins (CRPs) in all cells under each treatment, indicating that the nanoparticles greatly affected the expressions of CRP-coding genes. Additionally, about 26% of CRP-coding DEGs were enzyme genes in all cells, indicating that the nanoparticles greatly affected the expression of enzyme genes. Further experiments with the nanoparticles and a polyethylenimine (PEI)-coated magnetite FeNP revealed that the effect mainly resulted from DMSA carried into cells by the nanoparticles. This study thus first reported the cytotoxicity of DMSA at the gene transcription level as coating molecules of FeNPs. This study provides new insight into the molecular mechanism by which the DMSA-coated nanoparticles resulted in the transcriptional changes of many CRP-coding genes in cells. This study draws attention toward the intracellular cytotoxicity of DMSA as a coating molecule of nanoparticles, which has very low toxicity as an orally administered antidote due to its extracellular distribution.

  16. Effect of whey protein-based edible coatings and Natamycin on the quality and shelf life of Iranian white cheese

    Directory of Open Access Journals (Sweden)

    omid ramezani

    2016-11-01

    Full Text Available Cheese is a good source of protein, vitamins and minerals, especially calcium and phosphorus. Changes in the physical, chemical and microbial properties can affect the shelf life of the product. Therefore, increasing the shelf life of this dairy products is very important. The effect of whey protein concentrate-based edible coatings containing Natamycin (at 0.01, 0.02 and 0.03 percent concentrations on the shelf life of Iranian white cheese were studied during 60 days. The results showed that the optimized coatings containing 0.03% Natamycin can prevent the growth of Penicillium chrysogenum up to 60 days, while different treatments of coatings had not significant effect on organoleptic properties fat, pH, and acidity of the cheese samples. However it resulted in a loss of 11% of the moisture content. It was concluded that whey protein concentrate-based coatings containing Natamycin can extend the shelf life of Iranian white cheese.

  17. How Does the VSG Coat of Bloodstream Form African Trypanosomes Interact with External Proteins?

    Science.gov (United States)

    Schwede, Angela; Macleod, Olivia J S; MacGregor, Paula; Carrington, Mark

    2015-12-01

    Variations on the statement "the variant surface glycoprotein (VSG) coat that covers the external face of the mammalian bloodstream form of Trypanosoma brucei acts a physical barrier" appear regularly in research articles and reviews. The concept of the impenetrable VSG coat is an attractive one, as it provides a clear model for understanding how a trypanosome population persists; each successive VSG protects the plasma membrane and is immunologically distinct from previous VSGs. What is the evidence that the VSG coat is an impenetrable barrier, and how do antibodies and other extracellular proteins interact with it? In this review, the nature of the extracellular surface of the bloodstream form trypanosome is described, and past experiments that investigated binding of antibodies and lectins to trypanosomes are analysed using knowledge of VSG sequence and structure that was unavailable when the experiments were performed. Epitopes for some VSG monoclonal antibodies are mapped as far as possible from previous experimental data, onto models of VSG structures. The binding of lectins to some, but not to other, VSGs is revisited with more recent knowledge of the location and nature of N-linked oligosaccharides. The conclusions are: (i) Much of the variation observed in earlier experiments can be explained by the identity of the individual VSGs. (ii) Much of an individual VSG is accessible to antibodies, and the barrier that prevents access to the cell surface is probably at the base of the VSG N-terminal domain, approximately 5 nm from the plasma membrane. This second conclusion highlights a gap in our understanding of how the VSG coat works, as several plasma membrane proteins with large extracellular domains are very unlikely to be hidden from host antibodies by VSG.

  18. The generation of Turnip crinkle virus-like particles in plants by the transient expression of wild-type and modified forms of its coat protein

    Directory of Open Access Journals (Sweden)

    Keith eSaunders

    2015-12-01

    Full Text Available Turnip crinkle virus (TCV, a member of the genus carmovirus of the Tombusviridae family, has a genome consisting of a single positive-sense RNA molecule that is encapsidated in an icosahedral particle composed of 180 copies of a single type of coat protein. We have employed the CPMV-HT transient expression system to investigate the formation of TCV-like particles following the expression of the wild-type coat protein or modified forms of it that contain either deletions and/or additions insertions. Transient expression of the coat protein in plants results in the formation of capsid structures that morphologically resemble TCV virions (T=3 structure but encapsidate heterogeneous cellular RNAs, rather than the specific TCV coat protein messenger RNA. Expression of an amino-terminal deleted form of the coat protein resulted in the formation of smaller T=1 structures that are free of RNA. The possibility of utilising TCV as a carrier for the presentation of foreign proteins on the particle surface was also explored by fusing the sequence of GFP to the C-terminus of the coat protein. The expression of coat protein-GFP hybrids permitted the formation of VLPs but the yield of particles is diminished compared to the yield obtained with unmodified coat protein. Our results confirm the importance of the N-terminus of the coat protein for the encapsidation of RNA and show that the coat protein’s exterior P domain plays a key role in particle formation.

  19. Nanocomposited coatings produced by laser-assisted process to prevent silicone hydogels from protein fouling and bacterial contamination

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Guobang; Chen, Yi; Zhang, Jin, E-mail: jzhang@eng.uwo.ca

    2016-01-01

    Graphical abstract: Nanocomposited-coating was deposited on silicone hydrogel by using the matrix-assisted pulsed laser evaporation (MAPLE) process. The ZnO–PEG nanocomposited coating reduces over 50% protein absorption on silicone hydrogel, and can inhibit the bacterial growth efficiently. - Highlights: • We developed a nanocomposited coating to prevent silicone hydrogel from biofouling. • Matrix-assisted pulsed laser evaporation can deposit inorganic–organic nanomaterials. • The designed nanocomposited coating reduces protein absorption by over 50%. • The designed nanocomposited coating shows significant antimicrobial efficiency. - Abstract: Zinc oxide (ZnO) nanoparticles incorporating with polyethylene glycol (PEG) were deposited together on the surface of silicone hydrogel through matrix-assisted pulsed laser evaporation (MAPLE). In this process, frozen nanocomposites (ZnO–PEG) in isopropanol were irradiated under a pulsed Nd:YAG laser at 532 nm for 1 h. Our results indicate that the MAPLE process is able to maintain the chemical backbone of polymer and prevent the nanocomposite coating from contamination. The ZnO–PEG nanocomposited coating reduces over 50% protein absorption on silicone hydrogel. The cytotoxicity study shows that the ZnO–PEG nanocomposites deposited on silicone hydrogels do not impose the toxic effect on mouse NIH/3T3 cells. In addition, MAPLE-deposited ZnO–PEG nanocomposites can inhibit the bacterial growth significantly.

  20. Evaluation of antimicrobial edible coatings from a whey protein isolate base to improve the shelf life of cheese.

    Science.gov (United States)

    Ramos, Ó L; Pereira, J O; Silva, S I; Fernandes, J C; Franco, M I; Lopes-da-Silva, J A; Pintado, M E; Malcata, F X

    2012-11-01

    The objective of this work was to evaluate the effectiveness of antimicrobial edible coatings to wrap cheeses, throughout 60 d of storage, as an alternative to commercial nonedible coatings. Coatings were prepared using whey protein isolate, glycerol, guar gum, sunflower oil, and Tween 20 as a base matrix, together with several combinations of antimicrobial compounds-natamycin and lactic acid, natamycin and chitooligosaccharides (COS), and natamycin, lactic acid, and COS. Application of coating on cheese decreased water loss (~10%, wt/wt), hardness, and color change; however, salt and fat contents were not significantly affected. Moreover, the antimicrobial edible coatings did not permit growth of pathogenic or contaminant microorganisms, while allowing regular growth of lactic acid bacteria throughout storage. Commercial nonedible coatings inhibited only yeasts and molds. The antimicrobial edible coating containing natamycin and lactic acid was the best in sensory terms. Because these antimicrobial coatings are manufactured from food-grade materials, they can be consumed as an integral part of cheese, which represents a competitive advantage over nonedible coatings. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Characterization of a natural Plum pox virus isolate bearing a truncated coat protein.

    Science.gov (United States)

    Szathmáry, Erzsébet; Nádudvari, Júlia Novák; Szabó, László; Tóbiás, István; Balázs, Ervin; Palkovics, László

    2009-01-01

    Plum pox virus (PPV) isolates were collected in Hungary from plum varieties. PCR targeting the 3' genomic region resulted in a shorter PCR product in the case of the B1298 isolate bearing a 135-nucleotide deletion in frame in the N-terminal part of the coat protein (CP). The isolate was aphid-transmissible and the virion diameter was reduced compared to PPV-SK68. Detectability of this isolate by Western blot varied according to the antibody used. Integration of the deleted CP gene into an infectious PPV clone had no effect on infectivity and symptomatology. In competition experiments, B1298 had a considerable advantage in virus accumulation.

  2. Protein Adsorption Properties on Titanium with and without Calcium Titanate-coating

    Energy Technology Data Exchange (ETDEWEB)

    Ueta, J; Kanno, T; Tada, K; Horiuchi, J [Department Biotechnology and Environmental Chemistry, Kitami Institute of Technology, 165 Koen-cho, Kitami 090-8507, Hokkaido Pref. (Japan); Ohtsu, N, E-mail: kannotr@mail.kitami-it.ac.jp [Instrumental Analysis Center, Kitami Institute of Technology, 165 Koen-cho, Kitami 090-8507, Hokkaido Pref. (Japan)

    2011-10-29

    Adsorption properties of bovine serum albumin (BSA) and egg white lysozyme (LSZ) were examined at pH 5.15 on titanium coated with and without calcium titanate (CT). One CT-coated (CT-Ti), and two none-coated titaniums with different surface roughness (mirror-like-polished; Mi-Ti and mechanically-polished; Me-Ti) were prepared. The adsorbed amounts of both BSA and LSZ were in the order of Me-Ti > Mi-Ti > CT-Ti. Surface roughnes was in the order of Me-Ti > CT-Ti >> Mi-Ti, showing that Me-Ti had the most preferable for protein adsorption. Contact angle of water was Mi-Ti > Me-Ti > CT-Ti, suggesting that Mi-Ti was the most hydrophobic and being more available for adsorption. Therefore, the order of the adsorbed amounts was ascribed to complexation of these two factors; surface roughness and hydrophobicity. The molar adsorbed amounts of LSZ were larger than those of BSA by 3{approx}5 times for the three Ti plates, which was partly due to stronger electrostatic attraction between LSZ and the surface.

  3. Alterations in nanoparticle protein corona by biological surfactants: impact of bile salts on β-lactoglobulin-coated gold nanoparticles.

    Science.gov (United States)

    Winuprasith, Thunnalin; Chantarak, Sirinya; Suphantharika, Manop; He, Lili; McClements, David Julian

    2014-07-15

    The impact of biological surfactants (bile salts) on the protein (β-lactoglobulin) corona surrounding gold nanoparticles (200 nm) was studied using a variety of analytical techniques at pH 7: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); UV-visible (UV) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The bile salts adsorbed to the protein-coated nanoparticle surfaces and altered their interfacial composition, charge, and structure. SERS spectra of protein-coated nanoparticles after bile salt addition contained bands from both protein and bile salts, indicating that the protein was not fully displaced by the bile salts. UV, DLS and TEM techniques also indicated that the protein coating was not fully displaced from the nanoparticle surfaces. The impact of bile salts could be described by an orogenic mechanism: mixed interfaces were formed that consisted of islands of aggregated proteins surrounded by a sea of bile salts. This knowledge is useful for understanding the interactions of bile salts with protein-coated colloidal particles, which may be important for controlling the fate of colloidal delivery systems in the human gastrointestinal tract, or the gastrointestinal fate of ingested inorganic nanoparticles. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Shelf-life of fresh blueberries coated with quinoa protein/chitosan/sunflower oil edible film.

    Science.gov (United States)

    Abugoch, Lilian; Tapia, Cristián; Plasencia, Dora; Pastor, Ana; Castro-Mandujano, Olivio; López, Luis; Escalona, Victor H

    2016-01-30

    The aim of this study was to evaluate quinoa protein (Q), chitosan (CH) and sunflower oil (SO) as edible film material as well as the influence of this coating in extending the shelf-life of fresh blueberries stored at 4 °C and 75% relative humidity. These conditions were used to simulate the storage conditions in supermarkets and represent adverse conditions for testing the effects of the coating. The mechanical, barrier, and structural properties of the film were measured. The effectiveness of the coating in fresh blueberries (CB) was evaluated by changes in weight loss, firmness, color, molds and yeast count, pH, titratable acidity, and soluble solids content. The tensile strength and elongation at break of the edible film were 0.45 ± 0.29 MPa and 117.2% ± 7%, respectively. The water vapor permeability was 3.3 × 10(-12) ± 4.0 × 10(-13) g s(-1) m(-1) Pa(-1). In all of the color parameters CB presented significant differences. CB had slight delayed fruit ripening as evidenced by higher titratable acidity (0.3-0.5 g citric acid 100 g(-1)) and lower pH (3.4-3.6) than control during storage; however, it showed reduced firmness (up to 38%). The use of Q/CH/SO as a coating in fresh blueberries was able to control the growth of molds and yeasts during 32 days of storage, whereas the control showed an increasing of molds and yeast, between 1.8 and 3.1 log cycles (between 20 and 35 days). © 2015 Society of Chemical Industry.

  5. Conformation of the RNA-binding N-terminus of the coat protein of cowpea chlorotic mottle virus : a nuclear magnetic resonance and optical spectroscopy study

    NARCIS (Netherlands)

    Graaf, van der M.

    1992-01-01

    The objective of the study described in this thesis was to obtain information about protein-RNA interactions in cowpea chlorotic mottle virus (CCMV). CCMV consists of RNA and a protective protein coat, composed of 180 identical coat proteins. The positively charged N-terminal arm of the

  6. Albumin-coated SPIONs: an experimental and theoretical evaluation of protein conformation, binding affinity and competition with serum proteins.

    Science.gov (United States)

    Yu, Siming; Perálvarez-Marín, Alex; Minelli, Caterina; Faraudo, Jordi; Roig, Anna; Laromaine, Anna

    2016-08-14

    The variety of nanoparticles (NPs) used in biological applications is increasing and the study of their interaction with biological media is becoming more important. Proteins are commonly the first biomolecules that NPs encounter when they interact with biological systems either in vitro or in vivo. Among NPs, super-paramagnetic iron oxide nanoparticles (SPIONs) show great promise for medicine. In this work, we study in detail the formation, composition, and structure of a monolayer of bovine serum albumin (BSA) on SPIONs. We determine, both by molecular simulations and experimentally, that ten molecules of BSA form a monolayer around the outside of the SPIONs and their binding strength to the SPIONs is about 3.5 × 10(-4) M, ten times higher than the adsorption of fetal bovine serum (FBS) on the same SPIONs. We elucidate a strong electrostatic interaction between BSA and the SPIONs, although the secondary structure of the protein is not affected. We present data that supports the strong binding of the BSA monolayer on SPIONs and the properties of the BSA layer as a protein-resistant coating. We believe that a complete understanding of the behavior and morphology of BSA-SPIONs and how the protein interacts with SPIONs is crucial for improving NP surface design and expanding the potential applications of SPIONs in nanomedicine.

  7. Apoptosis inhibitor of macrophage (AIM) diminishes lipid droplet-coating proteins leading to lipolysis in adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Iwamura, Yoshihiro; Mori, Mayumi; Nakashima, Katsuhiko [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mikami, Toshiyuki; Murayama, Katsuhisa [Genomic Science Laboratories, Dainippon Sumitomo Pharma Co. Ltd., 3-1-98 Kasugadenaka, Konohana-ku, Osaka 554-0022 (Japan); Arai, Satoko [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Miyazaki, Toru, E-mail: tm@m.u-tokyo.ac.jp [Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer AIM induces lipolysis in a distinct manner from that of hormone-dependent lipolysis. Black-Right-Pointing-Pointer AIM ablates activity of peroxisome proliferator-activated receptor in adipocytes. Black-Right-Pointing-Pointer AIM reduces mRNA levels of lipid-droplet coating proteins leading to lipolysis. -- Abstract: Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown. Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPAR{gamma}), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPAR{gamma}-agonist or forced expression of FSP27, while it was synergized by a PPAR{gamma}-antagonist. Overall, distinct modes of lipolysis appear to take place in different physiological

  8. Characterisation of polystyrene coatings after plasma immersion ion implantation and adsorption of protein

    CERN Document Server

    Dekker, S; Steel, B; Bilek, M M M; McKenzie, D R; James, M

    2012-01-01

    A polystyrene film spun onto polished silicon substrates was implanted with either nitrogen or argon ions using plasma immersion ion implantation (PIII) and subsequently investigated by X-ray and neutron reflectometry, UV-VIS and FTIR ellipsometry, as well as by FTIR and Raman spectroscopy. The depth profile of the densified carbon structures resulting from the ion collision cascades in the polystyrene coating are clearly observed by both X-ray and neutron reflectometry. Argon ions produce a higher density modified layer at a shallower depth than nitrogen ions. The thickness measured for these graded layers agrees with the expected depths of ion implantation as calculated by SRIM. The sensitivity of X-ray and neutron reflectometry allows resolution of density and hydrogen content gradients within the graphitized layers. The treated layers were found to covalently immobilized protein directly from solution. The tropoelastin protein monolayers immobilized on the surface were characterized. Tropoelastin remained...

  9. Modification of Functional Properties of Whey Protein Isolate Nanocomposite Films and Coatings with Nanoclays

    Directory of Open Access Journals (Sweden)

    Kerstin Müller

    2017-01-01

    Full Text Available Whey protein based films have received considerable attention to be used for environment friendly packaging applications. However, such biopolymers are prevented for use in commercial packaging due to their limited mechanical and barrier performance. The addition of nanofillers is a common method to overcome those drawbacks of biopolymers. Whey protein isolate (WPI based nanocomposite cast films and coatings were produced using montmorillonite and vermiculite clay as nanofiller in different concentrations. Uniform distribution of filler within the polymeric matrix was confirmed by scanning electron microscopy. Mechanical properties such as tensile strength as well as Young’s modulus were increased after increasing the filler content, while elongation at break values decreased. All samples showed weak barrier potential against water vapor. Nanoclay incorporation, however, reduced water vapor transmission rates by approximately 50%. The oxygen barrier performance was improved for all nanocomposites. Results also indicated proportionality with the filler ratio according to applied models. The highest barrier improvement factors (BIF were greater than five for the cast films and even greater than sixteen for the coatings. Developed WPI-based composites depicted nanoenhanced material properties representing a promising alternative to fossil-based packaging films.

  10. Preparation of silica coated cobalt ferrite magnetic nanoparticles for the purification of histidine-tagged proteins

    Science.gov (United States)

    Aygar, Gülfem; Kaya, Murat; Özkan, Necati; Kocabıyık, Semra; Volkan, Mürvet

    2015-12-01

    Surface modified cobalt ferrite (CoFe2O4) nanoparticles containing Ni-NTA affinity group were synthesized and used for the separation of histidine tag proteins from the complex matrices through the use of imidazole side chains of histidine molecules. Firstly, CoFe2O4 nanoparticles with a narrow size distribution were prepared in an aqueous solution using the controlled co-precipitation method. In order to obtain small CoFe2O4 agglomerates, oleic acid and sodium chloride were used as dispersants. The CoFe2O4 particles were coated with silica and subsequently the surface of these silica coated particles (SiO2-CoFe2O4) was modified by amine (NH2) groups in order to add further functional groups on the silica shell. Then, carboxyl (-COOH) functional groups were added to the SiO2-CoFe2O4 magnetic nanoparticles through the NH2 groups. After that Nα,Nα-Bis(carboxymethyl)-L-lysine hydrate (NTA) was attached to carboxyl ends of the structure. Finally, the surface modified nanoparticles were labeled with nickel (Ni) (II) ions. Furthermore, the modified SiO2-CoFe2O4 magnetic nanoparticles were utilized as a new system that allows purification of the N-terminal His-tagged recombinant small heat shock protein, Tpv-sHSP 14.3.

  11. All-Optical Reversible Logic Gates with Optically Controlled Bacteriorhodopsin Protein-Coated Microresonators

    Directory of Open Access Journals (Sweden)

    Sukhdev Roy

    2012-01-01

    Full Text Available We present designs of all-optical reversible gates, namely, Feynman, Toffoli, Peres, and Feynman double gates, with optically controlled microresonators. To demonstrate the applicability, a bacteriorhodopsin protein-coated silica microcavity in contact between two tapered single-mode fibers has been used as an all-optical switch. Low-power control signals (<200 μW at 532 nm and at 405 nm control the conformational states of the protein to switch a near infrared signal laser beam at 1310 or 1550 nm. This configuration has been used as a template to design four-port tunable resonant coupler logic gates. The proposed designs are general and can be implemented in both fiber-optic and integrated-optic formats and with any other coated photosensitive material. Advantages of directed logic, high Q-factor, tunability, compactness, low-power control signals, high fan-out, and flexibility of cascading switches in 2D/3D architectures to form circuits make the designs promising for practical applications.

  12. Erythrocyte Membrane-Coated Upconversion Nanoparticles with Minimal Protein Adsorption for Enhanced Tumor Imaging.

    Science.gov (United States)

    Rao, Lang; Meng, Qian-Fang; Bu, Lin-Lin; Cai, Bo; Huang, Qinqin; Sun, Zhi-Jun; Zhang, Wen-Feng; Li, Andrew; Guo, Shi-Shang; Liu, Wei; Wang, Tza-Huei; Zhao, Xing-Zhong

    2017-01-25

    Upconversion nanoparticles (UCNPs) with superior optical and chemical features have been broadly employed for in vivo cancer imaging. Generally, UCNPs are surface modified with ligands for cancer active targeting. However, nanoparticles in biological fluids are known to form a long-lived "protein corona", which covers the targeting ligands on nanoparticle surface and dramatically reduces the nanoparticle targeting capabilities. Here, for the first time, we demonstrated that by coating UCNPs with red blood cell (RBC) membranes, the resulting cell membrane-capped nanoparticles (RBC-UCNPs) adsorbed virtually no proteins when exposed to human plasma. We further observed in various scenarios that the cancer targeting ability of folic acid (FA)-functionalized nanoparticles (FA-RBC-UCNPs) was rescued by the cell membrane coating. Next, the FA-RBC-UCNPs were successfully utilized for enhanced in vivo tumor imaging. Finally, blood parameters and histology analysis suggested that no significant systematic toxicity was induced by the injection of biomimetic nanoparticles. Our method provides a new angle on the design of targeted nanoparticles for biomedical applications.

  13. Multiplikasi, Induksi Planlet dan Seleksi Tembakau Hasil Transformasi Gen Coat Protein SMV Secara Kultur in Vitro

    Directory of Open Access Journals (Sweden)

    N.A. FITRIYAH

    2004-11-01

    Full Text Available A study has been conducted to screen and multiply calluses and buds oftobacco transformed with the Soybean Mosaic Virus (SMV coat protein gene and to induce them to plantlet formation by using MS medium with phytohormon treatments. The multiplication of calluses and buds was carried out by sub-culturing on MS medium using 0.3 mg/L NAA+1 mg/L BAP, followed by induction of plantlet formation on MS medium supplemented with NAA and BAP at varied concentration. The results showed that tobacco calluses transformed with SMV coat protein gene was multipliable on MS medium supplemented with NAA at a concentration of 0.3 mg/mL and BAP at 1 mg/L concentration. In this experiment kanamycin was used at a concentration of 100 μg/mL which resulted in the viability level of 84%. On MS medium supplemented with 0.3 mg/L NAA, 0.1 mg/L BAP, and 100 μg/mL kanamycin, induction of calluses to plantlet formation reached 20% level.

  14. Toxin delivery by the coat protein of an aphid-vectored plant virus provides plant resistance to aphids.

    Science.gov (United States)

    Bonning, Bryony C; Pal, Narinder; Liu, Sijun; Wang, Zhaohui; Sivakumar, S; Dixon, Philip M; King, Glenn F; Miller, W Allen

    2014-01-01

    The sap-sucking insects (order Hemiptera), including aphids, planthoppers, whiteflies and stink bugs, present one of the greatest challenges for pest management in global agriculture. Insect neurotoxins offer an alternative to chemical insecticides for controlling these pests, but require delivery into the insect hemocoel. Here we use the coat protein of a luteovirus, an aphid-vectored plant virus, to deliver a spider-derived, insect-specific toxin that acts within the hemocoel. The luteovirid coat protein is sufficient for delivery of fused proteins into the hemocoel of pea aphids, Acyrthosiphon pisum, without virion assembly. We show that when four aphid pest species-A. pisum, Rhopalosiphum padi, Aphis glycines and Myzus persicae-feed on a recombinant coat protein-toxin fusion, either in an experimental membrane sachet or in transgenic Arabidopsis plants, they experience significant mortality. Aphids fed on these fusion proteins showed signs of neurotoxin-induced paralysis. Luteovirid coat protein-insect neurotoxin fusions represent a promising strategy for transgenic control of aphids and potentially other hemipteran pests.

  15. Short-Chain Alkanethiol Coating for Small-Size Gold Nanoparticles Supporting Protein Stability

    Directory of Open Access Journals (Sweden)

    Cristina Cantarutti

    2017-11-01

    Full Text Available The application of gold nanoparticles (AuNPs is emerging in many fields, raising the need for a systematic investigation on their safety. In particular, for biomedical purposes, a relevant issue are certainly AuNP interactions with biomolecules, among which proteins are the most abundant ones. Elucidating the effects of those interactions on protein structure and on nanoparticle stability is a major task towards understanding their mechanisms at a molecular level. We investigated the interaction of the 3-mercaptopropionic acid coating of AuNPs (MPA-AuNPs with β2-microglobulin (β2m, which is a paradigmatic amyloidogenic protein. To this aim, we prepared and characterized MPA-AuNPs with an average diameter of 3.6 nm and we employed NMR spectroscopy and fluorescence spectroscopy to probe protein structure perturbations. We found that β2m interacts with MPA-AuNPs through a highly localized patch maintaining its overall native structure with minor conformational changes. The interaction causes the reversible precipitation of clusters that can be easily re-dispersed through brief sonication.

  16. Coating Nanoparticles with Plant-Produced Transferrin-Hydrophobin Fusion Protein Enhances Their Uptake in Cancer Cells

    DEFF Research Database (Denmark)

    Reuter, Lauri J.; Shahbazi, Mohammad-Ali; Makila, Ermei M.

    2017-01-01

    to a surfactant phase in an aqueous two-phase system, and the transferrin moiety was able to reversibly bind iron. Coating porous silicon nanoparticles with the fusion protein resulted in uptake of the nanoparticles in human cancer cells. This study provides a proof-of concept for the functionalization......The encapsulation of drugs to nanoparticles may offer a solution for targeted delivery. Here, we set out to engineer a self assembling targeting ligand by combining the functional properties of human transferrin and fungal hydrophobins in a single fusion protein. We showed that human transferrin...... of hydrophobin coatings with transferrin as a targeting ligand....

  17. A set of host proteins interacting with papaya ringspot virus NIa-Pro protein identified in a yeast two-hybrid system.

    Science.gov (United States)

    Gao, L; Shen, W T; Yan, P; Tuo, D C; Li, X Y; Zhou, P

    2012-01-01

    The protein-protein interactions between viral and host proteins play an essential role in plant virus infection and host defense. The potyviral nuclear inclusion protein a protease (NIa-Pro) is involved in various steps of viral infection. In this study, the host proteins interacting with papaya ringspot virus (PRSV) NIa-Pro were screened in a Carica papaya L. plant cDNA library using a Sos recruitment two-hybrid system (SRS). We confirmed that the full-length EIF3G, FBPA1, FK506BP, GTPBP, MSRB1, and MTL from papaya can interact specifically with PRSV NIa-Pro in yeast, respectively. These proteins fufill important functions in plant protein translation, biotic and abiotic stress, energy metabolism and signal transduction. In this paper, we discuss possible functions of interactions between these host proteins and NIa-Pro in PRSV infection and their role in host defense. Sos recruitment two-hybrid system; papaya ringspot virus; NIa-Pro; protein-protein interaction.

  18. Tyrosinase-catalysed coating of wool fibres with different protein-based biomaterials.

    Science.gov (United States)

    Jus, Suzana; Kokol, Vanja; Guebitz, Georg M

    2009-01-01

    The potential of tyrosinases to activate tyrosine residues of wool protein fibres for cross-linking with different materials like collagen, elastin and gelatine was assessed. Natural fibres like wool offer an excellent environment for the growth of micro-organisms when the conditions like moisture, oxygen and temperature are appropriate. Coating with collagen, a very useful biomaterial with bactericidal and fungicidal properties, could be used to improve the properties of wool-based materials, especially when applied in hygienically sensitive applications like in hospitals. Tyrosinases were shown to catalyse the oxidation of tyrosine residues in wool and wool hydrolysates as model substrates, as determined by UV-Vis spectroscopy. Structural differences of the surface were evident from the increase of the intensity in the NH bending and stretching regions in the spectra of NIR FT Raman analysis of the enzyme treated and grafted wool fibres. The durability of the coating was also shown by using FITC-labelled collagen that was bound to the wool fibres, even after severe washing. Additionally, antimicrobial properties were successfully imparted due to the collagen grafted on the wool fibres. The functional and mechanical properties of the treated wool fibres showed no significant changes.

  19. Zucchini tigré mosaic virus is a distinct potyvirus in the papaya ringspot virus cluster: molecular and biological insights.

    Science.gov (United States)

    Romay, G; Lecoq, H; Desbiez, C

    2014-02-01

    In recent years, three new potyviruses have been described in the papaya ringspot virus (PRSV) cluster. In addition, two types of PRSV are recognized, type W, infecting cucurbit plants, and type P, infecting papaya and also cucurbits. A third type, PRSV-T, was also partially described in Guadeloupe. Complete genome sequencing of four PRSV-T isolates showed that this virus is a related virus that is distinct from PRSV, and the name zucchini tigré mosaic virus (ZTMV) is proposed, in reference to the typical symptoms observed in zucchini squash. Eleven other viral isolates from different geographic origins were confirmed as ZTMV isolates using the complete sequence of the cylindrical inclusion (CI) coding region, whereas pairwise sequence similarities in the coat protein (CP) coding region did not unambiguously distinguish ZTMV isolates from PRSV isolates. The use of the CI coding region for species demarcation appears more suitable than the CP coding region for closely related viruses. Principal coordinates analysis based on the biological behavior of the viral isolates studied clustered PRSV-P, PRSV-W and ZTMV isolates into three different groups. Therefore, ZTMV is different from PRSV in its molecular and biological properties.

  20. Efficacy of coating activated carbon with milk proteins to prevent binding of bacterial cells from foods for PCR detection.

    Science.gov (United States)

    Opet, Nathan J; Levin, Robert E

    2013-08-01

    Foods contaminated with pathogens are common sources of illness. Currently, the most common and sensitive rapid detection method involves the PCR. However, food matrices are complex and contain inhibitors that limit the sensitivity of the PCR. The use of coated activated carbon can effectively facilitate the removal of PCR inhibitors without binding targeted bacterial cells from food samples. With the use of activated carbon coated with milk proteins, a cell recovery at pH 7.0 of 95.7%±2.0% was obtained, compared to control uncoated activated carbon, which yielded a cell recovery of only 1.1%±0.8%. In addition, the milk protein coated activated carbon was able to absorb similar amounts of soluble compounds as uncoated activated carbon, with the exception of bovine hemoglobin. This suggests that the use of milk proteins to coat activated carbon may therefore serve as a suitable replacement for bentonite in the coating of activated carbon, which has previously been used for the removal of PCR inhibitors from food. Copyright © 2013. Published by Elsevier B.V.

  1. Mutant CCL2 protein coating mitigates wear particle-induced bone loss in a murine continuous polyethylene infusion model.

    Science.gov (United States)

    Nabeshima, Akira; Pajarinen, Jukka; Lin, Tzu-Hua; Jiang, Xinyi; Gibon, Emmanuel; Córdova, Luis A; Loi, Florence; Lu, Laura; Jämsen, Eemeli; Egashira, Kensuke; Yang, Fan; Yao, Zhenyu; Goodman, Stuart B

    2017-02-01

    Wear particle-induced osteolysis limits the long-term survivorship of total joint replacement (TJR). Monocyte/macrophages are the key cells of this adverse reaction. Monocyte Chemoattractant Protein-1 (MCP-1/CCL2) is the most important chemokine regulating trafficking of monocyte/macrophages in particle-induced inflammation. 7ND recombinant protein is a mutant of CCL2 that inhibits CCL2 signaling. We have recently developed a layer-by-layer (LBL) coating platform on implant surfaces that can release biologically active 7ND. In this study, we investigated the effect of 7ND on wear particle-induced bone loss using the murine continuous polyethylene (PE) particle infusion model with 7ND coating of a titanium rod as a local drug delivery device. PE particles were infused into hollow titanium rods with or without 7ND coating implanted in the distal femur for 4 weeks. Specific groups were also injected with RAW 264.7 as the reporter macrophages. Wear particle-induced bone loss and the effects of 7ND were evaluated by microCT, immunohistochemical staining, and bioluminescence imaging. Local delivery of 7ND using the LBL coating decreased systemic macrophage recruitment, the number of osteoclasts and wear particle-induced bone loss. The development of a novel orthopaedic implant coating with anti-CCL2 protein may be a promising strategy to mitigate peri-prosthetic osteolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Nucleotide sequence of the coat protein gene of the Skierniewice isolate of plum pox virus (PPV)

    Energy Technology Data Exchange (ETDEWEB)

    Wypijewski, K.; Musial, W.; Augustyniak, J. [Uniwersytet Adama Mickiewicza, Poznan (Poland); Malinowski, T. [Research Institute of Pomology and Floriculture, Skierniewice (Poland)

    1994-12-31

    The coat protein (CP) gene of the Skierniewice isolate of plum pox virus (PPV-S) has been amplified using the reverse transcription - polymerase chain reaction (RT-PCR), cloned and sequenced. The nucleotide sequence of the gene and the deduced amino-acid sequences of PPV-S CP were compared with those of other PPV strains. The nucleotide sequence showed very high homology to most of the published sequences. The motif: Asp-Ala-Gly (DAG), important for the aphid transmissibility, was present in the amino-acid sequence. Our isolate did not react in ELISA with monoclonal antibodies MAb06 supposed to be specific for PPV-D. (author). 32 refs, 1 fig., 2 tabs.

  3. Lipid, protein and poly(NIPAM) coated mesoporous silica nanoparticles for biomedical applications.

    Science.gov (United States)

    Yang, Yang; Li, Junbai

    2014-05-01

    In the past decade, mesoporous silica nanoparticles (MSNs) as nanocarriers have showed much potential in advanced nanomaterials due to their large surface area and pore volume. Especially, more and more MSNs based nanodevices have been designed as efficient drug delivery systems (DDSs) or biosensors. In this paper, lipid, protein and poly(NIPAM) coated MSNs are reviewed from the preparation, properties and their potential application. We also introduce the preparative methods including physical adsorption, covalent binding and self-assembly on the MSNs' surfaces. Furthermore, the interaction between the aimed cells and these molecular modified MSNs is discussed. We also demonstrate their typical applications, such as photodynamic therapy, bioimaging, controlled release and selective recognition in biomedical field. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. The Coat Protein and NIa Protease of Two Potyviridae Family Members Independently Confer Superinfection Exclusion.

    Science.gov (United States)

    Tatineni, Satyanarayana; French, Roy

    2016-12-01

    Superinfection exclusion (SIE) is an antagonistic virus-virus interaction whereby initial infection by one virus prevents subsequent infection by closely related viruses. Although SIE has been described in diverse viruses infecting plants, humans, and animals, its mechanisms, including involvement of specific viral determinants, are just beginning to be elucidated. In this study, SIE determinants encoded by two economically important wheat viruses, Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) and Triticum mosaic virus (TriMV; genus Poacevirus, family Potyviridae), were identified in gain-of-function experiments that used heterologous viruses to express individual virus-encoded proteins in wheat. Wheat plants infected with TriMV expressing WSMV P1, HC-Pro, P3, 6K1, CI, 6K2, NIa-VPg, or NIb cistrons permitted efficient superinfection by WSMV expressing green fluorescent protein (WSMV-GFP). In contrast, wheat infected with TriMV expressing WSMV NIa-Pro or coat protein (CP) substantially excluded superinfection by WSMV-GFP, suggesting that both of these cistrons are SIE effectors encoded by WSMV. Importantly, SIE is due to functional WSMV NIa-Pro or CP rather than their encoding RNAs, as altering the coded protein products by minimally changing RNA sequences led to abolishment of SIE. Deletion mutagenesis further revealed that elicitation of SIE by NIa-Pro requires the entire protein while CP requires only a 200-amino-acid (aa) middle fragment (aa 101 to 300) of the 349 aa. Strikingly, reciprocal experiments with WSMV-mediated expression of TriMV proteins showed that TriMV CP, and TriMV NIa-Pro to a lesser extent, likewise excluded superinfection by TriMV-GFP. Collectively, these data demonstrate that WSMV- and TriMV-encoded CP and NIa-Pro proteins are effectors of SIE and that these two proteins trigger SIE independently of each other. Superinfection exclusion (SIE) is an antagonistic virus-virus interaction that prevents secondary

  5. Transgenic plums (Prunus domestica L.) express the plum pox virus coat protein gene.

    Science.gov (United States)

    Scorza, R; Ravelonandro, M; Callahan, A M; Cordts, J M; Fuchs, M; Dunez, J; Gonsalves, D

    1994-11-01

    Plum hypocotyl slices were transformed with the coat protein (CP) gene of plum pox virus (PPV-CP) following cocultivation with Agrobacterium tumefaciens containing the plasmid pGA482GG/PPVCP-33. This binary vector carries the PPV-CP gene construct, as well as the chimeric neomycin phosphotransferase and β-glucuronidase genes. Integration and expression of the transferred genes into regenerated plum plants was verified through kan resistance, GUS assays, and PCR amplification of the PPV-CP gene. Twenty-two transgenic clones were identified from approximately 1800 hypocotyl slices. DNA, mRNA, and protein analyses of five transgenic plants confirmed the integration of the engineered CP gene, the accumulation of CP mRNA and of PPV-CP-immunoreactive protein. CP mRNA levels ranged from high to undetectable levels, apparently correlated with gene structure, as indicated by DNA blot analysis. Western analysis showed that transgenic plants produced amounts of CP which generally correlated with amounts of detected mRNA.

  6. Heating-induced transition of Potyvirus Potato Virus A coat protein into β-structure.

    Science.gov (United States)

    Ksenofontov, Alexander L; Parshina, Evgenia Yu; Fedorova, Natalia V; Arutyunyan, Alexander M; Rumvolt, Reet; Paalme, Viiu; Baratova, Ludmila A; Järvekülg, Lilian; Dobrov, Eugeny N

    2016-01-01

    In our previous communication, we have reported that virions of plant Potyvirus Potato Virus A (PVA) have a peculiar structure characterized by high content of disordered regions in intravirus coat protein (CP). In this report, we describe unusual properties of the PVA CP. With the help of a number of physicochemical methods, we have observed that the PVA CP just released from the virions by heating at 60-70 °C undergoes association into oligomers and transition to β- (and even cross-β-) conformation. Transition to β-structure on heating has been recently reported for a number of viral and non-viral proteins. The PVA CP isolated by LiCl method was also transformed into cross-β-structure on heating to 60 °C. Using the algorithms for protein aggregation prediction, we found that the aggregation-prone segments should be located in the central region of a PVA CP molecule. Possibly this transition mimics some functions of PVA CP in the virus life cycle in infected plants.

  7. Humidity control and hydrophilic glue coating applied to mounted protein crystals improves X-ray diffraction experiments

    Science.gov (United States)

    Baba, Seiki; Hoshino, Takeshi; Ito, Len; Kumasaka, Takashi

    2013-01-01

    Protein crystals are fragile, and it is sometimes difficult to find conditions suitable for handling and cryocooling the crystals before conducting X-ray diffraction experiments. To overcome this issue, a protein crystal-mounting method has been developed that involves a water-soluble polymer and controlled humid air that can adjust the moisture content of a mounted crystal. By coating crystals with polymer glue and exposing them to controlled humid air, the crystals were stable at room temperature and were cryocooled under optimized humidity. Moreover, the glue-coated crystals reproducibly showed gradual transformations of their lattice constants in response to a change in humidity; thus, using this method, a series of isomorphous crystals can be prepared. This technique is valuable when working on fragile protein crystals, including membrane proteins, and will also be useful for multi-crystal data collection. PMID:23999307

  8. The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

    Science.gov (United States)

    Pourjavadi, Ali; Tehrani, Zahra Mazaheri; Mahmoudi, Negar

    2015-04-01

    In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating of PEG reduced the wrapping of the protein corona around the nanoparticles. This phenomenon caused increase in Dox release.

  9. Role of alfalfa mosaic virus coat protein in regulation of the balance between viral plus and minus strand RNA synthesis

    NARCIS (Netherlands)

    van der Kuyl, A. C.; Neeleman, L.; Bol, J. F.

    1991-01-01

    Replication of wild type RNA 3 of alfalfa mosaic virus (AIMV) and mutants with frameshifts in the P3 or coat protein (CP) genes was studied in protoplasts from tobacco plants transformed with DNA copies of AIMV RNAs 1 and 2. Accumulation of viral plus and minus strand RNAs was monitored with

  10. Surface-modified nanoparticles as a new, versatile, and mechanically robust nonadhesive coating : Suppression of protein adsorption and bacterial adhesion

    NARCIS (Netherlands)

    Holmes, P. F.; Currie, E. P. K.; Thies, J. C.; van der Mei, H. C.; Busscher, H. J.; Norde, W.

    2009-01-01

    The synthesis of surface-modified silica nanoparticles, chemically grafted with acrylate and poly(ethylene glycol) (PEG) groups, and the ability of the resulting crosslinked coatings to inhibit protein adsorption and bacterial adhesion are explored. Water contact angles, nanoindentation, and atomic

  11. Coat protein deletion mutants elicit more severe symptoms than wild-type virus in multiple cereal hosts

    Science.gov (United States)

    The coat protein (CP) of Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) tolerates deletion of amino acids 36 to 84 for efficient systemic infection of wheat. This study demonstrates that deletion of CP amino acids 58 to 84, but not 36 to 57, from WSMV genome induced severe ...

  12. Constrained modeling of spin-labeled major coat protein mutants from M13 bacteriophage in a phospholipid bilayer

    NARCIS (Netherlands)

    Bashtovyy, D.; Marsh, D.; Hemminga, M.A.; Pali, T.

    2001-01-01

    The family of three-dimensional molecular structures of the major coat protein from the M13 bacteriophage, which was determined in detergent micelles by NMR methods, has been analyzed by constrained geometry optimization in a phospholipid environment. A single-layer solvation shell of dioleoyl

  13. The location of coat protein and viral RNAs of alfalfa mosaic virus in infected tobacco leaves and protoplasts

    NARCIS (Netherlands)

    Pelt-Heerschap, H. van; Verbeek, H.; Slot, J.W.; Vloten-Doting, L. van

    The location of coat protein of alfalfa mosaic virus (AIMV) strain 425 was determined in protoplasts isolated from infected tobacco leaves and in in vitro inoculated tobacco protoplasts, using immunocytochemistry on ultrathin frozen sections labeled with colloidal gold. In infected tobacco leaves 5

  14. Mechanism of Protein Denaturation: Partial Unfolding of the P22 Coat Protein I-Domain by Urea Binding

    Science.gov (United States)

    Newcomer, Rebecca L.; Fraser, LaTasha C.R.; Teschke, Carolyn M.; Alexandrescu, Andrei T.

    2015-01-01

    The I-domain is an insertion domain of the bacteriophage P22 coat protein that drives rapid folding and accounts for over half of the stability of the full-length protein. We sought to determine the role of hydrogen bonds (H-bonds) in the unfolding of the I-domain by examining 3JNC’ couplings transmitted through H-bonds, the temperature and urea-concentration dependence of 1HN and 15N chemical shifts, and native-state hydrogen exchange at urea concentrations where the domain is predominantly folded. The native-state hydrogen-exchange data suggest that the six-stranded β-barrel core of the I-domain is more stable against unfolding than a smaller subdomain comprised of a short α-helix and three-stranded β-sheet. H-bonds, separately determined from solvent protection and 3JNC’ H-bond couplings, are identified with an accuracy of 90% by 1HN temperature coefficients. The accuracy is improved to 95% when 15N temperature coefficients are also included. In contrast, the urea dependence of 1HN and 15N chemical shifts is unrelated to H-bonding. The protein segments with the largest chemical-shift changes in the presence of urea show curved or sigmoidal titration curves suggestive of direct urea binding. Nuclear Overhauser effects to urea for these segments are also consistent with specific urea-binding sites in the I-domain. Taken together, the results support a mechanism of urea unfolding in which denaturant binds to distinct sites in the I-domain. Disordered segments bind urea more readily than regions in stable secondary structure. The locations of the putative urea-binding sites correlate with the lower stability of the structure against solvent exchange, suggesting that partial unfolding of the structure is related to urea accessibility. PMID:26682823

  15. The epsins define a family of proteins that interact with components of the clathrin coat and contain a new protein module

    DEFF Research Database (Denmark)

    Rosenthal, J A; Chen, H; Slepnev, V I

    1999-01-01

    with the binding of both proteins to Eps15. Epsin 2, like epsin 1, is enriched in brain, is present in a brain-derived clathrin-coated vesicle fraction, is concentrated in the peri-Golgi region and at the cell periphery of transfected cells, and partially colocalizes with clathrin. High overexpression of green...... fluorescent protein-epsin 2 mislocalizes components of the clathrin coat and inhibits clathrin-mediated endocytosis. The epsins define a new protein family implicated in membrane dynamics at the cell surface.......Epsin (epsin 1) is an interacting partner for the EH domain-containing region of Eps15 and has been implicated in conjunction with Eps15 in clathrin-mediated endocytosis. We report here the characterization of a similar protein (epsin 2), which we have cloned from human and rat brain libraries...

  16. Coating of nanoparticles on cryogel surface and subsequent double-modification for enhanced ion-exchange capacity of protein.

    Science.gov (United States)

    Tao, Shi-Peng; Wang, Chuan; Sun, Yan

    2014-09-12

    A novel composite cryogel monolith was developed by coating poly(glycidyl methacrylate) nanoparticles (NPs) onto the pore wall surface of poly(acrylamide) cryogel. The NPs-coated column was double-modified with poly(ethylenimine) (PEI) and diethylaminoethyl in sequence. Scanning electron microscopy revealed the dense coating of the NPs on the cryogel surface, but the NPs-coating did not result in distinct changes of the column porosity and permeability. The rough pore wall surface and extended polymer chains offered more binding sites, so the dynamic binding capacity of the composite cryogel bed for bovine serum albumin reached 11.7mg/mL bed volume at a flow rate of 6cm/min, which was 4.2 times higher than that of the cryogel bed modified with PEI without coating NPs (2.8mg/mL). The binding capacity as well as column efficiency decreased only slightly with increasing flow rate from 0.6 to 12cm/min. The results indicated that the strategy of NPs-coating incorporating with double ion-exchanger modifications is promising for enhancing cryogel capacities, and the novel material would be useful for high-speed protein chromatography. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Bilayered clathrin coats on endosomal vacuoles are involved in protein sorting toward lysosomes

    NARCIS (Netherlands)

    Sachse, M.; Urbé, S.; Oorschot, V.; Strous, G.J.; Klumperman, J.

    In many cells endosomal vacuoles show clathrin coats of which the function is unknown. Herein, we show that this coat is predominantly present on early endosomes and has a characteristic bilayered appearance in the electron microscope. By immunoelectron miscroscopy we show that the coat contains

  18. Production of polyclonal antibodies against Pelargonium zonate spot virus coat protein expressed in Escherichia coli and application for immunodiagnosis.

    Science.gov (United States)

    Gulati-Sakhuja, Anju; Sears, John L; Nuñez, Alberto; Liu, Hsing-Yeh

    2009-09-01

    Pelargonium zonate spot virus (PZSV) is identified recently in tomato plants in the United States. To develop serological diagnostic tools for the detection of this virus, the production of good quality antibodies is a necessity. The coat protein (CP) gene of a California isolate of PZSV was cloned into a bacterial expression vector (pTriEX-4 Ek/LIC). The plasmid pTriEX-4-PZSV-CP was transformed into Escherichia coli Rosetta 2(DE3)pLacI and the recombinant PZSV-CP was expressed as a fusion protein containing N-terminal hexa-histidine and S tags. Expressed PZSV-CP was purified under denaturing conditions by affinity chromatography yielding 3mg refolded protein per 200mL of bacterial culture, and used as an antigen for raising PZSV-CP antiserum in rabbits. Specificity of the antiserum to PZSV was shown by Western blot and ELISA. When used in Western blot analysis, the antiserum was able to detect the recombinant protein, the PZSV coat protein and PZSV infected plant samples. The antiserum was successfully used in indirect-ELISA at dilutions of up to 1:16,000 to detect PZSV in infected leaf samples. Direct ELISA was successful only with denatured antigens. This is the first report on production of polyclonal antiserum against recombinant coat protein of PZSV and its use for detection and diagnosis of virus using serological methods.

  19. Purification and biochemical characterization of a monomeric form of papaya mosaic potexvirus coat protein.

    Science.gov (United States)

    Lecours, Katia; Tremblay, Marie-Hélène; Gagné, Marie-Eve Laliberté; Gagné, Stéphane M; Leclerc, Denis

    2006-05-01

    Papaya mosaic virus (PapMV) is a flexuous rod shape virus made of 1400 subunits that assemble around a plus sense genomic RNA. The structure determination of PapMV and of flexuous viruses in general is a major challenge for both NMR and X-ray crystallography. In this report, we present the characterization of a truncated version of the PapMV coat protein (CP) that is suitable for NMR study. The deletion of the N-terminal 26 amino acids of the PapMV CP (CP27-215) generates a monomer that can be expressed to high level and easily purified for production of an adequate NMR sample. The RNA gel shift assay showed that CP27-215 lost its ability to bind RNA in vitro, suggesting that the multimerization of the subunit is important for this function. The fusion of a 6x His tag at the C-terminus improved the solubility of the monomer and allowed its concentration to 0.2 mM. The CD spectra of the truncated and the wild-type proteins were similar, suggesting that both proteins are well ordered and have a similar secondary structure. CP27-215 was 15N labeled for NMR studies and a 2D 1H-15N-HSQC spectrum confirmed the presence of a well-ordered structure and the monomeric form of the protein. These results show that CP27-215 is amenable to a complete and exhaustive NMR study that should lead to the first three-dimensional structure determination of a flexuous rod shape virus.

  20. Phosphatidylcholine-coated iron oxide nanomicelles for in vivo prolonged circulation time with an antibiofouling protein corona.

    Science.gov (United States)

    Groult, Hugo; Ruiz-Cabello, Jesús; Lechuga-Vieco, Ana Victoria; Mateo, Jesús; Benito, Marina; Bilbao, Izaskun; Martínez-Alcázar, María Paz; Lopez, Juan Antonio; Vázquez, Jesús; Herranz, Fernando F

    2014-12-08

    We report the synthesis of micellar phosphatidylcholine-coated superparamagnetic iron oxide nanoparticles as a new long circulation contrast agents for magnetic resonance imaging. Oleic acid-coated Fe3 O4 nanoparticles were first prepared through thermal degradation and then encapsulated into small clusters with a phosphatidylcholine coating to obtain hydrophilic nanomicelles. A thorough characterization confirmed the chemical nature of the coating and the excellent colloidal stability of these nanomicelles in aqueous media. Magnetization and relaxivity properties proved their suitability as magnetic resonance imaging (MRI) contrast agent and in vitro cell viability data showed low toxicity. Vascular lifetime and elimination kinetics in the liver were assessed by blood relaxometry and by in vivo MRI in rats and compared with "control" particles prepared with a polyethylene glycol derivative. These micellar particles had a lifetime in blood of more than 10 h, much longer than the control nanoparticles (≈2 h), which is remarkable considering that the coating molecule is a small biocompatible zwitterionic phospholipid. The protein corona was characterized after incubation with rat serum at different times by high-throughput proteomics, showing a higher proportion of bound apolipoproteins and other dysopsonins for the phosphatidylcholine particles. The antibiofouling properties of this corona and its resistance to the adsorption of proteins corroborate the observed enhanced stability and prolonged systemic circulation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Indrani; Pangule, Ravindra C.; Kane, Ravi S. [Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Ricketts Building, Troy, NY 12180 (United States)

    2011-02-08

    The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms.

    Science.gov (United States)

    Banerjee, Indrani; Pangule, Ravindra C; Kane, Ravi S

    2011-02-08

    The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Varieties of charge distributions in coat proteins of ssRNA+  viruses

    Science.gov (United States)

    Lošdorfer Božič, Anže; Podgornik, Rudolf

    2018-01-01

    A major part of the interactions involved in the assembly and stability of icosahedral, positive-sense single-stranded RNA (ssRNA+) viruses is electrostatic in nature, as can be inferred from the strong pH- and salt-dependence of their assembly phase diagrams. Electrostatic interactions do not act only between the capsid coat proteins (CPs), but just as often provide a significant contribution to the interactions of the CPs with the genomic RNA, mediated to a large extent by positively charged, flexible N-terminal tails of the CPs. In this work, we provide two clear and complementary definitions of an N-terminal tail of a protein, and use them to extract the tail sequences of a large number of CPs of ssRNA+  viruses. We examine the pH-dependent interplay of charge on both tails and CPs alike, and show that—in contrast to the charge on the CPs—the net positive charge on the N-tails persists even to very basic pH values. In addition, we note a limit to the length of the wild-type genomes of those viruses which utilize positively charged tails, when compared to viruses without charged tails and similar capsid size. At the same time, we observe no clear connection between the charge on the N-tails and the genome lengths of the viruses included in our study.

  4. Cascading Effects of Nanoparticle Coatings: Surface Functionalization Dictates the Assemblage of Complexed Proteins and Subsequent Interaction with Model Cell Membranes.

    Science.gov (United States)

    Melby, Eric S; Lohse, Samuel E; Park, Ji Eun; Vartanian, Ariane M; Putans, Rebecca A; Abbott, Hannah B; Hamers, Robert J; Murphy, Catherine J; Pedersen, Joel A

    2017-06-27

    Interactions of functionalized nanomaterials with biological membranes are expected to be governed by not only nanoparticle physiochemical properties but also coatings or "coronas" of biomacromolecules acquired after immersion in biological fluids. Here we prepared a library of 4-5 nm gold nanoparticles (AuNPs) coated with either ω-functionalized thiols or polyelectrolyte wrappings to examine the influence of surface functional groups on the assemblage of proteins complexing the nanoparticles and its subsequent impact on attachment to model biological membranes. We find that the initial nanoparticle surface coating has a cascading effect on interactions with model cell membranes by determining the assemblage of complexing proteins, which in turn influences subsequent interaction with model biological membranes. Each type of functionalized AuNP investigated formed complexes with a unique ensemble of serum proteins that depended on the initial surface coating of the nanoparticles. Formation of protein-nanoparticle complexes altered the electrokinetic, hydrodynamic, and plasmonic properties of the AuNPs. Complexation of the nanoparticles with proteins reduced the attachment of cationic AuNPs and promoted attachment of anionic AuNPs to supported lipid bilayers; this trend is observed with both lipid bilayers comprising 100% zwitterionic phospholipids and those incorporating anionic phosphatidylinositol. Complexation with serum proteins led to attachment of otherwise noninteracting oligo(ethylene glycol)-functionalized AuNPs to bilayers containing phosphatidylinositol. These results demonstrate the importance of considering both facets of the nano-bio interface: functional groups displayed on the nanoparticle surface and proteins complexing the nanoparticles influence interaction with biological membranes as does the molecular makeup of the membranes themselves.

  5. Coating Nanoparticles with Plant-Produced Transferrin-Hydrophobin Fusion Protein Enhances Their Uptake in Cancer Cells.

    Science.gov (United States)

    Reuter, Lauri J; Shahbazi, Mohammad-Ali; Mäkilä, Ermei M; Salonen, Jarno J; Saberianfar, Reza; Menassa, Rima; Santos, Hélder A; Joensuu, Jussi J; Ritala, Anneli

    2017-06-21

    The encapsulation of drugs to nanoparticles may offer a solution for targeted delivery. Here, we set out to engineer a self-assembling targeting ligand by combining the functional properties of human transferrin and fungal hydrophobins in a single fusion protein. We showed that human transferrin can be expressed in Nicotiana benthamiana plants as a fusion with Trichoderma reesei hydrophobins HFBI, HFBII, or HFBIV. Transferrin-HFBIV was further expressed in tobacco BY-2 suspension cells. Both partners of the fusion protein retained their functionality; the hydrophobin moiety enabled migration to a surfactant phase in an aqueous two-phase system, and the transferrin moiety was able to reversibly bind iron. Coating porous silicon nanoparticles with the fusion protein resulted in uptake of the nanoparticles in human cancer cells. This study provides a proof-of-concept for the functionalization of hydrophobin coatings with transferrin as a targeting ligand.

  6. Kinetic Effects on Self-Assembly and Function of Protein-Polymer Bioconjugates in Thin Films Prepared by Flow Coating

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Dongsook [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Huang, Aaron [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Olsen, Bradley D. [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA

    2016-11-04

    The self-assembly of nanostructured globular protein arrays in thin films is demonstrated using protein–polymer block copolymers based on a model protein mCherry and the polymer poly(oligoethylene glycol acrylate) (POEGA). Conjugates are flow coated into thin films on a poly(ethylene oxide) grafted Si surface, forming self-assembled cylindrical nanostructures with POEGA domains selectively segregating to the air–film interface. Long-range order and preferential arrangement of parallel cylinders templated by selective surfaces are demonstrated by controlling relative humidity. Long-range order increases with coating speed when the film thicknesses are kept constant, due to reduced nucleation per unit area of drying film. Fluorescence emission spectra of mCherry in films prepared at <25% relative humidity shows a small shift suggesting that proteins are more perturbed at low humidity than high humidity or the solution state.

  7. Fabrication and characterization of gold nano-wires templated on virus-like arrays of tobacco mosaic virus coat proteins

    Science.gov (United States)

    Wnęk, M.; Górzny, M. Ł.; Ward, M. B.; Wälti, C.; Davies, A. G.; Brydson, R.; Evans, S. D.; Stockley, P. G.

    2013-01-01

    The rod-shaped plant virus tobacco mosaic virus (TMV) is widely used as a nano-fabrication template, and chimeric peptide expression on its major coat protein has extended its potential applications. Here we describe a simple bacterial expression system for production and rapid purification of recombinant chimeric TMV coat protein carrying C-terminal peptide tags. These proteins do not bind TMV RNA or form disks at pH 7. However, they retain the ability to self-assemble into virus-like arrays at acidic pH. C-terminal peptide tags in such arrays are exposed on the protein surface, allowing interaction with target species. We have utilized a C-terminal His-tag to create virus coat protein-templated nano-rods able to bind gold nanoparticles uniformly. These can be transformed into gold nano-wires by deposition of additional gold atoms from solution, followed by thermal annealing. The resistivity of a typical annealed wire created by this approach is significantly less than values reported for other nano-wires made using different bio-templates. This expression construct is therefore a useful additional tool for the creation of chimeric TMV-like nano-rods for bio-templating.

  8. Influence of calcium-induced droplet heteroaggregation on the physicochemical properties of oppositely charged lactoferrin coated lutein droplets and whey protein isolate-coated DHA droplets.

    Science.gov (United States)

    Li, Xin; Wang, Xu; Xu, Duoxia; Cao, Yanping; Wang, Shaojia; Wang, Bei; Wang, Chengtao; Sun, Baoguo

    2017-08-01

    The influence of calcium-induced droplet heteroaggregation on the formation and physicochemical stability of mixed lutein and DHA emulsions was studied. Heteroaggregation was induced by mixing oppositely charged lactoferrin (LF)-coated lutein and whey protein isolate (WPI)-coated DHA emulsions with different CaCl 2 concentrations at pH 6.0. The droplet size, zeta-potential, transmission-physical stability and microstructure behavior (CLSM and Cryo-SEM) of single-protein emulsions and mixed emulsions were measured as a function of different CaCl 2 concentrations. Lutein degradation and DHA oxidation by measurement of lipid hydroperoxides and thiobarbituric acid reactive substances were determined during storage. The physical stability of the mixed emulsions could be modulated by controlling CaCl 2 concentrations. Microstructure behavior indicated that a mixed emulsion with 30 mM CaCl 2 promoted more droplets to form a special three-dimensional network and microcluster structures. The chemical stability of the mixed lutein and DHA emulsions was obviously enhanced by the addition of 30 mM CaCl 2 . The decreased surface areas of the DHA and lutein droplets and the physical barrier of the network of heteroaggregates against transition metals and free radicals could mainly explain the improvement in chemical stability. Calcium-induced droplet aggregation may be useful for creating specific food structures that lead to desirable physicochemical properties of multiple functional components.

  9. Immunodiagnosis of Citrus leprosis virus C using a polyclonal antibody to an expressed putative coat protein.

    Science.gov (United States)

    Choudhary, Nandlal; Roy, Avijit; Guillermo, Leon M; Picton, D D; Wei, G; Nakhla, M K; Levy, L; Brlansky, R H

    2013-11-01

    Citrus leprosis virus C (CiLV-C), a causal agent for citrus leprosis disease, is present in South and Central America and is a threat for introduction into the U.S. citrus industry. A specific, inexpensive and reliable antibody based detection system is needed for the rapid identification of CiLV-C. The CiLV-C is very labile and has not been purified in sufficient amount for antibody production. The p29 gene of CiLV-C genome that codes for the putative coat protein (PCP) was codon optimized for expression in Escherichia coli and synthesized in vitro. The optimized gene was sub-cloned into the bacterial expression vector pDEST17 and transferred into E. coli BL21AI competent cells. The expression of PCP containing N-terminal His-tag was optimized by induction with l-arabinose. Induced cells were disrupted by sonication and expressed PCP was purified by affinity chromatography using Ni-NTA agarose. The purified expressed PCP was then used as an immunogen for injections into rabbits to produce polyclonal antibody (PAb). The PAb specific to the expressed PCP was identified using Western blotting. The antibody was successfully used to detect CiLV-C in the symptomatic CiLV-C infected tissues using double antibody sandwich-enzyme-linked-immunosorbent (DAS-ELISA), indirect ELISA and dot-blot immunoassay (DBIA) formats. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Molecular identification based on coat protein sequences of the Barley yellow dwarf virus from Brazil

    Directory of Open Access Journals (Sweden)

    Talita Bernardon Mar

    2013-12-01

    Full Text Available Yellow dwarf disease, one of the most important diseases of cereal crops worldwide, is caused by virus species belonging to the Luteoviridae family. Forty-two virus isolates obtained from oat (Avena sativa L., wheat (Triticum aestivum L., barley (Hordeum vulgare L., corn (Zea mays L., and ryegrass (Lolium multiflorum Lam. collected between 2007 and 2008 from winter cereal crop regions in southern Brazil were screened by polymerase chain reaction (PCR with primers designed on ORF 3 (coat protein - CP for the presence of Barley yellow dwarf virus and Cereal yellow dwarf virus (B/CYDV. PCR products of expected size (~357 bp for subgroup II and (~831 bp for subgroup I were obtained for three and 39 samples, respectively. These products were cloned and sequenced. The subgroup II 3' partial CP amino acid deduced sequences were identified as BYDV-RMV (92 - 93 % of identity with "Illinois" Z14123 isolate. The complete CP amino acid deduced sequences of subgroup I isolates were confirmed as BYDV-PAV (94 - 99 % of identity and established a very homogeneous group (identity higher than 99 %. These results support the prevalence of BYDV-PAV in southern Brazil as previously diagnosed by Enzyme-Linked Immunosorbent Assay (ELISA and suggest that this population is very homogeneous. To our knowledge, this is the first report of BYDV-RMV in Brazil and the first genetic diversity study on B/CYDV in South America.

  11. Mussel adhesive protein coating: A potential therapeutic method for self-healing of cracked teeth

    Directory of Open Access Journals (Sweden)

    Li Bo-Lin

    2015-01-01

    Full Text Available Introduction: Nowadays, cracked tooth syndrome is the third main cause of tooth extraction, following caries and periodontal diseases, done in almost all the dental clinics. Nevertheless, the diagnosis and treatment of this condition remain controversial. All candidate therapeutics, such as occlusal adjustment, preventive filling, root canal therapy (RCT, and crown restoration, provide unpredictable outcomes. As such, methods to prevent further crack development and to induce crack self-healing must be developed. The Hypothesis: Mussels secreting adhesive foot protein (Mafp can attach to various surfaces under aqueous conditions. In nature, mussels adhere to stones and deposit layer by layer through mineralization, thereby forming mussel-stone composites with excellent mechanical property. Given the natural process of mussel-stone complex formation, we hypothesize that application of Mafp coating at the crack interface may mineralize the cracks by capturing calcium and phosphate ions from the saliva. This process consequently leads to crack self-healing and complete restoration of the tooth structure. Evaluation of the Hypothesis: To test our hypothesis, we need to develop a model in vivo. Cracked teeth disks are adhered together using Mafp solution. Then, the tooth disks are sutured on the interior side of the cheeks. After regular intervals, the disks are removed and characterized. Scanning electron microscopy is performed to evaluate the morphology of the crack interface. Microhardness and shear bond strength are used to evaluate the mechanical property of the healing cracked zone. Transmission electron microscopy is also conducted to evaluate the crystallinity of the crack interface.

  12. Analysis of the epitope structure of Plum pox virus coat protein.

    Science.gov (United States)

    Candresse, Thierry; Saenz, Pilar; García, Juan Antonio; Boscia, Donato; Navratil, Milan; Gorris, Maria Teresa; Cambra, Mariano

    2011-05-01

    Typing of the particular Plum pox virus (PPV) strain responsible in an outbreak has important practical implications and is frequently performed using strain-specific monoclonal antibodies (MAbs). Analysis in Western blots of the reactivity of 24 MAbs to a 112-amino-acid N-terminal fragment of the PPV coat protein (CP) expressed in Escherichia coli showed that 21 of the 24 MAbs recognized linear or denaturation-insensitive epitopes. A series of eight C-truncated CP fragments allowed the mapping of the epitopes recognized by the MAbs. In all, 14 of them reacted to the N-terminal hypervariable region, defining a minimum of six epitopes, while 7 reacted to the beginning of the core region, defining a minimum of three epitopes. Sequence comparisons allowed the more precise positioning of regions recognized by several MAbs, including those recognized by the 5B-IVIA universal MAb (amino acids 94 to 100) and by the 4DG5 and 4DG11 D serogroup-specific MAbs (amino acids 43 to 64). A similar approach coupled with infectious cDNA clone mutagenesis showed that a V74T mutation in the N-terminus of the CP abolished the binding of the M serogroup-specific AL MAb. Taken together, these results provide a detailed positioning of the epitopes recognized by the most widely used PPV detection and typing MAbs.

  13. Partially disordered structure in intravirus coat protein of potyvirus potato virus A.

    Directory of Open Access Journals (Sweden)

    Alexander L Ksenofontov

    Full Text Available Potyviruses represent the most biologically successful group of plant viruses, but to our knowledge, this work is the first detailed study of physicochemical characteristics of potyvirus virions. We measured the UV absorption, far and near UV circular dichroism spectra, intrinsic fluorescence spectra, and differential scanning calorimetry (DSC melting curves of intact particles of a potato virus A (PVA. PVA virions proved to have a peculiar combination of physicochemical properties. The intravirus coat protein (CP subunits were shown to contain an unusually high fraction of disordered structures, whereas PVA virions had an almost normal thermal stability. Upon heating from 20 °C to 55 °C, the fraction of disordered structures in the intravirus CP further increased, while PVA virions remained intact at up to 55 °C, after which their disruption (and DSC melting started. We suggest that the structure of PVA virions below 55 °C is stabilized by interactions between the remaining structured segments of intravirus CP. It is not improbable that the biological efficiency of PVA relies on the disordered structure of intravirus CP.

  14. Partially disordered structure in intravirus coat protein of potyvirus potato virus A.

    Science.gov (United States)

    Ksenofontov, Alexander L; Paalme, Viiu; Arutyunyan, Alexander M; Semenyuk, Pavel I; Fedorova, Natalia V; Rumvolt, Reet; Baratova, Ludmila A; Järvekülg, Lilian; Dobrov, Eugeny N

    2013-01-01

    Potyviruses represent the most biologically successful group of plant viruses, but to our knowledge, this work is the first detailed study of physicochemical characteristics of potyvirus virions. We measured the UV absorption, far and near UV circular dichroism spectra, intrinsic fluorescence spectra, and differential scanning calorimetry (DSC) melting curves of intact particles of a potato virus A (PVA). PVA virions proved to have a peculiar combination of physicochemical properties. The intravirus coat protein (CP) subunits were shown to contain an unusually high fraction of disordered structures, whereas PVA virions had an almost normal thermal stability. Upon heating from 20 °C to 55 °C, the fraction of disordered structures in the intravirus CP further increased, while PVA virions remained intact at up to 55 °C, after which their disruption (and DSC melting) started. We suggest that the structure of PVA virions below 55 °C is stabilized by interactions between the remaining structured segments of intravirus CP. It is not improbable that the biological efficiency of PVA relies on the disordered structure of intravirus CP.

  15. Prevalence of Tobacco mosaic virus in Iran and Evolutionary Analyses of the Coat Protein Gene

    Directory of Open Access Journals (Sweden)

    Athar Alishiri

    2013-09-01

    Full Text Available The incidence and distribution of Tobacco mosaic virus (TMV and related tobamoviruses was determined using an enzyme-linked immunosorbent assay on 1,926 symptomatic horticultural crops and 107 asymptomatic weed samples collected from 78 highly infected fields in the major horticultural crop-producing areas in 17 provinces throughout Iran. The results were confirmed by host range studies and reverse transcription-polymerase chain reaction. The overall incidence of infection by these viruses in symptomatic plants was 11.3%. The coat protein (CP gene sequences of a number of isolates were determined and disclosed to be a high identity (up to 100% among the Iranian isolates. Phylogenetic analysis of all known TMV CP genes showed three clades on the basis of nucleotide sequences with all Iranian isolates distinctly clustered in clade II. Analysis using the complete CP amino acid sequence showed one clade with two subgroups, IA and IB, with Iranian isolates in both subgroups. The nucleotide diversity within each sub-group was very low, but higher between the two clades. No correlation was found between genetic distance and geographical origin or host species of isolation. Statistical analyses suggested a negative selection and demonstrated the occurrence of gene flow from the isolates in other clades to the Iranian population.

  16. Porous multilayer-coated AFM tips for dip-pen nanolithography of proteins

    NARCIS (Netherlands)

    Wu, Chien-Ching; Xu, Huaping; Otto, Cees; Reinhoudt, David N; Lammertink, Rob G H; Huskens, Jurriaan; Subramaniam, Vinod; Velders, Aldrik H

    2009-01-01

    A simple and novel method for fabricating nanoporous-structure-coated silicon nitride tips for dip-pen nanolithography (DPN) by using the layer-by-layer (LbL) technique has been developed. The pore sizes can be adjusted by treating the LbL films coated onto the amino-terminated self-assembled

  17. PRODUCTION OF POLYCLONAL ANTIBODY TO THE COAT PROTEIN OF CITRUS TRISTEZA VIRUS IN CHICKEN EGGS

    Directory of Open Access Journals (Sweden)

    Nurhadi Nurhadi

    2016-10-01

    Full Text Available Citrus tristeza virus (CTV is one of the most destructive diseases in many citrus growing areas of Indonesia. Effective strategies for controlling CTV depend on diagnostic procedure namely enzyme-linked immunosorbent assay (ELISA. Study aimed to purify the CTV antigen and produced its polyclonal antibody. Virion of the severe CTV isolate designated UPM/ T-002 was concentrated by polyethylene glycol (PEG precipitation combined with low speed centrifugation. Semipurified antigen was further purified by sodium dodecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE. The specific coat protein (CP band of CTV with molecular weight of 25 kD was excised and eluted using elution buffer containing 0.25 M Tris-HCl pH 6.8 + 0.1% SDS, then used as antigen for injection into 6-month-old female of White Leghorn chicken. Results, showed than the specific polyclonal antibody raised against the 25-kDa CP had a titer of approximately 104, gave low background reaction with healthy plant sap and reacted specifically with CTV isolates. The reaction was equally strong for a severe, a moderate, a mild, and a symptomless isolate, suggesting a broad reaction range of this antibody toward different CTV isolates. Optimal virus titer can be obtained since virus loss during purification could be minimized and the highly purified antigen as an immunogen could be obtained by cutting out the CP band from SDS-PAGE gels. Large amount of highly titer of CTV antibody can be produced in chicken egg. The simplicity of the procedure makes it economically acceptable and technically adoptable because the antibody can be produced in basic laboratory.

  18. Comparative genetic diversity of potato virus Y populations based on coat protein gene.

    Science.gov (United States)

    Hosseini, H; Mehrvar, M; Zakiaghl, M; Siampour, M

    Potato virus Y (PVY) is an important plant pathogen with a wide host range including economically important crops of potato, tobacco, tomato, and pepper. The coat protein gene has been commonly used in studying molecular biology of plant viruses including PVY. In this study, we used a large dataset of CP sequences from isolates collected across the world to assess the detailed molecular evolution of PVY populations with a focus on the Iranian PVY population. Phylogenetic analysis showed that the world PVY population had two major lineages (O:C and N:NTN); each comprising several divergent sublineages. Results showed that the Iranian PVY isolates were distributed across the tree suggesting polyphyletic origin of the Iranian PVY population. Statistical analysis revealed great genetic differences between pairs of the PVY phylogenetic populations. Host populations and also geographical populations of PVY were genetically differentiated. The extent of the genetic diversification among PVY host and geographical populations were mild or moderate. Purifying selection was detected on the CP gene sequences of the PVY populations, suggesting that most of the mutations in the gene were harmful, thereby were eliminated by natural selection. We also detected a variety of recombination patterns to occur along the CP gene of the PVY strains. A significant number of the Iranian PVY isolates were found to be recombinant. Different analyses suggest that Iranian PVY population is highly diverse. In conclusion, results of this study demonstrated that different factors including mutation, host adaptation, geographical distinction and selection pressure shaped the genetic structure of the PVY populations.

  19. Dual function of novel pollen coat (surface proteins: IgE-binding capacity and proteolytic activity disrupting the airway epithelial barrier.

    Directory of Open Access Journals (Sweden)

    Mohamed Elfatih H Bashir

    Full Text Available BACKGROUND: The pollen coat is the first structure of the pollen to encounter the mucosal immune system upon inhalation. Prior characterizations of pollen allergens have focused on water-soluble, cytoplasmic proteins, but have overlooked much of the extracellular pollen coat. Due to washing with organic solvents when prepared, these pollen coat proteins are typically absent from commercial standardized allergenic extracts (i.e., "de-fatted", and, as a result, their involvement in allergy has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: Using a unique approach to search for pollen allergenic proteins residing in the pollen coat, we employed transmission electron microscopy (TEM to assess the impact of organic solvents on the structural integrity of the pollen coat. TEM results indicated that de-fatting of Cynodon dactylon (Bermuda grass pollen (BGP by use of organic solvents altered the structural integrity of the pollen coat. The novel IgE-binding proteins of the BGP coat include a cysteine protease (CP and endoxylanase (EXY. The full-length cDNA that encodes the novel IgE-reactive CP was cloned from floral RNA. The EXY and CP were purified to homogeneity and tested for IgE reactivity. The CP from the BGP coat increased the permeability of human airway epithelial cells, caused a clear concentration-dependent detachment of cells, and damaged their barrier integrity. CONCLUSIONS/SIGNIFICANCE: Using an immunoproteomics approach, novel allergenic proteins of the BGP coat were identified. These proteins represent a class of novel dual-function proteins residing on the coat of the pollen grain that have IgE-binding capacity and proteolytic activity, which disrupts the integrity of the airway epithelial barrier. The identification of pollen coat allergens might explain the IgE-negative response to available skin-prick-testing proteins in patients who have positive symptoms. Further study of the role of these pollen coat proteins in allergic

  20. Improvement of interfacial interactions using natural polyphenol-inspired tannic acid-coated nanoclay enhancement of soy protein isolate biofilms

    Science.gov (United States)

    Wang, Zhong; Kang, Haijiao; Zhang, Wei; Zhang, Shifeng; Li, Jianzhang

    2017-04-01

    In this study, a novel and economic surface modification technique for montmorillonite (MMT) nanosheets, a biocompatible coupling cross-linking agent, was developed on an attempt at improving the interfacial adhesion with soy protein isolate (SPI) matrix. Inspired by natural polyphenol, the "green dip-coating" method using tannic acid (TA) to surface-modify MMT (TA@MMT). SPI nanocomposite films modified with MMT or TA@MMT, as well as the control ones, were prepared via the casting method. The TA layer was successfully coated on the MMT surface through the (FeIII) ions coordination chemistry and the synthetic samples were characterized by the Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The compatibility and interfacial interactions between modified MMT and SPI matrix were greatly enhanced by the TA-FeIII coating on the MMT surface. The mechanical properties, water resistance, and thermal stability of the resultant biofilm were increased accordingly. Compared with that of the unmodified SPI film, the tensile strength of the nanocomposite films modified by the green dip-coating was increased by 113.3%. These SPI-based nanocomposite films showed the favorable potential in terms of food packing applications due to their efficient barriers to water vapor and UV and/or visible light.

  1. DnaK protein alleviates toxicity induced by citrate-coated gold nanoparticles in Escherichia coli

    National Research Council Canada - National Science Library

    Makumire, Stanley; Revaprasadu, Neerish; Shonhai, Addmore

    2015-01-01

    ... (called DnaK in prokaryotes) is one of the most prominent molecular chaperones. Since gold nanoparticles exhibit chaperone-like function in vitro, we investigated the effect of citrate-coated gold nanoparticles on the growth of E...

  2. New insights into protein secretion: TANGO1 runs rings around the COPII coat.

    Science.gov (United States)

    Glick, Benjamin S

    2017-04-03

    In this issue, Liu et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201611088) and Raote et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201608080) use super-resolution microscopy to visualize large COPII-coated endoplasmic reticulum (ER) export carriers. Rings of TANGO1 surround COPII, implicating TANGO1 in organizing ER exit sites and in regulating COPII coat dynamics and geometry. © 2017 Glick.

  3. Soybean seed coat chitinase as a defense protein against stored product pest Callosobruchus maculatus.

    Science.gov (United States)

    Silva, Nadia C M; Conceição, Jamile G; Ventury, Kayan Eudorico; De Sá, Leonardo F R; Oliveira, Eduardo A G; Santos, Izabela S; Gomes, Valdirene M; Costa, Monique N; Ferreira, Andre T S; Perales, Jonas; Xavier-Filho, Jose; Fernandes, Kátia V S; Oliveira, Antonia E A

    2017-12-18

    Chitinases (EC 3.2.1.14) are enzymes involved in the breaking of β-1,4-glycosidic linkages of chitin. In insects, chitin is present mainly in cuticle and in peritrophic membranes and peritrophic gel. Enzymes with the potential to damage peritrophic membranes and gel, such as chitinase, have been related to plant defense systems. Identification and characterisation of seed coat chitinase as a plant defensive molecule may indicate a more effective target for manipulation strategies, which may lead to the preventive consumption of embryonic tissues by the larvae and consequently the minimization of the seed damage. We studied the efficiency of soybean seed coat chitinase as a defense molecule against Callosobruchus maculatus insect. The seed coat chitinase was isolated and identified by mass spectrometry, immunoreacted with an anti-chitinase antibody and showed activity against chitin azure and 4-Methylumbelliferyl β-D-N,N',N''- triacetylchitotrioside. A chitinase fraction incorporated in artificial cotyledons at 0.1 % reduced larval survival about 77 % and at 0.5 %, the larval weight loss was 60 %. Chitinase FITC-labeled was detected in gut and feces of larvae. At 25 % in tick artificial seed coats chitinase showed a high toxicity to larvae, with mortality of 90 % and reduction of larval mass of 87 %. Seed coat chitinase is an important seed defensive molecule not only in the cotyledons, but also in the seed coats, acting as a part of the array of defense against Callosobruchus maculatus. This article is protected by copyright. All rights reserved.

  4. Properties of Whey-Protein-Coated Films and Laminates as Novel Recyclable Food Packaging Materials with Excellent Barrier Properties

    Directory of Open Access Journals (Sweden)

    Markus Schmid

    2012-01-01

    Full Text Available In case of food packaging applications, high oxygen and water vapour barriers are the prerequisite conditions for preserving the quality of the products throughout their whole lifecycle. Currently available polymers and/or biopolymer films are mostly used in combination with barrier materials derived from oil based plastics or aluminium to enhance their low barrier properties. In order to replace these non-renewable materials, current research efforts are focused on the development of sustainable coatings, while maintaining the functional properties of the resulting packaging materials. This article provides an introduction to food packaging requirements, highlights prior art on the use of whey-based coatings for their barriers properties, and describes the key properties of an innovative packaging multilayer material that includes a whey-based layer. The developed whey protein formulations had excellent barrier properties almost comparable to the ethylene vinyl alcohol copolymers (EVOH barrier layer conventionally used in food packaging composites, with an oxygen barrier (OTR of <2 [cm³(STP/(m²d bar] when normalized to a thickness of 100 μm. Further requirements of the barrier layer are good adhesion to the substrate and sufficient flexibility to withstand mechanical load while preventing delamination and/or brittle fracture. Whey-protein-based coatings have successfully met these functional and mechanical requirements.

  5. The 42-kDa coat protein of Andean potato mottle virus acts as a transcriptional activator in yeast

    Directory of Open Access Journals (Sweden)

    Vidal M.S.

    2002-01-01

    Full Text Available Interactions of viral proteins play an important role in the virus life cycle, especially in capsid assembly. Andean potato mottle comovirus (APMoV is a plant RNA virus with a virion formed by two coat proteins (CP42 and CP22. Both APMoV coat protein open reading frames were cloned into pGBT9 and pGAD10, two-hybrid system vectors. HF7c yeast cells transformed with the p9CP42 construct grew on yeast dropout selection media lacking tryptophan and histidine. Clones also exhibited ß-galactosidase activity in both qualitative and quantitative assays. These results suggest that CP42 protein contains an amino acid motif able to activate transcription of His3 and lacZ reporter genes in Saccharomyces cerevisiae. Several deletions of the CP42 gene were cloned into the pGBT9 vector to locate the region involved in this activation. CP42 constructions lacking 12 residues from the C-terminal region and another one with 267 residues deleted from the N-terminus are still able to activate transcription of reporter genes. However, transcription activation was not observed with construction p9CP42deltaC57, which does not contain the last 57 amino acid residues. These results demonstrate that a transcription activation domain is present at the C-terminus of CP42 between residues 267 and 374.

  6. Extensive polymorphism in the plasmodium vivax merozoite surface coat protein MSP-3alpha is limited to specific domains.

    Science.gov (United States)

    Rayner, J C; Corredor, V; Feldman, D; Ingravallo, P; Iderabdullah, F; Galinski, M R; Barnwell, J W

    2002-11-01

    Plasmodium merozoites are covered by a complex coat of surface proteins. Several of the Merozoite Surface Proteins (MSPs) that make up this coat have been proposed as vaccine candidates although some of the MSPs are known to be highly polymorphic. We present here the first survey and analysis of the polymorphism in the recently characterized P. vivax surface protein PvMSP-3alpha. Full length or partial sequences were obtained for the Pvmsp-3alpha gene from isolates originating in Central and South America, Asia and the Pacific. The Pvmsp-3alpha sequence is remarkably diverse, but this extensive diversity is largely restricted to certain domains of the encoded protein. An acidic C-terminal domain and a smaller hydrophilic N-terminus are relatively conserved, while a central domain containing coiled-coil heptad repeats is highly polymorphic and in some isolates of P. vivax is partially deleted. Unlike other MSPs, there is no evidence of allelic families of PvMSP-3alpha gene sequences, and no evidence that certain patterns of polymorphism group within isolates of similar geographical origin. The distribution and nature of polymorphism suggest that there are functional restrictions on mutations in this gene, and have implications for inclusion of PvMSP-3alpha as a candidate in a P. vivax vaccine.

  7. Generation of functional coatings on hydrophobic surfaces through deposition of denatured proteins followed by grafting from polymerization.

    Science.gov (United States)

    Goli, Kiran K; Rojas, Orlando J; Ozçam, A Evren; Genzer, Jan

    2012-05-14

    Hydrophilic coatings were produced on flat hydrophobic substrates featuring n-octadecyltrichlorosilane (ODTS) and synthetic polypropylene (PP) nonwoven surfaces through the adsorption of denatured proteins. Specifically, physisorption from aqueous solutions of α-lactalbumin, lysozyme, fibrinogen, and two soy globulin proteins (glycinin and β-conglycinin) after chemical (urea) and thermal denaturation endowed the hydrophobic surfaces with amino and hydroxyl functionalities, yielding enhanced wettability. Proteins adsorbed strongly onto ODTS and PP through nonspecific interactions. The thickness of adsorbed heat-denatured proteins was adjusted by varying the pH, protein concentration in solution, and adsorption time. In addition, the stability of the immobilized protein layer was improved significantly after interfacial cross-linking with glutaraldehyde in the presence of sodium borohydride. The amino and hydroxyl groups present on the protein-modified surfaces served as reactive sites for the attachment of polymerization initiators from which polymer brushes were grown by surface-initiated atom-transfer radical polymerization of 2-hydroxyethyl methacrylate. Protein denaturation and adsorption as well as the grafting of polymeric brushes were characterized by circular dichroism, ellipsometry, contact angle, and Fourier transform infrared spectroscopy in the attenuated total reflection mode.

  8. Mechanical properties of bare and protein-coated giant unilamellar phospholipid vesicles. A comparative study of micropipet aspiration and atomic force microscopy.

    Science.gov (United States)

    Dieluweit, Sabine; Csiszár, Agnes; Rubner, Wolfgang; Fleischhauer, Johannes; Houben, Sebastian; Merkel, Rudolf

    2010-07-06

    In this study, protein-coated giant phospholipid vesicles were used to model cell plasma membranes coated by surface protein layers that increase membrane stiffness under mechanical or osmotic stress. These changed mechanical properties like bending stiffness, membrane area compressibility modulus, and effective Young's modulus were determined by micropipet aspiration, while bending stiffness, effective Young's modulus, and effective spring constant of vesicles were analyzed by AFM. The experimental setups, the applied models, and the results using both methods were compared here. As demonstrated before, we found that bare vesicles were best probed by micropipet aspiration due to its high sensitivity. The mechanical properties of vesicles with protein surface layers were, however, better determined by AFM because it enables very local deformations of the membrane with barely any structural damage to the protein layer. Mechanical properties of different species of coating proteins, here streptavidin and avidin, could be clearly distinguished using this technique.

  9. Epitope imprinted polymer coating CdTe quantum dots for specific recognition and direct fluorescent quantification of the target protein bovine serum albumin.

    Science.gov (United States)

    Yang, Ya-Qiong; He, Xi-Wen; Wang, Yi-Zhi; Li, Wen-You; Zhang, Yu-Kui

    2014-04-15

    A novel epitope molecularly imprinted polymer (EMIP) for specific recognition and direct fluorescent quantification of the target protein bovine serum albumin (BSA) was demonstrated where polymerization was performed on the surface of silica nanospheres embedded CdTe quantum dots (QDs). The synthetic peptide derived from the surface-exposed C-terminus of bovine serum albumin (BSA, residues 599-607) was selected as the template molecule. The resulting EMIP film was able to selectively capture the template peptide and the corresponding target protein BSA via the recognition cavities. Based on the fluorescence quenching, the EMIP-coated QDs (molecular imprinted polymer coating CdTe QDs using epitope as the template) nanospheres were successfully applied to the direct fluorescence quantification of BSA. Compared with BMIP-coated QDs (molecular imprinted polymer coating CdTe QDs using BSA as the template), the imprinting factor and adsorption capacity of EMIP-coated QDs were greatly increased. The prepared EMIP-coated QDs can also discriminate even one mismatched sequences from the original sequences of the epitope of the BSA. The practical analytical performance of the EMIP-coated QDs was examined by evaluating the detection of BSA in the bovine calf serum sample with satisfactory results. In addition, the resulting EMIP-coated QDs nanospheres were also successfully applied to separating BSA from the bovine blood sample. © 2013 Published by Elsevier B.V.

  10. Analysis of potato virus Y coat protein epitopes recognized by three commercial monoclonal antibodies.

    Directory of Open Access Journals (Sweden)

    Yan-Ping Tian

    Full Text Available BACKGROUND: Potato virus Y (PVY, genus Potyvirus causes substantial economic losses in solanaceous plants. Routine screening for PVY is an essential part of seed potato certification, and serological assays are often used. The commercial, commonly used monoclonal antibodies, MAb1128, MAb1129, and MAb1130, recognize the viral coat protein (CP of PVY and distinguish PVYN strains from PVYO and PVYC strains, or detect all PVY strains, respectively. However, the minimal epitopes recognized by these antibodies have not been identified. METHODOLOGY/PRINCIPAL FINDINGS: SPOT peptide array was used to map the epitopes in CP recognized by MAb1128, MAb1129, and MAb1130. Then alanine replacement as well as N- and C-terminal deletion analysis of the identified peptide epitopes was done to determine critical amino acids for antibody recognition and the respective minimal epitopes. The epitopes of all antibodies were located within the 30 N-terminal-most residues. The minimal epitope of MAb1128 was 25NLNKEK30. Replacement of 25N or 27N with alanine weakened the recognition by MAb1128, and replacement of 26L, 29E, or 30K nearly precluded recognition. The minimal epitope for MAb1129 was 16RPEQGSIQSNP26 and the most critical residues for recognition were 22I and 23Q. The epitope of MAb1130 was defined by residues 5IDAGGS10. Mutation of residue 6D abrogated and mutation of 9G strongly reduced recognition of the peptide by MAb1130. Amino acid sequence alignment demonstrated that these epitopes are relatively conserved among PVY strains. Finally, recombinant CPs were produced to demonstrate that mutations in the variable positions of the epitope regions can affect detection with the MAbs. CONCLUSIONS/SIGNIFICANCE: The epitope data acquired can be compared with data on PVY CP-encoding sequences produced by laboratories worldwide and utilized to monitor how widely the new variants of PVY can be detected with current seed potato certification schemes or during the

  11. Cloning and expression of functional single-chain Fv antibodies directed against NIa and coat proteins of potato virus Y.

    Science.gov (United States)

    Rouis, Souad; Lafaye, Pierre; Jaoua-Aydi, Leila; Sghaier, Zidani; Ayadi, Hammadi; Gargouri-Bouzid, Radhia

    2006-10-01

    Three single-chain variable fragment (scFv) antibodies recognizing the nuclear inclusion a (NIa) and capsid proteins of potato virus Y were obtained from two mouse derived hybridoma clones secreting, respectively, an anti-NIa (22-1) and an anti-coat protein (136-13) monoclonal antibodies. The first monoclonal antibody was able to inhibit in vitro the PVY polyprotein cleavage by blocking the NIa protease activity. The amplified scFv cDNAs were first inserted into the TOPO vector and then sequenced. Several recombinant E. coli clones carrying the accurate scFv sequences were selected and the corresponding cDNAs were subcloned in pHEN phagemid and transferred in E. coli strain. The expressed scFv fragments showed an antibody activity that recognized the viral target proteins in infected tissues. Their activity was comparable to the parental monoclonal antibodies.

  12. Enhancing physicochemical properties of emulsions by heteroaggregation of oppositely charged lactoferrin coated lutein droplets and whey protein isolate coated DHA droplets.

    Science.gov (United States)

    Li, Xin; Wang, Xu; Xu, Duoxia; Cao, Yanping; Wang, Shaojia; Wang, Bei; Sun, Baoguo; Yuan, Fang; Gao, Yanxiang

    2018-01-15

    The formation and physicochemical stability of mixed functional components (lutein & DHA) emulsions through heteroaggregation were studied. It was formed by controlled heteroaggregation of oppositely charged lutein and DHA droplets coated by cationic lactoferrin (LF) and anionic whey protein isolate (WPI), respectively. Heteroaggregation was induced by mixing the oppositely charged LF-lutein and WPI-DHA emulsions together at pH 6.0. Droplet size, zeta-potential, transmission-physical stability, microrheological behavior and microstructure of the heteroaggregates formed were measured as a function of LF-lutein to WPI-DHA droplet ratio. Lutein degradation and DHA oxidation by measurement of lipid hydroperoxides and thiobarbituric acid reactive substances were determined. Upon mixing the two types of bioactive compounds droplets together, it was found that the largest aggregates and highest physical stability occurred at a droplet ratio of 40% LF-lutein droplets to 60% WPI-DHA droplets. Heteroaggregates formation altered the microrheological properties of the mixed emulsions mainly by the special network structure of the droplets. When LF-coated lutein droplets ratios were more than 30% and less than 60%, the mixed emulsions exhibited distinct decreases in the Mean Square Displacement, which indicated that their limited scope of Brownian motion and stable structure. Mixed emulsions with LF-lutein/WPI-DHA droplets ratio of 4:6 exhibited Macroscopic Viscosity Index with 13 times and Elasticity Index with 3 times of magnitudes higher than the individual emulsions from which they were prepared. Compared with the WPI-DHA emulsion or LF-lutein emulsion, the oxidative stability of the heteroaggregate of LF-lutein/WPI-DHA emulsions was improved. Heteroaggregates formed by oppositely charged bioactive compounds droplets may be useful for creating specific food structures that lead to desirable physicochemical properties, such as microrheological property, physical and chemical

  13. Effect of interfacial serum proteins on melanoma cell adhesion to biodegradable poly(l-lactic acid) microspheres coated with hydroxyapatite.

    Science.gov (United States)

    Shinto, Hiroyuki; Hirata, Takuya; Fukasawa, Tomonori; Fujii, Syuji; Maeda, Hayata; Okada, Masahiro; Nakamura, Yoshinobu; Furuzono, Tsutomu

    2013-08-01

    We have measured the interaction forces between a murine melanoma cell and a poly(l-lactic acid) (PLLA) microsphere coated with/without hydroxyapatite (HAp) nanoparticles (i.e., an HAp/PLLA or a bare PLLA microsphere) in a serum-free culture medium, using atomic force microscopy (AFM) with colloid probe technique, in order to investigate how the HAp-nanoparticle coating as well as interfacial serum proteins influence the cell-microsphere adhesion. The cell adhesion force of the HAp/PLLA microspheres was 1.4-fold stronger than that of the bare PLLA microspheres. When the microspheres were pretreated with a culture medium supplemented with 10% fetal bovine serum, the cell adhesion force of the HAp/PLLA microspheres was increased by a factor of 2.1; in contrast, no change was observed in the cell adhesion force of the bare PLLA microspheres before/after the pretreatment. Indeed, the cell adhesion force of the HAp/PLLA was 2.8-fold larger than that of the bare PLLA after the pretreatment. Additionally, we have investigated the effect of interfacial serum proteins on the zeta potentials of these microspheres. On the basis of the obtained results, possible mechanism of cell adhesion to the HAp/PLLA and bare PLLA microspheres in the presence/absence of the interfacial serum proteins is discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Performance optimization of soy and whey protein isolates as coating materials on chicken meat

    National Research Council Canada - National Science Library

    Kurt, Ş; Kılınççeker, O

    2011-01-01

    ... (WPI) on chicken meat, the effects of SPI (0 to 10%), WPI (0 to 10%), and pH (3 to 8) on coating pickup, frying loss, yield, moisture, and fat content of chicken meat were investigated by response surface methodology...

  15. Hybrid Alginate-Protein-Coated Graphene Oxide Microcapsules Enhance the Functionality of Erythropoietin Secreting C2C12 Myoblasts.

    Science.gov (United States)

    Saenz Del Burgo, Laura; Ciriza, Jesús; Acarregui, Argia; Gurruchaga, Haritz; Blanco, Francisco Javier; Orive, Gorka; Hernández, Rosa María; Pedraz, Jose Luis

    2017-03-06

    The beneficial effect of combining alginate hydrogel with graphene oxide (GO) on microencapsulated C2C12-myoblast viability has recently been described. However, the commercially available GO lacks homogeneity in size, this parameter being of high relevance for the cell fate in two-dimensional studies. In three-dimensional applications the capacity of this material for binding different kinds of proteins can result in the reduction of de novo released protein that can effectively reach the vicinity of the microcapsules. Undoubtedly, this could be an important hurdle in its clinical use when combined with alginate-PLL microcapsules. Here, we demonstrate that the homogenization of GO nanoparticles is not a mandatory preparation step in order to get the best of this material upon cell microencapsulation. In fact, when the superficial area of these particles is increased, higher amounts of the therapeutic protein erythropoietin (EPO) are adsorbed on their surface. On the other hand, we have been able to improve even more the favorable effects of this graphene derivative on microencapsulated cell viability by forming a protein biocorona. These proteins block the potential binding sites of EPO and, therefore, enhance the amount of therapeutic drug that is released. Finally, we prove that these hybrid alginate-protein-coated GO-microcapsules are functional in vivo.

  16. A biomolecule friendly photolithographic process for fabrication of protein microarrays on polymeric films coated on silicon chips.

    Science.gov (United States)

    Petrou, Panagiota S; Chatzichristidi, Margarita; Douvas, Antonios M; Argitis, Panagiotis; Misiakos, Konstantinos; Kakabakos, Sotirios E

    2007-04-15

    The last years, there is a steadily growing demand for methods and materials appropriate to create patterns of biomolecules for bioanalytical applications. Here, a photolithographic method for patterning biomolecules onto a silicon surface coated with a polymeric layer of high protein binding capacity is presented. The patterning process does not affect the polymeric film and the activity of the immobilized onto the surface biomolecules. Therefore, it permits sequential immobilization of different biomolecules on spatially distinct areas on the same solid support. The polymeric layer is based on a commercially available photoresist (AZ5214) that is cured at high temperature in order to provide a stable substrate for creation of protein microarrays by the developed photolithographic process. The photolithographic material consists of a (meth)acrylate copolymer and a sulfonium salt as a photoacid generator, and it is lithographically processed by thermal treatment at temperatures silicon surface, protein spots with diameters ranging from 2 to 50 microm were created. The proposed methodology provided good intra-spot homogeneity (CV proteins with their respective fluorescently labeled binding counterparts. Moreover, the polymeric film selected for immobilization of biomolecules presented high protein binding capacity, which was at least three folds higher than that obtained using aminosilanized surfaces. The proposed methodology is expected to facilitate considerably the fabrication of dense protein microarrays for bioanalytical applications.

  17. Protein-coated pH-responsive gold nanoparticles: Microwave-assisted synthesis and surface charge-dependent anticancer activity

    Directory of Open Access Journals (Sweden)

    Dickson Joseph

    2014-09-01

    Full Text Available The biocompatibility and ease of functionalization of gold nanoparticles underlie significant potential in biotechnology and biomedicine. Eight different proteins were examined in the preparation of gold nanoparticles (AuNPs in aqueous medium under microwave irradiation. Six of the proteins resulted in the formation of AuNPs. The intrinsic pH of the proteins played an important role in AuNPs with strong surface plasmon bands. The hydrodynamic size of the nanoparticles was larger than the values observed by TEM and ImageJ. The formation of a protein layer on the AuNPs accounts for this difference. The AuNPs exhibited sensitivity towards varying pH conditions, which was confirmed by determining the difference in the isoelectric points studied by using pH-dependent zeta potential titration. Cytotoxicity studies revealed anticancerous effects of the AuNPs at a certain micromolar concentration by constraining the growth of cancer cells with different efficacies due to the use of different proteins as capping agents. The positively charged AuNPs are internalized by the cells to a greater level than the negatively charged AuNPs. These AuNPs synthesized with protein coating holds promise as anticancer agents and would help in providing a new paradigm in area of nanoparticles.

  18. Copy number variation and missense mutations of the agouti signaling protein (ASIP) gene in goat breeds with different coat colors.

    Science.gov (United States)

    Fontanesi, L; Beretti, F; Riggio, V; Gómez González, E; Dall'Olio, S; Davoli, R; Russo, V; Portolano, B

    2009-01-01

    In goats, classical genetic studies reported a large number of alleles at the Agouti locus with effects on coat color and pattern distribution. From these early studies, the dominant A(Wt) (white/tan) allele was suggested to cause the white color of the Saanen breed. Here, we sequenced the coding region of the goat ASIP gene in 6 goat breeds (Girgentana, Maltese, Derivata di Siria, Murciano-Granadina, Camosciata delle Alpi, and Saanen), with different coat colors and patterns. Five single nucleotide polymorphisms (SNPs) were identified, 3 of which caused missense mutations in conserved positions of the cysteine-rich carboxy-terminal domain of the protein (p.Ala96Gly, p.Cys126Gly, and p.Val128Gly). Allele and genotype frequencies suggested that these mutations are not associated or not completely associated with coat color in the investigated goat breeds. Moreover, genotyping and sequencing results, deviation from Hardy-Weinberg equilibrium, as well as allele copy number evaluation from semiquantitative fluorescent multiplex PCR, indicated the presence of copy number variation (CNV) in all investigated breeds. To confirm the presence of CNV and evaluate its extension, we applied a bovine-goat cross-species array comparative genome hybridization (aCGH) experiment using a custom tiling array based on bovine chromosome 13. aCGH results obtained for 8 goat DNA samples confirmed the presence of CNV affecting a region of less that 100 kb including the ASIP and AHCY genes. In Girgentana and Saanen breeds, this CNV might cause the A(Wt) allele, as already suggested for a similar structural mutation in sheep affecting the ASIP and AHCY genes, providing evidence for a recurrent interspecies CNV. However, other mechanisms may also be involved in determining coat color in these 2 breeds. Copyright 2009 S. Karger AG, Basel.

  19. ZP domain proteins in the abalone egg coat include a paralog of VERL under positive selection that binds lysin and 18-kDa sperm proteins.

    Science.gov (United States)

    Aagaard, Jan E; Vacquier, Victor D; MacCoss, Michael J; Swanson, Willie J

    2010-01-01

    Identifying fertilization molecules is key to our understanding of reproductive biology, yet only a few examples of interacting sperm and egg proteins are known. One of the best characterized comes from the invertebrate archeogastropod abalone (Haliotis spp.), where sperm lysin mediates passage through the protective egg vitelline envelope (VE) by binding to the VE protein vitelline envelope receptor for lysin (VERL). Rapid adaptive divergence of abalone lysin and VERL are an example of positive selection on interacting fertilization proteins contributing to reproductive isolation. Previously, we characterized a subset of the abalone VE proteins that share a structural feature, the zona pellucida (ZP) domain, which is common to VERL and the egg envelopes of vertebrates. Here, we use additional expressed sequence tag sequencing and shotgun proteomics to characterize this family of proteins in the abalone egg VE. We expand 3-fold the number of known ZP domain proteins present within the VE (now 30 in total) and identify a paralog of VERL (vitelline envelope zona pellucida domain protein [VEZP] 14) that contains a putative lysin-binding motif. We find that, like VERL, the divergence of VEZP14 among abalone species is driven by positive selection on the lysin-binding motif alone and that these paralogous egg VE proteins bind a similar set of sperm proteins including a rapidly evolving 18-kDa paralog of lysin, which may mediate sperm-egg fusion. This work identifies an egg coat paralog of VERL under positive selection and the candidate sperm proteins with which it may interact during abalone fertilization.

  20. Synthesis of protein-coated biocompatible methotrexate-loaded PLA-PEG-PLA nanoparticles for breast cancer treatment

    Directory of Open Access Journals (Sweden)

    Salam Massadeh

    2016-06-01

    Full Text Available Background: PLA-PEG-PLA triblock polymer nanoparticles are promising tools for targeted dug delivery. The main aim in designing polymeric nanoparticles for drug delivery is achieving a controlled and targeted release of a specific drug at the therapeutically optimal rate and choosing a suitable preparation method to encapsulate the drug efficiently, which depends mainly on the nature of the drug (hydrophilic or hydrophobic. In this study, methotrexate (MTX-loaded nanoparticles were prepared by the double emulsion method. Method: Biodegradable polymer polyethylene glycol-polylactide acid tri-block was used with poly(vinyl alcohol as emulsifier. The resulting methotrexate polymer nanoparticles were coated with bovine serum albumin in order to improve their biocompatibility. This study focused on particle size distribution, zeta potential, encapsulation efficiency, loading capacity, and in vitro drug release at various concentrations of PVA (0.5%, 1%, 2%, and 3%. Results: Reduced particle size of methotrexate-loaded nanoparticles was obtained using lower PVA concentrations. Enhanced encapsulation efficiency and loading capacity was obtained using 1% PVA. FT-IR characterization was conducted for the void polymer nanoparticles and for drug-loaded nanoparticles with methotrexate, and the protein-coated nanoparticles in solid state showed the structure of the plain PEG-PLA and the drug-loaded nanoparticles with methotrexate. The methotrexate-loaded PLA-PEG-PLA nanoparticles have been studied in vitro; the drug release, drug loading, and yield are reported. Conclusion: The drug release profile was monitored over a period of 168 hours, and was free of burst effect before the protein coating. The results obtained from this work are promising; this work can be taken further to develop MTX based therapies.

  1. Atomic force microscopy imaging and single molecule recognition force spectroscopy of coat proteins on the surface of Bacillus subtilis spore.

    Science.gov (United States)

    Tang, Jilin; Krajcikova, Daniela; Zhu, Rong; Ebner, Andreas; Cutting, Simon; Gruber, Hermann J; Barak, Imrich; Hinterdorfer, Peter

    2007-01-01

    Coat assembly in Bacillus subtilis serves as a tractable model for the study of the self-assembly process of biological structures and has a significant potential for use in nano-biotechnological applications. In the present study, the morphology of B. subtilis spores was investigated by magnetically driven dynamic force microscopy (MAC mode atomic force microscopy) under physiological conditions. B. subtilis spores appeared as prolate structures, with a length of 0.6-3 microm and a width of about 0.5-2 microm. The spore surface was mainly covered with bump-like structures with diameters ranging from 8 to 70 nm. Besides topographical explorations, single molecule recognition force spectroscopy (SMRFS) was used to characterize the spore coat protein CotA. This protein was specifically recognized by a polyclonal antibody directed against CotA (anti-CotA), the antibody being covalently tethered to the AFM tip via a polyethylene glycol linker. The unbinding force between CotA and anti-CotA was determined as 55 +/- 2 pN. From the high-binding probability of more than 20% in force-distance cycles it is concluded that CotA locates in the outer surface of B. subtilis spores. Copyright (c) 2007 John Wiley & Sons, Ltd.

  2. Bypassing Protein Corona Issue on Active Targeting: Zwitterionic Coatings Dictate Specific Interactions of Targeting Moieties and Cell Receptors.

    Science.gov (United States)

    Safavi-Sohi, Reihaneh; Maghari, Shokoofeh; Raoufi, Mohammad; Jalali, Seyed Amir; Hajipour, Mohammad J; Ghassempour, Alireza; Mahmoudi, Morteza

    2016-09-07

    Surface functionalization strategies for targeting nanoparticles (NP) to specific organs, cells, or organelles, is the foundation for new applications of nanomedicine to drug delivery and biomedical imaging. Interaction of NPs with biological media leads to the formation of a biomolecular layer at the surface of NPs so-called as "protein corona". This corona layer can shield active molecules at the surface of NPs and cause mistargeting or unintended scavenging by the liver, kidney, or spleen. To overcome this corona issue, we have designed biotin-cysteine conjugated silica NPs (biotin was employed as a targeting molecule and cysteine was used as a zwitterionic ligand) to inhibit corona-induced mistargeting and thus significantly enhance the active targeting capability of NPs in complex biological media. To probe the targeting yield of our engineered NPs, we employed both modified silicon wafer substrates with streptavidin (i.e., biotin receptor) to simulate a target and a cell-based model platform using tumor cell lines that overexpress biotin receptors. In both cases, after incubation with human plasma (thus forming a protein corona), cellular uptake/substrate attachment of the targeted NPs with zwitterionic coatings were significantly higher than the same NPs without zwitterionic coating. Our results demonstrated that NPs with a zwitterionic surface can considerably facilitate targeting yield of NPs and provide a promising new type of nanocarriers in biological applications.

  3. Recyclability of PET/WPI/PE Multilayer Films by Removal of Whey Protein Isolate-Based Coatings with Enzymatic Detergents

    Directory of Open Access Journals (Sweden)

    Patrizia Cinelli

    2016-06-01

    Full Text Available Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET/polyethylene (PE multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at

  4. Ethylene glycol assisted preparation of Ti(4+)-modified polydopamine coated magnetic particles with rough surface for capture of phosphorylated proteins.

    Science.gov (United States)

    Ma, Xiangdong; Ding, Chun; Yao, Xin; Jia, Li

    2016-07-27

    The reversible protein phosphorylation is very important in regulating almost all aspects of cell life, while the enrichment of phosphorylated proteins still remains a technical challenge. In this work, polydopamine (PDA) modified magnetic particles with rough surface (rPDA@Fe3O4) were synthesized by introduction of ethylene glycol in aqueous solution. The PDA coating possessing a wealth of catechol hydroxyl groups could serve as an active medium to immobilize titanium ions through the metal-catechol chelation, which makes the fabrication of titanium ions modified rPDA@Fe3O4 particles (Ti(4+)-rPDA@Fe3O4) simple and very convenient. The spherical Ti(4+)-rPDA@Fe3O4 particles have a surface area of 37.7 m(2) g(-1) and superparamagnetism with a saturation magnetization value of 38.4 emu g(-1). The amount of Ti element in the particle was measured to be 3.93%. And the particles demonstrated good water dispersibility. The particles were used as adsorbents for capture of phosphorylated proteins and they demonstrated affinity and specificity for phosphorylated proteins due to the specific binding sites (Ti(4+)). Factors affecting the adsorption of phosphorylated proteins on Ti(4+)-rPDA@Fe3O4 particles were investigated. The adsorption capacity of Ti(4+)-rPDA@Fe3O4 particles for κ-casein was 1105.6 mg g(-1). Furthermore, the particles were successfully applied to isolate phosphorylated proteins in milk samples, which demonstrated that Ti(4+)-rPDA@Fe3O4 particles had potential application in selective separation of phosphorylated proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. State of the Art in the Development and Properties of Protein-Based Films and Coatings and Their Applicability to Cellulose Based Products: An Extensive Review

    Directory of Open Access Journals (Sweden)

    Maria-Beatrice Coltelli

    2015-12-01

    Full Text Available There is increasing research towards the substitution of petrochemicals by sustainable components. Biopolymers such as proteins, polysaccharides, and lipids derive from a variety of crop sources and most promisingly from waste streams generated during their processing by the agro food industry. Among those, proteins of different types such as whey, casein, gelatin, wheat gluten, soy protein or zein present a potential beyond the food and feed industry for the application in packaging. The general protein hydrophilicity promotes a good compatibility to polar surfaces, such as paper, and a good barrier to apolar gases, such as oxygen and carbon dioxide. The present review deals with the development of protein-based coatings and films. It includes relevant discussion for application in paper or board products, as well as an outlook on its future industrial potential. Proteins with suitable functionalities as food packaging materials are described as well as the different technologies for processing the coatings and the current state of the art about the coating formulations for selectively modulating barrier, mechanical, surface and end of life properties. Some insights onto regulations about packaging use, end of life and perspectives of such natural coating for decreasing the environmental impact of packages are given.

  6. Accumulation of a 5' proximal subgenomic RNA of Citrus tristeza virus is correlated with encapsidation by the minor coat protein.

    Science.gov (United States)

    Gowda, Siddarame; Tatineni, Satyanarayana; Folimonova, Svetlana Y; Hilf, Mark E; Dawson, William O

    2009-06-20

    During replication, Citrus tristeza virus (CTV) produces large amounts of two unusual subgenomic (sg) RNAs that are positive-stranded and 5' coterminal. Although these RNAs are produced in similar amounts and are similar in size, with LMT1 ( approximately 750 nt) only slightly larger than LMT2 ( approximately 650), we found that the similar sgRNAs are produced differently. We previously showed that the LMT1 RNA is produced by premature termination during genomic RNA synthesis. However, LMT2 production was found to correlate with virion assembly instead of RNA replication. The time course of accumulation of the LMT2 RNA occurred late, coinciding with virion accumulation. The long flexuous virions of CTV contain two coat proteins that encapsidate the virions in a polar manner. The major coat protein encapsidates approximately 97% of the virion, while the minor capsid protein encapsidates the remainder of the genome beginning in the 5' non-translated region with the transition zone at approximately 630 nucleotides from the 5' end. The section of the virion RNA that was encapsidated by CPm was identical in size to the LMT2 RNA, suggesting that the LMT2 RNA represented a portion of the viral RNA protected by CPm encapsidation. Mutations that abrogated encapsidation by CPm also abolished the accumulation of LMT2 RNA. Thus, these two unusual but similar RNAs are produced via different pathways, one from RNA replication and one processed by the virion assembly process. To our knowledge, this represents the first evidence of a viral RNA processed by the assembly mechanism.

  7. Improvement of interfacial interactions using natural polyphenol-inspired tannic acid-coated nanoclay enhancement of soy protein isolate biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhong; Kang, Haijiao; Zhang, Wei [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing, 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing, 100083 (China); Zhang, Shifeng, E-mail: shifeng.zhang@bjfu.edu.cn [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing, 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing, 100083 (China); Li, Jianzhang, E-mail: lijzh@bjfu.edu.cn [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing, 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing, 100083 (China)

    2017-04-15

    Highlights: • A novel interface of MMT was fabricated by natural polyphenol (TA)-inspired chemistry. • The resultant biomimetic surface exhibited good interface and surface compatibility. • TA can act as a bridge between MMT and SPI to enhance the interfacial interaction. • Surface-modified MMT gets the potential to be used in the modification of SPI biofilms for improving the mechanical properties and water resistance apparently. - Abstract: In this study, a novel and economic surface modification technique for montmorillonite (MMT) nanosheets, a biocompatible coupling cross-linking agent, was developed on an attempt at improving the interfacial adhesion with soy protein isolate (SPI) matrix. Inspired by natural polyphenol, the “green dip-coating” method using tannic acid (TA) to surface-modify MMT (TA@MMT). SPI nanocomposite films modified with MMT or TA@MMT, as well as the control ones, were prepared via the casting method. The TA layer was successfully coated on the MMT surface through the (Fe{sup III}) ions coordination chemistry and the synthetic samples were characterized by the Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The compatibility and interfacial interactions between modified MMT and SPI matrix were greatly enhanced by the TA-Fe{sup III} coating on the MMT surface. The mechanical properties, water resistance, and thermal stability of the resultant biofilm were increased accordingly. Compared with that of the unmodified SPI film, the tensile strength of the nanocomposite films modified by the green dip-coating was increased by 113.3%. These SPI-based nanocomposite films showed the favorable potential in terms of food packing applications due to their efficient barriers to water vapor and UV and/or visible light.

  8. Phosphorylation by Dyrk1A of clathrin coated vesicle-associated proteins: identification of the substrate proteins and the effects of phosphorylation.

    Directory of Open Access Journals (Sweden)

    Noriko Murakami

    Full Text Available Dyrk1A phosphorylated multiple proteins in the clathrin-coated vesicle (CCV preparations obtained from rat brains. Mass spectrometric analysis identified MAP1A, MAP2, AP180, and α- and β-adaptins as the phosphorylated proteins in the CCVs. Each protein was subsequently confirmed by [(32P]-labeling and immunological methods. The Dyrk1A-mediated phosphorylation released the majority of MAP1A and MAP2 and enhanced the release of AP180 and adaptin subunits from the CCVs. Furthermore, Dyrk1A displaced adaptor proteins physically from CCVs in a kinase-concentration dependent manner. The clathrin heavy chain release rate, in contrast, was not affected by Dyrk1A. Surprisingly, the Dyrk1A-mediated phosphorylation of α- and β-adaptins led to dissociation of the AP2 complex, and released only β-adaptin from the CCVs. AP180 was phosphorylated by Dyrk1A also in the membrane-free fractions, but α- and β-adaptins were not. Dyrk1A was detected in the isolated CCVs and was co-localized with clathrin in neurons from mouse brain sections and from primary cultured rat hippocampus. Previously, we proposed that Dyrk1A inhibits the onset of clathrin-mediated endocytosis in neurons by phosphorylating dynamin 1, amphiphysin 1, and synaptojanin 1. Current results suggest that besides the inhibition, Dyrk1A promotes the uncoating process of endocytosed CCVs.

  9. Enhanced healing of rabbit segmental radius defects with surface-coated calcium phosphate cement/bone morphogenetic protein-2 scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yi; Hou, Juan; Yin, ManLi [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang, Jing, E-mail: biomatwj@163.com [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Liu, ChangSheng, E-mail: csliu@sh163.net [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

    2014-11-01

    Large osseous defects remain a difficult clinical problem in orthopedic surgery owing to the limited effective therapeutic options, and bone morphogenetic protein-2 (BMP-2) is useful for its potent osteoinductive properties in bone regeneration. Here we build a strategy to achieve prolonged duration time and help inducting new bone formation by using water-soluble polymers as a protective film. In this study, calcium phosphate cement (CPC) scaffolds were prepared as the matrix and combined with sodium carboxymethyl cellulose (CMC-Na), hydroxypropylmethyl cellulose (HPMC), and polyvinyl alcohol (PVA) respectively to protect from the digestion of rhBMP-2. After being implanted in the mouse thigh muscles, the surface-modified composite scaffolds evidently induced ectopic bone formation. In addition, we further evaluated the in vivo effects of surface-modified scaffolds in a rabbit radius critical defect by radiography, three dimensional micro-computed tomographic (μCT) imaging, synchrotron radiation-based micro-computed tomographic (SRμCT) imaging, histological analysis, and biomechanical measurement. The HPMC-modified CPC scaffold was regarded as the best combination for segmental bone regeneration in rabbit radius. - Highlights: • A simple surface-coating method was used to fabricate composite scaffolds. • Growth factor was protected from rapid depletion via superficial coating. • Significant promotion of bone regeneration was achieved. • HPMC-modification displayed optimal effect of bone regeneration.

  10. Temperature-Triggered Protein Adsorption on Polymer-Coated Nanoparticles in Serum

    NARCIS (Netherlands)

    Koshkina, O.; Lang, T.; Thiermann, R.; Docter, D.; Stauber, R.H.; Secker, C.; Schlaad, H.; Weidner, S.; Mohr, B.; Maskos, M.; Bertin, A.

    2015-01-01

    The protein corona, which forms on the nanoparticle's surface in most biological media, determines the nanoparticle's physicochemical characteristics. The formation of the protein corona has a significant impact on the biodistribution and clearance of nanoparticles in vivo. Therefore, the ability to

  11. Structure and barrier properties of human embryonic stem cell-derived retinal pigment epithelial cells are affected by extracellular matrix protein coating.

    Science.gov (United States)

    Sorkio, Anni; Hongisto, Heidi; Kaarniranta, Kai; Uusitalo, Hannu; Juuti-Uusitalo, Kati; Skottman, Heli

    2014-02-01

    Extracellular matrix (ECM) interactions play a vital role in cell morphology, migration, proliferation, and differentiation of cells. We investigated the role of ECM proteins on the structure and function of human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells during their differentiation and maturation from hESCs into RPE cells in adherent differentiation cultures on several human ECM proteins found in native human Bruch's membrane, namely, collagen I, collagen IV, laminin, fibronectin, and vitronectin, as well as on commercial substrates of xeno-free CELLstart™ and Matrigel™. Cell pigmentation, expression of RPE-specific proteins, fine structure, as well as the production of basal lamina by hESC-RPE on different protein coatings were evaluated after 140 days of differentiation. The integrity of hESC-RPE epithelium and barrier properties on different coatings were investigated by measuring transepithelial resistance. All coatings supported the differentiation of hESC-RPE cells as demonstrated by early onset of cell pigmentation and further maturation to RPE monolayers after enrichment. Mature RPE phenotype was verified by RPE-specific gene and protein expression, correct epithelial polarization, and phagocytic activity. Significant differences were found in the degree of RPE cell pigmentation and tightness of epithelial barrier between different coatings. Further, the thickness of self-assembled basal lamina and secretion of the key ECM proteins found in the basement membrane of the native RPE varied between hESC-RPE cultured on compared protein coatings. In conclusion, this study shows that the cell culture substrate has a major effect on the structure and basal lamina production during the differentiation and maturation of hESC-RPE potentially influencing the success of cell integrations and survival after cell transplantation.

  12. The interaction of lipopolysaccharide-coated polystyrene particle with membrane receptor proteins on macrophage measured by optical tweezers

    Science.gov (United States)

    Wei, Ming-Tzo; Hua, Kuo-Feng; Hsu, Jowey; Karmenyan, Artashes; Hsu, Hsien-Yeh; Chiou, Arthur

    2006-08-01

    Lipopolysaccharide (LPS) is one of the cell wall components of Gram-positive bacteria recognized by and interacted with receptor proteins such as CD14 on macrophage cells. Such a process plays an important role in our innate immune system. In this paper, we report the application of optical tweezers (λ = 1064nm Gaussian beam focused by a water-immersed objective lens with N.A. = 1.0) to the study of the dynamics of the binding of a LPS-coated polystyrene particle (diameter = 1.5μm) onto the plasma membrane of a macrophage cell. We demonstrated that the binding rate increased significantly when the macrophage cell was pre-treated with the extract of Reishi polysaccharides (EORP) which has been shown to enhance the cell surface expression of CD14 (receptor of LPS) on macrophage cells.

  13. A CGMMV genome-replicon vector with partial sequences of coat protein gene efficiently expresses GFP in Nicotiana benthamiana.

    Science.gov (United States)

    Jailani, A Abdul Kader; Solanki, Vikas; Roy, Anirban; Sivasudha, T; Mandal, Bikash

    2017-04-02

    A highly infectious clone of Cucumber green mottle mosaic virus (CGMMV), a cucurbit-infecting tobamovirus was utilized for designing of gene expression vectors. Two versions of vector were examined for their efficacy in expressing the green fluorescent protein (GFP) in Nicotiana benthamiana. When the GFP gene was inserted at the stop codon of coat protein (CP) gene of the CGMMV genome without any read-through codon, systemic expression of GFP, as well as virion formation and systemic symptoms expression were obtained in N. benthamiana. The qRT-PCR analysis showed 23 fold increase of GFP over actin at 10days post inoculation (dpi), which increased to 45 fold at 14dpi and thereafter the GFP expression was significantly declined. Further, we show that when the most of the CP sequence is deleted retaining only the first 105 nucleotides, the shortened vector containing GFP in frame of original CP open reading frame (ORF) resulted in 234 fold increase of GFP expression over actin at 5dpi in N. benthamiana without the formation of virions and disease symptoms. Our study demonstrated that a simple manipulation of CP gene in the CGMMV genome while preserving the translational frame of CP resulted in developing a virus-free, rapid and efficient foreign protein expression system in the plant. The CGMMV based vectors developed in this study may be potentially useful for the production of edible vaccines in cucurbits. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Entamoeba histolytica uses ferritin as an iron source and internalises this protein by means of clathrin-coated vesicles.

    Science.gov (United States)

    López-Soto, Fernando; González-Robles, Arturo; Salazar-Villatoro, Lizbeth; León-Sicairos, Nidia; Piña-Vázquez, Carolina; Salazar, Eduardo Pérez; de la Garza, Mireya

    2009-03-01

    Entamoeba histolytica is a parasitic protozoan that produces dysentery and often reaches the liver, leading to abscess formation. Ferritin is an iron-storage protein that is mainly found in liver and spleen in mammals. The liver contains a plentiful source of iron for amoebae multiplying in that organ, making it a prime target for infection since iron is essential for the growth of this parasite. The aim of this study was to determine whether trophozoites are able to take up ferritin and internalise this protein for their growth in axenic culture. Interaction between the amoebae and ferritin was studied by flow cytometry, confocal laser-scanning microscopy and transmission electron microscopy. Amoebae were viable in iron supplied by ferritin. Trophozoites quickly internalised ferritin via clathrin-coated vesicles, a process that was initiated within the first 2 min of incubation. In 30 min, ferritin was found colocalizing with the LAMP-2 protein at vesicles in the cytosol. The uptake of ferritin was time- temperature- and concentration-dependent, specific and saturated at 46 nM of ferritin. Haemoglobin and holo-transferrin did not compete with ferritin for binding to amoebae. Amoebae cleaved ferritin leading to the production of several different sized fragments. Cysteine proteases of 100, 75 and 50 kDa from amoeba extracts were observed in gels copolymerised with ferritin. For a pathogen such as E. histolytica, the capacity to utilise ferritin as an iron source may well explain its high pathogenic potential in the liver.

  15. Silver and gold nanoparticle coated membranes applied to protein dot blots

    Science.gov (United States)

    Xie, F.; Drozdowicz-Tomsia, K.; Shtoyko, T.; Goldys, E. M.

    2011-02-01

    Detection and identification of low abundance biomarker proteins is frequently based on various types of membrane-based devices. Lowering of the protein detection limits is vital in commercial applications such as lateral flow assays and in Western blots widely used in proteomics. These currently suffer from insufficient detection sensitivity and low retention for small 2-5 kDa proteins. In this study, we report the deposition of two types of metal nanoparticles: gold colloids (50-95 nm diameter) and silver fractals onto a range of commonly used types of membranes including polyvinylidene fluoride (PVDF). Due to strong affinity of proteins to noble metals, such modified membranes have the potential to effectively capture trace proteins preventing their loss. The membranes modified by metal particles were characterized optically and by SEM. The membrane performance in protein dot blots was evaluated using the protein—fluorophore conjugates Deep Purple-bovine serum albumin and fluorescein—human serum albumin. We found that the metal nanoparticles increase light extinction by metals, which is balanced by increased fluorescence, so that the effective fluorescence signal is unchanged. This feature combined with the capture of proteins by the nanoparticles embedded in the membrane increases the detection limit of membrane assays.

  16. Surface modification of diamond-like carbon films with protein via polydopamine inspired coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tao Caihong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China); China and Graduate University of Chinese Academy of Sciences, Beijing 100080 (China); Yang Shengrong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China); Zhang Junyan, E-mail: zhangjunyan@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China); Wang Jinqing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18th, Lanzhou 730000 (China)

    2009-10-15

    In this paper, we report a facile two-step approach to immobilize proteins onto DLC surfaces. The first step was a simple immersion of DLC in a solution of dopamine. Polydopamine was deposited on DLC as a stable anchor to present protein molecules. Then the protein ad-layer was deposited on it. The chemical components of the modified DLC surfaces were characterized by Fourier transform infrared spectra and X-ray photoelectron spectroscopy. The biocompatibility of it was evaluated in vitro by the tetrazolium salt method. And it was indicated that the BSA modified surface had good haemocompatibility properties, and was cytocompatible to PC-12 cells.

  17. Clathrin Assembly Lymphoid Myeloid Leukemia (CALM) Protein: Localization in Endocytic-coated Pits, Interactions with Clathrin, and the Impact of Overexpression on Clathrin-mediated Traffic

    Science.gov (United States)

    Tebar, Francesc; Bohlander, Stefan K.; Sorkin, Alexander

    1999-01-01

    The clathrin assembly lymphoid myeloid leukemia (CALM) gene encodes a putative homologue of the clathrin assembly synaptic protein AP180. Hence the biochemical properties, the subcellular localization, and the role in endocytosis of a CALM protein were studied. In vitro binding and coimmunoprecipitation demonstrated that the clathrin heavy chain is the major binding partner of CALM. The bulk of cellular CALM was associated with the membrane fractions of the cell and localized to clathrin-coated areas of the plasma membrane. In the membrane fraction, CALM was present at near stoichiometric amounts relative to clathrin. To perform structure–function analysis of CALM, we engineered chimeric fusion proteins of CALM and its fragments with the green fluorescent protein (GFP). GFP–CALM was targeted to the plasma membrane–coated pits and also found colocalized with clathrin in the Golgi area. High levels of expression of GFP–CALM or its fragments with clathrin-binding activity inhibited the endocytosis of transferrin and epidermal growth factor receptors and altered the steady-state distribution of the mannose-6-phosphate receptor in the cell. In addition, GFP–CALM overexpression caused the loss of clathrin accumulation in the trans-Golgi network area, whereas the localization of the clathrin adaptor protein complex 1 in the trans-Golgi network remained unaffected. The ability of the GFP-tagged fragments of CALM to affect clathrin-mediated processes correlated with the targeting of the fragments to clathrin-coated areas and their clathrin-binding capacities. Clathrin–CALM interaction seems to be regulated by multiple contact interfaces. The C-terminal part of CALM binds clathrin heavy chain, although the full-length protein exhibited maximal ability for interaction. Altogether, the data suggest that CALM is an important component of coated pit internalization machinery, possibly involved in the regulation of clathrin recruitment to the membrane and/or the

  18. An efficient method for sonication assisted Agrobacterium-mediated transformation of coat protein (CP) coding genes into papaya (Carica papaya L.).

    Science.gov (United States)

    Jiang, Ling; Maoka, Tetsuo; Komori, Sadao; Fukamachi, Hiroshi; Kato, Hidenori; Ogawa, Kazunori

    2004-06-01

    An efficient method for the production of transgenic papaya was developed via Sonication Assisted Agrobacterium-mediated Transformation (SAAT) of somatic embryos. The plasmid pGA482G was modified to contain gene PTi-Epj-TL-PLDMV with CP coding sequence of PLDMV Japan strain and chimeric gene PTi-NP-YKT with multiple CP coding sequences from PRSV Taiwan strain, PRSV Hawaii strain and PRSV Thailand strain, respectively. Disarmed Agrobacterium tumefaciens strain LBA4404 carrying the binary plasmid pGA482G with the CP genes and nptII gene was used to transform embryo calli of papaya variety Sunset to produce transgenic papaya plants. The experiment was focused on the screening of effective transformation method. The engineered Agrobacterium grown overnight was diluted with an infection media of high osmotic pressure (1/2 MS medium contain 6% sucrose and 1% glucose, pH 5.7) and adjusted to optical density OD600nm = 0.15-0.20, embryonic calli were immerged in it for 30 min and treated with 5 s, 15 s, and 20 s sonication respectively during the infection. Results indicated that 15 s sonication treatment improved the transformation efficiency dramatically. After 15 s sonication treatment on embryo calli loaded in 15 ml sterile plastic tubes, 21 putative transgenic lines were produced from 80 pieces embryonic calli (26.3%) transformed by Agrobacterium [pGA482G/CPG] and 8 putative transgenic lines was produced from 48 pieces embryonic calli (16.7%) transferred by Agrobacterium [pGA482G/CPB], while only a single line came out of 64 pieces embryonic calli (1.6%) transformed by Agrobacterium [pGA482G/CPG] and none from 25 pieces embryonic calli transformed by Agrobacterium [pGA482G/CPB] in the non-treatment control. Results also showed that the best concentration of selection antibiotic was 120 mg/L kanamycin. A total of 42 resistant shoots were produced from 421 pieces of original embryonic calli in 9 months. The presence of the CP genes in the transgenic plants and their

  19. Molecular modeling of the RNA binding N-terminal part of cowpea chlorotic mottle virus coat protein in solution with phosphate ions

    NARCIS (Netherlands)

    van der Spoel, D.; Feenstra, K.A; Hemminga, M.A.; Berendsen, H.J.C.

    1996-01-01

    The RNA-binding N-terminal arm of the coat protein of cowpea ch[orotic mottle virus has been studied with five molecular dynamics simulations of 2.0 ns each. This 25-residue peptide (pep25) is highly charged: it contains six Arg and three Lys residues. An alpha-helical fraction of the sequence is

  20. Epitope identification and in silico prediction of the specificity of antibodies binding to the coat proteins of Potato Virus Y strains

    NARCIS (Netherlands)

    Keller, H.J.H.G.; Pomp, H.; Bakker, J.; Schots, A.

    2005-01-01

    A phage library containing 2.7 × 10(9) randomly expressed peptides was used to determine the epitopes of three monoclonal antibodies that bind to the coat protein of Potato Virus Y. Construction of the consensus sequences for the peptides obtained after three selection rounds indicated that each

  1. The combined use of enamel matrix proteins and a tetracycline-coated expanded polytetrafluoroethylene barrier membrane in the treatment of intra-osseous defects

    NARCIS (Netherlands)

    Sipos, PM; Loos, BG; Abbas, F; Timmerman, MF; van der Velden, U

    Objectives: The purpose of this split-mouth study was to evaluate the clinical response of enamel matrix proteins (EMPs, Emdogain Gel((R))) in intra-osseous defects with or without a combined application of a tetracycline-coated expanded polytetrafluoroethylene barrier membrane (e-PTFE,

  2. Changing folding and binding stability in a viral coat protein: a comparison between substitutions accessible through mutation and those fixed by natural selection.

    Directory of Open Access Journals (Sweden)

    Craig R Miller

    Full Text Available Previous studies have shown that most random amino acid substitutions destabilize protein folding (i.e. increase the folding free energy. No analogous studies have been carried out for protein-protein binding. Here we use a structure-based model of the major coat protein in a simple virus, bacteriophage φX174, to estimate the free energy of folding of a single coat protein and binding of five coat proteins within a pentameric unit. We confirm and extend previous work in finding that most accessible substitutions destabilize both protein folding and protein-protein binding. We compare the pool of accessible substitutions with those observed among the φX174-like wild phage and in experimental evolution with φX174. We find that observed substitutions have smaller effects on stability than expected by chance. An analysis of adaptations at high temperatures suggests that selection favors either substitutions with no effect on stability or those that simultaneously stabilize protein folding and slightly destabilize protein binding. We speculate that these mutations might involve adjusting the rate of capsid assembly. At normal laboratory temperature there is little evidence of directional selection. Finally, we show that cumulative changes in stability are highly variable; sometimes they are well beyond the bounds of single substitution changes and sometimes they are not. The variation leads us to conclude that phenotype selection acts on more than just stability. Instances of larger cumulative stability change (never via a single substitution despite their availability lead us to conclude that selection views stability at a local, not a global, level.

  3. Changing folding and binding stability in a viral coat protein: a comparison between substitutions accessible through mutation and those fixed by natural selection.

    Science.gov (United States)

    Miller, Craig R; Lee, Kuo Hao; Wichman, Holly A; Ytreberg, F Marty

    2014-01-01

    Previous studies have shown that most random amino acid substitutions destabilize protein folding (i.e. increase the folding free energy). No analogous studies have been carried out for protein-protein binding. Here we use a structure-based model of the major coat protein in a simple virus, bacteriophage φX174, to estimate the free energy of folding of a single coat protein and binding of five coat proteins within a pentameric unit. We confirm and extend previous work in finding that most accessible substitutions destabilize both protein folding and protein-protein binding. We compare the pool of accessible substitutions with those observed among the φX174-like wild phage and in experimental evolution with φX174. We find that observed substitutions have smaller effects on stability than expected by chance. An analysis of adaptations at high temperatures suggests that selection favors either substitutions with no effect on stability or those that simultaneously stabilize protein folding and slightly destabilize protein binding. We speculate that these mutations might involve adjusting the rate of capsid assembly. At normal laboratory temperature there is little evidence of directional selection. Finally, we show that cumulative changes in stability are highly variable; sometimes they are well beyond the bounds of single substitution changes and sometimes they are not. The variation leads us to conclude that phenotype selection acts on more than just stability. Instances of larger cumulative stability change (never via a single substitution despite their availability) lead us to conclude that selection views stability at a local, not a global, level.

  4. Direct site-directed photocoupling of proteins onto surfaces coated with β-cyclodextrins

    DEFF Research Database (Denmark)

    Städe, Lars W; Wimmer, Reinhard; Stensballe, Allan

    2010-01-01

    . Insertion of pBpa was verified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy. A molecular dynamic simulation, with water as solvent, showed high solvent accessibility of the pBpa benzophenone group in N27pBpa-cutinase mutant. The formation of an inclusion......A method called Dock'n'Flash was developed to offer site-specific capture and direct UVA-induced photocoupling of recombinant proteins. The method involves the tagging of recombinant proteins with photoreactive p-benzoyl-L-phenylalanine (pBpa) by genetic engineering. The photoreactive pBpa tag...... is used for affinity capture of the recombinant protein by beta-cyclodextrin (beta-CD), which provides hydrogen atoms to be abstracted in the photocoupling process. To exemplify the method, a recombinant, folded, and active N27pBpa mutant of cutinase from Fusarium solani pisi was produced in E. coli...

  5. Protein mediated synthesis of fluorescent Au-nanoclusters for metal sensory coatings

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Manja; Raff, Johannes [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

    2017-06-01

    Fluorescent Au-nanocluster were successfully synthesized and used for the selective detection of Cu{sup 2} {sup +}. The synthesized Au-BSA-nanoclusters remain functional also after immobilization and show high thermal stability. Additionally, the transfer of the protein mediated Au-nanocluster synthesis route to S-layer proteins was achieved. (The presented work is part of the project BIONEWS dealing with long-term stable cells for the set-up and regeneration of sensor and actor materials for strategic relevant metals, in particular rare earth elements).

  6. Improvement of Food Packaging-Related Properties of Whey Protein Isolate-Based Nanocomposite Films and Coatings by Addition of Montmorillonite Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Markus Schmid

    2017-11-01

    Full Text Available In this study, the effects of the addition of montmorillonite (MMT nanoplatelets on whey protein isolate (WPI-based nanocomposite films and coatings were investigated. The main objective was the development of WPI-based MMT nanocomposites with enhanced barrier and mechanical properties. WPI-based nanocomposite cast films and coatings were prepared by dispersing 0% (reference sample, 3, 6, 9% (w/w protein MMT, or, depending on the protein concentration, also 12 and 15% (w/w protein MMT into native WPI-based dispersions, followed by subsequent denaturation during the drying and curing process. The natural MMT nanofillers could be randomly dispersed into film-forming WPI-based nanodispersions, displaying good compatibility with the hydrophilic biopolymer matrix. As a result, by addition of 15% (w/w protein MMT into 10% (w/w dispersion WPI-based cast films or coatings, the oxygen permeability (OP was reduced by 91% for glycerol-plasticized and 84% for sorbitol-plasticized coatings, water vapor transmission rate was reduced by 58% for sorbitol-plasticized cast films. Due to the addition of MMT nanofillers, the Young’s modulus and tensile strength improved by 315 and 129%, respectively, whereas elongation at break declined by 77% for glycerol-plasticized cast films. In addition, comparison of plasticizer type revealed that sorbitol-plasticized cast films were generally stiffer and stronger, but less flexible compared glycerol-plasticized cast films. Viscosity measurements demonstrated good processability and suitability for up-scaled industrial processes of native WPI-based nanocomposite dispersions, even at high-nanofiller loadings. These results suggest that the addition of natural MMT nanofillers into native WPI-based matrices to form nanocomposite films and coatings holds great potential to replace well-established, fossil-based packaging materials for at least certain applications such as oxygen barriers as part of multilayer flexible packaging

  7. Proteomic characterization and evolutionary analyses of zona pellucida domain-containing proteins in the egg coat of the cephalochordate, Branchiostoma belcheri

    Directory of Open Access Journals (Sweden)

    Xu Qianghua

    2012-12-01

    Full Text Available Abstract Background Zona pellucida domain-containing proteins (ZP proteins have been identified as the principle constituents of the egg coat (EC of diverse metazoan taxa, including jawed vertebrates, urochordates and molluscs that span hundreds of millions of years of evolutionary divergence. Although ZP proteins generally contain the zona pellucida (ZP structural modules to fulfill sperm recognition and EC polymerization functions during fertilization, the primary sequences of the ZP proteins from the above-mentioned animal classes are drastically different, which makes it difficult to assess the evolutionary relationships of ZP proteins. To understand the origin of vertebrate ZP proteins, we characterized the egg coat components of Branchiostoma belcheri, an invertebrate species that belongs to the chordate subphylum Cephalochordata. Results Five ZP proteins (BbZP1-5 were identified by mass spectrometry analyses using the egg coat extracts from both unfertilized and fertilized eggs. In addition to the C-terminal ZP module in each of the BbZPs, the majority contain a low-density lipoprotein receptor domain and a von Willebrand factor type A (vWFA domain, but none possess an EGF-like domain that is frequently observed in the ZP proteins of urochordates. Fluorescence in situ hybridization and immuno-histochemical analyses of B. belcheri ovaries showed that the five BbZPs are synthesized predominantly in developing eggs and deposited around the extracellular space of the egg, which indicates that they are bona fide egg coat ZP proteins. BbZP1, BbZP3 and BbZP4 are significantly more abundant than BbZP2 and BbZP5 in terms of gene expression levels and the amount of mature proteins present on the egg coats. The major ZP proteins showed high polymorphism because multiple variants are present with different molecular weights. Sequence comparison and phylogenetic analysis between the ZP proteins from cephalochordates, urochordates and vertebrates

  8. Office blood pressure is a predictor of aortic elastic properties and urinary protein excretion in subjects with white coat hypertension.

    Science.gov (United States)

    Aznaouridis, Konstantinos; Vlachopoulos, Charalambos; Masoura, Konstantina; Pietri, Panagiota; Vyssoulis, Gregory; Ioakeimidis, Nikolaos; Stefanadis, Christodoulos; Tousoulis, Dimitrios

    2016-01-15

    White coat hypertension (WCH) is related to target organ damage and increased cardiovascular risk. Arterial elastic properties and urinary protein excretion are determinants of cardiovascular performance and predictors of outcomes. We investigated whether office blood pressure (BP) is a better determinant of arterial and renal function than the ambulatory BP in WCH patients. We studied 440 consecutive untreated non-diabetic patients with WCH (office BP >140/90 mmHg, mean daytime ambulatory BP 0.5). Hierarchical multilevel linear regression analysis showed that office systolic BP is an independent determinant of cfPWV (P=0.050), AIx (P=0.029), albumin (P=0.002) and ACR (P=0.001) and has a borderline association with α1-microglobulin (P=0.088). In non-diabetic WCH individuals, office systolic BP is an independent predictor of aortic elastic properties and urinary protein excretion, whereas ambulatory BP is not. This finding suggests that office BP may be a marker of cardiovascular risk in subjects with WCH. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Differential diagnosis of Brazilian strains of Citrus tristeza virus by epitope mapping of coat protein using monoclonal antibodies.

    Science.gov (United States)

    Peroni, Luís Antonio; Lorencini, Márcio; dos Reis, José Raimundo Ribeiro; Machado, Marcos Antonio; Stach-Machado, Dagmar Ruth

    2009-10-01

    Citrus tristeza virus (CTV) is one of the most important citrus pathogen, and among Brazilian CTV strains, the genotype Capão Bonito (CB) is the most harmful. Therefore, the coat protein (CP) gene were cloned and expressed as recombinant protein and used to develop four specific monoclonal antibodies (MAbs). Our previously data had showed these MAbs could recognize different strains of CTV and the present goal is to identify the epitopes of the recombinant CP by ELISA screening of overlapping recombinant peptides and to determine the binding specificity of CTV isolates in light of their antigenic domains onto CB strains. Three MAbs, 30.G.02, 37.G.11 and 39.07 recognized linear and no identical epitopes, but the fourth MAb, IC.04-12, probably had a conformational epitope, since it could not be identified by ELISA screening. Our previous data revealed MAb IC.04-12 do not recognize CP under denaturing conditions, but can identify weak CTV strains in ELISA involving crop samples. MAb 30.G.02 recognized an extremely conserved sequence and can be classified as "universal" antibody, and, interestingly, the epitope turned out by MAb 39.07 corresponded to severe CTV isolates. So, these MAbs can be applied in a differential screening by ELISA.

  10. A Protein-Polymer Bioconjugate-Coated Upconversion Nanosystem for Simultaneous Tumor Cell Imaging, Photodynamic Therapy, and Chemotherapy.

    Science.gov (United States)

    Dong, Chunhong; Liu, Zhongyun; Wang, Sheng; Zheng, Bin; Guo, Weisheng; Yang, Weitao; Gong, Xiaoqun; Wu, Xiaoli; Wang, Hanjie; Chang, Jin

    2016-12-07

    Combined cancer therapy possesses many advantages including improved tumoricidal efficacy, reduced side effects, and retarded drug resistance. Herein, a protein-polymer bioconjugate-coated multifunctional upconversion nanosystem, consisting of upconversion nanoparticles (UCNs) core, tailored amphiphilic protein-polymer bioconjugate shell, and photosensitizer zinc phthalocyanine (ZnPc) and antitumor drug doxorubicin coloaded inside, was elaborately developed for combined photodynamic therapy (PDT) and chemotherapy. In this system, UCNs core could convert deep penetrating near-infrared light to visible light for simultaneous cell fluorescence imaging and photodynamic therapy by activating ZnPc to generate cytotoxic ROS, while the protective shell of bovine serum albumin-poly(ε-caprolactone) (BSA-PCL) offered excellent water solubility, good stability, and low cytotoxicity. The ROS production test showed that this nanosystem could successfully generate singlet oxygen under NIR irradiation. A cellular uptake study demonstrated that intense fluorescence emission of the UCNs could be observed in HeLa cells, indicating their outstanding real-time imaging capability. More importantly, compared with single PDT or chemotherapy systems, the constructed combined therapy UCNs system demonstrated significantly enhanced tumor cell killing efficiency. On the basis of our findings, this multifunctional UCNs nanosystem could be a promising versatile theranostic nanoplatform for image-guided combined cancer therapy.

  11. Self-healing superhydrophobic fluoropolymer brushes as highly protein-repellent coatings

    NARCIS (Netherlands)

    Wang, Zhanhua; Zuilhof, Han

    2016-01-01

    Superhydrophobic surfaces with micro/nanostructures are widely used to prevent nonspecific adsorption of commercial polymeric and/or biological materials. Herein, a self-healing superhydrophobic and highly protein-repellent fluoropolymer brush was grafted onto nanostructured silicon by

  12. Sputter deposited bioceramic coatings: surface characterisation and initial protein adsorption studies using surface-MALDI-MS

    DEFF Research Database (Denmark)

    Boyd, A. R.; Burke, G. A.; Duffy, H.

    2011-01-01

    Protein adsorption onto calcium phosphate (Ca–P) bioceramics utilised in hard tissue implant applications has been highlighted as one of the key events that influences the subsequent biological response, in vivo. This work reports on the use of surface-matrix assisted laser desorption ionisation...

  13. An isoform of eukaryotic initiation factor 4E from Chrysanthemum morifolium interacts with Chrysanthemum virus B coat protein.

    Science.gov (United States)

    Song, Aiping; Lou, Wanghuai; Jiang, Jiafu; Chen, Sumei; Sun, Zuxia; Guan, Zhiyong; Fang, Weimin; Teng, Nianjun; Chen, Fadi

    2013-01-01

    Eukaryotic translation initiation factor 4E (eIF4E) plays an important role in plant virus infection as well as the regulation of gene translation. Here, we describe the isolation of a cDNA encoding CmeIF(iso)4E (GenBank accession no. JQ904592), an isoform of eIF4E from chrysanthemum, using RACE PCR. We used the CmeIF(iso)4E cDNA for expression profiling and to analyze the interaction between CmeIF(iso)4E and the Chrysanthemum virus B coat protein (CVBCP). Multiple sequence alignment and phylogenetic tree analysis showed that the sequence similarity of CmeIF(iso)4E with other reported plant eIF(iso)4E sequences varied between 69.12% and 89.18%, indicating that CmeIF(iso)4E belongs to the eIF(iso)4E subfamily of the eIF4E family. CmeIF(iso)4E was present in all chrysanthemum organs, but was particularly abundant in the roots and flowers. Confocal microscopy showed that a transiently transfected CmeIF(iso)4E-GFP fusion protein distributed throughout the whole cell in onion epidermis cells. A yeast two hybrid assay showed CVBCP interacted with CmeIF(iso)4E but not with CmeIF4E. BiFC assay further demonstrated the interaction between CmeIF(iso)4E and CVBCP. Luminescence assay showed that CVBCP increased the RLU of Luc-CVB, suggesting CVBCP might participate in the translation of viral proteins. These results inferred that CmeIF(iso)4E as the cap-binding subunit eIF(iso)4F may be involved in Chrysanthemum Virus B infection in chrysanthemum through its interaction with CVBCP in spatial.

  14. An isoform of eukaryotic initiation factor 4E from Chrysanthemum morifolium interacts with Chrysanthemum virus B coat protein.

    Directory of Open Access Journals (Sweden)

    Aiping Song

    Full Text Available BACKGROUND: Eukaryotic translation initiation factor 4E (eIF4E plays an important role in plant virus infection as well as the regulation of gene translation. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe the isolation of a cDNA encoding CmeIF(iso4E (GenBank accession no. JQ904592, an isoform of eIF4E from chrysanthemum, using RACE PCR. We used the CmeIF(iso4E cDNA for expression profiling and to analyze the interaction between CmeIF(iso4E and the Chrysanthemum virus B coat protein (CVBCP. Multiple sequence alignment and phylogenetic tree analysis showed that the sequence similarity of CmeIF(iso4E with other reported plant eIF(iso4E sequences varied between 69.12% and 89.18%, indicating that CmeIF(iso4E belongs to the eIF(iso4E subfamily of the eIF4E family. CmeIF(iso4E was present in all chrysanthemum organs, but was particularly abundant in the roots and flowers. Confocal microscopy showed that a transiently transfected CmeIF(iso4E-GFP fusion protein distributed throughout the whole cell in onion epidermis cells. A yeast two hybrid assay showed CVBCP interacted with CmeIF(iso4E but not with CmeIF4E. BiFC assay further demonstrated the interaction between CmeIF(iso4E and CVBCP. Luminescence assay showed that CVBCP increased the RLU of Luc-CVB, suggesting CVBCP might participate in the translation of viral proteins. CONCLUSIONS/SIGNIFICANCE: These results inferred that CmeIF(iso4E as the cap-binding subunit eIF(iso4F may be involved in Chrysanthemum Virus B infection in chrysanthemum through its interaction with CVBCP in spatial.

  15. The coat protein of Alternanthera mosaic virus is the elicitor of a temperature-sensitive systemic necrosis in Nicotiana benthamiana, and interacts with a host boron transporter protein

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyoun-Sub, E-mail: hyounlim@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Nam, Jiryun, E-mail: jilyoon@naver.com [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Seo, Eun-Young, E-mail: sey22@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Nam, Moon, E-mail: moonlit51@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Vaira, Anna Maria, E-mail: a.vaira@ivv.cnr.it [Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, 10300 Baltimore Avenue B-010A, Beltsville, MD 20705 (United States); Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, Torino 10135 (Italy); Bae, Hanhong, E-mail: hanhongbae@ynu.ac.kr [School of Biotechnology, Yeungnam University, Geongsan 712-749 (Korea, Republic of); Jang, Chan-Yong, E-mail: sunbispirit@gmail.com [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Cheol Ho, E-mail: chlee1219@hanmail.net [Department of Chemical and Biological Engineering, Seokyoung University, Seoul 136-704 (Korea, Republic of); Kim, Hong Gi, E-mail: hgkim@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Roh, Mark, E-mail: marksroh@gmail.com [Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, 10300 Baltimore Avenue B-010A, Beltsville, MD 20705 (United States); Laboratory of Floriculture and Plant Physiology, School of Bio-Resource Science, Dankook University, Cheonan, Chungnam 330-714 (Korea, Republic of); Hammond, John, E-mail: john.hammond@ars.usda.gov [Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, 10300 Baltimore Avenue B-010A, Beltsville, MD 20705 (United States)

    2014-03-15

    Different isolates of Alternanthera mosaic virus (AltMV; Potexvirus), including four infectious clones derived from AltMV-SP, induce distinct systemic symptoms in Nicotiana benthamiana. Virus accumulation was enhanced at 15 °C compared to 25 °C; severe clone AltMV 3-7 induced systemic necrosis (SN) and plant death at 15 °C. No interaction with potexvirus resistance gene Rx was detected, although SN was ablated by silencing of SGT1, as for other cases of potexvirus-induced necrosis. Substitution of AltMV 3-7 coat protein (CP{sub SP}) with that from AltMV-Po (CP{sub Po}) eliminated SN at 15 °C, and ameliorated symptoms in Alternanthera dentata and soybean. Substitution of only two residues from CP{sub Po} [either MN(13,14)ID or LA(76,77)IS] efficiently ablated SN in N. benthamiana. CP{sub SP} but not CP{sub Po} interacted with Arabidopsis boron transporter protein AtBOR1 by yeast two-hybrid assay; N. benthamiana homolog NbBOR1 interacted more strongly with CP{sub SP} than CP{sub Po} in bimolecular fluorescence complementation, and may affect recognition of CP as an elicitor of SN. - Highlights: • Alternanthera mosaic virus CP is an elicitor of systemic necrosis in N. benthamiana. • Virus-induced systemic necrosis is enhanced at 15 °C compared to 25 °C. • Induction of systemic necrosis is dependent on as few as two CP amino acid residues. • These residues are at subunit interfaces within the same turn of the virion helix. • Inducer/non-inducer CPs interact differentially with a boron transporter protein.

  16. Mutagenic analysis of potato virus X movement protein (TGBp1) and the coat protein (CP): in vitro TGBp1-CP binding and viral RNA translation activation.

    Science.gov (United States)

    Zayakina, Olga; Arkhipenko, Marina; Kozlovsky, Stanislav; Nikitin, Nikolai; Smirnov, Alexander; Susi, Petri; Rodionova, Nina; Karpova, Olga; Atabekov, Joseph

    2008-01-01

    Previously, we have shown that encapsidated Potato virus X (PVX) RNA was non-translatable in vitro, but could be converted into a translatable form by binding of the PVX movement protein TGBp1 to one end of the virion or by coat protein (CP) phosphorylation. Here, a mutagenic analysis of PVX CP and TGBp1 was used to identify the regions involved in TGBp1-CP binding and translational activation of PVX RNA by TGBp1. It was found that the C-terminal (C-ter) 10/18 amino acids region was not essential for virus-like particle (VP) assembly from CP and RNA. However, the VPs assembled from the CP lacking C-ter 10/18 amino acids were incapable of TGBp1 binding and being translationally activated. It was suggested that the 10-amino-acid C-ter regions of protein subunits located at one end of a polar helical PVX particle contain a domain accessible to TGBp1 binding and PVX remodelling. The non-translatable particles assembled from the C-ter mutant CP could be converted into a translatable form by CP phosphorylation. The TGBp1-CP binding activity was preserved unless a conservative motif IV was removed from TGBp1. By contrast, TGBp1-dependent activation of PVX RNA translation was abolished by deletions of various NTPase/helicase conservative motifs and their combinations. The motif IV might be essential for TGBp1-CP binding, but insufficient for PVX RNA translation activation. The evidence to discriminate between these two events, i.e. TGBp1 binding to the CP-helix and TGBp1-dependent RNA translation activation, is discussed.

  17. Coated microneedles for transdermal delivery

    OpenAIRE

    Gill, Harvinder S.; Prausnitz, Mark R.

    2006-01-01

    Coated microneedles have been shown to deliver proteins and DNA into the skin in a minimally invasive manner. However, detailed studies examining coating methods and their breadth of applicability are lacking. This study’s goal was to develop a simple, versatile and controlled microneedle coating process to make uniform coatings on microneedles and establish the breadth of molecules and particles that can be coated onto microneedles. First, microneedles were fabricated from stainless steel sh...

  18. Three-dimensional reconstructions of the bacteriophage CUS-3 virion reveal a conserved coat protein I-domain but a distinct tailspike receptor-binding domain

    Energy Technology Data Exchange (ETDEWEB)

    Parent, Kristin N., E-mail: kparent@msu.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378 (United States); Tang, Jinghua; Cardone, Giovanni [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378 (United States); Gilcrease, Eddie B. [University of Utah School of Medicine, Division of Microbiology and Immunology, Department of Pathology, Salt Lake City, UT 84112 (United States); Janssen, Mandy E.; Olson, Norman H. [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378 (United States); Casjens, Sherwood R., E-mail: sherwood.casjens@path.utah.edu [University of Utah School of Medicine, Division of Microbiology and Immunology, Department of Pathology, Salt Lake City, UT 84112 (United States); Baker, Timothy S., E-mail: tsb@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378 (United States); University of California, San Diego, Division of Biological Sciences, La Jolla, CA, 92093 (United States)

    2014-09-15

    CUS-3 is a short-tailed, dsDNA bacteriophage that infects serotype K1 Escherichia coli. We report icosahedrally averaged and asymmetric, three-dimensional, cryo-electron microscopic reconstructions of the CUS-3 virion. Its coat protein structure adopts the “HK97-fold” shared by other tailed phages and is quite similar to that in phages P22 and Sf6 despite only weak amino acid sequence similarity. In addition, these coat proteins share a unique extra external domain (“I-domain”), suggesting that the group of P22-like phages has evolved over a very long time period without acquiring a new coat protein gene from another phage group. On the other hand, the morphology of the CUS-3 tailspike differs significantly from that of P22 or Sf6, but is similar to the tailspike of phage K1F, a member of the extremely distantly related T7 group of phages. We conclude that CUS-3 obtained its tailspike gene from a distantly related phage quite recently. - Highlights: • Asymmetric and symmetric three-dimensional reconstructions of phage CUS-3 are presented. • CUS-3 major capsid protein has a conserved I-domain, which is found in all three categories of “P22-like phage”. • CUS-3 has very different tailspike receptor binding domain from those of P22 and Sf6. • The CUS-3 tailspike likely was acquired by horizontal gene transfer.

  19. Grouping and comparison of Indian citrus tristeza virus isolates based on coat protein gene sequences and restriction analysis patterns.

    Science.gov (United States)

    Roy, A; Ramachandran, P; Brlansky, R H

    2003-04-01

    Citrus tristeza virus (CTV) is an aphid-transmitted closterovirus, which causes one of the most important citrus diseases worldwide. Isolates of CTV differ widely in their biological properties. CTV-infected samples were collected from four locations in India: Bangalore (CTV-B), Delhi (CTV-D), Nagpur (CTV-N), and Pune (CTV-P), and were maintained by grafting into Kagzi lime ( Citrus aurantifolia (Christm. Swing.). All isolates produced typical vein clearing and flecking symptoms 6-8 weeks after grafting. In addition, CTV-B and CTV-P isolates produced stem-pitting symptoms after 8-10 months. The CTV coat protein gene (CPG) was amplified by RT-PCR using CPG specific primers, yielding an amplicon of 672 bp for all the isolates. Sequence analysis of the CPG amplicon of all the four Indian isolates showed 93-94% nucleotide sequence homology to the Californian CTV severe stem pitting isolate SY568 and 92-93% homology to the Japanese seedling yellows isolate NUagA and Israeli VT p346 isolates. In phylogenetic tree analysis, Indian CTV isolates appeared far different from other isolates as they formed a separate branch. Comparison among the Indian isolates was carried out by restriction analysis and restriction fragment length polymorphism (RFLP). Specific primers to various genome segments of well-characterized CTV isolates were used to further classify the Indian CTV isolates.

  20. Development of an asymmetric PCR-ELISA typing method for citrus tristeza virus based on the coat protein gene.

    Science.gov (United States)

    Nolasco, G; Santos, C; Silva, G; Fonseca, F

    2009-02-01

    The coat protein gene of isolates of citrus tristeza virus (CTV) from 20 citrus-producing regions around the world was amplified by RT-PCR, TA cloned, and characterized by SSCP. Haplotypes that produced different patterns within each geographic region were sequenced and a database of 153 accessions of CTV was assembled. Phylogenetic analysis revealed the existence of seven well-defined clusters (Coefficient of differentiation 0.78). An asymmetric PCR-ELISA typing (APET) assay was developed in the frame of this clustering pattern using a set of eight hybridisation probes. The membership of any unknown haplotype is determined by comparing its pattern of reaction against the whole set of probes and not, as previously done in hybridisation assays, in an all-or-nothing basis. Interpretation of the results is objective and done through a visual basic application that compares the rates of hydrolysis of the ELISA substrate of an assayed isolate to a matrix of rates of hydrolysis obtained from standard haplotypes. This assay was validated and showed a better ability to resolve haplotypes than other assays to which it was compared experimentally. It may be automated to the same extent as any ELISA.

  1. Bioactivities of Jc-SCRIP, a type 1 ribosome-inactivating protein from Jatropha curcas seed coat.

    Science.gov (United States)

    Nuchsuk, Chanthakan; Wetprasit, Nuanchawee; Roytrakul, Sittiruk; Choowongkomon, Kiattawee; T-Thienprasert, Nattanan; Yokthongwattana, Chotika; Arpornsuwan, Theerakul; Ratanapo, Sunanta

    2013-10-01

    In this study, a type 1 RIP, designated as Jc-SCRIP, was first isolated from the seed coat of Jatropha curcas Linn. It was purified by ammonium sulfate precipitation and chromatography on DEAE-Sephacel™ and CM-cellulose columns. Purification fold of Jc-SCRIP increased 113.8 times, and the yield was 1.13% of the total protein in the final step. It was shown to be a monomeric glycoprotein with a molecular mass of 38 938 Da, as determined by MALDI-TOF/MS. It exhibited hemagglutination activity and possessed strong N-glycosidase activity. The antimicrobial activity of Jc-SCRIP was tested against nine human pathogenic bacteria and one fungus; the most potent inhibitory activity was against Staphylococcus epidermidis ATCC 12228, with minimum inhibitory concentration value of 0.20 μm. Jc-SCRIP demonstrated in vitro cytotoxicity against human breast adenocarcinoma cell line (MCF-7), a colon adenocarcinoma (SW620), and a liver carcinoma cell line (HepG2), with IC50 values of 0.15, 0.25, and 0.40 mm, respectively. The results suggested that Jc-SCRIP may be a potential natural antimicrobial and anticancer agent in medical applications. © 2013 John Wiley & Sons A/S.

  2. Heterologous minor coat proteins of Citrus tristeza virus strains affect encapsidation, but the coexpression of HSP70h and p61 restores encapsidation to wild-type levels.

    Science.gov (United States)

    Tatineni, Satyanarayana; Gowda, Siddarame; Dawson, William O

    2010-07-05

    The long flexuous bipolar virions of Citrus tristeza virus (CTV), a Closterovirus, are encapsidated with two capsid proteins at opposite ends: the minor coat protein (CPm) encapsidates the 5' 630 nts of the genomic RNA and the major coat protein encapsidates the remainder of the genome. In this study, we found encapsidation of CTV CPm in the absence of other assembly-related proteins is highly specific in contrast to most plant viruses that allow virion assembly by a range of heterologous coat proteins. Heterologous CPms with 95-96% amino acid identity from related strains in CTV-CPm, a replicon with CPm as the only assembly-related ORF, either failed to initiate encapsidation or reduced encapsidation substantially. Substitution of subsets of amino acids revealed that the amino acids that differ between positions 121 and 180 of the VT strain, and 61 and 120 of the T3 strain were involved in specific encapsidation. We further mapped the specific encapsidation to a single amino acid: mutation of methionine(165) to threonine (VT type) or serine(105) to proline (T3 type) in CTV-CPm failed to form nucleocapsids. However, the heterologous CPm in combination with both HSP70h and p61 proteins, but not HSP70h or p61 alone, encapsidated at wild-type levels, suggesting that specific encapsidation by CPm was mitigated by the combination of HSP70h and p61. Thus, in addition to the previously described functions of HSP70h and p61 of greatly enhanced virion formation and restriction of CPm encapsidation to the 5' 630 nts of the genomic RNA, these proteins facilitate encapsidation by heterologous CPms. Published by Elsevier Inc.

  3. Protein-Carbohydrate Interaction between Sperm and the Egg-Coating Envelope and Its Regulation by Dicalcin, a Xenopus laevis Zona Pellucida Protein-Associated Protein

    Directory of Open Access Journals (Sweden)

    Naofumi Miwa

    2015-05-01

    Full Text Available Protein-carbohydrate interaction regulates multiple important processes during fertilization, an essential biological event where individual gametes undergo intercellular recognition to fuse and generate a zygote. In the mammalian female reproductive tract, sperm temporarily adhere to the oviductal epithelium via the complementary interaction between carbohydrate-binding proteins on the sperm membrane and carbohydrates on the oviductal cells. After detachment from the oviductal epithelium at the appropriate time point following ovulation, sperm migrate and occasionally bind to the extracellular matrix, called the zona pellucida (ZP, which surrounds the egg, thereafter undergoing the exocytotic acrosomal reaction to penetrate the envelope and to reach the egg plasma membrane. This sperm-ZP interaction also involves the direct interaction between sperm carbohydrate-binding proteins and carbohydrates within the ZP, most of which have been conserved across divergent species from mammals to amphibians and echinoderms. This review focuses on the carbohydrate-mediated interaction of sperm with the female reproductive tract, mainly the interaction between sperm and the ZP, and introduces the fertilization-suppressive action of dicalcin, a Xenopus laevis ZP protein-associated protein. The action of dicalcin correlates significantly with a dicalcin-dependent change in the lectin-staining pattern within the ZP, suggesting a unique role of dicalcin as an inherent protein that is capable of regulating the affinity between the lectin and oligosaccharides attached on its target glycoprotein.

  4. Effect of kafirin protein coating on sensory quality and shelf-life of 'Packham's Triumph' pears during ripening.

    Science.gov (United States)

    Buchner, Sonya; Kinnear, Marise; Crouch, Ian J; Taylor, Janet; Minnaar, Amanda

    2011-12-01

    Pears are exported in large quantities from South Africa, resulting in large revenues. Minimisation of quality losses once the fruit has reached the export destination is as important as following strict export and distribution protocols. Kafirin can form edible films. In this study an edible coating made from 20 g kg(-1) kafirin coating solution was applied as a postharvest treatment to retard quality deterioration of 'Packham's Triumph' pears during storage at the typical ripening temperature (20 °C). Changes in physicochemical and sensory quality were monitored over a period of 24 days. The kafirin coating was unable to retard the onset of ripening but decreased the respiration rate and retarded the progression of senescence. However, moisture loss was exacerbated in the kafirin-coated fruit during ripening at 20 °C, especially towards the end of the shelf-life. The kafirin coating extended the eat-ripe quality of the pears by 1-2 weeks. However, the appearance of the fruit was unacceptable after 14 days of storage in terms of wrinkled skin. Further work is needed to improve the water barrier properties of the kafirin coating by incorporating a wax or triglyceride into the coating formulation or more simply by applying a kafirin coating to waxed fruit. Copyright © 2011 Society of Chemical Industry.

  5. Dominant Red Coat Color in Holstein Cattle Is Associated with a Missense Mutation in the Coatomer Protein Complex, Subunit Alpha (COPA Gene.

    Directory of Open Access Journals (Sweden)

    Ben Dorshorst

    Full Text Available Coat color in Holstein dairy cattle is primarily controlled by the melanocortin 1 receptor (MC1R gene, a central determinant of black (eumelanin vs. red/brown pheomelanin synthesis across animal species. The major MC1R alleles in Holsteins are Dominant Black (MC1RD and Recessive Red (MC1Re. A novel form of dominant red coat color was first observed in an animal born in 1980. The mutation underlying this phenotype was named Dominant Red and is epistatic to the constitutively activated MC1RD. Here we show that a missense mutation in the coatomer protein complex, subunit alpha (COPA, a gene with previously no known role in pigmentation synthesis, is completely associated with Dominant Red in Holstein dairy cattle. The mutation results in an arginine to cysteine substitution at an amino acid residue completely conserved across eukaryotes. Despite this high level of conservation we show that both heterozygotes and homozygotes are healthy and viable. Analysis of hair pigment composition shows that the Dominant Red phenotype is similar to the MC1R Recessive Red phenotype, although less effective at reducing eumelanin synthesis. RNA-seq data similarly show that Dominant Red animals achieve predominantly pheomelanin synthesis by downregulating genes normally required for eumelanin synthesis. COPA is a component of the coat protein I seven subunit complex that is involved with retrograde and cis-Golgi intracellular coated vesicle transport of both protein and RNA cargo. This suggests that Dominant Red may be caused by aberrant MC1R protein or mRNA trafficking within the highly compartmentalized melanocyte, mimicking the effect of the Recessive Red loss of function MC1R allele.

  6. Dominant Red Coat Color in Holstein Cattle Is Associated with a Missense Mutation in the Coatomer Protein Complex, Subunit Alpha (COPA) Gene

    Science.gov (United States)

    Dorshorst, Ben; Henegar, Corneliu; Liao, Xiaoping; Sällman Almén, Markus; Rubin, Carl-Johan; Ito, Shosuke; Wakamatsu, Kazumasa; Stothard, Paul; Van Doormaal, Brian; Plastow, Graham; Barsh, Gregory S.; Andersson, Leif

    2015-01-01

    Coat color in Holstein dairy cattle is primarily controlled by the melanocortin 1 receptor (MC1R) gene, a central determinant of black (eumelanin) vs. red/brown pheomelanin synthesis across animal species. The major MC1R alleles in Holsteins are Dominant Black (MC1RD) and Recessive Red (MC1Re). A novel form of dominant red coat color was first observed in an animal born in 1980. The mutation underlying this phenotype was named Dominant Red and is epistatic to the constitutively activated MC1RD. Here we show that a missense mutation in the coatomer protein complex, subunit alpha (COPA), a gene with previously no known role in pigmentation synthesis, is completely associated with Dominant Red in Holstein dairy cattle. The mutation results in an arginine to cysteine substitution at an amino acid residue completely conserved across eukaryotes. Despite this high level of conservation we show that both heterozygotes and homozygotes are healthy and viable. Analysis of hair pigment composition shows that the Dominant Red phenotype is similar to the MC1R Recessive Red phenotype, although less effective at reducing eumelanin synthesis. RNA-seq data similarly show that Dominant Red animals achieve predominantly pheomelanin synthesis by downregulating genes normally required for eumelanin synthesis. COPA is a component of the coat protein I seven subunit complex that is involved with retrograde and cis-Golgi intracellular coated vesicle transport of both protein and RNA cargo. This suggests that Dominant Red may be caused by aberrant MC1R protein or mRNA trafficking within the highly compartmentalized melanocyte, mimicking the effect of the Recessive Red loss of function MC1R allele. PMID:26042826

  7. Isolation of a protein-containing cell surface component from Streptococcus sanguis which affects its adherence to saliva-coated hydroxyapatite.

    OpenAIRE

    Liljemark, W. F.; Bloomquist, C G

    1981-01-01

    The isolation and partial characterization of a protein-containing cell surface component from Streptococcus sanguis which blocks the adherence of this microbe to saliva-coated hydroxyapatite are described. Several methods of extraction were attempted. Sonication of whole cells and cell walls proved to be the most successful and yielded biologically active adherence-blocking components. The adherence-blocking ability of these components was effective in intraspecies blocking experiments. The ...

  8. Adhesion of Porphyromonas gingivalis and Tannerella forsythia to dentin and titanium with sandblasted and acid etched surface coated with serum and serum proteins - An in vitro study.

    Science.gov (United States)

    Eick, Sigrun; Kindblom, Christian; Mizgalska, Danuta; Magdoń, Anna; Jurczyk, Karolina; Sculean, Anton; Stavropoulos, Andreas

    2017-03-01

    To evaluate the adhesion of selected bacterial strains incl. expression of important virulence factors at dentin and titanium SLA surfaces coated with layers of serum proteins. Dentin- and moderately rough SLA titanium-discs were coated overnight with human serum, or IgG, or human serum albumin (HSA). Thereafter, Porphyromonas gingivalis, Tannerella forsythia, or a six-species mixture were added for 4h and 24h. The number of adhered bacteria (colony forming units; CFU) was determined. Arg-gingipain activity of P. gingivalis and mRNA expressions of P. gingivalis and T. forsythia proteases and T. forsythia protease inhibitor were measured. Coating specimens never resulted in differences exceeding 1.1 log10 CFU, comparing to controls, irrespective the substrate. Counts of T. forsythia were statistically significantly higher at titanium than dentin, the difference was up to 3.7 log10 CFU after 24h (p=0.002). No statistically significant variation regarding adhesion of the mixed culture was detected between surfaces or among coatings. Arg-gingipain activity of P. gingivalis was associated with log10 CFU but not with the surface or the coating. Titanium negatively influenced mRNA expression of T. forsythia protease inhibitor at 24h (p=0.026 uncoated, p=0.009 with serum). The present findings indicate that: a) single bacterial species (T. forsythia) can adhere more readily to titanium SLA than to dentin, b) low expression of T. forsythia protease inhibitor may influence the virulence of the species on titanium SLA surfaces in comparison with teeth, and c) surface properties (e.g. material and/or protein layers) do not appear to significantly influence multi-species adhesion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Minor Coat and Heat Shock Proteins Are Involved in the Binding of Citrus Tristeza Virus to the Foregut of Its Aphid Vector, Toxoptera citricida.

    Science.gov (United States)

    Killiny, N; Harper, S J; Alfaress, S; El Mohtar, C; Dawson, W O

    2016-11-01

    Vector transmission is a critical stage in the viral life cycle, yet for most plant viruses how they interact with their vector is unknown or is explained by analogy with previously described relatives. Here we examined the mechanism underlying the transmission of citrus tristeza virus (CTV) by its aphid vector, Toxoptera citricida, with the objective of identifying what virus-encoded proteins it uses to interact with the vector. Using fluorescently labeled virions, we demonstrated that CTV binds specifically to the lining of the cibarium of the aphid. Through in vitro competitive binding assays between fluorescent virions and free viral proteins, we determined that the minor coat protein is involved in vector interaction. We also found that the presence of two heat shock-like proteins, p61 and p65, reduces virion binding in vitro Additionally, treating the dissected mouthparts with proteases did not affect the binding of CTV virions. In contrast, chitinase treatment reduced CTV binding to the foregut. Finally, competition with glucose, N-acetyl-β-d-glucosamine, chitobiose, and chitotriose reduced the binding. These findings together suggest that CTV binds to the sugar moieties of the cuticular surface of the aphid cibarium, and the binding involves the concerted activity of three virus-encoded proteins. Limited information is known about the specific interactions between citrus tristeza virus and its aphid vectors. These interactions are important for the process of successful transmission. In this study, we localized the CTV retention site as the cibarium of the aphid foregut. Moreover, we demonstrated that the nature of these interactions is protein-carbohydrate binding. The viral proteins, including the minor coat protein and two heat shock proteins, bind to sugar moieties on the surface of the foregut. These findings will help in understanding the transmission mechanism of CTV by the aphid vector and may help in developing control strategies which interfere

  10. Biocatalytic methanolysis activities of cross-linked protein-coated microcrystalline lipase toward esterification/transesterification of relevant palm products.

    Science.gov (United States)

    Raita, Marisa; Laosiripojana, Navadol; Champreda, Verawat

    2015-03-01

    Biocatalysis by immobilized lipase is an efficient alternative process for conversion of crude vegetable oil with high free fatty acid content to biodiesel, which is the limit of the conventional alkaline-catalyzed reaction. In this study, influences of solid-state organic and inorganic buffer core matrices with different pKa on catalytic performance of cross-linked protein coated microcrystalline biocatalysts prepared from Thermomyces lanuginosus lipase (CL-PCMC-LIP) toward esterification of palmitic acid (PA), transesterification of refined palm oil (RPO), and co-ester/transesterification of crude palm oil (CPO) to fatty acid methyl ester (FAME) was studied. Glycine, CAPSO (3-(cyclohexylamino)-2-hydroxy-1-propanesulfonic acid), and TAPS ([(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)amino]-1-propanesulfonic acid) were shown to be potent core matrices for these reactions. The optimal reaction contained 4:1 [methanol]/[fatty acid] molar equivalence ratio with 20% (w/w) CL-PCMC-LIP on glycine in the presence of tert-butanol as a co-solvent. Deactivation effect of glycerol on the biocatalyst reactive surface was shown by FTIR, which could be alleviated by increasing co-solvent content. The maximal FAME yields from PA, RPO, and CPO reached 97.6, 94.9, and 95.5%, respectively on a molar basis under the optimum conditions after incubation at 50°C for 6h. The biocatalyst retained >80% activity after recycling in five consecutive batches. The work demonstrates the potential of CL-PCMC-LIP on one-step conversion of inexpensive crude fatty acid-rich feedstock to biodiesel. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Isolated Potato Virus A coat protein possesses unusual properties and forms different short virus-like particles.

    Science.gov (United States)

    Ksenofontov, Alexander L; Dobrov, Eugeny N; Fedorova, Natalia V; Serebryakova, Marina V; Prusov, Andrei N; Baratova, Ludmila A; Paalme, Viiu; Järvekülg, Lilian; Shtykova, Eleonora V

    2017-06-08

    In our previous study, we have observed that the isolated coat proteins (CP) of the Potyvirus Potato Virus A (PVA) virions exhibit an intrinsic tendency to self-associate into various multimeric forms containing some fractions of cross-β-structure. In this report, we studied the effect of solution conditions on the structure and dissociation of isolated PVA CP using a number of complementary physicochemical methods. Analysis of the structure of PVA CP in solution was performed by limited proteolysis with MALDI-TOF mass spectrometry analysis, transmission electron microscopy, intrinsic fluorescence spectroscopy, and synchrotron small angle X-ray scattering (SAXS). Overall structural characteristics of PVA CP obtained by combination of these methods and ab initio shape reconstruction by SAXS show that PVA CP forms large multi-subunit particles. We demonstrate that a mixture of compact virus-like particles (VLP) longer than 30 nm is assembled on dialysis of isolated CP into neutral pH buffer (at low ionic strength). Under conditions of high ionic strength (0.5 M NaCl) and high pH (pH 10.5), PVA dissociates into low compactness oval-shaped particles of approximately 30 subunits (20-30 nm). The results of limited trypsinolysis of these particles (enzyme/substrate ratio 1:100, 30 min) showed the existence of non-cleavable core-fragment, consisting of 137 amino acid residues. Trypsin treatment removed only a short N-terminal fragment in the intact virions. These particles are readily reassembled into regular VLPs by changing pH back to neutral. It is possible that these particles may represent some kind of intermediate in PVA assembly in vitro and in vivo.

  12. Processing and Validation of Whey-Protein-Coated Films and Laminates at Semi-Industrial Scale as Novel Recyclable Food Packaging Materials with Excellent Barrier Properties

    Directory of Open Access Journals (Sweden)

    E. Bugnicourt

    2013-01-01

    Full Text Available A biopolymer coating for plastic films was formulated based on whey protein, and its potential to replace current synthetic oxygen barrier layers used in food packaging such as ethylene vinyl alcohol copolymers (EVOH was tested. The whey-coating application was performed at semi-industrial scale. High barrier to oxygen with transmission rate down to ranges of 1 cm3 (STP m−2 d−1 bar−1 at and 50% relative humidity (r.h. but interesting humidity barrier down to ranges of 3 g m−2 d−1 (both normalized to 100 μm thickness were reached, outperforming most existing biopolymers. Coated films were validated for storing various food products showing that the shelf life and sensory attributes were maintained similar to reference packaging films while complying with food safety regulations. The developed whey coating could be enzymatically removed within 2 hours and is therefore compatible with plastic recycling operations to allow multilayer films to become recyclable by separating the other combined layers. A life cycle assessment was performed showing a significant reduction in the environmental impact of the packaging thanks in particular to the possibility of recycling materials as opposed to incinerating those containing EVOH or polyamide (PA, but due to the use of biosourced raw materials.

  13. In vitro cytotoxic effects of gold nanoparticles coated with functional acyl homoserine lactone lactonase protein from Bacillus licheniformis and their antibiofilm activity against Proteus species.

    Science.gov (United States)

    Vinoj, Gopalakrishnan; Pati, Rashmirekha; Sonawane, Avinash; Vaseeharan, Baskaralingam

    2015-02-01

    N-acylated homoserine lactonases are known to inhibit the signaling molecules of the biofilm-forming pathogens. In this study, gold nanoparticles were coated with N-acylated homoserine lactonase proteins (AiiA AuNPs) purified from Bacillus licheniformis. The AiiA AuNPs were characterized by UV-visible spectra, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The synthesized AiiA AuNPs were found to be spherical in shape and 10 to 30 nm in size. Treatment with AiiA protein-coated AuNPs showed maximum reduction in exopolysaccharide production, metabolic activities, and cell surface hydrophobicity and potent antibiofilm activity against multidrug-resistant Proteus species compared to treatment with AiiA protein alone. AiiA AuNPs exhibited potent antibiofilm activity at 2 to 8 μM concentrations without being harmful to the macrophages. We conclude that at a specific dose, AuNPs coated with AiiA can kill bacteria without harming the host cells, thus representing a potential template for the design of novel antibiofilm and antibacterial protein drugs to decrease bacterial colonization and to overcome the problem of drug resistance. In summary, our data suggest that the combined effect of the lactonase and the gold nanoparticles of the AiiA AuNPs has promising antibiofilm activity against biofilm-forming and multidrug-resistant Proteus species. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Adsorption behavior of acidic and basic proteins onto citrate-coated Au surfaces correlated to their native fold, stability, and pI.

    Science.gov (United States)

    Glomm, Wilhelm R; Halskau, Øyvind; Hanneseth, Ann-Mari D; Volden, Sondre

    2007-12-27

    The adsorption of eight different proteins (alpha-lactalbumin (types I and III), bovine serum albumin, hemoglobin, myoglobin, cytochrome c, alpha-casein, and lysozyme) onto a model anionic surface was performed at equivalent bulk (solvent, ionic strength, pH) and surface conditions. Adsorption was monitored on a quartz crystal microbalance with dissipation monitoring (QCM-D) with citrate-coated gold surfaces as adsorbents and has been correlated to native fold stability determined from near- and far-UV circular dichroism (CD) measurements. The proteins studied here were chosen based on their pI and documented knowledge about their structural stability and flexibility. Protein adsorption was found to be independent of global protein charge. Rather, binding occurs through oppositely charged patches on protein and surface. Moreover, data indicate that there is a correlation between secondary and tertiary structure stability and the adsorption characteristics at interfaces. Also, protein surface coverage, layer thickness, and flexibility can be tuned as a function of deposition method. This is discussed in terms of adsorption/spreading kinetics and intermolecular (protein-surface and protein-protein) interactions. Adsorption to surfaces can induce formation of supramolecular structures such as micelles (in the case of alpha-Cas) and multilayers (as for Hb). In the case of alpha-casein, this phenomenon depends on the deposition method and protein concentration. When ranking the surface coverage for proteins added in excess, the order is Lyz < Cyt c < Mb < BSA < alpha-La I < alpha-Cas < alpha-La III < Hb, which can be correlated to the proteins ability to form supramolecular structures (alpha-Cas, Hb), overall conformational flexibilities, and ability to form stable intermediates.

  15. Application of protein-phenolic based coating on tomatoes (Lycopersicum esculentum Aplicação de coberturas proteicas e fenólicas em tomates (Lycopersicum esculentum

    Directory of Open Access Journals (Sweden)

    Eliane Pereira Cipolatti

    2012-09-01

    Full Text Available The aim of this study was to investigate the use of protein-phenolic based coating made from fermented rice bran on cherry tomatoes (Lycopersicum esculentum. Tests were performed with glycerol 3% (v/v, glycerol with protein-phenolic rice bran extract (5%, glycerol with protein-phenolic extract after 96 hours of fermentation (5%, and a control (without coating. The coated cherry tomatoes were kept at room temperature for 28 days. Mass loss, pH and acidity, total soluble solids, and carotenoids were determined every 96 hours. The coating made from the biomass extract reduced the carotenoid and acidity levels in the fruits studied by 17 and 21.1%, respectively, compared to the control. The coating proved an efficient barrier to water vapor with mass loss of 57% less than the control suggesting that it can be used as an alternative for vegetable tissue conservation.Este trabalho teve como objetivo estudar a utilização de películas, à base de compostos proteicos e fenólicos provenientes de farelo de arroz fermentado, em tomates (Lycopersicum esculentum. Foram realizados testes com: glicerol 3% (v/v; glicerol com extrato fenólico e proteico do farelo de arroz (5%; glicerol com extrato fenólico e proteico da biomassa gerada em 96 hours (5%, e um controle (sem a película. Os tomates revestidos foram mantidos à temperatura ambiente durante 28 dias, sendo determinados, a cada 96 horas, os seguintes aspectos: a perda de massa, o pH e a acidez, os sólidos solúveis totais e os carotenoides. A película elaborada com os extratos da biomassa reduziu os níveis de carotenoides e acidez dos frutos estudados em 17 e 21,1%, respectivamente, em relação ao controle. A película também foi eficiente como barreira ao vapor de água; assim, com perda de massa 57% inferior à do controle, sugere-se que esta poderá ser utilizada como alternativa para conservação desse tecido vegetal.

  16. A neutral polyacrylate copolymer coating for surface modification of thiol-ene microchannels for improved performance of protein separation by microchip electrophoresis

    DEFF Research Database (Denmark)

    Mesbah, Kiarach; Mai, T.D.; Jensen, Thomas Glasdam

    2016-01-01

    We have investigated the behavior of thiol-ene substrates that is a class of promising materials for lab-on-a-chip electrophoresis applications. Two polymeric materials were prepared by copolymerization of N, N-dimethylacrylamide (DMA), (3-(methacryloyl-oxy)propyl)trimethoxysilane (PMA) and 3......-(DMA-PMAMAPS) copolymer were evaluated in terms of surface hydrophilicity, suppression and stability of electro-osmotic flow and prevention of protein adsorption. Surface modification of thiol-ene containing a 20 % excess of thiols with the terpolymer p-(DMA-PMA-MAPS) was found to offer the most stable coating and most...

  17. In vitro labeling of neural stem cells with poly-L-lysine coated super paramagnetic nanoparticles for green fluorescent protein transfection.

    Science.gov (United States)

    Albukhaty, Salim; Naderi-Manesh, Hossein; Tiraihi, Taki

    2013-04-01

    The magnetic nanoparticle-based transfection method is a relatively new technique for delivery of functional genes to target tissues. We aimed to evaluate the transfection efficiency of rat neural stem cell (NSC) using poly-L-lysine hydrobromide (PLL)-coated super paramagnetic iron oxide nanoparticles (SPION). The SPION was prepared and coated with PLL as transfection agent and the transfection efficiency was evaluated in rat NSC using enhanced green fluorescent protein-N1 plasmid containing GFP as a reporter gene. NSC was incubated for 24 h in cell culture media containing 25 µg/ml SPION and in different concentrations of PLL (0.25, 0.50, 0.75, 1 and 2 µg/ml). Cell viability was determined before and after transfection for every concentration using Trypan blue assay. Characterization of prepared uncoated (SPION) and coated (SPION-PLL) complexes were evaluated by a transmission electron microscope and the zeta potential. PLL at 0.75 μg/ml showed optimal results with 25 μg/ml SPION concentration compared with other PLL concentrations (0.25, 0.50, 1 and 2 μg/ml). The 18% efficiency of the transfected cells showed green fluorescence. Transfection with SPION is an efficient, non-viral gene transfere method.

  18. Immobilization of bacterial S-layer proteins from Caulobacter crescentus on iron oxide-based nanocomposite: synthesis and spectroscopic characterization of zincite-coated Fe₂O₃ nanoparticles.

    Science.gov (United States)

    Habibi, Neda

    2014-05-05

    Zinc oxide was coated on Fe2O3 nanoparticles using sol-gel spin-coating. Caulobacter crescentus have a crystalline surface layer (S-layer), which consist of one protein or glycoprotein species. The immobilization of bacterial S-layers obtained from C. crescentus on zincite-coated nanoparticles of iron oxide was investigated. The SDS PAGE results of S-layers isolated from C. crescentus showed the weight of 50 KDa. Nanoparticles of the Fe2O3 and zinc oxide were synthesized by a sol-gel technique. Fe2O3 nanoparticles with an average size of 50 nm were successfully prepared by the proper deposition of zinc oxide onto iron oxide nanoparticles surface annealed at 450 °C. The samples were characterized by field-emission scanning electron microscope (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Controlling the potential gastrointestinal fate of β-carotene emulsions using interfacial engineering: Impact of coating lipid droplets with polyphenol-protein-carbohydrate conjugate.

    Science.gov (United States)

    Liu, Fuguo; Ma, Cuicui; Zhang, Ruojie; Gao, Yanxiang; Julian McClements, David

    2017-04-15

    The impact of interfacial coatings comprised of polyphenol-protein-carbohydrate conjugates on the properties of nutraceutical-fortified lipid droplets during digestion was investigated. Surface-active chlorogenic acid-lactoferrin-polydextrose (CA-LF-PD) conjugate was synthesized as emulsifier to stabilize lipid droplets in β-carotene-enriched oil-in-water emulsions. Changes in droplet size, charge, and microstructure were monitored as β-carotene emulsions were passed through a simulated gastrointestinal tract model (mouth, stomach, small intestine). LF-coated droplets were unstable to flocculation at pH 8.0-9.0, due to the reduction in electrostatic repulsion, but CA-LF-PD conjugate-coated droplets were stable. Emulsions stabilized by ternary conjugate had better stability to droplet aggregation under simulated GIT conditions than other systems, which increased β-carotene bioaccessibility. The importance of including an oral phase in the simulated GIT model was also demonstrated. The ternary conjugate-stabilized emulsions developed in this study have potential applications as protectors and carriers of hydrophobic drugs, supplements and nutraceuticals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Precise Coating of a Wide Range of DNA Templates by a Protein Polymer with a DNA Binding Domain

    NARCIS (Netherlands)

    Hernandez-Garcia, Armando; Estrich, Nicole A.; Werten, Marc W.T.; Maarel, van der Johan R.C.; Labean, Thomas H.; Wolf, de Frits A.; Cohen Stuart, Martien A.; Vries, de Renko

    2017-01-01

    Emerging DNA-based nanotechnologies would benefit from the ability to modulate the properties (e.g., solubility, melting temperature, chemical stability) of diverse DNA templates (single molecules or origami nanostructures) through controlled, self-assembling coatings. We here introduce a DNA

  1. Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) scaffolds coated with PhaP-RGD fusion protein promotes the proliferation and chondrogenic differentiation of human umbilical cord mesenchymal stem cells in vitro.

    Science.gov (United States)

    Li, Xiaoli; Chang, Huimin; Luo, Huanan; Wang, Zhenghui; Zheng, Guoxi; Lu, Xiaoyun; He, Xijing; Chen, Fang; Wang, Ting; Liang, Jianmin; Xu, Min

    2015-03-01

    Human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs) have been widely used in tissue engineering. The aim of this study is to evaluate the ability of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) scaffolds coated with polyhydroxyalkanoate binding protein fused with arginyl-glycyl-aspartic acid (PhaP-RGD) to promote the proliferation and chondrogenic differentiation of hUC-MSCs seeded on them. The PhaP-RGD fusion protein was expressed by Escherichia coli. PHBHHx films were coated with PhaP-RGD fusion protein and the physiochemical properties were examined. hUC-MSCs were seeded on PHBHHx films with or without PhaP-RGD precoating and tested for changes in morphology, viability, and chondrogenic differentiation. We found that PhaP-RGD-coated PHBHHx films had similar surface morphology to uncoated PHBHHx. The water contact angle of the coated PHBHHx surface was lower than that of the uncoated surface (10.63° vs. 98.69°). At 7 and 14 days after seeding, the PhaP-RGD-coated PHBHHx group showed greater numbers of viable cells compared to the uncoated PHBHHx group. The expression levels of aggrecan and collagen II were enhanced in the PhaP-RGD-coated PHBHHx group relative to the uncoated PHBHHx group. Histological analysis using toluidine blue staining showed elevated formation of proteoglycan producing chondrocytes in the PhaP-RGD-coated PHBHHx group. Additionally, the synthesis of proteoglycan and collagen was significantly enhanced within the PhaP-RGD constructs. Taken together, PhaP-RGD coating promotes the proliferation and chondrogenic differentiation of hUC-MSCs seeded on PHBHHx films. PhaP-RGD-coated PHBHHx may be a useful scaffold for cartilage tissue engineering. © 2014 Wiley Periodicals, Inc.

  2. Papaya ringspot virus-P: characteristics, pathogenicity, sequence variability and control.

    Science.gov (United States)

    Tripathi, Savarni; Suzuki, Jon Y; Ferreira, Stephen A; Gonsalves, Dennis

    2008-05-01

    Papaya ringspot virus (PRSV) is an aphid-transmitted plant virus belonging to the genus Potyvirus, family Potyviridae, with a positive sense RNA genome. PRSV isolates belong to either one of two major strains, P or W. The P strains infect both papaya and cucurbits whereas the W strains infect only cucurbits. PRSV-P is found in all major papaya-growing areas. Virions are filamentous, non-enveloped and flexuous measuring 760-800 x 12 nm. Virus particles contain 94.5% protein and 5.5% nucleic acid. The protein component consists of the virus coat protein (CP), which has a molecular weight of about 36 kDa as estimated by Western blot analysis. Density of the sedimenting component in purified PRSV preparations is 1.32 g/cm(3) in CsCl. The PRSV genome consists of a unipartite linear single-stranded positive sense RNA of 10 326 nucleotides with a 5' terminus, genome-linked protein, VPg. The virus is naturally transmitted via aphids in a non-persistent manner. Both the CP and helper component (HC-Pro) are required for vector transmission. This virus can also be transmitted mechanically, and is typically not seed-transmitted. PRSV has a limited number of hosts belonging to the families Caricaceae, Chenopodiaceae and Cucurbitaceae. Propagation hosts are: Carica papaya, Cucurbita pepo and Cucumis metuliferus cv. accession 2459. Local lesion assay hosts are: Chenopodium quinoa and Chenopodium amaranticolor. Two transgenic papaya varieties, Rainbow and SunUp, with engineered resistance to PRSV have been commercially grown in Hawaii since 1998. Besides transgenic resistance, tolerant varieties, cross-protection and other cultural practices such as isolation and rogueing of infected plants are used to manage the disease. 00.057.0.01.045. 57010045. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/57010045.htm.

  3. Stoichiometry, Absolute Abundance, and Localization of Proteins in the Bacillus cereus Spore Coat Insoluble Fraction Determined Using a QconCAT Approach.

    Science.gov (United States)

    Stelder, Sacha K; Benito de Moya, Celia; Hoefsloot, Huub C J; de Koning, Leo J; Brul, Stanley; de Koster, Chris G

    2018-01-04

    Spores of Bacillus cereus pose a threat to food safety due to their high resistance to the heat or acid treatments commonly used to make food microbiologically safe. Spores may survive these treatments and later resume growth either on foodstuffs or, after ingestion, upon entering the gut they are capable of producing toxins, which cause either vomiting or diarrhea. The outer layers of the spore, the spore coat and exosporium, consist primarily of proteins that may serve as potential biomarkers for detection. The major morphogenetic protein CotE is important for correct assembly and attachment of the outermost layer, the exosporium, and by extension retention of many proteins. However, characterization of the proteins affected by deletion of CotE has been limited to electrophoretic patterns. Here we report the effect of CotE deletion on the insoluble fraction of the spore proteome through liquid chromatography-Fourier transform tandem mass spectrometry (LC-FTMS/MS) analysis. A total of 560 proteins have been identified in both mutant and wild-type spore coat isolates. A further 163 proteins were identified exclusively in wild-type spore isolates indicating that they are dependent on CotE for their association with the spore. Several of these are newly confirmed as associated with the exosporium, namely BC_2569 (BclF), BC_3345, BC_2427, BC_2878, BC_0666, BC_2984, BC_3481, and BC_2570. A total of 153 proteins were only identified in ΔCotE spore isolates. This was observed for proteins that are known or likely to be interacting with or are encased by CotE. Crucial spore proteins were quantified using a QconCAT reference standard, the first time this was used in a biochemically heterogeneous system. This allowed us to determine the absolute abundance of 21 proteins, which spanned across three orders of magnitude and together covered 5.66% ± 0.51 of the total spore weight. Applying the QconCAT methodology to the ΔCotE mutant allowed us to quantify 4.13% ± 0.14 of

  4. A functional chimaeric S-layer-enhanced green fluorescent protein to follow the uptake of S-layer-coated liposomes into eukaryotic cells.

    Science.gov (United States)

    Ilk, Nicola; Küpcü, Seta; Moncayo, Gerald; Klimt, Sigrid; Ecker, Rupert C; Hofer-Warbinek, Renate; Egelseer, Eva M; Sleytr, Uwe B; Sára, Margit

    2004-04-15

    The chimaeric gene encoding a C-terminally truncated form of the S-layer protein SbpA of Bacillus sphaericus CCM 2177 and the EGFP (enhanced green fluorescent protein) was ligated into plasmid pET28a and cloned and expressed in Escherichia coli. Just 1 h after induction of expression an intense EGFP fluorescence was detected in the cytoplasm of the host cells. Expression at 28 degrees C instead of 37 degrees C resulted in clearly increased fluorescence intensity, indicating that the folding process of the EGFP moiety was temperature sensitive. To maintain the EGFP fluorescence, isolation of the fusion protein from the host cells had to be performed in the presence of reducing agents. SDS/PAGE analysis, immunoblotting and N-terminal sequencing of the isolated and purified fusion protein confirmed the presence of both the S-layer protein and the EGFP moiety. The fusion protein had maintained the ability to self-assemble in suspension and to recrystallize on peptidoglycan-containing sacculi or on positively charged liposomes, as well as to fluoresce. Comparison of fluorescence excitation and emission spectra of recombinant EGFP and rSbpA(31-1068)/EGFP revealed identical maxima at 488 and 507 nm respectively. The uptake of liposomes coated with a fluorescent monomolecular protein lattice of rSbpA(31-1068)/EGFP into HeLa cells was studied by confocal laser-scanning microscopy. The major part of the liposomes was internalized within 2 h of incubation and entered the HeLa cells by endocytosis.

  5. Transient expression of Human papillomavirus type 16 L2 epitope fused to N- and C-terminus of coat protein of Potato virus X in plants.

    Science.gov (United States)

    Cerovska, Noemi; Hoffmeisterova, Hana; Moravec, Tomas; Plchova, Helena; Folwarczna, Jitka; Synkova, Helena; Ryslava, Helena; Ludvikova, Viera; Smahel, Michal

    2012-03-01

    Transient expression of foreign genes based on plant viral vectors is a suitable system for the production of relevant immunogens that can be used for the development of a new generation of vaccines against a variety of infectious diseases. In the present study the epitope derived from HPV-16 L2 minor capsid protein (amino acids 108-120) was expressed from Potato virus X (PVX)-based vector pGR106 as N- or C-terminal fusion with the PVX coat protein (PVX CP) in transgenic Nicotiana benthamiana plants. The fusion protein L2 108-120-PVX CP was successfully expressed in plants at a level of 170 mg/kg of fresh leaf tissue. The C-terminal fusion protein PVX CP- L2 108-120 was expressed using mutated vector sequence to avoid homologous recombination at a level of 8 mg/kg of fresh leaf tissue. Immunogenicity of L2 108-120-PVX CP virus-like particles was tested after immunization of mice by subcutaneous injection or tattoo administration. In animal sera the antibodies against the PVX CP and the L2 108-120 epitope were found after both methods of vaccine delivery.

  6. Incidence of Lettuce mosaic virus in lettuce and its detection by polyclonal antibodies produced against recombinant coat protein expressed in Escherichia coli.

    Science.gov (United States)

    Sharma, Prachi; Sharma, Susheel; Singh, Jasvir; Saha, Swati; Baranwal, V K

    2016-04-01

    Lettuce mosaic virus (LMV), a member of the genus Potyvirus of family Potyviridae, causes mosaic disease in lettuce has recently been identified in India. The virus is seed borne and secondary infection occurs through aphids. To ensure virus freedom in seeds it is important to develop diagnostic tools, for serological methods the production of polyclonal antibodies is a prerequisite. The coat protein (CP) gene of LMV was amplified, cloned and expressed using pET-28a vector in Escherichia coli BL21DE3 competent cells. The LMV CP was expressed as a fusion protein containing a fragment of the E. coli His tag. The LMV CP/His protein reacted positively with a commercial antiserum against LMV in an immunoblot assay. Polyclonal antibodies purified from serum of rabbits immunized with the fusion protein gave positive results when LMV infected lettuce (Lactuca sativa) was tested at 1:1000 dilution in PTA-ELISA. These were used for specific detection of LMV in screening lettuce accessions. The efficacy of the raised polyclonal antiserum was high and it can be utilized in quarantine and clean seed production. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Human heat-shock protein 60 receptor-coated paramagnetic beads show improved capture of Listeria monocytogenes in the presence of other Listeria in food.

    Science.gov (United States)

    Koo, O K; Aroonnual, A; Bhunia, A K

    2011-07-01

    To investigate the suitability of human Hsp60, a receptor for Listeria adhesion protein (LAP), on paramagnetic beads (PMB) to capture Listeria monocytogenes from food in the presence of other Listeria to facilitate rapid and specific detection of this pathogen. Commercially available streptavidin-coated PMBs were linked with biotinylated Hsp60 (PMB-Hsp60), and the bacterial capture efficiency from pure culture and meat samples was determined. Capture rate was also compared with the monoclonal antibody (MAb)-C11E9-coated beads (PMB-C11E9) and the commercial Dynabeads anti-Listeria. Captured cells were detected and quantified by plating on selective medium, quantitative real-time PCR (qPCR) and a light-scattering sensor. Overall, all ligand-coated beads had similar capture efficiency (varied from 1·8 to 9·2%) for L. monocytogenes under the conditions employed, and the minimum cell number required to achieve such capture was 10³ CFU ml⁻¹. PMB-Hsp60 had significantly greater capture efficiency for pathogenic Listeria (P Listeria. In contrast, PMB-C11E9 and Dynabeads anti-Listeria had similar capture efficiency for both. The efficacy of all PMBs to capture L. monocytogenes in the presence of Listeria innocua from food matrices was compared. Although Dynabeads anti-Listeria had the overall best capture efficiency, PMB-Hsp60 was able to selectively capture L. monocytogenes even in the presence of 10-100-fold more L. innocua cells from enriched meat samples. Data show that the human cell receptor, Hsp60, is suitable for the capture of pathogenic Listeria on PMB in the presence of other Listeria in food. As pathogen interaction with host cells is highly specific, host cell receptors could be used as alternate capture molecules on PMB to aid in specific detection of pathogens. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  8. Mapping differential cellular protein response of mouse alveolar epithelial cells to multi-walled carbon nanotubes as a function of atomic layer deposition coating.

    Science.gov (United States)

    Hilton, Gina M; Taylor, Alexia J; Hussain, Salik; Dandley, Erinn C; Griffith, Emily H; Garantziotis, Stavros; Parsons, Gregory N; Bonner, James C; Bereman, Michael S

    2017-04-01

    Carbon nanotubes (CNTs), a prototypical engineered nanomaterial, have been increasingly manufactured for a variety of novel applications over the past two decades. However, since CNTs possess fiber-like shape and cause pulmonary fibrosis in rodents, there is concern that mass production of CNTs will lead to occupational exposure and associated pulmonary diseases. The aim of this study was to use contemporary proteomics to investigate the mechanisms of cellular response in E10 mouse alveolar epithelial cells in vitro after exposure to multi-walled CNTs (MWCNTs) that were functionalized by atomic layer deposition (ALD). ALD is a method used to generate highly uniform and conformal nanoscale thin-film coatings of metals to enhance novel conductive properties of CNTs. We hypothesized that specific types of metal oxide coatings applied to the surface of MWCNTs by ALD would determine distinct proteomic profiles in mouse alveolar epithelial cells in vitro that could be used to predict oxidative stress and pulmonary inflammation. Uncoated (U)-MWCNTs were functionalized by ALD with zinc oxide (ZnO) to yield Z-MWCNTs or aluminum oxide (Al2O3) to yield A-MWCNTs. Significant differential protein expression was found in the following critical pathways: mTOR/eIF4/p70S6K signaling and Nrf-2 mediated oxidative stress response increased following exposure to Z-MWCNTs, interleukin-1 signaling increased following U-MWCNT exposure, and inhibition of angiogenesis by thrombospondin-1, oxidative phosphorylation, and mitochondrial dysfunction increased following A-MWCNT exposure. This study demonstrates that specific types of metal oxide thin film coatings applied by ALD produce distinct cellular and biochemical responses related to lung inflammation and fibrosis compared to uncoated MWCNT exposure in vitro.

  9. Wheat streak mosaic virus Coat Protein Deletion Mutants Elicit More Severe Symptoms Than Wild-Type Virus in Multiple Cereal Hosts.

    Science.gov (United States)

    Tatineni, Satyanarayana; Elowsky, Christian; Graybosch, Robert A

    2017-12-01

    Previously, we reported that coat protein (CP) of Wheat streak mosaic virus (WSMV) (genus Tritimovirus, family Potyviridae) tolerates deletion of amino acids 36 to 84 for efficient systemic infection of wheat. In this study, we demonstrated that WSMV mutants with deletion of CP amino acids 58 to 84 but not of 36 to 57 induced severe chlorotic streaks and spots, followed by acute chlorosis in wheat, maize, barley, and rye compared with mild to moderate chlorotic streaks and mosaic symptoms by wild-type virus. Deletion of CP amino acids 58 to 84 from the WSMV genome accelerated cell-to-cell movement, with increased accumulation of genomic RNAs and CP, compared with the wild-type virus. Microscopic examination of wheat tissues infected by green fluorescent protein-tagged mutants revealed that infection by mutants lacking CP amino acids 58 to 84 caused degradation of chloroplasts, resulting in acute macroscopic chlorosis. The profile of CP-specific proteins was altered in wheat infected by mutants causing acute chlorosis, compared with mutants eliciting wild-type symptoms. All deletion mutants accumulated CP-specific major protein similarly to that in wild-type virus; however, mutants that elicit acute chlorosis failed to accumulate a 31-kDa minor protein compared with wild-type virus or mutants lacking amino acids 36 to 57. Taken together, these data suggest that deletion of CP amino acids 58 to 84 from the WSMV genome enhanced accumulation of CP and genomic RNA, altered CP-specific protein profiles, and caused severe symptom phenotypes in multiple cereal hosts.

  10. One-step coating of silica capillaries for selective protein retention by Cu(II)-IDA IMAC.

    Science.gov (United States)

    Mehyou, Zeina; Lobinski, Ryszard; Hagège, Agnès

    2011-12-15

    A simple protocol to obtain Cu(II)-IDA (iminodiacetic acid)-modified capillaries was developed for immobilized metal ion affinity chromatography (IMAC). It consisted in the synthesis of IDA-silane used for a one-step coating of fused silica capillaries. The approach prevented the hydrolysis of silica potentially induced by two step coatings (γ-GPTMS, then IDA) employed in the conventional method of bonding iminodiacetic acid. The IDA content was quantified using a model relating the electroosmotic flow generated in IDA-modified capillaries to the charges induced by IDA species. The retention behavior of holotransferrin and bovine serum albumin on these IMAC columns was then investigated. Holotransferrin revealed a high affinity for Cu(II)-supports through a specific interaction with Cu(II) ions whereas albumin did not show any retention. The use of such columns for sample pretreatment before an HPLC analysis was proved to be successful. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Desorption of Lipases Immobilized on Octyl-Agarose Beads and Coated with Ionic Polymers after Thermal Inactivation. Stronger Adsorption of Polymers/Unfolded Protein Composites

    Directory of Open Access Journals (Sweden)

    Jose J. Virgen-Ortíz

    2017-01-01

    Full Text Available Lipases from Candida antarctica (isoform B and Rhizomucor miehei (CALB and RML have been immobilized on octyl-agarose (OC and further coated with polyethylenimine (PEI and dextran sulfate (DS. The enzymes just immobilized on OC supports could be easily released from the support using 2% SDS at pH 7, both intact or after thermal inactivation (in fact, after inactivation most enzyme molecules were already desorbed. The coating with PEI and DS greatly reduced the enzyme release during thermal inactivation and improved enzyme stability. However, using OC-CALB/RML-PEI-DS, the full release of the immobilized enzyme to reuse the support required more drastic conditions: a pH value of 3, a buffer concentration over 2 M, and temperatures above 45 °C. However, even these conditions were not able to fully release the thermally inactivated enzyme molecules from the support, being necessary to increase the buffer concentration to 4 M sodium phosphate and decrease the pH to 2.5. The formation of unfolded protein/polymers composites seems to be responsible for this strong interaction between the octyl and some anionic groups of OC supports. The support could be reused five cycles using these conditions with similar loading capacity of the support and stability of the immobilized enzyme.

  12. High-Density Single-Layer Coating of Gold Nanoparticles onto Multiple Substrates by Using an Intrinsically Disordered Protein of α-Synuclein for Nanoapplications.

    Science.gov (United States)

    Bhak, Ghibom; Lee, Junghee; Kim, Chang-Hyun; Chung, Dong Young; Kang, Jin Hyoun; Oh, Soojung; Lee, Jungsup; Kang, Jin Soo; Yoo, Ji Mun; Yang, Jee Eun; Rhoo, Kun Yil; Park, Sunghak; Lee, Somin; Nam, Ki Tae; Jeon, Noo Li; Jang, Jyongsik; Hong, Byung Hee; Sung, Yung-Eun; Yoon, Myung-Han; Paik, Seung R

    2017-03-15

    Functional graffiti of nanoparticles onto target surface is an important issue in the development of nanodevices. A general strategy has been introduced here to decorate chemically diverse substrates with gold nanoparticles (AuNPs) in the form of a close-packed single layer by using an omni-adhesive protein of α-synuclein (αS) as conjugated with the particles. Since the adsorption was highly sensitive to pH, the amino acid sequence of αS exposed from the conjugates and its conformationally disordered state capable of exhibiting structural plasticity are considered to be responsible for the single-layer coating over diverse surfaces. Merited by the simple solution-based adsorption procedure, the particles have been imprinted to various geometric shapes in 2-D and physically inaccessible surfaces of 3-D objects. The αS-encapsulated AuNPs to form a high-density single-layer coat has been employed in the development of nonvolatile memory, fule-cell, solar-cell, and cell-culture platform, where the outlying αS has played versatile roles such as a dielectric layer for charge retention, a sacrificial layer to expose AuNPs for chemical catalysis, a reaction center for silicification, and biointerface for cell attachment, respectively. Multiple utilizations of the αS-based hybrid NPs, therefore, could offer great versatility to fabricate a variety of NP-integrated advanced materials which would serve as an indispensable component for widespread applications of high-performance nanodevices.

  13. Isolation of a protein-containing cell surface component from Streptococcus sanguis which affects its adherence to saliva-coated hydroxyapatite.

    Science.gov (United States)

    Liljemark, W F; Bloomquist, C G

    1981-01-01

    The isolation and partial characterization of a protein-containing cell surface component from Streptococcus sanguis which blocks the adherence of this microbe to saliva-coated hydroxyapatite are described. Several methods of extraction were attempted. Sonication of whole cells and cell walls proved to be the most successful and yielded biologically active adherence-blocking components. The adherence-blocking ability of these components was effective in intraspecies blocking experiments. The extract obtained from cell walls of S. sanguis was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and shown to contain one major and two to three minor bands when stained with Coomassie blue. The molecular weight of the major band was estimated to be 70,000 to 90,000. Gel filtration of the sonified cell wall extract on 10% agarose yielded two active adherence-blocking peaks, the void volume and a second peak. Images PMID:6273317

  14. Amino acid sequences mediating vascular cell adhesion molecule 1 binding to integrin alpha 4: homologous DSP sequence found for JC polyoma VP1 coat protein

    Directory of Open Access Journals (Sweden)

    Michael Andrew Meyer

    2013-07-01

    Full Text Available The JC polyoma viral coat protein VP1 was analyzed for amino acid sequences homologies to the IDSP sequence which mediates binding of VLA-4 (integrin alpha 4 to vascular cell adhesion molecule 1. Although the full sequence was not found, a DSP sequence was located near the critical arginine residue linked to infectivity of the virus and binding to sialic acid containing molecules such as integrins (3. For the JC polyoma virus, a DSP sequence was found at residues 70, 71 and 72 with homology also noted for the mouse polyoma virus and SV40 virus. Three dimensional modeling of the VP1 molecule suggests that the DSP loop has an accessible site for interaction from the external side of the assembled viral capsid pentamer.

  15. Functional characterization of coat protein and V2 involved in cell to cell movement of Cotton leaf curl Kokhran virus-Dabawali.

    Directory of Open Access Journals (Sweden)

    C G Poornima Priyadarshini

    Full Text Available The functional attributes of coat protein (CP and V2 of the monopartite begomovirus, Cotton leaf curl Kokhran virus- Dabawali were analyzed in vitro and in vivo by their overexpression in E. coli, insect cells and transient expression in the plant system. Purified recombinant V2 and CP proteins were shown to interact with each other using ELISA and surface plasmon resonance. Confocal microscopy of Sf21 cells expressing V2 and CP proteins revealed that V2 localized to the cell periphery and CP to the nucleus. Deletion of the N terminal nuclear localization signal of CP restricted its distribution to the cytoplasm. GFP-V2 and YFP-CP transiently expressed in N. benthamiana plants by agroinfiltration substantiated the localization of V2 to the cell periphery and CP predominantly to the nucleus. Interestingly, upon coinfiltration, CP was found both in the nucleus and in the cytoplasm along with V2. These results suggest that the interaction of V2 and CP may have important implications in the cell to cell movement.

  16. Kinetic regulation of coated vesicle secretion

    CERN Document Server

    Foret, Lionel

    2008-01-01

    The secretion of vesicles for intracellular transport often rely on the aggregation of specialized membrane-bound proteins into a coat able to curve cell membranes. The nucleation and growth of a protein coat is a kinetic process that competes with the energy-consuming turnover of coat components between the membrane and the cytosol. We propose a generic kinetic description of coat assembly and the formation of coated vesicles, and discuss its implication to the dynamics of COP vesicles that traffic within the Golgi and with the Endoplasmic Reticulum. We show that stationary coats of fixed area emerge from the competition between coat growth and the recycling of coat components, in a fashion resembling the treadmilling of cytoskeletal filaments. We further show that the turnover of coat components allows for a highly sensitive switching mechanism between a quiescent and a vesicle producing membrane, upon a slowing down of the exchange kinetics. We claim that the existence of this switching behaviour, also tri...

  17. Differential trypanosome surface coat regulation by a CCCH protein that co-associates with procyclin mRNA cis-elements.

    Directory of Open Access Journals (Sweden)

    Pegine Walrad

    2009-02-01

    Full Text Available The genome of Trypanosoma brucei is unusual in being regulated almost entirely at the post-transcriptional level. In terms of regulation, the best-studied genes are procyclins, which encode a family of major surface GPI-anchored glycoproteins (EP1, EP2, EP3, GPEET that show differential expression in the parasite's tsetse-fly vector. Although procyclin mRNA cis-regulatory sequences have provided the paradigm for post-transcriptional control in kinetoplastid parasites, trans-acting regulators of procyclin mRNAs are unidentified, despite intensive effort over 15 years. Here we identify the developmental regulator, TbZFP3, a CCCH-class predicted RNA binding protein, as an isoform-specific regulator of Procyclin surface coat expression in trypanosomes. We demonstrate (i that endogenous TbZFP3 shows sequence-specific co-precipitation of EP1 and GPEET, but not EP2 and EP3, procyclin mRNA isoforms, (ii that ectopic overexpression of TbZFP3 does not perturb the mRNA abundance of procyclin transcripts, but rather that (iii their protein expression is regulated in an isoform-specific manner, as evidenced by mass spectrometric analysis of the Procyclin expression signature in the transgenic cell lines. The TbZFP3 mRNA-protein complex (TbZFP3mRNP is identified as a trans-regulator of differential surface protein expression in trypanosomes. Moreover, its sequence-specific interactions with procyclin mRNAs are compatible with long-established predictions for Procyclin regulation. Combined with the known association of TbZFP3 with the translational apparatus, this study provides a long-sought missing link between surface protein cis-regulatory signals and the gene expression machinery in trypanosomes.

  18. Degradation mechanisms of the Tomato yellow leaf curl virus coat protein following inoculation of tomato plants by the whitefly Bemisia tabaci.

    Science.gov (United States)

    Gorovits, Rena; Moshe, Adi; Ghanim, Murad; Czosnek, Henryk

    2014-10-01

    Tomato yellow leaf curl virus (TYLCV) is a begomovirus infecting tomato cultures worldwide. TYLCV is transmitted to plants by the whitefly Bemisia tabaci. Once in the plant, the virus is subjected to attack by the host-plant defences, which may include sequestration in aggregates, proteolysis, ubiquitination, 26S proteasome degradation and autophagy. Elucidating how the virus avoids destruction will make it possible to understand infection and possibly devise countermeasures. The accumulation of viral coat protein (CP) and of viral DNA in plants is a marker of a successful virus transmission by B. tabaci. In response to infection, tomato tissues display multiple ways of degrading TYLCV proteins and DNA. In this study it is shown that CP (in soluble and insoluble states) is the target of protease digestion, 26S proteasome degradation and autophagy. The highest degradation capacity was detected among soluble proteins and proteins in large aggregates/inclusion bodies; cytoplasmic extracts displayed higher activity than nuclear fractions. The very same fractions possessed the highest capacity to degrade viral genomic DNA. Separately, 26S proteasome degradation was associated with large aggregates (more pronounced in the nuclear than in the cytoplasmic fractions), which are indicators of a successful abduction of plants by viruses. Autophagy/lysosome/vacuole degradation was a characteristic of intermediate aggregates, sequestering the CP in the cytoplasm and retarding the development of large aggregates. Chloroplast proteases were active in soluble as well as in insoluble protein extracts. To the best of the authors' knowledge, this study is the first attempt to identify elements of the virus-targeted degradation machinery, which is a part of the plant response to virus invasion. © 2014 Society of Chemical Industry.

  19. CONFORMATION OF A PENTACOSAPEPTIDE REPRESENTING THE RNA-BINDING N-TERMINUS OF COWPEA CHLOROTIC MOTTLE VIRUS COAT PROTEIN IN THE PRESENCE OF OLIGOPHOSPHATES - A 2-DIMENSIONAL PROTON NUCLEAR-MAGNETIC-RESONANCE AND DISTANCE GEOMETRY STUDY

    NARCIS (Netherlands)

    VANDERGRAAF, M; SCHEEK, RM; VANDERLINDEN, CC; HEMMINGA, MA

    1992-01-01

    Conformational studies were performed on a synthetic pentacosapeptide representing the RNA-binding N-terminal region of the coat protein of cowpea chlorotic mottle virus. Two-dimensional proton NMR experiments were performed on the highly positively charged peptide containing six arginines and three

  20. Hairpin plum pox virus coat protein (hpPPV-CP) structure in 'HoneySweet' C5 plum provides PPV resistance when genetically engineered into plum (Prunus domestica) seedlings

    Science.gov (United States)

    The genetically engineered plum 'HoneySweet' (aka C5) has proven to be highly resistant to Plum pox virus (PPV) for over 10 years in field trials. The original vector used for transformation to develop 'HoneySweet' carried a single sense sequence of the full length PPV coat protein (ppv-cp) gene, y...

  1. The putative Agrobacterium transcriptional activator-like virulence protein VirD5 may target T-complex to prevent the degradation of coat proteins in the plant cell nucleus.

    Science.gov (United States)

    Wang, Yafei; Peng, Wei; Zhou, Xu; Huang, Fei; Shao, Lingyun; Luo, Meizhong

    2014-09-01

    Agrobacterium exports at least five virulence proteins (VirE2, VirE3, VirF, VirD2, VirD5) into host cells and hijacks some host plant factors to facilitate its transformation process. Random DNA binding selection assays (RDSAs), electrophoretic mobility shift assays (EMSAs) and yeast one-hybrid systems were used to identify protein-bound DNA elements. Bimolecular fluorescence complementation, glutathione S-transferase pull-down and yeast two-hybrid assays were used to detect protein interactions. Protoplast transformation, coprecipitation, competitive binding and cell-free degradation assays were used to analyze the relationships among proteins. We found that Agrobacterium VirD5 exhibits transcriptional activation activity in yeast, is located in the plant cell nucleus, and forms homodimers. A specific VirD5-bound DNA element designated D5RE (VirD5 response element) was identified. VirD5 interacted directly with Arabidopsis VirE2 Interacting Protein 1 (AtVIP1). However, the ternary complex of VirD5-AtVIP1-VirE2 could be detected, whereas that of VirD5-AtVIP1-VBF (AtVIP1 Binding F-box protein) could not. We demonstrated that VirD5 competes with VBF for binding to AtVIP1 and stabilizes AtVIP1 and VirE2 in the cell-free degradation system. Our results indicated that VirD5 may act as both a transcriptional activator-like effector to regulate host gene expression and a protector preventing the coat proteins of the T-complex from being quickly degraded by the host's ubiquitin proteasome system (UPS). © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  2. Evaluación de barreras vegetales en el manejo integrado de la mancha anular del papayo (PRSV-P en Michoacán, México Evaluation of plant barriers in an integrated management of papayo ringspot in Michoacan, Mexico

    Directory of Open Access Journals (Sweden)

    Patricia Rivas-Valencia

    2008-12-01

    Full Text Available El efecto de barreras vegetales como componente de un programa de manejo integrado (MI, se validó y adaptó en 1999 en Michoacán, México, para controlar la Mancha Anular del Papayo, enfermedad causada por el Papaya ringspot potyvirus type-P (PRSV-P. Se estableció un experimento en parcelas divididas con dos factores experimentales: barreras vegetales (Hibiscus sabdariffa, y componentes de MI: MI sin aspersión de citrolina (1.5% (MI-A, MI sin eliminación de plantas con síntomas iniciales de virosis antes de floración (MI-D y MI. Las barreras vegetales sembradas 20 días antes del trasplante del papayo y el desplante retrasaron en 19 días el inicio del progreso de epidemias en el MI lo que resultó en una mayor producción (14.2% que el resto de tratamientos, aunque fue superado por MI-A en vigor (4% en diámetro de tallo. La citrolina fue fitotóxica, disminuyó el vigor de plantas (5.3% y no limitó significativamente el desarrollo de la enfermedad ya que la intensidad de las epidemias (X0 = 47días, Yf = 84% y ABCPE = 3220% días fue similar al testigo. El uso de barreras vegetales por si sola aparentemente no es suficiente para la reducción de la incidencia y dispersión de la enfermedad. Los áfidos más abundantes, con reconocida capacidad transmisora del PRSV-P, fueron Aphis gossypii, A. nerii, A. spiraecola y Macrosiphum euphorbiae, los cuales representaron aproximadamente el 13% del total de áfidos capturados.The effect of plant barriers as a component of an integrated management program (IM was validated and adapted in 1999, in Michoacan, Mexico, to control papaya ringspot, caused by papaya ringspot potyvirus type-P (PRSV-P. A split-plot design was established with two experimental factors: plant barriers and components of IM: IM without oil sprinkling (IM-O, IM without plant rouging (IM-R, and complete IM. Plant barriers (Hibiscus sabdariffa, sowed 20 days before papaya transplanting, and plant rouging delayed the epidemics

  3. Analysis of the role of the coat protein N-terminal segment in Potato virus X virion stability and functional activity.

    Science.gov (United States)

    Lukashina, Elena; Ksenofontov, Alexander; Fedorova, Natalia; Badun, Gennady; Mukhamedzhanova, Anna; Karpova, Olga; Rodionova, Nina; Baratova, Lyudmila; Dobrov, Evgeny

    2012-01-01

    Previously, we have reported that intact Potato virus X (PVX) virions cannot be translated in cell-free systems, but acquire this capacity by the binding of PVX-specific triple gene block protein 1 (TGBp1) or after phosphorylation of the exposed N-terminal segment of intravirus coat protein (CP) by protein kinases. With the help of in vitro mutagenesis, a nonphosphorylatable PVX mutant (denoted ST PVX) was prepared in which all 12 S and T residues in the 20-residue-long N-terminal CP segment were substituted by A or G. Contrary to expectations, ST PVX was infectious, produced normal progeny and was translated in vitro in the absence of any additional factors. We suggest that the N-terminal PVX CP segment somehow participates in virion assembly in vivo and that CP subunits in ST virions may differ in structure from those in the wild-type (UK3 strain). In the present work, to test this suggestion, we performed a comparative tritium planigraphy study of CP structure in UK3 and ST virions. It was found that the profile of tritium incorporation into ST mutant virions in some CP segments differed from that of normal UK3 virions and from UK3 complexed with the PVX movement protein TGBp1. It is proposed that amino acid substitutions in ST CP and the TGBp1-driven remodelling of UK3 virions induce structural alterations in intravirus CPs. These alterations affect the predicted RNA recognition motif of PVX CP, but in different ways: for ST PVX, labelling is increased in α-helices 6 and 7, whereas, in remodelled UK3, labelling is increased in the β-sheet strands β3, β4 and β5. © 2011 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2011 BSPP AND BLACKWELL PUBLISHING LTD.

  4. Molecular modeling and in-silico engineering of Cardamom mosaic virus coat protein for the presentation of immunogenic epitopes of Leptospira LipL32.

    Science.gov (United States)

    Kumar, Vikram; Damodharan, S; Pandaranayaka, Eswari P J; Madathiparambil, Madanan G; Tennyson, Jebasingh

    2016-01-01

    Expression of Cardamom mosaic virus (CdMV) coat protein (CP) in E. coli forms virus-like particles. In this study, the structure of CdMV CP was predicted and used as a platform to display epitopes of the most abundant surface-associated protein, LipL32 of Leptospira at C, N, and both the termini of CdMV CP. In silico, we have mapped sequential and conformational B-cell epitopes from the crystal structure of LipL32 of Leptospira interrogans serovar Copenhageni str. Fiocruz L1-130 using IEDB Elipro, ABCpred, BCPRED, and VaxiJen servers. Our results show that the epitopes displayed at the N-terminus of CdMV CP are promising vaccine candidates as compared to those displayed at the C-terminus or at both the termini. LipL32 epitopes, EP2, EP3, EP4, and EP6 are found to be promising B-cell epitopes for vaccine development. Based on the type of amino acids, length, surface accessibility, and docking energy with CdMV CP model, the order of antigenicity of the LipL32 epitopes was found to be EP4 > EP3 > EP2 > EP6.

  5. A Sequence-Independent, Unstructured Internal Ribosome Entry Site Is Responsible for Internal Expression of the Coat Protein of Turnip Crinkle Virus.

    Science.gov (United States)

    May, Jared; Johnson, Philip; Saleem, Huma; Simon, Anne E

    2017-04-15

    To maximize the coding potential of viral genomes, internal ribosome entry sites (IRES) can be used to bypass the traditional requirement of a 5' cap and some/all of the associated translation initiation factors. Although viral IRES typically contain higher-order RNA structure, an unstructured sequence of about 84 nucleotides (nt) immediately upstream of the Turnip crinkle virus (TCV) coat protein (CP) open reading frame (ORF) has been found to promote internal expression of the CP from the genomic RNA (gRNA) both in vitro and in vivo An absence of extensive RNA structure was predicted using RNA folding algorithms and confirmed by selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) RNA structure probing. Analysis of the IRES region in vitro by use of both the TCV gRNA and reporter constructs did not reveal any sequence-specific elements but rather suggested that an overall lack of structure was an important feature for IRES activity. The CP IRES is A-rich, independent of orientation, and strongly conserved among viruses in the same genus. The IRES was dependent on eIF4G, but not eIF4E, for activity. Low levels of CP accumulated in vivo in the absence of detectable TCV subgenomic RNAs, strongly suggesting that the IRES was active in the gRNA invivo Since the TCV CP also serves as the viral silencing suppressor, early translation of the CP from the viral gRNA is likely important for countering host defenses. Cellular mRNA IRES also lack extensive RNA structures or sequence conservation, suggesting that this viral IRES and cellular IRES may have similar strategies for internal translation initiation.IMPORTANCE Cap-independent translation is a common strategy among positive-sense, single-stranded RNA viruses for bypassing the host cell requirement of a 5' cap structure. Viral IRES, in general, contain extensive secondary structure that is critical for activity. In contrast, we demonstrate that a region of viral RNA devoid of extensive secondary

  6. Human serum-derived protein removes the need for coating in defined human pluripotent stem cell culture

    Science.gov (United States)

    Pijuan-Galitó, Sara; Tamm, Christoffer; Schuster, Jens; Sobol, Maria; Forsberg, Lars; Merry, Catherine L. R.; Annerén, Cecilia

    2016-01-01

    Reliable, scalable and time-efficient culture methods are required to fully realize the clinical and industrial applications of human pluripotent stem (hPS) cells. Here we present a completely defined, xeno-free medium that supports long-term propagation of hPS cells on uncoated tissue culture plastic. The medium consists of the Essential 8 (E8) formulation supplemented with inter-α-inhibitor (IαI), a human serum-derived protein, recently demonstrated to activate key pluripotency pathways in mouse PS cells. IαI efficiently induces attachment and long-term growth of both embryonic and induced hPS cell lines when added as a soluble protein to the medium at seeding. IαI supplementation efficiently supports adaptation of feeder-dependent hPS cells to xeno-free conditions, clonal growth as well as single-cell survival in the absence of Rho-associated kinase inhibitor (ROCKi). This time-efficient and simplified culture method paves the way for large-scale, high-throughput hPS cell culture, and will be valuable for both basic research and commercial applications. PMID:27405751

  7. O-GlcNAc modification of the coat protein of the potyvirus Plum pox virus enhances viral infection.

    Science.gov (United States)

    Pérez, José de Jesús; Udeshi, Namrata D; Shabanowitz, Jeffrey; Ciordia, Sergio; Juárez, Silvia; Scott, Cheryl L; Olszewski, Neil E; Hunt, Donald F; García, Juan Antonio

    2013-08-01

    O-GlcNAcylation is a dynamic protein modification which has been studied mainly in metazoans. We reported previously that an Arabidopsis thaliana O-GlcNAc transferase modifies at least two threonine residues of the Plum pox virus (PPV) capsid protein (CP). Now, six additional residues were shown to be involved in O-GlcNAc modification of PPV CP. CP O-GlcNAcylation was abolished in the PPV CP7-T/A mutant, in which seven threonines were mutated. PPV CP7-T/A infected Nicotiana clevelandii, Nicotiana benthamiana, and Prunus persica without noticeable defects. However, defects in infection of A. thaliana were readily apparent. In mixed infections of wild-type arabidopsis, the CP7-T/A mutant was outcompeted by wild-type virus. These results indicate that CP O-GlcNAcylation has a major role in the infection process. O-GlcNAc modification may have a role in virion assembly and/or stability as the CP of PPV CP7-T/A was more sensitive to protease digestion than that of the wild-type virus. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Nucleotide and amino acid sequences of a coat protein of an Ukrainian isolate of Potato virus Y: comparison with homologous sequences of other isolates and phylogenetic analysis

    Directory of Open Access Journals (Sweden)

    Budzanivska I. G.

    2014-03-01

    Full Text Available Aim. Identification of the widespread Ukrainian isolate(s of PVY (Potato virus Y in different potato cultivars and subsequent phylogenetic analysis of detected PVY isolates based on NA and AA sequences of coat protein. Methods. ELISA, RT-PCR, DNA sequencing and phylogenetic analysis. Results. PVY has been identified serologically in potato cultivars of Ukrainian selection. In this work we have optimized a method for total RNA extraction from potato samples and offered a sensitive and specific PCR-based test system of own design for diagnostics of the Ukrainian PVY isolates. Part of the CP gene of the Ukrainian PVY isolate has been sequenced and analyzed phylogenetically. It is demonstrated that the Ukrainian isolate of Potato virus Y (CP gene has a higher percentage of homology with the recombinant isolates (strains of this pathogen (approx. 98.8– 99.8 % of homology for both nucleotide and translated amino acid sequences of the CP gene. The Ukrainian isolate of PVY is positioned in the separate cluster together with the isolates found in Syria, Japan and Iran; these isolates possibly have common origin. The Ukrainian PVY isolate is confirmed to be recombinant. Conclusions. This work underlines the need and provides the means for accurate monitoring of Potato virus Y in the agroecosystems of Ukraine. Most importantly, the phylogenetic analysis demonstrated the recombinant nature of this PVY isolate which has been attributed to the strain group O, subclade N:O.

  9. Citrus psorosis virus coat protein-derived hairpin construct confers stable transgenic resistance in citrus against psorosis A and B syndromes.

    Science.gov (United States)

    De Francesco, A; Costa, N; García, M L

    2017-04-01

    Citrus psorosis virus (CPsV) is the causal agent of psorosis, a serious and widespread citrus disease. Two syndromes of psorosis, PsA and PsB, have been described. PsB is the most aggressive and rampant form. Previously, we obtained Pineapple sweet orange plants transformed with a hairpin construct derived from the CPsV coat protein gene (ihpCP). Some of these plants were resistant to CPsV 90-1-1, a PsA isolate homologous to the transgene. In this study, we found that expression of the ihpCP transgene and siRNA production in lines ihpCP-10 and -15 were stable with time and propagation. In particular, line ihpCP-15 has been resistant for more than 2 years, even after re-inoculation. The ihpCP plants were also resistant against a heterologous CPsV isolate that causes severe PsB syndrome. Line ihpCP-15 manifested complete resistance while line ihpCP-10 was tolerant to the virus, although with variable behaviour, showing delay and attenuation in PsB symptoms. These lines are promising for a biotech product aimed at eradicating psorosis.

  10. The intrinsically disordered N-terminal arm of the brome mosaic virus coat protein specifically recognizes the RNA motif that directs the initiation of viral RNA replication.

    Science.gov (United States)

    Jacobs, Alexander; Hoover, Haley; Smith, Edward; Clemmer, David E; Kim, Chul-Hyun; Kao, C Cheng

    2018-01-09

    In the brome mosaic virus (BMV) virion, the coat protein (CP) selectively contacts the RNA motifs that regulate translation and RNA replication (Hoover et al., 2016. J. Virol. 90, 7748). We hypothesize that the unstructured N-terminal arm (NTA) of the BMV CP can specifically recognize RNA motifs. Using ion mobility spectrometry-mass spectrometry, we demonstrate that peptides containing the NTA of the CP were found to preferentially bind to an RNA hairpin motif that directs the initiation of BMV RNA synthesis. RNA binding causes the peptide to change from heterogeneous structures to a single family of structures. Fluorescence anisotropy, fluorescence quenching and size exclusion chromatography experiments all confirm that the NTA can specific recognize the RNA motif. The peptide introduced into plants along with BMV virion increased accumulation of the BMV CP and accelerated the rate of minus-strand RNA synthesis. The intrinsically disordered BMV NTA could thus specifically recognize BMV RNAs to affect viral infection. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Characterization of Citrus tristeza virus strains from southern China based on analysis of restriction patterns and sequences of their coat protein genes.

    Science.gov (United States)

    Jiang, Bo; Hong, Ni; Wang, Guo-Ping; Hu, John; Zhang, Jian-Kun; Wang, Cai-Xia; Liu, Yong; Fan, Xu-Dong

    2008-10-01

    Citrus tristeza virus (CTV) isolates collected from southern China were characterized by biological indexing on citrus indicators, restriction fragment length polymorphism (RFLP), and bi-directional reverse transcription-polymerase chain reaction (BD-PCR) analysis of their coat protein (CP) genes. Of the 30 isolates, only two isolates, N3 and N4, did not induce visible symptoms. Twenty-eight other isolates induced stem pitting and vein clearing, plant stunting, and leaf yellowing symptoms on Mexican lime, Duncan grapefruit, and sour orange seedlings. In BD-PCR analysis, a 392-bp fragment specific for the mild strains was amplified from isolates N3 and N4, and a 320-bp fragment specific for the severe strains was produced from the other 28 isolates. The RFLP analysis for RT-PCR products of the CP gene with restriction enzyme HinfI identified seven groups representing groups I-VI and a new group, which was not involved in the seven groups defined by Gillings (J Virol Methods 44:305-317, 1993). The sequences of the CP genes from 12 Chinese CTV isolates showed a high divergence, with 91.5-99.7% identities at the nucleotide level and 94.2-99.6% identities at the amino acid level. Our results suggest that the composition of CTV populations from China has a high genetic diversity in the CP gene.

  12. Diverse amino acid changes at specific positions in the N-terminal region of the coat protein allow Plum pox virus to adapt to new hosts.

    Science.gov (United States)

    Carbonell, Alberto; Maliogka, Varvara I; Pérez, José de Jesús; Salvador, Beatriz; León, David San; García, Juan Antonio; Simón-Mateo, Carmen

    2013-10-01

    Plum pox virus (PPV)-D and PPV-R are two isolates from strain D of PPV that differ in host specificity. Previous analyses of chimeras originating from PPV-R and PPV-D suggested that the N terminus of the coat protein (CP) includes host-specific pathogenicity determinants. Here, these determinants were mapped precisely by analyzing the infectivity in herbaceous and woody species of chimeras containing a fragment of the 3' region of PPV-D (including the region coding for the CP) in a PPV-R backbone. These chimeras were not infectious in Prunus persica, but systemically infected Nicotiana clevelandii and N. benthamiana when specific amino acids were modified or deleted in a short 30-amino-acid region of the N terminus of the CP. Most of these mutations did not reduce PPV fitness in Prunus spp. although others impaired systemic infection in this host. We propose a model in which the N terminus of the CP, highly relevant for virus systemic movement, is targeted by a host defense mechanism in Nicotiana spp. Mutations in this short region allow PPV to overcome the defense response in this host but can compromise the efficiency of PPV systemic movement in other hosts such as Prunus spp.

  13. Label-free fluorescent detection of thrombin activity based on a recombinant enhanced green fluorescence protein and nickel ions immobilized nitrilotriacetic acid-coated magnetic nanoparticles.

    Science.gov (United States)

    Wang, Ming; Lei, Chunyang; Nie, Zhou; Guo, Manli; Huang, Yan; Yao, Shouzhuo

    2013-11-15

    Herein, a novel label-free fluorescent assay has been developed to detect the activity of thrombin and its inhibitor, based on a recombinant enhanced green fluorescence protein (EGFP) and Ni(2+) ions immobilized nitrilotriacetic acid-coated magnetic nanoparticles (Ni(2+)-NTA MNPs). The EGFP, containing a thrombin cleavage site and a hexahistidine sequence (His-tag) at its N-terminal, was adsorbed onto Ni(2+)-NTA MNPs through Ni(2+)-hexahistidine interaction, and dragged out of the solution by magnetic separation. Thrombin can selectively digest EGFP accompanied by His-tag peptide sequence leaving, and the resulting EGFP cannot be captured by Ni(2+)-NTA MNPs and kept in supernatant. Hence the fluorescence change of supernatant can clearly represent the activity of thrombin. Under optimized conditions, such assay showed a relatively low detection limit (3.0×10(-4) U mL(-1)), and was also used to detect the thrombin inhibitor, Hirudin, and further applied to detect thrombin activity in serum. Combined with the satisfactory reusability of Ni(2+)-NTA MNPs, our method presents a promising candidate for simple, sensitive, and cost-saving protease activity detecting and inhibitor screening. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. The determinant of potyvirus ability to overcome the RTM resistance of Arabidopsis thaliana maps to the N-terminal region of the coat protein.

    Science.gov (United States)

    Decroocq, V; Salvador, B; Sicard, O; Glasa, M; Cosson, P; Svanella-Dumas, L; Revers, F; García, J A; Candresse, T

    2009-10-01

    In Arabidopsis thaliana Columbia (Col-0) plants, the restriction of Tobacco etch virus (TEV) long-distance movement involves at least three dominant RTM (restricted TEV movement) genes named RTM1, RTM2, and RTM3. Previous work has established that, while the RTM-mediated resistance is also effective against other potyviruses, such as Plum pox virus (PPV) and Lettuce mosaic virus (LMV), some isolates of these viruses are able to overcome the RTM mechanism. In order to identify the viral determinant of this RTM-resistance breaking, the biological properties of recombinants between PPV-R, which systemically infects Col-0, and PPV-PSes, restricted by the RTM resistance, were evaluated. Recombinants that contain the PPV-R coat protein (CP) sequence in an RTM-restricted background are able to systemically infect Col-0. The use of recombinants carrying chimeric CP genes indicated that one or more PPV resistance-breaking determinants map to the 5' half of the CP gene. In the case of LMV, sequencing of independent RTM-breaking variants recovered after serial passages of the LMV AF199 isolate on Col-0 plants revealed, in each case, amino acid changes in the CP N-terminal region, close to the DAG motif. Taken together, these findings demonstrate that the potyvirus CP N-terminal region determines the outcome of the interaction with the RTM-mediated resistance.

  15. Mimicking filtration and transport of rotavirus and adenovirus in sand media using DNA-labeled, protein-coated silica nanoparticles.

    Science.gov (United States)

    Pang, Liping; Farkas, Kata; Bennett, Grant; Varsani, Arvind; Easingwood, Richard; Tilley, Richard; Nowostawska, Urszula; Lin, Susan

    2014-10-01

    Rotavirus (RoV) and adenovirus (AdV) are important viral pathogens for the risk analysis of drinking water. Despite this, little is known about their retention and transport behaviors in porous media due to a lack of representative surrogates. We developed RoV and AdV surrogates by covalently coupling 70-nm sized silica nanoparticles with specific proteins and a DNA marker for sensitive detection. Filtration experiments using beach sand columns demonstrated the similarity of the surrogates' concentrations, filtration efficiencies and attachment kinetics to those of the target viruses. The surrogates showed the same magnitude of concentration reduction as the viruses. Conversely, MS2 phage (a traditional virus model) over-predicted concentrations of AdV and RoV by 1- and 2-orders of magnitude respectively. The surrogates remained stable in size, surface charge and DNA concentration for at least one year. They can be easily and rapidly detected down to a single particle. Preliminary tests suggest that they were readily detectable in a number of environmental waters and treated effluent. With up-scaling validation in pilot trials, the surrogates developed here could be a cost-effective new tool for studying virus retention and transport in porous media. Examples include assessing filter efficacy in water and wastewater treatment, tracking virus migration in groundwater after effluent land disposal, and establishing safe setback distances for groundwater protection. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Plasma treatment induces internal surface modifications of electrospun poly(L-lactic) acid scaffold to enhance protein coating

    Energy Technology Data Exchange (ETDEWEB)

    Jin Seo, Hyok; Hee Lee, Mi; Kwon, Byeong-Ju; Kim, Hye-Lee; Park, Jong-Chul [Cellbiocontrol Laboratory, Department of Medical Engineering, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Jin Lee, Seung [Department of Industrial Pharmacy, College of Pharmacy, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Kim, Bong-Jin; Wang, Kang-Kyun; Kim, Yong-Rok [Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749 (Korea, Republic of)

    2013-08-21

    Advanced biomaterials should also be bioactive with regard to desirable cellular responses, such as selective protein adsorption and cell attachment, proliferation, and differentiation. To enhance cell-material interactions, surface modifications have commonly been performed. Among the various surface modification approaches, atmospheric pressure glow discharge plasma has been used to change a hydrophobic polymer surface to a hydrophilic surface. Poly(L-lactic acid) (PLLA)-derived scaffolds lack cell recognition signals and the hydrophobic nature of PLLA hinders cell seeding. To make PLLA surfaces more conducive to cell attachment and spreading, surface modifications may be used to create cell-biomaterial interfaces that elicit controlled cell adhesion and maintain differentiated phenotypes. In this study, (He) gaseous atmospheric plasma glow discharge was used to change the characteristics of a 3D-type polymeric scaffold from hydrophobic to hydrophilic on both the outer and inner surfaces of the scaffold and the penetration efficiency with fibronectin was investigated. Field-emission scanning electron microscope images showed that some grooves were formed on the PLLA fibers after plasma treatment. X-ray photoelectron spectroscopy data also showed chemical changes in the PLLA structure. After plasma treatment, -CN (285.76 eV) was increased in C1s and -NH{sub 2} (399.70 eV) was increased significantly and –N=CH (400.80 eV) and –NH{sub 3}{sup +} (402.05 eV) were newly appeared in N1s. These changes allowed fibronectin to penetrate into the PLLA scaffold; this could be observed by confocal microscopy. In conclusion, helium atmospheric pressure plasma treatment was effective in modifying the polymeric scaffold, making it hydrophilic, and this treatment can also be used in tissue engineering research as needed to make polymers hydrophilic.

  17. Hibiscus chlorotic ringspot virus coat protein is essential for cell-to-cell and long-distance movement but not for viral RNA replication.

    Directory of Open Access Journals (Sweden)

    Shengniao Niu

    Full Text Available Hibiscus chlorotic ringspot virus (HCRSV is a member of the genus Carmovirus in the family Tombusviridae. In order to study its coat protein (CP functions on virus replication and movement in kenaf (Hibiscus cannabinus L., two HCRSV mutants, designated as p2590 (A to G in which the first start codon ATG was replaced with GTG and p2776 (C to G in which proline 63 was replaced with alanine, were constructed. In vitro transcripts of p2590 (A to G were able to replicate to a similar level as wild type without CP expression in kenaf protoplasts. However, its cell-to-cell movement was not detected in the inoculated kenaf cotyledons. Structurally the proline 63 in subunit C acts as a kink for β-annulus formation during virion assembly. Progeny of transcripts derived from p2776 (C to G was able to move from cell-to-cell in inoculated cotyledons but its long-distance movement was not detected. Virions were not observed in partially purified mutant virus samples isolated from 2776 (C to G inoculated cotyledons. Removal of the N-terminal 77 amino acids of HCRSV CP by trypsin digestion of purified wild type HCRSV virions resulted in only T = 1 empty virus-like particles. Taken together, HCRSV CP is dispensable for viral RNA replication but essential for cell-to-cell movement, and virion is required for the virus systemic movement. The proline 63 is crucial for HCRSV virion assembly in kenaf plants and the N-terminal 77 amino acids including the β-annulus domain is required in T = 3 assembly in vitro.

  18. An examination of the electrostatic interactions between the N-terminal tail of the Brome Mosaic Virus coat protein and encapsidated RNAs.

    Science.gov (United States)

    Ni, Peng; Wang, Zhao; Ma, Xiang; Das, Nayaran Chandra; Sokol, Paul; Chiu, Wah; Dragnea, Bogdan; Hagan, Michael; Kao, C Cheng

    2012-06-22

    The coat protein of positive-stranded RNA viruses often contains a positively charged tail that extends toward the center of the capsid and interacts with the viral genome. Electrostatic interaction between the tail and the RNA has been postulated as a major force in virus assembly and stabilization. The goal of this work is to examine the correlation between electrostatic interaction and amount of RNA packaged in the tripartite Brome Mosaic Virus (BMV). Nanoindentation experiment using atomic force microscopy showed that the stiffness of BMV virions with different RNAs varied by a range that is 10-fold higher than that would be predicted by electrostatics. BMV mutants with decreased positive charges encapsidated lower amounts of RNA while mutants with increased positive charges packaged additional RNAs up to ∼900 nt. However, the extra RNAs included truncated BMV RNAs, an additional copy of RNA4, potential cellular RNAs, or a combination of the three, indicating that change in the charge of the capsid could result in several different outcomes in RNA encapsidation. In addition, mutant with specific arginines changed to lysines in the capsid also exhibited defects in the specific encapsidation of BMV RNA4. The experimental results indicate that electrostatics is a major component in RNA encapsidation but was unable to account for all of the observed effects on RNA encapsidation. Thermodynamic modeling incorporating the electrostatics was able to predict the approximate length of the RNA to be encapsidated for the majority of mutant virions, but not for a mutant with extreme clustered positive charges. Cryo-electron microscopy of virions that encapsidated an additional copy of RNA4 revealed that, despite the increase in RNA encapsidated, the capsid structure was minimally changed. These results experimentally demonstrated the impact of electrostatics and additional restraints in the encapsidation of BMV RNAs, which could be applicable to other viruses. Copyright

  19. Three-dimensional structure of victorivirus HvV190S suggests coat proteins in most totiviruses share a conserved core.

    Directory of Open Access Journals (Sweden)

    Sarah E Dunn

    2013-03-01

    Full Text Available Double-stranded (dsRNA fungal viruses are currently assigned to six different families. Those from the family Totiviridae are characterized by nonsegmented genomes and single-layer capsids, 300-450 Å in diameter. Helminthosporium victoriae virus 190S (HvV190S, prototype of recently recognized genus Victorivirus, infects the filamentous fungus Helminthosporium victoriae (telomorph: Cochliobolus victoriae, which is the causal agent of Victoria blight of oats. The HvV190S genome is 5179 bp long and encompasses two large, slightly overlapping open reading frames that encode the coat protein (CP, 772 aa and the RNA-dependent RNA polymerase (RdRp, 835 aa. To our present knowledge, victoriviruses uniquely express their RdRps via a coupled termination-reinitiation mechanism that differs from the well-characterized Saccharomyces cerevisiae virus L-A (ScV-L-A, prototype of genus Totivirus, in which the RdRp is expressed as a CP/RdRp fusion protein due to ribosomal frameshifting. Here, we used transmission electron cryomicroscopy and three-dimensional image reconstruction to determine the structures of HvV190S virions and two types of virus-like particles (capsids lacking dsRNA and capsids lacking both dsRNA and RdRp at estimated resolutions of 7.1, 7.5, and 7.6 Å, respectively. The HvV190S capsid is thin and smooth, and contains 120 copies of CP arranged in a "T = 2" icosahedral lattice characteristic of ScV-L-A and other dsRNA viruses. For aid in our interpretations, we developed and used an iterative segmentation procedure to define the boundaries of the two, chemically identical CP subunits in each asymmetric unit. Both subunits have a similar fold, but one that differs from ScV-L-A in many details except for a core α-helical region that is further predicted to be conserved among many other totiviruses. In particular, we predict the structures of other victoriviruses to be highly similar to HvV190S and the structures of most if not all

  20. Initial preclinical safety of non-replicating human endogenous retrovirus envelope protein-coated baculovirus vector-based vaccines against human papillomavirus.

    Science.gov (United States)

    Han, Su-Eun; Kim, Mi-Gyeong; Lee, Soondong; Cho, Hee-Jeong; Byun, Youngro; Kim, Sujeong; Kim, Young Bong; Choi, Yongseok; Oh, Yu-Kyoung

    2013-12-01

    Human endogenous retrovirus (HERV) envelope protein-coated, baculovirus vector-based HPV 16 L1 (AcHERV-HPV16L1) is a non-replicating recombinant baculoviral vaccine. Here, we report an initial evaluation of the preclinical safety of AcHERV-HPV16L1 vaccine. In an acute toxicity study, a single administration of AcHERV-HPV16L1 DNA vaccine given intramuscularly (i.m.) to mice at a dose of 1 × 10(8) plaque-forming units (PFU) did not cause significant changes in body weight compared with vehicle-treated controls. It did cause a brief increase in the weights of some organs on day 15 post-treatment, but by day 30, all organ weights were not significantly different from those in the vehicle-treated control group. No hematological changes were observed on day 30 post-treatment. In a range-finding toxicity study with three doses of 1 × 10(7) , 2 × 10(7) and 5 × 10(7) PFU once daily for 5 days, the group treated with 5 × 10(7) PFU showed a transient decrease in the body weights from day 5 to day 15 post-treatment, but recovery to the levels similar to those in the vehicle-treated control group by post-treatment day 20. Organ weights were slightly higher for lymph nodes, spleen, thymus and liver after repeated dosing with 5 × 10(7) PFU on day 15, but had normalized by day 30. Moreover, repeated administration of AcHERV-HPV16L1 did not induce myosin-specific autoantibody in serum, and did not cause immune complex deposition or tissue damage at injection sites. Taken together, these results provide preliminary evidence of the preclinical safety of AcHERV-based HPV16L1 DNA vaccines in mice. Copyright © 2012 John Wiley & Sons, Ltd.

  1. Material Science Smart Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, A. I. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Sabirianov, R. F. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Namavar, Fereydoon [Univ. of Nebraska Medical Center, Omaha, NE (United States)

    2014-07-01

    The contribution of electrostatic interactions to the free energy of binding between model protein and a ceramic implant surface in the aqueous solvent, considered in the framework of the nonlocal electrostatic model, is calculated as a function of the implant low-frequency dielectric constant. We show that the existence of a dynamically ordered (low-dielectric) interfacial solvent layer at the protein-solvent and ceramic-solvent interface markedly increases charging energy of the protein and ceramic implant, and consequently makes the electrostatic contribution to the protein-ceramic binding energy more favorable (attractive). Our analysis shows that the corresponding electrostatic energy between protein and oxide ceramics depends nonmonotonically on the dielectric constant of ceramic, εC. Obtained results indicate that protein can attract electrostatically to the surface if ceramic material has a moderate εC below or about 35 (in particularly ZrO2 or Ta2O5). This is in contrast to classical (local) consideration of the solvent, which demonstrates an unfavorable electrostatic interaction of protein with typical metal oxide ceramic materials (εC>10). Thus, a solid implant coated by combining oxide ceramic with a reduced dielectric constant can be beneficial to strengthen the electrostatic binding of the protein-implant complex.

  2. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Intense UV photoluminescence is observed for intrinsic ZnO film. Keywords : thin films, oxidize zinc doped aluminium (ZnO:Al), sol-gel, spin coating, structural analysis, electric and optical properties. 1. Introduction. Depuis ces vingt dernières années les couches minces d'oxyde de zinc ont connu un intérêt croissant dans ...

  3. Silica-Coated Liposomes for Insulin Delivery

    Directory of Open Access Journals (Sweden)

    Neelam Dwivedi

    2010-01-01

    Full Text Available Liposomes coated with silica were explored as protein delivery vehicles for their enhanced stability and improved encapsulation efficiency. Insulin was encapsulated within the fluidic phosphatidylcholine lipid vesicles by thin film hydration at pH 2.5, and layer of silica was formed above lipid bilayer by acid catalysis. The presence of silica coating and encapsulated insulin was identified using confocal and electron microscopy. The native state of insulin present in the formulation was evident from Confocal Micro-Raman spectroscopy. Silica coat enhances the stability of insulin-loaded delivery vehicles. In vivo study shows that these silica coated formulations were biologically active in reducing glucose levels.

  4. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Dans ce travail nous avons préparé des couches minces de l'oxyde de zinc ZnO dopées à l'aluminium et non dopées par la technique Sol-Gel associée au « spin coating » sur des substrats en verre « pyrex » à partir de l'acétate de zinc dissous dans une solution de l'éthanol. Nous avons ensuite effectué des analyses ...

  5. Eps15R is a tyrosine kinase substrate with characteristics of a docking protein possibly involved in coated pits-mediated internalization

    DEFF Research Database (Denmark)

    Coda, L; Salcini, A E; Confalonieri, S

    1998-01-01

    eps15R was identified because of its relatedness to eps15, a gene encoding a tyrosine kinase substrate bearing a novel protein-protein interaction domain, called EH. In this paper, we report a biochemical characterization of the eps15R gene product(s). In NIH-3T3 cells, three proteins of 125, 108...

  6. Potential threat of a new pathotype of Papaya leaf distortion mosaic virus infecting transgenic papaya resistant to Papaya ringspot virus.

    Science.gov (United States)

    Bau, H-J; Kung, Y-J; Raja, J A J; Chan, S-J; Chen, K-C; Chen, Y-K; Wu, H-W; Yeh, S-D

    2008-07-01

    A virus identified as a new pathotype of Papaya leaf distortion mosaic virus (PLDMV, P-TW-WF) was isolated from diseased papaya in an isolated test-field in central Taiwan, where transgenic papaya lines resistant to Papaya ringspot virus (PRSV) were evaluated. The infected plants displayed severe mosaic, distortion and shoe-stringing on leaves; stunting in apex; and water-soaking on petioles and stems. This virus, which did not react in enzyme-linked immunosorbent assay with the antiserum to the PRSV coat protein, infected only papaya, but not the other 18 plant species tested. Virions studied under electron microscope exhibited morphology and dimensions of potyvirus particles. Reverse transcription-polymerase chain reaction conducted using potyvirus-specific primers generated a 1,927-nucleotide product corresponding to the 3' region of a potyvirus, showing high sequence identity to the CP gene and 3' noncoding region of PLDMV. Search for similar isolates with the antiserum against CP of P-TW-WF revealed scattered occurrence of PLDMV in Taiwan. Phylogenetic analysis of PLDMV isolates of Taiwan and Japan indicated that the Taiwan isolates belong to a separate genetic cluster. Since all the Taiwan isolates infected only papaya, unlike the cucurbit-infecting Japanese P type isolates, the Taiwan isolates are considered a new pathotype of PLDMV. Susceptibility of all our PRSV-resistant transgenic papaya lines to PLDMV indicates that the virus is an emerging threat for the application of PRSV-resistant transgenic papaya in Taiwan and elsewhere.

  7. Architecture and Assembly of the Bacillus subtilis Spore Coat

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  8. Architecture and assembly of the Bacillus subtilis spore coat.

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of "nanodot" particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  9. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  10. Graphene Coatings

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Bøggild, Peter

    2014-01-01

    Owing to its remarkable electrical and mechanical properties, graphene has been attracting tremendous interest in materials science. In particular, its chemical stability and impermeability make it a promising protective membrane. However, recent investigations reveal that single layer graphene...... cannot be used as a barrier in the long run, due to galvanic corrosion phenomena arising when oxygen or water penetrate through graphene cracks or domain boundaries. Here, we overcome this issue by using a multilayered (ML) graphene coating. Our lab- as well as industrial-scale tests demonstrate that ML...... graphene can effectively protect Ni in harsh environments, even after long term exposure. This is made possible by the presence of a high number of graphene layers, which can efficiently mask the cracks and domain boundaries defects found in individual layers of graphene. Our findings thus show...

  11. Controlled-release of bone morphogenetic protein-2 from a microsphere coating applied to acid-etched Ti6AL4V implants increases biological bone growth in vivo.

    Science.gov (United States)

    Fu, Yangmu; Zhang, Qiang; Sun, Yong; Liao, Weixiong; Bai, Xiaowei; Zhang, Lili; Du, Lina; Jin, Yiguang; Wang, Qi; Li, Zhongli; Wang, Yan

    2014-06-01

    A central clinical challenge regarding the surgical treatment of bone and joint conditions is the eventual loosening of an orthopedic implant as a result of insufficient bone ingrowth at the bone-implant interface. We investigated the in vivo effectiveness of a coating containing recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded microspheres applied to acid-etched Ti6Al4V cylinders for implantation. Three groups of rabbits (24 per group) were used for implantation: (1) acid-etched Ti6Al4V implants coated with a mixture of rhBMP-2-loaded microspheres (125 ng rhBMP-2/mg microspheres) and α-butyl cyanoacrylate; (2) acid-etched, uncoated implants; and (3) bare, smooth uncoated implants. After implantation, 12 rabbits from each group were used for bone ingrowth determination at 4, 5, 6, 7, 8, and 12 weeks (2 rabbits per time point), while the remainder were used for histological analysis and push-out testing at 12 weeks. Scanning electron microscopy showed significant improvement in bone growth of the rhBMP-2 microspheres/α-butyl cyanoacrylate group compared with the other groups (p<0.01). Histological analysis and push-out testing also demonstrated enhanced bone growth of the rhBMP-2 group over that in the other two groups (p<0.01). The rhBMP-2 group showed the most significant bone growth, suggesting that coating acid-etched implants with a mixture of rhBMP-2-loaded microspheres and α-butyl cyanoacrylate may be an effective method to improve the osseointegration of orthopedic implants. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. Electrocurtain coating process for coating solar mirrors

    Science.gov (United States)

    Kabagambe, Benjamin; Boyd, Donald W.; Buchanan, Michael J.; Kelly, Patrick; Kutilek, Luke A.; McCamy, James W.; McPheron, Douglas A.; Orosz, Gary R.; Limbacher, Raymond D.

    2013-10-15

    An electrically conductive protective coating or film is provided over the surface of a reflective coating of a solar mirror by flowing or directing a cation containing liquid and an anion containing liquid onto the conductive surface. The cation and the anion containing liquids are spaced from, and preferably out of contact with one another on the surface of the reflective coating as an electric current is moved through the anion containing liquid, the conductive surface between the liquids and the cation containing liquid to coat the conductive surface with the electrically conductive coating.

  13. Conditional lethal mutations separate the M13 procoat and Pf3 coat functions of YidC - Different YidC structural requirements for membrane protein insertion

    NARCIS (Netherlands)

    Chen, MY; Xie, K; Nouwen, N; Driessen, AJM; Dalbey, RE; Dalbey, Ross E.

    2003-01-01

    Conditional lethal YidC mutants have been isolated to decipher the role of YidC in the assembly of Sec-dependent and Sec-independent membrane proteins. We now show that the membrane insertion of the Sec-independent M13 procoat-lep protein is inhibited in a short time in a temperature-sensitive

  14. Direct patterning of probe proteins on an antifouling PLL-g-dextran coating for reducing the background signal of fluorescent immunoassays.

    Science.gov (United States)

    Egea, Amandine M C; Trévisiol, Emmanuelle; Vieu, Christophe

    2013-12-01

    The limit of detection of advanced immunoassays, biochips and micro/nano biodetection devices is impacted by the non-specific adsorption of target molecules at the sample surface. In this paper, we present a simple and versatile low cost method for generating active surfaces composed of antibodies arrays surrounded by an efficient anti-fouling layer, capable to decrease drastically the fluorescence background signal obtained after interaction with a solution to be analyzed. The technological process involves the direct micro-contact printing of the antibodies probe molecules on a pre-coated PLL-g-dextran thin layer obtained by contact printing using a flat PDMS stamp. Compared to other blocking strategies (ethanolamine blocking treatment, PLL-g-PEG incubation, PLL-g-dextran incubation, printing on a plasma-deposited PEO layer), our surface chemistry method is more efficient for reducing non-specific interactions responsible for a degraded signal/noise ratio.

  15. Coating formation during drying of ß-lactoglobulin: Gradual and sudden changes

    NARCIS (Netherlands)

    Bouman, J.; Vries, de R.J.; Venema, P.; Belton, P.; Baukh, V.; Huinink, H.; Linden, van der E.

    2015-01-01

    The drying dynamics of protein coatings is of importance for many applications. The main focus of research so far was to investigate macroscopic properties of protein coatings, leaving drying dynamics virtually unexplored. A unique combination of techniques is used to monitor drying of a coating

  16. Flow coating apparatus and method of coating

    Science.gov (United States)

    Hanumanthu, Ramasubrahmaniam; Neyman, Patrick; MacDonald, Niles; Brophy, Brenor; Kopczynski, Kevin; Nair, Wood

    2014-03-11

    Disclosed is a flow coating apparatus, comprising a slot that can dispense a coating material in an approximately uniform manner along a distribution blade that increases uniformity by means of surface tension and transfers the uniform flow of coating material onto an inclined substrate such as for example glass, solar panels, windows or part of an electronic display. Also disclosed is a method of flow coating a substrate using the apparatus such that the substrate is positioned correctly relative to the distribution blade, a pre-wetting step is completed where both the blade and substrate are completed wetted with a pre-wet solution prior to dispensing of the coating material onto the distribution blade from the slot and hence onto the substrate. Thereafter the substrate is removed from the distribution blade and allowed to dry, thereby forming a coating.

  17. Niobium pentoxide coating replacing zinc phosphate coating

    OpenAIRE

    RODRIGUES, P.R.P.; TERADA, M.; JUNIOR, O.R.A.; LOPES, A.C.; COSTA, I.; BANCZEK, E.P.

    2015-01-01

    A new coating made of niobium pentoxide, obtained through the sol-gel process, was developed for the carbon steel (SAE 1010). The corrosion protection provided by this coating was evaluated through electrochemical tests such as: open circuit potential, electrochemical impedance spectroscopy and anodic potentiodynamic polarization in NaCl 0,5 mol L-1 solution. The morphology and composition of the coatings were analyzed using scanning electronic microscopy, energy dispersive spectroscopy and X...

  18. Evaluation of Biological Toxicity of CdTe Quantum Dots with Different Coating Reagents according to Protein Expression of Engineering Escherichia coli

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2015-01-01

    Full Text Available The results obtained from toxicity assessment of quantum dots (QDs can be used to establish guidelines for the application of QDs in bioimaging. This paper focused on the design of a novel method to evaluate the toxicity of CdTe QDs using engineering Escherichia coli as a model. The toxicity of mercaptoacetic acid (MPA, glutathione (GSH, and L-cysteine (Cys capped CdTe QDs was analyzed according to the heterologous protein expression in BL21/DE3, engineering Escherichia coli extensively used for protein expression. The results showed that the MPA-CdTe QDs had more serious toxicity than the other two kinds of CdTe QDs. The microscopic images and SEM micrographs further proved that both the proliferation and the protein expression of engineering Escherichia coli were inhibited after treatment with MPA-CdTe QDs. The proposed method is important to evaluate biological toxicity of both QDs and other nanoparticles.

  19. Co-delivery of platelet-derived growth factor (PDGF-BB) and bone morphogenic protein (BMP-2) coated onto heparinized titanium for improving osteoblast function and osteointegration.

    Science.gov (United States)

    Kim, Sung Eun; Yun, Young-Pil; Lee, Jae Yong; Shim, June-Sung; Park, Kyeongsoon; Huh, Jung-Bo

    2015-12-01

    The aim of this study was to improve osteoblast function by delivering two growth factors, PDGF-BB and BMP-2, incorporated onto heparinized titanium (Hep-Ti) substrate. To achieve co-delivery of PDGF-BB and BMP-2, the surface of anodized Ti was immobilized with heparin, and then the two growth factors were coated onto the Hep-Ti surface. Incorporation of the two growth factors onto Hep-Ti was evaluated by SEM and XPS. Incorporated PDGF-BB and BMP-2 were released from the Hep-Ti substrate in a sustained manner. In vitro studies revealed that osteoblasts grown on PDGF-BB- and BMP-2-immobilized Hep-Ti increased ALP activity, calcium deposition, osteocalcin and osteopontin levels as compared to those grown on PDGF-BB alone- or BMP-2 alone-immobilized Hep-Ti. These results suggested that co-delivery of PDGF-BB and BMP-2 using Hep-Ti substrate will be a promising material for the enhancement of osteoblast function and osteointegration. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Species specific identification of spore-producing microbes using the gene sequence of small acid-soluble spore coat proteins for amplification based diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, Nancy (Decatur, GA)

    2002-01-01

    PCR (polymerase chain reaction) primers for the detection of certain Bacillus species, such as Bacillus anthracis. The primers specifically amplify only DNA found in the target species and can distinguish closely related species. Species-specific PCR primers for Bacillus anthracis, Bacillus globigii and Clostridium perfringens are disclosed. The primers are directed to unique sequences within sasp (small acid soluble protein) genes.

  1. Laser structuring of carbon nanoframe in a protein matrix for the creation of 3D composite materials and coatings for applications in tissue engineering

    Science.gov (United States)

    Gerasimenko, Alexander Yu.; Glukhova, Olga E.; Savostyanov, Georgy V.; Savelyev, Mikhail S.; Ichkitidze, Levan P.; Masloboev, Yurii P.; Selishchev, Sergey V.; Podgaetsky, Vitaly M.

    2017-07-01

    The results of experimental creation of nanocomposites using femtosecond laser are presented. We have theoretically proved the formation of a carbon nanotube frame in a protein matrix during laser structuring of single-walled carbon nanotubes. We have selected the technological parameters of synthesis of nanocomposites, which provide the proliferation of living cells.

  2. European coatings conference - Marine coatings. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This volume contains 13 lectures (manuscripts or powerpoint foils) with the following topics: 1. Impact of containerization on polyurethane and polyurea in marine and protective coatings (Malte Homann); 2. The application of combinatorial/high-throughput methods to the development of marine coatings (Bret Chisholm); 3. Progress and perspectives in the AMBIO (advanced nanostructured surfaces for the control of biofouling) Project (James Callow); 4. Release behaviour due to shear and pull-off of silicone coatings with a thickness gradient (James G. Kohl); 5. New liquid rheology additives for high build marine coatings (Andreas Freytag); 6. Effective corrosion protection with polyaniline, polpyrrole and polythiophene as anticorrosice additives for marine paints (Carlos Aleman); 7. Potential applications of sol gel technology for marine applications (Robert Akid); 8: Performance of biocide-free Antifouling Coatings for leisure boats (Bernd Daehne); 9. Novel biocidefree nanostructured antifouling coatings - can nano do the job? (Corne Rentrop); 10. One component high solids, VOC compliant high durability finish technology (Adrian Andrews); 11. High solid coatings - the hybrid solution (Luca Prezzi); 12. Unique organofunctional silicone resins for environmentally friendly high-performance coatings (Dieter Heldmann); 13. Silicone-alkyd paints for marine applications: from battleship-grey to green (Thomas Easton).

  3. CHARACTERISTICS OF PROTECTIVE COATINGS

    Directory of Open Access Journals (Sweden)

    Seljaev Vladimir Pavlovich

    2012-09-01

    Full Text Available On the basis of the computer program «Statistical analysis of color components for paint and varnish coatings», methods are suggested and experimental results are obtained for decorative characteristics polyurethane coatings.

  4. Corrosion inhibiting organic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  5. Nanocrystalline coatings properties forecasting

    Science.gov (United States)

    Eremin, E. N.; Yurov, V. M.; Guchenko, S. A.; Laurynas, V. Ch

    2017-06-01

    The paper considers various properties of nanocrystalline coatings. The methods of determining the surface tension of the deposited coating on the basis of the size dependence of their physical properties. It is shown that predict the mechanical properties of the coatings, their melting point, heat resistance, wear resistance, corrosion resistance, etc. It can be based on a theoretical evaluation of the surface tension.

  6. Spin coating of electrolytes

    Science.gov (United States)

    Stetter, Joseph R.; Maclay, G. Jordan

    1989-01-01

    Methods for spin coating electrolytic materials onto substrates are disclosed. More particularly, methods for depositing solid coatings of ion-conducting material onto planar substrates and onto electrodes are disclosed. These spin coating methods are employed to fabricate electrochemical sensors for use in measuring, detecting and quantifying gases and liquids.

  7. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  8. Coating of graphene

    OpenAIRE

    Schneider, G.F.; Dekker, C.

    2014-01-01

    The present invention is in the field of highly crystalline graphene and coating said graphene with a layer. Said graphene may have further structures, such as nanopores, nanogaps, and nanoribbons. The coated graphene can be used for biomolecular analysis and modification, such as DNA-sequencing, as a sensor, etc. The invention therefor also relates to use of coated graphene.

  9. The selection performance of an antibody library displayed on filamentous phage coat proteins p9, p3 and truncated p3.

    Science.gov (United States)

    Huovinen, Tuomas; Syrjänpää, Markku; Sanmark, Hanna; Seppä, Titta; Akter, Sultana; Khan, Liton Md Ferdhos; Lamminmäki, Urpo

    2014-09-19

    Filamentous phage display has become an ordinary tool to engineer antibody fragments. Several capsid proteins have been applied for displaying antibodies, of which gene III (p3) protein is used the most followed by experiments with gene IX (p9) protein. Despite the popularity, there are no library scale studies to objectively compare differences in the selection performance of the libraries, when displayed via different capsid proteins. In this study, an identical antibody repertoire was displayed as Fab fragments on p9, p3 and truncated p3 (p3Δ). In addition, the library clones were displayed as ScFv fragments on p3Δ and the Fab-p3 display valency was modulated by hyperphage and VCS-M13 superinfections. The selection performances of the libraries were followed in repeated parallel panning reactions against streptavidin (STR) and digoxigenin (DIG). Selection was successful with all display formats, but the enrichment of specific clones from Fab-p9 library was clearly less efficient than from the other libraries. The most diverse outputs were obtained from p3Δ display and the highest affinity anti-DIG antibodies from the ScFv repertoire. Unfortunately, the number of retrieved specific clones was too low for explicit analysis of the differences in the number of obtained unique clones from each library. However, severe reduction in sequence diversity was observed in p3-Fab libraries prior to panning, which in turn, materialized as a low number of unique specific clones. Oligovalent display by hyperphage resulted in a higher number of unique clones, but the same highest affinity anti-DIG Fab was recovered also by VCS-M13 superinfection. The compromised enrichment of the target-specific clones from the Fab repertoire as a fusion to p9 capsid protein in our experiments, the significant loss of functional diversity in Fab-p3 library after single phage packing cycle and the retrieval of higher affinity anti-digoxigenin clones as ScFv molecules than as Fab molecules from

  10. A case study to determine the geographical origin of unknown GM papaya in routine food sample analysis, followed by identification of papaya events 16-0-1 and 18-2-4.

    Science.gov (United States)

    Prins, Theo W; Scholtens, Ingrid M J; Bak, Arno W; van Dijk, Jeroen P; Voorhuijzen, Marleen M; Laurensse, Emile J; Kok, Esther J

    2016-12-15

    During routine monitoring for GMOs in food in the Netherlands, papaya-containing food supplements were found positive for the genetically modified (GM) elements P-35S and T-nos. The goal of this study was to identify the unknown and EU unauthorised GM papaya event(s). A screening strategy was applied using additional GM screening elements including a newly developed PRSV coat protein PCR. The detected PRSV coat protein PCR product was sequenced and the nucleotide sequence showed identity to PRSV YK strains indigenous to China and Taiwan. The GM events 16-0-1 and 18-2-4 could be identified by amplifying and sequencing events-specific sequences. Further analyses showed that both papaya event 16-0-1 and event 18-2-4 were transformed with the same construct. For use in routine analysis, derived TaqMan qPCR methods for events 16-0-1 and 18-2-4 were developed. Event 16-0-1 was detected in all samples tested whereas event 18-2-4 was detected in one sample. This study presents a strategy for combining information from different sources (literature, patent databases) and novel sequence data to identify unknown GM papaya events. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Antibacterial polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  12. ATHENA optimized coating design

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen

    2012-01-01

    The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed...... in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating...

  13. Evaluation of HVOF coatings

    Directory of Open Access Journals (Sweden)

    Mariana Landová

    2016-07-01

    Full Text Available Attention in this paper is devoted to the evaluation of wear coatings deposited using HVOF technology (high velocity oxy-fuel. There were evaluated three types of coatings based on WC-Co (next only 1343, WC-Co-Cr (next only 1350 and Cr3C2-25NiCr (next only 1375. There was assessed adherence of coatings, micro hardness, porosity and the tribological properties of erosive, abrasive, adhesive and wear resistance of coatings in terms of cyclic thermal load. Thanks to wide variety of suitable materials and their combinations, the area of utilization thermally sprayed coatings is very broad. It is possible to deposit coatings of various materials from pure metals to special alloys. The best results in the evaluated properties were achieved at the coating with the label 1375.

  14. Flexible Antibacterial Coatings.

    Science.gov (United States)

    Musil, Jindřich

    2017-05-16

    This article reviews the present state of the art in the field of flexible antibacterial coatings which efficiently kill bacteria on their surfaces. Coatings are formed using a reactive magnetron sputtering. The effect of the elemental composition and structure of the coating on its antibacterial and mechanical properties is explained. The properties of Cr-Cu-O, Al-Cu-N, and Zr-Cu-N antibacterial coatings are used as examples and described in detail. The efficiency of killing of bacteria was tested for the Escherichia coli bacterium. The principle of the formation of thick, flexible antibacterial coatings which are resistant to cracking under bending is explained. It is shown that magnetron sputtering enables production of robust, several-micrometer thick, flexible antibacterial coatings for long-term use. The antibacterial coatings produced by magnetron sputtering present huge potential for many applications.

  15. Anticorrosive coatings: a review

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Kiil, Søren; Dam-Johansen, Kim

    2009-01-01

    The main objective of this review is to describe some of the important topics related to the use of marine and protective coatings for anticorrosive purposes. In this context, "protective" refers to coatings for containers, offshore constructions, wind turbines, storage tanks, bridges, rail cars...... of volatile organic compounds (VOCs) have caused significant changes in the anticorrosive coating industry. The requirement for new VOC-compliant coating technologies means that coating manufacturers can no longer rely on the extensive track record of their time-served products to convince consumers......, and inhibitive coatings are outlined. In the past decades, several alternatives to organic solvent-borne coatings have reached the commercial market. This review also presents some of these technologies and discusses some of their advantages and limitations. Finally, some of the mechanisms leading to degradation...

  16. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  17. Physisorbed surface coatings for poly(dimethylsiloxane) and quartz microfluidic devices

    Science.gov (United States)

    Viefhues, M.; Manchanda, S.; Chao, T.-C.; Anselmetti, D.; Regtmeier, J.; Ros, A.

    2011-01-01

    Surface modifications of microfluidic devices are of essential importance for successful bioanalytical applications. Here, we investigate three different coatings for quartz and poly(dimethylsiloxane) (PDMS) surfaces. We employed a triblock copolymer with trade name F108, poly (l-lysine)-g-poly(ethylene glycol) (PLL-PEG), as well as the hybrid coating n-dodecyl-β-d-maltoside and methyl cellulose (DDM/MC). The impact of these coatings was characterized by measuring the electroosmotic flow (EOF), contact angle, and prevention of protein adsorption. Furthermore, we investigated the influence of static coatings, i.e., the incubation with the coating agent prior to measurements, and dynamic coatings, where the coating agent was present during the measurement. We found that all coatings on PDMS as well as quartz reduced EOF, increased reproducibility of EOF, reduced protein adsorption, and improved the wettability of the surfaces. Among the coating strategies tested, the dynamic coatings with DDM/MC and F108 demonstrated maximal reduction of EOF and protein adsorption and simultaneously best long-term stability concerning EOF. For PLL-PEG, a reversal in the EOF direction was observed. Interestingly, the static surface coating strategy with F108 proved to be as effective to prevent protein adsorption as dynamic coating with this block copolymer. These findings will allow optimized parameter choices for coating strategies on PDMS and quartz microfluidic devices in which control of EOF and reduced biofouling are indispensable. PMID:21847528

  18. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  19. Controllable coating of microneedles for transdermal drug delivery.

    Science.gov (United States)

    Chen, Jianmin; Qiu, Yuqin; Zhang, Suohui; Yang, Guozhong; Gao, Yunhua

    2015-03-01

    Coated microneedles have been paid much attention recently, and several coating strategies have been developed to address the problems during coating process. However, there are still some unresolved issues, such as, precise control requirements, microneedle substrate contamination and high processing temperature. The purpose of this study was to develop a simple and controllable method to make uniform coatings on microneedles at room temperature. This novel method avoids the contamination of microneedle substrate by providing both the adsorption force of thickener and micro-scale coating film produced by a newly design device. Thickeners were screened to enhance the mass of coatings. The parameters that influence the coatings were tested systematically, which made coating process controllable. Finally, three model drugs were coated onto microneedles to prove the method is applicable more broadly. In addition, insertion experiments were carried out to test the drug delivery feasibility of the coated microneedles. In conclusion, this study presents a simple and controllable method to coat microneedles with small molecular chemical drugs or large proteins for rapid skin drug delivery.

  20. Highly specific and rapid immuno-fluorescent visualization and detection of E. coli O104:H4 with protein-A coated magnetic beads based LST-MUG assay.

    Science.gov (United States)

    Barizuddin, Syed; Balakrishnan, Baskar; Stringer, R Cody; Dweik, Majed

    2015-08-01

    A method combining immunomagnetic separation and fluorescent sensing was developed to detect Escherichia coli (E. coli) O104:H4. The antibody specific to E. coli O104:H4 was immobilized on protein A-coated magnetic beads. This protein-A-anti E. coli O104:H4 complex was used to bind Fluorescein IsoThioCyanate (FITC) labeled E. coli O104:H4 antigen (whole cell) on it. The goal was to achieve a fluorescently detectable protein-A-anti E. coli O104:H4-E. coli O104:H4 complex on the magnetic beads. Fluorescent microscopy was used to image the magnetic beads. The resulting fluorescence on the beads was due to the FITC labeled antigen binding on the protein-A-anti E. coli O104:H4 immobilized magnetic beads. This visually proves the antigen-antibody binding. The fluorescent imaging results were obtained in 2 h if the minimum available bacteria in the sample were at least 10(5) CFU/ml. If no fluorescence was observed on the magnetic beads during fluorescent imaging, it indicates the bacterial concentration in the sample to be too low for it to have bound to the magnetic beads and hence no detection was possible. To detect bacterial concentration less than 10(5) CFU/ml in the sample, an additional step was required for detection. The magnetic bead complex was added to the LST-MUG (lauryl sulfate tryptose-4-methylumbelliferyl-β-D-glucuronide), a signaling reporter. The E. coli O104:H4 grows in LST-MUG and releases β-glucuronidase enzyme. This enzyme cleaves the MUG substrate that produces 4-methylumbelliferone, a highly fluorescent species. This fluorescence was detected using a spectrofluorometer. The emission peak in the fluorescent spectrum was found to be at 450 nm. The lower and upper detection range for this LST-MUG assay was found to be 2.05×10(5)-4.09×10(8) CFU/ml. The results for the LST-MUG assay for concentrations below 10(5) CFU/ml were ascertained in 8h. The advantages of this technique include the specific detection of bacteria without an enrichment step and

  1. Electrodeposited silk coatings for functionalized implant applications

    Science.gov (United States)

    Elia, Roberto

    The mechanical and morphological properties of titanium as well as its biocompatibility and osteoinductive characteristics have made it the material of choice for dental implant systems. Although the success rate of titanium implants exceeds 90% in healthy individuals, a large subset of the population has one or more risk factors that inhibit implant integration. Treatments and coatings have been developed to improve clinical outcomes via introduction of appropriate surface topography, texture and roughness or incorporation of bioactive molecules. It is essential that the coatings and associated deposition techniques are controllable and reproducible. Currently, methods of depositing functional coatings are dictated by numerous parameters (temperature, particle size distribution, pH and voltage), which result in variable coating thickness, strength, porosity and weight, and hinder or preclude biomolecule incorporation. Silk is a highly versatile protein with a unique combination of mechanical and physical properties, including tunable degradation, biocompatibility, drug stabilizing capabilities and mechanical properties. Most recently an electrogelation technique was developed which allows for the deposition of gels which dry seamlessly over the contoured topography of the conductive substrate. In this work we examine the potential use of silk electrogels as mechanically robust implant coatings capable of sequestering and releasing therapeutic agents. Electrodeposition of silk electrogels formed in uniform electric fields was characterized with respect to field intensity and deposition time. Gel formation kinetics were used to derive functions which allowed for the prediction of coating deposition over a range of process and solution parameters. Silk electrogel growth orientation was shown to be influenced by the applied electric field. Coatings were reproducible and tunable via intrinsic silk solution properties and extrinsic process parameters. Adhesion was

  2. Preliminary coating design and coating developments for ATHENA

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Ferreira, Desiree Della Monica; Christensen, Finn Erland

    2011-01-01

    We present initial novel coating design for ATHENA. We make use of both simple bilayer coatings of Ir and B4C and more complex constant period multilayer coatings to enhance the effective area and cover the energy range from 0.1 to 10 keV. We also present the coating technology used...... for these designs and present test results from coatings....

  3. Improved Manganese Phosphate Coatings

    Science.gov (United States)

    1975-04-01

    AD K/ . / R-TR-75-034 IMPROVED MANGANESE PHOSPHATE COATINGS HENRY CRAIN - APRIL 1975 RESEARCH DIRECTORATE DISTRIBUTION STATEMENT Approved for public...which superior manganese phosphate coatings are producel. The phosphate coatings were applied at temp- eratures above 2124F and with -.anganese...temperature for the conversion of mlnganese dihydrogen phosphate [(P(HjPO•’)] to manganese phosphate [Nns(PO4)J]. 1 A ii UNCLASSIFIED SE[CURITY CL. A

  4. Nanostructured Protective Coatings

    Science.gov (United States)

    2006-01-01

    understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V used for turbine blades, and developing a versatile...Phase I objectives, particularly in enhancing the understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V ...understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V used for turbine blades, and developing a versatile

  5. Smooth Compliant Antifoulant Coatings.

    Science.gov (United States)

    1982-09-30

    team reviewed the state of the art in marine antifoulant tech- nology. As part of this technology review, the team visited the Naval Ship Research and...high payoff is the incorporation of the biocide within the substrate polymer chain. This permits the antifoulant to be held chemi- cally rather than by...traditionally used red lead as a basis for protection against marine fouling. The antifoulant coating consists of a metal pretreatment coat, four coats of an

  6. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  7. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  8. Effectiveness of phages in the decontamination of Listeria monocytogenes adhered to clean stainless steel, stainless steel coated with fish protein, and as a biofilm.

    Science.gov (United States)

    Ganegama Arachchi, Geevika J; Cridge, Andrew G; Dias-Wanigasekera, Beatrice M; Cruz, Cristina D; McIntyre, Lynn; Liu, Rachel; Flint, Steve H; Mutukumira, Anthony N

    2013-10-01

    Listeria monocytogenes is a food-borne pathogen which causes listeriosis and is difficult to eradicate from seafood processing environments; therefore, more effective control methods need to be developed. This study investigated the effectiveness of three bacteriophages (LiMN4L, LiMN4p and LiMN17), individually or as a three-phage cocktail at ≈9 log₁₀ PFU/ml, in the lysis of three seafood-borne L. monocytogenes strains (19CO9, 19DO3 and 19EO3) adhered to a fish broth layer on stainless steel coupon (FBSSC) and clean stainless steel coupon (SSC), in 7-day biofilm, and dislodged biofilm cells at 15 ± 1 °C. Single phage treatments (LiMN4L, LiMN4p or LiMN17) decreased bacterial cells adhered to FBSSC and SSC by ≈3-4.5 log units. Phage cocktail reduced the cells on both surfaces (≈3.8-4.5 and 4.6-5.4 log10 CFU/cm², respectively), to less than detectable levels after ≈75 min (detection limit = 0.9 log₁₀ CFU/cm²). The phage cocktail at ≈5.8, 6.5 and 7.5 log₁₀ PFU/cm² eliminated Listeria contamination (≈1.5-1.7 log₁₀ CFU/cm²) on SSC in ≈15 min. One-hour phage treatments (LiMN4p, LiMN4L and cocktail) in three consecutive applications resulted in a decrease of 7-day L. monocytogenes biofilms (≈4 log₁₀ CFU/cm²) by ≈2-3 log units. Single phage treatments reduced dislodged biofilm cells of each L. monocytogenes strain by ≈5 log₁₀ CFU/ml in 1 h. The three phages were effective in controlling L. monocytogenes on stainless steel either clean or soiled with fish proteins which is likely to occur in seafood processing environments. Phages were more effective on biofilm cells dislodged from the surface compared with undisturbed biofilm cells. Therefore, for short-term phage treatments of biofilm it should be considered that some disruption of the biofilm cells from the surface prior to phage application will be required.

  9. Live-Cell Imaging of Clathrin Coats

    OpenAIRE

    Kural, Comert; Kirchhausen, Tom

    2012-01-01

    We compare the use of two-dimensional total internal reflection fluorescence microscopy with a rapid, simple-to-implement method for three-dimensional (3D) imaging using spinning-disk confocal microscopy suitable for reliable 3D tracking of clathrin-coated endocytic and endosomal carriers. These carriers contain about 20 EGFP (enhanced green fluorescent protein) equivalents of a chimeric fluorescent protein (either clathrin light chain or one of the clathrin adaptor subunits). Under tissue cu...

  10. Bio-Based Coatings for Paper Applications

    Directory of Open Access Journals (Sweden)

    Vibhore Kumar Rastogi

    2015-11-01

    Full Text Available The barrier resistance and wettability of papers are commonly controlled by the application of petroleum-based derivatives such as polyethylene, waxes and/or fluor- derivatives as coating. While surface hydrophobicity is improved by employing these polymers, they have become disfavored due to limitations in fossil-oil resources, poor recyclability, and environmental concerns on generated waste with lack of biodegradation. Alternatively, biopolymers including polysaccharides, proteins, lipids and polyesters can be used to formulate new pathways for fully bio-based paper coatings. However, difficulties in processing of most biopolymers may arise due to hydrophilicity, crystallization behavior, brittleness or melt instabilities that hinder a full exploitation at industrial scale. Therefore, blending with other biopolymers, plasticizers and compatibilizers is advantageous to improve the coating performance. In this paper, an overview of barrier properties and processing of bio-based polymers and their composites as paper coating will be discussed. In particular, recent technical advances in nanotechnological routes for bio-based nano- composite coatings will be summarized, including the use of biopolymer nanoparticles, or nanofillers such as nanoclay and nanocellulose. The combination of biopolymers along with surface modification of nanofillers can be used to create hierarchical structures that enhance hydrophobicity, complete barrier protection and functionalities of coated papers.

  11. Cellulose acetate propionate coated titanium: characterization and biotechnological application

    Directory of Open Access Journals (Sweden)

    Guilherme da Silva Gomes

    2007-12-01

    Full Text Available Surfaces of pure titanium and Ti coated with cellulose acetate propionate (CAP have been characterized by means of scanning electron microscopy X ray coupled with elemental microanalysis (SEM-EDS, ellipsometry, atomic force microscopy (AFM and contact angle measurements. Coating Ti surfaces with CAP ultrathin films reduced original surface roughness. Surface energy and wettability of CAP covered Ti surfaces pure Ti surfaces were similar. The adsorption of lysozyme (LYZ, an antibacterial protein, onto Ti and CAP-coated Ti surfaces has been studied by means of ellipsometry and atomic force microscopy (AFM. The adsorption of LYZ was mainly driven by hydrophobic interaction between protein hydrophobic residues and CAP propyl groups. Pure Ti and CAP coated Ti surfaces presented no cytotoxicity effect and proved to be adequate substrates for cell adhesion. The biocompatibility of CAP coated Ti surfaces was attributed to the surface enrichment in glucopyranosyl residues and short alkyl side groups.

  12. Superhydrophobic silica coating by dip coating method

    Energy Technology Data Exchange (ETDEWEB)

    Mahadik, Satish A., E-mail: superhydrophobicmaterial2100@gmail.com [Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Parale, Vinayak; Vhatkara, Rajiv S.; Mahadik, Dinesh B.; Kavale, Mahendra S. [Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Wagh, Pratap B.; Gupta, Satish [Applied Physics Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085 (India); Gurav, Jyoti [Empa, Advanced Materials Processing laboratory, 3602 Thun (Switzerland)

    2013-07-15

    Herein, we report a simple and low cost method for the fabrication of superhydrophobic coating surface on quartz substrates via sol-gel dip coating method at room temperature. Desired surface chemistry and texture growth for superhydrophobicity developed under double step sol–gel process at room temperature. The resultant superhydrophobic surfaces were characterized by Field-emission scanning electron microscopy (FE-SEM), Atomic force microscopy (AFM), water contact angle (WCA) measurement, differential thermal gravimetric analysis-differential thermal analysis (TGA-DTA) calorimetry and optical spectrometer. Coating shows the ultra high water contact angle about 168 ± 2° and water sliding angle 3 ± 1° and superoleophilic with petroleum oils. This approach allows a simple strategy for the fabrication process of superhydrophilic–superhydrophobic on same surfaces with high thermal stability of superhydrophobicity up to 560 °C. Thus, durability, special wettability and thermal stability of superhydrophobicity expand their application fields.

  13. Rocket Combustion Chamber Coating

    Science.gov (United States)

    Holmes, Richard R. (Inventor); McKechnie, Timothy N. (Inventor)

    2001-01-01

    A coating with the ability to protect (1) the inside wall (i.e., lining) of a rocket engine combustion chamber and (2) parts of other apparatuses that utilize or are exposed to combustive or high temperature environments. The novelty of this invention lies in the manner a protective coating is embedded into the lining.

  14. Coated electroactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Abouimrane, Ali

    2016-08-30

    A process includes suspending an electroactive material in a solvent, suspending or dissolving a carbon precursor in the solvent; and depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material. Compositions include a graphene-coated electroactive material prepared from a solution phase mixture or suspension of an electroactive material and graphene, graphene oxide, or a mixture thereof.

  15. Coating of graphene

    NARCIS (Netherlands)

    Schneider, G.F.; Dekker, C.

    2014-01-01

    The present invention is in the field of highly crystalline graphene and coating said graphene with a layer. Said graphene may have further structures, such as nanopores, nanogaps, and nanoribbons. The coated graphene can be used for biomolecular analysis and modification, such as DNA-sequencing, as

  16. Molecular Adsorber Coating

    Science.gov (United States)

    Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

    2011-01-01

    A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.

  17. Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

    Science.gov (United States)

    Zhang, Bill G. X.; Myers, Damian E.; Wallace, Gordon G.; Brandt, Milan; Choong, Peter F. M.

    2014-01-01

    Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants. PMID:25000263

  18. Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

    Directory of Open Access Journals (Sweden)

    Bill G. X. Zhang

    2014-07-01

    Full Text Available Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants.

  19. The Effect of Topdressing of Coated Urea Fertilizer at the Spikelet Formation Stage for Increasing Grain Protein Content of the Bread Wheat Cultivar “Setokirara” Motoharu Murata, Aki Uchiyama, Akihiko Ikejiri and Natsuko Harada

    National Research Council Canada - National Science Library

    Motoharu Murata; Aki Uchiyama; Akihiko Ikejiri; Natsuko Harada

    2017-01-01

    ...) in the bread wheat cultivar “Setokirara”. We examined whether it is possible to replace nitrogen topdressing, such as ammonium sulfate at the flowering stage, with the application of a coated urea fertilizer at the spikelet formation stage...

  20. Fluorine Based Superhydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Jean-Denis Brassard

    2012-05-01

    Full Text Available Superhydrophobic coatings, inspired by nature, are an emerging technology. These water repellent coatings can be used as solutions for corrosion, biofouling and even water and air drag reduction applications. In this work, synthesis of monodispersive silica nanoparticles of ~120 nm diameter has been realized via Stöber process and further functionalized using fluoroalkylsilane (FAS-17 molecules to incorporate the fluorinated groups with the silica nanoparticles in an ethanolic solution. The synthesized fluorinated silica nanoparticles have been spin coated on flat aluminum alloy, silicon and glass substrates. Functionalization of silica nanoparticles with fluorinated groups has been confirmed by Fourier Transform Infrared spectroscopy (FTIR by showing the presence of C-F and Si-O-Si bonds. The water contact angles and surface roughness increase with the number of spin-coated thin films layers. The critical size of ~119 nm renders aluminum surface superhydrophobic with three layers of coating using as-prepared nanoparticle suspended solution. On the other hand, seven layers are required for a 50 vol.% diluted solution to achieve superhydrophobicity. In both the cases, water contact angles were more than 150°, contact angle hysteresis was less than 2° having a critical roughness value of ~0.700 µm. The fluorinated silica nanoparticle coated surfaces are also transparent and can be used as paint additives to obtain transparent coatings.

  1. In vitro characterisation of zirconia coated by bioactive glass.

    Science.gov (United States)

    Bosetti, M; Vernè, E; Ferraris, M; Ravaglioli, A; Cannas, M

    2001-05-01

    An in vitro evaluation of a biomedical device, which combines the mechanical properties of zirconia substrates with the bioactivity of two different glass layers (AP40 and RKKP), was performed. In this work, data on different kinds of analysis were reported both on as-sintered zirconia samples and on RKKP- and AP40-coated zirconia substrates. Structure, composition and morphology of the apatite layer growth on the coated samples after 30 days of soaking in an acellular simulated body fluid, serum protein adsorption, fibroblasts and human osteoblast-like cells adhesion, growth, morphology and biochemical aspects were studied. Results of soaking test in SBF, revealed the growth of an apatite layer on the surface of the glass-coated samples. Proteins adsorbed to the materials were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and results evidenced that the two glass-coated materials bound a higher amount of total protein than did the zirconia substrate. Fibroblasts and osteoblast-like cells cultured on RKKP- and AP40-coated zirconia showed a higher proliferation rate, leading to confluent cultures with higher cell density and a generally better expression of osteoblast alkaline phosphatase activity in comparison with zirconia substrate. In conclusion, our results indicate that the surface chemical characteristics of the two glass coatings AP40 and RKKP, with no great differences between them, substantially enhance zirconia integration with bone cells at least in vitro. This effect may be of significance in the stability of glass-coated zirconia orthopaedic and dental implants.

  2. Aluminum phosphate coatings

    Science.gov (United States)

    Sambasivan, Sankar; Steiner, Kimberly A.; Rangan, Krishnaswamy K.

    2007-12-25

    Aluminophosphate compounds and compositions as can be used for substrate or composite films and coating to provide or enhance, without limitation, planarization, anti-biofouling and/or anti-microbial properties.

  3. Inorganic Coatings Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The inorganic Coatings Lab provides expertise to Navy and Joint Service platforms acquisition IPTs to aid in materials and processing choices which balance up-front...

  4. Friction surfaced Stellite6 coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rao, K. Prasad; Damodaram, R. [Department of Metallurgical and Materials Engineering - Indian Institute of Technology Madras, Chennai 600 036 (India); Rafi, H. Khalid, E-mail: khalidrafi@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Ram, G.D. Janaki [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Reddy, G. Madhusudhan [Metal Joining Group, Defence Metallurgical Research Laboratory (DMRL) Kanchanbagh, Hyderabad 500 058 (India); Nagalakshmi, R. [Welding Research Institute, Bharat Heavy Electricals Limited, Tiruchirappalli 620 014 (India)

    2012-08-15

    Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material for friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.

  5. Spin coating apparatus

    Science.gov (United States)

    Torczynski, John R.

    2000-01-01

    A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

  6. Biocompatibility of Niobium Coatings

    Directory of Open Access Journals (Sweden)

    René Olivares-Navarrete

    2011-09-01

    Full Text Available Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainless steel substrates and tissue culture plastic were also studied, in order to give comparative information. No toxic response was observed for any of the surfaces, indicating that the Nb coatings act as a biocompatible, bioinert material. Cell morphology was also studied by immune-fluorescence and the results confirmed the healthy state of the cells on the Nb surface. X-ray diffraction analysis of the coating shows that the film is polycrystalline with a body centered cubic structure. The surface composition and corrosion resistance of both the substrate and the Nb coating were also studied by X-ray photoelectron spectroscopy and potentiodynamic tests. Water contact angle measurements showed that the Nb surface is more hydrophobic than the SS substrate.

  7. Hydroxyapatite coatings for biomedical applications

    CERN Document Server

    Zhang, Sam

    2013-01-01

    Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

  8. Subchronic Immunotoxicity Assessment of Genetically Modified Virus-Resistant Papaya in Rats.

    Science.gov (United States)

    Lin, Hsin-Tang; Lee, Wei-Cheng; Tsai, Yi-Ting; Wu, Jhaol-Huei; Yen, Gow-Chin; Yeh, Shyi-Dong; Cheng, Ying-Huey; Chang, Shih-Chieh; Liao, Jiunn-Wang

    2016-07-27

    Papaya is an important fruit that provides a variety of vitamins with nutritional value and also holds some pharmacological properties, including immunomodulation. Genetically modified (GM) papaya plants resistant to Papaya ringspot virus (PRSV) infection have been generated by cloning the coat protein gene of the PRSV which can be used as a valuable strategy to fight PRSV infection and to increase papaya production. In order to assess the safety of GM papaya as a food, this subchronic study was conducted to assess the immunomodulatory responses of the GM papaya line 823-2210, when compared with its parent plant of non-GM papaya, Tainung-2 (TN-2), in Sprague-Dawley (SD) rats. Both non-GM and GM 823-2210 papaya fruits at low (1 g/kg bw) and high (2 g/kg bw) dosages were administered via daily oral gavage to male and female rats consecutively for 90 days. Immunophenotyping, mitogen-induced splenic cell proliferation, antigen-specific antibody response, and histopathology of the spleen and thymus were evaluated at the end of the experiment. Results of immunotoxicity assays revealed no consistent difference between rats fed for 90 days with GM 823-2210 papaya fruits, as opposed to those fed non-GM TN-2 papaya fruits, suggesting that with regard to immunomodulatory responses, GM 823-2210 papaya fruits maintain substantial equivalence to fruits of their non-GM TN-2 parent.

  9. Coated particle waste form development

    Energy Technology Data Exchange (ETDEWEB)

    Oma, K.H.; Buckwalter, C.Q.; Chick, L.A.

    1981-12-01

    Coated particle waste forms have been developed as part of the multibarrier concept at Pacific Northwest Laboratory under the Alternative Waste Forms Program for the Department of Energy. Primary efforts were to coat simulated nuclear waste glass marbles and ceramic pellets with low-temperature pyrolytic carbon (LT-PyC) coatings via the process of chemical vapor deposition (CVD). Fluidized bed (FB) coaters, screw agitated coaters (SAC), and rotating tube coaters were used. Coating temperatures were reduced by using catalysts and plasma activation. In general, the LT-PyC coatings did not provide the expected high leach resistance as previously measured for carbon alone. The coatings were friable and often spalled off the substrate. A totally different concept, thermal spray coating, was investigated at PNL as an alternative to CVD coating. Flame spray, wire gun, and plasma gun systems were evaluated using glass, ceramic, and metallic coating materials. Metal plasma spray coatings (Al, Sn, Zn, Pb) provided a two to three orders-of-magnitude increase in chemical durability. Because the aluminum coatings were porous, the superior leach resistance must be due to either a chemical interaction or to a pH buffer effect. Because they are complex, coated waste form processes rank low in process feasibility. Of all the possible coated particle processes, plasma sprayed marbles have the best rating. Carbon coating of pellets by CVD ranked ninth when compared with ten other processes. The plasma-spray-coated marble process ranked sixth out of eleven processes.

  10. Sterilization effects on starPEG coated polymer surfaces: characterization and cell viability.

    Science.gov (United States)

    Lleixà Calvet, Júlia; Grafahrend, Dirk; Klee, Doris; Möller, Martin

    2008-04-01

    Sterilization is frequently an issue for polymeric biomaterials including hydrogels, where autoclaving needs to be discarded, and gamma-irradiation and low temperature hydrogen peroxide gas plasma sterilization are already important alternatives. Coatings based on poly(ethylene glycol) are a well-known strategy to reduce unspecific protein interactions on biomaterial surfaces. Dense, ultrathin coatings of isocyanate terminated star-shaped poly(ethylene glycol) (starPEG) molecules have proven to be resistant to unspecific adsorption of proteins and enable direct biofunctionalization. The effectivity and stability of the starPEG coatings on poly(vinylidene fluoride) (PVDF) were studied after gamma-irradiation (normed dosis 25 kGy) and plasma sterilization (Sterrad 100S). The selected surface properties determined were: surface composition (X-ray photoelectron spectroscopy, XPS), wettability (sessile drop contact angle) and protein adsorption by fluorescence microscopy (Avidin-TexasRed, Bovine Serum Albumin-Rhodamin). Preliminary cell experiments with the cell line L929 were performed prior and after sterilization to investigate the cell repellence of the starPEG coatings as well as cell viability and specific cell adhesion on GRGDS-modified coatings. The starPEG coating undergoes a slight oxidation due to plasma and gamma-sterilization; this represents a minor variation confirmed by XPS and contact angle results. The non-sterilized starPEG and the plasma-sterilized coatings are protein repellent, however the protein adsorption on starPEG coated substrates is much stronger after gamma-sterilization for both avidin and bovine serum albumin. The cell experiments indicate that the starPEG coatings are appliable homogeneously by incubation and are non-cell adherent. Moreover, after both sterilization processes the starPEG coatings remain cell repellent and the GRGDS-modified coatings presented vital cells. Thus we conclude that the plasma sterilization is more convenient

  11. Steam initiated hydrotalcite conversion coatings

    DEFF Research Database (Denmark)

    Zhou, Lingli; Friis, Henrik; Roefzaad, Melanie

    2018-01-01

    in the following order: K2S2O8 > Na2SO4 > NH4NO3 > KNO3. Post-coating rinsing by Mg(CH3COO)2, in addition to Ce- and La- based salts, is capable of sealing the porous Al-Li HT coatings and increasing the corrosion resistance ability. The Ce modified Al-Li HT coatings show better corrosion protection than the La...... modified coatings, due to a behaviour of “active corrosion protection” that enables precipitation of insoluble Ce(IV) oxides to reinforce the existed HT coatings........ A range of coating processesased on the formation of HT surface layers has been developed to examine its effect on the coating's thicknessnd corrosion resistance properties. These varieties include pre-coating cleaning (grid blasting vs. chemicaltching), metal species in HT compounds (Al-Zn HT coating vs...

  12. Polydopamine coated capillaries for CE separations

    OpenAIRE

    Partyka, Jan

    2013-01-01

    We have tested CE separation of selected samples in capillaries with polydopamine modified surface. The capillaries were modified by polydopamine or polydopamine with an additive. The polydopamine coating with additive represents a simple and effective procedure for capillary alteration by another modificator such as hydroxyethyl cellulose, hydroxypropyl cellulose etc. In this work, we represent separation data from PrinCE system with UV detection for peptides, proteins and oligosaccha...

  13. Bio-Based Coatings for Paper Applications

    OpenAIRE

    Vibhore Kumar Rastogi; Pieter Samyn

    2015-01-01

    The barrier resistance and wettability of papers are commonly controlled by the application of petroleum-based derivatives such as polyethylene, waxes and/or fluor- derivatives as coating. While surface hydrophobicity is improved by employing these polymers, they have become disfavored due to limitations in fossil-oil resources, poor recyclability, and environmental concerns on generated waste with lack of biodegradation. Alternatively, biopolymers including polysaccharides, proteins, lipids ...

  14. Carbopol-lectin conjugate coated liposomes for oral peptide delivery.

    Science.gov (United States)

    Werle, Martin; Makhlof, Abdallah; Takeuchi, Hirofumi

    2010-03-01

    Within the current study, a delivery system based on a novel polymer-lectin conjugate (carbopol-lectin) was evaluated for the oral delivery of therapeutic peptides and proteins. It was demonstrated that covalent attachment of lectin to carbopol does neither decrease nor abolish the specific binding properties of lectin. Bioadhesion studies revealed that liposomes coated with carbopol lectin are more bioadhesive than liposomes coated with unmodified carbopol. Finally, the in vivo data suggest that carbopol-lectin conjugate coated liposomes are effective oral peptide delivery systems which are capable of increasing the pharmacological effect of orally administered calcitonin.

  15. Protective Woodcutting Tool Coatings

    Directory of Open Access Journals (Sweden)

    Svetlana D. Latushkina

    2016-01-01

    Full Text Available The modern woodworking industry applies resource-saving, environmentally appropriate technologies, providing both the metal removal performance enhancement and functioning with the optimal economic factors. Progressive cutting parameters require the application of the high-reliability cutting tools, eliminating machine-tool equipment standstill and increased cost of the expensive tool materials. In this paper it is suggested to increase the wood-cutting tool efficiency by means of the vacuum-arc separated coating deposition process optimization. The droplets are one of the main problems while generating vacuum-arc coatings, and they have a bad influence on the quality and operational coatings characteristics. The application of the separated system, allowing minimize the droplets content, is one of the most promising ways to solve this problem. Vacuum-arc deposition technique was used in this work to generate multicomponent coatings. The coatings deposition was directly carried out on the modernized vacuum-arc plant, equipped by Y-shaped macroparticles separator.

  16. Self-assembled hemocompatible coating on poly (vinyl chloride) surface

    Science.gov (United States)

    Zha, Zhengbao; Ma, Yan; Yue, Xiuli; Liu, Meng; Dai, Zhifei

    2009-11-01

    A stable hemocompatible coating was fabricated by consecutive alternating adsorption of iron (III) and two kinds of polysaccharides, heparin (Hep) and dextran sulfate (DS), onto poly (vinyl chloride) (PVC) surfaces via electrostatic interaction. The fluctuation of contact angles with the alternative deposition of iron (III) and polysaccharides verified the progressive buildup of the mulitilayer coating onto the PVC surface. Atomic force microscopy (AFM) analysis revealed that the PVC surfaces were completely masked by iron-polysaccharides multilayer coatings. The activated partial thromboplastin time (APTT) assay showed that both Hep/Fe 3+/Hep and DS/Fe 3+/Hep coated PVC were less thrombogenic than the uncoated one. Chromogenic assay for heparin activity proved definitively that the inhibition of locally produced thrombin was ascribed to the thromboresistance of the surface-bound heparin. Compared with the unmodified PVC surfaces, iron-polysaccharide multilayer coating presented a drastically reduced adhesion in vitro of platelets, polymorphonuclear neutrophil leukocytes (PMN) and peripheral blood mononuclear cells (PBMC). Interestingly, the DS/Fe 3+/Hep coating was found to exhibit higher hydrophilicity and stability, hence lower non-specific protein adsorption in comparison with Hep/Fe 3+/Hep coating due to the incorporation of dextran sulfate into the multilayer coating.

  17. Self-assembled hemocompatible coating on poly (vinyl chloride) surface

    Energy Technology Data Exchange (ETDEWEB)

    Zha Zhengbao; Ma Yan; Yue Xiuli; Liu Meng [Nanobiotechnology Division, State Key Laboratory of Urban Water Resources and Environment, School of Sciences, Harbin Institute of Technology, Harbin 150001 (China); Dai Zhifei, E-mail: zhifei.dai@hit.edu.cn [Nanobiotechnology Division, State Key Laboratory of Urban Water Resources and Environment, School of Sciences, Harbin Institute of Technology, Harbin 150001 (China)

    2009-11-15

    A stable hemocompatible coating was fabricated by consecutive alternating adsorption of iron (III) and two kinds of polysaccharides, heparin (Hep) and dextran sulfate (DS), onto poly (vinyl chloride) (PVC) surfaces via electrostatic interaction. The fluctuation of contact angles with the alternative deposition of iron (III) and polysaccharides verified the progressive buildup of the mulitilayer coating onto the PVC surface. Atomic force microscopy (AFM) analysis revealed that the PVC surfaces were completely masked by iron-polysaccharides multilayer coatings. The activated partial thromboplastin time (APTT) assay showed that both Hep/Fe{sup 3+}/Hep and DS/Fe{sup 3+}/Hep coated PVC were less thrombogenic than the uncoated one. Chromogenic assay for heparin activity proved definitively that the inhibition of locally produced thrombin was ascribed to the thromboresistance of the surface-bound heparin. Compared with the unmodified PVC surfaces, iron-polysaccharide multilayer coating presented a drastically reduced adhesion in vitro of platelets, polymorphonuclear neutrophil leukocytes (PMN) and peripheral blood mononuclear cells (PBMC). Interestingly, the DS/Fe{sup 3+}/Hep coating was found to exhibit higher hydrophilicity and stability, hence lower non-specific protein adsorption in comparison with Hep/Fe{sup 3+}/Hep coating due to the incorporation of dextran sulfate into the multilayer coating.

  18. A New Coating Process for Production of Coated Magnesium Powders

    National Research Council Canada - National Science Library

    2008-01-01

    .... In brief, Task 1 involved the construction and assembly of the coating system and supporting infrastructure, which was used for the scale-up and production of 1-lb batches of coated magnesium powder...

  19. Superheating in coated niobium

    OpenAIRE

    T. Junginger; Wasserman, W.; Laxdal, R. E.

    2017-01-01

    Using muon spin rotation it is shown that the field of first flux penetration H_entry in Nb is enhanced by about 30% if coated with an overlayer of Nb_3Sn or MgB_2. This is consistent with an increase from the lower critical magnetic field H_c1 up to the superheating field H_sh of the Nb substrate. In the experiments presented here coatings of Nb_3Sn and MgB_2 with a thickness between 50 and 2000nm have been tested. H_entry does not depend on material or thickness. This suggests that the ener...

  20. Advanced Coating Removal Techniques

    Science.gov (United States)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  1. Mechanically Invisible Polymer Coatings

    DEFF Research Database (Denmark)

    2014-01-01

    phase comprises particles, said particles comprising a filler material and an encapsulating coating of a second polymeric material, wherein the backbones of the first and second polymeric materials are the same. The composition may be used in electroactive polymers (EAPs) in order to obtain mechanically......The present invention relates to a composition comprising encapsulated particles in a polymeric material. The composition comprises a continuous phase and a discontinuous phase incorporated therein, wherein the continuous phase comprises a first polymeric material and wherein the discontinuous...... invisible polymer coatings....

  2. Pressure cryocooling protein crystals

    Science.gov (United States)

    Kim, Chae Un [Ithaca, NY; Gruner, Sol M [Ithaca, NY

    2011-10-04

    Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.

  3. Methods and means for coating paper by film coating

    NARCIS (Netherlands)

    van der Maarel, Marc; Ter Veer, Arend Berend Cornelis; Vrieling-Smit, Annet; Delnoye, Pierre

    2015-01-01

    This invention relates to the field of paper coating, more in particular to means and methods for providing paper with at least one layer of pigment using film coating to obtain a well printable surface. Provided is a method for preparing coated paper comprising the steps of: a) providing a

  4. Development of Polymeric Coatings for Antifouling Applications

    Science.gov (United States)

    Toumayan, Edward Philip

    grafting-from strategy based on polydopamine (PDA)-initiated surface polymerization was developed as a facile method capable of deposition on various substrates. In addition, the PDA method demonstrated polymerization of various monomer classes, enabling versatility in surface chemistry modification in a reproducible fashion. QCM-D then enabled the deposition of arbitrarily selected foulants onto these polymer-modified substrates. Protein fouling was employed as the basis for evaluating antifouling performance, though other foulants were also demonstrated. Improved resistance to protein fouling was corroborated by QCM-D experiments for hydrophilic and zwitterionic polymer coatings including poly(ethylene oxide) and poly(sulfobetaine methacrylate). The combination of PDA-initiated polymer films and QCM-D based fouling experiments provides a versatile and reproducible platform for antifouling research.

  5. Aesthetic coatings for steel bridge components.

    Science.gov (United States)

    2013-11-01

    The effectiveness of aesthetic coating systems for steel bridges was studied. Twelve 2-coat, 3-coat, and duplex : coating systems were selected and subjected to a series of accelerated weathering and mechanical tests to : determine their performance....

  6. Mussel-inspired dendritic polymers as universal multifunctional coatings.

    Science.gov (United States)

    Wei, Qiang; Achazi, Katharina; Liebe, Hendrik; Schulz, Andrea; Noeske, Paul-Ludwig Michael; Grunwald, Ingo; Haag, Rainer

    2014-10-20

    A rapid and universal approach for multifunctional material coatings was developed based on a mussel-inspired dendritic polymer. This new kind of polymer mimics not only the functional groups of mussel foot proteins (mfps) but also their molecular weight and molecular structure. The large number of catechol and amine groups set the basis for heteromultivalent anchoring and crosslinking. The molecular weight reaches 10 kDa, which is similar to the most adhesive mussel foot protein mfp-5. Also, the dendritic structure exposes its functional groups on the surface like the folded proteins. As a result, a very stable coating can be prepared on virtually any type of material surface within 10 min by a simple dip-coating method, which is as fast as the formation of mussel byssal threads in nature. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Mechanisms of Military Coatings Degradation

    Science.gov (United States)

    2003-08-01

    volume and bulk film compaction. Coating A is a less sterically and thermally stable biuret trimer of HDI in comparison to the HDI of coating system...developed coatings systems used by the Army, Marine Corps and Air Force. This study has incorporated numerous analytical tools and methods in an effort to...blistering. Peel away was evaluated as per ASTM D 3359, Method A and blistering was evaluated as per ASTM D 714. Coating systems are summarized

  8. Coating method for graphite

    Science.gov (United States)

    Banker, J.G.; Holcombe, C.E. Jr.

    1975-11-06

    A method of limiting carbon contamination from graphite ware used in induction melting of uranium alloys is provided. The graphite surface is coated with a suspension of Y/sub 2/O/sub 3/ particles in water containing about 1.5 to 4 percent by weight sodium carboxymethylcellulose.

  9. Coatings for transport industry

    Directory of Open Access Journals (Sweden)

    Krzysztof LUKASZKOWICZ

    2014-09-01

    Full Text Available The investigations concerned structural analysis, as well as mechanical properties and wear resistant of MeN/DLC double-layer coating deposited by hybrid PVD/PACVD method. In sliding dry friction conditions, after the break-in time, the friction coefficient for the investigated elements is set in the range between 0.03-0.06.

  10. The Spore Coat.

    Science.gov (United States)

    Driks, Adam; Eichenberger, Patrick

    2016-04-01

    Spores of Clostridiales and Bacillales are encased in a complex series of concentric shells that provide protection, facilitate germination, and mediate interactions with the environment. Analysis of diverse spore-forming species by thin-section transmission electron microscopy reveals that the number and morphology of these encasing shells vary greatly. In some species, they appear to be composed of a small number of discrete layers. In other species, they can comprise multiple, morphologically complex layers. In addition, spore surfaces can possess elaborate appendages. For all their variability, there is a consistent architecture to the layers encasing the spore. A hallmark of all Clostridiales and Bacillales spores is the cortex, a layer made of peptidoglycan. In close association with the cortex, all species examined possess, at a minimum, a series of proteinaceous layers, called the coat. In some species, including Bacillus subtilis, only the coat is present. In other species, including Bacillus anthracis, an additional layer, called the exosporium, surrounds the coat. Our goals here are to review the present understanding of the structure, composition, assembly, and functions of the coat, primarily in the model organism B. subtilis, but also in the small but growing number of other spore-forming species where new data are showing that there is much to be learned beyond the relatively well-developed basis of knowledge in B. subtilis. To help summarize this large field and define future directions for research, we will focus on key findings in recent years.

  11. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...

  12. Durable superhydrophobic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, John T.; Polyzos, Georgios; Schaeffer, Daniel A.

    2017-11-28

    A superhydrophobic coating including a plurality of particles and a resin. The particles covalently bond to the resin and the resin does not fill the pores of the superhydrophobic particles such that the three dimensional surface topology of the superhydrophobic particles is preserved.

  13. REFRACTORY COATING FOR GRAPHITE MOLDS

    Science.gov (United States)

    Stoddard, S.D.

    1958-06-24

    Refractory coating for graphite molds used in the casting of uranium is described. The coating is an alumino-silicate refractory composition which may be used as a mold surface in solid form or as a coating applied to the graphite mold. The composition consists of a mixture of ball clay, kaolin, alumina cement, alumina, water, sodium silicate, and sodium carbonate.

  14. Methods for Coating Particulate Material

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2013-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  15. A Coating-Free Nonfouling Polymeric Elastomer.

    Science.gov (United States)

    Hung, Hsiang-Chieh; Jain, Priyesh; Zhang, Peng; Sun, Fang; Sinclair, Andrew; Bai, Tao; Li, Bowen; Wu, Kan; Tsao, Caroline; Liu, Erik J; Sundaram, Harihara S; Lin, Xiaojie; Farahani, Payam; Fujihara, Timothy; Jiang, Shaoyi

    2017-08-01

    Medical devices face nonspecific biofouling from proteins, cells, and microorganisms, which significantly contributes to complications and device failure. Imparting these devices with nonfouling capabilities remains a major challenge, particularly for those made from elastomeric polymers. Current strategies, including surface coating and copolymerization/physical blending, necessitate compromise among nonfouling properties, durability, and mechanical strength. Here, a new strategy is reported to achieve both high bulk mechanical strength and excellent surface nonfouling properties, which are typically contradictory, in one material. This is realized through a nonfouling polymeric elastomer based on zwitterionic polycarboxybetaine derivatives. By hiding both charged moieties of the zwitterionic compounds with hydrocarbon ester and tertiary amine groups, the bulk polymer itself is elastomeric and hydrophobic while its superhydrophilic surface properties are restored upon hydrolysis. This coating-free nonfouling elastomer is a highly promising biomaterial for biomedical and engineering applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Superelastic Orthopedic Implant Coatings

    Science.gov (United States)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  17. NIa-pro of Papaya ringspot virus interacts with papaya methionine sulfoxide reductase B1.

    Science.gov (United States)

    Gao, Le; Shen, Wentao; Yan, Pu; Tuo, Decai; Li, Xiaoying; Zhou, Peng

    2012-12-05

    A chloroplast-localized papaya methionine sulfoxide reductase B1 (PaMsrB1) interacting with Papaya ringspot virus (PRSV) NIa-Pro was identified using a Sos recruitment two-hybrid system (SRS). SRS analysis of several deletion mutants of PRSV NIa-Pro and PaMsrB1 demonstrated that the C-terminal (residues 133-239) fragment of PRSV NIa-Pro and residues 112-175 of PaMsrB1 were necessary for this interaction between PRSV NIa-Pro and PaMsrB1. MsrB1 can repair Met-oxidized proteins damaged by reactive oxygen species (ROS). We confirmed that PRSV infection leads to ROS accumulation and a slight upregulation of level PaMsrB1 mRNA in papaya. This interaction between PaMsrB1 with PRSV NIa-Pro may disturb the import of PaMsrB1 into the chloroplasts. These results suggest that this specific interaction could interfere with PaMsrB1 into the chloroplasts to scavenge ROS caused by PRSV infection. This may be a novel mechanism of PRSV towards the host defense. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. High Solids Coating System

    Science.gov (United States)

    1979-04-01

    36622 Aircraft Gray No, 3� Dark Green No 30219 Tan No 17875 Tnsignia White D. Applicat ion In addition to conventionl . air ,3pray, evaluation of...requirements are 60% for gloss colors and 20% for camouflage colors. Adhesion of the coating to the elongated surfaces was evaluated by placing 250 masking...tape (3M) to the surface, insuring adhesion and then removing with one abrupt pull. Any paintI removal constitutes failure. 2. Heat Resistance Test

  19. for zeolite coating

    Directory of Open Access Journals (Sweden)

    Carlos Renato Rambo

    2006-01-01

    Full Text Available Biotemplating is the processing of microcellular ceramics by reproduction of natural morphologies, where the microstructural features of the biotemplate are maintained in the biomorphic ceramic. Different biotemplates with distinct pore anatomies were used to produce biomorphic supports for the zeolite coating: wood, cardboard, sea-sponge and sisal. The biomorphic ceramics were produced by distinguished processing routes: Al-gas infiltration-reaction, liquid-metal infiltration, dip-coating and sol-gel synthesis, in order to produce nitrides, carbides and oxides, depending on the processing conditions. The zeolite coating was performed by hydrothermal growth of MFI-type (Silicalite-1 and ZSM-5 zeolite crystals onto the internal pore walls of the biomorphic templates. The final biomorphic ceramic-zeolite composites were physically characterized, evaluated in terms of their gas adsorption capabilities and correlated to their microstructure and specific pore anatomy. The combination of the properties of the biomorphic ceramics with the adsorption properties of zeolites results in materials with distinct properties as potential candidates for adsorption and catalytic applications due to their characteristic porosity, molecular sieving capabilities and high thermo-mechanical strength.

  20. Electrospun vancomycin-loaded coating on titanium implants for the prevention of implant-associated infections.

    Science.gov (United States)

    Zhang, Li; Yan, Junwei; Yin, Zhaowei; Tang, Cheng; Guo, Yang; Li, Dong; Wei, Bo; Xu, Yan; Gu, Qiangrong; Wang, Liming

    2014-01-01

    The objectives of this work were to develop an antibiotic coating on the surface of a titanium plate to determine its antibacterial properties in vitro and in vivo. To prepare vancomycin-coated titanium implants, we adopted the electrospinning nanotechnique. The surface structure of the coating implants was observed using a scanning electron microscope. An elution method and a high-pressure liquid chromatography assay were used to characterize the release behavior of vancomycin from the coating. The antibacterial efficacy and the cytotoxicity of the coated titanium implants on osteoblasts were investigated in vitro. In addition, X-ray, white blood cell count, C-reactive protein, erythrocyte sedimentation rate, and pathological examination were performed to validate its antimicrobial efficacy in vivo. The antibiotic coating released 82.7% (approximately 528.2 μg) of total vancomycin loading in the coating in vitro. The release behavior of vancomycin from nanofiber coatings exhibited a biphasic release pattern with an initial burst on day 1, followed by a slow and controlled release over 28 days. There was no cytotoxicity observed in vitro for the vancomycin-loaded coating. The vancomycin-coated titanium implants were active in treating implant-associated infection in vivo. Thus, vancomycin-coated titanium implants may be a promising approach to prevent and treat implant-associated infections.

  1. The Effect of Xanthan Gum and Flaxseed Mucilage as Edible Coatings in Cheddar Cheese during Ripening

    Directory of Open Access Journals (Sweden)

    Afshin Soleimani-Rambod

    2018-02-01

    Full Text Available The object of this study was to investigate the possibility of using xanthan gum and flaxseed mucilage as edible coatings for Cheddar cheese during ripening for 90 days. Five samples of Cheddar cheese blocks were coated with different coating materials in triplicate as follows: Coated with polyvinyl acetate as control (C, coated with 0.5% xanthan gum (XG, coated with 0.75% flaxseed mucilage (FM1, coated with 1% flaxseed mucilage (FM2, and coated with 1.25% flaxseed mucilage (FM3. All samples were kept at 8 ± 2 °C in a cold room for 90 days. The statistical analysis of the results showed that the moisture content of the samples decreased and the protein content increased during the ripening period (P < 0.01. The pH, acidity, fat in dry matter, and TCA-SN/TN of samples were significantly affected by xanthan gum and flaxseed mucilage treatment (P < 0.01. The free fatty acid composition of samples was significantly affected by edible coatings. Edible coatings affected the growth of non-starter lactic acid bacteria and the total mesophilic aerobic bacteria in a non-significant manner (P > 0.01. The growth of starter bacteria was significantly altered under the effect of edible coating materials (P < 0.05. Tyrosine and tryptophan contents as an index of proteolysis, lipolysis, and sensory evaluation of samples were not significantly different.

  2. Lysis gene of bacteriophage MS2 is activated by translation termination at the overlapping coat gene

    NARCIS (Netherlands)

    Berkhout, B.; Schmidt, B. F.; van Strien, A.; van Boom, J.; van Westrenen, J.; van Duin, J.

    1987-01-01

    The 3' boundary of the coat gene of the RNA bacteriophage MS2 lies 46 nucleotides downstream from the beginning of the lysis (L) cistron. The translation of both reading frames is coupled; the synthesis of the lysis protein does not occur unless translation of the overlapping coat gene takes place.

  3. Advanced stent coating for drug delivery and in vivo biocompatibility

    Science.gov (United States)

    Liu, Yi; Wang, Wuchen; Acharya, Gayathri; Shim, Yoon-Bo; Choe, Eun Sang; Lee, Chi H.

    2013-10-01

    As an effort to alleviate stent-induced cardiovascular injury including restenosis and thrombosis, advanced drug-eluting stent (ADES) with a bilayer construct composed of a top-coat made of collagen and a base-coat incorporated with N-nitrosomelatonin (NOMela)-loaded PLGA nanoparticles has been developed. NOMela is a hydrophobic prodrug of nitric oxide (NO) that is an endogenous anti-platelet compound. ADES was coated with PLGA nanoparticles via either electrophoretic deposition (EPD) technique or dip-coating technique, and their coating characteristics and efficacies were compared. The drug-loading efficacy and in vitro drug-release profiles from ADES were expressed with various variables including the additives to the collagen layer, the number of layers of the collagen top-coat, the hydrophobicity/hydrophilicity of the loaded drug, the coating technique of nanoparticles, and the concentration of coating emulsions in the EPD method. The morphological status of cross-section and surface of ADES was evaluated by laser scanning confocal microscope and scanning electronic microscope. The real-time release profiles of NO were assessed using the NO-microbiosensor. The anti-platelet activity of ADES was evaluated on the rabbit whole blood using an aggregometer. The intima formation and protein expression in aorta were examined using an in vivo rat model. Both collagen and PLGA used in ADES are biodegradable polymers that fully degrade and consequently produce less inflammation responses. NO released from ADES significantly reduced platelet aggregation in the rabbit blood as compared with those exposed to the control stents. ADES coated with a double layer consisted of collagen and PLGA and containing NOMela was less antigenic at the implanted sites and alleviating intima formation and thrombosis. An external exposure of aorta to NO elicits distinct and specific effects on mitogen-activated protein kinase (MAPK) and Ca2+/calmodulin-dependent protein kinase II (Ca

  4. Advanced stent coating for drug delivery and in vivo biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi; Wang, Wuchen; Acharya, Gayathri [University of Missouri at Kansas City, Division of Pharmaceutical Sciences, School of Pharmacy (United States); Shim, Yoon-Bo [Pusan National University, Departments of Chemistry (Korea, Republic of); Choe, Eun Sang [Pusan National University, Departments of Biological Sciences (Korea, Republic of); Lee, Chi H., E-mail: leech@umkc.edu [University of Missouri at Kansas City, Division of Pharmaceutical Sciences, School of Pharmacy (United States)

    2013-10-15

    As an effort to alleviate stent-induced cardiovascular injury including restenosis and thrombosis, advanced drug-eluting stent (ADES) with a bilayer construct composed of a top-coat made of collagen and a base-coat incorporated with N-nitrosomelatonin (NOMela)-loaded PLGA nanoparticles has been developed. NOMela is a hydrophobic prodrug of nitric oxide (NO) that is an endogenous anti-platelet compound. ADES was coated with PLGA nanoparticles via either electrophoretic deposition (EPD) technique or dip-coating technique, and their coating characteristics and efficacies were compared. The drug-loading efficacy and in vitro drug-release profiles from ADES were expressed with various variables including the additives to the collagen layer, the number of layers of the collagen top-coat, the hydrophobicity/hydrophilicity of the loaded drug, the coating technique of nanoparticles, and the concentration of coating emulsions in the EPD method. The morphological status of cross-section and surface of ADES was evaluated by laser scanning confocal microscope and scanning electronic microscope. The real-time release profiles of NO were assessed using the NO-microbiosensor. The anti-platelet activity of ADES was evaluated on the rabbit whole blood using an aggregometer. The intima formation and protein expression in aorta were examined using an in vivo rat model. Both collagen and PLGA used in ADES are biodegradable polymers that fully degrade and consequently produce less inflammation responses. NO released from ADES significantly reduced platelet aggregation in the rabbit blood as compared with those exposed to the control stents. ADES coated with a double layer consisted of collagen and PLGA and containing NOMela was less antigenic at the implanted sites and alleviating intima formation and thrombosis. An external exposure of aorta to NO elicits distinct and specific effects on mitogen-activated protein kinase (MAPK) and Ca{sup 2+}/calmodulin-dependent protein kinase II (Ca

  5. Lotus Dust Mitigation Coating and Molecular Adsorber Coating

    Science.gov (United States)

    O'Connor, Kenneth M.; Abraham, Nithin S.

    2015-01-01

    NASA Goddard Space Flight Center has developed two unique coating formulations that will keep surfaces clean and sanitary and contain contaminants.The Lotus Dust Mitigation Coating, modeled after the self-cleaning, water-repellant lotus leaf, disallows buildup of dust, dirt, water, and more on surfaces. This coating, has been successfully tested on painted, aluminum, glass, silica, and some composite surfaces, could aid in keeping medical assets clean.The Molecular Adsorber Coating is a zeolite-based, sprayable molecular adsorber coating, designed to prevent outgassing in materials in vacuums. The coating works well to adsorb volatiles and contaminates in manufacturing and processing, such as in pharmaceutical production. The addition of a biocide would also aid in controlling bacteria levels.

  6. Nanoparticle/Polymer Nanocomposite Bond Coat or Coating

    Science.gov (United States)

    Miller, Sandi G.

    2011-01-01

    This innovation addresses the problem of coatings (meant to reduce gas permeation) applied to polymer matrix composites spalling off in service due to incompatibility with the polymer matrix. A bond coat/coating has been created that uses chemically functionalized nanoparticles (either clay or graphene) to create a barrier film that bonds well to the matrix resin, and provides an outstanding barrier to gas permeation. There is interest in applying clay nanoparticles as a coating/bond coat to a polymer matrix composite. Often, nanoclays are chemically functionalized with an organic compound intended to facilitate dispersion of the clay in a matrix. That organic modifier generally degrades at the processing temperature of many high-temperature polymers, rendering the clay useless as a nano-additive to high-temperature polymers. However, this innovation includes the use of organic compounds compatible with hightemperature polymer matrix, and is suitable for nanoclay functionalization, the preparation of that clay into a coating/bondcoat for high-temperature polymers, the use of the clay as a coating for composites that do not have a hightemperature requirement, and a comparable approach to the preparation of graphene coatings/bond coats for polymer matrix composites.

  7. Dense protective coatings, methods for their preparation and coated articles

    Science.gov (United States)

    Tulyani, Sonia; Bhatia, Tania; Smeggil, John G.

    2015-12-29

    A method for depositing a protective coating on a complex shaped substrate includes the steps of: (1) dipping a complex shaped substrate into a slurry to form a base coat thereon, the slurry comprising an aqueous solution, at least one refractory metal oxide, and at least one transient fluid additive present in an amount of about 0.1 percent to 10 percent by weight of the slurry; (2) curing the dipped substrate; (3) dipping the substrate into a precursor solution to form a top barrier coat thereon; and (4) heat treating the dipped, cured substrate to form a protective coating.

  8. Protein corona: Opportunities and challenges

    Science.gov (United States)

    Zanganeh, Saeid; Spitler, Ryan; Erfanzadeh, Mohsen; Alkilany, Alaaldin M.; Mahmoudi, Morteza

    2017-01-01

    In contact with biological fluids diverse type of biomolecules (e.g., proteins) adsorb onto nanoparticles forming protein corona. Surface properties of the coated nanoparticles, in terms of type and amount of associated proteins, dictate their interactions with biological systems and thus biological fate, therapeutic efficiency and toxicity. In this perspective, we will focus on the recent advances and pitfalls in the protein corona field. PMID:26783938

  9. Protein corona: Opportunities and challenges.

    Science.gov (United States)

    Zanganeh, Saeid; Spitler, Ryan; Erfanzadeh, Mohsen; Alkilany, Alaaldin M; Mahmoudi, Morteza

    2016-06-01

    In contact with biological fluids diverse type of biomolecules (e.g., proteins) adsorb onto nanoparticles forming protein corona. Surface properties of the coated nanoparticles, in terms of type and amount of associated proteins, dictate their interactions with biological systems and thus biological fate, therapeutic efficiency and toxicity. In this perspective, we will focus on the recent advances and pitfalls in the protein corona field. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Tablet coating by injection molding technology - Optimization of coating formulation attributes and coating process parameters.

    Science.gov (United States)

    Desai, Parind M; Puri, Vibha; Brancazio, David; Halkude, Bhakti S; Hartman, Jeremy E; Wahane, Aniket V; Martinez, Alexander R; Jensen, Keith D; Harinath, Eranda; Braatz, Richard D; Chun, Jung-Hoon; Trout, Bernhardt L

    2018-01-01

    We developed and evaluated a solvent-free injection molding (IM) coating technology that could be suitable for continuous manufacturing via incorporation with IM tableting. Coating formulations (coating polymers and plasticizers) were prepared using hot-melt extrusion and screened via stress-strain analysis employing a universal testing machine. Selected coating formulations were studied for their melt flow characteristics. Tablets were coated using a vertical injection molding unit. Process parameters like softening temperature, injection pressure, and cooling temperature played a very important role in IM coating processing. IM coating employing polyethylene oxide (PEO) based formulations required sufficient room humidity (>30% RH) to avoid immediate cracks, whereas other formulations were insensitive to the room humidity. Tested formulations based on Eudrajit E PO and Kollicoat IR had unsuitable mechanical properties. Three coating formulations based on hydroxypropyl pea starch, PEO 1,000,000 and Opadry had favorable mechanical (35% elongation, >95×10 4 J/m 3 toughness) and melt flow (>0.4g/min) characteristics, that rendered acceptable IM coats. These three formulations increased the dissolution time by 10, 15 and 35min, respectively (75% drug release), compared to the uncoated tablets (15min). Coated tablets stored in several environmental conditions remained stable to cracking for the evaluated 8-week time period. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Design of novel plasma sprayed hydroxyapatite-bond coat bioceramic systems

    Science.gov (United States)

    Heimann, R. B.

    1999-12-01

    Bond coats based on bioinert ceramic materials such as titania and zirconia were developed to increase the adhesion strength of the coating system hydroxyapatite-bond coat to Ti-6Al-4V alloy surfaces used for hip endoprostheses and dental root implants. The bond coats improved the adhesion strength, measured by a modified ASTM D 3167-76 peel test, by up to 100% and also the resorption resistance as determined by in vitro leaching in simulated protein-free body fluid for up to 28 days.

  12. Physical, Chemical and Microbial Characteristic of Gouda Cheese Using Propolis (Apis milifera Liguistica as Coating Material

    Directory of Open Access Journals (Sweden)

    Lilik Eka Radiati

    2012-02-01

    Full Text Available Gouda cheeses were coated with different coating materials consist of pliol, beeswax, and beeswax containing different concentration of propolis  by 0,2, 0,4 and 0,8%  and stored  during  ripening at 10oC period. The result showed that no different of moisture, fat and protein content, hardness, pH value of cheese products. The hydrolysis process at maturity caused decreasing of  pH value. Added propolis in the coating material could inhibited  mould and yeast growth significantly. Key words:  Gouda Cheese, propolis, edible coating

  13. 100% Solids Polyurethane Sequestration Coating

    Science.gov (United States)

    2014-04-11

    section of an aluminum flake loaded thiol-ene coating peeled off of a glass plate after cure. Adsorbents and Reactive Particles Nanoparticulate ...commercially to the oil drilling industry. The incorporation of CaCO3 nanoparticulate into thiol-ene coatings was demonstrated in our Phase I project...Porous, nanoparticulate SiO2 has also been identified and evaluated in coating systems. The effect of high capacity adsorbents on permeation through

  14. Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

    National Research Council Canada - National Science Library

    Liang, Kang; Ricco, Raffaele; Doherty, Cara M; Styles, Mark J; Bell, Stephen; Kirby, Nigel; Mudie, Stephen; Haylock, David; Hill, Anita J; Doonan, Christian J; Falcaro, Paolo

    2015-01-01

    ... termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks...

  15. Formation and antifouling properties of amphiphilic coatings on polypropylene fibers.

    Science.gov (United States)

    Goli, Kiran K; Rojas, Orlando J; Genzer, Jan

    2012-11-12

    We describe the formation of amphiphilic polymeric assemblies via a three-step functionalization process applied to polypropylene (PP) nonwovens and to reference hydrophobic self-assembled n-octadecyltrichlorosilane (ODTS) monolayer surfaces. In the first step, denatured proteins (lysozyme or fibrinogen) are adsorbed onto the hydrophobic PP or the ODTS surfaces, followed by cross-linking with glutaraldehyde in the presence of sodium borohydride (NaBH(4)). The hydroxyl and amine functional groups of the proteins permit the attachment of initiator molecules, from which poly (2-hydroxyethyl methacrylate) (PHEMA) polymer grafts are grown directly through "grafting from" atom transfer radical polymerization. The terminal hydroxyls of HEMA's pendent groups are modified with fluorinating moieties of different chain lengths, resulting in amphiphilic brushes. A palette of analytical tools, including ellipsometry, contact angle goniometry, Fourier transform infrared spectroscopy in the attenuated total reflection mode, and X-ray photoelectron spectroscopy is employed to determine the changes in physicochemical properties of the functionalized surfaces after each modification step. Antifouling properties of the resultant amphiphilic coatings on PP are analyzed by following the adsorption of fluorescein isothiocyanate-labeled bovine serum albumin as a model fouling protein. Our results suggest that amphiphilic coatings suppress significantly adsorption of proteins as compared with PP fibers or PP surfaces coated with PHEMA brushes. The type of fluorinated chain grafted to PHEMA allows modulation of the surface composition of the topmost layer of the amphiphilic coating and its antifouling capability.

  16. Modeling the self-assembly of clathrin coats

    NARCIS (Netherlands)

    Giani, Matteo

    2017-01-01

    The assembly of clathrin coats in the presence of adaptor proteins was studied through computer simulations using coarse-grained models and through statistical mechanics. Adopting a reductionist approach based on recent experimental results, we aimed at reproducing and studying the minimal

  17. Macrophage behavior on multilayered DNA-coatings in vitro.

    NARCIS (Netherlands)

    Beucken, J.J.J.P van der; Walboomers, X.F.; Vos, M.R-J.; Sommerdijk, N.A.J.M.; Nolte, R.J.M.; Jansen, J.A.

    2007-01-01

    A pivotal factor to consider in the development of biomaterials and biomaterial coatings is the inflammatory response to these materials. The insertion of implants is followed by protein adsorption and subsequent interactions with cellular components of the biological surroundings, in which

  18. Article Including Environmental Barrier Coating System

    Science.gov (United States)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  19. Axisymmetric fretting analysis in coated cylinder

    Indian Academy of Sciences (India)

    erties by coating the surface. There is rather scanty literature available on fretting analysis of coated components. Presence of such coatings has a large influence on the near surface state of stress. The effect of coatings on the severity of fretting is the focus of this paper. Results obtained for both hard and soft coatings are ...

  20. Coatings Technology Integration Office (CTIO)

    Data.gov (United States)

    Federal Laboratory Consortium — CTIO serves as the Air Force's central resource for aircraft coating systems and their applications. CTIO's primary objectives are pollution prevention and improved...

  1. Corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2016-07-01

    Full Text Available The titanium alloys are used in defense, aerospace, automobile, chemical plants and biomedical applications due to their very high strength and lightweight properties. However, corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperatures. In the present paper, duplex NiCrAlY/WC–Co coating is coated onto Ti6Al4V substrate to investigate the corrosion behavior of both coated samples and the substrate. The duplex coating was performed with NiCrAlY as the intermediate coat of 200 μm thickness deposited by HVOF process and WC–Co ceramic top coat with varying thicknesses of 250 μm, 350 μm and 450 μm deposited by DS process. Potentiodynamic polarization tests were employed to investigate the corrosion performance of duplex coated samples and substrate in Ringer’s solution at 37 °C and pH value was set to 5.7. Finally the results reveal that 350 μm thick coated samples showed highest corrosion resistance compared to 250 μm thick samples as well as bare substrate. However, the 450 μm thick coated sample showed poor corrosion resistance compared to the substrate. The scale formed on the samples upon corrosion was characterized by using SEM analysis to understand the degree of corrosion behavior.

  2. Electrochemically switchable polypyrrole coated membranes

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, Claudia, E-mail: weidlich@dechema.d [DECHEMA e.V., Karl-Winnacker-Institut, Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany); Mangold, Klaus-Michael [DECHEMA e.V., Karl-Winnacker-Institut, Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany)

    2011-04-01

    A method for coating membranes with polypyrrole (PPy) has been developed. Different membranes, such as microfiltration as well as ion exchanger membranes have been coated with PPy to yield electrical conductivity of the membranes. The coated membranes have been investigated by cyclic voltammetry and scanning electron microscopy and their permeability and permselectivity have been tested. The results show that PPy can be tailored as cation or anion exchanger and its porosity can be controlled to avoid any impairment of the membrane by the polymer layer. These PPy coated membranes can be applied as electrochemically switchable, functionalised membranes with controllabel and variable separation properties.

  3. Conduit Coating Abrasion Testing

    Science.gov (United States)

    Sullivan, Mary K.

    2013-01-01

    During my summer internship at NASA I have been working alongside the team members of the RESTORE project. Engineers working on the RESTORE project are creating ·a device that can go into space and service satellites that no longer work due to gas shortage or other technical difficulties. In order to complete the task of refueling the satellite a hose needs to be used and covered with a material that can withstand effects of space. The conduit coating abrasion test will help the researchers figure out what type of thermal coating to use on the hose that will be refueling the satellites. The objective of the project is to determine whether or not the conduit coating will withstand the effects of space. For the RESTORE project I will help with various aspects of the testing that needed to be done in order to determine which type of conduit should be used for refueling the satellite. During my time on the project I will be assisting with wiring a relay board that connected to the test set up by soldering, configuring wires and testing for continuity. Prior to the testing I will work on creating the testing site and help write the procedure for the test. The testing will take place over a span of two weeks and lead to an informative conclusion. Working alongside various RESTORE team members I will assist with the project's documentation and records. All in all, throughout my internship at NASA I hope to learn a number of valuable skills and be a part of a hard working team of engineers.

  4. Sequence diversity in the coat protein gene of Lettuce big-vein associated virus and Mirafiori lettuce big-vein virus infecting lettuce in Brazil Variabilidade genética na porção codificadora para a proteína capsidial do Lettuce big-vein associated virus e Mirafiori lettuce big-vein virus provenientes de alface no Brasil

    Directory of Open Access Journals (Sweden)

    Márcio Martinello Sanches

    2008-06-01

    Full Text Available Lettuce big vein associated virus (LBVaV and Mirafiori lettuce big vein virus (MLBVV have been found in mixed infection in Brazil causing the lettuce big vein disease. Analysis of part of the coat protein (CP gene of Brazilian isolates of LBVaV collected from lettuce, showed at least 93% amino acid sequence identity with other LBVaV isolates. Genetic diversity among MLBVV CP sequences was higher when compared to LBVaV CP sequences, with amino acid sequence identity ranging between 91% to 100%. Brazilian isolates of MLBVV belong to subgroup A, with one RsaI restriction site on the coat protein gene. There is no indication for a possible geografical origin for the Brazilian isolates of LBVaV and MLBVV.Lettuce big vein associated virus (LBVaV e Mirafiori lettuce big vein virus (MLBVV têm sido encontrados em infecções mistas no Brasil, causando a doença conhecida como engrossamento das nervuras da alface. Análise de parte do gene da proteína capsidial (CP de isolados brasileiros de LBVaV coletados em alface, indicou que estes possuem identidade superior a 93% com isolados coletados em diferentes regiões geográficas. A diversidade genética entre a CP de isolados de MLBVV de alface foi maior comparada às sequências da CP de LBVaV, com a identidade de aminoácidos variando entre 91 a 100%. Os isolados brasileiros de MLBVV pertencem ao subgrupo A, com um único sítio de restrição RsaI no gene da proteína capsidial. Não há indicação para uma provável origem geográfica dos isolados brasileiros de MLBVV e LBVaV.

  5. Microplasma sprayed hydroxyapatite coatings

    CERN Document Server

    Dey, Arjun

    2015-01-01

    ""This unique book on development of microplasma sprayed HAp coating has been organized in a very compact yet comprehensive manner. This book also highlights the horizons of future research that invites the attention of global community, particularly those in bio-medical materials and bio-medical engineering field. This book will surely act as a very useful reference material for both graduate/post-graduate students and researchers in the field of biomedical, orthopedic and manufacturing engineering and research. I truly believ that this is the first ever effort which covers almost all the

  6. Durable Hybrid Coatings

    Science.gov (United States)

    2007-10-01

    rich primers at 32% and 42% PVC. PVC Epon 828 (g) Epicure 2353 (g) MEK (g) Mg and Mg alloy Pigments (g) 3820 AM60 AZ91B LNR96 AM503 AZG...vol. ratio. Epon 1001-CX-75 is an epoxide containing 25 wt.% MIBK/xylene (vol. ratio 65/35) solvent mixture, and Epicure 3140 is a solventless...μm. Table 1. Formulation of Mg-rich Primer Coating Ingredients Weight, g Epon 1001-CX-75 67 111 Epicure 3140 9.5 Mg powder 95 Aerosil® R974 1

  7. Multifunctional Ceramic Nanostructured Coatings

    Science.gov (United States)

    2010-12-01

    Stansky D.V., Petrznik M.I., Levashov E.A., Mavrin B.N. // Surf. Coat. Tech. -2007.-V.201.- P . 6143-6147. 7. Kauffmann F., Dehm G., Schier V...5a. CONTRACT NUMBER STCU Registration No: P -253 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Anatolij Tarasovich Pugachov...lead to the increase in crystalline lattice rigidness, hardness, melting temperature and oxidation resistance in Me2B→MeB→ MeB2 line [13]. Boron p

  8. Biofunctionalised biocompatible titania coatings for implants

    Energy Technology Data Exchange (ETDEWEB)

    Faust, V.; Heidenau, F.; Stenzel, F. [Bayreuth Univ. (Germany). Friedrich-Baur-Research Inst. for Biomaterials; Schmidgall, J.; Lipps, G. [Bayreuth Univ. (Germany). Biochemistry Dept.; Ziegler, G. [Bayreuth Univ. (Germany). Friedrich-Baur-Research Inst. for Biomaterials; Bayreuth Univ. (Germany). Inst. for Materials Research

    2002-07-01

    The biological response of an organism to an implant can be influenced by structuring and/or functionalisation of the implant surface. The goal of our study is to improve the osseointegration of orthopaedic endoprothesis by coating metal substrates with dense or nanoporous titania layers combined with biofunctionalisation of the surface with peptides and proteins. The sol-gel method is used to produce titania coatings on medical relevant substrates such as titanium or titanium alloys. Control of the educt ratios and the processing, like drying the specimens in air (xerogel) or supercritical drying in an autoclave unit (aerogel), results in dense or nanoporous titania films. Pore diameters can be adjusted between 10 and 120 nanometers. A remarkable characteristic of the coatings is the high number of surface hydroxy functionalities even after calcination. These reactive groups give ideal conditions for the biofunctionalisation. The immobilisation of biological active substances is carried out by successive covalent silanisation with an aminosilane using a dicarbonic acid as a spacer molecule, and binding of peptides to the spacers. Biocompatibility and cytotoxicity of the materials were tested with cell culture assays. (orig.)

  9. Disease specific protein corona

    Science.gov (United States)

    Rahman, M.; Mahmoudi, M.

    2015-03-01

    It is now well accepted that upon their entrance into the biological environments, the surface of nanomaterials would be covered by various biomacromolecules (e.g., proteins and lipids). The absorption of these biomolecules, so called `protein corona', onto the surface of (nano)biomaterials confers them a new `biological identity'. Although the formation of protein coronas on the surface of nanoparticles has been widely investigated, there are few reports on the effect of various diseases on the biological identity of nanoparticles. As the type of diseases may tremendously changes the composition of the protein source (e.g., human plasma/serum), one can expect that amount and composition of associated proteins in the corona composition may be varied, in disease type manner. Here, we show that corona coated silica and polystyrene nanoparticles (after interaction with in the plasma of the healthy individuals) could induce unfolding of fibrinogen, which promotes release of the inflammatory cytokines. However, no considerable releases of inflammatory cytokines were observed for corona coated graphene sheets. In contrast, the obtained corona coated silica and polystyrene nanoparticles from the hypofibrinogenemia patients could not induce inflammatory cytokine release where graphene sheets do. Therefore, one can expect that disease-specific protein coronas can provide a novel approach for applying nanomedicine to personalized medicine, improving diagnosis and treatment of different diseases tailored to the specific conditions and circumstances.

  10. Monitoring of tablet coating processes with colored coatings.

    Science.gov (United States)

    Barimani, Shirin; Kleinebudde, Peter

    2018-02-01

    Endpoints of coating processes for colored tablets were determined using in-line Raman spectroscopy. Coatings were performed with six commercially available formulations of pink, yellow, red, beige, green and blue color. The coatings were comprising pigments and/or dyes, some causing fluorescence and interfering the Raman signal. Using non-contact optics, a Raman probe was used as process analytical technology (PAT) tool, and acquired spectra were correlated to the sprayed mass of aqueous coating suspension. Process endpoints were determined using univariate (UV) data analysis and three multivariate analysis methods, namely Projection to Latent Structures (PLS)-regression, Science-Based Calibration (SBC) and Multivariate Curve Resolution (MCR). The methods were compared regarding model performance parameters. The endpoints of all coating experiments could be predicted until a total coating time of 50min corresponding to coating thicknesses between 21 and 38µm, depending on the density of the coat formulation. With the exception of SBC, all calibration methods resulted in R 2 values higher than 0.9. Additionally, the methods were evaluated regarding their capability for in-line process monitoring. For each color, at least two methods were feasible to do this. Overall, PLS-regression led to best model performance parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Proteomics Analysis Reveals Distinct Corona Composition on Magnetic Nanoparticles with Different Surface Coatings: Implications for Interactions with Primary Human Macrophages.

    Directory of Open Access Journals (Sweden)

    Carmen Vogt

    Full Text Available Superparamagnetic iron oxide nanoparticles (SPIONs have emerged as promising contrast agents for magnetic resonance imaging. The influence of different surface coatings on the biocompatibility of SPIONs has been addressed, but the potential impact of the so-called corona of adsorbed proteins on the surface of SPIONs on their biological behavior is less well studied. Here, we determined the composition of the plasma protein corona on silica-coated versus dextran-coated SPIONs using mass spectrometry-based proteomics approaches. Notably, gene ontology (GO enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG pathway analysis revealed distinct protein corona compositions for the two different SPIONs. Relaxivity of silica-coated SPIONs was modulated by the presence of a protein corona. Moreover, the viability of primary human monocyte-derived macrophages was influenced by the protein corona on silica-coated, but not dextran-coated SPIONs, and the protein corona promoted cellular uptake of silica-coated SPIONs, but did not affect internalization of dextran-coated SPIONs.

  12. Proteomics Analysis Reveals Distinct Corona Composition on Magnetic Nanoparticles with Different Surface Coatings: Implications for Interactions with Primary Human Macrophages.

    Science.gov (United States)

    Vogt, Carmen; Pernemalm, Maria; Kohonen, Pekka; Laurent, Sophie; Hultenby, Kjell; Vahter, Marie; Lehtiö, Janne; Toprak, Muhammet S; Fadeel, Bengt

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have emerged as promising contrast agents for magnetic resonance imaging. The influence of different surface coatings on the biocompatibility of SPIONs has been addressed, but the potential impact of the so-called corona of adsorbed proteins on the surface of SPIONs on their biological behavior is less well studied. Here, we determined the composition of the plasma protein corona on silica-coated versus dextran-coated SPIONs using mass spectrometry-based proteomics approaches. Notably, gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed distinct protein corona compositions for the two different SPIONs. Relaxivity of silica-coated SPIONs was modulated by the presence of a protein corona. Moreover, the viability of primary human monocyte-derived macrophages was influenced by the protein corona on silica-coated, but not dextran-coated SPIONs, and the protein corona promoted cellular uptake of silica-coated SPIONs, but did not affect internalization of dextran-coated SPIONs.

  13. Proteomics Analysis Reveals Distinct Corona Composition on Magnetic Nanoparticles with Different Surface Coatings: Implications for Interactions with Primary Human Macrophages

    Science.gov (United States)

    Vogt, Carmen; Pernemalm, Maria; Kohonen, Pekka; Laurent, Sophie; Hultenby, Kjell; Vahter, Marie; Lehtiö, Janne; Toprak, Muhammet S.; Fadeel, Bengt

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have emerged as promising contrast agents for magnetic resonance imaging. The influence of different surface coatings on the biocompatibility of SPIONs has been addressed, but the potential impact of the so-called corona of adsorbed proteins on the surface of SPIONs on their biological behavior is less well studied. Here, we determined the composition of the plasma protein corona on silica-coated versus dextran-coated SPIONs using mass spectrometry-based proteomics approaches. Notably, gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed distinct protein corona compositions for the two different SPIONs. Relaxivity of silica-coated SPIONs was modulated by the presence of a protein corona. Moreover, the viability of primary human monocyte-derived macrophages was influenced by the protein corona on silica-coated, but not dextran-coated SPIONs, and the protein corona promoted cellular uptake of silica-coated SPIONs, but did not affect internalization of dextran-coated SPIONs. PMID:26444829

  14. Superheating in coated niobium

    Science.gov (United States)

    Junginger, T.; Wasserman, W.; Laxdal, R. E.

    2017-12-01

    Using muon spin rotation it is shown that the field of first flux penetration {H}{entry} in Nb is enhanced by about 30% if coated with an overlayer of Nb3Sn or MgB2. This is consistent with an increase from the lower critical magnetic field {H}{{c}1} up to the superheating field {H}{sh} of the Nb substrate. In the experiments presented here coatings of Nb3Sn and MgB2 with a thickness between 50 and 2000 nm have been tested. {H}{entry} does not depend on material or thickness. This suggests that the energy barrier at the boundary between the two materials prevents flux entry up to {H}{sh} of the substrate. A mechanism consistent with these findings is that the proximity effect recovers the stability of the energy barrier for flux penetration, which is suppressed by defects for uncoated samples. Additionally, a low temperature baked Nb sample has been tested. Here a 6% increase of {H}{entry} was found, also pushing {H}{entry} beyond {H}{{c}1}.

  15. Federal Highway Administration 100-year coating study.

    Science.gov (United States)

    2012-11-01

    The Federal Highway Administration 100-Year Coating Study was initiated in August 2009 to search for durable : coating systems at a reasonable cost. The objective of the study was to identify and evaluate coating materials that can : provide 100 year...

  16. An assessment of lactobiopolymer-montmorillonite composites for dip coating applications on fresh strawberries.

    Science.gov (United States)

    Junqueira-Gonçalves, Maria Paula; Salinas, Gonzalo E; Bruna, Julio E; Niranjan, Keshavan

    2017-04-01

    The use of biopolymer coatings appears as a good alternative to preserve highly perishable fruits, as well as the environment. Proteins generally produce films with good mechanical properties, although their highly hydrophilic nature limits the use in many applications. Nanoparticles, such as nanoclays, can play a critical role in improving barrier properties. The present study evaluated the effect of the addition of montmorillonite (MMT)-nanoparticles to a lacto-biopolymer coating, focusing on: (i) the morphological, thermal and barrier properties of the material and (ii) the shelf life of coated fresh strawberries. The addition of MMT improved the water vapor barrier property. Morphological and thermal analysis indicated a good interaction between the milk protein and the nanoclay, which was intercalated within the milk protein base (MPB) matrix, offering a more tortuous path to diffusing migrants. The MMT-MPB coating helped to significantly (P ≤ 0.05) reduce the weight loss, as well as oxygen uptake and the release of carbon dioxide, and improved the fruit firmness and reduced mould and yeast load compared to the uncoated fruits. The addition of MMT gave statistical difference (P ≤ 0.05) in terms of weight loss, subjective global appearance and purchase intention of coated fresh strawberries. The addition of nanofillers, such as MMT, into protein-based coating could improve its water vapour barrier and could affect, positively, some parameters of the shelf life of coated strawberries. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Intumescent coatings under fast heating

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere

    2012-01-01

    Intumescent coatings are widely used to delay or minimise the destructive effects of fire. They are usually tested under conditions that simulate the relatively slow build-up of heat in a normal fire. Here, the effects of damage during a fire causing sudden heating of the coating were studied....

  18. Westinghouse thermal barrier coatings development

    Energy Technology Data Exchange (ETDEWEB)

    Goedjen, J.G.; Wagner, G. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-01

    Westinghouse, in conjunction with the Department of Energy and Oak Ridge National Laboratory, has embarked upon a program for the development of advanced thermal barrier coatings for industrial gas turbines. Development of thermal barrier coatings (TBC`s) for industrial gas turbines has relied heavily on the transfer of technology from the aerospace industry. Significant differences in the time/temperature/stress duty cycles exist between these two coating applications. Coating systems which perform well in aerospace applications may not been optimized to meet power generation performance requirements. This program will focus on development of TBC`s to meet the specific needs of power generation applications. The program is directed at developing a state-of-the-art coating system with a minimum coating life of 25,000 hours at service temperatures required to meet increasing operating efficiency goals. Westinghouse has assembled a team of university and industry leaders to accomplish this goal. Westinghouse will coordinate the efforts of all program participants. Chromalloy Turbine Technologies, Inc. and Sermatech International, Inc. will be responsible for bond coat and TBC deposition technology. Praxair Specialty Powders, Inc. will be responsible for the fabrication of all bond coat and ceramic powders for the program. Southwest Research Institute will head the life prediction modelling effort; they will also be involved in coordinating nondestructive evaluation (NDE) efforts. Process modelling will be provided by the University of Arizona.

  19. Lignin based controlled release coatings

    NARCIS (Netherlands)

    Mulder, W.J.; Gosselink, R.J.A.; Vingerhoeds, M.H.; Harmsen, P.F.H.; Eastham, D.

    2011-01-01

    Urea is a commonly used fertilizer. Due to its high water-solubility, misuse easily leads to excess nitrogen levels in the soil. The aim of this research was to develop an economically feasible and biodegradable slow-release coating for urea. For this purpose, lignin was selected as coating

  20. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  1. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  2. Rapidly curable electrically conductive clear coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Mark P.; Anderson, Lawrence G.; Post, Gordon L.

    2018-01-16

    Rapidly curable electrically conductive clear coatings are applied to substrates. The electrically conductive clear coating includes to clear layer having a resinous binder with ultrafine non-stoichiometric tungsten oxide particles dispersed therein. The clear coating may be rapidly cured by subjecting the coating to infrared radiation that heats the tungsten oxide particles and surrounding resinous binder. Localized heating increases the temperature of the coating to thereby thermally cure the coating, while avoiding unwanted heating of the underlying substrate.

  3. Functional Plasma-Deposited Coatings

    Directory of Open Access Journals (Sweden)

    Mykhaylo Pashechko

    2017-12-01

    Full Text Available The paper focuses on the problem of low adhesion of plasma sprayed coatings to the substrate. The subsequent laser treatment modes and their influence on the coating-substrate interface were studied. This allows to decrease the level of metstability of the coating, thus decreasing its hardness down to 11-12 GPa on the surface and to about 9 GPa on depth of 400 µm. The redistribution of alloying elements through solid and liquid diffusion improves mechanical properties and rises the adhesion up to 450 MPa after remelting and up to 90-110 MPa after laser-aided thermal cycling. At he same time, remelting of coating helps to decrease its porosity down to 1%. Obtained complex of properties also allows to improve wear resistance of coatings and to decrease friction factor.

  4. Foundry Coating Technology: A Review

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

    2011-01-01

    The importance of foundry coating in improving the surface quality of castings cannot be over emphasized. The appli-cation of mould and core washes creates a high thermal integrity barrier between the metal and the mould resulting in the reduction of the thermal shock experienced by the sand system....... These thermal shock leads to series of surface de-fects such as veining/finning, metal penetration, burn-on/in, scab, rat tail, erosion etc. The use of coatings reduces the tendency of occurrence of these defects. However, the understanding of the coating, its components, characteristics and mechanism of action...... is important. In this review, a detailed description of these topics and examples are provided where necessary. A potential area of research in foundry coating development, using sol-gel process is suggested. The application of sol-gel technology in the development of foundry coatings is a novel approach....

  5. Layer by layer coating of NH2-silicate/polycarboxylic acid polymer saturated by Ni(2+) onto the super magnetic NiFe2O4 nanoparticles for sensitive and bio-valuable separation of His-tagged proteins.

    Science.gov (United States)

    Mirahmadi-Zare, Seyede Zohreh; Aboutalebi, Fatemeh; Allafchian, Maryam; Pirjamali, Leila; Nasr-Esfahani, Mohammad-Hossein

    2017-10-28

    Magnetic nanoparticles NiFe2O4 was synthesized and covered in the silicate lattice of (3-Aminopropyl) triethoxysilane (APS) by the sol-gel process. Subsequently, the EDTA-dianhydride was attached to the amino surface of magnetic nanoparticles (MNPs) during the nucleophilic attack. This polycarboxylic layer trapped the high level of nickel ions for selective bonding to the His-tagged recombinant protein. The surface of MNPs was investigated by TEM, XRD, SEM (EDSA), VSM, BET, FT-IR and zeta potential analysis which characterized the size, chemical lattice, morphology, magnetic strength, specific surface area, functional groups and charge of the surface of nanoparticles. The performance and validity of the nanoparticles were studied by the purification of His-tagged green fluorescence protein (His-GFP). Also, the safety of proposed Ni-MNPs in the purification procedure of His-tagged proteins for pharmaceutical applications was proved by the determination of the nickel leakage level in the purified final protein using atomic absorption spectroscopy. In vitro cytotoxicity of Ni-MNPs and trace metal ions was investigated by the MTS assay technique. In addition, the comparison of biological activity in purified protein (GM-CSF) and commercial sample did not show any toxic effect. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Multilayer Microlaminated Ceramic Thermal Barrier Coating

    National Research Council Canada - National Science Library

    Yu, Charles

    1997-01-01

    .... Both thermal and mechanical characteristics of the coatings can be potentially optimized, and the coating will be more tolerant towards strain damage, have better thermal insulation and provide...

  7. Functional hydrophobin-coating of thermally hydrocarbonized porous silicon microparticles.

    Science.gov (United States)

    Bimbo, Luis M; Mäkilä, Ermei; Raula, Janne; Laaksonen, Timo; Laaksonen, Päivi; Strommer, Katharina; Kauppinen, Esko I; Salonen, Jarno; Linder, Markus B; Hirvonen, Jouni; Santos, Hélder A

    2011-12-01

    Porous silicon (PSi) particles have been widely used in modulating the dissolution rate of various types of drugs loaded within its mesopores. This material can be surface treated in order to vary its hydrophobicity and several other properties, such as drug loading degree and release rate. Hydrophobins are a family of self-assembling proteins of fungal origin which have the ability to form layers on hydrophobic materials. This type of protein layer can modify the characteristics and control the binding properties of the surface on which it assembles. In this study, we have developed a procedure to coat thermally hydrocarbonized-PSi microparticles with hydrophobin II (HFBII) in order to modify the particles' hydrophobicity and to improve their biocompatibility, while maintaining intact the advantageous drug releasing properties of the PSi. The HFBII content adsorbed onto the particles was successfully quantified by a protein assay. Drug dissolution and permeation across Caco-2 cell monolayers were also conducted, together with viability studies in AGS, Caco-2 and HT-29 cells. The characterization and coating stability assessment showed that the HFBII-coating desorbs partially from the particles' surface as the pH increases. The HFBII coating also improved the biocompatibility of the particles without compromising the enhanced drug permeation or release. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Coatings to prevent frost

    DEFF Research Database (Denmark)

    Lusada, Ricardo; Holberg, Stefan; Bennedsen, Jeanette Marianne Dalgaard

    2016-01-01

    at temperatures just below 0°C, for example at −4°C, is low. Freezing of a single drop on aluminum leads, however, to instant freezing of the complete surface. On hydrophobic coatings, such a freezing drop is isolated; the frozen area grows slowly. At −4°C surface temperature in a +12°C/90% relative humidity...... environment, on surfaces providing a water contact angle hysteresis of about 10° and receding water contact angles higher than 90°, a rate for the growth of the average radius of the frozen area of about 2 µm/s was observed. Submitting the surface to an airflow of 1 m/s led to faster frost spreading in flow...

  9. Nature Inspired Surface Coatings

    Science.gov (United States)

    Rubner, Michael

    2011-04-01

    Materials Scientists more and more are looking to nature for clues on how to create highly functional surface coatings with exceptional properties. The fog harvesting capabilities of the Namib Desert beetle, the beautiful iridescent colors of the hummingbird, and the super water repellant abilities of the Lotus leaf are but a few examples of the amazing properties developed over many years in the natural world. Nature also makes extensive use of the pH-dependent behavior of weak functional groups such as carboxylic acid and amine functional groups. This presentation will explore synthetic mimics to the nano- and microstructures responsible for these fascinating properties. For example, we have demonstrated a pH-induced porosity transition that can be used to create porous films with pore sizes that are tunable from the nanometer scale to the multiple micron scale. The pores of these films, either nano- or micropores, can be reversibly opened and closed by changes in solution pH. The ability to engineer pH-gated porosity transitions in heterostructured thin films has led to the demonstration of broadband anti-reflection coatings that mimic the anti-reflection properties of the moth eye and pH-tunable Bragg reflectors with a structure and function similar to that found in hummingbird wings and the Longhorn beetle. In addition, the highly textured honeycomb-like surfaces created by the formation of micron-scale pores are ideally suited for the creation of superhydrophobic surfaces that mimic the behavior of the self-cleaning lotus leaf. The development of synthetic "backbacks" on immune system cells that may one day ferry drugs to disease sites will also be discussed.

  10. Avian Egg and Egg Coat.

    Science.gov (United States)

    Okumura, Hiroki

    2017-01-01

    An ovulated egg of vertebrates is surrounded by unique extracellular matrix, the egg coat or zona pellucida, playing important roles in fertilization and early development. The vertebrate egg coat is composed of two to six zona pellucida (ZP) glycoproteins that are characterized by the evolutionarily conserved ZP-domain module and classified into six subfamilies based on phylogenetic analyses. Interestingly, investigations of biochemical and functional features of the ZP glycoproteins show that the roles of each ZP-glycoprotein family member in the egg-coat formation and the egg-sperm interactions seemingly vary across vertebrates. This might be one reason why comprehensive understandings of the molecular basis of either architecture or physiological functions of egg coat still remain elusive despite more than 3 decades of intensive investigations. In this chapter, an overview of avian egg focusing on the oogenesis are provided in the first section, and unique features of avian egg coat, i.e., perivitelline layer, including the morphology, biogenesis pathway, and physiological functions are discussed mainly on chicken and quail in terms of the characteristics of ZP glycoproteins in the following sections. In addition, these features of avian egg coat are compared to mammalian zona pellucida, from the viewpoint that the structural and functional varieties of ZP glycoproteins might be associated with the evolutionary adaptation to their reproductive strategies. By comparing the egg coat of birds and mammals whose reproductive strategies are largely different, new insights into the molecular mechanisms of vertebrate egg-sperm interactions might be provided.

  11. Characterization and tribology of PEG-like coatings on UHMWPE for total hip replacements.

    Science.gov (United States)

    Kane, Sheryl R; Ashby, Paul D; Pruitt, Lisa A

    2010-03-15

    A crosslinked hydrogel coating similar to poly(ethylene glycol) (PEG) was covalently bonded to the surface of ultrahigh molecular weight polyethylene (UHMWPE) to improve the lubricity and wear resistance of the UHWMPE for use in total joint replacements. The chemistry, hydrophilicity, and protein adsorption resistance of the coatings were determined, and the wear behavior of the PEG-like coating was examined by two methods: pin-on-disk tribometry to evaluate macroscale behavior, and atomic force microscopy (AFM) to simulate asperity wear. As expected, the coating was found to be highly PEG-like, with approximately 83% ether content by x-ray photoelectron spectroscopy and more hydrophilic and resistant to protein adsorption than uncoated UHMWPE. Pin-on-disk testing showed that the PEG-like coating could survive 3 MPa of contact pressure, comparable to that experienced by total hip replacements. AFM nanoscratching experiments uncovered three damage mechanisms for the coatings: adhesion/microfracture, pure adhesion, and delamination. The latter two mechanisms appear to correlate well with wear patterns induced by pin-on-disk testing and evaluated by attenuated total reflection Fourier transform infrared spectroscopy mapping. Understanding the mechanisms by which the PEG-like coatings wear is critical for improving the behavior of subsequent generations of wear-resistant hydrogel coatings. (c) 2009 Wiley Periodicals, Inc.

  12. Integrated Glass Coating Manufacturing Line

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor [Enki Technology Inc., San Jose, CA (United States)

    2015-09-30

    This project aims to enable US module manufacturers to coat glass with Enki’s state of the art tunable functionalized AR coatings at the lowest possible cost and highest possible performance by encapsulating Enki’s coating process in an integrated tool that facilitates effective process improvement through metrology and data analysis for greater quality and performance while reducing footprint, operating and capital costs. The Phase 1 objective was a fully designed manufacturing line, including fully specified equipment ready for issue of purchase requisitions; a detailed economic justification based on market prices at the end of Phase 1 and projected manufacturing costs and a detailed deployment plan for the equipment.

  13. Laser-based coatings removal

    Energy Technology Data Exchange (ETDEWEB)

    Freiwald, J.G.; Freiwald, D.A. [F2 Associates, Inc., Albuquerque, NM (United States)

    1995-10-01

    Over the years as building and equipment surfaces became contaminated with low levels of uranium or plutonium dust, coats of paint were applied to stabilize the contaminants in place. Most of the earlier paint used was lead-based paint. More recently, various non-lead-based paints, such as two-part epoxy, are used. For D&D (decontamination and decommissioning), it is desirable to remove the paints or other coatings rather than having to tear down and dispose of the entire building. This report describes the use of pulse-repetetion laser systems for the removal of paints and coatings.

  14. Sar1 localizes at the rims of COPII-coated membranes in vivo.

    Science.gov (United States)

    Kurokawa, Kazuo; Suda, Yasuyuki; Nakano, Akihiko

    2016-09-01

    The Sar1 GTPase controls coat assembly on coat protein complex II (COPII)-coated vesicles, which mediate protein transport from the endoplasmic reticulum (ER) to the Golgi. The GTP-bound form of Sar1, activated by the ER-localized guanine nucleotide exchange factor (GEF) Sec12, associates with the ER membrane. GTP hydrolysis by Sar1, stimulated by the COPII-vesicle-localized GTPase-activating protein (GAP) Sec23, in turn causes Sar1 to dissociate from the membrane. Thus, Sar1 is cycled between active and inactive states, and on and off vesicle membranes, but its precise spatiotemporal regulation remains unknown. Here, we examined Sar1 localization on COPII-coated membranes in living Saccharomyces cerevisiae cells. Two-dimensional (2D) observation demonstrated that Sar1 showed modest accumulation around the ER exit sites (ERES) in a manner that was dependent on Sec16 function. Detailed three-dimensional (3D) observation further demonstrated that Sar1 localized at the rims of the COPII-coated membranes, but was excluded from the rest of the COPII membranes. Additionally, a GTP-locked form of Sar1 induced abnormally enlarged COPII-coated structures and covered the entirety of these structures. These results suggested that the reversible membrane association of Sar1 GTPase leads to its localization being restricted to the rims of COPII-coated membranes in vivo. © 2016. Published by The Company of Biologists Ltd.

  15. Neocellularization and neovascularization of nanosized bioactive glass-coated decellularized trabecular bone scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian

    2012-09-11

    In this study, the in vivo recellularization and neovascularization of nanosized bioactive glass (n-BG)-coated decellu-larized trabecular bone scaffolds were studied in a rat model and quantified using stereological analyses. Based on the highest amount of vascular endothelial growth factor (VEGF) secreted by human fibroblasts grown on n-BG coatings (0-1.245 mg/cm 2), decellularized trabecular bone samples (porosity: 43-81%) were coated with n-BG particles. Grown on n-BG particles at a coating density of 0.263 mg/cm2, human fibroblasts produced 4.3 times more VEGF than on uncoated controls. After 8 weeks of implantation in Sprague-Dawley rats, both uncoated and n-BG-coated samples were well infiltrated with newly formed tissue (47-48%) and blood vessels (3-4%). No significant differences were found in cellularization and vascularization between uncoated bone scaffolds and n-BG-coated scaffolds. This finding indicates that the decellularized bone itself may exhibit growth-promoting properties induced by the highly interconnected pore microarchitecture and/or proteins left behind on decellularized scaffolds. Even if we did not find proangiogenic effects in n-BG-coated bone scaffolds, a bioactive coating is considered to be beneficial to impart osteoinductive and osteoconductive properties to decellularized bone. n-BG-coated bone grafts have thus high clinical potential for the regeneration of complex tissue defects given their ability for recellularization and neovascularization. © 2012 Wiley Periodicals, Inc.

  16. Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

    KAUST Repository

    Bucs, Szilard

    2017-05-30

    Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

  17. In Vivo Electrochemical Analysis of a PEDOT/MWCNT Neural Electrode Coating

    Directory of Open Access Journals (Sweden)

    Nicolas A. Alba

    2015-10-01

    Full Text Available Neural electrodes hold tremendous potential for improving understanding of brain function and restoring lost neurological functions. Multi-walled carbon nanotube (MWCNT and dexamethasone (Dex-doped poly(3,4-ethylenedioxythiophene (PEDOT coatings have shown promise to improve chronic neural electrode performance. Here, we employ electrochemical techniques to characterize the coating in vivo. Coated and uncoated electrode arrays were implanted into rat visual cortex and subjected to daily cyclic voltammetry (CV and electrochemical impedance spectroscopy (EIS for 11 days. Coated electrodes experienced a significant decrease in 1 kHz impedance within the first two days of implantation followed by an increase between days 4 and 7. Equivalent circuit analysis showed that the impedance increase is the result of surface capacitance reduction, likely due to protein and cellular processes encapsulating the porous coating. Coating’s charge storage capacity remained consistently higher than uncoated electrodes, demonstrating its in vivo electrochemical stability. To decouple the PEDOT/MWCNT material property changes from the tissue response, in vitro characterization was conducted by soaking the coated electrodes in PBS for 11 days. Some coated electrodes exhibited steady impedance while others exhibiting large increases associated with large decreases in charge storage capacity suggesting delamination in PBS. This was not observed in vivo, as scanning electron microscopy of explants verified the integrity of the coating with no sign of delamination or cracking. Despite the impedance increase, coated electrodes successfully recorded neural activity throughout the implantation period.

  18. Characterization of gas tunnel type plasma sprayed hydroxyapatite-nanostructure titania composite coatings

    Science.gov (United States)

    Yugeswaran, S.; Kobayashi, A.; Ucisik, A. Hikmet; Subramanian, B.

    2015-08-01

    Hydroxyapatite (HA) can be coated onto metal implants as a ceramic biocompatible coating to bridge the growth between implants and human tissue. Meanwhile many efforts have been made to improve the mechanical properties of the HA coatings without affecting its bioactivity. In the present study, nanostructure titania (TiO2) was mixed with HA powder and HA-nanostructure TiO2 composite coatings were produced by gas tunnel type plasma spraying torch under optimized spraying conditions. For this purpose, composition of 10 wt% TiO2 + 90 wt% HA, 20 wt% TiO2 + 80 wt% HA and 30 wt% TiO2 + 70 wt% HA were selected as the feedstock materials. The phase, microstructure and mechanical properties of the coatings were characterized. The obtained results validated that the increase in weight percentage of nanostructure TiO2 in HA coating significantly increased the microhardness, adhesive strength and wear resistance of the coatings. Analysis of the in vitro bioactivity and cytocompatibility of the coatings were done using conventional simulated body fluid (c-SBF) solution and cultured green fluorescent protein (GFP) labeled marrow stromal cells (MSCs) respectively. The bioactivity results revealed that the composite coating has bio-active surface with good cytocompatibility.

  19. A degradable polydopamine coating based on disulfide-exchange reaction

    Science.gov (United States)

    Hong, Daewha; Lee, Hojae; Kim, Beom Jin; Park, Taegyun; Choi, Ji Yu; Park, Matthew; Lee, Juno; Cho, Hyeoncheol; Hong, Seok-Pyo; Yang, Sung Ho; Jung, Sun Ho; Ko, Sung-Bo; Choi, Insung S.

    2015-11-01

    Although the programmed degradation of biocompatible films finds applications in various fields including biomedical and bionanotechnological areas, coating methods have generally been limited to be substrate-specific, not applicable to any kinds of substrates. In this paper, we report a dopamine derivative, which allows for both universal coating of various substrates and stimuli-responsive film degradation, inspired by mussel-adhesive proteins. Two dopamine moieties are linked together by the disulfide bond, the cleavage of which enables the programmed film degradation. Mechanistic analysis of the degradable films indicates that the initial cleavage of the disulfide linkage causes rapid uptake of water molecules, hydrating the films, which leads to rapid degradation. Our substrate-independent coating of degradable films provides an advanced tool for drug delivery systems, tissue engineering, and anti-fouling strategies.Although the programmed degradation of biocompatible films finds applications in various fields including biomedical and bionanotechnological areas, coating methods have generally been limited to be substrate-specific, not applicable to any kinds of substrates. In this paper, we report a dopamine derivative, which allows for both universal coating of various substrates and stimuli-responsive film degradation, inspired by mussel-adhesive proteins. Two dopamine moieties are linked together by the disulfide bond, the cleavage of which enables the programmed film degradation. Mechanistic analysis of the degradable films indicates that the initial cleavage of the disulfide linkage causes rapid uptake of water molecules, hydrating the films, which leads to rapid degradation. Our substrate-independent coating of degradable films provides an advanced tool for drug delivery systems, tissue engineering, and anti-fouling strategies. Electronic supplementary information (ESI) available: Synthesis, characterization, and other additional details. See DOI: 10

  20. Hex Chrome Free Coatings for Electronics Overview

    Science.gov (United States)

    Kessel, Kurt

    2013-01-01

    The overall objective of the Hex Chrome Free Coatings for Electronics project is to evaluate and test pretreatment coating systems not containing hexavalent chrome in avionics and electronics housing applications. This objective will be accomplished by testing strong performing coating systems from prior NASA and DoD testing or new coating systems as determined by the stakeholders.

  1. Microneedles with intrinsic immunoadjuvant properties: microfabrication, protein stability, and modulated release.

    Science.gov (United States)

    Andrianov, Alexander K; Marin, Alexander; DeCollibus, Daniel P

    2011-01-01

    Intradermal immunization using microneedles requires compatible immunoadjuvant system. To address this challenge, we investigated microneedles coated with polyphosphazene polyelectrolyte, which served both as microfabrication material and an immunoadjuvant compound. Coated microneedles were fabricated by depositing formulations containing Poly[di(carboxylatophenoxy)phosphazene], PCPP, on metal shafts, and their physico-chemical characterization was conducted. Microfabrication of PCPP-coated microneedles exhibited strong dependence on protein-PCPP interactions in solutions and allowed for high efficiency of protein encapsulation. 70°C thermal inactivation studies demonstrated a remarkable increase in functional stability of protein in coated microneedles compared to solution formulation. A potential for modulation of protein release from coated microneedles has been demonstrated through ionic complexation of PCPP with small ions. Microneedles containing PCPP coatings provide improved protein stability, modulated release, and protein-friendly microfabrication process.

  2. Protective coatings for commercial particulates

    DEFF Research Database (Denmark)

    Kindl, B.; Teng, Y.H.; Liu, Y.L.

    1994-01-01

    SiC/Al composites are in large-scale production with Al-Si alloy matrices. The same composites with pure Al or low Si matrices need diffusion barriers on the SiC reinforcement to control the interfacial reaction. The present paper describes various approaches taken to obtain protective coatings...... of alumina and zirconia on SiC particulates by sol-gel techniques. Aqueous and organic precursors have been used. The extent of the reaction, i.e., the Si and Al4C3 content in the matrix, was determined by differential thermal analysis and X-ray diffraction. The reaction rates of some coated particulates...... in liquid Al are decreased by as much as one order of magnitude during the first 15 min of immersion. Pretreatments of the SiC surface, the composition and thickness of the coating interphase and heat treatments of the coated materials have been studied, and are discussed in relation to their effect...

  3. Cementless Hydroxyapatite Coated Hip Prostheses

    Science.gov (United States)

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  4. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  5. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  6. Positron studies of polymeric coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jean, Y.C. E-mail: jeany@umkc.edu; Mallon, P.E.; Zhang, R.; Chen Hongmin; Li Ying; Zhang Junjie; Wu, Y.C.; Sandreczki, T.C.; Suzuki, R.; Ohdaira, T.; Gu, X.; Nguyen, T

    2003-11-01

    In complicated coating systems, positrons have shown sensitivity in detecting the early stage of deterioration due to weathering, specially, in probing a specific location or depth of coatings from the surface through interfaces and the bulk. Existing extensive experimental positron data show that positron annihilation signals respond quantitatively to the deterioration process due to weathering. Now it is possible to detect the very early stage of coating deterioration at the atomic and molecular scale by using positrons, typically in days as compared to years by conventional methods. This paper summarizes recent positron studies in polymeric coatings. Correlations between positron data and a variety of chemical, physical and engineering data from ESR, AFM, cross-link density, gloss, and cyclic loading are presented.

  7. Method of measuring metal coating adhesion

    Science.gov (United States)

    Roper, J.R.

    A method for measuring metal coating adhesion to a substrate material comprising the steps of preparing a test coupon of substrate material having the metal coating applied to one surface thereof, applying a second metal coating of gold or silver to opposite surfaces of the test coupon by hot hollow cathode process, applying a coating to one end of each of two pulling rod members, joining the coated ends of the pulling rod members to said opposite coated surfaces of the test coupon by a solid state bonding technique and finally applying instrumented static tensile loading to the pulling rod members until fracture of the metal coating adhesion to the substrate material occurs.

  8. Coating of silicon pore optics

    DEFF Research Database (Denmark)

    Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland

    2009-01-01

    For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates...

  9. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  10. Electrically conductive polymer concrete coatings

    Science.gov (United States)

    Fontana, Jack J.; Elling, David; Reams, Walter

    1990-01-01

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  11. Evaluation of Manganese Phosphate Coatings.

    Science.gov (United States)

    1984-02-01

    D-AiD9 434 EVALUATION OF MANGANESE PHOSPHATE COTINGS(I) ARMY v/1 ARMAMENT RESEARCH R D DEVELO MENT CENTER IdATERYL lET NY I LARGE CALIBER WEAPON...5Y IIARS 163 TECHNICAL REPORT ARLCB-TR- 64003 EVALUATION OF MANGANESE PHOSPHATE COATINGS R. A. FARRARA FEBRUARY 1984 N US ARMY ARMAMENT RESEARCH AND...84003 _____________ 4. TTLE and -bitle)5. TYPE OF REPORT & PERIOD COVERED EVALUATION OF MANGANESE PHOSPHATE COATINGS Final 6. PERFORMING ORG. REPORT

  12. Coated substrate apparatus and method

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Zhenan; Diao, Ying; Mannsfeld, Stefan Christian Bernhardt; Tee, Chee-Keong; Becerril-Garcia, Hector A.; Zhou, Yan

    2018-01-09

    A coated substrate is formed with aligned objects such as small molecules, macromolecules and nanoscale particulates, such as inorganic, organic or inorganic/organic hybrid materials. In accordance with one or more embodiments, an apparatus or method involves an applicator having at least one surface patterned with protruded or indented features, and a coated substrate including a solution-based layer of objects having features and morphology attributes arranged as a function of the protruded or indented features.

  13. Silicone nanocomposite coatings for fabrics

    Science.gov (United States)

    Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

    2011-01-01

    A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

  14. Collective helicity switching of a DNA-coat assembly

    Science.gov (United States)

    Kim, Yongju; Li, Huichang; He, Ying; Chen, Xi; Ma, Xiaoteng; Lee, Myongsoo

    2017-07-01

    Hierarchical assemblies of biomolecular subunits can carry out versatile tasks at the cellular level with remarkable spatial and temporal precision. As an example, the collective motion and mutual cooperation between complex protein machines mediate essential functions for life, such as replication, synthesis, degradation, repair and transport. Nucleic acid molecules are far less dynamic than proteins and need to bind to specific proteins to form hierarchical structures. The simplest example of these nucleic acid-based structures is provided by a rod-shaped tobacco mosaic virus, which consists of genetic material surrounded by coat proteins. Inspired by the complexity and hierarchical assembly of viruses, a great deal of effort has been devoted to design similarly constructed artificial viruses. However, such a wrapping approach makes nucleic acid dynamics insensitive to environmental changes. This limitation generally restricts, for example, the amplification of the conformational dynamics between the right-handed B form to the left-handed Z form of double-stranded deoxyribonucleic acid (DNA). Here we report a virus-like hierarchical assembly in which the native DNA and a synthetic coat undergo repeated collective helicity switching triggered by pH change under physiological conditions. We also show that this collective helicity inversion occurs during translocation of the DNA-coat assembly into intracellular compartments. Translating DNA conformational dynamics into a higher level of hierarchical dynamics may provide an approach to create DNA-based nanomachines.

  15. Adhesion of thrombotic components to the surface of a clinically used oxygenator is not affected by Trillium coating

    NARCIS (Netherlands)

    van den Goor, J.M.; van Oeveren, W.; Rutten, P.M.; Tijssen, J.G.; Eijsman, L.

    2006-01-01

    The Trillium (R) coating is designed to minimize adsorption of protein and the attachment of cells and other particles. The present study was undertaken to investigate the effect of surface coating on the adhesion of thrombotic components (activated platelets, white blood cells and fibrin) to the

  16. The extracellular pollen coat in members of the Brassicaceae: composition, biosynthesis, and functions in pollination.

    Science.gov (United States)

    Murphy, D J

    2006-08-01

    I have used cellular and molecular genetic and bioinformatic approaches to characterise the components of the pollen coat in plants of the family Brassicaceae, including Arabidopsis thaliana and several brassicas including Brassica napus, B. oleracea, and B. rapa. The pollen coat in these species is mostly made up of a unique mixture of lipids that is highly enriched in acylated compounds, such as sterol esters and phospholipids. These acyl lipids are characterised by an unusually high degree of saturation. The fatty acids typically contain 70-90% saturated acyl residues such as myristate, palmitate, and stearate. The major sterol components of the pollen coat are saturated fatty acyl esters of stigmasterol, campesterol, and campestdienol. In addition to lipids, the second major component of the pollen coat is a specific group of proteins that is dominated by a family of proteins that we term pollenins. Although pollenins are by far the major protein components of the pollen coat of members of the Brassicaceae, proteomic analysis reveals that there are several additional protein components, including lipases, protein kinases, a pectin esterase, and a caleosin. The biosynthesis of these lipids and proteins and their significance for overall pollen function are reviewed and discussed.

  17. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  18. Spray-Deposited Superconductor/Polymer Coatings

    Science.gov (United States)

    Wise, Stephanie A.; Tran, Sang Q.; Hooker, Matthew W.

    1993-01-01

    Coatings that exhibit the Meissner effect formed at relatively low temperature. High-temperature-superconductor/polymer coatings that exhibit Meissner effect deposited onto components in variety of shapes and materials. Simple, readily available equipment needed in coating process, mean coatings produced economically. Coatings used to keep magnetic fields away from electronic circuits in such cryogenic applications as magnetic resonance imaging and detection of infrared, and in magnetic suspensions to provide levitation and/or damping of vibrations.

  19. Switchable antifouling coatings and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Michele L. Baca; Dirk, Shawn M.; Johnson, Ross Stefan

    2017-02-28

    The present invention relates to antifouling coatings capable of being switched by using heat or ultraviolet light. Prior to switching, the coating includes an onium cation component having antimicrobial and antibacterial properties. Upon switching, the coating is converted to a conjugated polymer state, and the cationic component is released with any adsorbed biofilm layer. Thus, the coatings herein have switchable and releasable properties. Methods of making and using such coatings are also described.

  20. The dead seed coat functions as a long-term storage for active hydrolytic enzymes.

    Directory of Open Access Journals (Sweden)

    Buzi Raviv

    Full Text Available Seed development culminates in programmed cell death (PCD and hardening of organs enclosing the embryo (e.g., pericarp, seed coat providing essentially a physical shield for protection during storage in the soil. We examined the proposal that dead organs enclosing embryos are unique entities that store and release upon hydration active proteins that might increase seed persistence in soil, germination and seedling establishment. Proteome analyses of dead seed coats of Brassicaceae species revealed hundreds of proteins being stored in the seed coat and released upon hydration, many are stress-associated proteins such as nucleases, proteases and chitinases. Functional analysis revealed that dead seed coats function as long-term storage for multiple active hydrolytic enzymes (e.g., nucleases that can persist in active forms for decades. Substances released from the dead seed coat of the annual desert plant Anastatica hierochuntica displayed strong antimicrobial activity. Our data highlighted a previously unrecognized feature of dead organs enclosing embryos (e.g., seed coat functioning not only as a physical shield for embryo protection but also as a long-term storage for active proteins and other substances that are released upon hydration to the "seedsphere" and could contribute to seed persistence in the soil, germination and seedling establishment.

  1. High quality protein microarray using in situ protein purification

    Directory of Open Access Journals (Sweden)

    Fleischmann Robert D

    2009-08-01

    Full Text Available Abstract Background In the postgenomic era, high throughput protein expression and protein microarray technologies have progressed markedly permitting screening of therapeutic reagents and discovery of novel protein functions. Hexa-histidine is one of the most commonly used fusion tags for protein expression due to its small size and convenient purification via immobilized metal ion affinity chromatography (IMAC. This purification process has been adapted to the protein microarray format, but the quality of in situ His-tagged protein purification on slides has not been systematically evaluated. We established methods to determine the level of purification of such proteins on metal chelate-modified slide surfaces. Optimized in situ purification of His-tagged recombinant proteins has the potential to become the new gold standard for cost-effective generation of high-quality and high-density protein microarrays. Results Two slide surfaces were examined, chelated Cu2+ slides suspended on a polyethylene glycol (PEG coating and chelated Ni2+ slides immobilized on a support without PEG coating. Using PEG-coated chelated Cu2+ slides, consistently higher purities of recombinant proteins were measured. An optimized wash buffer (PBST composed of 10 mM phosphate buffer, 2.7 mM KCl, 140 mM NaCl and 0.05% Tween 20, pH 7.4, further improved protein purity levels. Using Escherichia coli cell lysates expressing 90 recombinant Streptococcus pneumoniae proteins, 73 proteins were successfully immobilized, and 66 proteins were in situ purified with greater than 90% purity. We identified several antigens among the in situ-purified proteins via assays with anti-S. pneumoniae rabbit antibodies and a human patient antiserum, as a demonstration project of large scale microarray-based immunoproteomics profiling. The methodology is compatible with higher throughput formats of in vivo protein expression, eliminates the need for resin-based purification and circumvents

  2. Polyester based hybrid organic coatings

    Science.gov (United States)

    Wang, Xiaojiang

    Polyesters are a class of polymers widely used in organic coatings applications. In this work, four types of organic coatings based on polyester polyols were prepared: UV-curable polyester/poly(meth)acrylate coatings, thermal curable polyester polyurethane-urea coatings, thermal curable non-isocyanate polyurethane coatings, and UV-curable non-isocyanate polyurethane coatings. Polyester/poly(meth)acrylate block copolymers are synthesized using a combination of polycondensation and Atom-Transfer Radical Polymerization (ATRP). All block copolymers are characterized by means of Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). In the case of unsaturated-polyester-based block copolymers the main chain double bond in the polyester backbone remains almost unaffected during ATRP. The unsaturated block copolymers are crosslinkable and can form networks upon photo-irradiation in the presence of a suitable photoinitiator. These copolymers might be interesting candidates for coatings with better overall properties than those based on neat polyesters. Thermal curable polyester polyol based Polyurethane-Urea (PUU) coatings were formulated using Partially Blocked HDI isocyanurate (PBH), Isophorone Diamine (IPDA), and polyester polyol. As a comparison, the polyurethane coatings (PU) without adding IPDA were also prepared. The mechanical and viscoelastic properties of the PUU and PU coating were investigated by using tensile test and Dynamic Mechanical Thermal Analyzer (DMTA). It was found that PUU coating exhibited higher crosslink density, Tg, tensile modulus and strength than the corresponding PU coating. Thermal curable non-isocyanate polyurethane coatings were prepared by using polyamine and cyclic carbonate terminated polyester. Cyclic carbonate terminated polyester was synthesized from the reaction of the carbon dioxide and epoxidized polyester which was prepared from the polyester polyol. The properties of the epoxidized and cyclic carbonate

  3. Coatings and Tints of Spectacle Lenses

    Directory of Open Access Journals (Sweden)

    H. Zeki Büyükyıldız

    2012-10-01

    Full Text Available Spectacle lenses are made of mineral or organic (plastic materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1 Anti-reflection coatings, 2 Hard coatings, 3 Clean coat, 4 Mirror coatings, 5 Color tint coating (one of coloring processes, 6 Photochromic coating (one of photochromic processes, and 7 Anti-fog coatings. Anti-reflection coatings reduce unwanted reflections from the lens surfaces and increase light transmission. Hard coatings are applied for preventing the plastic lens surface from scratches and abrasion. Hard coatings are not required for the mineral lenses due to their hardness. Clean coat makes the lens surface smooth and hydrophobic. Thus, it prevents the adherence of dust, tarnish, and dirt particles on the lens surface. Mirror coatings are applied onto the sunglasses for cosmetic purpose. Color tinted and photochromic lenses are used for sun protection and absorption of the harmful UV radiations. Anti-fog coatings make the lens surface hydrophilic and prevent the coalescence of tiny water droplets on the lens surface that reduces light transmission. (Turk J Ophthalmol 2012; 42: 359-69

  4. Effect of hafnium and titanium coated implants on several blood biochemical markers after osteosynthesis in rabbits.

    Science.gov (United States)

    Yousef, Ashraf; Akhtyamov, Ildar; Shakirova, Faina; Zubairova, Lyaili; Gatina, Elmira; Aliev, Capital Ie Cyrilliclchin

    2014-01-01

    An experimental study comparing the dynamics of several biochemical markers before and after osteosynthesis, utilizing implants coated with titanium and hafnium nitrides and non-coated implants on rabbits' bones. The Study has been conducted on 30 rabbits of both sexes, at the age of 6-7 months, weighing 2526.5±74.4 gm. Animals underwent open osteotomy of the tibia in the middle third of the diaphysis followed by the intramedullary nailing. The level of alkaline phosphatase, calcium, phosphorus, total protein, glucose, ALT and AST were monitored for 60 days. the use of implants coated with titanium and hafnium nitrides, which have high strength, thermal and chemical stability, was not accompanied by the development of additional negative reactive changes compared to non-coated implants. Nanotechnology used in manufacturing bioinert coatings for implants for osteosynthesis, has made the post-operative period less complicated as reflected by less expressed changing in the markers of bone metabolism and hepatotoxicity.

  5. A protocol for the production of gliadin-cyanoacrylate nanoparticles for hydrophilic coating

    Science.gov (United States)

    This article presents a protocol for the production of protein-based nanoparticles that change the hydrophobic surface to hydrophilic by a simple spray coating. These nanoparticles are produced by the polymerization reaction of alkyl cyanoacrylate on the surface of cereal protein (gliadin) molecules...

  6. Spacecraft thermal control coatings

    Science.gov (United States)

    Guillaumon, Jean-Claude; Paillous, Alain

    1992-01-01

    The Experiment AO 138-6 was located on the trailing edge of the Long Duration Exposure Facility as part of the French Cooperative Payload (FRECOPA) Experiment. It was purely passive in nature: material specimens 2 x 2 cm, independently mounted in sample-holders, with their surface in the same reference plane, were exposed to space. Thirty samples were set in a vacuum-tight canister which was opened in space a few days after LDEF deployment and closed while still in orbit ten months later; twenty-four samples were directly exposed to space for the total flight duration (preflight handling, shuttle bay environment, separation from shuttle, shuttle environment, LEO environment, docking, descent, transfer to KSC). Materials included paints (conductive or nonconductive), SSM's, polymeric films, surface coatings, composite materials, and metals. After sample retrieving, inspection and measurements were carried out in atmospheric laboratory conditions on each sample: observation with binocular lenses and scanning electron microscopy, spectral relectance and transmittance using an integrating sphere in the wavelength range 280-2300 nm, emissivity by the means of a Gier & Dunkle portable reflectometer, electron spectroscopy for chemical analysis-x-ray photoelectron spectroscopy (ESCA-XPS), and Rutherford backscattering spectroscopy (RBS) measurements on some selected samples. The results obtained from flight were compared to laboratory data obtained in UV-irradiation tests when these data were available. As a general statement a good spectral concordance is observed for all samples not in the canister so long as air recoveries are taken into account. For one material, the degradation is more important for the sample in the canister than for those of the same material mounted at the surface of the tray; for most samples in the canister the degradation is slightly higher than the one which can be predicted from laboratory standard irradiations. Contamination problems having

  7. Covalent immobilization of carbohydrates on sol-gel-coated microplates.

    Science.gov (United States)

    Zou, Lan; Pang, Hei-Leung; Chan, Pak-Ho; Huang, Zhi-Shu; Gu, Lian-Quan; Wong, Kwok-Yin

    2008-09-01

    Carbohydrate microarrays have attracted increasing attention in recent years because of their ability to monitor biologically important protein-carbohydrate interactions in a high-throughput manner. Here we have developed an effective approach to immobilizing intact carbohydrates directly on polystyrene microtiter plates coated with amine-functionalized sol-gel monolayers. Lectin binding was monitored by fluorescence spectroscopy using these covalent arrays of carbohydrates that contained six mono- and di-saccharides on the microplates. In addition, binding affinities of lectin to carbohydrates were also quantitatively analyzed by determining IC(50) values of lectin-specific antibody with these arrays. Our results indicate that microplate-based carbohydrate arrays can be efficiently fabricated by covalent immobilization of intact carbohydrates on sol-gel-coated microplates. The microplate-based carbohydrate arrays can be applied for screening of protein-carbohydrate interactions in a high-throughput manner.

  8. Coating Carbon Fibers With Platinum

    Science.gov (United States)

    Effinger, Michael R.; Duncan, Peter; Coupland, Duncan; Rigali, Mark J.

    2007-01-01

    A process for coating carbon fibers with platinum has been developed. The process may also be adaptable to coating carbon fibers with other noble and refractory metals, including rhenium and iridium. The coated carbon fibers would be used as ingredients of matrix/fiber composite materials that would resist oxidation at high temperatures. The metal coats would contribute to oxidation resistance by keeping atmospheric oxygen away from fibers when cracks form in the matrices. Other processes that have been used to coat carbon fibers with metals have significant disadvantages: Metal-vapor deposition processes yield coats that are nonuniform along both the lengths and the circumferences of the fibers. The electrical resistivities of carbon fibers are too high to be compatible with electrolytic processes. Metal/organic vapor deposition entails the use of expensive starting materials, it may be necessary to use a furnace, and the starting materials and/or materials generated in the process may be hazardous. The present process does not have these disadvantages. It yields uniform, nonporous coats and is relatively inexpensive. The process can be summarized as one of pretreatment followed by electroless deposition. The process consists of the following steps: The surfaces of the fiber are activated by deposition of palladium crystallites from a solution. The surface-activated fibers are immersed in a solution that contains platinum. A reducing agent is used to supply electrons to effect a chemical reduction in situ. The chemical reduction displaces the platinum from the solution. The displaced platinum becomes deposited on the fibers. Each platinum atom that has been deposited acts as a catalytic site for the deposition of another platinum atom. Hence, the deposition process can also be characterized as autocatalytic. The thickness of the deposited metal can be tailored via the duration of immersion and the chemical activity of the solution.

  9. Clathrin Coat Disassembly Illuminates the Mechanisms of Hsp70 Force Generation

    Science.gov (United States)

    Liao, Hsien-Shun; Cuéllar, Jorge; Jin, Suping; Valpuesta, Jose M.; Jin, Albert J.; Lafer, Eileen M.

    2016-01-01

    Hsp70s use ATP hydrolysis to disrupt protein:protein associations or move macromolecules. One example is Hsc70-mediated disassembly of clathrin coats that form on vesicles during endocytosis. We exploit the exceptional features of these coats to test three models—Brownian ratchet, power-stroke and entropic pulling—proposed to explain how Hsp70s transform their substrates. Our data rule out the ratchet and power-stroke models, and instead support a collision pressure mechanism whereby collisions between clathrin coat walls and Hsc70s drive coats apart. Collision pressure is the complement to the pulling force described in the entropic pulling model. We also find that self-association can augment collision pressure to allow disassembly of clathrin lattices predicted to resist disassembly. These results illuminate how Hsp70s generate the forces that transform their substrates. PMID:27478930

  10. Development of the M2A1 Container Coatings ECP

    Science.gov (United States)

    2010-02-11

    52891 Acrylic E-Coat Urethane Powder Results APPLICATION Low End One-Coat Dip Enamel High End One-Coat Electrocoat High End One-Coat Top Coat Cure...Properties Data MIL-E-52891 Acrylic E-Coat Urethane Powder Results APPLICATION Low End One-Coat Dip Enamel High End One-Coat Electrocoat High End One-Coat...To complete a finishing cost analysis for painting ammunition containers. Compare equipment, layout and operating costs for Electrocoat and powder

  11. Ion Beam Sputtered Coatings of Bioglass

    Science.gov (United States)

    Hench, Larry L.; Wilson, J.; Ruzakowski, Patricia Henrietta Anne

    1982-01-01

    The ion beam sputtering technique available at the NASA-Lewis was used to apply coatings of bioglass to ceramic, metallic, and polymeric substrates. Experiments in vivo and in vitro described investigate these coatings. Some degree of substrate masking was obtained in all samples although stability and reactivity equivalent to bulk bioglass was not observed in all coated samples. Some degree of stability was seen in all coated samples that were reacted in vitro. Both metallic and ceramic substrates coated in this manner failed to show significantly improved coatings over those obtained with existing techniques. Implantation of the coated ceramic substrate samples in bone gave no definite bonding as seen with bulk glass; however, partial and patchy bonding was seen. Polymeric substrates in these studies showed promise of success. The coatings applied were sufficient to mask the underlying reactive test surface and tissue adhesion of collagen to bioglass was seen. Hydrophilic, hydrophobic, charged, and uncharged polymeric surfaces were successfully coated.

  12. Phase stability and biological property evaluation of plasma sprayed hydroxyapatite coatings for orthopedic and dental applications.

    Science.gov (United States)

    Vahabzadeh, Sahar; Roy, Mangal; Bandyopadhyay, Amit; Bose, Susmita

    2015-04-01

    In this work we have investigated the effects of strontium (Sr) dopant on in vitro protein release kinetics and in vivo osteogenic properties of plasma sprayed hydroxyapatite (HA) coatings, along with their dissolution behavior. Plasma sprayed HA coatings are widely used in load-bearing implants. Apart from osseointegration, the new generation of HA coating is expected to deliver biomolecules and/or drugs that can induce osteoinduction. This paper reports the preparation of crystalline and amorphous HA coatings on commercially pure titanium (Cp-Ti) using inductively coupled radio frequency (RF) plasma spray, and their stability at different solution pH. Coatings prepared at 110 mm working distance from the nozzle showed an average Ca ion release of 18 and 90 ppm in neutral and acidic environments, respectively. Decreasing the working distance to 90 mm resulted in the formation of a coating with less crystalline HA and phases with higher solubility products, and consequently higher dissolution over 32 days. A 92% release of a model protein bovine serum albumin (BSA) in phosphate buffer with pH of 7.4 was measured for Sr-doped HA (Sr-HA) coating, while only a 72% release could be measured for pure HA coating. Distortion of BSA during adsorption on coatings revealed a strong interaction between the protein and the coating, with an increase in α-helix content. Osteoid formation was found on Sr-HA implants as early as 7 weeks post implantation compared to HA coated and uncoated Ti implants. After 12 weeks post implantation, osteoid new bone was formed on HA implants; whereas, bone mineralization started on Sr-HA samples. While no osteoid was formed on bare Ti surfaces, bone was completely mineralized on HA and Sr-HA coatings after 16 weeks post implantation. Our results show that both phase stability and chemistry can have a significant influence toward in vitro and in vivo response of HA coatings on Ti implants. Copyright © 2015 Acta Materialia Inc. Published by

  13. Chemical composition and sensory analysis of roasted peanuts coated with prickly pear and algarrobo pod syrups

    OpenAIRE

    N. R. Grosso; Conci, S.; Ryan, L. C.; Olmedo, R. H.; Mestrallet, M. G.; Nepote, V.

    2008-01-01

    The objective of this work was to determine the chemical composition, sensory attributes and consumer acceptance of roasted peanuts coated with prickly pear (RP-P) and “algarrobo” pod syrups (RP-A). Roasted peanuts (RP) without coating had the highest oil content (50.4%) in comparison with the coated products RP-P and RP-A (45.3% and 46.7%, respectively). RP-P and RP-A showed lower protein percentage and higher carbohydrate content than RP. These results affe...

  14. Intestinal Diffusion Barrier: Unstirred Water Layer or Membrane Surface Mucous Coat?

    Science.gov (United States)

    Smithson, Kenneth W.; Millar, David B.; Jacobs, Lucien R.; Gray, Gary M.

    1981-12-01

    The dimensions of the small intestinal diffusion barrier interposed between luminal nutrients and their membrane receptors were determined from kinetic analysis of substrate hydrolysis by integral surface membrane enzymes. The calculated equivalent thickness of the unstirred water layer was too large to be compatible with the known dimensions of rat intestine. The discrepancy could be reconciled by consideration of the mucous coat overlying the intestinal surface membrane. Integral surface membrane proteins could not be labeled by an iodine-125 probe unless the surface coat was first removed. The mucoprotein surface coat appears to constitute an important diffusion barrier for nutrients seeking their digestive and transport sites on the outer intestinal membrane.

  15. Anodic-modified anticorrosive coatings

    Directory of Open Access Journals (Sweden)

    Michal Černý

    2011-01-01

    Full Text Available Steel machine parts are exposed to electrochemical corrosion. This applies to many environments including atmosphere, soil, water, and even various fertilizers. High-carbon steel and low-alloyed steel are not stable (in terms of thermo-dynamics, do not feature effective passivation, and even the corrosion products do not form a stable protection layer. As a result, special anti-corrosion protection is critical. In heavy-corrosion environment, paint systems containing Zn have proven to be very effective. Presented text describes verification of paint systems with high Zn content and compares them to galvanic Zn coatings. Steel samples with protective coatings have been tested in condensation chamber with neutral salt-spray. This way, corrosion resistance of Zn-rich paint systems and galvanic Zn coatings has been evaluated and compared. Galvanic Zn-coatings have shown complete decomposition during the chamber exposition. Thus, further testing was adopted for paint systems only with a special attention being paid to gradual degradation of anti-corrosion layer. Final part of the text lists reasons of coating degradation process and outlines possible solutions of the issue.

  16. A study of strontium doped calcium phosphate coatings on AZ31

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satish S., E-mail: sss42@pitt.edu [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Roy, Abhijit, E-mail: abr20@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun E.; Ohodnicki, John; Loghmanian, Autrine [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Banerjee, Ipsita [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, PA 15261 (United States)

    2014-07-01

    Calcium phosphate (CaP) coatings have been studied to tailor the uncontrolled non-uniform corrosion of Mg based alloys while simultaneously enhancing bioactivity. The use of immersion techniques to deposit CaP coatings is attractive due to the ability of the approach to coat complex structures. In the current study, AZ31 substrates were subjected to various pretreatment conditions prior to depositing Sr{sup 2+} doped and undoped CaP coatings. It was hypothesized that the bioactivity and corrosion protection of CaP coatings could be improved by doping with Sr{sup 2+}. Heat treatment to elevated temperatures resulted in the diffusion of alloying elements, Mg and Zn, into the pretreated layer. Sr{sup 2+} doped and undoped CaP coatings formed on the pretreated substrates consisted of biphasic mixtures of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA). Electrochemical corrosion experiments indicated that the extent of Sr{sup 2+} doping and pretreatment both influenced the corrosion protection. Cytotoxicity was evaluated with MC3T3-E1 mouse preosteoblasts and human mesenchymal stem cells (hMSCs). For both cell types, proliferation decreased upon increasing the Sr{sup 2+} concentration. However, both osteogenic gene and protein expression significantly increased upon increasing Sr{sup 2+} concentration. These results suggest that Sr{sup 2+} doped coatings are capable of promoting osteogenic differentiation on degradable Mg alloys, while also enhancing corrosion protection, in comparison to undoped CaP coatings.

  17. Chromate conversion coatings and their current application

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-04-01

    Full Text Available This paper describes formation, composition and possible production technologies of application chromate coatings. Summation of common examples of applications of these coatings in corrosion protection of metals and alloys is provided. Individual chromate coatings are divided by their dominant anions either with CrVI or CrIII. Restrictions of chromate coatings with dominantly CrVI and related toxicity of hexavalent chromium is discussed in detail. In conclusion, examples of both chromium and other, alternative coatings are summed up. Application of these coatings as a protection for concrete hot-dip galvanized reinforcement is also reviewed.

  18. Enhanced attached growth of microalgae Scenedesmus. LX1 through ambient bacterial pre-coating of cotton fiber carriers.

    Science.gov (United States)

    Zhuang, Lin-Lan; Azimi, Yaldah; Yu, Dawei; Wang, Wen-Long; Wu, Yin-Hu; Dao, Guo-Hua; Hu, Hong-Ying

    2016-10-01

    The role of bacteria/extracellular polymeric substances (EPS) coated carriers on attached microalgae growth in suspended-solid phase photobioreactor (sspBR) was assessed in this study. The results showed that pre-coating cotton with ambient bacteria and their EPS improved the attached microalgal growth by as much as 230% in terms of attached microalgae density. Additionally, the single cell dry weight, chemical composition and oxygen evolving activity of attached microalgae were significantly affected by the presence of bacteria/EPS coating on the cotton carriers. The protein content of microalgae cells cultivated in the ssPBRs with carriers coated by bacteria and sterilized bacteria were on average 26% and 15% more than uncoated carriers, respectively. Through absorbing and immobilizing nutrients from the bulk medium, the bacteria/EPS coating provided the attached microalgae with nitrogen/phosphorus for protein synthesis, especially during the late stages of batch cultivation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Self-Healing anticorrosive coatings

    DEFF Research Database (Denmark)

    Nesterova, Tatyana

    Self-healing anticorrosive coatings are multi-component so-called smart materials, which have been proposed as a way to long-lasting corrosion protection of steel structures. The presently most promising technology route is based on microcapsules, filled with active healing agents, and has been...... to capillary forces. The healing agents then start to react, form a polymer network, and =glue‘ the crack. The approach has been applied to development of an epoxy-based self-healing anticorrosive coating for above water heavy duty corrosion protection. Emphasis has been on investigation of practical issues...... associated with development and testing of this type of coating. A laboratory investigation, to identify the most suitable method for production of mechanically stable (filled with industrially relevant core materials) and forming a free-flowing powder upon drying microcapsules, has been performed. Four...

  20. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    Energy Technology Data Exchange (ETDEWEB)

    Pardun, Karoline [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Treccani, Laura, E-mail: treccani@uni-bremen.de [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Volkmann, Eike [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Streckbein, Philipp [University Hospital, Justus-Liebig-University Giessen, Department of Cranio-Maxillo-Facial Surgery, Klinikstrasse 33, 35385 Giessen (Germany); Heiss, Christian [University Hospital of Giessen-Marburg, Department of Trauma Surgery, Rudolf-Buchheim-Strasse 7, 35385 Giessen, Germany, (Germany); Laboratory of Experimental Surgery, Kerkraderstrasse 9, 35392 Giessen (Germany); Destri, Giovanni Li; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI, Viale A. Doria 6, 95125 Catania (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany)

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic.

  1. Nano-Ceramic Coated Plastics

    Science.gov (United States)

    Cho, Junghyun

    2013-01-01

    Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (plastics. One possible way of processing nanoceramic coatings at low temperatures (plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

  2. Explosives detection using nanoporous coatings

    Science.gov (United States)

    Pina, María P.; Pellejero, Ismael; Urbiztondo, Miguel; Sesé, Javier; Santamaría, J.

    2011-06-01

    Zeolite-coated cantilevers provided with internal heating elements have been developed and used for the selective detection of nitroderivates, in particular o-nitrotoluene as an example of an explosive-related molecule. In particular, Co exchanged commercial BEA zeolites have been deployed of rectangular Si cantilevers by microdropping technique. In particular, two different strategies have been demonstrated to increase the zeolite modified cantilevers performance: the sensing coating and the operating temperature. As a result, o-nitrotoluene LOD values below 1 ppm are attained at room temperature conditions; whereas the interference of toluene at concentrations below 1000 ppm is completely suppressed by heating the cantilever.

  3. Testing Cadmium-Free Coatings

    Science.gov (United States)

    2011-08-30

    Metallic Platings • Zinc (Zn) • Nickel (Ni) • Zinc Nickel (ZnNi) • Tin Zinc (SnZn) “ Paint -like” Coatings • Zinc-Rich • Magnesium-Rich • Zinc Aluminum-Rich...None of these match all properties of Cd 6 OPSEC approved for public release Fastener Coating Issues Cont’d Siloxane/Polysiloxane  Silicate ...Polymer-based Zirconium-based These passivation chemistries do not match all properties of Cr6+ Either paint adhesion is reduced Or Corrosion protection

  4. Corrosion-resistant coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

  5. Thick ceramic coating technique. Atsuniku ceramic coating gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Sata, N. (Government Industrial Reserach Institute, Tohoku, Sendai (Japan))

    1987-10-15

    This paper describes a thick ceramic coating technique that uses a reactive bonding process. This process coats interior of a metallic cylinder or surface of a metal having optional curvature with thick (2 mm to 3 mm) ceramics composed mainly of alumina. The process features easiness in coating and simplicity of the equipment. Reactive heat generated from thermit reaction melts iron and alumina as the reaction products, and produces molten ceramics which is cooled on the metal surface to deposit and solidify as a ceramics layer, thus completing the synthesis and the coating in one process. Its application fields would include reaction tubes, abrasive fluid tubes, and high-temperature fluid tubes that can utilize the ceramics' resistance to abrasion, corrosion and heat as well as heat insulation. The ceramics layer has a hardness of about Hv 1500 and porosity from 2 to 3%. The bonding strength between the substrate metal and the ceramics layer can achieve 10 MPa to 20 MPa as a result of surface oxidation treatment and cooling treatment given initially to prevent the outer wall temperature from rising. 2 figs.

  6. Durable Dust Repellent Coating for Metals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Durable Dust Repellent Coating (DDRC) consists of nano-phase silica, titania, or other oxide coatings to repel dust in a vacuum environment over a wide range of...

  7. Aesthetic coatings for Wisconsin bridge components : [brief].

    Science.gov (United States)

    2014-03-01

    Over the past several years, the Wisconsin Department of Transportation (WisDOT) has : experienced performance-related issues with aesthetic and protective coatings used on : Wisconsin bridges. Public agencies make significant investments in coating ...

  8. Reactive polymer coatings: A robust platform towards sophisticated surface engineering for biotechnology

    Science.gov (United States)

    Chen, Hsien-Yeh

    Functionalized poly(p-xylylenes) or so-called reactive polymers can be synthesized via chemical vapor deposition (CVD) polymerization. The resulting ultra-thin coatings are pinhole-free and can be conformally deposited to a wide range of substrates and materials. More importantly, the equipped functional groups can served as anchoring sites for tailoring the surface properties, making these reactive coatings a robust platform that can deal with sophisticated challenges faced in biointerfaces. In this work presented herein, surface coatings presenting various functional groups were prepared by CVD process. Such surfaces include aldehyde-functionalized coating to precisely immobilize saccharide molecules onto well-defined areas and alkyne-functionalized coating to click azide-modified molecules via Huisgen 1,3-dipolar cycloaddition reaction. Moreover, CVD copolymerization has been conducted to prepare multifunctional coatings and their specific functions were demonstrated by the immobilization of biotin and NHS-ester molecules. By using a photodefinable coating, polyethylene oxides were immobilized onto a wide range of substrates through photo-immobilization. Spatially controlled protein resistant properties were characterized by selective adsorption of fibrinogen and bovine serum albumin as model systems. Alternatively, surface initiator coatings were used for polymer graftings of polyethylene glycol) methyl ether methacrylate, and the resultant protein- and cell- resistant properties were characterized by adsorption of kinesin motor proteins, fibrinogen, and murine fibroblasts (NIH3T3). Accessibility of reactive coatings within confined microgeometries was systematically studied, and the preparation of homogeneous polymer thin films within the inner surface of microchannels was demonstrated. Moreover, these advanced coatings were applied to develop a dry adhesion process for microfluidic devices. This process provides (i) excellent bonding strength, (ii) extended

  9. Edible films and coatings: Sources, properties and application

    Directory of Open Access Journals (Sweden)

    Šuput Danijela Z.

    2015-01-01

    Full Text Available In order to extend product shelf life while preserving the quality scientific attention focused to biopolymers research that are base for edible films and coatings production. Another major advantage of this kind of food packaging is their eco-friendly status because biopolymers do not cause environmental problems as packaging materials derived from non-renewable energy sources do. Objective of this work was to review recently studied edible films and coatings - their sources, properties and possible application. As sources for edible biopolymers were highlighted polysaccharides, proteins and lipids. The most characteristic subgroups from each large group of compounds were selected and described regarding possible physical and mechanical protection; migration, permeation, and barrier functions. The most important biopolymers characteristic is possibility to act as active substance carriers and to provide controlled release. In order to achieve active packaging functions emulsifiers, antioxidants and antimicrobial agents can also be incorporated into film-forming solutions in order to protect food products from oxidation and microbial spoilage, resulting in quality improvement and enhanced safety. The specific application where edible films and coatings have potential to replace some traditional polymer packaging are explained. It can be concluded that edible films and coatings must be chosen for food packaging purpose according to specific applications, the types of food products, and the major mechanisms of quality deterioration.

  10. Coated woven materials and method of preparation

    Science.gov (United States)

    McCreary, W.J.; Carroll, D.W.

    Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is by coating with materials, with metals or with pyrolytic carbon. Materials are deposited in Chemical Vapor Deposition (CND) reactions using a fluidized bed so that the porosity of the woven materials is retained and the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

  11. Thermal barrier coating system having improved adhesion

    Science.gov (United States)

    Bill, R. C.; Sovey, J. S. (Inventor)

    1982-01-01

    The adherence between a ceramic thermal barrier coating and a metal bond coating is improved by ion sputtering a ceramic film on the bond cost. A ceramic thermal barrier coating is then plasma-sprayed onto this primer film. This improves the integrity and strength of the interface between the plasma-sprayed ceramic layer and metallic bond coat which insures stronger adherence between the metal and the ceramic.

  12. Fusion silicide coatings for tantalum alloys.

    Science.gov (United States)

    Warnock, R. V.; Stetson, A. R.

    1972-01-01

    Calculation of the performance of fusion silicide coatings under simulated atmospheric reentry conditions to a maximum temperature of 1810 K (2800 F). Both recently developed and commercially available coatings are included. Data are presented on oxidation rate with and without intentional defecting, the influence of the coatings on the ductile-brittle bend transition temperature, and the mechanical properties. Coatings appear capable of affording protection for at least 100 simulated cycles to 2600 F and 63 cycles to 2800 F.

  13. Zucchini shoestring virus: a distinct potyvirus in the papaya ringspot virus cluster.

    Science.gov (United States)

    Ibaba, J D; Laing, M D; Gubba, A

    2016-08-01

    Zucchini shoestring virus (ZSSV) has been proposed to be a putative potyvirus in the papaya ringspot virus (PRSV) cluster, based on the sequence similarity of its coat protein to those of related potyviruses. ZSSV has been associated with the outbreak of a damaging disease of baby marrow (Cucurbita pepo L.) that had been observed throughout the province of KwaZulu-Natal, in the Republic of South Africa (RSA). We report the genome sequence of ZSSV, determined by next-generation sequencing of total RNA extracted from an infected baby marrow (Cucurbita pepo L.). The ZSSV genome is 10,295 nucleotides long excluding the poly(A) tail and displays a typical potyvirus organization. Algerian watermelon mosaic virus (AWMV; EU410442.1) was identified as the closest relative of ZSSV, sharing the highest nucleotide sequence identity of 65.68%. The nucleotide and amino acid sequence identity values for each protein support the differentiation of ZSSV as a member of a distinct species in the genus Potyvirus. This taxonomic position was also confirmed using the Pairwise Sequence Comparison online tool from the National Center for Biotechnology Information. Phylogenetic analysis of the polyprotein coding sequence of ZSSV grouped ZSSV together with AWMV and Moroccan watermelon mosaic virus, but in different clusters. ZSSV is the second cucurbit-infecting virus in the PRSV cluster present in RSA.

  14. Effect of chitosan coatings enriched with cinnamon oil on proximate composition of rainbow trout fillets

    Science.gov (United States)

    Yıldız, Pınar Oǧuzhan

    2017-04-01

    The effects of chitosan coating enriched with cinnamon oil on proximate composition of rainbow trout (Oncorhynchus mykiss) during storage at 4°C was investigated. The treatments included the following: C1 (control samples), C2 (chitosan coating) and C3 (chitosan + 1 % [v/w] cinnamon EO added). The control and the coated fish samples were analysed for chemical (moisture, protein, lipid and ash) composition. The mean of moisture, protein, lipid and ash in the control samples (C1) were 70.3%, 20.1%, 2.6% and 1.2%, in coated samples (C2) 69.70%, 24.21%, 2.4% and 2.2% and coated+cinnamon oil samples (C3) 69.70%, 25.05%, 2.5% and 2.2%, respectively. Moisture and lipid contents in control groups were higher than other groups, but protein and ash contents were lower. Significant increases (p<0.05) in protein content were observed between samples, which subsequently decreased the moisture content of these samples.

  15. On air entrainment in coatings.

    Science.gov (United States)

    Simpkins, P G; Kuck, V J

    2003-07-15

    A series of experiments that clarify how air bubbles become entrained into coatings are described. The contact line dynamics at the air-liquid interface surrounding a fiber is characterized for a typical coating die operating under atmospheric and pressurized conditions. Glycerin and other viscous liquids are used to reveal that a critical fiber speed exists at which air entrainment begins. The observations confirm that the critical capillary number Ca(c) depends on the physical properties of the coating material, in the form of the Morton number. When the liquid supply is pressurized, the experiments show that adjusting the pressure can stabilize the displaced free surface interface at a prescribed location. Controlling the meniscus location in this way eliminates air entrainment. The threshold occurs when the applied pressure balances the shear exerted on the coating by the moving fiber. Using this approach it is possible to eliminate air entrainment and attain stable wetting at very large values of the capillary number, e.g., Ca congruent with 50.

  16. Terahertz antireflection coatings using metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hou-tong [Los Alamos National Laboratory; Zhou, Jiangfeng [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Azad, Abul K [Los Alamos National Laboratory; Chen, Frank [Los Alamos National Laboratory; Taylor, Antoinette J [Los Alamos National Laboratory

    2010-01-01

    We demonstrate terahertz metamaterial antireflection coatings (ARCs) that significantly reduce the reflection and enhance the transmission at an interface of dielectric media. They are able to operate over a wide range of incidence angles for both TM and TE polarizations. Experiments and finite-element simulations will be presented and discussed.

  17. Space stable thermal control coatings

    Science.gov (United States)

    Harada, Y.

    1977-01-01

    Efforts to develop an engineering paint were concentrated on inorganic silicate-bonded systems as opposed to the silicone coatings. The UV-vacuum stability of potassium silicate-Zn2TiO4 paints were shown to be quite good. Reflectance optimization of these systems is being studied by maximizing thickness and pigment to binder ratio.

  18. Moisture transport in coated plaster

    NARCIS (Netherlands)

    Goossens, E.L.J.; Van der Spoel, W.H.; Bancken, E.L.J.

    2001-01-01

    In the framework of the research project: 'Water balance of water-borne paint systems on plaster substrates in relation to fungal growth', a study is carried out to moisture transport mechanisms in coated gypsum plaster. In this contribution, the set-up of the study is described. Besides a

  19. Polymer-coated quantum dots

    NARCIS (Netherlands)

    Tomczak, N.; Liu, Rongrong; Vancso, Gyula J.

    2013-01-01

    Quantum Dots (QDs) are semiconductor nanocrystals with distinct photophysical properties finding applications in biology, biosensing, and optoelectronics. Polymeric coatings of QDs are used primarily to provide long-term colloidal stability to QDs dispersed in solutions and also as a source of

  20. Industrial Coatings at Extreme Conditions

    DEFF Research Database (Denmark)

    Subramanian, Srinath; Pérez Hornero, Clara; Pedersen, Lars Thorslund

    With the gradual depletion of oil wells operable at relatively lower temperatures and pressures, the upstream oil industry relies on High Pressure High Temperature (HPHT) wells to source crude oil and gas. HPHT well extraction and processing require anticorrosive coatings applied on substrates...